Showing papers by "University of North Carolina at Greensboro published in 2001"
Marine Biological Laboratory1, Oak Ridge National Laboratory2, Virginia Tech3, University of Georgia4, University of Illinois at Urbana–Champaign5, Landcare Research6, University of North Carolina at Greensboro7, University of New Hampshire8, Kansas State University9, Michigan State University10, Oregon State University11, Procter & Gamble12
TL;DR: A comparative 15N-tracer study of nitrogen dynamics in headwater streams from biomes throughout North America demonstrates that streams exert control over nutrient exports to rivers, lakes, and estuaries.
Abstract: A comparative 15 N-tracer study of nitrogen dynamics in headwater streams from biomes throughout North America demonstrates that streams exert control over nutrient exports to rivers, lakes, and estuaries. The most rapid uptake and transformation of inorganic nitrogen occurred in the smallest streams. Ammonium entering these streams was removed from the water within a few tens to hundreds of meters. Nitrate was also removed from stream water but traveled a distance 5 to 10 times as long, on average, as ammonium. Despite low ammonium concentration in stream water, nitrification rates were high, indicating that small streams are potentially important sources of atmospheric nitrous oxide. During seasons of high biological activity, the reaches of headwater streams typically export downstream less than half of the input of dissolved inorganic nitrogen from their watersheds.
1,407 citations
TL;DR: Fundamental studies of the ESI process are reviewed that are relevant to issues related to analyte chargeability and surface activity, and how accessible parameters such as nonpolar surface area and reversed phase HPLC retention time can be used to predict relative ESI response.
Abstract: In accomplishing successful electrospray ionization analyses, it is imperative to have an understanding of the effects of variables such as analyte structure, instrumental parameters, and solution composition. Here, we review some fundamental studies of the ESI process that are relevant to these issues. We discuss how analyte chargeability and surface activity are related to ESI response, and how accessible parameters such as nonpolar surface area and reversed phase HPLC retention time can be used to predict relative ESI response. Also presented is a description of how derivitizing agents can be used to maximize or enable ESI response by improving the chargeability or hydrophobicity of ESI analytes. Limiting factors in the ESI calibration curve are discussed. At high concentrations, these factors include droplet surface area and excess charge concentration, whereas at low concentrations ion transmission becomes an issue, and chemical interference can also be limiting. Stable and reproducible non-pneumatic ESI operation depends on the ability to balance a number of parameters, including applied voltage and solution surface tension, flow rate, and conductivity. We discuss how changing these parameters can shift the mode of ESI operation from stable to unstable, and how current-voltage curves can be used to characterize the mode of ESI operation. Finally, the characteristics of the ideal ESI solvent, including surface tension and conductivity requirements, are discussed. Analysis in the positive ion mode can be accomplished with acidified methanol/water solutions, but negative ion mode analysis necessitates special constituents that suppress corona discharge and facilitate the production of stable negative ions.
1,260 citations
TL;DR: In this paper, the need for businesses to rely on cross-functional new product teams to produce innovations in a global and technological nature of markets has heightened the need to depend on crossfunctional teams.
Abstract: Increasing competition resulting from the global and technological nature of markets has heightened the need for businesses to rely on cross-functional new product teams to produce innovations in a...
958 citations
TL;DR: Four-month temperament was modestly predictive of behavioral inhibition over the first 2 years of life and of behavioral reticence at age 4 and change in behavioral inhibition was related to experience of nonparental care.
Abstract: Four-month-old infants were screened (N = 433) for temperamental patterns thought to predict behavioral inhibition, including motor reactivity and the expression of negative affect. Those selected (N = 153) were assessed at multiple age points across the first 4 years of life for behavioral signs of inhibition as well as psychophysiological markers of frontal electroencephalogram (EEG) asymmetry. Four-month temperament was modestly predictive of behavioral inhibition over the first 2 years of life and of behavioral reticence at age 4. Those infants who remained continuously inhibited displayed right frontal EEG asymmetry as early as 9 months of age while those who changed from inhibited to noninhibited did not. Change in behavioral inhibition was related to experience of nonparental care. A second group of infants, selected at 4 months of age for patterns of behavior thought to predict temperamental exuberance, displayed a high degree of continuity over time in these behaviors.
811 citations
TL;DR: The authors show that a large share of the increase in work by single mothers can be attributed to the EITC and other tax changes, with smaller shares for welfare benet cuts, welfare waivers, training programs and child care programs.
Abstract: During 1984 -1996, welfare and tax policy were changed to encourage work by single mothers. The Earned Income Tax Credit was expanded, welfare benets were cut, welfare time limits were added, and welfare cases were terminated. Medicaid for the working poor was expanded, as were training programs and child care. During this same time period there were unprecedented increases in the employment and hours of single mothers. We show that a large share of the increase in work by single mothers can be attributed to the EITC and other tax changes, with smaller shares for welfare benet cuts, welfare waivers, training programs and child care programs.
696 citations
TL;DR: In this paper, a field survey of 461 self-managing work team members in four countries was used to examine whether employee resistance to such teams mediated the relationships between employee cultural values and job attitudes.
Abstract: Using a field survey of 461 self-managing work team members in four countries, we examined: (1) whether employee resistance to such teams mediated the relationships between employee cultural values and job attitudes and (2) whether the value-resistance relationships were stronger in some countries than in others. Results show that resistance mediated the cultural value-job attitude relationships, sometimes fully and sometimes partially, depending on which type of resistance (to teams or to self-management) and which type of cultural value was being examined. Theoretical and practical implications are discussed.
673 citations
TL;DR: For most individuals, the positive effects of regular exercise are exerted on blood lipids at low training volumes and accrue so that noticeable differences frequently occur with weekly energy expenditures of 1200 to 2200 kcal/wk, it appears that weekly exercise caloric expenditures that meet or exceed the higher end of this range are more likely to produce the desired lipid changes.
Abstract: Dose-response relationships between exercise training volume and blood lipid changes suggest that exercise can favourably alter blood lipids at low training volumes, although the effects may not be observable until certain exercise thresholds are met. The thresholds established from cross-sectional literature occur at training volumes of 24 to 32 km (15 to 20 miles) per week of brisk walking or jogging and elicit between 1200 to 2200 kcal/wk. This range of weekly energy expenditure is associated with 2 to 3 mg/dl increases in high-density lipoprotein-cholesterol (HDL-C) and triglyceride (TG) reductions of 8 to 20 mg/dl. Evidence from cross-sectional studies indicates that greater changes in HDL-C levels can be expected with additional increases in exercise training volume. HDL-C and TG changes are often observed after training regimens requiring energy expenditures similar to those characterised from cross-sectional data. Training programmes that elicit 1200 to 2200 kcal/wk in exercise are often effective at elevating HDL-C levels from 2 to 8 mg/dl, and lowering TG levels by 5 to 38 mg/dl. Exercise training seldom alters total cholesterol (TC) and low-density lipoprotein-cholesterol (LDL-C). However, this range of weekly exercise energy expenditure is also associated with TC and LDL-C reductions when they are reported. The frequency and extent to which most of these lipid changes are reported are similar in both genders, with the exception of TG. Thus, for most individuals, the positive effects of regular exercise are exerted on blood lipids at low training volumes and accrue so that noticeable differences frequently occur with weekly energy expenditures of 1200 to 2200 kcal/wk. It appears that weekly exercise caloric expenditures that meet or exceed the higher end of this range are more likely to produce the desired lipid changes. This amount of physical activity, performed at moderate intensities, is reasonable and attainable for most individuals and is within the American College of Sports Medicine's currently recommended range for healthy adults.
594 citations
Columbia University1, Rutgers University2, Ohio State University3, University of Maryland, College Park4, Hong Kong Baptist University5, The Chinese University of Hong Kong6, University of Osnabrück7, Towson University8, University of North Carolina at Greensboro9, University of North Carolina at Chapel Hill10
TL;DR: The authors found that the tendency for people to respond less favorably (i.e., with lower organizational commitment) to lower levels of voice was greater in low power distance cultures (United States and Germany) than in high power distance (People's Republic of China, Mexico, and Hong Kong) and found a similar interactive effect of voice and people's power distance beliefs on employees' work attitudes and job performance.
514 citations
TL;DR: It is shown that ERP technology faces additional challenges in developing countries related to economic, cultural, and basic infrastructure issues.
Abstract: There is an increasing need to implement a total business solution which supports major functionalities of a business. Enterprise resource planning (ERP) software is designed to meet this need, and has been widely adopted by organizations in developed countries. Meanwhile, ERP is beginning to appear in many organizations of developing countries. Little research has been conducted to compare the implementation practices of ERP in developed vs developing countries. Our research shows that ERP technology faces additional challenges in developing countries related to economic, cultural, and basic infrastructure issues. This article identifies a range of issues concerning ERP implementation by making a comparison of advanced and developing countries.
396 citations
Birkbeck, University of London1, University of Washington2, National Institutes of Health3, Temple University4, University of Texas at Austin5, Michigan State University6, Research Triangle Park7, Wellesley College8, Harvard University9, University of North Carolina at Greensboro10, Park University11, University of Wisconsin-Madison12
TL;DR: In the most comprehensive US study to date about connections among child care experiences, family factors, and children's early development, 1100 children have been followed from birth through age 7 as discussed by the authors.
372 citations
TL;DR: In this paper, a series of laboratory procedures designed to assess relations between maternal interactive style and emotional, behavioral and physiological regulation was performed on 65 mothers and their 24-month-old toddlers.
Abstract: Sixty-five mothers and their 24-month-old toddlers were observed in a series of laboratory procedures designed to assess relations between maternal interactive style and emotional, behavioral and physiological regulation. Emotional regulation was assessed by examining the child’s behaviors (aggression, distraction, object focus) when confronted by three emotion-eliciting tasks. Behavioral regulation was measured by examining children’s ability to comply to maternal requests and to inhibit behavior during a delay task. Physiological regulation was derived from children’s cardiac vagal tone responses to emotionally-arousing situations. Maternal interactive style was assessed by examining mothers’ strategies for child behavior management (negative controlling, positive guidance) during three mother-child tasks. Maternal behavior was related to regulation in each of the three domains. Negative maternal behavior was related to poor physiological regulation, less adaptive emotion regulation, and noncompliant behavior. Positive maternal behavior was correlated with compliance, but not with any of the physiological or emotional measures. These findings are discussed in terms of the adaptive value of self-regulation in early development, and the importance of identifying the causal relations between maternal behavior and child regulation.
TL;DR: For example, the authors found that major factors perceived to have positively influenced performance included mental skills and preparation, attitude towards the Olympics, support services and support facilitation, multifaceted preparation, physical preparation, and coaching.
Abstract: To gain a better understanding of factors perceived to have positively and/or negatively influenced Olympic athlete performance and to examine differences in performance factors cited by athletes who met or exceeded performance expectations and athletes who failed to meet expectations, 8 Atlanta and 7 Nagano Olympians were interviewed. Interviews were conducted via telephone, tape recorded, transcribed, and content analyzed by three investigators. Major factors perceived to have positively influenced performance included mental skills and preparation, attitude towards the Olympics, support services and support facilitation, multifaceted preparation, physical preparation, and coaching. Major factors perceived to have negatively influenced performance included departing from normal routine, media distractions, coach issues, overtraining, and injury. The two groups, those who met or exceeded expectations and those who did not meet expectations, differed on only a few positive performance factors, including a...
TL;DR: In this paper, the authors report the results of a qualitative analysis of female entrepreneurs' accounts of their role in their organizations using Relational Theory as the analytical frame, finding that women used a relational approach in working with employees and clients.
Abstract: This paper reports the results of a qualitative analysis of female entrepreneurs' accounts of their role in their organizations using Relational Theory as the analytical frame. Content analysis of focus group comments indicated that the women used a relational approach in working with employees and clients. Relational skills included preserving, mutual empowering, achieving, and creating team. Findings demonstrate that Relational Theory is a useful frame for identifying and explicating women entrepreneurs' interactive style in their own businesses. Implications and future directions for research are discussed.
TL;DR: In this paper, a re-examining of the Respondents' Bem Sex-Role Inventory (BSRI) with respect to past and present relevance is presented. But the results may differ considerably on the basis of the form and scoring method used.
Abstract: Respondents' Bem Sex-Role Inventory (BSRI; S. L. Bem, 1974) classifications may differ considerably on the basis of the form and scoring method used. The BSRI was reexamined with respect to past and present relevance.
TL;DR: The authors found that both emotional reactivity and emotion regulation were important predictors of at least two types of social behavior: conflict and cooperation, when accompanied by high venting or high focal-object focus.
Abstract: Fifty-six mothers and their 24-month-old toddlers were observed on two occasions in a series of laboratory procedures designed to assess relations between emotional functioning (emotional reactivity and emotion regulation) in an individual assessment and social behavior with a same-sex peer. Emotional reactivity was assessed using two frustration tasks designed to elicit distress. Emotional regulation was assessed by examining the child’s behaviors (venting, distraction, focal-object focus, self-orientation, and mother-orientation) when confronted by the two distress-eliciting tasks. Peer play behaviors were coded for social participation and peer-directed conflict (aggressive) behavior. The results indicated that both emotional reactivity and emotion regulation were important predictors of at least two types of social behavior: conflict and cooperation. Distress to frustration, when accompanied by high venting or high focal-object focus, was significantly related to conflict with peers but not when accompanied by distraction, mother-orientation or self-focused behaviors. These findings are discussed in terms of the adaptive value of emotion regulation skills in early development, and the importance of identifying the causal relations between child regulation and early social competence.
TL;DR: This article investigated the consequences of parent-child relationships during adolescence for young adults' well-being and substance use and found that coercive parental control in adolescence is associated with lower wellbeing and more substance use in young adults.
Abstract: This research investigated the consequences of parent-child relationships during adolescence for young adults' well-being and substance use. Analysis of longitudinal data from the National Survey of Families and Households provided support for the hypothesis that parent-adolescent relationships have long-term consequences for young adult well-being and behavior. The findings are consistent with individuation theory and show that coercive parental control in adolescence is associated with lower well-being and more substance use in young adulthood. The long-term effects of parenting were mediated in part by the effects of parenting on adolescent adjustment, which influenced well-being in young adulthood.
TL;DR: The content of explanations that 4 English-speaking children gave or asked for in everyday conversations recorded from 2 1/2 to 5 years of age are examined to suggest that young children draw on several complementary causal-explanatory theories to make sense of real-life events.
Abstract: This research examines the content of explanations that 4 English-speaking children gave or asked for in everyday conversations recorded from 2 1/2 to 5 years of age. Analyses of nearly 5,000 codable explanations (identified by markers like why or because) focused on the entity targeted for explanation (e.g., person, animal, object), the explanatory mode of causal reasoning (e.g., psychological, physical), and interrelations between these elements. Children's explanations focused on varied entities (animals, objects, and persons) and incorporated diverse modes (psychological, physical, social-conventional, and even biological reasoning). Children's pairings of entities with explanatory modes suggest appropriately constrained yet flexible causal reasoning. These data are consistent with the hypothesis that young children draw on several complementary causal-explanatory theories to make sense of real-life events.
TL;DR: In this article, a field survey of 81 self-managing work teams (SMWTs) in Belgium, Finland, the Philippines, and the United States was conducted to examine the extent to which team members' resistance to SMWTs mediated the relationships between team members’ cultural values and team effectiveness.
Abstract: Using a field survey of 81 self-managing work teams (SMWTs) in Belgium, Finland, the Philippines, and the United States, we examined the extent to which team members’ resistance to SMWTs mediated the relationships between team members’ cultural values and team effectiveness. Specifically, we found that teams higher, rather than lower, in collectivism were also more productive, cooperative, and empowered; and that these relationships were fully mediated by the level of team resistance to the team-related aspect of SMWTs. Also, we found that teams that were more, rather than less, doing-oriented were also more empowered, and that this relationship was fully mediated by the level of team resistance to the self-managing aspect of SMWTs. The findings suggest that it may behoove managers who are charged with implementing SMWTs to pay close attention to the predominant cultural values inherent in the teams they lead. Additional practical and theoretical implications are discussed.
TL;DR: The history and progression of the expression of GFP variants in transgenic plants are reviewed; GFP has been more important in monocot transformation compared with dicot transformation; and the potential utility of new fluorescent proteins is speculated upon.
Abstract: The green fluorescent protein (GFP) from the jellyfish Aequorea victoria has proven to be a powerful tool in plant genetic transformation studies. This paper reviews the history and the progression of the expression of GFP variants in transgenic plants. The distinguishing features of the most useful GFPs, such as those including the S65T chromophore mutation and those with dual excitation peaks, are discussed. The review also focuses on the utility of GFP as a visual selectable marker in aiding the plant transformation process; GFP has been more important in monocot transformation compared with dicot transformation. Finally, the potential utility of new fluorescent proteins is speculated upon.
TL;DR: Making concurrent reports did not affect subsequent retrospective reports, but describing strategies affected reported strategy production for both age groups and paired-associate recall for older adults.
Abstract: Strategy production during associative learning can be measured by self-reports made either concurrently with study or retrospectively. Both kinds of report presumably have strengths and weaknesses, yet a systematic comparison has not been conducted. Younger and older adults studied paired associates and reported strategy production using one or both kinds of report. Participants either received or did not receive descriptions of mediational strategies prior to study. Retrospective reports were not completely consistent with concurrent reports, suggesting that the validity of retrospective reports is somewhat diminished by forgetting. Making concurrent reports did not affect subsequent retrospective reports, but describing strategies affected reported strategy production for both age groups and paired-associate recall for older adults. A production deficiency constrained older adults' performance when they did not receive strategy descriptions prior to study. Discussion focuses on the relative utility of concurrent and retrospective reports of strategy production.
TL;DR: These results are the first to demonstrate uptake of chlorophyll derivatives by human intestinal cells and to support the potential importance ofchlorophylls as health-promoting phytochemicals.
Abstract: Although numerous studies have demonstrated the health benefits of chlorophyll derivatives, information regarding the digestion, absorption, and metabolism of these phytochemicals is quite limited To better understand the digestion of these pigments, green vegetables including fresh spinach puree (FSP), heat- and acid-treated spinach puree (HASP), and ZnCl(2)-treated spinach puree (ZnSP) were subjected to an in vitro digestion method which simulates both the gastric and small intestinal phases of the process Native chlorophylls were converted to Mg-free pheophytin derivatives during digestion Conversely, Zn-pheophytins were completely stable during the digestive process Transfer of lipophilic chlorophyll derivatives, as well as the carotenoids lutein and beta-carotene, into the aqueous micellar fraction from the food matrix was quantified Micellarization of total chlorophyll derivatives differed significantly (p 005) Intestinal cell uptake of micellarized pigments was investigated using HTB-37 (parent) and clonal TC7 lines of human Caco-2 cells Medium containing the pigment-enriched fraction generated during digestion was added to the apical surface of fully differentiated monolayers for 4 h Pigments were then extracted from cells and analyzed by C18 HPLC with photodiode array detection Both Caco-2 HTB-37 and TC7 clone cells accumulated 20-40% and 5-10% of micellarized carotenoid and chlorophyll derivatives, respectively These results are the first to demonstrate uptake of chlorophyll derivatives by human intestinal cells and to support the potential importance of chlorophylls as health-promoting phytochemicals
TL;DR: Stability coefficients indicated a reasonable degree of consistency in students' goal responses over time, but there were also significant mean-level changes inStudents' goals within the school year and significant linear declines in task-mastery and performance goals over time.
TL;DR: Mothers in high-income families and those who worked fewer hours were more likely to select a child-care arrangement based on its quality than on practical concerns such as cost, hours of operation, or location, and mothers who chose care based on quality were least likely to use care provided by a relative.
TL;DR: The data suggest that the reported antiobesity actions of a supplement containing a crude mixture of CLA isomers given to humans may be due to inhibition of lipogenesis by the trans-10, cis-12 isomer.
Abstract: We have previously shown that both a commercially available mixture of conjugated linoleic acid (CLA) isomers and the trans-10, cis-12 isomer of CLA reduced the triglyceride (TG) content and induced apoptosis in differentiating cultures of murine 3T3-L1 preadipocytes. However, the influence of CLA isomers on differentiating human (pre)adipocytes is unknown. Therefore, we conducted a series of studies using primary cultures of stromal vascular cells isolated from human adipose tissue to determine: 1) the influence of seeding density and thiazolidinedione (TZD) concentration on TG content; 2) the chronic dose response of cis-9, trans-11 CLA vs. trans-10, cis-12 CLA on TG content; 3) whether chronic linoleic acid supplementation could rescue the TG content of CLA-treated cultures; and 4) whether trans-10, cis-12-mediated reduction in cellular TG was due to decreased lipogenesis and/or increased lipolysis. In expt. 1, the TG content [micromol/(L x 10(6) cells)] increased as both seeding density and TZD concentration increased. For example, cultures seeded at 4 x 10(4) cells/cm(2) and supplemented with 10 micromol/L BRL 49653 had 10-fold more TG than similarly seeded cultures without BRL 49653. In expt. 2, TG content decreased as the level of trans-10, cis-12 CLA increased from 1 to 10 micromol/L, whereas the TG content increased with increasing concentrations of either linoleic acid or cis-9, trans-11 CLA. In expt. 3, linoleic acid supplementation restored the TG content of cultures treated with trans-10, cis-12 CLA compared with cultures treated with CLA alone, suggesting that attenuation of TG content by CLA is reversible. In expt. 4, glucose incorporation into total lipid decreased with increasing levels of trans-10, cis-12 CLA, whereas neither CLA isomer acutely affected lipolysis. These data suggest that the reported antiobesity actions of a supplement containing a crude mixture of CLA isomers given to humans may be due to inhibition of lipogenesis by the trans-10, cis-12 isomer.
TL;DR: GFP can be used as a tool to monitor transgene flow from crop species to wild relatives and was macroscopically detectable throughout the entire life cycle of canola.
Abstract: It is possible to monitor the movement of transgenes by tagging them with green fluorescent pro- tein (GFP). In order to develop a model to study trans- gene flow, canola (Brassica napus cv Westar) was trans- formed with two GFP constructs, mGFP5er (GFP only) and pSAM 12 (GFP linked to a synthetic Bacillus thuringiensis (Bt) cry1Ac endotoxin gene). Transformed callus sectors that fluoresced green were preferentially selected in the tissue culture process. Four independent GFP canola events and 12 events of GFP/Bt canola were regenerated through tissue culture. GFP fluorescence was macroscopically detectable throughout the entire life cycle of canola. The GFP/Bt events were insecticidal to neonate corn earworm (Helicoverpa zea) larvae and prevented herbivory damage. Fluorescence intensity at 508 nm varied between the independent transformation events, and ranged from 7.6× 10 5 to 13.8× 10 5 (counts per second) in contrast with the wild-type at 5.3 × 105 cps. Nine GFP/Bt and three GFP events were hybridized with three wild accessions of B. rapa. The resultant hybrids fluoresced green and were insecticidal to neonate corn earworm larvae to the same degree as the transgenic ca- nola parents. However, fluorescence intensities of the hemizygous F 1 hybrid lines were lower than the respec- tive original homozygous canola parents. Each F 1 hybrid line was backcrossed by hand onto the B. rapa parent, and transgenic backcrosses were produced at rates rang- ing from 15% to 34%. These data suggest that GFP can be used as a tool to monitor transgene flow from crop species to wild relatives.
TL;DR: In this article, the authors used data collected from 98 work teams, and assessed empowerment levels based on the aggregation of individual team member ratings as well as on a team consensus approach utilized after aggregation.
Abstract: Using data collected from 98 work teams, empowerment levels were assessed based on the aggregation of individual team member ratings as well as on a team consensus approach utilized after aggregation. These 2 methods of measuring team empowerment were then compared on their ability to predict manager ratings of team effectiveness on 4 dimensions. Findings demonstrated that the consensus method of measuring team empowerment explained significantly greater variance in team effectiveness than did the aggregation method alone. We discuss implications for team research and practice based on these findings and include a discussion on when using consensus after aggregation may be most appropriate.
TL;DR: In this paper, an evaluation of an in-school mentoring program for 16 underserved elementary youngsters is presented, focusing on self-control and respect for the rights of others; effort and participation; self-direction; and helping others.
Abstract: This report is an evaluation of an in-school mentoring program for 16 underserved elementary youngsters The goals of the program are related to a Personal and Social Responsibility Model (Hellison, 1995), which focuses on the following: (1) self-control and respect for the rights of others; (2) effort and participation; (3) self-direction; and (4) helping others Teacher and mentor journals, and student exit interviews, constituted the data sources Data sources were reviewed and a program-goal matrix was developed to determine the level of performance of each participant Results of the study indicated that the youngsters were able to apply the goal of effort to learning tasks in the classroom The club members struggled, however, to transfer some of the other values to the classroom One particular problematic area was the club members' inability to set personal goals in the classroom setting
TL;DR: Examination of beliefs and perspectives among people with type 2 diabetes mellitus about dietary requirements, food selection and eating patterns, and attitudes about self-management practices concluded that diabetes nutrition education programs should increase awareness of eating history, spousal support, and time management practices.
TL;DR: Combining isometric hip adduction with a mini-squat exercise significantly increases the activity of the quadriceps, however, based on the data it cannot conclude that this exercise preferentially recruits the VMO.
TL;DR: Variants that have similar effects on total response rate can be differentiated based on their effects on the componemts of response rate.
Abstract: The rate of a reinforced response is conceptualized as a composite of engagement bouts (visits) and responding during visits. Part I of this paper describes a method for estimating the rate of visit initiations and the average number of responses per visit from log survivor plots: the proportion) of interresponse times (IRTs) longer than some elapsed time (log scale) plotted as a function of elapsed time. In Part 2 the method is applied to IRT distributions from rats that obtained food pellets by nose poking a lighted key under various multiple schedules of reinforcement. As expected, total response rate increased as a function of (a) increasing the rate of reinforcement (i.e., variable-interval [VI] 4 min vs. VI 1 mi), (b) increasing the amount of the reinforcer (one food pellet vs. four pellets), (c) increasing the percentage of reinforcers that were contingent on nose poking (25% vs. 100%), and (d) requiring additional responses after the end of the VI schedule (i.e., adding a tandem variable-ratio [VR] 9 requirement). The first three of these variables (relative reinforcement) increased the visit-initiation rate. The tandem VR, in contrast, increased the number of responses per visit. Thus, variables that have similar effects on total response rate can be differentiated based on their effects on the componemts of response rate.