Written production of English compounds: effects of morphology and semantic transparency

The results of research on the processing of morphologically complex words are consistent with a lexical system that activates both whole-word and constituent representations during word recognition. In this study, we focus on written production and examine whether semantically priming the first constituent of a compound influences the ease of producing a compound (as measured by typing latencies), and whether any such priming effect depends on the semantic transparency of the compound’s constituents. We found that semantic transparency of the constituents affects whether semantic priming results in changes to processing. However, it is not only the semantic transparency of the primed constituent that exerts an influence—for example, the semantic transparency of the head affects whether semantically priming the modifier results in a change in typing times. We discuss these effects in terms of competition among the various representations as the compound is output, such that overall performance is a combination of facilitation and inhibition that changes over the course of the output.     

Modelling semantic transparency

We present models of semantic transparency in which the perceived transparency of English noun–noun compounds, and of their constituent words, is predicted on the basis of the expectedness of their semantic structure. We show that such compounds are perceived as more transparent when the first noun is more frequent, hence more expected, in the language generally; when the compound semantic relation is more frequent, hence more expected, in association with the first noun; and when the second noun is more productive, hence more expected, as the second element of a noun–noun compound. Taken together, our models of compound and constituent transparency lead us to two conclusions. Firstly, although compound transparency is a function of the transparencies of the constituents, the two constituents differ in the nature of their contribution. Secondly, since all the significant predictors in our models of compound transparency are also known predictors of processing speed, perceived transparency may itself be a reflex of ease of processing.     

Take Russia to 'task' on bioweapons transparency

In the run-up to his reelection, Russian president Vladimir Putin outlined 28 tasks to be undertaken by his administration, including one that commanded the development of weapons based on “genetic principles.” Political pressure must be applied by governments and professional societies to ensure that there is not a modern reincarnation of the Soviet biological warfare program.     

基于质构仪质地多面分析法对香菇质地评价

香菇Lentinula edodes质地是影响其食味品质和货架期的一系列重要品质指标.本研究首次基于质构仪质地多面分析法(TPA),结合传统感官评级对ZX6(浙香6号)和Lsm9两个香菇亲本及其2个杂交菌株(L1*11和L4*6)子实体的不同部位(菌柄P1、菌盖顶部P2、菌盖中心P3和菌盖侧边P4)的7个质地指标和2个...     

Roles of lumican and keratocan on corneal transparency

Lumican and keratocan are members of the small leucine-rich proteoglycan (SLRP) family, and are the major keratan sulfate (KS) proteoglycans in corneal stroma. Both lumican and keratocan are essential for normal cornea morphogenesis during embryonic development and maintenance of corneal topography in adults. This is attributed to their bi-functional characteristic (protein moiety binding collagen fibrils to regulate collagen fibril diameters, and highly charged glycosaminoglycan (GAG) chains extending out to regulate interfibrillar spacings) that contributes to their regulatory role in extracellular matrix assembly. The absence of lumican leads to formation of cloudy corneas in homozygous knockout mice due to altered collagenous matrix characterized by larger fibril diameters and disorganized fibril spacing. In contrast, keratocan knockout mice exhibit thin but clear cornea with insignificant alteration of stromal collaegenous matrix. Mutations of keratocan cause cornea plana in human, which is often associated with glaucoma. These observations suggest that lumican and keratocan have different roles in regulating formation of stromal extracellular matrix. Experimental evidence indicates that lumican may have additional biological functions, such as modulation of cell migration and epithelium-mesenchyme transition in wound healing and tumorgenesis, besides regulating collagen fibrillogenesis. Published in 2003.     

Membrane contacts and lens transparency

Two kinds of membrane contacts in the vertebrate lens are described. Fiber gap junctions are domains where small molecules can pass between lens cells. Membrane structures of ball-and-socket type interlock adjacent lens fibers and thus contribute to the structural integrity of the lens. Both of these membrane contacts appear crucial for the maintenance of lens transparency.     

Scribed transparency microplates mounted on a modified standard microplate

The immense cost effectiveness of using transparencies as analyte handling implements in microplate instrumentation offers the possibility of application even in resource-limited laboratories. In this work, a standard microplate was adapted to serve as the permanent base for disposable scribed transparencies. The approach is shown to ameliorate evaporation, which can affect assay accuracy when analytes need to be incubated for some time. It also offers assurance against fluorescence measurement errors due to the cross-talk of samples from adjacent wells.     

Successional dynamics of a semiarid grassland: effects of soil texture and disturbance size

We evaluated effects of soil texture and disturbance size on the successional dynamics of a semiarid grassland dominated by the perennial bunchgrass, Bouteloua gracilis (H.B.K.) Lag. ex Griffiths. A spatially-explicit gap dynamics simulation model was used to evaluate recovery patterns. The model simulates establishment, growth, and mortality of individual plants on an array of small plots through time at an annual time step. Each simulated disturbance consisted of a grid of plots of the same soil texture interconnected by processes associated with dispersal of B. gracilis seeds. Soil texture was incorporated into the model as effects on seed germination, seedling establishment, and subsequent growth of B. gracilis. Five soil texture classes and five disturbance sizes were simulated.Soil texture was more important to recovery of B. gracilis than either size of a disturbance or location of plots within a disturbance. Constraints on recruitment of seedlings had a greater effect on recovery than constraints associated with plant growth. Fastest recovery occurred on soils with the largest silt content, the variable that affects seedling establishment. Disturbances with slowest recovery were on soils with low silt contents, and either high or low water-holding capacity, the variable that affects plant growth. Biomass and recovery decreased as disturbance size increased, and as distance from a disturbed plot to the edge of the disturbance increased. In most cases, important interactions between soil texture and disturbance size on recovery were not found.     

The visual processing of motion-defined transparency

Our understanding of how the visual system processes motion transparency, the phenomenon by which multiple directions of motion are perceived to coexist in the same spatial region, has grown considerably in the past decade. There is compelling evidence that the process is driven by global-motion mechanisms. Consequently, although transparently moving surfaces are readily segmented over an extended space, the visual system cannot separate two motion signals that coexist in the same local region. A related issue is whether the visual system can detect transparently moving surfaces simultaneously or whether the component signals encounter a serial 'bottleneck' during their processing. Our initial results show that, at sufficiently short stimulus durations, observers cannot accurately detect two superimposed directions; yet they have no difficulty in detecting one pattern direction in noise, supporting the serial-bottleneck scenario. However, in a second experiment, the difference in performance between the two tasks disappears when the component patterns are segregated. This discrepancy between the processing of transparent and non-overlapping patterns may be a consequence of suppressed activity of global-motion mechanisms when the transparent surfaces are presented in the same depth plane. To test this explanation, we repeated our initial experiment while separating the motion components in depth. The marked improvement in performance leads us to conclude that transparent motion signals are represented simultaneously.     

Mechanisms of seed harvest by heteromyid rodents: soil texture effects on harvest rate and seed size selection

Summary Several lines of evidence show that soil texture plays an important role in the distribution of desert-dwelling heteromyid rodents. This is not surprising, since texture influences the energetic cost of digging burrows and of scratching at the soil surface to harvest buried seeds. Texture also may influence the efficiency with which seeds can be separated from the soil particles with which they are mixed. To explore mechanisms of particle separation by foraging heteromyids we measured seed harvest rates and size selection in the laboratory for a variety of seed sizes and soil textures. Harvest rate declined with increasing soil coarseness, and the preference for seeds of intermediate size that was apparent in fine soil disappeared when seeds were mixed with soil slightly coarser than the preferred seed size. In addition, there was evidence that particle separation efficiency is sensitive to the relative sizes of seeds and soil. A discontinity in the function relating harvest rate to soil texture occurred at finer soil textures for small seeds than for large seeds, suggesting that harvest techniques change once soil particle diameter equals or exceeds that of seeds. These results are consistent with the hypothesis that heteromyids use a combination of gravity-and rake-sorting mechanisms for particle separation.