104 research outputs found
Food Deserts and Migrant Farmworkers: Assessing Food Access in Oregon\u27s Willamette Valley
Food insecurity, often correlated with “food deserts,” affects migrant and seasonal farmworkers (MSFW) at greater rates than other populations. Our research evaluates the food desert experiences of MSFW communities in Oregon\u27s Willamette Valley. Through GIS mapping, interviews with MSFW, and food retailer inventories, our research helps elucidate the degree to which the geographical distribution of food retailers and the products they carry affects MSFW. Access to food retailers was assessed for distances of 0.25, 1.5, 5, and 10 miles. Mapping locations of registered MSFW labor camps (n = 62) and food retailers (n = 215) in the Willamette Valley revealed access to a food retailer within 0.25 mile for one labor camp and 1.5 miles for 46% of camps. All MSFW camps had access to a food retailer within 5 miles. Our research further suggests that using distance alone to determine food deserts may be deceptive as these numbers do not show the types of food retailers and challenges that MSFW in rural labor camps, who often lack access to personal vehicles and public transit, encounter when shopping for nutritionally and culturally appropriate foods. Migrant and seasonal farmworkers in the Willamette Valley experience significant physical and economic barriers to food access, especially culturally appropriate foods
Coupled Mg/Ca and clumped isotope analyses of foraminifera provide consistent water temperatures
The reliable determination of past seawater temperature is fundamental to paleoclimate studies. We test the robustness of two paleotemperature proxies by combining Mg/Ca and clumped isotopes (Δ47) on the same specimens of core top planktonic foraminifera. The strength of this approach is that Mg/Ca and Δ47 are measured on the same specimens of foraminifera, thereby providing two independent estimates of temperature. This replication constitutes a rigorous test of individual methods with the advantage that the same approach can be applied to fossil specimens. Aliquots for Mg/Ca and clumped analyses are treated in the same manner following a modified cleaning procedure of foraminifera for trace element and isotopic analyses. We analysed eight species of planktonic foraminifera from coretop samples over a wide range of temperatures from 2 to 29°C. We provide a new clumped isotope temperature calibrations using subaqueous cave carbonates, which is consistent with recent studies. Tandem Mg/Ca–Δ47 results follow an exponential curve as predicted by temperature calibration equations. Observed deviations from the predicted Mg/Ca-Δ47 relationship are attributed to the effects of Fe-Mn oxide coatings, contamination, or dissolution of foraminiferal tests. This coupled approach provides a high degree of confidence in temperature estimates when Mg/Ca and Δ47 yield concordant results, and can be used to infer the past δ18O of seawater (δ18Osw) for paleoclimate studies
Soliton equations and the zero curvature condition in noncommutative geometry
Familiar nonlinear and in particular soliton equations arise as zero
curvature conditions for GL(1,R) connections with noncommutative differential
calculi. The Burgers equation is formulated in this way and the Cole-Hopf
transformation for it attains the interpretation of a transformation of the
connection to a pure gauge in this mathematical framework. The KdV, modified
KdV equation and the Miura transformation are obtained jointly in a similar
setting and a rather straightforward generalization leads to the KP and a
modified KP equation.
Furthermore, a differential calculus associated with the Boussinesq equation
is derived from the KP calculus.Comment: Latex, 10 page
Data protection in elderly health care platforms
Ambient Assisted Living provides solutions to the increasing cognitive problems that affect the elderly population. To provide all features possible, Ambient Assisted Living projects require access to personal and private information of their users. Currently, the legal issues arisen in Ambient Assisted Living are a hot topic in the European Union, especially aspects regarding unsupervised data processing and cross-sharing of personal information. In this paper it is presented the iGenda project, which is a Cognitive Assistant inserted in the Ambient Assisted Living area which aims to build safe environments that adapt themselves to one’s individual needs. However, one of the issues is the protection of the data flowing within the system and the protection of user’s fundamental rights. It is also presented the principles and legal guarantees of data protection and transmission, and legal aspects are explained, embracing appropriate solutions to technological features that may be a threat.FEDER - Federación Española de Enfermedades Raras(TIN2015-65515-C4-1-R). COMPETE: POCI-01-0145-FEDER-007043 and FCT-Fundação para a Ciência e Tecnologia within the Project Scope UID/ CEC/00319/2013. A. Costa thanks the Fundação para a Ciência e a Tecnologia (FCT) the Post-Doc scholarship with the Ref. SFRH/BPD/102696/2014. This work is also partially supported by the MINECO/FEDER TIN2015-65515-C4-1-R
The caregiver perspective: an assistive AAL platform
The Ambient Assisted Living area has spawned several projects that aim to help the user on his/her daily activities. The AAL4ALL (ambient assisted living for all) project aims to develop a unified ecosystem using fully compatible devices and services. The UserAccess platform is part of the AAL4ALL and has as a goal to provide assistance to a type of actor that is commonly forgotten in the Ambient Assisted Living area, the caregiver. This paper presents the archi-tecture, implementation, and interfaces, along with a brief analysis of caregiver’s needs and work related issues.Project "AAL4ALL", co-financed by the European Community Fund FEDER, through COMPETE - Programa Operacional Factores de Competitividade (POFC). Foundation for Science and Technology (FCT), Lisbon, Portugal, through Project PEst-C/CTM/LA0025/2013 and the project PEst-OE/EEI/UI0752/2014.
Project CAMCoF - Context-aware Multimodal Communication Framework funded by ERDF -European Regional Development Fund through the COMPETE Programme (operational programme for competitiveness) and by National Funds through the FCT - Fundação para a Ciência e a Tecnologia (Portuguese Foundation for Science and Technology) within project FCOMP-01-0124-FEDER-028980
Magnetic state in URu2Si2, UPd2Al3 and UNi2Al3 probed by point contacts
The antiferromagnetic (AFM) state has been investigated in the three
heavy-fermion compounds URu2Si2, UPd2Al3, and UNi2Al3 by measuring dV/dI(V)
curves of point contacts at different temperatures (1.5-20 K) and magnetic
fields (0-28 T). The zero-bias maximum in dV/dI(V) for URu2Si2 points to a
partially gapped Fermi-surface related to the itinerant nature of the AFM state
contrary to UPd2Al3 where analogous features have not been found. The AFM state
in UNi2Al3 has more similarities with URu2Si2. For URu2Si2, the same critical
field of about 40 T along the easy c axis is found for all features in dV/dI(V)
corresponding to the Neel temperature, the gap in the electronic density of
states, and presumably the ordered moments.Comment: 10 pages incl. 5 figures, LaTex 2
Staggered Pairing Phenomenology for UPd_2Al_3 and UNi_2Al_3
We apply the staggered-pairing Ginzburg-Landau phenomenology to describe
superconductivity in UPd_2Al_3 and UNi_2Al_3. The phenomenology was applied
successfully to UPt_3 so it explains why these materials have qualitatively
different superconducting phase diagrams although they have the same
point-group symmetry. UPd_2Al_3 and UNi_2Al_3 have a two-component
superconducting order parameter transforming as an H-point irreducible
representation of the space group. Staggered superconductivity can induce
charge-density waves characterized by new Bragg peaks suggesting experimental
tests of the phenomenology.Comment: 4 pages, REVTeX, 2 Postscript figure
Breathing Current Domains in Globally Coupled Electrochemical Systems: A Comparison with a Semiconductor Model
Spatio-temporal bifurcations and complex dynamics in globally coupled
intrinsically bistable electrochemical systems with an S-shaped current-voltage
characteristic under galvanostatic control are studied theoretically on a
one-dimensional domain. The results are compared with the dynamics and the
bifurcation scenarios occurring in a closely related model which describes
pattern formation in semiconductors. Under galvanostatic control both systems
are unstable with respect to the formation of stationary large amplitude
current domains. The current domains as well as the homogeneous steady state
exhibit oscillatory instabilities for slow dynamics of the potential drop
across the double layer, or across the semiconductor device, respectively. The
interplay of the different instabilities leads to complex spatio-temporal
behavior. We find breathing current domains and chaotic spatio-temporal
dynamics in the electrochemical system. Comparing these findings with the
results obtained earlier for the semiconductor system, we outline bifurcation
scenarios leading to complex dynamics in globally coupled bistable systems with
subcritical spatial bifurcations.Comment: 13 pages, 11 figures, 70 references, RevTex4 accepted by PRE
http://pre.aps.or
RIM-BP2 primes synaptic vesicles via recruitment of Munc13-1 at hippocampal mossy fiber synapses
All synapses require fusion-competent vesicles and coordinated Ca(2+)-secretion coupling for neurotransmission, yet functional and anatomical properties are diverse across different synapse types. We show that the presynaptic protein RIM-BP2 has diversified functions in neurotransmitter release at different central murine synapses and thus contributes to synaptic diversity. At hippocampal pyramidal CA3-CA1 synapses, RIM-BP2 loss has a mild effect on neurotransmitter release, by only regulating Ca(2+)-secretion coupling. However, at hippocampal mossy fiber synapses, RIM-BP2 has a substantial impact on neurotransmitter release by promoting vesicle docking/priming and vesicular release probability via stabilization of Munc13-1 at the active zone. We suggest that differences in the active zone organization may dictate the role a protein plays in synaptic transmission and that differences in active zone architecture is a major determinant factor in the functional diversity of synapses
On the thermoelectricity of correlated electrons in the zero-temperature limit
The Seebeck coefficient of a metal is expected to display a linear
temperature-dependence in the zero-temperature limit. To attain this regime, it
is often necessary to cool the system well below 1K. We put under scrutiny the
magnitude of this term in different families of strongly-interacting electronic
systems. For a wide range of compounds (including heavy-fermion, organic and
various oxide families) a remarkable correlation between this term and the
electronic specific heat is found. We argue that a dimensionless ratio relating
these two signatures of mass renormalisation contains interesting information
about the ground state of each system. The absolute value of this ratio remains
close to unity in a wide range of strongly-correlated electron systems.Comment: 15 pages, including two figure
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