Yellow Disc Research Articles

Cover Feature: Improvement of Solid Photoluminescence of Tridentate Schiff Base Pt(II) Foldamer by Hybridizing Poly (4‐Vinylpyridine) (Eur. J. Inorg. Chem. 36/2022)

The Cover Feature shows the bis(tridentate Schiff base Pt(II)) complex containing dimethyl sulfoxide (Pt2L2DMSO) as a combination of yellow disks, gray disks, orange cones, and a black curved line. Pt2L2DMSO is unfolding due to the steric repulsion of the bulky ligand. The blue hexagons connected to the branched black lines stand for poly(4-vinylpyridine) (P4VP). The green curved figure in the background indicates hybridization. The top image shows the hybridization of Pt2L2DMSO and P4VP, which causes a ligand exchange reaction for Pt2L2DMSO, forming a folding network structure in the yellow membrane. The yellow membrane exhibits red photoluminescence under ultraviolet irradiation (green wavy arrow). The reddish thunder expresses phosphorescence. The bottom image in the cover shows hybridization of Pt2L2DMSO and 4-vinylpyridine (4VP), which causes a ligand exchange reaction for Pt2L2DMSO, forming the folding columnar packing structure in the brown block crystal. The black wavy arrow indicates non-radiative deactivation. The metallofoldamer crystal does not exhibit solid photoluminescence under ultraviolet irradiation, while the metallofoldamer membrane is luminescent, thanks to the hybridization with P4VP. The background color changes gradually from orange to gray at the bottom to orange at the top, showing the improvement of photoluminescence from bottom to top. More information can be found in the Research Article by H. Achira and co-workers.

Taxonomy and morphology of Phacidiella kunmingensis sp. nov. (Stictidaceae) from southwest China

Stictidaceae was formally introduced as a group of saprotrophic discomycetes. The majority of Stictidaceae species are documented and described from Europe, North America and South America. In contrast, knowledge on stictidaceous fungi in African and Asian continents is lacking. In this study, a novel saprophytic species, Phacidiella kunmingensis sp. nov. was discovered from dead woody twigs in Yunnan Province, China. The new species was described based on its sexual morph, which is characterized by apothecial ascomata, yellow disc, white-pruinose margin, crystalline exciple, filiform paraphyses, cylindrical asci and filiform, multiseptate, non-disarticulating ascospores. Its taxonomic position was inferred using phylogenetic analyses of combined LSU, ITS, mtSSU and rpb2 sequence and further confirmed by morphological studies.

The Complete Genome Sequence of Erigeron philadelphicus, the Philadelphia Fleabane.

The Philadelphia Fleabane (Erigeron philadelphicus) is a common flower across North America, growing along roadsides and in fields and woodlands. Each plant has 3 to 35 small daisy-like flowers at the top of the plant. Flowers are 0.5 - 0.8" across, with 150 or more pink to white thread-like petals and a yellow center disk. We present the whole genome sequence of this species. Illumina sequencing was performed on a single leaf from a wild-collected plant. The reads were assembled using a de novo method followed by a series of references from related species for finishing. The raw and assembled data is publicly available via Genbank: Sequence Read Archive (SRR13004263) and Assembly (GCA_024320915).

Erioscyphella abnormis (Lachnaceae: Ascomycota), an unrecorded species in Korea

In the course of the mycofloristic survey, the authors collected an ascomycetous mushroom with a small yellow disc covered with brownish hairs. The morphological and molecular identifications showed that this fungus is Erioscyphella abnormis , which has not been recorded in Korea. In this article, its diagnostic description, illustration, and cultural characteristics are provided.

Saxicolous Lichens in the Semi-Arid Caatinga in Brazil Show Substratum Shifts

Saxicolous lichens were investigated for the first time in the southern reaches of the Caatinga biome in Sergipe, NE Brazil. Only 20 species could be identified, and three more are described as new to science: Cresponea quinqueseptata Aptroot & M.Cáceres, sp. nov. with 5-septate ascospores and yellow pruinose discs; Fulgogasparrea intensa Aptroot & M.Cáceres, sp. nov. with a cinnabar red, appressed thallus with marginally elongated lobes; and Peltula nigrotestudinea Aptroot & M. Cáceres, sp. nov. with flat, black, isolated areoles. A number of substrate shifts was observed: 1) the new species of Peltula Nyl. does not grow in places with run-off as usual, but on top of the boulders, where it is in the best position to catch the precipitation, which is the limiting factor here; 2) Synalissa matogrossensis (Malme) Henssen, which was previously known only from the type locality, where it grows on limestone, was found on granite; the apparently considerable width of its ecological amplitude is unusual. Its position inside the Lichinaceae was confirmed by sequence data; 3) Xanthoparmelia succedans Elix & J.Johnst. was found growing on bark, rather high on trees. The corticolous occurrence is attributed to high diaspores pressure; 4) the area and thus the tree bark is wet enough part of the year to sustain the growth of a corticolous Lichinaceae (one of only two compared to 340 saxicolous and terricolous species in the family) and other cyanophilic lichens; and 5) the new Cresponea Egea & Torrente is the first saxicolous species in the genus in the tropics, where the genus is most speciose; its thallus is deeply endolithic.

Foraging Small White Butterflies, Pieris rapae, Search Flowers Using Color Vision

We demonstrate that the small white butterfly,Pieris rapae, uses color vision when searching flowers for foraging. We first trained newly emerged butterflies in a series of indoor behavioral experiments to take sucrose solution on paper disks, colored either blue, green, yellow, or red. After confirming that the butterflies were trained to visit a certain colored disk, we presented all disks simultaneously. The butterflies selected the disk of trained color, even among an array of disks with different shades of gray. We performed the training using monochromatic lights and measured the action spectrum of the feeding behavior to determine the targets’Pieris-subjective brightness. We used the subjective brightness information to evaluate the behavioral results and concluded thatPieris rapaebutterflies discriminate visual stimuli based on the chromatic content independent of the intensity: they have true color vision. We also found thatPierisbutterflies innately prefer blue and yellow disks, which appears to match with their flower preference in the field, at least in part.

Experimental and numerical research on fracture behaviors of sandstone under different loading rates

The macroscopic deformation process of rock is the external performance of microscopic damage in essence, and research from the macro and micro perspectives can effectively reveal the failure mechanism of rock. To further investigate the fracture behaviors of yellow sandstone disc specimens under different loading rates, seven groups of Brazilian disc splitting tests with different loading rates from 1 × 10–6 to 1 × 10–4 s–1 were carried out. A systematical investigation of loading rate effect on macroscopic mechanical responses and microscopic damage characteristics has been conducted from the stress–strain relationship obtained from material testing system, from damage three-dimensional localization based on acoustic emission techniques, and from fracture morphology by scanning electron microscope. In addition to laboratory experiment, parallel bond models of different grain size distribution indexes based on particle flow code were established. The coupling effect of loading rate and grain size distribution index was further analyzed. The results interpret that the effect of loading rate on rock fracture behaviors is determined by the process of crack initiation, propagation and coalescence, and it is also affected by distribution of different size grains. The differences of rock fracture behaviors under different loading rates were discussed from the mechanism of energy input and dissipation. The research have actual significance for stability design and evaluation of rock excavation engineering.

First record of Melampodium divaricatum (Asteraceae) in West Tropical Africa

A plant that showed morphological closeness to Aspilia africana (Pers) C. D. Adams (Asteraceae) was spotted and collected in 2015 along Afe Babalola University road, Ado‐Ekiti, Ekiti State, Nigeria with coordinates 7°36′59.99″N, 5°12′60.00″E. However, upon closer observation some distinct and peculiar characteristics that clearly distinguished it from Aspilia africana were revealed, e.g. sterility of the disc florets and production of achenes by ray florets only. Another striking character of the plant was total emptying of the capitulum after achene maturation, leaving an empty capitulum cup on the plant. Literature and herbarium searches revealed that the plant had neither been reported from West Tropical Africa nor collected in any herbarium in Nigeria before. The plant was eventually identified as Melampodium divaricatum (L.) which is an annual erect herb, distributed in tropical and subtropical regions but mostly restricted to Mexico, North America and Central America. Morphological, reproductive and cytological studies carried out on the plant revealed it to possess a highly branched erect pigmented stem, simple opposite sub sessile leaves with acute apex and distantly serrated margins, capitula with yellow unisexual disc and ray florets, sterile disc florets, fertile ray florets, relatively high pollen fertility (92.85%), a somatic chromosome number of 2n = 24 and regular formation of 12 bivalents, indicating the plant to be a diploid species. Further studies on Melampodium in Nigeria and a general revision of the flora of West Tropical Africa is suggested as well as the need to monitor M. divaricatum in the region since it appears to have the capacity to become invasive.

Provision Point-Source Materials Stimulates Play in Sows but Does Not Affect Aggression at Regrouping.

Simple SummaryIn most intensive pig production systems, pigs are often mixed into new groups. Sows are important to a production system, as they are the driver behind the farms’ productivity. The aggression that results from sows being mixed into new groups and formation of hierarchy can detrimentally affect production and welfare. This study aimed to determine the effect of providing access to materials on aggressive and play behaviors in gestating sows. Play behaviors were observed in the ‘enhanced’ pen and no play was observed in standard housing (without materials present). Aggression measures, salivary free cortisol concentrations, and injury counts were unaffected by treatment. The provision of point-source materials to sows at mixing had no impact on aggression; however, their presence maintained sow interest over the course of the experiment. Additionally, play behavior was observed in their presence, which may suggest that a more positive affect was induced when the materials were provided.When sows are mixed into groups, hierarchies form and resulting aggression and stress can affect production and welfare. This study determined the effect of providing point-source materials on aggressive and play behaviors in gestating sows. Large white cross Landrace sows were mixed after insemination; six pens of 12 sows were housed in ‘standard’ pens, and six pens of 12 sows were housed in ‘enhanced’ pens. The ‘enhanced’ pens each contained two rubber mats, eight strands of 24 mm-thick sisal rope and two yellow plastic disks, suspended from the roof. The sows remained in these pens until pregnancy confirmation. Salivary cortisol concentration, injury counts, and sow behaviors were recorded the day before mixing (day 1), mixing (day 0) and post-mixing day 1, day 4, day 7 and day 20. At farrowing, reproductive outcomes were obtained. Play was observed (including locomotor and object play) in the ‘enhanced’ pen, and percentage of time spent playing was greater on d4 (1.48 ± 0.3 Square root transformed data (2.84% non-transformed adjusted mean)), d7 (1.43 ± 0.3 (2.97%)) and d20 (1.64 ± 0.3 (3.84%)), compared to d0 (0.56 ± 0.3 (0.70%)) and d1 (0.87 ± 0.3 (1.67%) (p < 0.05)). No play was observed in standard housing. Aggression, salivary free cortisol concentrations and injuries were unaffected (p > 0.05). The provision of materials had no impact on aggression, although their presence maintained sow interest and play behavior, suggesting a positive effect.

An egg‐laying device to estimate the induction of sterility in Ceratitis capitata (Diptera: Tephritidae) sterile insect technique programmes

AbstractArea‐wide environmentally friendly pest control methods such as the sterile insect technique (SIT) are being developed and improved to contribute in managing agricultural, environmental and public health problems. A key aspect to evaluate performance of sterile males is to directly measure sterility induction in the field. Sterility induction has been estimated for tephritid fruit flies by recovering egg from host fruit in the field, the method is, however, impractical, and past efforts to develop artificial egg‐laying devices have not prospered. Here, we evaluated response of wild gravid Ceratitis capitata (Medfly) females to long‐distance fruit‐based chemical attractants, visual and tactile stimuli to develop an artificial egg‐laying device. The device combining the most attractive features was further tested under two deployment schemes. Finally, devices and deployment tactics were used to compare fertility levels between feral Medfly females under conventional management and under SIT. Agar spheres wrapped in plastic film, baited with pressed peach juice and visually enhanced with yellow discs received more egg than other combinations of attractive features. Such devices also received more eggs when deployed on fruitless trees and when placed on the orchard perimeter. The egg hatch in an orchard under conventional management was estimated at 86%, whilst egg hatch in an area under SIT was reduced to 31%. The egg‐laying devices are therefore useful to measure sterility induction and can be further improved by refining long‐distance attraction and deployment schemes.

Three new species of Senecio (Compositae: Senecioneae) from the Alto Marañón, Huánuco region, Central Peru

Three new species of Senecio (Compositae: Senecioneae) from Central Peru are described and illustrated. Morphological characters are used in order to distinguish them from the closest species. Senecio crassiandinus Montesinos &amp; Pino has succulent leaves with cuticle composed of translucid white glands, bright yellow disc florets with blotches of pale reddish-brown in the corolla throat and linear-oblong achenes covered with trichomes, which distinguish it from the other South American species of the genus. Senecio inghamii Montesinos has oblanceolate-ovate to rhombic-quadrate leaves, short-sized, with serrate-quadrate dentation, upper surface lustrous and glossy, lower surface densely covered with whitish lanuginose pubescence, capitules bear trilobulated ray florets, achenes copiously covered by fimbriate hairs which differentiates it from its closest relative, S. pensilis Greenm. Senecio roseoandinus Montesinos &amp; R. Zárate is a unique pubescent species characterized for being a perennial rhizomatous herb, with lanuginose and arachnoid trichomes, leaves elliptic-lanceolate, thick, densely arachnoid to glabrous (lustrous, glossy, dark green), margin entire to crenate, synflorescence in racemes, capitules discoid, corolla pale yellow but turning fuchsia-pink at maturity, achenes oblong, striate, and glabrous. All three new species are distributed in the Alto Marañon river mountain slopes, at altitudes ranging from 2000 up to 4200 m a.s.l. The species are, so far, only known from their type localities in the Huánuco region.

Quantity Discrimination in Trained Lizards (Podarcis sicula).

Quantitative abilities have been reported in many animal species. Two main methods have been extensively used: spontaneous choice tests and training procedures. A recent study showed that ruin lizards are capable of spontaneously discriminating between the surface area of two food items of different size, but failed when food was presented in sets of discrete items differing in number. In the present study, we used a training procedure to further investigate quantitative abilities in ruin lizards. Subjects were presented with two sets of yellow disks differing either in number (Experiment 1) or in area (Experiment 2) and were trained on different discriminations of increasing difficulty (1 vs. 4, 2 vs. 4, and 2 vs. 3). Results showed that lizards were more accurate in discriminating sets of discrete items differing in number than the area of two individual items, in contrast to what had earlier been observed in spontaneous choice tests. Although we cannot exclude other factors that affected the performance of ruin lizards, the poor accuracy here observed in both experiments might reflect a true limit in lizards’ quantitative abilities.

Nursing review of diagnosis and treatment of lumbar degenerative spondylolisthesis.

Background:In the lumbar spine, degenerative spondylolisthesis or degenerative (not traumatic) slippage of one vertebral body over another is divided into 4 grades – grade I (25%), grade II (50%), grade III (75%), and grade IV (100%). Dynamic X-rays, magnetic resonance (MR), and computed tomography (CT) scans document the slip secondary to arthritic changes of the facet joint plus stenosis, ossification of the yellow ligament, disc herniations, and synovial cysts. MR best demonstrates soft tissue pathology whereas CT better delineates ossific/calcified disease.Methods:Grade I degenerative spondylolisthesis, typically found at the L4–L5 level followed by L3–L4 and L5S1, is more common in females (ratio 2:1) over the age of 65. Symptoms include radiculopathy (root pain) and neurogenic claudication (e.g., pain with ambulation, requiring the patient to stop, rest, sit down). Symptoms/signs may include unilateral/bilateral radiculopathy and uni/multifocal motor, reflex, and sensory deficits in. Some may also present with a cauda equina syndrome (e.g., paraparesis/sphincter dysfunction).Results:Surgery for grade I-II spondylolisthesis may include laminectomy alone, laminectomy/noninstrumented fusion or with an instrumented fusion. Older patients with osteoporosis are more likely to have no fusion or a noninstrumented fusion. All fusions utilize autograft harvested from the laminectomy that may or may not be combined with a bone graft expander (to increase the fusion mass) combined with autogenous bone marrow aspirate. The fusion mass is placed over the transverse processes following decortication.Conclusions:Patients with multilevel spinal stenosis and degenerative spondylolisthesis may require decompressive lumbar laminectomies alone or in combination with noninstrumented or instrumented fusions.

Notes and Documents A Note on the Sindarin Translation of the Name Daisy

Notes and Documents A Note on the Sindarin Translation of the Name Daisy J. M. Silk (bio) An eye in a blue faceSaw an eye in a green face."That eye is like to this eye"Said the first eye,"But in low placeNot in high place." (H, v, 122). The answer to this riddle from The Hobbit is "sun on the daisies." The "eye in a blue face" refers to the sun in the blue sky, while the "eye in a green face" is a flower in a field. But although Gollum's answer seems obvious, in retrospect the choice of "daisy" out of all the possible flowers in the world reveals surprising insights about Tolkien's thought processes and inspirations. The riddle, as Yvette Kisor points out, depends on the etymology of the word "daisy" (Kisor, 569–70), which, as Douglas Anderson notes (H, v, 122, n. 16), is derived from Old English "dœġes ēaġe, 'day's eye'; so named from its covering the yellow disk in the evening and disclosing it in the morning" (Onions 242).1 The word "daisy"2 is thus a particularly fitting choice for the riddle's solution, considering that it connotes two parallel images: the image of a bright object against a monochromatic background, and the metaphorical interpretations of an eye in a face. One of the odd things about this riddle is that it refers to the eye in a green face as singular, but the answer is sun on the daisies—plural. Readers who try to figure out the answer before reading Gollum's solution (very difficult to do, as the answer is located only a few lines down the page) would seem to be more likely to guess "sun on a flower" than "sun on a particular species of flower."3 Even if they did manage to guess "daisy," it seems unlikely they would pluralize the answer, considering the fact that the riddle presents "an eye" as singular.4 There is more significance to this detail than there might appear to be. Bilbo's riddle appears to be Tolkien's earliest published reference to a daisy; perhaps his last appears in Sauron Defeated, volume IX of The History of Middle-earth. In this volume, Christopher Tolkien prints drafts of an epilogue for The Lord of the Rings that his father wrote and rejected in 1950 or 1951.5 This short text, which tells of Sam's life in [End Page 155] the Shire after Frodo's departure from Middle-earth, includes the "King's Letter," an invitation to Sam Gamgee and his family to meet Aragorn and Arwen by the shores of Lake Evendim. Tolkien wrote two copies of the letter: one in English and the other in Sindarin, and the names of Sam's children appear in both texts, so we can match these names in English with their translations in Sindarin. Most interesting, for our purposes, is the Sindarin name of Sam's fourth daughter: Arien. In English her name is given as Daisy (Sauron 117, 441). This translation may be surprising to readers who are familiar with The Silmarillion, in which Arien is the name of the Maia who guides the vessel of the sun through the sky and tends "the golden flowers in the gardens of Vána…" (S 99). Her name is closely associated with the sun. Indeed, the name Arien means "Maiden of the Sun" in Sindarin and is derived, Tolkien says, from the same root as the Quenya word áre, which means sunlight.6 According to the Etymologies found in The Lost Road and Other Writings, Quenya words are 'day' and arin 'morning,' as well as Noldorin ar-, are all derived from the root AR-, meaning 'day' (Lost Road 349). The name Arien is not a direct translation of Daisy, however, as the Epilogue might lead us to believe: rather, the Sindarin name is related to daisy's metaphorical meaning. Daisy refers directly to a flower, etymologically to the "day's eye," and, at the level of secondary metaphor, to the sun. Arien refers to a particular character related to the sun in the Silmarillion mythos. It may...

Spatial and temporal variation in volatile composition suggests olfactory division of labor within the trap flowers of Aristolochia gigantea

The olfactory components of floral advertisement can be complex, often showing dynamic patterns of emission and chemical composition that may reflect diverse functions related to pollination. In this study we investigated the spatial and temporal variation of volatile production in the distinctive kettle trap flowers of the Neotropical pipevine Aristolochia gigantea (Aristolochiaceae). These flowers show unusual complexity in scent chemistry and floral morphology in addition to conspicuous changes in scent at distinct stages during floral ontogeny. In this study, volatiles were collected from separate stages in development (bud, female, male, wilted flower), and from different functional units (limb, black ring, yellow disk, utricle, nectary) within each stage. Our results document a strikingly complex and dynamic floral scent composition for A. gigantea. Female stage floral emissions are dominated by sweet lemon-scented citronella-like compounds including (E)- and (Z)-citral, citronellol and citronellal, and at the same time include smaller amounts of pungent, brood-site associated volatiles such as dimethyl disulfide, 2-heptanone, and 3-methyl-1-butanol. Volatile emissions plummet one day later in male stage flowers, except for increased production of monoterpenoids and sesquiterpenoids, including a burst of linalool within the floral chamber. Volatiles emitted from wilted flowers resemble the vegetative background as soon as 48h post anthesis. Multidimensional scaling revealed unexpected differentiation of volatile emissions across spatial units of the complex flower (e.g. within vs. outside of the trap), as well as at different stages of sexual expression as flowers matured. These results suggest that protogynous kettle trap flowers or inflorescences utilize a chemical division of labor, in concert with visual and tactile cues, to choreograph pollinator behavior such that female and male floral functions are optimized.

Innate preference and learning of colour in the male cotton bollworm moth, Helicoverpa armigera.

We investigated colour discrimination and learning in adult males of the nocturnal cotton bollworm moth, Helicoverpa armigera, under a dim light condition. The naive moths preferred blue and discriminated the innately preferred blue from several shades of grey, indicating that the moths have colour vision. After being trained for 2 days to take nectar at a yellow disc, an innately non-preferred colour, moths learned to select yellow over blue. The choice distribution between yellow and blue changed significantly from that of naive moths. However, the dual-choice distribution of the trained moths was not significantly biased to yellow: the preference for blue is robust. We also tried to train moths to grey, which was not successful. The limited ability to learn colours suggests that H armigera may not strongly rely on colours when searching for flowers in the field, although they have the basic property of colour vision.

Alightment of Spotted Wing Drosophila (Diptera: Drosophilidae) on Odorless Disks Varying in Color.

Methods for trapping spotted wing drosophila, Drosophila suzukii (Matsmura) (Diptera: Drosophilidae), have not yet been optimized for detecting this devastating pest of soft-skinned fruits. Here, we report outcomes of choice and no-choice laboratory bioassays quantifying the rates of spotted wing drosophila alightment on 5-cm-diameter sticky disks of various colors, but no fruit odors. Red, purple, and black disks captured the most spotted wing drosophila when presented against a white background. Male and female spotted wing drosophila responded identically in these tests. Significantly more D. suzukii were captured on the red and yellow disks than those presenting the corresponding grayscale for that color, proving that D. suzukii perceives colors and not just the level of target brightness. Fluorescent red is the best candidate for trap color, while clear and white are the least desirable. However, when the background was switched to black, all nonfluorescent colors were equally acceptable to spotted wing drosophila, suggesting that background must be specified when reporting spotted wing drosophila color preference. Additional spotted wing drosophila research is justified on the effects of target color against natural backgrounds.

First Report of Target Leaf Spot Caused by Corynespora cassiicola on Cowpea in China.

Cowpea (Vigna unguiculata L.) is an important economic vegetable and is widely planted in China. During a survey of diseases in May 2009, a new leaf disease incited by the fungus Corynespora cassiicola was observed on cowpea growing in greenhouses in Shouguang city, Shandong Province, China. Circular lesions of different sizes were present on approximately 40% of the plants. Lesions were round with grayish brown centers surrounded by brownish concentric rings and ranged from 1 to 13 mm in diameter. Leaves with many lesions resulted in chlorosis, wilt, and defoliation. Yellow disk was observed on lesion edges of partly infected leaves. Abundant conidia and conidiophores appeared on the abaxial surface of leaves. To identify the causal pathogen, pieces of tissue from the leading border of lesions were sterilized in 75% ethanol for 1 min, rinsed in sterile water, transferred to potato dextrose agar (PDA), and then incubated at 28°C in an incubator. Colonies grew to 60 mm and were gray in color after 7 days. Conidiophores were straight and unbranched, pale or dark brown, and 63 to 211 × 4 to 8 μm. Conidia were born singly or in chains, obclavate or cylindrical, brown or olivaceous, 33 to 97 × 5 to 11 μm. Based on the above characteristics, the fungus was similar to C. cassiicola (Berk. & M.A. Curtis.) C.T. Wei (2). The internal transcribed spacer (ITS) region of rDNA was amplified using primers ITS1 and ITS2 and deposited in GenBank (Accession No. KC894915). A BLAST search in GenBank indicated precise match for a sequence of C. cassiicola from cowpea in American Samoa (1). To satisfy Koch's postulates, 20 one-month-old seedlings of cowpea were sprayed with a spore suspension (1 × 105 spores/ml) of one isolate of C. cassiicola until runoff. Another 20 seedlings, sprayed with sterile water, served as non-inoculated controls. Plants were placed in a humidity chamber at 28°C for 12 h and then transferred to a growth chamber at 28°C. Symptoms similar to those described above appeared after 7 days on inoculated plants; however, no symptoms were observed on non-inoculated controls. C. cassiicola was re-isolated from inoculated plants. The pathogen can cause diseases on a number of plants and lead to losses. In China, this pathogen has previously been recorded on about 20 genera of plants. It also included V. sinensis (3), a close plant with V. unguiculata. However, to our knowledge, this is the first report of target leaf spot caused by C. cassiicola on cowpea (V. unguiculata) in China. Control measures may be needed to manage the disease.

Blue moons and Martian sunsets

The familiar yellow or orange disks of the moon and sun, especially when they are low in the sky, and brilliant red sunsets are a result of the selective extinction (scattering plus absorption) of blue light by atmospheric gas molecules and small aerosols, a phenomenon explainable using the Rayleigh scattering approximation. On rare occasions, dust or smoke aerosols can cause the extinction of red light to exceed that for blue, resulting in the disks of the sun and moon to appear as blue. Unlike Earth, the atmosphere of Mars is dominated by micron-size dust aerosols, and the sky during sunset takes on a bluish glow. Here we investigate the role of dust aerosols in the blue Martian sunsets and the occasional blue moons and suns on Earth. We use the Mie theory and the Debye series to calculate the wavelength-dependent optical properties of dust aerosols most commonly found on Mars. Our findings show that while wavelength selective extinction can cause the sun's disk to appear blue, the color of the glow surrounding the sun as observed from Mars is due to the dominance of near-forward scattering of blue light by dust particles and cannot be explained by a simple, Rayleigh-like selective extinction explanation.

15. A twin with a mole! A case report of an extremely rare condition of molar pregnancy with a coexisting fetus progressing to a viable infant

<h3>Introduction</h3> Molar pregnancy with a coexisting twin fetus is an extreme rarity. The incidence of such an occurrence ranges from 1 in 10,000 to 100,000 pregnancies and this may increase with the greater use of assisted reproductive techniques. The management of these pregnancies is difficult due to complications such as fetal death, vaginal bleeding, pre-eclampsia and an increase risk for persistent trophoblastic disease. Delivery of a viable term normal infant from this combination is even rarer. <h3>Case report</h3> We report a case of molar pregnancy in a 36-year-old woman with a coexisting twin fetus which progressed to delivery of a viable healthy infant at term gestation. The submitted specimen was a twin placenta comprising two separate discs joined by a dividing membrane. One of the discs was pale yellow and small. Vesicles were not evident macroscopically. Microscopic examination showed a dichorionic diamniotic twin gestation. The placenta of the viable term gestation showed no significant abnormality while the separate yellow disc showed changes of hydatidiform mole with extensive infarct-like necrosis. <h3>Discussion</h3> Molar pregnancy with a coexisting twin fetus progressing to a healthy infant is an extremely rare entity. The management guidelines for decision making are limited as there are only a few published reports in the literature. We present this case report to highlight the existence of this extremely rare entity. In addition, it demonstrates that, despite the presence of a coexisting molar gestation, the non-molar gestation may progress to delivery of a normal healthy term infant.