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This study evaluates the Youth Development Program (YDP), a component of the federal Workforce Investment Act (WIA). We examine whether the YDP reduced dropout rates among youth in secondary schools in seven school districts in the impoverished Mississippi River Delta in southeast Arkansas. Initially, the program seems to have an impact. Students who participate in the program are less likely to drop out of school than students in a comparison group. However, when other factors are taken into consideration, such as whether the student was "over-age" for their grade (and thus likely had been "held back"), the effect that program participation had on the likelihood of dropping out disappears. In short, we find that when controlling for other factors, no statistically significant relationship exists between program participation and dropout rates. We discuss the implications of the WIA's YDP failure and school retention programs, more broadly.

The Ionian Zone (IZ) is one of the key elements of the fold and thrust belt (FTB) of the Albanian and Hellenides orogen and contains large outcrops of Triassic evaporites. The IZ consists of various thrust sheets with a general westward vergence, stacking over the Apulian and Pre‐Apulian zones, and repeating a thick carbonate sequence of Upper Triassic to Eocene age. Thrusting becomes younger toward the west with a piggyback sequence, starting during the latest Oligocene Epoch in the Internal Ionian and ending in the Pliocene in the External Ionian. We have studied the IZ in southern Albania and northwestern Greece using field observations and borehole data and by fully interpreting a recently acquired 2D seismic data set. Our objectives are to establish the geometry and nature of the contacts associated with the major Triassic outcrops, to unravel precursor salt diapirs, and to assess their role during the Alpine contraction. Salt structures include gentle salt pillows, isolated salt plugs and diapirs, thrust welds, and salt walls. Combining these observations with experimental modeling results, we show how these structures control the geometry and kinematics of the Alpine thrusts or the location and kinematics of recent strike‐slip faults. Salt minibasins have also been identified, demonstrating salt mobility conditioned Mesozoic sedimentation in the Ionian Basin. The use of salt‐tectonics principles to evaluate the structural style and evolution of the IZ FTB also opens new directions for interpreting the subsurface structure and evolution of the region. Key Points: The Ionian Zone in Greece and Albania is studied with surface geology, borehole data, and the interpretation of new seismic profilesTriassic salt pillows, isolated thick diapirs, and elongated salt walls condition the style of this Alpine fold and thrust beltThe role of pre‐existing diapirs is compared with experimental models [ABSTRACT FROM AUTHOR]

Scaled physical models of progradational sand wedges above a ductile polymer substrate have successfully simulated the formation of delta-top graben systems synchronous with the development of delta-toe fold-thrust belts. Delta-top graben systems are characterized by paired regional and counter-regional listric growth faults. The latter form without total removal of polymer from beneath the graben system. The delta-toe fold-thrust belts are formed by polymer bulges and fault-related detachment folds that have thickening of the ductile polymer in their cores. Multiload wedge models show the formation of younger delta-top extensional graben systems above older fold-thrust belts. The analog model results show structures similar to those found in many delta systems and provide kinematic models for their evolution.

We used seven scaled physical models to explore the near-surface structural evolution of shallowly buried, actively rising salt stocks. The models consisted of dry sand, ceramic microspheres and silicone. Previously dormant stocks rose because of lateral squeezing or pumping of salt from below. The pressure of rising salt created a dynamic bulge in the crest of the diapir, which arched the overlying roof sediments. Eventually this dynamic bulge collapsed and its overlying roof broke into rafts along subradial grabens. The rafts were dispersed outwards by shear traction of spreading salt, surmounting an upturned collar of country rock and eventually grounding at the front of the extrusive flow. Flow of salt around these stranded fragments created a lobate extrusion front, common in submarine salt sheets in the Gulf of Mexico and subaerial salt glaciers in Iran. Stock geometry, regional dip and roof density affected extrusion rates and spreading directions. Stocks leaning seaward extruded salt faster and farther than did upright stocks. Dense roofs foundered and plugged the vent, limiting surface extrusion. In tilted models, broad salt sheets spread asymmetrically downslope. Stock contents were inverted within the extruded salt sheet: successively deeper parts of the stock's core rose to the surface and overran salt extruded from the shallower parts of the diapir. As shortening continued, salt from the source layer reached the surface after being driven out by thrusting. A central thrust block, or primary indenter, moved ahead of surrounding thrust blocks, impinging against and squeezing the stock into an elliptical planform. After high shortening, secondary indenters converged obliquely into the salt stock, expelling salt from the periphery of the diapir. The models shed light on (1) the origin and fate of large rafts or carapace blocks atop allochthonous salt, (2) cuspate margins of salt sheets and (3) interaction of thrusting, diapir pinch-off and emplacement of allochthonous salt sheets. [ABSTRACT FROM AUTHOR]

The distribution of topically applied toremifene (0.5-1 mg/day for 5 days) in the ultraviolet B (UVB)-induced Monodelphis domestica opossum melanoma model was examined. The mean concentration of toremifene measured in the skin was 1200 nmol/g, or > 500 times that detected in any other tissues (blood, brain, liver, testicles, heart, uterus, eyes). In plasma, toremifene could be detected in only one animal of six (0.04 nmol/ml). Intraperitoneal administration of 0.5 mg toremifene daily for 5 days in three female animals resulted in a mean uterus concentration of 22.9 nmol/g, or 400-fold that achieved by topical administration of 0.5 mg/day in three other female Monodelphis (0.05 nmol/g). The cytostatic effect of toremifene was studied in three human melanoma cell lines and three experimental cell lines derived from UVB-induced melanocytic nevi in M. domestica. Toremifene had a cytostatic effect on all cell lines (50% growth-inhibitory concentrations, 5.8-9.6 microM). Topical toremifene administration yields high local concentration with minimal systemic distribution. In addition, toremifene has a cytostatic effect at achievable concentrations in a variety of melanomatous cell lines. [ABSTRACT FROM AUTHOR]

1. A fluorimetric method has been developed for measuring therapeutic concentrations of 6-thioguanine in human plasma. The drug was measured as an oxidized derivative, guanine 6-sulphonate. 2. 6-thioguanine was extracted from plasma by a novel procedure which isolated the drug from an interfering plasma components. This method involved the formation of the thioguanine phenyl mercury derivative in alkaline plasma and its extraction into toluene. The free drug was released by back-extraction into hydrochloric acid. 3. The assay is specific and shows a limit of sensitivity of 5 ng/ml. This was shown to be adequate for measuring plasma concentrations of 6-thioguanine after the administration of a 160 mg dose in a patient with leukaemia. [ABSTRACT FROM AUTHOR]