2,316 research outputs found

    Scanning electron microscopic studies on tongue of open-nesting honey bees Apis dorsata F. and Apis florea F. (Hymenoptera: Apidae)

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    Taste stimuli play vital role in the life of honey bees. Sensory structures observed on tongue of the honey bees with the help of Scanning electron microscopy (SEM) have become an important tool in analyzing honey bee biodiversity which offers an advanced diagnostic tool to study honey bee biogeography and determine adaptive variations to native flora. Tongue of honey bees present a high geographic variability in regard to the floral resources visited by the bees. The present study has determined to determine differences in the tongue ofopen-nesting bees by scanning electron microscopy of Apis dorsata and Apis florea. The two bees showed distinct morphological variations with respect to the lapping and sucking apparatus. It was observed that the ridges on the proximal region exhibited rough surface on A.dorsata whereas spinous in case of A.florea. Moreover, the arrangement of hair in the middle part of the tongue also differed in the two species. The shape of flabellum differed in the two species reason being the influence of native flora. It was observed that the shape of flabellum was oval in A.dorsata whereas in A.florea it was triangular. These differences indicated for the role of native flora and honey bee biodiversity

    Ultramorphology of antennal sensilla of open-nesting honey bees Apis florea F. and Apis dorsata F. (Hymenoptera: Apidae)

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    Antenna of honey bees is geniculate and has been known to possess a wide variety of sensilla. The sensilla are sensitive to odor, temperature, humidity, air pressure and gustatory stimuli. In the present investigation, ultrastructural study on the antenna of the two open-nesting worker honey bees- Apis florea F. - the dwarf honey bee and A. dorsata F. - the giant honey showed considerable amount of variation in the types and distribution pattern of sensilla in the two species. The antennal form as well as the sensilla arrangement has been suggested to be adapted to the pheromone perception need of regarding a particular species

    Calicovesicostomy for ureteropelvic junction obstruction in a solitary ectopic pelvic kidney

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    A solitary dysmorphic ectopic kidney is an uncommon congenital abnormality. This anomaly may be associated with ureteropelvic junction obstruction causing hydronephrosis and parenchymal thinning. We report such a case with non-dependent posteriorly placed pelvis in a pelvic kidney and its management. The perioperative results were satisfactory. This seems to be the first such case report of a calicovesicostomy used as a salvage procedure for an ectopic solitary kidney

    Squamous Cell Carcinoma in a Heel Ulcer in a Patient With Diabetes

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    A technique for measuring B-H curves of grain-oriented silicon steel along arbitrary directions has been developed. As the control of waveform is not necessary in this technique, it is possible to measure B-H curves up to high flux densities which are required for calculating flux distribution using the finite element method</p

    Multi-Robot-Assisted Human Crowd Evacuation using Navigation Velocity Fields

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    This work studies a robot-assisted crowd evacuation problem where we control a small group of robots to guide a large human crowd to safe locations. The challenge lies in how to model human-robot interactions and design robot controls to indirectly control a human population that significantly outnumbers the robots. To address the challenge, we treat the crowd as a continuum and formulate the evacuation objective as driving the crowd density to target locations. We propose a novel mean-field model which consists of a family of microscopic equations that explicitly model how human motions are locally guided by the robots and an associated macroscopic equation that describes how the crowd density is controlled by the navigation velocity fields generated by all robots. Then, we design density feedback controllers for the robots to dynamically adjust their states such that the generated navigation velocity fields drive the crowd density to a target density. Stability guarantees of the proposed controllers are proven. Agent-based simulations are included to evaluate the proposed evacuation algorithms

    Chilling stress effects on reproductive biology of chickpea

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    Chickpea is sensitive to chilling temperatures (<10°C), especially at its reproductive phase leading to floral abortion. The exact causes of reproductive failures are not fully understood. In the present study, we assessed the cold-induced damage to development and functioning of male and female components by growing an early flowering chickpea genotype ICCV 96029 under warm conditions of the glasshouse (control; average maximum and minimum temperature ≥28/15°C) as well as under cold conditions of the field (average maximum and minimum temperature ≤20/10°C during reproductive phase). Low temperature of the field environment restricted the vegetative growth and delayed all the phenological stages in comparison to control plants. Apart from this, it led to some vegetative aberrations like chlorosis, necrosis of leaf tips and curling of whole leaf. The damage to reproductive stage involved abscission of juvenile buds and flowers and abortion of pods. On the whole, pollen development at young microspore stage appeared to be severely affected in stressed conditions compared to the control conditions. Pollen viability was suppressed during stressed conditions (60%) compared to normal plants (95%). Stigma receptivity, in vivo pollen germination and pollen tube growth were inhibited in the stressed plants. Fluorescent studies showed that the stigma either did not show any pollen load or pollen grains did not germinate on its surface in stressed plants. Even when the pollen grains germinated, the pollen tubes rarely grew beyond the proximal region of the style; mostly the pollen tubes were impaired in their growth and did not reach the ovules leading to failure in fertilization. The egg and secondary nucleus in such ovules ultimately disintegrated without fertilizing and hence no seed formation occurred
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