Mandatory criteria for the application of variability-based parameters of fluid responsiveness: a prospective study in different groups of ICU patients

Background and objective

Stroke volume variation (SVV) has high sensitivity and specificity in predicting fluid responsiveness. However, sinus rhythm (SR) and controlled mechanical ventilation (CV) are mandatory for their application. Several studies suggest a limited applicability of SVV in intensive care unit (ICU) patients. We hypothesized that the applicability of SVV might be different over time and within certain subgroups of ICU patients. Therefore, we analysed the prevalence of SR and CV in ICU patients during the first 24 h of PiCCO-monitoring (primary endpoint) and during the total ICU stay. We also investigated the applicability of SVV in the subgroups of patients with sepsis, cirrhosis, and acute pancreatitis.

Methods

The prevalence of SR and CV was documented immediately before 1241 thermodilution measurements in 88 patients.Results: In all measurements, SVV was applicable in about 24%. However, the applicability of SVV was time-dependent: the prevalence of both SR and CV was higher during the first 24 h compared to measurements thereafter (36.1% vs. 21.9%; P<0.001). Within different subgroups, the applicability during the first 24 h of monitoring ranged between 0% in acute pancreatitis, 25.5% in liver failure, and 48.9% in patients without pancreatitis, liver failure, pneumonia or sepsis.

Conclusions

The applicability of SVV in a predominantly medical ICU is only about 25%–35%. The prevalence of both mandatory criteria decreases over time during the ICU stay. Furthermore, the applicability is particularly low in patients with acute pancreatitis and liver failure.

     

Conditioning copulatory behavior to an artificial object: Efficacy of stimulus fading

Copulatory behavior rarely occurs in response to an arbitrary inanimate object. However, such behavior can provide important information about the stimulus control of copulatory behavior. In the present study, male Japanese quail were administered 15–20 conditioning trials that included exposure to an inanimate object and an opportunity to copulate with a live female quail. For some subjects, the stimulus object was always entirely covered with terrycloth. For other birds, the stimulus object contained a taxidermically prepared head and neck of a quail hen. Fading consisted of gradually covering up the neck and then the head portions of the stimulus object over successive trials. After conditioning, all subjects were tested with the entirely covered object. The fading procedure facilitated the conditioning of copulatory behavior to the entirely artificial object. In subjects that received the fading procedure, learning did not depend on pairings of the stimulus object with copulatory opportunity. The results are discussed with respect to an associative mediation mechanism.     

Comparing Knowledge Bases and Reasoning Structures in Discussions of Mathematics and Pedagogy

While teaching, teachers need to access both their knowledge of mathematics and knowledge of pedagogy. Practice-based materials afford teachers opportunities to reason about both mathematics and pedagogy within the context of teaching. Accepted systems exist for explaining and reasoning in the domain of mathematics; logic, procedures, and representations all serve as instances of mathematics that bear common meaning in the domain. In contrast, there is not an accepted well-structured system for reasoning within the domain of pedagogy; rather, it is an inherently interpretive act. This paper explores differences in knowledge bases and reasoning by examining discourse about mathematics and pedagogy in a practice-based teacher education course. Mathematics conversations featured greater depth of conversation, more challenges, and more echoes of previous claims. Pedagogical conversations were denser and featured more qualified statements and more evidence from personal values or opinions. Implications for the design of teacher education and professional development experiences are presented.     

Rural Communities Lacking Multi-Sector Schooling Options: Indiana’s School Choice Deserts

ABSTRACT

Despite Indiana’s school choice landscape – including private school vouchers, tax-credit scholarships, inter-district and intra-district enrollment, magnet schools, and charter schools – not all Indiana communities have reasonable access to options outside of their traditional public schools. This research explores what lack-of-reasonable access differences – defined as greater than a 30-minute one-way drive time to a choice school – exist by locale, with a focus on rural communities. Geospatial analysis is used to identify “school choice deserts” lacking multi-sector schooling options in various communities. These deserts tend to exist wholly or mostly in rural areas, although Indiana students in grades K–8 exhibit greater access levels to non-traditional schools than those in high school.     

Fathers and mothers at play with their 2- and 3-year-olds: contributions to language and cognitive development

Father-child and mother-child engagements were examined longitudinally in relation to children's language and cognitive development at 24 and 36 months. The study involved a racially/ethnically diverse sample of low-income, resident fathers (and their partners) from the National Early Head Start evaluation study (n=290). Father-child and mother-child engagements were videotaped for 10 min at home during semistructured free play, and children's language and cognitive status were assessed at both ages. Fathers' and mothers' supportive parenting independently predicted children's outcomes after covarying significant demographic factors. Moreover, fathers' education and income were uniquely associated with child measures, and fathers' education consistently predicted the quality of mother-child engagements. Findings suggest direct and indirect effects of fathering on child development.     

The protective role of teacher–student relationships against peer victimization and psychosocial distress

This study examined whether teacher–student relationships protect against peer victimization and its negative psychosocial effects (i.e., depression, anxiety, and stress). Additionally, the influence of teacher–student relationships, peer relationships, and students’ perceptions of school order and discipline was investigated as these variables were expected to be negatively related to the former. Data were collected from high school‐aged adolescents (N = 539; 51% female) in the U.S. Southwest. Study results indicate that teacher–student relationships buffered against experiencing psychosocial distress associated with peer victimization. Although positive teacher–student relationships, peer relationships, and students’ perceptions of school order and discipline all were negatively associated with peer victimization and psychosocial distress, teacher–student relationships were robustly related to peer victimization and psychosocial distress over the influence of the previous variables. In other words, as a key study finding, teacher–student relationships may reduce the impact of peer victimization by mitigating its negative psychosocial effects in a robust yet relatively unexplored way. Therefore, although more research is needed, fostering positive teacher–student relationships might be an effective way to reduce peer victimization as well as its negative effects.     

Effects of microcomputer-administered diagnostic testing on immediate and continuing science achievement and attitudes

This investigation had three purposes: (1) to document any immediate and continuing benefits associated with the use of microcomputer-administered testing; (2) to determine what type of student might benefit most from microcomputer-administered diagnostic testing; and (3) to document the feasibility of microcomputer-administered diagnostic testing. The subjects of the study were enrolled in a biology course based on the BSCS Blue text. A random half of the students received behaviorally-stated performance objectives, while the remaining half received behaviorally-stated performance objectives in conjunction with microcomputer-administered diagnostic testing. The results of this study indicate that microcomputer-administered diagnostic testing can positively influence the immediate, but not the continuing, achievement of students in science. In addition, neither student aptitude nor achievement motivation level were found to interact with treatment or influence achievement. Affective data indicate that students react favorably to the use of objectives, computers, and diagnostic testing. Cost summary data reveal that when the expense of administering diagnostic testing by microcomputer is prorated over a five-year period, the cost of a diagnostic test is reduced to approximately three cents.     

Factors that impact social networking in online self-regulated learning activities

Educational technology research and development - Among the literature on self-regulated learning and social networking, the studies, which explore the impact of social networks on learning...