A Role for Contrast Gain Control in Skin Appearance

Apparent contrast can be suppressed or enhanced when presented within surrounding images. This contextual modulation is typically accounted for with models of contrast gain control. Similarly, the appearance of one part of a face is affected by the appearance of the other parts of the face. These influences are typically accounted for with models of face-specific holistic processing. Here we report evidence that facial skin appearance is modulated by adjacent surfaces. In four experiments we measured the appearance of skin evenness and wrinkles in images with increased or decreased contrast between facial skin and adjacent image regions. Increased contrast with adjacent regions made facial skin appear more even and less wrinkled. We found the effect whether faces were presented upright or inverted, and also when facial features were not present, ruling out face-specific holistic processing as an explanation yet fully consistent with contrast gain control. Because the mechanism is not face specific, contrast between skin and any adjacent surface should affect skin appearance. This suggests that adornments such as makeup, hair coloring, clothing, and jewelry could also affect skin appearance through contrast suppression or enhancement, linking these cultural practices to the structure and function of the visual system

Acrylamide Production Using Encapsulated Nitrile Hydratase from \u3cem\u3ePseudonocardia thermophila\u3c/em\u3e in a Sol–gel Matrix

The cobalt-type nitrile hydratase from Pseudonocardia thermophila JCM 3095 (PtNHase) was successfully encapsulated in tetramethyl orthosilicate sol–gel matrices to produce a PtNHase:sol–gel biomaterial. The PtNHase:sol–gel biomaterial catalyzed the conversion of 600 mM acrylonitrile to acrylamide in 60 min at 35 °C with a yields of \u3e90%. Treatment of the biomaterial with proteases confirmed that the catalytic activity is due to the encapsulated enzyme and not surface bound NHase. The biomaterial retained 50% of its activity after being used for a total of 13 consecutive reactions for the conversion of acrylonitrile to acrylamide. The thermostability and long-term storage of the PtNHase:sol–gel are substantially improved compared to the soluble NHase. Additionally, the biomaterial is significantly more stable at high concentrations of methanol (50% and 70%, v/v) as a co-solvent for the hydration of acrylonitrile than native PtNHase. These data indicate that PtNHase:sol–gel biomaterials can be used to develop new synthetic avenues involving nitriles as starting materials given that the conversion of the nitrile moiety to the corresponding amide occurs under mild temperature and pH conditions

The posterior nervous system of the nematode Caenorhabditis elegans: serial reconstruction of identified neurons and complete pattern of synaptic interactions

Serial-section electron microscopy has been used to reconstruct the cellular architecture of the posterior nervous system of the nematode Caenorhabditis elegans. Each of 40 neurons in the tail of the adult hermaphrodite can be reproducibly and unambiguously identified by a set of morphological features, including cell body position, fiber geometry and size, and staining properties. A complete list of synapses has been assembled for 2 isogenic animals, and these lists are compared with a third isogenic animal reconstructed by White et al. (1986). The set of neurons and their pattern of synaptic interactions is simple and reproducible. Most of the cells are involved in sensory transduction or in local signal processing to relay signals via a few interneurons to motoneurons and thence to body muscles. Because the tail neurons are well separated and fairly reproducible in position, the hermaphrodite tail lends itself to laser-ablation studies of sensory processing (cf. Chalfie et al., 1985). Most of the synapses in the tail are concentrated in the preanal ganglion. Among the approximately 150 synapses there, about 85% are dyadic chemical synapses. The dyadic synapses are involved in reproducible patterns that have several interesting features. Most neurons synapse onto a few preferred pairs of target cells, in patterns that suggest a combinatorial model of synapse specification that may be open to genetic analysis. Furthermore, most dyadic contacts A----B,C fit a pattern in which the 2 postsynaptic partners are involved elsewhere in unidirectional synapses B----C. Thus, the dyadic synapse may serve to diverge sensory signals into parallel pathways, which then reconverge. This divergence/reconvergence pattern eventually directs processed sensory signals to the ventral cord interneurons PVCL and PVCR. About 80–90% of the synapses fall into repeated classes of synapses. Many of the remaining synapses are widely scattered and irreproducible from one animal to the next. Some of these contacts may be developmental mistakes reflecting a degree of “noise” in synapse specification (Waddington, 1957)

The posterior nervous system of the nematode Caenorhabditis elegans: serial reconstruction of identified neurons and complete pattern of synaptic interactions

Serial-section electron microscopy has been used to reconstruct the cellular architecture of the posterior nervous system of the nematode Caenorhabditis elegans. Each of 40 neurons in the tail of the adult hermaphrodite can be reproducibly and unambiguously identified by a set of morphological features, including cell body position, fiber geometry and size, and staining properties. A complete list of synapses has been assembled for 2 isogenic animals, and these lists are compared with a third isogenic animal reconstructed by White et al. (1986). The set of neurons and their pattern of synaptic interactions is simple and reproducible. Most of the cells are involved in sensory transduction or in local signal processing to relay signals via a few interneurons to motoneurons and thence to body muscles. Because the tail neurons are well separated and fairly reproducible in position, the hermaphrodite tail lends itself to laser-ablation studies of sensory processing (cf. Chalfie et al., 1985). Most of the synapses in the tail are concentrated in the preanal ganglion. Among the approximately 150 synapses there, about 85% are dyadic chemical synapses. The dyadic synapses are involved in reproducible patterns that have several interesting features. Most neurons synapse onto a few preferred pairs of target cells, in patterns that suggest a combinatorial model of synapse specification that may be open to genetic analysis. Furthermore, most dyadic contacts A----B,C fit a pattern in which the 2 postsynaptic partners are involved elsewhere in unidirectional synapses B----C. Thus, the dyadic synapse may serve to diverge sensory signals into parallel pathways, which then reconverge. This divergence/reconvergence pattern eventually directs processed sensory signals to the ventral cord interneurons PVCL and PVCR. About 80–90% of the synapses fall into repeated classes of synapses. Many of the remaining synapses are widely scattered and irreproducible from one animal to the next. Some of these contacts may be developmental mistakes reflecting a degree of “noise” in synapse specification (Waddington, 1957)

USDA Research On Impacts of Predation

This research by the U.S. Department of Agriculture, Economic Research Service, was done at the direct request of Congress, and with special funding in fiscal years 1974 and 1975. Basic questions guiding the research were: 1. How sizable are predation losses? How many producers are effected? 2. What effect has predation had on the decline of the sheep industry? 3. What are benefits and cost of predator control programs

Lechenaultia peregrina, a new species of Goodeniaceae from northern Australia, New Guinea and the Moluccas

Morphological studies of Lechenaultia filiformis R.Br. have determined that more than one taxon is presently included under that name. We here recognise disjunct populations from north-east Queensland, north-east Northern Territory, New Guinea and the Moluccas as a new species, Lechenaultia peregrina R.W.Jobson & R.L.Barrett. This is the third tropical species of Lechenaultia currently recognised, however further studies are required to assess the status of about five additional entities in the Northern Territory and Western Australia currently included in L. filiformis s.l. Seed article morphology is critical for species delimitation in tropical Lechenaultia, but seed articles are often absent from collections, or only immature, as they fall quickly once ripe