Commentary.

ERIC Educational Resources Information Center

Scarr, Sandra

1995-01-01

Argues that Gottlieb rejects population sampling and statistical analyses of distributions as he proposes that his experimental brand of mechanistic science is the only legitimate approach to developmental research. Maintains that Gottlieb exaggerates developmental uncertainty, based on his own research with extreme environmental manipulations.…

Physical biology of human brain development.

PubMed

Budday, Silvia; Steinmann, Paul; Kuhl, Ellen

2015-01-01

Neurodevelopment is a complex, dynamic process that involves a precisely orchestrated sequence of genetic, environmental, biochemical, and physical events. Developmental biology and genetics have shaped our understanding of the molecular and cellular mechanisms during neurodevelopment. Recent studies suggest that physical forces play a central role in translating these cellular mechanisms into the complex surface morphology of the human brain. However, the precise impact of neuronal differentiation, migration, and connection on the physical forces during cortical folding remains unknown. Here we review the cellular mechanisms of neurodevelopment with a view toward surface morphogenesis, pattern selection, and evolution of shape. We revisit cortical folding as the instability problem of constrained differential growth in a multi-layered system. To identify the contributing factors of differential growth, we map out the timeline of neurodevelopment in humans and highlight the cellular events associated with extreme radial and tangential expansion. We demonstrate how computational modeling of differential growth can bridge the scales-from phenomena on the cellular level toward form and function on the organ level-to make quantitative, personalized predictions. Physics-based models can quantify cortical stresses, identify critical folding conditions, rationalize pattern selection, and predict gyral wavelengths and gyrification indices. We illustrate that physical forces can explain cortical malformations as emergent properties of developmental disorders. Combining biology and physics holds promise to advance our understanding of human brain development and enable early diagnostics of cortical malformations with the ultimate goal to improve treatment of neurodevelopmental disorders including epilepsy, autism spectrum disorders, and schizophrenia.

Geometric constrained variational calculus. II: The second variation (Part I)

NASA Astrophysics Data System (ADS)

Massa, Enrico; Bruno, Danilo; Luria, Gianvittorio; Pagani, Enrico

2016-10-01

Within the geometrical framework developed in [Geometric constrained variational calculus. I: Piecewise smooth extremals, Int. J. Geom. Methods Mod. Phys. 12 (2015) 1550061], the problem of minimality for constrained calculus of variations is analyzed among the class of differentiable curves. A fully covariant representation of the second variation of the action functional, based on a suitable gauge transformation of the Lagrangian, is explicitly worked out. Both necessary and sufficient conditions for minimality are proved, and reinterpreted in terms of Jacobi fields.

DYSLEXIA--IS THERE SUCH A THING.

ERIC Educational Resources Information Center

BOTEL, MORTON

THE THEORY OF DEVELOPMENTAL DYSLEXIA IS CONTRASTED WITH THE THEORY OF DEVELOPMENTAL IMMATURITY TO EXPLAIN EXTREME READING RETARDATION. DYSLEXIA IS DEFINED AS AN ORGANICALLY BASED READING DISABILITY WHICH IS DETERMINED INDIRECTLY SINCE NO ANATOMIC LESION, CHROMOSOME, OR GENE HAS YET BEEN FOUND RESPONSIBLE. DYSLEXIA IS USUALLY DEDUCED FROM (1)…

Pool desiccation and developmental thresholds in the common frog, Rana temporaria.

PubMed

Lind, Martin I; Persbo, Frida; Johansson, Frank

2008-05-07

The developmental threshold is the minimum size or condition that a developing organism must have reached in order for a life-history transition to occur. Although developmental thresholds have been observed for many organisms, inter-population variation among natural populations has not been examined. Since isolated populations can be subjected to strong divergent selection, population divergence in developmental thresholds can be predicted if environmental conditions favour fast or slow developmental time in different populations. Amphibian metamorphosis is a well-studied life-history transition, and using a common garden approach we compared the development time and the developmental threshold of metamorphosis in four island populations of the common frog Rana temporaria: two populations originating from islands with only temporary breeding pools and two from islands with permanent pools. As predicted, tadpoles from time-constrained temporary pools had a genetically shorter development time than those from permanent pools. Furthermore, the variation in development time among females from temporary pools was low, consistent with the action of selection on rapid development in this environment. However, there were no clear differences in the developmental thresholds between the populations, indicating that the main response to life in a temporary pool is to shorten the development time.

The development of contact force construction in the dynamic-contact task of cycling [corrected].

PubMed

Brown, Nicholas A T; Jensen, Jody L

2003-01-01

Purposeful movement requires that an individual produce appropriate joint torques to accelerate segments, and when environmental contact is involved, to develop task-appropriate contact forces. Developmental research has been confined largely to the mastery of unconstrained movement skills (pointing, kicking). The purpose of this study was to study the developmental progression that characterizes the interaction of muscular and non-muscular forces in tasks constrained by contact with the environment. Seven younger children (YC, 6-8 years), 7 older children (OC, 9-11 years) and 7 adults (AD) pedaled an ergometer (80 rpm) at an anthropometrically scaled cycling power. Resultant forces measured at the pedal's surface were decomposed into muscle, inertia and gravity components. Muscle pedal forces were further examined in terms of the underlying lower extremity joint torques and kinematic weights that constitute the muscular component of the pedal force. Data showed children applied muscle forces to the pedal in a significantly different manner compared to adults, and that this was due to the children's lower segmental mass and inertia. The children adjusted the contribution of the proximal joint muscle torques to compensate for reduced contributions to the resultant pedal force by gravitational and inertial components. These data show that smaller segmental mass and inertia limit younger children's ability to construct the dynamic-contact task of cycling in an adult-like form. On the basis of these results, however, the children's response was not "immature". Rather, the results show a task-appropriate adaptation to lower segmental mass and inertia. Copyright 2002 Elsevier Science Ltd.

Interpersonal Problems and Developmental Trajectories of Binge Eating Disorder

PubMed Central

Blomquist, Kerstin K.; Ansell, Emily B.; White, Marney A.; Masheb, Robin M.; Grilo, Carlos M.

2012-01-01

Objective To explore associations between specific interpersonal constructs and the developmental progression of behaviors leading to binge eating disorder (BED). Method Eighty-four consecutively evaluated, treatment-seeking obese (BMI ≥ 30) men and women with BED were assessed with structured diagnostic and clinical interviews and completed a battery of established measures to assess the current and developmental eating- and weight-related variables as well as interpersonal functioning. Results Using the interpersonal circumplex structural summary method, amplitude, elevation, the affiliation dimension, and the quadratic coefficient for the dominance dimension were associated with eating and weight-related developmental variables. The amplitude coefficient and more extreme interpersonal problems on the dominance dimension (quadratic)—i.e., problems with being extremely high (domineering) or low in dominance (submissive)—were significantly associated with ayounger age at onset of binge eating, BED, and overweight as well as accounted for significant variance in age at binge eating, BED, and overweight onset. Greater interpersonal problems with having an overly affiliative interpersonal style were significantly associated with, and accounted for significant variance in, ayounger age at diet onset. Discussion Findings provide further support for the importance of interpersonal problems among adults with BED and converge with recent work highlighting the importance of specific types of interpersonal problems for understanding heterogeneity and different developmental trajectories of individuals with BED. PMID:22727087

Using dry and wet year hydroclimatic extremes to guide future hydrologic projections

NASA Astrophysics Data System (ADS)

Oni, Stephen; Futter, Martyn; Ledesma, Jose; Teutschbein, Claudia; Buttle, Jim; Laudon, Hjalmar

2016-07-01

There are growing numbers of studies on climate change impacts on forest hydrology, but limited attempts have been made to use current hydroclimatic variabilities to constrain projections of future climatic conditions. Here we used historical wet and dry years as a proxy for expected future extreme conditions in a boreal catchment. We showed that runoff could be underestimated by at least 35 % when dry year parameterizations were used for wet year conditions. Uncertainty analysis showed that behavioural parameter sets from wet and dry years separated mainly on precipitation-related parameters and to a lesser extent on parameters related to landscape processes, while uncertainties inherent in climate models (as opposed to differences in calibration or performance metrics) appeared to drive the overall uncertainty in runoff projections under dry and wet hydroclimatic conditions. Hydrologic model calibration for climate impact studies could be based on years that closely approximate anticipated conditions to better constrain uncertainty in projecting extreme conditions in boreal and temperate regions.

Geometric constrained variational calculus I: Piecewise smooth extremals

NASA Astrophysics Data System (ADS)

Massa, Enrico; Bruno, Danilo; Luria, Gianvittorio; Pagani, Enrico

2015-05-01

A geometric setup for constrained variational calculus is presented. The analysis deals with the study of the extremals of an action functional defined on piecewise differentiable curves, subject to differentiable, non-holonomic constraints. Special attention is paid to the tensorial aspects of the theory. As far as the kinematical foundations are concerned, a fully covariant scheme is developed through the introduction of the concept of infinitesimal control. The standard classification of the extremals into normal and abnormal ones is discussed, pointing out the existence of an algebraic algorithm assigning to each admissible curve a corresponding abnormality index, related to the co-rank of a suitable linear map. Attention is then shifted to the study of the first variation of the action functional. The analysis includes a revisitation of Pontryagin's equations and of the Lagrange multipliers method, as well as a reformulation of Pontryagin's algorithm in Hamiltonian terms. The analysis is completed by a general result, concerning the existence of finite deformations with fixed endpoints.

Divergent Development of Manual Skills in Children Who Are Blind or Sighted

ERIC Educational Resources Information Center

Brambring, Michael

2007-01-01

This empirical study compared the average ages at which four children with congenital blindness acquired 32 fine motor skills with age norms for sighted children. The results indicated that the children experienced extreme developmental delays in the acquisition of manual skills and a high degree of variability in developmental delays within and…

Research Review: A Neuroscience Framework for Pediatric Anxiety Disorders

ERIC Educational Resources Information Center

Pine, Daniel S.

2007-01-01

Across a range of mammalian species, early developmental variations in fear-related behaviors constrain patterns of anxious behavior throughout life. Individual differences in anxiety among rodents and non-human primates have been shown to reflect early-life influences of genes and the environment on brain circuitry. However, in humans, the manner…

Developmental Correlates of Head Circumference at Birth and Two Years in a Cohort of Extremely Low Gestational Age Newborns

PubMed Central

Kuban, Karl C. K.; Allred, Elizabeth N.; O’Shea, T. Michael; Paneth, Nigel; Westra, Sjirk; Miller, Cindy; Rosman, N. Paul; Leviton, Alan

2009-01-01

Objectives To evaluate the developmental correlates of microcephaly evident at birth and at 2 years in a cohort born at extremely low gestational age. Methods We assessed development and motor function at 2 years of 958 children born before the 28th week of gestation, comparing those who had microcephaly at birth or 2 years with children with normal head circumference while considering the contribution of neonatal cranial ultrasound lesions. Results A total of 11% of infants in our sample had microcephaly at 2 years. Microcephaly at 2 years, but not at birth, predicts severe motor and cognitive impairments at 2 years. A total of 71% of children with congenital microcephaly had a normal head circumference at 2 years and had neurodevelopmental outcomes comparable with those with normal head circumference at birth and 2 years. Among children with microcephaly at 2 years, more than half had a Mental Developmental Index <70, and nearly a third had cerebral palsy. The risks were increased if the child also had cerebral white matter damage on a cranial ultrasound scan obtained 2 years previously. Conclusion Among extremely low gestational age newborns, microcephaly at 2 years, but not at birth, is associated with motor and cognitive impairment at age 2. PMID:19555967

Defining the diverse spectrum of inversions, complex structural variation, and chromothripsis in the morbid human genome.

PubMed

Collins, Ryan L; Brand, Harrison; Redin, Claire E; Hanscom, Carrie; Antolik, Caroline; Stone, Matthew R; Glessner, Joseph T; Mason, Tamara; Pregno, Giulia; Dorrani, Naghmeh; Mandrile, Giorgia; Giachino, Daniela; Perrin, Danielle; Walsh, Cole; Cipicchio, Michelle; Costello, Maura; Stortchevoi, Alexei; An, Joon-Yong; Currall, Benjamin B; Seabra, Catarina M; Ragavendran, Ashok; Margolin, Lauren; Martinez-Agosto, Julian A; Lucente, Diane; Levy, Brynn; Sanders, Stephan J; Wapner, Ronald J; Quintero-Rivera, Fabiola; Kloosterman, Wigard; Talkowski, Michael E

2017-03-06

Structural variation (SV) influences genome organization and contributes to human disease. However, the complete mutational spectrum of SV has not been routinely captured in disease association studies. We sequenced 689 participants with autism spectrum disorder (ASD) and other developmental abnormalities to construct a genome-wide map of large SV. Using long-insert jumping libraries at 105X mean physical coverage and linked-read whole-genome sequencing from 10X Genomics, we document seven major SV classes at ~5 kb SV resolution. Our results encompass 11,735 distinct large SV sites, 38.1% of which are novel and 16.8% of which are balanced or complex. We characterize 16 recurrent subclasses of complex SV (cxSV), revealing that: (1) cxSV are larger and rarer than canonical SV; (2) each genome harbors 14 large cxSV on average; (3) 84.4% of large cxSVs involve inversion; and (4) most large cxSV (93.8%) have not been delineated in previous studies. Rare SVs are more likely to disrupt coding and regulatory non-coding loci, particularly when truncating constrained and disease-associated genes. We also identify multiple cases of catastrophic chromosomal rearrangements known as chromoanagenesis, including somatic chromoanasynthesis, and extreme balanced germline chromothripsis events involving up to 65 breakpoints and 60.6 Mb across four chromosomes, further defining rare categories of extreme cxSV. These data provide a foundational map of large SV in the morbid human genome and demonstrate a previously underappreciated abundance and diversity of cxSV that should be considered in genomic studies of human disease.

Regional Brain Biometrics at Term-Equivalent Age and Developmental Outcome in Extremely Low-Birth-Weight Infants.

PubMed

Melbourne, Launice; Murnick, Jonathan; Chang, Taeun; Glass, Penny; Massaro, An N

2015-10-01

This study aims to evaluate individual regional brain biometrics and their association with developmental outcome in extremely low-birth-weight (ELBW) infants. This is a retrospective study evaluating term-equivalent magnetic resonance imaging (TE-MRI) from 27 ELBW infants with known developmental outcomes beyond 12 months corrected age. Regional biometric measurements were performed by a pediatric neuroradiologist blinded to outcome data. Measures included biparietal width, transcerebellar diameter (TCD), deep gray matter area (DGMA), ventricular dilatation, corpus callosum, and interhemispheric distance. The relationship between regional biometrics and Bayley-II developmental scores were evaluated with linear regression models. The study cohort had an average±standard deviation birth weight of 684±150 g, gestational age of 24.6±2 weeks and 48% males. DGMA was significantly associated with both cognitive and motor outcomes. Significant associations were also observed between TCD and corpus callosum splenium with cognitive and motor outcomes, respectively. Other biometric measures were not associated with outcome (p>0.05). DGMA<10.26 cm2 was highly specific for poor motor and cognitive outcome. TE-MRI biometrics reflecting impaired deep gray matter, callosal, and cerebellar size is associated with worse early childhood cognitive and motor outcomes. DGMA may be the most robust single biometric measure to predict adverse developmental outcome in preterm survivors. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Simple modification of Oja rule limits L1-norm of weight vector and leads to sparse connectivity.

PubMed

Aparin, Vladimir

2012-03-01

This letter describes a simple modification of the Oja learning rule, which asymptotically constrains the L1-norm of an input weight vector instead of the L2-norm as in the original rule. This constraining is local as opposed to commonly used instant normalizations, which require the knowledge of all input weights of a neuron to update each one of them individually. The proposed rule converges to a weight vector that is sparser (has more zero weights) than the vector learned by the original Oja rule with or without the zero bound, which could explain the developmental synaptic pruning.

Contributions of Dynamic and Thermodynamic Scaling in Subdaily Precipitation Extremes in India

NASA Astrophysics Data System (ADS)

Ali, Haider; Mishra, Vimal

2018-03-01

Despite the importance of subdaily precipitation extremes for urban areas, the role of dynamic and thermodynamic scaling in changes in precipitation extremes in India remains poorly constrained. Here we estimate contributions from thermodynamic and dynamic scaling on changes in subdaily precipitation extremes for 23 urban locations in India. Subdaily precipitation extremes have become more intense during the last few decades. Moreover, we find a twofold rise in the frequency of subdaily precipitation extremes during 1979-2015, which is faster than the increase in daily precipitation extremes. The contribution of dynamic scaling in this rise in the frequency and intensity of subdaily precipitation extremes is higher than the thermodynamic scaling. Moreover, half-hourly precipitation extremes show higher contributions from the both thermodynamic ( 10%/K) and dynamic ( 15%/K) scaling than daily (6%/K and 9%/K, respectively) extremes indicating the role of warming on the rise in the subdaily precipitation extremes in India. Our findings have implications for better understanding the dynamic response of precipitation extremes under the warming climate over India.

The Growth of Developmental Thought: Implications for a New Evolutionary Psychology

PubMed Central

Lickliter, Robert

2009-01-01

Evolution has come to be increasingly discussed in terms of changes in developmental processes rather than simply in terms of changes in gene frequencies. This shift is based in large part on the recognition that since all phenotypic traits arise during ontogeny as products of individual development, a primary basis for evolutionary change must be variations in the patterns and processes of development. Further, the products of development are epigenetic, not just genetic, and this is the case even when considering the evolutionary process. These insights have led investigators to reconsider the established notion of genes as the primary cause of development, opening the door to research programs focused on identifying how genetic and non-genetic factors coact to guide and constrain the process of development and its outcomes. I explore this growth of developmental thought and its implications for the achievement of a unified theory of heredity, development, and evolution and consider its implications for the realization of a new, developmentally-based evolutionary psychology. PMID:19956346

Extreme developmental temperatures result in morphological abnormalities in painted turtles (Chrysemys picta): a climate change perspective.

PubMed

Telemeco, Rory S; Warner, Daniel A; Reida, Molly K; Janzen, Fredric J

2013-06-01

Increases in extreme environmental events are predicted to be major results of ongoing global climate change and may impact the persistence of species. We examined the effects of heat and cold waves during embryonic development of painted turtles (Chrysemys picta) in natural nests on the occurrence of abnormal shell morphologies in hatchlings. We found that nests exposed to extreme hot temperatures for >60 h produced more hatchlings with abnormalities than nests exposed to extreme hot temperatures for shorter periods, regardless of whether or not nesting females displayed abnormal morphologies. We observed no effect of extreme cold nest temperatures on the occurrence of hatchlings with abnormalities. Moreover, the frequency of nesting females with abnormal shell morphologies was approximately 2-fold lower than that of their offspring, suggesting that such abnormalities are negatively correlated with survival and fitness. Female turtles could potentially buffer their offspring from extreme heat by altering aspects of nesting behavior, such as choosing shadier nesting sites. We addressed this hypothesis by examining the effects of shade cover on extreme nest temperatures and the occurrence of hatchling abnormalities. While shade cover was negatively correlated with the occurrence of extreme hot nest temperatures, it was not significantly correlated with abnormalities. Therefore, female choice of shade cover does not appear to be a viable target for selection to reduce hatchling abnormalities. Our results suggest that increases in the frequency and intensity of heat waves associated with climate change might perturb developmental programs and thereby reduce the fitness of entire cohorts of turtles. © 2012 Wiley Publishing Asia Pty Ltd, ISZS and IOZ/CAS.

Deficits of Visuospatial Attention with Reflexive Orienting Induced by Eye-Gazed Cues in Children with Developmental Coordination Disorder in the Lower Extremities: An Event-Related Potential Study

ERIC Educational Resources Information Center

Tsai, Chia-Liang; Pan, Chien-Yu; Chang, Yu-Kai; Wang, Chun-Hao; Tseng, Ko-Da

2010-01-01

The present study aims to investigate and compare the behavioral performance and event-related potentials (ERPs) measures in children with developmental coordination disorder (DCD) and typically developing (TD) children when performing the visuospatial attention task with reflexive orienting. Thirty children with DCD and 30 TD children were…

In silico predicted reproductive endocrine transcriptional regulatory networks during zebrafish (Danio rerio) development.

PubMed

Hala, D

2017-03-21

The interconnected topology of transcriptional regulatory networks (TRNs) readily lends to mathematical (or in silico) representation and analysis as a stoichiometric matrix. Such a matrix can be 'solved' using the mathematical method of extreme pathway (ExPa) analysis, which identifies uniquely activated genes subject to transcription factor (TF) availability. In this manuscript, in silico multi-tissue TRN models of brain, liver and gonad were used to study reproductive endocrine developmental programming in zebrafish (Danio rerio) from 0.25h post fertilization (hpf; zygote) to 90 days post fertilization (dpf; adult life stage). First, properties of TRN models were studied by sequentially activating all genes in multi-tissue models. This analysis showed the brain to exhibit lowest proportion of co-regulated genes (19%) relative to liver (23%) and gonad (32%). This was surprising given that the brain comprised 75% and 25% more TFs than liver and gonad respectively. Such 'hierarchy' of co-regulatory capability (brain

Kindergarten classroom functioning of extremely preterm/extremely low birth weight children.

PubMed

Wong, Taylor; Taylor, H Gerry; Klein, Nancy; Espy, Kimberly A; Anselmo, Marcia G; Minich, Nori; Hack, Maureen

2014-12-01

Cognitive, behavioral, and learning problems are evident in extremely preterm/extremely low birth weight (EPT/ELBW, <28 weeks gestational age or <1000 g) children by early school age. However, we know little about how they function within the classroom once they start school. To determine how EPT/ELBW children function in kindergarten classrooms compared to termborn normal birth weight (NBW) classmates and identify factors related to difficulties in classroom functioning. A 2001-2003 birth cohort of 111 EPT/ELBW children and 110 NBW classmate controls were observed in regular kindergarten classrooms during a 1-hour instructional period using a time-sample method. The groups were compared on frequencies of individual teacher attention, competing or offtask behaviors, task management/preparation, and academic responding. Regression analysis was also conducted within the EPT/ELBW group to examine associations of these measures with neonatal and developmental risk factors, kindergarten neuropsychological and behavioral assessments, and classroom characteristics. The EPT/ELBW group received more individual teacher attention and was more often off-task than the NBW controls. Poorer classroom functioning in the EPT/ELBW group was associated with higher neonatal and developmental risk, poorer executive function skills, more negative teaching ratings of behavior and learning progress, and classroom characteristics. EPT/ELBW children require more teacher support and are less able to engage in instructional activities than their NBW classmates. Associations of classroom functioning with developmental history and cognitive and behavioral traits suggest that these factors may be useful in identifying the children most in need of special educational interventions. Copyright © 2014 Elsevier Ltd. All rights reserved.

Carnegie Math Pathways 2015-2016 Impact Report: A Five-Year Review. Carnegie Math Pathways Technical Report

ERIC Educational Resources Information Center

Hoang, Hai; Huang, Melrose; Sulcer, Brian; Yesilyurt, Suleyman

2017-01-01

College math is a gateway course that has become a constraining gatekeeper for tens of thousands of students annually. Every year, over 500,000 students fail developmental mathematics, preventing them from achieving their college and career goals. The Carnegie Math Pathways initiative offers students an alternative. It comprises two Pathways…

Early Developmental and Psychosocial Risks and Longitudinal Behavioral Adjustment Outcomes for Preschool-Age Girls Adopted from China

ERIC Educational Resources Information Center

Tan, Tony Xing; Marfo, Kofi; Dedrick, Robert F.

2010-01-01

The central goal of this longitudinal study was to examine behavioral adjustment outcomes in a sample of preschool-age adopted Chinese girls. Research examining the effects of institutional deprivation on post-adoption behavioral outcomes for internationally adopted children has been constrained by the frequent unavailability of data on the…

Tensor-driven extraction of developmental features from varying paediatric EEG datasets.

PubMed

Kinney-Lang, Eli; Spyrou, Loukianos; Ebied, Ahmed; Chin, Richard Fm; Escudero, Javier

2018-05-21

Constant changes in developing children's brains can pose a challenge in EEG dependant technologies. Advancing signal processing methods to identify developmental differences in paediatric populations could help improve function and usability of such technologies. Taking advantage of the multi-dimensional structure of EEG data through tensor analysis may offer a framework for extracting relevant developmental features of paediatric datasets. A proof of concept is demonstrated through identifying latent developmental features in resting-state EEG. Approach. Three paediatric datasets (n = 50, 17, 44) were analyzed using a two-step constrained parallel factor (PARAFAC) tensor decomposition. Subject age was used as a proxy measure of development. Classification used support vector machines (SVM) to test if PARAFAC identified features could predict subject age. The results were cross-validated within each dataset. Classification analysis was complemented by visualization of the high-dimensional feature structures using t-distributed Stochastic Neighbour Embedding (t-SNE) maps. Main Results. Development-related features were successfully identified for the developmental conditions of each dataset. SVM classification showed the identified features could accurately predict subject at a significant level above chance for both healthy and impaired populations. t-SNE maps revealed suitable tensor factorization was key in extracting the developmental features. Significance. The described methods are a promising tool for identifying latent developmental features occurring throughout childhood EEG. © 2018 IOP Publishing Ltd.

ENVIRONMENTAL SCIENCE. Profiling risk and sustainability in coastal deltas of the world.

PubMed

Tessler, Z D; Vörösmarty, C J; Grossberg, M; Gladkova, I; Aizenman, H; Syvitski, J P M; Foufoula-Georgiou, E

2015-08-07

Deltas are highly sensitive to increasing risks arising from local human activities, land subsidence, regional water management, global sea-level rise, and climate extremes. We quantified changing flood risk due to extreme events using an integrated set of global environmental, geophysical, and social indicators. Although risks are distributed across all levels of economic development, wealthy countries effectively limit their present-day threat by gross domestic product-enabled infrastructure and coastal defense investments. In an energy-constrained future, such protections will probably prove to be unsustainable, raising relative risks by four to eight times in the Mississippi and Rhine deltas and by one-and-a-half to four times in the Chao Phraya and Yangtze deltas. The current emphasis on short-term solutions for the world's deltas will greatly constrain options for designing sustainable solutions in the long term. Copyright © 2015, American Association for the Advancement of Science.

Outcome at 3 years of age in a population-based cohort of extremely preterm infants.

PubMed

De Groote, Isabel; Vanhaesebrouck, Piet; Bruneel, Els; Dom, Lina; Durein, Isabelle; Hasaerts, Danielle; Laroche, Sabine; Oostra, Ann; Ortibus, Els; Roeyers, Herbert; van Mol, Christine

2007-10-01

To assess health and neurodevelopmental outcome at 3 years of age in neonatal intensive care unit (NICU)-surviving children who were born at 26 or fewer weeks of gestation in a geographically defined region of Belgium from 1999 through 2000. The study included a clinical examination and a standardized neurologic and developmental assessment. Disabilities were defined by international criteria. In 97% (92 of 95) of the children, accurate information on the presence of overall disability could be collected. Thirty-six percent (95% confidence interval [CI] 25-47%) of the formally assessed children (28 of 77) had deficient neuromotor development, with 5% of them showing severe sensory-communicative impairment. Mean (+/-standard deviation) scores on the Mental Developmental Index and Psychomotor Developmental Index were 81.2 (18.8) and 73.2 (17.8), respectively. Seventy percent (95% CI 60-80%) had a mental (Mental Developmental Index) or psychomotor (Psychomotor Developmental Index) impairment or both, assessed to be more than 1 standard deviation below the population mean. Mental and psychomotor outcome did not differ significantly when compared according to either gestational age, gender, or multiple birth (all P>.05). When either minor central dysfunction or cerebral palsy was not taken into account, normal mental development was recorded in 62% of the subjects. The cumulative of poor outcome (ie, disability- or prematurity-related death) among the 95 infants discharged alive was estimated to be 58% (95% CI 48-68%), representing 25 (26%) mildly-to-moderately disabled and 28 (29%) severely disabled toddlers, including two infants whose postdischarge deaths were directly related to prematurity. The average developmental outcome is poor in children born as extremely preterm infants. Finding early predictors of adverse outcome is a major challenge.

Constraining continuous rainfall simulations for derived design flood estimation

NASA Astrophysics Data System (ADS)

Woldemeskel, F. M.; Sharma, A.; Mehrotra, R.; Westra, S.

2016-11-01

Stochastic rainfall generation is important for a range of hydrologic and water resources applications. Stochastic rainfall can be generated using a number of models; however, preserving relevant attributes of the observed rainfall-including rainfall occurrence, variability and the magnitude of extremes-continues to be difficult. This paper develops an approach to constrain stochastically generated rainfall with an aim of preserving the intensity-durationfrequency (IFD) relationships of the observed data. Two main steps are involved. First, the generated annual maximum rainfall is corrected recursively by matching the generated intensity-frequency relationships to the target (observed) relationships. Second, the remaining (non-annual maximum) rainfall is rescaled such that the mass balance of the generated rain before and after scaling is maintained. The recursive correction is performed at selected storm durations to minimise the dependence between annual maximum values of higher and lower durations for the same year. This ensures that the resulting sequences remain true to the observed rainfall as well as represent the design extremes that may have been developed separately and are needed for compliance reasons. The method is tested on simulated 6 min rainfall series across five Australian stations with different climatic characteristics. The results suggest that the annual maximum and the IFD relationships are well reproduced after constraining the simulated rainfall. While our presentation focusses on the representation of design rainfall attributes (IFDs), the proposed approach can also be easily extended to constrain other attributes of the generated rainfall, providing an effective platform for post-processing of stochastic rainfall generators.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Saide, Pablo E.; Peterson, David A.; de Silva, Arlindo

We couple airborne, ground-based, and satellite observations; conduct regional simulations; and develop and apply an inversion technique to constrain hourly smoke emissions from the Rim Fire, the third largest observed in California, USA. Emissions constrained with multiplatform data show notable nocturnal enhancements (sometimes over a factor of 20), correlate better with daily burned area data, and are a factor of 2–4 higher than a priori estimates, highlighting the need for improved characterization of diurnal profiles and day-to-day variability when modeling extreme fires. Constraining only with satellite data results in smaller enhancements mainly due to missing retrievals near the emissions source,more » suggesting that top-down emission estimates for these events could be underestimated and a multiplatform approach is required to resolve them. Predictions driven by emissions constrained with multiplatform data present significant variations in downwind air quality and in aerosol feedback on meteorology, emphasizing the need for improved emissions estimates during exceptional events.« less

The transcension hypothesis: Sufficiently advanced civilizations invariably leave our universe, and implications for METI and SETI

NASA Astrophysics Data System (ADS)

Smart, John M.

2012-09-01

The emerging science of evolutionary developmental ("evo devo") biology can aid us in thinking about our universe as both an evolutionary system, where most processes are unpredictable and creative, and a developmental system, where a special few processes are predictable and constrained to produce far-future-specific emergent order, just as we see in the common developmental processes in two stars of an identical population type, or in two genetically identical twins in biology. The transcension hypothesis proposes that a universal process of evolutionary development guides all sufficiently advanced civilizations into what may be called "inner space," a computationally optimal domain of increasingly dense, productive, miniaturized, and efficient scales of space, time, energy, and matter, and eventually, to a black-hole-like destination. Transcension as a developmental destiny might also contribute to the solution to the Fermi paradox, the question of why we have not seen evidence of or received beacons from intelligent civilizations. A few potential evolutionary, developmental, and information theoretic reasons, mechanisms, and models for constrained transcension of advanced intelligence are briefly considered. In particular, we introduce arguments that black holes may be a developmental destiny and standard attractor for all higher intelligence, as they appear to some to be ideal computing, learning, forward time travel, energy harvesting, civilization merger, natural selection, and universe replication devices. In the transcension hypothesis, simpler civilizations that succeed in resisting transcension by staying in outer (normal) space would be developmental failures, which are statistically very rare late in the life cycle of any biological developing system. If transcension is a developmental process, we may expect brief broadcasts or subtle forms of galactic engineering to occur in small portions of a few galaxies, the handiwork of young and immature civilizations, but constrained transcension should be by far the norm for all mature civilizations. The transcension hypothesis has significant and testable implications for our current and future METI and SETI agendas. If all universal intelligence eventually transcends to black-hole-like environments, after which some form of merger and selection occurs, and if two-way messaging (a send-receive cycle) is severely limited by the great distances between neighboring and rapidly transcending civilizations, then sending one-way METI or probes prior to transcension becomes the only real communication option. But one-way messaging or probes may provably reduce the evolutionary diversity in all civilizations receiving the message, as they would then arrive at their local transcensions in a much more homogenous fashion. If true, an ethical injunction against one-way messaging or probes might emerge in the morality and sustainability systems of all sufficiently advanced civilizations, an argument known as the Zoo hypothesis in Fermi paradox literature, if all higher intelligences are subject to an evolutionary attractor to maximize their local diversity, and a developmental attractor to merge and advance universal intelligence. In any such environment, the evolutionary value of sending any interstellar message or probe may simply not be worth the cost, if transcension is an inevitable, accelerative, and testable developmental process, one that eventually will be discovered and quantitatively described by future physics. Fortunately, transcension processes may be measurable today even without good physical theory, and radio and optical SETI may each provide empirical tests. If transcension is a universal developmental constraint, then without exception all early and low-power electromagnetic leakage signals (radar, radio, television), and later, optical evidence of the exoplanets and their atmospheres should reliably cease as each civilization enters its own technological singularities (emergence of postbiological intelligence and life forms) and recognizes that they are on an optimal and accelerating path to a black-hole-like environment. Furthermore, optical SETI may soon allow us to map an expanding area of the galactic habitable zone we may call the galactic transcension zone, an inner ring that contains older transcended civilizations, and a missing planets problem as we discover that planets with life signatures occur at a much lower frequencies in this inner ring than in the remainder of the habitable zone.

Effects of home-based play-assisted stimulation on developmental performances of children living in extreme poverty: a randomized single-blind controlled trial.

PubMed

Worku, Berhanu Nigussie; Abessa, Teklu Gemechu; Wondafrash, Mekitie; Lemmens, Johan; Valy, Jan; Bruckers, Liesbeth; Kolsteren, Patrick; Granitzer, Marita

2018-02-05

Children living with foster families in a resource-limited setting such as Ethiopia are at risk of developmental problems. It is not yet clear whether intensive home-based developmental stimulation assisted by play can reduce these problems. The main objective of this study was to examine the effects of play-assisted intervention integrated into basic services on the developmental performance of children living with foster families in extreme poverty. A randomized single-blind (investigator) controlled trial design was used. The study was conducted in Jimma, South West Ethiopia. Using computer-generated codes, eligible children of 3-59 months in age were randomly allocated to intervention (n = 39) and control (n = 39) groups at a 1:1 ratio. Children in the intervention group received home-based play-assisted stimulation in addition to the basic services provided to children in both groups. The intervention consisted of an hour of play stimulation conducted during a weekly home visit over the course of six months. Personal-social, language, fine and gross motor outcomes were assessed using Denver II-Jimma, and social-emotional outcome was obtained using an adapted Ages and Stages Questionnaire: Social-Emotional (ASQ: SE). Information about sociodemographic characteristics was collected using a structured questionnaire. Anthropometric methods were used to determine nutritional status. The effects of the intervention on the abovementioned outcomes over the study period and group differences in change over time were examined using Generalized Estimating Equations (GEE). Statistically significant intervention effects were found for language (P = 0.0014), personal-social (P = 0.0087) and social-emotional (P <  0.0001) performances. At the midline of the study, language (effect size = 0.34) and social-emotional (effect size = - 0.603) benefits from the play-assisted stimulation had already been observed for the children in the intervention group. For language, the intervention effect depended on the child's sex (P = 0.0100) and for personal-social performance, on family income (P = 0.0300). Intensive home-based play-assisted stimulation reduced the developmental problems of children in foster families in the context of extreme poverty. Longer follow-up may reveal further improvements in the developmental performance of the children. The study was retrospectively registered on ClinicalTrials.gov on 17 November 2016, Study Identifier: NCT02988180 .

Life cycle stage and water depth affect flooding-induced adventitious root formation in the terrestrial species Solanum dulcamara

PubMed Central

Zhang, Qian; Visser, Eric J. W.; de Kroon, Hans; Huber, Heidrun

2015-01-01

Background and Aims Flooding can occur at any stage of the life cycle of a plant, but often adaptive responses of plants are only studied at a single developmental stage. It may be anticipated that juvenile plants may respond differently from mature plants, as the amount of stored resources may differ and morphological changes can be constrained. Moreover, different water depths may require different strategies to cope with the flooding stress, the expression of which may also depend on developmental stage. This study investigated whether flooding-induced adventitious root formation and plant growth were affected by flooding depth in Solanum dulcamara plants at different developmental stages. Methods Juvenile plants without pre-formed adventitious root primordia and mature plants with primordia were subjected to shallow flooding or deep flooding for 5 weeks. Plant growth and the timing of adventitious root formation were monitored during the flooding treatments. Key Results Adventitious root formation in response to shallow flooding was significantly constrained in juvenile S. dulcamara plants compared with mature plants, and was delayed by deep flooding compared with shallow flooding. Complete submergence suppressed adventitious root formation until up to 2 weeks after shoots restored contact with the atmosphere. Independent of developmental stage, a strong positive correlation was found between adventitious root formation and total biomass accumulation during shallow flooding. Conclusions The potential to deploy an escape strategy (i.e. adventitious root formation) may change throughout a plant’s life cycle, and is largely dependent on flooding depth. Adaptive responses at a given stage of the life cycle thus do not necessarily predict how the plant responds to flooding in another growth stage. As variation in adventitious root formation also correlates with finally attained biomass, this variation may form the basis for variation in resistance to shallow flooding among plants. PMID:26105188

Life cycle stage and water depth affect flooding-induced adventitious root formation in the terrestrial species Solanum dulcamara.

PubMed

Zhang, Qian; Visser, Eric J W; de Kroon, Hans; Huber, Heidrun

2015-08-01

Flooding can occur at any stage of the life cycle of a plant, but often adaptive responses of plants are only studied at a single developmental stage. It may be anticipated that juvenile plants may respond differently from mature plants, as the amount of stored resources may differ and morphological changes can be constrained. Moreover, different water depths may require different strategies to cope with the flooding stress, the expression of which may also depend on developmental stage. This study investigated whether flooding-induced adventitious root formation and plant growth were affected by flooding depth in Solanum dulcamara plants at different developmental stages. Juvenile plants without pre-formed adventitious root primordia and mature plants with primordia were subjected to shallow flooding or deep flooding for 5 weeks. Plant growth and the timing of adventitious root formation were monitored during the flooding treatments. Adventitious root formation in response to shallow flooding was significantly constrained in juvenile S. dulcamara plants compared with mature plants, and was delayed by deep flooding compared with shallow flooding. Complete submergence suppressed adventitious root formation until up to 2 weeks after shoots restored contact with the atmosphere. Independent of developmental stage, a strong positive correlation was found between adventitious root formation and total biomass accumulation during shallow flooding. The potential to deploy an escape strategy (i.e. adventitious root formation) may change throughout a plant's life cycle, and is largely dependent on flooding depth. Adaptive responses at a given stage of the life cycle thus do not necessarily predict how the plant responds to flooding in another growth stage. As variation in adventitious root formation also correlates with finally attained biomass, this variation may form the basis for variation in resistance to shallow flooding among plants. © The Author 2015. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Convergent occurrence of the developmental hourglass in plant and animal embryogenesis?

PubMed

Cridge, Andrew G; Dearden, Peter K; Brownfield, Lynette R

2016-04-01

The remarkable similarity of animal embryos at particular stages of development led to the proposal of a developmental hourglass. In this model, early events in development are less conserved across species but lead to a highly conserved 'phylotypic period'. Beyond this stage, the model suggests that development once again becomes less conserved, leading to the diversity of forms. Recent comparative studies of gene expression in animal groups have provided strong support for the hourglass model. How and why might such an hourglass pattern be generated? More importantly, how might early acting events in development evolve while still maintaining a later conserved stage? The discovery that an hourglass pattern may also exist in the embryogenesis of plants provides comparative data that may help us explain this phenomenon. Whether the developmental hourglass occurs in plants, and what this means for our understanding of embryogenesis in plants and animals is discussed. Models by which conserved early-acting genes might change their functional role in the evolution of gene networks, how networks buffer these changes, and how that might constrain, or confer diversity, of the body plan are also discused. Evidence of a morphological and molecular hourglass in plant and animal embryogenesis suggests convergent evolution. This convergence is likely due to developmental constraints imposed upon embryogenesis by the need to produce a viable embryo with an established body plan, controlled by the architecture of the underlying gene regulatory networks. As the body plan is largely laid down during the middle phases of embryo development in plants and animals, then it is perhaps not surprising this stage represents the narrow waist of the hourglass where the gene regulatory networks are the oldest and most robust and integrated, limiting species diversity and constraining morphological space. © The Author 2016. Published by Oxford University Press on behalf of the Annals of Botany Company.

Emerging technological and cultural shifts advancing drylands research and management

USDA-ARS?s Scientific Manuscript database

Sustainable provisioning of ecosystem services in dryland landscapes is complicated by extreme conditions that constrain biological responses to perturbation, vast spatial and temporal complexity, and uncertainty regarding the resilience of these ecosystems to management practices and climate change...

Does Nudging Squelch the Extremes in Regional Climate Modeling?

EPA Science Inventory

An important question in regional climate downscaling is whether to constrain (nudge) the interior of the limited-area domain toward the larger-scale driving fields. Prior research has demonstrated that interior nudging can increase the skill of regional climate predictions origin...

Varieties of preschool hyperactivity: multiple pathways from risk to disorder.

PubMed

Sonuga-Barke, Edmund J S; Auerbach, Judith; Campbell, Susan B; Daley, David; Thompson, Margaret

2005-03-01

In this paper we examine the characteristics of preschool attention deficit hyperactivity disorder (ADHD) from both mental disorder and developmental psychopathology points of view. The equivalence of preschool and school-aged hyperactivity as a behavioral dimension is highlighted together with the potential value of extending the use of the ADHD diagnostic category to the preschool period where these behaviours take an extreme and impairing form (assuming age appropriate diagnostic items and thresholds can be developed). At the same time, the importance of identifying pathways between risk and later ADHD is emphasized. Developmental discontinuity and heterogeneity are identified as major characteristics of these pathways. We argue that models that distinguish among different developmental types of early-emerging problems are needed. An illustrative taxonomy of four developmental pathways implicating preschool hyperactivity is presented to provide a framework for future research.

Ferns: the missing link in shoot evolution and development.

PubMed

Plackett, Andrew R G; Di Stilio, Verónica S; Langdale, Jane A

2015-01-01

Shoot development in land plants is a remarkably complex process that gives rise to an extreme diversity of forms. Our current understanding of shoot developmental mechanisms comes almost entirely from studies of angiosperms (flowering plants), the most recently diverged plant lineage. Shoot development in angiosperms is based around a layered multicellular apical meristem that produces lateral organs and/or secondary meristems from populations of founder cells at its periphery. In contrast, non-seed plant shoots develop from either single apical initials or from a small population of morphologically distinct apical cells. Although developmental and molecular information is becoming available for non-flowering plants, such as the model moss Physcomitrella patens, making valid comparisons between highly divergent lineages is extremely challenging. As sister group to the seed plants, the monilophytes (ferns and relatives) represent an excellent phylogenetic midpoint of comparison for unlocking the evolution of shoot developmental mechanisms, and recent technical advances have finally made transgenic analysis possible in the emerging model fern Ceratopteris richardii. This review compares and contrasts our current understanding of shoot development in different land plant lineages with the aim of highlighting the potential role that the fern C. richardii could play in shedding light on the evolution of underlying genetic regulatory mechanisms.

Extremes in ecology: Avoiding the misleading effects of sampling variation in summary analyses

USGS Publications Warehouse

Link, W.A.; Sauer, J.R.

1996-01-01

Surveys such as the North American Breeding Bird Survey (BBS) produce large collections of parameter estimates. One's natural inclination when confronted with lists of parameter estimates is to look for the extreme values: in the BBS, these correspond to the species that appear to have the greatest changes in population size through time. Unfortunately, extreme estimates are liable to correspond to the most poorly estimated parameters. Consequently, the most extreme parameters may not match up with the most extreme parameter estimates. The ranking of parameter values on the basis of their estimates are a difficult statistical problem. We use data from the BBS and simulations to illustrate the potential misleading effects of sampling variation in rankings of parameters. We describe empirical Bayes and constrained empirical Bayes procedures which provide partial solutions to the problem of ranking in the presence of sampling variation.

Erosion during extreme flood events dominates Holocene canyon evolution in northeast Iceland.

PubMed

Baynes, Edwin R C; Attal, Mikaël; Niedermann, Samuel; Kirstein, Linda A; Dugmore, Andrew J; Naylor, Mark

2015-02-24

Extreme flood events have the potential to cause catastrophic landscape change in short periods of time (10(0) to 10(3) h). However, their impacts are rarely considered in studies of long-term landscape evolution (>10(3) y), because the mechanisms of erosion during such floods are poorly constrained. Here we use topographic analysis and cosmogenic (3)He surface exposure dating of fluvially sculpted surfaces to determine the impact of extreme flood events within the Jökulsárgljúfur canyon (northeast Iceland) and to constrain the mechanisms of bedrock erosion during these events. Surface exposure ages allow identification of three periods of intense canyon cutting about 9 ka ago, 5 ka ago, and 2 ka ago during which multiple large knickpoints retreated large distances (>2 km). During these events, a threshold flow depth was exceeded, leading to the toppling and transportation of basalt lava columns. Despite continuing and comparatively large-scale (500 m(3)/s) discharge of sediment-rich glacial meltwater, there is no evidence for a transition to an abrasion-dominated erosion regime since the last erosive event because the vertical knickpoints have not diffused over time. We provide a model for the evolution of the Jökulsárgljúfur canyon through the reconstruction of the river profile and canyon morphology at different stages over the last 9 ka and highlight the dominant role played by extreme flood events in the shaping of this landscape during the Holocene.

Erosion during extreme flood events dominates Holocene canyon evolution in northeast Iceland

PubMed Central

Baynes, Edwin R. C.; Attal, Mikaël; Kirstein, Linda A.; Dugmore, Andrew J.; Naylor, Mark

2015-01-01

Extreme flood events have the potential to cause catastrophic landscape change in short periods of time (100 to 103 h). However, their impacts are rarely considered in studies of long-term landscape evolution (>103 y), because the mechanisms of erosion during such floods are poorly constrained. Here we use topographic analysis and cosmogenic 3He surface exposure dating of fluvially sculpted surfaces to determine the impact of extreme flood events within the Jökulsárgljúfur canyon (northeast Iceland) and to constrain the mechanisms of bedrock erosion during these events. Surface exposure ages allow identification of three periods of intense canyon cutting about 9 ka ago, 5 ka ago, and 2 ka ago during which multiple large knickpoints retreated large distances (>2 km). During these events, a threshold flow depth was exceeded, leading to the toppling and transportation of basalt lava columns. Despite continuing and comparatively large-scale (500 m3/s) discharge of sediment-rich glacial meltwater, there is no evidence for a transition to an abrasion-dominated erosion regime since the last erosive event because the vertical knickpoints have not diffused over time. We provide a model for the evolution of the Jökulsárgljúfur canyon through the reconstruction of the river profile and canyon morphology at different stages over the last 9 ka and highlight the dominant role played by extreme flood events in the shaping of this landscape during the Holocene. PMID:25675484

Association between cerebral palsy and microscopically verified placental infarction in extremely preterm infants.

PubMed

Vinnars, Marie-Therese; Vollmer, Brigitte; Nasiell, Josefine; Papadogiannakis, Nikos; Westgren, Magnus

2015-09-01

Previously, cerebral palsy has been associated with placental infarctions diagnosed macroscopically by midwifes. However, the risk of misclassification of infarctionsis is high without a histological verification. Therefore, the objective of this study was to study placental histopathology in relation to developmental outcome at 2.5 years corrected age in a population born extremely preterm. A prospective cohort study was carried out at Karolinska University Hospital, Stockholm, Sweden on a population of 139 live born infants delivered <27 gestational weeks during 2004-2007. A senior perinatal pathologist, who was blinded to outcome data, evaluated all placental slides microscopically. Neuromotor and sensory functions of the children were evaluated. Bayley Scales of Infant and Toddler Development-III (Bayley-III) were used to assess development at corrected age 2.5 years. The outcome data were evaluated without reference to obstetrical and pathology data. The primary outcome measure was neurological and developmental status at 2.5 years of corrected age. This was measured as diagnosis of cerebral palsy, visual impairment, hearing impairment as well as performance on Bayley-III scales evaluating cognitive, language and motor functions. Two out of seven children with placental infarction were diagnosed with cerebral palsy compared with one child of 51 without placental infarction (p = 0.036). For developmental outcome according to Bayley-III at 2.5 years no statistically significant associations with placental pathology were found. A possible association between placental infarction, verified by microscopic examination, and cerebral palsy has been identified in this extremely preterm population. © 2015 Nordic Federation of Societies of Obstetrics and Gynecology.

A categorical structure-activity relationship analysis of the developmental toxicity of antithyroid drugs.

PubMed

Cunningham, Albert R; Carrasquer, C Alex; Mattison, Donald R

2009-01-01

The choice of therapeutic strategies for hyperthyroidism during pregnancy is limited. Surgery and radioiodine are typically avoided, leaving propylthiouracil and methimazole in the US. Carbimazole, a metabolic precursor of methimazole, is available in some countries outside of the US. In the US propylthiouracil is recommended because of concern about developmental toxicity from methimazole and carbimazole. Despite this recommendation, the data on developmental toxicity of all three agents are extremely limited and insufficient to support a policy given the broad use of methimazole and carbimazole around the world. In the absence of new human or animal data we describe the development of a new structure-activity relationship (SAR) model for developmental toxicity using the cat-SAR expert system. The SAR model was developed from data for 323 compounds evaluated for human developmental toxicity with 130 categorized as developmental toxicants and 193 as nontoxicants. Model cross-validation yielded a concordance between observed and predicted results between 79% to 81%. Based on this model, propylthiouracil, methimazole, and carbimazole were observed to share some structural features relating to human developmental toxicity. Thus given the need to treat women with Graves's disease during pregnancy, new molecules with minimized risk for developmental toxicity are needed. To help meet this challenge, the cat-SAR method would be a useful in screening new drug candidates for developmental toxicity as well as for investigating their mechanism of action.

Implications of ecological energetics and biophysical and developmental constraints for life history variation in dinosaurs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dunham, A.E.; Overall, K.L.; Forster, C.A.

1988-01-01

There has been much recent speculation concerning the nature of life history variation in dinosaurs (Case, 1978; Bakker, 1986; Horner, 1982, 1984a). The purpose of this paper is to review the data on dinosaur life histories and to examine the nature and magnitude of the demographic and physiological factors that must have constrained life history variation in this group. 145 refs., 8 figs., 3 tabs.

THE DEVELOPMENT OF SLEEP-WAKE RHYTHMS AND THE SEARCH FOR ELEMENTAL CIRCUITS IN THE INFANT BRAIN

PubMed Central

Blumberg, Mark S.; Gall, Andrew J.; Todd, William D.

2014-01-01

Despite the predominance of sleep in early infancy, developmental science has yet to play a major role in shaping concepts and theories about sleep and its associated ultradian and circadian rhythms. Here we argue that developmental analyses help us to elucidate the relative contributions of the brainstem and forebrain to sleep-wake control and to dissect the neural components of sleep-wake rhythms. Developmental analysis also makes it clear that sleep-wake processes in infants are the foundation for those of adults. For example, the infant brainstem alone contains a fundamental sleep-wake circuit that is sufficient to produce transitions among wakefulness, quiet sleep, and active sleep. Also, consistent with the requirements of a “flip-flop” model of sleep-wake processes, this brainstem circuit supports rapid transitions between states. Later in development, strengthening bidirectional interactions between the brainstem and forebrain contribute to the consolidation of sleep and wake bouts, the elaboration of sleep homeostatic processes, and the emergence of diurnal or nocturnal circadian rhythms. The developmental perspective promoted here critically constrains theories of sleep-wake control and provides a needed framework for the creation of fully realized computational models. Finally, with a better understanding of how this system is constructed developmentally, we will gain insight into the processes that govern its disintegration due to aging and disease. PMID:24708298

The development of sleep-wake rhythms and the search for elemental circuits in the infant brain.

PubMed

Blumberg, Mark S; Gall, Andrew J; Todd, William D

2014-06-01

Despite the predominance of sleep in early infancy, developmental science has yet to play a major role in shaping concepts and theories about sleep and its associated ultradian and circadian rhythms. Here we argue that developmental analyses help us to elucidate the relative contributions of the brainstem and forebrain to sleep-wake control and to dissect the neural components of sleep-wake rhythms. Developmental analysis also makes it clear that sleep-wake processes in infants are the foundation for those of adults. For example, the infant brainstem alone contains a fundamental sleep-wake circuit that is sufficient to produce transitions among wakefulness, quiet sleep, and active sleep. In addition, consistent with the requirements of a "flip-flop" model of sleep-wake processes, this brainstem circuit supports rapid transitions between states. Later in development, strengthening bidirectional interactions between the brainstem and forebrain contribute to the consolidation of sleep and wake bouts, the elaboration of sleep homeostatic processes, and the emergence of diurnal or nocturnal circadian rhythms. The developmental perspective promoted here critically constrains theories of sleep-wake control and provides a needed framework for the creation of fully realized computational models. Finally, with a better understanding of how this system is constructed developmentally, we will gain insight into the processes that govern its disintegration due to aging and disease.

Developmental changes in facial expressions of emotions in the strange situation during the second year of life.

PubMed

Izard, Carroll E; Abe, Jo Ann A

2004-09-01

Infants' expressions of discrete emotions were coded during the more stressful episodes (4 through 8) of the Strange Situation at 13 and 18 months. The data showed a significant decrease in full-face expressions (more complex configurations of movements) and a significant increase in component expressions (simpler and more constrained patterns of movements). The authors interpreted this trend as a developmental change toward more regulated and less intense emotions. Consistent with this view, the aggregate index of infants' full-face negative emotion expressions, interpreted as reflecting relatively unregulated intense emotions, correlated significantly with maternal ratings of difficult temperament. The authors discuss alternative interpretations of the findings in terms of changes in reactivity/arousability and the emerging capacity for self-regulation. (c) 2004 APA, all rights reserved

Evolution in an extreme environment: developmental biases and phenotypic integration in the adaptive radiation of antarctic notothenioids.

PubMed

Hu, Yinan; Ghigliotti, Laura; Vacchi, Marino; Pisano, Eva; Detrich, H William; Albertson, R Craig

2016-06-29

Over the past 40 million years water temperatures have dramatically dropped in the Southern Ocean, which has led to the local extinction of most nearshore fish lineages. The evolution of antifreeze glycoproteins in notothenioids, however, enabled these ancestrally benthic fishes to survive and adapt as temperatures reached the freezing point of seawater (-1.86 °C). Antarctic notothenioids now represent the primary teleost lineage in the Southern Ocean and are of fundamental importance to the local ecosystem. The radiation of notothenioids has been fostered by the evolution of "secondary pelagicism", the invasion of pelagic habitats, as the group diversified to fill newly available foraging niches in the water column. While elaborate craniofacial modifications have accompanied this adaptive radiation, little is known about how these morphological changes have contributed to the evolutionary success of notothenioids. We used a 3D-morphometrics approach to investigate patterns of morphological variation in the craniofacial skeleton among notothenioids, and show that variation in head shape is best explained by divergent selection with respect to foraging niche. We document further an accelerated rate of morphological evolution in the icefish family Channichthyidae, and show that their rapid diversification was accompanied by the evolution of relatively high levels of morphological integration. Whereas most studies suggest that extensive integration should constrain phenotypic evolution, icefish stand out as a rare example of increased integration possibly facilitating evolutionary potential. Finally, we show that the unique feeding apparatus in notothenioids in general, and icefish in particular, can be traced to shifts in early developmental patterning mechanisms and ongoing growth of the pharyngeal skeleton. Our work suggests that ecological opportunity is a major factor driving craniofacial variation in this group. Further, the observation that closely related lineages can differ dramatically in integration suggests that this trait can evolve quickly. We propose that the evolution of high levels of phenotypic integration in icefishes may be considered a key innovation that facilitated their morphological evolution and subsequent ecological expansion.

Scarcity and Environmental Stress in Public Organizations: A Conjectural Essay.

ERIC Educational Resources Information Center

Bozeman, Barry; Slusher, E. Allen

1979-01-01

Assuming extreme scarcity, arguments are developed that public organizations could be expected to constrain their domain definition, allow domain selection to dictate technology, seek clientele suited to existing technologies, and, in general, take actions that will ensure that existing technologies are employed at capacity. (Author/IRT)

Advancing preparedness and response to drought and wildfires through North American transboudary collaboration

USDA-ARS?s Scientific Manuscript database

The economic, environmental, and social impacts of climate extremes across North America are significant. Drought in particular is one of the costliest and most prevalent natural hazards, and the impacts from drought are not constrained by any nation's borders. Coordination and communication between...

John B. Watson's Legacy: Learning and Environment.

ERIC Educational Resources Information Center

Horowitz, Frances Degen

1992-01-01

Evaluates John B. Watson's contributions to developmental psychology. Watson's insistence on objective methodology in psychology retains its influence, but his extreme environmentalism has been rejected. His concern with the principles of learning is reflected in the work of Hull and Skinner. (BC)

The movement patterns used to rise from a supine position by children with developmental delay and age-related differences in these.

PubMed

Hsue, Bih-Jen; Wang, Yun-Er; Chen, Yung-Jung

2014-09-01

The purposes of this study were to determine (1) movement patterns and strategies of children with mild to moderate developmental delay (DD) used to rise up and how they differ from those used by age-matched children with typical development (TD), (2) whether the movement patterns differ with age in children with DD, and (3) to determine the developmental sequences for the UE, AX and LE in children with DD and whether they are different from those used by children with TD. Sixty six children with TD and 31 children with DD aged two to six years were recruited. Peabody Developmental Motor Scale II (PDMS-2) was used to determine the motor performance level. The participants were recorded during rising for at least five repetitions. Two trained pediatric physical therapists viewed each video recording and classified the movement patterns of the upper extremities (UE), trunk/axial (AX) and lower extremities (LE) regions using descriptive categories developed by previous researchers. The DD and TD groups were further divided into four subgroups each using a one-year interval. The percentage of occurrence of the each UE, AX and LE movement was determined and compared across subgroups, and between each age-matched pair of TD and DD groups. The results demonstrated that the participants in the TD group clearly followed the proposed developmental sequence and the children with DD followed the developmental sequences but with different maturation speeds and greater variability, especially at the age of three to five years. The most common movement patterns used by the children in each of the DD subgroups were at least one developmental categorical pattern behind those used by the age-matched children with TD before five years old, except for the LE region. In the DD group, the movement patterns had moderate to high correlation with the child's motor performance level, indicating that the children with better motor performances used more developmentally advanced patterns in comparison with those with lower scores. However, besides motor maturity, numerous other intrinsic/extrinsic factors may affect the child's performance of this task. The information obtained in this study would assist therapists when working with the children with DD, so that they can provide individualized treatment rather than guiding all such children toward a single, mature pattern. Copyright © 2014 Elsevier Ltd. All rights reserved.

Building Trust: The Challenge of Building Partnership Capacity in U.S.-Mexico Military Relations

DTIC Science & Technology

2014-03-01

culture devoted to an extreme lineal hierarchy, especially during this developmental process, tends to hinder the ability of the member to retain and use...www.sedena.gob.mx/index.php/ educacion -militar. 25 educational objectives. These extreme vertical culture becomes a huge road block for those who want others to...in Veracruz and the acts of valor by the Mexican people— especially by the naval cadets—were fully embedded throughout the formation of all Mexican

Ferns: the missing link in shoot evolution and development

PubMed Central

Plackett, Andrew R. G.; Di Stilio, Verónica S.; Langdale, Jane A.

2015-01-01

Shoot development in land plants is a remarkably complex process that gives rise to an extreme diversity of forms. Our current understanding of shoot developmental mechanisms comes almost entirely from studies of angiosperms (flowering plants), the most recently diverged plant lineage. Shoot development in angiosperms is based around a layered multicellular apical meristem that produces lateral organs and/or secondary meristems from populations of founder cells at its periphery. In contrast, non-seed plant shoots develop from either single apical initials or from a small population of morphologically distinct apical cells. Although developmental and molecular information is becoming available for non-flowering plants, such as the model moss Physcomitrella patens, making valid comparisons between highly divergent lineages is extremely challenging. As sister group to the seed plants, the monilophytes (ferns and relatives) represent an excellent phylogenetic midpoint of comparison for unlocking the evolution of shoot developmental mechanisms, and recent technical advances have finally made transgenic analysis possible in the emerging model fern Ceratopteris richardii. This review compares and contrasts our current understanding of shoot development in different land plant lineages with the aim of highlighting the potential role that the fern C. richardii could play in shedding light on the evolution of underlying genetic regulatory mechanisms. PMID:26594222

Developmental mechanisms of macroevolutionary change in the tetrapod axis: A case study of Sauropterygia

PubMed Central

Soul, Laura C.; Benson, Roger B. J.

2017-01-01

Understanding how developmental processes change on macroevolutionary timescales to generate body plan disparity is fundamental to the study of vertebrate evolution. Adult morphology of the vertebral column directly reflects the mechanisms that generate vertebral counts (somitogenesis) and their regionalisation (homeotic effects) during embryonic development. Sauropterygians were a group of Mesozoic marine reptiles that exhibited an extremely high disparity of presacral vertebral/somite counts. Using phylogenetic comparative methods, we demonstrate that somitogenesis and homeotic effects evolved in a co‐ordinated way among sauropterygians, contrasting with the wider pattern in tetrapods, in which somitogenetic and homeotic shifts are uncorrelated. Changes in sauropterygian body proportions were primarily enabled by homeotic shifts, with a lesser, but important, contribution from differences in postpatterning growth among somites. High body plan plasticity was present in Triassic sauropterygians and was maintained among their Jurassic and Cretaceous descendants. The extreme disparity in the body plan of plesiosaurian sauropterygians did not result from accelerated rates of evolutionary change in neck length, but instead reflect this ancestral versatility of sauropterygian axial development. Our results highlight variation in modes of axial development among tetrapods, and show that heterogeneous statistical models can uncover novel macroevolutionary patterns for animal body plans and the developmental mechanisms that control them. PMID:28240769

Morphological interaction between the nasal septum and nasofacial skeleton during human ontogeny.

PubMed

Goergen, Matthew J; Holton, Nathan E; Grünheid, Thorsten

2017-05-01

The nasal septal cartilage is thought to be a key growth center that contributes to nasofacial skeletal development. Despite the developmental influence of the nasal septum however, humans often exhibit a high frequency of septal deviation suggesting discordance in the growth between the septum and surrounding nasofacial skeleton. While there are numerous etiological factors that contribute to septal deviation, the surrounding nasofacial skeleton may also act to constrain the septum, resulting in altered patterns of growth. That is, while the nasal septum has a direct morphogenetic influence on aspects of the nasofacial skeleton, other nasofacial skeletal components may restrict septal growth resulting in deviation. Detailing the developmental relationship between these structures is important not only for understanding the causal determinants of nasal septal deviation, but also for developing a broader understanding of the complex interaction between the facial skeleton and chondrocranium. We selected 66 non-syndromic subjects from the University of Minnesota Orthodontic Clinic who ranged from 7 to 18 years in age and had an existing pretreatment cone-beam computed tomography (CBCT) scan. Using CBCT data, we examined the developmental relationship between nasal septal deviation and the surrounding nasofacial skeleton. We measured septal deviation as a percentage of septal volume relative to a modeled non-deviated septum. We then collected a series of coordinate landmark data in the region immediately surrounding the nasal septum in the midsagittal plane representing the nasofacial skeleton. First, we examined ontogenetic changes in the magnitude of nasal septal deviation relative to chronological age and nasofacial size. Next, using Procrustes-based geometric morphometric techniques, we assessed the morphological relationship between nasal septal deviation and nasofacial skeletal shape. Our results indicate that variation in the magnitude of nasal septal deviation was established in our earliest age group and maintained throughout ontogeny. Moreover, nasal septal deviation was correlated with non-allometric variation in nasofacial shape restricted to the region of the anterior sphenoid body. Ultimately, our results suggest that early developmental variation in midline basicranial components may act to alter or constrain patterns of nasal septal growth. © 2017 Anatomical Society.

Lithium in halo stars - Constraining the effects of helium diffusion on globular cluster ages and cosmology

NASA Technical Reports Server (NTRS)

Deliyannis, Constantine P.; Demarque, Pierre

1991-01-01

Stellar evolutionary models with diffusion are used to show that observations of lithium in extreme halo stars provide crucial constraints on the magnitude of the effects of helium diffusion. The flatness of the observed Li-T(eff) relation severely constrains diffusion Li isochrones, which tend to curve downward toward higher T(eff). It is argued that Li observations at the hot edge of the plateau are particularly important in constraining the effects of helium diffusion; yet, they are currently few in number. It is proposed that additional observations are required there, as well as below 5500 K, to define more securely the morphology of the halo Li abundances. Implications for the primordial Li abundance are considered. It is suggested that a conservative upper limit to the initial Li abundance, due to diffusive effects alone, is 2.35.

Attentional control constrains visual short-term memory: Insights from developmental and individual differences

PubMed Central

Astle, D.E.; Nobre, A.C.; Scerif, G.

2014-01-01

The mechanisms by which attentional control biases mnemonic representations have attracted much interest but remain poorly understood. As attention and memory develop gradually over childhood and variably across individuals, assessing how participants of different ages and ability attend to mnemonic contents can elucidate their interplay. In Experiment 1, 7-, 10-year-olds and adults were asked to report whether a probe item had been part of a previously presented four-item array. The initial array could either be uncued, preceded (“pre-cued”) or followed (“retro-cued”) by a spatial cue orienting attention to one of the potential item locations. Performance across groups was significantly improved by both cue types and individual differences in children’s retrospective attentional control predicted their visual short-term and working memory span, whereas their basic ability to remember in the absence of cues did not. Experiment 2 imposed a variable delay between the array and the subsequent orienting cue. Cueing benefits were greater in adults compared to 10-year-olds, but they persisted even when cues followed the array by nearly 3 seconds, suggesting that orienting operated on durable short-term representations for both age groups. The findings indicate that there are substantial developmental and individual differences in the ability to control attention to memory and that in turn these differences constrain visual short-term memory capacity. PMID:20680889

Attentional control constrains visual short-term memory: insights from developmental and individual differences.

PubMed

Astle, Duncan E; Nobre, Anna C; Scerif, Gaia

2012-01-01

The mechanisms by which attentional control biases mnemonic representations have attracted much interest but remain poorly understood. As attention and memory develop gradually over childhood and variably across individuals, assessing how participants of different ages and ability attend to mnemonic contents can elucidate their interplay. In Experiment 1, 7-year-olds, 10-year-olds, and adults were asked to report whether a probe item had been part of a previously presented four-item array. The initial array could either be uncued, be preceded ("precued"), or followed ("retrocued") by a spatial cue orienting attention to one of the potential item locations. Performance across groups was significantly improved by both cue types, and individual differences in children's retrospective attentional control predicted their visual short-term and working memory span, whereas their basic ability to remember in the absence of cues did not. Experiment 2 imposed a variable delay between the array and the subsequent orienting cue. Cueing benefits were greater in adults than in 10-year-olds, but they persisted even when cues followed the array by nearly 3 seconds, suggesting that orienting operated on durable short-term representations for both age groups. The findings indicate that there are substantial developmental and individual differences in the ability to control attention to memory and that in turn these differences constrain visual short-term memory capacity.

Neurologic and developmental disability after extremely preterm birth. EPICure Study Group.

PubMed

Wood, N S; Marlow, N; Costeloe, K; Gibson, A T; Wilkinson, A R

2000-08-10

Small studies show that many children born as extremely preterm infants have neurologic and developmental disabilities. We evaluated all children who were born at 25 or fewer completed weeks of gestation in the United Kingdom and Ireland from March through December 1995 at the time when they reached a median age of 30 months. Each child underwent a formal assessment by an independent examiner. Development was evaluated with use of the Bayley Scales of Infant Development, and neurologic function was assessed by a standardized examination. Disability and severe disability were defined by predetermined criteria. At a median age of 30 months, corrected for gestational age, 283 (92 percent) of the 308 surviving children were formally assessed. The mean (+/-SD) scores on the Bayley Mental and Psychomotor Developmental Indexes, referenced to a population mean of 100, were 84+/-12 and 87+/-13, respectively. Fifty-three children (19 percent) had severely delayed development (with scores more than 3 SD below the mean), and a further 32 children (11 percent) had scores from 2 SD to 3 SD below the mean. Twenty-eight children (10 percent) had severe neuromotor disability, 7 (2 percent) were blind or perceived light only, and 8 (3 percent) had hearing loss that was uncorrectable or required aids. Overall, 138 children had disability (49 percent; 95 percent confidence interval, 43 to 55 percent), including 64 who met the criteria for severe disability (23 percent; 95 percent confidence interval, 18 to 28 percent). When data from 17 assessments by local pediatricians were included, 155 of the 314 infants discharged (49 percent) had no disability. Severe disability is common among children born as extremely preterm infants.

Zebrafish as a systems toxicology model for developmental neurotoxicity testing.

PubMed

Nishimura, Yuhei; Murakami, Soichiro; Ashikawa, Yoshifumi; Sasagawa, Shota; Umemoto, Noriko; Shimada, Yasuhito; Tanaka, Toshio

2015-02-01

The developing brain is extremely sensitive to many chemicals. Exposure to neurotoxicants during development has been implicated in various neuropsychiatric and neurological disorders, including autism spectrum disorder, attention deficit hyperactive disorder, schizophrenia, Parkinson's disease, and Alzheimer's disease. Although rodents have been widely used for developmental neurotoxicity testing, experiments using large numbers of rodents are time-consuming, expensive, and raise ethical concerns. Using alternative non-mammalian animal models may relieve some of these pressures by allowing testing of large numbers of subjects while reducing expenses and minimizing the use of mammalian subjects. In this review, we discuss some of the advantages of using zebrafish in developmental neurotoxicity testing, focusing on central nervous system development, neurobehavior, toxicokinetics, and toxicodynamics in this species. We also describe some important examples of developmental neurotoxicity testing using zebrafish combined with gene expression profiling, neuroimaging, or neurobehavioral assessment. Zebrafish may be a systems toxicology model that has the potential to reveal the pathways of developmental neurotoxicity and to provide a sound basis for human risk assessments. © 2014 Japanese Teratology Society.

The dynamics of folding instability in a constrained Cosserat medium

NASA Astrophysics Data System (ADS)

Gourgiotis, Panos A.; Bigoni, Davide

2017-04-01

Different from Cauchy elastic materials, generalized continua, and in particular constrained Cosserat materials, can be designed to possess extreme (near a failure of ellipticity) orthotropy properties and in this way to model folding in a three-dimensional solid. Following this approach, folding, which is a narrow zone of highly localized bending, spontaneously emerges as a deformation pattern occurring in a strongly anisotropic solid. How this peculiar pattern interacts with wave propagation in the time-harmonic domain is revealed through the derivation of an antiplane, infinite-body Green's function, which opens the way to integral techniques for anisotropic constrained Cosserat continua. Viewed as a perturbing agent, the Green's function shows that folding, emerging near a steadily pulsating source in the limit of failure of ellipticity, is transformed into a disturbance with wavefronts parallel to the folding itself. The results of the presented study introduce the possibility of exploiting constrained Cosserat solids for propagating waves in materials displaying origami patterns of deformation. This article is part of the themed issue 'Patterning through instabilities in complex media: theory and applications.'

Sibling Caregivers of People With Intellectual and Developmental Disabilities: Sociodemographic Characteristics and Material Hardship Prevalence.

PubMed

Sonik, Rajan A; Parish, Susan L; Rosenthal, Eliana S

2016-10-01

In growing numbers, people with intellectual and developmental disabilities are outliving their parents, or at least their parents' ability to care for them. Consequently, adult siblings without intellectual and developmental disabilities are increasingly taking on primary caregiving responsibilities. However, adult siblings have received little study generally, and sibling caregivers have received even less. We used nationally representative data from the Survey of Income and Program Participation (SIPP) to describe the social characteristics and material hardship levels of sibling caregivers, in comparison to the general working age adult population. This study finds moderate material hardship to be pervasive among sibling caregivers, though extreme levels of hardship are possibly being abated somewhat through public benefit programs. Implications for greater service needs are discussed.

Intensification of hot extremes in the United States

DOE Office of Scientific and Technical Information (OSTI.GOV)

Diffenbaugh, Noah; Ashfaq, Moetasim

Governments are currently considering policies that will limit greenhouse gas concentrations, including negotiation of an international treaty to replace the expiring Kyoto Protocol. Existing mitigation targets have arisen primarily from political negotiations, and the ability of such policies to avoid dangerous impacts is still uncertain. Using a large suite of climate model experiments, we find that substantial intensification of hot extremes could occur within the next 3 decades, below the 2 C global warming target currently being considered by policy makers. We also find that the intensification of hot extremes is associated with a shift towards more anticyclonic atmospheric circulationmore » during the warm season, along with warm-season drying over much of the U.S. The possibility that intensification of hot extremes could result from relatively small increases in greenhouse gas concentrations suggests that constraining global warming to 2 C may not be sufficient to avoid dangerous climate change.« less

Constraint elimination in dynamical systems

NASA Technical Reports Server (NTRS)

Singh, R. P.; Likins, P. W.

1989-01-01

Large space structures (LSSs) and other dynamical systems of current interest are often extremely complex assemblies of rigid and flexible bodies subjected to kinematical constraints. A formulation is presented for the governing equations of constrained multibody systems via the application of singular value decomposition (SVD). The resulting equations of motion are shown to be of minimum dimension.

Towards spatially constrained gust models

NASA Astrophysics Data System (ADS)

Bos, René; Bierbooms, Wim; van Bussel, Gerard

2014-06-01

With the trend of moving towards 10-20 MW turbines, rotor diameters are growing beyond the size of the largest turbulent structures in the atmospheric boundary layer. As a consequence, the fully uniform transients that are commonly used to predict extreme gust loads are losing their connection to reality and may lead to gross overdimensioning. More suiting would be to represent gusts by advecting air parcels and posing certain physical constraints on size and position. However, this would introduce several new degrees of freedom that significantly increase the computational burden of extreme load prediction. In an attempt to elaborate on the costs and benefits of such an approach, load calculations were done on the DTU 10 MW reference turbine where a single uniform gust shape was given various spatial dimensions with the transverse wavelength ranging up to twice the rotor diameter (357 m). The resulting loads displayed a very high spread, but remained well under the level of a uniform gust. Moving towards spatially constrained gust models would therefore yield far less conservative, though more realistic predictions at the cost of higher computation time.

Classification-Assisted Memetic Algorithms for Equality-Constrained Optimization Problems

NASA Astrophysics Data System (ADS)

Handoko, Stephanus Daniel; Kwoh, Chee Keong; Ong, Yew Soon

Regressions has successfully been incorporated into memetic algorithm (MA) to build surrogate models for the objective or constraint landscape of optimization problems. This helps to alleviate the needs for expensive fitness function evaluations by performing local refinements on the approximated landscape. Classifications can alternatively be used to assist MA on the choice of individuals that would experience refinements. Support-vector-assisted MA were recently proposed to alleviate needs for function evaluations in the inequality-constrained optimization problems by distinguishing regions of feasible solutions from those of the infeasible ones based on some past solutions such that search efforts can be focussed on some potential regions only. For problems having equality constraints, however, the feasible space would obviously be extremely small. It is thus extremely difficult for the global search component of the MA to produce feasible solutions. Hence, the classification of feasible and infeasible space would become ineffective. In this paper, a novel strategy to overcome such limitation is proposed, particularly for problems having one and only one equality constraint. The raw constraint value of an individual, instead of its feasibility class, is utilized in this work.

The ontogeny of Robin sequence.

PubMed

Logjes, Robrecht J H; Breugem, Corstiaan C; Van Haaften, Gijs; Paes, Emma C; Sperber, Geoffrey H; van den Boogaard, Marie-José H; Farlie, Peter G

2018-04-25

The triad of micrognathia, glossoptosis, and concomitant airway obstruction defined as "Robin sequence" (RS) is caused by oropharyngeal developmental events constrained by a reduced stomadeal space. This sequence of abnormal embryonic development also results in an anatomical configuration that might predispose the fetus to a cleft palate. RS is heterogeneous and many different etiologies have been described including syndromic, RS-plus, and isolated forms. For an optimal diagnosis, subsequent treatment and prognosis, a thorough understanding of the embryology and pathogenesis is necessary. This manuscript provides an update about our current understanding of the development of the mandible, tongue, and palate and possible mechanisms involved in the development of RS. Additionally, we provide the reader with an up-to-date summary of the different etiologies of this phenotype and link this to the embryologic, developmental, and genetic mechanisms. © 2018 Wiley Periodicals, Inc.

Survival and developmental disability in infants with birth weights of 501 to 800 grams, born between 1979 and 1994.

PubMed

O'Shea, T M; Klinepeter, K L; Goldstein, D J; Jackson, B W; Dillard, R G

1997-12-01

Because the survival rate has increased for extremely low birth weight neonates, many have raised the concern that the rate of developmental disability among survivors will also increase. To address this concern, we analyzed changes over time in survival and major neurosensory impairment in a sample of extremely low birth weight infants born between July 1, 1979, and June 30, 1994. The study sample included 513 infants with birth weights of 501 to 800 g who were cared for in either of the two neonatal intensive care units that serve a 17-county region in northwest North Carolina and who were born to mothers residing in that region. At 1 year of age (corrected for gestation), survivors were examined by a pediatrician and were tested using the Bayley Scales of Infant Development. Major neurosensory impairment was defined as cerebral palsy, a Bayley Mental Developmental Index <68, or blindness. A total of 209/216 (97%) of survivors were examined at 1 year of age. Epoch of birth was defined as follows: epoch 1, July 1, 1979 to June 30, 1984; epoch 2, July 1, 1984 to June 30, 1989; and epoch 3, July 1, 1989 to June 30, 1994. Survival rates for epochs 1, 2, and 3 were, respectively, 24/120 (20%), 63/175 (36%), and 129/218 (59%). In contrast, the proportions with a major neurosensory impairment did not increase over time; rates for successive epochs were 6/24 (25%), 17/61 (28%), and 26/124 (21%). Rates of cerebral palsy were 3/24 (13%), 12/61 (20%), and 9/124 (7%); rates of delayed mental development were 4/24 (17%), 12/61 (20%), and 17/124 (14%); and rates of blindness were 2/24 (8%), 0/62, and 5/124 (4%), respectively. This analysis suggests that the increasing survival of extremely low birth weight neonates since the late 1970s has not resulted in an increased rate of major developmental problems identifiable at 1 year of age.

Developmental constraints shape the evolution of the nematode mid-developmental transition.

PubMed

Zalts, Harel; Yanai, Itai

2017-03-27

Evolutionary theory assumes that genetic variation is uniform and gradual in nature, yet morphological and gene expression studies have revealed that different life-stages exhibit distinct levels of cross-species conservation. In particular, a stage in mid-embryogenesis is highly conserved across species of the same phylum, suggesting that this stage is subject to developmental constraints, either by increased purifying selection or by a strong mutational bias. An alternative explanation, however, holds that the same 'hourglass' pattern of variation may result from increased positive selection at the earlier and later stages of development. To distinguish between these scenarios, we examined gene expression variation in a population of the nematode Caenorhabditis elegans using an experimental design that eliminated the influence of positive selection. By measuring gene expression for all genes throughout development in 20 strains, we found that variations were highly uneven throughout development, with a significant depletion during mid-embryogenesis. In particular, the family of homeodomain transcription factors, whose expression generally coincides with mid-embryogenesis, evolved under high constraint. Our data further show that genes responsible for the integration of germ layers during morphogenesis are the most constrained class of genes. Together, these results provide strong evidence for developmental constraints as the mechanism underlying the hourglass model of animal evolution. Understanding the pattern and mechanism of developmental constraints provides a framework to understand how evolutionary processes have interacted with embryogenesis and led to the diversity of animal life on Earth.

Warmest extreme year in U.S. history alters thermal requirements for tree phenology.

PubMed

Carter, Jacob M; Orive, Maria E; Gerhart, Laci M; Stern, Jennifer H; Marchin, Renée M; Nagel, Joane; Ward, Joy K

2017-04-01

The frequency of extreme warm years is increasing across the majority of the planet. Shifts in plant phenology in response to extreme years can influence plant survival, productivity, and synchrony with pollinators/herbivores. Despite extensive work on plant phenological responses to climate change, little is known about responses to extreme warm years, particularly at the intraspecific level. Here we investigate 43 populations of white ash trees (Fraxinus americana) from throughout the species range that were all grown in a common garden. We compared the timing of leaf emergence during the warmest year in U.S. history (2012) with relatively non-extreme years. We show that (a) leaf emergence among white ash populations was accelerated by 21 days on average during the extreme warm year of 2012 relative to non-extreme years; (b) rank order for the timing of leaf emergence was maintained among populations across extreme and non-extreme years, with southern populations emerging earlier than northern populations; (c) greater amounts of warming units accumulated prior to leaf emergence during the extreme warm year relative to non-extreme years, and this constrained the potential for even earlier leaf emergence by an average of 9 days among populations; and (d) the extreme warm year reduced the reliability of a relevant phenological model for white ash by producing a consistent bias toward earlier predicted leaf emergence relative to observations. These results demonstrate a critical need to better understand how extreme warm years will impact tree phenology, particularly at the intraspecific level.

Symbol-string sensitivity and children's reading.

PubMed

Pammer, Kristen; Lavis, Ruth; Hansen, Peter; Cornelissen, Piers L

2004-06-01

In this study of primary school children, a novel 'symbol-string' task is used to assess sensitivity to the position of briefly presented non-alphabetic but letter-like symbols. The results demonstrate that sensitivity in the symbol-string task explains a unique proportion of the variability in children's contextual reading accuracy. Moreover, developmental dyslexic readers show reduced sensitivity in this task, compared to chronological age controls. The results suggest that limitations set by visuo-spatial processes and/or attentional iconic memory resources may constrain children's reading accuracy.

Stress resistance strategy in an arid land shrub: interactions between developmental instability and fractal dimention

USGS Publications Warehouse

Escos, J.; Alados, C.L.; Pugnaire, F. I.; Puigdefábregas, J.; Emlen, J.

2000-01-01

This paper investigates allocation of energy to mechanisms that generate and preserve architectural forms (i.e. developmental stability, complexity of branching patterns) and productivity (growth and reproduction) in response to environmental disturbances (i.e. grazing and resource availability). The statistical error in translational symmetry was used to detect random intra-individual variability during development. This can be thought of as a measure of developmental instability caused by stress. Additionally, we use changes in fractal complexity and shoot distribution of branch structures as an alternate indicator of stress. These methods were applied to Anthyllis cytisoides L., a semi-arid environment shrub, to ascertain the effect of grazing and slope exposure on developmental traits in a 2×2 factorial design. The results show that A. cytisoidesmaintains developmental stability at the expense of productivity. Anthyllis cytisoides was developmentally more stable when grazed and when on south-facing, as opposed to north-facing slopes. On the contrary, shoot length, leaf area, fractal dimension and reproductive-to-vegetative allocation ratio were larger in north- than in south-facing slopes. As a consequence, under extreme xeric conditions, shrub mortality increased in north-facing slopes, especially when not grazed. The removal of transpiring area and the reduction of plant competition favoured developmental stability and survival in grazed plants. Differences between grazed and ungrazed plants were most evident in more mesic (north-facing) areas.

Early developmental trajectories of preterm infants.

PubMed

Yaari, Maya; Mankuta, David; Harel-Gadassi, Ayelet; Friedlander, Edwa; Bar-Oz, Benjamin; Eventov-Friedman, Smadar; Maniv, Nimrod; Zucker, David; Yirmiya, Nurit

2017-11-04

Preterm infants are at risk for neuro-developmental impairments and atypical developmental trajectories. The aims of this study were to delineate early developmental trajectories of preterm and full-term infants. The cognitive, language, and motor development of 149 infants - 19 extremely preterm (EPT), 34 very preterm (VPT), 57 moderately preterm (MPT), and 39 full-term (FT) - was evaluated using Mullen Scales at 1, 4, 8, 12, and 18 months. Mixed models were applied to examine group differences. Gender, maternal education, and neurobehavior were included as predictors of developmental trajectories. The EPT and VPT infants achieved significantly lower scores than the FT infants in all domains, with a significantly increasing gap over time. The MPT infants' trajectories were more favorable than those of the EPT and VPT infants yet lower than the FT infants on the Visual Reception, Gross, and Fine Motor subscales. Male gender and lower maternal education were associated with lower scores that declined over time. Abnormal neonatal neurobehavior was associated lower Mullen scores and with less stability in scores over time. The EPT and VPT infants were found to have disadvantages across all domains. The MPT infants revealed more favorable developmental trajectories yet displayed vulnerability compared to the FT infants. Gender, maternal education, and neonatal neurobehavior are important in predicting the developmental outcomes of preterm infants. Copyright © 2017 Elsevier Ltd. All rights reserved.

Sample-Based Motion Planning in High-Dimensional and Differentially-Constrained Systems

DTIC Science & Technology

2010-02-01

Reachable Set . . . 88 6-1 LittleDog Robot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94 6-2 Dog bounding up stairs ...planning algorithm implemented on LittleDog, a quadruped robot . The motion planning algorithm successfully planned bounding trajectories over extremely...a motion planning algorithm implemented on LittleDog, a quadruped robot . The motion planning algorithm successfully planned bounding trajectories

Hemostasis in the Very Young.

PubMed

Kenet, Gili; Barg, Assaf Arie; Nowak-Göttl, Ulrike

2018-06-18

Hemostasis is a dynamic process that starts in utero. The coagulation system evolves with age, as evidenced by marked physiological differences in the concentration of the majority of hemostatic proteins in early life compared with adulthood. This concept, known as "developmental hemostasis," has important biological and clinical implications. Overall, impaired platelet function, along with physiologically reduced levels of vitamin K-dependent and contact coagulation factors, may cause poorer clot firmness even in healthy neonates. However, increased activity of von Willebrand factor and low levels of coagulation inhibitors that promote hemostasis counterbalance the delicate and immature hemostatic system. Since this hemostatic system has little reserve capacity, preterm neonates or sick infants are extremely vulnerable and predisposed to either hemorrhagic or thrombotic complications. This review will address the concept and manifestations of developmental hemostasis with respect to clinical disease phenotypes. It will discuss bleeding diagnosis in neonates, dealing especially with the devastating complications of intracerebral and pulmonary hemorrhage in preterm infants. Neonates, especially the sickest preterm ones, are also extremely susceptible to thrombotic complications; thus, thrombosis in neonates will be reviewed, with special focus on arterial ischemic perinatal stroke. Based on the concept of developmental hemostasis, the phenotypes of clinically relevant bleeding or thrombotic disorders among neonates may differ from those of older infants and children. Treatment options for these conditions will be suggested and reviewed. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

RNA interference can be used to disrupt gene function in tardigrades

PubMed Central

Tenlen, Jennifer R.; McCaskill, Shaina; Goldstein, Bob

2012-01-01

How morphological diversity arises is a key question in evolutionary developmental biology. As a long-term approach to address this question, we are developing the water bear Hypsibius dujardini (Phylum Tardigrada) as a model system. We expect that using a close relative of two well-studied models, Drosophila (Phylum Arthropoda) and Caenorhabditis elegans (Phylum Nematoda), will facilitate identifying genetic pathways relevant to understanding the evolution of development. Tardigrades are also valuable research subjects for investigating how organisms and biological materials can survive extreme conditions. Methods to disrupt gene activity are essential to each of these efforts, but no such method yet exists for the Phylum Tardigrada. We developed a protocol to disrupt tardigrade gene functions by double-stranded RNA-mediated RNA interference (RNAi). We show that targeting tardigrade homologs of essential developmental genes by RNAi produced embryonic lethality, whereas targeting green fluorescent protein did not. Disruption of gene functions appears to be relatively specific by two criteria: targeting distinct genes resulted in distinct phenotypes that were consistent with predicted gene functions, and by RT-PCR, RNAi reduced the level of a target mRNA and not a control mRNA. These studies represent the first evidence that gene functions can be disrupted by RNAi in the phylum Tardigrada. Our results form a platform for dissecting tardigrade gene functions for understanding the evolution of developmental mechanisms and survival in extreme environments. PMID:23187800

RNA interference can be used to disrupt gene function in tardigrades.

PubMed

Tenlen, Jennifer R; McCaskill, Shaina; Goldstein, Bob

2013-05-01

How morphological diversity arises is a key question in evolutionary developmental biology. As a long-term approach to address this question, we are developing the water bear Hypsibius dujardini (Phylum Tardigrada) as a model system. We expect that using a close relative of two well-studied models, Drosophila (Phylum Arthropoda) and Caenorhabditis elegans (Phylum Nematoda), will facilitate identifying genetic pathways relevant to understanding the evolution of development. Tardigrades are also valuable research subjects for investigating how organisms and biological materials can survive extreme conditions. Methods to disrupt gene activity are essential to each of these efforts, but no such method yet exists for the Phylum Tardigrada. We developed a protocol to disrupt tardigrade gene functions by double-stranded RNA-mediated RNA interference (RNAi). We showed that targeting tardigrade homologs of essential developmental genes by RNAi produced embryonic lethality, whereas targeting green fluorescent protein did not. Disruption of gene functions appears to be relatively specific by two criteria: targeting distinct genes resulted in distinct phenotypes that were consistent with predicted gene functions and by RT-PCR, RNAi reduced the level of a target mRNA and not a control mRNA. These studies represent the first evidence that gene functions can be disrupted by RNAi in the phylum Tardigrada. Our results form a platform for dissecting tardigrade gene functions for understanding the evolution of developmental mechanisms and survival in extreme environments.

Risk of neurodevelopmental impairment for outborn extremely preterm infants in an Australian regional network.

PubMed

Mahoney, Kate; Bajuk, Barbara; Oei, Julee; Lui, Kei; Abdel-Latif, Mohamed E

2017-01-01

To compare neurodevelopmental outcomes at 2-3 years in extremely premature outborn and inborn infants. Population-based retrospective cohort study. Geographically defined area of New South Wales (NSW) and the Australian Capital Territory (ACT) served by a network of 10 neonatal intensive care units (NICUs). All premature infants <29 weeks gestation born between 1998 and 2004 in the setting. At 2-3 years, corrected age, 1473 children were assessed with either the Griffiths Mental Developmental Scales (GMDS) or the Bayley Scales of Infant Development (BSID-II). Moderate/severe functional disability (FD) defined as: developmental delay (GMDS general quotient (GQ) or BSID-II mental developmental index (MDI)) > 2 standard deviations (SD) below the mean; cerebral palsy (CP) requiring aids; sensorineural or conductive deafness (requiring amplification); or bilateral blindness (visual acuity <6/60 in better eye). At 2-3 years, moderate/severe functional disability does not appear to be significantly different between outborn and inborn infants (adjusted OR 0.782; 95% CI 0.424-1.443). However, there were a significant number of outborn infants lost to follow up (23.3% versus 42.9%). In this cohort, at 2-3 years follow up neurodevelopmental outcome does not appear to be significantly different between outborn and inborn infants. These results should be interpreted with caution given the limitation of this study.

Extreme weather events and infectious disease outbreaks.

PubMed

McMichael, Anthony J

2015-01-01

Human-driven climatic changes will fundamentally influence patterns of human health, including infectious disease clusters and epidemics following extreme weather events. Extreme weather events are projected to increase further with the advance of human-driven climate change. Both recent and historical experiences indicate that infectious disease outbreaks very often follow extreme weather events, as microbes, vectors and reservoir animal hosts exploit the disrupted social and environmental conditions of extreme weather events. This review article examines infectious disease risks associated with extreme weather events; it draws on recent experiences including Hurricane Katrina in 2005 and the 2010 Pakistan mega-floods, and historical examples from previous centuries of epidemics and 'pestilence' associated with extreme weather disasters and climatic changes. A fuller understanding of climatic change, the precursors and triggers of extreme weather events and health consequences is needed in order to anticipate and respond to the infectious disease risks associated with human-driven climate change. Post-event risks to human health can be constrained, nonetheless, by reducing background rates of persistent infection, preparatory action such as coordinated disease surveillance and vaccination coverage, and strengthened disaster response. In the face of changing climate and weather conditions, it is critically important to think in ecological terms about the determinants of health, disease and death in human populations.

RETINOID METABOLISM IN FISH EMBRYOS FROM SENSITIVE AND RESISTANT POPULATIONS EXPOSED TO DIOXIN-LIKE COMPOUNDS

EPA Science Inventory

Early developmental stages of fish are extremely sensitive to a class of toxic and persistent environmental contaminants known as dioxin-like compounds (DLCs). Most of the toxicological actions of DLCs are mediated via the Aryl hydrocarbon Receptor (AhR) that regulates transcript...

Childhood Suicide and Myths Surrounding It.

ERIC Educational Resources Information Center

Greene, Dorothea B.

1994-01-01

Dispels five misconceptions surrounding the suicide of children: that children under the age of six do not commit suicide; that suicide in latency years is extremely rare; that psychodynamically and developmentally true depression is not possible in childhood; that child cannot understand finality of death; and that children are cognitively and…

Wrongful Adoption: Law, Policy and Practice.

ERIC Educational Resources Information Center

Freundlich, Madelyn; Peterson, Lisa

The past decade has seen an increase in cases where adoptive parents fail to receive accurate or complete information about a child's physical, emotional, or developmental problems or about the child's birth family and history. In these cases adoptive parents are confronted with extremely expensive medical care or mental health care. This…

Rural Education in Bangladesh - Problems and Prospects. IIEP Seminar Paper: 23.

ERIC Educational Resources Information Center

Haque, M.

As a land of extreme rural poverty and illiteracy, Bangladesh needs to consciously promote, develop, and support local institutions and participatory leadership, involving local people in the planning, development, and implementation of developmental policies. Begun in 1959, the Comilla experiment constitutes the rationale for institutional…

Dandy-Walker Malformation and Down Syndrome Association: Good Developmental Outcome and Successful Endoscopic Treatment of Hydrocephalus

PubMed Central

Nigri, Flavio; Cabral, Isaias Fiuza; da Silva, Raquel Tavares Boy; Pereira, Heloisa Viscaíno; Ribeiro, Carlos Roberto Telles

2014-01-01

The association of Down syndrome (DS) with Dandy Walker malformation (DWM) is extremely rare, with only 3 cases reported to date. All cases reported have shown a bad life expectancy and a bad developmental outcome. The present case reveals the possibility of a good prognosis. A 19-month-old male patient had successful endoscopic hydrocephalus treatment and a good developmental outcome. He probably had a better outcome because of good DS and DWM prognostic parameters. Our patient suffered from a DWM with vermis identification of 2 fissures and 3 lobes and a DS with a well-preserved tonus, which was not associated with other congenital systemic defects. We may conclude that the prognosis of DS-DWM association may separately depend on the degree of clinical and neurological involvement of each malformation. PMID:24932176

Dandy-walker malformation and down syndrome association: good developmental outcome and successful endoscopic treatment of hydrocephalus.

PubMed

Nigri, Flavio; Cabral, Isaias Fiuza; da Silva, Raquel Tavares Boy; Pereira, Heloisa Viscaíno; Ribeiro, Carlos Roberto Telles

2014-05-01

The association of Down syndrome (DS) with Dandy Walker malformation (DWM) is extremely rare, with only 3 cases reported to date. All cases reported have shown a bad life expectancy and a bad developmental outcome. The present case reveals the possibility of a good prognosis. A 19-month-old male patient had successful endoscopic hydrocephalus treatment and a good developmental outcome. He probably had a better outcome because of good DS and DWM prognostic parameters. Our patient suffered from a DWM with vermis identification of 2 fissures and 3 lobes and a DS with a well-preserved tonus, which was not associated with other congenital systemic defects. We may conclude that the prognosis of DS-DWM association may separately depend on the degree of clinical and neurological involvement of each malformation.

Developmental temperature affects the expression of ejaculatory traits and the outcome of sperm competition in Callosobruchus maculatus.

PubMed

Vasudeva, R; Deeming, D C; Eady, P E

2014-09-01

The outcome of post-copulatory sexual selection is determined by a complex set of interactions between the primary reproductive traits of two or more males and their interactions with the reproductive traits of the female. Recently, a number of studies have shown the primary reproductive traits of both males and females express phenotypic plasticity in response to the thermal environment experienced during ontogeny. However, how plasticity in these traits affects the dynamics of sperm competition remains largely unknown. Here, we demonstrate plasticity in testes size, sperm size and sperm number in response to developmental temperature in the bruchid beetle Callosobruchus maculatus. Males reared at the highest temperature eclosed at the smallest body size and had the smallest absolute and relative testes size. Males reared at both the high- and low-temperature extremes produced both fewer and smaller sperm than males reared at intermediate temperatures. In the absence of sperm competition, developmental temperature had no effect on male fertility. However, under conditions of sperm competition, males reared at either temperature extreme were less competitive in terms of sperm offence (P(2)), whereas those reared at the lowest temperature were less competitive in terms of sperm defence (P(1)). This suggests the developmental pathways that regulate the phenotypic expression of these ejaculatory traits are subject to both natural and sexual selection: natural selection in the pre-ejaculatory environment and sexual selection in the post-ejaculatory environment. In nature, thermal heterogeneity during development is commonplace. Therefore, we suggest the interplay between ecology and development represents an important, yet hitherto underestimated component of male fitness via post-copulatory sexual selection. © 2014 The Authors. Journal of Evolutionary Biology © 2014 European Society For Evolutionary Biology.

Constraining the Carbon Cycle through Tree Rings: A Case Study of the Valles Caldera, NM

NASA Astrophysics Data System (ADS)

Alexander, M. R.; Babst, F.; Moore, D. J.; Trouet, V.

2013-12-01

Terrestrial ecosystems take up approximately 120 Gt of carbon as Gross Primary Productivity (GPP) from the atmosphere annually, but it is challenging to track the allocation of that carbon throughout the biosphere. Here, we combine eddy covariance measurements of net carbon uptake with above ground biomass increments derived from tree-ring data to better understand the interannual variability associated with biomass accumulation. In the summer of 2012, we collected tree cores near two eddy covariance towers in the Jemez Mountains of northern New Mexico. One tower was located in an upper elevation mixed-conifer forest, and the other in a lower elevation Pinus ponderosa forest. Our analysis shows that the annual above ground biomass increment accounted for approximately 40% of the GPP at the lower elevation Pinus ponderosa site and approximately 70% of GPP at the upper elevation mixed-conifer site. We have also used the above ground biomass increment to constrain the Simple Photosynthesis EvapoTranspiration (SiPNET) model to gain a better understanding of allocation within the forest. Tree growth at both elevations was negatively influenced by spring (March-June) temperature and positively by cool season (October-April) precipitation and warm (May-September) and cool season PDSI. We also analyzed the six most extreme temperature and moisture (PDSI) years of the record to determine the response of productivity to climatic forcing. During the driest years, biomass production was reduced by 40% at the upper elevation site and 43% at the lower elevation site. During the hottest years of the record the biomass decreased 28% at the upper site and 45% at the lower site. Our results indicate that tree rings can be used to effectively constrain the above ground biomass component of a forest's carbon budget and to estimate allocation of carbon to woody biomass as a function of climate. However, many variables remain unknown. The combined results of the extreme year analyses and the derived biomass increments illustrate that the forests at the Valles Caldera are considerably less productive during years of extreme drought and warmer than average temperatures. With future projections calling for consecutive years of extreme conditions in the American Southwest, this could have a substantial effect on the overall productivity of these forests.

Patterns of threshold evolution in polyphenic insects under different developmental models.

PubMed

Tomkins, Joseph L; Moczek, Armin P

2009-02-01

Two hypotheses address the evolution of polyphenic traits in insects. Under the developmental reprogramming model, individuals exceeding a threshold follow a different developmental pathway from individuals below the threshold. This decoupling is thought to free selection to independently hone alternative morphologies, increasing phenotypic plasticity and morphological diversity. Under the alternative model, extreme positive allometry explains the existence of alternative phenotypes and divergent phenotypes are developmentally coupled by a continuous reaction norm, such that selection on either morph acts on both. We test the hypothesis that continuous reaction norm polyphenisms, evolve through changes in the allometric parameters of even the smallest males with minimal trait expression, whereas threshold polyphenisms evolve independent of the allometric parameters of individuals below the threshold. We compare two polyphenic species; the dung beetle Onthophagus taurus, whose allometry has been modeled both as a threshold polyphenism and a continuous reaction norm and the earwig Forficula auricularia, whose allometry is best modeled with a discontinuous threshold. We find that across populations of both species, variation in forceps or horn allometry in minor males are correlated to the population's threshold. These findings suggest that regardless of developmental mode, alternative morphs do not evolve independently of one another.

The Neuroscience of Consumer Choice

PubMed Central

Hsu, Ming; Yoon, Carolyn

2015-01-01

We review progress and challenges relating to scientific and applied goals of the nascent field of consumer neuroscience. Scientifically, substantial progress has been made in understanding the neurobiology of choice processes. Further advances, however, require researchers to begin clarifying the set of developmental and cognitive processes that shape and constrain choices. First, despite the centrality of preferences in theories of consumer choice, we still know little about where preferences come from and the underlying developmental processes. Second, the role of attention and memory processes in consumer choice remains poorly understood, despite importance ascribed to them in interpreting data from the field. The applied goal of consumer neuroscience concerns our ability to translate this understanding to augment prediction at the population level. Although the use of neuroscientific data for market-level predictions remains speculative, there is growing evidence of superiority in specific cases over existing market research techniques. PMID:26665152

Toward understanding the evolution of vertebrate gene regulatory networks: comparative genomics and epigenomic approaches.

PubMed

Martinez-Morales, Juan R

2016-07-01

Vertebrates, as most animal phyla, originated >500 million years ago during the Cambrian explosion, and progressively radiated into the extant classes. Inferring the evolutionary history of the group requires understanding the architecture of the developmental programs that constrain the vertebrate anatomy. Here, I review recent comparative genomic and epigenomic studies, based on ChIP-seq and chromatin accessibility, which focus on the identification of functionally equivalent cis-regulatory modules among species. This pioneer work, primarily centered in the mammalian lineage, has set the groundwork for further studies in representative vertebrate and chordate species. Mapping of active regulatory regions across lineages will shed new light on the evolutionary forces stabilizing ancestral developmental programs, as well as allowing their variation to sustain morphological adaptations on the inherited vertebrate body plan. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.

The Intriguing Case of the (Almost) Dark Galaxy AGC 229385

NASA Astrophysics Data System (ADS)

Salzer, John

2015-10-01

The ALFALFA blind HI survey has catalogued tens of thousands of HI sources over 7000 square degrees of high Galactic latitude sky. While the vast majority of the sources in ALFALFA have optical counterparts in existing wide-field surveys like SDSS, a class of objects has been identified that have no obvious optical counterparts in existing catalogs. Dubbed almost dark galaxies, these objects represent an extreme in the continuum of galaxy properties, with the highest HI mass-to-optical light ratios ever measured. We propose to use HST to observe AGC 229385, an almost dark object found in deep WIYN imaging to have an ultra-low surface brightness stellar component with extremely blue colors. AGC 229385 falls well off of all galaxy scaling relationships, including the Baryonic Tully-Fisher relation. Ground-based optical and HI data have been able to identify this object as extreme, but are insufficient to constrain the properties of its stellar component or its distance - for this, we need HST. Our science goals are twofold: to better constrain the distance to AGC 229385, and to investigate the stellar population(s) in this mysterious object. The requested observations will not only provide crucial insight into the properties and evolution of this specific system but will also help us understand this important class of ultra low surface brightness, gas-rich galaxies. The proposed observations are designed to be exploratory, yet they promise to pay rich dividends for a modest investment in observing time.

Exploring the Extreme Universe with the Fermi Gamma-Ray Space Telescope

NASA Technical Reports Server (NTRS)

Thompson, D. J.

2010-01-01

Because high-energy gamma rays are produced by powerful sources, the Fermi Gamma-ray Space Telescope provides a window on extreme conditions in the Universe. Some key observations of the constantly changing gamma-ray sky include: (1) Gamma-rays from pulsars appear to come from a region well above the surface of the neutron star; (2) Multiwavelength studies of blazars show that simple models of jet emission are not always adequate to explain what is seen; (3) Gamma-ray bursts can constrain models of quantum gravity; (4) Cosmic-ray electrons at energies approaching 1 TeV suggest a local source for some of these particles.

Canine tooth size and fitness in male mandrills (Mandrillus sphinx).

PubMed

Leigh, Steven R; Setchell, Joanna M; Charpentier, Marie; Knapp, Leslie A; Wickings, E Jean

2008-07-01

Sexual selection theory explains the evolution of exaggerated male morphologies and weaponry, but the fitness consequences of developmental and age-related changes in these features remain poorly understood. This long-term study of mandrill monkeys (Mandrillus sphinx) demonstrates how age-related changes in canine tooth weaponry and adult canine size correlate closely with male lifetime reproductive success. Combining long-term demographic and morphometric data reveals that male fitness covaries simply and directly with canine ontogeny, adult maximum size, and wear. However, fitness is largely independent of other somatometrics. Male mandrills sire offspring almost exclusively when their canines exceed approximately 30 mm, or two-thirds of average adult value (45 mm). Moreover, sires have larger canines than nonsires. The tooth diminishes through wear as animals age, corresponding with, and perhaps influencing, reproductive senescence. These factors combine to constrain male reproductive opportunities to a brief timespan, defined by the period of maximum canine length. Sexually-selected weaponry, especially when it is nonrenewable like the primate canine tooth, is intimately tied to the male life course. Our analyses of this extremely dimorphic species indicate that sexual selection is closely intertwined with growth, development, and aging, pointing to new directions for sexual selection theory. Moreover, the primate canine tooth has potential as a simple mammalian system for testing genetically-based models of aging. Finally, the tooth may record details of life histories in fossil primates, especially when sexual selection has played a role in the evolution of dimorphism.

Developmental studies of the lamprey and hierarchical evolutionary steps towards the acquisition of the jaw

PubMed Central

Kuratani, Shigeru

2005-01-01

The evolution of animal morphology can be understood as a series of changes in developmental programs. Among vertebrates, some developmental stages are conserved across species, representing particular developmental constraints. One of the most conserved stages is the vertebrate pharyngula, in which similar embryonic morphology is observed and the Hox code is clearly expressed. The oral developmental program also appears to be constrained to some extent, as both its morphology and the the Hox-code-default state of the oropharyngeal region are well conserved between the lamprey and gnathostome embryos. These features do not by themselves explain the evolution of jaws, but should be regarded as a prerequisite for evolutionary diversification of the mandibular arch. By comparing the pharyngula morphology of the lamprey and gnathostomes, it has become clear that the oral pattern is not entirely identical; in particular, the positional differentiation of the rostral ectomesenchyme is shifted between these animals. Therefore, the jaw seems to have arisen as an evolutionary novelty by overriding ancestral constraints, a process in which morphological homologies are partially lost. This change involves the heterotopic shift of tissue interaction, which appears to have been preceded by the transition from monorhiny to diplorhiny, as well as separation of the hypophysis. When gene expression patterns are compared between the lamprey and gnathostomes, cell-autonomously functioning genes tend to be associated with identical cell types or equivalent anatomical domains, whereas growth-factor-encoding genes have changed their expression domains during evolution. Thus, the heterotopic evolution may be based on changes in the regulation of signalling-molecule-encoding genes. PMID:16313390

Mineralogy of iron sulfides in CM1 and CI1 lithologies of the Kaidun breccia: Records of extreme to intense hydrothermal alteration

NASA Astrophysics Data System (ADS)

Harries, Dennis; Zolensky, Michael E.

2016-06-01

The polymict Kaidun microbreccia contains lithologies of C-type chondrites with euhedral iron sulfide crystals of hydrothermal origin. Our FIB-TEM study reveals that acicular sulfides in a CM1 lithology are composed of Fe-rich pyrrhotite with nonintegral vacancy superstructures (NC-pyrrhotite), troilite, and pentlandite, all showing distinct exsolution textures. Based on phase relations in the Fe-Ni-S system, we constrain the temperature of formation of the originally homogeneous monosulfide solid solution to the range of 100-300 °C. In some crystals the exsolution of pentlandite and the microtextural equilibration was incomplete, probably due to rapid cooling. We use thermodynamic modeling to constrain the physicochemical conditions of the extreme hydrothermal alteration in this lithology. Unless the CM1 lithology was sourced from a large depth in the parent body (internal pressure >85 bar) or the temperatures were in the lower range of the interval determined, the water was likely present as vapor. Previously described light δ34S compositions of sulfides in Kaidun's CM1 lithology are likely due to the loss of 34S-enriched H2S during boiling. Platy sulfide crystals in an adjacent, intensely altered CI1 lithology are composed of Fe-poor, monoclinic 4C-pyrrhotite and NC-pyrrhotite and probably formed at lower temperatures and higher fS2 relative to the CM1 lithology. However, a better understanding of the stability of Fe-poor pyrrhotites at temperatures below 300 °C is required to better constrain these conditions.

X-ray Constrained Extremely Localized Molecular Orbitals: Theory and Critical Assessment of the New Technique.

PubMed

Genoni, Alessandro

2013-07-09

Following the X-ray constrained wave function approach proposed by Jayatilaka, we have devised a new technique that allows to extract molecular orbitals strictly localized on small molecular fragments from sets of experimental X-ray structure factors amplitudes. Since the novel strategy enables to obtain electron distributions that have quantum mechanical features and that can be easily interpreted in terms of traditional chemical concepts, the method can be also considered as a new useful tool for the determination and the analysis of charge densities from high-resolution X-ray experiments. In this paper, we describe in detail the theory of the new technique, which, in comparison to our preliminary work, has been improved both treating the effects of isotropic secondary extinctions and introducing a new protocol to halt the fitting procedure against the experimental X-ray scattering data. The performances of the novel strategy have been studied both in function of the basis-sets flexibility and in function of the quality of the considered crystallographic data. The tests performed on four different systems (α-glycine, l-cysteine, (aminomethyl)phosphonic acid and N-(trifluoromethyl)formamide) have shown that the achievement of good statistical agreements with the experimental measures mainly depends on the quality of the crystal structures (i.e., geometry positions and thermal parameters) used in the X-ray constrained calculations. Finally, given the reliable transferability of the obtained Extremely Localized Molecular Orbitals (ELMOs), we envisage to exploit the novel approach to construct new ELMOs databases suited to the development of linear-scaling methods for the refinement of macromolecular crystal structures.

Correlation Between Mothers' Depression and Developmental Delay in Infants Aged 6-18 Months.

PubMed

Vameghi, Roshanak; Amir Ali Akbari, Sedigheh; Sajjadi, Homeira; Sajedi, Firoozeh; Alavimajd, Hamid

2015-08-23

Regarding the importance of children's developmental status and various factors that delay their development, this study was conducted to examine the correlation between mothers' depression levels and the developmental delay in infants. This descriptive study was performed on 1053 mothers and their infants' age 6 to18 month-old in medical centers affiliated with Shahid Beheshti University of Medical Sciences, Iran, in 2014-2015. The participants were selected through multi-stage random sampling. The following instruments were used in this study: A demographic and obstetric specification questionnaire, infant specification questionnaire, the Beck Depression Inventory, and the Ages and Stages Questionnaire to determine the status of the children's development. The data were analyzed using SPSS19 software, Mann-Whitney; independent T-test and logistic-Regression tests were used. The results showed that 491 mothers (46.7%) suffered mild to extremely severe depression. The delay in infant development was 11.8%. The Mann-Whitney test showed a correlation between mothers' depression levels and developmental delay in infants (P=0.001). Moreover, there was a significant correlation between mothers' depression and developmental delays in gross-motor and problem-solving skills (P<0/05). In logistic model age of infants showed significant correlation with developmental delay (P=0.004 OR=1.07), but unwanted pregnancy, gender of infants, type of delivery and socioeconomic status had no correlation with developmental delay. Given the correlation between mothers' depression and infant development, it is recommended to screen mothers for depression in order to perform early interventions in developmental delay.

Relative impact of weather vs. fuels on fire regimes in coastal California

Treesearch

Jon E. Keeley

2008-01-01

Extreme fire weather is of over riding importance in determining fire behavior in coastal chaparral and on these landscapes fire suppression policy has not resulted in fire exclusion. There is regional variation in foehn winds, which are most important in southern California. Under these severe fire weather conditions fuel age does not constrain fire behavior. As a...

An approximate, maximum terminal velocity descent to a point

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eisler, G.R.; Hull, D.G.

1987-01-01

No closed form control solution exists for maximizing the terminal velocity of a hypersonic glider at an arbitrary point. As an alternative, this study uses neighboring extremal theory to provide a sampled data feedback law to guide the vehicle to a constrained ground range and altitude. The guidance algorithm is divided into two parts: 1) computation of a nominal, approximate, maximum terminal velocity trajectory to a constrained final altitude and computation of the resulting unconstrained groundrange, and 2) computation of the neighboring extremal control perturbation at the sample value of flight path angle to compensate for changes in the approximatemore » physical model and enable the vehicle to reach the on-board computed groundrange. The trajectories are characterized by glide and dive flight to the target to minimize the time spent in the denser parts of the atmosphere. The proposed on-line scheme successfully brings the final altitude and range constraints together, as well as compensates for differences in flight model, atmosphere, and aerodynamics at the expense of guidance update computation time. Comparison with an independent, parameter optimization solution for the terminal velocity is excellent. 6 refs., 3 figs.« less

Proximity Navigation of Highly Constrained Spacecraft

NASA Technical Reports Server (NTRS)

Scarritt, S.; Swartwout, M.

2007-01-01

Bandit is a 3-kg automated spacecraft in development at Washington University in St. Louis. Bandit's primary mission is to demonstrate proximity navigation, including docking, around a 25-kg student-built host spacecraft. However, because of extreme constraints in mass, power and volume, traditional sensing and actuation methods are not available. In particular, Bandit carries only 8 fixed-magnitude cold-gas thrusters to control its 6 DOF motion. Bandit lacks true inertial sensing, and the ability to sense position relative to the host has error bounds that approach the size of the Bandit itself. Some of the navigation problems are addressed through an extremely robust, error-tolerant soft dock. In addition, we have identified a control methodology that performs well in this constrained environment: behavior-based velocity potential functions, which use a minimum-seeking method similar to Lyapunov functions. We have also adapted the discrete Kalman filter for use on Bandit for position estimation and have developed a similar measurement vs. propagation weighting algorithm for attitude estimation. This paper provides an overview of Bandit and describes the control and estimation approach. Results using our 6DOF flight simulator are provided, demonstrating that these methods show promise for flight use.

Is it adaptive to disengage from demands of social change? Adjustment to developmental barriers in opportunity-deprived regions

PubMed Central

Silbereisen, Rainer K.; Heckhausen, Jutta

2010-01-01

This paper investigates how individuals deal with demands of social and economic change in the domains of work and family when opportunities for their mastery are unfavorable. Theoretical considerations and empirical research suggest that with unattainable goals and unmanageable demands motivational disengagement and self-protective cognitions bring about superior outcomes than continued goal striving. Building on research on developmental deadlines, this paper introduces the concept of developmental barriers to address socioeconomic conditions of severely constrained opportunities in certain geographical regions. Mixed-effects methods were used to model cross-level interactions between individual-level compensatory secondary control and regional-level opportunity structures in terms of social indicators for the economic prosperity and family friendliness. Results showed that disengagement was positively associated with general life satisfaction in regions that were economically devastated and has less than average services for families. In regions that were economically well off and family-friendly, the association was negative. Similar results were found for self-protection concerning domain-specific satisfaction with life. These findings suggest that compensatory secondary control can be an adaptive way of mastering a demand when primary control is not possible. PMID:21170393

The origin of the bird's beak: new insights from dinosaur incubation periods.

PubMed

Yang, Tzu-Ruei; Sander, P Martin

2018-05-01

The toothless beak of modern birds was considered as an adaption for feeding ecology; however, several recent studies suggested that developmental factors are also responsible for the toothless beak. Neontological and palaeontological studies have progressively uncovered how birds evolved toothless beaks and suggested that the multiple occurrences of complete edentulism in non-avian dinosaurs were the result of selection for specialized diets. Although developmental biology and ecological factors are not mutually exclusive, the conventional hypothesis that ecological factors account for the toothless beak appears insufficient. A recent study on dinosaur incubation period using embryonic teeth posited that tooth formation rate limits developmental speed, constraining toothed dinosaur incubation to slow reptilian rates. We suggest that selection for tooth loss was a side effect of selection for fast embryo growth and thus shorter incubation. This observation would also explain the multiple occurrences of tooth loss and beaks in non-avian dinosaur taxa crownward of Tyrannosaurus Whereas our hypothesis is an observation without any experimental supports, more studies of gene regulation of tooth formation in embryos would allow testing for the trade-off between incubation period and tooth development. © 2018 The Author(s).

Kinematic Constraints Associated with the Acquisition of Overarm Throwing Part II: Upper Extremity Actions

ERIC Educational Resources Information Center

Stodden, David F.; Langendorfer, Stephen J.; Fleisig, Glenn S.; Andrews, James R.

2006-01-01

The purposes of this study were to: (a) examine the differences within 11 specific kinematic variables and an outcome measure (ball velocity) associated with component developmental levels of humerus and forearm action (Roberton & Halverson, 1984), and (b) if the differences in kinematic variables were significantly associated with the differences…

Diversifying Theory and Science: Expanding the Boundaries of Empirically Supported Interventions in School Psychology.

ERIC Educational Resources Information Center

Kratochwill, Thomas R.; Stoiber, Karen Callan

2000-01-01

Developmental psychopathology and principles advance in Hughes' target article can be useful to promote development, evaluation, and application of empirically supported interventions (ESIs), but embracing a pathological framework is extremely limited given the diversity in theoretical approaches relevant to school-based ESIs. Argues that in order…

Genomic Sciences for Developmentalists: A Merge of Science and Practice

ERIC Educational Resources Information Center

Grigorenko, Elena L.

2015-01-01

The etiological forces of development have been a central question for the developmental sciences (however defined) since their crystallization as a distinct branch of scientific inquiry. Although the history of these sciences contains examples of extreme positions capitalizing on either the predominance of the genome (i.e., the accumulation of…

A Biosocial Developmental Model of Borderline Personality: Elaborating and Extending Linehan’s Theory

PubMed Central

Crowell, Sheila E.; Beauchaine, Theodore P.; Linehan, Marsha M.

2009-01-01

Over the past several decades, research has focused increasingly on developmental precursors to psychological disorders that were previously assumed to emerge only in adulthood. This change in focus follows from the recognition that complex transactions between biological vulnerabilities and psychosocial risk factors shape emotional and behavioral development beginning at conception. To date, however, empirical research on the development of borderline personality is extremely limited. Indeed, in the decade since M. M. Linehan initially proposed a biosocial model of the development of borderline personality disorder, there have been few attempts to test the model among at-risk youth. In this review, diverse literatures are reviewed that can inform understanding of the ontogenesis of borderline pathology, and testable hypotheses are proposed to guide future research with at-risk children and adolescents. One probable pathway is identified that leads to borderline personality disorder; it begins with early vulnerability, expressed initially as impulsivity and followed by heightened emotional sensitivity. These vulnerabilities are potentiated across development by environmental risk factors that give rise to more extreme emotional, behavioral, and cognitive dysregulation. PMID:19379027

A biosocial developmental model of borderline personality: Elaborating and extending Linehan's theory.

PubMed

Crowell, Sheila E; Beauchaine, Theodore P; Linehan, Marsha M

2009-05-01

Over the past several decades, research has focused increasingly on developmental precursors to psychological disorders that were previously assumed to emerge only in adulthood. This change in focus follows from the recognition that complex transactions between biological vulnerabilities and psychosocial risk factors shape emotional and behavioral development beginning at conception. To date, however, empirical research on the development of borderline personality is extremely limited. Indeed, in the decade since M. M. Linehan initially proposed a biosocial model of the development of borderline personality disorder, there have been few attempts to test the model among at-risk youth. In this review, diverse literatures are reviewed that can inform understanding of the ontogenesis of borderline pathology, and testable hypotheses are proposed to guide future research with at-risk children and adolescents. One probable pathway is identified that leads to borderline personality disorder; it begins with early vulnerability, expressed initially as impulsivity and followed by heightened emotional sensitivity. These vulnerabilities are potentiated across development by environmental risk factors that give rise to more extreme emotional, behavioral, and cognitive dysregulation. (PsycINFO Database Record (c) 2009 APA, all rights reserved).

Asymmetric Facial Bone Fragmentation Mirrors Asymmetric Distribution of Cranial Neuromasts in Blind Mexican Cavefish.

PubMed

Gross, Joshua B; Gangidine, Andrew; Powers, Amanda K

2016-11-01

Craniofacial asymmetry is a convergent trait widely distributed across animals that colonize the extreme cave environment. Although craniofacial asymmetry can be discerned easily, other complex phenotypes (such as sensory organ position and numerical variation) are challenging to score and compare. Certain bones of the craniofacial complex demonstrate substantial asymmetry, and co-localize to regions harboring dramatically expanded numbers of mechanosensory neuromasts. To determine if a relationship exists between this expansion and bone fragmentation in cavefish, we developed a quantitative measure of positional symmetry across the left-right axis. We found that three different cave-dwelling populations were significantly more asymmetric compared to surface-dwelling fish. Moreover, cave populations did not differ in the degree of neuromast asymmetry. This work establishes a method for quantifying symmetry of a complex phenotype, and demonstrates that facial bone fragmentation mirrors the asymmetric distribution of neuromasts in different cavefish populations. Further developmental studies will provide a clearer picture of the developmental and cellular changes that accompany this extreme phenotype, and help illuminate the genetic basis for facial asymmetry in vertebrates.

Constraining the rate of oceanic deoxygenation leading up to a Cretaceous Oceanic Anoxic Event (OAE-2: ~94 Ma)

PubMed Central

Ostrander, Chadlin M.; Owens, Jeremy D.; Nielsen, Sune G.

2017-01-01

The rates of marine deoxygenation leading to Cretaceous Oceanic Anoxic Events are poorly recognized and constrained. If increases in primary productivity are the primary driver of these episodes, progressive oxygen loss from global waters should predate enhanced carbon burial in underlying sediments—the diagnostic Oceanic Anoxic Event relic. Thallium isotope analysis of organic-rich black shales from Demerara Rise across Oceanic Anoxic Event 2 reveals evidence of expanded sediment-water interface deoxygenation ~43 ± 11 thousand years before the globally recognized carbon cycle perturbation. This evidence for rapid oxygen loss leading to an extreme ancient climatic event has timely implications for the modern ocean, which is already experiencing large-scale deoxygenation. PMID:28808684

Challenges and opportunities in developmental integrative physiology☆

PubMed Central

Mueller, C.A.; Eme, J.; Burggren, W.W.; Roghair, R.D.; Rundle, S.D.

2015-01-01

This review explores challenges and opportunities in developmental physiology outlined by a symposium at the 2014 American Physiological Society Intersociety Meeting: Comparative Approaches to Grand Challenges in Physiology. Across animal taxa, adverse embryonic/fetal environmental conditions can alter morphological and physiological phenotypes in juveniles or adults, and capacities for developmental plasticity are common phenomena. Human neonates with body sizes at the extremes of perinatal growth are at an increased risk of adult disease, particularly hypertension and cardiovascular disease. There are many rewarding areas of current and future research in comparative developmental physiology. We present key mechanisms, models, and experimental designs that can be used across taxa to investigate patterns in, and implications of, the development of animal phenotypes. Intraspecific variation in the timing of developmental events can be increased through developmental plasticity (heterokairy), and could provide the raw material for selection to produce heterochrony — an evolutionary change in the timing of developmental events. Epigenetics and critical windows research recognizes that in ovo or fetal development represent a vulnerable period in the life history of an animal, when the developing organism may be unable to actively mitigate environmental perturbations. ‘Critical windows’ are periods of susceptibility or vulnerability to environmental or maternal challenges, periods when recovery from challenge is possible, and periods when the phenotype or epigenome has been altered. Developmental plasticity may allow survival in an altered environment, but it also has possible long-term consequences for the animal. “Catch-up growth” in humans after the critical perinatal window has closed elicits adult obesity and exacerbates a programmed hypertensive phenotype (one of many examples of “fetal programing”). Grand challenges for developmental physiology include integrating variation in developmental timing within and across generations, applying multiple stressor dosages and stressor exposure at different developmental timepoints, assessment of epigenetic and parental influences, developing new animal models and techniques, and assessing and implementing these designs and models in human health and development. PMID:25711780

Cognitive Plasticity and Cortical Modules

PubMed Central

Mercado, Eduardo

2009-01-01

Some organisms learn to calculate, accumulate knowledge, and communicate in ways that others do not. What factors determine which intellectual abilities a particular species or individual can easily acquire? I propose that cognitive-skill learning capacity reflects (a) the availability of specialized cortical circuits, (b) the flexibility with which cortical activity is coordinated, and (c) the customizability of cortical networks. This framework can potentially account for differences in learning capacity across species, individuals, and developmental stages. Understanding the mechanisms that constrain cognitive plasticity is fundamental to developing new technologies and educational practices that maximize intellectual advancements. PMID:19750239

Cognitive Plasticity and Cortical Modules.

PubMed

Mercado, Eduardo

2009-06-01

Some organisms learn to calculate, accumulate knowledge, and communicate in ways that others do not. What factors determine which intellectual abilities a particular species or individual can easily acquire? I propose that cognitive-skill learning capacity reflects (a) the availability of specialized cortical circuits, (b) the flexibility with which cortical activity is coordinated, and (c) the customizability of cortical networks. This framework can potentially account for differences in learning capacity across species, individuals, and developmental stages. Understanding the mechanisms that constrain cognitive plasticity is fundamental to developing new technologies and educational practices that maximize intellectual advancements.

Beryllium and Boron abundances in population II stars

NASA Technical Reports Server (NTRS)

1995-01-01

The scientific focus of this program was to undertake UV spectroscopic abundance analyses of extremely metal poor stars with attention to determining abundances of light elements such as beryllium and boron. The abundances are likely to reflect primordial abundances within the early galaxy and help to constrain models for early galactic nucleosynthesis. The general metal abundances of these stars are also important for understanding stellar evolution.

The cold-water climate shield: Delineating refugia for preserving salmonid fishes through the 21st century

Treesearch

Daniel J. Isaak; Michael K. Young; David E. Nagel; Dona L. Horan; Matthew C. Groce

2015-01-01

The distribution and future fate of ectothermic organisms in a warming world will be dictated by thermalscapes across landscapes. That is particularly true for stream fishes and cold-water species like trout, salmon, and char that are already constrained to high elevations and latitudes. The extreme climates in those environments also preclude invasions by most non-...

Compact genome of the Antarctic midge is likely an adaptation to an extreme environment.

PubMed

Kelley, Joanna L; Peyton, Justin T; Fiston-Lavier, Anna-Sophie; Teets, Nicholas M; Yee, Muh-Ching; Johnston, J Spencer; Bustamante, Carlos D; Lee, Richard E; Denlinger, David L

2014-08-12

The midge, Belgica antarctica, is the only insect endemic to Antarctica, and thus it offers a powerful model for probing responses to extreme temperatures, freeze tolerance, dehydration, osmotic stress, ultraviolet radiation and other forms of environmental stress. Here we present the first genome assembly of an extremophile, the first dipteran in the family Chironomidae, and the first Antarctic eukaryote to be sequenced. At 99 megabases, B. antarctica has the smallest insect genome sequenced thus far. Although it has a similar number of genes as other Diptera, the midge genome has very low repeat density and a reduction in intron length. Environmental extremes appear to constrain genome architecture, not gene content. The few transposable elements present are mainly ancient, inactive retroelements. An abundance of genes associated with development, regulation of metabolism and responses to external stimuli may reflect adaptations for surviving in this harsh environment.

Compact genome of the Antarctic midge is likely an adaptation to an extreme environment

PubMed Central

Kelley, Joanna L.; Peyton, Justin T.; Fiston-Lavier, Anna-Sophie; Teets, Nicholas M.; Yee, Muh-Ching; Johnston, J. Spencer; Bustamante, Carlos D.; Lee, Richard E.; Denlinger, David L.

2014-01-01

The midge, Belgica antarctica, is the only insect endemic to Antarctica, and thus it offers a powerful model for probing responses to extreme temperatures, freeze tolerance, dehydration, osmotic stress, ultraviolet radiation and other forms of environmental stress. Here we present the first genome assembly of an extremophile, the first dipteran in the family Chironomidae, and the first Antarctic eukaryote to be sequenced. At 99 megabases, B. antarctica has the smallest insect genome sequenced thus far. Although it has a similar number of genes as other Diptera, the midge genome has very low repeat density and a reduction in intron length. Environmental extremes appear to constrain genome architecture, not gene content. The few transposable elements present are mainly ancient, inactive retroelements. An abundance of genes associated with development, regulation of metabolism and responses to external stimuli may reflect adaptations for surviving in this harsh environment. PMID:25118180

Beyond High School: A Look Back on Student and Teacher Perspectives on Their Participation with Inclusive Friendship Programs in High School

ERIC Educational Resources Information Center

Regester, April

2009-01-01

Research has shown inclusive education to be extremely beneficial for students with developmental disabilities. One reported benefit is the increased accessibility to typical peers with the implication of increased opportunities to develop meaningful friendships. Many researchers and educators have developed strategies to help facilitate the…

TRANSGENERATIONAL AND DEVELOPMENTAL EXPOSURE OF JAPANESE MEDAKA (ORYZIAS LATIPES) TO ETHINYLESTRADIOL RESULTS IN ENDOCRINE AND REPRODUCTIVE DIFFERENCES IN THE RESPONSE TO ETHINYLESTRADIOL AS ADULTS

EPA Science Inventory

17a-Ethinylestradiol (EE), a synthetic estrogen found in birth control pills, has been detected in the effluent of municipal wastewater treatment plants in several countries. Because EE was designed to be extremely potent at the estrogen receptor (ER), environmental exposure to l...

The Process of Curriculum Development and Implementation for an Adolescent Health Project in Middle Schools

ERIC Educational Resources Information Center

Bindler, Ruth C.; Goetz, Summer; Butkus, Sue Nicholson; Power, Thomas G.; Ullrich-French, Sarah; Steele, Michael

2012-01-01

Childhood obesity has reached epidemic levels in developed countries and is showing no signs of abating. The causes of obesity in adolescence are extremely complex, and therefore approaches to prevention and treatments must be multifaceted. Early adolescence is a developmental period when youth are becoming more independent, are influenced by…

Effortful Control and Adaptive Functioning of Homeless Children: Variable-Focused and Person-Focused Analyses

ERIC Educational Resources Information Center

Obradovic, Jelena

2010-01-01

Homeless children show significant developmental delays across major domains of adaptation, yet research on protective processes that may contribute to resilient adaptation in this highly disadvantaged group of children is extremely rare. This study examined the role of effortful control for adaption in 58 homeless children, ages 5-6, during their…

Toddlers with Williams Syndrome Process Upright but Not Inverted Faces Holistically

ERIC Educational Resources Information Center

Cashon, Cara H.; Ha, Oh-Ryeong; DeNicola, Christopher A.; Mervis, Carolyn B.

2013-01-01

Holistic processing of upright, but not inverted, faces is a marker of perceptual expertise for faces. This pattern is shown by typically developing individuals beginning at age 7 months. Williams syndrome (WS) is a rare neurogenetic developmental disorder characterized by extreme interest in faces from a very young age. Research on the effects of…

Rhythmic grouping biases constrain infant statistical learning

PubMed Central

Hay, Jessica F.; Saffran, Jenny R.

2012-01-01

Linguistic stress and sequential statistical cues to word boundaries interact during speech segmentation in infancy. However, little is known about how the different acoustic components of stress constrain statistical learning. The current studies were designed to investigate whether intensity and duration each function independently as cues to initial prominence (trochaic-based hypothesis) or whether, as predicted by the Iambic-Trochaic Law (ITL), intensity and duration have characteristic and separable effects on rhythmic grouping (ITL-based hypothesis) in a statistical learning task. Infants were familiarized with an artificial language (Experiments 1 & 3) or a tone stream (Experiment 2) in which there was an alternation in either intensity or duration. In addition to potential acoustic cues, the familiarization sequences also contained statistical cues to word boundaries. In speech (Experiment 1) and non-speech (Experiment 2) conditions, 9-month-old infants demonstrated discrimination patterns consistent with an ITL-based hypothesis: intensity signaled initial prominence and duration signaled final prominence. The results of Experiment 3, in which 6.5-month-old infants were familiarized with the speech streams from Experiment 1, suggest that there is a developmental change in infants’ willingness to treat increased duration as a cue to word offsets in fluent speech. Infants’ perceptual systems interact with linguistic experience to constrain how infants learn from their auditory environment. PMID:23730217

CONSTRAINING SOLAR FLARE DIFFERENTIAL EMISSION MEASURES WITH EVE AND RHESSI

DOE Office of Scientific and Technical Information (OSTI.GOV)

Caspi, Amir; McTiernan, James M.; Warren, Harry P.

2014-06-20

Deriving a well-constrained differential emission measure (DEM) distribution for solar flares has historically been difficult, primarily because no single instrument is sensitive to the full range of coronal temperatures observed in flares, from ≲2 to ≳50 MK. We present a new technique, combining extreme ultraviolet (EUV) spectra from the EUV Variability Experiment (EVE) onboard the Solar Dynamics Observatory with X-ray spectra from the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI), to derive, for the first time, a self-consistent, well-constrained DEM for jointly observed solar flares. EVE is sensitive to ∼2-25 MK thermal plasma emission, and RHESSI to ≳10 MK; together, the twomore » instruments cover the full range of flare coronal plasma temperatures. We have validated the new technique on artificial test data, and apply it to two X-class flares from solar cycle 24 to determine the flare DEM and its temporal evolution; the constraints on the thermal emission derived from the EVE data also constrain the low energy cutoff of the non-thermal electrons, a crucial parameter for flare energetics. The DEM analysis can also be used to predict the soft X-ray flux in the poorly observed ∼0.4-5 nm range, with important applications for geospace science.« less

Building blocks of a fish head: Developmental and variational modularity in a complex system.

PubMed

Lehoux, Caroline; Cloutier, Richard

2015-11-01

Evolution of the vertebrate skull is developmentally constrained by the interactions among its anatomical systems, such as the dermatocranium and the sensory system. The interaction between the dermal bones and lateral line canals has been debated for decades but their morphological integration has never been tested. An ontogenetic series of 97 juvenile and adult Amia calva (Actinopterygii) was used to describe the patterning and modularity of sensory lateral line canals and their integration with supporting cranial bones. Developmental modules were tested for the otic canal and supratemporal commissure by computing correlations in the branching sequence of groups of pores. Landmarks were digitized on 25 specimens to test a priori hypotheses of variational and developmental modularity at the level of canals and dermal bones. Branching sequence suggests a specific patterning supported by significant positive correlations in the sequence of appearance of branches between bilateral sides. Differences in patterning between the otic canal and the supratemporal commissure and tests of modularity with geometric morphometrics suggest that both canals form distinct modules. The integration between bones and canals was insufficient to detect a module. However, both components were not independent. Groups of pores tended to disappear without affecting other groups of pores suggesting that they are quasi-independent units acting as modules. This study provides evidence of a hierarchical organization for the modular sensory system that could explain variation of pattern of canals among species and their association with dermal bones. © 2015 Wiley Periodicals, Inc.

Segmentation in cohesive systems constrained by elastic environments

NASA Astrophysics Data System (ADS)

Novak, I.; Truskinovsky, L.

2017-04-01

The complexity of fracture-induced segmentation in elastically constrained cohesive (fragile) systems originates from the presence of competing interactions. The role of discreteness in such phenomena is of interest in a variety of fields, from hierarchical self-assembly to developmental morphogenesis. In this paper, we study the analytically solvable example of segmentation in a breakable mass-spring chain elastically linked to a deformable lattice structure. We explicitly construct the complete set of local minima of the energy in this prototypical problem and identify among them the states corresponding to the global energy minima. We show that, even in the continuum limit, the dependence of the segmentation topology on the stretching/pre-stress parameter in this problem takes the form of a devil's type staircase. The peculiar nature of this staircase, characterized by locking in rational microstructures, is of particular importance for biological applications, where its structure may serve as an explanation of the robustness of stress-driven segmentation. This article is part of the themed issue 'Patterning through instabilities in complex media: theory and applications.'

Detection of photosynthetic responses of cool-temperate forests following extreme climate events using Bayesian inversion

NASA Astrophysics Data System (ADS)

Toda, M.; Knohl, A.; Herbst, M.; Keenan, T. F.; Yokozawa, M.

2016-12-01

The increase in extreme climate events associated with ongoing global warming may create severe damage to terrestrial ecosystems, changing plant structure and the eco-physiological functions that regulate ecosystem carbon exchange. However, most damage is usually due to moderate, rather than catastrophic, disturbances. The nature of plant functional responses to such disturbances, and the resulting effects on the terrestrial carbon cycle, remain poorly understood. To unravel the scientific question, tower-based eddy covariance data in the cool-temperate forests were used to constrain plant eco-physiological parameters in a persimoneous ecosystem model that may have affected carbon dynamics following extreme climate events using the statistic Bayesian inversion approach. In the present study, we raised two types of extreme events relevant for cool-temperate regions, i.e. a typhoon with mechanistic foliage destraction and a heat wave with severe drought. With appropriate evaluation of parameter and predictive uncertainties, the inversion analysis shows annual trajectory of activated photosynthetic responses following climate extremes compared the pre-disturbance state in each forest. We address that forests with moderate disturbance show substantial and rapid photosynthetic recovery, enhanced productivity, and, thus, ecosystem carbon exchange, although the effect of extreme climatic events varies depending on the stand successional phase and the type, intensity, timing and legacy of the disturbance.

Precipitation extreme changes exceeding moisture content increases in MIROC and IPCC climate models

PubMed Central

Sugiyama, Masahiro; Shiogama, Hideo; Emori, Seita

2010-01-01

Precipitation extreme changes are often assumed to scale with, or are constrained by, the change in atmospheric moisture content. Studies have generally confirmed the scaling based on moisture content for the midlatitudes but identified deviations for the tropics. In fact half of the twelve selected Intergovernmental Panel on Climate Change (IPCC) models exhibit increases faster than the climatological-mean precipitable water change for high percentiles of tropical daily precipitation, albeit with significant intermodel scatter. Decomposition of the precipitation extreme changes reveals that the variations among models can be attributed primarily to the differences in the upward velocity. Both the amplitude and vertical profile of vertical motion are found to affect precipitation extremes. A recently proposed scaling that incorporates these dynamical effects can capture the basic features of precipitation changes in both the tropics and midlatitudes. In particular, the increases in tropical precipitation extremes significantly exceed the precipitable water change in Model for Interdisciplinary Research on Climate (MIROC), a coupled general circulation model with the highest resolution among IPCC climate models whose precipitation characteristics have been shown to reasonably match those of observations. The expected intensification of tropical disturbances points to the possibility of precipitation extreme increases beyond the moisture content increase as is found in MIROC and some of IPCC models. PMID:20080720

Properties of an eclipsing double white dwarf binary NLTT 11748

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaplan, David L.; Walker, Arielle N.; Marsh, Thomas R.

2014-01-10

We present high-quality ULTRACAM photometry of the eclipsing detached double white dwarf binary NLTT 11748. This system consists of a carbon/oxygen white dwarf and an extremely low mass (<0.2 M {sub ☉}) helium-core white dwarf in a 5.6 hr orbit. To date, such extremely low-mass white dwarfs, which can have thin, stably burning outer layers, have been modeled via poorly constrained atmosphere and cooling calculations where uncertainties in the detailed structure can strongly influence the eventual fates of these systems when mass transfer begins. With precise (individual precision ≈1%), high-cadence (≈2 s), multicolor photometry of multiple primary and secondary eclipsesmore » spanning >1.5 yr, we constrain the masses and radii of both objects in the NLTT 11748 system to a statistical uncertainty of a few percent. However, we find that overall uncertainty in the thickness of the envelope of the secondary carbon/oxygen white dwarf leads to a larger (≈13%) systematic uncertainty in the primary He WD's mass. Over the full range of possible envelope thicknesses, we find that our primary mass (0.136-0.162 M {sub ☉}) and surface gravity (log (g) = 6.32-6.38; radii are 0.0423-0.0433 R {sub ☉}) constraints do not agree with previous spectroscopic determinations. We use precise eclipse timing to detect the Rømer delay at 7σ significance, providing an additional weak constraint on the masses and limiting the eccentricity to ecos ω = (– 4 ± 5) × 10{sup –5}. Finally, we use multicolor data to constrain the secondary's effective temperature (7600 ± 120 K) and cooling age (1.6-1.7 Gyr).« less

Using surface displacement derived from GRACE to constrain the water loading signal in cGPS measurements in the Amazon Basin

NASA Astrophysics Data System (ADS)

Jose, L.; Bennett, R. A.; Harig, C.

2017-12-01

Currently, cGPS data is well suited to track vertical changes in the Earth's surface. However, there are annual, semi-annual, and interannual signals within cGPS time series that are not well constrained. We hypothesize that these signals are primarily due to water loading. If this is the case, the conventional method of modeling cGPS data as an annual or semiannual sinusoid falls short, as such models cannot accurately capture all variations in surface displacement, especially those due to extreme hydrologic events. We believe that we can better correct the cGPS time series with another method we are developing wherein we use a time series of surface displacement derived from the GRACE geopotential field instead of a sinusoidal model to correct the data. Currently, our analysis is constrained to the Amazon Basin, where the signal due to water loading is large enough to appear in both the GRACE and cGPS measurements. The vertical signal from cGPS stations across the Amazon Basin show an apparent spatial correlation, which further supports our idea that these signals are due to a regional water loading signal. In our preliminary research, we used tsview for Matlab to find that the WRMS of the corrected cGPS time series can be reduced as much as 30% from the model corrected data to the GRACE corrected data. The Amazon, like many places around the world, has experienced extreme drought, in 2005, 2010, and recently in 2015. In addition to making the cGPS vertical signal more robust, the method we are developing has the potential to help us understand the effects of these weather events and track trends in water loading.

Constraints on dark matter from intergalactic radiation

NASA Technical Reports Server (NTRS)

Overduin, J. M.; Wesson, P. S.

1992-01-01

Several of the dark matter candidates that have been proposed are believed to be unstable to decay, which would contribute photons to the radiation field between galaxies. The main candidates of this type are light neutrinos and axions, primordial mini-black holes, and a nonzero 'vacuum' energy. All of these can be constrained in nature by observational data on the extragalactic background light and the microwave background radiation. Black holes and the vacuum can be ruled out as significant contributors to the 'missing mass'. Light axions are also unlikely candidates; however, those with extremely small rest energies (the so-called 'invisible' axions) remain feasible. Light neutrinos, like those proposed by Sciama, are marginally viable. In general, we believe that the intergalactic radiation field is an important way of constraining all types of dark matter.

Refining multi-model projections of temperature extremes by evaluation against land-atmosphere coupling diagnostics

NASA Astrophysics Data System (ADS)

Sippel, Sebastian; Zscheischler, Jakob; Mahecha, Miguel D.; Orth, Rene; Reichstein, Markus; Vogel, Martha; Seneviratne, Sonia I.

2017-05-01

The Earth's land surface and the atmosphere are strongly interlinked through the exchange of energy and matter. This coupled behaviour causes various land-atmosphere feedbacks, and an insufficient understanding of these feedbacks contributes to uncertain global climate model projections. For example, a crucial role of the land surface in exacerbating summer heat waves in midlatitude regions has been identified empirically for high-impact heat waves, but individual climate models differ widely in their respective representation of land-atmosphere coupling. Here, we compile an ensemble of 54 combinations of observations-based temperature (T) and evapotranspiration (ET) benchmarking datasets and investigate coincidences of T anomalies with ET anomalies as a proxy for land-atmosphere interactions during periods of anomalously warm temperatures. First, we demonstrate that a large fraction of state-of-the-art climate models from the Coupled Model Intercomparison Project (CMIP5) archive produces systematically too frequent coincidences of high T anomalies with negative ET anomalies in midlatitude regions during the warm season and in several tropical regions year-round. These coincidences (high T, low ET) are closely related to the representation of temperature variability and extremes across the multi-model ensemble. Second, we derive a land-coupling constraint based on the spread of the T-ET datasets and consequently retain only a subset of CMIP5 models that produce a land-coupling behaviour that is compatible with these benchmark estimates. The constrained multi-model simulations exhibit more realistic temperature extremes of reduced magnitude in present climate in regions where models show substantial spread in T-ET coupling, i.e. biases in the model ensemble are consistently reduced. Also the multi-model simulations for the coming decades display decreased absolute temperature extremes in the constrained ensemble. On the other hand, the differences between projected and present-day climate extremes are affected to a lesser extent by the applied constraint, i.e. projected changes are reduced locally by around 0.5 to 1 °C - but this remains a local effect in regions that are highly sensitive to land-atmosphere coupling. In summary, our approach offers a physically consistent, diagnostic-based avenue to evaluate multi-model ensembles and subsequently reduce model biases in simulated and projected extreme temperatures.

OCO-2 Column Carbon Dioxide and Biometric Data Jointly Constrain Parameterization and Projection of a Global Land Model

NASA Astrophysics Data System (ADS)

Shi, Z.; Crowell, S.; Luo, Y.; Rayner, P. J.; Moore, B., III

2015-12-01

Uncertainty in predicted carbon-climate feedback largely stems from poor parameterization of global land models. However, calibration of global land models with observations has been extremely challenging at least for two reasons. First we lack global data products from systematical measurements of land surface processes. Second, computational demand is insurmountable for estimation of model parameter due to complexity of global land models. In this project, we will use OCO-2 retrievals of dry air mole fraction XCO2 and solar induced fluorescence (SIF) to independently constrain estimation of net ecosystem exchange (NEE) and gross primary production (GPP). The constrained NEE and GPP will be combined with data products of global standing biomass, soil organic carbon and soil respiration to improve the community land model version 4.5 (CLM4.5). Specifically, we will first develop a high fidelity emulator of CLM4.5 according to the matrix representation of the terrestrial carbon cycle. It has been shown that the emulator fully represents the original model and can be effectively used for data assimilation to constrain parameter estimation. We will focus on calibrating those key model parameters (e.g., maximum carboxylation rate, turnover time and transfer coefficients of soil carbon pools, and temperature sensitivity of respiration) for carbon cycle. The Bayesian Markov chain Monte Carlo method (MCMC) will be used to assimilate the global databases into the high fidelity emulator to constrain the model parameters, which will be incorporated back to the original CLM4.5. The calibrated CLM4.5 will be used to make scenario-based projections. In addition, we will conduct observing system simulation experiments (OSSEs) to evaluate how the sampling frequency and length could affect the model constraining and prediction.

Extremely Lightweight Intrusion Detection (ELIDe)

DTIC Science & Technology

2013-12-01

devices that would be more commonly found in a dynamic tactical environment. As a point of reference, the Raspberry Pi single-chip computer (4) is...the ELIDe application onto a resource- constrained hardware platform more likely to be used in a mobile tactical network, and the Raspberry Pi was...chosen as that representative platform. ELIDe was successfully tested on a Raspberry Pi , its throughput was benchmarked at approximately 8.3 megabits

Developmental Changes in Early Comprehension and Production of Drawings: Evidence From Two Socioeconomic Backgrounds.

PubMed

Salsa, Analía M; Vivaldi, Romina

2017-01-01

Two studies examined young children's comprehension and production of representational drawings across and within 2 socioeconomic strata (SES). Participants were 130 middle-SES (MSES) and low-SES (LSES) Argentine children, from 30 to 60 months old, given a task with 2 phases, production and comprehension. The production phase assessed free drawing and drawings from simple 3-dimensional objects (model drawing); the comprehension phase assessed children's understanding of an adult's line drawings of the objects. MSES children solved the comprehension phase of the task within the studied age range; representational production emerged first in model drawing (42 months) and later in free drawing (48 months). The same developmental pathway was observed in LSES children but with a clear asynchrony in the age of onset of comprehension and production: Children understood the symbolic nature of drawings at 42 months old and the first representational drawings were found at 60 months old. These results provide empirical evidence that support the crucial influence of social experiences by organizing and constraining graphic development.

Endosperm turgor pressure decreases during early Arabidopsis seed development.

PubMed

Beauzamy, Léna; Fourquin, Chloé; Dubrulle, Nelly; Boursiac, Yann; Boudaoud, Arezki; Ingram, Gwyneth

2016-09-15

In Arabidopsis, rapid expansion of the coenocytic endosperm after fertilisation has been proposed to drive early seed growth, which is in turn constrained by the seed coat. This hypothesis implies physical heterogeneity between the endosperm and seed coat compartments during early seed development, which to date has not been demonstrated. Here, we combine tissue indentation with modelling to show that the physical properties of the developing seed are consistent with the hypothesis that elevated endosperm-derived turgor pressure drives early seed expansion. We provide evidence that whole-seed turgor is generated by the endosperm at early developmental stages. Furthermore, we show that endosperm cellularisation and seed growth arrest are associated with a drop in endosperm turgor pressure. Finally, we demonstrate that this decrease is perturbed when the function of POLYCOMB REPRESSIVE COMPLEX 2 is lost, suggesting that turgor pressure changes could be a target of genomic imprinting. Our results indicate a developmental role for changes in endosperm turgor pressure in the Arabidopsis seed. © 2016. Published by The Company of Biologists Ltd.

The evolution of phenotypic correlations and ‘developmental memory’

PubMed Central

Watson, Richard A.; Wagner, Günter P.; Pavlicev, Mihaela; Weinreich, Daniel M.; Mills, Rob

2014-01-01

Development introduces structured correlations among traits that may constrain or bias the distribution of phenotypes produced. Moreover, when suitable heritable variation exists, natural selection may alter such constraints and correlations, affecting the phenotypic variation available to subsequent selection. However, exactly how the distribution of phenotypes produced by complex developmental systems can be shaped by past selective environments is poorly understood. Here we investigate the evolution of a network of recurrent non-linear ontogenetic interactions, such as a gene regulation network, in various selective scenarios. We find that evolved networks of this type can exhibit several phenomena that are familiar in cognitive learning systems. These include formation of a distributed associative memory that can ‘store’ and ‘recall’ multiple phenotypes that have been selected in the past, recreate complete adult phenotypic patterns accurately from partial or corrupted embryonic phenotypes, and ‘generalise’ (by exploiting evolved developmental modules) to produce new combinations of phenotypic features. We show that these surprising behaviours follow from an equivalence between the action of natural selection on phenotypic correlations and associative learning, well-understood in the context of neural networks. This helps to explain how development facilitates the evolution of high-fitness phenotypes and how this ability changes over evolutionary time. PMID:24351058

The Multiple Dimensions of Child Abuse and Neglect: New Insights into an Old Problem. Child Trends Research Brief.

ERIC Educational Resources Information Center

Chalk, Rosemary; Gibbons, Alison; Scarupa, Harriet J.

Despite persistent media headlines about extreme cases of child abuse and neglect, the public remains largely uninformed about the developmental status of children affected by this tragic problem. The research brief draws on available data and recent research to summarize what is known about these outcomes in several critical areasphysical and…

Coexistence of true talon cusp and double dens invaginatus in a single tooth: a rare case report and review of the literature.

PubMed

Nu Nu Lwin, Hnin; Phyo Kyaw, Pyae; Wai Yan Myint Thu, Sai

2017-12-01

Co-occurrence of a talon cusp and double dens invaginatus is an extremely rare developmental dental anomaly. This case report represents a talon cusp with two dens invaginatus on a maxillary right lateral incisor. Early identification is needed for prevention of potential problems on the affected or opposing tooth.

Toxic Stress: Implications for Policy & Practice. An Interview with Developmental Psychologist Megan R. Gunnar

ERIC Educational Resources Information Center

Gunnar, Megan R.

2006-01-01

A growing body of science shows the critical effects of an extreme and sustained stressful environment for children on their developing brain architecture and the expression of genes in later life. Toxic stress can shift the brain into surviving in a way that's more rigid and less adaptive. For example, as a result of biologically altered brain…

Developmental constraints in cave beetles

PubMed Central

Cieslak, Alexandra; Fresneda, Javier; Ribera, Ignacio

2014-01-01

In insects, whilst variations in life cycles are common, the basic patterns typical for particular groups remain generally conserved. One of the more extreme modifications is found in some subterranean beetles of the tribe Leptodirini, in which the number of larval instars is reduced from the ancestral three to two and ultimately one, which is not active and does not feed. We analysed all available data on the duration and size of the different developmental stages and compared them in a phylogenetic context. The total duration of development was found to be strongly conserved, irrespective of geographical location, habitat type, number of instars and feeding behaviour of the larvae, with a single alteration of the developmental pattern in a clade of cave species in southeast France. We also found a strong correlation of the size of the first instar larva with adult size, again regardless of geographical location, ecology and type of life cycle. Both results suggest the presence of deeply conserved constraints in the timing and energy requirements of larval development. Past focus on more apparent changes, such as the number of larval instars, may mask more deeply conserved ontogenetic patterns in developmental timing. PMID:25354919

Developmental kinesiology: three levels of motor control in the assessment and treatment of the motor system.

PubMed

Kobesova, Alena; Kolar, Pavel

2014-01-01

Three levels of sensorimotor control within the central nervous system (CNS) can be distinguished. During the neonatal stage, general movements and primitive reflexes are controlled at the spinal and brain stem levels. Analysis of the newborn's spontaneous general movements and the assessment of primitive reflexes is crucial in the screening and early recognition of a risk for abnormal development. Following the newborn period, the subcortical level of the CNS motor control emerges and matures mainly during the first year of life. This allows for basic trunk stabilization, a prerequisite for any phasic movement and for the locomotor function of the extremities. At the subcortical level, orofacial muscles and afferent information are automatically integrated within postural-locomotor patterns. Finally, the cortical (the highest) level of motor control increasingly becomes activated. Cortical control is important for the individual qualities and characteristics of movement. It also allows for isolated segmental movement and relaxation. A child with impaired cortical motor control may be diagnosed with developmental dyspraxia or developmental coordination disorder. Human ontogenetic models, i.e., developmental motor patterns, can be used in both the diagnosis and treatment of locomotor system dysfunction. Copyright © 2013 Elsevier Ltd. All rights reserved.

Identifying candidate genes affecting developmental time in Drosophila melanogaster: pervasive pleiotropy and gene-by-environment interaction

PubMed Central

Mensch, Julián; Lavagnino, Nicolás; Carreira, Valeria Paula; Massaldi, Ana; Hasson, Esteban; Fanara, Juan José

2008-01-01

Background Understanding the genetic architecture of ecologically relevant adaptive traits requires the contribution of developmental and evolutionary biology. The time to reach the age of reproduction is a complex life history trait commonly known as developmental time. In particular, in holometabolous insects that occupy ephemeral habitats, like fruit flies, the impact of developmental time on fitness is further exaggerated. The present work is one of the first systematic studies of the genetic basis of developmental time, in which we also evaluate the impact of environmental variation on the expression of the trait. Results We analyzed 179 co-isogenic single P[GT1]-element insertion lines of Drosophila melanogaster to identify novel genes affecting developmental time in flies reared at 25°C. Sixty percent of the lines showed a heterochronic phenotype, suggesting that a large number of genes affect this trait. Mutant lines for the genes Merlin and Karl showed the most extreme phenotypes exhibiting a developmental time reduction and increase, respectively, of over 2 days and 4 days relative to the control (a co-isogenic P-element insertion free line). In addition, a subset of 42 lines selected at random from the initial set of 179 lines was screened at 17°C. Interestingly, the gene-by-environment interaction accounted for 52% of total phenotypic variance. Plastic reaction norms were found for a large number of developmental time candidate genes. Conclusion We identified components of several integrated time-dependent pathways affecting egg-to-adult developmental time in Drosophila. At the same time, we also show that many heterochronic phenotypes may arise from changes in genes involved in several developmental mechanisms that do not explicitly control the timing of specific events. We also demonstrate that many developmental time genes have pleiotropic effects on several adult traits and that the action of most of them is sensitive to temperature during development. Taken together, our results stress the need to take into account the effect of environmental variation and the dynamics of gene interactions on the genetic architecture of this complex life-history trait. PMID:18687152

Extremely preterm infants small for gestational age are at risk for motor impairment at 3 years corrected age.

PubMed

Kato, Takeshi; Mandai, Tsurue; Iwatani, Sota; Koda, Tsubasa; Nagasaka, Miwako; Fujita, Kaori; Kurokawa, Daisuke; Yamana, Keiji; Nishida, Kosuke; Taniguchi-Ikeda, Mariko; Tanimura, Kenji; Deguchi, Masashi; Yamada, Hideto; Iijima, Kazumoto; Morioka, Ichiro

2016-02-01

Few studies have targeted psychomotor development and associated perinatal risk factors in Japanese very low birth weight (VLBW) infants who are severely small for gestational age (SGA). A single-center study was conducted in 104 Japanese VLBW infants who were born preterm, due to maternal, umbilical cord, or placental abnormalities, between 2000 and 2007. Psychomotor development as a developmental quotient (DQ) was assessed using the Kyoto Scale of Psychological Development at 3 years corrected age. Severely SGA was defined as birth weight or length below -2 standard deviation values of the mean values at the same gestation. VLBW infants were divided into 2 subgroups based on gestational age at birth: ⩾28 weeks (n=64) and <28 weeks (n=40). DQs of infants with severe SGA were compared with those of infants who were appropriate for gestational age (AGA). Factors associated with developmental disabilities in VLBW infants with severe SGA (n=23) were determined. In the group born at ⩾28 weeks gestation, infants with severe SGA had normal DQ values and did not significantly differ from those with AGA. However, in the group born at <28 weeks gestation, severe SGA infants had significantly lower postural-motor DQ values than AGA infants. Gestational age <28 weeks was an independent factor for low postural-motor DQ, regardless of the cause of severe SGA or pregnancy termination. Extremely preterm newborns with severe SGA are at risk of motor developmental disability at age 3 years. Copyright © 2015 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

Metabolic and functional characterization of effects of developmental temperature in Drosophila melanogaster.

PubMed

Schou, Mads F; Kristensen, Torsten N; Pedersen, Anders; Karlsson, B Göran; Loeschcke, Volker; Malmendal, Anders

2017-02-01

The ability of ectotherms to respond to changes in their thermal environment through plastic mechanisms is central to their adaptive capability. However, we still lack knowledge on the physiological and functional responses by which ectotherms acclimate to temperatures during development, and in particular, how physiological stress at extreme temperatures may counteract beneficial acclimation responses at benign temperatures. We exposed Drosophila melanogaster to 10 developmental temperatures covering their entire permissible temperature range. We obtained metabolic profiles and reaction norms for several functional traits: egg-to-adult viability, developmental time, and heat and cold tolerance. Females were more heat tolerant than males, whereas no sexual dimorphism was found in cold tolerance. A group of metabolites, mainly free amino acids, had linear reaction norms. Several energy-carrying molecules, as well as some sugars, showed distinct inverted U-shaped norms of reaction across the thermal range, resulting in a positive correlation between metabolite intensities and egg-to-adult viability. At extreme temperatures, low levels of these metabolites were interpreted as a response characteristic of costs of homeostatic perturbations. Our results provide novel insights into a range of metabolites reported to be central for the acclimation response and suggest several new candidate metabolites. Low and high temperatures result in different adaptive physiological responses, but they also have commonalities likely to be a result of the failure to compensate for the physiological stress. We suggest that the regulation of metabolites that are tightly connected to the performance curve is important for the ability of ectotherms to cope with variation in temperature. Copyright © 2017 the American Physiological Society.

Developmental process emerges from extended brain-body-behavior networks

PubMed Central

Byrge, Lisa; Sporns, Olaf; Smith, Linda B.

2014-01-01

Studies of brain connectivity have focused on two modes of networks: structural networks describing neuroanatomy and the intrinsic and evoked dependencies of functional networks at rest and during tasks. Each mode constrains and shapes the other across multiple time scales, and each also shows age-related changes. Here we argue that understanding how brains change across development requires understanding the interplay between behavior and brain networks: changing bodies and activities modify the statistics of inputs to the brain; these changing inputs mold brain networks; these networks, in turn, promote further change in behavior and input. PMID:24862251

Theories of autism.

PubMed

Levy, Florence

2007-11-01

The purpose of the present paper was to review psychological theories of autism, and to integrate these theories with neurobiological findings. Cognitive, theory of mind, language and coherence theories were identified, and briefly reviewed. Psychological theories were found not to account for the rigid/repetitive behaviours universally described in autistic subjects, and underlying neurobiological systems were identified. When the developing brain encounters constrained connectivity, it evolves an abnormal organization, the features of which may be best explained by a developmental failure of neural connectivity, where high local connectivity develops in tandem with low long-range connectivity, resulting in constricted repetitive behaviours.

Sequestration of polyunsaturated fatty acids in membrane phospholipids of Caenorhabditis elegans dauer larva attenuates eicosanoid biosynthesis for prolonged survival.

PubMed

Lam, Sin Man; Wang, Zehua; Li, Jie; Huang, Xun; Shui, Guanghou

2017-08-01

Mechanistic basis governing the extreme longevity and developmental quiescence of dauer juvenile, a "non-ageing" developmental variant of Caenorhabditis elegans, has remained largely obscure. Using a lipidomic approach comprising multiple reaction monitoring transitions specific to distinct fatty acyl moieties, we demonstrated that in comparison to other developmental stages, the membrane phospholipids of dauer larva contain a unique enrichment of polyunsaturated fatty acids (PUFAs). Esterified PUFAs in phospholipids exhibited temporal accumulation throughout the course of dauer endurance, followed by sharp reductions prior to termination of diapause. Reductions in esterified PUFAs were accompanied by concomitant increases in unbound PUFAs, as well as their corresponding downstream oxidized derivatives (i.e. eicosanoids). Global phospholipidomics has unveiled that PUFA sequestration in membrane phospholipids denotes an essential aspect of dauer dormancy, principally via suppression of eicosanoid production; and a failure to upkeep membrane lipid homeostasis is associated with termination of dauer endurance. Copyright © 2017. Published by Elsevier B.V.

Attention Deficit Hyperactivity Disorder (ADHD): Controversy, Developmental Mechanisms, and Multiple Levels of Analysis.

PubMed

Hinshaw, Stephen P

2018-05-07

Controversy abounds regarding the symptom dimensions of attention problems, impulsivity, and hyperactivity, developmentally extreme and impairing levels of which compose the diagnostic category of attention deficit hyperactivity disorder (ADHD). I highlight causal factors, underlying mechanisms, developmental trajectories, and female manifestations of ADHD, integrating the psychobiological underpinnings of this syndrome with contextual factors related to its clinical presentation, impairments, and soaring increases in diagnosed prevalence. Indeed, despite strong heritability, ADHD is expressed via transactional patterns of influence linked to family-, school-, peer-, neighborhood-, and policy-related factors. Moreover, intervention strategies must take into account both pharmacologic and behavioral modalities if the goal is to enhance competencies, rather than symptom reduction per se. A comprehensive understanding of ADHD mandates multiple levels of analysis-spanning genes, neurotransmission, brain pathways, individual skill levels, family socialization, peer relationships, and educational and cultural forces-which must be integrated and synthesized to surpass reductionist accounts, reduce stigma, and maximize the impact of prevention- and intervention-related efforts.

Peripheral Innervation in Children with Global Developmental Delay: Biomarker for Risk for Self-Injurious Behavior?

PubMed Central

Symons, Frank J.; Tervo, Raymond C.; Barney, Chantel C.; Damerow, John; Selim, Mona; McAdams, Brian; Foster, Shawn; Crabb, Gwen Wendelschafer; Kennedy, William

2015-01-01

The relation between somatosensory mechanisms and self-injury among children with neurological impairments associated with developmental delay is not well understood. We evaluated the feasibility of procuring skin biopsies to examine epidermal nerve fiber density and reported self-injury. Following informed parental consent, epidermal skin biopsies were obtained from a distal leg site with no pre-existing skin damage from 11 children with global developmental delay (55% male; mean age = 36.8 months, 17–63 mo.). Visual microscopic examination and quantitative analyses showed extremely high epidermal nerve fiber density values for some children. Children with reported self-injury (5/11) had significantly (p < 0.02) greater density values (138.8, sd = 45.5) than children without self-injury (80.5, sd = 17.5). Results from this novel immunohistological analysis of skin in very young children with neurodevelopmental delays suggests it may be a useful tool to study peripheral innervation as a possible sensory risk factor for self-injury. PMID:25918119

Peripheral Innervation in Children With Global Developmental Delay: Biomarker for Risk for Self-Injurious Behavior?

PubMed

Symons, Frank J; Tervo, Raymond C; Barney, Chantel C; Damerow, John; Selim, Mona; McAdams, Brian; Foster, Shawn; Wendelschafer Crabb, Gwen; Kennedy, William

2015-11-01

The relation between somatosensory mechanisms and self-injury among children with neurologic impairments associated with developmental delay is not well understood. We evaluated the feasibility of procuring skin biopsies to examine epidermal nerve fiber density and reported self-injury. Following informed parental consent, epidermal skin biopsies were obtained from a distal leg site with no pre-existing skin damage from 11 children with global developmental delay (55% male; mean age = 36.8 months, 17-63 months). Visual microscopic examination and quantitative analyses showed extremely high epidermal nerve fiber density values for some children. Children with reported self-injury (5/11) had significantly (P < .02) greater density values (138.8, standard deviation = 45.5) than children without self-injury (80.5, standard deviation = 17.5). Results from this novel immunohistologic analysis of skin in very young children with neurodevelopmental delays suggest it may be a useful tool to study peripheral innervation as a possible sensory risk factor for self-injury. © The Author(s) 2015.

Developmental programming of happiness.

PubMed

Schmidt, Louis A; Fortier, Paz; Lahat, Ayelet; Tang, Alva; Mathewson, Karen J; Saigal, Saroj; Boyle, Michael H; Van Lieshout, Ryan J

2017-09-01

Being born at an extremely low birth weight (ELBW; <1,000 grams) is presumed to reflect a suboptimal intrauterine environment and thus presents an opportunity for examining developmental programming hypotheses. Interfacing prenatal programming and differential susceptibility hypotheses, we tested whether individuals with ELBW in different childhood rearing environments showed different attention biases to positive and negative facial emotions in adulthood. Using the oldest known, prospectively followed cohort of ELBW survivors, we found that relative to normal birth weight controls (NBW; >2,500 grams), ELBW survivors displayed the highest and lowest attention bias to happy faces at age 30-35, depending on whether their total family income at age 8 was relatively low (environmental match) or high (environmental mismatch), respectively. This bias to happy faces was associated with a reduced likelihood of emotional problems. Findings suggest that differential susceptibility to positive emotions may be prenatally programmed, with effects lasting into adulthood. We discuss implications for integrating prenatal programming and differential susceptibility hypotheses, and the developmental origins of postnatal plasticity and resilience. © 2017 Wiley Periodicals, Inc.

The Most Developmentally Truncated Fishes Show Extensive Hox Gene Loss and Miniaturized Genomes

PubMed Central

Malmstrøm, Martin; Britz, Ralf; Matschiner, Michael; Tørresen, Ole K; Hadiaty, Renny Kurnia; Yaakob, Norsham; Tan, Heok Hui; Jakobsen, Kjetill Sigurd; Salzburger, Walter; Rüber, Lukas

2018-01-01

Abstract The world’s smallest fishes belong to the genus Paedocypris. These miniature fishes are endemic to an extreme habitat: the peat swamp forests in Southeast Asia, characterized by highly acidic blackwater. This threatened habitat is home to a large array of fishes, including a number of miniaturized but also developmentally truncated species. Especially the genus Paedocypris is characterized by profound, organism-wide developmental truncation, resulting in sexually mature individuals of <8 mm in length with a larval phenotype. Here, we report on evolutionary simplification in the genomes of two species of the dwarf minnow genus Paedocypris using whole-genome sequencing. The two species feature unprecedented Hox gene loss and genome reduction in association with their massive developmental truncation. We also show how other genes involved in the development of musculature, nervous system, and skeleton have been lost in Paedocypris, mirroring its highly progenetic phenotype. Further, our analyses suggest two mechanisms responsible for the genome streamlining in Paedocypris in relation to other Cypriniformes: severe intron shortening and reduced repeat content. As the first report on the genomic sequence of a vertebrate species with organism-wide developmental truncation, the results of our work enhance our understanding of genome evolution and how genotypes are translated to phenotypes. In addition, as a naturally simplified system closely related to zebrafish, Paedocypris provides novel insights into vertebrate development. PMID:29684203

Association Between Early Low-Dose Hydrocortisone Therapy in Extremely Preterm Neonates and Neurodevelopmental Outcomes at 2 Years of Age.

PubMed

Baud, Olivier; Trousson, Clémence; Biran, Valérie; Leroy, Emilie; Mohamed, Damir; Alberti, Corinne

2017-04-04

Dexamethasone to prevent bronchopulmonary dysplasia in very preterm neonates was associated with adverse neurodevelopmental events. Early low-dose hydrocortisone treatment has been reported to improve survival without bronchopulmonary dysplasia but its safety with regard to neurodevelopment remains to be assessed. To assess whether early hydrocortisone therapy in extremely preterm infants is associated with neurodevelopmental impairment at 2 years of age. An exploratory secondary analysis of the PREMILOC (Early Low-Dose Hydrocortisone to Improve Survival without Bronchopulmonary Dysplasia in Extremely Preterm Infants) randomized clinical trial conducted between 2008 and 2014 in 21 French neonatal intensive care units. Randomization was stratified by gestational age groups. Neurodevelopmental assessments were completed from 2010 to 2016. After birth, patients were randomly assigned to receive placebo or hydrocortisone (0.5 mg/kg twice per day for 7 days, followed by 0.5 mg/kg per day for 3 days). The prespecified exploratory secondary outcome of neurodevelopmental impairment was based on a standardized neurological examination and the revised Brunet-Lézine scale (global developmental quotient score and subscores; mean norm, 100 [SD, 15]). The minimal clinically important difference on the global developmental quotient was 5 points. Of 1072 neonates screened, 523 were assigned to hydrocortisone (n = 256) or placebo (n = 267) and 406 survived to 2 years of age. A total of 379 patients (93%; 46% female) were evaluated (194 in the hydrocortisone group and 185 in the placebo group) at a median corrected age of 22 months (interquartile range, 21-23 months). The distribution of patients without neurodevelopmental impairment (73% in the hydrocortisone group vs 70% in the placebo group), with mild neurodevelopmental impairment (20% in the hydrocortisone group vs 18% in the placebo group), or with moderate to severe neurodevelopmental impairment (7% in the hydrocortisone group vs 11% in the placebo group) was not statistically significantly different between groups (P = .33). The mean global developmental quotient score was not statistically significantly different between groups (91.7 in the hydrocortisone group vs 91.4 in the placebo group; between-group difference, 0.3 [95% CI, -2.7 to 3.4]; P = .83). The incidence of cerebral palsy or other major neurological impairments was not significantly different between groups. In this exploratory analysis of secondary outcomes of a randomized clinical trial of extremely preterm infants, early low-dose hydrocortisone was not associated with a statistically significant difference in neurodevelopment at 2 years of age. Further randomized studies are needed to provide definitive assessment of the neurodevelopmental safety of hydrocortisone in extremely preterm infants. clinicaltrials.gov Identifier: NCT00623740.

IRTs of the ABCs: Children's Letter Name Acquisition

PubMed Central

Piasta, Shayne B.; Anthony, Jason L.; Lonigan, Christopher J.; Francis, David J.

2015-01-01

We examined the developmental sequence of letter name knowledge acquisition by children from 2 to five years of age. Data from 2 samples representing diverse regions, ethnicity, and socioeconomic backgrounds (ns = 1074 & 500) were analyzed using item response theory (IRT) and differential item functioning techniques. Results from factor analyses indicated that letter name knowledge represented a unidimensional skill; IRT results yielded significant differences between letters in both difficulty and discrimination. Results also indicated an approximate developmental sequence in letter name learning for the simplest and most challenging to learn letters -- but with no clear sequence between these extremes. Findings also suggested that children were most likely to first learn their first initial. We discuss implications for assessment and instruction. PMID:22710016

An extra-uterine system to physiologically support the extreme premature lamb

PubMed Central

Partridge, Emily A.; Davey, Marcus G.; Hornick, Matthew A.; McGovern, Patrick E.; Mejaddam, Ali Y.; Vrecenak, Jesse D.; Mesas-Burgos, Carmen; Olive, Aliza; Caskey, Robert C.; Weiland, Theodore R.; Han, Jiancheng; Schupper, Alexander J.; Connelly, James T.; Dysart, Kevin C.; Rychik, Jack; Hedrick, Holly L.; Peranteau, William H.; Flake, Alan W.

2017-01-01

In the developed world, extreme prematurity is the leading cause of neonatal mortality and morbidity due to a combination of organ immaturity and iatrogenic injury. Until now, efforts to extend gestation using extracorporeal systems have achieved limited success. Here we report the development of a system that incorporates a pumpless oxygenator circuit connected to the fetus of a lamb via an umbilical cord interface that is maintained within a closed ‘amniotic fluid' circuit that closely reproduces the environment of the womb. We show that fetal lambs that are developmentally equivalent to the extreme premature human infant can be physiologically supported in this extra-uterine device for up to 4 weeks. Lambs on support maintain stable haemodynamics, have normal blood gas and oxygenation parameters and maintain patency of the fetal circulation. With appropriate nutritional support, lambs on the system demonstrate normal somatic growth, lung maturation and brain growth and myelination. PMID:28440792

The first case of Horn Kolb Syndrome in Turkey, diagnosed prenatally at the 23(rd) week of a pregnancy: A very rare and unusual case far from the original geography.

PubMed

Temur, Ismail; Ulker, Kahraman; Volkan, Islim; Karaca, Mehmet; Ersoz, Mustafa; Gul, Abdulaziz; Adiguzel, Esat

2012-01-01

The aim of this report was to evaluate and announce the first documented appearance of Horn Kolb syndrome in Turkey. Acheiropodia (Horn Kolb Syndrome) is the bilateral congenital amputation of the distal parts of the 4 extremities. It is an autosomal recessive developmental disorder. The characteristic features are amputation of the upper and lower extremities with aplasia of the hands and feet. The disorder affects only the extremities without other systemic manifestations. In this report, we present the first known case of Horn Kolb syndrome in Turkey, along with the diagnostic features. Severe dysmorphic skeletal anomalies should be excluded as soon as the earlier gestational weeks in every pregnancy by visualizing all 4 limbs of the fetus in routine prenatal ultrasound screening.

An extra-uterine system to physiologically support the extreme premature lamb

NASA Astrophysics Data System (ADS)

Partridge, Emily A.; Davey, Marcus G.; Hornick, Matthew A.; McGovern, Patrick E.; Mejaddam, Ali Y.; Vrecenak, Jesse D.; Mesas-Burgos, Carmen; Olive, Aliza; Caskey, Robert C.; Weiland, Theodore R.; Han, Jiancheng; Schupper, Alexander J.; Connelly, James T.; Dysart, Kevin C.; Rychik, Jack; Hedrick, Holly L.; Peranteau, William H.; Flake, Alan W.

2017-04-01

In the developed world, extreme prematurity is the leading cause of neonatal mortality and morbidity due to a combination of organ immaturity and iatrogenic injury. Until now, efforts to extend gestation using extracorporeal systems have achieved limited success. Here we report the development of a system that incorporates a pumpless oxygenator circuit connected to the fetus of a lamb via an umbilical cord interface that is maintained within a closed `amniotic fluid' circuit that closely reproduces the environment of the womb. We show that fetal lambs that are developmentally equivalent to the extreme premature human infant can be physiologically supported in this extra-uterine device for up to 4 weeks. Lambs on support maintain stable haemodynamics, have normal blood gas and oxygenation parameters and maintain patency of the fetal circulation. With appropriate nutritional support, lambs on the system demonstrate normal somatic growth, lung maturation and brain growth and myelination.

Multicolor Photometry and Time-resolved Spectroscopy of Two sdBV Stars

NASA Astrophysics Data System (ADS)

Reed, M. D.; O'Toole, S. J.; Telting, J. H.; Østensen, R. H.; Heber, U.; Barlow, B. N.; Reichart, D. E.; Nysewander, M. C.; LaCluyze, A. P.; Ivarsen, K. M.; Haislip, J. B.; Bean, J.

2012-03-01

Observational mode constraints have mostly been lacking for short period pulsating sdB stars, yet such identifications are vital to constrain models. Time-resolved spectroscopy and multicolor photometry have been employed with mixed results for short-period pulsating sdB stars. Time-resolved spectroscopy has successfully measured radial velocity, temperature, and gravity variations in six pulsators, yet interpreting results is far from straightforward. Multicolor photometry requires extremely high precision to discern between low-degree modes, yet has been used effectively to eliminate high-degree modes. Combining radial velocity (RV) and multicolor measurements has also been shown as an effective means of constraining mode identifications. We present preliminary results for Feige 48 and EC 01541-1409 using both time-resolved spectroscopy and multicolor photometry and an initial examination of their pulsation modes using the atmospheric codes BRUCE and KYLIE.

A Multi-wavelength Study of an Isolated MSP Bow Shock

NASA Astrophysics Data System (ADS)

Romani, Roger W.; Slane, Patrick; Green, Andrew

2017-08-01

PSR J2124-3358 is the only single MSP known to sport an Halpha bow shock. This shock, now also seen in the UV, encloses an unusual X-ray pulsar wind nebula (PWN) with a long off-axis trail. Combining the X-ray and UV images with AAT/KOALA integral field spectroscopy of the Halpha emission, we have an unusually complete picture of the pulsar's (101 km/s transverse) motion and the latitudinal distribution of its wind flux. These images reveal the 3-D orientation of a hard-spectrum PWN jet and a softer equatorial outflow. Within the context of a thin shock model, we can constrain the total energy output of the pulsar and the neutron star moment of inertia. The IFU spectra show extreme Balmer dominance, which also constrains the nature of the UV shock emission.

Using Schumann Resonance Measurements for Constraining the Water Abundance on the Giant Planets - Implications for the Solar System Formation

NASA Technical Reports Server (NTRS)

Simoes, Fernando; Pfaff, Robert; Hamelin, Michel; Klenzing, Jeffrey; Freudenreich, Henry; Beghin, Christian; Berthelier, Jean-Jacques; Bromund, Kenneth; Grard, Rejean; Lebreton, Jean-Pierre;

Option pricing, stochastic volatility, singular dynamics and constrained path integrals

NASA Astrophysics Data System (ADS)

Contreras, Mauricio; Hojman, Sergio A.

2014-01-01

Stochastic volatility models have been widely studied and used in the financial world. The Heston model (Heston, 1993) [7] is one of the best known models to deal with this issue. These stochastic volatility models are characterized by the fact that they explicitly depend on a correlation parameter ρ which relates the two Brownian motions that drive the stochastic dynamics associated to the volatility and the underlying asset. Solutions to the Heston model in the context of option pricing, using a path integral approach, are found in Lemmens et al. (2008) [21] while in Baaquie (2007,1997) [12,13] propagators for different stochastic volatility models are constructed. In all previous cases, the propagator is not defined for extreme cases ρ=±1. It is therefore necessary to obtain a solution for these extreme cases and also to understand the origin of the divergence of the propagator. In this paper we study in detail a general class of stochastic volatility models for extreme values ρ=±1 and show that in these two cases, the associated classical dynamics corresponds to a system with second class constraints, which must be dealt with using Dirac’s method for constrained systems (Dirac, 1958,1967) [22,23] in order to properly obtain the propagator in the form of a Euclidean Hamiltonian path integral (Henneaux and Teitelboim, 1992) [25]. After integrating over momenta, one gets an Euclidean Lagrangian path integral without constraints, which in the case of the Heston model corresponds to a path integral of a repulsive radial harmonic oscillator. In all the cases studied, the price of the underlying asset is completely determined by one of the second class constraints in terms of volatility and plays no active role in the path integral.

Effects of constrained arm swing on vertical center of mass displacement during walking.

PubMed

Yang, Hyung Suk; Atkins, Lee T; Jensen, Daniel B; James, C Roger

2015-10-01

The purpose of this study was to determine the effects of constraining arm swing on the vertical displacement of the body's center of mass (COM) during treadmill walking and examine several common gait variables that may account for or mask differences in the body's COM motion with and without arm swing. Participants included 20 healthy individuals (10 male, 10 female; age: 27.8 ± 6.8 years). The body's COM displacement, first and second peak vertical ground reaction forces (VGRFs), and lowest VGRF during mid-stance, peak summed bilateral VGRF, lower extremity sagittal joint angles, stride length, and foot contact time were measured with and without arm swing during walking at 1.34 m/s. The body's COM displacement was greater with the arms constrained (arm swing: 4.1 ± 1.2 cm, arm constrained: 4.9 ± 1.2 cm, p < 0.001). Ground reaction force data indicated that the COM displacement increased in both double limb and single limb stance. However, kinematic patterns visually appeared similar between conditions. Shortened stride length and foot contact time also were observed, although these do not seem to account for the increased COM displacement. However, a change in arm COM acceleration might have contributed to the difference. These findings indicate that a change in arm swing causes differences in vertical COM displacement, which could increase energy expenditure. Copyright © 2015 Elsevier B.V. All rights reserved.

A strategy to implement and support pre-hospital emergency medical systems in developing, resource-constrained areas of South Africa.

PubMed

Sun, Jared H; Shing, Rachel; Twomey, Michele; Wallis, Lee A

2014-01-01

Resource-constrained countries are in extreme need of pre-hospital emergency care systems. However, current popular strategies to provide pre-hospital emergency care are inappropriate for and beyond the means of a resource-constrained country, and so new ones are needed-ones that can both function in an under-developed area's particular context and be done with the area's limited resources. In this study, we used a two-location pilot and consensus approach to develop a strategy to implement and support pre-hospital emergency care in one such developing, resource-constrained area: the Western Cape province of South Africa. Local community members are trained to be emergency first aid responders who can provide immediate, on-scene care until a Transporter can take the patient to the hospital. Management of the system is done through local Community Based Organizations, which can adapt the model to their communities as needed to ensure local appropriateness and feasibility. Within a community, the system is implemented in a graduated manner based on available resources, and is designed to not rely on the whole system being implemented first to provide partial function. The University of Cape Town's Division of Emergency Medicine and the Western Cape's provincial METRO EMS intend to follow this model, along with sharing it with other South African provinces. Copyright © 2012 Elsevier Ltd. All rights reserved.

The C20C+ Detection and Attribution Project

NASA Astrophysics Data System (ADS)

Stone, D. A.; Angélil, O. M.; Cholia, S.; Christidis, N.; Dittus, A. J.; Folland, C. K.; King, A.; Kinter, J. L.; Krishnan, H.; Min, S. K.; Shiogama, H.; Wehner, M. F.; Wolski, P.

2015-12-01

Over the past decade there has been a remarkable growth in interest concerning the effects of anthropogenic emissions on extreme weather. However, research has been constrained by the lack of a public climate-model-based data product optimised for investigation of extreme weather in the context of climate change, relying instead on products designed for other purposes or on bespoke simulations designed for the particular study and not generally applicable to other extremes. The international Climate of the 20th Century Plus (C20C+) Detection and Attribution Project is filling this gap by producing the first large ensemble, multi-model, multi-year, and multi-scenario historical climate data product, specifically designed for resolving variations in the occurrence and characteristics of extreme weather from year to year and their differences from what might have been in the absence of anthropogenic emissions. Updates on project status and tens of terabytes of simulation output are available at http://portal.nersc.gov/c20c.Here we describe the experimental design of the first phase of the project, conducted with six atmospheric climate models, and discuss its various strengths and weaknesses with respect to various types of extreme weather. We also present analyses of the relative importance of climate model, estimate of anthropogenic ocean warming, spatial and temporal scale, and aspects of experimental design on estimates of how much emissions have affected extreme weather.

Continued increase of extreme El Niño frequency long after 1.5 °C warming stabilization

NASA Astrophysics Data System (ADS)

Wang, Guojian; Cai, Wenju; Gan, Bolan; Wu, Lixin; Santoso, Agus; Lin, Xiaopei; Chen, Zhaohui; McPhaden, Michael J.

2017-08-01

The Paris Agreement aims to constrain global mean temperature (GMT) increases to 2 °C above pre-industrial levels, with an aspirational target of 1.5 °C. However, the pathway to these targets and the impacts of a 1.5 °C and 2 °C warming on extreme El Niño and La Niña events--which severely influence weather patterns, agriculture, ecosystems, public health and economies--is little known. Here, by analysing climate models participating in the Climate Model Intercomparison Project's Phase 5 (CMIP5; ref. ) under a most likely emission scenario, we demonstrate that extreme El Niño frequency increases linearly with the GMT towards a doubling at 1.5 °C warming. This increasing frequency of extreme El Niño events continues for up to a century after GMT has stabilized, underpinned by an oceanic thermocline deepening that sustains faster warming in the eastern equatorial Pacific than the off-equatorial region. Ultimately, this implies a higher risk of extreme El Niño to future generations after GMT rise has halted. On the other hand, whereas previous research suggests extreme La Niña events may double in frequency under the 4.5 °C warming scenario, the results presented here indicate little to no change under 1.5 °C or 2 °C warming.

Typical meteorological conditions associated with extreme nitrogen dioxide (NO2) pollution events over Scandinavia

NASA Astrophysics Data System (ADS)

Thomas, Manu Anna; Devasthale, Abhay

2017-10-01

Characterizing typical meteorological conditions associated with extreme pollution events helps to better understand the role of local meteorology in governing the transport and distribution of pollutants in the atmosphere. The knowledge of their co-variability could further help to evaluate and constrain chemistry transport models. Hence, in this study, we investigate the statistical linkages between extreme nitrogen dioxide (NO2) pollution events and meteorology over Scandinavia using observational and reanalysis data. It is observed that the south-westerly winds dominated during extreme events, accounting for 50-65 % of the total events depending on the season, while the second largest annual occurrence was from south-easterly winds, accounting for 17 % of total events. The specific humidity anomalies showed an influx of warmer and moisture-laden air masses over Scandinavia in the free troposphere. Two distinct modes in the persistency of circulation patterns are observed. The first mode lasts for 1-2 days, dominated by south-easterly winds that prevailed during 78 % of total extreme events in that mode, while the second mode lasted for 3-5 days, dominated by south-westerly winds that prevailed during 86 % of the events. The combined analysis of circulation patterns, their persistency, and associated changes in humidity and clouds suggests that NO2 extreme events over Scandinavia occur mainly due to long-range transport from the southern latitudes.

Worldwide variability in growth and its association with health: Incorporating body composition, developmental plasticity, and intergenerational effects.

PubMed

Wells, Jonathan C K

2017-03-01

In their seminal book "Worldwide variation in human growth," published in 1976, Eveleth and Tanner highlighted substantial variability within and between populations in the magnitude and schedule of human growth. In the four decades since then, research has clarified why growth variability is so closely associated with human health. First, growth patterns are strongly associated with body composition, both in the short- and long-term. Poor growth in early life constrains the acquisition of lean tissue, while compensatory "catch-up" growth may elevate body fatness. Second, these data are examples of the fundamental link between growth and developmental plasticity. Growth is highly sensitive to ecological stresses and stimuli during early "critical windows," but loses much of this sensitivity as it undergoes canalization during early childhood. Crucially, the primary source of stimuli during early "critical windows" is not the external environment itself, but rather maternal phenotype, which transduces the impact of ecological conditions. Maternal phenotype, representing many dimensions of "capital," thus generates a powerful impact on the developmental trajectory of the offspring. There is increasing evidence that low levels of maternal capital impact the offspring's size at birth, schedule of maturation, and body composition and physiological function in adulthood. While evidence has accrued of substantial heritability in adult height, it is clear that the pathway through which it is attained has major implications for metabolic phenotype. Integrating these perspectives is important for understanding how developmental plasticity may on the one hand contribute to adaptation, while on the other shape susceptibility to non-communicable disease. © 2017 Wiley Periodicals, Inc.

Conserved patterns of integrated developmental plasticity in a group of polyphenic tropical butterflies.

PubMed

van Bergen, Erik; Osbaldeston, Dave; Kodandaramaiah, Ullasa; Brattström, Oskar; Aduse-Poku, Kwaku; Brakefield, Paul M

2017-02-27

Developmental plasticity is thought to have profound macro-evolutionary effects, for example, by increasing the probability of establishment in new environments and subsequent divergence into independently evolving lineages. In contrast to plasticity optimized for individual traits, phenotypic integration, which enables a concerted response of plastic traits to environmental variability, may affect the rate of local adaptation by constraining independent responses of traits to selection. Using a comparative framework, this study explores the evolution of reaction norms for a variety of life history and morphological traits across five related species of mycalesine butterflies from the Old World tropics. Our data indicate that an integrated response of a suite of key traits is shared amongst these species. Interestingly, the traits that make up the functional suite are all known to be regulated by ecdysteroid signalling in Bicyclus anynana, one of the species included in this study, suggesting the same underlying hormonal regulator may be conserved within this group of polyphenic butterflies. We also detect developmental thresholds for the expression of alternative morphs. The phenotypic plasticity of a broad suite of morphological and life history traits is integrated and shared among species from three geographically independent lineages of mycalesine butterflies, despite considerable periods of independent evolution and exposure to disparate environments. At the same time, we have detected examples of evolutionary change where independent traits show different patterns of reaction norms. We argue that the expression of more robust phenotypes may occur by shifting developmental thresholds beyond the boundaries of the typical environmental variation.

Different Cranial Ontogeny in Europeans and Southern Africans

PubMed Central

Sardi, Marina L.; Ramírez Rozzi, Fernando V.

2012-01-01

Modern human populations differ in developmental processes and in several phenotypic traits. However, the link between ontogenetic variation and human diversification has not been frequently addressed. Here, we analysed craniofacial ontogenies by means of geometric-morphometrics of Europeans and Southern Africans, according to dental and chronological ages. Results suggest that different adult cranial morphologies between Southern Africans and Europeans arise by a combination of processes that involve traits modified during the prenatal life and others that diverge during early postnatal ontogeny. Main craniofacial changes indicate that Europeans differ from Southern Africans by increasing facial developmental rates and extending the attainment of adult size and shape. Since other studies have suggested that native subsaharan populations attain adulthood earlier than Europeans, it is probable that facial ontogeny is linked with other developmental mechanisms that control the timing of maturation in other variables. Southern Africans appear as retaining young features in adulthood. Facial ontogeny in Europeans produces taller and narrower noses, which seems as an adaptation to colder environments. The lack of these morphological traits in Neanderthals, who lived in cold environments, seems a paradox, but it is probably the consequence of a warm-adapted faces together with precocious maturation. When modern Homo sapiens migrated into Asia and Europe, colder environments might establish pressures that constrained facial growth and development in order to depart from the warm-adapted morphology. Our results provide some answers about how cranial growth and development occur in two human populations and when developmental shifts take place providing a better adaptation to environmental constraints. PMID:22558270

Transcription factors define the neuroanatomical organization of the medullary reticular formation

PubMed Central

Gray, Paul A.

2013-01-01

The medullary reticular formation contains large populations of inadequately described, excitatory interneurons that have been implicated in multiple homeostatic behaviors including breathing, viserosensory processing, vascular tone, and pain. Many hindbrain nuclei show a highly stereotyped pattern of localization across vertebrates suggesting a strong underlying genetic organization. Whether this is true for neurons within the reticular regions of hindbrain is unknown. Hindbrain neurons are derived from distinct developmental progenitor domains each of which expresses distinct patterns of transcription factors (TFs). These neuronal populations have distinct characteristics such as transmitter identity, migration, and connectivity suggesting developmentally expressed TFs might identify unique subpopulations of neurons within the reticular formation. A fate-mapping strategy using perinatal expression of reporter genes within Atoh1, Dbx1, Lmx1b, and Ptf1a transgenic mice coupled with immunohistochemistry (IHC) and in situ hybridization (ISH) were used to address the developmental organization of a large subset of reticular formation glutamatergic neurons. All hindbrain lineages have relatively large populations that extend the entire length of the hindbrain. Importantly, the location of neurons within each lineage was highly constrained. Lmx1b- and Dbx1- derived populations were both present in partially overlapping stripes within the reticular formation extending from dorsal to ventral brain. Within each lineage, distinct patterns of gene expression and organization were localized to specific hindbrain regions. Rostro-caudally sub-populations differ sequentially corresponding to proposed pseudo-rhombomereic boundaries. Dorsal-ventrally, sub-populations correspond to specific migratory positions. Together these data suggests the reticular formation is organized by a highly stereotyped developmental logic. PMID:23717265

Transcription factors define the neuroanatomical organization of the medullary reticular formation.

PubMed

Gray, Paul A

2013-01-01

The medullary reticular formation contains large populations of inadequately described, excitatory interneurons that have been implicated in multiple homeostatic behaviors including breathing, viserosensory processing, vascular tone, and pain. Many hindbrain nuclei show a highly stereotyped pattern of localization across vertebrates suggesting a strong underlying genetic organization. Whether this is true for neurons within the reticular regions of hindbrain is unknown. Hindbrain neurons are derived from distinct developmental progenitor domains each of which expresses distinct patterns of transcription factors (TFs). These neuronal populations have distinct characteristics such as transmitter identity, migration, and connectivity suggesting developmentally expressed TFs might identify unique subpopulations of neurons within the reticular formation. A fate-mapping strategy using perinatal expression of reporter genes within Atoh1, Dbx1, Lmx1b, and Ptf1a transgenic mice coupled with immunohistochemistry (IHC) and in situ hybridization (ISH) were used to address the developmental organization of a large subset of reticular formation glutamatergic neurons. All hindbrain lineages have relatively large populations that extend the entire length of the hindbrain. Importantly, the location of neurons within each lineage was highly constrained. Lmx1b- and Dbx1- derived populations were both present in partially overlapping stripes within the reticular formation extending from dorsal to ventral brain. Within each lineage, distinct patterns of gene expression and organization were localized to specific hindbrain regions. Rostro-caudally sub-populations differ sequentially corresponding to proposed pseudo-rhombomereic boundaries. Dorsal-ventrally, sub-populations correspond to specific migratory positions. Together these data suggests the reticular formation is organized by a highly stereotyped developmental logic.

'One health' and development priorities in resource-constrained countries: policy lessons from avian and pandemic influenza preparedness in Zambia.

PubMed

Mwacalimba, Kennedy Kapala; Green, Judith

2015-03-01

'One World, One Health' has become a key rallying theme for the integration of public health and animal health priorities, particularly in the governance of pandemic-scale zoonotic infectious disease threats. However, the policy challenges of integrating public health and animal health priorities in the context of trade and development issues remain relatively unexamined, and few studies to date have explored the implications of global disease governance for resource-constrained countries outside the main centres of zoonotic outbreaks. This article draws on a policy study of national level avian and pandemic influenza preparedness between 2005 and 2009 across the sectors of trade, health and agriculture in Zambia. We highlight the challenges of integrating disease control interventions amidst trade and developmental realities in resource-poor environments. One Health prioritizes disease risk mitigation, sidelining those trade and development narratives which speak to broader public health concerns. We show how locally important trade and development imperatives were marginalized in Zambia, limiting the effectiveness of pandemic preparedness. Our findings are likely to be generalizable to other resource-constrained countries, and suggest that effective disease governance requires alignment with trade and development sectors, as well as integration of veterinary and public health sectors. Published by Oxford University Press in association with The London School of Hygiene and Tropical Medicine © The Author 2014; all rights reserved.

Maternal influences on early development: preferred temperature prior to oviposition hastens embryogenesis and enhances offspring traits in the Children's python, Antaresia childreni.

PubMed

Lorioux, Sophie; DeNardo, Dale F; Gorelick, Root; Lourdais, Olivier

2012-04-15

Embryonic life is particularly sensitive to its surroundings, and the developmental environment can have long-lasting effects on offspring. In oviparous species, the impacts of the developmental environment on offspring traits are mostly examined during development within the egg. However, as more than 25% of the development of squamate reptiles can occur prior to oviposition, we explored the effect of thermal conditions on development prior to oviposition in an oviparous snake species, the Children's python (Antaresia childreni). We housed gravid female pythons under three thermal cycles: an optimal regime that reflected maternal preference in a non-constrained environment (constant preferred body temperature of gravid females, T(set)=31.5°C) and two mildly suboptimal regimes that shared the same mean temperature of 27.7°C, but differed in the duration at T(set). In one of the constraining regimes, females had access to T(set) for 4 h daily whereas in the other regime, females never reached T(set) (maximal temperature of 29.0°C). Thermal treatments were maintained throughout gravidity in all three groups, but, after oviposition, all eggs were incubated at T(set) until hatching. Compared with the optimal regime, the two suboptimal regimes had a longer duration of gravidity, which resulted in delayed hatching. Between the two suboptimal regimes, gravidity was significantly shorter in the treatment that included time at T(set). Furthermore, suboptimal regimes influenced offspring traits at hatching, including body morphology, antipredator behavior, strength and metabolism. However, partial access to maternal T(set) significantly enhanced several offspring traits, including performance. Our results demonstrate the importance of time at T(set) on early development and suggest an adaptive significance of maternal thermoregulation prior to oviposition.

A variational approach to probing extreme events in turbulent dynamical systems

PubMed Central

Farazmand, Mohammad; Sapsis, Themistoklis P.

2017-01-01

Extreme events are ubiquitous in a wide range of dynamical systems, including turbulent fluid flows, nonlinear waves, large-scale networks, and biological systems. We propose a variational framework for probing conditions that trigger intermittent extreme events in high-dimensional nonlinear dynamical systems. We seek the triggers as the probabilistically feasible solutions of an appropriately constrained optimization problem, where the function to be maximized is a system observable exhibiting intermittent extreme bursts. The constraints are imposed to ensure the physical admissibility of the optimal solutions, that is, significant probability for their occurrence under the natural flow of the dynamical system. We apply the method to a body-forced incompressible Navier-Stokes equation, known as the Kolmogorov flow. We find that the intermittent bursts of the energy dissipation are independent of the external forcing and are instead caused by the spontaneous transfer of energy from large scales to the mean flow via nonlinear triad interactions. The global maximizer of the corresponding variational problem identifies the responsible triad, hence providing a precursor for the occurrence of extreme dissipation events. Specifically, monitoring the energy transfers within this triad allows us to develop a data-driven short-term predictor for the intermittent bursts of energy dissipation. We assess the performance of this predictor through direct numerical simulations. PMID:28948226

High Energy Astrophysics Mission

NASA Technical Reports Server (NTRS)

White, Nicholas E.; Ormes, Jonathan F. (Technical Monitor)

2000-01-01

The nature of gravity and its relationship to the other three forces and to quantum theory is one of the major challenges facing us as we begin the new century. In order to make progress we must challenge the current theories by observing the effects of gravity under the most extreme conditions possible. Black holes represent one extreme, where the laws of physics as we understand them break down. The Universe as whole is another extreme, where its evolution and fate is dominated by the gravitational influence of dark matter and the nature of the Cosmological constant. The early universe represents a third extreme, where it is thought that gravity may somehow be unified with the other forces. NASA's "Cosmic Journeys" program is part of a NASA/NSF/DoE tri-agency initiative designed to observe the extremes of gravity throughout the universe. This program will probe the nature of black holes, ultimately obtaining a direct image of the event horizon. It will investigate the large scale structure of the Universe to constrain the location and nature of dark matter and the nature of the cosmological constant. Finally it will search for and study the highest energy processes, that approach those found in the early universe. I will outline the High Energy Astrophysics part of this program.

Distal Lower-Extremity Pain and Work Postures in the Quebec Population

PubMed Central

Messing, Karen; Tissot, France; Stock, Susan

2008-01-01

Objectives. Standing at work has been associated with discomfort and cardiovascular symptoms. Because standing postures vary in duration, mobility, and constraint, we explored associations between specific postures and pain in the lower extremities. Methods. We used multiple logistic regression to analyze associations between work factors and pain in the lower extremities during the previous 12 months that interfered with usual activities. We used data from among 7757 workers who were interviewed in the 1998 Quebec Health and Social Survey. Results. Among all respondents, 9.4% reported significant ankle or foot pain, and 6.4% had lower-leg or calf pain. Significantly more women than men had pain at both sites. Both leg or calf and ankle or foot pain were strongly associated with standing postures, whole-body vibration, psychological distress, female gender, and being aged 50 years or older. Constrained standing postures were associated with increased ankle or foot pain for both men and women and with leg or calf pain for women, compared with standing with freedom to sit at will. Conclusions. Freedom to sit at work may prevent lower-extremity pain. The effects of specific sitting and standing postures on cartilage, muscle, and the cardiovascular system may help explain discomfort in the lower extremities. PMID:17761561

How Do Microphysical Processes Influence Large-Scale Precipitation Variability and Extremes?

DOE PAGES

Hagos, Samson; Ruby Leung, L.; Zhao, Chun; ...

2018-02-10

Convection permitting simulations using the Model for Prediction Across Scales-Atmosphere (MPAS-A) are used to examine how microphysical processes affect large-scale precipitation variability and extremes. An episode of the Madden-Julian Oscillation is simulated using MPAS-A with a refined region at 4-km grid spacing over the Indian Ocean. It is shown that cloud microphysical processes regulate the precipitable water (PW) statistics. Because of the non-linear relationship between precipitation and PW, PW exceeding a certain critical value (PWcr) contributes disproportionately to precipitation variability. However, the frequency of PW exceeding PWcr decreases rapidly with PW, so changes in microphysical processes that shift the columnmore » PW statistics relative to PWcr even slightly have large impacts on precipitation variability. Furthermore, precipitation variance and extreme precipitation frequency are approximately linearly related to the difference between the mean and critical PW values. Thus observed precipitation statistics could be used to directly constrain model microphysical parameters as this study demonstrates using radar observations from DYNAMO field campaign.« less

How Do Microphysical Processes Influence Large-Scale Precipitation Variability and Extremes?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hagos, Samson; Ruby Leung, L.; Zhao, Chun

Convection permitting simulations using the Model for Prediction Across Scales-Atmosphere (MPAS-A) are used to examine how microphysical processes affect large-scale precipitation variability and extremes. An episode of the Madden-Julian Oscillation is simulated using MPAS-A with a refined region at 4-km grid spacing over the Indian Ocean. It is shown that cloud microphysical processes regulate the precipitable water (PW) statistics. Because of the non-linear relationship between precipitation and PW, PW exceeding a certain critical value (PWcr) contributes disproportionately to precipitation variability. However, the frequency of PW exceeding PWcr decreases rapidly with PW, so changes in microphysical processes that shift the columnmore » PW statistics relative to PWcr even slightly have large impacts on precipitation variability. Furthermore, precipitation variance and extreme precipitation frequency are approximately linearly related to the difference between the mean and critical PW values. Thus observed precipitation statistics could be used to directly constrain model microphysical parameters as this study demonstrates using radar observations from DYNAMO field campaign.« less

Exploring the Early Chemical Evolution of the Milky Way with LAMOST and Subaru

NASA Astrophysics Data System (ADS)

Li, Haining; Aoki, Wako; Honda, Satoshi; Zhao, Gang; Suda, Takuma; Christlieb, Norbert

Extremely Metal-Poor (EMP) stars ([Fe/H] < -3.0) provide fundamental evidence on the nucleosynthesis and enrichment of the first stars and supernovae. LAMOST will observe 6 million Galactic stars through a 5-year spectroscopic survey, and thus provide an unprecedented chance to enlarge the EMP star sample. In 2014, a joint project on EMP stars was initiated with the LAMOST survey and Subaru follow-up observation. So far, more than 70 EMP stars have been found and confirmed, including identifications of a number of chemically interesting objects: three UMP (ultra metal-poor) stars with [Fe/H] ˜ -4.0, including the second UMP turnoff star with Li detection; a super Li-rich (A(Li) = +3) EMP giant, which is the most extreme example of Li enhancement in red giants known to date; a few EMP stars showing extreme enhancements in neutron-capture elements. Statistics of a large sample of EMP stars will constrain formation of the Milky Way halo.

Potentially Extreme Population Displacement and Concentration in the Tropics Under Non-Extreme Warming

NASA Astrophysics Data System (ADS)

Hsiang, Solomon M.; Sobel, Adam H.

2016-06-01

Evidence increasingly suggests that as climate warms, some plant, animal, and human populations may move to preserve their environmental temperature. The distances they must travel to do this depends on how much cooler nearby surfaces temperatures are. Because large-scale atmospheric dynamics constrain surface temperatures to be nearly uniform near the equator, these displacements can grow to extreme distances in the tropics, even under relatively mild warming scenarios. Here we show that in order to preserve their annual mean temperatures, tropical populations would have to travel distances greater than 1000 km over less than a century if global mean temperature rises by 2 °C over the same period. The disproportionately rapid evacuation of the tropics under such a scenario would cause migrants to concentrate in tropical margins and the subtropics, where population densities would increase 300% or more. These results may have critical consequences for ecosystem and human wellbeing in tropical contexts where alternatives to geographic displacement are limited.

A Search for H(alpha) Emission in the Far Outer Discs of Extremely Large Spiral Galaxies

NASA Astrophysics Data System (ADS)

Rubin, Vera; Hunter, Deidre

2007-08-01

Little is known about the kinematics of galaxies far beyond the relatively bright regions sampled in radio or optical radial velocity studies. Most often, the velocities are obtained as part of large surveys, where the effort is made to obtain many rotation curves, rather than to extend a rotation curve as far as possible. Because the composition of dark matter remains unknown, it is important to devise observations that will help to constrain its properties. We propose to obtain ultra-deep Hα images (in the rest frame of the galaxy) for UGC 2885 and NGC 801, two extremely large Sc galaxies. We expect to detect Hα regions far beyond their nuclei and into the extreme outer disc, for which we will then obtain radial velocities. Increased knowledge concerning the kinematics of these galaxies will tighten the constraints on mass models, and shed light on the properties of dark matter. Ultimately, we hope to learn more about the outermost galaxy, where disc and halo blend.

Health-related quality of life and emotional and behavioral difficulties after extreme preterm birth: developmental trajectories.

PubMed

Vederhus, Bente Johanne; Eide, Geir Egil; Natvig, Gerd Karin; Markestad, Trond; Graue, Marit; Halvorsen, Thomas

2015-01-01

Background. Knowledge of long-term health related outcomes in contemporary populations born extremely preterm (EP) is scarce. We aimed to explore developmental trajectories of health-related quality of life (HRQoL) and behavior from mid-childhood to early adulthood in extremely preterm and term-born individuals. Methods. Subjects born at gestational age ≤28 weeks or with birth weight ≤1,000 g within a region of Norway in 1991-92 and matched term-born control subjects were assessed at 10 and 18 years. HRQoL was measured with the Child Health Questionnaire (CHQ) and behavior with the Child Behavior Checklist (CBCL), using parent assessment at both ages and self-assessment at 18 years. Results. All eligible EP (n = 35) and control children participated at 10 years, and 31 (89%) and 29 (83%) at 18 years. At 10 years, the EP born boys were given significantly poorer scores by their parents than term-born controls on most CHQ and CBCL scales, but the differences were minor at 18 years; i.e., significant improvements had occurred in several CHQ (self-esteem, general health and parental impact-time) and CBCL (total problem, internalizing and anxious/depressed) scales. For the girls, the differences were smaller at 10 years and remained unchanged by 18 years. Emotional/behavioral difficulties at 10 years similarly predicted poorer improvement on CHQ-scales for both EP and term-born subjects at 18 years. Self-assessment of HRQoL and behavior at 18 years was similar in the EP and term-born groups on most scales. Conclusions. HRQoL and behavior improved towards adulthood for EP born boys, while the girls remained relatively similar, and early emotional and behavioral difficulties predicted poorer development in HRQoL through adolescence. These data indicate that gender and a longitudinal perspective should be considered when addressing health and wellbeing after extremely preterm birth.

Segmentation in cohesive systems constrained by elastic environments

PubMed Central

Novak, I.

2017-01-01

The complexity of fracture-induced segmentation in elastically constrained cohesive (fragile) systems originates from the presence of competing interactions. The role of discreteness in such phenomena is of interest in a variety of fields, from hierarchical self-assembly to developmental morphogenesis. In this paper, we study the analytically solvable example of segmentation in a breakable mass–spring chain elastically linked to a deformable lattice structure. We explicitly construct the complete set of local minima of the energy in this prototypical problem and identify among them the states corresponding to the global energy minima. We show that, even in the continuum limit, the dependence of the segmentation topology on the stretching/pre-stress parameter in this problem takes the form of a devil's type staircase. The peculiar nature of this staircase, characterized by locking in rational microstructures, is of particular importance for biological applications, where its structure may serve as an explanation of the robustness of stress-driven segmentation. This article is part of the themed issue ‘Patterning through instabilities in complex media: theory and applications.’ PMID:28373383

Feature-constrained surface reconstruction approach for point cloud data acquired with 3D laser scanner

NASA Astrophysics Data System (ADS)

Wang, Yongbo; Sheng, Yehua; Lu, Guonian; Tian, Peng; Zhang, Kai

2008-04-01

Surface reconstruction is an important task in the field of 3d-GIS, computer aided design and computer graphics (CAD & CG), virtual simulation and so on. Based on available incremental surface reconstruction methods, a feature-constrained surface reconstruction approach for point cloud is presented. Firstly features are extracted from point cloud under the rules of curvature extremes and minimum spanning tree. By projecting local sample points to the fitted tangent planes and using extracted features to guide and constrain the process of local triangulation and surface propagation, topological relationship among sample points can be achieved. For the constructed models, a process named consistent normal adjustment and regularization is adopted to adjust normal of each face so that the correct surface model is achieved. Experiments show that the presented approach inherits the convenient implementation and high efficiency of traditional incremental surface reconstruction method, meanwhile, it avoids improper propagation of normal across sharp edges, which means the applicability of incremental surface reconstruction is greatly improved. Above all, appropriate k-neighborhood can help to recognize un-sufficient sampled areas and boundary parts, the presented approach can be used to reconstruct both open and close surfaces without additional interference.

A conditional approach to determining the effect of anthropogenic climate change on very rare events.

NASA Astrophysics Data System (ADS)

Wehner, Michael; Pall, Pardeep; Zarzycki, Colin; Stone, Daithi

2016-04-01

Probabilistic extreme event attribution is especially difficult for weather events that are caused by extremely rare large-scale meteorological patterns. Traditional modeling techniques have involved using ensembles of climate models, either fully coupled or with prescribed ocean and sea ice. Ensemble sizes for the latter case ranges from several 100 to tens of thousand. However, even if the simulations are constrained by the observed ocean state, the requisite large-scale meteorological pattern may not occur frequently enough or even at all in free running climate model simulations. We present a method to ensure that simulated events similar to the observed event are modeled with enough fidelity that robust statistics can be determined given the large scale meteorological conditions. By initializing suitably constrained short term ensemble hindcasts of both the actual weather system and a counterfactual weather system where the human interference in the climate system is removed, the human contribution to the magnitude of the event can be determined. However, the change (if any) in the probability of an event of the observed magnitude is conditional not only on the state of the ocean/sea ice system but also on the prescribed initial conditions determined by the causal large scale meteorological pattern. We will discuss the implications of this technique through two examples; the 2013 Colorado flood and the 2014 Typhoon Haiyan.

Determination of Differential Emission Measure from Solar Extreme Ultraviolet Images

NASA Astrophysics Data System (ADS)

Su, Yang; Veronig, Astrid M.; Hannah, Iain G.; Cheung, Mark C. M.; Dennis, Brian R.; Holman, Gordon D.; Gan, Weiqun; Li, Youping

2018-03-01

The Atmospheric Imaging Assembly (AIA) on board the Solar Dynamic Observatory (SDO) has been providing high-cadence, high-resolution, full-disk UV-visible/extreme ultraviolet (EUV) images since 2010, with the best time coverage among all the solar missions. A number of codes have been developed to extract plasma differential emission measures (DEMs) from AIA images. Although widely used, they cannot effectively constrain the DEM at flaring temperatures with AIA data alone. This often results in much higher X-ray fluxes than observed. One way to solve the problem is by adding more constraint from other data sets (such as soft X-ray images and fluxes). However, the spatial information of plasma DEMs are lost in many cases. In this Letter, we present a different approach to constrain the DEMs. We tested the sparse inversion code and show that the default settings reproduce X-ray fluxes that could be too high. Based on the tests with both simulated and observed AIA data, we provided recommended settings of basis functions and tolerances. The new DEM solutions derived from AIA images alone are much more consistent with (thermal) X-ray observations, and provide valuable information by mapping the thermal plasma from ∼0.3 to ∼30 MK. Such improvement is a key step in understanding the nature of individual X-ray sources, and particularly important for studies of flare initiation.

Extremal Optimization for estimation of the error threshold in topological subsystem codes at T = 0

NASA Astrophysics Data System (ADS)

Millán-Otoya, Jorge E.; Boettcher, Stefan

2014-03-01

Quantum decoherence is a problem that arises in implementations of quantum computing proposals. Topological subsystem codes (TSC) have been suggested as a way to overcome decoherence. These offer a higher optimal error tolerance when compared to typical error-correcting algorithms. A TSC has been translated into a planar Ising spin-glass with constrained bimodal three-spin couplings. This spin-glass has been considered at finite temperature to determine the phase boundary between the unstable phase and the stable phase, where error recovery is possible.[1] We approach the study of the error threshold problem by exploring ground states of this spin-glass with the Extremal Optimization algorithm (EO).[2] EO has proven to be a effective heuristic to explore ground state configurations of glassy spin-systems.[3

A case study of arithmetic facts dyscalculia caused by a hypersensitivity-to-interference in memory.

PubMed

De Visscher, Alice; Noël, Marie-Pascale

2013-01-01

While the heterogeneity of developmental dyscalculia is increasingly recognized, the different profiles have not yet been clearly established. Among the features underpinning types of developmental dyscalculia suggested in the literature, an impairment in arithmetic fact retrieval is particularly prominent. In this paper, we present a case study of an adult woman (DB) with very good cognitive capacities suffering from a specific and developmental arithmetic fact retrieval deficit. We test the main hypotheses about developmental dyscalculia derived from literature. We first explore the influential hypothesis of an approximate number system deficit, through estimation tasks, comparison tasks and a priming comparison task. Secondly, we evaluate whether DB's mathematical deficiencies are caused by a rote verbal memory deficit, using tasks involving completion of expressions, and reciting automatic series such as the alphabet and the months of the year. Alternatively, taking into account the extreme similarity of the arithmetic facts, we propose that a heightened sensitivity to interference could have prevented DB from memorizing the arithmetic facts. The pattern of DB's results on different tasks supports this hypothesis. Our findings identify a new etiology of a specific impairment of arithmetic facts storage, namely a hypersensitivity-to-interference. Copyright © 2012 Elsevier Ltd. All rights reserved.

Pancreas and gallbladder agenesis in a newborn with semilobar holoprosencephaly, a case report.

PubMed

Hilbrands, Robert; Keymolen, Kathelijn; Michotte, Alex; Marichal, Miriam; Cools, Filip; Goossens, Anieta; Veld, Peter In't; De Schepper, Jean; Hattersley, Andrew; Heimberg, Harry

2017-05-19

Pancreatic agenesis is an extremely rare cause of neonatal diabetes mellitus and has enabled the discovery of several key transcription factors essential for normal pancreas and beta cell development. We report a case of a Caucasian female with complete pancreatic agenesis occurring together with semilobar holoprosencephaly (HPE), a more common brain developmental disorder. Clinical findings were later confirmed by autopsy, which also identified agenesis of the gallbladder. Although the sequences of a selected set of genes related to pancreas agenesis or HPE were wild-type, the patient's phenotype suggests a genetic defect that emerges early in embryonic development of brain, gallbladder and pancreas. Developmental defects of the pancreas and brain can occur together. Identifying the genetic defect may identify a novel key regulator in beta cell development.

Hip and upper extremity kinematics in youth baseball pitchers.

PubMed

Holt, Taylor; Oliver, Gretchen D

2016-01-01

The purpose of this study was to examine the relationship between dynamic hip rotational range of motion and upper extremity kinematics during baseball pitching. Thirty-one youth baseball pitchers (10.87 ± 0.92 years; 150.03 ± 5.48 cm; 44.83 ± 8.04 kg) participated. A strong correlation was found between stance hip rotation and scapular upward rotation at maximum shoulder external rotation (r = 0.531, P = 0.002) and at ball release (r = 0.536, P = 0.002). No statistically significant correlations were found between dynamic hip rotational range of motion and passive hip range of motion. Hip range of motion deficits can constrain pelvis rotation and limit energy generation in the lower extremities. Shoulder pathomechanics can then develop as greater responsibility is placed on the shoulder to generate the energy lost from the proximal segments, increasing risk of upper extremity injury. Additionally, it appears that passive seated measurements of hip range of motion may not accurately reflect the dynamic range of motion of the hips through the progression of the pitch cycle.

Developmental Constraints on Learning Artificial Grammars with Fixed, Flexible and Free Word Order

PubMed Central

Nowak, Iga; Baggio, Giosuè

2017-01-01

Human learning, although highly flexible and efficient, is constrained in ways that facilitate or impede the acquisition of certain systems of information. Some such constraints, active during infancy and childhood, have been proposed to account for the apparent ease with which typically developing children acquire language. In a series of experiments, we investigated the role of developmental constraints on learning artificial grammars with a distinction between shorter and relatively frequent words (‘function words,’ F-words) and longer and less frequent words (‘content words,’ C-words). We constructed 4 finite-state grammars, in which the order of F-words, relative to C-words, was either fixed (F-words always occupied the same positions in a string), flexible (every F-word always followed a C-word), or free. We exposed adults (N = 84) and kindergarten children (N = 100) to strings from each of these artificial grammars, and we assessed their ability to recognize strings with the same structure, but a different vocabulary. Adults were better at recognizing strings when regularities were available (i.e., fixed and flexible order grammars), while children were better at recognizing strings from the grammars consistent with the attested distribution of function and content words in natural languages (i.e., flexible and free order grammars). These results provide evidence for a link between developmental constraints on learning and linguistic typology. PMID:29089910

Plastic rates of development and the effect of thermal extremes on offspring fitness in a cold-climate viviparous lizard.

PubMed

Cunningham, George D; Fitzpatrick, Luisa J; While, Geoffrey M; Wapstra, Erik

2018-05-23

Populations at the climatic margins of a species' distribution can be exposed to conditions that cause developmental stress, resulting in developmental abnormalities. Even within the thermal range of normal development, phenotypes often vary with developmental temperature (i.e., thermal phenotypic plasticity). These effects can have significant consequences for organismal fitness and, thus, population persistence. Reptiles, as ectotherms, are particularly vulnerable to thermal effects on development and are, therefore, considered to be at comparatively high risk from changing climates. Understanding the extent and direction of thermal effects on phenotypes and their fitness consequences is crucial if we are to make meaningful predictions of how populations and species will respond as climates warm. Here, we experimentally manipulated the thermal conditions experienced by females from a high-altitude, cold-adapted population of the viviparous skink, Niveoscincus ocellatus, to examine the consequences of thermal conditions at the margins of this population's normal temperature range. We found strong effects of thermal conditions on the development of key phenotypic traits that have implications for fitness. Specifically, we found that offspring born earlier as a result of high temperatures during gestation had increased growth over the first winter of life, but there was no effect on offspring survival, nor was there an effect of developmental temperature on the incidence of developmental abnormalities. Combined, our results suggest that advancing birth dates that result from warming climates may have positive effects in this population via increased growth. © 2018 Wiley Periodicals, Inc.

Melorheostosis and a review of the literature in China

PubMed Central

Yang, Yi; Tang, Qi; Yao, Zhenjun

2013-01-01

Summary Melorheostosis is an uncommon, non-genetic, non-developmental, sclerosing dysplasia of bone and adjacent soft tissues, with deformity of the extremity, pain, limb stiffness and limitation of motion. The characteristic radiographic appearance consists of irregular hyperostotic changes of the cortex resembling melted wax dripping down the side of a candle. In this review, clinical characteristics of Melorheostosis are discussed and reports in the Chinese literature are summarized. PMID:25343102

Melorheostosis and a review of the literature in China.

PubMed

Zhang, Chi; Dai, Wenda; Yang, Yi; Tang, Qi; Yao, Zhenjun

2013-05-01

Melorheostosis is an uncommon, non-genetic, non-developmental, sclerosing dysplasia of bone and adjacent soft tissues, with deformity of the extremity, pain, limb stiffness and limitation of motion. The characteristic radiographic appearance consists of irregular hyperostotic changes of the cortex resembling melted wax dripping down the side of a candle. In this review, clinical characteristics of Melorheostosis are discussed and reports in the Chinese literature are summarized.

ELF (Extremely Low Frequency) Communications System Ecological Monitoring Program: Summary of 1987 Progress

DTIC Science & Technology

1989-04-01

Development . Prenatal developmental stages are especially sensitive to environmental perturbations. At present, there is conflicting evidence of direct EM...effects on embryonic or fetal development . In addition, possible effects of the ELF system on parental behavior could also have an indirect effect on... development . The purpose of this element is to determine the incidence of abnormalities in embryonic development in tree swallows at treatment and control

The utility of early developmental assessments on understanding later nonverbal IQ in children who are deaf or hard of hearing.

PubMed

Meinzen-Derr, Jareen; Wiley, Susan; Phillips, Jannel; Altaye, Mekibib; Choo, Daniel I

2017-01-01

In children who are deaf or hard of hearing (DHH), it is helpful to have meaningful early measures of development in order to provide effective interventions and offer benchmarks that help recognize varied developmental trajectories. The main objective of this study was to compare results of an early developmental assessment prior to 3 years of age to later nonverbal IQ assessed between 3 and 6 years of age in children who are DHH. This study included children 3-6 years of age with bilateral permanent hearing who were enrolled in a prospective cohort study on developmental outcomes. As part of the study, children received the Leiter International Performance Scale-Revised, which provided a nonverbal Brief IQ, as well as standardized language assessment and behavioral checklists. Children were included in this analysis if they had received an early developmental assessment with the Gesell Developmental Schedules-Revised as part of a clinical visit with a developmental pediatrician. Correlation coefficients and multiple regression analysis were used to associate the scores on the Gesell (using a developmental quotient) with scores on the Leiter-R Brief IQ. Forty-five participants who enrolled in the observational study had available evaluation results from the Gesell and complete Brief IQ results from the Leiter-R. The adaptive domain of the Gesell had good correlation (r = 0.61, p < 0.0001) with the Brief IQ on the Leiter-R. Children who had stable developmental or intelligence classifications based on scores (<70, 70 to <85, 85 to <100, ≥100) over time were older (>24 months) at the early Gesell assessment. Degree of hearing loss or maternal education did not appear to confound the relationship between the Gesell and the Leiter-R. The adaptive domain of the Gesell Developmental Schedules - Revised administered in early childhood (under 3 years of age) has good correlation with the nonverbal Brief IQ on the Leiter International Performance Scale-R. Because children who are DHH have a higher likelihood of having a developmental disability compared to the general population, early developmental assessments are often important. Although early developmental assessments have their limitations, our results indicate that they are fairly robust indicators of later development. Such early indicators can be extremely useful in the clinical and educational management of children who are DHH. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Object exploration in extremely preterm infants between 6 and 9 months and relation to cognitive and language development at 24 months.

PubMed

Zuccarini, Mariagrazia; Guarini, Annalisa; Savini, Silvia; Iverson, Jana M; Aureli, Tiziana; Alessandroni, Rosina; Faldella, Giacomo; Sansavini, Alessandra

2017-09-01

Although early object exploration is considered a key ability for subsequent achievements, very few studies have analyzed its development in extremely low gestational age infants (ELGA- GA <28 weeks), whose early motor skills are delayed. Moreover, no studies have examined its developmental relationship with cognitive and language skills. The present study examined developmental change in Motor Object Exploration (MOE) and different types of MOE (Holding, Oral, Manual and Manual Rhythmic Exploration) in 20 ELGA and 20 full term (FT) infants observed during mother-infant play interaction at 6 and 9 months. It also explored whether specific types of MOE were longitudinally related to 24-month language and cognitive abilities (GMDS-R scores). ELGA infants increased MOE duration from 6 to 9 months, eliminating the initial difference with FT infants. In addition, ELGA infants showed a different pattern of Oral Exploration, that did not increase at 6 months and decrease at 9 months. Oral and Manual Exploration durations at 6 months were longitudinally related to 24-month GMDS-R language and cognitive performance scores respectively. We discuss the relevance of assessing early exploratory abilities in ELGA infants in order to implement customized intervention programs for supporting the development of these skills. Copyright © 2017 Elsevier Ltd. All rights reserved.

Parent-of-origin growth effects and the evolution of hybrid inviability in dwarf hamsters.

PubMed

Brekke, Thomas D; Good, Jeffrey M

2014-11-01

Mammalian hybrids often show abnormal growth, indicating that developmental inviability may play an important role in mammalian speciation. Yet, it is unclear if this recurrent phenotype reflects a common genetic basis. Here, we describe extreme parent-of-origin-dependent growth in hybrids from crosses between two species of dwarf hamsters, Phodopus campbelli and Phodopus sungorus. One cross type resulted in massive placental and embryonic overgrowth, severe developmental defects, and maternal death. Embryos from the reciprocal cross were viable and normal sized, but adult hybrid males were relatively small. These effects are strikingly similar to patterns from several other mammalian hybrids. Using comparative sequence data from dwarf hamsters and several other hybridizing mammals, we argue that extreme hybrid growth can contribute to reproductive isolation during the early stages of species divergence. Next, we tested if abnormal growth in hybrid hamsters was associated with disrupted genomic imprinting. We found no association between imprinting status at several candidate genes and hybrid growth, though two interacting genes involved in embryonic growth did show reduced expression in overgrown hybrids. Collectively, our study indicates that growth-related hybrid inviability may play an important role in mammalian speciation but that the genetic underpinnings of these phenotypes remain unresolved. © 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.

Time-resolved Spectroscopy and Multi-color Photometry Of The Pulsating and Short-period Binary Subdwarf B Star Feige 48

NASA Astrophysics Data System (ADS)

Reed, Mike; Baran, A.; O'Toole, S.

2012-05-01

Pulsating subdwarf B (sdB) stars can be used as probes of the helium fusing cores of horizontal branch stars. To probe these stars, asteroseismology must be able to observationally associate pulsation frequencies with modes. Time-resolved spectroscopy and multicolor photometry have been employed with mixed results for short-period pulsating sdB stars. Time-resolved spectroscopy has successfully measured radial velocity, temperature, and gravity variations in six pulsators, yet interpreting results is far from straightforward. Multicolor photometry requires extremely high precision to discern between low-degree modes, yet has been used effectively to eliminate high-degree modes. Combining RV and multicolor measurements has also been shows as an effective means of constraining mode identifications. I will present results for Feige 48 using both time-resolved spectroscopy and multicolor photometry and attempts to constrain their pulsation modes using the atmospheric codes BRUCE and KYLIE.

The Hydrological Sensitivity to Global Warming and Solar Geoengineering Derived from Thermodynamic Constraints

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kleidon, Alex; Kravitz, Benjamin S.; Renner, Maik

2015-01-16

We derive analytic expressions of the transient response of the hydrological cycle to surface warming from an extremely simple energy balance model in which turbulent heat fluxes are constrained by the thermodynamic limit of maximum power. For a given magnitude of steady-state temperature change, this approach predicts the transient response as well as the steady-state change in surface energy partitioning and the hydrologic cycle. We show that the transient behavior of the simple model as well as the steady state hydrological sensitivities to greenhouse warming and solar geoengineering are comparable to results from simulations using highly complex models. Many ofmore » the global-scale hydrological cycle changes can be understood from a surface energy balance perspective, and our thermodynamically-constrained approach provides a physically robust way of estimating global hydrological changes in response to altered radiative forcing.« less

What We Have Learned About Clusters From a Decade of Arcsecond Resolution X-ray Observations

NASA Technical Reports Server (NTRS)

Markevitch, Maxim

2012-01-01

This talk will briefly review the main findings from Chandra high angular resolution observations of galaxy clusters, emphasizing results on cluster astrophysics. Chandra has discovered shock fronts in merging systems, providing information on the shock Mach number and velocity, and for best-observed shocks, constraining the microphysical properties of the intracluster medium (ICM). Cold fronts, a Chandra discovery, are ubiquitous both in merging clusters and in the cool ccres of relaxed systems. They reveal the structure and strength of the intracluster magnetic fields and constrain the ICM viscosity a combined with radio data, these observations also shed light on the production of ultra-relativistic particles that are known to coexist with thermal plasma. Finally, in nearly all cool cores, Chandra observes cavities in the ICM that are produced by the central AGN. All these phenomena will be extremely interesting for high-resolution SZ studies.

Highly damped kinematic coupling for precision instruments

DOEpatents

Hale, Layton C.; Jensen, Steven A.

2001-01-01

A highly damped kinematic coupling for precision instruments. The kinematic coupling provides support while causing essentially no influence to its nature shape, with such influences coming, for example, from manufacturing tolerances, temperature changes, or ground motion. The coupling uses three ball-cone constraints, each combined with a released flexural degree of freedom. This arrangement enables a gain of higher load capacity and stiffness, but can also significantly reduce the friction level in proportion to the ball radius divided by the distance between the ball and the hinge axis. The blade flexures reduces somewhat the stiffness of the coupling and provides an ideal location to apply constrained-layer damping which is accomplished by attaching a viscoelastic layer and a constraining layer on opposite sides of each of the blade flexures. The three identical ball-cone flexures provide a damped coupling mechanism to kinematically support the projection optics system of the extreme ultraviolet lithography (EUVL) system, or other load-sensitive apparatus.

Primary sex determination of placental mammals: a modelling study uncovers dynamical developmental constraints in the formation of Sertoli and granulosa cells.

PubMed

Sánchez, Lucas; Chaouiya, Claudine

2016-05-26

Primary sex determination in placental mammals is a very well studied developmental process. Here, we aim to investigate the currently established scenario and to assess its adequacy to fully recover the observed phenotypes, in the wild type and perturbed situations. Computational modelling allows clarifying network dynamics, elucidating crucial temporal constrains as well as interplay between core regulatory modules. Relying on a comprehensive revision of the literature, we define a logical model that integrates the current knowledge of the regulatory network controlling this developmental process. Our analysis indicates the necessity for some genes to operate at distinct functional thresholds and for specific developmental conditions to ensure the reproducibility of the sexual pathways followed by bi-potential gonads developing into either testes or ovaries. Our model thus allows studying the dynamics of wild type and mutant XX and XY gonads. Furthermore, the model analysis reveals that the gonad sexual fate results from the operation of two sub-networks associated respectively with an initiation and a maintenance phases. At the core of the process is the resolution of two connected feedback loops: the mutual inhibition of Sox9 and ß-catenin at the initiation phase, which in turn affects the mutual inhibition between Dmrt1 and Foxl2, at the maintenance phase. Three developmental signals related to the temporal activity of those sub-networks are required: a signal that determines Sry activation, marking the beginning of the initiation phase, and two further signals that define the transition from the initiation to the maintenance phases, by inhibiting the Wnt4 signalling pathway on the one hand, and by activating Foxl2 on the other hand. Our model reproduces a wide range of experimental data reported for the development of wild type and mutant gonads. It also provides a formal support to crucial aspects of the gonad sexual development and predicts gonadal phenotypes for mutations not tested yet.

Practical considerations in the development of hemoglobin-based oxygen therapeutics.

PubMed

Kim, Hae Won; Estep, Timothy N

2012-09-01

The development of hemoglobin based oxygen therapeutics (HBOCs) requires consideration of a number of factors. While the enabling technology derives from fundamental research on protein biochemistry and biological interactions, translation of these research insights into usable medical therapeutics demands the application of considerable technical expertise and consideration and reconciliation of a myriad of manufacturing, medical, and regulatory requirements. The HBOC development challenge is further exacerbated by the extremely high intravenous doses required for many of the indications contemplated for these products, which in turn implies an extremely high level of purity is required. This communication discusses several of the important product configuration and developmental considerations that impact the translation of fundamental research discoveries on HBOCs into usable medical therapeutics.

Are orchids left and dandelions right? Frontal brain activation asymmetry and its sensitivity to developmental context.

PubMed

Fortier, Paz; Van Lieshout, Ryan J; Waxman, Jordana A; Boyle, Michael H; Saigal, Saroj; Schmidt, Louis A

2014-08-01

To clarify long-standing conceptual and empirical inconsistencies in models describing the relation between frontal brain asymmetry and emotion, we tested a theory of biological sensitivity to context. We examined whether asymmetry of alpha activation in frontal brain regions, as measured by resting electroencephalography, is sensitive to early developmental contexts. Specifically, we investigated whether frontal asymmetry moderates the association between birth weight and adult outcomes. Adults with left frontal asymmetry (LFA) who were born at extremely low birth weight exhibited high levels of attention problems and withdrawn behaviors in their 30s, whereas normal-birth-weight adults with LFA had low levels of these problem behaviors. Adults with right frontal asymmetry (RFA) displayed a relatively moderate amount of problem behavior regardless of birth weight. Our findings suggest that LFA is associated with sensitivity to developmental context and may help explain why LFA is associated with both positive and negative outcomes, whereas RFA seems to be associated with a more canalized process in some contexts. © The Author(s) 2014.

Neighborhood and school ethnic structuring and cultural adaptations among Mexican-origin adolescents.

PubMed

White, Rebecca M B; Updegraff, Kimberly A; Umaña-Taylor, Adriana J; Zeiders, Katharine H; Perez-Brena, Norma; Burleson, Elizabeth

2017-03-01

The ethnic and racial structuring of U.S. neighborhoods may have important implications for developmental competencies during adolescence, including the development of heritage and mainstream cultural orientations. In particular, living in highly concentrated Latino neighborhoods during early adolescence-which channels adolescents into related school environments-may promote retention of the ethnic or heritage culture, but it also may constrain adaptation to the mainstream U.S. culture. We tested these hypotheses longitudinally in a sample of 246 Mexican origin adolescents (50.8% girls) and their parents. Data were collected 4 times over 8 years, with adolescents averaging 12.5 (SD = .58) to 19.6 (SD = .66) years of age across the period of the study. Latino ethnic concentration in early adolescents' neighborhoods promoted the retention of Mexican cultural orientations; Latino ethnic concentration in middle schools undermined the development of mainstream U.S cultural orientations. Findings are discussed in terms of integrating cultural-developmental theory with mainstream neighborhood theory to improve understandings of neighborhood and school ethnic concentration effects on adolescent development. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Neighborhood and School Ethnic Structuring and Cultural Adaptations Among Mexican-Origin Adolescents

PubMed Central

White, Rebecca M. B.; Updegraff, Kimberly A.; Umaña-Taylor, Adriana J.; Zeiders, Katharine H.; Perez-Brena, Norma; Burleson, Elizabeth

2016-01-01

The ethnic and racial structuring of U.S. neighborhoods may have important implications for developmental competencies during adolescence, including the development of heritage and mainstream cultural orientations. In particular, living in highly concentrated Latino neighborhoods during early adolescence – which channels adolescents into related school environments – may promote retention of the ethnic or heritage culture, but it also may constrain adaptation to the mainstream U.S. culture. We tested these hypotheses longitudinally in a sample of 246 Mexican origin adolescents (50.8% girls) and their parents. Data were collected four times over eight years, with adolescents averaging 12.5 (SD = .58) to 19.6 (SD = .66) years of age across the period of the study. Latino ethnic concentration in early adolescents' neighborhoods promoted the retention of Mexican cultural orientations; Latino ethnic concentration in middle schools undermined the development of mainstream U.S cultural orientations. Findings are discussed in terms of integrating cultural-developmental theory with mainstream neighborhood theory to improve understandings of neighborhood and school ethnic concentration effects on adolescent development. PMID:27936822

Morphological integration in the appendicular skeleton of two domestic taxa: the horse and donkey.

PubMed

Hanot, Pauline; Herrel, Anthony; Guintard, Claude; Cornette, Raphaël

2017-10-11

Organisms are organized into suites of anatomical structures that typically covary when developmentally or functionally related, and this morphological integration plays a determinant role in evolutionary processes. Artificial selection on domestic species causes strong morphological changes over short time spans, frequently resulting in a wide and exaggerated phenotypic diversity. This raises the question of whether integration constrains the morphological diversification of domestic species and how natural and artificial selection may impact integration patterns. Here, we study the morphological integration in the appendicular skeleton of domestic horses and donkeys, using three-dimensional geometric morphometrics on 75 skeletons. Our results indicate that a strong integration is inherited from developmental mechanisms which interact with functional factors. This strong integration reveals a specialization in the locomotion of domestic equids, partly for running abilities. We show that the integration is stronger in horses than in donkeys, probably because of a greater degree of specialization and predictability of their locomotion. Thus, the constraints imposed by integration are weak enough to allow important morphological changes and the phenotypic diversification of domestic species. © 2017 The Author(s).

A Novel Experimental and Analytical Approach to the Multimodal Neural Decoding of Intent During Social Interaction in Freely-behaving Human Infants.

PubMed

Cruz-Garza, Jesus G; Hernandez, Zachery R; Tse, Teresa; Caducoy, Eunice; Abibullaev, Berdakh; Contreras-Vidal, Jose L

2015-10-04

Understanding typical and atypical development remains one of the fundamental questions in developmental human neuroscience. Traditionally, experimental paradigms and analysis tools have been limited to constrained laboratory tasks and contexts due to technical limitations imposed by the available set of measuring and analysis techniques and the age of the subjects. These limitations severely limit the study of developmental neural dynamics and associated neural networks engaged in cognition, perception and action in infants performing "in action and in context". This protocol presents a novel approach to study infants and young children as they freely organize their own behavior, and its consequences in a complex, partly unpredictable and highly dynamic environment. The proposed methodology integrates synchronized high-density active scalp electroencephalography (EEG), inertial measurement units (IMUs), video recording and behavioral analysis to capture brain activity and movement non-invasively in freely-behaving infants. This setup allows for the study of neural network dynamics in the developing brain, in action and context, as these networks are recruited during goal-oriented, exploration and social interaction tasks.

Magma storage prior to the 1912 eruption at Novarupta, Alaska

USGS Publications Warehouse

Hammer, J.E.; Rutherford, M.J.; Hildreth, W.

2002-01-01

New analytical and experimental data constrain the storage and equilibration conditions of the magmas erupted in 1912 from Novarupta in the 20th century's largest volcanic event. Phase relations at H2O+CO2 fluid saturation were determined for an andesite (58.7 wt% SiO2) and a dacite (67.7 wt%) from the compositional extremes of intermediate magmas erupted. The phase assemblages, matrix melt composition and modes of natural andesite were reproduced experimentally under H2O-saturated conditions (i.e., PH2O=PTOT) in a negatively sloping region in T-P space from 930 ??C/100 MPa to 960 ??C/75 MPa with fO2???N NO + 1. The H2O-saturated equilibration conditions of the dacite are constrained to a T-P region from 850 ??C/ 50 MPa to 880 ??C/25 MPa. If H2O-saturated, these magmas equilibrated at (and above) the level where coerupted rhyolite equilibrated (???100 MPa), suggesting that the andesite-dacite magma reservoir was displaced laterally rather than vertically from the rhyolite magma body. Natural mineral and melt compositions of intermediate magmas were also reproduced experimentally under saturation conditions with a mixed (H2O + CO2) fluid for the same range in PH2O. Thus, a storage model in which vertically stratified mafic to silicic intermediate magmas underlay H2O-saturated rhyolite is consistent with experimental findings only if the intermediates have XH2Ofl=0.7 and 0.9 for the extreme compositions, respectively. Disequilibrium features in natural pumice and scoria include pristine minerals existing outside their stability fields, and compositional zoning of titanomagnetite in contact with ilmenite. Variable rates of chemical equilibration which would eliminate these features constrain the apparent thermal excursion and re-distribution of minerals to the time scale of days.

Preservation of REE and Fe isotopes in altered stromatolites and the paleo-environmental record

NASA Astrophysics Data System (ADS)

Nies, S. M.; Shapiro, R. S.; Lalonde, S.

2015-12-01

Geochemical proxies are increasingly being used to unravel ancient ecosystems and environmental perturbations back to the earliest rock record on Earth. Along with more traditional fossils (stromatolites) and other biosignatures (e.g., lipids), the geochemical record is used specifically to evaluate biogenecity and to understand oxygenation of the atmosphere and ocean in the Archean and Paleoproterozoic. However, the effects of diagenesis, metamorphism, and other modes of secondary alteration are still poorly constrained, particularly as technological advances allow us to expand farther across the periodic table. Our study focused on the robustness and preservation of rare earth element (REE) and Fe isotope compositions of two stromatolitic units that have undergone contact and regional metamorphism. 18 samples were collected from cores, open pit mines, and field locations in Minnesota and Ontario from silicified iron formation (Biwabik-Gunflint formations). The samples were carefully constrained to one of two meter-scale stromatolitic units. Metamorphic grade ranged from essentially unmetamorphosed through prehnite-pumpellyite up to amphibolite (fayalite+hypersthene). Samples were also collected that represented deep secondary weathering, likely related to Cretaceous climatic extremes. Polished samples were first analyzed by electron microprobe and selected samples were further analyzed via laser ablation HR-ICP-MS to constrain trace element (n=13) and Fe isotopic variations (n=8). Preliminary results indicate that transition metal concentrations are surprisingly resilient to high-temperature metamorphic recrystallization. REE concentrations were analyzed in individual iron oxide grains, with full resolution (La to Lu) achieved for some samples and partial resolution (La to Nd) achieved for all samples. Core samples exhibited a relatively stable positive Ce anomaly occurring from low to extremely high alteration. Outcrop and mine samples indicate a shift from a negative Ce anomaly in less altered samples, to a positive Ce anomaly in highly altered samples. Collectively, our results imply that caution is warranted when making paleo-environmental inferences from samples with significantly different alteration histories.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gair, Jonathan R.; Tang, Christopher; Volonteri, Marta

One of the sources of gravitational waves for the proposed space-based gravitational wave detector, the Laser Interferometer Space Antenna (LISA), are the inspirals of compact objects into supermassive black holes in the centers of galaxies--extreme-mass-ratio inspirals (EMRIs). Using LISA observations, we will be able to measure the parameters of each EMRI system detected to very high precision. However, the statistics of the set of EMRI events observed by LISA will be more important in constraining astrophysical models than extremely precise measurements for individual systems. The black holes to which LISA is most sensitive are in a mass range that ismore » difficult to probe using other techniques, so LISA provides an almost unique window onto these objects. In this paper we explore, using Bayesian techniques, the constraints that LISA EMRI observations can place on the mass function of black holes at low redshift. We describe a general framework for approaching inference of this type--using multiple observations in combination to constrain a parametrized source population. Assuming that the scaling of the EMRI rate with the black-hole mass is known and taking a black-hole distribution given by a simple power law, dn/dlnM=A{sub 0}(M/M{sub *}){sup {alpha}}{sub 0}, we find that LISA could measure the parameters to a precision of {Delta}(lnA{sub 0}){approx}0.08, and {Delta}({alpha}{sub 0}){approx}0.03 for a reference model that predicts {approx}1000 events. Even with as few as 10 events, LISA should constrain the slope to a precision {approx}0.3, which is the current level of observational uncertainty in the low-mass slope of the black-hole mass function. We also consider a model in which A{sub 0} and {alpha}{sub 0} evolve with redshift, but find that EMRI observations alone do not have much power to probe such an evolution.« less

Neurodevelopmental outcome and growth at 18 to 22 months' corrected age in extremely low birth weight infants treated with early erythropoietin and iron.

PubMed

Ohls, Robin K; Ehrenkranz, Richard A; Das, Abhik; Dusick, Anna M; Yolton, Kimberly; Romano, Elaine; Delaney-Black, Virginia; Papile, Lu-Ann; Simon, Neal P; Steichen, Jean J; Lee, Kimberly G

2004-11-01

Clinical trials evaluating the use of erythropoietin (Epo) have demonstrated a limited reduction in transfusions; however, long-term developmental follow-up data are scarce. We compared anthropometric measurements, postdischarge events, need for transfusions, and developmental outcomes at 18 to 22 months' corrected age in extremely low birth weight (ELBW) infants treated with early Epo and supplemental iron therapy with that of placebo/control infants treated with supplemental iron alone. The National Institute of Child Health and Human Development Neonatal Research Network completed a randomized, controlled trial of early Epo and iron therapy in preterm infants < or =1250 g. A total of 172 ELBW (< or =1000-g birth weight) infants were enrolled (87 Epo and 85 placebo/control). Of the 72 Epo-treated and 70 placebo/control ELBW infants surviving to discharge, follow-up data (growth, development, rehospitalization, transfusions) at 18 to 22 months' corrected age were collected on 51 of 72 Epo-treated infants (71%) and 51 of 70 placebo/controls (73%) by certified examiners masked to the treatment group. Statistical significance was determined using chi2 analysis. There were no significant differences between treatment groups in weight or length or in the percentage of infants weighing <10th percentile either at the time of discharge or at follow-up, and no difference was found in the mean head circumference between groups. A similar percentage of infants in each group was rehospitalized (38% Epo and 35% placebo/control) for similar reasons. There were no differences between groups with respect to the percentage of infants with Bayley-II Mental Developmental Index <70 (34% Epo and 36% placebo/control), blindness (0% Epo and 2% placebo/control), deafness or hearing loss requiring amplification (2% Epo and 2% placebo/control), moderate to severe cerebral palsy (16% Epo and 18% placebo/control) or the percentage of infants with any of the above-described neurodevelopmental impairments (42% Epo and 44% placebo/control). Treatment of ELBW infants with early Epo and iron does not significantly influence anthropometric measurements, need for rehospitalization, transfusions after discharge, or developmental outcome at 18 to 22 months' corrected age.

Evolution of brain and culture: the neurological and cognitive journey from Australopithecus to Albert Einstein.

PubMed

Falk, Dean

2016-06-20

Fossil and comparative primatological evidence suggest that alterations in the development of prehistoric hominin infants kindled three consecutive evolutionary-developmental (evo-devo) trends that, ultimately, paved the way for the evolution of the human brain and cognition. In the earliest trend, infants' development of posture and locomotion became delayed because of anatomical changes that accompanied the prolonged evolution of bipedalism. Because modern humans have inherited these changes, our babies are much slower than other primates to reach developmental milestones such as standing, crawling, and walking. The delay in ancestral babies' physical development eventually precipitated an evolutionary reversal in which they became increasing unable to cling independently to their mothers. For the first time in prehistory, babies were, thus, periodically deprived of direct physical contact with their mothers. This prompted the emergence of a second evo-devo trend in which infants sought contact comfort from caregivers using evolved signals, including new ways of crying that are conserved in modern babies. Such signaling stimulated intense reciprocal interactions between prehistoric mothers and infants that seeded the eventual emergence of motherese and, subsequently, protolanguage. The third trend was for an extreme acceleration in brain growth that began prior to the last trimester of gestation and continued through infants' first postnatal year (early "brain spurt"). Conservation of this trend in modern babies explains why human brains reach adult sizes that are over three times those of chimpanzees. The fossil record of hominin cranial capacities together with comparative neuroanatomical data suggest that, around 3 million years ago, early brain spurts began to facilitate an evolutionary trajectory for increasingly large adult brains in association with neurological reorganization. The prehistoric increase in brain size eventually caused parturition to become exceedingly difficult, and this difficulty, known as the "obstetrical dilemma", is likely to constrain the future evolution of brain size and, thus, privilege ongoing evolution in neurological reorganization. In modern babies, the brain spurt is accompanied by formation and tuning (pruning) of neurological connections, and development of dynamic higher-order networks that facilitate acquisition of grammatical language and, later in development, other advanced computational abilities such as musical or mathematical perception and performance. The cumulative evidence suggests that the emergence and refinement of grammatical language was a prime mover of hominin brain evolution.

The evolution of environmental and genetic sex determination in fluctuating environments.

PubMed

Van Dooren, Tom J M; Leimar, Olof

2003-12-01

Twenty years ago, Bulmer and Bull suggested that disruptive selection, produced by environmental fluctuations, can result in an evolutionary transition from environmental sex determination (ESD) to genetic sex determination (GSD). We investigated the feasibility of such a process, using mutation-limited adaptive dynamics and individual-based computer simulations. Our model describes the evolution of a reaction norm for sex determination in a metapopulation setting with partial migration and variation in an environmental variable both within and between local patches. The reaction norm represents the probability of becoming a female as a function of environmental state and was modeled as a sigmoid function with two parameters, one giving the location (i.e., the value of the environmental variable for which an individual has equal chance of becoming either sex) and the other giving the slope of the reaction norm for that environment. The slope can be interpreted as being set by the level of developmental noise in morph determination, with less noise giving a steeper slope and a more switchlike reaction norm. We found convergence stable reaction norms with intermediate to large amounts of developmental noise for conditions characterized by low migration rates, small differential competitive advantages between the sexes over environments, and little variation between individual environments within patches compared to variation between patches. We also considered reaction norms with the slope parameter constrained to a high value, corresponding to little developmental noise. For these we found evolutionary branching in the location parameter and a transition from ESD toward GSD, analogous to the original analysis by Bulmer and Bull. Further evolutionary change, including dominance evolution, produced a polymorphism acting as a GSD system with heterogamety. Our results point to the role of developmental noise in the evolution of sex determination.

Control pole placement relationships

NASA Technical Reports Server (NTRS)

Ainsworth, O. R.

1982-01-01

Using a simplified Large Space Structure (LSS) model, a technique was developed which gives algebraic relationships for the unconstrained poles. The relationships, which were obtained by this technique, are functions of the structural characteristics and the control gains. Extremely interesting relationships evolve for the case when the structural damping is zero. If the damping is zero, the constrained poles are uncoupled from the structural mode shapes. These relationships, which are derived for structural damping and without structural damping, provide new insight into the migration of the unconstrained poles for the CFPPS.

Developmental Outcomes of Extremely Preterm Infants Born to Adolescent Mothers

PubMed Central

Bann, Carla; Higgins, Rosemary; Vohr, Betty

2015-01-01

BACKGROUND AND OBJECTIVES: Extremely preterm infants and infants born to adolescent mothers are at risk for adverse developmental. The objectives were to evaluate development and behavior outcomes of extremely low birth weight (ELBW) infants born to adolescent mothers <20 compared with adult mothers ≥20 years and to identify socioeconomic risk factors that affect outcomes. METHODS: Retrospective cohort analysis of 211 infants >27 weeks of adolescent mothers and 1723 infants of adult mothers at Neonatal Research Network centers from 2008 to 2011. Groups were compared and regression models were run to predict 18- to 22-month adverse outcomes. Primary outcomes were Bayley-III scores, neurodevelopmental impairment, and Brief Infant Toddler Social Emotional Assessment problem scores (BITSEA/P) ≥75th percentile. RESULTS: Adolescent mothers were more often single, Hispanic, less educated, and had public insurance. By 18 to 22 months, their children had significantly increased rates of having lived ≥3 places (21% vs 9%), state supervision (7% vs 3%), rehospitalization (56% vs 46%), and BITSEA/P ≥75th percentile (50% vs 32%) and nonsignificant Bayley-III language scores <85 (56% vs 49%, P = .07). In regression analysis, children of adolescent mothers were more likely to have BITSEA/P ≥75th percentile (relative risk 1.50, 95% confidence interval 1.08–2.07). Living ≥3 places and nonwhite race were predictors of adverse behavior. State supervision was an independent predictor of each Bayley-III composite <70 and neurodevelopmental impairment. CONCLUSIONS: ELBW infants of adolescent mothers experience high social and environmental risks that are associated with adverse behavior outcomes. These findings inform the need for comprehensive follow-up, coordinated care services, and behavior interventions for ELBW infants of adolescent mothers. PMID:25963007

Development and evolution of extreme synorganization in angiosperm flowers and diversity: a comparison of Apocynaceae and Orchidaceae.

PubMed

Endress, Peter K

2016-04-01

Apocynaceae and Orchidaceae are two angiosperm families with extreme flower synorganization. They are unrelated, the former in eudicots, the latter in monocots, but they converge in the formation of pollinia and pollinaria, which do not occur in any other angiosperm family, and for which extreme synorganization of floral organs is a precondition. In each family extensive studies on flower development and evolution have been performed; however, newer comparative studies focusing on flower synorganization and involving both families together are lacking. For this study an extensive search through the morphological literature has been conducted. Based on this and my own studies on flowers in various Apocynaceae and Orchidaceae and complex flowers in other angiosperms with scanning electron microscopy and with microtome section series, a review on convergent floral traits in flower development and architecture in the two families is presented. There is a tendency of protracted development of synorganized parts in Apocynaceae and Orchidaceae (development of synorganization of two or more organs begins earlier the more accentuated it is at anthesis). Synorganization (or complexity) also paves the way for novel structures. One of the most conspicuous such novel structures in Apocynaceae is the corona, which is not the product of synorganization of existing organs; however, it is probably enhanced by synorganization of other, existing, floral parts. In contrast to synorganized parts, the corona appears developmentally late. Synorganization of floral organs may lead to a large number of convergences in clades that are only very distantly related. The convergences that have been highlighted in this comparative study should be developmentally investigated directly in parallel in future studies. © The Author 2015. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Learning Disabilities in Extremely Low Birth Weight Children and Neurodevelopmental Profiles at Preschool Age.

PubMed

Squarza, Chiara; Picciolini, Odoardo; Gardon, Laura; Giannì, Maria L; Murru, Alessandra; Gangi, Silvana; Cortinovis, Ivan; Milani, Silvano; Mosca, Fabio

2016-01-01

At school age extremely low birth weight (ELBW) and extremely low gestational age (ELGAN) children are more likely to show Learning Disabilities (LDs) and difficulties in emotional regulation. The aim of this study was to investigate the incidence of LDs at school age and to detect neurodevelopmental indicators of risk for LDs at preschool ages in a cohort of ELBW/ELGAN children with broadly average intelligence. All consecutively newborns 2001-2006 admitted to the same Institution entered the study. Inclusion criteria were BW < 1000 g and/or GA < 28 weeks. Exclusion criteria were severe cerebral injuries, neurosensory disabilities, genetic abnormalities, and/or a Developmental Quotient below normal limits (< 1 SD) at 6 years. The presence of learning disabilities at school age was investigated through a parent-report questionnaire at children's age range 9-10 years. Neurodevelopmental profiles were assessed through the Griffiths Mental Development Scales at 1 and 2 years of corrected age and at 3, 4, 5, and 6 years of chronological age and were analyzed comparing two groups of children: those with LDs and those without. At school age 24 on 102 (23.5%) of our ELBW/ELGAN children met criteria for LDs in one or more areas, with 70.8% comorbidity with emotional/attention difficulties. Children with LDs scored significantly lower in the Griffiths Locomotor and Language subscales at 2 years of corrected age and in the Personal-social, Performance and Practical Reasoning subscales at 5 years of chronological age. Our findings suggest that, among the early developmental indicators of adverse school outcome, there is a poor motor experimentation, language delay, and personal-social immaturity. Cognitive rigidity and poor ability to manage practical situations also affect academic attainment. Timely detection of these early indicators of risk is crucial to assist the transition to school.

Development and evolution of extreme synorganization in angiosperm flowers and diversity: a comparison of Apocynaceae and Orchidaceae

PubMed Central

Endress, Peter K.

2016-01-01

Background and Aims Apocynaceae and Orchidaceae are two angiosperm families with extreme flower synorganization. They are unrelated, the former in eudicots, the latter in monocots, but they converge in the formation of pollinia and pollinaria, which do not occur in any other angiosperm family, and for which extreme synorganization of floral organs is a precondition. In each family extensive studies on flower development and evolution have been performed; however, newer comparative studies focusing on flower synorganization and involving both families together are lacking. Scope For this study an extensive search through the morphological literature has been conducted. Based on this and my own studies on flowers in various Apocynaceae and Orchidaceae and complex flowers in other angiosperms with scanning electron microscopy and with microtome section series, a review on convergent floral traits in flower development and architecture in the two families is presented. Key Findings There is a tendency of protracted development of synorganized parts in Apocynaceae and Orchidaceae (development of synorganization of two or more organs begins earlier the more accentuated it is at anthesis). Synorganization (or complexity) also paves the way for novel structures. One of the most conspicuous such novel structures in Apocynaceae is the corona, which is not the product of synorganization of existing organs; however, it is probably enhanced by synorganization of other, existing, floral parts. In contrast to synorganized parts, the corona appears developmentally late. Conclusions Synorganization of floral organs may lead to a large number of convergences in clades that are only very distantly related. The convergences that have been highlighted in this comparative study should be developmentally investigated directly in parallel in future studies. PMID:26292994

Development of a Serial Order in Speech Constrained by Articulatory Coordination

PubMed Central

Oohashi, Hiroki; Watanabe, Hama; Taga, Gentaro

2013-01-01

Universal linguistic constraints seem to govern the organization of sound sequences in words. However, our understanding of the origin and development of these constraints is incomplete. One possibility is that the development of neuromuscular control of articulators acts as a constraint for the emergence of sequences in words. Repetitions of the same consonant observed in early infancy and an increase in variation of consonantal sequences over months of age have been interpreted as a consequence of the development of neuromuscular control. Yet, it is not clear how sequential coordination of articulators such as lips, tongue apex and tongue dorsum constrains sequences of labial, coronal and dorsal consonants in words over the course of development. We examined longitudinal development of consonant-vowel-consonant(-vowel) sequences produced by Japanese children between 7 and 60 months of age. The sequences were classified according to places of articulation for corresponding consonants. The analyses of individual and group data show that infants prefer repetitive and fronting articulations, as shown in previous studies. Furthermore, we reveal that serial order of different places of articulations within the same organ appears earlier and then gradually develops, whereas serial order of different articulatory organs appears later and then rapidly develops. In the same way, we also analyzed the sequences produced by English children and obtained similar developmental trends. These results suggest that the development of intra- and inter-articulator coordination constrains the acquisition of serial orders in speech with the complexity that characterizes adult language. PMID:24223827

An atypical case of SCN9A mutation presenting with global motor delay and a severe pain disorder.

PubMed

Meijer, Inge Anita; Vanasse, Michel; Nizard, Sonia; Robitaille, Yves; Rossignol, Elsa

2014-01-01

Erythromelalgia due to heterozygous gain-of-function SCN9A mutations usually presents as a pure sensory-autonomic disorder characterized by recurrent episodes of burning pain and redness of the extremities. We describe a patient with an unusual phenotypic presentation of gross motor delay, childhood-onset erythromelalgia, extreme visceral pain episodes, hypesthesia, and self-mutilation. The investigation of the patient's motor delay included various biochemical analyses, a comparative genomic hybridization array (CGH), electromyogram (EMG), and muscle biopsy. Once erythromelalgia was suspected clinically, the SCN9A gene was sequenced. The EMG, CGH, and biochemical tests were negative. The biopsy showed an axonal neuropathy and neurogenic atrophy. Sequencing of SCN9A revealed a heterozygous missense mutation in exon 7; p.I234T. This is a case of global motor delay and erythromelalgia associated with SCN9A. The motor delay may be attributed to the extreme pain episodes or to a developmental perturbation of proprioceptive inputs. Copyright © 2013 Wiley Periodicals, Inc.

Mechanisms and pathways of growth failure in primordial dwarfism.

PubMed

Klingseisen, Anna; Jackson, Andrew P

2011-10-01

The greatest difference between species is size; however, the developmental mechanisms determining organism growth remain poorly understood. Primordial dwarfism is a group of human single-gene disorders with extreme global growth failure (which includes Seckel syndrome, microcephalic osteodysplastic primordial dwarfism I [MOPD] types I and II, and Meier-Gorlin syndrome). Ten genes have now been identified for microcephalic primordial dwarfism, encoding proteins involved in fundamental cellular processes including genome replication (ORC1 [origin recognition complex 1], ORC4, ORC6, CDT1, and CDC6), DNA damage response (ATR [ataxia-telangiectasia and Rad3-related]), mRNA splicing (U4atac), and centrosome function (CEP152, PCNT, and CPAP). Here, we review the cellular and developmental mechanisms underlying the pathogenesis of these conditions and address whether further study of these genes could provide novel insight into the physiological regulation of organism growth.

Poverty eradication in a carbon constrained world.

PubMed

Hubacek, Klaus; Baiocchi, Giovanni; Feng, Kuishuang; Patwardhan, Anand

2017-10-24

The UN Framework Convention on Climate Change aims to keep warming below 2 °C while recognizing developing countries' right to eradicate extreme poverty. Poverty eradication is also the first of the Sustainable Development Goals. This paper investigates potential consequences for climate targets of achieving poverty eradication. We find that eradicating extreme poverty, i.e., moving people to an income above $1.9 purchasing power parity (PPP) a day, does not jeopardize the climate target even in the absence of climate policies and with current technologies. On the other hand, bringing everybody to a still modest expenditure level of at least $2.97 PPP would have long-term consequences on achieving emission targets. Compared to the reference mitigation pathway, eradicating extreme poverty increases the effort by 2.8% whereas bringing everybody to at least $2.97 PPP would increase the required mitigation rate by 27%. Given that the top 10% global income earners are responsible for 36% of the current carbon footprint of households; the discourse should address income distribution and the carbon intensity of lifestyles.

The Spawns of Creative Behavior in Team Sports: A Creativity Developmental Framework.

PubMed

Santos, Sara D L; Memmert, Daniel; Sampaio, Jaime; Leite, Nuno

2016-01-01

Developing creativity in team sports players is becoming an increasing focus in sports sciences. The Creativity Developmental Framework is presented to provide an updated science based background. This Framework describes five incremental creative stages (beginner, explorer, illuminati, creator, and rise) and combines them into multidisciplinary approaches embodied in creative assumptions. In the first training stages, the emphasis is placed on the enrollment in diversification, deliberate play and physical literacy approaches grounded in nonlinear pedagogies. These approaches allow more freedom to discover different movement patterns increasing the likelihood of emerging novel, adaptive and functional solutions. In the later stages, the progressive specialization in sports and the differential learning commitment are extremely important to push the limits of the creative progress at higher levels of performance by increasing the range of skills configurations. Notwithstanding, during all developmental stages the teaching games for understanding, a game-centered approach, linked with the constraints-led approach play an important role to boost the tactical creative behavior. Both perspectives might encourage players to explore all actions possibilities (improving divergent thinking) and prevents the standardization in their actions. Overall, considering the aforementioned practice conditions the Creativity Developmental Framework scrutinizes the main directions that lead to a long-term improvement of the creative behavior in team sports. Nevertheless, this framework should be seen as a work in progress to be later used as the paramount reference in creativity training.

The Spawns of Creative Behavior in Team Sports: A Creativity Developmental Framework

PubMed Central

Santos, Sara D. L.; Memmert, Daniel; Sampaio, Jaime; Leite, Nuno

2016-01-01

Developing creativity in team sports players is becoming an increasing focus in sports sciences. The Creativity Developmental Framework is presented to provide an updated science based background. This Framework describes five incremental creative stages (beginner, explorer, illuminati, creator, and rise) and combines them into multidisciplinary approaches embodied in creative assumptions. In the first training stages, the emphasis is placed on the enrollment in diversification, deliberate play and physical literacy approaches grounded in nonlinear pedagogies. These approaches allow more freedom to discover different movement patterns increasing the likelihood of emerging novel, adaptive and functional solutions. In the later stages, the progressive specialization in sports and the differential learning commitment are extremely important to push the limits of the creative progress at higher levels of performance by increasing the range of skills configurations. Notwithstanding, during all developmental stages the teaching games for understanding, a game-centered approach, linked with the constraints-led approach play an important role to boost the tactical creative behavior. Both perspectives might encourage players to explore all actions possibilities (improving divergent thinking) and prevents the standardization in their actions. Overall, considering the aforementioned practice conditions the Creativity Developmental Framework scrutinizes the main directions that lead to a long-term improvement of the creative behavior in team sports. Nevertheless, this framework should be seen as a work in progress to be later used as the paramount reference in creativity training. PMID:27617000

Neurodevelopmental surveillance in the first 2 years after extremely preterm birth: evidence, challenges, and guidelines.

PubMed

Msall, Michael E

2006-03-01

During the past decade, major advances in maternal-fetal medicine and neonatology have resulted in unprecedented survival of very preterm babies. These babies represent a small fraction of infants born preterm, but present significant challenges with respect to respiratory, nutritional, and developmental vulnerabilities. Several efforts involving the UK, US, Canada, Australia, and the Netherlands have provided information on regional trends over time with respect to neonatal morbidities and neurodevelopmental outcomes through the first two years of life. Historically gross and fine motor, cognitive and communicative skills, vision and hearing performance have been the focus of assessment. Indicators of major neurodevelopmental disabilities at 2 years have included presence of severe neurosensory impairment, i.e. cerebral palsy, sensorineural hearing loss requiring aides, and blindness. In addition cognitive developmental disability has been generally defined as a Bayley MDI or developmental quotient <70, i.e. lower than 2 standard deviations below the mean. However these outcomes cannot reliably capture trajectories of resiliency as well as more complex developmental challenges in the domains of coordination, perception, attention, communication, and learning. Recently tools have become available for assessing functional status in gross motor, communicative, adaptive and social-emotional behaviours of imitation, regulation, and play. This review will describe the major progress in assessing early neurodevelopmental status of vulnerable survivors receiving new biomedical technologies, highlight challenges, and propose guidelines based on current best evidence.

Temporal genetic structure in a poecilogonous polychaete: the interplay of developmental mode and environmental stochasticity

PubMed Central

2014-01-01

Background Temporal variation in the genetic structure of populations can be caused by multiple factors, including natural selection, stochastic environmental variation, migration, or genetic drift. In benthic marine species, the developmental mode of larvae may indicate a possibility for temporal genetic variation: species with dispersive planktonic larvae are expected to be more likely to show temporal genetic variation than species with benthic or brooded non-dispersive larvae, due to differences in larval mortality and dispersal ability. We examined temporal genetic structure in populations of Pygospio elegans, a poecilogonous polychaete with within-species variation in developmental mode. P. elegans produces either planktonic, benthic, or intermediate larvae, varying both among and within populations, providing a within-species test of the generality of a relationship between temporal genetic variation and larval developmental mode. Results In contrast to our expectations, our microsatellite analyses of P. elegans revealed temporal genetic stability in the UK population with planktonic larvae, whereas there was variation indicative of drift in temporal samples of the populations from the Baltic Sea, which have predominantly benthic and intermediate larvae. We also detected temporal variation in relatedness within these populations. A large temporal shift in genetic structure was detected in a population from the Netherlands, having multiple developmental modes. This shift could have been caused by local extiction due to extreme environmental conditions and (re)colonization by planktonic larvae from neighboring populations. Conclusions In our study of P. elegans, temporal genetic variation appears to be due to not only larval developmental mode, but also the stochastic environment of adults. Large temporal genetic shifts may be more likely in marine intertidal habitats (e.g. North Sea and Wadden Sea) which are more prone to environmental stochasticity than the sub-tidal Baltic habitats. Sub-tidal and/or brackish (less saline) habitats may support smaller P. elegans populations and these may be more susceptible to the effects of random genetic drift. Moreover, higher frequencies of asexual reproduction and the benthic larval developmental mode in these populations leads to higher relatedness and contributes to drift. Our results indicate that a general relationship between larval developmental mode and temporal genetic variation may not exist. PMID:24447386

Temporal genetic structure in a poecilogonous polychaete: the interplay of developmental mode and environmental stochasticity.

PubMed

Kesäniemi, Jenni E; Mustonen, Marina; Boström, Christoffer; Hansen, Benni W; Knott, K Emily

2014-01-22

Temporal variation in the genetic structure of populations can be caused by multiple factors, including natural selection, stochastic environmental variation, migration, or genetic drift. In benthic marine species, the developmental mode of larvae may indicate a possibility for temporal genetic variation: species with dispersive planktonic larvae are expected to be more likely to show temporal genetic variation than species with benthic or brooded non-dispersive larvae, due to differences in larval mortality and dispersal ability. We examined temporal genetic structure in populations of Pygospio elegans, a poecilogonous polychaete with within-species variation in developmental mode. P. elegans produces either planktonic, benthic, or intermediate larvae, varying both among and within populations, providing a within-species test of the generality of a relationship between temporal genetic variation and larval developmental mode. In contrast to our expectations, our microsatellite analyses of P. elegans revealed temporal genetic stability in the UK population with planktonic larvae, whereas there was variation indicative of drift in temporal samples of the populations from the Baltic Sea, which have predominantly benthic and intermediate larvae. We also detected temporal variation in relatedness within these populations. A large temporal shift in genetic structure was detected in a population from the Netherlands, having multiple developmental modes. This shift could have been caused by local extiction due to extreme environmental conditions and (re)colonization by planktonic larvae from neighboring populations. In our study of P. elegans, temporal genetic variation appears to be due to not only larval developmental mode, but also the stochastic environment of adults. Large temporal genetic shifts may be more likely in marine intertidal habitats (e.g. North Sea and Wadden Sea) which are more prone to environmental stochasticity than the sub-tidal Baltic habitats. Sub-tidal and/or brackish (less saline) habitats may support smaller P. elegans populations and these may be more susceptible to the effects of random genetic drift. Moreover, higher frequencies of asexual reproduction and the benthic larval developmental mode in these populations leads to higher relatedness and contributes to drift. Our results indicate that a general relationship between larval developmental mode and temporal genetic variation may not exist.

Upper Extremity Muscle Activity During In-Phase and Anti-Phase Continuous Pushing Tasks.

PubMed

Gruevski, Kristina M; Hodder, Joanne N; Keir, Peter J

2017-11-01

To determine the effect of anti-phase, in-phase bimanual and unimanual simulated industrial pushing tasks and frequency on upper extremity muscle activity. Research investigating symmetrical (in-phase) and asymmetrical (anti-phase) pushing exertions is limited despite a high prevalence in industry. Fifteen female participants completed five pushing tasks using a dual handle apparatus at three frequencies: 15 cycles per minute (cpm), 30 cpm, and self-selected. Tasks included two bimanual symmetrical pushes (constrained and unconstrained), two bimanual asymmetrical pushes (reciprocating and continuous), and one right unimanual push. Surface electromyography (EMG) from the right anterior, middle, and posterior deltoid (AD, MD, and PD); right and left trapezius (RT and LT); right pectoralis major (PM); and right and left external obliques (REO and LEO) was collected and normalized to maximum voluntary effort. There was a task by frequency interaction in the AD, MD, PD, and RT ( p < .005), where activity in AD, MD, and PD was highest in the continuous task at 15 cpm, but activity was similar across task in 30 cpm and self-selected. Muscle activity coefficient of variation was lowest during continuous task across all frequencies. Continuous, anti-phase pushes and constrained, in-phase pushes had the highest muscle activity demands and the least amount of variability in muscle activity and therefore may present the greatest risk of injury. Anti-phase pushing is known to have a greater cognitive demand, and this study demonstrated that it also has a greater physical demand when performed continuously.

Order-constrained linear optimization.

PubMed

Tidwell, Joe W; Dougherty, Michael R; Chrabaszcz, Jeffrey S; Thomas, Rick P

2017-11-01

Despite the fact that data and theories in the social, behavioural, and health sciences are often represented on an ordinal scale, there has been relatively little emphasis on modelling ordinal properties. The most common analytic framework used in psychological science is the general linear model, whose variants include ANOVA, MANOVA, and ordinary linear regression. While these methods are designed to provide the best fit to the metric properties of the data, they are not designed to maximally model ordinal properties. In this paper, we develop an order-constrained linear least-squares (OCLO) optimization algorithm that maximizes the linear least-squares fit to the data conditional on maximizing the ordinal fit based on Kendall's τ. The algorithm builds on the maximum rank correlation estimator (Han, 1987, Journal of Econometrics, 35, 303) and the general monotone model (Dougherty & Thomas, 2012, Psychological Review, 119, 321). Analyses of simulated data indicate that when modelling data that adhere to the assumptions of ordinary least squares, OCLO shows minimal bias, little increase in variance, and almost no loss in out-of-sample predictive accuracy. In contrast, under conditions in which data include a small number of extreme scores (fat-tailed distributions), OCLO shows less bias and variance, and substantially better out-of-sample predictive accuracy, even when the outliers are removed. We show that the advantages of OCLO over ordinary least squares in predicting new observations hold across a variety of scenarios in which researchers must decide to retain or eliminate extreme scores when fitting data. © 2017 The British Psychological Society.

The self-reinforcing feedback between low soil fertility and chronic poverty

NASA Astrophysics Data System (ADS)

Barrett, Christopher B.; Bevis, Leah E. M.

2015-12-01

Most of the world's extreme poor, surviving on US$1.25 or less per day, live in rural areas and farm for a living. Many suffer chronic poverty that lasts for years or generations, rather than the transitory poverty that dominates developed, urban economies. Such chronic, structural poverty arises when an individual's productive assets -- such as their ability to work or their soils -- and the technologies and markets that transform their assets into food and income are insufficient to attain satisfactory living standards. Research reveals strong links between economic status and soil quality, and these can be self-reinforcing. For example, poor soil constrains agricultural production and household capital, and low household capital constrains investments in improving soils. Price, availability and access to credit can limit farmers' applications of nutrients, which are often the primary constraint on agricultural productivity. Soil micronutrient deficiencies can lead to dietary mineral deficiencies and negative health outcomes that further constrain productivity and household asset accumulation. Soils may also be important for smallholder resilience to stressors and shocks. For example, high-quality soil can reduce vulnerability to drought, and insurance against risk may promote investment in soils. Interventions such as fertilizer subsidies, micronutrient-fortified fertilizer and improved access to information, insurance and credit may all help break the soil-poverty cycle.

Conspicuous and aposematic spines in the animal kingdom

NASA Astrophysics Data System (ADS)

Inbar, Moshe; Lev-Yadun, Simcha

2005-04-01

Spines serve as a common physical defence mechanism in both the plant and animal kingdoms. Here we argue that as in plants, defensive animal spines are often conspicuous (shape and colour) and should be considered aposematic. Conspicuous spines may evolve as signals or serve as a cue for potential predators. Spine conspicuousness in animals has evolved independently across and within phyla occupying aquatic and terrestrial ecosystems, indicating that this convergent phenomenon is highly adaptive. Still, many spines are cryptic, suggesting that conspicuity is not simply constrained by developmental factors such as differences in the chemical composition of the integument. Aposematism does not preclude the signalling role of conspicuous spines in the sexual arena.

Frontal lobe activation during object permanence: data from near-infrared spectroscopy.

PubMed

Baird, Abigail A; Kagan, Jerome; Gaudette, Thomas; Walz, Kathryn A; Hershlag, Natalie; Boas, David A

2002-08-01

The ability to create and hold a mental schema of an object is one of the milestones in cognitive development. Developmental scientists have named the behavioral manifestation of this competence object permanence. Convergent evidence indicates that frontal lobe maturation plays a critical role in the display of object permanence, but methodological and ethical constrains have made it difficult to collect neurophysiological evidence from awake, behaving infants. Near-infrared spectroscopy provides a noninvasive assessment of changes in oxy- and deoxyhemoglobin and total hemoglobin concentration within a prescribed region. The evidence described in this report reveals that the emergence of object permanence is related to an increase in hemoglobin concentration in frontal cortex.

Combined dendro-documentary evidence of Central European hydroclimatic springtime extremes over the last millennium

NASA Astrophysics Data System (ADS)

Büntgen, Ulf; Brázdil, Rudolf; Heussner, Karl-Uwe; Hofmann, Jutta; Kontic, Raymond; Kyncl, Tomáš; Pfister, Christian; Chromá, Kateřina; Tegel, Willy

2011-12-01

A predicted rise in anthropogenic greenhouse gas emissions and associated effects on the Earth's climate system likely imply more frequent and severe weather extremes with alternations in hydroclimatic parameters expected to be most critical for ecosystem functioning, agricultural yield, and human health. Evaluating the return period and amplitude of modern climatic extremes in light of pre-industrial natural changes is, however, limited by generally too short instrumental meteorological observations. Here we introduce and analyze 11,873 annually resolved and absolutely dated ring width measurement series from living and historical fir ( Abies alba Mill.) trees sampled across France, Switzerland, Germany, and the Czech Republic, which continuously span the AD 962-2007 period. Even though a dominant climatic driver of European fir growth was not found, ring width extremes were evidently triggered by anomalous variations in Central European April-June precipitation. Wet conditions were associated with dynamic low-pressure cells, whereas continental-scale droughts coincided with persistent high-pressure between 35 and 55°N. Documentary evidence independently confirms many of the dendro signals over the past millennium, and further provides insight on causes and consequences of ambient weather conditions related to the reconstructed extremes. A fairly uniform distribution of hydroclimatic extremes throughout the Medieval Climate Anomaly, Little Ice Age and Recent Global Warming may question the common believe that frequency and severity of such events closely relates to climate mean stages. This joint dendro-documentary approach not only allows extreme climate conditions of the industrial era to be placed against the backdrop of natural variations, but also probably helps to constrain climate model simulations over exceptional long timescales.

Morphological integration of anatomical, developmental, and functional postcranial modules in the crab-eating macaque (Macaca fascicularis).

PubMed

Conaway, Mark A; Schroeder, Lauren; von Cramon-Taubadel, Noreen

2018-03-22

Integration and modularity reflect the coordinated action of past evolutionary processes and, in turn, constrain or facilitate phenotypic evolvability. Here, we analyze magnitudes of integration in the macaque postcranium to test whether 20 a priori defined modules are (1) more tightly integrated than random sets of postcranial traits, and (2) are differentiated based on mode of definition, with developmental modules expected to be more integrated than functional or anatomical modules. The 3D morphometric data collected for eight limb and girdle bones for 60 macaques were collated into anatomical, developmental, and functional modules. A resampling technique was used to create random samples of integration values for each module for statistical comparison. Our results found that not all a priori defined modules were more strongly integrated than random samples of postcranial traits and that specific types of modules did not present consistent patterns of integration. Rather, girdle and joint modules were consistently less integrated than limb modules, and forelimb elements were less integrated than hindlimbs. The results suggest that morphometrically complex modules tend to be less integrated than simple limb bones, irrespective of the number of available traits. However, differences in integration of the fore- and hindlimb more likely reflects the multitude of locomotory, feeding, and social functions involved. It remains to be tested whether patterns of integration identified here are primate universals, and to what extent they vary depending on phylogenetic or functional factors. © 2018 Wiley Periodicals, Inc.

The Sirenomelia Sequence: A Case History

PubMed Central

Fadhlaoui, Anis; Khrouf, Mohamed; Gaigi, Soumaya; Zhioua, Fethi; Chaker, Anis

2010-01-01

We report a case of sirenomelia sequence observed in an incident of preterm labor during the 29th gestational week. According to some authors, this syndrome should be classified separately from caudal regression syndrome and is likely to be the result of an abnormality taking place during the fourth gestational week, causing developmental abnormalities in the lower extremities, pelvis, genitalia, urinary tract and digestive organs. Despite recent progress in pathology, the etiopathogenesis of sirenomelia is still debated. PMID:21769253

Early developmental influences on self-esteem trajectories from adolescence through adulthood: Impact of birth weight and motor skills.

PubMed

Poole, Kristie L; Schmidt, Louis A; Ferro, Mark A; Missiuna, Cheryl; Saigal, Saroj; Boyle, Michael H; Van Lieshout, Ryan J

2018-02-01

While the trajectory of self-esteem from adolescence to adulthood varies from person to person, little research has examined how differences in early developmental processes might affect these pathways. This study examined how early motor skill development interacted with preterm birth status to predict self-esteem from adolescence through the early 30s. We addressed this using the oldest known, prospectively followed cohort of extremely low birth weight (<1000 g) survivors (N = 179) and normal birth weight controls (N = 145) in the world, born between 1977 and 1982. Motor skills were measured using a performance-based assessment at age 8 and a retrospective self-report, and self-esteem was reported during three follow-up periods (age 12-16, age 22-26, and age 29-36). We found that birth weight status moderated the association between early motor skills and self-esteem. Stable over three decades, the self-esteem of normal birth weight participants was sensitive to early motor skills such that those with poorer motor functioning manifested lower self-esteem, while those with better motor skills manifested higher self-esteem. Conversely, differences in motor skill development did not affect the self-esteem from adolescence to adulthood in individuals born at extremely low birth weight. Early motor skill development may exert differential effects on self-esteem, depending on whether one is born at term or prematurely.

LITHO1.0: An Updated Crust and Lithosphere Model of the Earth

NASA Astrophysics Data System (ADS)

Masters, G.; Ma, Z.; Laske, G.; Pasyanos, M. E.

2011-12-01

We are developing LITHO1.0: an updated crust and lithosphere model of the Earth. The overall plan is to take the popular CRUST2.0 model - a global model of crustal structure with a relatively poor representation of the uppermost mantle - and improve its nominal resolution to 1 degree and extend the model to include lithospheric structure. The new model, LITHO1.0, will be constrained by many different datasets including extremely large new datasets of relatively short period group velocity data. Other data sets include (but are not limited to) compilations of receiver function constraints and active source studies. To date, we have completed the compilation of extremely large global datasets of group velocity for Rayleigh and Love waves from 10mHz to 40mHz using a cluster analysis technique. We have also extended the method to measure phase velocity and are complementing the group velocity with global data sets of longer period phase data that help to constrain deep lithosphere properties. To model these data, we require a starting model for the crust at a nominal resolution of 1 degree. This has been developed by constructing a map of crustal thickness using data from receiver function and active source experiments where available, and by using CRUST2.0 where other constraints are not available. Particular care has been taken to make sure that the locations of sharp changes in crustal thickness are accurately represented. This map is then used as a template to extend CRUST2.0 to 1 degree nominal resolution and to develop starting maps of all crustal properties. We are currently modeling the data using two techniques. The first is a linearized inversion about the 3D crustal starting model. Note that it is important to use local eigenfunctions to compute Frechet derivatives due to the extreme variations in crustal structure. Another technique uses a targeted grid search method. A preliminary model for the crustal part of the model will be presented.

Occurrence of 1 ka-old corals on an uplifted reef terrace in west Luzon, Philippines: Implications for a prehistoric extreme wave event in the South China Sea region

NASA Astrophysics Data System (ADS)

Ramos, Noelynna T.; Maxwell, Kathrine V.; Tsutsumi, Hiroyuki; Chou, Yu-Chen; Duan, Fucai; Shen, Chuan-Chou; Satake, Kenji

2017-12-01

Recent 230Th dating of fossil corals in west Luzon has provided new insights on the emergence of late Quaternary marine terraces that fringe west Luzon Island facing the Manila Trench. Apart from regional sea level changes, accumulated uplift from aseismic and seismic processes may have influenced the emergence of sea level indicators such as coral terraces and notches. Varied elevations of middle-to-late Holocene coral terraces along the west Luzon coasts reveal the differential uplift that is probably associated with the movement of local onland faults or upper-plate structures across the Manila Trench forearc basin. In Badoc Island, offshore west of Luzon mainland, we found notably young fossil corals, dated at 945.1 ± 4.6 years BP and 903.1 ± 3.9 years BP, on top of a 5-m-high reef platform. To constrain the mechanism of emergence or emplacement of these fossil corals, we use field geomorphic data and wave inundation models to constrain an extreme wave event that affected west Luzon about 1000 years ago. Our preliminary tectonic and tsunami models show that a megathrust rupture will likely lead to subsidence of a large part of the west Luzon coast, while permanent coastal uplift is attributed to an offshore upper-plate rupture in the northern Manila Trench forearc region. The modeled source fault ruptures and tsunami lead to a maximum wave height of more than 3 m and inundation distance as far as 2 km along the coasts of western and northern Luzon. While emplacement of coral boulders by an unusually strong typhoon is also likely, modeled storm surge heights along west Luzon do not exceed 2 m even with Typhoon Haiyan characteristics. Whether tsunami or unusually strong typhoon, the occurrence of a prehistoric extreme wave event in west Luzon remains an important issue in future studies of coastal hazards in the South China Sea region.

Extreme climatic events constrain space use and survival of a ground-nesting bird.

PubMed

Tanner, Evan P; Elmore, R Dwayne; Fuhlendorf, Samuel D; Davis, Craig A; Dahlgren, David K; Orange, Jeremy P

2017-05-01

Two fundamental issues in ecology are understanding what influences the distribution and abundance of organisms through space and time. While it is well established that broad-scale patterns of abiotic and biotic conditions affect organisms' distributions and population fluctuations, discrete events may be important drivers of space use, survival, and persistence. These discrete extreme climatic events can constrain populations and space use at fine scales beyond that which is typically measured in ecological studies. Recently, a growing body of literature has identified thermal stress as a potential mechanism in determining space use and survival. We sought to determine how ambient temperature at fine temporal scales affected survival and space use for a ground-nesting quail species (Colinus virginianus; northern bobwhite). We modeled space use across an ambient temperature gradient (ranging from -20 to 38 °C) through a maxent algorithm. We also used Andersen-Gill proportional hazard models to assess the influence of ambient temperature-related variables on survival through time. Estimated available useable space ranged from 18.6% to 57.1% of the landscape depending on ambient temperature. The lowest and highest ambient temperature categories (<-15 °C and >35 °C, respectively) were associated with the least amount of estimated useable space (18.6% and 24.6%, respectively). Range overlap analysis indicated dissimilarity in areas where Colinus virginianus were restricted during times of thermal extremes (range overlap = 0.38). This suggests that habitat under a given condition is not necessarily a habitat under alternative conditions. Further, we found survival was most influenced by weekly minimum ambient temperatures. Our results demonstrate that ecological constraints can occur along a thermal gradient and that understanding the effects of these discrete events and how they change over time may be more important to conservation of organisms than are average and broad-scale conditions as typically measured in ecological studies. © 2016 The Authors. Global Change Biology Published by John Wiley & Sons Ltd.

Microbial decomposers not constrained by climate history along a Mediterranean climate gradient in southern California.

PubMed

Baker, Nameer R; Khalili, Banafshe; Martiny, Jennifer B H; Allison, Steven D

2018-06-01

Microbial decomposers mediate the return of CO 2 to the atmosphere by producing extracellular enzymes to degrade complex plant polymers, making plant carbon available for metabolism. Determining if and how these decomposer communities are constrained in their ability to degrade plant litter is necessary for predicting how carbon cycling will be affected by future climate change. We analyzed mass loss, litter chemistry, microbial biomass, extracellular enzyme activities, and enzyme temperature sensitivities in grassland litter transplanted along a Mediterranean climate gradient in southern California. Microbial community composition was manipulated by caging litter within bags made of nylon membrane that prevent microbial immigration. To test whether grassland microbes were constrained by climate history, half of the bags were inoculated with local microbial communities native to each gradient site. We determined that temperature and precipitation likely interact to limit microbial decomposition in the extreme sites along our gradient. Despite their unique climate history, grassland microbial communities were not restricted in their ability to decompose litter under different climate conditions across the gradient, although microbial communities across our gradient may be restricted in their ability to degrade different types of litter. We did find some evidence that local microbial communities were optimized based on climate, but local microbial taxa that proliferated after inoculation into litterbags did not enhance litter decomposition. Our results suggest that microbial community composition does not constrain C-cycling rates under climate change in our system, but optimization to particular resource environments may act as more general constraints on microbial communities. © 2018 by the Ecological Society of America.

Profound microcephaly, primordial dwarfism with developmental brain malformations: a new syndrome.

PubMed

Abdel-Salam, Ghada M H; Abdel-Hamid, Mohamed S; Saleem, Sahar N; Ahmed, Mahmoud K H; Issa, Mahmoud; Effat, Laila K; Kayed, Hisham F; Zaki, Maha S; Gaber, Khaled R

2012-08-01

We describe two sibs with a lethal form of profound congenital microcephaly, intrauterine and postnatal growth retardation, subtle skeletal changes, and poorly developed brain. The sibs had striking absent cranial vault with sloping of the forehead, large beaked nose, relatively large ears, and mandibular micro-retrognathia. Brain magnetic resonance imaging (MRI) revealed extremely simplified gyral pattern, large interhemispheric cyst and agenesis of corpus callosum, abnormally shaped hippocampus, and proportionately affected cerebellum and brainstem. In addition, fundus examination showed foveal hypoplasia with optic nerve atrophy. No abnormalities of the internal organs were found. This profound form of microcephaly was identified at 17 weeks gestation by ultrasound and fetal brain MRI helped in characterizing the developmental brain malformations in the second sib. Molecular analysis excluded mutations in potentially related genes such as RNU4ATAC, SLC25A19, and ASPM. These clinical and imaging findings are unlike that of any recognized severe forms of microcephaly which is believed to be a new microcephalic primordial dwarfism (MPD) with developmental brain malformations with most probably autosomal recessive inheritance based on consanguinity and similarly affected male and female sibs. Copyright © 2012 Wiley Periodicals, Inc.

Evolution of female-specific wingless forms in bagworm moths.

PubMed

Niitsu, Shuhei; Sugawara, Hirotaka; Hayashi, Fumio

2017-01-01

The evolution of winglessness in insects has been typically interpreted as a consequence of developmental and other adaptations to various environments that are secondarily derived from a winged morph. Several species of bagworm moths (Insecta: Lepidoptera, Psychidae) exhibit a case-dwelling larval life style along with one of the most extreme cases of sexual dimorphism: wingless female adults. While the developmental process that led to these wingless females is well known, the origins and evolutionary transitions are not yet understood. To examine the evolutionary patterns of wing reduction in bagworm females, we reconstruct the molecular phylogeny of over 30 Asian species based on both mitochondrial (cytochrome c oxidase subunit I) and nuclear (28S rRNA) DNA sequences. Under a parsimonious assumption, the molecular phylogeny implies that: (i) the evolutionary wing reduction towards wingless females consisted of two steps: (Step I) from functional wings to vestigial wings (nonfunctional) and (Step II) from vestigial wings to the most specialized vermiform adults (lacking wings and legs); and (ii) vermiform morphs evolved independently at least twice. Based on the results of our study, we suggest that the evolutionary changes in the developmental system are essential for the establishment of different wingless forms in insects. © 2016 Wiley Periodicals, Inc.

Plant response to gravity: towards a biosystems view of root gravitropism

NASA Astrophysics Data System (ADS)

Palme, Klaus; Volkmann, Dieter; Bennett, Malcolm J.; Gausepohl, Heinrich

2005-10-01

Plants are sessile organisms that originated and evolved in Earth's environment. They monitor a wide range of disparate external and internal signals and compute appropriate developmental responses. How do plant cells process these myriad signals into an appropriate response? How do they integrate these signals to reach a finely balanced decision on how to grow, how to determine the direction of growth and how to develop their organs to exploit the environment? As plant responses are generally irreversible growth responses, their signalling systems must compute each developmental decision with extreme care. One stimulus to which plants are continuously exposed is the gravity vector. Gravity affects adaptive growth responses that reorient organs towards light and nutrient resources. The MAP team was established by ESA to study in the model plant Arabidopsis thaliana the role of the hormone auxin in gravity-mediated growth control. Another goal was to dissect gravity perception and gravity signal transduction pathways.

Neonatal intensive care practices harmful to the developing brain.

PubMed

Chaudhari, Sudha

2011-06-01

There has been a marked increase in the survival of extremely low birth weight (ELBW) infants, but these babies have a long stay in the NICU. Strategies to decrease their neurodevelopmental impairment become very important. The maximum development of the brain occurs between 29-41 weeks. From the warm, dark, acquatic econiche, where the baby hears pleasant sounds like the mother's heart beat, the baby suddenly finds itself in the dry, cold, excessively bright, noisy, environment of the NICU. Noise, bright light, painful procedures, and ill-timed caregiving activities, adversely affect the infant's development. Excessive radiation from X-rays of babies on the ventilator and CT scans also affect the brain. Medications like steroids for chronic lung disease also cause damage to the brain. Aminoglycides and frusemide are known to cause hearing impairment. Hence a developmentally supportive, humanized care will go a long way in enhancing the developmental outcome of these babies.

Cornelia de Lange syndrome: a case study.

PubMed

Kalal, Goud Iravathy; Raina, Vimarsh P; Nayak, Veerabhadra S; Teotia, Pooja; Gupta, Bhushan V

2009-02-01

Cornelia de Lange syndrome (CDLS) is a relatively common multiple congenital anomaly/mental retardation disorder with an unknown genetic and molecular pathogenesis. The essential features of this developmental malformation syndrome are retardation in growth, developmental delay, various structural limb abnormalities, and distinctive facial features. Most cases are sporadic and are thought to result from a new dominant mutation. Consequently, hypotheses regarding the pathogenetic mechanisms underlying the two distinct phenotypes, classic and mild, are purely speculative. The recent discovery of molecular techniques and identification of the NIPBL gene has allowed etiologic diagnosis of this disorder. In this article, we describe a patient with CDLS in whom conventional cytogenetics, fluorescence in situ hybridization, and NIPBL gene mutation analysis determined an etiologic diagnosis, providing precise genetic counseling and facilitated the family to make an evidence-based decision for conception and also alleviated the extreme degree of anxiety associated with the thought of having a second child in this set of circumstances.

EEG - A Valuable Biomarker of Brain Injury in Preterm Infants.

PubMed

Pavlidis, Elena; Lloyd, Rhodri O; Boylan, Geraldine B

2017-01-01

This review focuses on the role of electroencephalography (EEG) in monitoring abnormalities of preterm brain function. EEG features of the most common developmental brain injuries in preterm infants, including intraventricular haemorrhage, periventricular leukomalacia, and perinatal asphyxia, are described. We outline the most common EEG biomarkers associated with these injuries, namely seizures, positive rolandic sharp waves, EEG suppression/increased interburst intervals, mechanical delta brush activity, and other deformed EEG waveforms, asymmetries, and asynchronies. The increasing survival rate of preterm infants, in particular those that are very and extremely preterm, has led to a growing demand for a specific and shared characterization of the patterns related to adverse outcome in this unique population. This review includes abundant high-quality images of the EEG patterns seen in premature infants and will provide a valuable resource for everyone working in developmental neuroscience. © 2017 S. Karger AG, Basel.

Current progress in orchid flowering/flower development research

PubMed Central

Wang, Hsin-Mei; Tong, Chii-Gong

2017-01-01

ABSTRACT Genetic pathways relevant to flowering of Arabidopsis are under the control of environmental cues such as day length and temperatures, and endogenous signals including phytohormones and developmental aging. However, genes and even regulatory pathways for flowering identified in crops show divergence from those of Arabidopsis and often do not have functional equivalents to Arabidopsis and/or existing species- or genus-specific regulators and show modified or novel pathways. Orchids are the largest, most highly evolved flowering plants, and form an extremely peculiar group of plants. Here, we briefly summarize the flowering pathways of Arabidopsis, rice and wheat and present them alongside recent discoveries/progress in orchid flowering and flower developmental processes including our transgenic Phalaenopsis orchids for LEAFY overexpression. Potential biotechnological applications in flowering/flower development of orchids with potential target genes are also discussed from an interactional and/or comparative viewpoint. PMID:28448202

Mechanisms and pathways of growth failure in primordial dwarfism

PubMed Central

Klingseisen, Anna; Jackson, Andrew P.

2011-01-01

The greatest difference between species is size; however, the developmental mechanisms determining organism growth remain poorly understood. Primordial dwarfism is a group of human single-gene disorders with extreme global growth failure (which includes Seckel syndrome, microcephalic osteodysplastic primordial dwarfism I [MOPD] types I and II, and Meier-Gorlin syndrome). Ten genes have now been identified for microcephalic primordial dwarfism, encoding proteins involved in fundamental cellular processes including genome replication (ORC1 [origin recognition complex 1], ORC4, ORC6, CDT1, and CDC6), DNA damage response (ATR [ataxia-telangiectasia and Rad3-related]), mRNA splicing (U4atac), and centrosome function (CEP152, PCNT, and CPAP). Here, we review the cellular and developmental mechanisms underlying the pathogenesis of these conditions and address whether further study of these genes could provide novel insight into the physiological regulation of organism growth. PMID:21979914

MAOA/B deletion syndrome in male siblings with severe developmental delay and sudden loss of muscle tonus.

PubMed

Saito, Mari; Yamagata, Takanori; Matsumoto, Ayumi; Shiba, Yusuke; Nagashima, Masako; Taniguchi, Shuhei; Jimbo, Eriko; Momoi, Mariko Y

2014-01-01

Deletion of the monoamine oxidase (MAO)-A and MAO-B was detected in two male siblings and in their mother. The approximately 800-kb deletion, extending from about 43.0MB to 43.8MB, was detected by array comparative genomic hybridization analysis. The MAOA and MAOB genes were included in the deletion, but the adjacent Norrie disease gene, NDP, was not deleted. The boys had short stature, hypotonia, severe developmental delays, episodes of sudden loss of muscle tone, exiting behavior, lip-smacking and autistic features. The serotonin levels in their cerebrospinal fluid were extremely elevated. Another set of siblings with this deletion was reported previously. We propose recognition of MAOA/B deletion syndrome as a distinct disorder. Copyright © 2013 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

An investigation of turbulent transport in the extreme lower atmosphere

NASA Technical Reports Server (NTRS)

Koper, C. A., Jr.; Sadeh, W. Z.

1975-01-01

A model in which the Lagrangian autocorrelation is expressed by a domain integral over a set of usual Eulerian autocorrelations acquired concurrently at all points within a turbulence box is proposed along with a method for ascertaining the statistical stationarity of turbulent velocity by creating an equivalent ensemble to investigate the flow in the extreme lower atmosphere. Simultaneous measurements of turbulent velocity on a turbulence line along the wake axis were carried out utilizing a longitudinal array of five hot-wire anemometers remotely operated. The stationarity test revealed that the turbulent velocity is approximated as a realization of a weakly self-stationary random process. Based on the Lagrangian autocorrelation it is found that: (1) large diffusion time predominated; (2) ratios of Lagrangian to Eulerian time and spatial scales were smaller than unity; and, (3) short and long diffusion time scales and diffusion spatial scales were constrained within their Eulerian counterparts.

Climate Impacts From a Removal of Anthropogenic Aerosol Emissions

NASA Astrophysics Data System (ADS)

Samset, B. H.; Sand, M.; Smith, C. J.; Bauer, S. E.; Forster, P. M.; Fuglestvedt, J. S.; Osprey, S.; Schleussner, C.-F.

2018-01-01

Limiting global warming to 1.5 or 2.0°C requires strong mitigation of anthropogenic greenhouse gas (GHG) emissions. Concurrently, emissions of anthropogenic aerosols will decline, due to coemission with GHG, and measures to improve air quality. However, the combined climate effect of GHG and aerosol emissions over the industrial era is poorly constrained. Here we show the climate impacts from removing present-day anthropogenic aerosol emissions and compare them to the impacts from moderate GHG-dominated global warming. Removing aerosols induces a global mean surface heating of 0.5-1.1°C, and precipitation increase of 2.0-4.6%. Extreme weather indices also increase. We find a higher sensitivity of extreme events to aerosol reductions, per degree of surface warming, in particular over the major aerosol emission regions. Under near-term warming, we find that regional climate change will depend strongly on the balance between aerosol and GHG forcing.

Extreme rejuvenation and softening in a bulk metallic glass.

PubMed

Pan, J; Wang, Y X; Guo, Q; Zhang, D; Greer, A L; Li, Y

2018-02-08

Rejuvenation of metallic glasses, bringing them to higher-energy states, is of interest in improving their plasticity. The mechanisms of rejuvenation are poorly understood, and its limits remain unexplored. We use constrained loading in compression to impose substantial plastic flow on a zirconium-based bulk metallic glass. The maximum measured effects are that the hardness of the glass decreases by 36%, and its excess enthalpy (above the relaxed state) increases to 41% of the enthalpy of melting. Comparably high degrees of rejuvenation have been reported only on microscopic scales at the centre of shear bands confined to low volume fractions. This extreme rejuvenation of a bulk glass gives a state equivalent to that obtainable by quenching the liquid at ~10 10  K s -1 , many orders of magnitude faster than is possible for bulk specimens. The contrast with earlier results showing relaxation in similar tests under tension emphasizes the importance of hydrostatic stress.

Measuring Ionization in Highly Compressed, Near-Degenerate Plasmas

NASA Astrophysics Data System (ADS)

Doeppner, Tilo; Kraus, D.; Neumayer, P.; Bachmann, B.; Collins, G. W.; Divol, L.; Kritcher, A.; Landen, O. L.; Pak, A.; Weber, C.; Fletcher, L.; Glenzer, S. H.; Falcone, R. W.; Saunders, A.; Chapman, D.; Baggott, R.; Gericke, D. O.; Yi, A.

2016-10-01

A precise knowledge of ionization at given temperature and density is required to accurately model compressibility and heat capacity of materials at extreme conditions. We use x-ray Thomson scattering to characterize the plasma conditions in plastic and beryllium capsules near stagnation in implosion experiments at the National Ignition Facility. We expect the capsules to be compressed to more than 20x and electron densities approaching 1025 cm-3, corresponding to a Fermi energy of 170 eV. Zinc Heα x-rays (9 keV) scattering at 120° off the plasma yields high sensitivity to K-shell ionization, while at the same time constraining density and temperature. We will discuss recent results in the context of ionization potential depression at these extreme conditions. This work was performed under the auspices of the US Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

Probing the extreme wind confinement of the most magnetic O star with COS spectroscopy

NASA Astrophysics Data System (ADS)

Petit, Veronique

2014-10-01

We propose to obtain phase-resolved UV spectroscopy of the recently discovered magnetic O star NGC 1624-2, which has the strongest magnetic field ever detected in a O-star, by an order of magnitude. We will use the strength and variability of the UV resonance line profiles to diagnose the density, velocity, and ionization structure of NGC 1624-2's enormous magnetosphere that results from entrapment of its stellar wind by its strong, nearly dipolar magnetic field. With this gigantic magnetosphere, NGC 1624-2 represents a new regime of extreme wind confinement that will constrain models of magnetized winds and their surface mass flux properties. A detailed understanding of such winds is necessary to study the rotational braking history of magnetic O-stars, which can shed new light on the fundamental origin of magnetism in massive, hot stars.

The Bragg Reflection Polarimeter On the Gravity and Extreme Magnetism Small Explorer Mission

NASA Astrophysics Data System (ADS)

Allured, Ryan; Griffiths, S.; Daly, R.; Prieskorn, Z.; Marlowe, H.; Kaaret, P.; GEMS Team

2011-09-01

The strong gravity associated with black holes warps the spacetime outside of the event horizon, and it is predicted that this will leave characteristic signatures on the polarization of X-ray emission originating in the accretion disk. The Gravity and Extreme Magnetism Small Explorer (GEMS) mission will be the first observatory with the capability to make polarization measurements with enough sensitivity to quantitatively test this prediction. Students at the University of Iowa are currently working on the development of the Bragg Reflection Polarimeter (BRP), a soft X-ray polarimeter sensitive at 500 eV, that is the student experiment on GEMS. The BRP will complement the main experiment by making a polarization measurement from accreting black holes below the main energy band (2-10 keV). This measurement will constrain the inclination of the accretion disk and tighten measurements of black hole spin.

Combined SDO/AIA, Hinode/XRT and FOXSI-2 microflare observations - DEM analysis and energetics

NASA Astrophysics Data System (ADS)

Panchapakesan, S. A.; Glesener, L.; Vievering, J. T.; Ryan, D.; Christe, S.; Inglis, A. R.; Buitrago-Casas, J. C.; Musset, S.; Krucker, S.

2017-12-01

The Focusing Optics X-ray Solar Imager (FOXSI) sounding rocket makes directimaging and spectral observation of the Sun in hard X-rays (HXRs) using highlysensitive focusing HXR optics. The second flight of FOXSI was launchedsuccessfully on 11 December 2014 and observed significant HXR emissions duringmicroflares. Some of these flares showed heating up to severalmillion Kelvin and were visible in the Extreme Ultraviolet (EUV) with the AtmosphericImaging Assembly (SDO/AIA). Spectral observations from FOXSI suggest emission upto 10-12 MK. We utilize SDO/AIA EUV, Hinode/XRT soft X-ray, and FOXSI-2 highenergy X-ray observations to derive the differential emission measure (DEM) ofthe microflares. The AIA and XRT observations provide broad temperaturecoverage but are poorly constrained at the hotter end. We therefore use FOXSI-2to better determine the high temperature component, thus producing a moreconstrained DEM than is possible with typically available observations. We usethis more highly constrained DEM to investigate the energetics of the observedmicroflares.

Explicit Simulation of Networks of Outlet Glaciers to Constrain Greenland's Sea Level Contribution

NASA Astrophysics Data System (ADS)

Ultee, E.; Bassis, J. N.

2017-12-01

Ice from the Greenland Ice Sheet drains to the ocean through hundreds of outlet glaciers, many of which are too small to be accurately resolved in continental-scale ice sheet models. Moreover, despite the fact that dynamic changes in Greenland outlet glaciers are currently responsible for about half of the ice sheet's contribution to global sea level, all but the largest are often excluded from major sea level assessments. We have previously developed and validated a simple model that simulates advance and retreat of networks of marine-terminating glaciers based on the perfect plastic approximation. Here we apply this model to a selection of forcing scenarios, representing both climate persistence and extreme scenarios, to constrain changes in calving flux from the most significant Greenland outlet glaciers. Our model can be implemented in standalone mode or as the calving module in a more sophisticated large-scale model, providing constraints on Greenland's future contribution to global sea level rise under a range of scenarios.

Testing general relativity and alternative theories of gravity with space-based atomic clocks and atom interferometers

NASA Astrophysics Data System (ADS)

Bondarescu, Ruxandra; Schärer, Andreas; Jetzer, Philippe; Angélil, Raymond; Saha, Prasenjit; Lundgren, Andrew

2015-05-01

The successful miniaturisation of extremely accurate atomic clocks and atom interferometers invites prospects for satellite missions to perform precision experiments. We discuss the effects predicted by general relativity and alternative theories of gravity that can be detected by a clock, which orbits the Earth. Our experiment relies on the precise tracking of the spacecraft using its observed tick-rate. The spacecraft's reconstructed four-dimensional trajectory will reveal the nature of gravitational perturbations in Earth's gravitational field, potentially differentiating between different theories of gravity. This mission can measure multiple relativistic effects all during the course of a single experiment, and constrain the Parametrized Post-Newtonian Parameters around the Earth. A satellite carrying a clock of fractional timing inaccuracy of Δ f / f ˜ 10-16 in an elliptic orbit around the Earth would constrain the PPN parameters |β - 1|, |γ - 1| ≲ 10-6. We also briefly review potential constraints by atom interferometers on scalar tensor theories and in particular on Chameleon and dilaton models.

Lepton flavor violating B meson decays via a scalar leptoquark

NASA Astrophysics Data System (ADS)

Sahoo, Suchismita; Mohanta, Rukmani

2016-06-01

We study the effect of scalar leptoquarks in the lepton flavor violating B meson decays induced by the flavor-changing transitions b →q li+lj- with q =s , d . In the standard model, these transitions are extremely rare as they are either two-loop suppressed or proceed via box diagrams with tiny neutrino masses in the loop. However, in the leptoquark model, they can occur at tree level and are expected to have significantly large branching ratios. The leptoquark parameter space is constrained using the experimental limits on the branching ratios of Bq→l+l- processes. Using such constrained parameter space, we predict the branching ratios of LFV semileptonic B meson decays, such as B+→K+(π+)li+lj-, B+→(K*+,ρ+)li+lj-, and Bs→ϕ li+lj-, which are found to be within the experimental reach of LHCb and the upcoming Belle II experiments. We also investigate the rare leptonic KL ,S→μ+μ-(e+e-) and KL→μ∓e± decays in the leptoquark model.

Global meteorological influences on the record UK rainfall of winter 2013-14

NASA Astrophysics Data System (ADS)

Knight, Jeff R.; Maidens, Anna; Watson, Peter A. G.; Andrews, Martin; Belcher, Stephen; Brunet, Gilbert; Fereday, David; Folland, Chris K.; Scaife, Adam A.; Slingo, Julia

2017-07-01

The UK experienced record average rainfall in winter 2013-14, leading to widespread and prolonged flooding. The immediate cause of this exceptional rainfall was a very strong and persistent cyclonic atmospheric circulation over the North East Atlantic Ocean. This was related to a very strong North Atlantic jet stream which resulted in numerous damaging wind storms. These exceptional meteorological conditions have led to renewed questions about whether anthropogenic climate change is noticeably influencing extreme weather. The regional weather pattern responsible for the extreme UK winter coincided with highly anomalous conditions across the globe. We assess the contributions from various possible remote forcing regions using sets of ocean-atmosphere model relaxation experiments, where winds and temperatures are constrained to be similar to those observed in winter 2013-14 within specified atmospheric domains. We find that influences from the tropics were likely to have played a significant role in the development of the unusual extra-tropical circulation, including a role for the tropical Atlantic sector. Additionally, a stronger and more stable stratospheric polar vortex, likely associated with a strong westerly phase of the stratospheric Quasi-Biennial Oscillation (QBO), appears to have contributed to the extreme conditions. While intrinsic climatic variability clearly has the largest effect on the generation of extremes, results from an analysis which segregates circulation-related and residual rainfall variability suggest that emerging climate change signals made a secondary contribution to extreme rainfall in winter 2013-14.

Energy Aware Clustering Algorithms for Wireless Sensor Networks

NASA Astrophysics Data System (ADS)

Rakhshan, Noushin; Rafsanjani, Marjan Kuchaki; Liu, Chenglian

2011-09-01

The sensor nodes deployed in wireless sensor networks (WSNs) are extremely power constrained, so maximizing the lifetime of the entire networks is mainly considered in the design. In wireless sensor networks, hierarchical network structures have the advantage of providing scalable and energy efficient solutions. In this paper, we investigate different clustering algorithms for WSNs and also compare these clustering algorithms based on metrics such as clustering distribution, cluster's load balancing, Cluster Head's (CH) selection strategy, CH's role rotation, node mobility, clusters overlapping, intra-cluster communications, reliability, security and location awareness.

Operating systems and network protocols for wireless sensor networks.

PubMed

Dutta, Prabal; Dunkels, Adam

2012-01-13

Sensor network protocols exist to satisfy the communication needs of diverse applications, including data collection, event detection, target tracking and control. Network protocols to enable these services are constrained by the extreme resource scarcity of sensor nodes-including energy, computing, communications and storage-which must be carefully managed and multiplexed by the operating system. These challenges have led to new protocols and operating systems that are efficient in their energy consumption, careful in their computational needs and miserly in their memory footprints, all while discovering neighbours, forming networks, delivering data and correcting failures.

Control of linear uncertain systems utilizing mismatched state observers

NASA Technical Reports Server (NTRS)

Goldstein, B.

1972-01-01

The control of linear continuous dynamical systems is investigated as a problem of limited state feedback control. The equations which describe the structure of an observer are developed constrained to time-invarient systems. The optimal control problem is formulated, accounting for the uncertainty in the design parameters. Expressions for bounds on closed loop stability are also developed. The results indicate that very little uncertainty may be tolerated before divergence occurs in the recursive computation algorithms, and the derived stability bound yields extremely conservative estimates of regions of allowable parameter variations.

Developing animals flout prominent assumptions of ecological physiology.

PubMed

Burggren, Warren W

2005-08-01

Every field of biology has its assumptions, but when they grow to be dogma, they can become constraining. This essay presents data-based challenges to several prominent assumptions of developmental physiologists. The ubiquity of allometry is such an assumption, yet animal development is characterized by rate changes that are counter to allometric predictions. Physiological complexity is assumed to increase with development, but examples are provided showing that complexity can be greatest at intermediate developmental stages. It is assumed that organs have functional equivalency in embryos and adults, yet embryonic structures can have quite different functions than inferred from adults. Another assumption challenged is the duality of neural control (typically sympathetic and parasympathetic), since one of these two regulatory mechanisms typically considerably precedes in development the appearance of the other. A final assumption challenged is the notion that divergent phylogeny creates divergent physiologies in embryos just as in adults, when in fact early in development disparate vertebrate taxa show great quantitative as well as qualitative similarity. Collectively, the inappropriateness of these prominent assumptions based on adult studies suggests that investigation of embryos, larvae and fetuses be conducted with appreciation for their potentially unique physiologies.

Perspectives on the Genetic Architecture of Divergence in Body Shape in Sticklebacks

PubMed Central

Reid, Duncan T.; Peichel, Catherine L.

2010-01-01

The body shape of fishes encompasses a number of morphological traits that are intrinsically linked to functional systems and affect various measures of performance, including swimming, feeding, and avoiding predators. Changes in shape can allow a species to exploit a new ecological niche and can lead to ecological speciation. Body shape results from the integration of morphological, behavioral and physiological traits. It has been well established that functional interdependency among traits plays a large role in constraining the evolution of shape, affecting both the speed and the repeated evolution of particular body shapes. However, it is less clear what role genetic or developmental constraints might play in biasing the rate or direction of the evolution of body shape. Here, we suggest that the threespine stickleback (Gasterosteus aculeatus) is a powerful model system in which to address the extent to which genetic or developmental constraints play a role in the evolution of body shape in fishes. We review the existing data that begins to address these issues in sticklebacks and provide suggestions for future areas of research that will be particularly fruitful for illuminating the mechanisms that contribute to the evolution of body shape in fishes. PMID:21082067

Strong Purifying Selection at Synonymous Sites in D. melanogaster

PubMed Central

Lawrie, David S.; Messer, Philipp W.; Hershberg, Ruth; Petrov, Dmitri A.

2013-01-01

Synonymous sites are generally assumed to be subject to weak selective constraint. For this reason, they are often neglected as a possible source of important functional variation. We use site frequency spectra from deep population sequencing data to show that, contrary to this expectation, 22% of four-fold synonymous (4D) sites in Drosophila melanogaster evolve under very strong selective constraint while few, if any, appear to be under weak constraint. Linking polymorphism with divergence data, we further find that the fraction of synonymous sites exposed to strong purifying selection is higher for those positions that show slower evolution on the Drosophila phylogeny. The function underlying the inferred strong constraint appears to be separate from splicing enhancers, nucleosome positioning, and the translational optimization generating canonical codon bias. The fraction of synonymous sites under strong constraint within a gene correlates well with gene expression, particularly in the mid-late embryo, pupae, and adult developmental stages. Genes enriched in strongly constrained synonymous sites tend to be particularly functionally important and are often involved in key developmental pathways. Given that the observed widespread constraint acting on synonymous sites is likely not limited to Drosophila, the role of synonymous sites in genetic disease and adaptation should be reevaluated. PMID:23737754

Evidence of an evolutionary hourglass pattern in herbivory-induced transcriptomic responses.

PubMed

Durrant, Matthew; Boyer, Justin; Zhou, Wenwu; Baldwin, Ian T; Xu, Shuqing

2017-08-01

Herbivory-induced defenses are specific and activated in plants when elicitors, frequently found in the herbivores' oral secretions, are introduced into wounds during attack. While complex signaling cascades are known to be involved, it remains largely unclear how natural selection has shaped the evolution of these induced defenses. We analyzed herbivory-induced transcriptomic responses in wild tobacco, Nicotiana attenuata, using a phylotranscriptomic approach that measures the origin and sequence divergence of herbivory-induced genes. Highly conserved and evolutionarily ancient genes of primary metabolism were activated at intermediate time points (2-6 h) after elicitation, while less constrained and young genes associated with defense signaling and biosynthesis of specialized metabolites were activated at early (before 2 h) and late (after 6 h) stages of the induced response, respectively - a pattern resembling the evolutionary hourglass pattern observed during embryogenesis in animals and the developmental process in plants and fungi. The hourglass patterns found in herbivory-induced defense responses and developmental process are both likely to be a result of signaling modularization and differential evolutionary constraints on the modules involved in the signaling cascade. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

Introduction

NASA Astrophysics Data System (ADS)

Bouma, Brett E.

1998-09-01

The pace of technological advancement of Optical Coherence Tomography (OCT) over the last several years has been extremely rapid. The field has progressed from one-dimensional low-coherence ranging to full three-dimensional imaging with individual two-dimensional images aquired at near video rate in a span of less than eight years. Imaging applications have included polymers and advanced composites, Ophthalmology, Developmental Biology, Gastroenterology, Urology, Cardiology, Neurology, and Gynecology. These preliminary studies indicate the great potential for OCT to make a significant impact, especially in clinical medicine.

Lymphoedema in Hereditary Recurrent Cholestasis from Birth

PubMed Central

Aagenaes, Øystein; Sigstad, Helge; Bjørn-Hansen, Ragnar

1970-01-01

An inherited disorder characterized by a combination of lymphoedema and intrahepatic cholestasis is described in a Norwegian kindred. The jaundice is evident soon after birth, and recurrent episodes occur throughout life. The oedema starts at about school age and subsequently progresses; it is due to hypoplasia of the lymph vessels of the lower extremities. The cause of the cholestasis has not been established, but a structural intrahepatic developmental defect is suggested. ImagesFIG. 2FIG. 3FIG. 4FIG. 5FIG. 6 PMID:5477684

A case of deletion 14(q22.1-->q22.3) associated with anophthalmia and pituitary abnormalities.

PubMed Central

Elliott, J; Maltby, E L; Reynolds, B

1993-01-01

An interstitial deletion of the region q22.1-->q22.3 of chromosome 14 is described in a child with bilateral anophthalmia, dysmorphic features including micrognathia, small tongue, and high arched palate, developmental and growth retardation, undescended testes with a micropenis, and hypothyroidism. Interstitial deletions of the long arm of chromosome 14 are extremely rare, but this case seems to confirm that the region q22 is specifically concerned with pituitary and eye development. Images PMID:7682620

Enabling fast charging – A battery technology gap assessment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ahmed, Shabbir; Bloom, Ira; Jansen, Andrew N.

The battery technology literature is reviewed, with an emphasis on key elements that limit extreme fast charging. Key gaps in existing elements of the technology are presented as well as developmental needs. Among these needs are advanced models and methods to detect and prevent lithium plating; new positive-electrode materials which are less prone to stress-induced failure; better electrode designs to accommodate very rapid diffusion in and out of the electrode; and thermal management and pack designs to accommodate the higher operating voltage.

Enabling fast charging – A battery technology gap assessment

DOE PAGES

Ahmed, Shabbir; Bloom, Ira; Jansen, Andrew N.; ...

2017-10-23

The battery technology literature is reviewed, with an emphasis on key elements that limit extreme fast charging. Key gaps in existing elements of the technology are presented as well as developmental needs. Among these needs are advanced models and methods to detect and prevent lithium plating; new positive-electrode materials which are less prone to stress-induced failure; better electrode designs to accommodate very rapid diffusion in and out of the electrode; and thermal management and pack designs to accommodate the higher operating voltage.

The Impact of Short-Term Video Games on Performance among Children with Developmental Delays: A Randomized Controlled Trial

PubMed Central

Hsieh, Ru-Lan; Lee, Wen-Chung; Lin, Jui-Hsiang

2016-01-01

This prospective, randomized controlled study investigated the effects of short-term interactive video game playing among children with developmental delays participating in traditional rehabilitation treatment at a rehabilitation clinic. One hundred and one boys and 46 girls with a mean age of 5.8 years (range: 3 to 12 years) were enrolled in this study. All patients were confirmed to suffer from developmental delays, and were participating in traditional rehabilitation treatment. Children participated in two periods of 4 weeks each, group A being offered intervention of eight 30-minute sessions of interactive video games in the first period, and group B in the second, in addition to the traditional rehabilitation treatment. The physical, psychosocial, and total health of the children was periodically assessed using the parent-reported Pediatric Quality of Life Inventory-Generic Core Scales (PedsQL); and the children’s upper extremity and physical function, transfer and basic mobility, sports and physical functioning, and global functioning were assessed using the Pediatric Outcomes Data Collection Instrument. Parental impact was evaluated using the PedsQL-Family Impact Module for family function, PedsQL-Health Satisfaction questionnaire for parents’ satisfaction with their children’s care and World Health Organization-Quality of Life-Brief Version for quality of life. Compared with the baseline, significant improvements of physical function were observed in both groups (5.6 ± 19.5, p = 0.013; 4.7 ± 13.8, p = 0.009) during the intervention periods. No significant improvement of psychosocial health, functional performance, or family impact was observed in children with developmental delays. Short-term interactive video game play in conjunction with traditional rehabilitation treatment improved the physical health of children with developmental delays. Trial Registration: ClinicalTrials.gov NCT02184715 PMID:26983099

The Impact of Short-Term Video Games on Performance among Children with Developmental Delays: A Randomized Controlled Trial.

PubMed

Hsieh, Ru-Lan; Lee, Wen-Chung; Lin, Jui-Hsiang

2016-01-01

This prospective, randomized controlled study investigated the effects of short-term interactive video game playing among children with developmental delays participating in traditional rehabilitation treatment at a rehabilitation clinic. One hundred and one boys and 46 girls with a mean age of 5.8 years (range: 3 to 12 years) were enrolled in this study. All patients were confirmed to suffer from developmental delays, and were participating in traditional rehabilitation treatment. Children participated in two periods of 4 weeks each, group A being offered intervention of eight 30-minute sessions of interactive video games in the first period, and group B in the second, in addition to the traditional rehabilitation treatment. The physical, psychosocial, and total health of the children was periodically assessed using the parent-reported Pediatric Quality of Life Inventory-Generic Core Scales (PedsQL); and the children's upper extremity and physical function, transfer and basic mobility, sports and physical functioning, and global functioning were assessed using the Pediatric Outcomes Data Collection Instrument. Parental impact was evaluated using the PedsQL-Family Impact Module for family function, PedsQL-Health Satisfaction questionnaire for parents' satisfaction with their children's care and World Health Organization-Quality of Life-Brief Version for quality of life. Compared with the baseline, significant improvements of physical function were observed in both groups (5.6 ± 19.5, p = 0.013; 4.7 ± 13.8, p = 0.009) during the intervention periods. No significant improvement of psychosocial health, functional performance, or family impact was observed in children with developmental delays. Short-term interactive video game play in conjunction with traditional rehabilitation treatment improved the physical health of children with developmental delays. ClinicalTrials.gov NCT02184715.

Implications of Binary Black Hole Detections on the Merger Rates of Double Neutron Stars and Neutron Star–Black Holes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gupta, Anuradha; Arun, K. G.; Sathyaprakash, B. S., E-mail: axg645@psu.edu, E-mail: kgarun@cmi.ac.in, E-mail: bss25@psu.edu

We show that the inferred merger rate and chirp masses of binary black holes (BBHs) detected by advanced LIGO (aLIGO) can be used to constrain the rate of double neutron star (DNS) and neutron star–black hole (NSBH) mergers in the universe. We explicitly demonstrate this by considering a set of publicly available population synthesis models of Dominik et al. and show that if all the BBH mergers, GW150914, LVT151012, GW151226, and GW170104, observed by aLIGO arise from isolated binary evolution, the predicted DNS merger rate may be constrained to be 2.3–471.0 Gpc{sup −3} yr{sup −1} and that of NSBH mergersmore » will be constrained to 0.2–48.5 Gpc{sup −3} yr{sup −1}. The DNS merger rates are not constrained much, but the NSBH rates are tightened by a factor of ∼4 as compared to their previous rates. Note that these constrained DNS and NSBH rates are extremely model-dependent and are compared to the unconstrained values 2.3–472.5 Gpc{sup −3} yr{sup −1} and 0.2–218 Gpc{sup −3} yr{sup −1}, respectively, using the same models of Dominik et al. (2012a). These rate estimates may have implications for short Gamma Ray Burst progenitor models assuming they are powered (solely) by DNS or NSBH mergers. While these results are based on a set of open access population synthesis models, which may not necessarily be the representative ones, the proposed method is very general and can be applied to any number of models, thereby yielding more realistic constraints on the DNS and NSBH merger rates from the inferred BBH merger rate and chirp mass.« less

How flexible is phenotypic plasticity? Developmental windows for trait induction and reversal.

PubMed

Hoverman, Jason T; Relyea, Rick A

2007-03-01

Inducible defenses allow prey to modulate their phenotypic responses to the level of predation risk in the environment and reduce the cost of constitutive defenses. Inherent in this statement is that prey must alter their phenotypes during development in order to form these defenses. This has lead many ecologists and evolutionary biologists to call for studies that examine developmental plasticity to provide insights into the importance of development in controlling the trajectories of trait formation, the integration of phenotypes over ontogeny, and the establishment of developmental windows for trait formation and reversal. By moving away from studies that focus on a single point in development, we can obtain a more complete understanding of the phenotypic decisions and limitations of prey. We exposed freshwater snails (Helisoma trivolvis) to environments in which predatory water bugs (Belostoma flumineum) were always absent, always present, or added and removed at different points in development. We discovered that snails formed morphological defenses against water bugs. Importantly, after the initial induction of defenses, snails showed similar developmental trajectories as snails reared without predators. Further, the snails possessed wide developmental windows for inducible defenses that extended past sexual maturity. However, being induced later in development appeared to have an associated cost (i.e., decreased shell thickness) that was not found when water bugs were always present. This epiphenotype (i.e., new shell formation as an extension of the current shell) suggests that resource limitation plays an important role in responses to temporal variation in predation risk and may have critical ecological costs that limit the benefits of the inducible defense. Lastly, the ability of snails to completely reverse their defenses was limited to early in ontogeny due to the constraints associated with modular growth of shell material. In sum, we demonstrate that taking a developmental perspective is extremely valuable for understanding the ecology of inducible defenses.

[Symmetry is beauty - or is it? The rise and fall of fluctuating asymmetry].

PubMed

Debat, Vincent

Fluctuating asymmetry is the stochastic, minor deviation from perfect symmetry in bilaterally symmetrical organisms. It reflects the limit of developmental precision. Such a precision can be influenced by various factors, both internal (genetic mutations, stochastic variation at every levels of development) and external (environmental influences). Fluctuating asymmetry has receive an extreme attention for the past few decades, that culminated in the 90s: it has been used as an estimator of heterozygosity, fitness, environmental stress, and widely applied to human biology, sociobiology and psychology before being more or less discredited in the early 2000s. The reasons for such an extreme popularity and then disgrace are discussed here. Far from suggesting to abandon the study of fluctuating asymmetry, we indicate some of the most promising research avenues. ‡. © 2016 médecine/sciences – Inserm.

Biogenic volatile organic compound emissions from senescent maize leaves and a comparison with other leaf developmental stages

NASA Astrophysics Data System (ADS)

Mozaffar, A.; Schoon, N.; Bachy, A.; Digrado, A.; Heinesch, B.; Aubinet, M.; Fauconnier, M.-L.; Delaplace, P.; du Jardin, P.; Amelynck, C.

2018-03-01

Plants are the major source of Biogenic Volatile Organic Compounds (BVOCs) which have a large influence on atmospheric chemistry and the climate system. Therefore, understanding of BVOC emissions from all abundant plant species at all developmental stages is very important. Nevertheless, investigations on BVOC emissions from even the most widespread agricultural crop species are rare and mainly confined to the healthy green leaves. Senescent leaves of grain crop species could be an important source of BVOCs as almost all the leaves senesce on the field before being harvested. For these reasons, BVOC emission measurements have been performed on maize (Zea mays L.), one of the most cultivated crop species in the world, at all the leaf developmental stages. The measurements were performed in controlled environmental conditions using dynamic enclosures and proton transfer reaction mass spectrometry (PTR-MS). The main compounds emitted by senescent maize leaves were methanol (31% of the total cumulative BVOC emission on a mass of compound basis) and acetic acid (30%), followed by acetaldehyde (11%), hexenals (9%) and m/z 59 compounds (acetone/propanal) (7%). Important differences were observed in the temporal emission profiles of the compounds, and both yellow leaves during chlorosis and dry brown leaves after chlorosis were identified as important senescence-related BVOC sources. Total cumulative BVOC emissions from senescent maize leaves were found to be among the highest for senescent Poaceae plant species. BVOC emission rates varied strongly among the different leaf developmental stages, and senescent leaves showed a larger diversity of emitted compounds than leaves at earlier stages. Methanol was the compound with the highest emissions for all the leaf developmental stages and the contribution from the young-growing, mature, and senescent stages to the total methanol emission by a typical maize leaf was 61, 13, and 26%, respectively. This study shows that BVOC emissions from senescent maize leaves cannot be neglected and further investigations in field conditions are recommended to further constrain the BVOC emissions from this important C4 crop species.

There is no highly conserved embryonic stage in the vertebrates: implications for current theories of evolution and development.

PubMed

Richardson, M K; Hanken, J; Gooneratne, M L; Pieau, C; Raynaud, A; Selwood, L; Wright, G M

1997-08-01

Embryos of different species of vertebrate share a common organisation and often look similar. Adult differences among species become more apparent through divergence at later stages. Some authors have suggested that members of most or all vertebrate clades pass through a virtually identical, conserved stage. This idea was promoted by Haeckel, and has recently been revived in the context of claims regarding the universality of developmental mechanisms. Thus embryonic resemblance at the tailbud stage has been linked with a conserved pattern of developmental gene expression - the zootype. Haeckel's drawings of the external morphology of various vertebrates remain the most comprehensive comparative data purporting to show a conserved stage. However, their accuracy has been questioned and only a narrow range of species was illustrated. In view of the current widespread interest in evolutionary developmental biology, and especially in the conservation of developmental mechanisms, re-examination of the extent of variation in vertebrate embryos is long overdue. We present here the first review of the external morphology of tailbud embryos, illustrated with original specimens from a wide range of vertebrate groups. We find that embryos at the tailbud stage - thought to correspond to a conserved stage - show variations in form due to allometry, heterochrony, and differences in body plan and somite number. These variations foreshadow important differences in adult body form. Contrary to recent claims that all vertebrate embryos pass through a stage when they are the same size, we find a greater than 10-fold variation in greatest length at the tailbud stage. Our survey seriously undermines the credibility of Haeckel's drawings, which depict not a conserved stage for vertebrates, but a stylised amniote embryo. In fact, the taxonomic level of greatest resemblance among vertebrate embryos is below the subphylum. The wide variation in morphology among vertebrate embryos is difficult to reconcile with the idea of a phyogenetically-conserved tailbud stage, and suggests that at least some developmental mechanisms are not highly constrained by the zootype. Our study also highlights the dangers of drawing general conclusions about vertebrate development from studies of gene expression in a small number of laboratory species.

Skull Development, Ossification Pattern, and Adult Shape in the Emerging Lizard Model Organism Pogona vitticeps: A Comparative Analysis With Other Squamates.

PubMed

Ollonen, Joni; Da Silva, Filipe O; Mahlow, Kristin; Di-Poï, Nicolas

2018-01-01

The rise of the Evo-Devo field and the development of multidisciplinary research tools at various levels of biological organization have led to a growing interest in researching for new non-model organisms. Squamates (lizards and snakes) are particularly important for understanding fundamental questions about the evolution of vertebrates because of their high diversity and evolutionary innovations and adaptations that portrait a striking body plan change that reached its extreme in snakes. Yet, little is known about the intricate connection between phenotype and genotype in squamates, partly due to limited developmental knowledge and incomplete characterization of embryonic development. Surprisingly, squamate models have received limited attention in comparative developmental studies, and only a few species examined so far can be considered as representative and appropriate model organism for mechanistic Evo-Devo studies. Fortunately, the agamid lizard Pogona vitticeps (central bearded dragon) is one of the most popular, domesticated reptile species with both a well-established history in captivity and key advantages for research, thus forming an ideal laboratory model system and justifying his recent use in reptile biology research. We first report here the complete post-oviposition embryonic development for P. vitticeps based on standardized staging systems and external morphological characters previously defined for squamates. Whereas the overall morphological development follows the general trends observed in other squamates, our comparisons indicate major differences in the developmental sequence of several tissues, including early craniofacial characters. Detailed analysis of both embryonic skull development and adult skull shape, using a comparative approach integrating CT-scans and gene expression studies in P. vitticeps as well as comparative embryology and 3D geometric morphometrics in a large dataset of lizards and snakes, highlights the extreme adult skull shape of P. vitticeps and further indicates that heterochrony has played a key role in the early development and ossification of squamate skull bones. Such detailed studies of embryonic character development, craniofacial patterning, and bone formation are essential for the establishment of well-selected squamate species as Evo-Devo model organisms. We expect that P. vitticeps will continue to emerge as a new attractive model organism for understanding developmental and molecular processes underlying tissue formation, morphology, and evolution.

Skull Development, Ossification Pattern, and Adult Shape in the Emerging Lizard Model Organism Pogona vitticeps: A Comparative Analysis With Other Squamates

PubMed Central

Ollonen, Joni; Da Silva, Filipe O.; Mahlow, Kristin; Di-Poï, Nicolas

2018-01-01

The rise of the Evo-Devo field and the development of multidisciplinary research tools at various levels of biological organization have led to a growing interest in researching for new non-model organisms. Squamates (lizards and snakes) are particularly important for understanding fundamental questions about the evolution of vertebrates because of their high diversity and evolutionary innovations and adaptations that portrait a striking body plan change that reached its extreme in snakes. Yet, little is known about the intricate connection between phenotype and genotype in squamates, partly due to limited developmental knowledge and incomplete characterization of embryonic development. Surprisingly, squamate models have received limited attention in comparative developmental studies, and only a few species examined so far can be considered as representative and appropriate model organism for mechanistic Evo-Devo studies. Fortunately, the agamid lizard Pogona vitticeps (central bearded dragon) is one of the most popular, domesticated reptile species with both a well-established history in captivity and key advantages for research, thus forming an ideal laboratory model system and justifying his recent use in reptile biology research. We first report here the complete post-oviposition embryonic development for P. vitticeps based on standardized staging systems and external morphological characters previously defined for squamates. Whereas the overall morphological development follows the general trends observed in other squamates, our comparisons indicate major differences in the developmental sequence of several tissues, including early craniofacial characters. Detailed analysis of both embryonic skull development and adult skull shape, using a comparative approach integrating CT-scans and gene expression studies in P. vitticeps as well as comparative embryology and 3D geometric morphometrics in a large dataset of lizards and snakes, highlights the extreme adult skull shape of P. vitticeps and further indicates that heterochrony has played a key role in the early development and ossification of squamate skull bones. Such detailed studies of embryonic character development, craniofacial patterning, and bone formation are essential for the establishment of well-selected squamate species as Evo-Devo model organisms. We expect that P. vitticeps will continue to emerge as a new attractive model organism for understanding developmental and molecular processes underlying tissue formation, morphology, and evolution. PMID:29643813

On the widespread capacity for, and functional significance of, extreme inbreeding in ferns.

PubMed

Sessa, Emily B; Testo, Weston L; Watkins, James E

2016-08-01

Homosporous vascular plants utilize three different mating systems, one of which, gametophytic selfing, is an extreme form of inbreeding only possible in homosporous groups. This mating system results in complete homozygosity in all progeny and has important evolutionary and ecological implications. Ferns are the largest group of homosporous land plants, and the significance of extreme inbreeding for fern evolution has been a subject of debate for decades. We cultured gametophytes in the laboratory and quantified the relative frequencies of sporophyte production from isolated and paired gametophytes, and examined associations between breeding systems and several ecological and evolutionary traits. The majority of fern species studied show a capacity for gametophytic selfing, producing sporophytes from both isolated and paired gametophytes. While we did not follow sporophytes to maturity to investigate potential detrimental effects of homozygosity at later developmental stages, our results suggest that gametophytic selfing may have greater significance for fern evolution and diversification than has previously been realized. We present evidence from the largest study of mating behavior in ferns to date that the capacity for extreme inbreeding is prevalent in this lineage, and we discuss its implications and relevance and make recommendations for future studies of fern mating systems. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

The evolution of ecological tolerance in prokaryotes

NASA Technical Reports Server (NTRS)

Knoll, A. H.; Bauld, J.

1989-01-01

The ecological ranges of Archaeobacteria and Eubacteria are constrained by a requirement for liquid water and the physico-chemical stability limits of biomolecules, but within this broad envelope, prokaryotes have evolved adaptations that permit them to tolerate a remarkable spectrum of habitats. Laboratory experiments indicate that prokaryotes can adapt rapidly to novel environmental conditions, yet geological studies suggest early diversification and long-term stasis within the prokaryotic kingdoms. These apparently contradictory perspectives can be reconciled by understanding that, in general, rates and patterns of prokaryotic evolution reflect the developmental history of the Earth's surface environments. Our understanding of modern microbial ecology provides a lens through which our accumulating knowledge of physiology, molecular phylogeny and the Earth's history can be integrated and focussed on the phenomenon of prokaryotic evolution.

Using metabolic flux data to further constrain the metabolic solution space and predict internal flux patterns: the Escherichia coli spectrum.

PubMed

Wiback, Sharon J; Mahadevan, Radhakrishnan; Palsson, Bernhard Ø

2004-05-05

Constraint-based metabolic modeling has been used to capture the genome-scale, systems properties of an organism's metabolism. The first generation of these models has been built on annotated gene sequence. To further this field, we now need to develop methods to incorporate additional "omic" data types including transcriptomics, metabolomics, and fluxomics to further facilitate the construction, validation, and predictive capabilities of these models. The work herein combines metabolic flux data with an in silico model of central metabolism of Escherichia coli for model centric integration of the flux data. The extreme pathways for this network, which define the allowable solution space for all possible flux distributions, are analyzed using the alpha-spectrum. The alpha-spectrum determines which extreme pathways can and cannot contribute to the metabolic flux distribution for a given condition and gives the allowable range of weightings on each extreme pathway that can contribute. Since many extreme pathways cannot be used under certain conditions, the result is a "condition-specific" solution space that is a subset of the original solution space. The alpha-spectrum results are used to create a "condition-specific" extreme pathway matrix that can be analyzed using singular value decomposition (SVD). The first mode of the SVD analysis characterizes the solution space for a given condition. We show that SVD analysis of the alpha-spectrum extreme pathway matrix that incorporates measured uptake and byproduct secretion rates, can predict internal flux trends for different experimental conditions. These predicted internal flux trends are, in general, consistent with the flux trends measured using experimental metabolic flux analysis techniques. Copyright 2004 Wiley Periodicals, Inc.

Characterizing the Disk of a Recent Massive Collisional Event

NASA Astrophysics Data System (ADS)

Song, Inseok

2015-10-01

Debris disks play a key role in the formation and evolution of planetary systems. On rare occasions, circumstellar material appears as strictly warm infrared excess in regions of expected terrestrial planet formation and so present an interesting opportunity for the study of terrestrial planetary regions. There are only a few known cases of extreme, warm, dusty disks which lack any colder outer component including BD+20 307, HD 172555, EF Cha, and HD 23514. We have recently found a new system TYC 8830-410-1 belonging to this rare group. Warm dust grains are extremely short-lived, and the extraordinary amount of warm dust near these stars can only be plausibly explainable by a recent (or on-going) massive transient event such as the Late Heavy Bombardment (LHB) or plantary collisions. LHB-like events are seen generally in a system with a dominant cold disk, however, warm dust only systems show no hint of a massive cold disk. Planetary collisions leave a telltale sign of strange mid-IR spectral feature such as silica and we want to fully characterize the spectral shape of the newly found system with SOFIA/FORCAST. With SOFIA/FORCAST, we propose to obtain two narrow band photometric measurements between 6 and 9 microns. These FORCAST photometric measurements will constrain the amount and temperature of the warm disk in the system. There are less than a handful systems with a strong hint of recent planetary collisions. With the firmly constrained warm disk around TYC 8830-410-1, we will publish the discovery in a leading astronomical journal accompanied with a potential press release through SOFIA.

The Nustar Spectrum of Mrk 335: Extreme Relativistic Effects Within Two Gravitational Radii of the Event Horizon?

NASA Technical Reports Server (NTRS)

Parker, M. L.; Wilkins, D. R.; Fabian, A. C.; Grupe, D.; Dauser, T.; Matt, G.; Harrison, F. A.; Brenneman, L.; Boggs, S. E.; Christensen, F. E.;

CLASH: EXTREME EMISSION-LINE GALAXIES AND THEIR IMPLICATION ON SELECTION OF HIGH-REDSHIFT GALAXIES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Xingxing; Wang, Junxian; Shu, Xinwen

2015-03-01

We utilize the Cluster Lensing And Supernova survey with Hubble observations of 25 clusters to search for extreme emission-line galaxies (EELGs). The selections are carried out in two central bands: F105W (Y {sub 105}) and F125W (J {sub 125}), as the flux of the central bands could be enhanced by the presence of [O III] λλ4959, 5007 at redshifts of ∼0.93-1.14 and 1.57-1.79, respectively. The multiband observations help to constrain the equivalent widths (EWs) of emission lines. Thanks to cluster lensing, we are able to identify 52 candidates down to an intrinsic limiting magnitude of 28.5 and to a rest-framemore » [O III] λλ4959, 5007 EW of ≅ 3700 Å. Our samples include a number of EELGs at lower luminosities that are missed in other surveys, and the extremely high EW can only be found in such faint galaxies. These EELGs can mimic a dropout feature similar to that of high-redshift galaxies and contaminate the color-color selection of high-redshift galaxies when the signal-to-noise ratio is limited or the band coverage is incomplete.« less

MaRIE theory, modeling and computation roadmap executive summary

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lookman, Turab

The confluence of MaRIE (Matter-Radiation Interactions in Extreme) and extreme (exascale) computing timelines offers a unique opportunity in co-designing the elements of materials discovery, with theory and high performance computing, itself co-designed by constrained optimization of hardware and software, and experiments. MaRIE's theory, modeling, and computation (TMC) roadmap efforts have paralleled 'MaRIE First Experiments' science activities in the areas of materials dynamics, irradiated materials and complex functional materials in extreme conditions. The documents that follow this executive summary describe in detail for each of these areas the current state of the art, the gaps that exist and the road mapmore » to MaRIE and beyond. Here we integrate the various elements to articulate an overarching theme related to the role and consequences of heterogeneities which manifest as competing states in a complex energy landscape. MaRIE experiments will locate, measure and follow the dynamical evolution of these heterogeneities. Our TMC vision spans the various pillar science and highlights the key theoretical and experimental challenges. We also present a theory, modeling and computation roadmap of the path to and beyond MaRIE in each of the science areas.« less

High-redshift post-reionization cosmology with 21cm intensity mapping

NASA Astrophysics Data System (ADS)

Obuljen, Andrej; Castorina, Emanuele; Villaescusa-Navarro, Francisco; Viel, Matteo

2018-05-01

We investigate the possibility of performing cosmological studies in the redshift range 2.5

Habitat productivity constrains the distribution of social spiders across continents – case study of the genus Stegodyphus

PubMed Central

2013-01-01

Introduction Sociality has evolved independently multiple times across the spider phylogeny, and despite wide taxonomic and geographical breadth the social species are characterized by a common geographical constrain to tropical and subtropical areas. Here we investigate the environmental factors that drive macro-ecological patterns in social and solitary species in a genus that shows a Mediterranean–Afro-Oriental distribution (Stegodyphus). Both selected drivers (productivity and seasonality) may affect the abundance of potential prey insects, but seasonality may further directly affect survival due to mortality caused by extreme climatic events. Based on a comprehensive dataset including information about the distribution of three independently derived social species and 13 solitary congeners we tested the hypotheses that the distribution of social Stegodyphus species relative to solitary congeners is: (1) restricted to habitats of high vegetation productivity and (2) constrained to areas with a stable climate (low precipitation seasonality). Results Using spatial logistic regression modelling and information-theoretic model selection, we show that social species occur at higher vegetation productivity than solitary, while precipitation seasonality received limited support as a predictor of social spider occurrence. An analysis of insect biomass data across the Stegodyphus distribution range confirmed that vegetation productivity is positively correlated to potential insect prey biomass. Conclusions Habitat productivity constrains the distribution of social spiders across continents compared to their solitary congeners, with group-living in spiders being restricted to areas with relatively high vegetation productivity and insect prey biomass. As known for other taxa, permanent sociality likely evolves in response to high predation pressure and imposes within-group competition for resources. Our results suggest that group living is contingent upon productive environmental conditions where elevated prey abundance meet the increased demand for food of social groups. PMID:23433065

Description and Codification of Miscanthus × giganteus Growth Stages for Phenological Assessment

PubMed Central

Tejera, Mauricio D.; Heaton, Emily A.

2017-01-01

Triploid Miscanthus × giganteus (Greef et Deu. ex Hodkinson et Renvoize) is a sterile, perennial grass used for biomass production in temperate environments. While M. × giganteus has been intensively researched, a scale standardizing description of M. × giganteus morphological stages has not been developed. Here we provide such a scale by adapting the widely-used Biologische Bundesanstalt, Bundessortenamt, CHemische Industrie (BBCH) scale and its corresponding numerical code to describe stages of morphological development in M. × giganteus using observations of the “Freedom” and “Illinois” clone in Iowa, USA. Descriptive keys with images are also presented. Because M. × giganteus plants overlap in the field, the scale was first applied to individual stems and then scaled up to assess plants or communities. Of the 10 principal growth stages in the BBCH system, eight were observed in M. × giganteus. Each principal stage was subdivided into secondary stages to enable a detailed description of developmental progression. While M. × giganteus does not have seed development stages, descriptions of those stages are provided to extend the scale to other Miscanthus genotypes. We present methods to use morphological development data to assess phenology by calculating the onset, duration, and abundance of each developmental stage. This scale has potential to harmonize previously described study-specific scales and standardize results across studies. Use of the precise staging presented here should more tightly constrain estimates of developmental parameters in crop models and increase the efficacy of timing-sensitive crop management practices like pest control and harvest. PMID:29062320

Adapting to the unpredictable: reproductive biology of vertebrates in the Australian wet-dry tropics.

PubMed

Shine, Richard; Brown, Gregory P

2008-01-27

In the wet-dry tropics of northern Australia, temperatures are high and stable year-round but monsoonal rainfall is highly seasonal and variable both annually and spatially. Many features of reproduction in vertebrates of this region may be adaptations to dealing with this unpredictable variation in precipitation, notably by (i) using direct proximate (rainfall-affected) cues to synchronize the timing and extent of breeding with rainfall events, (ii) placing the eggs or offspring in conditions where they will be buffered from rainfall extremes, and (iii) evolving developmental plasticity, such that the timing and trajectory of embryonic differentiation flexibly respond to local conditions. For example, organisms as diverse as snakes (Liasis fuscus, Acrochordus arafurae), crocodiles (Crocodylus porosus), birds (Anseranas semipalmata) and wallabies (Macropus agilis) show extreme annual variation in reproductive rates, linked to stochastic variation in wet season rainfall. The seasonal timing of initiation and cessation of breeding in snakes (Tropidonophis mairii) and rats (Rattus colletti) also varies among years, depending upon precipitation. An alternative adaptive route is to buffer the effects of rainfall variability on offspring by parental care (including viviparity) or by judicious selection of nest sites in oviparous taxa without parental care. A third type of adaptive response involves flexible embryonic responses (including embryonic diapause, facultative hatching and temperature-dependent sex determination) to incubation conditions, as seen in squamates, crocodilians and turtles. Such flexibility fine-tunes developmental rates and trajectories to conditions--especially, rainfall patterns--that are not predictable at the time of oviposition.

AgroClimate: Simulating and Monitoring the Risk of Extreme Weather Events from a Crop Phenology Perspective

NASA Astrophysics Data System (ADS)

Fraisse, C.; Pequeno, D.; Staub, C. G.; Perry, C.

2016-12-01

Climate variability, particularly the occurrence of extreme weather conditions such as dry spells and heat stress during sensitive crop developmental phases can substantially increase the prospect of reduced crop yields. Yield losses or crop failure risk due to stressful weather conditions vary mainly due to stress severity and exposure time and duration. The magnitude of stress effects is also crop specific, differing in terms of thresholds and adaptation to environmental conditions. To help producers in the Southeast USA mitigate and monitor the risk of crop losses due to extreme weather events we developed a web-based tool that evaluates the risk of extreme weather events during the season taking into account the crop development stages. Producers can enter their plans for the upcoming season in a given field (e.g. crop, variety, planting date, acreage etc.), select or not a specific El Nino Southern Oscillation (ENSO) phase, and will be presented with the probabilities (ranging from 0 -100%) of extreme weather events occurring during sensitive phases of the growing season for the selected conditions. The DSSAT models CERES-Maize, CROPGRO-Soybean, CROPGRO-Cotton, and N-Wheat phenology models have been translated from FORTRAN to a standalone versions in R language. These models have been tested in collaboration with Extension faculty and producers during the 2016 season and their usefulness for risk mitigation and monitoring evaluated. A companion AgroClimate app was also developed to help producers track and monitor phenology development during the cropping season.

Using Extreme Tropical Precipitation Statistics to Constrain Future Climate States

NASA Astrophysics Data System (ADS)

Igel, M.; Biello, J. A.

2017-12-01

Tropical precipitation is characterized by a rapid growth in mean intensity as the column humidity increases. This behavior is examined in both a cloud resolving model and with high-resolution observations of precipitation and column humidity from CloudSat and AIRS, respectively. The model and the observations exhibit remarkable consistency and suggest a new paradigm for extreme precipitation. We show that the total precipitation can be decomposed into a product of contributions from a mean intensity, a probability of precipitation, and a global PDF of column humidity values. We use the modeling and observational results to suggest simple, analytic forms for each of these functions. The analytic representations are then used to construct a simple expression for the global accumulated precipitation as a function of the parameters of each of the component functions. As the climate warms, extreme precipitation intensity and global precipitation are expected to increase, though at different rates. When these predictions are incorporated into the new analytic expression for total precipitation, predictions for changes due to global warming to the probability of precipitation and the PDF of column humidity can be made. We show that strong constraints can be imposed on the future shape of the PDF of column humidity but that only weak constraints can be set on the probability of precipitation. These are largely imposed by the intensification of extreme precipitation. This result suggests that understanding precisely how extreme precipitation responds to climate warming is critical to predicting other impactful properties of global hydrology. The new framework can also be used to confirm and discount existing theories for shifting precipitation.

Evaluation of NASA's MERRA Precipitation Product in Reproducing the Observed Trend and Distribution of Extreme Precipitation Events in the United States

NASA Technical Reports Server (NTRS)

Ashouri, Hamed; Sorooshian, Soroosh; Hsu, Kuo-Lin; Bosilovich, Michael G.; Lee, Jaechoul; Wehner, Michael F.; Collow, Allison

2016-01-01

This study evaluates the performance of NASA's Modern-Era Retrospective Analysis for Research and Applications (MERRA) precipitation product in reproducing the trend and distribution of extreme precipitation events. Utilizing the extreme value theory, time-invariant and time-variant extreme value distributions are developed to model the trends and changes in the patterns of extreme precipitation events over the contiguous United States during 1979-2010. The Climate Prediction Center (CPC) U.S.Unified gridded observation data are used as the observational dataset. The CPC analysis shows that the eastern and western parts of the United States are experiencing positive and negative trends in annual maxima, respectively. The continental-scale patterns of change found in MERRA seem to reasonably mirror the observed patterns of change found in CPC. This is not previously expected, given the difficulty in constraining precipitation in reanalysis products. MERRA tends to overestimate the frequency at which the 99th percentile of precipitation is exceeded because this threshold tends to be lower in MERRA, making it easier to be exceeded. This feature is dominant during the summer months. MERRA tends to reproduce spatial patterns of the scale and location parameters of the generalized extreme value and generalized Pareto distributions. However, MERRA underestimates these parameters, particularly over the Gulf Coast states, leading to lower magnitudes in extreme precipitation events. Two issues in MERRA are identified: 1) MERRA shows a spurious negative trend in Nebraska and Kansas, which is most likely related to the changes in the satellite observing system over time that has apparently affected the water cycle in the central United States, and 2) the patterns of positive trend over the Gulf Coast states and along the East Coast seem to be correlated with the tropical cyclones in these regions. The analysis of the trends in the seasonal precipitation extremes indicates that the hurricane and winter seasons are contributing the most to these trend patterns in the southeastern United States. In addition, the increasing annual trend simulated by MERRA in the Gulf Coast region is due to an incorrect trend in winter precipitation extremes.

Final Technical Report for DE-SC0005467

DOE Office of Scientific and Technical Information (OSTI.GOV)

Broccoli, Anthony J.

2014-09-14

The objective of this project is to gain a comprehensive understanding of the key atmospheric mechanisms and physical processes associated with temperature extremes in order to better interpret and constrain uncertainty in climate model simulations of future extreme temperatures. To achieve this objective, we first used climate observations and a reanalysis product to identify the key atmospheric circulation patterns associated with extreme temperature days over North America during the late twentieth century. We found that temperature extremes were associated with distinctive signatures in near-surface and mid-tropospheric circulation. The orientations and spatial scales of these circulation anomalies vary with latitude, season,more » and proximity to important geographic features such as mountains and coastlines. We next examined the associations between daily and monthly temperature extremes and large-scale, recurrent modes of climate variability, including the Pacific-North American (PNA) pattern, the northern annular mode (NAM), and the El Niño-Southern Oscillation (ENSO). The strength of the associations are strongest with the PNA and NAM and weaker for ENSO, and also depend upon season, time scale, and location. The associations are stronger in winter than summer, stronger for monthly than daily extremes, and stronger in the vicinity of the centers of action of the PNA and NAM patterns. In the final stage of this project, we compared climate model simulations of the circulation patterns associated with extreme temperature days over North America with those obtained from observations. Using a variety of metrics and self-organizing maps, we found the multi-model ensemble and the majority of individual models from phase 5 of the Coupled Model Intercomparison Project (CMIP5) generally capture the observed patterns well, including their strength and as well as variations with latitude and season. The results from this project indicate that current models are capable of simulating the large-scale meteorological patterns associated with daily temperature extremes and they suggest that such models can be used to evaluate the extent to which changes in atmospheric circulation will influence future changes in temperature extremes.« less

Evaluation of NASA’s MERRA Precipitation Product in Reproducing the Observed Trend and Distribution of Extreme Precipitation Events in the United States

DOE PAGES

Ashouri, Hamed; Sorooshian, Soroosh; Hsu, Kuo-Lin; ...

2016-02-03

This study evaluates the performance of NASA's Modern-Era Retrospective Analysis for Research and Applications (MERRA) precipitation product in reproducing the trend and distribution of extreme precipitation events. Utilizing the extreme value theory, time-invariant and time-variant extreme value distributions are developed to model the trends and changes in the patterns of extreme precipitation events over the contiguous United States during 1979-2010. The Climate Prediction Center (CPC)U.S.Unified gridded observation data are used as the observational dataset. The CPC analysis shows that the eastern and western parts of the United States are experiencing positive and negative trends in annual maxima, respectively. The continental-scalemore » patterns of change found in MERRA seem to reasonably mirror the observed patterns of change found in CPC. This is not previously expected, given the difficulty in constraining precipitation in reanalysis products. MERRA tends to overestimate the frequency at which the 99th percentile of precipitation is exceeded because this threshold tends to be lower in MERRA, making it easier to be exceeded. This feature is dominant during the summer months. MERRAtends to reproduce spatial patterns of the scale and location parameters of the generalized extreme value and generalized Pareto distributions. However, MERRA underestimates these parameters, particularly over the Gulf Coast states, leading to lower magnitudes in extreme precipitation events. Two issues in MERRA are identified: 1)MERRAshows a spurious negative trend in Nebraska andKansas, which ismost likely related to the changes in the satellite observing system over time that has apparently affected the water cycle in the central United States, and 2) the patterns of positive trend over theGulf Coast states and along the East Coast seem to be correlated with the tropical cyclones in these regions. The analysis of the trends in the seasonal precipitation extremes indicates that the hurricane and winter seasons are contributing the most to these trend patterns in the southeastern United States. The increasing annual trend simulated by MERRA in the Gulf Coast region is due to an incorrect trend in winter precipitation extremes.« less

Bending Genders: The Biology of Natural Sex Change in Fish.

PubMed

Todd, Erica V; Liu, Hui; Muncaster, Simon; Gemmell, Neil J

2016-01-01

Sexual fate is no longer seen as an irreversible deterministic switch set during early embryonic development but as an ongoing battle for primacy between male and female developmental trajectories. That sexual fate is not final and must be actively maintained via continuous suppression of the opposing sexual network creates the potential for flexibility into adulthood. In many fishes, sexuality is not only extremely plastic, but sex change is a usual and adaptive part of the life cycle. Sequential hermaphrodites begin life as one sex, changing sometime later to the other, and include species capable of protandrous (male-to-female), protogynous (female-to-male), or serial (bidirectional) sex change. Natural sex change involves coordinated transformations across multiple biological systems, including behavioural, anatomical, neuroendocrine, and molecular axes. We here review the biological processes underlying this amazing transformation, focussing particularly on its molecular basis, which remains poorly understood, but where new genomic technologies are significantly advancing our understanding of how sex change is initiated and progressed at the molecular level. Knowledge of how a usually committed developmental process remains plastic in sequentially hermaphroditic fishes is relevant to understanding the evolution and functioning of sexual developmental systems in vertebrates generally, as well as pathologies of sexual development in humans. © 2016 S. Karger AG, Basel.

Annual killifish adaptations to ephemeral environments: Diapause i in two austrolebias species.

PubMed

Arezo, María José; Papa, Nicolás G; Berois, Nibia; Clivio, Graciela; Montagne, Jimena; De la Piedra, Soledad

2017-11-01

Many organisms are able to survive in extreme environments by entering a state of dormancy. In dormancy, vital activities are reduced until environmental conditions are compatible with active life. Annual killifishes show a special developmental pattern characterized by a phase of dispersion-reaggregation of the blastomeres that separates epiboly from organogenesis, and the capability to enter dormancy in diapause. High tolerance to environmental stress confers annual killifish embryos the condition of extremophiles. At present, the questions of our research group are focused on the understanding of the mechanisms involved in diapause regulation through an interdisciplinary approach. As a first step, it is necessary to characterize diapauses at morphological and physiological levels and to evaluate induction cues under laboratory conditions. In this context, we characterized diapause I in two Austrolebias species. Our experimental approach to induce diapause I was successful and revealed the co-existence of two diapause I phenotypes named A and B instead of one. These phenotypes showed a tendency for lower total extractable RNA content compared with active developmental stages (80-100% epiboly and early reaggregate). These phenotypes are alternative diapause I stages and may have ecological relevance because both were found in embryos in natural ponds. Developmental Dynamics 246:848-857, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Personality and Psychopathology: A Stagnant Field in Need of Development

PubMed Central

Durbin, C. Emily; Hicks, Brian M.

2014-01-01

A dominant paradigm in psychopathology research proposes that individual differences in personality are centrally involved in the origins and manifestations of psychopathology, and structural models of personality and psychopathology have been extremely useful in helping to organize associations among many traits and disorders. However, these models merely describe patterns of covariation; they do not explain the processes by which these patterns emerge. We argue that the field is stagnated, as it is overly focused on the demonstration of concurrent associations and on confirming a spectrum model that proposes traits and disorders are manifestations of the same underlying constructs. We contend that if the field is to move toward an understanding of causal processes, it must integrate knowledge and principles of personality development and developmental psychopathology. To begin this integration, we review (1) normative trends in personality change, (2) age-related changes in the prevalence of disorders, and (3) the impact of onset and chronicity on the severity of disorders. We propose several developmental processes that may contribute to the co-development of personality and psychopathology. We then present novel empirical findings to illustrate how a developmental perspective on traits and disorders can inform new hypotheses, and propose principles and hypotheses that should guide future research. PMID:25544802

Resource quality affects weapon and testis size and the ability of these traits to respond to selection in the leaf-footed cactus bug, Narnia femorata.

PubMed

Sasson, Daniel A; Munoz, Patricio R; Gezan, Salvador A; Miller, Christine W

2016-04-01

The size of weapons and testes can be central to male reproductive success. Yet, the expression of these traits is often extremely variable. Studies are needed that take a more complete organism perspective, investigating the sources of variation in both traits simultaneously and using developmental conditions that mimic those in nature. In this study, we investigated the components of variation in weapon and testis sizes using the leaf-footed cactus bug, Narnia femorata (Hemiptera: Coreidae) on three natural developmental diets. We show that the developmental diet has profound effects on both weapon and testis expression and scaling. Intriguingly, males in the medium-quality diet express large weapons but have relatively tiny testes, suggesting complex allocation decisions. We also find that heritability, evolvability, and additive genetic variation are highest in the high-quality diet for testis and body mass. This result suggests that these traits may have an enhanced ability to respond to selection during a small window of time each year when this diet is available. Taken together, these results illustrate that normal, seasonal fluctuations in the nutritional environment may play a large role in the expression of sexually selected traits and the ability of these traits to respond to selection.

Evoecotoxicology: Environmental Changes and Life Features Development during the Evolutionary Process—the Record of the Past at Developmental Stages of Living Organisms

PubMed Central

Herkovits, Jorge

2006-01-01

For most of evolutionary history, scientific understanding of the environment and life forms is extremely limited. In this commentary I discuss the hypothesis that ontogenetic features of living organisms can be considered biomarkers of coevolution between organisms and physicochemical agents during Earth’s history. I provide a new vision of evolution based on correlations between metabolic features and stage-dependent susceptibility of organisms to physicochemical agents with well-known environmental signatures. Thus, developmental features potentially reflect environmental changes during evolution. From this perspective, early multicellular life forms would have flourished in the anoxic Earth more than 2 billion years ago, which is at least 1.2 billion years in advance of available fossil evidence. The remarkable transition to aerobic metabolism in gastrula-stage embryos potentially reflects evolution toward tridermic organisms by 2 billion years ago. Noteworthy changes in embryonic resistance to physicochemical agents at different developmental stages that can be observed in living organisms potentially reflect the influence of environmental stress conditions during different periods of evolutionary history. Evoecotoxicology, as a multidisciplinary and transdisciplinary approach, can enhance our understanding of evolution, including the phylogenetic significance of differences in susceptibility/resistance to physicochemical agents in different organisms. PMID:16882515

BRAIN MYELINATION IN PREVALENT NEUROPSYCHIATRIC DEVELOPMENTAL DISORDERS

PubMed Central

BARTZOKIS, GEORGE

2008-01-01

Current concepts of addiction focus on neuronal neurocircuitry and neurotransmitters and are largely based on animal model data, but the human brain is unique in its high myelin content and extended developmental (myelination) phase that continues until middle age. The biology of our exceptional myelination process and factors that influence it have been synthesized into a recently published myelin model of human brain evolution and normal development that cuts across the current symptom-based classification of neuropsychiatric disorders. The developmental perspective of the model suggests that dysregulations in the myelination process contribute to prevalent early-life neuropsychiatric disorders, as well as to addictions. These disorders share deficits in inhibitory control functions that likely contribute to their high rates of comorbidity with addiction and other impulsive behaviors. The model posits that substances such as alcohol and psychostimulants are toxic to the extremely vulnerable myelination process and contribute to the poor outcomes of primary and comorbid addictive disorders in susceptible individuals. By increasing the scientific focus on myelination, the model provides a rational biological framework for the development of novel, myelin-centered treatments that may have widespread efficacy across multiple disease states and could potentially be used in treating, delaying, or even preventing some of the most prevalent and devastating neuropsychiatric disorders. PMID:18668184

Cognitive and motor function of neurologically impaired extremely low birth weight children.

PubMed

Bernardo, Janine; Friedman, Harriet; Minich, Nori; Taylor, H Gerry; Wilson-Costello, Deanne; Hack, Maureen

2015-01-01

Rates of neurological impairment among extremely low birth weight children (ELBW [<1 kg]) have decreased since 2000; however, their functioning is unexamined. To compare motor and cognitive functioning of ELBW children with neurological impairment, including cerebral palsy and severe hypotonia/hypertonia, between two periods: 1990 to 1999 (n=83) and 2000 to 2005 (n=34). Measures of function at 20 months corrected age included the Mental and Psychomotor Developmental Indexes of the Bayley Scales of Infant Development and the Gross Motor Functional Classification System as primary outcomes and individual motor function items as secondary outcomes. Analysis failed to reveal significant differences for the primary outcomes, although during 2000 to 2005, sitting significantly improved in children with neurological impairment (P=0.003). Decreases in rates of neurological impairment among ELBW children have been accompanied by a suggestion of improved motor function, although cognitive function has not changed.

The laugh of Satan: a study of a familial murderer.

PubMed

McCully, R S

1978-02-01

A teenage murderer who killed his mother, his tiny half-brother, and his step-father was studied through the imagery he associated to three different editions of inkblots. These sets included the Rorschach, Behn-Rorschach, and Ka-Ro plates. The data were used to theorize about clues, dynamics, and diagnosis in this extreme case of adolescent violence. Family background and developmental history are included. The author takes the position that a conventional analysis of these data alone is not sufficient to fully understand familial murderers. Several of C.G. Jung's concepts, notably his view about the power of shadow-projections to influence conscious percepts and his philosophy about evil as a collective phenomenon, were used to speculate about ways we might extend our understanding of this subject's extreme form of violence. Defining the archetype as an energy-complex, the discussion theorized about possible ways different forms of paranoid ideation may arise.

On Bernstein type inequalities and a weighted Chebyshev approximation problem on ellipses

NASA Technical Reports Server (NTRS)

Freund, Roland

1989-01-01

A classical inequality due to Bernstein which estimates the norm of polynomials on any given ellipse in terms of their norm on any smaller ellipse with the same foci is examined. For the uniform and a certain weighted uniform norm, and for the case that the two ellipses are not too close, sharp estimates of this type were derived and the corresponding extremal polynomials were determined. These Bernstein type inequalities are closely connected with certain constrained Chebyshev approximation problems on ellipses. Some new results were also presented for a weighted approximation problem of this type.

Extreme Programming: Maestro Style

NASA Technical Reports Server (NTRS)

Norris, Jeffrey; Fox, Jason; Rabe, Kenneth; Shu, I-Hsiang; Powell, Mark

2009-01-01

"Extreme Programming: Maestro Style" is the name of a computer programming methodology that has evolved as a custom version of a methodology, called extreme programming that has been practiced in the software industry since the late 1990s. The name of this version reflects its origin in the work of the Maestro team at NASA's Jet Propulsion Laboratory that develops software for Mars exploration missions. Extreme programming is oriented toward agile development of software resting on values of simplicity, communication, testing, and aggressiveness. Extreme programming involves use of methods of rapidly building and disseminating institutional knowledge among members of a computer-programming team to give all the members a shared view that matches the view of the customers for whom the software system is to be developed. Extreme programming includes frequent planning by programmers in collaboration with customers, continually examining and rewriting code in striving for the simplest workable software designs, a system metaphor (basically, an abstraction of the system that provides easy-to-remember software-naming conventions and insight into the architecture of the system), programmers working in pairs, adherence to a set of coding standards, collaboration of customers and programmers, frequent verbal communication, frequent releases of software in small increments of development, repeated testing of the developmental software by both programmers and customers, and continuous interaction between the team and the customers. The environment in which the Maestro team works requires the team to quickly adapt to changing needs of its customers. In addition, the team cannot afford to accept unnecessary development risk. Extreme programming enables the Maestro team to remain agile and provide high-quality software and service to its customers. However, several factors in the Maestro environment have made it necessary to modify some of the conventional extreme-programming practices. The single most influential of these factors is that continuous interaction between customers and programmers is not feasible.

Life history constrains biochemical development in the highly specialized odontocete echolocation system

PubMed Central

Koopman, Heather N; Zahorodny, Zoey P

2008-01-01

The vertebrate head has undergone enormous modification from the features borne by early ancestors. The growth of skull bones has been well studied in many species, yet little is known about corresponding soft tissue development. Among mammals, some of the most unusual examples of cranial evolution exist in the toothed whales (odontocetes). Specialized fat bodies in toothed whale heads play important roles in sound transmission and reception. These fat bodies contain unique endogenous lipids, with favourable acoustic properties, arranged in highly organized, three-dimensional patterns. We link variation in developmental rates of acoustic fats with life-history strategy, using bottlenose dolphins and harbour porpoises. Porpoise acoustic fats attain adult configurations earlier (less than 1 year) and at a faster pace than dolphins. The accelerated lipid accumulation in porpoises reflects the earlier need for fully functional echolocation systems. Dolphins enjoy 3–6 years of maternal care; porpoises must achieve total independence by approximately nine months. Further, a stereotypic ‘blueprint’ for the spatial distribution of lipids is established prior to birth, demonstrating the highly conserved nature of the intricate biochemical arrangement in acoustic tissues. This system illustrates an unusual case of soft tissue development being constrained by life history, rather than the more commonly observed mechanistic or phyletic constraints. PMID:18611851

Language complexity modulates 8- and 10-year-olds' success at using their theory of mind abilities in a communication task.

PubMed

Wang, J Jessica; Ali, Muna; Frisson, Steven; Apperly, Ian A

2016-09-01

Basic competence in theory of mind is acquired during early childhood. Nonetheless, evidence suggests that the ability to take others' perspectives in communication improves continuously from middle childhood to the late teenage years. This indicates that theory of mind performance undergoes protracted developmental changes after the acquisition of basic competence. Currently, little is known about the factors that constrain children's performance or that contribute to age-related improvement. A sample of 39 8-year-olds and 56 10-year-olds were tested on a communication task in which a speaker's limited perspective needed to be taken into account and the complexity of the speaker's utterance varied. Our findings showed that 10-year-olds were generally less egocentric than 8-year-olds. Children of both ages committed more egocentric errors when a speaker uttered complex sentences compared with simple sentences. Both 8- and 10-year-olds were affected by the demand to integrate complex sentences with the speaker's limited perspective and to a similar degree. These results suggest that long after children's development of simple visual perspective-taking, their use of this ability to assist communication is substantially constrained by the complexity of the language involved. Copyright © 2015 Elsevier Inc. All rights reserved.

Biological Extreme Events - Past, Present, and Future

NASA Astrophysics Data System (ADS)

Gutschick, V. P.

2010-12-01

Biological extreme events span wide ranges temporally and spatially and in type - population dieoffs, extinctions, ecological reorganizations, changes in biogeochemical fluxes, and more. Driving variables consist in meteorology, tectonics, orbital changes, anthropogenic changes (land-use change, species introductions, reactive N injection into the biosphere), and evolution (esp. of diseases). However, the mapping of extremes in the drivers onto biological extremes as organismal responses is complex, as laid out originally in the theoretical framework of Gutschick and BassiriRad (New Phytologist [2003] 100:21-42). Responses are nonlinear and dependent on (mostly unknown and) complex temporal sequences - often of multiple environmental variables. The responses are species- and genotype specific. I review extreme events over from past to present over wide temporal scales, while noting that they are not wholly informative of responses to the current and near-future drivers for at least two reasons: 1) the current combination of numerous environmental extremes - changes in CO2, temperature, precipitation, reactive N, land fragmentation, O3, etc. -is unprecedented in scope, and 2) adaptive genetic variation for organismal responses is constrained by poorly-characterized genetic structures (in organisms and populations) and by loss of genetic variation by genetic drift over long periods. We may expect radical reorganizations of ecosystem and biogeochemical functions. These changes include many ecosystem services in flood control, crop pollination and insect/disease control, C-water-mineral cycling, and more, as well as direct effects on human health. Predictions of such changes will necessarily be very weak in the critical next few decades, given the great deal of observation, experimentation, and theory construction that will be necessary, on both organisms and drivers. To make the research efforts most effective will require extensive, insightful planning, beginning immediately. Massive dieoff of conifers in the US Southwest, an extreme event driven by a remarkably uncommon co-occurrence of high temperature, drought, and long active season for insects

Applying Customized Climate Advisory Information to Translate Extreme Rainfall Events into Farming Options in the Sudan-Sahel of West Africa

NASA Astrophysics Data System (ADS)

Salack, S.; Worou, N. O.; Sanfo, S.; Nikiema, M. P.; Boubacar, I.; Paturel, J. E.; Tondoh, E. J.

2017-12-01

In West Africa, the risk of food insecurity linked to the low productivity of small holder farming increases as a result of rainfall extremes. In its recent evolution, the rainy season in the Sudan-Sahel zone presents mixed patterns of extreme climatic events. In addition to intense rain events, the distribution of events is associated with pockets of intra-seasonal long dry spells. The negative consequences of these mixed patterns are obvious on the farm: soil water logging, erosion of arable land, dwartness and dessication of crops, and loss in production. The capacity of local farming communities to respond accordingly to rainfall extreme events is often constrained by lack of access to climate information and advisory on smart crop management practices that can help translate extreme rainfall events into farming options. The objective of this work is to expose the framework and the pre-liminary results of a scheme that customizes climate-advisory information package delivery to subsistence farmers in Bakel (Senegal), Ouahigouya & Dano (Burkina Faso) and Bolgatanga (Ghana) for sustainable family agriculture. The package is based on the provision of timely climate information (48-hours, dekadal & seasonal) embedded with smart crop management practices to explore and exploite the potential advantage of intense rainfall and extreme dry spells in millet, maize, sorghum and cowpea farming communities. It is sent via mobile phones and used on selected farms (i.e agro-climatic farm schools) on which some small on-farm infrastructure were built to alleviate negative impacts of weather. Results provide prominent insight on how co-production of weather/climate information, customized access and guidiance on its use can induce fast learning (capacity building of actors), motivation for adaptation, sustainability, potential changes in cropping system, yields and family income in the face of a rainfall extremes at local scales of Sudan-Sahel of West Africa. Keywords: Climate Information, Smart Practices, Farming Options, Agro-Climatic Farm Schools, Sudan-Sahel

Do Vascular Networks Branch Optimally or Randomly across Spatial Scales?

PubMed Central

Newberry, Mitchell G.; Savage, Van M.

2016-01-01

Modern models that derive allometric relationships between metabolic rate and body mass are based on the architectural design of the cardiovascular system and presume sibling vessels are symmetric in terms of radius, length, flow rate, and pressure. Here, we study the cardiovascular structure of the human head and torso and of a mouse lung based on three-dimensional images processed via our software Angicart. In contrast to modern allometric theories, we find systematic patterns of asymmetry in vascular branching, potentially explaining previously documented mismatches between predictions (power-law or concave curvature) and observed empirical data (convex curvature) for the allometric scaling of metabolic rate. To examine why these systematic asymmetries in vascular branching might arise, we construct a mathematical framework to derive predictions based on local, junction-level optimality principles that have been proposed to be favored in the course of natural selection and development. The two most commonly used principles are material-cost optimizations (construction materials or blood volume) and optimization of efficient flow via minimization of power loss. We show that material-cost optimization solutions match with distributions for asymmetric branching across the whole network but do not match well for individual junctions. Consequently, we also explore random branching that is constrained at scales that range from local (junction-level) to global (whole network). We find that material-cost optimizations are the strongest predictor of vascular branching in the human head and torso, whereas locally or intermediately constrained random branching is comparable to material-cost optimizations for the mouse lung. These differences could be attributable to developmentally-programmed local branching for larger vessels and constrained random branching for smaller vessels. PMID:27902691

Is Statistical Learning Constrained by Lower Level Perceptual Organization?

PubMed Central

Emberson, Lauren L.; Liu, Ran; Zevin, Jason D.

2013-01-01

In order for statistical information to aid in complex developmental processes such as language acquisition, learning from higher-order statistics (e.g. across successive syllables in a speech stream to support segmentation) must be possible while perceptual abilities (e.g. speech categorization) are still developing. The current study examines how perceptual organization interacts with statistical learning. Adult participants were presented with multiple exemplars from novel, complex sound categories designed to reflect some of the spectral complexity and variability of speech. These categories were organized into sequential pairs and presented such that higher-order statistics, defined based on sound categories, could support stream segmentation. Perceptual similarity judgments and multi-dimensional scaling revealed that participants only perceived three perceptual clusters of sounds and thus did not distinguish the four experimenter-defined categories, creating a tension between lower level perceptual organization and higher-order statistical information. We examined whether the resulting pattern of learning is more consistent with statistical learning being “bottom-up,” constrained by the lower levels of organization, or “top-down,” such that higher-order statistical information of the stimulus stream takes priority over the perceptual organization, and perhaps influences perceptual organization. We consistently find evidence that learning is constrained by perceptual organization. Moreover, participants generalize their learning to novel sounds that occupy a similar perceptual space, suggesting that statistical learning occurs based on regions of or clusters in perceptual space. Overall, these results reveal a constraint on learning of sound sequences, such that statistical information is determined based on lower level organization. These findings have important implications for the role of statistical learning in language acquisition. PMID:23618755

Enabling fast charging - A battery technology gap assessment

NASA Astrophysics Data System (ADS)

Ahmed, Shabbir; Bloom, Ira; Jansen, Andrew N.; Tanim, Tanvir; Dufek, Eric J.; Pesaran, Ahmad; Burnham, Andrew; Carlson, Richard B.; Dias, Fernando; Hardy, Keith; Keyser, Matthew; Kreuzer, Cory; Markel, Anthony; Meintz, Andrew; Michelbacher, Christopher; Mohanpurkar, Manish; Nelson, Paul A.; Robertson, David C.; Scoffield, Don; Shirk, Matthew; Stephens, Thomas; Vijayagopal, Ram; Zhang, Jiucai

2017-11-01

The battery technology literature is reviewed, with an emphasis on key elements that limit extreme fast charging. Key gaps in existing elements of the technology are presented as well as developmental needs. Among these needs are advanced models and methods to detect and prevent lithium plating; new positive-electrode materials which are less prone to stress-induced failure; better electrode designs to accommodate very rapid diffusion in and out of the electrode; measure temperature distributions during fast charge to enable/validate models; and develop thermal management and pack designs to accommodate the higher operating voltage.

Submandibular ectopic thyroid with normally located thyroid gland.

PubMed

Yılmaz, Mahmut Sinan; Aytürk, Semra; Güven, Mehmet; Dilek, Fatma Hüsniye

2014-01-01

Ectopic thyroid is a rare developmental anomaly of the thyroid gland which is defined as the presence of thyroid tissue at a site other than the pretracheal area. Nearly 1 to 3% of all ectopic thyroids are located in the lateral neck. Simultaneous submandibular ectopic thyroid tissue presenting with a functional orthotopic thyroid gland is extremely rare. In this article, we report a 37-year-old female case admitted to our clinic with a complaint of swollen neck in whom ultrasonography revealed submandibular ectopic thyroid tissue presenting with an orthotopic thyroid gland.

Anesthetic considerations in Leigh disease: Case report and literature review.

PubMed

Terkawi, Abdullah Sulieman; Wani, Tariq M; Al-Shuaibi, Khalid M; Tobias, Joseph D

2012-04-01

Leigh disease is an extremely rare disorder, characterized by a progressive neurodegenerative course, with subacute necrotizing encephalomyelopathy. It usually presents in infancy with developmental delay, seizures, dysarthria, and ataxia. These patients may also develop episodes of lactic acidosis that usually lead to respiratory failure and death. Due to the rarity of the condition, the most appropriate anesthetic plan remains unclear. We present a patient with Leigh disease, who required general anesthesia. The pathogenesis of the disease is discussed and previous reports of perioperative care from the literature are reviewed.

Gestational lead exposure induces developmental abnormalities and up-regulates apoptosis of fetal cerebellar cells in rats.

PubMed

Mousa, Alyaa M; Al-Fadhli, Ameera S; Rao, Muddanna S; Kilarkaje, Narayana

2015-01-01

Lead (Pb), a known environmental toxicant, adversely affects almost all organ systems. In this study, we investigated the effects of maternal lead exposure on fetal rat cerebellum. Female Sprague-Dawley rats were given lead nitrate in drinking water (0, 0.5, and 1%) for two weeks before conception, and during pregnancy. Fetuses were collected by caesarian section on gestational day 21 and observed for developmental abnormalities. The fetal cerebellar sections from control and 1% lead group were stained with cresyl violet. Immunohistochemical expressions of p53, Bax, Bcl-2, and caspase 3 were quantified by AnalySIS image analyzer (Life Science, Germany). Lead exposure induced developmental abnormalities of eyes, ear, limbs, neck and ventral abdominal wall; however, these abnormalities were commonly seen in the 1% lead-treated group. In addition, lead also caused fetal mortality and reduced body growth in both dose groups and reduced brain weight in the 1% lead-treated group. The fetal cerebella from the 1% lead-treated group showed unorganized cerebellar cortical layers, and degenerative changes in granule and Purkinje cells such as the formation of clumps of Nissl granules. An increase in Bax and caspase 3, and a decrease in Bcl-2 (p < 0.05), but not in p53, showed apoptosis of the neurons. In conclusion, gestational lead exposure in rats induces fetal toxicity and developmental abnormalities. The lead exposure also impairs development of cerebellar layers, induces structural changes, and apoptosis in the fetal cerebellar cortex. These results suggest that lead exposure during gestation is extremely toxic to developing cerebellum in rats.

A diploblastic radiate animal at the dawn of cambrian diversification with a simple body plan: distinct from Cnidaria?

PubMed

Yasui, Kinya; Reimer, James D; Liu, Yunhuan; Yao, Xiaoyong; Kubo, Daisuke; Shu, Degan; Li, Yong

2013-01-01

Microfossils of the genus Punctatus include developmental stages such as blastula, gastrula, and hatchlings, and represent the most complete developmental sequence of animals available from the earliest Cambrian. Despite the extremely well-preserved specimens, the evolutionary position of Punctatus has relied only on their conical remains and they have been tentatively assigned to cnidarians. We present a new interpretation of the Punctatus body plan based on the developmental reconstruction aided by recent advances in developmental biology. Punctatus developed from a rather large egg, gastrulated in a mode of invagination from a coeloblastura, and then formed a mouth directly from the blastopore. Spiny benthic hatchlings were distinguishable from swimming or crawling ciliate larvae found in cnidarians and sponges. A mouth appeared at the perihatching embryonic stage and was renewed periodically during growth, and old mouths transformed into the body wall, thus elongating the body. Growing animals retained a small blind gut in a large body cavity without partitioning by septa and did not form tentacles, pedal discs or holdfasts externally. A growth center at the oral pole was sufficient for body patterning throughout life, and the body patterning did not show any bias from radial symmetry. Contrary to proposed cnidarian affinity, the Punctatus body plan has basic differences from that of cnidarians, especially concerning a spacious body cavity separating ectoderm from endoderm. The lack of many basic cnidarian characters in the body patterning of Punctatus leads us to consider its own taxonomic group, potentially outside of Cnidaria.

A Diploblastic Radiate Animal at the Dawn of Cambrian Diversification with a Simple Body Plan: Distinct from Cnidaria?

PubMed Central

Yasui, Kinya; Reimer, James D.; Liu, Yunhuan; Yao, Xiaoyong; Kubo, Daisuke; Shu, Degan; Li, Yong

2013-01-01

Background Microfossils of the genus Punctatus include developmental stages such as blastula, gastrula, and hatchlings, and represent the most complete developmental sequence of animals available from the earliest Cambrian. Despite the extremely well-preserved specimens, the evolutionary position of Punctatus has relied only on their conical remains and they have been tentatively assigned to cnidarians. We present a new interpretation of the Punctatus body plan based on the developmental reconstruction aided by recent advances in developmental biology. Results Punctatus developed from a rather large egg, gastrulated in a mode of invagination from a coeloblastura, and then formed a mouth directly from the blastopore. Spiny benthic hatchlings were distinguishable from swimming or crawling ciliate larvae found in cnidarians and sponges. A mouth appeared at the perihatching embryonic stage and was renewed periodically during growth, and old mouths transformed into the body wall, thus elongating the body. Growing animals retained a small blind gut in a large body cavity without partitioning by septa and did not form tentacles, pedal discs or holdfasts externally. A growth center at the oral pole was sufficient for body patterning throughout life, and the body patterning did not show any bias from radial symmetry. Conclusions Contrary to proposed cnidarian affinity, the Punctatus body plan has basic differences from that of cnidarians, especially concerning a spacious body cavity separating ectoderm from endoderm. The lack of many basic cnidarian characters in the body patterning of Punctatus leads us to consider its own taxonomic group, potentially outside of Cnidaria. PMID:23840375

A 2000-year palaeoflood record from northwest England from lake sediments

NASA Astrophysics Data System (ADS)

Schillereff, Daniel; Chiverrell, Richard; Macdonald, Neil; Hooke, Janet

2014-05-01

Greater insight into the relationship between climatic fluctuations and the frequency and magnitude of precipitation events over recent centuries is crucial in the context of future warming and projected intensification of hydrological extremes. However, the detection of trends in flood frequency and intensity is not a straightforward task as conventional flood series derived from instrumental sources rarely span sufficiently long timescales to capture the most extreme events. Usefully, the geomorphic effects of extreme hydrological events can be effectively recorded in upland lake basins as efficient sediment trapping preserves discharge-related proxy indicators (e.g., particle size). Provided distinct sedimentary signatures of historic floods are discernable and the sediment sequence can be well-constrained in time, these lacustrine archives offer a valuable data resource. We demonstrate that a series of sediment cores (3 - 5 m length) from Brotherswater, northwest England, contain numerous coarse-grained laminations, discerned by applying high-resolution (0.5 cm) laser granulometry, which are interpreted as reflecting a palaeoflood record extending to ~2000 yr BP. The presence of thick facies which exhibit inverse grading underlying normal grading, most likely reflecting the waxing and waning of flood-induced hyperpycnal flows, supports our palaeoflood interpretation. Data from an on-going sediment trapping protocol at Brotherswater that shows a relationship between river discharge (recorded via short-term lake level change representing flood events) and the calibre of particles captured in the traps lends further support to our interpretation. Well-constrained chronologies were constructed for the cores through integrating radionuclide (210Pb, 137Cs, 241Am, 14C) dating within a Bayesian age-depth modelling protocol. Geochemical markers of known-age that reflect phases of local point-source lead (Pb) mining were used to resolve time periods where radiocarbon dates returned multiple possible age solutions. We subsequently build a regression model using the time-window where recorded river discharge and the sedimentary record overlap (1961-2013) in order to reconstruct discharge estimates for the palaeoflood laminations. These quantitative palaeoflood data can thus be inserted into statistical flood frequency analyses and compared with outputs using instrumental data and regional flood information.

Landscape of histone modifications in a sponge reveals the origin of animal cis-regulatory complexity

PubMed Central

Gaiti, Federico; Jindrich, Katia; Fernandez-Valverde, Selene L; Roper, Kathrein E; Degnan, Bernard M; Tanurdžić, Miloš

2017-01-01

Combinatorial patterns of histone modifications regulate developmental and cell type-specific gene expression and underpin animal complexity, but it is unclear when this regulatory system evolved. By analysing histone modifications in a morphologically-simple, early branching animal, the sponge Amphimedonqueenslandica, we show that the regulatory landscape used by complex bilaterians was already in place at the dawn of animal multicellularity. This includes distal enhancers, repressive chromatin and transcriptional units marked by H3K4me3 that vary with levels of developmental regulation. Strikingly, Amphimedon enhancers are enriched in metazoan-specific microsyntenic units, suggesting that their genomic location is extremely ancient and likely to place constraints on the evolution of surrounding genes. These results suggest that the regulatory foundation for spatiotemporal gene expression evolved prior to the divergence of sponges and eumetazoans, and was necessary for the evolution of animal multicellularity. DOI: http://dx.doi.org/10.7554/eLife.22194.001 PMID:28395144

A Developmental Approach to Machine Learning?

PubMed Central

Smith, Linda B.; Slone, Lauren K.

2017-01-01

Visual learning depends on both the algorithms and the training material. This essay considers the natural statistics of infant- and toddler-egocentric vision. These natural training sets for human visual object recognition are very different from the training data fed into machine vision systems. Rather than equal experiences with all kinds of things, toddlers experience extremely skewed distributions with many repeated occurrences of a very few things. And though highly variable when considered as a whole, individual views of things are experienced in a specific order – with slow, smooth visual changes moment-to-moment, and developmentally ordered transitions in scene content. We propose that the skewed, ordered, biased visual experiences of infants and toddlers are the training data that allow human learners to develop a way to recognize everything, both the pervasively present entities and the rarely encountered ones. The joint consideration of real-world statistics for learning by researchers of human and machine learning seems likely to bring advances in both disciplines. PMID:29259573

Developmental reprogramming by UV-B radiation in plants.

PubMed

Dotto, Marcela; Casati, Paula

2017-11-01

Plants are extremely plastic organisms with the ability to adapt and respond to the changing environmental conditions surrounding them. Sunlight is one of the main resources for plants, both as a primary energy source for photosynthesis and as a stimulus that regulates different aspects of their growth and development. UV-B comprises wavelengths that correspond to a high energy region of the solar spectrum capable of reaching the biosphere, influencing plant growth. It is currently believed that plants are able to acclimate when growing under the influence of this radiation and perceive it as a signal, without stress signs. Nonetheless, many UV-B induced changes are elicited after DNA damage occurs as a consequence of exposure. In this review we focus on the influence of UV-B on leaf, flower and root development and emphasize the limited understanding of the molecular mechanisms for most of this developmental processes affected by UV-B documented over the years of research in this area. Copyright © 2017 Elsevier B.V. All rights reserved.

Development of social anxiety disorder secondary to attention deficit/hyperactivity disorder (the developmental hypothesis).

PubMed

Koyuncu, Ahmet; Alkın, Tunç; Tükel, Raşit

2018-04-01

Social anxiety disorder (SAD) may develop secondary to childhood attention deficit/hyperactivity (ADHD) in a subgroup of the patients with SAD. Patients pass through a number of identifiable stages of developmental pathways to SAD as they grow up. Patients with ADHD have maladaptive behaviours in social settings due to the symptoms of ADHD. These behaviours are criticized by their parents and social circle; they receive insults, humiliation and bullying. After each aversive incident, the individual feels shame and guilt. A vicious cycle emerges. The patients then develop social fears and a cognitive inhibition that occurs in social situations. The inhibition increases gradually as the fear persists and the individual becomes withdrawn. Patients start to monitor themselves and to focus on others' feedback. Finally, performative social situations become extremely stimulating for them and may trigger anxiety/panic attacks. If this hypothesis is proven, treatment of 'patients with SAD secondary to ADHD' should focus on the primary disease. © 2016 John Wiley & Sons Australia, Ltd.

Morphological, Histobiochemical and Molecular Characterisation of Low Lignin Phloem Fibre (llpf) Mutant of Dark Jute (Corchorus olitorius L.).

PubMed

Choudhary, S B; Chowdhury, I; Singh, R K; Pandey, S P; Sharma, H K; Anil Kumar, A; Karmakar, P G; Kumari, N; Souframanien, J; Jambhulkar, S J

2017-11-01

Lignin is a versatile plant metabolite challenging high-end industrial applications of several plant products including jute. Application of developmental mutant in regulation of lignification in jute may open up door for much awaited jute based diversified products. In the present study, a novel dark jute (Corchorus olitorius L.) mutant with low lignin (7.23%) in phloem fibre being compared to wild-type JRO 204 (13.7%) was identified and characterised. Unique morphological features including undulated stem, petiole and leaf vein distinguished the mutant in gamma ray irradiated mutant population. Histological and biochemical analysis revealed reduced lignification of phloem fibre cells of the plant. RT-PCR analysis demonstrated temporal transcriptional regulation of CCoAMT1 gene in the mutant. The mutant was found an extremely useful model to study phloem fibre developmental biology in the crop besides acting as a donor genetic stock for low lignin containing jute fibre in dark jute improvement programme.

Spin-Orbit Misalignment of Two-Planet-System KOI-89 Via Gravity Darkening

NASA Astrophysics Data System (ADS)

Ahlers, Jonathon; Barnes, Jason W.; Barnes, Rory

2015-12-01

We investigate the potential causes of spin-orbit misalignment in multiplanetary systems via two-planet-system KOI-89. We focus on this system because it can experimentally constrain the outstanding hypotheses that have been proposed to cause misalignments. Using gravity darkening, we constrain both the spin-orbit angles and the angle between the planes of the orbits. Our best-fit model shows that the 85-day-orbit and 208-day-orbit planets are misaligned from the host star's rotation axis by 72° ± 3° and 73° (+11 -5°), respectively. From these results, we limit KOI-89's potential causes of spin-orbit misalignment based on three criteria: agreement with KOI-89's fundamental parameters, the capability to cause extreme misalignment, and conformance with mutually aligned planets. Our results disfavor planet-embryo collisions, chaotic evolution of stellar spin, magnetic torquing, coplanar high-eccentricity migration, and inclination resonance, limiting possible causes to star-disk binary interactions, disk warping via planet-disk interactions, Kozai resonance, planet-planet scattering, or internal gravity waves in the convective interior of the star.

Design forms of total knee replacement.

PubMed

Walker, P S; Sathasivam, S

2000-01-01

The starting point of this article is a general design criterion applicable to all types of total knee replacement. This criterion is then expanded upon to provide more specifics of the required kinematics, and the forces which the total knee must sustain. A characteristic which differentiates total knees is the amount of constraint which is required, and whether the constraint is translational or rotational. The different forms of total knee replacement are described in terms of these constraints, starting with the least constrained unicompartments to the almost fully constrained fixed and rotating hinges. Much attention is given to the range of designs in between these two extreme types, because they constitute by far the largest in usage. This category includes condylar replacements where the cruciate ligaments are preserved or resected, posterior cruciate substituting designs and mobile bearing knees. A new term, 'guided motion knees', is applied to the growing number of designs which control the kinematics by the use of intercondylar cams or specially shaped and even additional bearing surfaces. The final section deals with the selection of an appropriate design of total knee for specific indications based on the design characteristics.

Constraining physical parameters of ultra-fast outflows in PDS 456 with Monte Carlo simulations

NASA Astrophysics Data System (ADS)

Hagino, K.; Odaka, H.; Done, C.; Gandhi, P.; Takahashi, T.

2014-07-01

Deep absorption lines with extremely high velocity of ˜0.3c observed in PDS 456 spectra strongly indicate the existence of ultra-fast outflows (UFOs). However, the launching and acceleration mechanisms of UFOs are still uncertain. One possible way to solve this is to constrain physical parameters as a function of distance from the source. In order to study the spatial dependence of parameters, it is essential to adopt 3-dimensional Monte Carlo simulations that treat radiation transfer in arbitrary geometry. We have developed a new simulation code of X-ray radiation reprocessed in AGN outflow. Our code implements radiative transfer in 3-dimensional biconical disk wind geometry, based on Monte Carlo simulation framework called MONACO (Watanabe et al. 2006, Odaka et al. 2011). Our simulations reproduce FeXXV and FeXXVI absorption features seen in the spectra. Also, broad Fe emission lines, which reflects the geometry and viewing angle, is successfully reproduced. By comparing the simulated spectra with Suzaku data, we obtained constraints on physical parameters. We discuss launching and acceleration mechanisms of UFOs in PDS 456 based on our analysis.

Witnessing the reionization history using Cosmic Microwave Background observation from Planck

NASA Astrophysics Data System (ADS)

Hazra, Dhiraj Kumar; Smoot, George F.

2017-11-01

We constrain the history of reionization using the data from Planck 2015 Cosmic Microwave Background (CMB) temperature and polarization anisotropy observations. We also use prior constraints on the reionization history at redshifts ~7-8 obtained from Lyman-α emission observations. Using the free electron fractions at different redshifts as free parameters, we construct the complete reionization history using polynomials. Our construction provides an extremely flexible framework to search for the history of reionization as a function of redshifts. We present a conservative and an optimistic constraint on reionization that are categorized by the flexibilities of the models and datasets used to constrain them, and we report that CMB data marginally favors extended reionization histories. In both the cases, we find the mean values of optical depth to be larger (≈0.09 and 0.1) than what we find in standard steplike reionization histories (0.079 ± 0.017). At the same time we also find that the maximum free electron fraction allowed by the data for redshifts more than 15 is ~0.25 at 95.4% confidence limit in the case of optimistic constraint.

Direct Observations of Clouds on Brown Dwarfs: A Spitzer Study of Extreme Cases

NASA Astrophysics Data System (ADS)

Burgasser, Adam; Cruz, Kelle; Cushing, Michael; Kirkpatrick, J. Davy; Looper, Dagny; Lowrance, Patrick; Marley, Mark; Saumon, Didier

2008-03-01

Clouds play a fundamental role in the emergent spectral energy distributions and observed variability of very low mass stars and brown dwarfs, yet hey have only been studied indirectly thus far. Recent indications of a broad silicate grain absorption feature in the 8-11 micron spectra of mid-type L dwarfs, and evidence that the strength of this absorption varies according to broad-band near-infrared color, may finally allow the first direct studies of clouds and condensate grain properties in brown dwarf atmospheres. We propose to observe a sample of 18 ``extreme'' L dwarfs - objects with unusually blue and red near-infrared colors - with IRAC and IRS to study the 8-11 micron feature in detail (including grain size distributions and bulk compositions), and to constrain advanced condensate cloud atmosphere models currently in development. Our program provides a unique examination of the general processes of cloud formation by focusing on the relatively warm photospheres of late-type brown dwarfs.

Multi-band implications of external-IC flares

NASA Astrophysics Data System (ADS)

Richter, Stephan; Spanier, Felix

2015-02-01

Very fast variability on scales of minutes is regularly observed in Blazars. The assumption that these flares are emerging from the dominant emission zone of the very high energy (VHE) radiation within the jet challenges current acceleration and radiation models. In this work we use a spatially resolved and time dependent synchrotron-self-Compton (SSC) model that includes the full time dependence of Fermi-I acceleration. We use the (apparent) orphan γ -ray flare of Mrk501 during MJD 54952 and test various flare scenarios against the observed data. We find that a rapidly variable external radiation field can reproduce the high energy lightcurve best. However, the effect of the strong inverse Compton (IC) cooling on other bands and the X-ray observations are constraining the parameters to rather extreme ranges. Then again other scenarios would require parameters even more extreme or stronger physical constraints on the rise and decay of the source of the variability which might be in contradiction with constraints derived from the size of the black hole's ergosphere.

A rate distortion approach to protein symmetry.

PubMed

Wallace, Rodrick

2010-08-01

A spontaneous symmetry breaking argument is applied to the problem of protein folding, via a rate distortion analysis of the relation between genome coding and the final condensation of the protein molten globule that is, in spirit, analogous to Tlusty's (2007) exploration of the evolution of the genetic code. In the 'energy' picture, the average distortion between codon message and final protein structure, under constraints driven by evolutionary selection, serves as a temperature analog, so that low values limit the possible distribution of protein forms, producing the canonical folding funnel. A dual 'developmental' perspective sees the rate distortion function itself as the temperature analog, and permits incorporation of chaperons or toxic exposures as catalysts, driving the system to different possible outcomes or affecting the rate of convergence. The rate distortion function appears constrained by the availability of metabolic free energy, with implications for prebiotic evolution, and a nonequilibrium empirical Onsager treatment provides an adaptable statistical model that can be fitted to data, in the same manner as a regression equation. In sum, mechanistic models of protein folding fail to account for the observed spectrum of protein folding and aggregation disorders, suggesting that a biologically based cognitive paradigm describing folding will be needed for understanding the etiology, prevention, and treatment of these diseases. The developmental formalism introduced here may contribute substantially to such a paradigm.

Multiple time-scales and the developmental dynamics of social systems

PubMed Central

Flack, Jessica C.

2012-01-01

To build a theory of social complexity, we need to understand how aggregate social properties arise from individual interaction rules. Here, I review a body of work on the developmental dynamics of pigtailed macaque social organization and conflict management that provides insight into the mechanistic causes of multi-scale social systems. In this model system coarse-grained, statistical representations of collective dynamics are more predictive of the future state of the system than the constantly in-flux behavioural patterns at the individual level. The data suggest that individuals can perceive and use these representations for strategical decision-making. As an interaction history accumulates the coarse-grained representations consolidate. This constrains individual behaviour and provides the foundations for new levels of organization. The time-scales on which these representations change impact whether the consolidating higher-levels can be modified by individuals and collectively. The time-scales appear to be a function of the ‘coarseness’ of the representations and the character of the collective dynamics over which they are averages. The data suggest that an advantage of multiple timescales is that they allow social systems to balance tradeoffs between predictability and adaptability. I briefly discuss the implications of these findings for cognition, social niche construction and the evolution of new levels of organization in biological systems. PMID:22641819

Multiple time-scales and the developmental dynamics of social systems.

PubMed

Flack, Jessica C

2012-07-05

To build a theory of social complexity, we need to understand how aggregate social properties arise from individual interaction rules. Here, I review a body of work on the developmental dynamics of pigtailed macaque social organization and conflict management that provides insight into the mechanistic causes of multi-scale social systems. In this model system coarse-grained, statistical representations of collective dynamics are more predictive of the future state of the system than the constantly in-flux behavioural patterns at the individual level. The data suggest that individuals can perceive and use these representations for strategical decision-making. As an interaction history accumulates the coarse-grained representations consolidate. This constrains individual behaviour and provides the foundations for new levels of organization. The time-scales on which these representations change impact whether the consolidating higher-levels can be modified by individuals and collectively. The time-scales appear to be a function of the 'coarseness' of the representations and the character of the collective dynamics over which they are averages. The data suggest that an advantage of multiple timescales is that they allow social systems to balance tradeoffs between predictability and adaptability. I briefly discuss the implications of these findings for cognition, social niche construction and the evolution of new levels of organization in biological systems.

Extremely preterm birth affects boys more and socio-economic and neonatal variables pose sex-specific risks.

PubMed

Månsson, Johanna; Fellman, Vineta; Stjernqvist, Karin

2015-05-01

The early identification of at-risk extremely preterm (EPT) children could improve long-term outcomes. This study sought to investigate sex differences in developmental outcomes and to identify sex-specific predictors at two and a half years of age. We assessed 217 boys and 181 girls born before 27-week gestation using the Bayley Scales of Infant and Toddler Development, third edition (Bayley-III), as a part of the Extremely Preterm Infants in Sweden Study. Sex-specific differences were calculated. Socio-economic, birth and neonatal factors were calculated separately for boys and girls using regression models. Girls scored significantly higher than boys on all Bayley-III indices. In both sexes, brain injury, long-term ventilator treatment and foreign-born mothers predicted lower scores. Receiving breast milk by hospital discharge predicted higher scores. Severe retinopathy of prematurity was the strongest predictor of cognitive and language deficits in boys. High parental education predicted higher cognitive and language scores in girls, whereas severe bronchopulmonary dysplasia was the strongest predictor of motor deficits. Extreme prematurity seems to affect boys more than girls. Socio-economic and neonatal factors confer similar risks or protections on both sexes, but some variables pose sex-specific risks. An awareness of risk factors may provide the basis for treatment and follow-up guidelines. ©2015 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

Abrasive, Silica Phytoliths and the Evolution of Thick Molar Enamel in Primates, with Implications for the Diet of Paranthropus boisei

PubMed Central

Rabenold, Diana; Pearson, Osbjorn M.

2011-01-01

Background Primates—including fossil species of apes and hominins—show variation in their degree of molar enamel thickness, a trait long thought to reflect a diet of hard or tough foods. The early hominins demonstrated molar enamel thickness of moderate to extreme degrees, which suggested to most researchers that they ate hard foods obtained on or near the ground, such as nuts, seeds, tubers, and roots. We propose an alternative hypothesis—that the amount of phytoliths in foods correlates with the evolution of thick molar enamel in primates, although this effect is constrained by a species' degree of folivory. Methodology/Principal Findings From a combination of dietary data and evidence for the levels of phytoliths in plant families in the literature, we calculated the percentage of plant foods rich in phytoliths in the diets of twelve extant primates with wide variation in their molar enamel thickness. Additional dietary data from the literature provided the percentage of each primate's diet made up of plants and of leaves. A statistical analysis of these variables showed that the amount of abrasive silica phytoliths in the diets of our sample primates correlated positively with the thickness of their molar enamel, constrained by the amount of leaves in their diet (R2 = 0.875; p<.0006). Conclusions/Significance The need to resist abrasion from phytoliths appears to be a key selective force behind the evolution of thick molar enamel in primates. The extreme molar enamel thickness of the teeth of the East African hominin Paranthropus boisei, long thought to suggest a diet comprising predominantly hard objects, instead appears to indicate a diet with plants high in abrasive silica phytoliths. PMID:22163299

Climate and CO2 coupling in the early Cenozoic Greenhouse

NASA Astrophysics Data System (ADS)

Rae, J. W. B.; Greenop, R.; Kaminski, M.; Sexton, P. F.; Foster, G. L.; Greene, S. E.; Littley, E.; Kirtland Turner, S.; Ridgwell, A.

2017-12-01

The early Cenozoic is a time of climatic extremes: hyperthermals pepper the transition from extreme global warmth to the start of Cenozoic cooling, with these evolving climate regimes accompanied by major changes in ocean chemistry and biota. The exogenic carbon cycle, and ocean-atmospheric CO2 in particular, is thought to have played a key role in these climatic changes, but the carbon chemistry of the early Cenozoic ocean remains poorly constrained. Here we present new boron isotope data from benthic foraminifera, which can be used to constrain relative changes in ocean pH. These are coupled with modelling experiments performed with the cGenie Earth system model to provide new constraints on the carbon cycle and carbonate system of the early Cenozoic. While our benthic boron isotope data do not readily provide a record of surface ocean CO2 , they do place constraints on the whole ocean-atmosphere carbonate system, alongside changes in ocean circulation and biogeochemistry, and also have relatively robust calcite tests and small `vital effects'. During the late Paleocene ascent to peak greenhouse conditions and the middle Eocene descent towards the icehouse, our boron isotope data show close coupling with benthic δ18O, demonstrating a clear link between CO2 and climate. However within the early Eocene our boron isotope data reveal more dynamic changes in deep ocean pH, which may be linked to changes in ocean circulation. Overall, our data demonstrate the ability of CO2 to regulate the climate system across varying boundary conditions, and the influence of both the long-term carbon cycle and shorter-term ocean biogeochemical cycling on Earth's climate.

Regularized joint inverse estimation of extreme rainfall amounts in ungauged coastal basins of El Salvador

USGS Publications Warehouse

Friedel, M.J.

2008-01-01

A regularized joint inverse procedure is presented and used to estimate the magnitude of extreme rainfall events in ungauged coastal river basins of El Salvador: Paz, Jiboa, Grande de San Miguel, and Goascoran. Since streamflow measurements reflect temporal and spatial rainfall information, peak-flow discharge is hypothesized to represent a similarity measure suitable for regionalization. To test this hypothesis, peak-flow discharge values determined from streamflow recurrence information (10-year, 25-year, and 100-year) collected outside the study basins are used to develop regional (country-wide) regression equations. Peak-flow discharge derived from these equations together with preferred spatial parameter relations as soft prior information are used to constrain the simultaneous calibration of 20 tributary basin models. The nonlinear range of uncertainty in estimated parameter values (1 curve number and 3 recurrent rainfall amounts for each model) is determined using an inverse calibration-constrained Monte Carlo approach. Cumulative probability distributions for rainfall amounts indicate differences among basins for a given return period and an increase in magnitude and range among basins with increasing return interval. Comparison of the estimated median rainfall amounts for all return periods were reasonable but larger (3.2-26%) than rainfall estimates computed using the frequency-duration (traditional) approach and individual rain gauge data. The observed 25-year recurrence rainfall amount at La Hachadura in the Paz River basin during Hurricane Mitch (1998) is similar in value to, but outside and slightly less than, the estimated rainfall confidence limits. The similarity in joint inverse and traditionally computed rainfall events, however, suggests that the rainfall observation may likely be due to under-catch and not model bias. ?? Springer Science+Business Media B.V. 2007.

Thermodynamic optimization of mixed refrigerant Joule- Thomson systems constrained by heat transfer considerations

NASA Astrophysics Data System (ADS)

Hinze, J. F.; Klein, S. A.; Nellis, G. F.

2015-12-01

Mixed refrigerant (MR) working fluids can significantly increase the cooling capacity of a Joule-Thomson (JT) cycle. The optimization of MRJT systems has been the subject of substantial research. However, most optimization techniques do not model the recuperator in sufficient detail. For example, the recuperator is usually assumed to have a heat transfer coefficient that does not vary with the mixture. Ongoing work at the University of Wisconsin-Madison has shown that the heat transfer coefficients for two-phase flow are approximately three times greater than for a single phase mixture when the mixture quality is between 15% and 85%. As a result, a system that optimizes a MR without also requiring that the flow be in this quality range may require an extremely large recuperator or not achieve the performance predicted by the model. To ensure optimal performance of the JT cycle, the MR should be selected such that it is entirely two-phase within the recuperator. To determine the optimal MR composition, a parametric study was conducted assuming a thermodynamically ideal cycle. The results of the parametric study are graphically presented on a contour plot in the parameter space consisting of the extremes of the qualities that exist within the recuperator. The contours show constant values of the normalized refrigeration power. This ‘map’ shows the effect of MR composition on the cycle performance and it can be used to select the MR that provides a high cooling load while also constraining the recuperator to be two phase. The predicted best MR composition can be used as a starting point for experimentally determining the best MR.

Life detection strategy for Jovian's icy moons: Lessons from subglacial Lake Vostok exploration

NASA Astrophysics Data System (ADS)

Bulat, Sergey; Alekhina, Irina; Marie, Dominique; Petit, Jean-Robert

2010-05-01

The objective was to estimate the microbial content of accretion ice originating from the subglacial Lake Vostok buried beneath 4-km thick East Antarctic ice sheet with the ultimate goal to discover microbial life in this extreme icy environment. The DNA study constrained by Ancient DNA research criteria was used as a main approach. The flow cytometry was implemented in cell enumerating. As a result, both approaches showed that the accretion ice contains the very low unevenly distributed biomass indicating that the water body should also be hosting a highly sparse life. Up to now, the only accretion ice featured by mica-clay sediments presence allowed the recovery a pair of bacterial phylotypes. This unexpectedly included the chemolithoautotrophic thermophile Hydrogenophilus thermoluteolus and one more unclassified phylotype both passing numerous contaminant controls. In contrast, the deeper and cleaner accretion ice with no sediments presence and near detection limit gas content gave no reliable signals. Thus, the results obtained testify that the search for life in the Lake Vostok is constrained by a high chance of forward-contamination. The subglacial Lake Vostok seems to represent the only extremely clean giant aquatic system on the Earth providing a unique test area for searching for life on icy worlds. The life detection strategy for (sub)glacial environments elsewhere (e.g., Jovian's Europa) should be based on stringent decontamination procedures in clean-room facilities, establishment of on-site contaminant library, implementation of appropriate methods to reach detection level for signal as low as possible, verification of findings through ecological settings of a given environment and repetition at an independent laboratory within the specialized laboratory network.

A Risk-Constrained Multi-Stage Decision Making Approach to the Architectural Analysis of Mars Missions

NASA Technical Reports Server (NTRS)

Kuwata, Yoshiaki; Pavone, Marco; Balaram, J. (Bob)

2012-01-01

This paper presents a novel risk-constrained multi-stage decision making approach to the architectural analysis of planetary rover missions. In particular, focusing on a 2018 Mars rover concept, which was considered as part of a potential Mars Sample Return campaign, we model the entry, descent, and landing (EDL) phase and the rover traverse phase as four sequential decision-making stages. The problem is to find a sequence of divert and driving maneuvers so that the rover drive is minimized and the probability of a mission failure (e.g., due to a failed landing) is below a user specified bound. By solving this problem for several different values of the model parameters (e.g., divert authority), this approach enables rigorous, accurate and systematic trade-offs for the EDL system vs. the mobility system, and, more in general, cross-domain trade-offs for the different phases of a space mission. The overall optimization problem can be seen as a chance-constrained dynamic programming problem, with the additional complexity that 1) in some stages the disturbances do not have any probabilistic characterization, and 2) the state space is extremely large (i.e, hundreds of millions of states for trade-offs with high-resolution Martian maps). To this purpose, we solve the problem by performing an unconventional combination of average and minimax cost analysis and by leveraging high efficient computation tools from the image processing community. Preliminary trade-off results are presented.

Jets in Hydrogen-poor Superluminous Supernovae: Constraints from a Comprehensive Analysis of Radio Observations

NASA Astrophysics Data System (ADS)

Coppejans, D. L.; Margutti, R.; Guidorzi, C.; Chomiuk, L.; Alexander, K. D.; Berger, E.; Bietenholz, M. F.; Blanchard, P. K.; Challis, P.; Chornock, R.; Drout, M.; Fong, W.; MacFadyen, A.; Migliori, G.; Milisavljevic, D.; Nicholl, M.; Parrent, J. T.; Terreran, G.; Zauderer, B. A.

2018-03-01

The energy source powering the extreme optical luminosity of hydrogen-stripped superluminous supernovae (SLSNe-I) is not known, but recent studies have highlighted the case for a central engine. Radio and/or X-ray observations are best placed to track the fastest ejecta and probe the presence of outflows from a central engine. We compile all the published radio observations of SLSNe-I to date and present three new observations of two new SLSNe-I. None were detected. Through modeling the radio emission, we constrain the subparsec environments and possible outflows in SLSNe-I. In this sample, we rule out on-axis collimated relativistic jets of the kind detected in gamma-ray bursts (GRBs). We constrain off-axis jets with opening angles of 5° (30°) to energies of {E}{{k}}< 4× {10}50 {erg} ({E}{{k}}< {10}50 {erg}) in environments shaped by progenitors with mass-loss rates of \\dot{M}< {10}-4 {M}ȯ {yr}}-1 (\\dot{M}< {10}-5 {M}ȯ {yr}}-1) for all off-axis angles, assuming fiducial values {ε }e=0.1 and {ε }B=0.01. The deepest limits rule out emission of the kind seen in faint uncollimated GRBs (with the exception of GRB 060218) and from relativistic SNe. Finally, for the closest SLSN-I, SN 2017egm, we constrain the energy of an uncollimated nonrelativistic outflow like those observed in normal SNe to {E}{{k}}≲ {10}48 erg.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ashouri, Hamed; Sorooshian, Soroosh; Hsu, Kuo-Lin

This study evaluates the performance of NASA's Modern-Era Retrospective Analysis for Research and Applications (MERRA) precipitation product in reproducing the trend and distribution of extreme precipitation events. Utilizing the extreme value theory, time-invariant and time-variant extreme value distributions are developed to model the trends and changes in the patterns of extreme precipitation events over the contiguous United States during 1979-2010. The Climate Prediction Center (CPC)U.S.Unified gridded observation data are used as the observational dataset. The CPC analysis shows that the eastern and western parts of the United States are experiencing positive and negative trends in annual maxima, respectively. The continental-scalemore » patterns of change found in MERRA seem to reasonably mirror the observed patterns of change found in CPC. This is not previously expected, given the difficulty in constraining precipitation in reanalysis products. MERRA tends to overestimate the frequency at which the 99th percentile of precipitation is exceeded because this threshold tends to be lower in MERRA, making it easier to be exceeded. This feature is dominant during the summer months. MERRAtends to reproduce spatial patterns of the scale and location parameters of the generalized extreme value and generalized Pareto distributions. However, MERRA underestimates these parameters, particularly over the Gulf Coast states, leading to lower magnitudes in extreme precipitation events. Two issues in MERRA are identified: 1)MERRAshows a spurious negative trend in Nebraska andKansas, which ismost likely related to the changes in the satellite observing system over time that has apparently affected the water cycle in the central United States, and 2) the patterns of positive trend over theGulf Coast states and along the East Coast seem to be correlated with the tropical cyclones in these regions. The analysis of the trends in the seasonal precipitation extremes indicates that the hurricane and winter seasons are contributing the most to these trend patterns in the southeastern United States. The increasing annual trend simulated by MERRA in the Gulf Coast region is due to an incorrect trend in winter precipitation extremes.« less

An end to endless forms: epistasis, phenotype distribution bias, and nonuniform evolution.

PubMed

Borenstein, Elhanan; Krakauer, David C

2008-10-01

Studies of the evolution of development characterize the way in which gene regulatory dynamics during ontogeny constructs and channels phenotypic variation. These studies have identified a number of evolutionary regularities: (1) phenotypes occupy only a small subspace of possible phenotypes, (2) the influence of mutation is not uniform and is often canalized, and (3) a great deal of morphological variation evolved early in the history of multicellular life. An important implication of these studies is that diversity is largely the outcome of the evolution of gene regulation rather than the emergence of new, structural genes. Using a simple model that considers a generic property of developmental maps-the interaction between multiple genetic elements and the nonlinearity of gene interaction in shaping phenotypic traits-we are able to recover many of these empirical regularities. We show that visible phenotypes represent only a small fraction of possibilities. Epistasis ensures that phenotypes are highly clustered in morphospace and that the most frequent phenotypes are the most similar. We perform phylogenetic analyses on an evolving, developmental model and find that species become more alike through time, whereas higher-level grades have a tendency to diverge. Ancestral phenotypes, produced by early developmental programs with a low level of gene interaction, are found to span a significantly greater volume of the total phenotypic space than derived taxa. We suggest that early and late evolution have a different character that we classify into micro- and macroevolutionary configurations. These findings complement the view of development as a key component in the production of endless forms and highlight the crucial role of development in constraining biotic diversity and evolutionary trajectories.

Immune defense and reproductive pace of life in Peromyscus mice.

PubMed

Martin, Lynn B; Weil, Zachary M; Nelson, Randy J

2007-10-01

Immune activity is variable within and among vertebrates despite the potentially large fitness costs of pathogens to their hosts. From the perspective of life history theory, immunological variability may be the consequence of counterbalancing investments in immune defense against other expensive physiological processes, namely, reproduction. In the present study, we tested the hypothesis that immune defense among captive-bred, disease-free Peromyscus mice would be influenced by their reproductive life history strategies. Specifically, we expected that small species that reproduce prolifically and mature rapidly (i.e., fast pace of life) would favor inexpensive, nonspecific immune defenses to promote reproductive proclivity. Alternatively, we expected that large species that mature slowly and invest modestly in reproduction over multiple events (i.e., slow pace of life) would favor developmentally expensive, specific immune defenses and avoid cheap, nonspecific ones because such defenses are predisposed to self-damage. We found that species exhibited either strong ability to kill (gram-negative) bacteria, a developmentally inexpensive defense, or strong ability to produce antibodies against a novel protein, a developmentally expensive defense, but not both. Cell-mediated inflammation also varied significantly among species, but in a unique fashion relative to bacteria killing or antibody production; wound healing was comparatively similar among species. These results indicate that Peromyscus species use immune strategies that are constrained to a dominant axis, but this axis is not determined solely by reproductive pace of life. Further comparisons, ideally with broader phylogenetic coverage, could identify what ecological and evolutionary forces produce the pattern we detected. Importantly, our study indicates that species may not be differentially immunocompetent; rather, they use unique defense strategies to prevent infection.

The architecture and dynamics of developing mind: experiential structuralism as a frame for unifying cognitive developmental theories.

PubMed

Demetriou, A; Efklides, A; Platsidou, M

1993-01-01

This Monograph presents a theory of cognitive development. The theory argues that the mind develops across three fronts. The first refers to a general processing system that defines the general potentials of mind to develop cognitive strategies and skills. The second refers to a hypercognitive system that governs self-understanding and self-regulation. The third involves a set of specialized structural systems (SSSs) that are responsible for the representation and processing of different reality domains. There are specific forces that are responsible for this organization of mind. These are expressed in the Monograph in terms of a set of five organizational principles. The developmental course of the major systems is outlined. Developmental change is ascribed by the theory to the interaction between the various systems. Different types of development require different change mechanisms. Five studies are presented that provide empirical support for these postulates. Study 1 demonstrated the organizational power of principles and SSSs. Study 2 showed that the SSSs constrain the effect of learning. Study 3 established that the hypercognitive system does function as the interface between tasks and SSS-specific processes or between SSSs and general cognitive functions such as attention and memory. Study 4 investigated the relations between one of the components of the processing system, storage, and two different SSSs expressed via two different symbolic systems, namely, the numeric and the imaginal. Finally, Study 5 examined the interaction between the components of the processing system and the relations between each of these components and one SSS, namely, the quantitative-relational SSS. The theoretical implications of these studies with regard to general issues, such as the nature of representation, the causation of cognitive change, and individual differences in cognitive development, are discussed in the concluding chapter.

Intraspecific priority effects modify compensatory responses to changes in hatching phenology in an amphibian.

PubMed

Murillo-Rincón, Andrea P; Kolter, Nora A; Laurila, Anssi; Orizaola, Germán

2017-01-01

In seasonal environments, modifications in the phenology of life-history events can alter the strength of time constraints experienced by organisms. Offspring can compensate for a change in timing of hatching by modifying their growth and development trajectories. However, intra- and interspecific interactions may affect these compensatory responses, in particular if differences in phenology between cohorts lead to significant priority effects (i.e. the competitive advantage that early-hatching individuals have over late-hatching ones). Here, we conducted a factorial experiment to determine whether intraspecific priority effects can alter compensatory phenotypic responses to hatching delay in a synchronic breeder by rearing moor frog (Rana arvalis) tadpoles in different combinations of phenological delay and food abundance. Tadpoles compensated for the hatching delay by speeding up their development, but only when reared in groups of individuals with identical hatching phenology. In mixed phenology groups, strong competitive effects by non-delayed tadpoles prevented the compensatory responses and delayed larvae metamorphosed later than in single phenology treatments. Non-delayed individuals gained advantage from developing with delayed larvae by increasing their developmental and growth rates as compared to single phenology groups. Food shortage prolonged larval period and reduced mass at metamorphosis in all treatments, but it did not prevent compensatory developmental responses in larvae reared in single phenology groups. This study demonstrates that strong intraspecific priority effects can constrain the compensatory growth and developmental responses to phenological change, and that priority effects can be an important factor explaining the maintenance of synchronic life histories (i.e. explosive breeding) in seasonal environments. © 2016 The Authors. Journal of Animal Ecology © 2016 British Ecological Society.

Death or Neurodevelopmental Impairment at 18 To 22 Months in a Randomized Trial of Early Dexamethasone to Prevent Death or Chronic Lung Disease in Extremely Low Birth Weight Infants

PubMed Central

Stark, Ann R.; Carlo, Waldemar A.; Vohr, Betty R; Papile, Lu Ann; Saha, Shampa; Bauer, Charles R.; Donovan, Edward F.; Oh, William; Shankaran, Seetha; Tyson, Jon E.; Wright, Linda L.; Poole, W. Kenneth; Das, Abhik; Stoll, Barbara J.; Fanaroff, Avroy A.; Korones, Sheldon B.; Ehrenkranz, Richard A.; Stevenson, David K.; Peralta-Carcelen, Myriam; Adams-Chapman, Ira; Wilson-Costello, Deanne E.; Bada, Henrietta S.; Heyne, Roy J.; Johnson, Yvette R.; Lee, Kimberly Gronsman; Steichen, Jean J.; Hintz, Susan R.

2014-01-01

Objective To evaluate the incidence of death or neurodevelopmental impairment (NDI) at 18 to 22 months corrected age in subjects enrolled in a trial of early dexamethasone treatment to prevent death or chronic lung disease in extremely low birth weight infants. Methods Evaluation of infants at 18 to 22 months corrected age included anthropomorphic measurements, a standard neurological examination, and the Bayley Scales of Infant Development-II, including the Mental Developmental Index (MDI) and the Psychomotor Developmental Index (PDI). NDI was defined as moderate or severe cerebral palsy, MDI or PDI less than 70, blindness, or hearing impairment. Results Death or NDI at 18 to 22 months corrected age was similar in the dexamethasone and placebo groups (65 vs 66 percent, p= 0.99 among those with known outcome). The proportion of survivors with NDI was also similar, as were mean values for weight, length, and head circumference and the proportion of infants with poor growth (50 vs 41 percent, p=0.42 for weight less than 10th percentile). Forty nine percent of infants in the placebo group received treatment with corticosteroid compared to 32% in the dexamethasone group (p=0.02). Conclusion The risk of death or NDI and rate of poor growth were high but similar in the dexamethasone and placebo groups. The lack of a discernible effect of early dexamethasone on neurodevelopmental outcome may be due to frequent clinical corticosteroid use in the placebo group. PMID:23992673

Mortality, Disenrollment, and Spending Persistence in Medicaid and CHIP.

PubMed

DeLia, Derek

2017-03-01

Research on spending persistence has not focused on Medicaid and the Children's Health Insurance Program (Medicaid/CHIP), which includes a complex and growing population. The objective of the study was to describe patterns of expenditure persistence, mortality, and disenrollment among nondually eligible Medicaid/CHIP enrollees and identify factors predicting these outcomes. The study is based on New Jersey Medicaid/CHIP claims data from 2011 to 2014. Descriptive and multinomial regression methods were used to characterize persistently extreme spenders, defined as those appearing in the top 1% of statewide spending every year, according to demographics, Medicaid/CHIP eligibility, nursing facility residence, patient risk scores, and clinical diagnostic categories measured in 2011. Similar analyses were done for persistently high spenders (ie, always in the top 10% but not always top 1%) as well as decedents, disenrollees, and moderate spenders (ie, at least 1 year outside of the top 10%). Nondually eligible NJ Medicaid/CHIP enrollees in 2011. One fourth of extreme spenders in 2011 remained in that category throughout 2011-2014. Almost all (89.3%) of the persistently extreme spenders were aged, blind, or disabled. Within the aged, blind, or disabled population, the strongest predictors of persistently extreme spending were diagnoses involving developmental disability, HIV/AIDS, central nervous system conditions, psychiatric disorders, type 1 diabetes, and renal conditions. Individuals in nursing facilities and those with very high risk scores were more likely to die or have persistently high spending than to have persistently extreme spending. The study highlights unique features of spending persistence within Medicaid/CHIP and provides methodological contributions to the broader persistence literature.

Developmental link between sex and nutrition; doublesex regulates sex-specific mandible growth via juvenile hormone signaling in stag beetles.

PubMed

Gotoh, Hiroki; Miyakawa, Hitoshi; Ishikawa, Asano; Ishikawa, Yuki; Sugime, Yasuhiro; Emlen, Douglas J; Lavine, Laura C; Miura, Toru

2014-01-01

Sexual dimorphisms in trait expression are widespread among animals and are especially pronounced in ornaments and weapons of sexual selection, which can attain exaggerated sizes. Expression of exaggerated traits is usually male-specific and nutrition sensitive. Consequently, the developmental mechanisms generating sexually dimorphic growth and nutrition-dependent phenotypic plasticity are each likely to regulate the expression of extreme structures. Yet we know little about how either of these mechanisms work, much less how they might interact with each other. We investigated the developmental mechanisms of sex-specific mandible growth in the stag beetle Cyclommatus metallifer, focusing on doublesex gene function and its interaction with juvenile hormone (JH) signaling. doublesex genes encode transcription factors that orchestrate male and female specific trait development, and JH acts as a mediator between nutrition and mandible growth. We found that the Cmdsx gene regulates sex differentiation in the stag beetle. Knockdown of Cmdsx by RNA-interference in both males and females produced intersex phenotypes, indicating a role for Cmdsx in sex-specific trait growth. By combining knockdown of Cmdsx with JH treatment, we showed that female-specific splice variants of Cmdsx contribute to the insensitivity of female mandibles to JH: knockdown of Cmdsx reversed this pattern, so that mandibles in knockdown females were stimulated to grow by JH treatment. In contrast, mandibles in knockdown males retained some sensitivity to JH, though mandibles in these individuals did not attain the full sizes of wild type males. We suggest that moderate JH sensitivity of mandibular cells may be the default developmental state for both sexes, with sex-specific Dsx protein decreasing sensitivity in females, and increasing it in males. This study is the first to demonstrate a causal link between the sex determination and JH signaling pathways, which clearly interact to determine the developmental fates and final sizes of nutrition-dependent secondary-sexual characters.

Epidemiology of fractures in people with severe and profound developmental disabilities

USGS Publications Warehouse

Glick, N.R.; Fischer, M.H.; Heisey, D.M.; Leverson, G.E.; Mann, D.C.

2005-01-01

Fractures are more prevalent among people with severe and profound developmental disabilities than in the general population. In order to characterize the tendency of these people to fracture, and to identify features that may guide the development of preventive strategies, we analyzed fracture epidemiology in people with severe and profound developmental disabilities who lived in a stable environment. Data from a 23-year longitudinal cohort registry of 1434 people with severe and profound developmental disabilities were analyzed to determine the effects of age, gender, mobility, bone fractured, month of fracture, and fracture history upon fracture rates. Eighty-five percent of all fractures involved the extremities. The overall fracture rate increased as mobility increased. In contrast, femoral shaft fracture risk was substantially higher in the least mobile [relative risk (RR), 10.36; 95% confidence interval (CI), 3.29-32.66] compared with the most mobile group. Although the overall fracture rate was not associated with age, the femoral shaft fractures decreased but hand/foot fractures increased with age. Overall fracture risk declined in August and September (RR, 0.70; 95% CI, 0.55-0.89), being especially prominent for tibial/fibular fractures (RR, 0.31; 95% CI, 0.13-0.70). Gender was not a factor in fracture risk. Two primary fracture mechanisms are apparent: one, largely associated with lack of weight-bearing in people with the least mobility, is exemplified by femoral fractures during non-traumatic events as simple as diapering or transfers; the other, probably due to movement- or fall-related trauma, is exemplified by hand/foot fractures in people who ambulate. The fracture experience of people with severe and profound developmental disabilities is unique and, because it differs qualitatively from postmenopausal osteoporosis, may require population-specific methods for assessing risk, for improving bone integrity, and for reduction of falls and accidents. ?? International Osteoporosis Foundation and National Osteoporosis Foundation 2004.

Developmental Link between Sex and Nutrition; doublesex Regulates Sex-Specific Mandible Growth via Juvenile Hormone Signaling in Stag Beetles

PubMed Central

Gotoh, Hiroki; Miyakawa, Hitoshi; Ishikawa, Asano; Ishikawa, Yuki; Sugime, Yasuhiro; Emlen, Douglas J.; Lavine, Laura C.; Miura, Toru

2014-01-01

Sexual dimorphisms in trait expression are widespread among animals and are especially pronounced in ornaments and weapons of sexual selection, which can attain exaggerated sizes. Expression of exaggerated traits is usually male-specific and nutrition sensitive. Consequently, the developmental mechanisms generating sexually dimorphic growth and nutrition-dependent phenotypic plasticity are each likely to regulate the expression of extreme structures. Yet we know little about how either of these mechanisms work, much less how they might interact with each other. We investigated the developmental mechanisms of sex-specific mandible growth in the stag beetle Cyclommatus metallifer, focusing on doublesex gene function and its interaction with juvenile hormone (JH) signaling. doublesex genes encode transcription factors that orchestrate male and female specific trait development, and JH acts as a mediator between nutrition and mandible growth. We found that the Cmdsx gene regulates sex differentiation in the stag beetle. Knockdown of Cmdsx by RNA-interference in both males and females produced intersex phenotypes, indicating a role for Cmdsx in sex-specific trait growth. By combining knockdown of Cmdsx with JH treatment, we showed that female-specific splice variants of Cmdsx contribute to the insensitivity of female mandibles to JH: knockdown of Cmdsx reversed this pattern, so that mandibles in knockdown females were stimulated to grow by JH treatment. In contrast, mandibles in knockdown males retained some sensitivity to JH, though mandibles in these individuals did not attain the full sizes of wild type males. We suggest that moderate JH sensitivity of mandibular cells may be the default developmental state for both sexes, with sex-specific Dsx protein decreasing sensitivity in females, and increasing it in males. This study is the first to demonstrate a causal link between the sex determination and JH signaling pathways, which clearly interact to determine the developmental fates and final sizes of nutrition-dependent secondary-sexual characters. PMID:24453990

Evolution of unusual morphologies in Lentibulariaceae (bladderworts and allies) and Podostemaceae (river-weeds): a pictorial report at the interface of developmental biology and morphological diversification

PubMed Central

Rutishauser, Rolf

2016-01-01

Background Various groups of flowering plants reveal profound (‘saltational’) changes of their bauplans (architectural rules) as compared with related taxa. These plants are known as morphological misfits that appear as rather large morphological deviations from the norm. Some of them emerged as morphological key innovations (perhaps ‘hopeful monsters’) that gave rise to new evolutionary lines of organisms, based on (major) genetic changes. Scope This pictorial report places emphasis on released bauplans as typical for bladderworts (Utricularia, approx. 230 secies, Lentibulariaceae) and river-weeds (Podostemaceae, three subfamilies, approx. 54 genera, approx. 310 species). Bladderworts (Utricularia) are carnivorous, possessing sucking traps. They live as submerged aquatics (except for their flowers), as humid terrestrials or as epiphytes. Most Podostemaceae are restricted to rocks in tropical river-rapids and waterfalls. They survive as submerged haptophytes in these extreme habitats during the rainy season, emerging with their flowers afterwards. The recent scientific progress in developmental biology and evolutionary history of both Lentibulariaceae and Podostemaceae is summarized. Conclusions Lentibulariaceae and Podostemaceae follow structural rules that are different from but related to those of more typical flowering plants. The roots, stems and leaves – as still distinguishable in related flowering plants – are blurred (‘fuzzy’). However, both families have stable floral bauplans. The developmental switches to unusual vegetative morphologies facilitated rather than prevented the evolution of species diversity in both families. The lack of one-to-one correspondence between structural categories and gene expression may have arisen from the re-use of existing genetic resources in novel contexts. Understanding what developmental patterns are followed in Lentibulariaceae and Podostemaceae is a necessary prerequisite to discover the genetic alterations that led to the evolution of these atypical plants. Future molecular genetic work on morphological misfits such as bladderworts and river-weeds will provide insight into developmental and evolutionary aspects of more typical vascular plants. PMID:26589968

Evolution of unusual morphologies in Lentibulariaceae (bladderworts and allies) and Podostemaceae (river-weeds): a pictorial report at the interface of developmental biology and morphological diversification.

PubMed

Rutishauser, Rolf

2016-04-01

Various groups of flowering plants reveal profound ('saltational') changes of their bauplans (architectural rules) as compared with related taxa. These plants are known as morphological misfits that appear as rather large morphological deviations from the norm. Some of them emerged as morphological key innovations (perhaps 'hopeful monsters') that gave rise to new evolutionary lines of organisms, based on (major) genetic changes. This pictorial report places emphasis on released bauplans as typical for bladderworts (Utricularia, approx. 230 secies, Lentibulariaceae) and river-weeds (Podostemaceae, three subfamilies, approx. 54 genera, approx. 310 species). Bladderworts (Utricularia) are carnivorous, possessing sucking traps. They live as submerged aquatics (except for their flowers), as humid terrestrials or as epiphytes. Most Podostemaceae are restricted to rocks in tropical river-rapids and waterfalls. They survive as submerged haptophytes in these extreme habitats during the rainy season, emerging with their flowers afterwards. The recent scientific progress in developmental biology and evolutionary history of both Lentibulariaceae and Podostemaceae is summarized. Lentibulariaceae and Podostemaceae follow structural rules that are different from but related to those of more typical flowering plants. The roots, stems and leaves - as still distinguishable in related flowering plants - are blurred ('fuzzy'). However, both families have stable floral bauplans. The developmental switches to unusual vegetative morphologies facilitated rather than prevented the evolution of species diversity in both families. The lack of one-to-one correspondence between structural categories and gene expression may have arisen from the re-use of existing genetic resources in novel contexts. Understanding what developmental patterns are followed in Lentibulariaceae and Podostemaceae is a necessary prerequisite to discover the genetic alterations that led to the evolution of these atypical plants. Future molecular genetic work on morphological misfits such as bladderworts and river-weeds will provide insight into developmental and evolutionary aspects of more typical vascular plants. © The Author 2015. Published by Oxford University Press on behalf of the Annals of Botany Company.

Simulated heat waves affected alpine grassland only in combination with drought.

PubMed

De Boeck, Hans J; Bassin, Seraina; Verlinden, Maya; Zeiter, Michaela; Hiltbrunner, Erika

2016-01-01

The Alpine region is warming fast, and concurrently, the frequency and intensity of climate extremes are increasing. It is currently unclear whether alpine ecosystems are sensitive or resistant to such extremes. We subjected Swiss alpine grassland communities to heat waves with varying intensity by transplanting monoliths to four different elevations (2440-660 m above sea level) for 17 d. Half of these were regularly irrigated while the other half were deprived of irrigation to additionally induce a drought at each site. Heat waves had no significant impacts on fluorescence (Fv /Fm , a stress indicator), senescence and aboveground productivity if irrigation was provided. However, when heat waves coincided with drought, the plants showed clear signs of stress, resulting in vegetation browning and reduced phytomass production. This likely resulted from direct drought effects, but also, as measurements of stomatal conductance and canopy temperatures suggest, from increased high-temperature stress as water scarcity decreased heat mitigation through transpiration. The immediate responses to heat waves (with or without droughts) recorded in these alpine grasslands were similar to those observed in the more extensively studied grasslands from temperate climates. Responses following climate extremes may differ in alpine environments, however, because the short growing season likely constrains recovery. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

The fastest disk wind in APM 08279+5255 and its acceleration mechanism

NASA Astrophysics Data System (ADS)

Hagino, K.; Done, C.; Odaka, H.; Watanabe, S.; Takahashi, T.

2017-10-01

The luminous high-z quasar APM 08279+5255 has the most powerful ultra-fast outflow (UFO), which is claimed as the fastest disk wind with velocity of 0.7c. This extreme velocity is very important for constraining the physical mechanism to launch the UFOs because only magnetic driving mechanism can accelerate the winds up to velocities above 0.3c, at which radiation drag effects prevent radiation driving. We reanalyze all the observed data of this source with our spectral model of highly ionized disk winds constructed by 3D Monte Carlo radiation transfer simulation. This was applied to an archetypal disk wind in PDS 456, and successfully reproduced all the spectra observed with Suzaku in spite of their strong spectral variability. By applying our spectral model to APM 08279+5255, all the spectra observed with XMM-Newton, Chandra and Suzaku are explained with less extreme outflow velocities of 0.1-0.2c. In our analysis, the high energy absorption features, which were previously interpreted as absorption lines with extremely fast velocities, are produced by iron-K absorption edges from moderately ionized clumps embedded in the highly ionized wind. We also investigate the broadband SED, and find that it is X-ray weak and UV bright, which prefers the radiation driving.

I-Love-Q to the extreme

NASA Astrophysics Data System (ADS)

Silva, Hector O.; Yunes, Nicolás

2018-01-01

Certain bulk properties of neutron stars, in particular their moment of inertia, rotational quadrupole moment and tidal Love number, when properly normalized, are related to one another in a nearly equation of state independent way. The goal of this paper is to test these relations with extreme equations of state at supranuclear densities constrained to satisfy only a handful of generic, physically sensible conditions. By requiring that the equation of state be (i) barotropic and (ii) its associated speed of sound be real, we construct a piecewise function that matches a tabulated equation of state at low densities, while matching a stiff equation of state parametrized by its sound speed in the high-density region. We show that the I-Love-Q relations hold to 1 percent with this class of equations of state, even in the extreme case where the speed of sound becomes superluminal and independently of the transition density. We also find further support for the interpretation of the I-Love-Q relations as an emergent symmetry due to the nearly constant eccentricity of isodensity contours inside the star. These results reinforce the robustness of the I-Love-Q relations against our current incomplete picture of physics at supranuclear densities, while strengthening our confidence in the applicability of these relations in neutron star astrophysics.

PHASE QUANTIZATION STUDY OF SPATIAL LIGHT MODULATOR FOR EXTREME HIGH-CONTRAST IMAGING

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dou, Jiangpei; Ren, Deqing, E-mail: jpdou@niaot.ac.cn, E-mail: jiangpeidou@gmail.com

2016-11-20

Direct imaging of exoplanets by reflected starlight is extremely challenging due to the large luminosity ratio to the primary star. Wave-front control is a critical technique to attenuate the speckle noise in order to achieve an extremely high contrast. We present a phase quantization study of a spatial light modulator (SLM) for wave-front control to meet the contrast requirement of detection of a terrestrial planet in the habitable zone of a solar-type star. We perform the numerical simulation by employing the SLM with different phase accuracy and actuator numbers, which are related to the achievable contrast. We use an optimizationmore » algorithm to solve the quantization problems that is matched to the controllable phase step of the SLM. Two optical configurations are discussed with the SLM located before and after the coronagraph focal plane mask. The simulation result has constrained the specification for SLM phase accuracy in the above two optical configurations, which gives us a phase accuracy of 0.4/1000 and 1/1000 waves to achieve a contrast of 10{sup -10}. Finally, we have demonstrated that an SLM with more actuators can deliver a competitive contrast performance on the order of 10{sup -10} in comparison to that by using a deformable mirror.« less

Phase Quantization Study of Spatial Light Modulator for Extreme High-contrast Imaging

NASA Astrophysics Data System (ADS)

Dou, Jiangpei; Ren, Deqing

2016-11-01

Direct imaging of exoplanets by reflected starlight is extremely challenging due to the large luminosity ratio to the primary star. Wave-front control is a critical technique to attenuate the speckle noise in order to achieve an extremely high contrast. We present a phase quantization study of a spatial light modulator (SLM) for wave-front control to meet the contrast requirement of detection of a terrestrial planet in the habitable zone of a solar-type star. We perform the numerical simulation by employing the SLM with different phase accuracy and actuator numbers, which are related to the achievable contrast. We use an optimization algorithm to solve the quantization problems that is matched to the controllable phase step of the SLM. Two optical configurations are discussed with the SLM located before and after the coronagraph focal plane mask. The simulation result has constrained the specification for SLM phase accuracy in the above two optical configurations, which gives us a phase accuracy of 0.4/1000 and 1/1000 waves to achieve a contrast of 10-10. Finally, we have demonstrated that an SLM with more actuators can deliver a competitive contrast performance on the order of 10-10 in comparison to that by using a deformable mirror.

The Effects of Spectral Nudging on Arctic Temperature and Precipitation Extremes as Produced by the Pan-Arctic WRF

NASA Astrophysics Data System (ADS)

Glisan, J. M.; Gutowski, W. J.; Higgins, M.; Cassano, J. J.

2011-12-01

Pan-Arctic WRF (PAW) simulations produced using the 50-km wr50a domain developed for the fully-coupled Regional Arctic Climate Model (RACM) were found to produce deep atmospheric circulation biases over the northern Pacific Ocean, manifested in pressure, geopotential height, and temperature fields. Various remedies were unsuccessfully tested to correct these large biases, such as modifying the physical domain or using different initial/boundary conditions. Spectral (interior) nudging was introduced as a way of constraining the model to be more consistent with observed behavior. However, such control over numerical model behavior raises concerns over how much nudging may affect unforced variability and extremes. Strong nudging may reduce or filter out extreme events, since the nudging pushes the model toward a relatively smooth, large-scale state. The question then becomes - what is the minimum spectral nudging needed to correct the biases occurring on the RACM domain while not limiting PAW simulation of extreme events? To determine this, case studies were devised, using a six-member PAW ensemble on the RACM grid with varying spectral nudging strength. Two simulations were run, one in the cold season (January 2007) and one in a warm season (July 2007). Precipitation and 2-m temperature fields were extracted from the output and analyzed to determine how changing spectral nudging strength impacts both temporal and spatial temperature and precipitation extremes. The maximum and minimum temperatures at each point from among the ensemble members were examined, on the 95th confidence interval. The maximum and minimums over the simulation period will also be considered. Results suggest that there is a marked lack of sensitivity to the degrees of nudging. Moreover, it appears nudging strength can be considerably smaller than the standard strength and still produce reliably good simulations.

Determination of electron-nucleus collisions geometry with forward neutrons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zheng, L.; Aschenauer, E.; Lee, J. H.

2014-12-29

There are a large number of physics programs one can explore in electron-nucleus collisions at a future electron-ion collider. Collision geometry is very important in these studies, while the measurement for an event-by-event geometric control is rarely discussed in the prior deep-inelastic scattering experiments off a nucleus. This paper seeks to provide some detailed studies on the potential of tagging collision geometries through forward neutron multiplicity measurements with a zero degree calorimeter. As a result, this type of geometry handle, if achieved, can be extremely beneficial in constraining nuclear effects for the electron-nucleus program at an electron-ion collider.

Wide-angle Optical Telescope for the EUSO Experiments

NASA Technical Reports Server (NTRS)

Hillman, L. W.; Takahaski, Y.; Zuccaro, A.; Lamb, D.; Pitalo, K.; Lopado, A.; Keys, A.

2003-01-01

Future spacebased air shower experiments, including the planned Extreme Universe Space Observatory (EUSO) mission, require a wide-angle telescope in the near-UV wavelengths 330 - 400 nm. Widest possible target aperture of earth's atmosphere, such as greater than 10(exp 5) square kilometers sr, can be viewed within the field-of-view of 30 degrees from space. EUSO's optical design is required to be compact, being constrained by the allocated mass and diameter for use in space. Two doublesided Fresnel lenses with 2.5-m diameter are chosen for the baseline design. It satisfies the imaging resolution of 0.1 degree over the 30-degree field of view.

Advanced asymmetric synthesis of (1R,2S)-1-amino-2-vinylcyclopropanecarboxylic acid by alkylation/cyclization of newly designed axially chiral Ni(II) complex of glycine Schiff base.

PubMed

Kawashima, Aki; Shu, Shuangjie; Takeda, Ryosuke; Kawamura, Akie; Sato, Tatsunori; Moriwaki, Hiroki; Wang, Jiang; Izawa, Kunisuke; Aceña, José Luis; Soloshonok, Vadim A; Liu, Hong

2016-04-01

Asymmetric synthesis of (1R,2S)-1-amino-2-vinylcyclopropanecarboxylic acid (vinyl-ACCA) is in extremely high demand due to the pharmaceutical importance of this tailor-made, sterically constrained α-amino acid. Here we report the development of an advanced procedure for preparation of the target amino acid via two-step SN2 and SN2' alkylation of novel axially chiral nucleophilic glycine equivalent. Excellent yields and diastereoselectivity coupled with reliable and easy scalability render this method of immediate use for practical synthesis of (1R,2S)-vinyl-ACCA.

Classical fragile-X phenotype in a female infant disclosed by comprehensive genomic studies.

PubMed

Jorge, Paula; Garcia, Elsa; Gonçalves, Ana; Marques, Isabel; Maia, Nuno; Rodrigues, Bárbara; Santos, Helena; Fonseca, Jacinta; Soares, Gabriela; Correia, Cecília; Reis-Lima, Margarida; Cirigliano, Vincenzo; Santos, Rosário

2018-05-10

We describe a female infant with Fragile-X syndrome, with a fully expanded FMR1 allele and preferential inactivation of the homologous X-chromosome carrying a de novo deletion. This unusual and rare case demonstrates the importance of a detailed genomic approach, the absence of which could be misguiding, and calls for reflection on the current clinical and diagnostic workup for developmental disabilities. We present a female infant, referred for genetic testing due to psychomotor developmental delay without specific dysmorphic features or relevant family history. FMR1 mutation screening revealed a methylated full mutation and a normal but inactive FMR1 allele, which led to further investigation. Complete skewing of X-chromosome inactivation towards the paternally-inherited normal-sized FMR1 allele was found. No pathogenic variants were identified in the XIST promoter. Microarray analysis revealed a 439 kb deletion at Xq28, in a region known to be associated with extreme skewing of X-chromosome inactivation. Overall results enable us to conclude that the developmental delay is the cumulative result of a methylated FMR1 full mutation on the active X-chromosome and the inactivation of the other homologue carrying the de novo 439 kb deletion. Our findings should be taken into consideration in future guidelines for the diagnostic workup on the diagnosis of intellectual disabilities, particularly in female infant cases.

Developmental regulation of the effects of fibroblast growth factor-2 and 1-octanol on neuronogenesis: implications for a hypothesis relating to mitogen-antimitogen opposition

NASA Technical Reports Server (NTRS)

Goto, T.; Takahashi, T.; Miyama, S.; Nowakowski, R. S.; Bhide, P. G.; Caviness, V. S. Jr

2002-01-01

Neocortical neurons arise from a pseudostratified ventricular epithelium (PVE) that lies within the ventricular zone (VZ) at the margins of the embryonic cerebral ventricles. We examined the effects of fibroblast growth factor-2 (FGF-2) and 1-octanol on cell output behavior of the PVE in explants of the embryonic mouse cerebral wall. FGF-2 is mitogenic and 1-octanol antimitogenic in the PVE. Whereas all postmitotic cells migrate out of the VZ in vivo, in the explants some postmitotic cells remain within the VZ. We refer to these cells as the indeterminate or I fraction, because they neither exit from the VZ nor reenter S phase as part of the proliferative (P) fraction. They are considered to be either in an extremely prolonged G(1) phase, unable to pass the G(1)/S transition, or in the G(0) state. The I fate choice is modulated by both FGF-2 and 1-octanol. FGF-2 decreased the I fraction and increased the P fraction. In contrast, 1-octanol increased the I fraction and nearly eliminated the P fraction. The effects of FGF-2 and 1-octanol were developmentally regulated, in that they were observed in the developmentally advanced lateral region of the cerebral wall but not in the medial region. Copyright 2002 Wiley-Liss, Inc.

Development, malaria and adaptation to climate change: a case study from India.

PubMed

Garg, Amit; Dhiman, R C; Bhattacharya, Sumana; Shukla, P R

2009-05-01

India has reasons to be concerned about climate change. Over 650 million people depend on climate-sensitive sectors, such as rain-fed agriculture and forestry, for livelihood and over 973 million people are exposed to vector borne malarial parasites. Projection of climatic factors indicates a wider exposure to malaria for the Indian population in the future. If precautionary measures are not taken and development processes are not managed properly some developmental activities, such as hydro-electric dams and irrigation canal systems, may also exacerbate breeding grounds for malaria. This article integrates climate change and developmental variables in articulating a framework for integrated impact assessment and adaptation responses, with malaria incidence in India as a case study. The climate change variables include temperature, rainfall, humidity, extreme events, and other secondary variables. Development variables are income levels, institutional mechanisms to implement preventive measures, infrastructure development that could promote malarial breeding grounds, and other policies. The case study indicates that sustainable development variables may sometimes reduce the adverse impacts on the system due to climate change alone, while it may sometimes also exacerbate these impacts if the development variables are not managed well and therefore they produce a negative impact on the system. The study concludes that well crafted and well managed developmental policies could result in enhanced resilience of communities and systems, and lower health impacts due to climate change.

Development, Malaria and Adaptation to Climate Change: A Case Study from India

NASA Astrophysics Data System (ADS)

Garg, Amit; Dhiman, R. C.; Bhattacharya, Sumana; Shukla, P. R.

2009-05-01

India has reasons to be concerned about climate change. Over 650 million people depend on climate-sensitive sectors, such as rain-fed agriculture and forestry, for livelihood and over 973 million people are exposed to vector borne malarial parasites. Projection of climatic factors indicates a wider exposure to malaria for the Indian population in the future. If precautionary measures are not taken and development processes are not managed properly some developmental activities, such as hydro-electric dams and irrigation canal systems, may also exacerbate breeding grounds for malaria. This article integrates climate change and developmental variables in articulating a framework for integrated impact assessment and adaptation responses, with malaria incidence in India as a case study. The climate change variables include temperature, rainfall, humidity, extreme events, and other secondary variables. Development variables are income levels, institutional mechanisms to implement preventive measures, infrastructure development that could promote malarial breeding grounds, and other policies. The case study indicates that sustainable development variables may sometimes reduce the adverse impacts on the system due to climate change alone, while it may sometimes also exacerbate these impacts if the development variables are not managed well and therefore they produce a negative impact on the system. The study concludes that well crafted and well managed developmental policies could result in enhanced resilience of communities and systems, and lower health impacts due to climate change.

Intranasal insulin to improve developmental delay in children with 22q13 deletion syndrome: an exploratory clinical trial.

PubMed

Schmidt, H; Kern, W; Giese, R; Hallschmid, M; Enders, A

2009-04-01

The 22q13 deletion syndrome (Phelan-McDermid syndrome) is characterised by a global developmental delay, absent or delayed speech, generalised hypotonia, autistic behaviour and characteristic phenotypic features. Intranasal insulin has been shown to improve declarative memory in healthy adult subjects and in patients with Alzheimer disease. To assess if intranasal insulin is also able to improve the developmental delay in children with 22q13 deletion syndrome. We performed exploratory clinical trials in six children with 22q13 deletion syndrome who received intranasal insulin over a period of 1 year. Short-term (during the first 6 weeks) and long-term effects (after 12 months of treatment) on motor skills, cognitive functions, or autonomous functions, speech and communication, emotional state, social behaviour, behavioural disorders, independence in daily living and education were assessed. The children showed marked short-term improvements in gross and fine motor activities, cognitive functions and educational level. Positive long-term effects were found for fine and gross motor activities, nonverbal communication, cognitive functions and autonomy. Possible side effects were found in one patient who displayed changes in balance, extreme sensitivity to touch and general loss of interest. One patient complained of intermittent nose bleeding. We conclude that long-term administration of intranasal insulin may benefit motor development, cognitive functions and spontaneous activity in children with 22q13 deletion syndrome.

Developmental Origins of Perfectionism Among African American Youth

PubMed Central

Herman, Keith C.; Trotter, Reid; Reinke, Wendy M.; Ialongo, Nicholas

2013-01-01

The present study used a person-centered latent variable approach to classify types of perfectionism among 6th-grade African American children living in an urban setting. In particular, the authors were interested in determining whether an adaptive subtype could be found and validated against external criteria. The authors also attempted to identify any developmental precursors that could reliably differentiate the perfectionist subtypes. A social learning and competence framework was used to select potential 1st-grade risk and protective factors for future perfectionism profiles. Four classes best described the children’s perfectionism scores in 6th grade. Three of these classes resembled the profiles most commonly seen in prior perfectionism research (Non-Critical/Adaptive, Critical/Maladaptive, and Non-Perfectionist). The fourth class, Non-Striving, was characterized by extremely low levels of reported personal standards. Sixth-grade correlates confirmed the distinctiveness of these classes. In particular, the Critical/Maladaptive and Non-Striving classes had higher rates of internalizing symptoms and disorders. Additionally, several 1st-grade predictors suggested unique developmental origins of these classes. The Critical/Maladaptive class was characterized by lower academic skills and elevated teacher-rated attention problems, hyperactivity, shyness, and peer rejection. The Non-Striving class had higher rates of family alcohol problems and lower levels of parent praise. Implications regarding the universal and culture-specific origins and effects of perfectionism are discussed. PMID:21574697

Comparative anatomy and histology of developmental and parasitic stages in the life cycle of the lined sea anemone Edwardsiella lineata.

PubMed

Reitzel, Adam M; Daly, Marymegan; Sullivan, James C; Finnerty, John R

2009-02-01

The evolution of parasitism is often accompanied by profound changes to the developmental program. However, relatively few studies have directly examined the developmental evolution of parasitic species from free-living ancestors. The lined sea anemone Edwardsiella lineata is a relatively recently evolved parasite for which closely related free-living outgroups are known, including the starlet sea anemone Nematostella vectensis. The larva of E. lineata parasitizes the ctenophore Mnemiopsis leidyi, and, once embedded in its host, the anemone assumes a novel vermiform body plan. That we might begin to understand how the developmental program of this species has been transformed during the evolution of parasitism, we characterized the gross anatomy, histology, and cnidom of the parasitic stage, post-parasitic larval stage, and adult stage of the E. lineata life cycle. The distinct parasitic stage of the life cycle differs from the post-parasitic larva with respect to overall shape, external ciliation, cnida frequency, and tissue architecture. The parasitic stage and planula both contain holotrichs, a type of cnida not previously reported in Edwardsiidae. The internal morphology of the post-parasitic planula is extremely similar to the adult morphology, with a complete set of mesenterial tissue and musculature despite this stage having little external differentiation. Finally, we observed 2 previously undocumented aspects of asexual reproduction in E. lineata: (1) the parasitic stage undergoes transverse fission via physal pinching, the first report of asexual reproduction in a pre-adult stage in the Edwardsiidae; and (2) the juvenile polyp undergoes transverse fission via polarity reversal, the first time this form of fission has been reported in E. lineata.

Pigmentary changes and atopic dermatitis in a patient with Seckel syndrome.

PubMed

Brackeen, Amy; Babb-Tarbox, Michelle; Smith, Jennifer

2007-01-01

Seckel syndrome is a very rare form of primordial dwarfism characterized by antenatal and postnatal growth delay, proportionate extreme short stature, a prominent beak-like nose, hypoplasia of the malar area, small chin, microcephaly, deformed ears lacking lobules, skeletal malformations, mental retardation, and developmental delay. This syndrome has been described with associated disorders of orthopedic, neurologic, hematologic, cardiac, and ocular systems; however, only a few reports mention dermatologic involvement. We describe a 5-year-old girl with classic Seckel syndrome who presented with moderately severe atopic dermatitis and diffuse hypopigmented macules and papules.

Enabling fast charging – A battery technology gap assessment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ahmed, Shabbir; Bloom, Ira; Jansen, Andrew N.

The battery technology literature is reviewed, with an emphasis on key elements that limit extreme fast charging. Key gaps in existing elements of the technology are presented as well as developmental needs. Among these needs are advanced models and methods to detect and prevent lithium plating; new positive-electrode materials which are less prone to stress-induced failure; better electrode designs to accommodate very rapid diffusion in and out of the electrode; measure temperature distributions during fast charge to enable/validate models; and develop thermal management and pack designs to accommodate the higher operating voltage.

Enabling fast charging – A battery technology gap assessment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ahmed, Shabbir; Bloom, Ira; Jansen, Andrew N.

The battery technology literature is reviewed, with an emphasis on key elements that limit extreme fast charging. Key gaps in existing elements of the technology are presented as well as developmental needs. Among these needs are advanced models and methods to detect and prevent lithium plating; new positive-electrode materials which are less prone to stress-induced failure; better electrode designs to accommodate very rapid diffusion in and out of the electrode; measure temperature distributions during fast charge to enable / validate models; and develop thermal management and pack designs to accommodate the higher operating voltage.

Arctic daily temperature and precipitation extremes: Observed and simulated physical behavior

NASA Astrophysics Data System (ADS)

Glisan, Justin Michael

Simulations using a six-member ensemble of Pan-Arctic WRF (PAW) were produced on two Arctic domains with 50-km resolution to analyze precipitation and temperature extremes for various periods. The first study used a domain developed for the Regional Arctic Climate Model (RACM). Initial simulations revealed deep atmospheric circulation biases over the northern Pacific Ocean, manifested in pressure, geopotential height, and temperature fields. Possible remedies to correct these large biases, such as modifying the physical domain or using different initial/boundary conditions, were unsuccessful. Spectral (interior) nudging was introduced as a way of constraining the model to be more consistent with observed behavior. However, such control over numerical model behavior raises concerns over how much nudging may affect unforced variability and extremes. Strong nudging may reduce or filter out extreme events, since the nudging pushes the model toward a relatively smooth, large-scale state. The question then becomes---what is the minimum spectral nudging needed to correct biases while not limiting the simulation of extreme events? To determine this, we use varying degrees of spectral nudging, using WRF's standard nudging as a reference point during January and July 2007. Results suggest that there is a marked lack of sensitivity to varying degrees of nudging. Moreover, given that nudging is an artificial forcing applied in the model, an important outcome of this work is that nudging strength apparently can be considerably smaller than WRF's standard strength and still produce reliable simulations. In the remaining studies, we used the same PAW setup to analyze daily precipitation extremes simulated over a 19-year period on the CORDEX Arctic domain for winter and summer. We defined these seasons as the three-month period leading up to and including the climatological sea ice maximum and minimum, respectively. Analysis focused on four North American regions defined using climatological records, regional weather patterns, and geographical/topographical features. We compared simulated extremes with those occurring at corresponding observing stations in the U.S. National Climate Data Center's (NCDC's) Global Summary of the Day. Our analysis focused on variations in features of the extremes such as magnitudes, spatial scales, and temporal regimes. Using composites of extreme events, we also analyzed the processes producing these extremes, comparing circulation, pressure, temperature and humidity fields from the ERA-Interim reanalysis and the model output. The analysis revealed the importance of atmospheric convection in the Arctic for some extreme precipitation events and the overall importance of topographic precipitation. The analysis established the physical credibility of the simulations for extreme behavior, laying a foundation for examining projected changes in extreme precipitation. It also highlighted the utility of the model for extracting behavior that one cannot discern directly from the observations, such as summer convective precipitation.

The Kids' Empathic Development Scale (KEDS): a multi-dimensional measure of empathy in primary school-aged children.

PubMed

Reid, Corinne; Davis, Helen; Horlin, Chiara; Anderson, Mike; Baughman, Natalie; Campbell, Catherine

2013-06-01

Empathy is an essential building block for successful interpersonal relationships. Atypical empathic development is implicated in a range of developmental psychopathologies. However, assessment of empathy in children is constrained by a lack of suitable measurement instruments. This article outlines the development of the Kids' Empathic Development Scale (KEDS) designed to assess some of the core affective, cognitive and behavioural components of empathy concurrently. The KEDS assesses responses to picture scenarios depicting a range of individual and interpersonal situations differing in social complexity. Results from 220 children indicate the KEDS measures three related but distinct aspects of empathy that are also related to existing measures of empathy and cognitive development. Scores on the KEDS show age and some gender-related differences in the expected direction. © 2012 The British Psychological Society.

A developmental approach to complex PTSD: childhood and adult cumulative trauma as predictors of symptom complexity.

PubMed

Cloitre, Marylene; Stolbach, Bradley C; Herman, Judith L; van der Kolk, Bessel; Pynoos, Robert; Wang, Jing; Petkova, Eva

2009-10-01

Exposure to multiple traumas, particularly in childhood, has been proposed to result in a complex of symptoms that includes posttraumatic stress disorder (PTSD) as well as a constrained, but variable group of symptoms that highlight self-regulatory disturbances. The relationship between accumulated exposure to different types of traumatic events and total number of different types of symptoms (symptom complexity) was assessed in an adult clinical sample (N = 582) and a child clinical sample (N = 152). Childhood cumulative trauma but not adulthood trauma predicted increasing symptom complexity in adults. Cumulative trauma predicted increasing symptom complexity in the child sample. Results suggest that Complex PTSD symptoms occur in both adult and child samples in a principled, rule-governed way and that childhood experiences significantly influenced adult symptoms. Copyright © 2009 International Society for Traumatic Stress Studies.

Successful psychotherapy for psychogenic seizures in men.

PubMed

Quinn, Maria Clare; Schofield, Margot J; Middleton, Warwick

2012-01-01

This qualitative study examined factors contributing to the development and successful treatment of psychogenic non-epileptic seizures (PNES), in civilian men. In-depth interviews were conducted with therapist-client dyads comprising two male clients who had been successfully treated for PNES and their therapists. A theory-building case study approach provided evidence that those factors known to contribute to PNES and other somatoform symptoms in females and in males engaged in war also contributed to these symptoms in these two civilian males. In addition, PNES in these civilian males occurred in contexts where masculine identity was developmentally curtailed and socially constrained. Successful treatments occurred in long-term therapeutic relationships that sanctioned verbal expression of strong emotion and provided the attunement necessary for development of a robust masculine identity. These findings have implications for the funding of therapy, and training of therapists.

Changes in neurodevelopmental outcomes at 18 to 22 months' corrected age among infants of less than 25 weeks' gestational age born in 1993-1999.

PubMed

Hintz, Susan R; Kendrick, Douglas E; Vohr, Betty R; Poole, W Kenneth; Higgins, Rosemary D

2005-06-01

Increased survival rates for extremely preterm, extremely low birth weight infants during the postsurfactant era have been reported, but data on changes in neurosensory and developmental impairments are sparse. To compare neuromotor and neurodevelopmental outcomes at 18 to 22 months' corrected age for infants of <25 weeks' estimated gestational age (EGA) who were born in the 1990s. This was a multicenter, retrospective, comparative analysis of infants of <25 weeks' EGA, with birth weights of 501 to 1000 g, born between January 1993 and June 1996 (epoch I) or between July 1996 and December 1999 (epoch II), in the National Institute of Child Health and Human Development Neonatal Research Network. Neurodevelopmental assessments were performed at 18 to 22 months' corrected age. Logistic-regression models were constructed to evaluate the independent risk of cerebral palsy, Mental Development Index of <70, Psychomotor Development Index of <70, and neurodevelopmental impairment. A total of 366 patients in epoch I and 473 patients in epoch II were evaluated. Prenatal steroid use, cesarean section, surfactant treatment, bronchopulmonary dysplasia, and severe retinopathy of prematurity were more likely in epoch II, whereas Apgar scores of <5 at 5 minutes, patent ductus arteriosus, and severe intraventricular hemorrhage were more likely in epoch I. The prevalences of cerebral palsy, Psychomotor Development Index of <70, and neurodevelopmental impairment were similar between epochs. The prevalences of Mental Development Index of <70 were 40% for epoch I and 47% for epoch II. Regression analysis revealed that epoch II was an independent risk factor for Mental Developmental Index of <70 (epoch I versus II: odds ratio: 0.63; 95% confidence interval: 0.45-0.87) but not for other outcomes. Early childhood neurodevelopmental outcomes among infants of <25 weeks' EGA are not improving in the postsurfactant era, despite more aggressive perinatal and neonatal treatment. Later childhood follow-up assessment is needed to delineate trends in severe cognitive impairment in this extremely high-risk group.

Extreme hyponatraemia with intact neurological outcome in a young child with Addison’s disease

PubMed Central

Smith, John-Paul; Burren, Christine; Cherinet, Yonas

2011-01-01

The authors present the case of a 6-year-old boy with a good neurological outcome from extreme hyponatraemia caused by autoimmune hypoadrenalism. He presented with 1 week of reduced appetite, lethargy, vomiting and one episode of diarrhoea. He was described as being slightly unsteady on his feet. Clinically he was alert, although intermittently confused, with dry mucous membranes and sunken eyes. Serum sodium was 96 mmol/l with normal serum potassium and renal function. He was initially treated with 3% saline intravenously, and his serum sodium increased to 128 mmol/l by day 3. He developed slurred speech and ataxia on day 4, although MRI brain showed no evidence of pontine myelinosis, and the symptoms resolved over 1 week. A Synacthen test on day 10 confirmed a diagnosis of Addison’s disease and he was commenced on hydrocortisone and fludrocortisone replacement therapy. At 5 months follow-up there are no obvious neurological or developmental sequelae. PMID:22679234

Segmentation in Tardigrada and diversification of segmental patterns in Panarthropoda.

PubMed

Smith, Frank W; Goldstein, Bob

2017-05-01

The origin and diversification of segmented metazoan body plans has fascinated biologists for over a century. The superphylum Panarthropoda includes three phyla of segmented animals-Euarthropoda, Onychophora, and Tardigrada. This superphylum includes representatives with relatively simple and representatives with relatively complex segmented body plans. At one extreme of this continuum, euarthropods exhibit an incredible diversity of serially homologous segments. Furthermore, distinct tagmosis patterns are exhibited by different classes of euarthropods. At the other extreme, all tardigrades share a simple segmented body plan that consists of a head and four leg-bearing segments. The modular body plans of panarthropods make them a tractable model for understanding diversification of animal body plans more generally. Here we review results of recent morphological and developmental studies of tardigrade segmentation. These results complement investigations of segmentation processes in other panarthropods and paleontological studies to illuminate the earliest steps in the evolution of panarthropod body plans. Copyright © 2016 Elsevier Ltd. All rights reserved.

ADHD among young adults born at extremely low birth weight: the role of fluid intelligence in childhood

PubMed Central

Lahat, Ayelet; Van Lieshout, Ryan J.; Saigal, Saroj; Boyle, Michael H.; Schmidt, Louis A.

2014-01-01

Poor executive function (EF) has been linked to attention-deficit/hyperactivity disorder (ADHD). Children born at extremely low birth weight (ELBW; <1000 g) have been found to show both poor EF, as well as elevated levels of symptoms of ADHD. In the present study, we examined whether fluid intelligence moderates the link between birth weight and later ADHD symptoms by prospectively following a cohort of 179 survivors who were born at ELBW. When participants were 8 years-old, they were matched with 145 normal birth weight (NBW; ≥2500 g) control participants. At age 8, fluid intelligence was measured, and during young adulthood (ages 22–26), participants' self-reported levels of ADHD symptoms were examined. We found that ELBW survivors, who also showed poor fluid intelligence, had the highest rates of ADHD symptoms, and particularly, symptoms of inattention. These findings point to the importance of examining developmental trajectories that contribute to risk for psychopathology in those exposed to intrauterine adversity. PMID:24904465

Disorders of extreme stress (DESNOS) symptoms are associated with type and severity of interpersonal trauma exposure in a sample of healthy young women.

PubMed

Ford, Julian D; Stockton, Patricia; Kaltman, Stacey; Green, Bonnie L

2006-11-01

Childhood abuse and other developmentally adverse interpersonal traumas may put young adults at risk not only for posttraumatic stress disorder (PTSD) but also for impairment in affective, cognitive, biological, and relational self-regulation ("disorders of extreme stress not otherwise specified"; DESNOS). Structured clinical interviews with 345 sophomore college women, most of whom (84%) had experienced at least one traumatic event, indicated that the DESNOS syndrome was rare (1% prevalence), but DESNOS symptoms were reported by a majority of respondents. Controlling for PTSD and other anxiety or affective disorders, DESNOS symptom severity was associated with a history of single-incident interpersonal trauma and with more severe interpersonal trauma in a dose-response manner. Noninterpersonal trauma was associated with elevated prevalence of PTSD and dissociation but not with DESNOS severity. Study findings indicate that persistent posttraumatic problems with self-regulation warrant attention, even in relatively healthy young adult populations.

Movement characteristics of persons with prader-willi syndrome rising from supine.

PubMed

Belt, A B; Hertel, T A; Mante, J R; Marks, T; Rockett, V L; Wade, C; Clayton-Krasinski, D

2001-01-01

The purposes of this study were to: 1) determine if previously published descriptors of the supine to stand rising task in healthy individuals could be applied to the movements of persons with Prader-Willi Syndrome (PWS); and 2) assess upper extremity (UE), axial region (AX), and lower extremity (LE) movements among subjects with PWS compared with controls. Nine subjects with PWS (seven-36 years of age) and matched controls were videotaped performing 10 rising trials. The UE, AX, and LE movements were classified using published descriptors. Occurrence frequencies of movement patterns, duration of movement, and the relationships among body region movement score, BMI, and age were determined. Subjects with PWS utilized developmentally less advanced asymmetrical rising patterns, took longer to rise, and demonstrated less within subject variability than controls. Categorical descriptors, with minor modifications, can be used to describe rising movements in persons with PWS. Knowledge of successful rising patterns may assist PTs when examining or planning intervention strategies for teaching the rising task.

Neurological consequences of systemic inflammation in the premature neonate.

PubMed

Patra, Aparna; Huang, Hong; Bauer, John A; Giannone, Peter J

2017-06-01

Despite substantial progress in neonatal care over the past two decades leading to improved survival of extremely premature infants, extreme prematurity continues to be associated with long term neurodevelopmental impairments. Cerebral white matter injury is the predominant form of insult in preterm brain leading to adverse neurological consequences. Such brain injury pattern and unfavorable neurologic sequelae is commonly encountered in premature infants exposed to systemic inflammatory states such as clinical or culture proven sepsis with or without evidence of meningitis, prolonged mechanical ventilation, bronchopulmonary dysplasia, necrotizing enterocolitis and chorioamnionitis. Underlying mechanisms may include cytokine mediated processes without direct entry of pathogens into the brain, developmental differences in immune response and complex neurovascular barrier system that play a critical role in regulating the cerebral response to various systemic inflammatory insults in premature infants. Understanding of these pathologic mechanisms and clinical correlates of such injury based on serum biomarkers or brain imaging findings on magnetic resonance imaging will pave way for future research and translational therapeutic opportunities for the developing brain.

Model design for predicting extreme precipitation event impacts on water quality in a water supply reservoir

NASA Astrophysics Data System (ADS)

Hagemann, M.; Jeznach, L. C.; Park, M. H.; Tobiason, J. E.

2016-12-01

Extreme precipitation events such as tropical storms and hurricanes are by their nature rare, yet have disproportionate and adverse effects on surface water quality. In the context of drinking water reservoirs, common concerns of such events include increased erosion and sediment transport and influx of natural organic matter and nutrients. As part of an effort to model the effects of an extreme precipitation event on water quality at the reservoir intake of a major municipal water system, this study sought to estimate extreme-event watershed responses including streamflow and exports of nutrients and organic matter for use as inputs to a 2-D hydrodynamic and water quality reservoir model. Since extreme-event watershed exports are highly uncertain, we characterized and propagated predictive uncertainty using a quasi-Monte Carlo approach to generate reservoir model inputs. Three storm precipitation depths—corresponding to recurrence intervals of 5, 50, and 100 years—were converted to streamflow in each of 9 tributaries by volumetrically scaling 2 storm hydrographs from the historical record. Rating-curve models for concentratoin, calibrated using 10 years of data for each of 5 constituents, were then used to estimate the parameters of a multivariate lognormal probability model of constituent concentrations, conditional on each scenario's storm date and streamflow. A quasi-random Halton sequence (n = 100) was drawn from the conditional distribution for each event scenario, and used to generate input files to a calibrated CE-QUAL-W2 reservoir model. The resulting simulated concentrations at the reservoir's drinking water intake constitute a low-discrepancy sample from the estimated uncertainty space of extreme-event source water-quality. Limiting factors to the suitability of this approach include poorly constrained relationships between hydrology and constituent concentrations, a high-dimensional space from which to generate inputs, and relatively long run-time for the reservoir model. This approach proved useful in probing a water supply's resilience to extreme events, and to inform management responses, particularly in a region such as the American Northeast where climate change is expected to bring such events with higher frequency and intensity than have occurred in the past.

Constraining Type Ia Supernova Progenitor Scenarios with Extremely Late-time Photometry of Supernova SN 2013aa

NASA Astrophysics Data System (ADS)

Jacobson-Galán, Wynn V.; Dimitriadis, Georgios; Foley, Ryan J.; Kilpatrick, Charles D.

2018-04-01

We present Hubble Space Telescope observations and photometric measurements of the Type Ia supernova (SN Ia) SN 2013aa 1500 days after explosion. At this epoch, the luminosity is primarily dictated by the amounts of radioactive {}57{{Co}} and {}55{{Fe}}, while at earlier epochs, the luminosity depends on the amount of radioactive {}56{{Co}}. The ratio of odd-numbered to even-numbered isotopes depends significantly on the density of the progenitor white dwarf (WD) during the SN explosion, which, in turn, depends on the details of the progenitor system at the time of ignition. From a comprehensive analysis of the entire light curve of SN 2013aa, we measure a M({}57{{Co}})/M({}56{{Co}}) ratio of {0.02}-0.02+0.01, which indicates a relatively low central density for the progenitor WD at the time of explosion, consistent with DD progenitor channels. We estimate M({}56{{Ni}}) = 0.732 +/- 0.151 {M}ȯ , and place an upper limit on the abundance of {}55{{Fe}}. A recent study reported a possible correlation between M({}57{{Co}})/M({}56{{Co}}) and stretch for four SNe Ia. SN 2013aa, however, does not fit this trend, indicating either SN 2013aa is an extreme outlier or the correlation does not hold up with a larger sample. The M({}57{{Co}})/M({}56{{Co}}) measured for the expanded sample of SNe Ia with photometry at extremely late times has a much larger range than that of explosion models, perhaps limiting conclusions about SN Ia progenitors drawn from extremely late-time photometry.

Dynamical properties and extremes of Northern Hemisphere climate fields over the past 60 years

NASA Astrophysics Data System (ADS)

Faranda, Davide; Messori, Gabriele; Alvarez-Castro, M. Carmen; Yiou, Pascal

2017-12-01

Atmospheric dynamics are described by a set of partial differential equations yielding an infinite-dimensional phase space. However, the actual trajectories followed by the system appear to be constrained to a finite-dimensional phase space, i.e. a strange attractor. The dynamical properties of this attractor are difficult to determine due to the complex nature of atmospheric motions. A first step to simplify the problem is to focus on observables which affect - or are linked to phenomena which affect - human welfare and activities, such as sea-level pressure, 2 m temperature, and precipitation frequency. We make use of recent advances in dynamical systems theory to estimate two instantaneous dynamical properties of the above fields for the Northern Hemisphere: local dimension and persistence. We then use these metrics to characterize the seasonality of the different fields and their interplay. We further analyse the large-scale anomaly patterns corresponding to phase-space extremes - namely time steps at which the fields display extremes in their instantaneous dynamical properties. The analysis is based on the NCEP/NCAR reanalysis data, over the period 1948-2013. The results show that (i) despite the high dimensionality of atmospheric dynamics, the Northern Hemisphere sea-level pressure and temperature fields can on average be described by roughly 20 degrees of freedom; (ii) the precipitation field has a higher dimensionality; and (iii) the seasonal forcing modulates the variability of the dynamical indicators and affects the occurrence of phase-space extremes. We further identify a number of robust correlations between the dynamical properties of the different variables.

Nuclear Magnetic Resonance Observations of Octahedral Aluminum in Forsterite, Clinoenstatite and Periclase.

NASA Astrophysics Data System (ADS)

McCarty, R. J.; Stebbins, J. F.

2015-12-01

This research seeks to constrain the crystallographic site preferences of aluminum in forsterite, clinoenstatite and periclase, mantle minerals in which this element is only found at low concentrations. Improved site preference information will help constrain thermodynamic descriptions of the substitution mechanisms, making them more useful to geobarometric and geothermometric techniques. Using high field magic angle spinning nuclear magnetic resonance (NMR) and electron probe microanalysis (EPMA), we constrain the site preferences of minor and trace amounts (2000 to 400 mol ppm) of aluminum in extremely pure synthetic forsterite, clinoenstatite and periclase. The primary challenge of this research is determining how much of each of the aluminum species observed by NMR in the bulk sample (abundances and coordinations) resides in the major synthesized mineral. In our samples, the aluminum partitions between small amounts (often <1%) of impurity phases with high aluminum concentrations, such as glass and accessory crystals, and the major, intended phase with low aluminum concentrations. We use EPMA composition maps to locate scarce impurity phases and EPMA point analyses to determine the aluminum concentrations in both the intended major phase and in the impurity phases. Long NMR acquisitions (several days) and careful subtraction of rotor background signals (present in even 'low-Al' zirconia rotor materials) are required to obtain adequate signal-to-noise ratios at such low concentrations. Ordered octahedral aluminum has been identified in forsterite, clinoenstatite, and periclase. Disordered 4, 5 and 6 coordinated aluminum species have also been observed, but it is still unclear if the disordered species are in the major mineral phases, the impurity phases or both.

Late Wisconsin and early holocene glacial history, inner Ross Embayment, Antarctica

NASA Technical Reports Server (NTRS)

Denton, George H.; Bockheim, James G.; Wilson, Scott C.; Stuiver, Minze

1991-01-01

Lateral drift sheets of outlet glaciers that pass through the Transantarctic Mountains constrain past changes of the huge Ross ice drainage system of the Antarctic Ice Sheet. Drift stratigraphy suggests correlation of Reedy III (Reedy Glacier), Beardmore, Britannia (Hatherton/Darwin Glaciers), Ross Sea (McMurdo Sound), and younger (Terra Nova Bay) drifts; radiocarbon dates place the outer limits of Ross Sea drift in late Wisconsin time at 24,000 to 13,000 yr B.P. Outlet glacier profiles from these drifts constrain late Wisconsin ice sheet surface elevations. Within these constraint, two extreme late Wisconsin reconstructions are given of the Ross ice drainage system. Both show little elevation change of the polar plateau coincident with extensive ice shelf grounding along the inner Ross Embayment. However, in the central Ross Embayment, one reconstruction shows floating shelf ice, where as the other shows a grounded ice sheet. Massive late Wisconsin/Holocene recession of grounded ice from the western Ross Embayment, which was underway at 13,040 yr B.P. and completed by 6600 to 6020 yr B.P., was accompanied by little change in plateau ice levels inland of the Transantarctic Mountains.

Constraints on pulsar masses from the maximum observed glitch

NASA Astrophysics Data System (ADS)

Pizzochero, P. M.; Antonelli, M.; Haskell, B.; Seveso, S.

2017-07-01

Neutron stars are unique cosmic laboratories in which fundamental physics can be probed in extreme conditions not accessible to terrestrial experiments. In particular, the precise timing of rotating magnetized neutron stars (pulsars) reveals sudden jumps in rotational frequency in these otherwise steadily spinning-down objects. These 'glitches' are thought to be due to the presence of a superfluid component in the star, and offer a unique glimpse into the interior physics of neutron stars. In this paper we propose an innovative method to constrain the mass of glitching pulsars, using observations of the maximum glitch observed in a star, together with state-of-the-art microphysical models of the pinning interaction between superfluid vortices and ions in the crust. We study the properties of a physically consistent angular momentum reservoir of pinned vorticity, and we find a general inverse relation between the size of the maximum glitch and the pulsar mass. We are then able to estimate the mass of all the observed glitchers that have displayed at least two large events. Our procedure will allow current and future observations of glitching pulsars to constrain not only the physics of glitch models but also the superfluid properties of dense hadronic matter in neutron star interiors.

A frozen Gaussian approximation-based multi-level particle swarm optimization for seismic inversion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Jinglai, E-mail: jinglaili@sjtu.edu.cn; Lin, Guang, E-mail: lin491@purdue.edu; Computational Sciences and Mathematics Division, Pacific Northwest National Laboratory, Richland, WA 99352

2015-09-01

In this paper, we propose a frozen Gaussian approximation (FGA)-based multi-level particle swarm optimization (MLPSO) method for seismic inversion of high-frequency wave data. The method addresses two challenges in it: First, the optimization problem is highly non-convex, which makes hard for gradient-based methods to reach global minima. This is tackled by MLPSO which can escape from undesired local minima. Second, the character of high-frequency of seismic waves requires a large number of grid points in direct computational methods, and thus renders an extremely high computational demand on the simulation of each sample in MLPSO. We overcome this difficulty by threemore » steps: First, we use FGA to compute high-frequency wave propagation based on asymptotic analysis on phase plane; Then we design a constrained full waveform inversion problem to prevent the optimization search getting into regions of velocity where FGA is not accurate; Last, we solve the constrained optimization problem by MLPSO that employs FGA solvers with different fidelity. The performance of the proposed method is demonstrated by a two-dimensional full-waveform inversion example of the smoothed Marmousi model.« less

High Resolution X-ray Spectroscopy and Star Formation: HETG Observations of the Pre-Main Sequence Stellar Cluster IC 348

NASA Astrophysics Data System (ADS)

Principe, David; Huenemoerder, David P.; Schulz, Norbert; Kastner, Joel H.; Weintraub, David; Preibisch, Thomas

2018-01-01

We present Chandra High Energy Transmission Grating (HETG) observations of the ∼3 Myr old pre-main sequence (pre-MS) stellar cluster IC 348. With 400-500 cluster members at a distance of ∼300 pc, IC 348 is an ideal target to observe a large number of X-ray sources in a single pointing and is thus an extremely efficient use of Chandra-HETG. High resolution X-ray spectroscopy offers a means to investigate detailed spectral characteristic of X-ray emitting plasmas and their surrounding environments. We present preliminary results where we compare X-ray spectral signatures (e.g., luminosity, temperature, column density, abundance) of the X-ray brightest pre-MS stars in IC 348 with spectral type, multiwavelength signatures of accretion, and the presence of circumstellar disks at multiple stages of pre-MS stellar evolution. Assuming all IC 348 members formed from the same primordial molecular cloud, any disparity between coronal abundances of individual members, as constrained by the identification and strength of emission lines, will constrain the source(s) of coronal chemical evolution at a stage of pre-MS evolution vital to the formation of planets.

Unveiling the Nature of Giant Ellipticals and their Stellar Halos with the VST

NASA Astrophysics Data System (ADS)

Spavone, M.; Capaccioli, M.; Napolitano, N. R.; Iodice, E.; Grado, A.; Limatola, L.; Cooper, A. P.; Cantiello, M.; Forbes, D. A.; Paolillo, M.; Schipani, P.

2017-12-01

Observations of diffuse starlight in the outskirts of galaxies provide fundamental constraints on the cosmological context of galaxy assembly in the Lambda Cold Dark Matter model, which predicts that galaxies grow through a combination of in-situ star formation and accretion of stars from other galaxies. Accreted stars are expected to dominate in the outer parts of galaxies. Since dynamical timescales are longer in these regions, substructures related to accretion, such as streams and shells, can persist over many Gyr. In this work we use extremely deep g- and i-band images of six massive early- type galaxies (ETGs) from the VEGAS survey to constrain the properties of their accreted stellar components. The wide field of view of OmegaCAM on the VLT Survey Telescope (VST) also allows us to investigate the properties of small stellar systems (such as globular clusters, ultra-compact dwarfs and satellite galaxies) in the halos of our galaxies. By fitting light profiles, and comparing the results to simulations of elliptical galaxy assembly, we have identified signatures of a transition between relaxed and unrelaxed accreted components and can constrain the balance between in-situ and accreted stars.

ISM Properties of a Massive Dusty Star-forming Galaxy Discovered at z ˜ 7

NASA Astrophysics Data System (ADS)

Strandet, M. L.; Weiss, A.; De Breuck, C.; Marrone, D. P.; Vieira, J. D.; Aravena, M.; Ashby, M. L. N.; Béthermin, M.; Bothwell, M. S.; Bradford, C. M.; Carlstrom, J. E.; Chapman, S. C.; Cunningham, D. J. M.; Chen, Chian-Chou; Fassnacht, C. D.; Gonzalez, A. H.; Greve, T. R.; Gullberg, B.; Hayward, C. C.; Hezaveh, Y.; Litke, K.; Ma, J.; Malkan, M.; Menten, K. M.; Miller, T.; Murphy, E. J.; Narayanan, D.; Phadke, K. A.; Rotermund, K. M.; Spilker, J. S.; Sreevani, J.

2017-06-01

We report the discovery and constrain the physical conditions of the interstellar medium of the highest-redshift millimeter-selected dusty star-forming galaxy to date, SPT-S J031132-5823.4 (hereafter SPT0311-58), at z=6.900+/- 0.002. SPT0311-58 was discovered via its 1.4 mm thermal dust continuum emission in the South Pole Telescope (SPT)-SZ survey. The spectroscopic redshift was determined through an Atacama Large Millimeter/submillimeter Array 3 mm frequency scan that detected CO(6-5), CO(7-6), and [{{C}} {{I}}](2-1), and subsequently was confirmed by detections of CO(3-2) with the Australia Telescope Compact Array and [{{C}} {{II}}] with APEX. We constrain the properties of the ISM in SPT0311-58 with a radiative transfer analysis of the dust continuum photometry and the CO and [{{C}} {{I}}] line emission. This allows us to determine the gas content without ad hoc assumptions about gas mass scaling factors. SPT0311-58 is extremely massive, with an intrinsic gas mass of {M}{gas}=3.3+/- 1.9× {10}11 {M}⊙ . Its large mass and intense star formation is very rare for a source well into the epoch of reionization.

A compact and accurate semi-global potential energy surface for malonaldehyde from constrained least squares regression

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mizukami, Wataru, E-mail: wataru.mizukami@bristol.ac.uk; Tew, David P., E-mail: david.tew@bristol.ac.uk; Habershon, Scott, E-mail: S.Habershon@warwick.ac.uk

2014-10-14

We present a new approach to semi-global potential energy surface fitting that uses the least absolute shrinkage and selection operator (LASSO) constrained least squares procedure to exploit an extremely flexible form for the potential function, while at the same time controlling the risk of overfitting and avoiding the introduction of unphysical features such as divergences or high-frequency oscillations. Drawing from a massively redundant set of overlapping distributed multi-dimensional Gaussian functions of inter-atomic separations we build a compact full-dimensional surface for malonaldehyde, fit to explicitly correlated coupled cluster CCSD(T)(F12*) energies with a root mean square deviations accuracy of 0.3%–0.5% up tomore » 25 000 cm{sup −1} above equilibrium. Importance-sampled diffusion Monte Carlo calculations predict zero point energies for malonaldehyde and its deuterated isotopologue of 14 715.4(2) and 13 997.9(2) cm{sup −1} and hydrogen transfer tunnelling splittings of 21.0(4) and 3.2(4) cm{sup −1}, respectively, which are in excellent agreement with the experimental values of 21.583 and 2.915(4) cm{sup −1}.« less

Women's responses to intimate partner violence in Rwanda: Rethinking agency in constrained social contexts.

PubMed

Mannell, Jenevieve; Jackson, Sharon; Umutoni, Aline

2016-01-01

This paper explores instances of agency in women's responses to intimate partner violence (IPV) in Rwanda. The literature on women's responses to IPV conceptualises agency primarily as an individual's capacity to take action by reporting violence or leaving a relationship, obscuring other ways women may respond to violence in contexts where reporting or leaving are unlikely. We aim to replace this narrow conceptualisation of agency with a social constructivist focus on the meanings women attribute to possible IPV responses. We draw on data from a study of IPV in Rwanda, which includes semi-structured interviews with women experiencing violence and four focus group discussions with women community members (n = 39). Our findings highlight sociocultural, economic, political-legal and historical constraints that shape women's actions in this context. In relation to these constraints, women describe four possible responses to IPV: reporting the violence; seeking emotional support; 'fighting back' against violence; or remaining silent. While reporting and leaving violent relationships are identified, women also discuss the social constraints that make these actions extremely difficult. In designing effective strategies, we conclude that public health strategies need to consider women's understandings of their own actions, particularly in social contexts where certain actions may be constrained.

Constraining MHD Disk-Winds with X-ray Absorbers

NASA Astrophysics Data System (ADS)

Fukumura, Keigo; Tombesi, F.; Shrader, C. R.; Kazanas, D.; Contopoulos, J.; Behar, E.

2014-01-01

From the state-of-the-art spectroscopic observations of active galactic nuclei (AGNs) the robust features of absorption lines (e.g. most notably by H/He-like ions), called warm absorbers (WAs), have been often detected in soft X-rays (< 2 keV). While the identified WAs are often mildly blueshifted to yield line-of-sight velocities up to ~100-3,000 km/sec in typical X-ray-bright Seyfert 1 AGNs, a fraction of Seyfert galaxies such as PG 1211+143 exhibits even faster absorbers (v/ 0.1-0.2) called ultra-fast outflows (UFOs) whose physical condition is much more extreme compared with the WAs. Motivated by these recent X-ray data we show that the magnetically- driven accretion-disk wind model is a plausible scenario to explain the characteristic property of these X-ray absorbers. As a preliminary case study we demonstrate that the wind model parameters (e.g. viewing angle and wind density) can be constrained by data from PG 1211+143 at a statistically significant level with chi-squared spectral analysis. Our wind models can thus be implemented into the standard analysis package, XSPEC, as a table spectrum model for general analysis of X-ray absorbers.

The King of Norway: negative individuation, the hero myth and psychopathic narcissism in extreme violence and the life of Anders Behring Breivik.

PubMed

Virtanen, Harri

2013-11-01

The paper discusses negative individuation and the hero myth as developmental concepts. It is suggested that in negative individuation healthy psychological development is hindered and goes astray. Aggression then becomes the central psychic system. Repressed anger is the core element in psychopathic narcissism (Diamond) and malignant narcissism (Kernberg). Both Diamond and Kernberg extend narcissistic personality structure to antisocial, psychopathic personality in an effort to better understand extreme violence. According to Freud, love (libido) and hate (the death drive) are the major motivational systems in the human psyche. In contrast to Freud, Jung sees libido as a life force in general, not simply as a sexual drive. Jung writes about evil and the shadow but does not present a comprehensive theory of the negative development of an individual's life. The concept of negative individuation connects the shadow and the death drive with psychopathology, psychiatry and psychotherapy. In this paper, I explore these concepts in the light of contemporary affect theory according to Kernberg. I also ask how ideology is tied to extreme violence and how it is possible that narcissistic personality structures can lead to such radically different outcomes as were manifested in the lives of Anders Behring Breivik and Steve Jobs. © 2013, The Society of Analytical Psychology.

Congenital abnormalities of the inferior vena cava presenting clinically in adolescent males.

PubMed

Halparin, Jessica; Monagle, Paul; Newall, Fiona

2015-04-01

Congenital anatomic abnormality of the inferior vena cava (IVC) is an important risk factor for the development of spontaneous proximal lower extremity deep vein thrombosis (DVT) in young adults. The incidence of DVT associated with congenital IVC anomalies in paediatric populations has not been described, and the implications of IVC anomalies for treatment and outcomes of DVT are unknown. This study reports a series of five adolescent males with spontaneous lower extremity DVTs and underlying congenital IVC abnormalities. Cases were identified by searching the institutional database of patients treated with anticoagulation for venous thromboembolism at a tertiary children's hospital. The demographics, clinical presentations, imaging findings, treatment courses, and outcomes are described. All cases occurred in males, and accounted for approximately twenty percent of adolescent males presenting with DVT. IVC abnormality is likely an under-recognized risk factor for DVT in this age group, and detailed vascular imaging should be pursued in adolescents with spontaneous proximal lower extremity DVT when initial ultrasonography does not delineate the proximal clot extent. Management requires individual risk-benefit assessment in the context of providing developmentally appropriate care. Further research is required to establish long-term outcomes and determine optimal treatment strategies. Copyright © 2015 Elsevier Ltd. All rights reserved.

Extreme Growth Failure is a Common Presentation of Ligase IV Deficiency

PubMed Central

Murray, Jennie E; Bicknell, Louise S; Yigit, Gökhan; Duker, Angela L; van Kogelenberg, Margriet; Haghayegh, Sara; Wieczorek, Dagmar; Kayserili, Hülya; Albert, Michael H; Wise, Carol A; Brandon, January; Kleefstra, Tjitske; Warris, Adilia; van der Flier, Michiel; Bamforth, J Steven; Doonanco, Kurston; Adès, Lesley; Ma, Alan; Field, Michael; Johnson, Diana; Shackley, Fiona; Firth, Helen; Woods, C Geoffrey; Nürnberg, Peter; Gatti, Richard A; Hurles, Matthew; Bober, Michael B; Wollnik, Bernd; Jackson, Andrew P

2014-01-01

Ligase IV syndrome is a rare differential diagnosis for Nijmegen breakage syndrome owing to a shared predisposition to lympho-reticular malignancies, significant microcephaly, and radiation hypersensitivity. Only 16 cases with mutations in LIG4 have been described to date with phenotypes varying from malignancy in developmentally normal individuals, to severe combined immunodeficiency and early mortality. Here, we report the identification of biallelic truncating LIG4 mutations in 11 patients with microcephalic primordial dwarfism presenting with restricted prenatal growth and extreme postnatal global growth failure (average OFC −10.1 s.d., height −5.1 s.d.). Subsequently, most patients developed thrombocytopenia and leucopenia later in childhood and many were found to have previously unrecognized immunodeficiency following molecular diagnosis. None have yet developed malignancy, though all patients tested had cellular radiosensitivity. A genotype–phenotype correlation was also noted with position of truncating mutations corresponding to disease severity. This work extends the phenotypic spectrum associated with LIG4 mutations, establishing that extreme growth retardation with microcephaly is a common presentation of bilallelic truncating mutations. Such growth failure is therefore sufficient to consider a diagnosis of LIG4 deficiency and early recognition of such cases is important as bone marrow failure, immunodeficiency, and sometimes malignancy are long term sequelae of this disorder. PMID:24123394

Political attitudes in adolescence and emerging adulthood: Developmental changes in mean level, polarization, rank-order stability, and correlates.

PubMed

Rekker, Roderik; Keijsers, Loes; Branje, Susan; Meeus, Wim

2015-06-01

This three-wave cohort-sequential longitudinal study (N = 1302) examined the development of two core political attitudes, economic egalitarianism and ethnocentrism, among Dutch youths between age 12 and 31. Longitudinal regression analyses revealed a curvilinear mean level development for both attitudes, reflecting an increased disagreement with economic redistribution and multiculturalism around late adolescence. Furthermore, attitudes became decreasingly polarized (i.e., less extreme) and increasingly stable with age. Finally, several effects of attitudes' correlates gradually changed: The effect of educational level on ethnocentrism increased with age, whereas the effect of gender diminished. Regional effects on ethnocentrism developed as youths resided in a new area. No age-related change was found in the effect of parental SES. Overall, these findings support the idea that attitudes mature during the formative phase of adolescence and that this process slows down during emerging adulthood. Furthermore, these results support developmental explanations for the association between attitudes and their correlates. Copyright © 2015 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

Developmental phenotypic plasticity helps bridge stochastic weather events associated with climate change.

PubMed

Burggren, Warren

2018-05-10

The slow, inexorable rise in annual average global temperatures and acidification of the oceans are often advanced as consequences of global change. However, many environmental changes, especially those involving weather (as opposed to climate), are often stochastic, variable and extreme, particularly in temperate terrestrial or freshwater habitats. Moreover, few studies of animal and plant phenotypic plasticity employ realistic (i.e. short-term, stochastic) environmental change in their protocols. Here, I posit that the frequently abrupt environmental changes (days, weeks, months) accompanying much longer-term general climate change (e.g. global warming over decades or centuries) require consideration of the true nature of environmental change (as opposed to statistical means) coupled with an expansion of focus to consider developmental phenotypic plasticity. Such plasticity can be in multiple forms - obligatory/facultative, beneficial/deleterious - depending upon the degree and rate of environmental variability at specific points in organismal development. Essentially, adult phenotypic plasticity, as important as it is, will be irrelevant if developing offspring lack sufficient plasticity to create modified phenotypes necessary for survival. © 2018. Published by The Company of Biologists Ltd.

Effects of music therapy for children and adolescents with psychopathology: a meta-analysis.

PubMed

Gold, Christian; Voracek, Martin; Wigram, Tony

2004-09-01

The objectives of this review were to examine the overall efficacy of music therapy for children and adolescents with psychopathology, and to examine how the size of the effect of music therapy is influenced by the type of pathology, client's age, music therapy approach, and type of outcome. Eleven studies were included for analysis, which resulted in a total of 188 subjects for the meta-analysis. Effect sizes from these studies were combined, with weighting for sample size, and their distribution was examined. After exclusion of an extreme positive outlying value, the analysis revealed that music therapy has a medium to large positive effect (ES =.61) on clinically relevant outcomes that was statistically highly significant (p <.001) and statistically homogeneous. No evidence of a publication bias was identified. Effects tended to be greater for behavioural and developmental disorders than for emotional disorders; greater for eclectic, psychodynamic, and humanistic approaches than for behavioural models; and greater for behavioural and developmental outcomes than for social skills and self-concept. Implications for clinical practice and research are discussed.

Stranger in a Strange Land: Using Heterotopic Transplantations to Study Nature vs Nurture in Brain Development.

PubMed

Petros, Timothy J

2018-01-01

The mammalian brain develops from a simple sheet of neuroepithelial cells into an incredibly complex structure containing billions of neurons with trillions of synapses. Understanding how intrinsic genetic programs interact with environmental cues to generate neuronal diversity and proper connectivity is one of the most daunting challenges in developmental biology. We recently explored this issue in forebrain GABAergic inhibitory interneurons, an extremely diverse population of neurons that are classified into distinct subtypes based on morphology, neurochemical markers, and electrophysiological properties. Immature interneurons were harvested from one brain region and transplanted into a different region, allowing us to assess how challenging cells in a new environment affected their fate. Do these grafted cells adopt characteristics of the host environment or retain features from the donor environment? We found that the proportion of interneuron subgroups is determined by the host region, but some interneuron subtypes maintain features attributable to the donor environment. In this commentary, I expound on potential mechanisms that could underlie these observations and explore the implications of these findings in a greater context of developmental neuroscience.

Gigantism and comparative life-history parameters of tyrannosaurid dinosaurs.

PubMed

Erickson, Gregory M; Makovicky, Peter J; Currie, Philip J; Norell, Mark A; Yerby, Scott A; Brochu, Christopher A

2004-08-12

How evolutionary changes in body size are brought about by variance in developmental timing and/or growth rates (also known as heterochrony) is a topic of considerable interest in evolutionary biology. In particular, extreme size change leading to gigantism occurred within the dinosaurs on multiple occasions. Whether this change was brought about by accelerated growth, delayed maturity or a combination of both processes is unknown. A better understanding of relationships between non-avian dinosaur groups and the newfound capacity to reconstruct their growth curves make it possible to address these questions quantitatively. Here we study growth patterns within the Tyrannosauridae, the best known group of large carnivorous dinosaurs, and determine the developmental means by which Tyrannosaurus rex, weighing 5,000 kg and more, grew to be one of the most enormous terrestrial carnivorous animals ever. T. rex had a maximal growth rate of 2.1 kg d(-1), reached skeletal maturity in two decades and lived for up to 28 years. T. rex's great stature was primarily attained by accelerating growth rates beyond that of its closest relatives.

Do more intelligent brains retain heightened plasticity for longer in development? A computational investigation.

PubMed

Thomas, Michael S C

2016-06-01

Twin studies indicate that the heritability of general cognitive ability - the genetic contribution to individual differences - increases with age. Brant et al. (2013) reported that this increase in heritability occurs earlier in development for low ability children than high ability children. Allied with structural brain imaging results that indicate faster thickening and thinning of cortex for high ability children (Shaw et al., 2006), Brant and colleagues argued higher cognitive ability represents an extended sensitive period for brain development. However, they admitted no coherent mechanistic account can currently reconcile the key empirical data. Here, computational methods are employed to demonstrate the empirical data can be reconciled without recourse to variations in sensitive periods. These methods utilized population-based artificial neural network models of cognitive development. In the model, ability-related variations stemmed from the timing of the increases in the non-linearity of computational processes, causing dizygotic twins to diverge in their behavior. These occurred in a population where: (a) ability was determined by the combined small contributions of many neurocomputational factors, and (b) individual differences in ability were largely genetically constrained. The model's explanation of developmental increases in heritability contrasts with proposals that these increases represent emerging gene-environment correlations (Haworth et al., 2010). The article advocates simulating inherited individual differences within an explicitly developmental framework. Copyright © 2016 The Author. Published by Elsevier Ltd.. All rights reserved.

Parental care mitigates carry-over effects of poor early conditions on offspring growth

USGS Publications Warehouse

Auer, Sonya K.; Martin, Thomas E.

2017-01-01

Poor developmental conditions can have long-lasting negative effects on offspring phenotypes, but impacts often differ among species. Contrasting responses may reflect disparities in experimental protocols among single-species studies or inherent differences among species in their sensitivity to early conditions and/or ability to mitigate negative impacts. We used a common experimental protocol to assess and compare the role of parental care in mitigating effects of poor early conditions on offspring among 4 sympatric bird species in the wild. We experimentally induced low incubation temperatures and examined effects on embryonic developmental rates, hatching success, nestling growth rates, and parental responses. We examined the generality of these effects across 4 species that differ in their phylogenetic history, breeding ecology, and life histories. We found that cooling led to delayed hatching in all species, but carry-over effects on offspring differed among species. Parents of some but not all species increased their offspring provisioning rates in response to experimental cooling with critical benefits for offspring growth rates. Our study shows for the first time that species exhibit clear differences in the degree to which they are affected by poor early conditions. Observed differences among species demonstrate that parental care is a critical mechanism for mitigating potential negative effects on offspring and suggest that parental responses may be constrained to varying degrees by ecology and life histories.

Direct impact of the sustained decline in the photosystem II efficiency upon plant productivity at different developmental stages.

PubMed

Tian, Yonglan; Ungerer, Petra; Zhang, Huayong; Ruban, Alexander V

2017-05-01

The impact of chronic photoinhibition of photosystem II (PSII) on the productivity of plants remains unknown. The present study investigated the influences of persistent decline in the PSII yield on morphology and productivity of Arabidopsis plants that were exposed to lincomycin at two different developmental stages (seedling and rosette stage). The results indicated that, although retarded, the lincomycin treated plants were able to accomplish the entire growth period with only 50% of the maximum quantum yield of primary photochemistry (Fv/Fm) of the control plants. The decline in quantum yield limited the electron transport rate (ETR). The impact of lincomycin on NPQ was not significant in seedlings, but was pronounced in mature plants. The treated plants produced an above ground biomass of 50% compared to control plants. Moreover, a linear relationship was found between the above ground biomass and total rosette leaf area, and the slope was decreased due to photoinhibition. The starch accumulation was highly inhibited by lincomycin treatment. Lincomycin induced a significant decrease in seed yield with plants treated from the rosette state showing higher yield than those treated from the seedling stage. Our data suggest that the sustained decline of PSII efficiency decreases plant productivity by constraining the ETR, leaf development and starch production. Copyright © 2017 Elsevier GmbH. All rights reserved.

Infants' statistical learning: 2- and 5-month-olds' segmentation of continuous visual sequences.

PubMed

Slone, Lauren Krogh; Johnson, Scott P

2015-05-01

Past research suggests that infants have powerful statistical learning abilities; however, studies of infants' visual statistical learning offer differing accounts of the developmental trajectory of and constraints on this learning. To elucidate this issue, the current study tested the hypothesis that young infants' segmentation of visual sequences depends on redundant statistical cues to segmentation. A sample of 20 2-month-olds and 20 5-month-olds observed a continuous sequence of looming shapes in which unit boundaries were defined by both transitional probability and co-occurrence frequency. Following habituation, only 5-month-olds showed evidence of statistically segmenting the sequence, looking longer to a statistically improbable shape pair than to a probable pair. These results reaffirm the power of statistical learning in infants as young as 5 months but also suggest considerable development of statistical segmentation ability between 2 and 5 months of age. Moreover, the results do not support the idea that infants' ability to segment visual sequences based on transitional probabilities and/or co-occurrence frequencies is functional at the onset of visual experience, as has been suggested previously. Rather, this type of statistical segmentation appears to be constrained by the developmental state of the learner. Factors contributing to the development of statistical segmentation ability during early infancy, including memory and attention, are discussed. Copyright © 2015 Elsevier Inc. All rights reserved.

Morphological Variation in Anuran Limbs: Constraints and Novelties.

PubMed

Fabrezi, Marissa; Goldberg, Javier; Chuliver Pereyra, Mariana

2017-09-01

Anurans have three primary types of locomotion: walking, jumping, and swimming. Additionally, they may dig, climb, grasp, etc. All adult anurans have four limbs, with four fingers on the hands and five toes on the feet. We summarized and updated knowledge on the interspecific variation within anuran limbs, then discuss how developmental constraints (e.g., in size) and novelties may have influenced anuran diversification through the locomotion. We analyze morphological variation from limb bud stages up to the final limb form resulting from certain skeletal organization and growth. We find limited morphometric variations in the skeleton of different developmental modules (i.e., skull, trunk, urostyle, limbs) indicate that the anuran body shape is largely constrained. We identify specializations of the stylopodium, zeugopodium, and proximal carpals/tarsals that have evolved to facilitiate saltatorial locomotion. We show that the anuran prepollex and prehallux are not vestigial digits and that they have come to serve specialized function. Medial rotation of the manus in anurans appears to have evolved to help distribute the force of impact upon landing at the end of a jump. Additional skeletal elements in anuran limbs are intercalary elements and sesamoids. The intercalary elements appear within neobatrachians and are integrated with digital pads in lineages capable of locomotion on smooth vertical surfaces. They have allowed arboreal anurans to occupy a wide range of arboreal habitats. © 2017 Wiley Periodicals, Inc.

SpoVT: From Fine-Tuning Regulator in Bacillus subtilis to Essential Sporulation Protein in Bacillus cereus

PubMed Central

Eijlander, Robyn T.; Holsappel, Siger; de Jong, Anne; Ghosh, Abhinaba; Christie, Graham; Kuipers, Oscar P.

2016-01-01

Sporulation is a highly sophisticated developmental process adopted by most Bacilli as a survival strategy to withstand extreme conditions that normally do not support microbial growth. A complicated regulatory cascade, divided into various stages and taking place in two different compartments of the cell, involves a number of primary and secondary regulator proteins that drive gene expression directed toward the formation and maturation of an endospore. Such regulator proteins are highly conserved among various spore formers. Despite this conservation, both regulatory and phenotypic differences are observed between different species of spore forming bacteria. In this study, we demonstrate that deletion of the regulatory sporulation protein SpoVT results in a severe sporulation defect in Bacillus cereus, whereas this is not observed in Bacillus subtilis. Although spores are initially formed, the process is stalled at a later stage in development, followed by lysis of the forespore and the mother cell. A transcriptomic investigation of B. cereus ΔspoVT shows upregulation of genes involved in germination, potentially leading to premature lysis of prespores formed. Additionally, extreme variation in the expression of species-specific genes of unknown function was observed. Introduction of the B. subtilis SpoVT protein could partly restore the sporulation defect in the B. cereus spoVT mutant strain. The difference in phenotype is thus more than likely explained by differences in promoter targets rather than differences in mode of action of the conserved SpoVT regulator protein. This study stresses that evolutionary variances in regulon members of sporulation regulators can have profound effects on the spore developmental process and that mere protein homology is not a foolproof predictor of similar phenotypes. PMID:27790204

SpoVT: From Fine-Tuning Regulator in Bacillus subtilis to Essential Sporulation Protein in Bacillus cereus.

PubMed

Eijlander, Robyn T; Holsappel, Siger; de Jong, Anne; Ghosh, Abhinaba; Christie, Graham; Kuipers, Oscar P

2016-01-01

Sporulation is a highly sophisticated developmental process adopted by most Bacilli as a survival strategy to withstand extreme conditions that normally do not support microbial growth. A complicated regulatory cascade, divided into various stages and taking place in two different compartments of the cell, involves a number of primary and secondary regulator proteins that drive gene expression directed toward the formation and maturation of an endospore. Such regulator proteins are highly conserved among various spore formers. Despite this conservation, both regulatory and phenotypic differences are observed between different species of spore forming bacteria. In this study, we demonstrate that deletion of the regulatory sporulation protein SpoVT results in a severe sporulation defect in Bacillus cereus , whereas this is not observed in Bacillus subtilis . Although spores are initially formed, the process is stalled at a later stage in development, followed by lysis of the forespore and the mother cell. A transcriptomic investigation of B. cereus Δ spoVT shows upregulation of genes involved in germination, potentially leading to premature lysis of prespores formed. Additionally, extreme variation in the expression of species-specific genes of unknown function was observed. Introduction of the B. subtilis SpoVT protein could partly restore the sporulation defect in the B. cereus spoVT mutant strain. The difference in phenotype is thus more than likely explained by differences in promoter targets rather than differences in mode of action of the conserved SpoVT regulator protein. This study stresses that evolutionary variances in regulon members of sporulation regulators can have profound effects on the spore developmental process and that mere protein homology is not a foolproof predictor of similar phenotypes.

The developmental effects of extremely low frequency electric fields on visual and somatosensory evoked potentials in adult rats.

PubMed

Gok, Deniz Kantar; Akpinar, Deniz; Hidisoglu, Enis; Ozen, Sukru; Agar, Aysel; Yargicoglu, Piraye

2016-01-01

The purpose of our study was to investigate the developmental effects of extremely low frequency electric fields (ELF-EFs) on visual evoked potentials (VEPs) and somatosensory-evoked potentials (SEPs) and to examine the relationship between lipid peroxidation and changes of these potentials. In this context, thiobarbituric acid reactive substances (TBARS) levels were determined as an indicator of lipid peroxidation. Wistar albino female rats were divided into four groups; Control (C), gestational (prenatal) exposure (Pr), gestational+ postnatal exposure (PP) and postnatal exposure (Po) groups. Pregnant rats of Pr and PP groups were exposed to 50 Hz electric field (EF) (12 kV/m; 1 h/day), while those of C and Po groups were placed in an inactive system during pregnancy. Following parturition, rats of PP and Po groups were exposed to ELF-EFs whereas rats of C and Pr groups were kept under the same experimental conditions without being exposed to any EF during 68 days. On postnatal day 90, rats were prepared for VEP and SEP recordings. The latencies of VEP components in all experimental groups were significantly prolonged versus C group. For SEPs, all components of PP group, P2, N2 components of Pr group and P1, P2, N2 components of Po group were delayed versus C group. As brain TBARS levels were significantly increased in Pr and Po groups, retina TBARS levels were significantly elevated in all experimental groups versus C group. In conclusion, alterations seen in evoked potentials, at least partly, could be explained by lipid peroxidation in the retina and brain.

The evolution of cerebrotypes in birds.

PubMed

Iwaniuk, Andrew N; Hurd, Peter L

2005-01-01

Multivariate analyses of brain composition in mammals, amphibians and fish have revealed the evolution of 'cerebrotypes' that reflect specific niches and/or clades. Here, we present the first demonstration of similar cerebrotypes in birds. Using principal component analysis and hierarchical clustering methods to analyze a data set of 67 species, we demonstrate that five main cerebrotypes can be recognized. One type is dominated by galliforms and pigeons, among other species, that all share relatively large brainstems, but can be further differentiated by the proportional size of the cerebellum and telencephalic regions. The second cerebrotype contains a range of species that all share relatively large cerebellar and small nidopallial volumes. A third type is composed of two species, the tawny frogmouth (Podargus strigoides) and an owl, both of which share extremely large Wulst volumes. Parrots and passerines, the principal members of the fourth group, possess much larger nidopallial, mesopallial and striatopallidal proportions than the other groups. The fifth cerebrotype contains species such as raptors and waterfowl that are not found at the extremes for any of the brain regions and could therefore be classified as 'generalist' brains. Overall, the clustering of species does not directly reflect the phylogenetic relationships among species, but there is a tendency for species within an order to clump together. There may also be a weak relationship between cerebrotype and developmental differences, but two of the main clusters contained species with both altricial and precocial developmental patterns. As a whole, the groupings do agree with behavioral and ecological similarities among species. Most notably, species that share similarities in locomotor behavior, mode of prey capture or cognitive ability are clustered together. The relationship between cerebrotype and behavior/ecology in birds suggests that future comparative studies of brain-behavior relationships will benefit from adopting a multivariate approach. Copyright 2005 S. Karger AG, Basel.

Performance of Waterless Concrete

NASA Technical Reports Server (NTRS)

Toutanji, Houssam; Evans, Steve; Grugel, Richard N.

2010-01-01

The development of permanent lunar bases is constrained by performance of construction materials and availability of in-situ resources. Concrete seems a suitable construction material for the lunar environment, but water, one of its major components, is an extremely scarce resource on the Moon. This study explores an alternative to hydraulic concrete by replacing the binding mix of concrete (cement and water) with sulfur. Sulfur is a volatile element on the lunar surface that can be extracted from lunar soils by heating. Sulfur concrete mixes were prepared to investigate the effect of extreme environmental conditions on the properties of sulfur concrete. A hypervelocity impact test was conducted, having as its target a 5-cm cubic sample of sulfur concrete. This item consisted of JSC-1 lunar regolith simulant (65%) and sulfur (35%). The sample was placed in the MSFC Impact Test Facility s Micro Light Gas Gun target chamber, and was struck by a 1-mm diameter (1.4e-03 g) aluminum projectile at 5.85 km/s. In addition, HZTERN code, provided by NASA was used to study the effectiveness of sulfur concrete when subjected to space radiation.

Comparison of two methods for estimating base flow in selected reaches of the South Platte River, Colorado

USGS Publications Warehouse

Capesius, Joseph P.; Arnold, L. Rick

2012-01-01

The Mass Balance results were quite variable over time such that they appeared suspect with respect to the concept of groundwater flow as being gradual and slow. The large degree of variability in the day-to-day and month-to-month Mass Balance results is likely the result of many factors. These factors could include ungaged stream inflows or outflows, short-term streamflow losses to and gains from temporary bank storage, and any lag in streamflow accounting owing to streamflow lag time of flow within a reach. The Pilot Point time series results were much less variable than the Mass Balance results and extreme values were effectively constrained. Less day-to-day variability, smaller magnitude extreme values, and smoother transitions in base-flow estimates provided by the Pilot Point method are more consistent with a conceptual model of groundwater flow being gradual and slow. The Pilot Point method provided a better fit to the conceptual model of groundwater flow and appeared to provide reasonable estimates of base flow.

How Extreme is TRAPPIST-1? A look into the planetary system’s extreme-UV radiation environment

NASA Astrophysics Data System (ADS)

Peacock, Sarah; Barman, Travis; Shkolnik, Evgenya L.

2018-01-01

The ultracool dwarf star TRAPPIST-1 hosts three earth-sized planets at orbital distances where water has the potential to exist in liquid form on the planets’ surface. Close-in exoplanets, such as these, become vulnerable to water loss as stellar XUV radiation heats and expands their upper atmospheres. Currently, little is known about the high-energy radiation environment around TRAPPIST-1. Recent efforts to quantify the XUV radiation rely on empirical relationships based on X-ray or Lyman alpha line observations and yield very different results. The scaling relations used between the X-ray and EUV emission result in high-energy irradiation of the planets 10-1000x greater than present day Earth, stripping atmospheres and oceans in 1 Gyr, while EUV estimated from Lyman alpha flux is much lower. Here we present upper-atmosphere PHOENIX models representing the minimum and maximum potential EUV stellar flux from TRAPPIST-1. We use GALEX FUV and NUV photometry for similar aged M stars to determine the UV flux extrema in an effort to better constrain the high-energy radiation environment around TRAPPIST-1.

Extreme weather and experience influence reproduction in an endangered bird

USGS Publications Warehouse

Reichert, Brian E.; Cattau, Christopher E.; Fletcher, Robert J.; Kendall, William L.; Kitchens, Wiley M.

2012-01-01

Using a 14-year time series spanning large variation in climatic conditions and the entirety of a population's breeding range, we estimated the effects of extreme weather conditions (drought) on the state-specific probabilities of breeding and survival of an endangered bird, the Florida Snail Kite (Rostrhamus sociabilis plumbeus). Our analysis accounted for uncertainty in breeding status assignment, a common source of uncertainty that is often ignored when states are based on field observations. Breeding probabilities in adult kites (>1 year of age) decreased during droughts, whereas the probability of breeding in young kites (1 year of age) tended to increase. Individuals attempting to breed showed no evidence of reduced future survival. Although population viability analyses of this species and other species often implicitly assume that all adults will attempt to breed, we find that breeding probabilities were significantly <1 for all 13 estimable years considered. Our results suggest that experience is an important factor determining whether or not individuals attempt to breed during harsh environmental conditions and that reproductive effort may be constrained by an individual's quality and/or despotic behavior among individuals attempting to breed.

Application of multivariable search techniques to structural design optimization

NASA Technical Reports Server (NTRS)

Jones, R. T.; Hague, D. S.

1972-01-01

Multivariable optimization techniques are applied to a particular class of minimum weight structural design problems: the design of an axially loaded, pressurized, stiffened cylinder. Minimum weight designs are obtained by a variety of search algorithms: first- and second-order, elemental perturbation, and randomized techniques. An exterior penalty function approach to constrained minimization is employed. Some comparisons are made with solutions obtained by an interior penalty function procedure. In general, it would appear that an interior penalty function approach may not be as well suited to the class of design problems considered as the exterior penalty function approach. It is also shown that a combination of search algorithms will tend to arrive at an extremal design in a more reliable manner than a single algorithm. The effect of incorporating realistic geometrical constraints on stiffener cross-sections is investigated. A limited comparison is made between minimum weight cylinders designed on the basis of a linear stability analysis and cylinders designed on the basis of empirical buckling data. Finally, a technique for locating more than one extremal is demonstrated.

Exploring the extremely low surface brightness sky: distances to 23 newly discovered objects in Dragonfly fields

NASA Astrophysics Data System (ADS)

van Dokkum, Pieter

2016-10-01

We are obtaining deep, wide field images of nearby galaxies with the Dragonfly Telephoto Array. This telescope is optimized for low surface brightness imaging, and we are finding many low surface brightness objects in the Dragonfly fields. In Cycle 22 we obtained ACS imaging for 7 galaxies that we had discovered in a Dragonfly image of the galaxy M101. Unexpectedly, the ACS data show that only 3 of the galaxies are members of the M101 group, and the other 4 are very large Ultra Diffuse Galaxies (UDGs) at much greater distance. Building on our Cycle 22 program, here we request ACS imaging for 23 newly discovered low surface brightness objects in four Dragonfly fields centered on the galaxies NGC 1052, NGC 1084, NGC 3384, and NGC 4258. The immediate goals are to construct the satellite luminosity functions in these four fields and to constrain the number density of UDGs that are not in rich clusters. More generally, this complete sample of extremely low surface brightness objects provides the first systematic insight into galaxies whose brightness peaks at >25 mag/arcsec^2.

Recent Very Hot Summers in Northern Hemispheric Land Areas Measured by Wet Bulb Globe Temperature Will Be the Norm Within 20 Years

NASA Astrophysics Data System (ADS)

Li, Chao; Zhang, Xuebin; Zwiers, Francis; Fang, Yuanyuan; Michalak, Anna M.

2017-12-01

Wet bulb globe temperature (WBGT) accounts for the effect of environmental temperature and humidity on thermal comfort, and can be directly related to the ability of the human body to dissipate excess metabolic heat and thus avoid heat stress. Using WBGT as a measure of environmental conditions conducive to heat stress, we show that anthropogenic influence has very substantially increased the likelihood of extreme high summer mean WBGT in northern hemispheric land areas relative to the climate that would have prevailed in the absence of anthropogenic forcing. We estimate that the likelihood of summer mean WGBT exceeding the observed historical record value has increased by a factor of at least 70 at regional scales due to anthropogenic influence on the climate. We further estimate that, in most northern hemispheric regions, these changes in the likelihood of extreme summer mean WBGT are roughly an order of magnitude larger than the corresponding changes in the likelihood of extreme hot summers as simply measured by surface air temperature. Projections of future summer mean WBGT under the RCP8.5 emissions scenario that are constrained by observations indicate that by 2030s at least 50% of the summers will have mean WBGT higher than the observed historical record value in all the analyzed regions, and that this frequency of occurrence will increase to 95% by mid-century.

The NIR Ca ii triplet at low metallicity. Searching for extremely low-metallicity stars in classical dwarf galaxies

NASA Astrophysics Data System (ADS)

Starkenburg, E.; Hill, V.; Tolstoy, E.; González Hernández, J. I.; Irwin, M.; Helmi, A.; Battaglia, G.; Jablonka, P.; Tafelmeyer, M.; Shetrone, M.; Venn, K.; de Boer, T.

2010-04-01

The NIR Ca ii triplet absorption lines have proven to be an important tool for quantitative spectroscopy of individual red giant branch stars in the Local Group, providing a better understanding of metallicities of stars in the Milky Way and dwarf galaxies and thereby an opportunity to constrain their chemical evolution processes. An interesting puzzle in this field is the significant lack of extremely metal-poor stars, below [Fe/H] = -3, found in classical dwarf galaxies around the Milky Way using this technique. The question arises whether these stars are really absent, or if the empirical Ca ii triplet method used to study these systems is biased in the low-metallicity regime. Here we present results of synthetic spectral analysis of the Ca ii triplet, that is focused on a better understanding of spectroscopic measurements of low-metallicity giant stars. Our results start to deviate strongly from the widely-used and linear empirical calibrations at [Fe/H] < -2. We provide a new calibration for Ca ii triplet studies which is valid for -0.5 ≥ [Fe/H] ≥ -4. We subsequently apply this new calibration to current data sets and suggest that the classical dwarf galaxies are not so devoid of extremely low-metallicity stars as was previously thought. Using observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere, Chile proposal 171.B-0588.

Upper-extremity phocomelia reexamined: a longitudinal dysplasia.

PubMed

Goldfarb, Charles A; Manske, Paul R; Busa, Riccardo; Mills, Janith; Carter, Peter; Ezaki, Marybeth

2005-12-01

In contrast to longitudinal deficiencies, phocomelia is considered a transverse, intercalated segmental dysplasia. Most patients demonstrate severe, but not otherwise classifiable, upper-extremity deformities, which usually cannot be placed into one of three previously described phocomelia groups. Additionally, these phocomelic extremities do not demonstrate true segmental deficits; the limb is also abnormal proximal and distal to the segmental defect. The purpose of this investigation was to present evidence that upper-extremity abnormalities in patients previously diagnosed as having phocomelia in fact represent a proximal continuum of radial or ulnar longitudinal dysplasia. The charts and radiographs of forty-one patients (sixty extremities) diagnosed as having upper-extremity phocomelia were reviewed retrospectively. On the basis of the findings on the radiographs, the disorders were categorized into three groups: (1) proximal radial longitudinal dysplasia, which was characterized by an absent proximal part of the humerus, a nearly normal distal part of the humerus, a completely absent radius, and a radial-sided hand dysplasia; (2) proximal ulnar longitudinal dysplasia, characterized by a short one-bone upper extremity that bifurcated distally and by severe hand abnormalities compatible with ulnar dysplasia; and (3) severe combined dysplasia, with type A characterized by an absence of the forearm segment (i.e., the radius and ulna) and type B characterized by absence of the arm and forearm (i.e., the hand attached to the thorax). Twenty-nine limbs in sixteen patients could be classified as having proximal radial longitudinal dysplasia. Systemic medical conditions such as thrombocytopenia-absent radius syndrome were common in those patients, but additional musculoskeletal conditions were rare. Twenty limbs in seventeen patients could be classified as having proximal ulnar longitudinal dysplasia. Associated musculoskeletal abnormalities, such as proximal femoral focal deficiency, were common in those patients. Eleven limbs in ten patients were identified as having severe combined dysplasia, which was type A in seven of them and type B in four. Four patients with severe combined dysplasia had congenital cardiac anomalies, and four had associated musculoskeletal abnormalities. Three of the four patients with the type-B disorder had a contralateral ulnar longitudinal dysplasia. We propose that cases previously classified as upper-extremity phocomelia represent a spectrum of severe longitudinal dysplasia, as none of the sixty extremities that we studied demonstrated a true intercalary deficiency. These findings have both developmental and genetic implications.

Radii and Orbits of Hot Jupiters

NASA Astrophysics Data System (ADS)

Wu, Yanqin

2011-09-01

Hot jupiters suffer extreme external (stellar) and internal (tidal, Ohmic and wind-power) heating. These lead to peculiar thermal evolution, which is potentially self-destrutive. For instance, the amount of energy deposited during tidal dissipation far exceeds the planets' binding energy. If this energy is mostly deposited in shallow layers, it does little damage to the planet. However, the presence of stellar insolation changes the picture, and Ohmic/wind-power heating further modifies the subsequent evolution of these jupiters. A diversity of planetary sizes results. We tie these thermodynamical processes together with the migration history of hot jupiters to explain the orbital distribution and physical radii of hot jupiters. Moreover, we constrain the location of tidal heating inside the planet.

Inverse lithography using sparse mask representations

NASA Astrophysics Data System (ADS)

Ionescu, Radu C.; Hurley, Paul; Apostol, Stefan

2015-03-01

We present a novel optimisation algorithm for inverse lithography, based on optimization of the mask derivative, a domain inherently sparse, and for rectilinear polygons, invertible. The method is first developed assuming a point light source, and then extended to general incoherent sources. What results is a fast algorithm, producing manufacturable masks (the search space is constrained to rectilinear polygons), and flexible (specific constraints such as minimal line widths can be imposed). One inherent trick is to treat polygons as continuous entities, thus making aerial image calculation extremely fast and accurate. Requirements for mask manufacturability can be integrated in the optimization without too much added complexity. We also explain how to extend the scheme for phase-changing mask optimization.

Are interpretations of ancient marine temperatures constrained by the presence of ancient marine organisms?

NASA Technical Reports Server (NTRS)

Valentine, J. W.

1985-01-01

The relationship between marine temperature and marine organisms is investigated. The adaptation of organisms to extreme temperatures is studied; it is observed that chemautotrophic and chemoheterotrophic prokaryotes adapt to 100 C, photoautotrophic prokaryotes to 73 C, and fungi to 60 C. The physiological and molecular factors related to thermal limits in organisms such as enzymes, lipids, or plasma membranes, are examined. Two types of thermal adaptations, resistance and capacity, are detected in organisms. Reasons for species distributions according to temperature barriers are proposed by Read (1967) and Bullock (1955) and are related to enzyme limits. The effects of an organism's composition on thermal stability is analyzed.

Solar rotation effects on the thermospheres of Mars and Earth.

PubMed

Forbes, Jeffrey M; Bruinsma, Sean; Lemoine, Frank G

2006-06-02

The responses of Earth's and Mars' thermospheres to the quasi-periodic (27-day) variation of solar flux due to solar rotation were measured contemporaneously, revealing that this response is twice as large for Earth as for Mars. Per typical 20-unit change in 10.7-centimeter radio flux (used as a proxy for extreme ultraviolet flux) reaching each planet, we found temperature changes of 42.0 +/- 8.0 kelvin and 19.2 +/- 3.6 kelvin for Earth and Mars, respectively. Existing data for Venus indicate values of 3.6 +/- 0.6 kelvin. Our observational result constrains comparative planetary thermosphere simulations and may help resolve existing uncertainties in thermal balance processes, particularly CO2 cooling.

Computer program for single input-output, single-loop feedback systems

NASA Technical Reports Server (NTRS)

1976-01-01

Additional work is reported on a completely automatic computer program for the design of single input/output, single loop feedback systems with parameter uncertainly, to satisfy time domain bounds on the system response to step commands and disturbances. The inputs to the program are basically the specified time-domain response bounds, the form of the constrained plant transfer function and the ranges of the uncertain parameters of the plant. The program output consists of the transfer functions of the two free compensation networks, in the form of the coefficients of the numerator and denominator polynomials, and the data on the prescribed bounds and the extremes actually obtained for the system response to commands and disturbances.

Linear analysis using secants for materials with temperature dependent nonlinear elastic modulus and thermal expansion properties

NASA Astrophysics Data System (ADS)

Pepi, John W.

2017-08-01

Thermally induced stress is readily calculated for linear elastic material properties using Hooke's law in which, for situations where expansion is constrained, stress is proportional to the product of the material elastic modulus and its thermal strain. When material behavior is nonlinear, one needs to make use of nonlinear theory. However, we can avoid that complexity in some situations. For situations in which both elastic modulus and coefficient of thermal expansion vary with temperature, solutions can be formulated using secant properties. A theoretical approach is thus presented to calculate stresses for nonlinear, neo-Hookean, materials. This is important for high acuity optical systems undergoing large temperature extremes.

Photometric Follow-up of Eclipsing Binary Candidates from KELT and Kepler

NASA Astrophysics Data System (ADS)

Garcia Soto, Aylin; Rodriguez, Joseph E.; Bieryla, Allyson; KELT survey

2018-01-01

Eclipsing binaries (EBs) are incredibly valuable, as they provide the opportunity to precisely measure fundamental stellar parameters without the need for stellar models. Therefore, we can use EBs to directly test stellar evolution models. Constraining the stellar properties of stars is important since they directly influence our understanding of any planets orbiting them. Using the Harvard University's Clay 0.4m telescope and Fred Lawrence Whipple Observatory’s 1.2m telescope on Mount Hopkins, Arizona, we conducted follow-up multi-band photometric observations of EB candidates from the Kilodegree Extremely Little Telescope (KELT) survey and the Kepler mission. We will present our follow-up observations and AstroImageJ analysis on these 5 EB systems.

The Ha Noi Expert Statement: recognition of maternal mental health in resource-constrained settings is essential for achieving the Millennium Development Goals.

PubMed

Fisher, Jane Rw; de Mello, Meena Cabral; Izutsu, Takashi; Tran, Tuan

2011-01-07

Mental health problems in women during pregnancy and after childbirth and their adverse consequences for child health and development have received sustained detailed attention in high-income countries. In contrast, evidence has only been generated more recently in resource-constrained settings.In June 2007 the United Nations Population Fund, the World Health Organization, the Key Centre for Women's Health in Society, a WHO Collaborating Centre for Women's Health and the Research and Training Centre for Community Development in Vietnam convened the first international expert meeting on maternal mental health and child health and development in resource-constrained settings. It aimed to appraise the evidence about the nature, prevalence and risks for common perinatal mental disorders in women; the consequences of these for child health and development and ameliorative strategies in these contexts.The substantial disparity in rates of perinatal mental disorders between women living in high- and low-income settings, suggests social rather than biological determinants. Risks in resource-constrained contexts include: poverty; crowded living situations; limited reproductive autonomy; unintended pregnancy; lack of empathy from the intimate partner; rigid gender stereotypes about responsibility for household work and infant care; family violence; poor physical health and discrimination. Development is adversely affected if infants lack day-to-day interactions with a caregiver who can interpret their cues, and respond effectively. Women with compromised mental health are less able to provide sensitive, responsive infant care. In resource-constrained settings infants whose mothers are depressed are less likely to thrive and to receive optimal care than those whose mothers are well.The meeting outcome is the Hanoi Expert Statement (Additional file 1). It argues that the Millennium Development Goals to improve maternal health, reduce child mortality, promote gender equality and empower women, achieve universal primary education and eradicate extreme poverty and hunger cannot be attained without a specific focus on women's mental health. It was co-signed by the international expert group; relevant WHO and UNFPA departmental representatives and international authorities. They concur that social rather than medical responses are required. Improvements in maternal mental health require a cross-sectoral response addressing poverty reduction, women's rights, social protection, violence prevention, education and gender in addition to health.

Suppression of severe achondroplasia with developmental delay and acanthosis nigricans by the p.Thr651Pro mutation.

PubMed

Manickam, Kandamurugu; Donoghue, Daniel J; Meyer, April N; Snyder, Pamela J; Prior, Thomas W

2014-01-01

Severe achondroplasia with developmental delay and acanthosis nigricans (SADDAN) is an extremely rare severe skeletal dysplasia characterized by significant developmental delay, brain structural abnormalities, hearing loss, and acanthosis nigricans. The disorder is the result of a single missense mutation at codon 650 (p.Lys650Met) in the fibroblast growth factor receptor 3 gene (FGFR3). We describe a child who initially presented with a mild achondroplasia or hypochondroplasia like phenotype. Molecular analysis of the FGFR3 gene showed the common SADDAN mutation and a second novel mutation at codon 651 (p.Thr651Pro). Both mutations were shown to occur on the same allele (cis) and de novo. Transient transfection studies with FGFR3 double mutant constructs show that the p.Thr651Pro mutation causes a dramatic decrease in constitutive receptor kinase activity than that observed by the p.Lys650Met mutation. Our data suggest that the molecular effect by the p.Thr651Pro is to elicit a conformational change that decreases the FGFR3 tyrosine kinase activity, which is constitutively activated by the SADDAN mutation. Due to the inheritance of both a gain-of-function and a loss-of-function mutation, we conclude that a reduction of constitutive activation caused the milder skeletal phenotype. Although the occurrence of double mutations are expected to be rare, the presence of other FGFR3 modifiers may be responsible for some of the clinically discrepant skeletal dysplasia cases. © 2013 Wiley Periodicals, Inc.

The invasive Asian tiger mosquito Aedes albopictus (Diptera: Culicidae) in Germany: Local reproduction and overwintering.

PubMed

Walther, D; Scheuch, D E; Kampen, H

2017-02-01

Within the framework of a German mosquito monitoring programme, the 'Mueckenatlas' (mosquito atlas) has been established as an instrument of citizen participation in mosquito mapping. In 2015, a strikingly large number of Aedes albopictus, which had not been considered established in Germany, was submitted. Three of six collection sites showed local reproduction, with demonstration of developmental stages over three months at two sites. The third populated site was checked only once in October. Developmental stages of Ae. albopictus were found again at these three sites in spring 2016, including one site in southeastern Germany where reproduction had already been documented in 2014. Although population genetic analyses performed on specimens collected at the latter locality in 2014 and 2015 did not provide proof for hibernation, the finding of developmental stages at this and two other very same sites as in the year before and at very early times in the season strongly suggest accomplished overwintering of Ae. albopictus in Germany. Obviously, the second extremely mild winter in Germany in a row and ongoing adaptation of Ae. albopictus to the temperate European climate allow the species to push northwards from endemic regions in the south. Due to the vector competence of Ae. albopictus for numerous pathogens, including dengue, chikungunya and Zika viruses, action should be taken immediately after the detection of local reproduction to eliminate the populations. Copyright © 2016 Elsevier B.V. All rights reserved.

Development of hemipenes in the ball python snake Python regius.

PubMed

Leal, Francisca; Cohn, Martin J

2015-01-01

Within amniotes, external copulatory organs have undergone extensive morphological diversification. One of the most extreme examples is squamate (lizards and snakes) hemipenes, which are paired copulatory organs that extend from the lateral margins of the cloaca. Here, we describe the development of hemipenes in a basal snake, the ball python (Python regius). Snake hemipenes arise as a pair of lateral swellings on either side of the caudal part of the cloaca, and these paired outgrowths persist to form the left and right hemipenes. In non-squamate amniotes, external genitalia form from paired swellings that arise on the anterior side of the cloaca, which then fuse medially to form a single genital tubercle, the anlagen of the penis or clitoris. Whereas in non-squamate amniotes, Sonic hedgehog (Shh)-expressing cells of the cloacal endoderm form the urethral or sulcus epithelium and are required for phallus outgrowth, the hemipenes of squamates lack an endodermal contribution, and the sulcus does not express Shh. Thus, snake hemipenes differ from the genital tubercles of non-squamate amniotes both in their embryonic origins and in at least part of patterning mechanisms, which raises the possibility that hemipenes may not be direct homologs of the unpaired amniote penis. Nonetheless, we find that some developmental genes show similar expression patterns in snake hemipenes buds and non-squamate genital tubercles, suggesting that homologous developmental mechanisms are involved in aspects of external genital development across amniotes, even when these structures may have different developmental origins and may have arisen independently during evolution.

Urban land use and geohazards in the Itanagar Capital city, Arunachal Pradesh, India: Need for geoethics in urban disaster resilience governance in a changing climate

NASA Astrophysics Data System (ADS)

Acharjee, Swapna

2013-04-01

The capital city, Itanagar, Arunachal Pradesh, India is exposed to the multiple geohazards as the city is located in the region which experiences extreme physical phenomenon due to changing climate in the tectonically active North-Eastern Himalayas. The geohazards in Itanagar includes landslides, floods, soil erosion and earthquakes. The high decadal growth rate of 111.36% in 1991-2001 census has brought in many challenges with respect to the capital city developmental planning. Due to rapid and haphazard growth in urban land use the people residing in the city are gradually becoming more vulnerable to the geohazards in the past decades. The city condition at present has raised issues of grave concern related to effective hazard management. It is observed that geoscientific approach is violated at many places in the urban developmental activities along the central spine, the National Highway-52A of the capital city. There is an urgent need of geoscientists to apprise the urban populace about land suitability and stability in terms of rock types, soil, slope, geomorphology, groundwater condition etc. and the vulnerability of the existing urban land use to landslides, flood, soil erosion and earthquakes. In this paper major issue, critical issues and elements at risk are discussed in the context of ethics in geohazard management and developmental planning for urban disaster resilience governance in a changing climate.

Rediscovering the chick embryo as a model to study retinal development

PubMed Central

2012-01-01

The embryonic chick occupies a privileged place among animal models used in developmental studies. Its rapid development and accessibility for visualization and experimental manipulation are just some of the characteristics that have made it a vertebrate model of choice for more than two millennia. Until a few years ago, the inability to perform genetic manipulations constituted a major drawback of this system. However, the completion of the chicken genome project and the development of techniques to manipulate gene expression have allowed this classic animal model to enter the molecular age. Such techniques, combined with the embryological manipulations that this system is well known for, provide a unique toolkit to study the genetic basis of neural development. A major advantage of these approaches is that they permit targeted gene misexpression with extremely high spatiotemporal resolution and over a large range of developmental stages, allowing functional analysis at a level, speed and ease that is difficult to achieve in other systems. This article provides a general overview of the chick as a developmental model focusing more specifically on its application to the study of eye development. Special emphasis is given to the state of the art of the techniques that have made gene gain- and loss-of-function studies in this model a reality. In addition, we discuss some methodological considerations derived from our own experience that we believe will be beneficial to researchers working with this system. PMID:22738172

The evolution of 'bricolage'.

PubMed

Duboule, D; Wilkins, A S

1998-02-01

The past ten years of developmental genetics have revealed that most of our genes are shared by other species throughout the animal kingdom. Consequently, animal diversity might largely rely on the differential use of the same components, either at the individual level through divergent functional recruitment, or at a more integrated level, through their participation in various genetic networks. Here, we argue that this inevitably leads to an increase in the interdependency between functions that, in turn, influences the degree to which novel variations can be tolerated. In this 'transitionist' scheme, evolution is neither inherently gradualist nor punctuated but, instead, progresses from one extreme to the other, together with the increased complexity of organisms.

Kinematic constraints associated with the acquisition of overarm throwing part II: upper extremity actions.

PubMed

Stodden, David F; Langendorfer, Stephen J; Fleisig, Glenn S; Andrews, James R

2006-12-01

The purposes of this study were to: (a) examine the differences within 11 specific kinematic variables and an outcome measure (ball velocity) associated with component developmental levels of humerus and forearm action (Roberton & Halverson, 1984), and (b) if the differences in kinematic variables were significantly associated with the differences in component levels, determine potential kinematic constraints associated with skilled throwing acquisition. Significant differences among component levels in five of six humerus kinematic variables (p <.01) and all five forearm kinematic variables (p < .01) were identified using multivariate analysis of variance. These kinematic variables represent potential control parameters and, therefore, constraints on overarm throwing acquisition.

Using medaka embryos as a model system to study biological effects of the electromagnetic fields on development and behavior.

PubMed

Lee, Wenjau; Yang, Kun-Lin

2014-10-01

The electromagnetic fields (EMFs) of anthropogenic origin are ubiquitous in our environments. The health hazard of extremely low frequency and radiofrequency EMFs has been investigated for decades, but evidence remains inconclusive, and animal studies are urgently needed to resolve the controversies regarding developmental toxicity of EMFs. Furthermore, as undersea cables and technological devices are increasingly used, the lack of information regarding the health risk of EMFs to aquatic organisms needs to be addressed. Medaka embryos (Oryzias latipes) have been a useful tool to study developmental toxicity in vivo due to their optical transparency. Here we explored the feasibility of using medaka embryos as a model system to study biological effects of EMFs on development. We also used a white preference test to investigate behavioral consequences of the EMF developmental toxicity. Newly fertilized embryos were randomly assigned to four groups that were exposed to an EMF with 3.2kHz at the intensity of 0.12, 15, 25, or 60µT. The group exposed to the background 0.12µT served as the control. The embryos were exposed continually until hatch. They were observed daily, and the images were recorded for analysis of several developmental endpoints. Four days after hatching, the hatchlings were tested with the white preference test for their anxiety-like behavior. The results showed that embryos exposed to all three levels of the EMF developed significantly faster. The endpoints affected included the number of somites, eye width and length, eye pigmentation density, midbrain width, head growth, and the day to hatch. In addition, the group exposed to the EMF at 60µT exhibited significantly higher levels of anxiety-like behavior than the other groups did. In conclusion, the EMF tested in this study accelerated embryonic development and heightened anxiety-like behavior. Our results also demonstrate that the medaka embryo is a sensitive and cost-efficient in vivo model system to study developmental toxicity of EMFs. Copyright © 2014 Elsevier Inc. All rights reserved.

Plant developmental responses to climate change.

PubMed

Gray, Sharon B; Brady, Siobhan M

2016-11-01

Climate change is multi-faceted, and includes changing concentrations of greenhouse gases in the atmosphere, rising temperatures, changes in precipitation patterns, and increasing frequency of extreme weather events. Here, we focus on the effects of rising atmospheric CO 2 concentrations, rising temperature, and drought stress and their interaction on plant developmental processes in leaves, roots, and in reproductive structures. While in some cases these responses are conserved across species, such as decreased root elongation, perturbation of root growth angle and reduced seed yield in response to drought, or an increase in root biomass in shallow soil in response to elevated CO 2 , most responses are variable within and between species and are dependent on developmental stage. These variable responses include species-specific thresholds that arrest development of reproductive structures, reduce root growth rate and the rate of leaf initiation and expansion in response to elevated temperature. Leaf developmental responses to elevated CO 2 vary by cell type and by species. Variability also exists between C 3 and C 4 species in response to elevated CO 2 , especially in terms of growth and seed yield stimulation. At the molecular level, significantly less is understood regarding conservation and variability in molecular mechanisms underlying these traits. Abscisic acid-mediated changes in cell wall expansion likely underlie reductions in growth rate in response to drought, and changes in known regulators of flowering time likely underlie altered reproductive transitions in response to elevated temperature and CO 2 . Genes that underlie most other organ or tissue-level responses have largely only been identified in a single species in response to a single stress and their level of conservation is unknown. We conclude that there is a need for further research regarding the molecular mechanisms of plant developmental responses to climate change factors in general, and that this lack of data is particularly prevalent in the case of interactive effects of multiple climate change factors. As future growing conditions will likely expose plants to multiple climate change factors simultaneously, with a sum negative influence on global agriculture, further research in this area is critical. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Embodied social interaction constitutes social cognition in pairs of humans: a minimalist virtual reality experiment.

PubMed

Froese, Tom; Iizuka, Hiroyuki; Ikegami, Takashi

2014-01-14

Scientists have traditionally limited the mechanisms of social cognition to one brain, but recent approaches claim that interaction also realizes cognitive work. Experiments under constrained virtual settings revealed that interaction dynamics implicitly guide social cognition. Here we show that embodied social interaction can be constitutive of agency detection and of experiencing another's presence. Pairs of participants moved their "avatars" along an invisible virtual line and could make haptic contact with three identical objects, two of which embodied the other's motions, but only one, the other's avatar, also embodied the other's contact sensor and thereby enabled responsive interaction. Co-regulated interactions were significantly correlated with identifications of the other's avatar and reports of the clearest awareness of the other's presence. These results challenge folk psychological notions about the boundaries of mind, but make sense from evolutionary and developmental perspectives: an extendible mind can offload cognitive work into its environment.

The Developmental Dynamics of Terrorist Organizations

PubMed Central

Clauset, Aaron; Gleditsch, Kristian Skrede

2012-01-01

We identify robust statistical patterns in the frequency and severity of violent attacks by terrorist organizations as they grow and age. Using group-level static and dynamic analyses of terrorist events worldwide from 1968–2008 and a simulation model of organizational dynamics, we show that the production of violent events tends to accelerate with increasing size and experience. This coupling of frequency, experience and size arises from a fundamental positive feedback loop in which attacks lead to growth which leads to increased production of new attacks. In contrast, event severity is independent of both size and experience. Thus larger, more experienced organizations are more deadly because they attack more frequently, not because their attacks are more deadly, and large events are equally likely to come from large and small organizations. These results hold across political ideologies and time, suggesting that the frequency and severity of terrorism may be constrained by fundamental processes. PMID:23185267

Energy conversion approaches and materials for high-efficiency photovoltaics.

PubMed

Green, Martin A; Bremner, Stephen P

2016-12-20

The past five years have seen significant cost reductions in photovoltaics and a correspondingly strong increase in uptake, with photovoltaics now positioned to provide one of the lowest-cost options for future electricity generation. What is becoming clear as the industry develops is that area-related costs, such as costs of encapsulation and field-installation, are increasingly important components of the total costs of photovoltaic electricity generation, with this trend expected to continue. Improved energy-conversion efficiency directly reduces such costs, with increased manufacturing volume likely to drive down the additional costs associated with implementing higher efficiencies. This suggests the industry will evolve beyond the standard single-junction solar cells that currently dominate commercial production, where energy-conversion efficiencies are fundamentally constrained by Shockley-Queisser limits to practical values below 30%. This Review assesses the overall prospects for a range of approaches that can potentially exceed these limits, based on ultimate efficiency prospects, material requirements and developmental outlook.

Embodied social interaction constitutes social cognition in pairs of humans: A minimalist virtual reality experiment

PubMed Central

Froese, Tom; Iizuka, Hiroyuki; Ikegami, Takashi

2014-01-01

Scientists have traditionally limited the mechanisms of social cognition to one brain, but recent approaches claim that interaction also realizes cognitive work. Experiments under constrained virtual settings revealed that interaction dynamics implicitly guide social cognition. Here we show that embodied social interaction can be constitutive of agency detection and of experiencing another's presence. Pairs of participants moved their “avatars” along an invisible virtual line and could make haptic contact with three identical objects, two of which embodied the other's motions, but only one, the other's avatar, also embodied the other's contact sensor and thereby enabled responsive interaction. Co-regulated interactions were significantly correlated with identifications of the other's avatar and reports of the clearest awareness of the other's presence. These results challenge folk psychological notions about the boundaries of mind, but make sense from evolutionary and developmental perspectives: an extendible mind can offload cognitive work into its environment. PMID:24419102

Flowering time and seed dormancy control use external coincidence to generate life history strategy.

PubMed

Springthorpe, Vicki; Penfield, Steven

2015-03-31

Climate change is accelerating plant developmental transitions coordinated with the seasons in temperate environments. To understand the importance of these timing advances for a stable life history strategy, we constructed a full life cycle model of Arabidopsis thaliana. Modelling and field data reveal that a cryptic function of flowering time control is to limit seed set of winter annuals to an ambient temperature window which coincides with a temperature-sensitive switch in seed dormancy state. This coincidence is predicted to be conserved independent of climate at the expense of flowering date, suggesting that temperature control of flowering time has evolved to constrain seed set environment and therefore frequency of dormant and non-dormant seed states. We show that late flowering can disrupt this bet-hedging germination strategy. Our analysis shows that life history modelling can reveal hidden fitness constraints and identify non-obvious selection pressures as emergent features.

Sex differences in the developing brain as a source of inherent risk.

PubMed

McCarthy, Margaret M

2016-12-01

Brain development diverges in males and females in response to androgen production by the fetal testis. This sexual differentiation of the brain occurs during a sensitive window and induces enduring neuroanatomical and physiological changes that profoundly impact behavior. What we know about the contribution of sex chromosomes is still emerging, highlighting the need to integrate multiple factors into understanding sex differences, including the importance of context. The cellular mechanisms are best modeled in rodents and have provided both unifying principles and surprising specifics. Markedly distinct signaling pathways direct differentiation in specific brain regions, resulting in mosaicism of relative maleness, femaleness, and sameness through-out the brain, while canalization both exaggerates and constrains sex differences. Non-neuronal cells and inflammatory mediators are found in greater number and at higher levels in parts of male brains. This higher baseline of inflammation is speculated to increase male vulnerability to developmental neuropsychiatric disorders that are triggered by inflammation.

Systems-based practice in graduate medical education: systems thinking as the missing foundational construct.

PubMed

Colbert, Colleen Y; Ogden, Paul E; Ownby, Allison R; Bowe, Constance

2011-04-01

Since 2001, residencies have struggled with teaching and assessing systems-based practice (SBP). One major obstacle may be that the competency alone is not sufficient to support assessment. We believe the foundational construct underlying SBP is systems thinking, absent from the current Accreditation Council for Graduate Medical Education competency language. Systems thinking is defined as the ability to analyze systems as a whole. The purpose of this article is to describe psychometric issues that constrain assessment of SBP and elucidate the role of systems thinking in teaching and assessing SBP. Residency programs should incorporate systems thinking models into their curricula. Trainees should be taught to understand systems at an abstract level, in order to analyze their own healthcare systems, and participate in quality and patient safety activities. We suggest that a developmental trajectory for systems thinking be developed, similar to the model described by Dreyfus and Dreyfus.

Developmental flexibility in the age of globalization: autonomy and identity development among immigrant adolescents.

PubMed

Fuligni, Andrew J; Tsai, Kim M

2015-01-03

The socioeconomic and cultural changes that result from an increasingly interconnected world have been speculated to have important implications for the nature of adolescent development. Unfortunately, the historical time necessary for these changes to take place means that definitive research on the impact of globalization necessarily will be slow in forthcoming. Adolescents from immigrant families, however, already experience the social and cultural shifts thought to typify globalization, and an analysis of their experiences could shed light on what to expect as existing national barriers become more permeable. The value of flexibility in the face of great social and cultural change appears to be the dominant theme from research on immigrant youth, although that flexibility can be constrained by socioeconomic, ethnic, and racial stratification systems in host societies. This review highlights the implications of these findings for what may lie ahead for teenagers as globalization continues to expand.

Infant Statistical Learning

PubMed Central

Saffran, Jenny R.; Kirkham, Natasha Z.

2017-01-01

Perception involves making sense of a dynamic, multimodal environment. In the absence of mechanisms capable of exploiting the statistical patterns in the natural world, infants would face an insurmountable computational problem. Infant statistical learning mechanisms facilitate the detection of structure. These abilities allow the infant to compute across elements in their environmental input, extracting patterns for further processing and subsequent learning. In this selective review, we summarize findings that show that statistical learning is both a broad and flexible mechanism (supporting learning from different modalities across many different content areas) and input specific (shifting computations depending on the type of input and goal of learning). We suggest that statistical learning not only provides a framework for studying language development and object knowledge in constrained laboratory settings, but also allows researchers to tackle real-world problems, such as multilingualism, the role of ever-changing learning environments, and differential developmental trajectories. PMID:28793812

Spectrum of gross motor function in extremely low birth weight children with cerebral palsy at 18 months of age.

PubMed

Vohr, Betty R; Msall, Michael E; Wilson, Dee; Wright, Linda L; McDonald, Scott; Poole, W Kenneth

2005-07-01

The purpose of this study was to evaluate the relationship between cerebral palsy (CP) diagnoses as measured by the topographic distribution of the tone abnormality with level of function on the Gross Motor Function Classification System (GMFCS) and developmental performance on the Bayley Scales of Infant Development II (BSID-II). It was hypothesized that (1) the greater the number of limbs involved, the higher the GMFCS and the lower the BSID-II Motor Scores and (2) there would be a spectrum of function and skill achievement on the GMFCS and BSID-II Motor Scores for children in each of the CP categories. A multicenter, longitudinal cohort study was conducted of 1860 extremely low birth weight (ELBW) infants who were born between August 1, 1995 and February 1, 1998, and evaluated at 18 to 22 months' corrected age. Children were categorized into impairment groups on the basis of the typography of neurologic findings: spastic quadriplegia, triplegia, diplegia, hemiplegia, monoplegia, hypotonic and/or athetotic CP, other abnormal neurologic findings, and normal. The neurologic category then was compared with GMFCS level and BSID-II Motor Scores. A total of 282 (15.2%) of the 1860 children evaluated had CP. Children with more limbs involved had more abnormal GMFCS levels and lower BSID-II scores, reflecting more severe functional limitations. However, for each CP diagnostic category, there was a spectrum of gross motor functional levels and BSID-II scores. Although more than 1 (26.6%) in 4 of the children with CP had moderate to severe gross motor functional impairment, 1 (27.6%) in 4 had motor functional skills that allowed for ambulation. Given the range of gross motor skill outcomes for specific types of CP, the GMFCS is a better indicator of gross motor functional impairment than the traditional categorization of CP that specifies the number of limbs with neurologic impairment. The neurodevelopmental assessment of young children is optimized by combining a standard neurologic examination with measures of gross and fine motor function (GMFCS and Bayley Psychomotor Developmental Index). Additional studies to examine longer term functional motor and adaptive-functional developmental skills are required to devise strategies that delineate therapies to optimize functional performance.

The Relationship of Maternal Prepregnancy Body Mass Index and Pregnancy Weight Gain to Neurocognitive Function at Age 10 Years among Children Born Extremely Preterm.

PubMed

Jensen, Elizabeth T; van der Burg, Jelske W; O'Shea, Thomas M; Joseph, Robert M; Allred, Elizabeth N; Heeren, Tim; Leviton, Alan; Kuban, Karl C K

2017-08-01

To assess the association between maternal prepregnancy body mass index and adequacy of pregnancy weight gain in relation to neurocognitive function in school-aged children born extremely preterm. Study participants were 535 ten-year-old children enrolled previously in the prospective multicenter Extremely Low Gestational Age Newborns cohort study who were products of singleton pregnancies. Soon after delivery, mothers provided information about prepregnancy weight. Prepregnancy body mass index and adequacy of weight gain were characterized based on this information. Children underwent a neurocognitive evaluation at 10 years of age. Maternal prepregnancy obesity was associated with increased odds of a lower score for Differential Ability Scales-II Verbal IQ, for Developmental Neuropsychological Assessment-II measures of processing speed and visual fine motor control, and for Wechsler Individual Achievement Test-III Spelling. Children born to mothers who gained an excessive amount of weight were at increased odds of a low score on the Oral and Written Language Scales Oral Expression assessment. Conversely, children whose mother did not gain an adequate amount of weight were at increased odds of a lower score on the Oral and Written Language Scales Oral Expression and Wechsler Individual Achievement Test-III Word Reading assessments. In this cohort of infants born extremely preterm, maternal obesity was associated with poorer performance on some assessments of neurocognitive function. Our findings are consistent with the observational and experimental literature and suggest that opportunities may exist to mitigate risk through education and behavioral intervention before pregnancy. Copyright © 2017 Elsevier Inc. All rights reserved.

Intra-arterial intervention chemotherapy for sarcoma and cancerous ulcer via an implanted pump.

PubMed

Liu, Cheng; Cui, Qiu; Guo, Jun; Li, Dingfeng; Zeng, Yanjun

2014-04-01

To observe the efficacy of intra-arterial chemotherapy with subcutaneously implanted pump for soft tissue sarcoma in extremities and cancerous ulcer. 31 patients with ulcerative skin squamous cell carcinoma or sarcoma in extremities who received treatment during the period from July 2003 to November 2011 at our hospital were recruited, including 15 male and 16 female patients, aging between 14 and 83 with average age of 49 years old. 10 patients had tumor in upper extremities and 21 patients in lower extremities. The pathological types of studied cases include 9 cases with skin squamous cell carcinoma, 6 cases with synovial sarcoma, 5 cases with malignant fibrous histiocytoma, 3 cases with liposarcoma, 3 cases with osteosarcoma, 2 cases with malignant melanoma, 2 cases with epidermoid sarcoma, and 1 case with protuberans. The main symptoms of cancerous ulcer were pain, infection and hemorrhage; All the studied patients were administrated with cisplatin and doxorubicin by intra-arterial chemotherapy pump, and the patients with squamous cell carcinoma were additionally applied with bleomycin and patients with malignant melanoma were additionally applied with dacarbazine. The chemotherapy efficiency was observed after at 3 cycles of intra-arterial chemotherapy. The total remission rate of pain (RR) was 87 %, and total remission rate of ulcer cicatrization (RR) was 71 %, with ulcer cicatrizing spontaneously in 9 cases and obvious homeostasis in 5 cases with bleeding ulcers. 19 patients underwent surgery after chemotherapy, in which 16 cases had limb-salvage surgery and 3 cases underwent lower leg amputation after chemotherapy, and 3 patients out of 16 cases had local recurrence (19 %). The subcutaneous intra-arterial targeting chemotherapy could be applied to treat refractory sarcoma and cancerous ulcer in extremities to significantly increase the chemotherapeutic concentration at tumor area so as to effectively constrain the tumor rupture induced main symptoms including pain, infection and bleeding, which would help to make a decreased blood supplied and well defined tumor boundary to finally decrease the recurrence rate.

Reconstructing extreme AMOC events through nudging of the ocean surface: a perfect model approach

NASA Astrophysics Data System (ADS)

Ortega, Pablo; Guilyardi, Eric; Swingedouw, Didier; Mignot, Juliette; Nguyen, Sébastien

2017-11-01

While the Atlantic Meridional Overturning Circulation (AMOC) is thought to be a crucial component of the North Atlantic climate, past changes in its strength are challenging to quantify, and only limited information is available. In this study, we use a perfect model approach with the IPSL-CM5A-LR model to assess the performance of several surface nudging techniques in reconstructing the variability of the AMOC. Special attention is given to the reproducibility of an extreme positive AMOC peak from a preindustrial control simulation. Nudging includes standard relaxation techniques towards the sea surface temperature and salinity anomalies of this target control simulation, and/or the prescription of the wind-stress fields. Surface nudging approaches using standard fixed restoring terms succeed in reproducing most of the target AMOC variability, including the timing of the extreme event, but systematically underestimate its amplitude. A detailed analysis of the AMOC variability mechanisms reveals that the underestimation of the extreme AMOC maximum comes from a deficit in the formation of the dense water masses in the main convection region, located south of Iceland in the model. This issue is largely corrected after introducing a novel surface nudging approach, which uses a varying restoring coefficient that is proportional to the simulated mixed layer depth, which, in essence, keeps the restoring time scale constant. This new technique substantially improves water mass transformation in the regions of convection, and in particular, the formation of the densest waters, which are key for the representation of the AMOC extreme. It is therefore a promising strategy that may help to better constrain the AMOC variability and other ocean features in the models. As this restoring technique only uses surface data, for which better and longer observations are available, it opens up opportunities for improved reconstructions of the AMOC over the last few decades.

Constraining relationships between rainfall and landsliding with satellite derived rainfall measurements and landslide inventories.

NASA Astrophysics Data System (ADS)

Marc, Odin; Malet, Jean-Philippe; Stumpf, Andre; Gosset, Marielle

2017-04-01

In mountainous and hilly regions, landslides are an important source of damage and fatalities. Landsliding correlates with extreme rainfall events and may increase with climate change. Still, how precipitation drives landsliding at regional scales is poorly understood quantitatively in part because constraining simultaneously landsliding and rainfall across large areas is challenging. By combining optical images acquired from satellite observation platforms and rainfall measurements from satellite constellations we are building a database of landslide events caused by with single storm events. We present results from storm-induced landslides from Brazil, Taiwan, Micronesia, Central America, Europe and the USA. We present scaling laws between rainfall metrics derived by satellites (total rainfall, mean intensity, antecedent rainfall, ...) and statistical descriptors of landslide events (total area and volume, size distribution, mean runout, ...). Total rainfall seems to be the most important parameter driving non-linearly the increase in total landslide number, and area and volume. The maximum size of bedrock landslides correlates with the total number of landslides, and thus with total rainfall, within the limits of available topographic relief. In contrast, the power-law scaling exponent of the size distribution, controlling the relative abundance of small and large landslides, appears rather independent of the rainfall metrics (intensity, duration and total rainfall). These scaling laws seem to explain both the intra-storm pattern of landsliding, at the scale of satellite rainfall measurements ( 25kmx25km), and the different impacts observed for various storms. Where possible, we evaluate the limits of standard rainfall products (TRMM, GPM, GSMaP) by comparing them to in-situ data. Then we discuss how slope distribution and other geomorphic factors (lithology, soil presence,...) modulate these scaling laws. Such scaling laws at the basin scale and based only on a-priori information (topography, lithology, …) and rainfall metrics available from meteorological forecast may allow to better anticipate and mitigates landsliding associated with extreme rainfall events.

Dust models post-Planck: constraining the far-infrared opacity of dust in the diffuse interstellar medium

NASA Astrophysics Data System (ADS)

Fanciullo, L.; Guillet, V.; Aniano, G.; Jones, A. P.; Ysard, N.; Miville-Deschênes, M.-A.; Boulanger, F.; Köhler, M.

2015-08-01

Aims: We compare the performance of several dust models in reproducing the dust spectral energy distribution (SED) per unit extinction in the diffuse interstellar medium (ISM). We use our results to constrain the variability of the optical properties of big grains in the diffuse ISM, as published by the Planck collaboration. Methods: We use two different techniques to compare the predictions of dust models to data from the Planck HFI, IRAS, and SDSS surveys. First, we fit the far-infrared emission spectrum to recover the dust extinction and the intensity of the interstellar radiation field (ISRF). Second, we infer the ISRF intensity from the total power emitted by dust per unit extinction, and then predict the emission spectrum. In both cases, we test the ability of the models to reproduce dust emission and extinction at the same time. Results: We identify two issues. Not all models can reproduce the average dust emission per unit extinction: there are differences of up to a factor ~2 between models, and the best accord between model and observation is obtained with the more emissive grains derived from recent laboratory data on silicates and amorphous carbons. All models fail to reproduce the variations in the emission per unit extinction if the only variable parameter is the ISRF intensity: this confirms that the optical properties of dust are indeed variable in the diffuse ISM. Conclusions: Diffuse ISM observations are consistent with a scenario where both ISRF intensity and dust optical properties vary. The ratio of the far-infrared opacity to the V band extinction cross-section presents variations of the order of ~20% (40-50% in extreme cases), while ISRF intensity varies by ~30% (~60% in extreme cases). This must be accounted for in future modelling. Appendices are available in electronic form at http://www.aanda.org

Constraining the long-term climate reponse to stratospheric sulfate aerosols injection by the short-term volcanic climate response

NASA Astrophysics Data System (ADS)

Plazzotta, M.; Seferian, R.; Douville, H.; Kravitz, B.; Tilmes, S.; Tjiputra, J.

2016-12-01

Rising greenhouse gas emissions are leading to global warming and climate change, which will have multiple impacts on human society. Geoengineering methods like solar radiation management by stratospheric sulfate aerosols injection (SSA-SRM) aim at treating the symptoms of climate change by reducing the global temperature. Since a real-world testing cannot be implemented, Earth System Models (ESMs) are useful tools to assess the climate impacts of such geoengineering methods. However, coordinated simulations performed with the Geoengineering Model Intercomparison Project (GeoMIP) have shown that climate cooling in response to a continuous injection of 5Tg of SO2 per year under RCP45 future projection (the so-called G4 experiment) differs substantially between ESMs. Here, we employ a volcano analog approach to constrain the climate response in SSA-SRM geoengineering simulations across an ensemble of 10 ESMs. We identify an emergent relationship between the long-term cooling in responses to the mitigation of the clear-sky surface downwelling shortwave radiation (RSDSCS), and the short-term cooling related to the change in RSDSCS during the major tropical volcanic eruptions observed over the historical period (1850-2005). This relationship explains almost 80% of the multi-model spread. Combined with contemporary observations of the latest volcanic eruptions (satellite observations and model reanalyzes), this relationship provides a tight constraint on the climate impacts of SSA-SRM. We estimate that a continuous injection of SO2 aerosols into the stratosphere will reduce the global average temperature of continental land surface by 0.47 K per W m-2, impacting both hydrological and carbon cycles. Compared with the unconstrained ESMs ensemble (range from 0.32 to 0.92 K per W m-2 ), our estimate represents much higher confidence ways to assess the impacts of SSA-SRM on the climate while ruling the most extreme projections of the unconstrained ensemble extremely unlikely.

Thermoregulation and habitat selection in wood turtles Glyptemys insculpta: chasing the sun slowly.

PubMed

Dubois, Y; Blouin-Demers, G; Shipley, B; Thomas, D

2009-09-01

1. It is widely accepted that reptiles are able to regulate behaviourally their body temperature (T(b)), but this generalization is primarily based on studies of lizards and snakes in the temperate zone. Because the precision of T(b) regulation may vary considerably between taxa and over geographical ranges, studies of semi-terrestrial turtles in climatic extremes are relevant to the understanding of reptilian thermoregulation. 2. We studied thermoregulation in 21 free-ranging wood turtles (Glyptemys insculpta) at the northern limit of their range in Québec, using miniature data loggers to measure their internal T(b) and external temperature (T(ext)) continuously. We simultaneously recorded the available operative environmental temperature (T(e)) using 23 physical models randomly moved within each habitat type, and we located turtles using radiotelemetry. 3. The habitat used by wood turtles was thermally constraining and the target temperature (T(set)) was only achievable by basking during a short 5-h time window on sunny days. Wood turtles did show thermoregulatory abilities, as determined by the difference between turtle T(b) distribution and the null distribution of T(e) that resulted in T(b) closer to T(set). Although most individuals regulated their T(b) between 09.00 h and 16.00 h on sunny days, regulation was imprecise, as indicated by an index of thermoregulation precision (| T(b) - T(set) |). 4. The comparison of habitat use to availability indicated selection of open habitats. The hourly mean shuttling index (| T(ext) - T(b) |) suggested that turtles used sun/shade shuttling from 09.00 to 16.00 h to elevate their T(b) above mean T(e). 5. Based on laboratory respirometry data, turtles increased their metabolic rate by 20-26% over thermoconformity, and thus likely increased their energy gain which is assumed to be constrained by processing rate at climatic extremes.

Extreme Wolf-Rayet Galaxies with HST/COS: Understanding CIII] Emission in the Reionization Era

NASA Astrophysics Data System (ADS)

Stark, Daniel

2017-08-01

The first deep spectra of reionization-era galaxies have revealed strong UV nebular emission in high-ionization lines. This is in striking contrast to massive galaxies at lower redshifts, where emission from CIII], OIII], HeII, and CIV is rarely seen. These lines will likely be the only probe available for the most distant galaxies JWST will detect; but we are still unprepared to interpret them. Modeling predicts that intense UV nebular emission can only be produced below a tenth solar metallicity. However, recent HST/COS observations of local galaxies suggest that extreme populations of Wolf-Rayet (WR) stars, the hot exposed cores of massive O stars, may be capable of powering CIII] at metallicities as high as a half-solar. If these moderately metal-poor extreme WR galaxies are indeed a viable source of strong CIII] emission, our interpretation of CIII] detections in the reionization era will be dramatically altered; but we presently have sufficient UV coverage for only three examples. Here, we propose HST/COS G160M and G185M observations of an additional seven extreme WR galaxies spanning 0.5 dex in metallicity around half-solar. These observations will constrain the maximum CIII] equivalent width these galaxies can power as a function of metallicity. The moderate resolution gratings will robustly characterize the massive O and WR star populations, allowing us to link the nebular emission directly to the massive stars responsible. These data will provide a stringent test for the population synthesis codes which will be applied to JWST observations. Without this empirical baseline, our understanding of the most distant galaxies JWST finds will be severely limited.

[Extremely Low Birthweight Infants in Iceland. Health and development.].

PubMed

Georgsdóttir, Ingibjœrg; Sæmundsen, Evald; Símonardóttir, Ingibjœrg; Halldórsson, Jónas G; Egilson, Snæfríður Thorn; Leósdóttir, Thornóra; Ingvarsdóttir, Brynhildur; Sindrason, Einar; Dagbjartsson, Atli

2003-01-01

Survival of extremely low birthweight infants (BW<1000g) in Iceland has increased in recent years, especially since the availability of surfactant therapy for Respiratory Distress Syndrome of Prematurity. This study was part of a geographically defined national study on survival, health, development and longterm outcome of extremely low birthweight (ELBW) infants in Iceland focusing on health, development and disabilities with reference to a control group. Information from the National Birth Registry on births in Iceland of ELBW infants weighing 500-999g was collected in two periods 1982-90 and 1991-95, before and after surfactant therapy became available. Information on pregnancy, birth, diseases in the newborn period and later health problems was collected from hospital records. The ELBW infants born in 1991-95 and matched control children were enrolled to a prospective study on longterm health and development. The children undervent medical examinations and developmental testing at 5 years of age in 1996-2001. Comparison was made between the two groups of ELBW infants and between ELBW infants and control children born in 1991-95. In 1982-90 the longterm survival of ELBW infants at 5 years of age was 22% and 52% in 1991-95. In both periods 1982-90 and 1991-95 similar data was found on ELBW infants regarding mothers health, pregnancy, birth and neonatal period. Difference was found in maternal age being significantly higher (p=0.02) and significally more deliveries by cesarian section (p=0.02) in the latter period. The two groups of ELBW infants were similar regarding sex, birthweight and diseases in the newborn period. Comparison between 35 ELBW infants and 55 control children born 1991-95 showed that significantly more mothers of ELBW children smoked during pregnancy (p=0.003) and suffered from various diseases (p=0.001). More ELBW children were born by cesarian section (p=0.001) than control children and their parents reported more longterm health problems regarding astma (p=0.001), convulsions (p=0.001), difficulties in swallowing (p=0.001) and weight gaining (p=0.005). At five years of age significantly more ELBW children born in 1991-95 compared to control children had abnormal general physical examination (p

Climate change impacts on tropical cyclones and extreme sea levels in the South Pacific — A regional assessment

NASA Astrophysics Data System (ADS)

Walsh, Kevin J. E.; McInnes, Kathleen L.; McBride, John L.

2012-01-01

This paper reviews the current understanding of the effect of climate change on extreme sea levels in the South Pacific region. This region contains many locations that are vulnerable to extreme sea levels in the current climate, and projections indicate that this vulnerability will increase in the future. The recent publication of authoritative statements on the relationship between global warming and global sea level rise, tropical cyclones and the El Niño-Southern Oscillation phenomenon has motivated this review. Confident predictions of global mean sea level rise are modified by regional differences in the steric (density-related) component of sea level rise and changing gravitational interactions between the ocean and the ice sheets which affect the regional distribution of the eustatic (mass-related) contribution to sea level rise. The most extreme sea levels in this region are generated by tropical cyclones. The intensity of the strongest tropical cyclones is likely to increase, but many climate models project a substantial decrease in tropical cyclone numbers in this region, which may lead to an overall decrease in the total number of intense tropical cyclones. This projection, however, needs to be better quantified using improved high-resolution climate model simulations of tropical cyclones. Future changes in ENSO may lead to large regional variations in tropical cyclone incidence and sea level rise, but these impacts are also not well constrained. While storm surges from tropical cyclones give the largest sea level extremes in the parts of this region where they occur, other more frequent high sea level events can arise from swell generated by distant storms. Changes in wave climate are projected for the tropical Pacific due to anthropogenically-forced changes in atmospheric circulation. Future changes in sea level extremes will be caused by a combination of changes in mean sea level, regional sea level trends, tropical cyclone incidence and wave climate. Recommendations are given for research to increase understanding of the response of these factors to climate change. Implications of the results for adaptation research are also discussed.

Geometrically constrained kinematic global navigation satellite systems positioning: Implementation and performance

NASA Astrophysics Data System (ADS)

Asgari, Jamal; Mohammadloo, Tannaz H.; Amiri-Simkooei, Ali Reza

2015-09-01

GNSS kinematic techniques are capable of providing precise coordinates in extremely short observation time-span. These methods usually determine the coordinates of an unknown station with respect to a reference one. To enhance the precision, accuracy, reliability and integrity of the estimated unknown parameters, GNSS kinematic equations are to be augmented by possible constraints. Such constraints could be derived from the geometric relation of the receiver positions in motion. This contribution presents the formulation of the constrained kinematic global navigation satellite systems positioning. Constraints effectively restrict the definition domain of the unknown parameters from the three-dimensional space to a subspace defined by the equation of motion. To test the concept of the constrained kinematic positioning method, the equation of a circle is employed as a constraint. A device capable of moving on a circle was made and the observations from 11 positions on the circle were analyzed. Relative positioning was conducted by considering the center of the circle as the reference station. The equation of the receiver's motion was rewritten in the ECEF coordinates system. A special attention is drawn onto how a constraint is applied to kinematic positioning. Implementing the constraint in the positioning process provides much more precise results compared to the unconstrained case. This has been verified based on the results obtained from the covariance matrix of the estimated parameters and the empirical results using kinematic positioning samples as well. The theoretical standard deviations of the horizontal components are reduced by a factor ranging from 1.24 to 2.64. The improvement on the empirical standard deviation of the horizontal components ranges from 1.08 to 2.2.

Microbial Decomposers Not Constrained by Climate History Along a Mediterranean Climate Gradient

NASA Astrophysics Data System (ADS)

Baker, N. R.; Khalili, B.; Martiny, J. B. H.; Allison, S. D.

2017-12-01

The return of organic carbon to the atmosphere through terrestrial decomposition is mediated through the breakdown of complex organic polymers by extracellular enzymes produced by microbial decomposer communities. Determining if and how these decomposer communities are constrained in their ability to degrade plant litter is necessary for predicting how carbon cycling will be affected by future climate change. To address this question, we deployed fine-pore nylon mesh "microbial cage" litterbags containing grassland litter with and without local inoculum across five sites in southern California, spanning a gradient of 10.3-22.8° C in mean annual temperature and 100-400+ mm mean annual precipitation. Litterbags were deployed in October 2014 and collected four times over the course of 14 months. Recovered litter was assayed for mass loss, litter chemistry, microbial biomass, extracellular enzymes (Vmax and Km­), and enzyme temperature sensitivities. We hypothesized that grassland litter would decompose most rapidly in the grassland site, and that access to local microbial communities would enhance litter decomposition rates and microbial activity in the other sites along the gradient. We determined that temperature and precipitation likely interact to limit microbial decomposition in the extreme sites along our gradient. Despite their unique climate history, grassland microbes were not restricted in their ability to decompose litter under different climate conditions. Although we observed a strong correlation between bacterial biomass and mass loss across the gradient, litter that was inoculated with local microbial communities lost less mass despite having greater bacterial biomass and potentially accumulating more microbial residues. Our results suggest that microbial community composition may not constrain C-cycling rates under climate change in our system. However, there may be community constraints on decomposition if climate change alters litter chemistry, a mechanism only indirectly addressed by our design.

Birth to breast--a feeding care map for the NICU: helping the extremely low birth weight infant navigate the course.

PubMed

Dougherty, Dorothy; Luther, Maureen

2008-01-01

Breast milk has been shown to contribute significantly to positive neurodevelopmental and medical outcomes in the extremely low birth weight (ELBW) infant population. It is crucial that ELBW infants receive their mother's colostrum as a first feeding, followed by expressed breast milk for as long as possible. Evidence-based literature supports the difficult challenges both mothers and ELBW infants face if they are to succeed at breast pumping and breastfeeding. Influencing factors include the medical fragility of the infant, limited frequency and duration of kangaroo care between mother and infant, lack of an adequate volume of breast milk, as well as inconsistent or incorrect information surrounding the use of breast milk and breastfeeding. A feeding care map as described in this article can help the bedside nurse assist the mother-ELBW infant dyad in optimizing breast milk volumes, laying the groundwork for breastfeeding. Displaying supportive practices and preterm infant developmental milestones, the map categorizes infant, maternal, and dyad feeding issues along a progressive time line from admission to discharge.

Learning about cognition risk with the radial-arm maze in the developmental neurotoxicology battery.

PubMed

Levin, Edward D

2015-01-01

Cognitive dysfunction has been found in epidemiological studies to be among the most sensitive impairments associated with developmental exposure to a variety of environmental contaminants from heavy metals to polyhalogenated hydrocarbons and pesticides. These chemicals have been also shown to impair cognitive function after developmental exposure in experimental animal models. The radial-arm maze (RAM) has proven to be a sensitive and reliable way to assess both learning and memory in a variety of species, most often in rats and mice. The RAM is a very adaptable test method that takes advantage of rodents' instinct to explore new places in the environment to forage. That is, rodents do not need to be trained to run through the maze; they will normally do this from the initial session of testing. Training with differential reinforcement for arm choices provides a more rigorous test of learning and memory. The RAM is quite adaptable for assessing various aspects of cognition. Although the RAM has been mostly used to assess spatial learning and memory, it can be configured to assess non-spatial memory as well. Both working and reference memory can be easily distinguished. The RAM can be run with both appetitive (food reinforced) and aversive (water escape) motivators. The RAM has been found to be sensitive to a wide variety of developmental toxicants including heavy metals such as mercury and pesticides such as chlorpyrifos. There is an extremely rich literature especially with rats showing the effects of many types of brain lesions and drug effects so that the participation of a wide variety of neural systems in RAM performance is known. These systems, notably the hippocampus and frontal cortex, and acetylcholine and glutamate neurotransmitter systems, are the same neural systems that have been shown in humans to be critical for learning and memory. This considerably aids the interpretation of neurobehavioral toxicity studies. Copyright © 2015 Elsevier Inc. All rights reserved.

Natural variation in stomatal abundance of Arabidopsis thaliana includes cryptic diversity for different developmental processes

PubMed Central

Delgado, Dolores; Alonso-Blanco, Carlos; Fenoll, Carmen; Mena, Montaña

2011-01-01

Background and Aims Current understanding of stomatal development in Arabidopsis thaliana is based on mutations producing aberrant, often lethal phenotypes. The aim was to discover if naturally occurring viable phenotypes would be useful for studying stomatal development in a species that enables further molecular analysis. Methods Natural variation in stomatal abundance of A. thaliana was explored in two collections comprising 62 wild accessions by surveying adaxial epidermal cell-type proportion (stomatal index) and density (stomatal and pavement cell density) traits in cotyledons and first leaves. Organ size variation was studied in a subset of accessions. For all traits, maternal effects derived from different laboratory environments were evaluated. In four selected accessions, distinct stomatal initiation processes were quantitatively analysed. Key Results and Conclusions Substantial genetic variation was found for all six stomatal abundance-related traits, which were weakly or not affected by laboratory maternal environments. Correlation analyses revealed overall relationships among all traits. Within each organ, stomatal density highly correlated with the other traits, suggesting common genetic bases. Each trait correlated between organs, supporting supra-organ control of stomatal abundance. Clustering analyses identified accessions with uncommon phenotypic patterns, suggesting differences among genetic programmes controlling the various traits. Variation was also found in organ size, which negatively correlated with cell densities in both organs and with stomatal index in the cotyledon. Relative proportions of primary and satellite lineages varied among the accessions analysed, indicating that distinct developmental components contribute to natural diversity in stomatal abundance. Accessions with similar stomatal indices showed different lineage class ratios, revealing hidden developmental phenotypes and showing that genetic determinants of primary and satellite lineage initiation combine in several ways. This first systematic, comprehensive natural variation survey for stomatal abundance in A. thaliana reveals cryptic developmental genetic variation, and provides relevant relationships amongst stomatal traits and extreme or uncommon accessions as resources for the genetic dissection of stomatal development. PMID:21447490

Teratology on the crossroads: historical aspects and modern approaches.

PubMed

Ujházy, Eduard; Mach, Mojmír; Navarová, Jana; Dubovický, Michal

2012-01-01

Teratology is the science of congenital developmental disorders (CDDs), overt or latent defects of the organism resulting from the effect of internal and external factors on developmental processes. In this article the significance and position of present-day teratology is discussed in the context of development of this branch of science and related disciplines. The authors present an updated overview of the most important milestones and stages of the development of teratology. Based on the analysis of the historical development of theses and theories that represent a decisive contribution to this field, we present a survey of the fundamental principles of experimental and clinical teratology. The aim of observing these principles is to get insight into developmental relations and to understand mechanisms of action on the level of cell populations (elementary morphogenetic processes), tissues and organs. It is important to realize that any negative intervention into the normal course of these processes, either on genetic or non-genetic basis, inevitably leads to a sequence of subsequent changes resulting in the development of congenital developmental disorders. Despite modern approaches of molecular biology and genetics, along with top diagnostic techniques, we are still not able to identify the actual cause in more than 50% of all congenital defects. One-half of the unidentified cases are referred to as "multifactorial", a term that is rather ambiguous. It either means that some of the basic principles of teratogenesis still escape our attention, or the interpretation of some of the well known principles might be misleading. A third possibility is rather pessimistic. The development of the individual is so sophisticated and dependent on a delicate network of a multitude of factors mutually affecting each other that it is extremely prone to give rise to a plethora of spontaneous errors which are unpredictable and impossible to prevent. Nevertheless, the long and complicated history of scientific endeavour has yielded considerable present-day knowledge on causes and mechanisms of CDDs, a history whose beginnings date back to antiquity.

Understanding extreme rainfall events in Australia through historical data

NASA Astrophysics Data System (ADS)

Ashcroft, Linden; Karoly, David John

2016-04-01

Historical climate data recovery is still an emerging field in the Australian region. The majority of Australia's instrumental climate analyses begin in 1900 for rainfall and 1910 for temperature, particularly those focussed on extreme event analysis. This data sparsity for the past in turn limits our understanding of long-term climate variability, constraining efforts to predict the impact of future climate change. To address this need for improved historical data in Australia, a new network of recovered climate observations has recently been developed, centred on the highly populated southeastern Australian region (Ashcroft et al., 2014a, 2014b). The dataset includes observations from more than 39 published and unpublished sources and extends from British settlement in 1788 to the formation of the Australian Bureau of Meteorology in 1908. Many of these historical sources provide daily temperature and rainfall information, providing an opportunity to improve understanding of the multidecadal variability of Australia's extreme events. In this study we combine the historical data for three major Australian cities - Melbourne, Sydney and Adelaide - with modern observations to examine extreme rainfall variability over the past 174 years (1839-2013). We first explore two case studies, combining instrumental and documentary evidence to support the occurrence of severe storms in Sydney in 1841 and 1844. These events appear to be at least as extreme as Sydney's modern 24-hour rainfall record. Next we use a suite of rainfall indices to assess the long-term variability of rainfall in southeastern Australia. In particular, we focus on the stationarity of the teleconnection between the El Niño-Southern Oscillation (ENSO) phenomenon and extreme rainfall events. Using ENSO reconstructions derived from both palaeoclimatic and documentary sources, we determine the historical relationship between extreme rainfall in southeastern Australia and ENSO, and examine whether or not this relationship has remained stable since the early to mid-19th century. Ashcroft, L., Gergis, J., Karoly, D.J., 2014a. A historical climate dataset for southeastern Australia, 1788-1859. Geosci. Data J. 1, 158-178. doi:10.1002/gdj3.19 Ashcroft, L., Karoly, D.J., Gergis, J., 2014b. Southeastern Australian climate variability 1860-2009: A multivariate analysis. Int. J. Climatol. 34, 1928-1944. doi:10.1002/joc.3812

Neoproterozoic marine carbonates and their paleoceanographic significance

NASA Astrophysics Data System (ADS)

Hood, Ashleigh van Smeerdijk; Wallace, Malcolm William

2018-01-01

The primary mineralogy of marine carbonate precipitates has been a crucial factor in constraining the major element composition of ancient oceans. Secular changes in Phanerozoic marine chemistry, including Mg/Ca, have been well-documented using the original carbonate mineralogy of ooids, marine cements and biominerals. However, the history of Precambrian seawater chemistry is not as well constrained, partially due to the prevalence of dolomitisation in the Precambrian geological record. The Neoproterozoic ( 1000 Ma to 541 Ma) record of primary carbonate mineralogy is documented here using a combination of literature data and new analysis of marine carbonate precipitates from the Otavi Fold Belt, Namibia, the Death Valley succession, USA and the Adelaide Fold Belt, Australia. These data suggest that the last 460 million years of the Proterozoic were dominated by aragonite and high-Mg calcite precipitation in shallow marine settings. In contrast, low-Mg calcite has only been recognised in a small number of formations. In addition to aragonite and calcite precipitation, marine dolomite precipitation was widespread in Neoproterozoic oceans, including mimetic (syn-sedimentary) dolomitisation and primary dolomite marine cementation. The combination of marine aragonite, high Mg-calcite and dolomite precipitation during the Neoproterozoic suggests extremely high seawater Mg/Ca conditions relative to Phanerozoic oceans. Marine dolomite precipitation may also be linked to widespread marine anoxia during this time.

Constraining the reversing and non-reversing modes of the geodynamo. New insights from magnetostratigraphy.

NASA Astrophysics Data System (ADS)

Gallet, Y.; Pavlov, V.; Shatsillo, A.; Hulot, G.

2015-12-01

Constraining the evolution in the geomagnetic reversal frequency over hundreds of million years is not a trivial matter. Beyond the fact that there are long periods without reversals, known as superchrons, and periods with many reversals, the way the reversal frequency changes through time during reversing periods is still debated. A smooth evolution or a succession of stationary segments have both been suggested to account for the geomagnetic polarity time scale since the Middle-Late Jurassic. Sudden changes from a reversing mode to a non-reversing mode of the geodynamo may also well have happened, the switch between the two modes having then possibly been controlled by the thermal conditions at the core-mantle boundary. There is, nevertheless, a growing set of magnetostratigraphic data, which could help decipher a proper interpretation of the reversal history, in particular in the early Paleozoic and even during the Precambrian. Although yielding a fragmentary record, these data reveal the occurrence of both additional superchrons and periods characterized by extremely high, not to say extraordinary, magnetic reversal frequencies. In this talk, we will present a synthesis of these data, mainly obtained from Siberia, and discuss their implication for the magnetic reversal behavior over the past billion years.

Weighted mining of massive collections of [Formula: see text]-values by convex optimization.

PubMed

Dobriban, Edgar

2018-06-01

Researchers in data-rich disciplines-think of computational genomics and observational cosmology-often wish to mine large bodies of [Formula: see text]-values looking for significant effects, while controlling the false discovery rate or family-wise error rate. Increasingly, researchers also wish to prioritize certain hypotheses, for example, those thought to have larger effect sizes, by upweighting, and to impose constraints on the underlying mining, such as monotonicity along a certain sequence. We introduce Princessp , a principled method for performing weighted multiple testing by constrained convex optimization. Our method elegantly allows one to prioritize certain hypotheses through upweighting and to discount others through downweighting, while constraining the underlying weights involved in the mining process. When the [Formula: see text]-values derive from monotone likelihood ratio families such as the Gaussian means model, the new method allows exact solution of an important optimal weighting problem previously thought to be non-convex and computationally infeasible. Our method scales to massive data set sizes. We illustrate the applications of Princessp on a series of standard genomics data sets and offer comparisons with several previous 'standard' methods. Princessp offers both ease of operation and the ability to scale to extremely large problem sizes. The method is available as open-source software from github.com/dobriban/pvalue_weighting_matlab (accessed 11 October 2017).

Neutrino footprint in large scale structure

NASA Astrophysics Data System (ADS)

Garay, Carlos Peña; Verde, Licia; Jimenez, Raul

2017-03-01

Recent constrains on the sum of neutrino masses inferred by analyzing cosmological data, show that detecting a non-zero neutrino mass is within reach of forthcoming cosmological surveys. Such a measurement will imply a direct determination of the absolute neutrino mass scale. Physically, the measurement relies on constraining the shape of the matter power spectrum below the neutrino free streaming scale: massive neutrinos erase power at these scales. However, detection of a lack of small-scale power from cosmological data could also be due to a host of other effects. It is therefore of paramount importance to validate neutrinos as the source of power suppression at small scales. We show that, independent on hierarchy, neutrinos always show a footprint on large, linear scales; the exact location and properties are fully specified by the measured power suppression (an astrophysical measurement) and atmospheric neutrinos mass splitting (a neutrino oscillation experiment measurement). This feature cannot be easily mimicked by systematic uncertainties in the cosmological data analysis or modifications in the cosmological model. Therefore the measurement of such a feature, up to 1% relative change in the power spectrum for extreme differences in the mass eigenstates mass ratios, is a smoking gun for confirming the determination of the absolute neutrino mass scale from cosmological observations. It also demonstrates the synergy between astrophysics and particle physics experiments.

Constraining the 2012-2014 growing season Alaskan methane budget using CARVE aircraft measurements

NASA Astrophysics Data System (ADS)

Hartery, S.; Chang, R. Y. W.; Commane, R.; Lindaas, J.; Miller, S. M.; Wofsy, S. C.; Karion, A.; Sweeney, C.; Miller, C. E.; Dinardo, S. J.; Steiner, N.; McDonald, K. C.; Watts, J. D.; Zona, D.; Oechel, W. C.; Kimball, J. S.; Henderson, J.; Mountain, M. E.

2015-12-01

Soil in northen latitudes contains rich carbon stores which have been historically preserved via permafrost within the soil bed; however, recent surface warming in these regions is allowing deeper soil layers to thaw, influencing the net carbon exchange from these areas. Due to the extreme nature of its climate, these eco-regions remain poorly understood by most global models. In this study we analyze methane fluxes from Alaska using in situ aircraft observations from the 2012-2014 Carbon in Arctic Reservoir Vulnerability Experiment (CARVE). These observations are coupled with an atmospheric particle transport model which quantitatively links surface emissions to atmospheric observations to make regional methane emission estimates. The results of this study are two-fold. First, the inter-annual variability of the methane emissions was found to be <1 Tg over the area of interest and is largely influenced by the length of time the deep soil remains unfrozen. Second, the resulting methane flux estimates and mean soil parameters were used to develop an empirical emissions model to help spatially and temporally constrain the methane exchange at the Alaskan soil surface. The empirical emissions model will provide a basis for exploring the sensitivity of methane emissions to subsurface soil temperature, soil moisture, organic carbon content, and other parameters commonly used in process-based models.

The Thermal Conductivity of Earth's Core: A Key Geophysical Parameter's Constraints and Uncertainties

NASA Astrophysics Data System (ADS)

Williams, Q.

2018-05-01

The thermal conductivity of iron alloys at high pressures and temperatures is a critical parameter in governing ( a) the present-day heat flow out of Earth's core, ( b) the inferred age of Earth's inner core, and ( c) the thermal evolution of Earth's core and lowermost mantle. It is, however, one of the least well-constrained important geophysical parameters, with current estimates for end-member iron under core-mantle boundary conditions varying by about a factor of 6. Here, the current state of calculations, measurements, and inferences that constrain thermal conductivity at core conditions are reviewed. The applicability of the Wiedemann-Franz law, commonly used to convert electrical resistivity data to thermal conductivity data, is probed: Here, whether the constant of proportionality, the Lorenz number, is constant at extreme conditions is of vital importance. Electron-electron inelastic scattering and increases in Fermi-liquid-like behavior may cause uncertainties in thermal conductivities derived from both first-principles-associated calculations and electrical conductivity measurements. Additional uncertainties include the role of alloying constituents and local magnetic moments of iron in modulating the thermal conductivity. Thus, uncertainties in thermal conductivity remain pervasive, and hence a broad range of core heat flows and inner core ages appear to remain plausible.

Design of novel neurokinin 1 receptor antagonists based on conformationally constrained aromatic amino acids and discovery of a potent chimeric opioid agonist-neurokinin 1 receptor antagonist.

PubMed

Ballet, Steven; Feytens, Debby; Buysse, Koen; Chung, Nga N; Lemieux, Carole; Tumati, Suneeta; Keresztes, Attila; Van Duppen, Joost; Lai, Josephine; Varga, Eva; Porreca, Frank; Schiller, Peter W; Vanden Broeck, Jozef; Tourwé, Dirk

2011-04-14

A screening of conformationally constrained aromatic amino acids as base cores for the preparation of new NK1 receptor antagonists resulted in the discovery of three new NK1 receptor antagonists, 19 [Ac-Aba-Gly-NH-3',5'-(CF(3))(2)-Bn], 20 [Ac-Aba-Gly-NMe-3',5'-(CF(3))(2)-Bn], and 23 [Ac-Tic-NMe-3',5'-(CF(3))(2)-Bn], which were able to counteract the agonist effect of substance P, the endogenous ligand of NK1R. The most active NK1 antagonist of the series, 20 [Ac-Aba-Gly-NMe-3',5'-(CF(3))(2)-Bn], was then used in the design of a novel, potent chimeric opioid agonist-NK1 receptor antagonist, 35 [Dmt-D-Arg-Aba-Gly-NMe-3',5'-(CF(3))(2)-Bn], which combines the N terminus of the established Dmt(1)-DALDA agonist opioid pharmacophore (H-Dmt-D-Arg-Phe-Lys-NH(2)) and 20, the NK1R ligand. The opioid component of the chimeric compound 35, that is, Dmt-D-Arg-Aba-Gly-NH(2) (36), also proved to be an extremely potent and balanced μ and δ opioid receptor agonist with subnanomolar binding and in vitro functional activity.

Projected strengthening of Amazonian dry season by constrained climate model simulations

NASA Astrophysics Data System (ADS)

Boisier, Juan P.; Ciais, Philippe; Ducharne, Agnès; Guimberteau, Matthieu

2015-07-01

The vulnerability of Amazonian rainforest, and the ecological services it provides, depends on an adequate supply of dry-season water, either as precipitation or stored soil moisture. How the rain-bearing South American monsoon will evolve across the twenty-first century is thus a question of major interest. Extensive savanization, with its loss of forest carbon stock and uptake capacity, is an extreme although very uncertain scenario. We show that the contrasting rainfall projections simulated for Amazonia by 36 global climate models (GCMs) can be reproduced with empirical precipitation models, calibrated with historical GCM data as functions of the large-scale circulation. A set of these simple models was therefore calibrated with observations and used to constrain the GCM simulations. In agreement with the current hydrologic trends, the resulting projection towards the end of the twenty-first century is for a strengthening of the monsoon seasonal cycle, and a dry-season lengthening in southern Amazonia. With this approach, the increase in the area subjected to lengthy--savannah-prone--dry seasons is substantially larger than the GCM-simulated one. Our results confirm the dominant picture shown by the state-of-the-art GCMs, but suggest that the `model democracy' view of these impacts can be significantly underestimated.

Forests synchronize their growth in contrasting Eurasian regions in response to climate warming.

PubMed

Shestakova, Tatiana A; Gutiérrez, Emilia; Kirdyanov, Alexander V; Camarero, Jesús Julio; Génova, Mar; Knorre, Anastasia A; Linares, Juan Carlos; Resco de Dios, Víctor; Sánchez-Salguero, Raúl; Voltas, Jordi

2016-01-19

Forests play a key role in the carbon balance of terrestrial ecosystems. One of the main uncertainties in global change predictions lies in how the spatiotemporal dynamics of forest productivity will be affected by climate warming. Here we show an increasing influence of climate on the spatial variability of tree growth during the last 120 y, ultimately leading to unprecedented temporal coherence in ring-width records over wide geographical scales (spatial synchrony). Synchrony in growth patterns across cold-constrained (central Siberia) and drought-constrained (Spain) Eurasian conifer forests have peaked in the early 21st century at subcontinental scales (∼ 1,000 km). Such enhanced synchrony is similar to that observed in trees co-occurring within a stand. In boreal forests, the combined effects of recent warming and increasing intensity of climate extremes are enhancing synchrony through an earlier start of wood formation and a stronger impact of year-to-year fluctuations of growing-season temperatures on growth. In Mediterranean forests, the impact of warming on synchrony is related mainly to an advanced onset of growth and the strengthening of drought-induced growth limitations. Spatial patterns of enhanced synchrony represent early warning signals of climate change impacts on forest ecosystems at subcontinental scales.

Forests synchronize their growth in contrasting Eurasian regions in response to climate warming

PubMed Central

Shestakova, Tatiana A.; Gutiérrez, Emilia; Kirdyanov, Alexander V.; Camarero, Jesús Julio; Génova, Mar; Knorre, Anastasia A.; Linares, Juan Carlos; Sánchez-Salguero, Raúl; Voltas, Jordi

2016-01-01

Forests play a key role in the carbon balance of terrestrial ecosystems. One of the main uncertainties in global change predictions lies in how the spatiotemporal dynamics of forest productivity will be affected by climate warming. Here we show an increasing influence of climate on the spatial variability of tree growth during the last 120 y, ultimately leading to unprecedented temporal coherence in ring-width records over wide geographical scales (spatial synchrony). Synchrony in growth patterns across cold-constrained (central Siberia) and drought-constrained (Spain) Eurasian conifer forests have peaked in the early 21st century at subcontinental scales (∼1,000 km). Such enhanced synchrony is similar to that observed in trees co-occurring within a stand. In boreal forests, the combined effects of recent warming and increasing intensity of climate extremes are enhancing synchrony through an earlier start of wood formation and a stronger impact of year-to-year fluctuations of growing-season temperatures on growth. In Mediterranean forests, the impact of warming on synchrony is related mainly to an advanced onset of growth and the strengthening of drought-induced growth limitations. Spatial patterns of enhanced synchrony represent early warning signals of climate change impacts on forest ecosystems at subcontinental scales. PMID:26729860

Synthesis of Chromone, Quinolone, and Benzoxazinone Sulfonamide Nucleosides as Conformationally Constrained Inhibitors of Adenylating Enzymes Required for Siderophore Biosynthesis

PubMed Central

Engelhart, Curtis A.; Aldrich, Courtney C.

2013-01-01

MbtA catalyzes the first committed step of mycobactin biosynthesis in Mycobacterium tuberculosis (Mtb) and is responsible for the incorporation of salicylic acid into the mycobactin siderophores. 5′-O-[N-(Salicyl)sulfamoyl]adenosine (Sal-AMS) is an extremely potent nucleoside inhibitor of MbtA that possesses excellent activity against whole-cell Mtb, but suffers from poor bioavailability. In an effort to improve the bioavailability, we have designed four conformationally constrained analogues of Sal-AMS that remove two rotatable bonds and the ionized sulfamate group based on computational and structural studies. Herein we describe the synthesis, biochemical, and microbiological evaluation of chromone-, quinolone-, and benzoxazinone-3-sulfonamide derivatives of Sal-AMS. We developed new chemistry to assemble these three heterocycles from common β-ketosulfonamide intermediates. The synthesis of the chromone- and quinolone-3-sulfonamide intermediates features formylation of a β-ketosulfonamide employing dimethylformamide dimethyl acetal to afford an enaminone that can react intramolecularly with a phenol or intermolecularly with a primary amine via addition-elimination reaction(s). The benzoxazinone-3-sulfonamide was prepared by nitrosation of a β-ketosulfonamide followed by intramolecular nucleophilic aromatic substitution. Mitsunobu coupling of these bicyclic sulfonamides with a protected adenosine derivative followed by global deprotection provides a concise synthesis of the respective inhibitors. PMID:23805993