An Investigation of Incremental Effects of Interspersed Math Items on Task-Related Behavior

The purpose of this study was to replicate and extend research on task interspersal. The authors investigated whether changes in on-task behavior of two middle school students were functionally related to changes in the relative percentages of easy and difficult items on math worksheets. They found that the participants remained on task longer while completing worksheets with 33 and 67% interspersed easy problems than while completing worksheets without the interspersed easy problems. Participants’ accuracy in answering the target problems was not affected, however, by the interspersal procedure. The authors concluded that interspersing easy items on independent math seatwork assignments can increase on-task behavior

Very Long-term Retention of the Control of Variables Strategy Following a Brief Intervention

Middle school students (n = 354) were tested for their understanding of the control of variables strategy (CVS) 2.5 years after participating in a study comparing three different interventions for teaching CVS. The key finding was that the pattern of effects observed in the 4th grade continued to be observed in the 6th grade. This was because (a) students who had mastered CVS in the 4th grade were likely to continue to perform at mastery levels in the 6th grade whereas (b) the learning of students who had not mastered CVS in 4th grade was independent of the teaching intervention they had received in the 4th-grade study. These findings demonstrate that a brief intervention of direct instruction in CVS can produce long-lasting learning of the principle of controlling variables

Bone marrow transplantation and approaches to avoid graft-versus-host disease (GVHD)

Haematopoietic stem cell transplantation (HSCT) offers promise for the treatment of haematological and immune disorders, solid tumours, and as a tolerance inducing regimen for organ transplantation. Allogeneic HSCTs engraftment requires immunosuppression and the anti-tumour effects are dependent upon the immune effector cells that are contained within or generated from the donor graft. However, significant toxicities currently limit its efficacy. These problems include: (i) graft-versus-host disease (GVHD) in which donor T cells attack the recipient resulting in multi-organ attack and morbidity, (ii) a profound period of immune deficiency following HSCT, and (iii) donor graft rejection. Currently available methods to prevent or treat GVHD with systemic immunosuppression can lead to impaired immune recovery, increased opportunistic infections, and higher relapse rates. This review will provide an overview of GVHD pathophysiology and discuss the roles of various cells, pathways, and factors in the GVHD generation process and in the preservation of graft-versus-tumour effects. Variables that need to be taken into consideration in attempting to extrapolate preclinical results to the clinical paradigm will be highlighted