1,464 research outputs found
Flat parameter-space metric for all-sky searches for gravitational-wave pulsars
All-sky, broadband, coherent searches for gravitational-wave pulsars are
computationally limited. It is therefore important to make efficient use of
available computational resources, notably by minimizing the number of
templates used to cover the signal parameter space of sky position and
frequency evolution. For searches over the sky, however, the required template
density (determined by the parameter-space metric) is different at each sky
position, which makes it difficult in practice to achieve an efficient
covering. Previous work on this problem has found various choices of sky and
frequency coordinates that render the parameter-space metric approximately
constant, but which are limited to coherent integration times of either less
than a few days, or greater than several months. These limitations restrict the
sensitivity achievable by hierarchical all-sky searches, and hinder the
development of follow-up pipelines for interesting gravitational-wave pulsar
candidates. We present a new flat parameter-space metric approximation, and
associated sky and frequency coordinates, that do not suffer from these
limitations. Furthermore, the new metric is numerically well-conditioned, which
facilitates its practical use.Comment: 19 pages, 20 figure
Quantum Phase Transitions for Bosons in One Dimension
We study the ground state phase diagram and the critical properties of
interacting Bosons in one dimension by means of a quantum Monte Carlo
technique. The direct experimental realization is a chain of Josephson
junctions. For finite-range interactions we find a novel intermediate phase
which shows neither solid order nor superfluidity. We determine the location of
this phase and study the critical behaviour of the various transitions. For
on-site interaction only, we map out the phase diagram as a function of the
hopping strength and the chemical potential.Comment: 11 pages, revtex, 2 eps-figure
Coprolite Analysis: The analysis of ancient human feces for dietary data
Although archaeological fieldwork is hot and dirty, the most “earthy” side of the discipline is the laboratory analysis of coprolites. Each coprolite contains the remains of one to several actual meals eaten in prehistory, and analysis of many coprolites provides a picture of ancient diet that is unique in accuracy.
The term coprolite originally referred to fossilized feces in paleontological context. In archaeology, the term broadened to refer to any formed fecal mass, including mineralized, desiccated, or frozen feces and even the intestinal contents of mummies. Coprolites contain the remains of animals (parasites) that lived in the humans, the foods that humans ate, and the remains of animals that lived in the feces after defecation. The majority of recognizable remains consist of undigested or partly digested food residue. With the naked eye, one can identify plant cuticle, bark, seeds, fruit coats, fibers, animal bone, feathers, lizard and fish scales, mollusc shell, crustacean fragments, fish otoliths, insects, and other food items. Microscopic remains include parasites, pollen grains, phytoliths, other small plant structures, animal hair, fungal spores, diatoms, mites, and starch granules. In short, anything indigestible that people swallowed can be found. Beyond visual identification, chemical components of coprolites include proteins, lipids, steroids, carbon and nitrogen isotopes, and many major and trace elements.
The analytical techniques developed by Callen, Bryant, and Reinhard, combined with the statistical techniques of Minnis and Sutton, have proven to be particularly powerful for reconstruction of ancient cuisine, diet, and health. The future of coprolite research will see more such statistical evaluation of coprolite information
Coprolite Analysis: The analysis of ancient human feces for dietary data
Although archaeological fieldwork is hot and dirty, the most “earthy” side of the discipline is the laboratory analysis of coprolites. Each coprolite contains the remains of one to several actual meals eaten in prehistory, and analysis of many coprolites provides a picture of ancient diet that is unique in accuracy.
The term coprolite originally referred to fossilized feces in paleontological context. In archaeology, the term broadened to refer to any formed fecal mass, including mineralized, desiccated, or frozen feces and even the intestinal contents of mummies. Coprolites contain the remains of animals (parasites) that lived in the humans, the foods that humans ate, and the remains of animals that lived in the feces after defecation. The majority of recognizable remains consist of undigested or partly digested food residue. With the naked eye, one can identify plant cuticle, bark, seeds, fruit coats, fibers, animal bone, feathers, lizard and fish scales, mollusc shell, crustacean fragments, fish otoliths, insects, and other food items. Microscopic remains include parasites, pollen grains, phytoliths, other small plant structures, animal hair, fungal spores, diatoms, mites, and starch granules. In short, anything indigestible that people swallowed can be found. Beyond visual identification, chemical components of coprolites include proteins, lipids, steroids, carbon and nitrogen isotopes, and many major and trace elements.
The analytical techniques developed by Callen, Bryant, and Reinhard, combined with the statistical techniques of Minnis and Sutton, have proven to be particularly powerful for reconstruction of ancient cuisine, diet, and health. The future of coprolite research will see more such statistical evaluation of coprolite information
Paleopharmacology
An emerging field devoted to the exploration of the archaeological record for evidence of medicinal plants.
In the future, archaeology will have a role in pharmaceutical research. In the late twentieth century, much of the world’s pharmaceutical research has been based on ethnographic documentation of tribally recognized medicinal plants. Once the active chemical compounds in the plants are identified, they are either extracted or synthesized for commercial use. The American film Medicine Man depicts this approach. As shown in the film, such pharmacological research is threatened by declining tribal populations with loss of traditional herbal knowledge coupled with declining biodiversity. With the loss of ethnopharmacological information, the knowledge of ancient cultures can be tapped through archaeology. Every prehistoric culture had some sort of healthcare system, and a pharmacopoeia was integral in each ancient cultural system. Most medicinal compounds used were derived from plants. In theory, the archaeological record can be used to identify medicinal plants used in ancient times. In practice, new archaeological research has demonstrated the presence of anomalous plant finds that, under scrutiny, prove to have had a medicinal use. Therefore, the reserve knowledge of medicinal plants can be expanded by exploring the archaeological record for relevant botanical remains.
The paleopharmacological approach compares archaeological data with ethnographic and plantchemistry data. Through this approach, researchers identify specific ailments treated with plant extracts and identify the physiologically active compounds in the plant. Thus, paleopharmacology employs archaeological and ethnographic investigation of the ancient use of medicinal plants in the light of what is known about plant chemistry and physiology.
The paleopharmacological record also includes textual information from ancient cultures that document medicinal plant usage. Most documentation of pharmacopoeias comes from the Old World. For example, Morris Weiss and Raoul Perrot have separately summarized aspects of Etruscan medicine and medieval medicine, respectively. In A.D. 77, Dioscorides (Greek physician and pharmacologist) wrote the De Materia Medica, which summarized Greco-Roman knowledge of medicinal plants. Medieval medical practitioners based their Materia Medicalis on this work. The Greeks and Romans were influenced by the herbal knowledge of the Egyptians. In 1989, Lise Manniche summarized the Egyptian pharmacopoeia from several Egyptian texts, including the Papyrus Ebers, which dates to 1550 B.C. At least three Aztec documents describe a New World pharmacopoeia that was studied by Bernard Ortiz de Montellano in 1975
Paleoamerican diet, migration and morphology in Brazil
During the early Holocene two main paleoamerican cultures thrived in Brazil: the Tradição Nordeste in the semi-desertic Sertão and the Tradição Itaparica in the high plains of the Planalto Central. Here we report on paleodietary singals of a Paleoamerican found in a third Brazilian ecological setting--a riverine shellmound, or sambaqui, located in the Atlantic forest. Most sambaquis are found along the coast. The peoples associated with them subsisted on marine resources. We are reporting a different situation from the oldest recorded riverine sambaqui, called Capelinha. Capelinha is a relatively small sambaqui established along a river 60 km from the Atlantic Ocean coast. It contained the well-preserved remains of a Paleoamerican known as Luzio dated to 9,945±235 years ago; the oldest sambaqui dweller so far. Luzio's bones were remarkably well preserved and allowed for stable isotopic analysis of diet. Although artifacts found at this riverine site show connections with the Atlantic coast, we show that he represents a population that was dependent on inland resources as opposed to marine coastal resources. After comparing Luzio's paleodietary data with that of other extant and prehistoric groups, we discuss where his group could have come from, if terrestrial diet persisted in riverine sambaquis and how Luzio fits within the discussion of the replacement of paleamerican by amerindian morphology. This study adds to the evidence that shows a greater complexity in the prehistory of the colonization of and the adaptations to the New World
Review of \u3ci\u3e NEBRASKAland Magazine\u27s The Cellars of Time: Paleontology and Archaeology in Nebraska\u3c/i\u3e Vol 72, No. I. Lincoln: Nebraska Game and Parks Commission, 1994
This is a popular-oriented work designed to acquaint Nebraskans with the paleontology and archaeology of their state. The work is divided in halves. The first half summarizes the paleontological work in Nebraska. The second half summarizes the archaeological culture history of the state. The paleontology portion is a must read, holistic work. It is written almost entirely by Michael R. Voorhies with one insert by Margaret R. Bolick. Voorhies has a wonderful writing style that enables him to translate complicated, technical subjects into plain English. Thus, the paleontology is summarized in wonderful prose that is a delight to read. The technical subjects that Voorhies presents are numerous. He describes the role of microfauna as a gauge of evolution that is also useful for finding oil and other essential commodities. His description of the advance and retreat of seas and glaciers in the context of paleoenvironmental studies is clearly written and easily understandable. He details the way that less dramatic climatic changes can be studied by examining changes in vertebrate fauna such as tortoises, snakes, shrews and other animals. Bolick\u27s description of pollen studies, and floral studies combined with Voorhies\u27s discussion of stratigraphy, and other paleontological techniques brings the reader to a clear understanding of the nature of paleontological research. These discussions are interspersed with captivating descriptions of a multitude of ancient animal species and significant paleontologic sites. In these descriptions, Voorhies makes clear the methods by which paleontologists determine how extinct animals lived, what their habitats were like, and the nature of their behaviors. The history of paleontology in the state is summarized and major personalities in that history are presented in vignelle form. Current paleontologists, curators, preparators, and exhibits staff are pictured or described. Importantly, he goes beyond the description of professionals. Throughout his section, Voorhies gives credit to non-professionals, ranging from ranchers to high school students, responsible for making important finds. In doing so, he provides the important impression that Nebraska\u27s paleontology is an ancient legacy for all of the state\u27s citizens to responsibly investigate and report. In short, the paleontology section is information packed and makes for fascinating reading. It serves as an inspiration for academic researchers who have an interest in public writing
Review of \u3ci\u3eRivers of Change: Essays on Early Agriculture in Eastern North America\u3c/i\u3e by Bruce D. Smith
Between 1970 and 1990 there was a burst of paleoethnobotanical research into prehistoric Native American subsistence practices across North America which has resulted recently in numerous regional syntheses. No synthesis is more salient or cogent than that presented for eastern North America by Bruce D. Smith who has been a key researcher in the area of prehistoric subsistence
Review of \u3ci\u3e NEBRASKAland Magazine\u27s The Cellars of Time: Paleontology and Archaeology in Nebraska\u3c/i\u3e Vol 72, No. I. Lincoln: Nebraska Game and Parks Commission, 1994
This is a popular-oriented work designed to acquaint Nebraskans with the paleontology and archaeology of their state. The work is divided in halves. The first half summarizes the paleontological work in Nebraska. The second half summarizes the archaeological culture history of the state. The paleontology portion is a must read, holistic work. It is written almost entirely by Michael R. Voorhies with one insert by Margaret R. Bolick. Voorhies has a wonderful writing style that enables him to translate complicated, technical subjects into plain English. Thus, the paleontology is summarized in wonderful prose that is a delight to read. The technical subjects that Voorhies presents are numerous. He describes the role of microfauna as a gauge of evolution that is also useful for finding oil and other essential commodities. His description of the advance and retreat of seas and glaciers in the context of paleoenvironmental studies is clearly written and easily understandable. He details the way that less dramatic climatic changes can be studied by examining changes in vertebrate fauna such as tortoises, snakes, shrews and other animals. Bolick\u27s description of pollen studies, and floral studies combined with Voorhies\u27s discussion of stratigraphy, and other paleontological techniques brings the reader to a clear understanding of the nature of paleontological research. These discussions are interspersed with captivating descriptions of a multitude of ancient animal species and significant paleontologic sites. In these descriptions, Voorhies makes clear the methods by which paleontologists determine how extinct animals lived, what their habitats were like, and the nature of their behaviors. The history of paleontology in the state is summarized and major personalities in that history are presented in vignelle form. Current paleontologists, curators, preparators, and exhibits staff are pictured or described. Importantly, he goes beyond the description of professionals. Throughout his section, Voorhies gives credit to non-professionals, ranging from ranchers to high school students, responsible for making important finds. In doing so, he provides the important impression that Nebraska\u27s paleontology is an ancient legacy for all of the state\u27s citizens to responsibly investigate and report. In short, the paleontology section is information packed and makes for fascinating reading. It serves as an inspiration for academic researchers who have an interest in public writing
Confusing a Pollen Grain with a Parasite Egg: an Appraisal of “Paleoparasitological Evidence of Pinworm (\u3ci\u3eEnterobius Vermicularis\u3c/i\u3e) Infection in a Female Adolescent Residing in Ancient Tehran”
There is often the risk of confusing pollen grains with helminth eggs from archaeological sites. Thousands to millions of pollen grains can be recovered from archaeological burial sediments that represent past ritual, medication and environment. Some pollen grain types can be similar to parasite eggs. Such a confusion is represented by the diagnosis of enterobiasis in ancient Iran. The authors of this study confused a joint-pine (Ephedra spp.) pollen grain with a pinworm egg. This paper describes the specific Ephedra pollen morphology that can be confused with pinworm eggs
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