Synthetic peptide and peptido-mimetic filaments and tubes represent a diverse class of nanomaterials with a broad range of potential applications, such as drug delivery, vaccine development, synthetic catalyst design, encapsulation, and energy transduction. The structures of these filaments comprise supramolecular polymers based on helical arrangements of subunits that can be derived from self-assembly of monomers based on diverse structural motifs. In recent years, structural analyses of these materials at near-atomic resolution (NAR) have yielded critical insights into the relationship between sequence, local conformation, and higher-order structure and morphology. This structural information offers the opportunity for development of new tools to facilitate the predictable and reproducible de novo design of synthetic helical filaments. However, these studies have also revealed several significant impediments to the latter process – most notably, the common occurrence of structural polymorphism due to the lability of helical symmetry in structural space. This article summarizes the current state of knowledge on the structures of designed peptide and peptido-mimetic filamentous assemblies, with a focus on structures that have been solved to NAR for which reliable atomic models are available.

The elm zigzag sawfly, Aproceros leucopoda Takeuchi (Hymenoptera: Argidae), was reported for the first time in North America during the summer of 2020. Characteristic zigzag defoliation was reported in the province of Québec, Canada, on the community science website, iNaturalist. Field trips conducted to the site resulted in the collection of live specimens (a few larvae and a cocoon from which an adult emerged) and onsite observation of diagnostic defoliation and empty cocoons, confirming the presence of this exotic species in Canada. Subsequent inspection of elm trees by naturalists and scientists in the south of the province led to the conclusion that the species is more widely distributed than first expected and that the invasion is not localised to a small area. Preliminary genetic data pointed to a possible European origin of the Canadian population, but conclusive assignment to source will require examination of more specimens and the collection of reference sequences from different European and Asian populations. This is a good example of the importance of community science in the detection of new invasive species.

OBJECTIVES/GOALS: Pancreatic cysts are comprised of both precancerous mucinous lesions and non-mucinous lesions with minimal malignant potential. Our goal is to improve our ability to classify the type of cyst using a combination of novel radiomic features and cyst fluid proteolytic activity. METHODS/STUDY POPULATION: Preoperative pancreatic protocol CT images from 30 patients with proteolytic assay characterization, followed by surgical resection with a pathologically confirmed pancreatic cyst diagnosis between 2016-2019 will be used in this study. We will contour images using the widely available software 3D Slicer, and extract radiomic features using IBEX software. We will analyze area under the ROC curves to identify the radiomic features that best differentiate mucinous from non-mucinous cysts, and identify features to be cross validated. The predictive ability of identified radiomic features combined with proteolytic assay will be determined by performing multiple logistic regression analysis and comparing AUROC analysis. We will determine sensitivity and specificity for individual, as well as combinations of, analytes to determine the optimal classifier. RESULTS/ANTICIPATED RESULTS: We anticipate that the predictive ability, sensitivity, and specificity of utilizing radiomic features combined with proteolytic assay data will exceed the performance of any individual test. DISCUSSION/SIGNIFICANCE OF IMPACT: This work is designed to provide a predictive radiomic model that will enable us to better identify mucinous cysts that require further evaluation, and potentially prevent unnecessary surgery in other patients. Ultimately, we would like to improve the accuracy of noninvasive radiographic evaluation using radiomic markers. CONFLICT OF INTEREST DESCRIPTION: Dr. Charles Craik is a co-founder of Alaunus Biosciences, Inc.

Archaeological investigations at three Formative period sites near San Martín Tilcajete in the Valley of Oaxaca, Mexico, have recovered a sequence of temples. The temples span the period when the Zapotec state emerged with its capital at Monte Albán during the Late Monte Albán I phase (300–100 bc), coinciding with Monte Albán's conquest of neighbouring regions. Zapotec rituals of sanctification practised in pre-state times may have been affected by Monte Albán's military expansionism. The historically documented case of military expansion and political unification of the Hawaiian islands by the paramount, Kamehameha, shows similarities in the adoption of ideology and religious institutions. Among them are the establishment of standardized temples and the ascendance of a militaristic ideology and ritual order attuned to the early state rulers' coercive authority.

The 2005 articles by Stoltman et al. and Flannery et al. to which Neff et al. (this issue) have responded are not an indictment of instrumental neutron activation analysis (INAA) but, rather, of the way Blomster et al. (2005) misuse it and of the hyperbolic culture-historical claims they have made from their INAA results. It has long been acknowledged that INAA leads not to sources but to chemical composition groups. Based on composition groups derived from an extremely unsystematic collection of sherds from only seven localities, Blomster et al. claim that the Olmec received no carved gray or kaolin white pottery from other regions; they also claim that neighboring valleys in the Mexican highlands did not exchange such pottery with each other. Not only can one not leap directly from the elements in potsherds to such sweeping culture-historical conclusions, it is also the case that other lines of evidence (including petrographic analysis) have for 40+ years produced empirical evidence to the contrary. In the end, it was their commitment to an unfalsifiable model of Olmec superiority that led Blomster et al. to bypass the logic of archaeological inference.

A masonry and adobe construction called the “Area I Palace” was excavated by the authors at the site of El Palenque (SMT-llb), located near San Martín Tilcajete in the Ocotlán district of the Valley of Oaxaca, Mexico. The Area I Palace covered 850 m2 and consisted of nine interconnected structures, one of which was an elaborate residence that measured 16 m by 16 m and had eight rooms arranged around an interior patio. Several additional platforms and two paved courtyards were probably more ceremonial in nature. There is evidence that multiple work groups were involved in the construction of the palace. The associated ceramics and four radiocarbon samples indicate that the palace was built at the beginning of the Late Monte Albán I phase (300–100 B.C.) and abandoned in the first century B.C. It is argued that the Area I Palace is one of earliest known examples of a Zapotec quihuitào or royal palace.

Architect, author and teacher, Michael Brawne was also an arq contributor and referee. His article ‘Research, design and Popper’ published in our second issue (1/2, pp 10–15) was an analysis of the similarity between architectural design and scientific research based on Karl Popper's hypothetico-deductive theory. It cut straight to the heart of the declared subject of this journal. Reading it again, one can almost hear Michael – with his characteristically precise enunciation (and often exquisitely drawly voice) – elucidating his argument.

The following celebration of Michael and his contribution to architecture speaks eloquently about the man and his teaching but surprisingly little about his completed buildings – especially those of the '60s and '70s. There was something very rigorous about these. Indeed, Charles Correa asserts that the houses in Hampstead are ‘among the half-dozen most important pieces of architecture’ constructed in the UK over the last 50 years.

It was in the first Hampstead house that, in 1962, there emerged the surface mounted vertical mullions that were to appear again – always subtly related to the internal spatial arrangement – in later projects. And there was his use on the upper levels of his buildings of steeply sloping Cor-Ten sheet (something that today's generation, who seem to have rediscovered this problematic material, could well learn from). In plan, his buildings often made a powerful use of the diagonal (the Cambridge influence perhaps?) and occasionally revealed his admiration for Alvar Aalto's work. This thoughtful, highly distinctive body of work extended from country cottage conversions and extensions to competition designs such as his ‘groundscraper’ high-density housing entry for the Portsdown competition.

And what of Michael's exhibition designs? Following the 1965 publication of his book, The New Museum, it was a field in London which he seemed to dominate for much of the late '60s and the '70s – with shows such as the stunning Art in Revolution at the Hayward Gallery in 1971 and the exquisite Age of Neo-Classicism at the Royal Academy in the following year. In the mid '90s, his work for ecclesiastical museums in Germany was equally elegant and well-judged. And, over the last six years, recalling his artist father, he turned to making sculpture at Bath College.

Michael Brawne is remembered here by some of his contemporaries, fellow teachers and students. The first contribution, by Bob Allies, is reproduced by permission from The Independent newspaper in which it appeared on 16 August 2003.

Recently obtained radiocarbon determinations from the Cañada de Cuicatlán, Oaxaca, Mexico, have made it possible to revise the chronological placement of the Perdido phase (from 600-200 B. C. to 750-300 B. C.) and the Lomas phase (from 200 B. C.-A. D. 200 to 300 B. C.-A. D. 200), the latter being the phase for which substantial evidence of a Zapotec conquest of the Cañada has been recovered. The revised chronology brings the Lomas phase into close alignment with the Late Monte Albán I (300-100 B. C.) and the Monte Albán II (100 B. C.-A. D. 200) phases, during which the early Zapotec state emerged with its capital at Monte Albán in the Oaxaca Valley. The new Cañada dates support the proposition that territorial expansion outside the Oaxaca Valley played a major role very early in the process of Zapotec primary state formation. This strategy of extra-Valley expansion appears to have been initiated before all areas within the Oaxaca Valley were fully integrated into the Zapotec state.

In this article we discuss the Prehispanic earthen causeways (calzadas) that traverse the llanos (humid savannas) of Barinas state, Venezuela. A salient question is why the calzadas in this area connect some archaeological sites but not others. Some scholars have proposed that the calzadas were constructed primarily as an adaptive response to seasonal flooding. We assess this proposition by examining Late Gaván phase (A. D. 550-1000) data from along the Río Canaguá and find a lack of positive association between sites that experience seasonal inundations and linkage to the calzada network. Instead, we conclude that the configuration of Late Gaván calzadas is better explained by a series of economic, military, and religious factors, all related to the political dynamics of chiefdom organization on the regional level.