Non-Pauli Effects from Noncommutative Spacetimes

Noncommutative spacetimes lead to nonlocal quantum field theories (qft's) where spin-statistics theorems cannot be proved. For this reason, and also backed by detailed arguments, it has been suggested that they get corrected on such spacetimes leading to small violations of the Pauli principle. In a recent paper \cite{Pauli}, Pauli-forbidden transitions from spacetime noncommutativity were calculated and confronted with experiments. Here we give details of the computation missing from this paper. The latter was based on a spacetime $\mathcal{B}_{\chi\vec{n}}$ different from the Moyal plane. We argue that it quantizes time in units of $\chi$. Energy is then conserved only mod $\frac{2\pi}{\chi}$. Issues related to superselection rules raised by non-Pauli effects are also discussed in a preliminary manner.Comment: 15 Pages, 1 Table, Full details and further developments of arXiv:1003.2250. This version is close to the one accepted by JHE

A large terrestrial source of methyl iodide

We have identified terrestrial sources of methyl iodide (CH3I) and assessed their importance in its atmospheric budget using a synthesis of field observations. Measurements include those from NASA DC‐8 research flights over the United States and the North Atlantic, the AIRMAP long‐term ground‐observing network in New England, and a field campaign at Duke Forest, North Carolina. We found an average CH3I flux of ∼2,700 ng m−2 d−1 to the atmosphere from midlatitude vegetation and soils, a value similar in magnitude to previous estimates of the oceanic source strength. The large‐scale aircraft measurements of vertical profiles over the continental U.S. showed CH3I‐mixing ratios comparable to and greater than those observed over the North Atlantic. Overall, midlatitude terrestrial biomes appear to contribute 33 Gg yr−1 to the CH3I global budget

A large terrestrial source of methyl iodide

We have identified terrestrial sources of methyl iodide (CH3I) and assessed their importance in its atmospheric budget using a synthesis of field observations. Measurements include those from NASA DC-8 research flights over the United States and the North Atlantic, the AIRMAP long-term ground-observing network in New England, and a field campaign at Duke Forest, North Carolina. We found an average CH3I flux of ∼2,700 ng m-2 d-1 to the atmosphere from midlatitude vegetation and soils, a value similar in magnitude to previous estimates of the oceanic source strength. The large-scale aircraft measurements of vertical profiles over the continental U.S. showed CH3I-mixing ratios comparable to and greater than those observed over the North Atlantic. Overall, midlatitude terrestrial biomes appear to contribute 33 Gg yr-1 to the CH3I global budget. Copyright 2007 by the American Geophysical Union

Bromoform and dibromomethane measurements in the seacoast region of New Hampshire, 2002-2004

Atmospheric measurements of bromoform (CHBr3) and dibromomethane (CH2Br2) were conducted at two sites, Thompson Farm (TF) in Durham, New Hampshire (summer 2002-2004), and Appledore Island (AI), Maine (summer 2004). Elevated mixing ratios of CHBr3 were frequently observed at both sites, with maxima of 37.9 parts per trillion by volume (pptv) and 47.4 pptv for TF and AI, respectively. Average mixing ratios of CHBr3 and CH2Br2 at TF for all three summers ranged from 5.3-6.3 and 1.3-2.3 pptv, respectively. The average mixing ratios of both gases were higher at AI during 2004, consistent with AI's proximity to sources of these bromocarbons. Strong negative vertical gradients in the atmosphere corroborated local sources of these gases at the surface. At AI, CHBr3 and CH2Br2 mixing ratios increased with wind speed via sea-to-air transfer from supersaturated coastal waters. Large enhancements of CHBr3 and CH2Br2 were observed at both sites from 10 to 14 August 2004, coinciding with the passage of Tropical Storm Bonnie. During this period, fluxes of CHBr3 and CH2Br3 were 52.4 ± 21.0 and 9.1 ± 3.1 nmol m-2 h-1, respectively. The average fluxes of CHBr3 and CH2Br2 during nonevent periods were 18.9 ± 12.3 and 2.6 ± 1.9 nmol m-2 h-1, respectively. Additionally, CHBr3 and CH2Br2 were used as marine tracers in case studies to (1) evaluate the impact of tropical storms on emissions and distributions of marine-derived gases in the coastal region and (2) characterize the transport of air masses during pollution episodes in the northeastern United States. Copyright 2008 by the American Geophysical Union

CPT and Lorentz-invariance violation

The largest gap in our understanding of nature at the fundamental level is perhaps a unified description of gravity and quantum theory. Although there are currently a variety of theoretical approaches to this question, experimental research in this field is inhibited by the expected Planck-scale suppression of quantum-gravity effects. However, the breakdown of spacetime symmetries has recently been identified as a promising signal in this context: a number of models for underlying physics can accommodate minuscule Lorentz and CPT violation, and such effects are amenable to ultrahigh-precision tests. This presentation will give an overview of the subject. Topics such as motivations, the SME test framework, mechanisms for relativity breakdown, and experimental tests will be reviewed. Emphasis is given to observations involving antimatter.Comment: 6 page

The kinetic Alfvén-like nature of turbulent fluctuations in the Earth's magnetosheath: MMS measurement of the electron Alfvén ratio

The Magnetospheric MultiScale (MMS) mission is used to investigate turbulent fluctuations in the Earth's magnetosheath. The unique combination of multiple spacecraft and high time resolution plasma and electromagnetic field data provided by MMS makes it an ideal mission to study the nature of turbulence and energy conversion. The multiple spacecraft allow the determination of the wavevector directions and plasma frame frequencies of the fluctuations. Moreover, the particle velocities allow the determination of the ion and electron Alfvén ratios, giving an additional diagnostic to reveal the nature of the turbulent fluctuations. Finally, the currents (determined from plasma moments) and the three-dimensional electric field measurements allow the determination of a scale-dependent energy conversion rate. The results reveal that the fluctuations predominantly have kinetic Alfvén wave-like properties at wavenumbers near kpi~1 (where ρi is the ion gyroradius) and that Landau damping is an important pathway for converting energy

Characterization of postharvest physiology attributes of six commercially grown tomato varieties in Kenya

Tomato (Lycopersicon esculentum Mill) is the leading vegetable in terms of production in Kenya. The Kenyan local market has a wide variety of tomato cultivars with a wide range of morphological and sensorial characteristics. However, information on the nutritional and postharvest quality of these varieties is lacking. The aim of this research was to investigate and identify tomato varieties of superior postharvest quality and recommend them to small and medium scale farmers. In this study, six tomato varieties were grown in a greenhouse and analyzed at three maturity stages (mature green, turning and red ripe). The tomatoes were analyzed at specific days after harvest and storage at room temperature (25o C). Percentage weight loss, color, respiration and ethylene production rates were analyzed to assess the postharvest quality of the tomatoes. The color was measured using a Minolta Chromameter while the respiration rate and ethylene production rates were determined using the static system approach. Color, weight loss, respiration and ethylene production rates were positively affected by storage time when harvested at the three maturity stages. The percentage weight loss of the tomato fruits was higher in the determinate varieties, and at the turning stage of maturity (3.8 %). Minor color changes were observed after storage of the tomatoes harvested at red stage for six days. Both rates of respiration and ethylene production were low, with the respiration rate ranging between 56-10 ml CO2 Kg-1h-1. The Chonto F1 variety had the highest rate of ethylene production (5.4 μL C2H4 Kg-1h-1) on the 4th day of storage after harvest at the red ripe stage. Overall, the indeterminate tomato varieties displayed better postharvest quality that can prolong the fruits shelf life for marketing. In turn, the turning stage of maturity proved to be a better stage to harvest tomatoes as the color development was more uniform.Keywords: Tomato, varieties, postharvest quality, respiration rate, ethylene, colo

Possible coexistence of kinetic Alfvén and ion Bernstein modes in sub-ion scale compressive turbulence in the solar wind

We investigate compressive turbulence at sub-ion scales with measurements from the Magnetospheric MultiScale Mission. The tetrahedral configuration and high time resolution density data obtained by calibrating spacecraft potential allow an investigation of the turbulent density fluctuations in the solar wind and their three-dimensional structure in the sub-ion range. The wave-vector associated with the highest energy density at each spacecraft frequency is obtained by application of the multipoint signal resonator technique to the four-point density data. The fluctuations show a strong wave-vector anisotropy k⊥ k� where the parallel and perpendicular symbols are with respect to the mean magnetic-field direction. The plasma frame frequencies show two populations, one below the proton cyclotron frequency ω<ci consistent with kinetic Alfvén wave (KAW) turbulence. The second component has higher frequencies ω>ci consistent with ion Bernstein wave turbulence. Alternatively, these fluctuations may constitute KAWs that have undergone multiple wave-wave interactions, causing a broadening in the plasma frame frequencies. The scale-dependent kurtosis in this wavevector region shows a reduction in intermittency at the small scales which can also be explained by the presence of wave activity. Our results suggest that small-scale turbulence exhibits linear-wave properties of kinetic Alfvén and possibly ion-Bernstein (magnetosonic) waves. Based on our results, we speculate that these waves may play a role in describing the observed reduction in intermittency at sub-ion scales

Substantial subpial cortical demyelination in progressive multiple sclerosis: have we underestimated the extent of cortical pathology?

Aim: Multiple sclerosis (MS) is an inflammatory demyelinating and neurodegenerative disease. Much of the complex symptomatology relates to pathology outside the classic white matter plaque, whereby lesions of the cortical grey matter, which are difficult to resolve by conventional clinical imaging, are in part predictive of outcome. We investigated the extent of grey matter pathology in whole coronal macrosections to reassess the contribution of cortical pathology to total demyelinating lesion area in progressive MS. Methods: Twenty-two cases of progressive MS were prepared as whole bi-hemispheric macrosections for histology, immunostaining and quantitative analysis of lesion number and relative area, leptomeningeal inflammation and microglial/macrophage activation. Results: Cortical grey matter demyelination was seen in all cases, which was more extensive than in white and deep grey matter (hippocampus, thalamus and basal ganglia) and accounted for 0.8%-60.2% of the entire measurable cortical ribbon. The pattern of cortical grey matter demyelination was predominantly subpial (mean 90.9%, range 60%-100%, of total cortical grey matter lesion area) and cases with the largest areas of subpial cortical lesions had more and larger deep grey matter lesions, greater numbers of activated microglia/macrophages, both in lesions as well as in normal cortical grey matter, together with elevated leptomeningeal inflammation and lymphoid-like structures. White matter lesion area was unchanged when compared with the progressive MS cases with little subpial cortical demyelination. Conclusion: Analysis of whole coronal macrosections reveals cortical demyelination is more extensive than reported by conventional histological methods. Cases of progressive MS with substantial subpial cortical demyelination that is independent of underlying white matter lesion area support the implications that these lesions may in-part arise through different pathogenetic mechanisms. Biomarkers and/or imaging correlates of this subpial pathology are required if we are to fully comprehend the clinical disease process

SoC-based biomedical embedded system design of arrhythmia detector

Arrhythmia is an irregular heartbeat where the blood may not be delivered effectively throughout the body and cause sudden cardiac arrest (SCA). Immediate treatment is required to prevent SCA. However, most of the existing electrocardiogram (ECG) monitoring devices are bulky, cost expensive and lack arrhythmia detection and classification system. This paper proposes a front-end on-board graphical interface design of System-on-Chip (SoC) based arrhythmia detector which can be used as a first screening device for cardiac disease patient. The system consists of a knowledge-based arrhythmia classifier which is able to identify three types of arrhythmias which are ventricular fibrillation (VF), premature ventricular contractions (PVCs) and second-degree atrioventricular (AV) block. The system has been evaluated and benchmarked with ECG data from MIT-BIH arrhythmia database. The results show that its accuracy is up to 99.25% with a computation time of 6.385 seconds. It is highly portable and relatively inexpensive for installation in small clinics and home monitoring