scholarly journals Distance and Size Discrimination in a Water Stick Insect, ranatra linearis (Heteroptera)

1986 ◽  
Vol 120 (1) ◽  
pp. 59-77
Author(s):  
ANN CLOAREC
Keyword(s):  
Prey Capture ◽  
Stick Insect ◽  
Normal Adult ◽  
Central Position ◽  
Size Discrimination ◽  
Stick Insects ◽  
Distance Position ◽  
Prey Items

The role of vision in distance, position and size discrimination in prey capture has been investigated in normal adult water stick insects (Ranatra linearis L.: Heteroptera) and in ones with one eye covered. Both monocular and intact Ranatra were able to discriminate between two targets subtending the same angle but presented at different distances. They usually chose the target nearer to their foreleg claws. Although monocular subjects undershot more often than controls, they could still estimate distance correctly. When presented with two different-sized targets at the same distance, both monocular and intact subjects usually preferred the larger target within a 1°-10° range, even though monocular animals chose the larger object less consistently. They were able to distinguish between two targets differing in size by only 1°. Asymmetrical presentations of two identical targets stressed the importance of the central position. Intact animals always preferred the target nearer their midline. These data also revealed the unexpected ability of Ranatra to strike accurately at two targets or prey items simultaneously. When two identical targets were presented simultaneously and symmetrically, aims were directed at both targets, and one was grasped by each raptorial foreleg, thus indicating an absence of confusion.

scholarly journals Sensory Feedback During Active Movements of Stick Insects

1987 ◽  
Vol 133 (1) ◽  
pp. 137-156 ◽  
Author(s):  
G. WEILAND ◽  
U. T. KOCH
Keyword(s):  
Control System ◽  
Stick Insect ◽  
Middle Part ◽  
Chordotonal Organ ◽  
Voluntary Movements ◽  
Joint Movement ◽  
Stick Insects ◽  
Velocity Changes ◽  
Changing Role

In the stick insect Carausius momsus, the role of the chordotonal organ was investigated using a new experimental arrangement which artificially closes the femur-tibia control system. The chordotonal organ was stimulated during voluntary movements by applying trapezoidal ramp stimuli in the closed-loop configuration. The results demonstrate that the feedback loop is used to control the end points of joint movement. In addition, it was found that the control system counteracts experimentally applied velocity changes imposed during the middle part of the movements. Acceleration-sensitive units are shown to contribute to the reaction. The results show that during active voluntary movements reflexes measured in the inactive animal are neither simply incorporated in a servo-system nor suppressed. Instead their characteristics are altered so that the voluntary movements are executed as intended by the animal. Thus reflexes cannot be considered as a fixed behavioural unit; rather their changing role must be analysed in the context of the behaviour studied.

scholarly journals Neuronal Innervation of the Subgenual Organ Complex and the Tibial Campaniform Sensilla in the Stick Insect Midleg

Insects ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 40 ◽  
Author(s):  
Johannes Strauß
Keyword(s):  
Physiological Role ◽  
Stick Insect ◽  
Campaniform Sensilla ◽  
Innervation Pattern ◽  
Branching Points ◽  
Stick Insects ◽  
Sensory Structures ◽  
Evolutionary Comparisons ◽  
Subgenual Organ

Mechanosensory organs in legs play are crucial receptors in the feedback control of walking and in the detection of substrate-borne vibrations. Stick insects serve as a model for the physiological role of chordotonal organs and campaniform sensilla. This study documents, by axonal tracing, the neural innervation of the complex chordotonal organs and groups of campaniform sensilla in the proximal tibia of the midleg in Sipyloidea sipylus. In total, 6 nerve branches innervate the different sensory structures, and the innervation pattern associates different sensilla types by their position. Sensilla on the anterior and posterior tibia are innervated from distinct nerve branches. In addition, the variation in innervation is studied for five anatomical branching points. The most common variation is the innervation of the subgenual organ sensilla by two nerve branches rather than a single one. The fusion of commonly separated nerve branches also occurred. However, a common innervation pattern can be demonstrated, which is found in >75% of preparations. The variation did not include crossings of nerves between the anterior and posterior side of the leg. The study corrects the innervation of the posterior subgenual organ reported previously. The sensory neuroanatomy and innervation pattern can guide further physiological studies of mechanoreceptor organs and allow evolutionary comparisons to related insect groups.

scholarly journals The role of leg touchdown for the control of locomotor activity in the walking stick insect

2015 ◽  
Vol 113 (7) ◽  
pp. 2309-2320 ◽  
Author(s):  
Joscha Schmitz ◽  
Matthias Gruhn ◽  
Ansgar Büschges
Keyword(s):  
Muscle Activation ◽  
Stance Phase ◽  
Stick Insect ◽  
Afferent Input ◽  
Flexor Muscle ◽  
Locomotor Control ◽  
Burst Intensity ◽  
Stick Insects ◽  
Additional Feedback

Much is known on how select sensory feedback contributes to the activation of different motoneuron pools in the locomotor control system of stick insects. However, even though activation of the stance phase muscles depressor trochanteris, retractor unguis, flexor tibiae and retractor coxae is correlated with the touchdown of the leg, the potential sensory basis of this correlation or its connection to burst intensity remains unknown. In our experiments, we are using a trap door setup to investigate how ground contact contributes to stance phase muscle activation and burst intensity in different stick insect species, and which afferent input is involved in the respective changes. While the magnitude of activation is changed in all of the above stance phase muscles, only the timing of the flexor tibiae muscle is changed if the animal unexpectedly steps into a hole. Individual and combined ablation of different force sensors on the leg demonstrated influence from femoral campaniform sensilla on flexor muscle timing, causing a significant increase in the latencies during control and air steps. Our results show that specific load feedback signals determine the timing of flexor tibiae activation at the swing-to-stance transition in stepping stick insects, but that additional feedback may also be involved in flexor muscle activation during stick insect locomotion. With respect to timing, all other investigated stance phase muscles appear to be under sensory control other than that elicited through touchdown.

scholarly journals Essential role of DOT1L in maintaining normal adult hematopoiesis

Cell Research ◽  
2011 ◽  
Vol 21 (9) ◽  
pp. 1370-1373 ◽  
Author(s):  
Anh T Nguyen ◽  
Jin He ◽  
Olena Taranova ◽  
Yi Zhang
Keyword(s):  
Essential Role ◽  
Normal Adult

Translate to resist

2021 ◽  
Author(s):  
Jasmin Esin Duraner
Keyword(s):  
Central Position ◽  
Counter Narrative ◽  
Sociopolitical Context ◽  
The Way

Abstract The emergence of the LGBTI+ movement has faced considerable challenges in the Turkish sociopolitical context due to the dominance and oppression of the long-established traditional and conservative institutions such as religion, family, and state. In Turkey, translation occupies a central position in the way knowledge is produced and organized to subvert heteronormativity and homo/transphobia, and struggle for rights. LGBTI News Turkey is the most conspicuous LGBTI+ organization in relation to this, since the platform focuses exclusively on translation. I discuss the role of the activist translators in the representation of LGBTI+ individuals globally by constructing a “narrative” (Baker 2006a) for the LGBTI+ community in Turkey. I also elaborate the concepts of fidelity and invisibility within activist translation, and the methods activist-translators employ to create and disseminate a counter narrative against the dominant public narrative, and question how they position themselves in the LGBTI+ movement.

scholarly journals Recent progress in orexin/hypocretin physiology and pharmacology

2012 ◽  
Vol 3 (5) ◽  
pp. 447-463 ◽  
Author(s):  
Jyrki P. Kukkonen
Keyword(s):  
Stress Response ◽  
Recent Progress ◽  
Central Position ◽  
Future Directions

AbstractOrexin peptides and their cognate receptors were discovered 14 years ago. They soon took a very central position in the regulation of sleep and wakefulness. Active studies have further elucidated these functions as well as the role of orexins in, for instance, appetite, metabolism, analgesia, addiction, and stress response. This review summarizes all the important fields but especially aims at focusing on novel findings and future directions.

Intersegmental Coordination of Walking Movements in Stick Insects

2005 ◽  
Vol 93 (3) ◽  
pp. 1255-1265 ◽  
Author(s):  
Björn Ch. Ludwar ◽  
Marie L. Göritz ◽  
Joachim Schmidt
Keyword(s):  
Motor Pattern ◽  
Central Pattern Generators ◽  
Stick Insect ◽  
Neural Mechanisms ◽  
Chordotonal Organ ◽  
Adjacent Segment ◽  
Body Segments ◽  
Stick Insects ◽  
Pattern Generators ◽  
Leg Movements

Locomotion requires the coordination of movements across body segments, which in walking animals is expressed as gaits. We studied the underlying neural mechanisms of this coordination in a semi-intact walking preparation of the stick insect Carausius morosus. During walking of a single front leg on a treadmill, leg motoneuron (MN) activity tonically increased and became rhythmically modulated in the ipsilateral deafferented and deefferented mesothoracic (middle leg) ganglion. The pattern of modulation was correlated with the front leg cycle and specific for a given MN pool, although it was not consistent with functional leg movements for all MN pools. In an isolated preparation of a pair of ganglia, where one ganglion was made rhythmically active by application of pilocarpine, we found no evidence for coupling between segmental central pattern generators (CPGs) that could account for the modulation of MN activity observed in the semi-intact walking preparation. However, a third preparation provided evidence that signals from the front leg's femoral chordotonal organ (fCO) influenced activity of ipsilateral MNs in the adjacent mesothoracic ganglion. These intersegmental signals could be partially responsible for the observed MN activity modulation during front leg walking. While afferent signals from a single walking front leg modulate the activity of MNs in the adjacent segment, additional afferent signals, local or from contralateral or posterior legs, might be necessary to produce the functional motor pattern observed in freely walking animals.

scholarly journals REFLEKSI EPISTIMOLOGI DALAM METODOLOGI PENELITIAN (Suatu Kontemplasi atas Pekerjaan Penelitian)

2013 ◽  
Vol 5 (2) ◽  
Author(s):  
Saifullah Saifullah
Keyword(s):  
Research Methodology ◽  
Positive Impact ◽  
Research Process ◽  
Central Position ◽  
Building Science ◽  
Scientific Disciplines ◽  
Science Community ◽  
Quality Of Research

<p>Research methodology is the application of epistemology in philosophical which is realized by logico hypotetico verificative-deducto hypothetico verificative. The results of the evaluation of the quality of the research methodology that gave rise buildings recently become a standard formula valid and tested public. In this context it is necessary scrutiny of the functioning and the importance of pre usability, and value the benefits of the research process so that the quality of research produced a positive impact on building science researchers. The role of the researcher holds a central position of being able to adjust the ground circumstances. Benefit value for the benefit of life as the goal of research in theory and practical should be explicitly and implicitly always accompanies every step of research. A consequence of the value of the benefits of scientific research which is undertaken is delivering research results to the user community. The use of research methodologies in the study strongly influenced the extent of the ability of researchers and scientists at the clump science community are able to map the identity of the building a distinctive methodology of scientific disciplines that is useful for subsequent research.</p> <p>Metodologi Penelitian merupakan penerapan epistimologi secara filsafati yang diwujudkan dengan logico  hypotetico  verificative-deducto  hypothetico  verificative.  Hasil  evaluasi terhadap  kualitas  bangunan  metodologi  penelitian  yang  memunculkan  formula  baru menjadi standar yang valid dan teruji publik. Dalam konteks ini maka perlu pencermatan tentang fungsi dan kegunaan akan pentingnya pra, proses dan nilai manfaat riset agar kualitas riset yang dihasilkan berdampak positif pada bangunan keilmuan peneliti. Peran peneliti  memegang  posisi  sentral  karena  mampu  menyesuaikan  situasi  dan  kondisi lapangan. Nilai kemanfaatan bagi kemaslahatan hidup sebagai tujuan riset secara teoritis dan praktis sebaiknya secara eksplisit dan implisit selalu menyertai setiap langkah riset. Konsekuensi ilmiah dalam nilai manfaat riset yang dilakukan adalah menyampaikan hasilhasil riset ke masyarakat pengguna. Penggunaan metodologi penelitian dalam riset sangat dipengaruhi sejauhmana kemampuan peneliti dan komunitas ilmuan pada rumpun ilmu mampu memetakan jati diri bangunan metodologi disiplin keilmuan yang khas sehingga bermanfaat bagi peneliti berikutnya.</p>

scholarly journals WOMAN AS A ‘TRANSFORMER’ IN PAULO COELHO’S THE ZAHIR

2020 ◽  
pp. 181-185
Author(s):  
Jagdish Joshi ◽  
Neha Hariyani
Keyword(s):  
Significant Role ◽  
Deep Understanding ◽  
Central Position ◽  
Seminal Work

Paulo Coelho is an eminent Brazilian writer of the present times. His novels reflect his deep understanding of mythology and mysticism and are a blend of tradition and modernity. Woman plays a significant role in the metamorphosis of the protagonist in Coelho’s novels. This paper intends to study the role of woman in his novel The Zahir, in the light of Campbell’s theory of Initiation in his seminal work The Hero with a Thousand Faces. Campbell’s theory of Initiation accords a central position to woman. She performs various roles and becomes instrumental in bringing about the transformation of the hero. The more the hero initiates into his adventure, the more fascinating does he find the woman, changing herself in accordance with the needs of the hero as dictated by destiny Initially, woman in The Zahir seems to hold a subordinate position. She is even regarded as a mere commodity by the hero. But as the narrative develops, the role of the woman, true to Campbell’s remark undergoes a series of transfigurations, the deeper the hero initiates into his inner quest the subtler the woman becomes. From a mere commodity the woman transfigures into a guide, from a guide into a divine energy, capable of bringing about the inner transformation of the hero.

Sign in / Sign up

Export Citation Format

Share Document