In addition to host-derived factors, pharmacologic agents also have profound impact on MDSC . Chemotherapeutic agents belonging to different classes have been reported to inhibit MDSC . Although this effect may well be secondary to inhibition of hematopoietic progenitors, there may be grounds for search of selectivity based on long-known differential effects of these agents on immunocompetent cells and macrophages.
32.
Although Eph-ephrin activation is usually associated with decreased growth cone survival and the repellence of migrating axons, it has recently been demonstrated that growth cone survival does not depend just on Eph-ephrin activation, but rather on the differential effects of " forward " signaling by the Eph receptor or " reverse " signaling by the ephrin ligand on growth cone survival.
33.
There are now three existing competing hypotheses : 1 ) Media Malaise hypothesis ( that predicts a general negative effect ), 2 ) the Virtuous Circle hypothesis ( that predicts a general positive effect ), and 3 ) the Differential Effect hypothesis ( that predicts a positive effect from newspapers, and a null or negative effect from television ) " ( Fraile, 2011 ).
34.
Beutler, Moleiro and Talebi reviewed 20 studies that inspected the differential effects of therapist directiveness as moderated by client resistance and found that 80 % ( n = 16 ) of the studies demonstrated that directive interventions were most productive among clients who had relatively low levels of state or trait-like resistance, while nondirective interventions worked best among clients who had relatively high levels of resistance.
35.
If the expected value of under the null hypothesis is not equal to zero, then a situation where we reject the null hypothesis could either be due to an actual differential effect between teaching strategies and, or it could be due to non-independence in the assignment of students to the and groups ( even in the complete absence of an effect due to the teaching strategy ).
