Now showing items 4146-4165 of 13762

    • Foliar Nutrient Content Mediates Grazing Effects on Species Dominance and Plant Community Biomass

      Liang, Maowei; Gornish, Elise S.; Mariotte, Pierre; Chen, Jiquan; Liang, Cunzhu; Univ Arizona, Sch Nat Resources & Environm (RANGELAND ECOLOGY & MANAGEMENT, 2019-11)
      Grazing-induced changes in plant community structure can be altered by the biogeochemical regime of the ecosystem. However, responses of community structure (e.g., changes in biomass, canopy height, and stand density) to grazing-induced changes in foliar nutrient content—whether species-specific or species group-specific (dominant vs. subordinate)—are still poorly studied. We conducted a grazing experiment with four sheep stocking rates in the typical steppe of Inner Mongolia, China. We identified the dominant (Leymus chinensis and Stipa grandis) and subordinate species (Anemarrhena asphodeloides and Cleistogenes squarrosa) and examined grazing-induced changes in the relative abundance and foliar carbon (C), nitrogen (N), and phosphorus (P) contents of these species. We explored subsequent consequences on the mechanisms driving grazing-induced succession in grasslands using structural equation models (SEMs). Aboveground biomass and relative abundance increased for S. grandis, decreased for L. chinensis and A. asphodeloides in response to grazing, but did not change for C. squarrosa. Higher grazing intensity increased foliar N and P contents of subordinate species, whereas no changes occurred with increasing grazing intensity for dominant species. SEMs confirmed that the dominants were homeostatic in response to grazing while the subordinates were more flexible and adjusted foliar nutrient content to grazing intensity. Moreover, SEMs indicated that the relative abundance of species was mediated by foliar C content of both groups, whereas community biomass was dependent on foliar N and P content for the dominants but only foliar P content for the subordinates. Our findings highlight that grazing-induced shifts in plant dominance is species specific rather than group specific (dominant vs. subordinate) and that foliar nutrient content has a key role in mediating plant community compositions and biomass under grazing-managed succession.
    • Follicular Regulatory CD8 T Cells Impair the Germinal Center Response in SIV and Ex Vivo HIV Infection

      Miles, Brodie; Miller, Shannon M.; Folkvord, Joy M.; Levy, David N.; Rakasz, Eva G.; Skinner, Pamela J.; Connick, Elizabeth; Univ Arizona, Div Infect Dis (PUBLIC LIBRARY SCIENCE, 2016-10-07)
      During chronic HIV infection, viral replication is concentrated in secondary lymphoid follicles. Cytotoxic CD8 T cells control HIV replication in extrafollicular regions, but not in the follicle. Here, we show CXCR5(hi)CD44(hi)CD8 T cells are a regulatory subset differing from conventional CD8 T cells, and constitute the majority of CD8 T cells in the follicle. This subset, CD8 follicular regulatory T cells (CD8 T-FR), expand in chronic SIV infection, exhibit enhanced expression of Tim-3 and IL-10, and express less perforin compared to conventional CD8 T cells. CD8 T-FR modestly limit HIV replication in follicular helper T cells (T-FH), impair T-FH IL-21 production via Tim-3, and inhibit IgG production by B cells during ex vivo HIV infection. CD8 T-FR induce T-FH apoptosis through HLA-E, but induce less apoptosis than conventional CD8 T cells. These data demonstrate that a unique regulatory CD8 population exists in follicles that impairs GC function in HIV infection.
    • Follow-up of the Neutron Star Bearing Gravitational-wave Candidate Events S190425z and S190426c with MMT and SOAR

      Hosseinzadeh, G.; Cowperthwaite, P. S.; Gomez, S.; Villar, V. A.; Nicholl, M.; Margutti, R.; Berger, E.; Chornock, R.; Paterson, K.; Fong, W.; et al. (IOP PUBLISHING LTD, 2019-07-18)
      On 2019 April 25.346 and 26.640 UT the Laser Interferometer Gravitational-Wave Observatory (LIGO) and Virgo gravitational-wave (GW) observatory announced the detection of the first candidate events in Observing Run 3 that contained at least one neutron star (NS). S190425z is a likely binary neutron star (BNS) merger at d(L) = 156 +/- 41 Mpc, while S190426c is possibly the first NS-black hole (BH) merger ever detected, at d(L) = 377 +/- 100 Mpc, although with marginal statistical significance. Here we report our optical follow-up observations for both events using the MMT 6.5 m telescope, as well as our spectroscopic follow-up of candidate counterparts (which turned out to be unrelated) with the 4.1 m SOAR telescope. We compare to publicly reported searches, explore the overall areal coverage and depth, and evaluate those in relation to the optical/near-infrared (NIR) kilonova emission from the BNS merger GW170817, to theoretical kilonova models, and to short gamma-ray burst (SGRB) afterglows. We find that for a GW170817-like kilonova, the partial volume covered spans up to about 40% for S190425z and 60% for S190426c. For an on-axis jet typical of SGRBs, the search effective volume is larger, but such a configuration is expected in at most a few percent of mergers. We further find that wide-field gamma-ray and X-ray limits rule out luminous on-axis SGRBs, for a large fraction of the localization regions, although these searches are not sufficiently deep in the context of the gamma-ray emission from GW170817 or off-axis SGRB afterglows. The results indicate that some optical follow-up searches are sufficiently deep for counterpart identification to about 300 Mpc, but that localizations better than 1000 deg(2) are likely essential.
    • Following the Lithium: Tracing li-bearing molecules across age, mass, and gravity in brown dwarfs

      Gharib-Nezhad, E.; Marley, M.S.; Batalha, N.E.; Visscher, C.; Freedman, R.S.; Lupu, R.E.; Lunar and Planetary Laboratory, University of Arizona (IOP Publishing Ltd, 2021)
      Lithium is an important element for the understanding of ultracool dwarfs because it is lost to fusion at masses above ~68MJ. Hence, the presence of atomic Li has served as an indicator of the nearby H-burning boundary at about 75MJ between brown dwarfs and very low mass stars. Historically, the "lithium test,"a search for the presence of the Li line at 670.8 nm, has been a marker if an object has a substellar mass. While the Li test could, in principle, be used to distinguish masses of later-type L-T dwarfs, Li is predominantly no longer found as an atomic gas but rather a molecular species such as LiH, LiF, LiOH, and LiCl in cooler atmospheres. The L- and T-type dwarfs are quite faint at 670 nm and thus challenging targets for high-resolution spectroscopy. But only recently have experimental molecular line lists become available for the molecular Li species, allowing molecular Li mass discrimination. Here we generated the latest opacity of these Li-bearing molecules and performed a thermochemical equilibrium atmospheric composition calculation of their abundances. Finally, we computed thermal emission spectra for a series of radiative-convective equilibrium models of cloudy and cloudless brown dwarf atmospheres (with Teff = 500-2400 K and log g = 4.0-5.0) to understand where the presence of atmospheric lithium-bearing species is most easily detected as a function of brown dwarf mass and age. After atomic Li, the best spectral signatures were found to be LiF at 10.5-12.5 μm and LiCl at 14.5-18.5 μm. Also, LiH shows a narrow feature at ~9.38 μm. © 2021. The American Astronomical Society. All rights reserved.
    • Following the TRAIL: Gift-Cultures and Collaborative Efforts for the Library Community

      Oxnam, Maliaca; Waltz, Marie; Blake, Joni; University of Arizona Libraries; Center for Research Libraries; Greater Western Library Alliance (2008-05-02)
      This session will examine the development of the Technical Report Archive & Image Library (TRAIL) and its current meta-community. Participants in the Greater Western Library Alliance's (GWLA) TRAIL project have developed a model for complex collaborations that includes both 1) shared management for physical collections; and 2) shared large-scale digital conversion processes. The model supports achieving a shared vision, regardless of the number of participants, geographic location, collection scope, or member assets and is accomplished through the recognition and use of learning organization techniques, social capital and gift-culture principles. The session will cover the structure that has been developed to address geographic barriers and workflow issues for this massive digitizing project. Discussion will also include how the structure offers institutions a flexible, short-term way to participate in a digitizing project, without breaking the bank or investing in additional computer systems. Audience participation and feedback on the model will be encouraged.
    • Following the yellow brick road: Yellow slip clays and the production of Rio Grande Glaze Ware in north central New Mexico

      Eckert, Suzanne L.; Schleher, Kari L.; Snow, David H.; Univ Arizona, Arizona State Museum (ELSEVIER SCIENCE BV, 2018-08-24)
      This provenance study of yellow-firing clays in north central New Mexico examines whether clays recovered in the vicinity of Tunque Pueblo (LA 240) may have been used as slip clays at contemporaneous San Marcos Pueblo (LA 98). A sample of 72 ceramic sherds, bricks, and clays were analyzed through chemical characterization using laser-ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). We argue that Tunque potters were using a subset of clays available at their village to produce pottery. Although San Marcos potters appear to have possibly been using clay from Tunque Pueblo to slip their vessels, these clays were not the same as those used by Tunque potters. Given San Marcos potters' apparent reliance on this slip clay over time, we argue our findings demonstrate that extremely stable social networks were developed and sustained among Rio Grande Pueblo households and communities across north central New Mexico during the late prehispanic and early colonial periods (1400-1680 CE).
    • Food parenting practices for 5 to 12 year old children: a concept map analysis of parenting and nutrition experts input

      O’Connor, Teresia M.; Mâsse, Louise C.; Tu, Andrew W.; Watts, Allison W.; Hughes, Sheryl O.; Beauchamp, Mark R.; Baranowski, Tom; Pham, Truc; Berge, Jerica M.; Fiese, Barbara; et al. (BIOMED CENTRAL LTD, 2017-09-11)
      Background: Parents are an important influence on children's dietary intake and eating behaviors. However, the lack of a conceptual framework and inconsistent assessment of food parenting practices limits our understanding of which food parenting practices are most influential on children. The aim of this study was to develop a food parenting practice conceptual framework using systematic approaches of literature reviews and expert input. Method: A previously completed systematic review of food parenting practice instruments and a qualitative study of parents informed the development of a food parenting practice item bank consisting of 3632 food parenting practice items. The original item bank was further reduced to 110 key food parenting concepts using binning and winnowing techniques. A panel of 32 experts in parenting and nutrition were invited to sort the food parenting practice concepts into categories that reflected their perceptions of a food parenting practice conceptual framework. Multi-dimensional scaling produced a point map of the sorted concepts and hierarchical cluster analysis identified potential solutions. Subjective modifications were used to identify two potential solutions, with additional feedback from the expert panel requested. Results: The experts came from 8 countries and 25 participated in the sorting and 23 provided additional feedback. A parsimonious and a comprehensive concept map were developed based on the clustering of the food parenting practice constructs. The parsimonious concept map contained 7 constructs, while the comprehensive concept map contained 17 constructs and was informed by a previously published content map for food parenting practices. Most of the experts (52%) preferred the comprehensive concept map, while 35% preferred to present both solutions. Conclusion: The comprehensive food parenting practice conceptual map will provide the basis for developing a calibrated Item Response Modeling (IRM) item bank that can be used with computerized adaptive testing. Such an item bank will allow for more consistency in measuring food parenting practices across studies to better assess the impact of food parenting practices on child outcomes and the effect of interventions that target parents as agents of change.
    • The footprints of 16 year trends of Arctic springtime cloud and radiation properties on September sea ice retreat

      Huang, Yiyi; Dong, Xiquan; Xi, Baike; Dolinar, Erica K.; Stanfield, Ryan E.; Univ Arizona, Dept Hydrol & Atmospher Sci; Department of Hydrology & Atmospheric Sciences; University of Arizona; Tucson Arizona USA; Department of Hydrology & Atmospheric Sciences; University of Arizona; Tucson Arizona USA; Department of Atmospheric Sciences; University of North Dakota; Grand Forks North Dakota USA; Department of Atmospheric Sciences; University of North Dakota; Grand Forks North Dakota USA; et al. (AMER GEOPHYSICAL UNION, 2017-02-27)
      The most prominent September Arctic sea ice decline over the period of 2000-2015 occurs over the Siberian Sea, Laptev Sea, and Kara Sea. The satellite observed and retrieved sea ice concentration (SIC) and cloud/radiation properties over the Arctic (70 degrees-90 degrees N) have been used to investigate the impact of springtime cloud and radiation properties on September SIC variation. Positive trends of cloud fractions, cloud water paths, and surface downward longwave flux at the surface over the September sea ice retreat areas are found over the period of 1 March to 14 May, while negative trends are found over the period of 15 May to 28 June. The spatial distributions of correlations between springtime cloud/radiation properties and September SIC have been calculated, indicating that increasing cloud fractions and downward longwave flux during springtime tend to enhance sea ice melting due to strong cloud warming effect. Surface downward and upward shortwave fluxes play an important role from May to June when the onset of sea ice melting occurs. The comparison between linearly detrended and nondetrended of each parameter indicates that significant impact of cloud and radiation properties on September sea ice retreat occurs over the Chukchi/Beaufort Sea at interannual time scale, especially over the period of 31 March to 29 April, while strongest climatological trends are found over the Laptev/Siberian Sea.
    • Forage yield and quality as affected by salt stress in different ratios of Sorghum bicolor-Bassia indica intercropping

      Hedayati-Firoozabadi, A.; Kazemeini, S. A.; Pirasteh-Anosheh, H.; Ghadiri, H.; Pessarakli, Mohammad; Univ Arizona, Coll Agr & Life Sci, Sch Plant Sci (Informa UK Limited, 2020-06-24)
      Salinity tolerance is presumed to be improved in the intercropping system, however, there has been inadequate evidence to scientifically prove this. In the current study, the effect of salinity was examined on forage yield and quality of sorghum and kochia in an intercropping system with different planting ratios in a two-year field trial at Shiraz University. The treatments included three salinity levels of irrigation water; 2 (non-saline as a control), 7 and 14 dS m(-1)in main plots and planting ratios; sole sorghum (SS), sorghum-1/3 kochia (S2K1), 1/2 sorghum-1/2 kochia (SK), 1/3 sorghum- kochia (S1K2) and sole kochia in subplots. The results showed that salt stress decreased forage yield of both plants, especially of sorghum. Salt stress at 14 dS m(-1)reduced fresh and dry weights by 44.9% and 62.4% in sorghum, and 38.7% and 23.3% in kochia, respectively. Salinity also reduced forage quality assessed in terms of crude protein, ash, neutral detergent fiber (NDF), acid detergent fiber (ADF), and total digestible nutrients (TDN). The optimum intercropping systems did not change forage yield, but it increased forage quality via reducing ash, ADF and NDF. The optimum planting ratio was S(2)K(1)for both sorghum and kochia, while the SK ratio was suitable for kochia only. Under non-saline conditions, the sole crop cultivation was a better system, while under saline conditions intercropping with a low density of another plant led to higher dry and fresh weights, as well as lower ash, ADF and NDF for each plant. Since kochia performed as a dominant plant, sorghum growth was considerably suppressed under the high density of kochia (i.e., S1K2), especially at 14 dS m(-1)salinity level, which might have been due to high salt tolerance of kochia. Based on the findings of the current study, it could be inferred that in regions with limited freshwater, optimum planting ratio (SK in general for both plants) in an intercropping system could improve the quality of forage with no significant reduction in forage quantity.
    • Forager Mobility in Constructed Environments

      Haas, Randall; Kuhn, Steven L.; Univ Arizona, Sch Anthropol (UNIV CHICAGO PRESS, 2019-07-19)
      As obligate tool users, humans habitually reconfigure resource distributions on landscapes. Such resource restructuring would have played a nontrivial role in shaping hunter-gatherer mobility decisions and emergent land-use patterns. This paper presents a model of hunter-gatherer mobility in which the habitual deposition of material resources at places on landscapes biases the future mobility decisions of energy-optimizing foragers. Thus foragers effectively construct the environments to which they adapt. With the aid of an agent-based model, this simple niche-construction model is used to deduce four predictions for emergent structure in hunter-gatherer settlement patterns. The predictions are tested against archaeological data from a hunter-gatherer settlement system in the Lake Titicaca Basin, Peru, 7,000–5,000 cal BP. Good agreement is found between the predicted and empirical patterns, demonstrating the model’s efficacy and suggesting a behavioral explanation for structural properties of hunter-gatherer settlement systems. The niche-construction behavior and its self-organized properties may have been key components in the emergence of socioeconomic complexity in human societies.
    • Foraging preferences of leafcutter bees in three contrasting geographical zones

      Sinu, Palatty Allesh; Bronstein, Judith L.; Univ Arizona, Dept Ecol & Evolutionary Biol (WILEY, 2018-05)
      AimLeafcutter bees use plants as pollen and nectar sources, but also cut leaf discs and use them to line their nests. Which plant species they choose as nesting material and why they do so have remained obscure. We asked the following: (1) How are the plant species used by leafcutter bees distributed phylogenetically? (2) Does plant choice differ across geographical regions, and if so, in what ways? (3) Are the leaf plant species natives or exotics? (4) What plant and leaf traits predict selection of plant species by leafcutter bees? And (5) Does the abundance of individuals per species in the habitat influence leafcutter bees' plant preferences? LocationTropical South Asia, temperate eastern Canada and US Sonoran Desert MethodsWe mapped taxa known to be used by leafcutter bees both from our own study and published literature onto the most recent angiosperm phylogeny. To determine what plant and leaf traits predict leaf selection, we monitored 6,120 individuals of 214 native and exotic plant species planted in a 3-sq. km. arboretum in Arizona and recorded leaf damage inflicted by bees. ResultsMegachile showed a strong preference for species in the rosid clade, particularly the phylogenetic cluster of Fabales, Fagales and Rosales. Thirty-two to forty-five percentage of the leaf plant species were exotic to a given region. Membership in the rosid clade and Fabaceae family predicted plant preference, whereas the plant species' local abundance and geographical origin did not. Leaf water content, morphotype and the presence of latex were important factors influencing plant choice, whereas leaf shape and size did not. Main conclusionThese patterns point to plant groups whose availability should be monitored to assure persistence of leafcutter bees. Their preference for specific globally distributed plant clades, yet ability to readily adopt certain exotic plant species as nest resources, likely augments their ability to persist.
    • Foraging strategy predicts foraging economy in a facultative secondary nectar robber

      Richman, Sarah K.; Irwin, Rebecca E.; Bronstein, Judith L.; Univ Arizona, Dept Ecol & Evolutionary Biol (WILEY, 2017-09)
      In mutualistic interactions, the decision whether to cooperate or cheat depends on the relative costs and benefits of each strategy. In pollination mutualisms, secondary nectar robbing is a facultative behavior employed by a diverse array of nectar-feeding organisms, and is thought to be a form of cheating. Primary robbers create holes in floral tissue through which they feed on nectar, whereas secondary robbers, which often lack chewing mouthparts, feed on nectar through existing holes. Because primary robbers make nectar more readily available to secondary robbers, primary robbers facilitate the behaviors of secondary robbers. However, the net effect of facilitation on secondary robber fitness has not been empirically tested: it is unknown whether the benefit secondary robbers receive is strong enough to overcome the cost of competing with primary robbers for a shared resource. We conducted foraging experiments using the bumble bee Bombus bifarius, which can alternatively forage legitimately' (from the floral opening) or secondary-rob. We measured the relative foraging efficiencies (handling time per flower, flowers visited per minute, proportion of foraging bout spent consuming nectar) of these alternative behaviors, and tested whether the frequency of primary robbing and nectar standing crop in primary-robbed flowers of Linaria vulgaris (Plantaginaceae) affected foraging efficiency. Surprisingly, there was no effect of primary robbing frequency on the foraging efficiency of secondary-robbing B. bifarius. Instead, foraging strategy was a major predictor of foraging efficiency, with legitimate foraging being significantly more efficient than secondary robbing. Legitimate foraging was the more common strategy used by B. bifarius in our study; however, it is rarely used by B. bifarius foraging on L. vulgaris in nature, despite indications that it is more efficient. Our results suggest the need for deeper investigations into why bees adopt secondary robbing as a foraging strategy, specifically, the environmental contexts that promote the behavior.
    • Force, torque, linear momentum, and angular momentum in classical electrodynamics

      Mansuripur, Masud; Univ Arizona, Coll Opt Sci (SPRINGER, 2017-10)
      The classical theory of electrodynamics is built upon Maxwell's equations and the concepts of electromagnetic (EM) field, force, energy, and momentum, which are intimately tied together by Poynting's theorem and by the Lorentz force law. Whereas Maxwell's equations relate the fields to their material sources, Poynting's theorem governs the flow of EM energy and its exchange between fields and material media, while the Lorentz law regulates the back-and-forth transfer of momentum between the media and the fields. An alternative force law, first proposed by Einstein and Laub, exists that is consistent with Maxwell's equations and complies with the conservation laws as well as with the requirements of special relativity. While the Lorentz law requires the introduction of hidden energy and hidden momentum in situations where an electric field acts on a magnetized medium, the Einstein-Laub (E-L) formulation of EM force and torque does not invoke hidden entities under such circumstances. Moreover, total force/torque exerted by EM fields on any given object turns out to be independent of whether the density of force/torque is evaluated using the law of Lorentz or that of Einstein and Laub. Hidden entities aside, the two formulations differ only in their predicted force and torque distributions inside matter. Such differences in distribution are occasionally measurable, and could serve as a guide in deciding which formulation, if either, corresponds to physical reality.
    • Force-free foliations

      Compère, Geoffrey; Gralla, Samuel E.; Lupsasca, Alexandru; Univ Arizona, Dept Phys (AMER PHYSICAL SOC, 2016-12-08)
      Electromagnetic field configurations with vanishing Lorentz force density are known as force-free and appear in terrestrial, space, and astrophysical plasmas. We explore a general method for finding such configurations based on formulating equations for the field lines rather than the field itself. The basic object becomes a foliation of spacetime or, in the stationary axisymmetric case, of the half-plane. We use this approach to find some new stationary and axisymmetric solutions, one of which could represent a rotating plasma vortex near a magnetic null point.
    • Forebrain Shh overexpression improves cognitive function and locomotor hyperactivity in an aneuploid mouse model of Down syndrome and its euploid littermates

      Gao, F.J.; Klinedinst, D.; Fernandez, F.-X.; Cheng, B.; Savonenko, A.; Devenney, B.; Li, Y.; Wu, D.; Pomper, M.G.; Reeves, R.H.; et al. (BioMed Central Ltd, 2021)
      Down syndrome (DS) is the leading genetic cause of intellectual disability and causes early-onset dementia and cerebellar hypoplasia. The prevalence of attention deficit hyperactivity disorder is elevated in children with DS. The aneuploid DS mouse model “Ts65Dn” shows prominent brain phenotypes, including learning and memory deficits, cerebellar hypoplasia, and locomotor hyperactivity. Previous studies indicate that impaired Sonic hedgehog (Shh) signaling contributes to neurological phenotypes associated with DS and neurodegenerative diseases. However, because of a lack of working inducible Shh knock-in mice, brain region-specific Shh overexpression and its effects on cognitive function have not been studied in vivo. Here, with Gli1-LacZ reporter mice, we demonstrated that Ts65Dn had reduced levels of Gli1, a sensitive readout of Shh signaling, in both hippocampus and cerebellum at postnatal day 6. Through site-specific transgenesis, we generated an inducible human Shh knock-in mouse, TRE-bi-hShh-Zsgreen1 (TRE-hShh), simultaneously expressing dually-lipidated Shh-Np and Zsgreen1 marker in the presence of transactivator (tTA). Double transgenic mice “Camk2a-tTA;TRE-hShh” and “Pcp2-tTA;TRE-hShh” induced Shh overexpression and activated Shh signaling in a forebrain and cerebellum, respectively, specific manner from the perinatal period. Camk2a-tTA;TRE-hShh normalized locomotor hyperactivity and improved learning and memory in 3-month-old Ts65Dn, mitigated early-onset severe cognitive impairment in 7-month-old Ts65Dn, and enhanced spatial cognition in euploid mice. Camk2a-tTA;TRE-hShh cohort maintained until 600days old showed that chronic overexpression of Shh in forebrain from the perinatal period had no effect on longevity of euploid or Ts65Dn. Pcp2-tTA;TRE-hShh did not affect cognition but mitigated the phenotype of cerebellar hypoplasia in Ts65Dn. Our study provides the first in vivo evidence that Shh overexpression from the perinatal period protects DS brain integrity and enhances learning and memory in normal mice, indicating the broad therapeutic potential of Shh ligand for other neurological conditions. Moreover, the first inducible hShh site-specific knock-in mouse could be widely used for spatiotemporal Shh signaling regulation. © 2021, The Author(s).
    • Foreign Geographical Indications, Consumer Preferences, and the Domestic Market for Cheese

      Slade, Peter; Michler, Jeffrey D; Josephson, Anna; Univ Arizona, Dept Agr & Resource Econ (OXFORD UNIV PRESS INC, 2019-08-07)
      The protection of geographical indications (GIs) is an important feature of modern trade agreements. In the Canada-European Union Comprehensive Economic and Trade Agreement (CETA), Canada agreed to stronger protections for GIs of European cheeses and other food products. Under this agreement, new Canadian producers can no longer label cheese as “feta” but instead must refer to it as “imitation feta,” “feta style,” or “feta type.” We use a choice experiment to determine the effect of this agreement on Canadian cheese producers. We find that the effect of GI recognition varies depending on the terms used to label Canadian cheese and the information given to consumers. The results imply that policies that give greater latitude to food marketers will weaken the impact of GI recognition.
    • Foreign-language phonetic development leads to first-language phonetic drift: Plosive consonants in native portuguese speakers learning english as a foreign language in Brazil

      Osborne, D.M.; Simonet, M.; University of Arizona (MDPI AG, 2021)
      Fifty-six Portuguese speakers born and raised in Brazil produced Portuguese words beginning in one of four plosives, /p b k g/. Twenty-eight of them were monolinguals (controls), and the rest were learners of English as a foreign language (EFL). The learners were also asked to produce English words beginning with one of four plosives, /p b k g/. We measured the plosives’ voice onset times (VOT) to address the following research questions: Do foreign-language learners, whose exposure to native English oral input is necessarily limited, form new sound categories specific to their additional language? Does engaging in the learning of a foreign language affect the phonetics of one’s native language? The EFL learners were found to differ from the controls in their production of Portuguese voiced (but not voiceless) plosives—prevoicing was longer in learner speech. The learners displayed different VOT targets for voiced (but not voiceless) consonants as a function of the language they were speaking—prevoicing was longer in Portuguese. In EFL learners’ productions, English sounds appear to be fundamentally modeled on phonologically similar native sounds, but some phonetic development (or reorganization) is found. Phonetic development induced by foreign-language learning may lead to a minor reconfiguration of the phonetics of native language sounds. EFL learners may find it challenging to learn the pronunciation patterns of English, likely due to the reduced access to native oral input. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.
    • Forensic bitemark identification: weak foundations, exaggerated claims

      Saks, Michael J.; Albright, Thomas; Bohan, Thomas L.; Bierer, Barbara E.; Bowers, C. Michael; Bush, Mary A.; Bush, Peter J.; Casadevall, Arturo; Cole, Simon A.; Denton, M. Bonner; et al. (OXFORD UNIV PRESS, 2016-12-01)
      Several forensic sciences, especially of the pattern-matching kind, are increasingly seen to lack the scientific foundation needed to justify continuing admission as trial evidence. Indeed, several have been abolished in the recent past. A likely next candidate for elimination is bitemark identification. A number of DNA exonerations have occurred in recent years for individuals convicted based on erroneous bitemark identifications. Intense scientific and legal scrutiny has resulted. An important National Academies review found little scientific support for the field. The Texas Forensic Science Commission recently recommended a moratorium on the admission of bitemark expert testimony. The California Supreme Court has a case before it that could start a national dismantling of forensic odontology. This article describes the (legal) basis for the rise of bitemark identification and the (scientific) basis for its impending fall. The article explains the general logic of forensic identification, the claims of bitemark identification, and reviews relevant empirical research on bitemark identification-highlighting both the lack of research and the lack of support provided by what research does exist. The rise and possible fall of bitemark identification evidence has broader implications-highlighting the weak scientific culture of forensic science and the law's difficulty in evaluating and responding to unreliable and unscientific evidence.
    • Forest responses to last‐millennium hydroclimate variability are governed by spatial variations in ecosystem sensitivity

      Rollinson, Christine R.; Dawson, Andria; Raiho, Ann M.; Williams, John W.; Dietze, Michael C.; Hickler, Thomas; Jackson, Stephen T.; McLachlan, Jason; JP Moore, David; Poulter, Benjamin; et al. (Wiley, 2020-12-29)
      Forecasts of future forest change are governed by ecosystem sensitivity to climate change, but ecosystem model projections are under-constrained by data at multidecadal and longer timescales. Here, we quantify ecosystem sensitivity to centennial-scale hydroclimate variability, by comparing dendroclimatic and pollen-inferred reconstructions of drought, forest composition and biomass for the last millennium with five ecosystem model simulations. In both observations and models, spatial patterns in ecosystem responses to hydroclimate variability are strongly governed by ecosystem sensitivity rather than climate exposure. Ecosystem sensitivity was higher in models than observations and highest in simpler models. Model-data comparisons suggest that interactions among biodiversity, demography and ecophysiology processes dampen the sensitivity of forest composition and biomass to climate variability and change. Integrating ecosystem models with observations from timescales extending beyond the instrumental record can better understand and forecast the mechanisms regulating forest sensitivity to climate variability in a complex and changing world. © 2020 John Wiley & Sons Ltd
    • The forgotten land use class: Mapping of fallow fields across the Sahel using Sentinel-2

      Tong, Xiaoye; Brandt, Martin; Hiernaux, Pierre; Herrmann, Stefanie; Rasmussen, Laura Vang; Rasmussen, Kjeld; Tian, Feng; Tagesson, Torbern; Zhang, Wenmin; Fensholt, Rasmus; et al. (ELSEVIER SCIENCE INC, 2020-03-15)
      Remote sensing-derived cropland products have depicted the location and extent of agricultural lands with an ever increasing accuracy. However, limited attention has been devoted to distinguishing between actively cropped fields and fallowed fields within agricultural lands, and in particular so in grass fallow systems of semi-arid areas. In the Sahel, one of the largest dryland regions worldwide, crop-fallow rotation practices are widely used for soil fertility regeneration. Yet, little is known about the extent of fallow fields since fallow is not explicitly differentiated within the cropland class in any existing remote sensing-based land use/cover maps, regardless of the spatial scale. With a 10 m spatial resolution and a 5-day revisit frequency, Sentinel-2 satellite imagery made it possible to disentangle agricultural land into cropped and fallow fields, facilitated by Google Earth Engine (GEE) for big data handling. Here we produce the first Sahelian fallow field map at a 10 m resolution for the baseline year 2017, accomplished by designing a remote sensing driven protocol for generating reference data for mapping over large areas. Based on the 2015 Copernicus Dynamic Land Cover map at 100 m resolution, the extent of fallow fields in the cropland class is estimated to be 63% (403,617 km(2)) for the Sahel in 2017. Similar results are obtained for five contemporary cropland products, with fallow fields occupying 57-62% of the cropland area. Yet, it is noted that the total estimated area coverage depends on the quality of the different cropland products. The share of cropped fields within the Copernicus cropland area is found to be higher in the arid regions (200-300 mm rainfall) as compared to the semi-arid regions (300-600 mm rainfall). The woody cover fraction within cropped and fallow fields is found to have a reversed pattern between arid (higher woody cover in cropped fields) and semi-arid (higher woody cover in fallow fields) regions. The method developed, using cloud-based Earth Observation (EO) data and computation on the GEE platform, is expected to be reproducible for mapping the extent of fallow fields across global croplands. Future applications based on multi-year time series is expected to improve our understanding of crop-fallow rotation dynamics in grass fallow systems being key in teasing apart how cropland intensification and expansion affect environmental variables, such as soil fertility, crop yields and local livelihoods in low-income regions such as the Sahel.