SCAMP:standardised, concentrated, additional macronutrients, parenteral nutrition in very preterm infants: a phase IV randomised, controlled exploratory study of macronutrient intake, growth and other aspects of neonatal care

<p>Abstract</p> <p>Background</p> <p>Infants born <29 weeks gestation are at high risk of neurocognitive disability. Early postnatal growth failure, particularly head growth, is an important and potentially reversible risk factor for impaired neurodevelopmental outcome. Inadequate nutrition is a major factor in this postnatal growth failure, optimal protein and calorie (macronutrient) intakes are rarely achieved, especially in the first week. Infants <29 weeks are dependent on parenteral nutrition for the bulk of their nutrient needs for the first 2-3 weeks of life to allow gut adaptation to milk digestion. The prescription, formulation and administration of neonatal parenteral nutrition is critical to achieving optimal protein and calorie intake but has received little scientific evaluation. Current neonatal parenteral nutrition regimens often rely on individualised prescription to manage the labile, unpredictable biochemical and metabolic control characteristic of the early neonatal period. Individualised prescription frequently fails to translate into optimal macronutrient delivery. We have previously shown that a standardised, concentrated neonatal parenteral nutrition regimen can optimise macronutrient intake.</p> <p>Methods</p> <p>We propose a single centre, randomised controlled exploratory trial of two standardised, concentrated neonatal parenteral nutrition regimens comparing a standard macronutrient content (maximum protein 2.8 g/kg/day; lipid 2.8 g/kg/day, dextrose 10%) with a higher macronutrient content (maximum protein 3.8 g/kg/day; lipid 3.8 g/kg/day, dextrose 12%) over the first 28 days of life. 150 infants 24-28 completed weeks gestation and birthweight <1200 g will be recruited. The primary outcome will be head growth velocity in the first 28 days of life. Secondary outcomes will include a) auxological data between birth and 36 weeks corrected gestational age b) actual macronutrient intake in first 28 days c) biomarkers of biochemical and metabolic tolerance d) infection biomarkers and other intravascular line complications e) incidence of major complications of prematurity including mortality f) neurodevelopmental outcome at 2 years corrected gestational age</p> <p>Trial registration</p> <p>Current controlled trials: <a href="http://www.controlled-trials.com/ISRCTN76597892">ISRCTN76597892</a>; EudraCT Number: 2008-008899-14</p

Neuroelectric Evidence for Cognitive Association Formation: An Event-Related Potential Investigation

Although many types of learning require associations to be formed, little is known about the brain mechanisms engaged in association formation. In the present study, we measured event-related potentials (ERPs) while participants studied pairs of semantically related words, with each word of a pair presented sequentially. To narrow in on the associative component of the signal, the ERP difference between the first and second words of a pair (Word2-Word1) was derived separately for subsequently recalled and subsequently not-recalled pairs. When the resulting difference waveforms were contrasted, a parietal positivity was observed for subsequently recalled pairs around 460 ms after the word presentation onset, followed by a positive slow wave that lasted until around 845 ms. Together these results suggest that associations formed between semantically related words are correlated with a specific neural signature that is reflected in scalp recordings over the parietal region

Participant Nonnaiveté and the reproducibility of cognitive psychology

Many argue that there is a reproducibility crisis in psychology. We investigated nine well-known effects from the cognitive psychology literature—three each from the domains of perception/action, memory, and language, respectively—and found that they are highly reproducible. Not only can they be reproduced in online environments, but they also can be reproduced with nonnaïve participants with no reduction of effect size. Apparently, some cognitive tasks are so constraining that they encapsulate behavior from external influences, such as testing situation and prior recent experience with the experiment to yield highly robust effects

Recall termination in free recall

Although much is known about the dynamics of memory search in the free recall task, relatively little is known about the factors related to recall termination. Reanalyzing individual trial data from 14 prior studies (1,079 participants in 28,015 trials) and defining termination as occurring when a final response is followed by a long nonresponse interval, we observed that termination probability increased throughout the recall period and that retrieval was more likely to terminate following an error than following a correct response. Among errors, termination probability was higher following prior-list intrusions and repetitions than following extralist intrusions. To verify that this pattern of results can be seen in a single study, we report a new experiment in which 80 participants contributed recall data from a total of 9,122 trials. This experiment replicated the pattern observed in the aggregate analysis of the prior studies

RECAPP-XPR: A smartphone application for presenting and recalling experimentally controlled stimuli over longer timescales

We report two experiments that used smartphone applications for presenting and recalling verbal stimuli over extended timescales. In Experiment 1, we used an iPhone application that we had developed, called RECAPP-XPR, to present 76 participants with a single list of eight words presented at a rate of one word every hour, followed by a test of free recall an hour later. The experiment was exceptionally easy to schedule, taking only between 5 and 10 min to set up using a web-based interface. RECAPP-XPR randomly samples the stimuli, presents the stimuli, and collects the free recall data. The stimuli disappear shortly after they have been presented, and RECAPP-XPR collects data on when each stimulus was viewed. In Experiment 2, the study was replicated using the widely used image-sharing application Snapchat. A total of 197 participants were tested by 38 student experimenters, who manually presented the stimuli as “snaps” of experimentally controlled stimuli using the same experimental rates that had been used in Experiment 1. Like all snaps, these stimuli disappeared from view after a very short interval. In both experiments, we observed significant recall advantages for the first and last list items (primacy and recency effects, respectively), and there were clear tendencies to make more transitions at output between near-neighboring items, with a forward-ordered bias, consistent with temporal contiguity effects. The respective advantages and disadvantages of RECAPP-XPR and Snapchat as experimental software packages are discussed, as is the relationship between single-study-list smartphone experiments and long-term recency studies of real-world events

Annual cycle of the legume pod borer Maruca vitrata Fabricius (Lepidoptera: Crambidae) in southwestern Burkina Faso

Maruca vitrata is an economically significant insect pest of cowpea in sub-Saharan Africa. Understanding the seasonal population patterns of M. vitrata is essential for the establishment of effective pest management strategies. M. vitrata larval populations on cultivated cowpea and adult flying activities were monitored in addition to scouting for host plants and parasitoids during 2 consecutive years in 2010 and 2011 in southwestern Burkina Faso. Our data suggest that M. vitrata populations overlapped on cultivated cowpea and alternate host plants during the rainy season. During the cowpea off-season, M. vitrata maintained a permanent population on the wild host plants Mucuna poggei and Daniella oliveri. The parasitoid fauna include three species, Phanerotoma leucobasis Kri., Braunsia kriegeri End. and Bracon sp. Implications of these finding for pest management strategies are discussed

Systematic Review of Potential Health Risks Posed by Pharmaceutical, Occupational and Consumer Exposures to Metallic and Nanoscale Aluminum, Aluminum Oxides, Aluminum Hydroxide and Its Soluble Salts

Aluminum (Al) is a ubiquitous substance encountered both naturally (as the third most abundant element) and intentionally (used in water, foods, pharmaceuticals, and vaccines); it is also present in ambient and occupational airborne particulates. Existing data underscore the importance of Al physical and chemical forms in relation to its uptake, accumulation, and systemic bioavailability. The present review represents a systematic examination of the peer-reviewed literature on the adverse health effects of Al materials published since a previous critical evaluation compiled by Krewski et al. (2007). Challenges encountered in carrying out the present review reflected the experimental use of different physical and chemical Al forms, different routes of administration, and different target organs in relation to the magnitude, frequency, and duration of exposure. Wide variations in diet can result in Al intakes that are often higher than the World Health Organization provisional tolerable weekly intake (PTWI), which is based on studies with Al citrate. Comparing daily dietary Al exposures on the basis of “total Al”assumes that gastrointestinal bioavailability for all dietary Al forms is equivalent to that for Al citrate, an approach that requires validation. Current occupational exposure limits (OELs) for identical Al substances vary as much as 15-fold. The toxicity of different Al forms depends in large measure on their physical behavior and relative solubility in water. The toxicity of soluble Al forms depends upon the delivered dose of Al+ 3 to target tissues. Trivalent Al reacts with water to produce bidentate superoxide coordination spheres [Al(O2)(H2O4)+ 2 and Al(H2O)6 + 3] that after complexation with O2•−, generate Al superoxides [Al(O2•)](H2O5)]+ 2. Semireduced AlO2• radicals deplete mitochondrial Fe and promote generation of H2O2, O2 • − and OH•. Thus, it is the Al+ 3-induced formation of oxygen radicals that accounts for the oxidative damage that leads to intrinsic apoptosis. In contrast, the toxicity of the insoluble Al oxides depends primarily on their behavior as particulates. Aluminum has been held responsible for human morbidity and mortality, but there is no consistent and convincing evidence to associate the Al found in food and drinking water at the doses and chemical forms presently consumed by people living in North America and Western Europe with increased risk for Alzheimer\u27s disease (AD). Neither is there clear evidence to show use of Al-containing underarm antiperspirants or cosmetics increases the risk of AD or breast cancer. Metallic Al, its oxides, and common Al salts have not been shown to be either genotoxic or carcinogenic. Aluminum exposures during neonatal and pediatric parenteral nutrition (PN) can impair bone mineralization and delay neurological development. Adverse effects to vaccines with Al adjuvants have occurred; however, recent controlled trials found that the immunologic response to certain vaccines with Al adjuvants was no greater, and in some cases less than, that after identical vaccination without Al adjuvants. The scientific literature on the adverse health effects of Al is extensive. Health risk assessments for Al must take into account individual co-factors (e.g., age, renal function, diet, gastric pH). Conclusions from the current review point to the need for refinement of the PTWI, reduction of Al contamination in PN solutions, justification for routine addition of Al to vaccines, and harmonization of OELs for Al substances

Working Memory Underpins Cognitive Development, Learning, and Education

Working memory is the retention of a small amount of information in a readily accessible form. It facilitates planning, comprehension, reasoning, and problem-solving. I examine the historical roots and conceptual development of the concept and the theoretical and practical implications of current debates about working memory mechanisms. Then I explore the nature of cognitive developmental improvements in working memory, the role of working memory in learning, and some potential implications of working memory and its development for the education of children and adults. The use of working memory is quite ubiquitous in human thought, but the best way to improve education using what we know about working memory is still controversial. I hope to provide some directions for research and educational practice