1,066 research outputs found
‘But You Don’t Look Like a Syrian’: Migrant Narrative Beyond the Dichotomous Divide in Migration Studies
RAM-Efficient External Memory Sorting
In recent years a large number of problems have been considered in external
memory models of computation, where the complexity measure is the number of
blocks of data that are moved between slow external memory and fast internal
memory (also called I/Os). In practice, however, internal memory time often
dominates the total running time once I/O-efficiency has been obtained. In this
paper we study algorithms for fundamental problems that are simultaneously
I/O-efficient and internal memory efficient in the RAM model of computation.Comment: To appear in Proceedings of ISAAC 2013, getting the Best Paper Awar
Fruit Color Properties of Different Cultivars of Dates (Phoenix dactylifera, L.)
Rosana G. Moreira, Editor-in-Chief; Texas A&M UniversityThis is a paper from International Commission of Agricultural Engineering (CIGR, Commission Internationale du Genie Rural) E-Journal Volume 8 (2006): Fruit Color Properties of Different Cultivars of Dates (Phoenix dactylifera, L.). Manuscript FP 05 005. Vol. VIII. March, 2006
Machine Learning Universal Bosonic Functionals
The one-body reduced density matrix plays a fundamental role in
describing and predicting quantum features of bosonic systems, such as
Bose-Einstein condensation. The recently proposed reduced density matrix
functional theory for bosonic ground states establishes the existence of a
universal functional that recovers quantum correlations
exactly. Based on a novel decomposition of , we have developed a method
to design reliable approximations for such universal functionals: our results
suggest that for translational invariant systems the constrained search
approach of functional theories can be transformed into an unconstrained
problem through a parametrization of an Euclidian space. This simplification of
the search approach allows us to use standard machine-learning methods to
perform a quite efficient computation of . For the
Bose-Hubbard model, we present a comparison between our approach and Quantum
Monte Carlo.Comment: 12 pages, 6 figure
Blunted Spontaneous Sympathetic Baroreflex Sensitivity in Young Healthy Black Men
The prevalence and severity of hypertension in black individuals are greater than in any other racial/ethnic group in the United States. The arterial baroreflex dynamically regulates blood pressure (BP) on a beat-to-beat basis via alterations in cardiac output and peripheral vascular resistance, and impairments in arterial baroreflex function are well-documented in patients with hypertension. Previous reports suggest that black individuals have a reduced cardiac baroreflex sensitivity compared to their white counterparts. However, the peripheral sympathetic component of the arterial baroreflex has never been examined in young healthy black individuals. PURPOSE: We sought to compare spontaneous sympathetic baroreflex sensitivity between young healthy black and white men. METHODS: Seven healthy black (age: 20 ± 1 years, BMI: 24.3 ± 1.3 kg/m2) and seven healthy white (age: 22 ± 1 years, BMI: 27.0 ± 1.2 kg/m2) men participated in the study. Heart rate (ECG), beat-to-beat BP (finger photoplethysmography) and muscle sympathetic nerve activity (MSNA; peroneal microneurography) were continuously measured during a 20-minute resting period. MSNA was quantified as burst incidence (bursts/100 heartbeats) and averaged over 3-mmHg diastolic BP bins for each individual. The linear relationship between the spontaneous changes in MSNA and diastolic BP was assessed using a weighted linear regression analysis. Sympathetic baroreflex sensitivity was quantified as the slope of MSNA burst incidence to diastolic BP. RESULTS: Heart rate, systolic BP, diastolic BP and mean arterial pressure was not different between the 2 groups (p \u3e 0.05 for all). MSNA burst incidence was also similar between the two groups (black men, 16 ± 2.2 burst/100 heartbeats vs. white men, 21.4 ± 2.0 bursts/100 heartbeats, p = 0.10). The slope of MSNA burst incidence to diastolic BP was significantly lower in black compared to white men (black men, -2.20 ± 0.4 bursts/100 heartbeats/mmHg vs. white men, -3.36 ± 0.3 bursts/100 heartbeats/mmHg, p = 0.03). CONCLUSION: These preliminary data suggest that young healthy black men have a blunted sympathetic baroreflex sensitivity compared to white men
Exploring the Potential Role of Family History of Hypertension on Racial Differences in Sympathetic Vascular Transduction
The prevalence of hypertension in Non-Hispanic Black (BL) men surpasses all other racial groups. Our laboratory has previously demonstrated exaggerated vasoconstrictor and blood pressure (BP) responses to spontaneous bursts of muscle sympathetic nerve activity (MSNA; sympathetic vascular transduction) in young, healthy BL men compared to their Non-Hispanic White (WH) counterparts. Because a family history of hypertension (FHH) further compounds cardiovascular risk, we wanted to begin to explore the potential impact of a positive (+) FHH on sympathetic vascular transduction. Whether a +FHH influences sympathetic vascular transduction in WH and/or BL men remains unknown. PURPOSE: To begin to explore if +FHH influences sympathetic vascular transduction within and between racial groups. METHODS: 22 men, nine with a +FHH (4 BL men) and 13 without a FHH (-FHH; 6 BL men) were recruited. Beat-to-beat BP (Finometer), femoral artery blood flow (Doppler ultrasound), and MSNA were measured during a 20-minute quiet rest. The mean BP and leg vascular conductance (LVC; blood flow/mean BP) responses to spontaneous bursts of MSNA were quantified via a signal averaging technique. RESULTS: Resting heart rate, BP, and MSNA were not significantly different between groups (all p\u3e0.05). As previously demonstrated by our laboratory, the BL men exhibited an augmented sympathetic vascular transduction compared to the WH men (e.g., peak BP response, WH men: Δ4.1±0.3, BL men: Δ5.6±0.7 mmHg, p=0.04). When accounting for FHH within the groups, the peak BP (WH +FHH: Δ4.4±0.6 vs. WH -FHH: Δ3.8±0.4 mmHg, p=0.4) and nadir LVC responses (WH +FHH: Δ-0.5±0.07 vs. WH -FHH: Δ-0.5±0.09 ml·min-¹·mmHg-¹, p=0.7) were not significantly different between WH men +FHH and WH men –FHH. Likewise, the BL men +FHH exhibited similar peak BP (BL +FHH: Δ6.2±0.7 vs. BL -FHH: Δ5.3±1.1 mmHg, p=0.5) and nadir LVC (BL +FHH: Δ-1.1±0.44 vs. BL -FHH: Δ-0.6±0.10 ml·min-¹·mmHg-¹, p=0.2) responses to bursts of MSNA compared to the BL men –FHH. CONCLUSION: These preliminary findings do not support a role for +FHH in augmented sympathetic vascular transduction, therefore suggesting that racial differences in sympathetic vascular transduction are independent of FHH
RF-compass: Robot object manipulation using RFIDs
Modern robots have to interact with their environment, search for objects, and move them around. Yet, for a robot to pick up an object, it needs to identify the object's orientation and locate it to within centimeter-scale accuracy. Existing systems that provide such information are either very expensive (e.g., the VICON motion capture system valued at hundreds of thousands of dollars) and/or suffer from occlusion and narrow field of view (e.g., computer vision approaches).
This paper presents RF-Compass, an RFID-based system for robot navigation and object manipulation. RFIDs are low-cost and work in non-line-of-sight scenarios, allowing them to address the limitations of existing solutions. Given an RFID-tagged object, RF-Compass accurately navigates a robot equipped with RFIDs toward the object. Further, it locates the center of the object to within a few centimeters and identifies its orientation so that the robot may pick it up. RF-Compass's key innovation is an iterative algorithm formulated as a convex optimization problem. The algorithm uses the RFID signals to partition the space and keeps refining the partitions based on the robot's consecutive moves.We have implemented RF-Compass using USRP software radios and evaluated it with commercial RFIDs and a KUKA youBot robot. For the task of furniture assembly, RF-Compass can locate furniture parts to a median of 1.28 cm, and identify their orientation to a median of 3.3 degrees.National Science Foundation (U.S.
Benthic foraminifera distribution and sedimentary environmental evolution of a carbonate platform: A case study of the Guadalupian (middle Permian) in eastern Sichuan Basin
Benthic foraminifera are significant indicators of habitat changes and are useful for paleoenvironmental reconstruction. During the Permian period, the variation in species, individual sizes, and morphological characteristics of the different assemblages, such as the fusulinids, is a clue to paleoecological and paleoenvironmental interpretations. The eastern part of the Sichuan Basin, located near the equator in the middle Permian, Guadalupian period, was precipitated by thick beds of marine carbonate rocks with numerous benthic foraminifera. In this study, we record the species and calculate the frequency of benthic foraminifera from 445 thin sections of Guadalupian (Maokou Formation) marine carbonate rocks. Seven types of benthic foraminiferal biofacies are recognized and associated with five sedimentary microfacies in the Erya and Huilongchang sections, eastern Sichuan area. During the early Guadalupian period, small uniserial nodosariids and Endothyrida dominated the benthic foraminiferal assemblages; in the middle Guadalupian period, species of Miliolida, Ammodiscidae, and uniserial nodosariids were common; however, the species of Fusulinida, such as Schwagerina sp. and Verbeekina sp., were abundant in the late Guadalupian period. The associated sedimentary microfacies indicates a shallow open platform to marginal platform. In our study area, the early Guadalupian was deposited in an open platform to grain shoals. This was followed by gradual shallowing as the sedimentary environment shifted to marginal shallow shoals from the middle to late Guadalupian period until the paleoweathering abruptly terminated the deposition at the end of the Guadalupian period
Reação da cultivar Navelina ISA 315 (Citrus sinensis L. Osb.), à clorose variegada dos citros em condições de campo.
A clorose variegada dos citros (CVC), causada pela bactéria Xylella fastidiosa, está presente no Estado de São Paulo desde 1987. Todas as variedades comerciais de laranjas doces são afetadas. Causa redução da produção, principalmente pela acentuada redução no tamanho dos frutos. (LARANJEIRA et al., 2005). A CVC é transmitida por meio de borbulhas contaminadas e por cigarrinhas das famílias Cicadellidae, em citros existem diversas espécies transmissoras de X. fastidiosa, porém a eficiência na transmissão é inferior a 15%, e este índice pode variar entre espécies em função de mecanismos fisiológicos e comportamentais (YAMAMOTO, 2007; LOPES, 1996). Os sintomas característicos da doença são cloroses internervais amareladas na face superior da folha com correspondente necroses de tons de marrom na face inferior, a frutificação tem tendência de ser em pencas onde os frutos tornam-se rígidos, pequenos e com uma concentração de açúcar maior que o normal (LARANJEIRA et al., 2005).pdf 12
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