Soil aldehydes: A scientific study of a new class of soil constituents unfavorable to crops,their occurrence,properties and elimination in practical agriculture     

Joshua J. Skinner 《Journal of The Franklin Institute》1918,186(6):723-741

The experimental results show that aldehydes are harmful to plant growth in aqueous culture solutions, in nutrient solutions, in soil in pots, and in soil in the field.The effects of six aldehydes—namely, salicylic aldehyde, vanillin, benzaldehyde, heliotropine, formaldehyde, and paraformaldehyde—were studied in nutrient-culture solutions and each proved to be detrimental to plant growth.The effect of the compounds varied according to the composition of the nutrient solutions. Salicylic aldehyde was least harmful in solutions composed of a high percentage of phosphates. Vanillin was least harmful in solutions with a high percentage of nitrates. Benzaldehyde was about equally harmful in all the nutrient solutions. It was slightly more harmful, however, in the high nitrate solutions than in the mainly phosphatic or potassic cultures. Paraformaldehyde was also least harmful in the phosphate culture, but formaldehyde and heliotropine showed harmful effects to an equal degree in almost all cultures, regardless of their composition.Salicylic aldehyde and vanillin were found to occur in soils quite frequently, especially in soils of low productivity. The isolated substance from the soils was harmful to plants when dissolved in aqueous solution.The two aldehydes were harmful in some soils and not in others. The field studies show that the added aldehydes disappeared in some soils and not in others. There was no harmful action where the aldehydes were destroyed. The soils in which the aldehydes were destroyed have strong biological activities, good oxidation powers, and are fertile.The results of the experimental work presented in this paper further show that unfertile soils, where due to the presence of harmful aldehydes, can be made productive by good drainage and by the use of lime and certain fertilizers. This is demonstrated, first, by the growth of plants in nutrient solutions, where it is shown that phosphates partially overcome the bad effects of salicylic aldehyde, and that nitrates ameliorate the harmfulness of another aldehyde, vanillin. Second, by the more normal absorption of phosphates by plants growing in solutions containing salicylic aldehyde. Third, by the growth of plants in soil in pots, which shows that the harmful action of salicylic aldehyde is partially overcome by lime and phosphates and the effects of vanillin by lime and nitrate fertilizers. Fourth, by the growth of plants in field soils to which aldehydes were added, which again shows that lime and phosphates lessen the harmfulness of salicylic aldehyde and lime and nitrates alter the effects of vanillin. Fifth, by chemical tests in which it was shown that salicylic aldehyde, when added to a soil, was destroyed where lime and phosphates were added, and vanillin was destroyed where lime and nitrates were added. Sixth, by the improved productivity from the addition of lime and phosphates to a soil in which salicylic aldehyde was naturally formed and persisted for a period of years.  相似文献   

Rats in a levered T-maze task show evidence of time–place discriminations in two different measures     

Scott H. Deibel  Andrew B. Lehr  Chelsea Maloney  Matthew L. Ingram  Leanna M. Lewis  Anne-Marie P. Chaulk  Pam D. Chaulk  Darlene M. Skinner  Christina M. Thorpe 《Learning & behavior》2017,45(2):184-190

It is difficult for rats to learn to go to an arm of a T-maze to receive food that is dependent on the time of day, unless the amount of food in each daily session is different. In the same task, rats show evidence of time–place discriminations if they are required to press levers in the arms of the T-maze, but learning is only evident when the first lever press is considered, and not the first arm visited. These data suggest that rats struggle to use time as a discriminative stimulus unless the rewards/events differ in some dimension, or unless the goal locations can be visited prior to making a response. If both of these conditions are met in the same task, it might be possible to compare time–place learning in two different measures that essentially indicate performance before and after entering the arms of the T-maze. In the present study, we investigated time–place learning in rats with a levered T-maze task in which the amounts of food varied depending on the time of day. The first arm choices and first lever presses both indicated that the rats had acquired time–place discriminations, and both of these measures became significantly different from chance during the same block. However, there were subtle differences between the two measures, which suggest that time–place discrimination is aided by visiting the goal locations.  相似文献   

The Development and Correlates of Gender Role Orientations in African‐American Youth          下载免费PDF全文

Olivenne D. Skinner  Susan M. McHale 《Child development》2018,89(5):1704-1719

This study charted the development of gendered personality qualities, activity interests, and attitudes across adolescence (approximately ages 9–18) among 319 African‐American youth from 166 families. The relations between daily time spent with father, mother, and male and female peers—the gendered contexts of youth's daily activities—and (changes in) these gender role orientations were also assessed. Boys and girls differed in their gender role orientations in stereotypical ways: interest in masculine and feminine activities, and attitude traditionality generally declined, but instrumentality increased across adolescence and expressivity first increased and later decreased. Some gender differences and variations in change were conditioned by time spent with same‐ and other‐sex gender parents and peers. The most consistent pattern was time with male peers predicting boys' stereotypical characteristics.  相似文献   

A preliminary investigation of the concurrent validity of reading comprehension rate: A direct,dynamic measure of reading comprehension     

Christine E. Neddenriep  Andrea D. Hale  Christopher H. Skinner  Renee O. Hawkins  Beth D. Winn 《Psychology in the schools》2007,44(4):373-388

Reading comprehension rate (RCR) is a direct measure of reading skills that may be useful in formatively evaluating students reading beyond the fourth‐grade level. To investigate the concurrent validity of RCR, we correlated RCR, reading comprehension level (RCL), and words correct per minute (WC/M) with the Broad Reading Cluster Scores of the Woodcock‐Johnson III Tests of Achievement (WJ‐III ACH) across 88 students in 4th, 5th, and 10th grades. Results showed that aloud‐RCR was significantly correlated with the WJ‐III ACH scores for 4th‐grade (r = .90; n = 22), 5th‐grade (r = .87; n = 29), and 10th‐grade (r = .65; n = 37) students. Regression analysis specified a one‐predictor model for 4th‐grade students (aloud‐RCR), a two‐predictor model for 5th‐grade students (WC/M and aloud‐RCR), and a one‐predictor model for 10th‐grade students (WC/M). Discussion focuses on directions for future research and applied issues related to RCR probe passage development. © 2007 Wiley Periodicals, Inc. Psychol Schs 44: 373–388, 2007.  相似文献   

Social Participation of Children with Disabilities in Inclusive Preschool Programs: Program Typology and Ecological Features     

Ling-Ling Tsao  Samuel L. Odom  Virginia Buysse  Marti Skinner  Tracy West  Joann Vitztum-Komanecki 《Exceptionality》2013,21(3):125-140

The purpose of this study was to examine the social participation of young children with disabilities in inclusive preschool programs. One hundred forty-three preschool-aged children with disabilities were observed in classrooms representing four organizational contexts: community-based, Head Start, public school, and blended. Children's and adults' social behavior was positive across settings, and children in blended programs engaged in significantly more positive social behavior with adults. Peer social engagement did not differ across organizational contexts. Activity initiator was an ecological variable that affected children's social engagement in that children engaged in significantly more interaction with peers in child-initiated activities and significantly more interaction with adults in adult-initiated activities.).  相似文献   

A study of sewage and trade wastes at bridgeport,Connecticut     

W.W. Skinner  J.W. Sale 《Journal of The Franklin Institute》1921,192(6):785-799

  相似文献   

Teachers who abuse: the impact on school communities     

Julie Skinner 《Educational research; a review for teachers and all concerned with progress in education》2013,55(2):161-174

This paper addresses issues that may arise of a teacher or school employee is abusing pupils within the school community. Interviews were conducted with a number of respondents who had experienced situations of abuse within the school context. The incidents used, as case examples, all concern sexual abuse, although the framework developed could be used to examine different types of abuse. The paper concludes that changes in legislation and guidelines can improve practice, but that less tangible issues will continue to be involved when dealing with abuse, and that raising awareness of the issues is a key factor.  相似文献   

A comparison of class‐wide taped problems and cover,copy, and compare for enhancing mathematics fluency     

Brian C. Poncy  Christopher H. Skinner  Elizabeth McCallum 《Psychology in the schools》2012,49(8):744-755

An adapted alternating treatments design was used to compare the effects of class‐wide applications of Taped Problems (TP) and Cover, Copy, and Compare (CCC) procedures designed to enhance subtraction fact fluency in an intact third‐grade classroom. During the TP procedure, a tape provided an auditory prompt (i.e., the problem), followed by a 2‐second delay and then the correct answer. Students attempted to supply the correct answer before the answer was provided by the tape. During the CCC procedure, students would cover a math‐fact family triangle, attempt to write one of two possible problems and answer, write the reciprocal fact and answer, and evaluate their responses. Results show that TP caused greater increases in subtraction fact fluency than CCC or a control condition. Discussion focuses on preventing student math deficits, issues regarding alternating treatments designs, and future directions for research. © 2012 Wiley Periodicals, Inc.  相似文献   

Correction to: The Transition from Aerobic to Anaerobic Metabolism     

James S. Skinner  Thomas M. McLellan 《Research quarterly for exercise and sport》2013,84(2)

  相似文献   

Implementing RFID in a hospital library: a scoping study     

Norwood J  Skinner B 《Health information and libraries journal》2012,29(2):162-165

This article discusses a scoping study on implementing radio frequency identification device (RFID) in a hospital library context, conducted by Joseph Norwood for his MA dissertation at the University of Brighton. The study was carried out during the summer of 2011 to support possible RFID implementation at the Brighton and Sussex University Hospitals (BSUH) Trust, and the library staff were able to use the findings to good effect to create a business plan. This article also acts as the template for the new Dissertations into Practice feature, which was introduced in the March issue (Marshall, A. Health Information and Libraries Journal 2012, 29, 72). The dissertation highlighted here is very practical in nature and had immediate and quantifiable benefits for the Trust library. Future feature articles are likely to reflect the range of health-related dissertation topics which students choose and will include studies on user information behaviour, information services related to mental health and well-being, as well as the impact of technology on health-related library or information services.AM.  相似文献