5,140 research outputs found
Ancient technology and punctuated change: Detecting the emergence of the Edomite Kingdom in the Southern Levant.
While the punctuated equilibrium model has been employed in paleontological and archaeological research, it has rarely been applied for technological and social evolution in the Holocene. Using metallurgical technologies from the Wadi Arabah (Jordan/Israel) as a case study, we demonstrate a gradual technological development (13th-10th c. BCE) followed by a human agency-triggered punctuated "leap" (late-10th c. BCE) simultaneously across the entire region (an area of ~2000 km2). Here, we present an unparalleled, diachronic archaeometallurgical dataset focusing on elemental analysis of dozens of well-dated slag samples. Based on the results, we suggest punctuated equilibrium provides an innovative theoretical model for exploring ancient technological changes in relation to larger sociopolitical conditions-in the case at hand the emergence of biblical Edom-, exemplifying its potential for more general cross-cultural applications
Cellular excitability and the regulation of functional neuronal identity: from gene expression to neuromodulation
The intrinsic properties of a neuron determine the translation of synaptic input to axonal output. It is this input– output relationship that is the heart of all nervous system activity. As such, the overall regulation of the intrinsic excitability of a neuron directly determines the output of that neuron at a given point in time, giving the cell a unique “functional identity.” To maintain this distinct functional output, neurons must adapt to changing patterns of synaptic excitation. These adaptations are essential to prevent neurons from either falling silent as synaptic excitation falls or becoming saturated as excitation increases. In the absence of stabilizing mechanisms, activity-dependent plasticity could drive neural activity to saturation or quiescence. Furthermore, as cells adapt to changing patterns of synaptic input, presumably the overall balance of intrinsic conductances of the cell must be maintained so that reliable output is achieved (Daoudal and Debanne, 2003; Turrigiano and Nelson, 2004; Frick and Johnston, 2005). Although these regulatory phenomena have been well documented, the molecular and physiological mechanisms involved are poorly understood
Publish, Don\u27t Perish: Experienced Authors Share Ideas
In the past. many Extension agents and specialists didn\u27t think much about publish or perish. But with everchanging university administrators and policies, Extension workers now recognize the importance of publishing in refereed journals. Because of this, communication specialists are increasingly writing joumal articles and also are being asked to help subject-matter specialists and field agents prepare articles for publishing.
Information gleaned from five Oregon State University faculty shows the importance of writing only about what interests you, getting to know others in your field, deciding where to market your work, seeking constructive criticism, and developing long-range strategies for publishing
340 years of atmospheric circulation characteristics reconstructed from an eastern Antarctic Peninsula ice core
Copyright @ 2006 American Geophysical Union (AGU)Precipitation delivery mechanisms for Dolleman Island (DI), located off the east coast of the Antarctic Peninsula, are investigated using reanalysis and back trajectory data. The Southern Annular Mode (SAM) and ENSO are both shown to influence precipitation delivery and event size. Precipitation delivery variability is compared against the interannual variation of chemical data from two DI ice cores. Nitrate concentration in the cores is strongly linked with the ratio of easterly to westerly back trajectories arriving at DI, as described by a Cross-Peninsula Index (CPI) defined in this paper. This CPI is used subsequently to reconstruct the atmospheric circulation characteristics for the 340-year ice core record. The analysis highlights a period of increased easterlies during 1720–1780 and an increase in westerlies for 1950–1980, the latter concomitant with a positive SAM trend and western Peninsula warming. The reconstruction also reveals periods when polynyas may have been present in the Weddell Sea
Effect of Fluoride and Cobalt on Forming Enamel: Scanning Electron Microscope and X-Ray Microanalysis Study
The forming surfaces of enamel of rat incisors were examined by scanning electron microscope one hour after injection of either 5 mg/100 g body weight of sodium fluoride or 12 mg/100 g body weight of cobalt chloride. The cell debris from the surfaces of the separated incisors was either gently wiped off with soft facial tissues or chemically removed by treating with NaOH, NaOCl or trypsin. Best results to remove cell debris were obtained from 0.25% trypsin treatment.
SEM studies revealed that the surface of the normal secretory enamel was characteristic in appearance with well-developed smooth prism outlines. In fluoride specimens the prism outlines were feathery in appearance, laced with protruding spine-shaped clusters of mineral crystals. In the case of cobalt treatment, prism outlines were less uniform and in some areas they were incomplete.
The calcium concentration of surface enamel was significantly lower in the cobalt-treated specimens than those from control and fluoride-treated animals. The Ca:Mg ratio was also lower in cobalt-treated specimens as compared to control and fluoride-treated ones
Consent-Based Humanitarian Intervention: Giving Sovereign Responsibility Back to the Sovereign
The repeated failure of the United Nations Charter regime to respond to humanitarian crises— and to prevent interventions outside the regime—has laid bare a conflict that lies at the heart of modern international law. This failure has revealed that the twin commitments on which the post-World War II international legal system has been built— sovereign rights and sovereign responsibilities— are often deeply at odds. The response of scholars to this tension has often been to choose sides in the fight. Scholars who place greater value on human rights than state sovereignty have sought to craft exceptions to the prohibition on the use or threat of force. Those who place greater value on sovereignty (and, they would argue, democratic rule of law), have rejected any humanitarian intervention not authorized by the Security Council as illegal and on occasion have portrayed the human rights movement as “anti-sovereigntist” and even “antidemocratic.” In this Article, we offer another way forward— one that aims to respect sovereign rights while helping states meet their sovereign responsibilities and thereby alleviate the tension between the twin commitments of the modern international legal system. Rather than seek to craft an exception to state sovereignty to meet humanitarian aims, we argue for empowering states to meet their sovereign responsibility through what we call “consent-based intervention.
Brief on the future of non-MARC authority
The Indiana University PCC Non-MARC Authorities Issues Group was formed in response to the Program for Cooperative Cataloging’s (PCC) call for "… a well-articulated plan as to how [a non-MARC authorities] future could work based on [ideas from the PCC community]." Of particular interest were ideas that could serve as a bridge "between an ideal world and what [catalogers] can do now to create [that world]." In this brief paper, the group proposes many changes that may ease the transition from MARC to library linked open data with a particular focus on authority data. The group outlines policy changes that may promote robust, granular data encoding practices and encourage the addition of meaningful linkages to FRBR Group 1 and Group 2 entities. In addition to forward-thinking policies and standards, our community is in need of a strong advocate for metadata curation systems. Having proper tools will enable catalogers to focus on the intellectual activities associated with metadata creation, curation, and strategy
Triumph Over Tragedy, Second Edition: A Curriculum for Extension Professionals Responding to Disasters and Terrorism
We describe Triumph Over Tragedy, Second Edition: A Community Response to Managing Trauma in Times of Disaster and Terrorism, a curriculum designed to assist Extension professionals and other community stakeholders in helping their communities prepare for, and respond to, trauma associated with natural and human-made disasters. In the post-September 11, 2001 environment, it is imperative that community professionals become involved in planning for the psychological impact of these events
Virtual reality suturing task as an objective test for robotic experience assessment
BackgroundWe performed a pilot study using a single virtual-simulation suturing module as an objective measurement to determine functional use of the robotic system. This study will assist in designing a study for an objective, adjunctive test for use by a surgical proctor.MethodsAfter IRB approval, subjects were recruited at a robotic renal surgery course to perform two attempts of the "Tubes" module without warm-up using the Da Vinci® Surgical Skills Simulator™. The overall MScore (%) from the simulator was compared among various skill levels to provide construct validity. Correlation with MScore and number of robotic cases was performed and pre-determined skill groups were tested. Nine metrics that make up the overall score were also tested via paired t test and subsequent logistic regression to determine which skills differed among experienced and novice robotic surgeons.ResultsWe enrolled 38 subjects with experience ranging from 0- < 200 robotic cases. Median time to complete both tasks was less than 10 min. The MScore on the first attempt was correlated to the number of previous robotic cases (R(2) = 0.465; p = 0.003). MScore was different between novice and more experienced robotic surgeons on the first (44.7 vs. 63.9; p = 0.005) and second attempt (56.0 vs. 69.9; p = 0.037).ConclusionA single virtual simulator exercise can provide objective information in determining proficient use of the robotic surgical system
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