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OBJECTIVES/SPECIFIC AIMS: In patients with recurrent glioblastoma (GBM) who undergo a second surgery following standard chemoradiotherapy, histopathologic examination of the resected tissue often reveals a combination of viable tumor and treatment-related inflammatory changes. However, it remains unclear whether the degree of viable tumor Versus “treatment effect” in these specimens impacts prognosis. We sought to determine whether the percentage of viable tumor Versus “treatment effect” in recurrent GBM surgical samples, as assessed by a trained neuropathologist and quantified on a continuous scale, is associated with overall survival. METHODS/STUDY POPULATION: We reviewed the records of 47 patients with histopathologically confirmed GBM who underwent surgical resection as the first therapeutic modality for suspected radiographic progression following standard radiation therapy and temozolomide. The percentage of viable tumor Versus “treatment effect” in each specimen was estimated by one neuropathologist who was blinded to patient outcomes. RESULTS/ANTICIPATED RESULTS: After adjusting for other known prognostic factors in a multivariate Cox proportional hazards model, there was no association between the degree of viable tumor and overall survival (HR 0.83; 95% CI, 0.20–3.4; p=0.20). DISCUSSION/SIGNIFICANCE OF IMPACT: These results suggest that, in patients who undergo resection for recurrent GBM following standard first-line chemoradiotherapy, histopathologic quantification of the degree of viable tumor Versus “treatment effect” present in the surgical specimen has limited prognostic influence and clinical utility.
Federal agencies are made responsible for managing the historic properties under their jurisdiction by the National Historic Preservation Act of 1966, as amended. A component of this responsibility is to mitigate the effect of a federal undertaking on historic properties through mitigation often through documentation. Providing public access to this documentation has always been a challenge. To address the issue of public access to mitigation information, personnel from Argonne National Laboratory created the Box Digital Display Platform, a system for communicating information about historic properties to the public. The platform, developed for the US Army Dugway Proving Ground, uses short introductory videos to present a topic but can also incorporate photos, drawings, GIS information, and documents. The system operates from a small, self-contained computer that can be attached to any digital monitor via an HDMI cable. The system relies on web-based software that allows the information to be republished as a touch-screen device application or as a website. The system does not connect to the Internet, and this increases security and eliminates the software maintenance fees associated with websites. The platform is designed to incorporate the products of past documentation to make this information more accessible to the public; specifically those documentations developed using the Historic American Building Survey/ Historic American Engineering Record (HABS/HAER) standards. Argonne National Laboratory’s Box Digital Display Platform can assist federal agencies in complying with the requirements of the National Historic Preservation Act.
To examine the delivery and assessment of psychiatry at undergraduate level in the six medical schools in the Republic of Ireland offering a medical degree programme.
A narrative description of the delivery and assessment of psychiatry at undergraduate level by collaborative senior faculty members from all six universities in Ireland.
Psychiatry is integrated to varying degrees across all medical schools. Clinical experience in general adult psychiatry and sub-specialities is provided by each medical school; however, the duration of clinical attachment varies, and the provision of some sub-specialities (i.e. forensic psychiatry) is dependent on locally available resources. Five medical schools provide ‘live’ large group teaching sessions (lectures), and all medical schools provide an array of small group teaching sessions. Continuous assessment encompasses 10–35% of the total assessment marks, depending on the medical school. Only one medical school does not provide a clinical examination in the form of an Objective Structured Clinical Examination with viva examinations occurring at three medical schools.
Many similarities exist in relation to the delivery of psychiatry at undergraduate level in Ireland. Significant variability exists in relation to assessment with differences in continuous assessment, written and clinical exams and the use of vivas noted. The use of e-learning platforms has increased significantly in recent years, with their role envisaged to include cross-disciplinary teaching sessions and analysis of examinations and individual components within examinations which will help refine future examinations and enable greater sharing of resources between medical schools.
We describe two cases of infant botulism due to Clostridium butyricum producing botulinum type E neurotoxin (BoNT/E) and a previously unreported environmental source. The infants presented at age 11 days with poor feeding and lethargy, hypotonia, dilated pupils and absent reflexes. Faecal samples were positive for C. butyricum BoNT/E. The infants recovered after treatment including botulism immune globulin intravenous (BIG-IV). C. butyricum BoNT/E was isolated from water from tanks housing pet ‘yellow-bellied’ terrapins (Trachemys scripta scripta): in case A the terrapins were in the infant's home; in case B a relative fed the terrapin prior to holding and feeding the infant when both visited another relative. C. butyricum isolates from the infants and the respective terrapin tank waters were indistinguishable by molecular typing. Review of a case of C. butyricum BoNT/E botulism in the UK found that there was a pet terrapin where the infant was living. It is concluded that the C. butyricum-producing BoNT type E in these cases of infant botulism most likely originated from pet terrapins. These findings reinforce public health advice that reptiles, including terrapins, are not suitable pets for children aged <5 years, and highlight the importance of hand washing after handling these pets.
Tena Quichua (ISO 639-3: quw) belongs to the Quechuan language family, as part of the peripheral variety Quechua IIB (Torero 1964, Cerrón-Palomino 1987, Gordon 2005). It is spoken in the Eastern Amazonian region of Ecuador on the Napo River above the mouth of the Rio Coca, primarily on three tributaries: the Misahualli, the Arajuno, and the Ansuc. Tena Quichua is bounded on the North and East by Napo Quichua and on the South by Pastaza Quichua. Previous research on the division of Ecuadorian dialects is summarized by Carpenter (1984: 3–4). Although it is beyond the scope of this Illustration, we hope that our description of Tena Quichua will prove useful in future work on the relations between these three Amazonian dialects of Ecuadorian Quichua. Below, a brief summary of Tena dialect identification and formation is given, followed by a description of present-day bilingualism in the region and data collection procedures.
In this paper, we propose novel algorithms for reconfiguring modular robots that are composed of n atoms. Each atom has the shape of a unit cube and can expand/contract each face by half a unit, as well as attach to or detach from faces of neighboring atoms. For universal reconfiguration, atoms must be arranged in 2 × 2 × 2 modules. We respect certain physical constraints: each atom reaches at most constant velocity and can displace at most a constant number of other atoms. We assume that one of the atoms has access to the coordinates of atoms in the target configuration.
Our algorithms involve a total of O(n2) atom operations, which are performed in O(n) parallel steps. This improves on previous reconfiguration algorithms, which either use O(n2) parallel steps or do not respect the constraints mentioned above. In fact, in the settings considered, our algorithms are optimal. A further advantage of our algorithms is that reconfiguration can take place within the union of the source and target configuration space, and only requires local communication.
We know from Section 2.2.2 that configuration spaces of general linkages that are permitted to self-intersect, even in ℝ2, can have exponentially many connected components. On the other hand, we know from Section 22.214.171.124 (p. 59) and Section 5.1.2 (p. 66) that configuration spaces of open and closed 3D chains that are permitted to self-intersect have just one connected component. We also know from Section 5.3 (p. 70) that configuration spaces of planar chains have just one connected component when permitted to move into ℝ3 but forbidden to self-cross. We have until now avoided the most natural questions, which concern chains embedded in ℝd, with motion confined to the same space ℝd, without self-crossings. These questions avoid the generality of linkages on the one hand, and the special assumptions of planar embeddings or projections on the other hand.
The main question addressed in this context is which types of linkages always have connected configuration spaces. A linkage with a connected configuration space is unlocked: no two configurations are prevented from reaching each other. If a linkage in 3D or higher dimensions has a disconnected configuration space, it is locked. But for connectivity of the configuration space to be possible in 2D, we need to place an additional constraint, because planar closed chains cannot be turned “inside-out” as they could in Section 5.1.2 when we permitted the chain to self-intersect.
We return to Open Problem 21.1 (p. 300): can every convex polyhedron be cut along its edges and unfolded flat into the plane to a single nonoverlapping simple polygon, a net for the polyhedron? This chapter explores the relatively meager evidence for and against a positive answer to this question, as well as several more developed, tangentially related topics.
Applications in Manufacturing
Although this problem is pursued primarily for its mathematical intrigue, it is not solely of academic interest: manufacturing parts from sheet metal (cf. Section 1.2.2, p. 13) leads directly to unfolding issues. A 3D part is approximated as a polyhedron, its surface is mapped to a collection of 2D flat patterns, each is cut from a sheet of metal and folded by a bending machine (Kim et al. 1998), and the resulting pieces assembled to form the final part. Clearly it is essential that the unfolding be nonoverlapping and great efficiency is gained if it is a single piece. The author of a Ph.D. thesis in this area laments that “Unfortunately, there is no theorem or efficient algorithm that can tell if a given 3D shape is unfoldable [without overlap] or not” (Wang 1997, p. 81). In general, those in manufacturing are most keenly interested in unfolding nonconvex polyhedra and, given the paucity of theoretical results to guide them, have relied on heuristic methods. One of the more impressive commercial products is TouchCAD by Lundströom Design, which has been used, for example, to design a one-piece vinyl cover for mobile phones (see Figure 22.1).
In this chapter we gather a few miscellaneous results and questions pertaining to “curved origami,” in either the folded shape or the creases themselves, and to its opposite, “rigid origami,” where the regions between the creases are forbidden from flexing. In general, little is known and we will merely list a few loosely related topics.
FOLDING PAPER BAGS
We have seen that essentially any origami can be folded if one allows continuous bending and folding of the paper, effectively permitting an infinite number of creases (Theorem 11.6.2). Recall this result was achieved by permitting a continuous “rolling” of the paper (Section 11.6.1, p. 189). In contrast one can explore what has been called rigid origami, which permits only a finite number of creases, between which the paper must stay rigid and flat, like a plate (Balkcom 2004; Balkcom and Mason 2004; Hull 2006, p. 222). One example of the difference between rigid and traditional origami is the inversion of a (finite) cone. Connelly (1993) shows how this can be done by continuous rolling of creases, but he has proved that such inversion is impossible with any finite set of creases.
One surprising result in this area is that the standard grocery shopping bag, which is designed to fold flat, cannot do so without bending the faces (Balkcom et al. 2004). Consider the shopping bag shown in Figure 20.1.
We believe that research in mathematical origami has been somewhat hampered by lack of clear, formal foundation. This chapter provides one such foundation, following the work of Demaine et al. (2004, 2006a). Specifically, this chapter defines three key notions: what is a piece of paper, what constitutes an individual folded state (at an instant of time) of a piece of paper, and when a continuum of these folded states (animated through time) forms a valid folding motion of a piece of paper. Each of these notions is intuitively straightforward, but the details are quite complicated, particularly for folded states and (to a lesser extent) for folding motions. In the final section (Section 11.6, p. 189), this chapter also proves a relationship between these notions: every folded state can be achieved by a folding motion. At first glance, one would not normally even distinguish between these two notions, so it is no surprise that they are equivalent. The formal equivalence is nonetheless useful, however, because it allows most of the other theorems in this book to focus on constructing folded states, knowing that such constructions can be extended to folding motions as well.
While we feel the level of formalism developed in this chapter is important, it may not be of interest to every reader. Many will be content to skip this entire chapter and follow the rest of the book using the intuitive notion that mathematical paper is just like real paper except that the paper has zero thickness.
The tree method of origami design is a general approach for “true” origami design (in contrast to the other topics that we discuss, which involve less usual forms of origami). In short, the tree method enables design of efficient and practical origami within a particular class of 3D shapes. Some components of this method, such as special cases of the constituent molecules and the idea of disk packing, as well as other methods for origami design, have been explored in the Japanese technical origami community, in particular by Jun Maekawa, Fumiaki Kawahata, and Toshiyuki Meguro. This work has led to several successful designs, but a full survey is beyond our scope (see Lang 1998, 2003). It suffices to say that the explosion in origami design over the last 20 years, during which the majority of origami models have been designed, may largely be due to an understanding of these general techniques.
Here we concentrate on Robert Lang's work (Lang 1994a, b, 1996, 1998, 2003), which is the most extensive. Over the past decade, starting around 1993, Lang developed the tree method to the point where an algorithm and computer program have been explicitly defined and implemented: TreeMaker is freely available and runs on most platforms. Lang himself has used it to create impressively intricate origami designs that would be out of reach without his algorithm. Figure 16.1 shows one such example.
At how many points must a tangled chain in space be cut to ensure that it can be completely unraveled? No one knows. Can every paper polyhedron be squashed flat without tearing the paper? No one knows. How can an unfolded, precreased rectangular map be refolded, respecting the creases, to its original flat state? Can a single piece of paper fold to two different Platonic solids, say to a cube and to a tetrahedron, without overlapping paper? Can every convex polyhedron be cut along edges and unfolded flat in one piece without overlap? No one knows the answer to any of these questions.
These are just five of the many unsolved problems in the area of geometric folding and unfolding, the topic of this book. These problems have the unusual characteristic of being easily comprehended but they are nevertheless deep. Many also have applications to other areas of science and engineering. For example, the first question above (chain cutting) is related to computing the folded state of a protein from its amino acid sequence, the venerable “protein folding problem.” The second question (flattening) is relevant to the design of automobile airbags. A solution to the last question above (unfolding without overlap) would assist in manufacturing a three-dimensional (3D) part by cutting a metal sheet and folding it with a bending machine.
Our focus in this book is on geometric folding as it sits at the juncture between computer science and mathematics.
This second part concerns various forms of paper folding, often called origami. We start in this chapter with a historical background of paper and paper folding (Section 10.1), and of its study from mathematical and computational points of view (Section 10.2). This history can safely be skipped by the uninterested reader. Then in Section 10.3 we define several basic pieces of terminology for describing origami, before providing an overview of Part II in Section 10.4.
HISTORY OF ORIGAMI
The word “origami” comes from Japanese; it is the combination of roots “oru,” which means “fold,” and “kami,” which means “paper.” While origami was originally popularized largely by Japanese culture, its origins are believed to be pre-Japanese, roughly coinciding with the invention of paper itself. Paper, in turn, is believed to have been invented by Ts'ai Lun, a Chinese court official, in 105 a.d. The invention of paper was motivated by the then-recent invention of the camel hair brush, from 250 b.c., which could be used for writing and calligraphy.
Paper, and presumably paper folding at the same time, spread throughout the world over a long period. Buddhist monks spread paper through Korea to Japan in the sixth century a.d. Arabs occupying Samarkand, Uzbekistan, from 751 a.d. brought paper to Egypt in the 900s, and from there continued west. The Moors brought paper (and at the same time, mathematics) to Spain during their invasion in the 700s. In the 1100s, paper making became established in Jativa, Spain.