A geometric basis for the standard-model gauge group

A geometric approach to the standard model in terms of the Clifford algebra Cl_7 is advanced. A key feature of the model is its use of an algebraic spinor for one generation of leptons and quarks. Spinor transformations separate into left-sided ("exterior") and right-sided ("interior") types. By definition, Poincare transformations are exterior ones. We consider all rotations in the seven-dimensional space that (1) conserve the spacetime components of the particle and antiparticle currents and (2) do not couple the right-chiral neutrino. These rotations comprise additional exterior transformations that commute with the Poincare group and form the group SU(2)_L, interior ones that constitute SU(3)_C, and a unique group of coupled double-sided rotations with U(1)_Y symmetry. The spinor mediates a physical coupling of Poincare and isotopic symmetries within the restrictions of the Coleman--Mandula theorem. The four extra spacelike dimensions in the model form a basis for the Higgs isodoublet field, whose symmetry requires the chirality of SU(2). The charge assignments of both the fundamental fermions and the Higgs boson are produced exactly.Comment: 17 pages, LaTeX requires iopart. Accepted for publication in J. Phys. A: Math. Gen. 9 Mar 2001. Typos correcte

Astigmatism and Pseudoaccommodation in Pseudophakic Eyes

noAdvanced IOLs with circumferential zones of different power provide pseudoaccommodation. We investigated the potential for power variation with meridian, namely astigmatism, to provide pseudo-accommodation. With appropriate power and axis orientations, acceptable pseudo-accommodation can be achieved

Feeding the fire: Tracing the mass-loading of 10^7 K galactic outflows with O VI absorption

Galactic outflows regulate the amount of gas galaxies convert into stars. However, it is difficult to measure the mass outflows remove because they span a large range of temperatures and phases. Here, we study the rest-frame ultraviolet spectrum of a lensed galaxy at z~2.9 with prominent interstellar absorption lines from O I, tracing neutral gas, up to O VI, tracing transitional phase gas. The O VI profile mimics weak low-ionization profiles at low velocities, and strong saturated profiles at high velocities. These trends indicate that O VI gas is co-spatial with the low-ionization gas. Further, at velocities blueward of -200 km/s the column density of the low-ionization outflow rapidly drops while the O VI column density rises, suggesting that O VI is created as the low-ionization gas is destroyed. Photoionization models do not reproduce the observed O VI, but adequately match the low-ionization gas, indicating that the phases have different formation mechanisms. Photoionized outflows are more massive than O VI outflows for most of the observed velocities, although the O VI mass outflow rate exceeds the photoionized outflow at velocities above the galaxy's escape velocity. Therefore, most gas capable of escaping the galaxy is in a hot outflow phase. We suggest that the O VI absorption is a temporary by-product of conduction transferring mass from the photoionized phase to an unobserved hot wind, and discuss how this mass-loading impacts the observed circum-galactic medium.Comment: 17 pages, 12 figures, accepted for publication in MNRA

Review of Such Silver Currents: The Story of William and Lucy Clifford

This is the first biography to record the shared and separate lives of an unusual couple, a mathematical genius called William Clifford and his literary wife, Lucy. Their biographer, M. Chisholm, has had to confront the problem of different lives and interests since the Cliffords shared only four years of marriage, but she has arranged a considerable amount of research sensibly, showing where their concerns diverged and coincided. During their time in London (1875-9) the Cliffords were at the centre of a fascinating group of celebrities, literary and scientific, who were drawn to their Sunday afternoon salons. We are likely to warm to the account of their friendship with George Eliot and Lewes, and to appreciate both William Clifford\u27s favourable review of Lewes\u27s Problems of Life and Mind and his generous recommendation of Daniel Deronda to Lucy (\u27One feels that one is looking at things with a large-minded sympathetic companion\u27). Lucy\u27s memories of her first visit as a young wife to the Priory are attractively detailed: despite breathless awe, her responses are lively, observant, natural. Lewes reminds her of \u27a rather small, active, very intelligent dog\u27. She is intensely moved by George Eliot, especially by \u27the kindly expression on her wonderful face. Wonderful? Yes, and like a horse\u27s ... a strange variety of horse that was full of knowledge, and beauty of thought, and mysteries of which the ordinary human being had no conception\u27. Interestingly, she notices that \u27the talk was a little sententious, a little too good ... so that it seldom had an air of spontaneity ... the best things were generally said by George Eliot herself\u27. In 1879, when her husband died at 33, Lucy was comforted by a letter from George Eliot linking her loss with her own loss of Lewes four months earlier: \u27I understand it all\u27. The early years of Lucy\u27s long widowhood were difficult when she had to care for her children, establish herself as a writer, and organize her salon, but for nearly fifty years she was sustained by her many friendships with the famous. The list of writers is extraordinary, including among others, William and Henry James, Leslie Stephen, Thomas Huxley, Kipling, Rhoda Broughton, Oliver Wendell Holmes Jr, James Russell Lowell, Olive Schreiner and Hardy. Even Ezra Pound appeared at one of her Sunday tea-parties. She once upset Kipling and more than once exasperated Virginia Woolf, but on the whole she inspired affection (\u27I love you so very, very much\u27, wrote Henry James). She was loyal to her friends, faithful in correspondence, generous by nature, and eager to help other writers. One friend maintained that she always had \u27some mute inglorious Milton up her sleeve\u27

Juvenile myelomonocytic leukemia (JMML)

Review on juvenile myelomonocytic leukemia, with data on clinics, pathology, and involved genes

Characterizing Shallow Groundwater Nutrient Contribution to California Central Coast Agricultural Sites and Estuaries

Shallow groundwater and shallow groundwater nitrogen have been suspected to influence agricultural tile drains, agricultural drainage ditches, and estuaries within the Lower Salinas Valley (LSV) of California’s Central Coast. This study used geochemical tracers to evaluate the influence of groundwater to each of these water sources. For agricultural sites, groundwater discharge estimates revealed between 51% ± 16% to 95% ± 30% of tile drain water was sourced from shallow groundwater. Stable isotopes of water (2HH2O and 18OH2O) confirmed that sump-influenced ditches are influenced by tile drain discharge, and that tile drains are influenced by shallow groundwater. Further, average nitrate as nitrogen (NO3-N) concentrations revealed that NO3-N in sumpinfluenced ditches were an order of magnitude higher (i.e., 33.78 to 95.21 mg L-1 NO3-N) than non-sump-influenced drainage ditches (i.e., 3.38 to 8.50 mg L-1 NO3-N). Nitrogen concentrations of shallow groundwater were also significantly lower than those of tile drain and sump water, which suggested that shallow groundwater was not the main source of nitrogen to agricultural drainage water. Stable isotopes of nitrate (15NNO3 and 18ONO3) within sump-influenced ditches were similar to those in tile drain effluent. However, groundwater nutrient discharge estimates revealed that 2.9 ± 0.7 to 5.4 ± 1.2 kg/d NO3-N of the total 9.4 ± 2.1 kg/d NO3-N from tile drains comes from shallow groundwater, further suggesting that legacy nutrients in shallow groundwater were not the primary source of nutrients to tile drains. Finally, statistical analyses (ANOVA and PERMANOVA) of nitrogen tracers reveals a lack of seasonality in agricultural drainage system nutrient content that requires further investigation to evaluate correlation with annual NO3-N variability of local estuaries and waterways (e.g., Moro Cojo Slough). This study is the first assessment of shallow groundwater influence to agricultural drainage systems via tile drains in the LSV and provides essential information for regional growers regarding nutrient water quality monitoring and best management practices, particularly in light of recent regulatory adoption of the Irrigated Lands Regulatory Program (Ag Order 4.0). Geochemical tracers were also employed to evaluate the influence of shallow groundwater on characteristic wet season NO3-N increases observed within California Central Coast estuaries. During February 2019, the characteristic NO3-N spike was observed in Moro Cojo Slough, the Moss Landing Harbor, Monterey Bay, Elkhorn Slough, and the Old Salinas River. NO3-N concentrations decreased in Moro Cojo Slough during the dry season, which highlighted the annual variability of nutrients associated with Central Coast estuaries. Radon-222 (222Rn) activities in Moro Cojo Slough surface water did not increase between wet season or dry season downstream monitoring. However, activities were greater along the channel length during the 2019 wet season (2.58 ± 1.39 dpm L-1 222Rn) than during the 2019 dry season (0.81 ± 0.57 dpm L-1 222Rn). Using surface water and groundwater 222Rn activities, groundwater discharge estimates revealed that advective groundwater flux remained low during both seasons in Moro Cojo Slough. Shallow groundwater nitrogen flux estimates revealed that groundwater was not a major source of nitrogen to Moro Cojo Slough during the wet season. Elevated dry season shallow groundwater NH4-N concentrations suggested that groundwater may significantly contribute to dry season surface water nitrogen in Moro Cojo. 222Rn activities in Elkhorn Slough (2.38 ± 1.42 dpm L-1 222Rn) were similar in magnitude to Moro Cojo Slough, while 222Rn activities in the Old Salinas River were an order of magnitude higher (25.0 ± 4.25 dpm L-1 222Rn ). Paired with our findings from Old Salinas River watershed agricultural drainage ditches and tile drains, we argue that elevated 222Rn activities in the Old Salinas River were from 222Rn-rich tile drain discharge rather than from advection of shallow groundwater to the channel. These findings highlight that groundwater via advective flux is not a significant source of water or nitrogen to California Central Coast estuaries, but that shallow groundwater discharge via tile drains plays an important role within the watershed

Use of derived forcing functions at Centaur main engine cutoff in predicting transient loads on Mariner Mars 1971 and Viking spacecraft

Mathematical models for prediction of acceleration responses and reaction forces and moments at base of Mariner Mars 71 and Viking spacecraft from Centaur main engine cutof