scholarly journals Flies land upside down on a ceiling using rapid visually mediated rotational maneuvers

2019 ◽  
Vol 5 (10) ◽  
pp. eaax1877 ◽  
Author(s):  
Pan Liu ◽  
Sanjay P. Sane ◽  
Jean-Michel Mongeau ◽  
Jianguo Zhao ◽  
Bo Cheng
Keyword(s):  
Full Range ◽  
Statistical Analyses ◽  
Expansion Velocity ◽  
Strongly Correlated ◽  
Sensory Cues ◽  
Body Rotation ◽  
Variable Pitch ◽  
Leg Extension ◽  
Sensorimotor Processes ◽  
Serial Sequence

Flies and other insects routinely land upside down on a ceiling. These inverted landing maneuvers are among the most remarkable aerobatic feats, yet the full range of these behaviors and their underlying sensorimotor processes remain largely unknown. Here, we report that successful inverted landing in flies involves a serial sequence of well-coordinated behavioral modules, consisting of an initial upward acceleration followed by rapid body rotation and leg extension, before terminating with a leg-assisted body swing pivoted around legs firmly attached to the ceiling. Statistical analyses suggest that rotational maneuvers are triggered when flies’ relative retinal expansion velocity reaches a threshold. Also, flies exhibit highly variable pitch and roll rates, which are strongly correlated to and likely mediated by multiple sensory cues. When flying with higher forward or lower upward velocities, flies decrease the pitch rate but increase the degree of leg-assisted swing, thereby leveraging the transfer of body linear momentum.

scholarly journals How Specific Are Learning Disabilities?

2021 ◽  
pp. 002221942098298
Author(s):  
Robin L. Peterson ◽  
Lauren M. McGrath ◽  
Erik G. Willcutt ◽  
Janice M. Keenan ◽  
Richard K. Olson ◽  
...  
Keyword(s):  
Learning Disabilities ◽  
Reading Comprehension ◽  
Full Range ◽  
Written Expression ◽  
Strongly Correlated ◽  
Math Problem Solving ◽  
Confirmatory Factor ◽  
Bifactor Models ◽  
And Mathematics ◽  
Specific Learning

Despite historical emphasis on “specific” learning disabilities (SLDs), academic skills are strongly correlated across the curriculum. Thus, one can ask how specific SLDs truly are. To answer this question, we used bifactor models to identify variance shared across academic domains (academic g), as well as variance unique to reading, mathematics, and writing. Participants included 686 children aged 8 to 16. Although the sample was overselected for learning disabilities, we intentionally included children across the full range of individual differences in this study in response to growing recognition that a dimensional, quantitative view of SLD is more accurate than a categorical view. Confirmatory factor analysis identified five academic domains (basic reading, reading comprehension, basic math, math problem-solving, and written expression); spelling clustered with basic reading and not writing. In the bifactor model, all measures loaded significantly on academic g. Basic reading and mathematics maintained variance distinct from academic g, consistent with the notion of SLDs in these domains. Writing did not maintain specific variance apart from academic g, and evidence for reading comprehension-specific variance was mixed. Academic g was strongly correlated with cognitive g ( r = .72) but not identical to it. Implications for SLD diagnosis are discussed.

The Coupled Motion of the Femur and Patella During In Vivo Weightbearing Knee Flexion

2007 ◽  
Vol 129 (6) ◽  
pp. 937-943 ◽  
Author(s):  
Guoan Li ◽  
Ramprasad Papannagari ◽  
Kyung Wook Nha ◽  
Louis E. DeFrate ◽  
Thomas J. Gill ◽  
...  
Keyword(s):  
Knee Joint ◽  
Knee Flexion ◽  
External Rotation ◽  
Full Range ◽  
Surgical Techniques ◽  
Base Line ◽  
Strongly Correlated ◽  
Patellar Tilt ◽  
Coupled Motion ◽  
Kinematic Coupling

The movement of the knee joint consists of a coupled motion between the tibiofemoral and patellofemoral articulations. This study measured the six degrees-of-freedom kinematics of the tibia, femur, and patella using dual-orthogonal fluoroscopy and magnetic resonance imaging. Ten normal knees from ten living subjects were investigated during weightbearing flexion from full extension to maximum flexion. The femoral and the patellar motions were measured relative to the tibia. The femur externally rotated by 12.9deg and the patella tilted laterally by 16.3deg during the full range of knee flexion. Knee flexion was strongly correlated with patellar flexion (R2=0.91), posterior femoral translation was strongly correlated to the posterior patellar translation (R2=0.87), and internal-external rotation of the femur was correlated to patellar tilt (R2=0.73) and medial-lateral patellar translation (R2=0.63). These data quantitatively indicate a kinematic coupling between the tibia, femur, and patella, and provide base line information on normal knee joint kinematics throughout the full range of weightbearing flexion. The data also suggest that the kinematic coupling of tibia, femur, and patella should be considered when investigating patellar pathologies and when developing surgical techniques to treat knee joint diseases.

scholarly journals Kinetochore genes are coordinately up-regulated in human tumors as part of a FoxM1-related cell division program

2014 ◽  
Vol 25 (13) ◽  
pp. 1983-1994 ◽  
Author(s):  
Prathapan Thiru ◽  
David M. Kern ◽  
Kara L. McKinley ◽  
Julie K. Monda ◽  
Florencia Rago ◽  
...  
Keyword(s):  
Cell Division ◽  
Chromosome Segregation ◽  
Full Range ◽  
Strongly Correlated ◽  
Forkhead Transcription Factor ◽  
Altered Expression ◽  
Normal Tissues ◽  
Related Cell ◽  
Expression Behavior ◽  
General Activation

The key player in directing proper chromosome segregation is the macromolecular kinetochore complex, which mediates DNA–microtubule interactions. Previous studies testing individual kinetochore genes documented examples of their overexpression in tumors relative to normal tissue, leading to proposals that up-regulation of specific kinetochore genes may promote tumor progression. However, kinetochore components do not function in isolation, and previous studies did not comprehensively compare the expression behavior of kinetochore components. Here we analyze the expression behavior of the full range of human kinetochore components in diverse published expression compendia, including normal tissues and tumor samples. Our results demonstrate that kinetochore genes are rarely overexpressed individually. Instead, we find that core kinetochore genes are coordinately regulated with other cell division genes under virtually all conditions. This expression pattern is strongly correlated with the expression of the forkhead transcription factor FoxM1, which binds to the majority of cell division promoters. These observations suggest that kinetochore gene up-regulation in cancer reflects a general activation of the cell division program and that altered expression of individual kinetochore genes is unlikely to play a causal role in tumorigenesis.

scholarly journals Collapse Mechanism and Full-Range Analysis of Overturning Failure of Continuous Girder Bridges

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Taiyu Song ◽  
Qinger Deng ◽  
Guoping Li
Keyword(s):  
Rotation Axis ◽  
Design Method ◽  
Deformable Body ◽  
Full Range ◽  
Collapse Mechanism ◽  
Beam Model ◽  
Body Rotation ◽  
Range Analysis ◽  
Girder Bridges ◽  
Practical Design

In recent years, failings of girders due to overturning in continuous girder bridges have repeatedly occurred in China. To investigate the overturning collapse mechanism and also to evaluate the rationality of anti-overturning design method using beam element models that are commonly adopted in practical design, detailed 3D finite solid element models of a typical single-column pier three-span continuous box girder bridge were built and a full-range numerical analysis of the models was conducted. The solid models included the prestressing effect and diaphragms. Both boundary and geometric nonlinearities were taken into consideration. Bearings were modeled considering the actual construction and dimensions of pot rubber bearings, the material characteristics and boundary conditions of rubber pads, and the contact properties between each part of the bearings. The analysis results revealed that the behavior of the bridge approached the nonlinear state at the onset of first bearing disengagement; the rotation (overturning) mechanism of the girder was gradually transitioned from deformable-body rotation to rigid-body rotation; all the end and middle bearings had been disengaged totally or locally at ultimate overturning failure. The analysis results also showed that bearing disengagements would lead to the ineffectiveness of the constraint in the transverse direction, which significantly reduced the overturning ultimate load and structural ductility before the final collapse. Prior to the first bearing disengagement, the vertical reactions calculated from the beam model were in good agreement with those from the solid model, while the transverse reactions were not. The behaviors were inaccurate after bearing disengagement in the beam models in which the movement of the rotation axis and transition of rotation mechanism failed to be realized. Reliable transverse stoppers and tensile anchors at bearing sections were recommended to efficiently improve anti-overturning stability and ductility in practical design.

scholarly journals Tibial Tubercle Avulsion Fracture with Multiple Concomitant Injuries in an Adolescent Male Athlete

2018 ◽  
Vol 2018 ◽  
pp. 1-5 ◽  
Author(s):  
Avinesh Agarwalla ◽  
Richard Puzzitiello ◽  
Austin V. Stone ◽  
Brian Forsythe
Keyword(s):  
Compartment Syndrome ◽  
Patellar Tendon ◽  
Avulsion Fracture ◽  
Full Range ◽  
Adolescent Male ◽  
Tibial Tubercle ◽  
Concomitant Injuries ◽  
Avulsion Fractures ◽  
Leg Extension ◽  
Tibial Tubercle Avulsion Fracture

Tibial tubercle avulsion fractures are an uncommon injury occurring due to strong contraction of the quadriceps femoris muscle during leg extension, ultimately causing failure of the physis at the patellar tendon insertion. This injury has been previously reported with various concomitant injuries, such as compartment syndrome from bleeding into the anterior compartment, vascular injury, patellar tendon avulsion, and meniscal injury—exhibited only with fracture types that extend intra-articularly. We report the case of a 14-year-old healthy adolescent male basketball player who sustained this injury as a result of a collision with another player. He initially reported to the emergency department and then presented to our practice, where he was diagnosed with a tibial tubercle avulsion fracture with patellar tendon rupture. During the operative management of these injuries, it was noted that fascial tissue avulsed through the injury site causing subacute extensive bleeding within the anterolateral compartments. Due to concerns of compartment syndrome, a fascial release was performed along the anterolateral compartments. By five months postoperatively, the patient demonstrated near-normal function, no evidence of extensor lag, and nearly full range of motion. Unlike previously reported cases, this is the first report of a patient who suffered such an injury with multiple concomitant injuries to the neighboring structures. Due to the severity of compartment syndrome and the variability in its temporal presentation from the initial injury, it is paramount that careful evaluation of vascular integrity and a low threshold for fasciotomy be in place to prevent vascular compromise.

Outbursts of comet Schwassmann-Wachmann 1, and the cloud of interplanetary boulders

1974 ◽  
Vol 22 ◽  
pp. 307 ◽  
Author(s):  
Zdenek Sekanina
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Interplanetary Space ◽  
Porous Matrix ◽  
Maximum Diameter ◽  
Expansion Velocity ◽  
Solid Constituent ◽  
Meteoric Material ◽  
Periodic Comet

AbstractIt is suggested that the outbursts of Periodic Comet Schwassmann-Wachmann 1 are triggered by impacts of interplanetary boulders on the surface of the comet’s nucleus. The existence of a cloud of such boulders in interplanetary space was predicted by Harwit (1967). We have used the hypothesis to calculate the characteristics of the outbursts – such as their mean rate, optically important dimensions of ejected debris, expansion velocity of the ejecta, maximum diameter of the expanding cloud before it fades out, and the magnitude of the accompanying orbital impulse – and found them reasonably consistent with observations, if the solid constituent of the comet is assumed in the form of a porous matrix of lowstrength meteoric material. A Monte Carlo method was applied to simulate the distributions of impacts, their directions and impact velocities.

The Concurrent Validity of the Minnesota Child Development Inventory as a Measure of Young Children's Language Development

1989 ◽  
Vol 54 (1) ◽  
pp. 101-105 ◽  
Author(s):  
J. Bruce Tomblin ◽  
Cynthia M. Shonrock ◽  
James C. Hardy
Keyword(s):  
Child Development ◽  
Language Development ◽  
Expressive Language ◽  
Strong Predictor ◽  
Receptive Language ◽  
Strongly Correlated ◽  
Language Measure ◽  
The Mean ◽  
Child Development Inventory ◽  
Mean Length Of Utterance

The extent to which the Minnesota Child Development Inventory (MCDI), could be used to estimate levels of language development in 2-year-old children was examined. Fifty-seven children between 23 and 28 months were given the Sequenced Inventory of Communication Development (SICD), and at the same time a parent completed the MCDI. In addition the mean length of utterance (MLU) was obtained for each child from a spontaneous speech sample. The MCDI Expressive Language scale was found to be a strong predictor of both the SICD Expressive scale and MLU. The MCDI Comprehension-Conceptual scale, presumably a receptive language measure, was moderately correlated with the SICD Receptive scale; however, it was also strongly correlated with the expressive measures. These results demonstrated that the Expressive Language scale of the MCDI was a valid predictor of expressive language for 2-year-old children. The MCDI Comprehension-Conceptual scale appeared to assess both receptive and expressive language, thus complicating its interpretation.

Time Block After Time Block

ASHA Leader ◽  
2013 ◽  
Vol 18 (8) ◽  
pp. 40-45 ◽  
Author(s):  
Judy Rudebusch ◽  
JoAnn Wiechmann
Keyword(s):  
Full Range ◽  
Time Block ◽  
School Based ◽  
Schedule Activity

To offer a full range of RTI and IEP services, school-based SLPs can schedule activity blocks rather than go student by student—here's how.

The Use of Neuroplastic Principles Affects the Swallow Motor Plan of a Patient in Severe Cognitive Decline: A Case Study

2016 ◽  
Vol 1 (15) ◽  
pp. 79-83
Author(s):  
Ed Bice ◽  
Kristine E. Galek
Keyword(s):  
Central Nervous System ◽  
Cognitive Decline ◽  
Full Range ◽  
Movement Speed ◽  
Positive Outcomes ◽  
Verbal Cues ◽  
Motor Plan ◽  
Bolus Size ◽  
The Central Nervous System

Dysphagia is common in patients with dementia. Dysphagia occurs as a result of changes in the sensory and motor function of the swallow (Easterling, 2007). It is known that the central nervous system can undergo experience-dependent plasticity, even in those individuals with dementia (Park & Bischof, 2013). The purpose of this study was to explore whether or not the use of neuroplastic principles would improve the swallow motor plan and produce positive outcomes of a patient in severe cognitive decline. The disordered swallow motor plan was manipulated by focusing on a neuroplastic principles of frequency (repetition), velocity of movement (speed of presentation), reversibility (Use it or Lose it), specificity and adaptation, intensity (bolus size), and salience (Crary & Carnaby-Mann, 2008). After five therapeutic sessions, the patient progressed from holding solids in her mouth with decreased swallow initiation to independently consuming a regular diet with full range of liquids with no oral retention and no verbal cues.

Symptom Validity Testing

2018 ◽  
Vol 23 (6) ◽  
pp. 14-15
Author(s):  
Lee H. Ensalada
Keyword(s):  
Memory Deficits ◽  
Symptom Validity ◽  
Sensory Cues ◽  
Validity Testing ◽  
Symptom Validity Testing ◽  
Tunnel Vision ◽  
Blurry Vision ◽  
The Common ◽  
Fatigue Evaluation ◽  
Choice Testing

Abstract Symptom validity testing (SVT), also known as forced-choice testing, is a means of assessing the validity of sensory and memory deficits, including tactile anesthesias, paresthesias, blindness, color blindness, tunnel vision, blurry vision, and deafness. The common feature among these symptoms is a claimed inability to perceive or remember a sensory signal. SVT comprises two elements: a specific ability is assessed by presenting a large number of items in a multiple-choice format, and then the examinee's performance is compared to the statistical likelihood of success based on chance alone. These tests usually present two alternatives; thus the probability of simply guessing the correct response (equivalent to having no ability at all) is 50%. Thus, scores significantly below chance performance indicate that the sensory cues must have been perceived, but the examinee chose not to report the correct answer—alternative explanations are not apparent. SVT also has the capacity to demonstrate that the examinee performed below the probabilities of chance. Scoring below a norm can be explained by fatigue, evaluation anxiety, inattention, or limited intelligence. Scoring below the probabilities of chance alone most likely indicates deliberate deceptions and is evidence of malingering because it provides strong evidence that the examinee received the sensory cues and denied the perception. Even so, malingering must be evaluated from the total clinical context.

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