Presence Of Dark Research Articles

Double loss-of-function mutation in EARLY FLOWERING 3 and CRYPTOCHROME 2 genes delays flowering under continuous light but accelerates it under long days and short days: an important role for Arabidopsis CRY2 to accelerate flowering time in continuous light

The photoperiodic response is one of the adaptation mechanisms to seasonal changes of lengths of day and night. The circadian clock plays pivotal roles in this process. In Arabidopsis, LHY, CCA1, ELF3, and other clock proteins play major roles in maintaining circadian rhythms. lhy;cca1 double mutants with severe defects in circadian rhythms showed accelerated flowering under short days (SDs), but delayed flowering under continuous light (LL). The protein level of the floral repressor SVP increased in lhy;cca1 mutants under LL, and the late-flowering phenotype of lhy;cca1 mutants was partially suppressed by svp, flc, or elf3. ELF3 interacted with both CCA1 and SVP, and elf3 suppressed the SVP accumulation in lhy;cca1 under LL. These results suggest that the unique mechanism of the inversion of the flowering response of lhy;cca1 under LL may involve both the ELF3-SVP/FLC-dependent and -independent pathways. In this work, elf3-1 seeds were mutagenized with heavy-ion beams and used to identify mutation(s) that delayed flowering under LL but not long days (LDs) or SDs even without ELF3. In this screening, seven candidate lines named suppressor of elf3 1 (self1), sel3, sel5, sel7, sel14, sel15, and sel20 were identified. Genetic analysis indicated that sel20 was a new deletion allele of a mutation in the blue light receptor, CRY2. A late-flowering phenotype and decrease of FT expression in the elf3;sel20 double mutant was obvious under LL but not under SDs or LDs. These results indicated that the late-flowering phenotype in the double mutant elf3;sel20 as well as in lhy;cca1 was affected by the presence of darkness. The results suggest that CRY2 may play more essential roles in the acceleration of flowering under LL than LDs or SDs.

Prevalence of Acanthosis Nigricans in an urban population in Sri Lanka and its utility to detect metabolic syndrome

BackgroundInsulin resistance (IR) plays a major role in the pathogenesis of metabolic syndrome. Acanthosis nigricans (AN) is an easily detectable skin condition that is strongly associated with IR. The aims of this study were, firstly, to investigate the prevalence of AN among adults in an urban Sri Lankan community and secondly, to describe its utility to detect metabolic syndrome.FindingsIn a community based investigation, 35-64 year adults who were selected using stratified random sampling, underwent interview, clinical examination, liver ultrasound scanning, and biochemical and serological tests. Metabolic syndrome was diagnosed on revised ATP III criteria for Asian populations. AN was identified by the presence of dark, thick, velvety skin in the neck.2957 subjects were included in this analysis. The prevalence of AN, metabolic syndrome and type 2 diabetes mellitus were 17.4%, 34.8% and 19.6%, respectively. There was a strong association between AN and metabolic syndrome. The sensitivity, specificity, positive predictive value and negative predictive value of AN to detect metabolic syndrome were 28.2%, 89.0%, 45.9% and 79.0% for males, and 29.2%, 88.4%, 65.6% and 62.3% for females, respectively.ConclusionsAN was common in our study population, and although it did not have a high enough sensitivity to be utilized as a screening test for metabolic syndrome, the presence of AN strongly predicts metabolic syndrome.

Kapselendoskopie: Vorbereitung und Prokinetika

Durch die Einführung der Kapselendoskopie wurde die Untersuchung des Dünndarms revolutioniert, insbesondere die Diagnostik einer mittleren gastrointestinalen Blutung. Die Diagnostik mittels der Kapselendoskopie kann jedoch eingeschränkt sein durch das Vorhandensein von Stuhlresten oder Luftblasen. Im Gegensatz zur Hersteller­empfehlung verbessert die Vorbereitung mittels Darmlavage die Sicht auf die Mukosa und erhöht hierdurch die diagnostische Ausbeute. Ein weiteres Problem ist die inkomplette Untersuchung des Dünndarms durch eine verzögerte Magen- und / oder Dünndarmtransitzeit. In mehreren Studien konnte kein eindeutiger Vorteil für den zusätzlichen Einsatz eines Prokinetikums gezeigt werden.

Wormholes supported by polytropic phantom energy

It is generally agreed that the acceleration of the Universe can best be explained by the presence of dark or phantom energy. The equation of state of the latter shows that the null energy condition is violated. Such a violation is the primary ingredient for sustaining traversable wormholes. This paper discusses wormholes supported by a more general form called polytropic phantom energy. Its equation of state results in significant generalizations of the phantom-energy and, in some cases, the generalized Chaplygin-gas wormhole models, both of which continue to receive considerable attention from researchers. Several specific solutions are explored, namely, a constant redshift function, a particular choice of the shape function, and an isotropic-pressure model with various shape functions. Some of the wormhole spacetimes are asymptotically flat, but most are not.

Histochemical technique for the detection of chloride cells in fish

Chloride cells are responsible for ionic exchanges in the fish gill. These cells have been widely studied, considering its importance in vital functions of the gill, and because they proliferate when exposed to unfavorable environments. One of the main characteristic of these cells is an acidic cytoplasm, which has been used for identification through histochemical techniques with dyes such as Toluidine Blue and Hematoxylin and Eosin. However, these techniques can be problematic, since epithelial cells can, in certain situations, acquire acidic characteristics similar to those of chloride cells, thus staining in a similar way. Among other functions, chloride cells play a role in calcium uptake from the environment, and therefore have a high concentration of this element. Based on this information, this study aims at developing a specific protocol for the identification of chloride cells. With this purpose, the Von Kossa method specific for calcium was used combined with Hematoxylin counterstaining. Chloride cells had cytoplasm slightly stained with Hematoxylin and the presence of dark stained granules dispersed in the cytoplasm resulted from the Von Kossa reaction due to the calcium present in these cells. This was not found in any other gill cell. Thus, the technique used in this study was specific and efficient to identify chloride cells in fish gills.

The Life History and Nymphal Generic Character Development ofSweltsa adamanteaSurdick (Plecoptera; Chloroperlidae) in an Oregon Summer-Dry Headwater Stream

ABSTRACT This is only the second report of the life history, and first on ontogenic nymphal development, for any of the 22 western species of North American Sweltsa. Concurrent monthly collections of nymphs, with bi-weekly collections of adults from emergence traps, from an intermittent Oregon stream over 10 years yielded an interesting assemblage of stoneflies, including Sweltsa adamantea with no congeners. Adults were taken from emergence traps from 2001 to 2007, and the head-capsule widths of 1,159 nymphs from 1999 to 2007 collections were individually measured. Counts of antennal and cereal segments, windpad presence and backward projecting length, presence of dark, thoracic sternocoxal hairs ( a diagnostic character in late instar Sweltsa), diameter of compound eyes, general presence and length of body hairs, and sexual dimorphism were determined for 68 nymphs representing an array of 0.27 to 1.86mm head capsule widths from 2004 to 2007 collections. Eggs were studied and photographed with SEM. The li...

Rimertown / an atlas by Laura Walker

173 Book Notes Rimertown / an atlas, by Laura Walker University of California Press, 2008 reviewed by Sharon Lynn Osmond Walking this morning in the shaggy plenitude of my garden, I thought about Laura Walker’s poems. As on previous days during the past few months, phrases from her second collection, Rimertown / an atlas, filled my head. The poems in this book have become as palpable to me as the plants that lean into this path and in many ways as and troubling and unruly. Today, on my left I noticed a thickened clot of foliage and bent to examine it. Under a buoyant green spill of Geranium sylvaticum were layers of brittle, brown decay—an accrual of several seasons. Under these layers, on a jagged rock, was a forgotten pair of high-heeled sandals. Their green insoles were curled now and their green leather rotting. Perched there, the shoes seemed to punctuate a rift between disparities: an upright, rusty cylinder and a sprawling patch of wild pink geraniums. Seeing them, I remembered the staccato click of my mother’s high heels as she walked back and forth across our kitchen’s blue linoleum, slender and red-lipped, unaware that she had come to the edge of a landscape that would soon thicken with personal sorrow. Green Shoes. Memory. Decay. Resurrection. The “dark ground of cognition.” Buried layers of memory inform Laura Walker’s work of inquiry in Rimertown / an atlas. In poems titled “map” or “story ” and in untitled prose paragraphs, she excavates the site of her childhood in rural North Carolina, disturbing and finally destroying boundaries between geography and psyche. Her probing is intrusive and risky, pushing her again and again into a breach where consciousness is vertiginous and the retrieval of knowledge is dangerous. In “Map 42,” for example, Walker explores falling into what might be seen as an afterworld: . . . in falling off the edge sinewy and stiff, lines merging we come back to idea parchment CRSP09 nonfiction.indd 173 1/30/2009 12:55:49 PM colorado review 174 “Edge” marks a wilderness where landscape, thought, and written word bleed into each other. Falling is prelude to entering perplexity, necessary preparation for learning to live darkly underground among roots where plotted site-lines and the waking logic of narrative purpose have blurred and disappeared (“come down, oh come down”). Walker’s investigative poetics is careful, deliberate, lyrical. It is also ragged and paratactic, housing fragments of remembered conversations and shards of half-understood stories. The poems become an archive of vernacular echoes where the singularities of an inscribed landscape reside. This landscape, mapped and given, has sunk under layers of history and human experience. It is a place where sentences veer away from their teleological goal and wander instead off course and into a syntactic realm of illogic and uncertainty (“carried stairwise, back pasture / collated . collected, its leaves and thistles”). Like Thomas Hardy’s Egdon Heath, Rimertown broods and seems quasi-conscious. It is an entelechy that casts its dark presence over the lives of its inhabitants (“we are in its shadows”). Its world is field, and field is contained, not within boundaries mapped on parchment merely, but within lines of ephemeral , blue inflorescence as well: “bachelor buttons lining the field”; “cornflowers towing the field”; “morning glory buttons the fields”; “morning glories choke the field.” Place guards its own stasis (“fences radiating inertia”), and yet it is endemically haunted and disordered—a surreal tenement for the random and disorganized: “there were hundreds of brown dresses floating among crows”; “thrift spilling its banks, a chimney where nevermore.” And it preserves a troubling kind of “oneness” (atonement?) with its denizens (“we sat down and fed ourselves dirt”). Body ingests landscape; body inscribes upon itself the map of place (“added line to line, increments of flesh”). Within such oneness, fracture is violent. Dreaming gives way to waking , to “seeing,” painfully: hands held fervently against the face that in knotting. in knowing red sorrows and awake Tension between desire and act, rising and falling, death and CRSP09 nonfiction.indd 174 1/30/2009 12:55:49 PM 175 Book Notes resurrection articulates an informing duality, and associated with this duality is...

Broadening and intensity redistribution in theNa(3p)hyperfine excitation spectra due to optical pumping in the weak excitation limit

Detailed analysis of spectral line broadening and variations in relative intensities of hyperfine spectral components due to optical pumping is presented. Hyperfine levels of sodium $3{p}_{1/2}$ and $3{p}_{3/2}$ levels are selectively excited in a supersonic beam at various laser intensities under the conditions when optical pumping time is shorter than transit time of atoms through the laser beam. The excitation spectra exhibit significant line broadening at laser intensities well below the saturation intensity, and redistribution of intensities of hyperfine spectral components is observed, which in some cases is contradicting with intuitive expectations. Theoretical analysis of the dynamics of optical pumping shows that spectral line broadening sensitively depends on the branching coefficient of the laser-driven transition. Analytical expressions for branching ratio dependent critical Rabi frequency and critical laser intensity are derived, which give the threshold for onset of noticeable line broadening by optical pumping. The critical laser intensity has its smallest value for transitions with branching coefficient equal to 0.5, and it can be much smaller than the saturation intensity. Transitions with larger and smaller branching coefficients are relatively less affected. The theoretical excitation spectra were calculated numerically by solving density matrix equations of motion using the split propagation technique, and they well-reproduce the observed effects of line broadening and peak intensity variations. The calculations also show that presence of dark (i.e., not laser coupled) Zeeman sublevels in the lower state results in effective branching coefficients which vary with laser intensity and differ from those implied by the sum rules, and this can lead to peculiar changes in peak ratios of hyperfine components of the spectra.

Preparations and Prokinetics

The evaluation of the importance of bowel preparations, prokinetics and postural tricks for bowel cleanliness, completeness of evaluation, and ultimately for the diagnostic yield of VCE is hampered by several factors. First, most studies are published in abstract form. Second, the methodological quality of the studies is rather low, because randomized comparisons are only a small minority. Third,there is no accepted and validated scale to evaluate bowel cleanliness. For all of these reasons, comparisons between studies are very difficult, and drawing general conclusions is almost impossible. As a consequence, at the Fifth International Conference on Capsule Endoscopy [9], only a limited measure of consensus could be reached on the fact that preparations/prokinetics probably improve the quality of small bowel cleanliness. It also was agreed that it is possible that preps/prokinetics improve GTT, SBTT and completeness of examination, and that keeping the patients recumbent in the right lateral position may shorten the GTT. It was noted, however, that the best type of preparation, and dose and time of administration remain to be determined. Additionally, data on prokinetics and postural tricks are insufficient to reach a firm conclusion. Unanswered questions concern the effect of medications on the diagnostic yield of VCE, whether prokinetics increase the miss rate, whether preparations/prokinetics cause adverse effects and the influence of medications on patient acceptance.

Gross and cytological characteristics of normal canine anal-sac secretions.

A study was conducted to characterize the gross and cytological characteristics of secretions from normal canine anal sacs. Fifty dogs with no recent history of anal-sac disease were selected consecutively and their anal sacs manually expressed. Of the 47 dogs with known or estimated ages, 27 were < 1 year olds. However, these youngest dogs were not significantly different from the rest in cell counts, viscosity, or presence of dark or light solid portions of the secretions. For all dogs combined, the secretions typically contained 41 (median) corneocytes per 400x magnification microscopic field, lots of basophilic background debris, and a mixture of Gram-positive cocci (173 per field; median), Gram-positive rods (29 per field; median), and Gram-negative rods (two per field; median). Although median counts across 10 400x fields per sac indicated no leucocytes or yeasts, many of the normal dogs had an occasional 400x field with non-degenerate neutrophils and yeasts. Erythrocytes were not a feature of these anal-sac secretions, and mononuclear leucocytes were found only rarely. Extreme heterogeneity existed in gross colour, consistency and the amount of solid material. Thus, these latter parameters probably would not be valid indicators of anal-sac disease.

Latinegras: Desired Women--Undesirable Mothers, Daughters, Sisters, and Wives

Latinegras:Desired Women—Undesirable Mothers, Daughters, Sisters, and Wives Marta I. Cruz-Janzen (bio) Latinegras are Latinas of obvious black ancestry and undeniable ties to Africa, women whose ancestral mothers were abducted from the rich lands that cradled them to become and bear slaves, endure the lust of their masters, and nurture other women's children. They are the mothers of generations stripped of their identity and rich heritage that should have been their legacy. Latinegras are women who cannot escape the many layers of racism, sexism, and inhumanity that have marked their existence. Painters, poets, singers, and writers have exalted their beauty, loyalty, and strength, but centuries of open assaults and rapes have also turned them into concubines, prostitutes, and undesirable mothers, daughters, sisters, and wives. Latinegras are marked by a cruel, racialized history because of the shades of their skin, the colors and shapes of their eyes, and the textures and hues of their hair. They are the darkest negras, morenas, and prietas, the brown and golden cholas and mulatas, and the wheat-colored trigueñas. They are the light-skinned jabás with black features and the grifas with white looks but whose hair defiantly announces their ancestry. They are the Spanish-looking criollas, and the pardas and zambas who carry indigenous blood. Latinegras represent the mirrors that most Latinos would like to shatter because they reflect the blackness Latinos don't want to see in themselves.1 I am a Latinegra, born to a world that denies my humanity as a black person, a woman, and a Latina; born to a world where other Latinos reject me and deny my existence even though I share their heritage. As Lillian Comas-Diáz writes, the combination of race, ethnicity, and gender makes Latinegras a "minority within a minority."2 Racism and sexism have been with me all my life. I was raised in Puerto Rico during the 1950s and 1960s, and lived on and off in the United States during the 1970s and 1980s. Today, I still live in both worlds, and most of the gender and race themes I grew up with remain. This essay is my personal and historical narrative of the intersection of racism and sexism that has defined my life and that of other Latinegras. [End Page 168] Somos una Raza Pura/Pura Rebelde (We Are a Pure Race/Pure Rebel) "Aquí, el que no tiene inga, tiene mandinga. El que no tiene congo, tiene carabalí. ¿Y pa'los que no saben ná, tu abuela a'onde está?" This popular expression reveals what most Latinos throughout Latin America, and particularly in the Caribbean, know but wish to hide. It attests to the broad racial mixing that exists as well as to its denial. It states: "Here, those who don't have Inga, have Mandinga. Those who don't have Congo, have Carabali. And those who claim not to know, where's your grandma at?" The Ingas, or Incas, were indigenous Indians. Mandingas and Congos were Africans. Carabalis were runaway slaves, both African and indigenous Indians, feared for their rebelliousness. The question, "Where is your grandmother at?" publicly mocks the hypocrisy of white-looking persons who conceal their blackness and deny their ancestral black mothers. Such expressions permeated my childhood and revealed the many contradictions of my world. Growing up biracial in Puerto Rico, I became aware of Latino racism at a very young age. As the child of a white Puerto Rican mother, whose family counted their drops of pure Spanish blood and resented our dark presence, and a very prieto (dark black) Puerto Rican father, I became aware of the social and economic gulf that prevails within this purportedly harmonious, integrated society. My paternal grandparents were educated, considered middle-class, and lived in a white neighborhood of paved streets and nice homes. Theirs was a neat wooden house with electricity, indoor plumbing, and a telephone. A large concrete balcony and front fence were decorated with ornamental wrought iron. Grandma kept a beautiful front flower garden. They were the only blacks in the neighborhood, always conscious of their neighbors' watchful and critical eyes. We were careful never to set foot outside the house...

Reflectance Spectra of Plumage Areas Colored by Green Feather Pigments

-Only rarely are green plumage colors due to the presence of green pigments. The best known is turacoverdin. Two galliform species (Ithaginis, Rollolus), Jacana and some anseriform species (Somateria, Nettapus) also have green pigments. The reflectance spectra of plumage pigmented by turacoverdin are characterized by distinct minima at about 570 and 610 nm. These minima represent absorption bands as confirmed by a transmittance spectrum of a turacoverdin extract. Surprisingly, the spectra of the two galliform species and Jacana also exhibit the characteristics of the turacoverdin spectrum, while that of Somateria is different. I show that the pigments of Ithaginis, Rollolus, and Jacana also resemble turacoverdin in containing copper in relatively high concentration, and conclude that these pigments are identical with or closely related to turacoverdin. Intraand interspecific variation in reflectance spectra is assumed to be largely determined by the presence of dark, nongreen pigments in the plumage. The spectrum of turacoverdin supports the hypothesis that the pigment is closely related to the well-known red pigment of turacos (Musophagidae)-turacin. However, the chemical constitution of turacoverdin remains unknown. The presence of turacoverdin and turacin in the plumage of the Musophagidae hitherto has been considered an autapomorphy of the turacos. The fact the turacoverdin also is present in two possibly related galliform taxa argues for phylogenetic relationships between the Musophagidae and the Galliformes. Received 3 April 1991, accepted 10 January 1992. GREEN, noniridescent plumage colors can be produced in a number of ways (Auber 1957). The combination of a structural blue color with yellow pigments, as found in parrots, is best known (Frank 1939, Dyck 1971). The olive-green colors obtained by the juxtaposition of yellow and blackish pigments (apposition colors; Auber 1957, Dyck 1978) also are widespread. Central to my two studies is the question of the evolution of plumage colors that resemble the green colors of leaves, without chlorophyll being available as a feather pigment (Needham 1974:81). In principle, the simplest way to produce a green plumage color is to deposit a green pigment within the feather keratin. This possibility has been realized in only a limited number of cases. The best-known green feather pigment is turacoverdin. This is found in some turacos (Musophagidae), especially the species of Tauraco and Musophaga, and possibly also in the Great Blue Turaco (Corythaeola cristata; Krukenberg 1882, Moreau 1958). Preliminary chemical studies have been carried out (Moreau 1958). Other known green pigments are zooprasinin in the remiges of the Jacana (Jacana spinosa, Jacanidae; Rensch 1925), phasianoverdin in belly feathers of the Blood Pheasant (Ithaginis cruentus, Phasianidae; Gotz 1925), and a green pigment in much of the plumage of the Roulroul (Crested Wood-Partridge, Rollolus roulroul, Phasianidae), especially the female (Volker 1961). The green pigments in some anseriform species (Nettapus, Somateria; Auber 1957) are poorly known (Brush 1978). I describe the reflectance spectra of green plumage areas in several species and discuss factors that influence the shapes of the spectra. I compare the reflectance spectra with the spectrum of turacoverdin in extract and from this infer the probable identity of some of the pigments. MATERIALS AND METHODS Most measurements were performed on study skins from the Zoological Museum, University of Copenhagen, and the British Museum (Natural History). A few measurements were also carried out on mounted specimens. The spectrum of the nape of an adult male Eider (Somateria mollissima) was scanned on feathers taken from a newly dead bird. Feathers plucked from live birds were obtained from the Zoological Garden, Copenhagen, and kept four months in the dark before measurement. Reflectance spectra were obtained on a Beckman DK-2A spectrophotometer with a reflectance attachment and using a reference of magnesium oxide. The illuminated spot was approximately 8 x 8 mm.

Dark cells of cystinosis: Occurrence in renal allografts

Twenty-four biopsies of renal allografts, generally cadaveric, from 20 patients with cystinosis were examined by light, polarization, phase contrast, and electron microscopy. The unusual dark cells previously reported in the native kidneys and livers of patients with cystinosis were observed in 12 of the 24 biopsies. The cells were present in the interstitium in all of these 12 biopsies, in glomeruli in one biopsy, and in the tubular lumen in two biopsies. They were evident by light and electron microscopy in stained and unstained ultrathin sections, and could be discerned solely in Epon sections. The dark appearance resulted from the presence of dark, fine granular material in the cytoplasm and nucleus and in cytoplasmic inclusions. The cells were judged to be macrophages. They were present as early as 3 months following transplantation and bore no relationship to interstitial crystals or inflammation. The dark cells have two important implications: cystine storage may not be limited to lysosomes, and dark cells are a morphologic alternative to the traditional identifying configuration of cystine in tissues, namely crystals.

Glass produced by underground nuclear explosions

Detonation of an underground nuclear explosive deposits a large amount of energy in what can be considered to be a point source in space and time. The strong shock wave produced propagates spherically outward, initially vaporizing the explosive and nearby rock and subsequently melting, then heating the surrounding rock as the energy density decreases. The vaporized material expands adiabatically forming a cavity. As the energy in the vaporized material is dissipated during the cavity formation process, the explosive and rock debris condense and mix with the melted rock. The melt flows to the bottom of the cavity where it is cooled and quenched by fractured rock fragments falling from above as the cavity collapses. Measurements on a large number of underground nuclear explosions indicate that approximately 740 tons of rock and/or soil are melted for every kiloton (1012 cal) of explosive energy, or approximately 25% of the explosive energy goes to melting rock. The resulting glass composition reflects the composition of the unaltered rock with debris from the explosive added. A wide range of physical appearances has been observed, ranging from white pumice to dense, dark lava. In general, bulk composition and color vary with the amount of explosive iron incorporated into the glass. By inference, all the refractory explosion products are mixed with the solidified melt, although the degree of mixing inferred is highly variable. Recent electron microprobe studies of glasses produced by the low yield Rainier event in welded tuff have produced the following results: (1) glasses are dehydrated relative to the host media, (2) glasses are extremely heterogeneous with respect to major element chemistry on a 20 μm scale, (3) a ubiquitous feature is the presence of dark “marble-cake” regions in the glass; these are locally enriched in iron and may be related to the nuclear device debris, (4) optically amorphous regions with chemistries of the crystalline phases are found in the glasses and provide evidence of shock melting, (5) only limited major element redistribution and homogenization occur within the cavity. The short duration of the thermal pulse and the high viscosity of the melts produced by the Rainier event precluded re-homogenization by diffusion or convection, respectively.

Ultrastructural organization of the mammalian pineal gland during postnatal ontogenesis.

Ultrastructural organization of the components composing the mammal pineal gland is analyzed on the basis of literature data and personal observations. Variations in the form, size and ultrastructural organization of the cellular elements in the pineal gland--pinealocytes, interstitial and glial cells--are discussed. The problem of dark and light pinealocytes is considered as a part of a general biological problem on the presence of dark and light cells as a reflection of the law on "intermittent activity of functional structures". An attention is paid to the organization of the microcirculatory bed and pericapillary space to the peculiarities of the secretory process in the organ. Dynamic changes in the cytologic organization of pinealocytes and other components of the organ in the postnatal ontogenesis are presented in detales.

CONTRAST AND INDUCTION IN RATS ON MULTIPLE SCHEDULES1

Eight rats were trained on a variable-interval schedule in the presence of a light (Phase I). Responding was then extinguished in the presence of darkness that alternated with the light (Phase II). Reinforcement was then introduced in the presence of darkness (Phase III). Several rats were then returned to the condition of Phase II (Phase IV) and then to that of Phase III (Phase V). The responding of most rats showed clear behavioral contrast in Phase II-i.e., an increase in responding in the presence of the light. When, for three rats, Phase III was introduced early after the occurrence of positive contrast, either positive induction occurred, i.e., an increase in responding in the presence of the light, or there was little change. Negative contrast did not occur. It was further shown that positive contrast dissipates over time, thus replicating a result previously obtained with pigeons and that the positive induction effect seems also to dissipate over time. The introduction of reinforcement in the presence of darkness (Phases III and V) after the dissipation of positive contrast seemed to have little consistent effect.

Idaho Discomycetes. II

SUMMARYThe new species Plectania milleri and Sarcosoma latahensis are described in the family Sarcoscyphaceae. Plectania milleri is closely related to P. melastoma but is distinguished from this and other species of sect. Plectania by its stellate margin and by the presence of dark, branched hyphae in the medullary excipulum. Sarcosoma latahensis is a highly gelatinous species with eguttulate ascospores and an extensive tomentum of smooth, subhyaline to olive brown hyphae. The new combination Sarcosoma mexicana (&z.tbd; Bulgaria mexicana Ellis & Holway) is also proposed.Sarcosoma latahensis develops a Verticicladium conidial state when cultured on Thuja-Tsuga extract agar. Plectania milleri and S. mexicana form rudimentary stromata on this medium.

Negative Stain Morphology of Herpesvirus-Type Particles Extracted From Tissue Cultures of Human Cells

Recent findings of Herpesvirus-type particles in human tissue culture cells originating from “normal” and cancerous individuals have been described. Negative stain studies on the fine structure of these particles (EB-3) indicate that they belong to the herpes group of viruses. However, isolation, immunofluorescence and “coating” tests have ruled out the possibility that this virus is Herpes simplex, Herpes zoster, varicella or cytomegalovirus.It has recently been suggested that members of the papova virus group, although all having the same number of capsomeres, are distinguished from each other by the type of lattice skew present on their capsid. We attempted to detect a similar morphological distinction between the Herpesvirus-type particles and the virus of Herpes simplex. Figure 1 demonstrates the presence of three six-fold capsomeres located along the edge of a triangular face in between two five-fold capsomeres. Since these five capsomeres are located along a straight line the capsid must have a regular icosadeltahedral lattice and must have 162 capsomeres. This makes it identical to the capsid of Herpes simplex virus. We have also repeatedly observed the presence of dark “furrows” on the surface of particles permeated with phosphotungstic acid (PTA) (Fig. 2). Their disposition is compatible only with a regular icosahedral lattice.