A comparison of imitation strategies in observational learning of action patterns

The effects of different arrangements of demonstration and imitation of modeled actions on the learning of the 26 handshapes of the American manual alphabet were investigated. A concurrent group (N =16), which imitated handshapes concurrently with their demonstration, was compared with a delayed group (N = 16), which delayed imitation until 3 handshapes had been displayed, and with a combination group (N = 16), which practiced under a combination of concurrent conditions early in acquisition and delayed conditions later in acquisition. Following acquisition, learning was assessed by means of immediate and long-term recall and recognition tests. The delayed group was superior to the concurrent group in long-term serial recall and in immediate and long-term recognition of 3-letter sequences (in nonserial order); the performance of the combination group was between those of the delayed and concurrent groups. Therefore, delaying imitation in acquisition required subjects to expend more cognitive effort to retain and produce handshapes when requested than did concurrent imitation. This was beneficial to development of task knowledge that could be relied on for postacquisition recall and recognition of handshapes.

The effects of degradable and undegradable intake protein on the performance of lactating first-calf heifers

Two 60-d experiments were conducted to evaluate the effects of supplementing degradable (DIP) and(or) undegradable (UIP) intake protein on the performance of lactating first-calf heifers. Diets were formulated to meet the requirements for either DIP, metabolizable protein (MP), or both when diets contained low-quality grass hay and an efficiency of microbial protein synthesis estimate of 10%. In Exp. 1, 32 individually fed first-calf heifers (avg 395 kg) were allotted to a 2 x 2 factorial arrangement of treatments (main effects of DIP, MP, and DIP x MP interaction) 1 d after calving. Cows consumed a basal diet of chopped crested wheat grass hay (4.3% CP, 67% DIP) ad libitum. Supplemental DIP and UIP were supplied by varying the ratios of soybean meal (75% DIP) and a heat-treated, protected soybean meal (70% UIP). Cow weight gain was better (P < 0.01) when adequate DIP was supplied than when DIP was deficient. However, calf weight gain was not increased by supplementing the cow with DIP. Supplemental UIP did not (P > 0.40) improve cow or calf weight gain. Blood urea N levels were higher (P < 0.01) for cows receiving supplemental DIP and UIP. However, milk production estimates were similar among treatments, as were digestibilities of OM and ADF. Nitrogen digestibility was greater when supplemental DIP was fed, but providing additional UIP did not (P = 0.15) change N digestibilities. Experiment 2 evaluated similar supplements using the same experimental design to determine changes in cow and calf weight gain, body condition score, and pregnancy rate. Seventy-two first-calf heifers (avg 441 kg) were allotted to supplement treatments 1 d after calving and were fed grass hay (5% CP, 53% DIP, 10% microbial efficiency) for ad libitum consumption for 60 d. Supplements were individually fed three times/week. Varying the ratios of soybean meal, heat-treated soybean meal, and corn gluten meal provided additional DIP and UIP. Unlike in Exp. 1, supplemental UIP improved (P < 0.05) cow weight gain. Calves from dams supplemented with DIP gained 5 kg more weight after 60 d than calves from dams deficient in DIP. Pregnancy rates in the fall were similar (P = 0.90) among treatments. These data suggest that DIP was more limiting in Exp. 1 than was UIP. Supplementing UIP in Exp. 2 improved cow weight gains but did not improve calf gains. Data suggest that the efficiency of microbial protein synthesis for this forage-based diet was probably less than 10%.

Effects of racial socialization and racial identity on acculturative stress in African American college students

The aim of this study was to determine if racial identity mediates the relation between racial socialization and acculturative stress in African American university students, once demographic factors are accounted for. In a sample of 84 participants, significant relations were found between racial socialization and acculturative stress, racial socialization and racial identity, and racial identity and acculturative stress. Partial support for a mediational model was found, with the best predictors of acculturative stress being immersion attitudes and internalization attitudes.

The interaction of observational learning with overt practice: effects on motor skill learning

This study explored various methods of combining observational learning via demonstration with the effects of overt practice for learning a discrete action pattern. Three groups were compared that varied by the timing of demonstration in relation to practice. An all-pre-practice demonstration group viewed 10 pre-practice videotape demonstrations of an expert performing the skill, and then engaged in practice. An interspersed demonstration group viewed one pre-practice demonstration, then initiated practice on the skill. Every three attempts, practice was halted while participants viewed another demonstration, with this pattern repeated throughout acquisition. A combination demonstration group experienced elements of each schedule by viewing five demonstrations prior to practice, then five more once practice had begun (one every three attempts) so that modeling was completed by mid-acquisition. Ratings of form and accuracy were assessed in an acquisition phase, an immediate retention test, and a 48-h retention test. Group main effects for form scores were detected in acquisition, immediate, and 48-h retention, with the combination group obtaining the highest form scores, followed by the all-pre-practice group, and finally the interspersed group. These findings suggest that several modeling exposures before practice and several more exposures in the early stages of practice were optimal for acquisition and retention of form.

Infections in total joint replacements

This article helps orthopaedic nurses identify patients most susceptible to infection, to identify signs and symptoms of infected joints, and to understand current treatment regimens. The incidence of infection in total joint replacements (TJR) is low, but once infection is established, the morbidity is high and the limb may be threatened. Infection remains one of the most devastating complications of TJR, and the goal is to prevent all TJR infections.

The relationship between strategies of coping and perception of pain in three chronic pain groups

Examined the relationship between perception of pain, personality, coping and the reactions of family members in three chronic pain groups (sickle cell anemia, arthritis, and low back pain). Sixty black Ss equally distributed in the three medically diagnosed pain groups completed the McGill Pain Questionnaire, Maudsley Personality Inventory, a self-control measure, and the modified spouse response questionnaire. Nonsignificant association was detected between measures of pain and neuroticism; a significant inverse relationship was found between self-controlling behaviors and the affective dimension of pain; the relationship between perceived solicitous behavior and intensity and quality of pain differentiated the sickle cell and arthritic groups from the low back pain group; for the low back pain group, intensity of pain was related significantly to solicitous behaviors of family members, but the reverse was true for the arthritic and sickle cell groups.

Growth-inhibitory effect of diphenylhydantoin on murine astrocytomas

In previous work reported from this laboratory we found that diphenylhydantoin (DPH) inhibited the growth of 7 of 10 tissue-cultured human astrocytoma cell lines in a microtiter system. In this report we describe significant growth inhibition by DPH of two murine astrocytoma tissue cultures and correlate these in vitro findings with the in vivo activity of DPH in rat subcutaneous and intracranial tumor models. In the in vivo studies, rats were inoculated either subcutaneously or intracranially with RT9 or C6 rat gliomas. DPH or placebo was injected intraperitoneally in doses ranging from 50 to 150 mg/kg daily for 15 days. The DPH-treated rats showed significantly slower rates of tumor growth than untreated rats (p less than 0.01) in both the subcutaneous and intracranial models. At sacrifice, the tumor volume of the rats with subcutaneous tumors treated with DPH (100 mg/kg daily) was 62% less than the tumor volume of the control rats. Also, the number of "clonogenic" cells and thus, indirectly, the number of actively dividing tumor cells was 54% less in the intracranial tumors of the DPH-treated rats. These findings indicate that DPH may be a potentially useful adjunctive agent in the clinical chemotherapy of astrocytic tumors. Furthermore, the data presented indicate that in vitro test results are predictive for in vivo effects, supporting the idea that tissue culture can be used to screen for the effectiveness of clinically used chemotherapeutic agents.