Thin Black Line Research Articles

New Insights in Smooth Occluding Contours for Nonphotorealistic Rendering.

Computing occluding contours is often a crucial step in stroke-based artistic 3-D stylization for movies, video games, and visualizations. However, many existing applications use only simple curve stylization techniques, such as thin black lines or hand-animated strokes. This is because sophisticated procedural stylization requires accurate curve topology, which has long been an unsolved research problem. This article describes a recent theoretical breakthrough in the topology problem. Specifically, the new theory points out that existing contour algorithms often generate curves that cannot have any valid visibility, and new algorithms show how to correct the problem. This article surveys classes of algorithms that can compute contours accurately and identifies new research opportunities.

Displaying Diverse Spectra Using a Thin White Line Screen (TWLS)

Gas emission tubes are widely used laboratory and demonstration apparatus because the line source nature of the tube produces line spectra when viewed directly through a diffraction grating. These are long and distinctly visible images of the tube, located to either side of the zeroth order at an angle determined by the wavelength. A continuous spectrum with each distinct color being a vertical line is produced by an incandescent bulb having a vertical line filament. P. J. Ouseph first contrasted spectra from thin white and black lines in an interesting activity reported in this journal in 1989. For more detail about why line spectra are useful, see Appendix I at TPT Online. I am reporting here a simple and useful method for presenting the spectral distribution of diverse sources and filters, or the reflected light from colored samples (inks, color swatches, etc.), that has the same visual impact and didactic benefits of the line sources noted above. This technique was devised as part of inquiry curriculum for the Light and Color class at Bellevue College.

“The Burial and Unburial of Women”: <i>Thin Black Line(s)</i> and Tracing “Moments and Connections” in Black British Women’s Art Histories

As an artist who refuses categorically to shy away from both the “history of slavery” and the “contemporary grievances” arising from a white-dominated British art world, Lubaina Himid created a curatorial tour de force with her Thin Black Line(s) exhibition, on display at Tate Britain in 2011–2012. She adopted an array of signifying practices designed to riff off, reclaim, and revise the ideological biases and racialized blind spots of the Tate as a national institution. Himid’s long history of exhibiting Black British women’s work reflects her determination to fight against their “collective invisibility in the art world” as they “engaged with the social, cultural, political and aesthetic issues of the time” by undertaking a “conceptual reframing of the image of black and Asian women themselves.” Working with the spatial constraints of just one room in which to exhibit a decades-long history of Black British women artists and art making, Himid also had to rely upon numerous strategies to confront the obstacles presented by the Tate’s decision to mount Thin Black Line(s) not as a full-scale exhibition but as an “in-focus display.” This meant that it was not given as extensive a budget or as large an exhibition space as the Tate exhibitions appearing as part of their regular programming, and also not accorded the same levels of marketing, advertising, and scholarly attention. Himid set about solving these problems by engaging in diverse extra-curatorial practices and also by contesting and critiquing these limitations within the space itself. Himid’s self-reflexive strategies became a form of “guerrilla curating” as she engaged in a multitude of methods designed to critique, interrogate, and displace—if not outright reject—the challenges presented by the ideologically confining and tokenizing framing of the Tate as an exhibition space.

A new species of Lophodermium on needles of mountain pine (Pinus mugo) from the Giant Mountains in Poland

A fungus tentatively identified as Lophodermium sp. was repeatedly isolated from living secondary needles of mountain pine (Pinus mugo) in the Giant Mountains of Poland. Needles showed symptoms of yellow spots, gradual discolouration and premature falling in July. Thin black zone lines, subepidermal conidiomata and partially subepidermal ascomata morphologically similar to L. pinastri occurred on fallen needles in litter below the same trees. Evidence from internal transcribed spacers of rDNA and the gene for actin showed that strains isolated from symptom-bearing needles and fruiting structures were identical, and differed from other Lophodermium species known from pine, including L. pinastri. The fungus differs subtly from L. pinastri, for example, in the lengths of its conidiomata, ascomata and asci, but can be reliably distinguished only by molecular data. Known only on mountain pine from the Giant Mountains, it is described here as L. corconticum sp. nov.

Travelling with Imoinda: Art, Authorship, and Critique

Travelling with Imoinda:Art, Authorship, and Critique Joan Anim-Addo (bio) Click for larger view View full resolution Joan Anim-Addo Photograph by A. H. Jerriod Avant © 2014 [End Page 570] This article raises questions concerning art, authorship, and to a lesser extent, critique, specifically in relation to my opera libretto Imoinda, or She Who Will Lose Her Name, written in 1997, given a first rehearsed reading in London in 1998 and first published in 2003 in Italy. Considering the scale of the art involved in this full-length work of music-theater, in terms of writing but also in relation to performance, I am interested to reflect upon what keeps those of us, black women especially, who find ourselves as artists woefully under-resourced in our diverse locations, nonetheless committed to developing that which seems at times to be an impossible practice. In the process of reflection, I borrow from the seminal Black British visual artists’ exhibition by black women curated by Lubaina Himid in 1985, the notion of “the thin black line.”1 For this purpose, the “thin black line” resonates ideas about resistance that retrospectively and disturbingly evoke 1980s Britain with its indifference or hostility to that which might yet be referred to as black arts practice. Addressing the question of commitment, I propose to consider desire in this context as perverse (in practical terms) and readily conjugated with commitment to highlight black arts practice as a perverse commitment. In this light, it is useful to be reminded that perverse commitment speaks also to the persistent, albeit largely dormant—and I contend still dominant—view of black arts practice in the diaspora. Notably, for example, Dame Janet Suzman, actor and ex-wife of Trevor Nunn, artistic director of the National Theatre, London, declared: “Theatre is a white invention, a European invention, and white people go to it. It’s in their DNA. It starts with Shakespeare” (Alberge and Brown). Readily discerned in this statement is a belief system that can be traced back to Enlightenment ideas of G. W. F. Hegel who posited that the “Negro” stands outside culture and “the history of intellectual, technological, moral, and cultural progress,” which in Michelle Wright’s words is “guided by the Absolute of reason.” She also reminds us of Hegel’s comments on the slave trade, “that slavery was most likely the only way Africans would learn to appreciate freedom and thus develop into subjects” (Wright 8). Later pseudo-scientific thought only aggravated that discursive reality which the “Enlightenment” had begun to produce. Following such enlightened tradition, Suzman adds further that “[theatre] is not in their [black] culture” and clinches her explanation with “Just as their stuff is not in white culture.” She states categorically: “Theatre is a totally European invention, as is tragedy. Other countries don’t do tragedy. It’s an invention by the Greeks.” Should it not be considered perverse on the part of black artists to persist in writing for the theater—especially theater considered high art—in the face of such clear-cut cultural battle lines drawn by (white) cultural gatekeepers in the diaspora? [End Page 571] Suzman is quoted at length because she articulates freely the substance of that which must be resisted by black artists. I underscore, too, the black artist’s propensity towards resistance or the “thin black line” (Himid) which in effect functions as intense engagement with a process of re(member)ing, as June D. Bobb refers to it with reference to the poets Derek Walcott and Kamau Brathwaite. Thus, to write Beloved, Toni Morrison has also felt the need to access the interior life of slaves via her imagination to bear witness to, in her words, “the interior life of people who didn’t write [their history] (which doesn’t mean that they didn’t have it)” and to “fill in the blanks that the slave narrative left” (Morrison 183). In addition, perhaps especially within the diaspora, there are levels at which the compulsion to act upon what is known though not always acknowledged as “shared knowledge,” as Glissant writes of it, is overwhelming. About Imoinda, or She Who Will Lose Her Name My idea for Imoinda was...

Creeping Hair in the Beard Area.

Dear Editor: Creeping disease is a skin disease caused by a parasite that tunnels its way through the skin, leaving a visible red, itchy, linear eruption. The most representative example of creeping disease is cutaneous larva migrans. In rare cases, a creeping in the skin may mimic creeping disease. A 31-year-old Korean man presented with a single linear, thin, and wavy black line embedded within the superficial skin on the right submandibular region (Fig. 1, black arrows). The skin lesion was detected incidentally 1 month previously. The black line, 7 cm long when stretched, extended horizontally and laterally along Langer's line. The wavy black line was easily moved and stretched by pressure, and restored quickly. The lateral tip was exposed out of the skin when pushed laterally. The black line was easily and completely removed by pulling its exposed tip with a steady pressure by using forceps (Fig. 2A). Interestingly, a light and scanning electron microscopic examination confirmed the black line to be (Fig. 2B). Creeping hair, also known as migrating hair, embedded hair, pili cuniculati (burrowing hair), or cutaneous pili migrans, was diagnosed. Fig. 1 A single linear, thin, and wavy black line was embedded within the superficial skin on the right chin (black arrows). It showed lateral extension along the direction of Langer's line and the same growing direction with surrounding (inset, red arrows). ... Fig. 2 (A) The creeping was easily and completely removed. (B) Hair shaft viewed under a light microscope (×400) and a scanning electron microscope (inset: ×2,000). Creeping is often initially misdiagnosed as cutaneous parasitic infections such as cutaneous larva migrans. Some characteristics that can differentiate between creeping and cutaneous larva migrans, to achieve an accurate diagnosis, are as follows1. First, although there is no pruritus in patients with creeping hair, patients with cutaneous larva migrans have intense itch symptoms and secondary dermatitis. Second, in creeping hair, the penetrating can move in only one direction. However, cutaneous larva migrans can move in any direction and generally leaves more tortuous tracts. Third, creeping is easily and completely removed by slight pulling at the other side of the root. Fourth, the growth direction of creeping is identical to that of the normal surrounding hairs (Fig. 1, red arrows). Finally, once removed, it can be easily confirmed to be by using light microscopy. In this case, the creeping was not considered to have an external source, but was believed to have grown inside the skin, burrowing in the uppermost dermis2. This ingrowing beard may be associated with minor trauma due to shaving with a safety razor and a lateral oblique growth on the lateral chin (Fig. 1, red arrows). However, some reported cases showed eruptions on the plantar region due to the penetration of a fragment from the outside, which could be termed hair as a foreign body2,3. Previous reports of creeping hair, including the present case, involve penetration by thick, dark hair, and the individuals are most likely of Asian origin4. This may be associated with the fact that among all ethnic groups, in Asians has the largest cross-sectional area with the highest tensile strength5. Cases of creeping are extremely rare, and we believe that this is the first Korean case. In conclusion, dermatologists should always consider the possibility of creeping hair, although rare, in patients showing creeping eruptions.

Texture variations suppress suprathreshold brightness and colour variations.

Discriminating material changes from illumination changes is a key function of early vision. Luminance cues are ambiguous in this regard, but can be disambiguated by co-incident changes in colour and texture. Thus, colour and texture are likely to be given greater prominence than luminance for object segmentation, and better segmentation should in turn produce stronger grouping. We sought to measure the relative strengths of combined luminance, colour and texture contrast using a suprathreshhold, psychophysical grouping task. Stimuli comprised diagonal grids of circular patches bordered by a thin black line and contained combinations of luminance decrements with either violet, red, or texture increments. There were two tasks. In the Separate task the different cues were presented separately in a two-interval design, and participants indicated which interval contained the stronger orientation structure. In the Combined task the cues were combined to produce competing orientation structure in a single image. Participants had to indicate which orientation, and therefore which cue was dominant. Thus we established the relative grouping strength of each cue pair presented separately, and compared this to their relative grouping strength when combined. In this way we observed suprathreshold interactions between cues and were able to assess cue dominance at ecologically relevant signal levels. Participants required significantly more luminance and colour compared to texture contrast in the Combined compared to Separate conditions (contrast ratios differed by about 0.1 log units), showing that suprathreshold texture dominates colour and luminance when the different cues are presented in combination.

Administration of a Tryptophan Metabolite, Indole-3-Carboxaldehyde, Reduces Graft Versus Host Disease Morbidity and Mortality and Enhances Gastrointestinal Barrier Function in a Murine Model of Allogeneic Bone Marrow Transplantation

Background:Allogeneic bone marrow transplantation for patients with hematological malignancies is curative, but the success of the procedure is limited by graft versus host disease (GvHD). Donor T-cells present in the graft are critical for the graft-versus-leukemia effect (GvL) of the transplant and important in facilitating bone marrow reconstitution, but also contribute to development of GvHD, and the risk of GvHD increases dramatically when the donor and recipient are not matched at all of the HLA loci. Hence, there is an urgent need for new approaches to curb GvHD and facilitate transplantation of HLA mismatched grafts to improve patient outcomes. Here, we have used an MHC-mismatched mouse model of GvHD to develop a novel and powerful approach to improve the success of allogeneic bone marrow transplantation by limiting GvHD. We identified a tryptophan metabolite, indole-3-carboxaldehyde (ICA), a dietary component present in foods such as collard greens and broccoli, that prevents lethal GvHD and allows normal engraftment by allogeneic donor bone marrow when fed to transplant recipients for the first few weeks after transplant.Methods:Lethally irradiated B10.BR (H2k) mice were transplanted with 3 x 106 T cell depleted bone marrow cells (TCD-BM) alone or the combination of TCD-BM plus 2 x 106 purified T cells from B6 (H2b) donor mice. Mice received daily gavage with 100 mg/kg or 150 mg/kg ICA or vehicle through day 38 post-transplant. Survival and clinical manifestations of GvHD were monitored through day 62. Histopathology of the gut, cytokines in serum and colon homogenates, intracellular cytokine staining of donor T-cells and bacterial counts in mesenteric lymph nodes (using blood agar plates) were measured in a separate cohort of experimental mice euthanized on day 20. Additionally, a secondary transplant was conducted to test the allo-proliferative capacity (in vivo CFSE dilution assay) and GvHD activity of T-cells from spleens of mice in the TCD-BM + T cells + 150 mg/kg ICA group that survived to day 62, compared to B6 T cells, in combination with fresh B6 TCD-BM, in B10.BR recipients.Results and Conclusion:Figure 1 shows survival curves for mice transplanted with TCD-BM + T-cells that were fed vehicle (red), 100 mg/kg/day of ICA (blue), or 150 mg/kg/day of ICA (green) by oral gavage. Only 7% of the recipients of TCD-BM + T cells treated with vehicle only survived to day 46. ICA administration improved survival in a dose-dependent manner: recipients given 100 mg/kg/day of ICA had 20% survival at day 52 (**p = 0.009) and administration of 150 mg/kg/day of ICA resulted in 83% survival of recipients of TCD-BM + T cells (***p <0.001). ICA was well tolerated without serious toxicity in recipients of BM grafts without GvHD-causing T-cells (thin black solid line). ICA-treated recipients of TCD-BM + T cells had improved thymopoiesis and decreased levels of inflammatory cytokines. Histological analysis of colonic tissue from these ICA-treated recipients also showed marked reduction of GvHD pathology and decreased bacterial colonization of mesenteric lymph nodes (MLN) compared to vehicle-treated control animals (Figure 2, *p < 0.01), indicating enhanced gastrointestinal barrier function. T cells recovered from ICA-treated TCD-BM + T cell transplant recipients at day 62 had been rendered tolerant to recipient type alloantigens in secondary transplant in vivo assays as shown by reduced proliferation of CFSE-stained T cells and lack of GvHD activity in secondary B10.BR recipients.These data indicate that enteral administration of ICA, a natural compound present in food, causes a dramatic reduction of GvHD in a MHC mismatched model of allogeneic bone marrow transplantation. We postulate that this effect is mediated through activation of the aryl hydrocarbon receptor in innate lymphoid cells in the lamina propria of the gut, stimulating regeneration of the gut epithelium and reducing trans-epithelial migration of gut bacteria that contribute to GvHD. Further development and exploration of the mechanism by which ICA treatment reduces GvHD could have a major impact on improving the safety of allogeneic bone marrow transplantation, and increase the availability of donors for those patients who currently lack an HLA matched sibling or volunteer donor. [Display omitted] [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Fomitiporia baccharidis comb. nov., a little known species from high elevation Andean forests and its affinities within the neotropical Fomitiporia lineages

In the frame of a revision of the Fomitiporia species with pileate basidiomata in the New World, several collections originating from Andean, high elevation forests of Argentina were found to represent a terminal clade in multilocus phylogenetic inferences (including nuclear ribosomal partial LSU and ITS-5.8S, partial tef1-α and RPB2 genes). These collections also represent a singular morphotype within Fomitiporia, characterized by mostly pileate basidiomata, with a soft corky consistency, roughly sulcate pilei, a “duplex” context with a thin black line, and dextrinoid basidiospores, averaging 5.9 × 5.3 μm. It also has a well-marked autecology, occurring on shrubby trees in high elevation forests along the Andean range. A search in the literature for a name pointed toward Phellinus baccharidis, despite the fact that this species was repeatedly described with non-dextrinoid basidiospores. Examination of the type of P. baccharidis confirmed the main morphological features as previously described, but for the reaction of basidiospores in Melzer’s reagent, which was found to be strongly positive (dextrinoid), and an overall similarity with our own specimens; hence, the new combination Fomitiporia baccharidis is proposed. The species is redescribed and illustrated. It is so far known from Argentina and Ecuador. Its phylogenetic relationships with the South American Fomitiporia are briefly discussed.

Global Positioning System Constraints on Active Crustal Deformation in Central Panama

Online Material: Figures of three‐component GPS displacements and residuals; table of derived velocities. The tectonic setting of central Panama has been controlled primarily by the collision of the Central American Arc with the South American continent, beginning in Miocene time (e.g., Coates et al. , 2004). Ongoing collision at a rate of about 25 mm/yr has been inferred using campaign‐style Global Positioning System (GPS) surveys from a sparse, long‐baseline network covering the collision zone (e.g., Trenkamp et al. , 2002; Fig. 1). The central portion of the Panama block (Figs. 1 and 2) is commonly described as a nondeforming microplate (e.g., Trenkamp et al. , 2002; Bird, 2003; Argus et al. , 2011). However, appreciable Pleistocene crustal deformation has been suggested in central Panama based on an analysis of the landscape and paleoseismological trenches (Rockwell et al. , 2010a), and is likely a consequence of ongoing collision diffusely absorbing a fraction of Cocos–Nazca–Caribbean–South America relative plate motion (Rockwell, Bennett et al. , 2010). Figure 1. The regional tectonic setting of Central America. Plate boundaries from Bird (2003) are shown with thick lines, superimposed on shaded topography and bathymetry. The political border of Panama is highlighted with a thin black line. Vectors show the approximate sense of motion of the various plates, including the Panama block, relative to a South America fixed‐velocity reference frame. Ongoing collision of the Panama block with the Northern Andes block continent results in appreciable deformation of central Panama and northwest South America. NPDB shows the location of the North Panama deformed belt, which separates the Caribbean plate from the Panama block. The small square in the Panama block shows the area of Figure 2, which encompasses the Rio Gatun, Limon, and Pedro Miguel faults, …

Maestro di Pico i iluminacije u inkunabuli De Civitate Dei (Nicolas Jenson, Venecija, 1475.) u samostanu Sv. Duje u Kraju na Pašmanu

Maestro di Pico i iluminacije u inkunabuli De Civitate Dei (Nicolas Jenson, Venecija, 1475.) u samostanu Sv. Duje u Kraju na Pašmanu

Negative frequency tuning of a carbon nanotube nano-electromechanical resonator under tension (Phys. Status Solidi B 12/2013)

On the back cover, a single wall carbon nanotube is displayed (thin black line in the sketch) that is grown across a trench and contact electrodes (green), cooled to milli-Kelvin temperatures, and then characterized in electronic transport measurements. A quantum dot forms within the suspended segment at these temperatures. The typical Coulomb “diamond” pattern of differential conductance displays distinct signatures of electromechanical feedback and self-excitation (background measurement, yellow arrows). Using a radio-frequency cw source, driven mechanical resonances of the nanotube can be detected in dc transport - as exemplified by the red line, a measurement of time-averaged dc current as a function of the driving frequency. Stiller et al. (pp. 2518–2522) find higher harmonic resonances at integer multiples of the fundamental frequency, indicating that the nanotube is a string under tension. Applying a finite gate voltage to the highly doped chip substrate (light blue), the mechanical resonance strongly shifts to lower frequencies. This can be explained by electrostatic softening of the vibration mode.

Millie and the Big Rescue by Alexander Steffensmeier (review)

Reviewed by: Millie and the Big Rescue by Alexander Steffensmeier Jeannette Hulick Steffensmeier, Alexander . Millie and the Big Rescue; written and illus. by Alexander Steffensmeier; tr. from the German. Walker, 2013. [40p]. Library ed. ISBN 978-0-8027-3403-7 $17.89 Trade ed. ISBN 978-0-8027-3402-0 $16.99 Reviewed from galleys R 4-6 yrs. Millie the cow loves to play hide-and-seek with the other farm animals, but one day she hides a little too well in the top of a large tree and becomes stuck. One by one the other animals, and even the farmer, try to rescue her, only to become stuck themselves. The farmer enlists the hens (the only ones capable of going up and down at will) to carry a message to a neighbor while Millie and the animals enjoy cake and tea (also fetched by the hens) as they await rescue. When finally back on the ground, the farmer offers cake to the rescuing firefighters and the neighbor, only to [End Page 116] discover the cake is still up in the tree. The entire party returns to the branches to enjoy a snack and the lovely view. The writing in this German import is steady and amusing: "'This is so relaxing,' the farmer said. 'As long [as] nobody has to use the bathroom.'" The various antics of the farm animals, particularly the chickens (one continually sports a Sherlock-style deerstalker, one tries unsuccessfully to hide headfirst in a birdhouse), and Millie's pop-eyed bewilderment are sure to evoke chuckles as well. The deftly drafted illustrations sport thickly dappled color framed by thin black lines; the large page size will lend the book to group sharing, although kids will need to get close to appreciate all the details of the animals' actions. This could be easily incorporated into farm- and cow-themed storytimes or units, but plan to share it twice in any case, once for the story and once for the illustrations. Copyright © 2013 The Board of Trustees of the University of Illinois

Windblown by Édouard Manceau (review)

Reviewed by: Windblown by Édouard Manceau Jeannette Hulick, Reviewer Manceau, Édouard Windblown; written and illus. by Édouard Manceau; tr. from the French by Sarah Quinn. OwlKids, 2013 26p ISBN 978-1-926973-77-7 $16.95 R 3–6 yrs The wind blows a series of random shapes onto the blank white pages of this picture book, shapes that are then arranged as parts of various animals, with additional thin black lines completing details for each critter. A cumulative “House That Jack Built”–style litany accompanies the changing arrangement of shapes: they first take the form of a chicken’s head (“‘They’re mine!’ said the chicken. ‘I saw them lying around!’”), then the head, fin, and tail of a fish (“‘No, they’re mine!’ replied the fish. ‘I’m the one who cut the paper into the pieces that the chicken saw lying around’”), and so on. This continues from chicken to fish to bird to snail to frog, until the wind intercedes and scatters them toward the reader: “They’re yours now too. What will you do?” Although the story is very slight, the shape-rearranging is entertaining and the crisp, bold shapes—a large, light blue semi-circle, an orange pie-shaped wedge, a set of gray and black circles, and a red tulip-like shape—are visually appealing against the plain white backdrop. This title lends itself to a number of uses, from the obvious creative shape-arranging indicated in the book (a printable page of the book’s shapes is available online), to lessons on wind or simple drawing techniques à la Ed Emberley. Pair this with one of Lois Ehlert’s shape-based picture books such as Color Zoo (BCCB 9/89), Emberley’s Go Away, Big Green Monster (BCCB 3/93), or even Matisse’s famed cut-paper collages for a enjoyable lesson/storytime on shape and form. Copyright © 2013 The Board of Trustees of the University of Illinois

Texture dominates saliency in suprathreshold combinations of texture, colour and luminance.

Comparing sensitivities to different cues does not necessarily tell us about their relative saliencies when combined at suprathreshold. Measurements of the relative saliency of combined cues are important as they indicate the relative weightings given by vision to different cues in naturalistic situations, for example in order to highlight warnings. We sought to measure the relative saliencies of combined luminance, colour and texture contrast using a psychophysical task. Stimuli were small circular patches bordered by a thin black line and containing combinations of luminance decrements, purple or red colour contrast, and increments in the contrast of a binary noise texture. The patches were arranged in a diagonal grid on a mid grey background. There were two tasks: 1 ‘Separate’, in which the different cues were presented separately in a two-interval design and participants indicated which interval contained the stronger orientation structure; 2. ‘Combined’, in which different cues were combined within each patch but arranged to produce competing orientation structure, and participants had to indicate which orientation, and therefore cue, was dominant. We varied the contrast ratio between the cues around suprathreshold baseline levels to find the points of subjective equality in both tasks. Participants required significantly more luminance and colour contrast in the Combined compared to Separate conditions (contrast ratios differed by about 0.1 log units). This result shows that suprathreshold texture is more salient than colour or luminance when the different cues are presented in combination.

Multifocal Attention Filters Targets from Distracters within and beyond Primate MT Neurons' Receptive Field Boundaries

Visual attention has been classically described as a spotlight that enhances the processing of a behaviorally relevant object. However, in many situations, humans and animals must simultaneously attend to several relevant objects separated by distracters. To account for this ability, various models of attention have been proposed including splitting of the attentional spotlight into multiple foci, zooming of the spotlight over a region of space, and switching of the spotlight among objects. We investigated this controversial issue by recording neuronal activity in visual area MT of two macaques while they attended to two translating objects that circumvented a third distracter object located inside the neurons' receptive field. We found that when the attended objects passed through or nearby the receptive field, neuronal responses to the distracter were either decreased or remained unaltered. These results demonstrate that attention can split into multiple spotlights corresponding to relevant objects while filtering out interspersed distracters.

The Sound of Old Media

In the field of hand-made film, sound and music are a limited part of the media due to the character of the medium; there are only a few sound tracks with poor quality. Hand-made film may be considered ‘old media’ or ‘traditional media’ that are not as popular today due to the spread of digital technologies. However, the limited character of this medium and the low quality of the sound tracks become a very attractive and creative limitation for the author’s recent works. She discusses two recent works for experimental film and sound, The Thin Black Line (2007) and flowing_water (2008) which explore how the limitation of media allows expansion of the sonic and visual arts.

Critical Role of 7,8-Didemethyl-8-hydroxy-5-deazariboflavin for Photoreactivation in Chlamydomonas reinhardtii

DNA photolyases use two noncovalently bound chromophores to catalyze photoreactivation, the blue light-dependent repair of DNA that has been damaged by ultraviolet light. FAD is the catalytic chromophore for all photolyases and is essential for photoreactivation. The identity of the second chromophore is often 7,8-didemethyl-8-hydroxy-5-deazariboflavin (FO). Under standard light conditions, the second chromophore is considered nonessential for photoreactivation because DNA photolyase bound to only FAD is sufficient to catalyze the repair of UV-damaged DNA. phr1 is a photoreactivation-deficient strain of Chlamydomonas. In this work, the PHR1 gene of Chlamydomonas was cloned through molecular mapping and shown to encode a protein similar to known FO synthases. Additional results revealed that the phr1 strain was deficient in an FO-like molecule and that this deficiency, as well as the phr1 photoreactivation deficiency, could be rescued by transformation with DNA constructs containing the PHR1 gene. Furthermore, expression of a PHR1 cDNA in Escherichia coli produced a protein that generated a molecule with characteristics similar to FO. Together, these results indicate that the Chlamydomonas PHR1 gene encodes an FO synthase and that optimal photoreactivation in Chlamydomonas requires FO, a molecule known to serve as a second chromophore for DNA photolyases.

“Tutto è zuppa!”: Making the Superego Enjoy in Calvino’s Il cavaliere inesistente

Research Article| May 01 2010 “Tutto è zuppa!”: Making the Superego Enjoy in Calvino’s Il cavaliere inesistente Robert A. Rushing Robert A. Rushing Search for other works by this author on: This Site Google Romanic Review (2010) 101 (3): 561–577. https://doi.org/10.1215/26885220-101.3.561 Cite Icon Cite Share Icon Share Facebook Twitter LinkedIn MailTo Permissions Search Site Citation Robert A. Rushing; “Tutto è zuppa!”: Making the Superego Enjoy in Calvino’s Il cavaliere inesistente. Romanic Review 1 May 2010; 101 (3): 561–577. doi: https://doi.org/10.1215/26885220-101.3.561 Download citation file: Zotero Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search Books & JournalsAll JournalsRomanic Review Search Advanced Search The text of this article is only available as a PDF. Copyright © 2010 The Trustees of Columbia University2010 Article PDF first page preview Close Modal Issue Section: Articles You do not currently have access to this content.

Color averaging linked to contours, textures and orientation

A blurry, multicolored plaid was made by superimposing two crossed colored sinusoidal gratings: a horizontal red/green grating, and a vertical blue/yellow grating. [Disregarding 'monocular rivalry', which may just be an artifact from eye movements], we have found ways to enhance the visibility of either the vertical or the horizontal grating. We superimposed thin black lines, spaced half a spatial period apart, on the plaid. Vertical lines made the plaid look like a blue/yellow vertical grating. Horizontal lines made it look like a horizontal red/green grating. The perceived were stable and homogeneous between the bars. Similar effects were found for gratings that differed in spatial phase. A red/green and a blue/yellow vertical grating were superimposed shifted by 90°. Now superimposed vertical lines that lined up with the red-green grating made the plaid look like a vertical red/green grating. Displacing the vertical lines sideways to line up with the blue/yellow grating made the plaid look like a vertical blue/yellow grating. Instead of black contours, we can define regions with equiluminous second-order textures, with the same results. We conclude that the visual system combines or averages colors within regions defined by achromatic contours or textures. Another technique did not use superimposed lines, but relied on pre-adaptation to noisy vertical lines twinkling randomly in width and position. This adapted the visual system to vertical. Now the plaid of crossed gratings looked like a horizontal red-green grating. Conversely, adapting to noisy horizontal lines made the plaid look like a vertical blue/yellow grating. Thus the achromatic adapting orientation altered the perceived color of the test plaid. We conclude that the visual system enhances or suppresses colors together with orientation, perhaps owing to double-duty neural units tuned to both color and orientation.