Explore the vast range of titles available.

The basic principles of lost-wax casting, a metallurgical technology invented independently in the Old and New World, are relatively well understood. Yet researchers across the globe still struggle to explain technological variability in this process, which has important ramifications for understanding the origin, development, and spread of lost-wax casting. This paper reports the discovery of an assemblage of ceramic molds that were utilized to make internal clay cores for lost-wax casting at Tututepec, a Late Postclassic (AD 1100–1522) capital located in the southern Mexican state of Oaxaca. The molds enabled artisans to make highly standardized hollow metal artifacts, such as beads and ornaments, that served as adornments for high status individuals. Lost-wax casting, including internal core technology, initially spread to Mesoamerica from the Isthmo-Colombian Area, yet no molds similar to those found in Oaxaca have been reported from these \"donor\" regions. Interestingly, core technology was also an important component of lost-wax casting in many areas of the Old World. Thus, the analysis presented here will contribute to comparative studies of lost-wax casting worldwide. Furthermore, this study introduces evidence for metal production from household excavations to examine the social context of metalworking in Oaxaca. The results challenge the once prevalent assumption that Oaxacan metallurgy was the exclusive domain of rulers, and instead strongly suggests that elites and commoners collaborated in this enterprise. Finally, the evidence presented here also confirms Tututepec's role as an important goldworking center in Postclassic Mesoamerica.

This article reviews the history of the barium swallow from its early role in radiology to its current status as an important diagnostic test in modern radiology practice. Though a variety of diagnostic procedures can be performed to evaluate patients with dysphagia or other pharyngeal or esophageal symptoms, the barium study has evolved into a readily available, non-invasive, and cost-effective technique that can facilitate the selection of additional diagnostic tests and guide decisions about medical, endoscopic, or surgical management. This article focuses on the evolution of fluoroscopic equipment, radiography, and contrast media for evaluating the pharynx and esophagus, the importance of understanding pharyngoesophageal relationships, and major advances that have occurred in the radiologic diagnosis of select esophageal diseases, including gastroesophageal reflux disease, infectious esophagitis, eosinophilic esophagitis, esophageal carcinoma, and esophageal motility disorders.

Departing from the political economy perspective taken by the vast majority of volumes devoted to Mesoamerican obsidian,Obsidian Reflectionsis an examination of obsidian's sociocultural dimensions-particularly in regard to Mesoamerican world view, religion, and belief systems. Exploring the materiality of this volcanic glass rather than only its functionality, this book considers the interplay among people, obsidian, and meaning and how these relationships shaped patterns of procurement, exchange, and use. An international group of scholars hailing from Belize, France, Japan, Mexico, and the United States provides a variety of case studies from Mexico, Guatemala, Belize, and Honduras. The authors draw on archaeological, iconographic, ethnographic, and ethnohistoric data to examine obsidian as a touchstone for cultural meaning, including references to sacrificial precepts, powerful deities, landscape, warfare, social relations, and fertility. Obsidian Reflectionsunderscores the necessity of understanding obsidian from within its cultural context-the perspective of the indigenous people of Mesoamerica. It will be of great interest to Mesoamericanists as well as students and scholars of lithic studies and material culture.

Introduction: Intra-abdominal pressure (IAP) monitoring is crucial for the detection and prevention of intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS). In the 1970s, air-filled catheters (AFCs) for urodynamic studies were introduced as a solution to overcome the limitations of water-perfused catheters. Recent studies have shown that for correct IAP measurement with traditional AFC, the bladder needs to be primed with 25 mL of saline solution to allow pressure wave transmission to the transducer outside of the body, which limits continuous IAP monitoring. Methods: In this study, a novel triple balloon, air-filled TraumaGuard (TG) catheter system from Sentinel Medical Technologies (Jacksonville, FL, USA) with a unique balloon-in-balloon design was evaluated in a porcine and cadaver model of IAH via laparoscopy (IAPgold). Results: In total, 27 and 86 paired IAP measurements were performed in two pigs and one human cadaver, respectively. The mean IAPTG was 20.7 ± 10.7 mmHg compared to IAPgold of 20.3 ± 10.3 mmHg in the porcine study. In the cadaver investigation, the mean IAPTG was 15.6 ± 10.8 mmHg compared to IAPgold of 14.4 ± 10.4 mmHg. The correlation, concordance, bias, precision, limits of agreement, and percentage error were all in accordance with the WSACS (Abdominal Compartment Society) recommendations and guidelines for research. Conclusions: These findings support the use of the TG catheter for continuous IAP monitoring, providing early detection of elevated IAP, thus enabling the potential for prevention of IAH and ACS. Confirmation studies with the TraumaGuard system in critically ill patients are warranted to further validate these findings.

This paper examines Euler characteristics and characteristic classes in the motivic setting. We establish a motivic version of the Becker–Gottlieb transfer, generalizing a construction of Hoyois. Making calculations of the Euler characteristic of the scheme of maximal tori in a reductive group, we prove a generalized splitting principle for the reduction from$\\operatorname{GL}_{n}$or$\\operatorname{SL}_{n}$to the normalizer of a maximal torus (in characteristic zero). Ananyevskiy’s splitting principle reduces questions about characteristic classes of vector bundles in$\\operatorname{SL}$-oriented,$\\unicode[STIX]{x1D702}$-invertible theories to the case of rank two bundles. We refine the torus-normalizer splitting principle for$\\operatorname{SL}_{2}$to help compute the characteristic classes in Witt cohomology of symmetric powers of a rank two bundle, and then generalize this to develop a general calculus of characteristic classes with values in Witt cohomology.

Scholarship of ancient Mesoamerica has traditionally focused on ruling institutions and elite culture, contributing to the often-unchallenged assumption that elites dominated their unwitting commoner subjects. Similarly, the political economy is typically conceived of as an exclusive product of elite strategies. Researchers are now paying greater attention to commoner lives, yet many continue to think of social relationships dichotomously, in terms of elite domination and commoner resistance. I argue that an analysis of political economy through the lens of social negotiation, as informed by postructural theory, encourages more dynamic characterizations of commoner— elite social relationships. I utilize this approach to examine the political economy of Late Postclassic Tututepec (Oaxaca), drawing on the results of household excavations and ethnohistoric data. I argue that commoners may have negotiated a favorable position with Tututepec elites by offering their support in return for a range of benefits, including a measure of economic autonomy and wealth. Estudios de Mesoamérica antigua se han enfocado en las instituciones de gobernantes y cultura elitista. Esta mentalidad ha contribuido a la presunción que las élites dominan a los sujetos inconscientemente. Típicamente se concibe la economía política como un producto exclusivo de estrategias de las élites, investigadores han empezado a prestar atención a la vida plebeya, pero muchos siguen pensando en relaciones sociales dicotómicamente, en términos de dominación elitista y resistencia plebeya. Sostengo que el análisis de economía política con una mirada de negociación social, inspirado en la teoría posestructuralista, promueve caracterizaciones más dinámicas en los relatos entre plebeyos y elites. Utilizo este método al examinar la economía política posclásica tardía de Tututepec basada en resultados de excavaciones de habitaciones e información etnohistórica. Sostengo que los plebeyos pudieron haber negociado una posición favorable con las élites de Tututepec ofreciendo apoyo a cambio de beneficios, incluyendo medidas de autonomía económica y riqueza.

In this article, we present the most significant results of the Monte Albán Geophysical Archaeology Project. Using ground-penetrating radar, gradiometry, and electrical resistance, we carried out a systematic survey of the site's Main Plaza to identify buried prehispanic features that might shed light on Monte Albán's early history. The most important discoveries include three buried structures dating between the Danibaan (500–300 BC) and Nisa phases (100 BC–AD 100). We argue that the largest structure, measuring 18 × 18 m, was probably a temple platform and that all three of the structures were razed and buried by the end of the Nisa phase at the latest. Furthermore, we contend that these events were part of a major renovation and expansion of the site's Main Plaza that occurred during a pivotal period of dramatic sociopolitical transformation in the Zapotec capital.

Fluoroscopic esophagography is a widely available, safe, and inexpensive test for detecting gastroesophageal reflux disease. In this article, we review the technique for performing a high-quality esophagram, including upright, double-contrast views of the esophagus and cardia with high-density barium; prone, single-contrast views of the esophagus with low-density barium; and evaluation of gastroesophageal reflux. We then discuss the radiographic findings associated with gastroesophageal reflux disease, including esophageal dysmotility, reflux esophagitis, peptic strictures, and Barrett’s esophagus. Finally, we consider the differential diagnosis for the various radiographic findings associated with this condition. When carefully performed and interpreted, the esophagram is a useful test for evaluating gastroesophageal reflux disease and its complications.

Using the motivic stable homotopy category over a field k , a smooth variety X over k has an Euler characteristic (X/k) in the Grothendieck-Witt ring GW(k) . The rank of (X/k) is the classical Z -valued Euler characteristic, defined using singular cohomology or étale cohomology, and the signature of (X/k) under a real embedding k R gives the topological Euler characteristic of the real points X^(R) . We develop tools to compute (X/k) , assuming k has characteristic 2 and apply these to refine some classical formulas in enumerative geometry, such as formulas for the top Chern class of the dual, symmetric powers and tensor products of bundles, to identities for the Euler classes in Chow-Witt groups. We also refine the classical Riemann-Hurwitz formula to an identity in GW(k) and compute (X/k) for hypersurfaces in P^n+1_k defined by a polynomial of the form _i=0^n+1a_iX_i^m ; this latter includes the case of an arbitrary quadric hypersurface. This paper is a revision of [ M. Levine ,\"Toward an enumerative geometry with quadratic forms\", Preprint, ].

The esophagus may be involved by a variety of morphologic abnormalities, including nodules and plaques, ulceration, distal esophageal strictures and rings, upper or midesophageal strictures, and diffuse narrowing (also known as a small-caliber esophagus). The use of a pattern approach for evaluating esophageal disease on barium studies facilitates diagnosis of a host of pathologic conditions associated with these morphologic abnormalities. This article therefore presents an approach for diagnosing esophageal disease on barium studies that emphasizes the radiographic and clinical features used to differentiate the underlying causes of disease and the diagnostic pitfalls associated with performing and interpreting these studies.