The angiogenetic effect of intramuscular administration of b-FGF and a-FGF on cardiac muscle: the influence of exercise on muscle angiogenesis     

Efthimiadou A  Asimakopoulos B  Nikolettos N  Giatromanolaki A  Sivridis E  Lialiaris TS  Papachristou DN  Kontoleon E 《Journal of sports sciences》2006,24(8):849-854

Although angiogenetic therapy using recombinant growth factors holds much hope for the treatment of ischaemic diseases, there are still many unanswered questions, including the method of administration, the correct dose of these factors, and the duration of the therapeutic approach. Exercise has also been suggested to induce neovascularizaiton in muscles. We evaluated the angiogenetic effects of the intramuscular administration of basic-fibroblast growth factor (b-FGF) and acidic-fibroblast growth factor (a-FGF) in rat heart, compared with rats who exercised daily. In conclusion, both the intramuscular administration of b-FGF and exercise increased significantly angiogenesis in the heart in contrast to the intramuscular administration of a-FGF, which was ineffective.  相似文献   

A Longitudinal Study of High‐Risk Children: Educational Outcomes     

Byron Egeland  Brian Abery 《International Journal of Disability, Development & Education》1991,38(3):271-287

DATA FROM the Mother‐Child Project, a longitudinal study of high‐risk children, indicated that the percentage of children referred for school‐based problems was approximately 40% in grades one, two and three. Basically all of the children who were referred were receiving some form of educational services. Similarly, the majority of children achieving below the 25th percentile on a standardized achievement test were receiving special educational services. The reasons some of the low‐achieving students were not receiving services were higher social adjustment, better work habits and a past educational history of success as compared to those low‐achieving students who were receiving services. Greater differences between served and unserved groups were found on historical rather than current measures, which suggests that the chronicity of educational problems had a major impact in determining which students received services. The results suggest that across the large number of schools serving high‐risk children in our sample, excellent decisions were made in terms of who received special educational assistance. There did not appear to be any bias in the referral process or in making the decision of whom to serve. This finding contradicts the results of other investigators in this area. The results from the current investigation indicate that a high proportion of high‐risk children were having difficulty in school. We were encouraged to find, however, that the high‐risk students in need of special assistance were being served.  相似文献   

含慢变量非线性系统边值问题奇摄动     

陈育森  黄蔚章 《福建师大福清分校学报》1996,(2):10-17

本研究含慢变量非线性系统边值问题：x′=f(t,x,y,ε)x(1,ε)= α（ε）εy″=F（t，x，y，y′，ε），y（1,ε）=b(ε),y(0,ε=c(ε)当F（t,x,y,y′，ε)关于y′的Jacabi矩阵Fy′的特征值具有非零实部时，应用对角化技巧证明了摄动解的存在性，并给出了解的零阶近似。  相似文献   

Effects of varying trial distribution,intra- and extramaze cues,and amount of reward on proactive interference in the radial maze     

J. S. Cohen  S. Reid  K. Chew 《Learning & behavior》1994,22(2):134-142

Rats are typically less accurate in their arm selections in the radial maze over successive trials in a session (Roberts & Dale, 1981). In the present study, rats’ choice accuracy declined when such trials were separated by 2-min (massed) but not by 2-h (spaced) intertriai intervals. Changing intramaze visual/tactile arm stimuli (Experiments 1 and 3) or extramaze landmark stimuli (Experiment 4) between trials weakened the massed-trials effect, but changing the number of food pellets per arm, either alone or in conjunction with changes in intramaze cues (Experiments 2 and 3), did not. The rats also tended to avoid the spatial locations of their last four choices on a previous trial during their first four choices on a current trial, and more so with massed than with spaced trials. These findings indicate that intertriai proactive interference (PI) occurred only with massed trials and was weakened by changing intra- and extramaze cues between such trials.  相似文献   

Methodological Issues in Cross-Syndrome Comparisons: Matching Procedures, Sensitivity (Se), and Specificity (Sp)     

Carolyn B. Mervis  & Byron F. Robinson 《Monographs of the Society for Research in Child Development》1999,64(1):115-130

  相似文献   

Washability of fine sizes of coal on tables,with particular reference to Washington and Alaskan coals     

Byron M. Bird 《Journal of The Franklin Institute》1927,204(2):273-274

  相似文献   

The Scientist as School Teacher     

Waksman  Byron H. 《Journal of Science Education and Technology》2003,12(1):51-57

Many scientists, driven by the teaching impulse, idealism, or the wish to see science thrive in the United States, take up one or another form of school teaching or participate in programs designed to enhance science teachers' knowledge of science and science teaching skills. Funding is available, from governmental and private sources, to support innovative programs designed to increase the supply of well-trained science teachers. The provision of new funds to support graduate programs in fundamental science that provide a separate track for graduate students who choose a career in teaching, in preference to a career in the laboratory, is a particularly promising development. It is essential that such programs include proper training in pedagogy. Above all, the Nation must recognize the need to provide proper long-term salary support for science teachers in the public schools countrywide, if any of the programs to improve teaching is to succeed.  相似文献   

Response-independent habituation of the orienting response in the preweanling rat     

Rick Richardson  Harlene Hayne  Byron A. Campbell 《Learning & behavior》1992,20(1):17-24

The effect of pattern of stimulus presentation on habituation of the cardiac component of the orienting response to an auditory stimulus was investigated in four experiments. The duration of stimulus presentation was held constant, but some animals were given six 10-sec stimulus presentations and others were given a single 60-sec stimulus. During the first 10 sec of the auditory stimulus, heart rate (HR) decreased approximately 40 beats per minute (bpm) in both groups, but during subsequent 10-sec epochs, the changes in HR were markedly different in the two groups. For those animals given a single 60-sec stimulus, the cardiac orienting response did not habituate; that is, HR either continued to decrease or remained approximately 40 bpm below baseline. In contrast, those animals given six 10-sec stimulus presentations showed smaller decreases in HR with each successive stimulus presentation, and after approximately four presentations, no detectable change in HR was observed. Despite these dramatic differences in habituation of the cardiac component of the orienting response, neither group oriented to the auditory stimulus when it was presented again following a short retention interval. Moreover, with increasing retention intervals, both groups showed the same forgetting function (reappearance of the orienting response). The implications of these findings for theories of the orienting response as well as theories of habituation are discussed.  相似文献   

Dyslexia quotient: An index of reading ability     

Carl L. Kline M.D.  Marjorie Ashbrenner M.A.  Byron Barrington PhD  Louis Reimer M.S.W. 《Annals of dyslexia》1968,18(1):23-31

Summary A new index for expressing degree of reading disability in children is presented. Called the Dyslexia Quotient (D. Q.), it has the advantages of being simple to calculate and of being expressed in round numbers. Standardization of this new index is presented. In addition, the use of the Dyslexia Quotient in 50 patients who completed intensive dyslexia therapy is presented. An age-improvement distribution diagram, using the D. Q. is given. The authors suggest that the Dyslexia Quotient offers a valuable universal means of indicating degree of reading disability at any grade or age level.  相似文献   

Identification of child maltreatment using prospective and self-report methodologies: a comparison of maltreatment incidence and relation to later psychopathology     

Shaffer A  Huston L  Egeland B 《Child abuse & neglect》2008,32(7):682-692

OBJECTIVES: One of the greatest methodological problems in the study of childhood maltreatment is the discrepancy in methods by which cases of child maltreatment are identified. The current study compared incidents of maltreatment identified prospectively, retrospectively, or through a combination of both methods. METHOD: Within a cohort of 170 participants followed from birth to age 19, incidents of maltreatment which occurred prior to age 17.5 were identified via prospective case review and interviewer ratings of retrospective self-reports. Multi-informant measures of behavior problems were obtained at age 16, and diagnostic assessments of psychopathology were completed at age 17.5. RESULTS: While the maximal number of maltreatment cases was identified by using a combination of all available identification methods, the prospective method was the single most comprehensive method for identifying the most cases of childhood physical abuse, sexual abuse, and neglect. Those who were identified as maltreated by a combination of both prospective and self-report methods experienced the greatest number of incidences of maltreatment (i.e., 49% of this group experienced more than one type of maltreatment) and displayed the most emotional and behavioral problems in late adolescence (i.e., 74% met diagnostic criteria for a clinical disorder). CONCLUSIONS: This study emphasizes the variability in the incidence rates of maltreatment and the psychological outcomes that result from utilizing different methods of identification. The most severe cases of maltreatment are likely to be identified by both prospective and retrospective methods; however, cases that are identified solely through retrospective self-report may have unique relations to psychopathology in late adolescence. PRACTICE IMPLICATIONS: Reliance on a single method to identify childhood maltreatment incidents often overlooks many cases. Comparing both prospective case reviews and retrospective self-reports in late adolescence, the most severe cases of multiple incidents of abuse were most likely to be identified by both methodologies. The less severe maltreatment incidents were more likely to be missed, either by prospective methods or, more frequently, by self-report methods. Practitioners must be continually sensitive to possible abuse histories among their clients, seeking out information from multiple sources whenever feasible. Additionally, the potential effects of abuse disclosure on pre-existing or developing psychopathology should be considered.  相似文献