Growth Performance of Holstein Dairy Calves Supplemented with a Probiotic

Administration of antibiotics in both therapeutic and sub-therapeutic doses has been the standard practice for dealing with pathogenic bacteria problems in farm animals since the 1940s. Several types of antibiotics are currently used to promote weight gain and feed efficiency in domestic livestock. There is growing concern that the use of antibiotics as growth promoters may result in the development of resistant populations of pathogenic bacteria and, in turn, influence the therapeutic use of antibiotics. The indiscriminate and improper use of antibiotics in food-producing animals could result in the presence of residues in milk, meat, and other animal food products consumed by humans. One possible alternative to antibiotics is the use of probiotics. Probiotics can be defined as “live microbial feed supplements which beneficially affect the host animal by improving its intestinal microbial balance” (Fuller, 1989). Probiotics introduce beneficial microorganisms into the gut which act to maintain optimal conditions within the gastrointestinal tract and inhibit the growth of pathogenic or other undesirable bacteria

Rumen Microbial Protein Synthesis in Cows Fed Dried Whey

Two rumen fistulated Holstein cows, weighing approximately 550 kg, were used in a switchback design experiment to evaluate the effects of consuming large amounts (38% of total ration dry matter) of dried whey on rumen microbial protein synthesis. Cows were fed total mixed rations consisting of (dry matter basis) 45% corn silage, 10% alfalfa hay, and 45% concentrate mix. The concentrate mix was primarily corn and soybean meal (control) or 85% dried whole whey. Dry matter intakes averaged 16.4 and 15.3 kg/day for control and whey diets. Concentrations of bacteria and protozoa in rumen contents were estimated using diaminopimelic acid and aminoethylphosphonic acid, respectively, as markers. Diaminopimelic acid-N as percent of bacterial-N was similar for both diets (.61 and .63% for control and whey diets). Likewise, aminoethylphosphonic acid-N as percent of protozoal-N was similar for both diets (.17 and .19% for control and whey diets). For the control diet, total rumen-N was estimated to be 45% bacterial-N and 27% protozoal-N. Bacterial-N and protozoal-N, respectively, accounted for 52 and 22% of the total rumen-N in the cows fed the whey diet. Rumen fluid volume (33.8 and 39.2 liters for control and dried whey diets) and dilution rates (10.2 and 12.8%/h), as estimated with polyethylene glycol, were higher when fed dried whey. Rumen ammonia (5.0 and 3.4 mg/dl) was lower when fed dried whey. Butyrate (16.5 and 24.4 moles/100 moles total volatile fatty acids) was higher while propionate was lower (32.4 and 23.2 moles/100 moles total volatile fatty acids) when fed dried whey; concentrations of other volatile fatty acids were similar with both diets. Bacterial synthesis appeared to be increased when cows were fed a diet containing large amounts of dried whey

How Does Practice-Based Teacher Preparation Influence Novices' First-Year Instruction?

Background/Context Teacher preparation suffers from a lack of evidence that guides the design of learning experiences to produce well-prepared beginners. An increasing number of teacher educators are experimenting with practice-embedded approaches to prepare novices for ambitious instruction. This study examines the role of core instructional practices introduced during preparatory experiences in shaping novices’ first-year teaching. Research design Employing a mixed-methods approach, we compare the first-year teaching of two groups of individuals with secondary science certification, one of which comprises graduates from a practice-embedded preparation program, and the other graduates from programs that did not feature practice-embedded preparation. A total of 116 science lessons taught by 41 first-year teachers were analyzed, focusing on the quality of student opportunities to learn (OTL) observed during the lessons. Research questions This study sought answers to two research questions: 1) What are the characteristics of students’ OTL from first-year teachers, one group of whom learned a set of core instructional practices during their preparation program and the other group of whom were not exposed to core practices? 2) Who provides opportunities for students to engage in meaningful disciplinary practices as outlined in the Next Generation Science Standards, during the first year of teaching, if any? How did they create such opportunities? Findings Independent-sample t-tests showed that there are significant mean differences between the two groups (t=3.1∼8.9; p <.001), on four metrics associated with their students’ opportunities to learn. In-depth qualitative case studies reveal two ways that core practices shape instruction in new teachers’ classrooms: (a) they support novices in formulating an actionable curricular vision as advocated by the science education community, and (b) they appear to help novices notice, attend to, and build upon students’ ideas in classrooms with the use of strategies and tools recommended by the program. Conclusions/Recommendations A focus on a set of strategic and intentional practices, designed to help teachers achieve rigorous and equitable learning goals, has potential as a curricular frame for teacher preparation. But the emphasis should be placed on the vision and pedagogical goals that underlie the core practices, rather than the ungrounded use of strategies or tools themselves

Rigor and Responsiveness in Classroom Activity

Background/Context: There are few examples from classrooms or the literature that provide a clear vision of teaching that simultaneously promotes rigorous disciplinary activity and is responsive to all students. Maintaining rigorous and equitable classroom discourse is a worthy goal, yet there is no clear consensus of how this actually works in a classroom. Focus of Study: What does highly rigorous and responsive talk sound like and how is this dialogue embedded in the social practices and activities of classrooms? Our aim was to examine student and teacher interactions in classroom episodes (warm-ups, small group conversations, whole group conversation, etc.) and contribute to a growing body of research that specifies equity in classroom practice. Research Design: This mixed-method study examines differences in discourse within and across classroom episodes (warm-ups, small group conversations, whole group conversation, etc.) that elevated, or failed to elevate, students’ explanatory rigor in equitable ways. Data include 222 secondary science lessons (1,174 episodes) from 37 novice teachers. Lessons were videotaped and analyzed for the depth of students’ explanatory talk and the quality of responsive dialogue. Findings: The findings support three statistical claims. First, high levels of rigor cannot be attained in classrooms where teachers are unresponsive to students’ ideas or puzzlements. Second, the architecture of a lesson matters. Teachers and students engaging in highly rigorous and responsive lessons turned potentially trivial episodes (such as warm-ups) of science activity into robust learning experiences, connected to other episodes in the same lesson. Third, episodes featuring one or more forms of responsive talk elevated rigor. There were three forms of responsive talk observed in classrooms: building on students’ science ideas, attending to students’ participation in the learning community, and folding in students’ lived experiences. Small but strategic moves within these forms were consequential for supporting rigor. Conclusions/Recommendations: This paper challenges the notion that rigor and responsiveness are attributes of curricula or individual teachers. Rigorous curriculum is necessary but not sufficient for ambitious and equitable science learning experiences; the interactions within the classroom are essential for sustaining the highest quality of scientific practice and sense-making. The data supported the development of a framework that articulates incremental differences in supporting students’ explanatory rigor and three dimensions of responsiveness. We describe implications for using this framework in the design of teacher programs and professional development models

Behaving Optimistically: How the (Un)Desirability of an Outcome Can Bias People’s Preparations for It

Past research on the desirability bias and on bracing for bad news has focused on the potential influence of outcome desirability on people’s stated expectations. The present studies examined its influence on behavior—that is, what is done in anticipation of, or preparation for, an uncertain outcome. In five studies, the desirability of possible outcomes for an event, which was uncertain and uncontrollable by the participant, was manipulated, and preparation behavior was measured. Study 1 used a hypothetical‐events paradigm. Studies 2 and 3 involved a computer activity in which behavior was tracked on a trial‐by‐trial basis. In Studies 4 and 5, the uncertain event was the ending of a videotaped basketball game. Rather than exhibiting bracing or a reluctance to tempt fate, participants tended to behave in a manner consistent with an optimistic desirability bias. In a subset of studies, predictions and likelihood judgments were also solicited; the differential effects of outcome desirability on these measures are discussed. Copyright © 2015 John Wiley & Sons, Ltd.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135587/1/bdm1918_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/135587/2/bdm1918.pd

ARTICLE PERSONALITY AND SOCIAL PSYCHOLOGY BULLETIN Chambers et al. / EGOCENTRISM AND EVENT FREQUENCY Egocentrism, Event Frequency, and Comparative Optimism: When What Happens Frequently Is "More Likely to Happen to Me"

Three studies investigated the role of nonmotivated egocentric processes in comparative optimism (and pessimism). According to an egocentric-processes account, when people judge their comparative likelihood of experiencing an event (e.g., "Compared to the average person, how likely are you to become wealthy?"), they consider their own chances of experiencing the event more so than the referent's chances. This should produce higher comparative estimates when an event's absolute frequency is high rather than low-a prediction supported in Study 1, which manipu- Peopleareoftenoveroptimisticaboutthefuture.They tend to believe that they are more likely than others to experience good fortune and less likely to suffer harm. Although these beliefs suffer from a logical fallacy-not everyone can be uniquely invulnerable-this unrealistic optimism is well documented. Weinstein (1980) had student participants rate their likelihood of experiencing various positive and negative life events (e.g., developing a stomach ulcer, achieving professional recognition) relative to their peers. He found that the average likelihood responses given by participants tended to be "above average" for positive events but "below average" for negative events. Since Weinstein's (1980) study, the comparative optimism bias has been found with a variety of other subject populations (e.g., Although motivated reasoning can play a major role in producing comparative optimism, nonmotivational factors also may play a critical, if not sufficient, role The research described in this article investigated how a nonmotivated form of egocentrism might underlie various patterns of comparative optimism and pessimism. In this article, we do not intend to dismiss the role of motivation in producing comparative optimism effects, but rather, we hope to better explicate the way in which egocentrism and a specific event characteristic interact to produce comparative optimism (and comparative pessimism). The event characteristic that is of key importance in the present work is the overall frequency of the event. Consider a case in which most individuals from a group assert that their chances of being falsely accused of a serious crime are less than that of other people in the group. A motivational account would assume that the undesirable nature of the event is a key reason why people report being less vulnerable than others to that event. However, the infrequent nature of this event might be important as well. From an objective standpoint, overall event frequency should be irrelevant; being falsely accused of a serious crime tends to be an improbable event for both the self and others. Therefore, an individual should use both absolute likelihood information for the self (e.g., "My chances of being falsely accused of a serious crime are low") and absolute likelihood information for others (e.g., "Other people's chances are low too") to formulate a comparative estimate (e.g., "My chances are the same as others of being falsely accused of a serious crime"). Nevertheless, empirical evidence suggests that people often fail to integrate information about others in their comparative judgments If people are affected by such egocentrism, then their comparative estimates for events should differ as a function of event base rate. Comparative estimates for their chances of experiencing a high base-rate event (e.g., having a cold this winter) should be high because people note their own high likelihood of experiencing the event without fully integrating others' high likelihood of experiencing the event. Similarly, comparative estimates for a low base-rate event should be low because people consider their own low likelihood of experiencing the event without fully integrating others' low likelihood of experiencing the event. Thus, comparative-judgment biases that might appear to arise from motivated reasoning, such as people believing they are less likely than others to be falsely accused of a serious crime, may actually result from nonmotivated sources of bias, such as egocentrism. The idea that comparative optimism can result from egocentrism was described by In this article, we report three studies conducted to further investigate the influence of event frequency on comparative estimates. Three features of the present investigation distinguish it from previous studies of comparative optimism and event frequency. First, we directly manipulated the perceived frequency of events using a novel time frame manipulation in Experiments 1 and 2. This manipulation helps us to avoid unidentified potential confounds between the frequency and other characteristics of events that might have existed in previous studies. Second, we empirically distinguish between two different explanations for the relation between event frequency and comparative optimism-egocentrism and focalism, which is described later. Third, we tested for systematic cases of comparative pessimism. If people consider only their own personal likelihood, then people should exhibit reliable comparative pessimism with respect to highly frequent, undesirable events and highly infrequent, desirable events. Previous work has documented reliable relationships between event frequency and comparative optimism (e.g., PERSONALITY AND SOCIAL PSYCHOLOGY BULLETIN Such results would illustrate that the role of event frequency and egocentrism can, at least at times, outweigh motivational considerations. Thus, to test for comparative pessimism and the independent influences of event frequency and desirability, we solicited comparative estimates across a broad array of both undesirable and desirable events that also varied substantially (either naturally or by manipulation) in event frequency. Finally, we also sought to assess the relation between perceived event frequency and an indirect index of comparative optimism-specifically, the differences between absolute estimates for the self and absolute estimates for others. The egocentric-processes account specifies that biases in comparative estimates arise through the differential impact of absolute estimates for the self and others, not as a result of biases in the formation of absolute estimates. Therefore, the egocentric-processes account predicts that there should be no relation between event frequency and differences in absolute estimates for self and others but a positive relation with comparative estimates. Such a finding would be counter to the results of a study by OVERVIEW In Study 1, we utilized a novel manipulation to increase or decrease the perceived frequency of an event and investigated the effect of this manipulation on participants' comparative estimates. Participants in this study were asked to provide comparative estimates either for an event within a short time frame (e.g., within the next 2 weeks) or for the same event within a long time frame (e.g., within the next 3 months). In Study 2, we attempted to address one possible alternative explanation for the results of Study 1 and to strengthen our claim that egocentric processes best account for the influence of event frequency on comparative estimates. We did this by employing the same time frame manipulation that was used in Study 1 but asked participants to provide comparative estimates for the average student (instead of for the self as in Study 1). In Study 3, we sought to investigate the relation between perceived event frequency, controllability, and desirability with both absolute and comparative likelihood estimates across a broad array of events. By obtaining both types of likelihood estimates, we were able to test several predictions made by the egocentricprocesses account. STUDY 1 To examine the influence of event frequency on comparative estimates for desirable and undesirable events, we directly manipulated the perceived frequency of each of the tested events, thereby avoiding a situation in which frequent and infrequent events under investigation can differ in systematic ways unrelated to the frequency dimension. Specifically, participants provided comparative estimates for a given event either in a short time frame (e.g., occurring within the next 3 days) or a long time frame (e.g., occurring within the next 4 weeks). Our egocentric-processes account suggests that when participants make a comparative estimate for an event (e.g., "Compared to the average student, how likely is it that you will purchase your dream home in the next 32 years [6 years]?"), thoughts about their own absolute likelihood of experiencing the event would have a greater influence on their comparative estimates than would thoughts about the absolute likelihood for other people. Because the absolute frequency of an event is necessarily greater in a long time frame than in a short time frame, we predict that participants will make higher comparative estimates for an event in a long rather than short time frame condition, regardless of the desirability of the event. Method Participants. Participants (N = 52) were recruited from an introductory psychology course at the University of Iowa (UI). They received partial credit for a research exposure requirement. Procedure. Participants were randomly assigned to complete one of two versions of a questionnaire that presented 16 critical events generated by the authors for this study (see Appendix A). In version 1, participants were presented with 8 events in a long time frame and 8 events in a short time frame. Half of the events in each of the time frame conditions were undesirable and half were desirable. In version 2, the time frame for each event was reversed. Thus, for each of the questionnaire versions, participants gave comparative estimates for 4 undesirable events in a short time frame, 4 undesirable events in a long time frame, 4 desirable events in a short time frame, and 4 desirable events in a long time frame. For each event, participants indicated their comparative estimates in an item phrased, for example, "Compared to the average UI student, how likely is it that you will purchase your dream home in the next 32 years [6 years]?" (-4 = much less likely than the average UI student to +4 = much more likely than the average UI student). Chambers et al. / EGOCENTRISM AND EVENT FREQUENCY 1345 Results and Discussion We calculated for each participant the averages for his or her comparative estimates for the undesirable events in a short time frame, for the undesirable events in a long time frame, for the desirable events in a short time frame, and for the desirable events in a long time frame. These averaged estimates were then submitted to a 2 (questionnaire version: 1 or 2) × 2 (time frame: short or long) × 2 (desirability: undesirable or desirable) mixedmodel ANOVA, with questionnaire version as a betweensubjects factor and both time frame and desirability as within-subjects factors. The key finding was a significant main effect of time frame, F(1, 50) = 82.70, p < .001. As predicted, participants gave higher comparative estimates for events in a long time frame (M = 0.66, SD = 1.23) than in a short time frame (M = -0.64, SD = 1.14). In addition, a significant main effect was found for desirability, F(1, 50) = 63.48, p < .001. Participants gave higher estimates for desirable events (M = 0.69, SD = 1.26) than for undesirable events (M = -0.67, SD = 1.10). Because these main effects were not qualified by a Time Frame × Desirability interaction, F(1, 50) = 2.36, p > .10, we may conclude that the influence of the time frame manipulation was not dependent on the desirability of the event. In fact, simple effect tests reveal that participants gave higher comparative estimates for the desirable events in a long time frame (M = 1.44, SD = 1.23) than in a short time frame (M = -0.06, SD = 1.29), t(51) = 6.53, p < .001. Participants also gave higher comparative estimates for the undesirable events in a long time frame (M = -0.13, SD = 1.22) than in a short time frame (M = -1.21, SD = 0.98), t(51) = 6.35, p < .001. In addition to these key findings, the ANOVA also revealed a significant Time Frame × Questionnaire Version interaction, F(1, 50) = 16.60, p < .001, a nonsignificant Desirability × Questionnaire Version interaction, F(1, 50) = 2.83, p > .10, and a significant Time Frame × Desirability × Questionnaire Version interaction, F(1, 50) = 8.04, p < .01. However, the effects involving the questionnaire version factor are inconsequential because they are simply a product of our arbitrary choices as to which events to assign to the long or short time frame in the two versions of the questionnaire. The desirability main effect is consistent with the idea that participants were motivated to maintain optimistic comparative beliefs; for the events tested in this study, participants tended to report higher comparative likelihoods of experiencing the positive rather than negative events. However, the time frame main effect, which was predicted by the egocentric processing account, cannot readily be explained by motivated reasoning. It is interesting to note with help fro

Towards a Strategy to Fight the Computer Science (Cs) Declining Phenomenon

International audienceEuropean students have give reasons why they reject computer science (CS) as a program of study in higher education [1]. The constant decrease in the number of students choosing to study this subject has had consequences in different European sectors, such as the economic sector or the education sector, among others [2]. Some of the reasons for this rejection are related to the degree of difficulty of the skills that are needed to master CS. This study aims to identify these skills by firstly comparing CS curricula across several European universities and then comparing these curricula with same level programs in other areas of study. It will highlight some misconceptions students have concerning CS programs and will demonstrate that Technology Enhanced Learning (TEL) may have a major role to play in combating the decline of CS professionals by providing dynamic learning environments; where students can acquire the knowledge and skills which are unique to the field of CS