1,081 research outputs found
Geographic Patterns of Early Holocene New World Dental Morphological Variation
Dental anthropology played a seminal role in early studies of the peopling of the New World, and was a foundation of the early three wave model proposed by Greenberg, Turner and Zegura. In recent years, however, developments in anthropological genetics, craniometry, and archaeological discoveries have largely omit-ted dental anthropology from debates regarding Native American origins. Here we consider this situation and reassert dental anthropology\u27s relevance to the topic by presenting an inter-individual analysis of Paleoindian and Paleoamerican dentitions. A small set of dental morphological variables was used to estimate Gower similarity coefficients between individual specimens. The resulting similarity matrix was ordinated using multidimensional scaling; all analyses were per-formed in Clustan v. 7.05. While results should be considered preliminary, patterns of variation suggest morphological similarity along both coasts of North and South America with a somewhat distinct grouping of North American Paleoindians deriving from more inland portions of the continent. This pattern is consistent with recent genetic scenarios, notably the bicoastal model presented by O\u27Rourke and Raff (2010), which indicates that Paleoindians may have taken multiple migration routes from Beringia, moving along both coasts as well as through the ice free corridor. Future studies may build on this work to reintegrate dental data and analysis into research concerning the peopling of the New World
Quantum optical signal processing in diamond
Controlling the properties of single photons is essential for a wide array of
emerging optical quantum technologies spanning quantum sensing, quantum
computing, and quantum communications. Essential components for these
technologies include single photon sources, quantum memories, waveguides, and
detectors. The ideal spectral operating parameters (wavelength and bandwidth)
of these components are rarely similar; thus, frequency conversion and spectral
control are key enabling steps for component hybridization. Here we perform
signal processing of single photons by coherently manipulating their spectra
via a modified quantum memory. We store 723.5 nm photons, with 4.1 nm
bandwidth, in a room-temperature diamond crystal; upon retrieval we demonstrate
centre frequency tunability over 4.2 times the input bandwidth, and bandwidth
modulation between 0.5 to 1.9 times the input bandwidth. Our results
demonstrate the potential for diamond, and Raman memories in general, to be an
integrated platform for photon storage and spectral conversion.Comment: 6 pages, 4 figure
Global Journalist: Photojournalists on working through a pandemic (2020)
In these highlights of a March 20, 2020 Global Journalist webinar, three photographers for West Coast news outlets discuss the challenges they face to keeping the public informed and themselves safe during the COVID-19 pandemic. Hosts: Kat Duncan, Trevor Hook. Guests: Kent Porter, Paige Cornwell, Carlos Gonzalez
Storage and retrieval of ultrafast single photons using a room-temperature diamond quantum memory
We report the storage and retrieval of single photons, via a quantum memory,
in the optical phonons of room-temperature bulk diamond. The THz-bandwidth
heralded photons are generated by spontaneous parametric downconversion and
mapped to phonons via a Raman transition, stored for a variable delay, and
released on demand. The second-order correlation of the memory output is
, demonstrating preservation of non-classical
photon statistics throughout storage and retrieval. The memory is low-noise,
high-speed and broadly tunable; it therefore promises to be a versatile
light-matter interface for local quantum processing applications.Comment: 6 pages, 4 figure
Storage of polarization-entangled THz-bandwidth photons in a diamond quantum memory
Bulk diamond phonons have been shown to be a versatile platform for the
generation, storage, and manipulation of high-bandwidth quantum states of
light. Here we demonstrate a diamond quantum memory that stores, and releases
on demand, an arbitrarily polarized 250 fs duration photonic qubit. The
single-mode nature of the memory is overcome by mapping the two degrees of
polarization of the qubit, via Raman transitions, onto two spatially distinct
optical phonon modes located in the same diamond crystal. The two modes are
coherently recombined upon retrieval and quantum process tomography confirms
that the memory faithfully reproduces the input state with average fidelity
with a total memory efficiency of . In an
additional demonstration, one photon of a polarization-entangled pair is stored
in the memory. We report that entanglement persists in the retrieved state for
up to 1.3 ps of storage time. These results demonstrate that the diamond phonon
platform can be used in concert with polarization qubits, a key requirement for
polarization-encoded photonic processing
Developing an eBook for First Responders: Exploring Arts-Based Interventions to Counter Burnout and Build Resilience
The researchers in this project studied the prevalence and impact of burnout among first responders, after which they produced CRISP (Creative Resilience Initiatives for Service Providers), a groundbreaking art therapy-based program published in an electronic book format aimed at addressing burnout and fostering resilience among first responders. Our program aims to foster resilience by integrating art therapy\u27s Expressive Therapies Continuum (ETC) model with Diversity, Equity, and Inclusion and anti-racism strategies. The ETC model aligns with inclusive and diverse practices as it emphasizes a system-focused approach in using creativity, self-reflection, and cultivation of effective body-mind empathy. The CRISP eBook features 18 arts-based activities, each accompanied by relevant psychoeducation and self-reflective questions. These activities engage first responders in kinesthetic, sensorial, perceptual, affective, cognitive, and symbolic components of information processing in the ETC, utilizing multifaceted creativity as a powerful tool for building resilience and countering burnout signs that can lead to depersonalized and biased practices in their work. Future studies are warranted to assess the efficacy of art interventions, such as those explored in the CRISP eBook, in addressing the unique stressors faced by first responders
Estimating Farmers’ Internal Value of Crop Residues in Smallholder Crop-Livestock Systems: A South Asia case study
Crop residues (CR) are an important, internally produced resource with several uses on smallholder, mixed crop-livestock farms, including livestock feed, mulch, fuel and construction material. This study sets out to develop a method to estimate the internal shadow value of CR as feed and as mulch for smallholder households. The study uses a South Asia case study as illustration using data from a set of village and household surveys in three different sites. The estimated shadow prices were higher for CR as mulch than for CR as feed at all three sites. These results reject the null hypothesis that the estimated shadow price for CR as feed is greater than the shadow price for CR as mulch. Since the null hypothesis was formed based on observing household behavior, the rejection of the null hypothesis implies that there are other reasons to explain why more households use CR as feed versus as mulch
Visual spatial attention and spatial working memory do not draw on shared capacity-limited core processes
The extent to which similar capacity limits in visual attention and visual working memory indicate a common shared underlying mechanism is currently still debated. In the spatial domain, the multiple object tracking (MOT) task has been used to assess the relationship between spatial attention and spatial working memory though existing results have been inconclusive. In three dual task experiments we examined the extent of interference between attention to spatial positions and memory for spatial positions. When the position monitoring task required keeping track of target identities through colour-location binding, we found a moderate detrimental effect of position monitoring on spatial working memory and an ambiguous interaction effect. However, when this task requirement was removed, load increases in neither task were detrimental to the other. The only very moderate interference effect that remained resided in an interaction between load types but was not consistent with shared capacity between tasks – rather it was consistent with content-related crosstalk between spatial representations. Contrary to propositions that spatial attention and spatial working memory may draw on a common shared set of core processes, these findings indicate that for a purely spatial task, perceptual attention and working memory appear to recruit separate core capacity-limited processes
Valuing Consortial Resources: A Framework for Assessment
Grounded assessment begins with establishing the goals of an institution and its users, but there is an added layer of complexity in determining value at the consortial level, where individual institutions will naturally perceive the value of a particular resource differently. The shared resources of a consortium are also often diverse in both format and acquisition method. How should the relative value between e-books and streaming media be compared? Between leased and demand-driven acquisitions? Between open access and collaboratively owned models
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