Harps under Heavy Fog Conditions: Superior to Meshes but Prone to Tangling.

In arid yet foggy regions, fog harvesting is emerging as a promising approach to combat water scarcity. The mesh netting used by current fog harvesters suffers from inefficient drainage, which severely constrains the water collection efficiency. Recently, it was demonstrated that fog harps can significantly enhance water harvesting as the vertical wire array does not obstruct the drainage pathway. However, fabrication limitations resulted in a very low shade coefficient of 18% for the initial fog harp prototype and the field testing was geographically confined to light fog conditions. Here, we use wire-electrical discharge machining (wire-EDM) to machine ultrafine comb arrays; winding the harp wire along a comb-embedded reinforced frame enabled a shade coefficient of 50%. To field test under heavy fog conditions, we placed the harvesters on a closed-circuit test road and inundated them with fog produced by an array of overlying fog towers. On average, the fog harps collected about three times more water than the mesh netting. During fog harvesting, the harp wires were observed to tangle together due to the surface tension of water. We developed a rational model to predict the extent of the tangling problem for any given fog harp design. By designing next-generation fog harps to be anti-tangling, we expect that even larger performance multipliers will be possible compared to the current mesh harvesters.

Persistent feeding difficulties among infants with fetal opioid exposure: mechanisms and clinical reasoning.

Aims: Infants with fetal exposure to opioids have varying pattern of feeding difficulties mainly manifesting as difficulties with aerodigestive adaptation and disruptive feeding behavior. The reasons are unclear; in a pilot study, we determined basal and adaptive pharyngo-esophageal motility in a group of infants with fetal exposure to opioids and persistent feeding difficulties impeding their discharge. Methods: Six infants with fetal opioid exposure compared to 12 controls who underwent basal and adaptive pharyngo-esophageal manometry to characterize the basis for their symptoms. Spontaneous swallows (N = 180) and pharyngeal stimuli (N = 113)-induced swallowing responses were analyzed. Results: Resting upper esophageal sphincter (UES) pressure was similar in both the groups, but resting lower esophageal sphincter (LES) pressure was significantly high and it relaxed slowly and inadequately in opioid-exposed infants (p < .05). Upon pharyngeal provocation, opioid-exposed infants had higher LES nadir pressure, increased duration of esophageal body contraction at proximal-, mid-, and distal-esophagus, as well as greater area under the curve with distal esophageal waveforms, compared to controls (all p < .05). Conclusions: These pilot observations are suggestive of up-regulation of central vagal effects with heightened cholinergic excitatory responses and inadequate relaxation responses at the foregut, and may form the basis for persistent feeding difficulties in opioid-exposed infants. Abnormality with both sensory and motor aspects of vagal reflexes may be contributory.

Deliberate practice improves pediatric residents' skills and team behaviors during simulated neonatal resuscitation.

OBJECTIVE: To evaluate the skills and team behavior of pediatric residents during resuscitation with a high-fidelity mannequin before and after a deliberate practice intervention. METHODS: Each month residents participate in two 90-minute videorecorded sessions (2-3 weeks apart) in an "off-site" delivery room during their neonatal ICU rotation. Teams responded to a scenario that required 5 skills (positive pressure ventilation, chest compressions, endotracheal intubation, umbilical vein catheterization, and epinephrine administration). Skills were scored for technique and timeliness and team behaviors for communication, management, and leadership. A 2-hour focused intervention was given between sessions. RESULTS: In all, 33 residents (11 teams) completed the sessions. Gaps in procedural skills noted during the first session were corrected. Timeliness for completion of skills remained below expectations. Improvements in team behaviors were noted. CONCLUSIONS: Deliberate practice improved procedural skills and team performance. Lack of improvement in timeliness suggests that a different educational paradigm is required.

Pediatrics residents' preparedness for neonatal resuscitation assessed using high-fidelity simulation.

BACKGROUND: Pediatrics residents are expected to demonstrate preparedness for neonatal resuscitation, yet research has shown gaps in residents' readiness to perform this skill. OBJECTIVE: To evaluate procedural skills and team performance of pediatrics residents during neonatal resuscitation (NR) using a high-fidelity mannequin, and to assess residents' confidence in their NR skills before and after training. METHODS: Two teams of residents (all had completed NR program training) participated in 2 separate, 90-minute sessions (2 to 3 weeks apart) in an off-site delivery room during their neonatal intensive care rotation. Residents' confidence in assisting and leading NR was surveyed before each session. Teams participated in a scenario (adapted from the NR program), which required 5 skills (positive pressure ventilation, chest compressions, endotracheal intubation, umbilical vein catheterization, and epinephrine administration). Video recording was used for debriefing and scoring. Skills were scored for technique and timeliness, and team behaviors were scored for communication, management, and leadership. RESULTS: Twenty-six residents (11 teams) completed 2 paired sessions. Self-confidence scores increased between the 2 sessions but were not correlated with performance. Gaps in procedural skill performance were observed, and timeliness for most skills did not meet expectations. Significant improvement in team communication was noted. CONCLUSIONS: Important gaps in procedural skill performance, particularly timeliness, were detected by NR simulation training; residents' improvements in self-confidence did not reflect gains in actual performance. Their relative unpreparedness for NR (despite prior certification) highlights the need for deliberate practice and specific team training before and during neonatal intensive care delivery room rotations.

Anti-inflammatory effects of PPAR-gamma agonists directly correlate with PPAR-gamma expression during acute pancreatitis.

Peroxisome proliferator-activated receptors (PPARs) are ligand-inducible transcription factors that regulate cellular energy and lipid metabolism. PPAR-gamma agonists also have potent anti-inflammatory properties through down-regulation of early inflammatory response genes. The role of PPAR-gamma in acute pancreatitis has not been adequately examined. In this study, we determined the effect of PPAR-gamma agonists on the severity of pancreatitis and sought to correlate PPAR-gamma expression in pancreatic acinar cells and the severity of acute pancreatitis in vivo. Acute pancreatitis was induced in mice by hyperstimulation with the cholecystokinin analog, cerulein. PPAR-gamma agonists were administered by intraperitoneal injection 15-30 minutes before induction of pancreatitis (pretreatment) or at various times after induction of pancreatitis (treatment). Pancreata and serum were harvested over the course of 24 hours. Serum amylase activity and glucose levels were measured. Pancreata were used for histological evaluation as well as protein and mRNA analysis. Pretreatment of mice with the PPAR-gamma agonists 15-deoxy-Delta12, 14-prostaglandin J(2), or troglitazone significantly reduced the severity of pancreatitis in a dose-dependent manner. This reduction was indicated by reduced serum amylase activity and histological damage (leukocyte infiltration, vacuolization, and necrosis). Although cerulein decreased PPAR-gamma expression in the pancreas, pretreatment with agonists maintained PPAR-gamma expression early in acute pancreatitis. The expression of PPAR-gamma inversely correlated with pancreatitis severity and expression of the proinflammatory cytokines, interleukin-6, and tumor necrosis factor-alpha. Treatment with troglitazone after the induction of pancreatitis reduced serum amylase activity. The results suggest that PPAR-gamma plays a direct role in the inflammatory cascade during the early events of acute pancreatitis. Our data are the first to demonstrate that PPAR-gamma agonists represent a promising therapeutic strategy for acute pancreatitis.