728 research outputs found
Context-Free Path Queries on RDF Graphs
Navigational graph queries are an important class of queries that canextract
implicit binary relations over the nodes of input graphs. Most of the
navigational query languages used in the RDF community, e.g. property paths in
W3C SPARQL 1.1 and nested regular expressions in nSPARQL, are based on the
regular expressions. It is known that regular expressions have limited
expressivity; for instance, some natural queries, like same generation-queries,
are not expressible with regular expressions. To overcome this limitation, in
this paper, we present cfSPARQL, an extension of SPARQL query language equipped
with context-free grammars. The cfSPARQL language is strictly more expressive
than property paths and nested expressions. The additional expressivity can be
used for modelling graph similarities, graph summarization and ontology
alignment. Despite the increasing expressivity, we show that cfSPARQL still
enjoys a low computational complexity and can be evaluated efficiently.Comment: 25 page
Review of Intellectual Capital Components Research
The success of the organizations in a competitive business environment is depending on the intellectual capital, which is considered as strategic assets for sustainability of the organization. In the knowledge-based economy, modern and high tech organizations not only concentrate on innovation, services, marketing, research and development, instead pay particular attention to the organization intellectual capital. The aim of this paper is to investigate theoretically and empirically contributions in the subject of intellectual capital in an endeavor to recognize the components of intellectual capital. However, to achieve the objective of this paper a comprehensive related literature review was performed. The related literature showed that there are nine dimensions of intellectual capital that have been identified
Millimeter Wave Communications
Millimeter wave (mmWave) technologies promise to revolutionize wireless networks by enabling multi-gigabit data rates. However, they suffer from high attenuation, and hence have to use highly directional antennas to focus their power on the receiver. Existing radios have to scan the space to find the best alignment between the transmitter’s and receiver’s beams, a process that takes up to a few seconds. This delay is problematic in a network setting where the base station needs to quickly switch between users and accommodate mobile clients.
We present Agile-Link, the first mmWave beam steering system that is demonstrated to find the correct beam alignment without scanning the space. Instead of scanning, Agile- Link hashes the beam directions using a few carefully chosen hash functions. It then identifies the correct alignment by tracking how the energy changes across different hash functions. Our results show that Agile-Link reduces beam steering delay by orders of magnitude.National Science Foundation (U.S.
Common variants in FOXP1 are associated with generalized vitiligo
In a recent genome-wide association study of generalized vitiligo, we identified ten confirmed susceptibility loci. By testing additional loci that showed suggestive association in the genome-wide study, using two replication cohorts of European descent, we observed replicated association of generalized vitiligo with variants at 3p13 encompassing FOXP1 (rs17008723, combined P = 1.04 × 10−8) and with variants at 6q27 encompassing CCR6 (rs6902119, combined P = 3.94 × 10−7)
Relativistic spin-0 particle in a box: bound states, wavepackets, and the disappearance of the Klein paradox
The "particle in a box" problem is investigated for a relativistic particle
obeying the Klein-Gordon equation. To find the bound states, the standard
methods known from elementary non-relativistic quantum mechanics can only be
employed for "shallow" wells. For deeper wells, when the confining potentials
become supercritical, we show that a method based on a scattering expansion
accounts for Klein tunneling (undamped propagation outside the well) and the
Klein paradox (charge density increase inside the well). We will see that in
the infinite well limit, the wavefunction outside the well vanishes and Klein
tunneling is suppressed: quantization is thus recovered, similarly to the
non-relativistic particle in a box. In addition, we show how wavepackets can be
constructed semi-analytically from the scattering expansion, accounting for the
dynamics of Klein tunneling in a physically intuitive wa
Evolution of strictly localized states in non-interacting quantum field theories with background fields
We investigate the construction of spin-1/2 fermionic and spin-0 bosonic
wave-packets having compact spatial support in the framework of a computational
quantum field theory (QFT) scheme offering space-time solutions of the
relativistic wave equations in background fields. In order to construct
perfectly localized wave-packets, we introduce a spatial density operator
accounting for particles of both positive and negative charge. We examine
properties of the vacuum and single-particle expectation values of this
operator and compare them to the standard QFT particle and anti-particle
spatial densities. The formalism is illustrated by computing numerically the
Klein tunneling dynamics of strictly localized wave-packets impinging on a
supercritical electrostatic step. The density operator introduced here could be
useful to model situations in which it is desirable to avoid dealing with the
infinite spatial tails intrinsic to pure particle or anti-particle
wave-packets
Exercise protects against obesity induced semen abnormalities via downregulating stem cell factor, upregulating Ghrelin and normalizing oxidative stress
Increased oxidative stress and hormonal imbalance have been hypothesized to underlie infertility in obese animals. However, recent evidence suggests that Ghrelin and Stem Cell Factor (SCF) play an important role in fertility, in lean individuals. Therefore, this study aimed at investigating whether changes in the levels of Ghrelin and SCF in rat testes underlie semen abnormal parameters observed in obese rats, and secondly, whether endurance exercise or
Orlistat can protect against changes in Ghrelin, SCF, and/or semen parameters in diet induced obese rats. Obesity was modelled in male Wistar rats using High Fat Diet (HFD) 12-week protocol. Eight week-old rats (n=40) were divided into four groups, namely, Group I: fed with a standard diet (12 % of calories as fat); Group II: fed HFD (40 % of calories as fat); Group III: fed the HFD with a concomitant dose of Orlistat (200 mg/kg); and Group IV: fed the HFD
and underwent 30 min daily swimming exercise.
The model was validated by measuring the
levels of testosterone, FSH, LH, estradiol, leptin, triglycerides, total, HDL, and LDL cholesterol, and final change in body weight. Levels were consistent with published obesity models (see Results). As predicted, the HFD group had a 76.8 % decrease in sperm count, 44.72 % decrease in sperm motility, as well as 47.09 % increase in abnormal sperm morphology. Unlike the control group, in the HFD group (i.e. obese
rats) Ghrelin mRNA and protein were elevated, while SCF mRNA and protein were diminished in the testes. Furthermore, in the HFD group, SOD and GPx activities were significantly reduced, 48.5±5.8 % (P=0.0012) and 45.6±4.6 % (P=0.0019), respectively, while TBARS levels were significantly increased (112.7±8.9 %, P≤0.0001). Finally, endurance exercise training and Orlistat administration individually and differentially protected semen parameters in obese rats. The mechanism includes, but is not limited to, normalizing the levels of Ghrelin, SCF, SOD, GPx and TBARS. In rat testes, diet induced obesity down regulates SCF expression, upregulates Ghrelin expression, and deteriorate oxidative stress levels, which are collectively detrimental to semen parameters. Exercise, and to a lesse
r extent Orlistat administration, protected effectively against this detrimental effect
ROOTING OF DATE PALM (PHOENIX DACTYLIFERA L.) OFFSHOOTS BY ISOPROTHIOLANE (IPT)
The experiment was conducted at Alhassa Oasis (25° 22′ N' latitude; 49°34′ E longitude) and altitude is 179 m a.s.l , Kingdom of Saudi Arabia. Treatments included the following Isoprothiolane (IPT) concentrations incorporated at the bottom of offshoot hole: control (without IPT), 25g, 50g, 75g, 100g, 200g and 500g / offshoot hole. The offshoots weight ranged between 25 – 30 kg. The IPT concentrations of 75 and 100 g/ offshoot hole seemed to be quite optimal for improving rooting of date palm offshoots. The best rooting percentage, length of root, root fresh and dry weights were obtained under 75 and 100 g/ offshoot whole IPT concentrations. Offshoots under the control and the lowest and highest IPT treatments reflected poor rooting ability. The chlorophyll content data although looked relatively similar between treatments, a slight edge of 75 and 100 g/ offshoot hole was noticeable. This relative edge might have played a significant role in the photosynthetic ability of offshoots. The efficiency of rooting of offshoots under both concentrations might have resulted from their edged photosynthetic ability
ROOTING OF DATE PALM (PHOENIX DACTYLIFERA L.) OFFSHOOTS BY ISOPROTHIOLANE (IPT)
The experiment was conducted at Alhassa Oasis (25° 22′ N' latitude; 49°34′ E longitude) and altitude is 179 m a.s.l , Kingdom of Saudi Arabia. Treatments included the following Isoprothiolane (IPT) concentrations incorporated at the bottom of offshoot hole: control (without IPT), 25g, 50g, 75g, 100g, 200g and 500g / offshoot hole. The offshoots weight ranged between 25 – 30 kg. The IPT concentrations of 75 and 100 g/ offshoot hole seemed to be quite optimal for improving rooting of date palm offshoots. The best rooting percentage, length of root, root fresh and dry weights were obtained under 75 and 100 g/ offshoot whole IPT concentrations. Offshoots under the control and the lowest and highest IPT treatments reflected poor rooting ability. The chlorophyll content data although looked relatively similar between treatments, a slight edge of 75 and 100 g/ offshoot hole was noticeable. This relative edge might have played a significant role in the photosynthetic ability of offshoots. The efficiency of rooting of offshoots under both concentrations might have resulted from their edged photosynthetic ability
Assessing the exposure-response relationship of sleep disturbance and vibration in field and laboratory settings
Exposure to nocturnal freight train vibrations may impact sleep, but exposure-response relationships are lacking. The European project CargoVibes evaluated sleep disturbance both in the field and in the laboratory and provides unique data, as measures of response and exposure metrics are comparable. This paper therefore provides data on exposure-response relationships of vibration and sleep disturbance and compares the relationships evaluated in the laboratory and the field. Two field studies (one in Poland and one in the Netherlands) with 233 valid respondents in total, and three laboratory studies in Sweden with a total of 59 subjects over 350 person-nights were performed. The odds ratios (OR) of sleep disturbance were analyzed in relation to nighttime vibration exposure by ordinal logit regression, adjusting for moderating factors common for the studies. Outcome specific fractions were calculated for eleven sleep outcomes and supported comparability between the field and laboratory settings. Vibration exposure was significantly associated to sleep disturbance, OR = 3.51 (95% confidence interval 2.6–4.73) denoting a three and a half times increased odds of sleep disturbance with one unit increased 8 h nighttime log10 Root Mean Square vibration. The results suggest no significant difference between field and laboratory settings OR = 1.37 (0.59–3.19). However, odds of sleep disturbance were higher in the Netherlands as compared to Sweden, indicating unexplained differences between study populations or countries, possibly related to cultural and contextual differences and uncertainties in exposure assessments. Future studies should be carefully designed to record explanatory factors in the field and enhance ecological validity in the laboratory. Nevertheless, the presented combined data set provides a first set of exposure response relationships for vibration-induced sleep disturbance, which are useful when considering public health outcomes among exposed populations
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