Fly eyes are not still: a motion illusion in Drosophila flight supports parallel visual processing.

Most animals shift gaze by a 'fixate and saccade' strategy, where the fixation phase stabilizes background motion. A logical prerequisite for robust detection and tracking of moving foreground objects, therefore, is to suppress the perception of background motion. In a virtual reality magnetic tether system enabling free yaw movement, Drosophila implemented a fixate and saccade strategy in the presence of a static panorama. When the spatial wavelength of a vertical grating was below the Nyquist wavelength of the compound eyes, flies drifted continuously and gaze could not be maintained at a single location. Because the drift occurs from a motionless stimulus - thus any perceived motion stimuli are generated by the fly itself - it is illusory, driven by perceptual aliasing. Notably, the drift speed was significantly faster than under a uniform panorama, suggesting perceptual enhancement as a result of aliasing. Under the same visual conditions in a rigid-tether paradigm, wing steering responses to the unresolvable static panorama were not distinguishable from those to a resolvable static pattern, suggesting visual aliasing is induced by ego motion. We hypothesized that obstructing the control of gaze fixation also disrupts detection and tracking of objects. Using the illusory motion stimulus, we show that magnetically tethered Drosophila track objects robustly in flight even when gaze is not fixated as flies continuously drift. Taken together, our study provides further support for parallel visual motion processing and reveals the critical influence of body motion on visuomotor processing. Motion illusions can reveal important shared principles of information processing across taxa

GDI reference manual

Journal ArticleGDI is a dialog interface tool library for C + + applications. It facilitates the design and implementation of graphical, object-oriented user interfaces for workstations equipped with a graphical display, a mouse and a keyboard. GDI's design allows for its portability onto a multitude of platforms. This is achieved by separating the user interface from the application program, as well as the orderly detachment of system independent user- interface tools from the system dependent, low level, window operations

High frequency of the D allele of the angiotensin-converting enzyme gene in Arabic populations

<p>Abstract</p> <p>Background</p> <p>The angiotensin-converting enzyme (ACE) gene in humans has an insertion-deletion (I/D) polymorphic state in intron 16 on chromosome 17q23. This polymorphism has been widely investigated in different populations due to its association with the renin-angiotensin system. However, similar studies for Arab populations are limited. This study addresses the distribution of the ACE gene polymorphism in three Arab populations (Egyptians, Jordanians and Syrians).</p> <p>Findings</p> <p>The polymorphisms of ACE gene were investigated using polymerase chain reaction for detection of an I/D mutation. The results showed a high frequency of the ACE <it>D </it>allele among the three Arab populations, Egyptians (0.67), Jordanians (0.66) and Syrians (0.60), which is similar to those obtained from previous studies for Arab populations.</p> <p>Conclusion</p> <p>The relationship between ACE alleles and disease in these three Arab populations is still not known, but the present results clearly suggest that geographic origin should be carefully considered in the increasing number of studies on the association between ACE alleles and disease etiology. This study adds to the data showing the wide variation in the distribution of the ACE alleles in different populations and highlights that great care needs to be taken when interpreting clinical data on the association of the ACE alleles with different diseases.</p

Distribution of the HIV resistance CCR5-Δ32 allele among Egyptians and Syrians

A mutant allele of the β-chemokine receptor gene CCR5 bearing a 32-basepair (bp) deletion that prevents cell invasion by the primary transmitting strain of HIV-1 has recently been characterized. Individuals homozygous for the mutation are resistant to infection, even after repeated high-risk exposure, but this resistance appears not absolute, as isolated cases of HIV-positive deletion homozygotes are emerging. The consequence of the heterozygous state is not clear, but it may delay the progression to AIDS in infected individuals. In order to evaluate the frequency distribution of CCR5-Δ32 polymorphism among Egyptians, a total of 200 individuals (154 from Ismailia and 46 from Sinai) were tested. Only two heterozygous individuals from Ismailia carried the CCR5-Δ32 allele (0.6%), and no homozygous (Δ32/Δ32) individuals were detected among the tested samples. The presence of the CCR5-Δ32 allele among Egyptians may be attributed to the admixture with people of European descent. Thus we conclude that the protective deletion CCR5-Δ32 is largely absent in the Egyptian population. © 2006 Elsevier B.V. All rights reserved

Cycling Versus Treadmill Potentiation Effects Following High-Intensity Interval Training

High-intensity interval training (HIIT) has emerged as a popular form of exercise, with intermittent bouts of higher and lower intensity cycles. Not well understood to date is the influence of HIIT exercise modality (e.g., cycling vs treadmill running) on measures of jump performance. A generally accepted metric for assessing performance and overall athleticism involves performing a countermovement jump (CMJ). Furthermore, heavy exercise has been shown to improve muscle performance using post-activation potentiation. Purpose: This study compared the effects of HIIT bouts of cycling vs treadmill running on CMJ concentric impulse, peak takeoff force, and jump height. Methods: Eleven young, active adults (5 females, 6 males, 27.20 ± 3.42 years) completed 30-minute 4x4 HIIT protocols on a treadmill and stationary bike with a 7-day interval between measures. Participants also performed CMJs before and after the exercise bouts using VALD force plates. Impulse was calculated during the first 100ms of the concentric portion of takeoff and peak takeoff force was normalized to body weight. Values are presented as percent change. Results: Average concentric impulse increased by 3.2% following the cycling protocol and 4.7% following the treadmill protocol. Peak net takeoff force increased by 5.98 & following the cycling protocol and 8.57% following the treadmill protocol. These changes led to no difference in jump height following the cycling protocol (0.80%); however, jump height increased by an average of 4.05% following the running protocol. Discussion: This study illustrates that both cycling and running HIIT protocols can increase certain CMJ variables such as impulse and takeoff force. However, the treadmill HIIT protocol demonstrated a larger magnitude of change compared to cycling. The larger increase in these variables following running may have accounted for the increase in jump height seen after running and not after cycling. Treadmill running HIIT may simulate the post-activation potentiation phenomenon seen after strength training due to its higher-impact loading compared to cycling. These results could be of interest to athletic populations, as the results may help athletes decrease their risk of injury and increase performance

Allele frequencies of the human platelet antigen-1 in the Egyptian population

<p>Abstract</p> <p>Background</p> <p>The human platelet alloantigen system HPA-1 in the Egyptian population was examined by polymerase chain reaction using sequence-specific primers (PCR-SSP). The objectives of this study were to evaluate the allele frequency of HPA-1a and -1b in healthy Egyptian individuals and compare these with the international literature. Human platelet antigen (HPA) systems are associated with alloimmunization and organ transplantation rejection as well as the development of cardiovascular disease. Of the various HPA systems, HPA-1 specifically has been considered to be the most important antigenic system implicated in the Caucasian population. No study has yet examined this system in the Egyptian populations, however. We therefore investigated the allele frequency of the HPA-1 system in the Egyptian population.</p> <p>Findings</p> <p>To determine the allele frequency of the HPA-1a and -1b, we tested genomic DNAs from 206 healthy, unrelated Egyptian individuals using PCR-SSP. Our results showed that the 1a/1a genotype was the most predominant (59.22%) followed by 1a/1b (34.95%) and 1b/1b (5.83%) with allele frequencies for 1a and 1b of 0.77 and 0.23, respectively, in the population.</p> <p>Conclusion</p> <p>As compared with other geographic groups, a relatively high allele frequency of the HPA-1b in the Egyptian population may indicate a higher risk of alloimmunization. This study is the first to investigate the allele frequency of the HPA-1 system in the Egyptian population and serves as an outline for future clinical research associated with platelet disorders in this group.</p

Paul and Isaiah's servants : Paul's theological reading of Isaiah 40-66 in 2 Corinthians 5:14 - 6:10

Paul's reading of the Old Testament continues to witness to the significance of reading the Old Testament Christianly. This dissertation argues that a theological approach to understanding Paul's appeal to and reading of the Old Testament, especially Isaiah, offers important insights into the ways in which Christians should read the Old Testament and a two-testament canon today. By way of example, this dissertation explores the ways in which Isaiah 40-66's canonical from presents the gospel in miniature with its movement from Israel to Servant to servants. It is subsequently argued that Paul follows this literary movement in his own theological reflection in 2 Corinthians 5:14-6:10. Jesus takes on the unique role and identity of the Servant of Isaiah 40-55, and Paul takes on the role of the servants of the Servant in Isaiah 53-66. From this exegetical exploration conclusions are drawn in the final chapter that seek to apply a term from the history of interpretation to Paul's reading, that is, the plain sense of Scripture. What does an appeal to plain sense broker? And does Paul's reading of the Old Testament look anything like a plain sense reading? The conclusion is, yes, Paul is reading the Old Testament in such a way that the literal sense and its figural potential and capacity are not divorced but are actually organically linked in what can be termed a plain sense reading

SINEs of a nearly perfect character

Mobile elements have been recognized as powerful tools for phylogenetic and population-level analyses. However, issues regarding potential sources of homoplasy and other misleading events have been raised. We have collected available data for all phylogenetic and population level studies of primates utilizing Alu insertion data and examined them for potentially homoplasious and other misleading events. Very low levels of each potential confounding factor in a phylogenetic or population analysis (i.e., lineage sorting, parallel insertions, and precise excision) were found. Although taxa known to be subject to high levels of these types of events may indeed be subject to problems when using SINE analysis, we propose that most taxa will respond as the order Primates has-by the resolution of several long-standing problems observed using sequence-based methods. © 2006 Society of Systematic Biologists