Longitudinal Pupil Research Articles

Exploratory spatial analysis: Understanding the geography of risks for trafficking and preventive efforts through the implementation of kNOw MORE!—: an educational program in middle and high schools in San Diego, California

Human trafficking (HT) violates human rights and brings long-lasting consequences for victims. This study aimed to geographically and statistically analyze (1) the implementation of a youth educational prevention program, kNOw MORE! (kM!) located in San Diego County (SD); (2) clusters of student participants who desired to talk further about trafficking after participating in kM!; (3) clusters of SD regions that included protective factors based on mental and social services for survivors of HT and similar populations; and (4) the low and high risk clusters for trafficking within SD. kM! is a preventive program that seeks to increase knowledge and self-efficacy to prevent trafficking. kM! is designed to increase knowledge and self-efficacy among middle and high school students to prevent HT. Databases used included the U.S. Census, the California Longitudinal Pupil Achievement Data System, kM!’s (2016–2020), among others. Results indicate that kM! was implemented throughout the six regions of SD. These presentations reached a total of N = 11,586 participants. Analysis of ZIP codes highlighted the South and East regions as representing the highest cluster for kM!’s presentations. Central, North Inland, and South Regions of SD are among the ones with highest percentiles of HT vulnerability scores. Regarding protective factors, the Central Region of San Diego contains the highest clustering of mental health and social services. These findings can assist diverse stakeholders and leaders to geographically strategize their anti-trafficking efforts. However, complete and uniform open databases at multiple levels are required to best inform the associations between geographical spaces and HT vulnerability.

Ectoplasm, ghost in the R cell machine?

Drosophila photoreceptors (R cells) are an extreme instance of sensory membrane amplification via apical microvilli, a widely deployed and deeply conserved operation of polarized epithelial cells. Developmental rotation of R cell apices aligns rhabdomere microvilli across the optical axis and enables enormous membrane expansion in a new, proximal distal dimension. R cell ectoplasm, the specialized cortical cytoplasm abutting the rhabdomere is likewise enormously amplified. Ectoplasm is dominated by the actin-rich terminal web, a conserved operational domain of the ancient vesicle-transport motor, Myosin V. R cells harness Myosin V to move two distinct cargoes, the biosynthetic traffic that builds the rhabdomere during development, and the migration of pigment granules that mediates the adaptive "longitudinal pupil" in adults, using two distinct Rab proteins. Ectoplasm further shapes a distinct cortical endosome compartment, the subrhabdomeral cisterna (SRC), vital to normal cell function. Reticulon, a protein that promotes endomembrane curvature, marks the SRC. R cell visual arrestin 2 (Arr2) is predominantly cytoplasmic in dark-adapted photoreceptors but on illumination it translocates to the rhabdomere, where it quenches ongoing photosignaling by binding to activated metarhodopsin. Arr2 translocation is "powered" by diffusion; a motor is not required to move Arr2 and ectoplasm does not obstruct its rapid diffusion to the rhabdomere.

Calcium-Activated Myosin V Closes the Drosophila Pupil

Approximately 40 years ago, an elegant automatic-gain control was revealed in compound eye photoreceptors: In bright light, an assembly of small pigment granules migrates to the cytoplasmic face of the photosensitive membrane organelle, the rhabdomere, where they attenuate waveguide propagation along the rhabdomere. This migration results in a "longitudinal pupil" that reduces rhodopsin exposure by a factor of 0.8 log units. Light-induced elevation of cytosolic free Ca(2+) triggers the migration of pigment granules, and pigment granules fail to migrate in a mutant deficient in photoactivated TRP calcium channels. However, the mechanism that moves photoreceptor pigment granules remains elusive. Are the granules actively pulled toward the rhabdomere upon light, or are they instead actively pulled into the cytoplasm in the absence of light? Here we show that Ca(2+)-activated Myosin V (MyoV) pulls pigment granules to the rhabdomere. Thus, one of MyoV's several functions is also as a sensory-adaptation motor. In vitro, Ca(2+) both activates and inhibits MyoV motility; in vivo, its role is undetermined. This first demonstration of an in vivo role for Ca(2+) in MyoV activity shows that in Drosophila photoreceptors, Ca(2+) stimulates MyoV motility.

Extending the field of view of an adaptively corrected telescope by longitudinal pupil displacement

A simple scheme is proposed to increase the corrected field of view of a telescope equipped with adaptive optics. The optical system's entrance pupil is projected forward into the atmosphere and is slightly reduced in size. The field in any given direction is then imaged through just a portion of the main aperture, while the full aperture is used to collect light from the reference beacons, which may be either natural stars or laser beacons. The enlargement of the field of view is proportional to the reduction in pupil size and therefore comes at some cost in flux and resolution. A numerical simulation shows that the trade-off is modest and may in many cases be advantageous.

Promoting prosocial pupil behaviour: 1‐A multilevel theoretical model

Background. Usually much attention is given to different forms of antisocial pupil behaviour. One of the possibilities to prevent or reduce this behaviour is to stimulate educational conditions that foster prosocial pupil behaviour. Aim. To specify a theoretical multilevel model to promote prosocial pupil behaviour. The model should allow empirical checks on the occurrence of pupil level effects because of educational changes at the classroom and school level. Methods. Information from the literature and previous research is used to construct a three‐level model in which longitudinal pupil effects are caused by classroom and school characteristics, while controlling for covariables. The causal class and school variables mainly refer to pupils’ participation and responsibility in specifying and controlling behavioural and didactic rules, and are assumed to be related to didactic differentiation during lessons. Results. The multilevel theorising results in a model of social‐pedagogical and didactic class and school variables, of home and peer support variables, and of their potential effects on the development of a pupil's prosocial behaviour. The three‐level model will be empirically checked in a second article (this issue).

Design Considerations For Multiple Telescope Imaging Arrays

The basic principles for designing and implementing multiple telescope imaging arrays are presented. A generalized treatment is formulated that permits determination of the amount of residual errors that can be tolerated in lateral and longitudinal pupil geometry matching, magnification matching, azimuthal asymmetry, and telescope boresighting. A specific design goal is a modular system of independent telescopes configured to have the equivalent performance of a monolithic aperture of the same diameter as the array. This telescope array, known as the Multipurpose Multiple Telescope Testbed (MMTT), is designed to provide high resolution imagery over a wide field of view. The requirement for wide field of view performance imposes rigid tolerances that must be satisfied at every stage of development. The work described here derives the subsystem tolerances that must be met. Special means by which some of the more rigid requirements can be satisfied are also briefly described.

Pigment migration in the compound eye of Manduca sexta: Effects of light, nitrogen and carbon dioxide

Migration of screening pigment granules was studied in the secondary pigment cells of the compound eye of the tobacco hornworm moth Manduca sexta. The granules aggregate at the distal ends of these elongate cells during dark-adaptation, and disperse proximally during light-adaptation, to provide a longitudinal pupil regulating the entrance of light into the eye. Pigment position was measured directly during the couse of migration in sectioned quick-frozen eyes, and the pupillary response was measured in the intact eyes of living moths by reflectance microscopy. The influences of nitrogen and carbon dioxide anaesthesia on pigment migration were investigated in the light of earlier studies on other speicies showing that hypoxia results in dispersal. In accordance with these previous studies, rapid dispersal results from nitrogen hypoxia in Manduca, the pigment spreading farther than it does in light-adaptation. By contrast, the pigment disperses only slightly in response to carbon dioxide hypoxia. Carbon dioxide also inhibits the rapid, extensive dispersal caused by light and nitrogen. Thus the pseudopupil of the eye remains dilated in carbon dioxide anaesthetized moths even under bright illumination. Light-induced dispersal is restored with the addition of oxygen to the carbon dioxide atmosphere. These results suggest, contrary to the conclusions of earlier studies, that pigment dispersal in light-adaptation requires metabolic energy. The inhibition of pigment migration by carbon dioxide is unlikely to be the result of hypoxia; we suggest that low cellular pH affects the mechanism of pigment-granule motility.

Calcium Enables Photoreceptor Pigment Migration in A Mutant Fly

ABSTRACT Upon bright illumination, pigment granules in the photoreceptors of the fly compound eye migrate transversely toward the rhabdomeres (Kirschfeld & Franceschini, 1969). The granules absorb light passing down the rhabdomeric light guide, thereby reducing the light available to the visual pigment. This light-regulating mechanism is found in a number of invertebrate eyes (Stavenga, 1979) and has been termed the ‘longitudinal pupil’ (Franceschini, 1972).

Spectral effects of the pupil in fly photoreceptors

Photoreceptors of flies contain pigment granules which upon illumination of the receptors migrate towards the rhabdomere and act as a ‘longitudinal pupil’. Data in the literature concerning the effect of the pupil on the spectral sensitivity are contradictory. Therefore spectral sensitivity ofMusca photoreceptors upon light adaptation was reinvestigated. The change in spectral sensitivity of fly photoreceptors upon light adaptation as measured by Hardie (1979) was confirmed. Taking into account waveguide optics this change was explained from absorbance spectra of pupillary granules, measured by microspectrophotometry in squash preparations. Furthermore the pupil absorbance spectrum determined in vivo (Stavenga et al. 1973) was interpreted. The absence of a change in spectral sensitivity upon light adaptation measured by pupillary reflexion (Bernard and Stavenga 1979) is explained by a local-triggering of the pupil.

Evidence for a longitudinal pupil in the blowfly eye from studies with light and electron microscopes

Elektronenoptische Untersuchungen mit der Gefrieratzmethode an Augen der Normalform von Calliphora erythrocephala (Meig.) ergeben, das im dunkeladaptierten Zustand die Rhabdomere 1–6 in den Retinulazellen dicht von Vesikeln umgeben sind, die wahrscheinlich durch Pinocytose an den Mikrovilli der Rhabdomere entstehen. Diese Blaschen fehlen im helladaptierten Zustand nahezu vollig. Die optische Dichte des umgebenden Mediums der lichtleitenden Rhabdomere wird dadurch im Dunkel-Auge herabgesetzt, was mit Hilfe der Becke-Methode im Lichtmikroskop festgestellt werden konnte. Physikalische Berechnungen mit den Gleichungen der geometrischen Optik ergeben, das durch diese Brechzahlanderung in den Sinneszellen im dunkeladaptierten Auge der physiologisch wirksame Lichtflus in den Rhabdomeren l–6 im grunen Spektralbereich um etwa 30% erhoht werden kann.