Black Trays Research Articles

Rasprostranjenost vrste Heptatoma pellucens (Fabricius, 1776) (Diptera: Tabanidae) u Hrvatskoj

The genus Heptatoma contains only one species, Hepatoma pellucens, distributed almost throughout the whole Palaearctic region. Without the author’s and collaborator’s (J. Mikuska) previous and current research, this species had been recorded in six localities in Croatia. The author’s previous unpublished data recorded the species in localities of Donja Bistra, Popovac, Šenkovec, Vinica and Duzluk. The findings of this species in the localities of Branjina, Karanac, Kotlina, on Bansko Hill in the Croatian part of Baranja during this year represent new locality records alongside unpublished ones. The total number of recorded localities where Heptatoma pellucens appears in Croatia has increased to 40. From all collected specimens from previous and current research (242), 29.34% (71) of specimens of this species in Croatia were collected during 2022. In the sample collected in 2022, 97.18% of specimens were collected by liquid oil trap (shiny black trays filled with transparent vegetable oil). The sex ratio of the collected specimens in 2022 showed there were 1.7 times more males than females, unlike in previous research where only one male specimen was recorded.

Comparative Effect of Varieties and Types of Containers on Seed Germination and Seedling Growth of Geranium (Palergonium graveolens)

Geranium (Pelargonium graveolens L’Hér.) is an important commercial horticultural plant extensively used in outdoor landscaping. Seed emergence has always remained a problem in geranium due to its hard seed nature. Hence its germination and other emergence-related attributes need to be adequately tested. The purpose of this study was to evaluate the germination and seedling growth of geraniums under different types of containers. In this regard, the seeds of two varieties of geranium viz. Large FID mixed and Star mixed were planted in different types of containers. The containers included black trays plastic pots, plastic bags, and nonwoven fabric bags. The seed emergence and other germination related parameters were significantly affected by the different types of containers. However, varieties exhibited similar responses for most germination and growth characteristics. Data were collected for seed germination, mean germination time, germination index and seedling vigor index. The type of containers showed a significant impact on seedling growth and development. The taller plants with more leaves and maximum biomass production were recorded from seeds sown in nonwoven fabric type bags. The results pertaining to varieties demonstrated that Star mixed showed better emergence and vigorous seedlings in comparison with large FID mixed. The taller seedlings with maximum leaves and shoot biomass were also recorded from Star mixed grown in nonwoven fabric type bags. Based on the results, it is concluded that germanium may be raised in nonwoven fabric bags for better seed emergence and seedling growth and development.

Early-stage dark treatment promotes hypocotyl elongation associated with varying effects on yield and quality in sunflower and arugula microgreens

Microgreens growing under electric (artificial) lighting in controlled environments often have short hypocotyls, which can be difficult for machine harvest. To investigate whether early-stage dark treatment can promote hypocotyl elongation without compromising microgreen yield and quality, two different seed-size species, sunflower (Helianthus annuus ‘Black oil’) and arugula (Eruca sativa ‘Rocket’), were tested. Seeds of sunflower and arugula were sown in pots, and the pots were placed inside support trays. During the first 5 days after seeding, half of the pots per species within each tray were covered with an upside-down black tray as dark treatment, and another half were kept under light. The light treatment was provided by continuous (24-h) lighting with a combination of red (85%) and blue (15%) light-emitting diodes at a photosynthetic photo flux density of around 100 μmol·m−2·s−1. After 5 days of dark treatment, the black covers were removed and the plants were grown under the above lighting treatment till harvesting. The microgreens were harvested at 7 d and 12 d after seeding for sunflower and arugula, respectively. Early-stage dark treatment promoted hypocotyl elongation by 26% and 28% for sunflower and arugula, respectively. Microgreen yield was increased by 13% for sunflower and reduced by 24% for arugula under dark treatment. Dark treatment increased cotyledon succulence by 14% for sunflower, but reduced cotyledon size by about 25% for arugula despite increases in red color and succulence of arugula hypocotyls. For both species, cotyledon color and soluble solids content were not affected by dark treatment.

How can Asphalt Roads Extend the Range of In Situ Polarized Light Pollution? A Complex Ecological Trap of Ephemera danica and a Possible Remedy

When an artificial surface (e.g. an asphalt road) reflects strongly and horizontally polarized light as water bodies do in the nature, polarotactic aquatic insects, like the creek-dwelling Ephemera danica mayflies easily become deceived. After swarming above the creek surface, E. danica females begin their upstream compensatory flight and can be deflected at bridges with an asphalt road and continue their flight above the road surface. Thus, the water-mimicking optical signal of the road may deceive water-seeking polarotactic mayflies and lead them to distant, polarized-light-polluting surfaces, which elicit anomalous oviposition. On an asphalt road crossing a creek, we deployed polarizing insect traps at different distances from the bridge. The traps captured E. danica mayflies and their catch numbers indicated that these mayflies originated from the direction of the bridge, proving that they followed the track of the road. Our results suggest that distant polarized-light-polluting objects along an asphalt road can trap mayflies emerging from a creek crossing the road. The combination of an asphalt road and a man-made in situ (local) polarizing surface forms a complex ecological trap, being capable of luring aquatic insects from greater distances. To eliminate the oviposition of dangered polarotactic aquatic insects emerging from a creek onto the asphalt road crossing the creek, we suggest to deploy strongly and horizontally polarizing water-filled black trays along the edge of the road during the swarming period. Thus, the eggs of the deceived insects can be moved back to the creek in order to assist the conservation of the offspring-generation.

Murmuration

Murmuration T.M. Williams (bio) She left a little at a time. The way the starlings do, lifting from a line off into nowhere, one by one until they're gone completely. First was the index finger on her right hand. She was numb from sugar, so she didn't notice when it started to cook. That smell that mixed with the mustard greens told her. Like hog meat. And later the scent [End Page 9] of gangrene, warm black rot, til the doctor took it down to the bottom knuckle. "Maybe they can get you a fake one to put on it, Avalyn," her sister Connie had said, staring at the fat round piece. It was smooth and alert, like it might push through and grow itself again. "Wonder what they'd latch it on with?" Her children banned her from cooking after that, said they didn't want her anywhere near a stove. Cooking was all she had. She told them that. She cried. And she argued with them and cussed them too, but the three banded together and were firm. It was sandwiches or whatever Bev, her oldest and her only girl, fed her from then on. Barbeque chips in a big plastic bowl. Ham and cheese on Bunny bread on a paper plate. A Hungry Man in its heat-warped black tray with mashed potatoes still cold in the middle. Sometimes some kind of candy Mamaw wanted but wasn't supposed to have that would push her reading over three hundred and get her all worked up thinking about blindness and needles in her unfeeling feet. Whatever it was would be set on top of her oxygen machine. It was the one her father had breathed on, lungs like two rotten apples from all the coal dust he ate. When I came home in the summers I would visit her. We sat in the sun, her chimes going in the wind, our bodies held up by blue and pink fold-out chairs faded by light and rub. We looked out on the things that weren't there. The tree her husband had planted back when he was somebody she could love, cut down after it splintered in a storm. And the swimming pool that her son—my dad—had taken down after it sat empty two summers. Our chairs were on the lip of the deck, the wood reaching out in curved remembering. It was an easy way of being, an open-eyed meditation in the warmth near the edge with her there. "You glad to be back home?" she said, and I said, "Yeah." "You gonna make a doctor? Or you ain't decided yet?" [End Page 10] "No way. I'd work in the mines before I'd be a doctor or a lawyer," I said and smiled. It was a birthright to brave the bowels of the mountains, and I knew I could do it even if I never did. "Your daddy might could get you on." She winked and turned her pink tumbler to her lips. There were stories of women in the mines. The one I knew was of a woman who worked over at Rockhouse, the only female on the day shift. She took up with the bolt-machine man, who happened to be married to my cousin at the time. The men made crass jokes about the miner woman's calloused hands and the coal dust that caulked the lines in her skin. Walking up the back road with her little collie dog on a string was Jan, who lived five houses down. She stopped and put her hand on the top of the chain fence. "Hidee, Ava! How you a-doin, honey?" Jan was almost sickly thin and tanning-bed brown. Mamaw waved with her right hand, but just as quick as she had raised it she pulled it back down to her lap. Seventy-five years with that finger, two months without. I forget. She told me this later that evening when we were grabbing a hold of the sticks of orange dreamsicles. I watched her talk to Jan. Ms. Avalyn. You could tell she had been...

A horizontally polarizing liquid trap enhances the tabanid-capturing efficiency of the classic canopy trap

Host-seeking female tabanid flies, that need mammalian blood for the development of their eggs, can be captured by the classic canopy trap with an elevated shiny black sphere as a luring visual target. The design of more efficient tabanid traps is important for stock-breeders to control tabanids, since these blood-sucking insects can cause severe problems for livestock, especially for horse- and cattle-keepers: reduced meat/milk production in cattle farms, horses cannot be ridden, decreased quality of hides due to biting scars. We show here that male and female tabanids can be caught by a novel, weather-proof liquid-filled black tray laid on the ground, because the strongly and horizontally polarized light reflected from the black liquid surface attracts water-seeking polarotactic tabanids. We performed field experiments to reveal the ideal elevation of the liquid trap and to compare the tabanid-capturing efficiency of three different traps: (1) the classic canopy trap, (2) the new polarization liquid trap, and (3) the combination of the two traps. In field tests, we showed that the combined trap captures 2.4-8.2 times more tabanids than the canopy trap alone. The reason for the larger efficiency of the combined trap is that it captures simultaneously the host-seeking female and the water-seeking male and female tabanids. We suggest supplementing the traditional canopy trap with the new liquid trap in order to enhance the tabanid-capturing efficiency.

Effect of Color and Mesh Size on Growth Performance and Net Fouling of Suspended Hatchery Trays for Crassostrea belcheri (Sowerby 1871) Oysters

The effects of mesh size and color on growth performance and net fouling of suspended plastic mesh trays during nursery culture of spat and juvenile hatchery-reared tropical oysters, Crassostrea belcheri (Sowerby 1871), was studied for 60 days. Mesh diameter significantly affected the absolute growth rate in shell width, the specific growth rate, and the final survival of smallspat (p<0.05). Mesh diameter and color had non-significant effects (p>0.05) on the growth performance of large spat. There were no significant interactive effects between mesh size and color on growth performance of small or large spats. Mesh size and color significantly affected (p<0.05) the net fouling rate: the rate was high on small mesh (0.35 cm) and low on large mesh (0.72 cm) for small spat, high on black trays and low on green trays for large spat. There were no significant interactive effects of mesh size and color (p>0.05) on the fouling rate for either small or large spats.

Cost effectiveness analysis of the application of concrete

Abstract The waterproof quality of concrete structures prevents the penetration of water into the structure as the outflow of water through concrete dam. Water penetration can lead to the limitation or abolishment of the function of structures. Waterproof structures can be made in different construction methods, e.g. as a Black Tray, Brown Tray or White Tray. Each of these variants has its advantages and disadvantages, but the White Tray is preferred in this paper. In this construction method adequate measures are taken in order to prevent the formation of water‐bearing cracks.

COST EFFECTIVENESS ANALYSIS OF THE APPLICATION OF CONCRETE

The waterproof quality of concrete structures prevents the penetration of water into the structure as the outflow of water through concrete dam. Water penetration can lead to the limitation or abolishment of the function of structures. Waterproof structures can be made in different construction methods, e.g. as a Black Tray, Brown Tray or White Tray. Each of these variants has its advantages and disadvantages, but the White Tray is preferred in this paper. In this construction method adequate measures are taken in order to prevent the formation of water‐bearing cracks.

TRAY COLOR INFLUENCES GROWTH AND QUALITY OF LETTUCE AND TOMATO TRANSPLANTS.

Two cultivars of tomato (Lycopersicon esculentum) and leaf lettuce (Lactuca sativa) were evaluated using two plug trays, polyethylene and polystyrene in two colors, black and white. Cells were 2 cm square inverted pyramid and 5 cm deep. Temperatures 0.3 cm below the surface of the media in the black trays average 2 to 4°C warmer than in the white trays. Night temperatures were not influenced by tray color. There was no apparent interaction between color and tray composition. Tomato plants grown in black trays had longer, smaller diameter stems than those in the white trays. Total leaf area, plant fresh and dry weights, however, were not affected by tray color. Leaf lettuce grown in black trays had greater total leaf area than those in white trays. Leaf numbers were not affected by tray color. Plants of tomato and lettuce grown in white trays were shorter, stockier, and easier to handle during transplanting than those produced in black trays. Both cultivars of tomato and lettuce responded similarly to tray color and composition.

Conceptual conditional discrimination inSaimiri sciureus

The present work introduced a task which superimposed a tray brightness, stimulus-response contingency on previously acquired, highly successful, one-trial oddity performance. Continuing with new one-trial oddity problems, the new contingency was that responses to the odd objects were rewarded on a white tray and responses to the nonodd objects were rewarded on the black tray. Since there is no opportunity to learn specific stimuli or stimulus patterns, successful performance may be interpreted as having a conceptual basis. All monkeys achieved criterion (90% based on 18/20) and statistically significant performances (p<.001). Discussion considered the appropriate nomenclature to describe a conceptual conditional discrimination task and the necessary evidence to justify a conceptual interpretation of conditional discrimination behavior.

A Photo-Electric Wool Staplemeter

THE possibility of constructing a photo-electric apparatus capable of measuring the variations in fibre-length and diameter, and hence of 'tippiness' and 'break' in wool staples, has been exercising the mind of one of us (H. G.) for some time past, but only after reading a recent paper by Lord1 were steps taken towards its realization. An experimental model, constructed by the other (R. E. B.), was ready in December 1947. In this model, the wool staple, after it has been prepared as described below, is laid lengthwise under a sheet of glass on an optically black tray (Fig. 1). The tray is capable of moving between two guides along the floor of a light-tight compartment of the apparatus. A 100-watt pearl lamp illuminates a narrow rectangular slit which is focused by means of a cylindrical lens to produce, on the tray top and at right-angles to its motion, a narrow rectangular light image approximately in. wide and 3 in. long. The scattered light from the wool is measured by means of a photo-cell which is located directly above the light image. This cell is connected to a direct-current amplifier2 the output of which is noted on a 0–50 micro-ammeter.