The biology of vision of Drosophila.

Phototransduction systems in vertebrates and invertebrates share a great deal of similarity in overall strategy but differ significantly in the underlying molecular machinery. Both are rhodopsin-based G protein-coupled signaling cascades displaying exquisite sensitivity and broad dynamic range. However, light activation of vertebrate photoreceptors leads to activation of a cGMP-phosphodiesterase effector and the generation of a hyperpolarizing response. In contrast, activation of invertebrate photoreceptors, like Drosophila, leads to stimulation of phospholipase C and the generation of a depolarizing receptor potential. The comparative study of these two systems of phototransduction offers the opportunity to understand how similar biological problems may be solved by different molecular mechanisms of signal transduction. The study of this process in Drosophila, a system ideally suited to genetic and molecular manipulation, allows us to dissect the function and regulation of such a complex signaling cascade in its normal cellular environment. In this manuscript I review some of our recent findings and the strategies used to dissect this process.

Seed dispersal characteristics to polar regions by means of visitors

Invasive alien species are among the primary causes of biodiversity change globally, with the risks thereof broadly understood for most regions of the world. They are similarly thought to be among the most significant conservation threats to Antarctica, especially as climate change proceeds in the region. However, no comprehensive, continent-wide evaluation of the risks to Antarctica posed by such species has been undertaken. Here we do so by sampling, identifying, and mapping the vascular plant propagules carried by all categories of visitors to Antarctica during the International Polar Year's first season (2007-2008) and assessing propagule establishment likelihood based on their identity and origins and on spatial variation in Antarctica's climate. For an evaluation of the situation in 2100, we use modeled climates based on the Intergovernmental Panel on Climate Change's Special Report on Emissions Scenarios Scenario A1B [Nakicenovic N, Swart R, eds (2000) Special Report on Emissions Scenarios: A Special Report of Working Group III of the Intergovernmental Panel on Climate Change (Cambridge University Press, Cambridge, UK)]. Visitors carrying seeds average 9.5 seeds per person, although as vectors, scientists carry greater propagule loads than tourists. Annual tourist numbers (~33,054) are higher than those of scientists (~7,085), thus tempering these differences in propagule load. Alien species establishment is currently most likely for the Western Antarctic Peninsula. Recent founder populations of several alien species in this area corroborate these findings. With climate change, risks will grow in the Antarctic Peninsula, Ross Sea, and East Antarctic coastal regions. Our evidence-based assessment demonstrates which parts of Antarctica are at growing risk from alien species that may become invasive and provides the means to mitigate this threat now and into the future as the continent's climate changes.

Letters from the front. Being a record of the part played by officers of the Bank in the great war, 1914-1919.

v.1: Introd. 1920; v.2: Introd. 1921.

Extracts from minutes of proceedings and papers laid before the conference. Printed by order of Parliament.

Issued in London as Parliamentary paper (Cd. 8566)

The vision of William concerning Piers Plowman, together with Vita de Dowel, Dobet, et Dobest, secundum Wit et Resoun,

Pt. 1-3 have added t.-p.

The explorations of Captain James Cook in the Pacific, as told by selections of his own journals, 1768-1779.

Mode of access: Internet.

Historical and critical remarks upon the modern hexametrists and upon Mr. Southey's Vision of judgment.

Mode of access: Internet.

The vision of judgment; or, A present for the Whigs of '76 & '37 [microform]. In ten parts.

Master microform held by: LCP.

The Army Nurse Corps : a commemoration of World War II service.

Mode of access: Internet.

The Women's Army Corps : a commemoration of World War II service.

Mode of access: Internet.

The vision of William concerning Piers Plowman, together with Vita de Dowel, Dobet, et Dobest, secundum Wit et Resoun,

Parts 1-3 have added t.-p.

A flight to the moon, or, The vision of Randalthus /

Shaw & Shoemaker

Discriminating depth in corrugated stereo surfaces: facilitation by a pedestal is explained by removal of uncertainty

With luminance gratings, psychophysical thresholds for detecting a small increase in the contrast of a weak ‘pedestal’ grating are 2–3 times lower than for detection of a grating when the pedestal is absent. This is the ‘dipper effect’ – a reliable improvement whose interpretation remains controversial. Analogies between luminance and depth (disparity) processing have attracted interest in the existence of a ‘disparity dipper’. Are thresholds for disparity modulation (corrugated surfaces), facilitated by the presence of a weak disparity-modulated pedestal? We used a 14-bit greyscale to render small disparities accurately, and measured 2AFC discrimination thresholds for disparity modulation (0.3 or 0.6 c/deg) of a random texture at various pedestal levels. In the first experiment, a clear dipper was found. Thresholds were about 2× lower with weak pedestals than without. But here the phase of modulation (0 or 180 deg) was varied from trial to trial. In a noisy signal-detection framework, this creates uncertainty that is reduced by the pedestal, which thus improves performance. When the uncertainty was eliminated by keeping phase constant within sessions, the dipper effect was weak or absent. Monte Carlo simulations showed that the influence of uncertainty could account well for the results of both experiments. A corollary is that the visual depth response to small disparities is probably linear, with no threshold-like nonlinearity.

Reasoning Methods for Designing and Surveying Relationships Described by Sets of Functional Constraints

This work is supported by the Hungarian Scientific Research Fund (OTKA), grant T042706.

A hazai kis- és középvállalkozások elektronikus banki ügyintézéssel kapcsolatos szokásai, attitűdjei és jövőképei (E-banking habits, attitudes and vision of the hungarian small and medium enterprises)

A közelmúltban készült kutatásban a szerzők azt vizsgálták, hogy a kis- és középvállalkozásokban az elektronikus banki ügyintézéssel kapcsolatban milyen szokásaik, attitűdjeik és jövőképeik alakultak ki. A több mint ötszáz KKV-vezetővel készült interjú alapján elmondható, hogy a vállalkozás elektronikus ügyintézéssel kapcsolatos hozzáállása egyáltalán nem, vagy csak nagyon gyenge mértékben hozható összefüggésbe a cég objektív tulajdonságaival, például a létszámmal, az árbevétellel vagy a tevékenységi körrel. Egyértelműen látszik, hogy már az elektronikus banki ügyintézéssel kapcsolatos fogalmak értelmezése is problémát jelent a KKV-vezetők egy részénél. A tudásbeli hiányosságok pedig egyértelműen befolyásolják az e-banking attitűdöt és a használati szokásokat, pedig az elektronikus csatornákat használók elégedettsége minden vizsgált bank ügyfeleinek esetében 80% fölötti értékeket mutat. Így a legfontosabb kérdés az, hogy miként lehetne megértetni a „Szkeptikusok”-kal és a „Mérlegelők”-kel, hogy érdemes a „Haladók” klaszterébe tartozni. Az ügyfélelégedettség sikertényezői egyértelműen a biztonság, az időben és térben széles körű elérhetőség és az egyszerű használat. A válaszadók jövőképe szerint a banki szolgáltatások igénybevétele egyre inkább eltolódik majd az elektronikus csatornák irányába. Jelen cikkben a kutatás legfontosabb tanulságait mutatják be a szerzők. _________ The authors’ research was conducted to explore the ebanking attitudes, habits and vision of small and medium enterprises. By the interviews of more than 500 managers of SMEs, it is concluded that e-banking attitudes are not, or not significantly related to the objective characteristics of the enterprises, e.g. to the number of employment, the revenues or its activities. It became clear, that the interpretation of the specific e-banking terms means an important problem for some managers. The deficiencies of knowledge have direct effects on e-banking attitude and the use of electronic banking methods of the enterprises, although the value of the satisfaction level is above 80% among the customers of each examined banks. Thus, the main objective is to explain to the “Scepticals” and the “Considerers” the benefits of the “Progressives” cluster. The most important success factors of customer satisfaction are safety, availability in time and space and ease of use. According to the vision of the respondents, banking services will probably be shifted towards e-channels. In this study, the most important findings of our researches were summarized.