scholarly journals Aimed Limb Movements in a Hemimetabolous Insect are Intrinsically Compensated for Allometric Wing Growth by Developmental Mechanisms

2019 ◽  
Author(s):  
Alexandra J. Patel ◽  
Thomas Matheson
Keyword(s):  
Motor Pattern ◽  
Distal Tibia ◽  
The Body ◽  
Limb Movements ◽  
Body Morphology ◽  
Hemimetabolous Insect ◽  
Kinematic Analyses ◽  
Wing Growth ◽  
External Stimuli ◽  
Wing Tip

ABSTRACTFor aimed limb movements to remain functional they must be adapted to developmental changes in body morphology and sensory-motor systems. Insects use their limbs to groom the body surface or to dislodge external stimuli, but they face the particular problem of adapting these movements to step-like changes in body morphology during metamorphosis or moulting. Locusts are hemimetabolous insects in which the imaginal moult to adulthood results in a sudden and dramatic allometric growth of the wings relative to the body and the legs. We show that, despite this, hind limb scratches aimed at mechanosensory stimuli on the wings remain targeted to appropriate locations after moulting. In juveniles, the tips of the wings extend less than half way along the abdomen, but in adults they extend well beyond the posterior end. Kinematic analyses were used to examine the scratching responses of juveniles (5th instars) and adults to touch of anterior (wing base) and posterior (distal abdomen) targets that develop isometrically, and to wing tip targets that are anterior in juveniles but posterior in adults. Juveniles reach the (anterior) wing tip with the distal tibia of the hind leg using anterior rotation of the thoraco-coxal and coxo-trochanteral (‘hip’) joints and flexion of the femoro-tibial (‘knee’) joint. Adults, however, reach the corresponding (but now posterior) wing tip using posterior rotation of the hip and extension of the knee, reflecting a different underlying motor pattern. This change in kinematics occurs immediately after the adult moult without learning, indicating that the switch is developmentally programmed.SUMMARY STATEMENTA developmentally programmed change in the scratching movements of locusts permits adult animals to aim their movements at new wing tip targets, without learning.

scholarly journals A wing growth organizer in a hemimetabolous insect suggests wing origin

2021 ◽  
Author(s):  
Takahiro Ohde ◽  
Taro Mito ◽  
Teruyuki Niimi
Keyword(s):  
Body Wall ◽  
The Body ◽  
Marker Genes ◽  
Wing Development ◽  
Gryllus Bimaculatus ◽  
Genetic Changes ◽  
Origin And Evolution ◽  
Insect Wings ◽  
Hemimetabolous Insect ◽  
Wing Growth

ABSTRACTThe origin and evolution of insect wings remain enigmatic after a century-long discussion. Molecular dissection of wing development in hemimetabolous insects, in which the first functional wings evolved, is key to understand genetic changes required for wing evolution. We investigatedDrosophilawing marker genes in the cricket,Gryllus bimaculatus, and foundapterousandvestigialshow critical functions in nymphal tergal identity and margin formation, respectively. We further demonstrate that margin cells in the lateral-anterior tergal region constitute a growth organizer of wing blades. Transcriptome and RNAi analyses unveiled that Wnt, Fat-Dachsous, and Hippo pathways are involved in disproportional growth ofGrylluswings. Our data collectively support the idea that tergal margin cells of a wingless ancestor gave rise to the body wall extension required for evolution of the first powered flight.

scholarly journals Strategies for the Development of pH-Responsive Synthetic Polypeptides and Polymer-Peptide Hybrids: Recent Advancements

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 624
Author(s):  
Cintya Dharmayanti ◽  
Todd A. Gillam ◽  
Manuela Klingler-Hoffmann ◽  
Hugo Albrecht ◽  
Anton Blencowe
Keyword(s):  
Functional Groups ◽  
Hybrid Materials ◽  
Tumour Microenvironment ◽  
The Body ◽  
Supramolecular Interactions ◽  
Biological Interactions ◽  
Ph Responsive ◽  
Form Complex ◽  
Synthetic Polypeptides ◽  
External Stimuli

Synthetic polypeptides and polymer-peptide hybrid materials have been successfully implemented in an array of biomedical applications owing to their biocompatibility, biodegradability and ability to mimic natural proteins. In addition, these materials have the capacity to form complex supramolecular structures, facilitate specific biological interactions, and incorporate a diverse selection of functional groups that can be used as the basis for further synthetic modification. Like conventional synthetic polymers, polypeptide-based materials can be designed to respond to external stimuli (e.g., light and temperature) or changes in the environmental conditions (e.g., redox reactions and pH). In particular, pH-responsive polypeptide-based systems represent an interesting avenue for the preparation of novel drug delivery systems that can exploit physiological or pathological pH variations within the body, such as those that arise in the extracellular tumour microenvironment, intracellularly within endosomes/lysosomes, or during tissue inflammation. Here, we review the significant progress made in advancing pH-responsive polypeptides and polymer-peptide hybrid materials during the last five years, with a particular emphasis on the manipulation of ionisable functional groups, pH-labile linkages, pH-sensitive changes to secondary structure, and supramolecular interactions.

Motor pattern of periodic limb movements during sleep

Neurology ◽  
2001 ◽  
Vol 57 (2) ◽  
pp. 300-304 ◽  
Author(s):  
F. Provini ◽  
R. Vetrugno ◽  
S. Meletti ◽  
G. Plazzi ◽  
L. Solieri ◽  
...  
Keyword(s):  
Motor Pattern ◽  
Periodic Limb Movements ◽  
Limb Movements

The C-start escape response ofPolypterus senegalus: bilateral muscle activity and variation during stage 1 and 2

2002 ◽  
Vol 205 (17) ◽  
pp. 2591-2603 ◽  
Author(s):  
Eric D. Tytell ◽  
George V. Lauder
Keyword(s):  
Muscle Activity ◽  
Escape Response ◽  
High Speed ◽  
Wave Speed ◽  
Activity Patterns ◽  
Motor Pattern ◽  
The Body ◽  
Wide Range ◽  
Fast Start ◽  
Stage 1

SUMMARYThe fast-start escape response is the primary reflexive escape mechanism in a wide phylogenetic range of fishes. To add detail to previously reported novel muscle activity patterns during the escape response of the bichir, Polypterus, we analyzed escape kinematics and muscle activity patterns in Polypterus senegalus using high-speed video and electromyography (EMG). Five fish were filmed at 250 Hz while synchronously recording white muscle activity at five sites on both sides of the body simultaneously (10 sites in total). Body wave speed and center of mass velocity, acceleration and curvature were calculated from digitized outlines. Six EMG variables per channel were also measured to characterize the motor pattern. P. senegalus shows a wide range of activity patterns, from very strong responses, in which the head often touched the tail, to very weak responses. This variation in strength is significantly correlated with the stimulus and is mechanically driven by changes in stage 1 muscle activity duration. Besides these changes in duration, the stage 1 muscle activity is unusual because it has strong bilateral activity, although the observed contralateral activity is significantly weaker and shorter in duration than ipsilateral activity. Bilateral activity may stiffen the body, but it does so by a constant amount over the variation we observed; therefore, P. senegalus does not modulate fast-start wave speed by changing body stiffness. Escape responses almost always have stage 2 contralateral muscle activity, often only in the anterior third of the body. The magnitude of the stage 2 activity is the primary predictor of final escape velocity.

scholarly journals A New Radiographic Method for Estimating Tibial Malrotation

2020 ◽  
Vol 7 (3) ◽  
pp. 121-128
Author(s):  
Hamidreza Yazdi ◽  
◽  
Mohammad Taher Ghaderi ◽  
Alireza Yousof Gomrokchi ◽  
Parham Pezeshk ◽  
...  
Keyword(s):  
Lower Limb ◽  
Evaluation Method ◽  
Bone Fractures ◽  
Distal Tibia ◽  
Bone Diseases ◽  
The Body ◽  
University Hospital ◽  
Radiographic Evaluation ◽  
Minor Trauma ◽  
Lower Limb Injury

Background: Diaphyseal tibial fractures are the most frequent bone fractures in the body and are usually treated with intramedullary nailing method. However, this approach is responsible for 41% of the rotational deviation.  Objectives: This study aimed to provide a radiographic evaluation method to determine tibial malrotation in closed fixation of tibia bone fractures during or after the operation. Methods: This study was conducted in a university hospital from May 2015 to March 2016. All patients referring to the hospital with the complaints of minor trauma around the ankle and knee requiring radiographic evaluation of both joints were enrolled in the study. The inclusion criteria included being 20 and 50 years old; having normal axial, sagittal, and coronal lower limb alignment; lacking previous lower limb injury (such as fractures of the tibia or fibula), ankle or knee sprain; not having previous lower limb surgery, metabolic or congenital bone diseases, or malignancy. In all cases, a standard Anteroposterior (AP) radiograph of the knee was taken, and then, without changing the limb position or image setting, an AP radiograph of the ankle was obtained. The overlap between the distal tibia and fibula was measured in the PACS program environment.   Results: Fifty cases were included in this study. The Mean±SD ages of males and females were 29.08±2.49 years and 31.46±2.04 years, respectively. The range of distal tibia-fibula overlap one centimeter above the tibiotalar joint line was 7.81 to 9.09 mm (confidence interval of 95%), and its percentage to the fibula shaft width at the same level was 49.43% to 54.35%. Conclusion: According to the results, distal tibia-fibula overlap when the knee is in the true AP position, regardless of the side and gender, is 7.81 to 9.09 mm or 49.43% to 54.35%.

scholarly journals THE ROLE OF PHYSICAL THERAPY IN EDUCATING A CORRECT BODY POSTURE IN SCHOOL CHILDREN

GYMNASIUM ◽  
2017 ◽  
Vol XVII (1) ◽  
Author(s):  
Alina Mihaela Cristuță
Keyword(s):  
Physical Therapy ◽  
Motor Skills ◽  
School Children ◽  
The Body ◽  
Body Posture ◽  
Intervention Programs ◽  
Intervention Measures ◽  
Specific Assessment ◽  
External Stimuli

Posture expresses the way in which the body receives external stimuli and gets ready to react, constantly adapting to the demands, according to the difficulty and to the individual's motor skills. The aim of this study is to educate the correct body posture through specific physical therapy means. The hypotheses presume that: by performing a specific assessment, one can spot the bad postures that are frequently adopted by school children; through specific intervention programs, one can educate, correct, and form a correct posture reflex. The objectives were to: assess the school children in order to spot physical deficiencies; to educate a correct posture and to form a correct posture reflex. The research methods were established according to the objectives. In the end, it can be concluded that this research  regarding the education of posture in school children has contributed to the prevention of instalment of physical deficiencies and to their correction, and the intervention measures were effective in educating the correct body posture.

SPECIAL REVIEWS

PEDIATRICS ◽  
1951 ◽  
Vol 7 (2) ◽  
pp. 269-293
Author(s):  
CHARLES C. CHAPPLE
Keyword(s):  
The Body ◽  
Caloric Content ◽  
Maturation Factor ◽  
Drug Actions ◽  
The Common ◽  
Cellular Permeability ◽  
The One ◽  
External Stimuli ◽  
The Brain

A study has been made of the known phenomena which affect the biologic organism. Certain correlations have been found and other correlations are logically inferred. The common grounds of anatomic structures, the anatomic responses to endocrine stimuli, the interrelationships and interdependencies of the endocrines and external stimuli have been followed and have been related to cellular permeability and hyaluronic acid. Cellular phases, including the rhythmic alternations in physiologic functions, have been delineated and their importance stressed. Further, the probability is advanced that this rhythmicity originates physiologically in the brain but that the brain itself is capable of receiving transmissions from within and without the body, and disseminating them, again rhythmically, in normal or altered amplitude and frequency. Further experimental evidence of these correlations and their practical extrapolations into drug actions and the therapy of infections and metabolic disease will be reported and will include clinical, animal and in vitro studies. At present, the following conclusions seem justified: 1. No component of the body is capable of independent action. 2. Action in any component is reflected, according to its magnitude and directness of application, upon all the body. 3. All such actions are mediated by the brain. 4. There is a dynamic, rhythmic cyclicity in physiologic action which can be altered in amplitude and frequency. 5. These rhythms are alternations of cellular tenseness and relaxation. 6. The concomitants of the tense phase are compactness, impermeability, electric conductivity and contraction of all cells, and these characteristics might be described collectively as the factors operative in maturing the cell. The concomitants of the relaxed phase are laxness, permeability, electric resistance and expansion of all cells and are factors of growth. 7. The phase of tenseness is accompanied by an increase in certain hormonal activities and that of relaxation by an increase in others. 8. The hormones may be causes of the phase or the results of it. 9. Infectious disease cannot act as an extraneous agent capable of bringing its own engine into such a highly integrated mechanism but must act on the body through its ability to affect one of the body's mechanisms. 10. Drugs must act through the same channels available to disease. 11. Foods may contain, in addition to their caloric content, components capable of stimulating either the phase of cellular expansion or cellular compaction, particularly foods from the reproductive systems of plants or animals (milk, eggs, cereal, for example). 12. Vitamins each stimulate one phase and should be evaluated in terms of positive actions. 13. Inherent growth and maturation factors are not of fixed capacity in an individual but beyond certain limits must be supplied him or applied to him constantly. 14. The hormone most manifest in the tense phase is estrogen and so may be considered the maturation factor, and the one most manifest in the phase of relaxation or cell division is progesterone, which may be considered the growth factor.

A Study of Water Surface Deformation Due to Tip Vortices Wing-in-Ground Effect

2007 ◽  
Vol 51 (02) ◽  
pp. 182-186
Author(s):  
Tracie J. Barber
Keyword(s):  
Water Surface ◽  
Surface Deformation ◽  
Three Dimensional ◽  
Ground Effect ◽  
Aerodynamic Performance ◽  
The Body ◽  
Vehicle Design ◽  
Two Dimensional ◽  
Tip Vortices ◽  
Wing Tip

The accurate prediction of ground effect aerodynamics is an important aspect of wing-in-ground (WIG) effect vehicle design. When WIG vehicles operate over water, the deformation of the nonrigid surface beneath the body may affect the aerodynamic performance of the craft. The likely surface deformation has been considered from a theoretical and numerical position. Both two-dimensional and three-dimensional cases have been considered, and results show that any deformation occurring on the water surface is likely to be caused by the wing tip vortices rather than an increased pressure distribution beneath the wing.

The Effect of Labyrinthectomy on the Co-ordination of Limb Movements in the Toad

1947 ◽  
Vol 24 (1-2) ◽  
pp. 36-41
Author(s):  
J. GRAY ◽  
H. W. LISSMANN
Keyword(s):  
Normal Animal ◽  
The Body ◽  
Limb Movements ◽  
Membranous Labyrinth ◽  
Freely Suspended ◽  
Two Sides

1. After bilateral labyrinthectomy, a toad can only walk normally if the stimulus which excites it to move is applied symmetrically on the two sides of the body. If the stimulus is asymmetrical, the animal's path curves towards the unstimulated side; if the stimulus is relatively intense the animal ‘circles’ persistently towards the unstimulated side. The ambulatory response of a normal animal to an asymmetrical stimulus is dependent on both proprioceptive and labyrinthine activity. 2. After bilateral labyrinthectomy, both hindlimbs exhibit swimming movements when the animal is freely suspended in water but co-ordination between the two limbs is lost. Evidence is put forward which suggests that the swimming rhythm of the limbs may be dependent on rhythmical excitation of the membranous labyrinth. No swimming occurs when the limbs of a labyrinthectomized toad are de-afferentated. 3. The removal of both labyrinths does not abolish the power of the limbs to right the animal when placed on its back. The mechanics of the righting movement are described.

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