Perfect Cover Research Articles

A 3D tailored monolithic glass chip for stimulating and recording zebrafish neuronal activity with a commercial light sheet microscope

Microfluidic technology is unrivaled in its ability to apply soluble chemical stimuli with high spatiotemporal precision. Analogous, light–sheet microscopy is unmatched in its ability of low phototoxic but fast volumetric in vivo imaging with single cell resolution. Due to their optical translucency during the larval stages, zebrafish (Danio rerio) are an ideal model to combine both techniques; yet, thus far this required light–sheet microscopes, which were in most cases custom–built and adapted to the available softlithographic chip technology. Our aim was to use a commercial light–sheet microscope to illuminate a microfluidic chip from two opposite lateral directions and to record images with the detection objective placed orthogonally above the chip. Deep tissue penetration can be achieved by superimposing beams from opposite directions to form a single light sheet. But a microfluidic chip that allows a) targeted stimulus application in a closed microenvironment, b) interference–free incoupling of excitation light from two directions and c) outcoupling of fluorescence in the perpendicular direction through an optically perfect cover glass was not known until now. Here, we present a monolithic glass chip with the required plane-parallel sidewalls and cover slide closure at the top, constructed by advanced femtosecond laser ablation, thermal bonding and surface smoothing processes. In addition, the 3D shape of a fish fixator unit was tailored to match the body shape of a zebrafish larva to ensure stable positioning during whole–brain recording. With hydrodynamic focusing a targeted partial exposure of the larva’s head to chemical stimuli and fast position switching (in less than 10 s) was possible. With the capabilities of this unique monolithic glass chip and its up–scalable wafer–level fabrication process, the new NeuroExaminer is prone to become an excellent addition to neurobiology laboratories already equipped with high–quality commercial light sheet microscopes.

Materials with switchable radiometric properties: Could they become the perfect greenhouse cover?

Greenhouses shelter the crop from unfavourable environmental conditions and the covering largely contributes to creating beneficial growing conditions inside. There is no perfect greenhouse cover for all combinations of crop and climatic regions. Usually a greenhouse cover has permanent optical properties determining the amount of solar radiation entering the greenhouse. Consequently during crop growth, the amount and quality (spectrum, direct/diffuse ratio) of the solar radiation is not ideal for the crop. Growers try to compensate for this by using different additional techniques such as temporary coatings, screens (mobile or fixed, etc.) and heating or cooling. New materials are currently being developed, whose optical properties can be (almost) instantaneously changed (materials with switchable properties). This will allow growers to gain real-time control on the quantity and quality of the light entering the greenhouse to match crop requirement. The present study uses advanced simulation models to predict the potential of covers with switchable properties to improve tomato yield and use of resources in different climatic regions (mild winter and tropical) and with different greenhouse types (artisan and industrial type). Results indicate that covers with switchable properties have advantages over permanent properties for most combinations of filter type/location. Only in very extreme tropical climates will covering materials with permanent filter properties have advantages. Furthermore, simulations models can play a major role in optimising the switchable filter design.

Bartali's Bicycle: The True Story of Gino Bartali, Italy's Secret Hero by Megan Hoyt

Reviewed by: Bartali's Bicycle: The True Story of Gino Bartali, Italy's Secret Hero by Megan Hoyt Elizabeth Bush Hoyt, Megan Bartali's Bicycle: The True Story of Gino Bartali, Italy's Secret Hero; illus. by Iacopo Bruno. Quill Tree, 2021 [40p] Trade ed. ISBN 9780062908117 $17.99 Reviewed from digital galleys R 5-8 yrs By the time Germany occupied Italy during World War II, cyclist Gino Bartali was already a familiar sight, winding through villages throughout years of intense training, easily recognizable as the celebrated winner of the 1938 Tour de France. Driven to do more than win races during a period of international crisis, Bartali joined a resistance movement and turned covert courier, packing counterfeit ID papers into his hollow handlebars and delivering them to Jews desperate to flee. His high profile proved a perfect cover, since previous training routines had established a long, visible route, and his celebrity could be used as distraction as other resistance members spirited away Jews from under the noses of guards busy managing Bartali's adoring crowds. Hoyt trims many of the political particulars away from her text (Hitler appears only in a back view as "a powerful leader," and even the war is unnamed), allowing younger listeners to focus on the heroism and older listeners to cull the end matter for specifics critical to understanding Bartali's larger story. There readers learn how deeply Bartali buried his own heroics and how later testimonies from Holocaust survivors brought him belated recognition by Yad Vashem as Righteous Among the Nations. Iacopo's crisp digitally colored pencil illustrations subtly incorporate muted reds and greens of the Italian flag, highlighting the patriotic service Bartali rendered to his country even as the scenes focus on speed and cunning. A timeline and resources are included; quote citations, unfortunately, are not. [End Page 216] Copyright © 2021 The Board of Trustees of the University of Illinois

Evaluating continuity of care incorporating a time protective effect of general practitioner care on diabetes related potentially preventable hospitalisations: An application of threshold effects model

Background Continuity of care with a general practitioner (GP) is vital for management of chronic conditions including diabetes as it provides proactive care facilitating opportunities to prevent or delay progression of disease.
 Aim To capture the proportion of time people with diabetes are under the protective effect of contact with a GP using the Cover Index and its effect on potentially preventable hospitalisation (PPH) and length of stay (LOS).
 Methods The linked self-report and administrative health service data of 267,153 participants in the 45 and Up study in New South Wales (NSW) in 2006-2009, obtained from the NSW Centre for Health Record Linkage and the Australian Government Department of Human Services, were used. A cohort of 21,965 people aged 45+ years identified with diabetes before July 2009 and followed up to 2015 were included in the analysis. Time duration protective effect of GP contact was estimated according to severity of diabetes using threshold effect models and then used to calculate the Cover Index. The effect of levels of GP cover on PPH and unplanned PPH and related LOS were estimated using negative binomial models weighted for the inverse probability of treatment to control for observed pre-treatment covariate imbalance.
 Results Perfect GP cover was observed among 56% of people in the study cohort. Compared with low GP cover, having perfect GP cover was significantly associated with lower PPH (IRR 0.21, 95%CI 0.13-0.35), LOS for PPH (IRR 0.12, 95%CI 0.06-0.24), unplanned PPH (IRR 0.36, 95%CI 0.19-0.68) and LOS for unplanned PPH (IRR 0.39, 95%CI 0.17-0.85) after controlling for the observed pre-treatment covariate imbalance.
 Conclusion This study suggests that longitudinal continuity of care measured by incorporating a time protective effect of a GP (cover) may be an important factor associated with reduction in PPHs and length of stay independent of other measures of longitudinal continuity.

‘In my file, I am two different people’: Max Gluckman and A.L. Epstein, the Australian National University, and Australian Security Intelligence Organisation, 1958–60

ABSTRACTSecurity services in the Cold War introduced an ethos of secrecy, where state persecution of academics without due process could be justified by the imputation of communism. Australian security services viewed the work of social anthropologists as providing a perfect cover for subversive activities among undeveloped peoples. This applied especially to anthropologists seeking to conduct research in the Australian colony of Papua New Guinea. Australian security services surveillance of suspected subversives was assisted by information from MI5 and security services in the African colonies.

Perfect Matching Covers of Cubic Graphs of Oddness 2

A perfect matching cover of a graph $G$ is a set of perfect matchings of $G$ such that each edge of $G$ is contained in at least one member of it. Berge conjectured that every bridgeless cubic graph has a perfect matching cover of order at most 5. The Berge Conjecture is largely open and it is even unknown whether a constant integer $c$ does exist such that every bridgeless cubic graph has a perfect matching cover of order at most $c$. In this paper, we show that a bridgeless cubic graph $G$ has a perfect matching cover of order at most 11 if $G$ has a 2-factor in which the number of odd circuits is 2.

Crystalline Ordering and Large Fugacity Expansion for Hard-Core Lattice Particles.

Using an extension of Pirogov-Sinai theory, we prove phase transitions, corresponding to sublattice orderings, for a general class of hard-core lattice particle systems with a finite number of perfect coverings. These include many cases for which such transitions have been proven. The proof also shows that for these systems the Gaunt-Fisher expansion of the pressure in powers of the inverse fugacity (aside from an explicit logarithmic term) has a nonzero radius of convergence.

Writing a perfect cover letter

Writing a perfect cover letter

A subspace covering problem in the [formula omitted]-cube

In this short note we consider the following problem stated in the paper Ahlswede et al. (2003). Let En={0,1}n⊂Rn and let Ern⊂En be the vectors of weight r. How many k-subspaces of Rn are needed to cover the elements of Ern? A k-subspace V is called optimal if V∩Ern has maximum size, taken over all k-subspaces V⊂Rn. We are interested in covering of Ern by a set V of optimal k-subspaces. In case V is a covering with V∩U∩Ern=0̸, for all distinct V,U∈V, we have a perfect covering. We here address the simplest case: r=2 with k≤4. It turns out that complete solution to the case k=3 follows from known results on packings and coverings of a complete graph with cycles of length four. For the case k=4 we show that perfect coverings of E2n always exist, provided the obvious divisibility condition for n holds. Similarly, we define the covering problem for En, that is the covering of the vectors of En by k-subspaces. We show that a perfect covering of En by k-subspaces does not exist, except for the case n=2k=4.

To go into hiding on camouflage meta-surfaces

Inspired by the natural phenomena that rough sea surfaces often mask the ship target when the wind comes big, or another case in point, vehicles can usually hide themselves in the mountains with dense vegetation. Here in this paper, we demonstrate a practical strategy of hiding by using gradient-index meta-surfaces based on the quasi-conformal transformation optics. Different from the prevalent choice of the invisible cloak to virtually extinguish an object that is wrapped inside, our approach aims to suppress the detectability of the target through creating diffuse reflections by proposing the camouflage meta-surface underneath. Our design, possessing a flat and slim profile with solely a few randomly distributed dielectrics on a metallic sheet, can readily offer the perfect cover to mask the hiding object adjacently above in a broad frequency range.

Darkly Dreaming (in) Authenticity: The Self/Persona Opposition in Dexter

In ‘Darkly Dreaming (in) Authenticity: The Self/Persona Opposition in Dexter,’ Glenn D'Cruz uses Dexter Morgan, the novelised serial killer and Showtime TV anti-hero to examine the connections between self and persona and the discourse of authenticity. D’Cruz foresees a series of challenges for persona studies and considers key concerns ahead, in terms of the critical vocabulary and scholarly agenda and addresses the need for critical genealogy of the term ‘persona’.

Women's Rights at Risk

On the face of it, Wu Mei (not her real name) represents the modern Chinese woman who has achieved spectacular success. Just thirtyone years old, she makes around one million RMB (roughly $150,000) a year as an attorney in Beijing, a salary that likely places her in the top 1 percent income bracket in China. Slender and beautiful, she could be the perfect cover model for a magazine feature on "China's richest women." Yet, as she speaks, a darker picture emerges. Wu recently managed to obtain a divorce from her abusive husband after five years of marriage, but only by giving up her home, her life savings, and most of her belongings.

Conference Report: Masculinities Between the National and the Transnational, 1980 to the Present: An International Conference (Kent State University, August 5-7, 2011)

Phyllida Lloyd's recent award-winning film, The Lady (2012), which depicts former British Prime Minister Margaret Thatcher and her rise to power, features a montage in which Thatcher is seen dancing with U.S. president Ronald Reagan. The short sequence is an eerie yet fitting emblem of the 1980s and a fascinating (gender) image on a number of levels, not just because both political leaders are impersonated by actors in this danse macabre, but because their individual political careers have been read as masculinity performances- on the one side, the B-movie Cowboy-turned-President, and on the other the Iron Lady, whose alleged lack of femininity was constantly levelled against her and became part of her public image. A conference on British and American Masculinities since 1980 inevitably has to deal with the long shadow cast by the Thatcher and Reagan years, and many of the papers presented during the three-day conference, Masculinities Between the National & the Transnational, 1980 to the Present, held at Kent State University, August 5-7, 2011, indeed addressed the diverse cultural and political ramifications of this era. It was the second of three conferences to emerge from the ongoing research project, Towards Comparative Masculinity Studies, a transatlantic cooperation initiated by Prof. Stefan Horlacher (Dresden University of Technology) and Prof. Kevin Floyd (Kent State University), sponsored by the Alexander von Humboldt Foundation and Kent State University. Having already welcomed scholars from three different continents in Dresden in 2010 in order to offer transnational perspectives on masculinity and the intersections between literary production and gendered identities in the post-war era up until the beginning of the Thatcher/Reagan years, this time, global developments in masculinities of the past thirty years were interrogated by scholars from the United States, the United Kingdom, Estonia, New Zealand, and Germany. In his opening address, conference co-organiser and host Kevin Floyd (Kent State) summarised the current state of research in the field of Masculinity Studies which has undergone both diversification and differentiation in recent years, moving from the groundbreaking work in the 1980s which focused on (monolithic) masculinity as a response to feminism towards post-1990s differentiation, which is dominated by a pluralised conceptualisation of masculinities. With a number of influential studies on male images, representations and embodiments of male identity having been published in recent years, Floyd stressed that there was an increased need not just to re-address traditional questions, but to interrogate masculinities from a transnational and international perspective in the political climate of the past thirty years. He argued that the emphasis of this conference would also have to include perspectives outside the strictly delineated field in order to examine how the neoliberalist movement which started with the rise of Thatcher and Reagan in the U.K. and in the U.S., respectively, has shaped male identity politics in contemporary narratives. Following a short welcoming address by Timothy S. Moerland, Dean of the College of Arts and Sciences at Kent State University, the first conference panel (entitled Handle with Care) invested much thought into the fragility of male identity constructions, but also addressed the perception of monstrous embodiments of masculinity in popular media. Seth Friedman (DePauw University) dealt with the disguises of male movie villains in Constructing the Perfect Cover, focusing on the way contemporary misdirection films- narratives with twist endings-force the viewers not only to reinterpret the events they have been presented, but also to question their beliefs about gender. Characteristically, the protagonist of misdirection films is male and finds out that he has been living a dream or a hallucination. The villains in both Bryan Singer's The Usual Suspects (1995) and Shyamalan's Unbreakable (2000), on the other hand, reveal a paradoxical constellation at the heart of these narratives. …

Super-moonshine for Conway's largest sporadic group

We study a self-dual N=1 super vertex operator algebra and prove that the full symmetry group is Conway's largest sporadic simple group. We verify a uniqueness result that is analogous to that conjectured to characterize the Moonshine vertex operator algebra (VOA). The action of the automorphism group is sufficiently transparent that one can derive explicit expressions for all the McKay-Thompson series. A corollary of the construction is that the perfect double cover of the Conway group may be characterized as a point-stabilizer in a spin module for the Spin group associated to a 24-dimensional Euclidean space

Partial and perfect path covers of cographs

A set P of disjoint paths in a graph G is called a (complete) path cover of G if every vertex of G belongs to one of the paths in P . A path cover of any subgraph of G is called a partial path cover of G. For fixed k>0, a k-blanket of graph G is a partial path cover P of G, consisting of exactly k paths, that maximizes the size of the subgraph covered by P . A k-core of graph G is a partial path cover P of G, consisting of exactly k paths, that minimizes the sum, over all vertices v of G, of the distance of v to its closest path in P . The problems of finding a k-blanket or a k-core (for fixed k) of an arbitrary graph G as well as the dual minimum-path-cover problem (find a path cover of minimum size) are all NP-hard. A linear-time algorithm is known (C.J. Chang and D. Kuo, SIAM J. Discrete Math. 9 (1996) 309–316) for the minimum-path-cover problem on cographs (graphs that can be constructed from a collection of isolated vertices by union and complement operations). However, prior to this paper, polynomial-time algorithms for the k -core problem were known only for trees — and even then for k = 1, 2 only (Becker and Perl, Discrete Appl. Math. 11 (1985) 103–113; Morgan and Slater, SIAM J. Appl. Math. 37 (1979) 539–560). In this paper, we introduce a variant of a minimum path cover, called a perfect path cover. We show that every cograph has a perfect path cover, and we exploit this to obtain an O( m + n log n)-time algorithm for finding, for any arbitrary k, a k-blanket or a k-core of a arbitrary cograph on n vertices and m edges.

In search of the perfect cover: Using the RFP process to select a commercial binder

In search of the perfect cover: Using the RFP process to select a commercial binder

In search of the perfect cover: Using the RFP process to select a commercial binder

In search of the perfect cover: Using the RFP process to select a commercial binder

The perfect cover: British intelligence, the Soviet Fleet and distant water trawler operations, 1963–1974

The perfect cover: British intelligence, the Soviet Fleet and distant water trawler operations, 1963–1974

A note on perfect multiple coverings of the Hamming space

Let Q be an alphabet of size q>or=2. The Hamming space Q/sup n/ that consists of all n-tuples of elements of Q is a metric space, provided with the Hamming distance function. A perfect multiple covering (PMC) is a code C in Q/sup n/ such that there exist fixed numbers r and mu with the property that every word in Q/sup n/ is within distance r from exactly mu codewords of C. The authors give a few constructions of PMCs and investigate in detail the problem of determining all possible parameters of PMCs with r=1. >

Updating of the geological and geothermal research on Milos island

The oldest geologic formations outcropping in Milos are an Alpine age crystalline basement and a transgressive marine Neogene sequence. The island is mainly volcanic. It belongs to the Aegean Active Arc, within which the Milos archipelago shows the most important volcanism in terms of quantity, variety of products and duration of activity (3.5−0.8 M.a.). The volcanic products belong to the calc-alkaline suite characteristic of island arcs, with composition varying between basaltic andesites (rare) to rhyolites. There are no large central volcanic edifices but different, frequently coeval eruption centres. The initial and intermediate phases of activity were mainly pyroclastic and submarine, whereas the last one (0.1 M.a.) was subaerial and formed “tuff rings”, surge deposits and lava flows, all of homogenous rhyolitic composition. Recent detailed studies have addressed the mechanism of feeding and the type of magmatic chambers beneath Milos. Distention tectonics have two main phases: an earlier one (Pliocene) with NE-SW direction and a much more intense recent (quaternary) one, trending NW-SE. The geological, tectonic and magmatic activity favoured the formation of a high enthalpy geothermal field. Many fossil and active thermal manifestations exist: hot springs, fumaroles, hot grounds, phreatic explosion craters. The hydrothermal alteration of the volcanites produced, by self sealing, a perfect cover for the geothermal fluids. Geothermometry of the surface fluids indicated high values for the source temperatures and very high geothermal gradients (5–10°C/1Om) were measured in central and eastern Milos. Geoelectric soundings defined the structure at depth and a shallower zone with very low resistivities, corresponding to levels with saline and mainly hot water. Such geothermally anomalous zones, defined by two different methods, together with superficial geological and tectonic information, permitted the location of sites for deep drilling. Five exploratory wells 1000–1400m deep gave satisfactory results of flow rate (40–120 t/h), temperature (300–320°C) and enthalpy. The geophysical survey was extended later to the whole island and also included gravimetric measurements.