bluuebunny/crossref_metadata_2025 huggingface dataset:
Association of nucleated red blood cells in blood and arterial oxygen partial tension
Authors: Kuert Sandra , Holland-Letz Tim , Friese Jochen , Stachon Axel
Published: December 2010

Background:Several studies suggest that the detection of nucleated red blood cells (NRBCs) in hospitalized patients indicates an increased risk of mortality. This study evaluates the impact of low arterial oxygen partial tension (pO2) on NRBC appearance and prognosis in NRBC positive patients.

Methods:NRBCs in blood, arterial blood gases, and other laboratory parameters were monitored daily in 234 surgical intensive care patients. pO2was assessed in relation to mortality and the detection of NRBCs.

Results:NRBCs were found in 67 patients (28.6%). Mortality was significantly higher in NRBC positive patients (41.8%, 28/67) than in those that were NRBC negative (3.0%, 5/167). Multivariate logistic regression showed an increased mortality in NRBC positive patients (odds ratio 5.79; 95% confidence interval (CI) 1.07–31.33, p<0.05). NRBC positive patients showed significantly lower pO2levels during intensive care treatment than NRBC negative patients. Prior to the initial detection of NRBCs in the peripheral blood, pO2levels were significantly lower in patients who died than in surviving patients. After the first appearance of NRBCs, no significant difference in pO2between these groups was found.

Conclusions:The detection of NRBCs is of prognostic significance concerning patient mortality. In NRBC positive patients, hypoxemia occurs more frequently. Low-levels of pO2seem to precede the appearance of NRBCs, especially in those patients with high risk of mortality.
Serum creatinine concentrations in male and female elite swimmers. Correlation with body mass index and evaluation of estimated glomerular filtration rate
Authors: Milić Radoje , Banfi Giuseppe , Del Fabbro Massimo , Dopsaj Milivoj
Published: December 2010

Background: Creatinine concentrations in athletes could be higher than in sedentary people due to higher muscle mass; a correlation between body mass index (BMI) and creatinine concentrations has been described only in male athletes participating in different sports.

Methods: Elite swimmers (28 males and 26 females) belonging to the National Teams of Slovenia were recruited during the period 1999–2009. The evaluation of possible modifications to serum creatinine concentrations during a single season were performed in 10 males and seven females who were evaluated four times during a season. Serum creatinine was analyzed using the Jaffe method. Pearson's simple correlation analysis was used to test the association between serum creatinine and BMI. Creatinine values and BMI were compared using the unpaired Student t-test. Creatinine values during the different phases of the season were compared using a one-way analysis of variance test.

Results: The values for creatinine are related to BMI in male and female swimmers. It should be noted that there is a significant difference (p<0.001) for estimated glomerular filtration rate (eGFR) values obtained by Cockcroft and Gault equation, but not for the Modification of Diet in Renal Disease (MDRD) equation. The values of creatinine were stable in each athlete during various training cycle periods in the observed competition year.

Conclusions: The study confirms that in a large and representative group of elite swimmers, creatinine concentration is strictly correlated to BMI. The use of creatinine-based eGFR formulas should be used with caution in athletes.
Antidepressant Effect of Optogenetic Stimulation of the Medial Prefrontal Cortex
Authors: Covington Herbert E. , Lobo Mary Kay , Maze Ian , Vialou Vincent , Hyman James M. , Zaman Samir , LaPlant Quincey , Mouzon Ezekiel , Ghose Subroto , Tamminga Carol A. , Neve Rachael L. , Deisseroth Karl , Nestler Eric J.
Published: December 2010

Brain stimulation and imaging studies in humans have highlighted a key role for the prefrontal cortex in clinical depression; however, it remains unknown whether excitation or inhibition of prefrontal cortical neuronal activity is associated with antidepressant responses. Here, we examined cellular indicators of functional activity, including the immediate early genes (IEGs)zif268(egr1),c-fos, andarc, in the prefrontal cortex of clinically depressed humans obtained postmortem. We also examined these genes in the ventral portion of the medial prefrontal cortex (mPFC) of mice after chronic social defeat stress, a mouse model of depression. In addition, we used viral vectors to overexpress channel rhodopsin 2 (a light-activated cation channel) in mouse mPFC to optogenetically drive “burst” patterns of cortical firingin vivoand examine the behavioral consequences. Prefrontal cortical tissue derived from clinically depressed humans displayed significant reductions in IEG expression, consistent with a deficit in neuronal activity within this brain region. Mice subjected to chronic social defeat stress exhibited similar reductions in levels of IEG expression in mPFC. Interestingly, some of these changes were not observed in defeated mice that escape the deleterious consequences of the stress, i.e., resilient animals. In those mice that expressed a strong depressive-like phenotype, i.e., susceptible animals, optogenetic stimulation of mPFC exerted potent antidepressant-like effects, without affecting general locomotor activity, anxiety-like behaviors, or social memory. These results indicate that the activity of the mPFC is a key determinant of depression-like behavior, as well as antidepressant responses.
Synaptic Localization and Activity of ADAM10 Regulate Excitatory Synapses through N-Cadherin Cleavage
Authors: Malinverno Matteo , Carta Mario , Epis Roberta , Marcello Elena , Verpelli Chiara , Cattabeni Flaminio , Sala Carlo , Mulle Christophe , Di Luca Monica , Gardoni Fabrizio
Published: December 2010

N-Cadherin has an important role during dendrite arborization, axon guidance, and synaptogenesis. In particular, at synaptic sites, N-cadherin is involved in the regulation of cell–cell adhesion and in morphology and plasticity control. Recent studies have shown that N-cadherin can be cleaved by the metalloproteinase ADAM10. Here we demonstrate that impairing ADAM10 localization and activity at synaptic sites decreases its processing of N-cadherin. This leads to an accumulation of the full-length form of N-cadherin, to an increase in spine head width, and to modifications of the number and function of glutamate receptors of AMPA type, bothin vitroandin vivo. Our results indicate a key role for ADAM10 in the complex sequence of events through which N-cadherin affects spine maturation and controls structure and function of glutamatergic synapses.
The Prefrontal Cortex Communicates with the Amygdala to Impair Learning after Acute Stress in Females but Not in Males
Authors: Maeng Lisa Y. , Waddell Jaylyn , Shors Tracey J.
Published: December 2010

Acute stress exposure enhances classical eyeblink conditioning in male rats, whereas exposure to the same event dramatically impairs performance in females (Wood and Shors, 1998; Wood et al., 2001). We hypothesized that stress affects learning differently in males and females because different brain regions and circuits are being activated. In the first experiment, we determined that neuronal activity within the medial prefrontal cortex (mPFC) during the stressful event is necessary to disrupt learning in females. In both males and females, the mPFC was bilaterally inactivated with GABA agonist muscimol before the stressor. Inactivation prevented only the impaired performance in females; it had no consequence for performance in males. However, in the second experiment, excitation of the mPFC alone with GABA antagonist picrotoxin was insufficient to elicit the stress effect that was prevented through the inactivation of this region in females. Therefore, we hypothesized that the mPFC communicates with the basolateral amygdala to disrupt learning in females after the stressor. To test this hypothesis, these structures were disconnected from each other with unilateral excitotoxic (NMDA) lesions on either the same or opposite sides of the brain. Females with contralateral lesions, which disrupt the connections on both sides of the brain, were able to learn after the stressful event, whereas those with ipsilateral lesions, which disrupt only one connection, did not learn after the stressor. Together, these data indicate that the mPFC is critically involved in females during stress to impair subsequent learning and does so via communication with the amygdala.
Glial Fibrillary Tangles and JAK/STAT-Mediated Glial and Neuronal Cell Death in aDrosophilaModel of Glial Tauopathy
Authors: Colodner Kenneth J. , Feany Mel B.
Published: December 2010

A subset of neurodegenerative tauopathies is characterized by abundant filamentous inclusions of hyperphosphorylated tau in both neurons and glia. Although the contribution of neuronal tau to behavioral changes and neuronal loss in neurodegenerative diseases has been studied extensively, the functional consequences of tau deposition in glial cells have been less well characterized. To investigate the role of abnormal tau accumulation and aggregation in glial cells, we created aDrosophilamodel of glial tauopathy by expressing human wild-type tau in adult fly glial cells. Glial expression of tau resulted in robust aggregation of phosphorylated tau into fibrillary inclusions similar to human glial tangles. Tangle formation was accompanied by shortened lifespan and age-dependent apoptotic cell death of both glia and neurons. Genetic manipulation of Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling modified toxicity of glial tau. We also identified a synergistic interaction of combined tau expression in neurons and glial cells. In summary, we present a genetically tractable model of glial fibrillary tau tangle formation and identify JAK/STAT signaling as mediating the death of both glia and neurons in this model.
Ventral Tegmental Afferents in Stress-Induced Reinstatement: The Role of cAMP Response Element-Binding Protein
Authors: Briand Lisa A. , Vassoler Fair M. , Pierce R. Christopher , Valentino Rita J. , Blendy Julie A.
Published: December 2010

The transcription factor cAMP response element-binding protein (CREB) is required for stress- but not drug-induced reinstatement of cocaine conditioned place preference. To reveal the neural circuitry associated with this CREB dependence, we injected a retrograde tracer into the ventral tegmental area (VTA) and identified afferents that were activated after stress or cocaine exposure in both naive and cocaine-conditioned mice. Neuronal activation, as assessed by Fos expression, was greatly reduced in the dorsal and ventral bed nucleus of the stria terminalis (BNST), lateral septum, and nucleus accumbens shell in mice lacking CREB (CREBαΔ mice) after a 6 min swim stress but not after cocaine exposure (20 mg/kg). Additionally, activation of VTA afferent neurons in the ventral BNST and the infralimbic cortex in CREBαΔ mice was blunted in response to stress. This pattern of neuronal activation persisted in mice that were conditioned to a cocaine place preference procedure before stress exposure. Furthermore, lidocaine inactivation (0.4 μl, 4%) studies demonstrated the necessity of BNST activation for swim-stress-induced reinstatement of cocaine-conditioned reward. Together, the present studies demonstrate that CREB is required for the activation of a unique circuit that converges on the dopamine reward pathway to elicit reinstatement of drug reward and points to the BNST as a key intersection between stress and reward circuits.
Response Characteristics of Basolateral and Centromedial Neurons in the Primate Amygdala
Authors: Mosher Clayton P. , Zimmerman Prisca E. , Gothard Katalin M.
Published: December 2010

Based on cellular architecture and connectivity, the main nuclei of the primate amygdala are divided in two clusters: basolateral (BL) and centromedial (CM). These anatomical features suggest a functional division of labor among the nuclei. The BL nuclei are thought to be involved primarily in evaluating the emotional significance or context-dependent relevance of all stimuli, including social signals such as facial expressions. The CM nuclei appear to be involved in allocating attention to stimuli of high significance and in initiating situation-appropriate autonomic responses. The goal of this study was to determine how this division of labor manifests in the response properties of neurons recorded from these two nuclear groups. We recorded the activity of 454 single neurons from identified nuclear sites in three monkeys trained to perform an image-viewing task. The task required orienting and attending to cues that predicted trial progression and viewing images with broadly varying emotional content. The two populations of neurons showed large overlaps in neurophysiological properties. We found, however, that CM neurons show higher firing and less regular spiking patterns than BL neurons. Furthermore, neurons in the CM nuclei were more likely to respond to task events (fixation, image on, image off), whereas neurons in the BL nuclei were more likely to respond selectively to the content of stimulus images. The overlap in the physiological properties of the CM and BL neurons suggest distributed processing across the nuclear groups. The differences, therefore, appear to be a processing bias rather than a hallmark of mutually exclusive functions.
Emergent Dynamics of Fast Ripples in the Epileptic Hippocampus
Authors: Ibarz Jose M. , Foffani Guglielmo , Cid Elena , Inostroza Marion , Menendez de la Prida Liset
Published: December 2010

Fast ripples are a type of transient high-frequency oscillations recorded from the epileptogenic regions of the hippocampus and the temporal cortex of epileptic humans and rodents. These events presumably reflect hypersynchronous bursting of pyramidal cells. However, the oscillatory spectral content of fast ripples varies from 250 to 800 Hz, well above the maximal firing frequency of most hippocampal pyramidal neurons. How such high-frequency oscillations are generated is therefore unclear. Here, we combine computational simulations of fast ripples with multisite and juxtacellular recordingsin vivoto examine the underlying mechanisms in the hippocampus of epileptic rats. We show that populations of bursting cells firing individually at 100–400 Hz can create fast ripples according to two main firing regimes: (1) in-phase synchronous firing resulting in “pure” fast ripples characterized by single spectral peaks that reflect single-cell behavior and (2) out-of-phase firing that results in “emergent” fast ripples. Using simulations, we found that fast ripples generated under these two different regimes can be quantitatively separated by their spectral characteristics, and we took advantage of this separability to examine their dynamicsin vivo. We found that in-phase firing can reach frequencies up to 300 Hz in the CA1 and up to 400 Hz in the dentate gyrus. The organization of out-of-phase firing is determined by firing delays between cells discharging at low frequencies. The two firing regimes compete dynamically, alternating randomly from one fast ripple event to the next, and they reflect the functional dynamic organization of the different regions of the hippocampus.
Motor Learning Reduces Eye Movement Variability through Reweighting of Sensory Inputs
Authors: Guo Cong C. , Raymond Jennifer L.
Published: December 2010

Motor learning can improve both the accuracy and precision of motor performance. We analyzed changes in the average trajectory and the variability of smooth eye movements during motor learning in rhesus monkeys. Training with a compound visual–vestibular stimulus could reduce the variability of the eye movement responses without altering the average responses. This improvement of eye movement precision was achieved by shifting the reliance of the movements from a more variable, visual signaling pathway to a less variable, vestibular signaling pathway. Thus, cerebellum-dependent motor learning can improve the precision of movements by reweighting sensory inputs with different variability.
Visual Experience Induces Long-Term Potentiation in the Primary Visual Cortex
Authors: Cooke Sam F. , Bear Mark F.
Published: December 2010

Stimulus-specific response potentiation (SRP) is a robust form of experience-dependent plasticity that occurs in primary visual cortex. In awake mice, visual evoked potentials (VEPs) recorded in layer 4 of binocular visual cortex undergo increases in amplitude with repeated presentation of a sinusoidal grating stimulus over days. This effect is highly specific to the experienced stimulus. Here, we test whether the mechanisms of thalamocortical long-term potentiation (LTP), induced with a theta burst electrical stimulation (TBS) of the dorsal lateral geniculate nucleus, are sufficient to account for SRP. First, we demonstrate that LTP similarly enhances the amplitude of VEPs, but in a way that generalizes across multiple stimuli, spatial frequencies, and contrasts. Second, we show that LTP occludes the subsequent expression of SRP. Third, we reveal that previous SRP occludes TBS-induced LTP of the VEP evoked by the experienced stimulus, but not by unfamiliar stimuli. Finally, we show that SRP is rapidly and selectively reversed by local cortical infusion of a peptide that inhibits PKMζ, a constitutively active kinase known to maintain NMDA receptor-dependent LTP and memory. Thus, SRP is expressed by the same core mechanisms as LTP. SRP therefore provides a simple assay to assess the integrity of LTP in the intact nervous system. Moreover, the results suggest that LTP of visual cortex, like SRP, can potentially be exploited to improve vision.
H-Reflex Up-Conditioning Encourages Recovery of EMG Activity and H-Reflexes after Sciatic Nerve Transection and Repair in Rats
Authors: Chen Yi , Wang Yu , Chen Lu , Sun Chenyou , English Arthur W. , Wolpaw Jonathan R. , Chen Xiang Yang
Published: December 2010

Operant conditioning of the spinal stretch reflex or its electrical analog, the H-reflex, produces spinal cord plasticity and can thereby affect motoneuron responses to primary afferent input. To explore whether this conditioning can affect the functional outcome after peripheral nerve injury, we assessed the effect of up-conditioning soleus (SOL) H-reflex on SOL and tibialis anterior (TA) function after sciatic nerve transection and repair. Sprague Dawley rats were implanted with EMG electrodes in SOL and TA and stimulating cuffs on the posterior tibial nerve. After control data collection, the sciatic nerve was transected and repaired and the rat was exposed for 120 d to continued control data collection (TC rats) or SOL H-reflex up-conditioning (TU rats). At the end of data collection, motoneurons that had reinnervated SOL and TA were labeled retrogradely. Putative primary afferent terminals [i.e., terminals containing vesicular glutamate transporter-1 (VGLUT1)] on SOL motoneurons were studied immunohistochemically. SOL (and probably TA) background EMG activity recovered faster in TU rats than in TC rats, and the final recovered SOL H-reflex was significantly larger in TU than in TC rats. TU and TC rats had significantly fewer labeled motoneurons and higher proportions of double-labeled motoneurons than untransected rats. VGLUT1 terminals were significantly more numerous on SOL motoneurons of TU than TC rats. Combined with the larger H-reflexes in TU rats, this anatomical finding supports the hypothesis that SOL H-reflex up-conditioning strengthened primary afferent reinnervation of SOL motoneurons. These results suggest that H-reflex up-conditioning may improve functional recovery after nerve injury and repair.
Renal Calcification in NICU Patients
Authors: Karlowicz M. Gary
Published: December 2010

Sequential renal ultrasonographic studies have shown renal calcifications to be more common in neonatal intensive care unit (NICU) patients than is commonly believed, especially in extremely low-birthweight (ELBW) infants. A family history of kidney stones is an independent risk factor for renal calcifications in ELBW infants. Understanding the role of inhibitors and promoters in crystal formation helps in understanding the pathophysiology of nephrocalcinosis. Identification of the presence or absence of hypercalcemia and hypercalciuria is an effective method of directing the diagnostic evaluation of infants who have nephrocalcinosis. Fortunately, ultrasonographic renal calcifications resolve spontaneously in most NICU patients. Renal calcifications can be associated with persistent abnormalities in renal function if hypercalciuria continues, such as in the rare very low-birthweight (VLBW) infant who receives long-term furosemide therapy after hospital discharge. Only in rare cases, often inborn errors of metabolism, can renal calcifications in NICU patients progress to chronic renal injury, such as in infants who have primary hyperoxaluria that involves persistence of oxalate in the urine, a potent promoter of calcium crystal formation.
Haitian, Chinese, Somali, Ethiopian, and Asian/Pacific Islander Perspectives on Research
Authors: Foley Susan M. , Raphael Renald , Adolphe Martin , Wu Joseph , Tamene Binyam , Rubin Carolyn Leung , Yusuf Abdirahman
Published: December 2010

Researchers often approach community-based organizations as an access point to engage underserved populations in studies. In this article, 5 representatives of community organizations present their perspectives on the complexity of researcher-community partnerships and the nuances of engaging Haitian, Ethiopian, Somali, Chinese, and Asian/Pacific Islander populations in research. Each representative presents recommendations for gaining trust and understanding within their communities and challenge researchers to move beyond seeking knowledge and into social action that improves the lives of their constituents.
Words and Numbers: A Parent's Perspective on Disability Research
Authors: Bostic Elizabeth
Published: December 2010

This piece is the commentary by Elizabeth Bostic, providing a parent view point on research and program development that affects children and youth with special health needs and chronic conditions. She points to the differences in culture between the general public and researchers and the need for the language we all speak to reflect common understanding.
Enhancing Developmentally Oriented Primary Care: An Illinois Initiative to Increase Developmental Screening in Medical Homes
Authors: Allen Scott G. , Berry Anita D. , Brewster Juanona A. , Chalasani Ram K. , Mack Patricia K.
Published: December 2010

In 2005, the Enhancing Developmentally Oriented Primary Care (EDOPC) project of the Illinois chapter of the American Academy of Pediatrics and the Illinois Department of Healthcare and Family Services began a project to improve the delivery and financing of preventive health and developmental services for children in Illinois. The leaders of this initiative sought to increase primary care providers' use of validated tools for developmental, social/emotional, maternal depression, and domestic violence screening and to increase early awareness of autism symptoms during pediatric well-child visits in children aged 0 to 3 years. These screenings facilitate identification of children at risk and those who need referral for further evaluation. Primary barriers to such screenings include lack of practitioner confidence in using validated screening tools. In this article we describe the accomplishments of the EDOPC project, which created training programs to address these barriers. This training is delivered by EDOPC staff and peer educators (physicians and nurse practitioners) in medical practices. The EDOPC project enhanced confidence and intent to screen among a large group of Illinois primary health care providers. Among a sample of primary care sites at which chart reviews were conducted, the EDOPC project increased developmental screening rates to the target of 85% of patients at most sites and increased social/emotional screening rates to the same target rate in nearly half of the participating practices.
Embedding Field Research on Mentored Inclusive Recreation in an Urban Population—The Evolution of Opening Doors: Project Adventure
Authors: Glader Laurie , Huntington Noelle , Horan Kelly , Davidson Emily
Published: December 2010

Community-based interventions have greater relevance and a greater chance of success and sustainability when the community is collaboratively involved in the research process. Opening Doors: Project Adventure is a research project designed to evaluate the impact of community-based inclusive recreation, using supportive mentoring, on children and youth with disabilities and special health care needs (CYDS). The project has a central goal of engaging CYDS who are members of underrepresented minorities, including those who face linguistic, cultural, and/or financial barriers to participation. In this article we describe the process of working with community partners and the lessons learned in the development and implementation of Project Adventure.
Youth-Based Participatory Research: Lessons Learned From a Transition Research Study
Authors: Rosen-Reynoso Myra , Kusminsky Matthew , Gragoudas Stelios , Putney Heather , Crossman Morgan K. , Sinclair James , Yarde Jadine
Published: December 2010

Transitions to postsecondary education for youth with disabilities, special health care needs, or both are often challenging. Adults design most interventions aimed at assisting youth in the transition process. In this article, we report on how youth can enhance transition interventions and research. Youth representing a variety of community-based organizations that serve diverse immigrant populations served as co-researchers in a randomized controlled study called OPT4College, a program that provides postsecondary education transition support for youth with disabilities, special health care needs, or both. This youth-based participatory study used an iterative process that is quite different from the traditional research-study flow. The involvement of empowered youth and communities, in concert with academic and public health partners, increases the probability of creating interventions that ensure successful postsecondary transitions for youth with disabilities, special health care needs, or both.
Identifying What Pediatric Residents Are Taught About Children and Youth With Special Health Care Needs and the Medical Home
Authors: Nazarian Beverly L. , Glader Laurie , Choueiri Roula , Shipman Deborah L. , Sadof Matthew
Published: December 2010

OBJECTIVE:

To describe what and how pediatric residents in Massachusetts are taught about children and youth with special health care needs (CYSHCN) and the medical home.

PARTICIPANTS AND METHODS:

Faculty members and residents at Massachusetts' 5 pediatric residency programs were interviewed to identify current curricula and teaching methods related to care of CYSHCN. In addition, residents were surveyed to quantify these concepts.

RESULTS:

Thirty-one faculty members and 25 residents were interviewed. Most exposure to CYSHCN was reported to occur in inpatient settings. However, most formal teaching about CYSHCN was described as occurring in the ambulatory setting. Promising educational strategies included home and community visits, inclusion of CYSHCN in resident continuity panels, and simulation and role-playing. Overall, the programs had little training emphasis on the lives and needs of CYSHCN and their families outside the hospital setting. Twenty (80%) of the residents interviewed completed the written survey instrument. They noted a high degree of comfort in caring for CYSHCN in various settings and involving families in decision-making about their child's care but expressed less comfort in identifying community resources and collaborating with community agencies and schools.

CONCLUSIONS:

Programs offer a variety of successful educational and clinical experiences related to the medical home and CYSHCN. The results of our study indicate that residents and faculty members believe that residents would benefit from more formal training opportunities to learn directly from families and community representatives about caring for CYSHCN.
Neonatal and Infant Mandibular Distraction as an Alternative to Tracheostomy in Severe Obstructive Sleep Apnea
Authors: Hammoudeh Jeffrey , Bindingnavele Vijay K. , Davis Brian , Davidson Ward Sally L. , Sanchez-Lara Pedro A. , Kleiber Grant , Mobin Sheila S. Nazarian , Francis Cameron S. , Urata Mark M.
Published: December 2010

Context

Surgical management for severe obstructive sleep apnea has been tracheostomy, which has significant morbidity.

Objective

To determine the efficacy of internal mandibular distraction in treating severe obstructive sleep apnea in infants and neonates.

Design

Retrospective review of medical records of 29 patients who underwent internal mandibular distraction for obstructive sleep apnea secondary to micrognathia.

Setting

Nonprofit, academic, pediatric medical center.

Patients

A total of 29 infants with obstructive sleep apnea were studied. Nine were included in the respiratory failure group requiring intubation prior to distraction surgery. The other 20 were included in the respiratory distress group and underwent preoperative polysomnography that assessed the severity of obstructive sleep apnea as measured by the apnea-hypopnea index. One patient expired following surgery; the remaining 28 underwent postoperative polysomnography determining their postoperative apnea-hypopnea index.

Interventions

Bilateral mandibular distraction with internal microdistractors.

Main Outcome Measure

Improvement in the apnea-hypopnea index or extubation.

Results

The nine respiratory failure patients avoided tracheostomy and were successfully extubated postdistraction. Eight in this group had postoperative polysomnographies showing a mean apnea-hypopnea index of 3.13 (range, 0 to 13.9). All 20 patients in the respiratory distress group underwent polysomnography and showed improved apnea-hypopnea indices ( p < .001). The mean pre-op apnea-hypopnea index was 39.7 (range, 4.5 to 177), and the mean post-op apnea-hypopnea index was 5.8 (range, 0 to 34). Average improvement in the apnea-hypopnea index was 33.9. The mean follow-up period was 18.7 months (1.6 to 45.2 months).

Conclusions

Infants with micrognathia and obstructive sleep apnea may avoid tracheostomy and its inherent risks and complications by undergoing internal mandibular distraction, which is a viable alternative to tracheostomy.
Denitrification and total nitrate uptake in streams of a tropical landscape
Authors: Potter J. D. , McDowell W. H. , Merriam J. L. , Peterson B. J. , Thomas S. M.
Published: December 2010

Rapid increases in nitrogen (N) loading are occurring in many tropical watersheds, but the fate of N in tropical streams is not well documented. Rates of nitrate uptake and denitrification were measured in nine tropical low‐order streams with contrasting land use as part of the Lotic Intersite Nitrogen eXperiment II (LINX II) in Puerto Rico using short term (24‐hour) additions of K15NO3 and NaBr. Background nitrate concentrations ranged from 105 to 997 μg N/L, and stream nitrate uptake lengths were long, varying from 315 to 8480 m (median of 1200 m). Other indices of nitrate uptake (mass transfer coefficient, Vf [cm/s], and whole‐stream nitrate uptake rate, U [μg N·m−2·s−1]) were low in comparison to other regions and were related to chemical, biological, and physical parameters. Denitrification rates were highly variable (0–133 μg N·m−2·min−1; median = 15 μg N·m−2·min−1), were dominated by the end product N2 (rather than N2O), and were best predicted by whole‐stream respiration rates and stream NO3 concentration. Denitrification accounted for 1–97% of nitrate uptake with five of nine streams having 35% or more of nitrate uptake via denitrification, showing that denitrification is a substantial sink for nitrate in tropical streams. Whole‐stream nitrate uptake and denitrification in our study streams closely followed first‐order uptake kinetics, indicating that NO3 uptake is limited by delivery of substrate (NO3) to the organisms involved in uptake or denitrification. In the context of whole‐catchment nitrogen budgets, our finding that in‐stream denitrification results in lower proportional production of N2O than terrestrial denitrification suggests that small streams can be viewed as the preferred site of denitrification in a watershed in order to minimize greenhouse gas N2O emissions. Conservation of small streams is thus critical in tropical ecosystem management.
TEACHING EARLY BRAILLE LITERACY SKILLS WITHIN A STIMULUS EQUIVALENCE PARADIGM TO CHILDREN WITH DEGENERATIVE VISUAL IMPAIRMENTS
Authors: Toussaint Karen A. , Tiger Jeffrey H.
Published: December 2010

Despite the need for braille literacy, there has been little attempt to systematically evaluate braille‐instruction programs. The current study evaluated an instructive procedure for teaching early braille‐reading skills with 4 school‐aged children with degenerative visual impairments. Following a series of pretests, braille instruction involved providing a sample braille letter and teaching the selection of the corresponding printed letter from a comparison array. Concomitant with increases in the accuracy of this skill, we assessed and captured the formation of equivalence classes through tests of symmetry and transitivity among the printed letters, the corresponding braille letters, and their spoken names.
APPLYING SIGNAL‐DETECTION THEORY TO THE STUDY OF OBSERVER ACCURACY AND BIAS IN BEHAVIORAL ASSESSMENT
Authors: Lerman Dorothea C. , Tetreault Allison , Hovanetz Alyson , Bellaci Emily , Miller Jonathan , Karp Hilary , Mahmood Angela , Strobel Maggie , Mullen Shelley , Keyl Alice , Toupard Alexis
Published: December 2010

We evaluated the feasibility and utility of a laboratory model for examining observer accuracy within the framework of signal‐detection theory (SDT). Sixty‐one individuals collected data on aggression while viewing videotaped segments of simulated teacher—child interactions. The purpose of Experiment 1 was to determine if brief feedback and contingencies for scoring accurately would bias responding reliably. Experiment 2 focused on one variable (specificity of the operational definition) that we hypothesized might decrease the likelihood of bias. The effects of social consequences and information about expected behavior change were examined in Experiment 3. Results indicated that feedback and contingencies reliably biased responding and that the clarity of the definition only moderately affected this outcome.
AN ANALYSIS OF A CONTINGENCY PROGRAM ON DESIGNATED DRIVERS AT A COLLEGE BAR
Authors: Kazbour Richard R. , Bailey Jon S.
Published: December 2010

The present study evaluated the effects of prompts and incentives on designated drivers in a bar. We defined the dependent variable as the percentage of customers either functioning as or riding with a designated driver. We used an ABCA design to evaluate the effectiveness of prompts and incentives on the dependent variable. Results indicated that the intervention was successful at increasing the ratio of safe to unsafe passengers in a bar.
DEVELOPING STIMULUS CONTROL OF THE HIGH‐RATE SOCIAL‐APPROACH RESPONSES OF AN ADULT WITH MENTAL RETARDATION: A MULTIPLE‐SCHEDULE EVALUATION
Authors: Grow Laura L. , LeBlanc Linda A. , Carr James E.
Published: December 2010

We evaluated a multiple schedule in which the extinction (S‐) components were signaled overtly by a black lanyard and the reinforcement (S+) components were not correlated with any programmed stimuli in developing stimulus control over the high‐rate social‐approach responses of an adult with mental retardation. Responding was consistently low in the presence of the S‐ and consistently high when the lanyard was absent (i.e., the S+ condition). Component durations were thinned successfully to a level that was manageable for caregivers.
THE EFFECTS OF SELF‐MONITORING ON THE PROCEDURAL INTEGRITY OF A BEHAVIORAL INTERVENTION FOR YOUNG CHILDREN WITH DEVELOPMENTAL DISABILITIES
Authors: Plavnick Joshua B. , Ferreri Summer J. , Maupin Angela N.
Published: December 2010

The effects of self‐monitoring on the procedural integrity of token economy implementation by 3 staff in a special education classroom were evaluated. The subsequent changes in academic readiness behaviors of 2 students with low‐incidence disabilities were measured. Multiple baselines across staff and students showed that procedural integrity increased when staff used monitoring checklists, and students' academic readiness behavior also increased. Results are discussed with respect to the use of self‐monitoring and the importance of procedural integrity in public school settings.
PROMPTING SAFETY BELT USE: COMPARATIVE IMPACT ON THE TARGET BEHAVIOR AND RELEVANT BODY LANGUAGE
Authors: Cox Matthew G. , Geller E. Scott
Published: December 2010

Researchers used two behavioral prompts to compare increases in safety belt use: a Click It or Ticket prompt or a Flash‐for‐Life prompt. Participants were 1,822 unbuckled drivers exiting two student parking lots of a large university. Research assistants identified unbuckled drivers, flashed one of the two prompts, and recorded whether drivers buckled after the prompt and the drivers' facial expressions and hand gestures. Findings and implications are discussed.
EVALUATION OF STIMULUS CONTROL OVER A COMMUNICATION RESPONSE AS AN INTERVENTION FOR STEREOTYPICAL RESPONDING
Authors: Anderson Cynthia M. , Doughty Shannon S. , Doughty Adam H. , Williams Dean C. , Saunders Kathryn J.
Published: December 2010

Stereotypical behavior maintained by automatic reinforcement often does not result in harm but may be undesirable in some situations. In the current investigation, participants were 2 individuals who engaged in nonharmful stereotypical responses shown in an analogue functional analysis to be insensitive to social contingencies. After bringing these responses under stimulus control using differential punishment, both participants learned a mand to terminate punishment for stereotypy. We also assessed whether the mand could be brought under stimulus control.
MATCHING IN AN UNDISTURBED NATURAL HUMAN ENVIRONMENT
Authors: McDowell J. J. , Caron Marcia L.
Published: December 2010

Data from the Oregon Youth Study, consisting of the verbal behavior of 210 adolescent boys determined to be at risk for delinquency (targets) and 210 of their friends (peers), were analyzed for their conformance to the complete family of matching theory equations in light of recent findings from the basic science, and using recently developed analytic techniques. Equations of the classic and modern theories of matching were fitted as ensembles to rates and time allocations of the boys' rule‐break and normative talk obtained from conversations between pairs of boys. The verbal behavior of each boy in a conversation was presumed to be reinforced by positive social responses from the other boy. Consistent with recent findings from the basic science, the boys' verbal behavior was accurately described by the modern but not the classic theory of matching. These findings also add support to the assertion that basic principles and processes that are known to govern behavior in laboratory experiments also govern human social behavior in undisturbed natural environments.
CONCURRENT REINFORCEMENT SCHEDULES FOR PROBLEM BEHAVIOR AND APPROPRIATE BEHAVIOR: EXPERIMENTAL APPLICATIONS OF THE MATCHING LAW
Authors: Borrero Carrie S. W. , Vollmer Timothy R. , Borrero John C. , Bourret Jason C. , Sloman Kimberly N. , Samaha Andrew L. , Dallery Jesse
Published: December 2010

This study evaluated how children who exhibited functionally equivalent problem and appropriate behavior allocate responding to experimentally arranged reinforcer rates. Relative reinforcer rates were arranged on concurrent variable‐interval schedules and effects on relative response rates were interpreted using the generalized matching equation. Results showed that relative rates of responding approximated relative rates of reinforcement. Finally, interventions for problem behavior were evaluated and differential reinforcement of alternative behavior and extinction procedures were implemented to increase appropriate behavior and decrease problem behavior. Practical considerations for the application of the generalized matching equation specific to severe problem behavior are discussed, including difficulties associated with defining a reinforced response, and obtaining steady state responding in clinical settings.
Experimental Evaluation of the Effect of Drillstring Rotation in the Suspension of a Cuttings Bed
Authors: Loureiro B. V. , de Paula R. S. , Serafim M. B. , Martins A. L.
Published: December 2010

Drill string rotation has been the target of several studies involving its influence on the suspension of drilled cuttings deposited in the bottom part of highly inclined and horizontal wells. Since some studies found in the literature exhibit divergence over the effect of the drill string rotation on the suspension of cuttings, this project is intended to quantify the capacity for suspension of particles from the cuttings bed for different fluids and different sedimentation heights, in cylindrical horizontal wells.

Quantifying the suspended mass in the annular geometry of the well was modeled after an experimental set-up on the physical problem, which allows tangential flow in the annular space. Flow visualization and image processing techniques support the study.
Effects of Wellbore Density Changes on Downhole Pressure During Buildup Analysis in Gas/Condensate Reservoirs
Authors: Palacios R.
Published: December 2010

Numerous reservoir models can be found in the literature to evaluate pressure tests covering most practical behaviors. Wellbore effects were recognized and treated from the very beginning of pressure transient analysis development. Since build up pressure is normally analyzed, downhole shut in is recommended to minimize wellbore storage effects, however most tests in Gas-Condensate reservoirs, pressure build ups are obtained shutting the well in at surface.

Phase redistribution and density changes occur in the wellbore during pressure build up and often modifies the pressure derivative shape inducing to the use of wrong formation models. Is normal to find pressure transient analyses indicating near wellbore limits, mobility changes or even fractures behaviors and not mention of wellbore density changes effects on downhole pressure.

This article is intended to show how these effects lead to wrong interpretations and, in consequence, to wrong formation parameters values. A correction method, advantages and disadvantages, will also be indicated.
Using Step-Rate Test to Prove Gradient of Propagation Equations
Authors: Suzart J. , Luduvice R. , Moreto R.
Published: December 2010

Performing rock-mechanics studies using core samples can be expensive. Researchers trying to obtain these samples for laboratory analysis often find the samples are broken or cracked. This leads to various attempts to obtain samples from a rock. In addition to the rock analysis, other challenges include stress relaxation relative to the subsurface and fluid exchange during the experiment. Based on this, other methods for obtaining values involving rock mechanics, such as the current charts from hydraulic fracturing, are now a focus and a part of "optimizations" or innovations in the calculation processes.

The studies presented in this paper include derivation of rock-mechanics equations and the values from empirical results correlated with field application by step-rate tests. The proposed equations show different results from those presented in other studies. However, the values are different as a function of the specific conditions of each formation, such as depth, overburden stresses, compaction, and pore pressure.

To avoid this scenario, it is important to know the minimum pressure that causes fractures. The estimation can be based on density, overburden, Poisson's ratio, and minimum horizontal stress. However, it is now possible to monitor fracturing-stimulation operations in real time, which allows understanding of formation-pressure response. This includes fracture-extension behavior and avoiding screenout risks related to unexpected high pressure applied on the formation while drilling and maintaining well and equipment integrities.

There are few scenarios where the formulated equations can be proven. One is presented in this paper using a step-rate test. The paper uses modified Eaton's equations that are representatives of interest. The modified equations are used to estimate parameters of the minimum horizontal stress, fracture-extension gradient, overburden, and Poisson's ratio. To validate the present method, the estimation results are compared to available step-rate test results from the Sergipe basin.
The Correct Shale-Volume Characterization Increases Hydrocarbon Reserves: Case Study of Cretaceous Formation, Lake Maracaibo, Venezuela
Authors: Rodolfo Soto B. , Arteaga Duarry , Martin Cintia , Rodriguez Freddy
Published: December 2010

Today, natural fracture and/or connected vuggy systems in carbonate reservoirs contribute significantly to hydrocarbon production. Combining concepts from normal distribution with normalization and soft computing techniques improves quantification of actual shale volumes for a reservoir with complex stratigraphy and natural fractures. This is especially important for cases when very few log curves are available to solve a high number of unknown lithologic variables. We applied our new methodology successfully in the Cretaceous formation, Lake Maracaibo, which is composed primarily of limestones with some dolomites and siliciclastics (glauconitic sandstones, siltstones, and shales).

It is common to use the standard gamma ray log (SGR) or total contribution from all three elements—uranium (U), potassium (K), thorium (Th)—as an indicator of shale content. The presence of highly radioactive black organic material and/or natural fractures in the formation results in a big difference from the X-ray diffraction data. This causes an overestimation of shale volume and therefore affects the original oil in place (OOIP) and reserves. We present a novel methodology that combines normal distribution and normalization to predict CGR from SGR and deep resistivity, Rt. We applied the cross correlation technique to validate our methodology, and the model CGR matches the actual CGR very well.

Next, we used the elemental capture spectroscopy (ECS) logs to quantify the actual clay volume (Vsh). Then, we used soft computing techniques to develop a shale volume model using CGR and Rt as independent variables and the Vsh from ECS as the dependent variable. Running the model for validation in three wells with ECS achieved a correlation coefficient of 0.9.

The average shale volume using our model is 12.5%, much lower than the former linear shale-volume model, which averaged 28.4%. This has had a great impact on the OOIP and reserves of our reservoir, as it would for other complex carbonate reservoirs.