Feeding Mechanism Research Articles

Internal Water Flows and Particles Abstraction in <i>Daphnia</i>

The operational function of the trunk limbs (thoracic appendages), of Daphnia, P3 and P4, is a long-term disputed definition between “solid walls”, sieving filters. Sieving is unlikely process for routine particle collection, particle capture is not a simple mechanical process and not by sieving alone. Analysis promotion supported by direct observational examination of the in-vivo cinematographic slow-motion film and magnified solid photos of tethered Daphnia by high-speed camera (250 frames per second) resulted in a definite interpretation presented in this paper. The Daphnia’s feeding mechanism achieves particles abstraction not by sieving. The existence of two internal alternate water flow routs was indicated: Lateral and Median. These micro flow structures are suggested as vulnerability reduction.

Effects of the Aluminum Alloy with Intermetallic a Phase on the Microstructural and Corrosion Resistance

Aluminum alloy are getting increased attention mainly because of their application in the automotive and aerospace industries and there is a significant scientific and industrial interest in use of Al-Mg-Si-Mn-Fe alloys in automotive applications to reduce the weight and production cost of vehicles, besides, only in the last five decades have attempts been made to study the feeding mechanisms of aluminum-silicon alloys, according to statement of Dash and Makhlouf

Seismic Tomography of Kamchatkan Volcanoes

Abstract—The Kamchatka Peninsula is one of the most tectonically active regions in the world, where intensive and diverse modern volcanic activity takes place. In the recent decade, substantial progress in the investigation of deep structures beneath Kamchatka has been achieved owing to numerous tomography studies based on seismological data provided by permanent stations and temporary networks deployed in some key areas. The goal of this review is summarizing and systematizing dozens of separate multiscale geophysical studies in Kamchatka and constructing an integral model of volcano-feeding systems. An important part of this review contains the description of results of various seismic studies related to the Klyuchevskoy group volcanoes, which can now be considered one of the best studied volcanic areas in the world. The results of the regional-scale seismic tomography reveal the existence of the Pacific slab window, which determines the particular activity of the Klyuchevskoy group volcanoes. Middle-scale tomography studies have found traces of an ascending hot mantle flow that passes through the slab window, reaches the bottom of the crust below Shiveluch Volcano, and then propagates laterally toward the Klyuchevskoy group. Seismic models of the entire crust in the area of the Klyuchevskoy group were used to identify different mechanisms of magmatic feeding of three most active volcanoes: Klyuchevskoy, Bezymianny, and Tolbachik. The data of local networks deployed on several volcanoes of Kamchatka were used to image the magma sources in the upper crust, which are directly responsible for the current eruption activity. The comparison of the results for the Kamchatka volcanoes with tomography models of several other volcanoes of the world allowed determining some common features and differences in feeding active magmatic systems.

Editorial 2022

Editorial 2022

Experimental analysis of the influence of discharge gap on EDM performance

In order to reduce the machining time and improve the surface quality of holes, a high speed self adjusting electrical discharge machining (EDM) approach is needed with independent flushing system that were able to remove the debris in the machining process. With the change in the gap distance and depth of the hole drilled, the electrode automatically adjusts the gap with the help of a linear actuator. For that, the optimum gap distance for getting maximum result is crucial. Taguchi L27 orthogonal array technique is used for the preliminary experimental analysis. The study revealed that discharge gap which is proportional to the gap voltage is the most influential parameter that affects the surface finish and material removal rate. The formation mechanism of the hole in the copper plate had found out, in order to get the optimum gap distance for the maximum MRR, TWR, and ROC. The results from the comparison experiment shows that the best result will be get at 0.5 mm gap distance and this can be taken as the optimum gap distance for the automatic feeding mechanism. In addition, low voltage and current would benefit for the EDM process working in micro level and for the removal of the recast layer.

IoT System on Dynamic Fish Feeder Based on Fish Existence for Agriculture Aquaponic Breeders

Maintaining and breeding fish in a pond are a crucial task for a large fish breeder. The main issues for fish breeders are pond management such as the production of food for fishes and to maintain the pond water quality. The dynamic or technological system for breeders has been invented and becomes important to get maximum profit return for aquaponic breeders in maintaining fishes. This research presents a developed prototype of a dynamic fish feeder based on fish existence. The dynamic fish feeder is programmed to feed where sensors detected the fish's existence. A microcontroller board NodeMCU ESP8266 is programmed for the developed hardware. The controller controls the feeding and feedback mechanism based on attached sensors. An ultrasonic sensor is programmed with the controller to detect the level of food and waterproof ultrasonic to detect existing fish. The humidity sensor was used to measure the humidity in the food container to control the food freshness. Two servo motors were used to move the waterproof sensor to attract the fish and to dispense the food to the fish when existed. The result presents four measured levels that are the temperature of the food container, the quality of food based on humidity measured, fish detection counter and level of fish food in the container. Data analytics on all the measured levels was presented on the ThingSpeak platform by using Blynk to get data collections from all sensors. This research is significant for fish breeders that support IR4.0 system connected online and mobile apps which also contribute to today’s agriculture.

Macroevolutionary trends in theropod dinosaur feeding mechanics

Theropod dinosaurs underwent some of the most remarkable dietary changes in vertebrate evolutionary history, shifting from ancestral carnivory1-3 to hypercarnivory4,5 and omnivory/herbivory,6-9 with some taxa eventually reverting to carnivory.10-12 The mandible is an important tool for food acquisition in vertebrates and reflects adaptations to feeding modes and diets.13,14 The morphofunctional modifications accompanying the dietary changes in theropod dinosaurs are not well understood because most of the previous studies focused solely on the cranium and/or were phylogenetically limited in scope,12,15-21 while studies that include multiple clades are usually based on linear measurements and/or discrete osteological characters.8,22 Given the potential relationship between macroevolutionary change and ontogenetic pattern,23 we explore whether functional morphological patterns observed in theropod mandibular evolution show similarities to the ontogenetic trajectory. Here, we use finite element analysis to study the mandibles of non-avialan coelurosaurian theropods and demonstrate how feeding mechanics vary between dietary groups and major clades. We reveal an overall reduction in feeding-induced stresses along all theropod lineages through time. This is facilitated by a post-dentary expansion and the development of a downturned dentary in herbivores and an upturned dentary in carnivores likely via the "curved bone effect." We also observed the same reduction in feeding-induced stress in an ontogenetic series of jaws of the tyrannosaurids Tarbosaurus and Tyrannosaurus, which is best attributed to bone functional adaptation. This suggests that this common tendency for structural strengthening of the theropod mandible through time, irrespective of diet, is linked to "functional peramorphosis" of bone functional adaptations acquired during ontogeny.

ROLE OF PLANT SECONDARY METABOLITES IN COMBATING PEST INDUCED STRESS IN BRINJAL (SOLANUM MELONGENA L.)

Brinjal or eggplant (Solanum melongena L.) is known as a vegetable of diet because it contains high moisture and low calorific value. It is also a good source of antioxidants and phytonutrients. Brinjal is widely grown in the South and South-East Asian countries and is the second most important vegetable in India. It belongs to the Solanaceae family. Shoot and fruit borer (Leucinodes orbonalis) pest of brinjal is the most widespread one and it has the ability to affect any of the developmental stages of brinjal. Plants and their insect herbivores have had a long and intimate evolutionary association that has resulted in many complex interactions mediated by specialized plant metabolites like phenolics, alkaloids, terpenoids, cyanogenic glycosides etc. Frequent and excessive use of insecticides has become a common practice now which only increases the probability of resistance development and resurgence of pest. Hence to develop an effective approach to combat this pest understanding of its feeding mechanism and chemistry of its interaction with the fruit is necessary. The importance of the secondary metabolites in the field of chemical biology and in pest management is discussed in this study.

The molecular mechanisms and factors affecting the feeding habits of silkworm (Lepidoptera: Bombyxidae)

• The feeding factors of silkworm mainly depend on the gustatory system and the olfactory system. • There is a regular pattern of changes from eating mode to static mode in silkworms. • There are endogenous regulation mechanisms in both the up-regulation and down-regulation of eating motivation. Food is critical to the survival and development of insects. Bombyx mori (Lepidoptera: Bombycidae), a Lepidoptera model insect with economic significance, is a well-known oligophagous insect that mainly feeds on mulberry leaves. The feeding characteristics of this particular species provide an excellent model for studying the food selection of insect host plants. In recent years, there has been an increasing number of studies on the factors affecting the feeding of silkworms, especially with the development of molecular technology. Many mysteries have been gradually solved. This paper summarizes and discusses the factors that affect the feeding of silkworms, with a focus on the molecular mechanisms of silkworm feeding. It is hoped that this work will be helpful for further research on artificial diets for silkworms and disease control in lepidopteran insects.

In Vitro Flow Visualization in a Lactating Human Breast Model.

Human milk extraction from the breast is affected by the infant's oral activities. Natural suckling by the infant includes both intraoral vacuum and peripheral oral compression during breastfeeding. However, the contribution of each of these motions to milk extraction at the outlet and at the duct bifurcations is unclear. In this work, we investigated the flow field in a lactating breast model considering bifurcated milk ducts and multiphase breast-infant interactions. A bio-inspired breastfeeding simulator device was utilized to mimic an infant's oral feeding mechanism during breastfeeding and extract the human milk-mimicking Fluid from the transparent and elastic lactating breast phantom during experiments. Using a particle image velocimetry system, we found that the oscillatory flow under vacuum pressure provides a higher velocity field at the outlet compared to that when an infant applies both vacuum and oral compression pressures. Additionally, the intraoral vacuum coordinated with the oral peripheral compression causes stronger vorticities and secondary flows at the adjunction of the bifurcated ducts than the vacuum-only case. Vacuum-only extraction yields an increase in flow velocity at the outlet and could be one of the reasons for nipple pain, whereas infant's oral activities on the breast generated more vortices in the milk duct adjunctions and might cause milk duct clogs. This phenomenon is rationalized based on the validation of a previous in vivo clinical study of milk production compared between commercial pumps and infant suckling. The fact that milk consumption of vacuum-only extraction is less than that of vacuum plus oral compression further explains the effectiveness of applying a natural suckling pattern in human lactation.

Ultrasound-activated ciliary bands for microrobotic systems inspired by starfish

Cilia are short, hair-like appendages ubiquitous in various biological systems, which have evolved to manipulate and gather food in liquids at regimes where viscosity dominates inertia. Inspired by these natural systems, synthetic cilia have been developed and utilized in microfluidics and microrobotics to achieve functionalities such as propulsion, liquid pumping and mixing, and particle manipulation. Here, we demonstrate ultrasound-activated synthetic ciliary bands that mimic the natural arrangements of ciliary bands on the surface of starfish larva. Our system leverages nonlinear acoustics at microscales to drive bulk fluid motion via acoustically actuated small-amplitude oscillations of synthetic cilia. By arranging the planar ciliary bands angled towards (+) or away (−) from each other, we achieve bulk fluid motion akin to a flow source or sink. We further combine these flow characteristics with a physical principle to circumvent the scallop theorem and realize acoustic-based propulsion at microscales. Finally, inspired by the feeding mechanism of a starfish larva, we demonstrate an analogous microparticle trap by arranging + and − ciliary bands adjacent to each other.

Ultramorphological Comparison of Proboscis and Associated Sensilla of Scotogramma trifolii and Protoschinia scutosa (Lepidoptera: Noctuidae)

Simple SummaryThe clover cutworm, Scotogramma trifolii Rottemberg, and the spotted clover moth, Protoschinia scutosa (Denis & Schiffermuller), are worldwide polyphagous pests, and the larvae feed mainly on the leaf backs of many agricultural crops. However, the food sources and feeding habits of the adults are still poorly known. We investigated the ultramorphology of the proboscis and associated sensilla of S. trifolii and P. scutosa using scanning electron microscopy. The results show that the proboscises of S. trifolii and P. scutosa are structurally similar, both including three sensillum types and three zones (Zone 1–3). The sensillum chaeticum is non-porous hair-like, the sensillum basiconicum is a short smooth cone with a sensory pore on the blunt tip, and each sensillum styloconicum is composed of a uniporous sensory cone inserted into a ribbed stylus. In addition, the movement and fluid uptake mechanisms of the proboscis and the possible function of sensilla are briefly discussed.The proboscis is an important feeding organ for the glossatan moths, mainly adapted to the flower and non-flower visiting habits. The clover cutworm, Scotogramma trifolii Rottemberg, and the spotted clover moth, Protoschinia scutosa (Denis & Schiffermuller), are serious polyphagous pests, attacking numerous vegetables and crops, resulting in huge economic losses. However, the feeding behavior and mechanisms of the adult stage remain unsatisfactorily explored. In this study, the proboscis morphology of S. trifolii and P. scutosa are described in detail using scanning electron microscopy, with the aim of investigating the morphological differences and feeding behavior of these two species. The proboscises of S. trifolii and P. scutosa are similar in morphology and structure and are divided into three zones (Zone 1–3) based on the morphological changes of the dorsal legulae. Three sensillum types are located on the proboscises of both species, sensilla chaetica, sensilla basiconica, and sensilla styloconica. Significant differences were observed in the length of the proboscis and each zone between these two species, as well as in sensilla size and number. Based on the morphology of the proboscis and associated sensilla, S. trifolii and P. scutosa are potential flower visitors, which was also reinforced by the pollen observed at the proboscis tip. These results will strengthen our understanding of the structure of the proboscis related to the feeding behavior of Noctuidae.

Observations on feeding behaviour of fresh water prawn Macrobrachium lamarrei (Crustacea: Decapoda)

Freshwater prawn are promising candidates for aquaculture and knowledge of food and feeding habit is must for successful culture. Present study investigates the feeding mechanism and role of appendages in feeding behaviour of freshwater prawn, Macrobrachium lamarrei. Mostly preferred food was dried prawn powder and least preferred was groundnut cake. Prawns showed cannibalistic behaviour frequently in lab. Antenna and antennules were the main sensory appendages which help in locating and orientation while I & II chelate legs were used for detection, catching and transferring of food up to the mouth. Maxillipedes, maxilla and maxillula played the supportive role. Mechanism of feeding and functional role of different appendages in feeding behaviour have been discussed.

Design and Development of Dipole Array Antenna for Wi-Fi Applications

This paper illustrates the design and development of the series-fed two-dipole-array antenna (STDA) for Wi-Fi applications. The proposed antenna consists of two dipole elements of different lengths, which are serially joined by the coplanar strip line. The design incorporates a coaxial/probe feeding technique with balun as an alternative feeding mechanism. The main goal of this paper was to create a high-gain antenna with an array configuration for Wi-Fi applications. For STDA array configurations, antenna performance parameters such as return loss, radiation pattern, gain, and directivity are investigated. It operates at 2.4 GHz and has a high gain of 21.6 dBi when used with a reflector. In order to improve overall gain, the STDA was analyzed for different array configurations in the formation of 1 × 4, 1 × 8, and 2 × 8 STDA arrays. The proposed antenna is made of a FR-4 substrate with a dielectric constant of 4.4 and a loss tangent (tan) of 0.007 and a thickness of 1.6 mm. An antenna measures approximately 105 mm × 80 mm in size. The proposed antenna meets the requirements for a 2.4-GHz antenna with a bandwidth of 200 MHz, and thus, it is found to be suitable for Wi-Fi applications.

Solving the problems of underwater mecha-nized and automatic arc welding of various metal structures with a wet method

A complex of problems related to semi-automatic and automatic underwater wet welding, concerning both equipment and ways of implementation of arc process, has been considered. An analysis of existing developments in the considered field of welding has been carried out, and the most rational designs of semi-automatic machines for welding with flux-cored electrode wire have been revealed. It is shown that the semiautomatic device with a submerged block is the most rational design; the feeding mechanism, placed in the block, has its own additional body, filled with insulating-lubricating liquid, in which the drive motor is submerged. It is noted that a peculiarity of welding-in-fusion in aqueous medium is unpleasant formation of joints on the vertical plane. The most effective ways of improving semi-automatic and automatic machines related to modulated processes and processes with controlled pulse feeding of electrode wire are presented. It is shown that lately the most effective choice of electric motor is its valve design. At the same time, the feeding mechanism in the gearless version is possible. Specially designed computerized control and regulation system is used for realization of semiautomatic machine's work cycle and the chosen algorithm of electrode wire feeding. The results of electrode wire pulse feeding application on properties of welded joints are given. It is determined that characteristics of pulse feeding (frequency, duty cycle) influence geometric characteristics of the weld, as well as strength properties, in particular yield and time resistance limits, which, among other things, is caused by reduction of nonmetallic inclusions in the weld metal and the weld zone. External types of beads welded in aqueous medium on the vertical plane are given, it is obvious that formation when using pulse and modulated modes is significantly better than when conducting electric arc process with conventional feeding of the electrode wire. The ways of further improvement of the equipment for welding in aqueous medium by a wet method are shown. One of the most promising ways to improve technical and technological capabilities of mechanized equipment for welding in aqueous medium is the creation and application of systems with combined influence on the process.

Esophagus-Inspired Actuator for Solid Transportation via the Synergy of Lubrication and Contractile Deformation.

Directional transportation of objects has important applications from energy transfer and intelligent robots to biomedical devices. Although breakthroughs in liquid migration on 2D surfaces or 3D tubular devices have been achieved, realizing smooth/on‐demand transportation of constrained solids within a 3D cavity environment under harsh pressurized environment still remains a daunting challenge, where strong interface friction force becomes the main obstacle restricting the movement of solids. Inspired by typical feeding mechanism in natural esophagus system which synergistically couples a lubricating mucosa surface with the peristaltic contraction deformation of the cavity, herein, this challenge is addressed by constructing an esophagus‐inspired layered tubular actuator with a slippery inner surface and responsive hydrogel matrix to realize spherical solid propulsion by photo(thermo)‐induced cavity deformation. The as‐constructed tubular actuator containing Fe3O4 nanoparticles exhibits local volumetric shrinkage upon NIR‐irradiation, which can generate large hydrodynamic pressure and considerable mechanical extrusion force (F driving force ≈ 0.18 N) to overcome low interface friction force (f friction force ≈ 0.03 N), enabling on‐demand transportation of constrained (pressure: 0.103 MPa) spherical solids over a long distance in an arbitrary direction. This actuator is anticipated to be used as bionic medicine transportation devices or artificial in vitro esophagus simulation systems, for example, to help formula eating‐related physiotherapy plans for patients and astronauts.

Tongue Morphology in Horned Lizards (Phrynosomatidae: <i>Phrynosoma</i>) and its Relationship to Specialized Feeding and Diet

In lizards, the tongue is joined to the mandible by the median genioglossus medialis muscle and the larger, paired genioglossus lateralis muscles. These muscles run through a frenulum and along the sides of the tongue, forming its walls. In horned lizards, however, the genioglossus lateralis muscles fail to join the tongue for most of its length, forming separate ridges evident in the floor of the mouth lateral to the body of the tongue. This unique tongue morphology co-occurs with horned lizards’ ability to consume large numbers of potentially lethal harvester ants, a diet enabled by a feeding mechanism in which ants are rapidly immobilized with strings of mucus before immediate swallowing. Circumstantial evidence implicates the unusual morphology of the genioglossus lateralis muscles in the mucus-binding system.

Relatively low tooth replacement rate in a sauropod dinosaur from the Early Cretaceous Ruyang Basin of central China.

Tooth replacement rate is an important feature related to feeding mechanics and food choices for dinosaurs. However, only a few data points are available for sauropod dinosaurs, partially due to rarity of relevant fossil material. Four somphospondylan sauropod species have been recovered from the Lower Cretaceous Aptian–Albian Haoling Formation in the Ruyang Basin, Henan Province of central China, but no cranial material has been reported except for a single crown. Here we report the discovery of the rostral portion of a left dentary with replacement teeth in its first five alveoli. Comparative anatomical study shows the partial dentary can be assigned to a member of early diverging somphospondylans. The non-destructive tooth length-based approach to estimating tooth formation time and replacement rate is adopted here. The estimated tooth replacement rate is 76 days, faster than that of Brachiosaurus (83 days) and much lower than typical late diverging lithostrotian titanosaurians (20 days). Thus, this discovery adds an intermediate tooth replacement rate in the evolution of titanosauriform sauropods and supports the idea that evolution of tooth replacement rate is clade-specific. This discovery also provides more information to understand the Ruyang sauropod assemblage, which includes one of the most giant dinosaurs to have walked our Earth (Ruyangosaurus giganteus).

A 28 GHz 2 × 2 Antenna Array with 10 Beams Using Passive SPDT Switch Beamforming Network.

In this paper, a dual-polarized four-port 2 × 2 series fed antenna array operating at 28 GHz with beam-switching capability is proposed. The antenna array uses a simple passive beamforming network to switch the main beam. The presented antenna design is suitable for 5G user equipment and high data rates applications by which it has a compact size with low cost and complexity. The size of the antenna is 37.2 × 37.2 mm including the ground plane, and it produces 10 different switched beams by using only two simple 3 dB/90 couplers which create the required amplitudes and phase excitations for the antenna elements. A one-port simple feeding mechanism including Peregrine PE42525 SPDT switch modules and a power divider is used to generate and measure the 10 switched beams. The antenna design is implemented on a two-layer 0.203 mm thick low-loss ( = 0.0027) Rogers 4003C substrate, and it has a measured 10 dB impedance bandwidth of 4 GHz (14.3%, from 26 GHz to 30 GHz) for all ports. Measured peak isolation between any dual-polarized ports of the antenna is better than 30 dB. The antenna has an average measured realized gain of 8.9 dBi and around 10 dB side lobe level (SLL) for all beams. The antenna has 3-dB coverage of 80 to 90 in 2D space and it has a maximum of ±26 beam-steering angle. The antenna is designed and simulated using Ansys HFSS and fabricated using regular PCB processing.

Parallel morphological evolution and habitat-dependent sexual dimorphism in cave- vs. surface populations of the Asellus aquaticus (Crustacea: Isopoda: Asellidae) species complex.

Studying parallel evolution (repeated, independent evolution of similar phenotypes in similar environments) is a powerful tool to understand environment‐dependent selective forces. Surface‐dwelling species that repeatedly and independently colonized caves provide unique models for such studies. The primarily surface‐dwelling Asellus aquaticus species complex is a good candidate to carry out such research, because it colonized several caves in Europe. By comparing 17 functional morphological traits between six cave and nine surface populations of the A. aquaticus species complex, we investigated population divergence in morphology and sexual dimorphism. We found habitat‐dependent population divergence in 10 out of 17 traits, likely reflecting habitat‐driven changes in selection acting on sensory systems, feeding, grooming, and antipredator mechanisms. Sexual dimorphism was present in 15 traits, explained by sexual selection acting on male traits important in male–male agonistic behavior or mate guarding and fecundity selection acting on female traits affecting offspring number and nursing. In eight traits, the degree of sexual dimorphism was habitat dependent. We conclude that cave‐related morphological changes are highly trait‐ and function‐specific and that the strength of sexual/fecundity selection strongly differs between cave and surface habitats. The considerable population variation within habitat type warrants further studies to reveal cave‐specific adaptations besides the parallel patterns.