Red synchrotron jets in Parkes quasars

We present model fits to spectral energy distributions in the optical and near-infrared of >100 flat-spectrum radio quasars from the Parkes Half-Jansky Flat-spectrum Sample. We find that ∼40 per cent of the sources have power-law spectral energy distributions (SEDs), while a similar number show evidence for two primary components: a blue power law and optical synchrotron emission. The blue power law is similar to the dominant component observed in the spectra of optically selected quasars. There is strong evidence that the synchrotron component has a turnover in the ultraviolet–optical rest frame of the spectrum. In the remaining sources, it is likely that the synchrotron peaks at longer wavelengths. This mixture of two components is supported by optical polarization measurements in a subgroup of the sources. The sources with power-law SEDs show evidence for an excess number of red power-law slopes compared with optically selected quasars. There are additional spectral components in some of the sources, such as dust and the underlying galaxy, which have not been considered here.     

Ediacaran ice-rafting and coeval asteroid impact,South Australia: insights into the terminal Proterozoic environment

Isolated quartzose pebbles, clusters of quartz granules, orthogonal aggregates of poorly sorted quartzose coarse sand, and ovoid pellets (≤2 mm long) of quartz silt occur in hemipelagic marine mudstone of the mid-Ediacaran Bunyeroo Formation exposed in the Adelaide Geosyncline (Adelaide Rift Complex), and ovoid pellets of quartz silt in cores of the correlative marine Dey Dey Mudstone from deep drillholes in the Officer Basin, South Australia. This detritus is interpreted respectively as dropstones, dumps, and frozen aggregates dispersed by sea ice possibly of seasonal origin, and till pellets transported by glacial ice. The ice-rafted material in the Bunyeroo Formation only has been found <10 m stratigraphically below and above a horizon of dacitic ejecta related to the 90 km diameter Acraman impact structure in the Mesoproterozoic Gawler Range Volcanics 300 km to the west. Furthermore, till pellets have been identified 4.4 to 68 m below distal Acraman ejecta in the Dey Dey Mudstone >500 km northwest of the impact site. The Acraman impact took place at a low paleolatitude (～12.5°) and would have adversely affected the global environment. The stratigraphic observations imply, however, that the impact occurred during, but did not trigger, a cold interval marked by sea ice and glacial ice, although the temporal relationship with Ediacaran glaciations elsewhere in Australia and on other continents is unclear. Release from the combined environmental stresses of a frigid, glacial climate near sea-level and a major impact in low latitudes may have been a factor influencing subsequent Ediacaran biotic evolution.     

The Changing Electoral Landscape of the Western United States

The Western periphery constitutes one of the primary electoral sections of the United States in presidential history. The Western periphery, although at times volatile, emerged as a Republican stronghold beginning with Dwight Eisenhower's regional electoral sweeps in the 1950s. This electoral epoch of Republican popularity in the West has been referred to as the new Western normal vote. Despite long-sustained presidential successes, since the 1988 presidential election, Democratic presidential candidates have been able to win certain states in the Republican-dominated region. This research examines the historical dynamics of Republican support in the West by identifying shifts in voting behavior between past and present epochs. We attempt to explain recent changes by exploring the historical character of the West, its demographic dynamics, and the recent turbulence within the Republican Party. County-level election returns from 1952 to 2016 are used, along with traditional and folded T-mode factor analysis, spatial regression modeling, and cartographic analysis. We conclude that the region's normal vote is deteriorating, a new electoral pattern is emerging, and these developments correspond with increasing volatility within the Republican Party.     

中国大城市低收入邻里及其居民的贫困集聚度和贫困决定因素

基于2007 年在中国6 个大城市开展的大规模家庭户调查,采用FGT指数法和逻辑回归分析方法,探讨中国大城市低收入邻里及其居民的贫困集聚程度和决定因素。研究发现,老城衰败邻里的贫困集聚度最高,同时承受多重不利状况的下岗/失业人员的贫困集聚度也是最高;事实贫困、被剥夺感与社会福利分配之间存在不匹配现象。在贫困的决定因素方面,制度保障和市场薪酬对城市贫困的发生具有同等重要的作用,但对不同低收入邻里和不同社会群体又表现出不同的关联性。随着市场作用的加强,市场薪酬机制正在成为贫困产生的更为重要的决定性因素。     

Oscillations of the Intertropical Convergence Zone and the genesis of easterly waves Part II: numerical verification

A companion paper (Part I: Toma and Webster 2008), argued that the characteristics of the mean Intertropical Convergence Zone (ITCZ) arise from instabilities associated with the strong cross-equatorial pressure gradient (CEPG) that exists in the eastern Pacific Ocean as a result of the latitudinal sea-surface temperature (SST) gradient. Furthermore, it was argued that instabilities of the mean ITCZ resulted in the in situ development of easterly waves. Thus, in Part I, it was hypothesized that the mean and transient state of eastern Pacific convection was due to local processes and less so to the advection of waves from the North Atlantic Ocean. To test this hypothesis and, at the same time, consider others such as a possible role of the equatorial and subtropical orography in generating local instabilities, a series of controlled numerical experiments are designed using the WRF regional model. The domain of the model was configured to include the western Atlantic Ocean, the Isthmus of Panama and the eastern Pacific Ocean to 155°W. Lateral boundaries were set at 40°N and 40°S, thus containing the mountains of Central America, the Andes and the Sierra Madre of Mexico. In a series of experiments, analysis products were used as boundary conditions that were successively updated four times per day, set as 10-day running average fields or as running mean monthly fields. Finally, the model was run with topography essentially eliminated over the land areas. Although there are differences between the details of the resultant fields, the location of mean convection and the form of the transients remain the same. It is concluded, in support of the theoretical and diagnostic studies of Part I that orographic forcing or waves generated in the North Atlantic Ocean are not the major causes of the mean and transient nature of disturbances in the eastern Pacific.     

Goethite adsorption of Cu(II), Pb(II), Cd(II), and Zn(II) in the presence of sulfate: Properties of the ternary complex

Adsorption of Cu²⁺, Zn²⁺, Cd²⁺, and Pb²⁺ onto goethite is enhanced in the presence of sulfate. This effect, which has also been observed on ferrihydrite, is not predicted by the diffuse layer model (DLM) using adsorption constants derived from single sorbate systems. However, by including ternary surface complexes with the stoichiometry FeOHMSO₄, where FeOH is a surface adsorption site and M²⁺ is a cation, the effect of SO₄²⁻ on cation adsorption was accurately predicted for the range of cation, goethite and SO₄²⁻ concentrations studied. While the DLM does not provide direct molecular scale insights into adsorption reactions there are several properties of ternary complexes that are evident from examining trends in their formation constants. There is a linear relationship between ternary complex formation constants and cation adsorption constants, which is consistent with previous spectroscopic evidence indicating ternary complexes involve cation binding to the oxide surface. Comparing the data from this work to previous studies on ferrihydrite suggests that ternary complex formation on ferrihydrite involves complexes with the same or similar structure as those observed on goethite. In addition, it is evident that ternary complex formation constants are larger where there is a stronger metal-ligand interaction. This is also consistent with spectroscopic studies of goethite-M²⁺-SO₄²⁻ and phthalate systems showing surface species with metal-ligand bonding. Recommended values of ternary complex formation constants for use in SO₄-rich environments, such as acid mine drainage, are presented.