Navigating the Middle Grades and Preparing Students for High School Graduation

This brief presents preliminary findings from an exploratory study of New York City students' transitions into, through, and out of the middle grades. Our analysis reveals that students' attendance and achievement in their early schooling (fourth grade) predict whether students are likely to graduate from high school many years later. Further, we find that many students begin the middle grades on-track to graduate high school but fall off this trajectory before the end of eighth grade. These findings suggest that teachers and administrators should pay close attention to students whose attendance and math achievement fall during the middle grades, as these students are particularly at risk for not graduating from high school on time

Five unconventional fuels: geology and environment

Unconventional fuels may present a viable partial replacement for conventional fossil fuel reservoirs (such as sandstone and limestone) in rocks onshore and offshore. These alternative fuels are obtained from distinct sources and employ extraction technologies which are very different to those used to extract conventional hydrocarbons. Oil sands (also known as tar sands or bituminous sands) are loose sand or partially consolidated sandstone containing viscous bitumen. Resources occur in Canada, Kazakhstan and Russia and estimated worldwide deposits represent 2500 billion barrels of oil in place. Oil sands have only recently been considered to be part of the world's oil reserves, as higher oil prices and new technology enable profitable extraction and processing. Converting oil sands to liquid fuels requires energy for steam injection and refining. Methane from coal includes gas recovered from active (coal mine methane or CMM) and abandoned mines (abandoned mine methane or AMM), as well as methane recovered from undisturbed or ‘virgin’ coal seams (usually known as coal bed methane or CBM). Gas from these sources is already produced on a modest scale and exploration is ongoing for further prospects. Gas can also be derived from coal by combustion of underground coal seams in situ to produce synthetic gas (‘syngas’). This process is usually known as 'underground coal gasification' (UCG). This technology is also in its infancy both in terms of engineering the subsurface process and in the understanding of subsurface and surface environmental impacts. Methane hydrates (methane gas trapped in ‘cages’ of water molecules, resembling ice) have been recovered from, or are postulated for, virtually all marine shallow sediment continental margins around the world and a few areas onshore. Volumes of about 2 x 1014m3 methane in‐place have been estimated for this potential resource. To quantify reserve potential and to identify suitable methods of methane extraction, a full understanding of how hydrates are held within sediments is required. A less well known unconventional fuel is subsurface hydrogen. Small flows of hydrogen naturally occur in some mines and in deep oceans associated with abiogenic and biogenic methane, nitrogen and helium. The main geological environment that is promising for exploration is the tectonic remnants of ancient ocean floor known as ophiolites. The main accessible onshore areas are where ophiolites are found tectonically emplaced within fold belts. Though unconventional fuels represent an enormous resource overall, some of the technology is immature and many of the environmental impacts of their exploitation are unknown. Apart from subsurface hydrogen, all are hydrocarbons and thus are constrained in their use in countries which may limit carbon emissions either now or in the future

Bisaccate pollen from the Early Permian OSPZ3a Sub-Biozone of the Lower Gharif Member, Oman

The OSPZ3a Sub-Biozone, associated with the lowest part of the Lower Gharif Member, is part of biozonal scheme that was intended to unify the palynological schemes across Arabia. This paper describes and illustrates the main bisaccate pollen taxa from the OSPZ3a Sub-Biozone of the Well A cored well, Oman, between 2842.69 and 2852.82 m, where they are unusually well preserved. Pteruchipollenites indarraensis which is the most common bisaccate pollen taxon, reaching 40 to 50% of assemblages, is here placed in synonymy with Alisporites tenuicorpus Balme, 1970, the latter being its junior synonym. Striatopodocarpites cancellatus consistently first occurs in the OSPZ3a Sub-Biozone, and well-preserved specimens are present in Well A, but Arabian specimens appear to have a wider range of morphology, mainly in the arrangement of taeniae, than the type material. The relationship of the genus Striatopodocarpites to Verticipollenites Bharadwaj, 1962, Lahirites Bharadwaj, 1962 and Hindipollenites Bharadwaj, 1962 is also examined with the result that Striatopodocarpites is asserted as the senior synonym. The taeniate bisaccate pollen Hamiapollenites fusiformis Marques-Toigo, 1974 is unusually common in the Well A assemblages and its morphology is found to be distinct from the similar multi-taeniate bisaccate taxon Striatoabieites multistriatus (Balme and Hennelly) Hart, 1964, with which it is sometimes placed in synonymy

Permian palynostratigraphy: a global overview

Permian palynostratigraphic schemes are used primarily to correlate coal- and hydrocarbon-bearing rocks within basins and between basins, sometimes at high levels of biostratigraphic resolution. Up to now, their main shortcoming has been the lack of correlation with schemes outside the basins, coalfields and hydrocarbon fields that they serve, and chiefly a lack of correlation with the international Permian scale. This is partly because of phytogeographical provinciality from the Guadalupian onwards, making correlation between regional palynostratigraphic schemes difficult. However, local high-resolution palynostratigraphic schemes for regions are now being linked either by assemblage-level quantitative taxonomic comparison or by the use of single well-characterized palynological taxa that occur across Permian phytogeographical provinces. Such taxa include: Scutasporites spp., Vittatina spp., Weylandites spp., Lueckisporites virkkiae, Otynisporites eotriassicus and Converrucosisporites confluens. These palynological correlations are being facilitated and supplemented with radiometric, magnetostratigraphic, independent faunal and strontium isotopic dating

Shale gas in North America and Europe

According to the U.S. Energy Information Administration, shale gas will provide half of the United States’ domestic gas by 2035. The United States has already moved from being one of the world's largest importers of gas to being self-sufficient in less than a decade, bringing hundreds of thousands of jobs and attracting back companies that long ago left America in search of cheap manufacturing costs. But the increase in shale gas extraction has also had an environmental cost. There is clear scientific evidence of leaking shale gas wells and induced earthquakes, and in some areas a population increasingly turning against the industry. The technology of horizontal drilling and hydraulic fracturing that was developed in the United States is now being tried outside the United States, including in Europe, Argentina, and China. There are clear reasons why shale gas might be attractive to Europe. It may offer security of energy supply to some countries particularly dependent on Russian gas; it could stimulate growth and jobs; and it could supply a cleaner fuel than coal in power stations. However, prospective shale often underlies areas of high population density in Europe, and moreover, populations that are unfamiliar with onshore gas operations. The main challenge in Europe therefore is not mainly technological but for the industry to achieve a “social license” and for Government and regulations to be manifestly protecting the public and property

The age of the Carboniferous-Permian Converrucosisporites confluens oppel biozone : new data from the Ganigobis shale member (Dwyka Group) of Namibia

The establishment of the Converrucosisporites confluens Oppel Zone in the Canning Basin of Australia in cored intervals from the Calytrix No. 1 Borehole was considered to be an advance in Gondwana Carboniferous–Permian palynostratigraphy. This was because the zone is associated with a marine fauna that suggests a correlation with the standard Russian Early Permian stages. Moreover the index species has a wide occurrence in Gondwana outside Australia, for example Antarctica, Argentina, Brazil, India, Oman, Saudi Arabia, and Uruguay. The zone was originally considered middle to late Asselian in age, but this was later revised to latest Asselian to Early Sakmarian. Converrucosisporites confluens is reported here from the Ganigobis Shale Member of Namibia in a well-preserved and diverse assemblage including four of the fourteen specified accessory taxa for the Converrucosisporites confluens Oppel Zone. Ash layer IIb of the Ganigobis Shale Member is radiometrically dated as 302.0 ±3.0 Ma (i.e. Pennsylvanian; Gzhelian or Kasimovian) thus the Converrucosisporites confluens Oppel Zone may range earlier than previously thought. Preliminary study of the range top of Converrucosisporites confluens in Argentina and Uruguay suggests that it ranges younger there than in Western Australia with the possibility that the Converrucosisporites confluens Oppel Zone may also be younger than previously thought

PALYNOLOGY OF THE PERMIAN OF THE MAKHTESH QATAN-2, RAMON-1 AND BOQER-1 BOREHOLES ARQOV FORMATION, NEGEV, ISRAEL

Palynological assemblages from cores 11 to 14 of Makhtesh Qatan-2, core 3 of Ramon-1 and core 3 of Boqer-1 boreholes from the Arqov Formation of the subsurface of the Negev, southern Israel, suggest that at least part of the Arqov Formation can be characterised by Cedripites priscus, Reduviasporonites chalastus and particularly Pretricolpipollenites bharadwajii, while the Saad Formation contains a slightly less diverse assemblage lacking the three taxa above. Palynological evidence is broadly consistent with other palaeontological evidence suggesting that the Saad Formation is in part likely to be Wuchiapingian in age, and the Arqov Formation is at least in part Changhsingian. These conclusions are tentative because core data is restricted to very few well penetrations and a total lack of surface exposure of the Permian

Universality of the gauge-ball spectrum of the four-dimensional pure U(1) gauge theory

We continue numerical studies of the spectrum of the pure U(1) lattice gauge theory in the confinement phase, initiated in our previous work. Using the extended Wilson action $S = -\sum_P [\beta \cos(\Theta_P) + \gamma \cos(2\Theta_P)]$ we address the question of universality of the phase transition line in the ($\beta,\gamma$) plane between the confinement and the Coulomb phases. Our present results at $\gamma= -0.5$ for the gauge-ball spectrum are fully consistent with the previous results obtained at $\gamma= -0.2$. Again, two different correlation length exponents, $\nu_{ng} = 0.35(3)$ and $\nu_{g} = 0.49(7)$, are obtained in different channels. We also confirm the stability of the values of these exponents with respect to the variation of the distance from the critical point at which they are determined. These results further demonstrate universal critical behaviour of the model at least up to correlation lengths of 4 lattice spacings when the phase transition is approached in some interval at $\gamma\leq -0.2$.Comment: 16 page

First results with non-perturbative fermion improvement

We present initial results for light hadron masses and nucleon structure functions using a recent proposal for eliminating all $O(a)$ effects from Wilson fermion simulations in the quenched approximation. With initially limited statistics, we find a much more linear APE plot and a value of the axial coupling $g_A$ nearer to the experimental point than with comparable runs using unimproved Wilson fermions.Comment: 3 pages, 2 PostScript figures, LaTeX 2.09 with espcrc2.sty v2.6, amstex and epsf, talk presented at LATTICE96(phenomenology) by P. Stephenso