We investigated whether individual differences in overall receptive vocabulary knowledge measured at the beginning of the year moderated the effects of a kindergarten vocabulary intervention that ...supplemented classroom vocabulary instruction. We also examined whether moderation would offset the benefits of providing Tier-2 vocabulary intervention within a multitiered-system-of-support (MTSS) or response-to-intervention framework. Participants included students from two previous studies identified as at risk for language and learning difficulties who were randomly assigned in clusters to receive small-group vocabulary intervention in addition to classroom vocabulary instruction (n = 825) or to receive classroom vocabulary instruction only (n = 781). A group of not-at-risk students (n = 741) who received classroom vocabulary instruction served as a reference group. Initial vocabulary knowledge measured at pretest moderated the impact of intervention on experimenter-developed measures of expressive vocabulary learning and listening comprehension favoring students with higher initial vocabulary knowledge. Tier-2 intervention substantially counteracted the Matthew effect for target word learning. Intervention effects on listening comprehension depended on students’ initial vocabulary knowledge. Implications present benefits and challenges of supporting vocabulary learning within an MTSS framework.
The heparin recall of 2008 Hedlund, KD; Coyne, DP; Sanford, DM ...
Perfusion,
01/2013, Letnik:
28, Številka:
1
Journal Article
Recenzirano
Heparin is one of the oldest drugs still in widespread clinical use. Its discovery in 1916 predates the establishment of the Food and Drug Administration. Since 1935, over 15,000 research papers have ...been published on the effects of heparin. Because the exact chemical formula of heparin is unknown, synthetic manufacturing has proven difficult. In 2008, a worldwide recall of heparin occurred. Scientists determined that a contaminant known as oversulfated chondroitin sulfate was responsible for the numerous deaths and adverse events. This contaminant was first traced to a chemical plant in Changzou, China. This article will review the discovery of heparin and the adulteration process that jeopardized the world’s heparin supply.
Leptin is a 16-kDa protein recently identified as the obese gene product involved in body weight regulation. Administration of recombinant leptin to ob/ob mice, which have a genetic defect in leptin ...production, reduces food intake and increases energy expenditure. Leptin is synthesized by fat cells, and in normal humans, plasma concentrations are proportional to adiposity. The physiological actions and the degradation pathways of leptin in humans are unknown. We investigated renal elimination of leptin by comparing plasma leptin concentrations in end-stage renal disease (ESRD) patients with normal controls. Our hypothesis was that if renal filtration is a significant route of elimination, the hormone would accumulate in ESRD patients. Mean plasma levels in 141 ESRD patients (26.8 +/- 5.7 and 38.3 +/- 5.6 micrograms/L for males and females, respectively) were significantly higher (P < 0.001) than mean values obtained in normal controls (11.9 +/- 3.1 and 21.2 +/- 3.0 micrograms/L for males and females, respectively). Leptin concentrations in ESRD patients correlated directly with body mass index (BMI; r = 0.77 for men and 0.78 for women). The rate of increase in leptin concentrations with BMI was significantly greater in ESRD patients (5.5 and 6.6 micrograms/L/U BMI for men and women, respectively) than in normal controls (1.4 and 2.6 micrograms/L/U for men and women, respectively). Pre- and postdialysis leptin levels in hemodialysis patients were similar. Western blot of plasma from ESRD patients with high leptin levels showed bands corresponding to the intact protein (16 kDa) with no lesser or greater molecular mass species observed. Leptin concentrations in patients with ESRD did not correlate with measures of residual renal function (serum creatinine, beta 2-microglobulin, PTH, or GH levels). Similarly, we found no correlation between leptin levels and the number of years patients had been on dialysis or with recent weight changes. We conclude that intact leptin is increased in ESRD patients, but does not appear to cause decreased weight. As leptin levels did not correlate with residual renal function, increased production may account for the high levels observed.
Abstract A low-grade myofibroblastic sarcoma was removed from the pyriform fossa of a 44-year-old man. It recurred 4 years later and was removed radically through an incision in the neck. There has ...been no further recurrence after 11 years.
The purpose of the two studies reported in this article was to evaluate the effectiveness of extended vocabulary instruction during storybook reading with kindergarten students within a small-group ...intervention setting. Extended vocabulary instruction is characterized by explicit teaching that includes both contextual and definitional information, multiple exposures to target words in varied contexts, and experiences that promote deep processing of word meanings. In Study One, we compared extended instruction of target words to incidental exposure. In Study Two, we compared extended instruction to embedded instruction (i.e., providing simple definitions within the context of the story). Our findings indicated that extended instruction resulted in greater word learning than either incidental exposure or embedded instruction. Moreover, students maintained much of their understanding of word meanings six to eight weeks after instruction. Implications are discussed in relation to a tri-level approach to vocabulary instruction and intervention for kindergarten students at risk for language and reading disabilities.
