Pupil-teacher gender interaction effects on scholastic outcomes in England and the USA

The difference between girls and boys academic performance is a major issue on both sides of the Atlantic. Do boys and girls fair better with a teacher of their own gender? This paper investigates the presence of such ?pupil-teacher gender interactions? on scholastic performance. We use data from PIRLS and TIMSS on Reading, Science and Maths at grade 4 and grade 8 for England and the USA for data from 1995, 1999, 2001 and 2003. We find evidence of gender interaction effects in the form of both positive male interaction effects in Maths scores in the US and Science scores in England at grade 8. Further, using individual fixed effects, Gain score analysis of the difference between Maths and Science scores confirms the presence of Maths gender interaction effects in England (but not the USA) at grade 8 by 2003 when these effects were not present in 1995 or 1999. --

Asymmetrical dynamics of voltage spread in retinal horizontal cell networks

This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.Lateral voltage spread in electrically coupled retinal horizontal cell networks is the substrate of center-surround antagonism in bipolar and ganglion cells. We studied its spatial and temporal properties in more detail in turtle L1 horizontal cells by using a contrast border as light stimulus. Experimental data were contrasted with expectations from a linear continuum model to specify the impact of nonlinearities. The assumptions for the diffusion term of the continuum model were justified by neurobiotin labeling. Measured voltage spread revealed two different length constants Λ+ and Λ0, under illuminated and nonilluminated regions of the retina, respectively, as predicted by the linear model. Length constants in the illuminated region showed strong temporal dynamics. For the initial phase of the horizontal cell responses Λ+ was larger than Λo. This was also in accordance with the model. Right at the peak of the response, however, Λ+ dropped below Λo and did not change any more. It is this temporal reversal of asymmetry in voltage spread and not the decrease of Λ+ itself that is lacked by the linear model. The observed independence of the mean ratio Λ+/Λo from light intensity in both the peak and the plateau phases of horizontal cell responses contradicts the linear assumption, too. These two effects have to be addressed to local nonlinearities in the horizontal cell network like a negative feedback loop from photoreceptors and/or voltage-dependent conductances. Due to the failure of the linear model, firm conclusions about the membrane resistance and the coupling resistance of the horizontal cell network cannot be drawn from length constant measurements.Peer Reviewe

The development of study-specific self-efficacy during grammar school.(Zur Entwicklung der studienspezifischen Selbstwirksamkeit in der Oberstufe)

Article is in German. Even if more and more German adolescents acquire a university entrance qualification, not all of them finally enrol at a university. In particular, the transition from school to university strongly depends on parent’s education. Even with the same marks in school, adolescents from non-academic households are less likely to enrol in universities than adolescents from academic housholds. One important reason is their lower belief to master a university study. This study analyses a specific intervention in grammar school to improve study-specific self- efficacy, the belief in one’s capabilities to master a university study, using a longitudinal design. We apply a difference-in-difference framework and show that programme participation significantly improves the study-specific self-efficacy for puplis from non- academic families but not for those from academic families. Hence, such a programme could reduce social disparities between both groups

Bat Eyes Have Ultraviolet-Sensitive Cone Photoreceptors

Mammalian retinae have rod photoreceptors for night vision and cone photoreceptors for daylight and colour vision. For colour discrimination, most mammals possess two cone populations with two visual pigments (opsins) that have absorption maxima at short wavelengths (blue or ultraviolet light) and long wavelengths (green or red light). Microchiropteran bats, which use echolocation to navigate and forage in complete darkness, have long been considered to have pure rod retinae. Here we use opsin immunohistochemistry to show that two phyllostomid microbats, Glossophaga soricina and Carollia perspicillata, possess a significant population of cones and express two cone opsins, a shortwave-sensitive (S) opsin and a longwave-sensitive (L) opsin. A substantial population of cones expresses S opsin exclusively, whereas the other cones mostly coexpress L and S opsin. S opsin gene analysis suggests ultraviolet (UV, wavelengths <400 nm) sensitivity, and corneal electroretinogram recordings reveal an elevated sensitivity to UV light which is mediated by an S cone visual pigment. Therefore bats have retained the ancestral UV tuning of the S cone pigment. We conclude that bats have the prerequisite for daylight vision, dichromatic colour vision, and UV vision. For bats, the UV-sensitive cones may be advantageous for visual orientation at twilight, predator avoidance, and detection of UV-reflecting flowers for those that feed on nectar

Substance P: A neurotransmitter of amacrine and ganglion cells in the vertebrate retina

A short history and summary of the occurrence of substance P in the vertebrate body is presented. Substance P is now generally accepted to be a neurotransmitter and can be visualized by immunocytochemistry to occur in various nerve cells in the CNS. In the retina, substance P-immunoreactivity (SP-IR) occurs in amacrine cell populations in al1 the species so far studied. In some vertebrates retinas SP is also apparent in one or more ganglion cell types. Anatomical investigations have revealed the morphology and connectivity of SP-IR amacrine cells: they branch in severa1 strata of the inner plexiform layer receiving input from bipolar and amacrine cells and making synapses upon bipolar and ganglion cells. Most commonly SP-IR amacrines emit axon-like process that pass to both the outer plexiform layer and the ganglion cell and nerve fiber layers. These processes often end upon the retina1 vasculature. SP-IR ganglion cells have been described in turtle, rabbit and human retinas. In turtle, intracellular dye injection has revealed the morphology of one type of SPIR ganglion cell as being a large-field monostratified cell with a branches in the outer stratum of the inner plexiform layer. It may correspond to a «Dogiel cell» type. Intracellular investigation of SP-IR amacrine cells in turtle reveal their physiological responses to be ONOFF in nature with some color-coding characteristics. In general SP acts as an excitatory neurotransmitter raising the spontaneous activity leve1 of ganglion cell responses. The SP-IR ganglion cell is an OFF-center unit in the turtle retina and may be driven in the center of its receptive field by luminosity bipolar cells and in its surround by amacrine cells with color-opponent properties