atta colombica function: Topics by Science.gov

Sample records for atta colombica function

Magnetic anisotropy and organization of nanoparticles in heads and antennae of neotropical leaf-cutter ants, Atta colombica

USDA-ARS?s Scientific Manuscript database

Oriented magnetic nanoparticles have been suggested as a good candidate for a magnetic sensor in ants. Behavioral evidence for a magnetic compass in Neotropical leafcutter ants, Atta colombica (Formicidae: Attini), motivated a study of the arrangement of magnetic particles in the ants’ four major bo...
Do leaf-cutter ants Atta colombica obtain their magnetic sensors from soil?

USDA-ARS?s Scientific Manuscript database

How animals sense, process and use magnetic information has remained largely elusive. In insects, ferromagnetic particles are candidates for a magnetic sensor. Recent studies suggest that ferromagnetic minerals from soil can be incorporated into the antennae of the migratory ant Pachycondola margina...
Complete Genome of Enterobacteriaceae Bacterium Strain FGI 57, a Strain Associated with Leaf-Cutter Ant Fungus Gardens

PubMed Central

Aylward, Frank O.; Tremmel, Daniel M.; Bruce, David C.; Chain, Patrick; Chen, Amy; Walston Davenport, Karen; Detter, Chris; Han, Cliff S.; Han, James; Huntemann, Marcel; Ivanova, Natalia N.; Kyrpides, Nikos C.; Markowitz, Victor; Mavrommatis, Kostas; Nolan, Matt; Pagani, Ioanna; Pati, Amrita; Pitluck, Sam; Deshpande, Shweta; Goodwin, Lynne; Woyke, Tanja

2013-01-01

The Enterobacteriaceae bacterium strain FGI 57 was isolated from a fungus garden of the leaf-cutter ant Atta colombica. Analysis of its single 4.76-Mbp chromosome will shed light on community dynamics and plant biomass degradation in ant fungus gardens. PMID:23469353
Complete Genome of Serratia sp. Strain FGI 94, a Strain Associated with Leaf-Cutter Ant Fungus Gardens

PubMed Central

Aylward, Frank O.; Tremmel, Daniel M.; Starrett, Gabriel J.; Bruce, David C.; Chain, Patrick; Chen, Amy; Davenport, Karen W.; Detter, Chris; Han, Cliff S.; Han, James; Huntemann, Marcel; Ivanova, Natalia N.; Kyrpides, Nikos C.; Markowitz, Victor; Mavrommatis, Kostas; Nolan, Matt; Pagani, Ioanna; Pati, Amrita; Pitluck, Sam; Teshima, Hazuki; Deshpande, Shweta; Goodwin, Lynne; Woyke, Tanja

2013-01-01

Serratia sp. strain FGI 94 was isolated from a fungus garden of the leaf-cutter ant Atta colombica. Analysis of its 4.86-Mbp chromosome will help advance our knowledge of symbiotic interactions and plant biomass degradation in this ancient ant-fungus mutualism. PMID:23516234
Cellulose-Enriched Microbial Communities from Leaf-Cutter Ant (Atta colombica) Refuse Dumps Vary in Taxonomic Composition and Degradation Ability

DOE PAGES

Lewin, Gina R.; Johnson, Amanda L.; Soto, Rolando D. Moreira; ...

2016-03-21

Deconstruction of the cellulose in plant cell walls is critical for carbon flow through ecosystems and for the production of sustainable cellulosic biofuels. Our understanding of cellulose deconstruction is largely limited to the study of microbes in isolation, but in nature, this process is driven by microbes within complex communities. In Neotropical forests, microbes in leaf-cutter ant refuse dumps are important for carbon turnover. These dumps consist of decaying plant material and a diverse bacterial community, as shown here by electron microscopy. To study the portion of the community capable of cellulose degradation, we performed enrichments on cellulose using materialmore » from five Atta colombica refuse dumps. The ability of enriched communities to degrade cellulose varied significantly across refuse dumps. 16S rRNA gene amplicon sequencing of enriched samples identified that the community structure correlated with refuse dump and with degradation ability. Overall, samples were dominated by Bacteroidetes, Gammaproteobacteria, and Betaproteobacteria. Half of abundant operational taxonomic units (OTUs) across samples were classified within general containing known cellulose degraders, including Acidovorax, the most abundant OTU detected across samples, which was positively correlated with cellulolytic ability. Lastly, a representative Acidovorax strain was isolated, but did not grow on cellulose alone. Phenotypic and compositional analyses of enrichment cultures, such as those presented here, help link community composition with cellulolytic ability and provide insight into the complexity of community-based cellulose degradation.« less
Cellulose-Enriched Microbial Communities from Leaf-Cutter Ant (Atta colombica) Refuse Dumps Vary in Taxonomic Composition and Degradation Ability

PubMed Central

Lewin, Gina R.; Johnson, Amanda L.; Soto, Rolando D. Moreira; Perry, Kailene; Book, Adam J.; Horn, Heidi A.; Pinto-Tomás, Adrián A.; Currie, Cameron R.

2016-01-01

Deconstruction of the cellulose in plant cell walls is critical for carbon flow through ecosystems and for the production of sustainable cellulosic biofuels. Our understanding of cellulose deconstruction is largely limited to the study of microbes in isolation, but in nature, this process is driven by microbes within complex communities. In Neotropical forests, microbes in leaf-cutter ant refuse dumps are important for carbon turnover. These dumps consist of decaying plant material and a diverse bacterial community, as shown here by electron microscopy. To study the portion of the community capable of cellulose degradation, we performed enrichments on cellulose using material from five Atta colombica refuse dumps. The ability of enriched communities to degrade cellulose varied significantly across refuse dumps. 16S rRNA gene amplicon sequencing of enriched samples identified that the community structure correlated with refuse dump and with degradation ability. Overall, samples were dominated by Bacteroidetes, Gammaproteobacteria, and Betaproteobacteria. Half of abundant operational taxonomic units (OTUs) across samples were classified within genera containing known cellulose degraders, including Acidovorax, the most abundant OTU detected across samples, which was positively correlated with cellulolytic ability. A representative Acidovorax strain was isolated, but did not grow on cellulose alone. Phenotypic and compositional analyses of enrichment cultures, such as those presented here, help link community composition with cellulolytic ability and provide insight into the complexity of community-based cellulose degradation. PMID:26999749
Cellulose-Enriched Microbial Communities from Leaf-Cutter Ant (Atta colombica) Refuse Dumps Vary in Taxonomic Composition and Degradation Ability

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

Lewin, Gina R.; Johnson, Amanda L.; Soto, Rolando D. Moreira

Deconstruction of the cellulose in plant cell walls is critical for carbon flow through ecosystems and for the production of sustainable cellulosic biofuels. Our understanding of cellulose deconstruction is largely limited to the study of microbes in isolation, but in nature, this process is driven by microbes within complex communities. In Neotropical forests, microbes in leaf-cutter ant refuse dumps are important for carbon turnover. These dumps consist of decaying plant material and a diverse bacterial community, as shown here by electron microscopy. To study the portion of the community capable of cellulose degradation, we performed enrichments on cellulose using materialmore » from five Atta colombica refuse dumps. The ability of enriched communities to degrade cellulose varied significantly across refuse dumps. 16S rRNA gene amplicon sequencing of enriched samples identified that the community structure correlated with refuse dump and with degradation ability. Overall, samples were dominated by Bacteroidetes, Gammaproteobacteria, and Betaproteobacteria. Half of abundant operational taxonomic units (OTUs) across samples were classified within general containing known cellulose degraders, including Acidovorax, the most abundant OTU detected across samples, which was positively correlated with cellulolytic ability. Lastly, a representative Acidovorax strain was isolated, but did not grow on cellulose alone. Phenotypic and compositional analyses of enrichment cultures, such as those presented here, help link community composition with cellulolytic ability and provide insight into the complexity of community-based cellulose degradation.« less
Genetic caste polymorphism and the evolution of polyandry in Atta leaf-cutting ants

NASA Astrophysics Data System (ADS)

Evison, Sophie Elizabeth Frances; Hughes, William O. H.

2011-08-01

Multiple mating by females with different males (polyandry) is difficult to explain in many taxa because it carries significant costs to females, yet benefits are often hard to identify. Polyandry is a derived trait in social insects, the evolutionary origins of which remain unclear. One of several leading hypotheses for its evolution is that it improves division of labour by increasing intra-colonial genetic diversity. Division of labour is a key player in the ecological success of social insects, and in many successful species of ants is based on morphologically distinct castes of workers, each with their own task specialisations. Atta leaf-cutting ants exhibit one of the most extreme and complicated forms of morphologically specialised worker castes and have been reported to be polyandrous but with relatively low mating frequencies (~2.5 on average). Here, we show for the first time that there is a significant genetic influence on worker size in Atta colombica leaf-cutting ants. We also provide the first estimate of the mating frequency of Atta cephalotes (four matings) and, by analysing much higher within-colony sample sizes, find that Atta are more polyandrous than previously thought (approximately six to seven matings). The results show that high polyandry and a genetic influence on worker caste are present in both genera of leaf-cutting ants and add weight to the hypothesis that division of labour is a potential driver of the evolution of polyandry in this clade of ants.
Chemical disguise of myrmecophilous cockroaches and its implications for understanding nestmate recognition mechanisms in leaf-cutting ants.

PubMed

Nehring, Volker; Dani, Francesca R; Calamai, Luca; Turillazzi, Stefano; Bohn, Horst; Klass, Klaus-Dieter; d'Ettorre, Patrizia

2016-08-05

Cockroaches of the genus Attaphila regularly occur in leaf-cutting ant colonies. The ants farm a fungus that the cockroaches also appear to feed on. Cockroaches disperse between colonies horizontally (via foraging trails) and vertically (attached to queens on their mating flights). We analysed the chemical strategies used by the cockroaches to integrate into colonies of Atta colombica and Acromyrmex octospinosus. Analysing cockroaches from nests of two host species further allowed us to test the hypothesis that nestmate recognition is based on an asymmetric mechanism. Specifically, we test the U-present nestmate recognition model, which assumes that detection of undesirable cues (non-nestmate specific substances) leads to strong rejection of the cue-bearers, while absence of desirable cues (nestmate-specific substances) does not necessarily trigger aggression. We found that nests of Atta and Acromyrmex contained cockroaches of two different and not yet described Attaphila species. The cockroaches share the cuticular chemical substances of their specific host species and copy their host nest's colony-specific cuticular profile. Indeed, the cockroaches are accepted by nestmate but attacked by non-nestmate ant workers. Cockroaches from Acromyrmex colonies bear a lower concentration of cuticular substances and are less likely to be attacked by non-nestmate ants than cockroaches from Atta colonies. Nest-specific recognition of Attaphila cockroaches by host workers in combination with nest-specific cuticular chemical profiles suggest that the cockroaches mimic their host's recognition labels, either by synthesizing nest-specific substances or by substance transfer from ants. Our finding that the cockroach species with lower concentration of cuticular substances receives less aggression by both host species fully supports the U-present nestmate recognition model. Leaf-cutting ant nestmate recognition is thus asymmetric, responding more strongly to differences than to similarities.
Leaf processing behaviour in Atta leafcutter ants: 90% of leaf cutting takes place inside the nest, and ants select pieces that require less cutting.

PubMed

Garrett, Ryan W; Carlson, Katherine A; Goggans, Matthew Scott; Nesson, Michael H; Shepard, Christopher A; Schofield, Robert M S

2016-01-01

Leafcutter ants cut trimmings from plants, carry them to their underground nests and cut them into smaller pieces before inoculating them with a fungus that serves as a primary food source for the colony. Cutting is energetically costly, so the amount of cutting is important in understanding foraging energetics. Estimates of the cutting density, metres of cutting per square metre of leaf, were made from samples of transported leaf cuttings and of fungal substrate from field colonies of Atta cephalotes and Atta colombica. To investigate cutting inside the nest, we made leaf-processing observations of our laboratory colony, A. cephalotes. We did not observe the commonly reported reduction of the leaf fragments into a pulp, which would greatly increase the energy cost of processing. Video clips of processing behaviours, including behaviours that have not previously been described, are linked. An estimated 2.9 (±0.3) km of cutting with mandibles was required to reduce a square metre of leaf to fungal substrate. Only about 12% (±1%) of this cutting took place outside of the nest. The cutting density and energy cost is lower for leaf material with higher ratios of perimeter to area, so we tested for, and found that the laboratory ants had a preference for leaves that were pre-cut into smaller pieces. Estimates suggest that the energy required to transport and cut up the leaf material is comparable to the metabolic energy available from the fungus grown on the leaves, and so conservation of energy is likely to be a particularly strong selective pressure for leafcutter ants.
Endophytic fungi reduce leaf-cutting ant damage to seedlings

PubMed Central

Bittleston, L. S.; Brockmann, F.; Wcislo, W.; Van Bael, S. A.

2011-01-01

Our study examines how the mutualism between Atta colombica leaf-cutting ants and their cultivated fungus is influenced by the presence of diverse foliar endophytic fungi (endophytes) at high densities in tropical leaf tissues. We conducted laboratory choice trials in which ant colonies chose between Cordia alliodora seedlings with high (Ehigh) or low (Elow) densities of endophytes. The Ehigh seedlings contained 5.5 times higher endophyte content and a greater diversity of fungal morphospecies than the Elow treatment, and endophyte content was not correlated with leaf toughness or thickness. Leaf-cutting ants cut over 2.5 times the leaf area from Elow relative to Ehigh seedlings and had a tendency to recruit more ants to Elow plants. Our findings suggest that leaf-cutting ants may incur costs from cutting and processing leaves with high endophyte loads, which could impact Neotropical forests by causing variable damage rates within plant communities. PMID:20610420
The effects of disturbance threat on leaf-cutting ant colonies: a laboratory study.

PubMed

Norman, V C; Pamminger, T; Hughes, W O H

2017-01-01

The flexibility of organisms to respond plastically to their environment is fundamental to their fitness and evolutionary success. Social insects provide some of the most impressive examples of plasticity, with individuals exhibiting behavioral and sometimes morphological adaptations for their specific roles in the colony, such as large soldiers for nest defense. However, with the exception of the honey bee model organism, there has been little investigation of the nature and effects of environmental stimuli thought to instigate alternative phenotypes in social insects. Here, we investigate the effect of repeated threat disturbance over a prolonged (17 month) period on both behavioral and morphological phenotypes, using phenotypically plastic leaf-cutting ants ( Atta colombica ) as a model system. We found a rapid impact of threat disturbance on the behavioral phenotype of individuals within threat-disturbed colonies becoming more aggressive, threat responsive, and phototactic within as little as 2 weeks. We found no effect of threat disturbance on morphological phenotypes, potentially, because constraints such as resource limitation outweighed the benefit for colonies of producing larger individuals. The results suggest that plasticity in behavioral phenotypes can enable insect societies to respond to threats even when constraints prevent alteration of morphological phenotypes.
Major changes in microbial diversity and community composition across gut sections of a juvenile Panchlora cockroach

PubMed Central

Gontang, Erin A.; Aylward, Frank O.; Carlos, Camila; Glavina del Rio, Tijana; Chovatia, Mansi; Fern, Alison; Lo, Chien-Chi; Malfatti, Stephanie A.; Tringe, Susannah G.; Currie, Cameron R.; Kolter, Roberto

2017-01-01

Investigations of gut microbiomes have shed light on the diversity and genetic content of these communities, and helped shape our understanding of how host-associated microorganisms influence host physiology, behavior, and health. Despite the importance of gut microbes to metazoans, our understanding of the changes in diversity and composition across the alimentary tract, and the source of the resident community are limited. Here, using community metagenomics and 16S rRNA gene sequencing, we assess microbial community diversity and coding potential in the foregut, midgut, and hindgut of a juvenile Panchlora cockroach, which resides in the refuse piles of the leaf-cutter ant species Atta colombica. We found a significant shift in the microbial community structure and coding potential throughout the three gut sections of Panchlora sp., and through comparison with previously generated metagenomes of the cockroach’s food source and niche, we reveal that this shift in microbial community composition is influenced by the ecosystems in which Panchlora sp. occurs. While the foregut is composed of microbes that likely originate from the symbiotic fungus gardens of the ants, the midgut and hindgut are composed of a microbial community that is likely cockroach-specific. Analogous to mammalian systems, the midgut and hindgut appear to be dominated by Firmicutes and Bacteroidetes with the capacity for polysaccharide degradation, suggesting they may assist in the degradation of dietary plant material. Our work underscores the prominence of community changes throughout gut microbiomes and highlights ecological factors that underpin the structure and function of the symbiotic microbial communities of metazoans. PMID:28545131
Major changes in microbial diversity and community composition across gut sections of a juvenile Panchlora cockroach

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

Gontang, Erin A.; Aylward, Frank O.; Carlos, Camila

Investigations of gut microbiomes have shed light on the diversity and genetic content of these communities, and helped shape our understanding of how host-associated microorganisms influence host physiology, behavior, and health. Despite the importance of gut microbes to metazoans, our understanding of the changes in diversity and composition across the alimentary tract, and the source of the resident community are limited. Here, using community metagenomics and 16S rRNA gene sequencing, we assess microbial community diversity and coding potential in the foregut, midgut, and hindgut of a juvenile Panchlora cockroach, which resides in the refuse piles of the leaf-cutter ant speciesmore » Atta colombica. We found a significant shift in the microbial community structure and coding potential throughout the three gut sections of Panchlora sp., and through comparison with previously generated metagenomes of the cockroach's food source and niche, we reveal that this shift in microbial community composition is influenced by the ecosystems in which Panchlora sp. occurs. While the foregut is composed of microbes that likely originate from the symbiotic fungus gardens of the ants, the midgut and hindgut are composed of a microbial community that is likely cockroach-specific. Analogous to mammalian systems, the midgut and hindgut appear to be dominated by Firmicutes and Bacteroidetes with the capacity for polysaccharide degradation, suggesting they may assist in the degradation of dietary plant material. Our work underscores the prominence of community changes throughout gut microbiomes and highlights ecological factors that underpin the structure and function of the symbiotic microbial communities of metazoans.« less
Major changes in microbial diversity and community composition across gut sections of a juvenile Panchlora cockroach

DOE PAGES

Gontang, Erin A.; Aylward, Frank O.; Carlos, Camila; ...

2017-05-18

Investigations of gut microbiomes have shed light on the diversity and genetic content of these communities, and helped shape our understanding of how host-associated microorganisms influence host physiology, behavior, and health. Despite the importance of gut microbes to metazoans, our understanding of the changes in diversity and composition across the alimentary tract, and the source of the resident community are limited. Here, using community metagenomics and 16S rRNA gene sequencing, we assess microbial community diversity and coding potential in the foregut, midgut, and hindgut of a juvenile Panchlora cockroach, which resides in the refuse piles of the leaf-cutter ant speciesmore » Atta colombica. We found a significant shift in the microbial community structure and coding potential throughout the three gut sections of Panchlora sp., and through comparison with previously generated metagenomes of the cockroach's food source and niche, we reveal that this shift in microbial community composition is influenced by the ecosystems in which Panchlora sp. occurs. While the foregut is composed of microbes that likely originate from the symbiotic fungus gardens of the ants, the midgut and hindgut are composed of a microbial community that is likely cockroach-specific. Analogous to mammalian systems, the midgut and hindgut appear to be dominated by Firmicutes and Bacteroidetes with the capacity for polysaccharide degradation, suggesting they may assist in the degradation of dietary plant material. Our work underscores the prominence of community changes throughout gut microbiomes and highlights ecological factors that underpin the structure and function of the symbiotic microbial communities of metazoans.« less
Major changes in microbial diversity and community composition across gut sections of a juvenile Panchlora cockroach.

PubMed

Gontang, Erin A; Aylward, Frank O; Carlos, Camila; Glavina Del Rio, Tijana; Chovatia, Mansi; Fern, Alison; Lo, Chien-Chi; Malfatti, Stephanie A; Tringe, Susannah G; Currie, Cameron R; Kolter, Roberto

2017-01-01

Investigations of gut microbiomes have shed light on the diversity and genetic content of these communities, and helped shape our understanding of how host-associated microorganisms influence host physiology, behavior, and health. Despite the importance of gut microbes to metazoans, our understanding of the changes in diversity and composition across the alimentary tract, and the source of the resident community are limited. Here, using community metagenomics and 16S rRNA gene sequencing, we assess microbial community diversity and coding potential in the foregut, midgut, and hindgut of a juvenile Panchlora cockroach, which resides in the refuse piles of the leaf-cutter ant species Atta colombica. We found a significant shift in the microbial community structure and coding potential throughout the three gut sections of Panchlora sp., and through comparison with previously generated metagenomes of the cockroach's food source and niche, we reveal that this shift in microbial community composition is influenced by the ecosystems in which Panchlora sp. occurs. While the foregut is composed of microbes that likely originate from the symbiotic fungus gardens of the ants, the midgut and hindgut are composed of a microbial community that is likely cockroach-specific. Analogous to mammalian systems, the midgut and hindgut appear to be dominated by Firmicutes and Bacteroidetes with the capacity for polysaccharide degradation, suggesting they may assist in the degradation of dietary plant material. Our work underscores the prominence of community changes throughout gut microbiomes and highlights ecological factors that underpin the structure and function of the symbiotic microbial communities of metazoans.
The Hymenopterous Poison Apparatus. X. Morphological and Behavioral Changes in Atta texana (Hymenoptera: Formicidae)

Treesearch

Henry R. Hermann; John C. Moser; Allen N. Hunt

1970-01-01

Atta texana (Buckley) and other members of this genus no longer utilize the 8th and 9th gonapophyses as part of their defensive system. Although the sclerites that comprise the stinging apparatus in most aculeate Hymenoptera are present in the species, they seem to function only in the deposition of trail pheromones. A mechanical and chemical defense...
Expressed sequence tags from Atta laevigata and identification of candidate genes for the control of pest leaf-cutting ants.

PubMed

Rodovalho, Cynara M; Ferro, Milene; Fonseca, Fernando Pp; Antonio, Erik A; Guilherme, Ivan R; Henrique-Silva, Flávio; Bacci, Maurício

2011-06-17

Leafcutters are the highest evolved within Neotropical ants in the tribe Attini and model systems for studying caste formation, labor division and symbiosis with microorganisms. Some species of leafcutters are agricultural pests controlled by chemicals which affect other animals and accumulate in the environment. Aiming to provide genetic basis for the study of leafcutters and for the development of more specific and environmentally friendly methods for the control of pest leafcutters, we generated expressed sequence tag data from Atta laevigata, one of the pest ants with broad geographic distribution in South America. The analysis of the expressed sequence tags allowed us to characterize 2,006 unique sequences in Atta laevigata. Sixteen of these genes had a high number of transcripts and are likely positively selected for high level of gene expression, being responsible for three basic biological functions: energy conservation through redox reactions in mitochondria; cytoskeleton and muscle structuring; regulation of gene expression and metabolism. Based on leafcutters lifestyle and reports of genes involved in key processes of other social insects, we identified 146 sequences potential targets for controlling pest leafcutters. The targets are responsible for antixenobiosis, development and longevity, immunity, resistance to pathogens, pheromone function, cell signaling, behavior, polysaccharide metabolism and arginine kynase activity. The generation and analysis of expressed sequence tags from Atta laevigata have provided important genetic basis for future studies on the biology of leaf-cutting ants and may contribute to the development of a more specific and environmentally friendly method for the control of agricultural pest leafcutters.
Expressed sequence tags from Atta laevigata and identification of candidate genes for the control of pest leaf-cutting ants

PubMed Central

2011-01-01

Background Leafcutters are the highest evolved within Neotropical ants in the tribe Attini and model systems for studying caste formation, labor division and symbiosis with microorganisms. Some species of leafcutters are agricultural pests controlled by chemicals which affect other animals and accumulate in the environment. Aiming to provide genetic basis for the study of leafcutters and for the development of more specific and environmentally friendly methods for the control of pest leafcutters, we generated expressed sequence tag data from Atta laevigata, one of the pest ants with broad geographic distribution in South America. Results The analysis of the expressed sequence tags allowed us to characterize 2,006 unique sequences in Atta laevigata. Sixteen of these genes had a high number of transcripts and are likely positively selected for high level of gene expression, being responsible for three basic biological functions: energy conservation through redox reactions in mitochondria; cytoskeleton and muscle structuring; regulation of gene expression and metabolism. Based on leafcutters lifestyle and reports of genes involved in key processes of other social insects, we identified 146 sequences potential targets for controlling pest leafcutters. The targets are responsible for antixenobiosis, development and longevity, immunity, resistance to pathogens, pheromone function, cell signaling, behavior, polysaccharide metabolism and arginine kynase activity. Conclusion The generation and analysis of expressed sequence tags from Atta laevigata have provided important genetic basis for future studies on the biology of leaf-cutting ants and may contribute to the development of a more specific and environmentally friendly method for the control of agricultural pest leafcutters. PMID:21682882
Isolation, identification, synthesis and biological activity of volatile compounds from the heads of Atta ants

Treesearch

R. G. Riley; R. M. Silverstein; John C. Moser

1974-01-01

S-(+)-4-methyl-3-hetanone has been identified as the principal alarm pheromone of Atta texana and Atta cephalotes. Both enantiomers of 4-methyl-3-heptanone have been synthesized and their biological activities have been compared on both species of ants. Comparison of the geometric averages of responnse rations, at...

An Exploration of Naquib Al-Attas' Theory of Islamic Education as "Ta'Dib" as an 'Indigenous' Educational Philosophy

ERIC Educational Resources Information Center

Ahmed, Farah

2018-01-01

This paper explores the 'indigenous' philosophy of education of Syed Muhammad Naquib al-Attas, a Malay-Muslim scholar who's theoretical work culminated in the establishment of a counter-colonial higher education institution. Through presenting al-Attas' life and philosophy and by exploring the arguments of his critics, I aim to shed light on the…
Leaf-cutting antAtta laevigata (Formicidae: Attini) marks its territory with colony-specific dufour gland secretion.

PubMed

Salzemann, A; Nagnan, P; Tellier, F; Jaffe, K

1992-02-01

The workers of the leaf-cutting antAtta laevigata were found to mark a territory around their nest and along trunk trails. Elsewhere, we reported that the territorial mark had orientation and agonistic functions. The presence of this mark induced an alarm behavior in intruder workers and stimulated the residents' aggressiveness. Of the parts of the body tested, only the extracts from gaster or Dufour gland were able to induce the same agonistic behavior. The compoundsn-heptadecane, (Z)-9-nonadecene, 8,11-nonadecadiene, and (Z)-9-tricosene, secreted by Dufour gland were identified on foraging trails in the field as components of the territorial odor.
Cytogenetic data on the threatened leafcutter ant Atta robusta Borgmeier, 1939 (Formicidae: Myrmicinae: Attini).

PubMed

Barros, Luísa Antônia Campos; Aguiar, Hilton Jeferson Alves Cardoso de; Teixeira, Gisele Amaro; Mariano, Cléa Dos Santos Ferreira; Teixeira, Marcos da Cunha; Delabie, Jacques Hubert Charles; Pompolo, Silvia das Graças

2015-10-01

The karyotype of the threatened ant species Atta robusta is described so as to establish the evolutionary relationships of this taxon with other leafcutter ants. Standard Giemsa staining, C-banding, NOR banding, fluorochromes CMA3/DAPI, Hsc-FA technique and Fluorescence in situ Hybridization (FISH) using 18S rDNA probe were conducted on a population from Aracruz, state of Espírito Santo, Brazil, allowing for comparisons with data available on Atta and other fungus-growing ant species. The diploid chromosome number observed for A. robusta was 2n=22, and the karyotypic formula was 18m+2sm+2st. Heterochromatic blocks were observed in the centromeric region of most chromosomes, where one pair of metacentric chromosomes is characterized by a GC-rich heterochromatic band in the interstitial region of its long arm. The detection of 18S rDNA using FISH confirmed the presence of single NOR for A. robusta. This is the first report of rDNA 18S detection using FISH for leafcutter ants. The cytogenetic results of this study confirm the information available for Atta and allow us to confirm the conserved chromosome number, morphology and banding pattern within the genus for the taxa studied to date, which included species from three out of the four groups of Atta indicated by molecular data. The accumulation of cytogenetic data on fungus-growing ants enhances the understanding of the genomic evolutionary patterns of Atta, since it belongs to a group of recent origin between the most well studied ants. Cytogenetic data does not indicate restrictions in relocation or reintroduction in areas where populations were extinct due to the conserved karyotype. This study allows for cytogenetic comparison of A. robusta with other ants of Atta, emphasizing the importance of chromosomal information for species conservation. Copyright © 2015 Académie des sciences. Published by Elsevier SAS. All rights reserved.
The ATTA-Hefei Instrument for Radioactive Noble-gas Dating

NASA Astrophysics Data System (ADS)

Hu, S.; Cheng, C.; Cheng, G.; Sun, Y. R.; Tu, L.; Yang, G.

2013-12-01

Long-lived noble-gas isotopes 85Kr (10.8 y), 39Ar (269 y) and 81Kr (229 ky) are ideal tracers for dating environmental samples such as groundwater and ice. Together with 14C, these nuclides can be used to cover the whole range of 100-106 y. Atom Trap Trace Analysis (ATTA) is an emerging method for the analysis of these isotopes at an isotopic abundance level as low as 10^-16 [1,2]. The ATTA instrument built in Hefei, China, can determine the isotopic abundances of 85Kr and 81Kr with typically 5-10% accuracy using krypton gas samples of a few micro-liters (STP) krypton gas [3]. The krypton gas sample can be extracted from several liters of air using a distillation-chromatograph setup with a typical efficiency of 85%, while the air sample can be extracted from groundwater or ices. The typical sample size for ATTA measurement is 100L groundwater or 40Kg ices. One such ATTA beamline can handle about 100 samples per year. [1] Chen, C. Y. et al. Ultrasensitive isotope trace analyses with a magneto-optical trap. Science 286, 1139-1141 (1999). [2] Jiang, W. et al. 39Ar detection at the 10-16 isotopic abundance level with atom trap trace analysis. Phys. Rev. Lett. 106, 103001 (2011). [3] Yang, G. -M. et al. Analysis of 85Kr: a comparison at the 10-14 level using micro-liter samples, Sci. Rep. 3, 1596 (2013). Relative uncertainty of the determined 85Kr abundance by the ATTA-Hefei instrument.
Initial deployment of the cardiogenic gene regulatory network in the basal chordate, Ciona intestinalis.

PubMed

Woznica, Arielle; Haeussler, Maximilian; Starobinska, Ella; Jemmett, Jessica; Li, Younan; Mount, David; Davidson, Brad

2012-08-01

The complex, partially redundant gene regulatory architecture underlying vertebrate heart formation has been difficult to characterize. Here, we dissect the primary cardiac gene regulatory network in the invertebrate chordate, Ciona intestinalis. The Ciona heart progenitor lineage is first specified by Fibroblast Growth Factor/Map Kinase (FGF/MapK) activation of the transcription factor Ets1/2 (Ets). Through microarray analysis of sorted heart progenitor cells, we identified the complete set of primary genes upregulated by FGF/Ets shortly after heart progenitor emergence. Combinatorial sequence analysis of these co-regulated genes generated a hypothetical regulatory code consisting of Ets binding sites associated with a specific co-motif, ATTA. Through extensive reporter analysis, we confirmed the functional importance of the ATTA co-motif in primary heart progenitor gene regulation. We then used the Ets/ATTA combination motif to successfully predict a number of additional heart progenitor gene regulatory elements, including an intronic element driving expression of the core conserved cardiac transcription factor, GATAa. This work significantly advances our understanding of the Ciona heart gene network. Furthermore, this work has begun to elucidate the precise regulatory architecture underlying the conserved, primary role of FGF/Ets in chordate heart lineage specification. Copyright © 2012 Elsevier Inc. All rights reserved.
A volatile trail Pheromone of the Leaf-Cutting Ant, Atta Texana

Treesearch

J. H. Tumlinson; John C. Moser; R. M. Silverstein; R. G. Brownlee; J. M. Ruth

1972-01-01

The major volatile trail-marking pheromone of the Texas leaf-cutting Ant, Atta texana, was isolated, identified as methyl 4-methylpyrrole-2-carboxylate, and synthesized. The synthesized pheromone elicited strong trail-following response from workers in the laboratory and field.
Differences in Forage-Acquisition and Fungal Enzyme Activity Contribute to Niche Segregation in Panamanian Leaf-Cutting Ants

PubMed Central

Kooij, Pepijn W.; Liberti, Joanito; Giampoudakis, Konstantinos; Schiøtt, Morten; Boomsma, Jacobus J.

2014-01-01

The genera Atta and Acromyrmex are often grouped as leaf-cutting ants for pest management assessments and ecological surveys, although their mature colony sizes and foraging niches may differ substantially. Few studies have addressed such interspecific differences at the same site, which prompted us to conduct a comparative study across six sympatric leaf-cutting ant species in Central Panama. We show that foraging rates during the transition between dry and wet season differ about 60 fold between genera, but are relatively constant across species within genera. These differences appear to match overall differences in colony size, especially when Atta workers that return to their nests without leaves are assumed to carry liquid food. We confirm that Panamanian Atta specialize primarily on tree-leaves whereas Acromyrmex focus on collecting flowers and herbal leaves and that species within genera are similar in these overall foraging strategies. Species within genera tended to be spaced out over the three habitat categories that we distinguished (forest, forest edge, open grassland), but each of these habitats normally had only a single predominant Atta and Acromyrmex species. We measured activities of twelve fungus garden decomposition enzymes, belonging to the amylases, cellulases, hemicellulases, pectinases and proteinases, and show that average enzyme activity per unit of fungal mass in Atta gardens is lower than in Acromyrmex gardens. Expression profiles of fungal enzymes in Atta also appeared to be more specialized than in Acromyrmex, possibly reflecting variation in forage material. Our results suggest that species- and genus-level identities of leaf-cutting ants and habitat-specific foraging profiles may give predictable differences in the expression of fungal genes coding for decomposition enzymes. PMID:24718261
ATTA-3: a State-of-the-Art Instrument for Radio-Krypton Dating

NASA Astrophysics Data System (ADS)

Jiang, W.; Zappala, J. C.; Bailey, K.; Lu, Z.; Müller, P.; O'Connor, T. P.

2013-12-01

The ATTA-3 instrument at Argonne has recently enabled routine Kr-81 dating. The instrument is based on Atom Trap Trace Analysis (ATTA), a novel laser based atom counting technique that allows detection of long lived noble gas radioisotopes (Kr-81, Kr-85 and Ar-39) with extremely low abundance (1E-16 to 1E-10). At the center of the instrument is a magneto-optical trap (MOT), which traps and counts only the atoms of the desired isotope. This unique feature makes ATTA free of interference from any other isotopes or molecular species. For Kr-81 dating in the age range of 150 - 1,500 kyr, the required sample size is 5 - 10 micro-L STP of krypton gas, which can be extracted from approximately 100 - 200 kg of water or 40 - 80 kg of ice. Several recent developments in our lab may lead to further improvements to the current ATTA-3 apparatus: 1) The isotopic abundance ratio between the unknown, rare isotope (either Kr-81 or Kr-85) and the stable, abundant isotope (Kr-83) is measured. Here the stable isotope serves as a control isotope. A new method has been developed that allows more accurate measurements of the control isotope Kr-83. Combined with the ability to measure the rare Kr-81 and Kr-85 isotopes, this scheme allows ATTA-3 to directly determine 81Kr/Kr and 85Kr/Kr ratios without other supplemental measurements, to reduce the overall uncertainties of the measured isotope ratios, and also to improve the long term stability of the system. 2) The current capacity of the ATTA-3 instrument is about 120 samples per year. The throughput is mainly limited by the so called 'memory effect', which is caused by the residual samples trapped in the system after each measurement. These residual samples are gradually released in subsequent measurements, causing cross-sample contaminations. In order to mitigate this problem, we wash the system with a xenon discharge for about 36 hours between measurements. This practice limits the overall sample processing speed. Preliminary investigations of the memory effect indicate that it can be reduced and the wash time between measurements shortened. This will increase the number of samples that the ATTA-3 instrument can handle annually in the future. This work is supported by DOE, Office of Nuclear Physics, under contract DE-AC02-06CH11357.
Functional role of phenylacetic acid from metapleural gland secretions in controlling fungal pathogens in evolutionarily derived leaf-cutting ants.

PubMed

Fernández-Marín, Hermógenes; Nash, David R; Higginbotham, Sarah; Estrada, Catalina; van Zweden, Jelle S; d'Ettorre, Patrizia; Wcislo, William T; Boomsma, Jacobus J

2015-05-22

Fungus-farming ant colonies vary four to five orders of magnitude in size. They employ compounds from actinomycete bacteria and exocrine glands as antimicrobial agents. Atta colonies have millions of ants and are particularly relevant for understanding hygienic strategies as they have abandoned their ancestors' prime dependence on antibiotic-based biological control in favour of using metapleural gland (MG) chemical secretions. Atta MGs are unique in synthesizing large quantities of phenylacetic acid (PAA), a known but little investigated antimicrobial agent. We show that particularly the smallest workers greatly reduce germination rates of Escovopsis and Metarhizium spores after actively applying PAA to experimental infection targets in garden fragments and transferring the spores to the ants' infrabuccal cavities. In vitro assays further indicated that Escovopsis strains isolated from evolutionarily derived leaf-cutting ants are less sensitive to PAA than strains from phylogenetically more basal fungus-farming ants, consistent with the dynamics of an evolutionary arms race between virulence and control for Escovopsis, but not Metarhizium. Atta ants form larger colonies with more extreme caste differentiation relative to other attines, in societies characterized by an almost complete absence of reproductive conflicts. We hypothesize that these changes are associated with unique evolutionary innovations in chemical pest management that appear robust against selection pressure for resistance by specialized mycopathogens. © 2015 The Author(s) Published by the Royal Society. All rights reserved.
Functional role of phenylacetic acid from metapleural gland secretions in controlling fungal pathogens in evolutionarily derived leaf-cutting ants

PubMed Central

Fernández-Marín, Hermógenes; Nash, David R.; Higginbotham, Sarah; Estrada, Catalina; van Zweden, Jelle S.; d'Ettorre, Patrizia; Wcislo, William T.; Boomsma, Jacobus J.

2015-01-01

Fungus-farming ant colonies vary four to five orders of magnitude in size. They employ compounds from actinomycete bacteria and exocrine glands as antimicrobial agents. Atta colonies have millions of ants and are particularly relevant for understanding hygienic strategies as they have abandoned their ancestors' prime dependence on antibiotic-based biological control in favour of using metapleural gland (MG) chemical secretions. Atta MGs are unique in synthesizing large quantities of phenylacetic acid (PAA), a known but little investigated antimicrobial agent. We show that particularly the smallest workers greatly reduce germination rates of Escovopsis and Metarhizium spores after actively applying PAA to experimental infection targets in garden fragments and transferring the spores to the ants' infrabuccal cavities. In vitro assays further indicated that Escovopsis strains isolated from evolutionarily derived leaf-cutting ants are less sensitive to PAA than strains from phylogenetically more basal fungus-farming ants, consistent with the dynamics of an evolutionary arms race between virulence and control for Escovopsis, but not Metarhizium. Atta ants form larger colonies with more extreme caste differentiation relative to other attines, in societies characterized by an almost complete absence of reproductive conflicts. We hypothesize that these changes are associated with unique evolutionary innovations in chemical pest management that appear robust against selection pressure for resistance by specialized mycopathogens. PMID:25925100
Contents and Structure Atta texana Nest in Summer

Treesearch

John C. Moser

1963-01-01

A large nest of Atta texana (Buckley) in central Louisiana was partially excavated in August 1960. Twelve dormancy, 5 detritus, and 93 fungus-garden cavities were found. Fungus-garden cavities near the surface outnumbered those at lower depths and contained most of the fungus material and brood. Inquilines were most numerous in detritus cavities....
Synthetic analogs of the trail pheromone of the leaf-cutting ant, Atta texana (Buckley)

Treesearch

Philip E. Sonnet; John C. Moser

1972-01-01

The preparation and bioassay of a number of analogs of the trail-following pheromone of the town ant, Atta texana (Buckley), are described. Although several compounds were quite active, isomers of the pheromone were not. The results are discussed wit ha vew to the probable conformations of these molecules.
Comparative morpho-physiology of the metapleural glands of two Atta leaf-cutting ant queens nesting in clayish and organic soils.

PubMed

Vieira, Alexsandro Santana; Camargo-Mathias, Maria Izabel; Roces, Flavio

2015-09-01

Queens of leaf-cutting ants found their nests singly, each consisting of a vertical tunnel and a final horizontal chamber. Because of the claustral mode of nest founding, the queen and/or her initial fungus garden are exposed to threats imposed by several soil pathogens, and the antibiotic secretions produced by their metapleural glands are considered a main adaptation to deal with them. Nests of two Atta leaf-cutting ant species, Atta vollenweideri and Atta sexdens rubropilosa, occur in different soil types, alfisols and oxisols. Their queens are known to excavate the initial nest in different soil horizons, clayish and organic, respectively, which differ in their fertility and associated microbiota. The aim of the present study was to comparatively investigate the morpho-physiology of the metapleural glands in queens of A. vollenweideri and A. sexdens rubropilosa, addressing the question whether the distinct selective pressure imposed by the microbiota in the two different soil types led to morpho-physiological differences in the metapleural glands that were consistent with their antiseptic function. The results revealed that metapleural glands of A. sexdens rubropilosa have a larger number of secretory cells, and consequently a higher production of antibiotic secretions, which may have been selected to allow nest founding at the superficial horizon of oxisols rich in organic matter and microorganisms. Glands of A. vollenweideri, on the contrary, presented fewer secretory cells, suggesting less production of antibiotic secretions. We argue that the excavation of deep founding nests in A. vollenweideri was primarily selected for during evolution to avoid the risk posed by flooding, and further hypothesize that a reduced number of cells in their metapleural glands occurred because of a weak pathogen-driven selective pressure at the preferred soil depth. Copyright © 2015 Elsevier Ltd. All rights reserved.
Extended-Range Passive RFID and Sensor Tags

NASA Technical Reports Server (NTRS)

Fink, Patrick W.; Kennedy, Timothy F.; Lin, Gregory Y.; Barton, Richard

2012-01-01

Extended-range passive radio-frequency identification (RFID) tags and related sensor tags are undergoing development. A tag of this type incorporates a retroreflective antenna array, so that it reflects significantly more signal power back toward an interrogating radio transceiver than does a comparable passive RFID tag of prior design, which does not incorporate a retroreflective antenna array. Therefore, for a given amount of power radiated by the transmitter in the interrogating transceiver, a tag of this type can be interrogated at a distance greater than that of the comparable passive RFID or sensor tag of prior design. The retroreflective antenna array is, more specifically, a Van Atta array, named after its inventor and first published in a patent issued in 1959. In its simplest form, a Van Atta array comprises two antenna elements connected by a transmission line so that the signal received by each antenna element is reradiated by the other antenna element (see Figure 1). The phase relationships among the received and reradiated signals are such as to produce constructive interference of the reradiated signals; that is, to concentrate the reradiated signal power in a direction back toward the source. Hence, an RFID tag equipped with a Van Atta antenna array automatically tracks the interrogating transceiver. The effective gain of a Van Atta array is the same as that of a traditional phased antenna array having the same number of antenna elements. Additional pairs of antenna elements connected by equal-length transmission lines can be incorporated into a Van Atta array to increase its directionality. Like some RFID tags here-to-fore commercially available, an RFID or sensor tag of the present developmental type includes one-port surface-acoustic-wave (SAW) devices. In simplified terms, the mode of operation of a basic one-port SAW device as used heretofore in an RFID device is the following: An interrogating radio signal is converted, at an input end, from an electrical signal to an acoustic wave that propagates along a surface and encounters multiple reflectors suitably positioned along the surface. Upon returning to the input end, the reflected acoustic wave is re-converted to an electrical signal, which, in turn, is reradiated from an antenna. The distances between the reflectors in the SAW device and the corresponding times between reflections encode the identifying or sensory information onto the reradiated signal. The fundamental problem in the present development is how to combine a Van Atta antenna array (which is inherently a multiple-port device) and one or more one-port SAW device(s) into a single, compact, passive unit that can function as a retroreflective RFID tag. The solution is to use one or more hybrid, half-power 90 couplers. A basic unit of this type, shown in Figure 2, includes a half-power 90 hybrid coupler; two identical SAW devices (SAW1 and SAW2) connected to ports 3 and 4 of the coupler, respectively; and antenna elements connected to ports 1 and 2 of the coupler. Necessarily omitting details for the sake of brevity, it must suffice to report that the phase relationships among the coupler inputs and outputs are such as to couple the incident signal from the antenna elements to the SAW devices and couple the reflected signals from the SAW devices back to the antenna elements in the phase relationships required for a Van Atta array. Hence, the reradiated signal is automatically directed back toward the interrogating transceiver and contains identifying and/or sensory information encoded in time intervals between reflections.
Mating activities of Atta texana (Hymenoptera, Formicidae)

Treesearch

John C. Moser

1967-01-01

The town ant, Atta texana (Buckley) is the northernmost representative of the most specialized genus of Attini, a New World tribe of fungus-growing myrmicine ants. Colonies are found in central Louisiana; easter, central and southern Texas; and eastern Mexico as far south as Vera Cruz. They are restricted to sandy soils and are usually located on...
Technical Manual for Attitudes Towards Teaching All Students (ATTAS-mm) Instrument

ERIC Educational Resources Information Center

Gregory, Jess L.; Noto, Lori A.

2012-01-01

The general education teacher has the greatest influence on a student's success in school, and a teacher's attitude towards inclusion is a major factor in determining whether inclusion will be successful. The ATTAS-mm is a 9-item scale with strong reliability and validity. The three subscales: believing all students can succeed in general…
Pholeomyia comans (Diptera: Milichiidae) an associate of Atta texana: larval anatomy and notes on biology

Treesearch

John C. Moser; Stuart E. Neff

1971-01-01

Adults of Pholeomyia comans enter the nests of Atta texana and lay eggs in the underground detritus cavities, where the maggots feed on exhausted fungus garden substrate and nest refuse recently deposited by workers. The thirdstage larva and the puparium are described. A diapriid wasp was obtained from P. comans puparia. One...
Trail Pheromones: Responses of the Texas Leafcutting Ant, Atta texana to Select Halo- and Cyanopyrrole-2-Aldehydes, Ketones, and Esters

Treesearch

P. E. Sonnet; John C. Moser

1973-01-01

Several halo- and cyanopyrroles related to the trail pheromone of Atta texana (Buckley), were prepared and tested by a faster and more sensitive bioassay that was previously available. Responsiveness of the ants in descending order to these compounds, based on the substituent in the number two position, is: esters, methyl ketones, aldehydes. Slight...
Comparative physical mapping of 18S rDNA in the karyotypes of six leafcutter ant species of the genera Atta and Acromyrmex (Formicidae: Myrmicinae).

PubMed

Teixeira, Gisele Amaro; Barros, Luísa Antônia Campos; de Aguiar, Hilton Jeferson Alves Cardoso; das Graças Pompolo, Silvia

2017-10-01

Leafcutter ants of the Atta and Acromyrmex genera are important plagues in different cultures. Cytogenetic data on chromosome number, morphology, and chromosomal banding pattern are only available for 17 species of leafcutter ants. Molecular cytogenetic data for the detection of ribosomal genes by the FISH technique are scarce, and only 15 Neotropical ant species have been studied. This study aimed to physically map the 18S ribosomal RNA genes (rDNA) of six leafcutter ants belonging to the genera Atta and Acromyrmex using FISH. The results were compared with data on the fluorochrome CMA 3 currently available for these species. All analyzed species presented the 18S rDNA on one pair of chromosomes. In Acromyrmex subterraneus molestans and Ac. aspersus, FISH signals were observed in the terminal region of the short arm of the largest subtelocentric pair, while in Atta bisphaerica, A. laevigata, and A. sexdens, FISH signals were observed in the interstitial region of the long arm of the fourth metacentric pair. In Acromyrmex striatus, 18S rDNA was located in the interstitial region of the second metacentric pair. The karyotypic formula for Ac. aspersus was 2n = 38 (8m + 10sm + 16st + 4a), representing the first report in this species. The observed 18S rDNA regions in A. laevigata, A. sexdens, A. bisphaerica, Ac. aspersus, and Ac. subterraneus molestans corresponded to the CMA 3 + bands, while in Ac. striatus, several GC-rich bands and one pair of 18S rDNA bands were observed. No differential bands were visible using the DAPI fluorochrome. Karyotype uniformity with previously studied Atta spp. was also observed at the level of molecular cytogenetics using 18S rDNA FISH. A difference in the size of the chromosomal pair carrying the 18S rDNA gene was observed in Ac. striatus (2n = 22) and Atta spp. (2n = 22) highlighting the dissimilarity between these species. The results from the present study contribute to the description of 18S rDNA clusters in Neotropical ants.
Atom Trap Trace Analysis: Developments & Applications

NASA Astrophysics Data System (ADS)

Zappala, Jake Christopher

Atom Trap Trace Analysis (ATTA) is an efficient and selective laser-based atom counting technique that provides radiokrypton 81Kr and 85Kr dating to the earth science community. 81Kr (half-life = 230,000 yr) is an ideal tracer for old water and ice with mean residence times of 105-106 years, a range beyond the reach of 14C-dating. 85Kr (half-life = 10.7 yr) is an increasingly important tracer for young groundwater in the age range of 5-50 years. Over the past three years, we have implemented a number of developments that have improved the precision and efficiency of the ATTA technique. These developments have further allowed us to make new leaps in the analysis of both isotopes. For 81Kr, we have demonstrated measurements of 81Kr/Kr with relative one-sigma uncertainties of 1% and placed an improved limit on anthropogenic 81Kr in the atmosphere, removing a systematic constraint to high precision 81Kr-dating. For 85Kr, we have developed new methodologies that increase sample throughput from 1 sample every 48 hours to 6 samples in 24 hours. All the while, we have used the ATTA-3 system at Argonne National Laboratory to continue and provide sample measurements to the scientific community and have now completed over 230 measurements in more than 25 collaborative projects which together span all seven continents. Finally we have investigated options for further development of the ATTA technique given the growing demand and new applications present within the scientific community at large. Ultimately, we aspire, through ATTA, to make radiokrypton dating as readily and easily available as radiocarbon dating.

A new genus and species of Macrochelidae (Acari:Mesostigmata) associated with the Texas leaf cutting ant, Atta texana (Buckley) in Louisiana, USA

Treesearch

Gerald W. Krantz; John Moser

2012-01-01

Adults and nymphs of a new genus and species of the family Macrochelidae are described from detritus cavities of the leaf-cutting ant, Atta texana. This new species is notable in having peritremes with no posterior loop, a series of small subterminal teeth on the fixed cheliceral digit rather than the single large tooth typical of other macrochelids...
Ittigahat wa Nozom at-Ta lim fi al-Gonhouriyyah al-Arabiyyah al-Mouttahidah wa Makanat at-ta lim at-tougari fiha (Education in the United Arab Republic: Its Structure and Orientation, and the Position of Commercial Studies within the Educational System).

ERIC Educational Resources Information Center

Ministry of Education, Cairo (United Arab Republic).

This document is an English-language abstract (approximately 1,500 words) surveying Egyptian education. Elementary education is compulsory. It begins between the ages of six and eight and lasts six years. The curriculum includes Arabic, religion, social subjects, hygiene, arithmetic, community singing, music, physical education, drawing and…
Creative Thinking, Professional Artists, and Parkinson's Disease.

PubMed

Canesi, Margherita; Rusconi, Maria Luisa; Moroni, Federica; Ranghetti, Alessandra; Cereda, Emanuele; Pezzoli, Gianni

2016-01-01

An increase in artistic-like production in Parkinson's disease (PD) has been associated with compulsive and repetitive behaviours after the introduction of dopaminergic treatment (DT). Recent data suggest that it could be due to the emergence of artistic-like skills triggered by DT. In order to evaluate whether artistic production and creative thinking are influenced by DT or linked to artistic-like skills, we characterize creativity features in PD and healthy controls (HC) including professional artists. Three groups of PD out-patients were included consecutively: professional artists (PD-A), patients with (PD-C) and without artistic-like production (PD-NC). Twenty-four gender and age-matched HC were included: professional artists (HC-A) and non-artists (HC-NC). All patients were evaluated by means of a) a battery of neuropsychological tests and a semi-structured interview; b) the Abbreviated Torrance Test for Adults (ATTA) for creative thinking; c) the Minnesota Impulsive Disorders Interview (mMIDI) and a screening for impulse control disorders (ICDs) for compulsive behaviour. ATTA total score was significantly higher in HC-A and PD-A than in the other groups. Although PD-NC showed the lowest ATTA total score the difference vs HC-NC was not significant. ATTA scores were not significantly correlated with DT dosage and duration. mMIDI tests were positive only in PD. There were no differences in ICDs among PD groups. Our results do not support a relationship between DT and the emergence of artistic creativity. We believe that DT may increase the drive to create and that further studies in "on" and "off" medication are needed to clarify this issue.
Discovering the Giant Nest Architecture of Grass-Cutting Ants, Atta capiguara (Hymenoptera, Formicidae)

PubMed Central

Forti, Luiz Carlos; Protti de Andrade, Ana Paula; Camargo, Roberto da Silva; Caldato, Nadia; Moreira, Aldenise Alves

2017-01-01

Atta capiguara is a grass-cutting ant species frequently found in Cerrado biome. However, little is known about the giant nest architecture of this ant. In this study, we investigated the architecture of three A. capiguara nests from a fragment of Cerrado in Botucatu, São Paulo, Brazil. Casts were made of the nests by filling them with cement to permit better visualization of internal structures such as chambers and tunnels. After excavation, the depth and dimensions (length, width, and height) of the chambers were measured. The results showed the shape of Atta capiguara nests consisting of mounds of loose soil with unique features resembling a conic section. The fungus chambers were found distant from the mound of loose soil and were spaced apart and distributed laterally at the soil profile. The waste chambers were located beneath the largest mound of loose soil. Both the fungus and waste chambers were separated and distant. Our study contributes to a better understanding of the so far unknown nest architecture of the grass-cutting ant A. capiguara. PMID:28350352
A chimeric protein of aluminum-activated malate transporter generated from wheat and Arabidopsis shows enhanced response to trivalent cations.

PubMed

Sasaki, Takayuki; Tsuchiya, Yoshiyuki; Ariyoshi, Michiyo; Ryan, Peter R; Yamamoto, Yoko

2016-07-01

TaALMT1 from wheat (Triticum aestivum) and AtALMT1 from Arabidopsis thaliana encode aluminum (Al)-activated malate transporters, which confer acid-soil tolerance by releasing malate from roots. Chimeric proteins from TaALMT1 and AtALMT1 (Ta::At, At::Ta) were previously analyzed in Xenopus laevis oocytes. Those studies showed that Al could activate malate efflux from the Ta::At chimera but not from At::Ta. Here, functions of TaALMT1, AtALMT1 and the chimeric protein Ta::At were compared in cultured tobacco BY-2 cells. We focused on the sensitivity and specificity of their activation by trivalent cations. The activation of malate efflux by Al was at least two-fold greater in the chimera than the native proteins. All proteins were also activated by lanthanides (erbium, ytterbium, gadolinium, and lanthanum), but the chimera again released more malate than TaALMT1 or AtALMT1. In Xenopus oocytes, Al, ytterbium, and erbium activated inward currents from the native TaALMT1 and the chimeric protein, but gadolinium only activated currents from the chimera. Lanthanum inhibited currents from both proteins. These results demonstrated that function of the chimera protein was altered compared to the native proteins and was more responsive to a range of trivalent cations when expressed in plant cells. Copyright © 2016 Elsevier B.V. All rights reserved.
Assessment of Accelerated Acquisition of Defense Programs

DTIC Science & Technology

2016-09-01

I N S T I T U T E F O R D E F E N S E A N A L Y S E S Assessment of Accelerated Acquisition of Defense Programs Richard H. Van Atta R. Royce...Defense for Acquisition . The views, opinions, and findings should not be construed as representing the official position of either the Department of...S T I T U T E F O R D E F E N S E A N A L Y S E S IDA Paper P-8161 Assessment of Accelerated Acquisition of Defense Programs Richard H. Van Atta
Effect of dietary curries on the glycaemic index.

PubMed

Pirasath, S; Thayaananthan, K; Balakumar, S; Arasaratnam, V

2010-12-01

Determination of the glycaemic index (GI) of different basic foods in combination with different curries. METHODS; Healthy volunteers (n = 20) of 21.05 (+/- 0.92) years old, 53.90 (+/- 9.36) kg in body weight, 153.92 (+/- 9.15) cm in height and 20.55 (+/- 2.22) kgm(-2) of body mass index were included. After overnight fasting, 75g of glucose and each test food containing 75g of digestible carbohydrate were administered and blood glucose level measured half hourly for two hours. The GI was calculated and analysed by randomised complete block design using SAS analytical package. The mean GI values of parboiled rice ('Mottaikarupan') either with green leaf curry (Amaranthus) or gravy (soya meat) or green leaf curry and gravy were 47.47 (+/- 11.21), 56.30 (+/- 9.31) and 54.67 (+/- 10.03) % respectively. The mean GI of 'kurakkan pittu' (Eleucine coracana) with the above curries were 57.51 (+/- 5.52), 63.25 (+/- 8.86) and 59.25 (+/- 5.49) % respectively. The mean GI of 'atta pittu' (whole wheat grain flour) with the above curries were 44.40 (+/-14.27), 50.80 (+/- 9.35) and 46.29 (+/- 8.90) % respectively. The GI of parboiled rice or 'kurakkan pittu' or 'atta pittu' with green leaf curry differed significantly (p < 0.05) from other combined foods. The GI of parboiled rice or 'kurakkan pittu' or 'atta pittu' with gravy or green leaf curry and gravy did not differ significantly (p > 0.05) among them. 'Kurakkan pittu' is inferior to 'atta pittu' and parboiled rice. Including curries to basic foods altered the GI. Therefore, when dietary advice is given to diabetic patients, not only the basic foods, but also the curries to be consumed have to be considered.
Household Coverage of Fortified Staple Food Commodities in Rajasthan, India.

PubMed

Aaron, Grant J; Sodani, Prahlad R; Sankar, Rajan; Fairhurst, John; Siling, Katja; Guevarra, Ernest; Norris, Alison; Myatt, Mark

2016-01-01

A spatially representative statewide survey was conducted in Rajasthan, India to assess household coverage of atta wheat flour, edible oil, and salt. An even distribution of primary sampling units were selected based on their proximity to centroids on a hexagonal grid laid over the survey area. A sample of n = 18 households from each of m = 252 primary sampling units PSUs was taken. Demographic data on all members of these households were collected, and a broader dataset was collected about a single caregiver and a child in the first 2 years of life. Data were collected on demographic and socioeconomic status; education; housing conditions; recent infant and child mortality; water, sanitation, and hygiene practices; food security; child health; infant and young child feeding practices; maternal dietary diversity; coverage of fortified staples; and maternal and child anthropometry. Data were collected from 4,627 households and the same number of caregiver/child pairs. Atta wheat flour was widely consumed across the state (83%); however, only about 7% of the atta wheat flour was classified as fortifiable, and only about 6% was actually fortified (mostly inadequately). For oil, almost 90% of edible oil consumed by households in the survey was classified as fortifiable, but only about 24% was fortified. For salt, coverage was high, with almost 85% of households using fortified salt and 66% of households using adequately fortified salt. Iodized salt coverage was also high; however, rural and poor population groups were less likely to be reached by the intervention. Voluntary fortification of atta wheat flour and edible oil lacked sufficient industry consolidation to cover significant portions of the population. It is crucial that appropriate delivery channels are utilized to effectively deliver essential micronutrients to at-risk population groups. Government distribution systems are likely the best means to accomplish this goal.
Life-history traits and parasitism rates of four phorid species (Diptera: Phoridae), parasitoids of Atta vollenweideri (Hymenoptera: Formicidae) in Argentina.

PubMed

Guillade, Andrea C; Folgarait, Patricia J

2011-02-01

Leaf-cutting ants in the genus Atta F. (Formicidae, Attini) are among the most important pest arthropods in Central and South America, consuming more vegetation than any other animal group. Among the organisms attacking ants in nature, flies of the family Phoridae have been proposed as the most promising biocontrol agents for pest ants. Four phorid species, Apocephalus setitarsus Brown, Myrmosicarius brandaoi Disney, Myrmosicarius gonzalezae Disney, and Eibesfeldtphora trilobata Disney, were reared from ants collected at Atta vollenweideri Forel nests and off foraging trails in Santa Fe province in Argentina. E. trilobata attacked larger ants and had bigger adults than the other species, also exhibiting the longest developmental time. Correlations between size of hosts and size of adults, as well as between size of adults and developmental times, could be established only in some cases. No differences were found between the sizes of the hosts from which males and females emerged. The natural percentage of parasitism varied throughout the seasons and seemed to be influenced by the extreme drought affecting the study site. We discuss why all four species would be suitable candidates for integrating an assemblage of biocontrol agents against A. vollenweideri.
Developmental regulation of gonadotropin-releasing hormone gene expression by the MSX and DLX homeodomain protein families.

PubMed

Givens, Marjory L; Rave-Harel, Naama; Goonewardena, Vinodha D; Kurotani, Reiko; Berdy, Sara E; Swan, Christo H; Rubenstein, John L R; Robert, Benoit; Mellon, Pamela L

2005-05-13

Gonadotropin-releasing hormone (GnRH) is the central regulator of the hypothalamic-pituitary-gonadal axis, controlling sexual maturation and fertility in diverse species from fish to humans. GnRH gene expression is limited to a discrete population of neurons that migrate through the nasal region into the hypothalamus during embryonic development. The GnRH regulatory region contains four conserved homeodomain binding sites (ATTA) that are essential for basal promoter activity and cell-specific expression of the GnRH gene. MSX and DLX are members of the Antennapedia class of non-Hox homeodomain transcription factors that regulate gene expression and influence development of the craniofacial structures and anterior forebrain. Here, we report that expression patterns of the Msx and Dlx families of homeodomain transcription factors largely coincide with the migratory route of GnRH neurons and co-express with GnRH in neurons during embryonic development. In addition, MSX and DLX family members bind directly to the ATTA consensus sequences and regulate transcriptional activity of the GnRH promoter. Finally, mice lacking MSX1 or DLX1 and 2 show altered numbers of GnRH-expressing cells in regions where these factors likely function. These findings strongly support a role for MSX and DLX in contributing to spatiotemporal regulation of GnRH transcription during development.
Gene Expression Profile Analysis is Directly Affected by the Selected Reference Gene: The Case of Leaf-Cutting Atta Sexdens

PubMed Central

Máximo, Wesley P. F.; Zanetti, Ronald; Paiva, Luciano V.

2018-01-01

Although several ant species are important targets for the development of molecular control strategies, only a few studies focus on identifying and validating reference genes for quantitative reverse transcription polymerase chain reaction (RT-qPCR) data normalization. We provide here an extensive study to identify and validate suitable reference genes for gene expression analysis in the ant Atta sexdens, a threatening agricultural pest in South America. The optimal number of reference genes varies according to each sample and the result generated by RefFinder differed about which is the most suitable reference gene. Results suggest that the RPS16, NADH and SDHB genes were the best reference genes in the sample pool according to stability values. The SNF7 gene expression pattern was stable in all evaluated sample set. In contrast, when using less stable reference genes for normalization a large variability in SNF7 gene expression was recorded. There is no universal reference gene suitable for all conditions under analysis, since these genes can also participate in different cellular functions, thus requiring a systematic validation of possible reference genes for each specific condition. The choice of reference genes on SNF7 gene normalization confirmed that unstable reference genes might drastically change the expression profile analysis of target candidate genes. PMID:29419794
On the morphology of the worker immatures of the leafcutter ant Atta sexdens Linnaeus (Hymenoptera: Formicidae).

PubMed

Solis, Daniel Russ; Fox, Eduardo Gonçalves Paterson; Ceccato, Marcela; Reiss, Itamar Cristina; Décio, Pâmela; Lorenzon, Natalia; Da Silva, Natiele Gonçalves; Bueno, Odair Correa

2012-08-01

Leafcutter ants of the genus Atta Fabricius are serious agricultural pests. Morphological studies of immature stages within this group are few, and the data provided for species of considerable importance are usually incomplete. In this study, the immatures of Atta sexdens Linnaeus are described and compared using light and scanning electron microscopy. Only specimens from founding stage colonies (i.e., lacking adult workers) were used. The existence of four larval instars was estimated by a frequency plot of maximum head widths, and the larvae of different instars differed from each other mainly by their bodily dimensions. Worker larvae belonged to two distinct morphological castes: (1) gardeners and nurses and (2) within-nest generalists. The worker larvae described in this study differed from a previous description of the same species by the following traits: the existence of a genal lobe, the number of clypeal hairs, the presence of two hairs on the ninth abdominal somite, the presence of hairs on the anterior surface of the labrum, and the shape of the maxillary palpus. This study provides a comparative analysis of immature stages of A. sexdens that may be relevant to future morphological and biological studies of the Attini. Copyright © 2012 Wiley Periodicals, Inc.
Leaf-cutting ants: an unexpected microenvironment holding human opportunistic black fungi.

PubMed

Duarte, A P M; Attili-Angelis, D; Baron, N C; Forti, L C; Pagnocca, F C

2014-09-01

Fungus-growing ants of the genus Atta are known for their leaf-cutting habit, a lifestyle they have maintained since their 50-million-year-old co-evolution with a mutualistic fungus, cultivated as food. Recent studies have highlighted that, in addition to the mutualistic fungus, nests of ants harbor a great diversity of microbial communities. Such microorganisms include the dematiaceous fungi, which are characterized by their melanized cell walls. In order to contribute to the knowledge of fungal ecology, as well as opportunistic strains that may be dispersed by these social insects, we isolated and identified fungi carried by gynes of Atta capiguara and Atta laevigata, collected from colonies located in Fazenda Santana, Botucatu (São Paulo, Brazil). The isolation was carried out using the oil flotation technique, which is suitable for the growth of black fungi. Inoculated plates were incubated at 25 and 35 °C until black cultures were visible (20-45 days). Isolates were identified based on microscopic and molecular characteristics. Some isolated genera were: Cladophialophora, Cladosporium, Exophiala, Ochroconis, Phaeococcomyces, Phialophora and Penidiella. Hyaline species were also found. The results obtained from this work showed that leaf-cutting gynes may contribute to the dispersal of opportunistic dematiaceous fungi. It is suggested that more attention should be paid to this still unexplored subject.
Harsh Working Conditions and Poor Eating Habits: Health-Related Concerns of Female Head Porters (Kayayei) in the Mallam Atta Market, Accra, Ghana.

PubMed

Nyarko, Samuel Harrenson; Tahiru, Abdul Majeed

2018-01-01

The kaya business is known to pose significant health-related risks to female migrants. This study sought to explore the health-related concerns of female head porters in the Mallam Atta market, Accra, Ghana. A qualitative study was conducted in which twenty female head porters at the Mallam Atta market in Accra were interviewed. A thematic analysis was performed and the emerging themes were presented and supported with quotations from the respondents. Poor accommodation and eating habits, harsh working conditions, and lack of knowledge about health conditions exposed the respondents to several health-related concerns like neck pains, skin rashes, malaria, cholera, and stomach ache among other infections. The popular means of seeking health care was through purchasing drugs from pharmacies or drug peddlers instead of health facilities. Financial constraints, lack of faith in the National Health Insurance Scheme, and long waiting periods at the health facilities militated against seeking appropriate health care at the hospitals and clinics. Political willpower needs to be strengthened for poverty reduction strategies such as training of hairdressing, dress and soap making, and shea butter processing for women from the Northern regions in order to ameliorate their livelihoods and/or reduce migration to the south.
Modeling of intercontinental Saharan dust transport: What consequences on atmospheric concentrations and deposition fluxes in the Caribbean?

NASA Astrophysics Data System (ADS)

Laurent, Benoit; Formenti, Paola; Desboeufs, Karine; Vincent, Julie; Denjean, Cyrielle; Siour, Guillaume; Mayol-Bracero, Olga L.

2015-04-01

The Dust Aging and Transport from Africa to the Caribbean (Dust-AttaCk) project aims todocument the physical and optical properties of long-range transported African dust to the Caribbean. A comprehensive field campaign was conducted in Cape San Juan, Puerto Rico (18.38°N 65.62°W) during June-July 2012, offering the opportunity to constrain the way Saharan dust are transported from North Africa to the Caribbean by 3D models. Our main objectives are: (i) to discuss the ability of the CHIMERE Eulerian off-line chemistry-transport model to simulate atmospheric Saharan dust loads observed in the Caribbean during the Dust-AttaCk campaign, as well as the altitude of the dust plumes transport over the North Atlantic Ocean up to the Caribbean, (ii) to study the main Saharan dust emission source areas contributing to the dust loads in the Caribbean, (iii) to estimate the Saharan dust deposition in the Caribbean for deposition events observed during the Dust-AttaCk campaign. The dust model outputs are hourly dust concentration fields in µg m-3 for 12 aerosol size bins up to 30 µm and for each of the 15 sigma pressure vertical levels, column integrated dustaerosol optical depth (AOD), and dry and wet deposition fluxes.The simulations performed for the Dust-AttaCk campaign period as well as satellite observations (MODIS AOD, SEVIRI AOD) are used to identify the Saharan emission source regions activated and to study the evolution of the dust plumes tothe Cape San Juan station. In complement, the vertical transport of dust plumes transported from Saharan dust sources and over the North Atlantic Ocean is investigated combining model simulations and CALIOP observations. Aerosol surface concentrations and AOD simulated with CHIMERE are compared with sin-situ observations at Cape San Juan and AERONET stations. Wet deposition measurements performed allow us to constrain dust deposition flux simulated in the Caribbean after long-range transport.
Relationship between population growth of the red flour beetle Tribolium castaneum and protein and carbohydrate content in flour and starch.

PubMed

Wong, Nellie; Lee, Chow-Yang

2011-12-01

The effects of eight diets (atta flour, wheat flour, self-rising flour, rice flour, custard powder, corn flour, tapioca starch, and potato starch) on the development of the red flour beetle, Tribolium castaneum (Herbst), reared at 29-31 degrees C and 66-70% RH were assessed. Five pairs of male and female T. castaneum were reared on the respective diets for 28 d before the experimental setup was dismantled and adult counts were recorded. In another experiment, the insects were allowed to mate and oviposit in each flour or starch type over a period of 7 d before being removed. The counting of pupae and adult emergence began on the day of emergence and was continued on a daily basis until day 140. Proximate analysis was performed for chemical composition of each diet, and the numbers of new adults that developed were found to be positively correlated (r2 = 0.97; P < 0.05) with the protein content and negatively correlated (r2 = 0.93; P < 0.05) with the carbohydrate content. For T. castaneum, the suitable diets were ranked as follows: atta flour > wheat flour > self-rising flour > rice flour > custard powder > corn flour > tapioca starch > potato starch. T. castaneum larval development to the pupal and adult stages developed significantly faster in atta flour (P < 0.05) than in the other diets, and the greatest number of progeny was produced from beetles reared on atta flour. Fewer adults emerged from wheat flour, self-rising flour, and rice flour, and no new emergences were recorded for the remaining diets. Developmental rate was much slower in beetles reared on diets in which a low number in progeny was produced. These data illustrate that different diets can influence the sustainability of these insects and affect their development and growth.
Developmental Regulation of Gonadotropin-releasing Hormone Gene Expression by the MSX and DLX Homeodomain Protein Families*

PubMed Central

Givens, Marjory L.; Rave-Harel, Naama; Goonewardena, Vinodha D.; Kurotani, Reiko; Berdy, Sara E.; Swan, Christo H.; Rubenstein, John L. R.; Robert, Benoit; Mellon, Pamela L.

2010-01-01

Gonadotropin-releasing hormone (GnRH) is the central regulator of the hypothalamic-pituitary-gonadal axis, controlling sexual maturation and fertility in diverse species from fish to humans. GnRH gene expression is limited to a discrete population of neurons that migrate through the nasal region into the hypothalamus during embryonic development. The GnRH regulatory region contains four conserved homeodomain binding sites (ATTA) that are essential for basal promoter activity and cell-specific expression of the GnRH gene. MSX and DLX are members of the Antennapedia class of non-Hox homeodomain transcription factors that regulate gene expression and influence development of the craniofacial structures and anterior forebrain. Here, we report that expression patterns of the Msx and Dlx families of homeodomain transcription factors largely coincide with the migratory route of GnRH neurons and co-express with GnRH in neurons during embryonic development. In addition, MSX and DLX family members bind directly to the ATTA consensus sequences and regulate transcriptional activity of the GnRH promoter. Finally, mice lacking MSX1 or DLX1 and 2 show altered numbers of GnRH-expressing cells in regions where these factors likely function. These findings strongly support a role for MSX and DLX in contributing to spatiotemporal regulation of GnRH transcription during development. PMID:15743757
Comparison of radial growth rate of the mutualistic fungus of Atta sexdens rubropilosa forel in two culture media

PubMed Central

Miyashira, C.H.; Tanigushi, D.G.; Gugliotta, A.M.; Santos, D.Y.A.C.

2010-01-01

In vitro culture of the mutualistic fungus of leaf-cutting ants is troublesome due to its low growth rate, which leads to storage problems and contaminants accumulation. This paper aims at comparing the radial growth rate of the mutualistic fungus of Atta sexdens rubropilosa Forel in two different culture media (Pagnocca B and MEA LP). Although total MEA LP radial growth was greater all along the bioassay, no significant difference was detected between growth efficiencies of the two media. Previous evidences of low growth rate for this fungus were confirmed. Since these data cannot point greater efficiency of one culture medium over the other, MEA LP medium is indicated for in vitro studies with this mutualistic fungus due its simpler composition and translucent color, making the analysis easier. PMID:24031524
Metagenomic and metaproteomic insights into bacterial communities in leaf-cutter ant fungus gardens

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

Aylward, Frank O.; Burnum, Kristin E.; Scott, Jarrod J.

2012-09-01

Herbivores gain access to nutrients stored in plant biomass largely by harnessing the metabolic activities of microbes. Leaf-cutter ants of the genus Atta are a hallmark example; these dominant Neotropical herbivores cultivate symbiotic fungus gardens on massive quantities of fresh plant forage. As the external digestive system of the ants, fungus gardens facilitate the production and sustenance of millions of workers in mature Atta colonies. Here we use metagenomic, and metaproteomic techniques to characterize the bacterial diversity and overall physiological potential of fungus gardens from two species of Atta. Our analysis of over 1.2 Gbp of community metagenomic sequence andmore » three 16S pyrotag libraries reveals that, in addition to harboring the dominant fungal crop, these ecosystems contain abundant populations of Enterobacteriaceae, including the genera Enterobacter, Pantoea, Klebsiella, Citrobacter, and Escherichia. We show that these bacterial communities possess genes commonly associated with lignocellulose degradation, and likely participate in the processing of plant biomass. Additionally, we demonstrate that bacteria in these environments encode a diverse suite of biosynthetic pathways, and that they may enrich the nitrogen-poor forage of the ants with B-vitamins, amino acids, and proteins. These results are consistent with the hypothesis that fungus gardens are highly-specialized fungus-bacteria communities that efficiently convert plant material into usable energy for their ant hosts. Together with recent investigations into the microbial symbionts of vertebrates, our work underscores the importance of microbial communities to the ecology and evolution of herbivorous metazoans.« less
A domain-based approach for analyzing the function of aluminum-activated malate transporters from wheat (Triticum aestivum) and Arabidopsis thaliana in Xenopus oocytes.

PubMed

Sasaki, Takayuki; Tsuchiya, Yoshiyuki; Ariyoshi, Michiyo; Ryan, Peter R; Furuichi, Takuya; Yamamoto, Yoko

2014-12-01

Wheat and Arabidopsis plants respond to aluminum (Al) ions by releasing malate from their root apices via Al-activated malate transporter. Malate anions bind with the toxic Al ions and contribute to the Al tolerance of these species. The genes encoding the transporters in wheat and Arabidopsis, TaALMT1 and AtALMT1, respectively, were expressed in Xenopus laevis oocytes and characterized electrophysiologically using the two-electrode voltage clamp system. The Al-activated currents generated by malate efflux were detected for TaALMT1 but not for AtALMT1. Chimeric proteins were generated by swapping the N- and C-terminal halves of TaALMT1 and AtALMT1 (Ta::At and At::Ta). When these chimeras were characterized in oocytes, Al-activated malate efflux was detected for the Ta::At chimera but not for At::Ta, suggesting that the N-terminal half of TaALMT1 is necessary for function in oocytes. An additional chimera, Ta(48)::At, generated by swapping 17 residues from the N-terminus of AtALMT1 with the equivalent 48 residues from TaALMT1, was sufficient to support transport activity. This 48 residue region includes a helical region with a putative transmembrane domain which is absent in AtALMT1. The deletion of this domain from Ta(48)::At led to the complete loss of transport activity. Furthermore, truncations and a deletion at the C-terminal end of TaALMT1 indicated that a putative helical structure in this region was also required for transport function. This study provides insights into the structure-function relationships of Al-activated ALMT proteins by identifying specific domains on the N- and C-termini of TaALMT1 that are critical for basal transport function and Al responsiveness in oocytes. © The Author 2014. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Extended Range Passive Wireless Tag System and Method

NASA Technical Reports Server (NTRS)

Fink, Patrick W. (Inventor); Lin, Gregory Y. (Inventor); Kennedy, Timothy F. (Inventor)

2013-01-01

A passive wireless tag assembly comprises a plurality of antennas and transmission lines interconnected with circuitry and constructed and arranged in a Van Atta array or configuration to reflect an interrogator signal in the direction from where it came. The circuitry may comprise at least one surface acoustic wave (SAW)-based circuit that functions as a signal reflector and is operatively connected with an information circuit. In another embodiment, at least one delay circuit and/or at least one passive modulation circuit(s) are utilized. In yet another embodiment, antennas connected to SAW-based devices are mounted to at least one of the orthogonal surfaces of a corner reflector.
Metagenomic and metaproteomic insights into bacterial communities in leaf-cutter ant fungus gardens.

PubMed

Aylward, Frank O; Burnum, Kristin E; Scott, Jarrod J; Suen, Garret; Tringe, Susannah G; Adams, Sandra M; Barry, Kerrie W; Nicora, Carrie D; Piehowski, Paul D; Purvine, Samuel O; Starrett, Gabriel J; Goodwin, Lynne A; Smith, Richard D; Lipton, Mary S; Currie, Cameron R

2012-09-01

Herbivores gain access to nutrients stored in plant biomass largely by harnessing the metabolic activities of microbes. Leaf-cutter ants of the genus Atta are a hallmark example; these dominant neotropical herbivores cultivate symbiotic fungus gardens on large quantities of fresh plant forage. As the external digestive system of the ants, fungus gardens facilitate the production and sustenance of millions of workers. Using metagenomic and metaproteomic techniques, we characterize the bacterial diversity and physiological potential of fungus gardens from two species of Atta. Our analysis of over 1.2 Gbp of community metagenomic sequence and three 16S pyrotag libraries reveals that in addition to harboring the dominant fungal crop, these ecosystems contain abundant populations of Enterobacteriaceae, including the genera Enterobacter, Pantoea, Klebsiella, Citrobacter and Escherichia. We show that these bacterial communities possess genes associated with lignocellulose degradation and diverse biosynthetic pathways, suggesting that they play a role in nutrient cycling by converting the nitrogen-poor forage of the ants into B-vitamins, amino acids and other cellular components. Our metaproteomic analysis confirms that bacterial glycosyl hydrolases and proteins with putative biosynthetic functions are produced in both field-collected and laboratory-reared colonies. These results are consistent with the hypothesis that fungus gardens are specialized fungus-bacteria communities that convert plant material into energy for their ant hosts. Together with recent investigations into the microbial symbionts of vertebrates, our work underscores the importance of microbial communities in the ecology and evolution of herbivorous metazoans.
Metagenomic and metaproteomic insights into bacterial communities in leaf-cutter ant fungus gardens

PubMed Central

Aylward, Frank O; Burnum, Kristin E; Scott, Jarrod J; Suen, Garret; Tringe, Susannah G; Adams, Sandra M; Barry, Kerrie W; Nicora, Carrie D; Piehowski, Paul D; Purvine, Samuel O; Starrett, Gabriel J; Goodwin, Lynne A; Smith, Richard D; Lipton, Mary S; Currie, Cameron R

2012-01-01

Herbivores gain access to nutrients stored in plant biomass largely by harnessing the metabolic activities of microbes. Leaf-cutter ants of the genus Atta are a hallmark example; these dominant neotropical herbivores cultivate symbiotic fungus gardens on large quantities of fresh plant forage. As the external digestive system of the ants, fungus gardens facilitate the production and sustenance of millions of workers. Using metagenomic and metaproteomic techniques, we characterize the bacterial diversity and physiological potential of fungus gardens from two species of Atta. Our analysis of over 1.2 Gbp of community metagenomic sequence and three 16S pyrotag libraries reveals that in addition to harboring the dominant fungal crop, these ecosystems contain abundant populations of Enterobacteriaceae, including the genera Enterobacter, Pantoea, Klebsiella, Citrobacter and Escherichia. We show that these bacterial communities possess genes associated with lignocellulose degradation and diverse biosynthetic pathways, suggesting that they play a role in nutrient cycling by converting the nitrogen-poor forage of the ants into B-vitamins, amino acids and other cellular components. Our metaproteomic analysis confirms that bacterial glycosyl hydrolases and proteins with putative biosynthetic functions are produced in both field-collected and laboratory-reared colonies. These results are consistent with the hypothesis that fungus gardens are specialized fungus–bacteria communities that convert plant material into energy for their ant hosts. Together with recent investigations into the microbial symbionts of vertebrates, our work underscores the importance of microbial communities in the ecology and evolution of herbivorous metazoans. PMID:22378535
Rapid processing of 85Kr/Kr ratios using Atom Trap Trace Analysis

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

Zappala, J. C.; Bailey, K.; Mueller, P.

In this paper, we report a methodology for measuring 85Kr/Kr isotopic abundances using Atom Trap Trace Analysis (ATTA) that increases sample measurement throughput by over an order of magnitude to six samples per 24 h. The noble gas isotope 85Kr (half-life = 10.7 years) is a useful tracer for young groundwater in the age range of 5–50 years. ATTA, an efficient and selective laser-based atom counting method, has recently been applied to 85Kr/Kr isotopic abundance measurements, requiring 5–10 μL of krypton gas at STP extracted from 50 to 100 L of water. Previously, a single such measurement required 48 h.more » In conclusion, our new method demonstrates that we can measure 85Kr/Kr ratios with 3–5% relative uncertainty every 4 h, on average, with the same sample requirements.« less
Genetic diversity and structure of Atta robusta (Hymenoptera, Formicidae, Attini), an endangered species endemic to the restinga ecoregion

PubMed Central

dos Reis, Evelyze Pinheiro; Fernandes Salomão, Tânia Maria; de Oliveira Campos, Lucio Antonio; Tavares, Mara Garcia

2014-01-01

The genetic diversity and structure of the ant Atta robusta were assessed by ISSR (inter-simple sequence repeats) in 72 colonies collected from 10 localities in the Brazilian states of Espírito Santo (48 colonies) and Rio de Janeiro (24 colonies). The ISSR pattern included 67 bands, 51 of them (76.1%) polymorphic. Analysis of molecular variance (AMOVA) revealed a high level (57.4%) of inter-population variation, which suggested a high degree of genetic structure that was confirmed by UPGMA (unweighted pair-group method using an arithmetic average) cluster analysis. The significant correlation between genetic and geographic distances (r = 0.64, p < 0.05) indicated isolation that reflected the distance between locations. Overall, the populations were found to be genetically divergent. This finding indicates the need for management plans to preserve and reduce the risk of extinction of A. robusta. PMID:25249782
A pest is a pest is a pest? The dilemma of neotropical leaf-cutting ants: Keystone taxa of natural ecosystems

NASA Astrophysics Data System (ADS)

Fowler, Harold G.; Pagani, Maria Inez; da Silva, Osvaldo Aulino; Forti, Luis Carlos; da Silva, Virgilio Pereira; de Vasconcelos, Heraldo Luis

1989-11-01

Leaf-cutting ants of the genera Acromyrmex and Atta are considered the principal polyphagous pests of the Neotropics Although some members of these genera are of economic importance, have a broad geographic distribution, and are extremely good colonizers, others are endemic and closely interact with native ecosystems. Control is generally practiced against any colony, irrespective of its taxonomic status. Indiscriminate control coupled with habitat destruction threatens endemic species with extinction, and, through habitat simplification, favors other pest species. As nests of Atta are large, having several square meters of nest surface, the endemic taxa can be easily used as environmental indicators for natural ecosystems Likewise, the pest species can be used to detect environmental disturbance As these ants are keystone species and easily identified by nonspecialists, efforts should be made to integrate these into viable conservation programs
Rapid processing of 85Kr/Kr ratios using Atom Trap Trace Analysis

DOE PAGES

Zappala, J. C.; Bailey, K.; Mueller, P.; ...

2017-03-11

In this paper, we report a methodology for measuring 85Kr/Kr isotopic abundances using Atom Trap Trace Analysis (ATTA) that increases sample measurement throughput by over an order of magnitude to six samples per 24 h. The noble gas isotope 85Kr (half-life = 10.7 years) is a useful tracer for young groundwater in the age range of 5–50 years. ATTA, an efficient and selective laser-based atom counting method, has recently been applied to 85Kr/Kr isotopic abundance measurements, requiring 5–10 μL of krypton gas at STP extracted from 50 to 100 L of water. Previously, a single such measurement required 48 h.more » In conclusion, our new method demonstrates that we can measure 85Kr/Kr ratios with 3–5% relative uncertainty every 4 h, on average, with the same sample requirements.« less
Setting a limit on anthropogenic sources of atmospheric 81Kr through Atom Trap Trace Analysis

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

Zappala, J. C.; Bailey, K.; Jiang, W.

In this study, we place a 2.5% limit on the anthropogenic contribution to the modern abundance of 81Kr/Kr in the atmosphere at the 90% confidence level. Due to its simple production and transport in the terrestrial environment, 81Kr (half-life = 230,000 years) is an ideal tracer for old water and ice with mean residence times in the range of 105–106 years. In recent years, 81Kr-dating has been made available to the earth science community thanks to the development of Atom Trap Trace Analysis (ATTA), a laser-based atom counting technique. Further upgrades and improvements to the ATTA technique now allow usmore » to demonstrate 81Kr/Kr measurements with relative uncertainties of 1% and place this new limit on anthropogenic 81Kr. As a result of this limit, we have removed a potential systematic constraint for 81Kr-dating.« less
Atom Trap Trace Analysis for radiokrypton and radioargon dating

NASA Astrophysics Data System (ADS)

Williams, William; Jiang, Wei; Sun, Yun; Bailey, Kevin; Davis, Andrew; Hu, Shuiming; Lu, Zheng-Tian; Mueller, Peter; O'Connor, Thomas; Purtschert, Roland; Sturchio, Neil

2011-05-01

Atom Trap Trace Analysis (ATTA), a MOT-based atom counting method, is used to analyze three noble gas radioisotopes (81Kr, 85Kr, 39Ar) covering a wide range of geological ages and applications in the earth sciences. Their isotopic abundances are extremely low, in the range of 10-16 - 10-11. Yet, ATTA can trap and unmistakably detect these rare isotopes one atom at a time. The system is currently limited by the excitation efficiency of the RF discharge that produces the metastable atoms (Kr* & Ar*) needed for laser trapping. To further improve the MOT loading rate, we plan to replace the RF discharge with a photon excitation scheme that employs a VUV light source at 124 nm. The VUV source can be a lamp or a free electron laser. This work is supported by DOE, Office of Nuclear Physics and by NSF, Division of Earth Sciences.
Setting a limit on anthropogenic sources of atmospheric 81Kr through Atom Trap Trace Analysis

DOE PAGES

Zappala, J. C.; Bailey, K.; Jiang, W.; ...

2017-02-09

In this study, we place a 2.5% limit on the anthropogenic contribution to the modern abundance of 81Kr/Kr in the atmosphere at the 90% confidence level. Due to its simple production and transport in the terrestrial environment, 81Kr (half-life = 230,000 years) is an ideal tracer for old water and ice with mean residence times in the range of 105–106 years. In recent years, 81Kr-dating has been made available to the earth science community thanks to the development of Atom Trap Trace Analysis (ATTA), a laser-based atom counting technique. Further upgrades and improvements to the ATTA technique now allow usmore » to demonstrate 81Kr/Kr measurements with relative uncertainties of 1% and place this new limit on anthropogenic 81Kr. As a result of this limit, we have removed a potential systematic constraint for 81Kr-dating.« less
Genetic diversity and structure of Atta robusta (Hymenoptera, Formicidae, Attini), an endangered species endemic to the restinga ecoregion.

PubMed

Dos Reis, Evelyze Pinheiro; Fernandes Salomão, Tânia Maria; de Oliveira Campos, Lucio Antonio; Tavares, Mara Garcia

2014-09-01

The genetic diversity and structure of the ant Atta robusta were assessed by ISSR (inter-simple sequence repeats) in 72 colonies collected from 10 localities in the Brazilian states of Espírito Santo (48 colonies) and Rio de Janeiro (24 colonies). The ISSR pattern included 67 bands, 51 of them (76.1%) polymorphic. Analysis of molecular variance (AMOVA) revealed a high level (57.4%) of inter-population variation, which suggested a high degree of genetic structure that was confirmed by UPGMA (unweighted pair-group method using an arithmetic average) cluster analysis. The significant correlation between genetic and geographic distances (r = 0.64, p < 0.05) indicated isolation that reflected the distance between locations. Overall, the populations were found to be genetically divergent. This finding indicates the need for management plans to preserve and reduce the risk of extinction of A. robusta.
Monoculture of Leafcutter Ant Gardens

PubMed Central

Mueller, Ulrich G.; Scott, Jarrod J.; Ishak, Heather D.; Cooper, Michael; Rodrigues, Andre

2010-01-01

Background Leafcutter ants depend on the cultivation of symbiotic Attamyces fungi for food, which are thought to be grown by the ants in single-strain, clonal monoculture throughout the hundreds to thousands of gardens within a leafcutter nest. Monoculture eliminates cultivar-cultivar competition that would select for competitive fungal traits that are detrimental to the ants, whereas polyculture of several fungi could increase nutritional diversity and disease resistance of genetically variable gardens. Methodology/Principal Findings Using three experimental approaches, we assessed cultivar diversity within nests of Atta leafcutter ants, which are most likely among all fungus-growing ants to cultivate distinct cultivar genotypes per nest because of the nests' enormous sizes (up to 5000 gardens) and extended lifespans (10–20 years). In Atta texana and in A. cephalotes, we resampled nests over a 5-year period to test for persistence of resident cultivar genotypes within each nest, and we tested for genetic differences between fungi from different nest sectors accessed through excavation. In A. texana, we also determined the number of Attamyces cells carried as a starter inoculum by a dispersing queens (minimally several thousand Attamyces cells), and we tested for genetic differences between Attamyces carried by sister queens dispersing from the same nest. Except for mutational variation arising during clonal Attamyces propagation, DNA fingerprinting revealed no evidence for fungal polyculture and no genotype turnover during the 5-year surveys. Conclusions/Significance Atta leafcutter ants can achieve stable, fungal monoculture over many years. Mutational variation emerging within an Attamyces monoculture could provide genetic diversity for symbiont choice (gardening biases of the ants favoring specific mutational variants), an analog of artificial selection. PMID:20844760
Inquiline roach responds to trail-marking substance of leaf-cutting ants

Treesearch

John C. Moser

1964-01-01

Nymphs and females of the roach inquiline, Attaphila fungicola W. M. Wheeler, respond to odor-trail substances of Atta texana (Buckley) and Trachymyrmex septentrionalis (McCook).The ants are more sensitive than roaches to the pheromone.
Trail-marking substance of the Texas leaf-cutting ant: source and potency

Treesearch

John C. Moser; Murray S. Blum

1963-01-01

The trail-marking substance of Atta texana (Buckley) is formed in the true poison gland and deposited by the sting. This attractant is initially produced by teneral workers. The substance obtained from mature, large workers is the most potent.
Characterization of IntA, a Bidirectional Site-Specific Recombinase Required for Conjugative Transfer of the Symbiotic Plasmid of Rhizobium etli CFN42

PubMed Central

Hernández-Tamayo, Rogelio; Sohlenkamp, Christian; Puente, José Luis; Brom, Susana

2013-01-01

Site-specific recombination occurs at short specific sequences, mediated by the cognate recombinases. IntA is a recombinase from Rhizobium etli CFN42 and belongs to the tyrosine recombinase family. It allows cointegration of plasmid p42a and the symbiotic plasmid via site-specific recombination between attachment regions (attA and attD) located in each replicon. Cointegration is needed for conjugative transfer of the symbiotic plasmid. To characterize this system, two plasmids harboring the corresponding attachment sites and intA were constructed. Introduction of these plasmids into R. etli revealed IntA-dependent recombination events occurring at high frequency. Interestingly, IntA promotes not only integration, but also excision events, albeit at a lower frequency. Thus, R. etli IntA appears to be a bidirectional recombinase. IntA was purified and used to set up electrophoretic mobility shift assays with linear fragments containing attA and attD. IntA-dependent retarded complexes were observed only with fragments containing either attA or attD. Specific retarded complexes, as well as normal in vivo recombination abilities, were seen even in derivatives harboring only a minimal attachment region (comprising the 5-bp central region flanked by 9- to 11-bp inverted repeats). DNase I-footprinting assays with IntA revealed specific protection of these zones. Mutations that disrupt the integrity of the 9- to 11-bp inverted repeats abolish both specific binding and recombination ability, while mutations in the 5-bp central region severely reduce both binding and recombination. These results show that IntA is a bidirectional recombinase that binds to att regions without requiring neighboring sequences as enhancers of recombination. PMID:23935046
Outdoor Recreation and Adventure Tourism: Unique but Allied Industries

ERIC Educational Resources Information Center

Bailey, Andrew W.; Kang, H. K.; Lewis, T. Grant

2017-01-01

Outdoor recreation and adventure tourism are overlapping industries serving similar clientele. While descriptive marketing research exists for both industries (George Washington University School of Business [GW], Adventure Travel Trade Association [ATTA], & Xola Consulting [XC], 2010; Outdoor Foundation [OF], 2014), there is no clear…
Prevalence of the genus Cladosporium on the integument of leaf-cutting ants characterized by 454 pyrosequencing.

PubMed

Duarte, A P M; Ferro, M; Rodrigues, A; Bacci, M; Nagamoto, N S; Forti, L C; Pagnocca, F C

2016-09-01

The relationship of attine ants with their mutualistic fungus and other microorganisms has been studied during the last two centuries. However, previous studies about the diversity of fungi in the ants' microenvironment are based mostly on culture-dependent approaches, lacking a broad characterization of the fungal ant-associated community. Here, we analysed the fungal diversity found on the integument of Atta capiguara and Atta laevigata alate ants using 454 pyrosequencing. We obtained 35,453 ITS reads grouped into 99 molecular operational taxonomic units (MOTUs). Data analysis revealed that A. capiguara drones had the highest diversity of MOTUs. Besides the occurrence of several uncultured fungi, the mycobiota analysis revealed that the most abundant taxa were the Cladosporium-complex, Cryptococcus laurentii and Epicoccum sp. Taxa in the genus Cladosporium were predominant in all samples, comprising 67.9 % of all reads. The remarkable presence of the genus Cladosporium on the integument of leaf-cutting ants alates from distinct ant species suggests that this fungus is favored in this microenvironment.
Biogeography of mutualistic fungi cultivated by leafcutter ants

USDA-ARS?s Scientific Manuscript database

Leafcutter ants propagate co-evolving fungi for food. The nearly 50 species of leafcutter ants (Atta, Acromyrmex) range from Argentina to the USA, with the greatest species diversity in southern South America. We elucidate the biogeography of fungi cultivated by leafcutter ants using DNA-sequence an...
DYNAMIC CONDUCTIVITY MEASUREMENTS IN HUMIC AND FULVIC ACID SOLUTIONS. (R828158)

EPA Science Inventory

Conductivity changes of dilute aqueous humic and fulvic acids solutions were monitored after the addition of small quantities of Cu, Cd, Pb, and Zn. The solutions were stirred at a constant and reproducible rate, and measurements proceeded until stable conductivities were atta...
Preparation of water and ice samples for 39Ar dating by atom trap trace analysis (ATTA)

NASA Astrophysics Data System (ADS)

Schwefel, R.; Reichel, T.; Aeschbach-Hertig, W.; Wagenbach, D.

2012-04-01

Atom trap trace analysis (ATTA) is a new and promising method to measure very rare noble gas radioisotopes in the environment. The applicability of this method for the dating of very old groundwater with 81Kr has already been demonstrated [1]. Recent developments now show its feasibility also for the analysis of 39Ar [2,3], which is an ideal dating tracer for the age range between 50 and 1000 years. This range is of interest in the fields of hydro(geo)logy, oceanography, and glaciology. We present preparation (gas extraction and Ar separation) methods for groundwater and ice samples for later analysis by the ATTA technique. For groundwater, the sample size is less of a limitation than for applications in oceanography or glaciology. Large samples are furthermore needed to enable a comparison with the classical method of 39Ar detection by low-level counting. Therefore, a system was built that enables gas extraction from several thousand liters of water using membrane contactors. This system provides degassing efficiencies greater than 80 % and has successfully been tested in the field. Gas samples are further processed to separate a pure Ar fraction by a gas-chromatographic method based on Li-LSX zeolite as selective adsorber material at very low temperatures. The gas separation achieved by this system is controlled by a quadrupole mass spectrometer. It has successfully been tested and used on real samples. The separation efficiency was found to be strongly temperature dependent in the range of -118 to -130 °C. Since ATTA should enable the analysis of 39Ar on samples of less than 1 ccSTP of Ar (corresponding to about 100 ml of air, 2.5 l of water or 1 kg of ice), a method to separate Ar from small amounts of gas was developed. Titanium sponge was found to absorb 60 ccSTP of reactive gases per g of the getter material with reasonably high absorption rates at high operating temperatures (~ 800 ° C). Good separation (higher than 92 % Ar content in residual gas) was achieved by this gettering process. The other main remaining component is H2, which can be further reduced by operating the Ti getter at lower temperature. Furthermore, a system was designed to degas ice samples, followed by Ar separation by gettering. Ice from an alpine glacier was successfully processed on this system.

A Hybrid Density Functional Study of Atomic Hydrogen and Oxygen Adsorptions on the (0001) Surface of Non-Magnetic DHCP Americium

NASA Astrophysics Data System (ADS)

Amdani-Moten, Shafaq; Atta-Fynn, Raymond; Ray, Asok

2010-03-01

As our group have recently shown^+, hybrid density functional theory (HDFT) which replaces a fraction (40%) of approximate DFT exchange with exact Hartree-Fock exchange yield structural, magnetic, and electronic properties for Americium-I that are in excellent agreement with experimental data. As a natural progression, ab initio calculations for atomic adsorptions on the (0001) surface of non-magnetic americium have been performed using HDFT. The americium surface is modeled by a seven-layer slab using inversion symmetry consisting of one atom per layer and non-magnetic ABAC stacking arrangement of these layers. Top, bridge, hcp and fcc chemisorption sites have been investigated with energies optimized with respect to the adatom distance from the surface. Details of the chemisorptions processes as well as comparisons of different sites will be presented. ^+ R. Atta-Fynn and A. K. Ray, Chemical Physics Letters, 482, 223-227 (2009).
Estimating timber losses from a town ant colony with aerial photographs

Treesearch

John C. Moser

1986-01-01

Aerial photographs were used to locate an individual nest of Atta texana (Buckley) and to estimate the area of damage in a plantation of loblolly pine (Pinus taeda L.). Stumpage loss from the nest over a period of 30 years was estimated to be $653.
Reliability and Factor Structure of the Attitude toward Tutoring Agent Scale (ATTAS)

ERIC Educational Resources Information Center

Adcock, Amy B.; Van Eck, Richard N.

2005-01-01

Pedagogical agents are gaining acceptance as effective learning tools (Baylor & Ryu, 2003; Moreno, Mayer, Spires & Lester 2001; Moreno, 2004). The increase in the use of agents highlights the need for standardized measurements for evaluating user performance in these environments. While learning gains are a primary variable of interest in such…
Analysis of 85Kr: a comparison at the 10-14 level using micro-liter samples

PubMed Central

Yang, G. -M.; Cheng, C. -F.; Jiang, W.; Lu, Z. -T.; Purtschert, R.; Sun, Y. -R.; Tu, L. -Y.; Hu, S. -M.

2013-01-01

The isotopic abundance of 85Kr in the atmosphere, currently at the level of 10−11, has increased by orders of magnitude since the dawn of nuclear age. With a half-life of 10.76 years, 85Kr is of great interest as tracers for environmental samples such as air, groundwater and ice. Atom Trap Trace Analysis (ATTA) is an emerging method for the analysis of rare krypton isotopes at isotopic abundance levels as low as 10−14 using krypton gas samples of a few micro-liters. Both the reliability and reproducibility of the method are examined in the present study by an inter-comparison among different instruments. The 85Kr/Kr ratios of 12 samples, in the range of 10−13 to 10−10, are measured independently in three laboratories: a low-level counting laboratory in Bern, Switzerland, and two ATTA laboratories, one in Hefei, China, and another in Argonne, USA. The results are in agreement at the precision level of 5%. PMID:23549244
Radio-Krypton Dating with 20kg of Water or Ice

NASA Astrophysics Data System (ADS)

Hu, S. M.; Gu, J. Q.; Jiang, W.; Lu, Z. T.; Ritterbusch, F.; Yang, G. M.

2016-12-01

Long-lived noble-gas isotopes 85Kr (10.8 y), 39Ar (269 y) and 81Kr (229 ky) are ideal tracers for dating environmental samples such as groundwater and ice. Together with 14C, these nuclides can be used to cover the whole range of 100 - 106 y. To meet the increasing demands from the earth science community, a new, improved ATTA apparatus for radio-krypton analysis is being developed at the University of Science and Technology of China (USTC). From 2017, this instrument will be capable to analyze several hundred samples per year and also reduce the sample requirement to 1-2.5 μL STP of krypton gas, which can be extracted from 20-50 kg of water or 8-20 kg of ice. In parallel, a new sampling machine for use in the field is under test at USTC, which weighs less than 20kg and can be carried by one person. With this new dating tool sharpened, we believe that many more interesting applications can be carried out in collaboration with the earth science communities. (http://atta.ustc.edu.cn)
The construction of ventilation turrets in Atta vollenweideri leaf-cutting ants: Carbon dioxide levels in the nest tunnels, but not airflow or air humidity, influence turret structure

PubMed Central

Roces, Flavio

2017-01-01

Nest ventilation in the leaf-cutting ant Atta vollenweideri is driven via a wind-induced mechanism. On their nests, workers construct small turrets that are expected to facilitate nest ventilation. We hypothesized that the construction and structural features of the turrets would depend on the colony’s current demands for ventilation and thus might be influenced by the prevailing environmental conditions inside the nest. Therefore, we tested whether climate-related parameters, namely airflow, air humidity and CO2 levels in the outflowing nest air influenced turret construction in Atta vollenweideri. In the laboratory, we simulated a semi-natural nest arrangement with fungus chambers, a central ventilation tunnel providing outflow of air and an aboveground building arena for turret construction. In independent series, different climatic conditions inside the ventilation tunnel were experimentally generated, and after 24 hours, several features of the built turret were quantified, i.e., mass, height, number and surface area (aperture) of turret openings. Turret mass and height were similar in all experiments even when no airflow was provided in the ventilation tunnel. However, elevated CO2 levels led to the construction of a turret with several minor openings and a larger total aperture. This effect was statistically significant at higher CO2 levels of 5% and 10% but not at 1% CO2. The construction of a turret with several minor openings did not depend on the strong differences in CO2 levels between the outflowing and the outside air, since workers also built permeated turrets even when the CO2 levels inside and outside were both similarly high. We propose that the construction of turrets with several openings and larger opening surface area might facilitate the removal of CO2 from the underground nest structure and could therefore be involved in the control of nest climate in leaf-cutting ants. PMID:29145459
The construction of ventilation turrets in Atta vollenweideri leaf-cutting ants: Carbon dioxide levels in the nest tunnels, but not airflow or air humidity, influence turret structure.

PubMed

Halboth, Florian; Roces, Flavio

2017-01-01

Nest ventilation in the leaf-cutting ant Atta vollenweideri is driven via a wind-induced mechanism. On their nests, workers construct small turrets that are expected to facilitate nest ventilation. We hypothesized that the construction and structural features of the turrets would depend on the colony's current demands for ventilation and thus might be influenced by the prevailing environmental conditions inside the nest. Therefore, we tested whether climate-related parameters, namely airflow, air humidity and CO2 levels in the outflowing nest air influenced turret construction in Atta vollenweideri. In the laboratory, we simulated a semi-natural nest arrangement with fungus chambers, a central ventilation tunnel providing outflow of air and an aboveground building arena for turret construction. In independent series, different climatic conditions inside the ventilation tunnel were experimentally generated, and after 24 hours, several features of the built turret were quantified, i.e., mass, height, number and surface area (aperture) of turret openings. Turret mass and height were similar in all experiments even when no airflow was provided in the ventilation tunnel. However, elevated CO2 levels led to the construction of a turret with several minor openings and a larger total aperture. This effect was statistically significant at higher CO2 levels of 5% and 10% but not at 1% CO2. The construction of a turret with several minor openings did not depend on the strong differences in CO2 levels between the outflowing and the outside air, since workers also built permeated turrets even when the CO2 levels inside and outside were both similarly high. We propose that the construction of turrets with several openings and larger opening surface area might facilitate the removal of CO2 from the underground nest structure and could therefore be involved in the control of nest climate in leaf-cutting ants.
Eye size and behaviour of day- and night-flying leafcutting ant alates

Treesearch

John C. Moser; John D. Reeve; José Maunício S. Bento; Terezinha M.C. Della Lucia; R. Scott Cameron; Natalie M. Heck

2004-01-01

The morphology of insect eyes often seems to be shaped by evolution to match their behaviour and lifestyle. Here the relationship between the nuptial flight behaviour of 10 Atta species (Hymenoptera: Fonnicidae) and the eye size of male and female alates, including the compound eyes, ommatidia facets, and ocelli were examined. These species can be...
The Antiaircraft Journal. Volume 94, Number 4, July-August 1953

DTIC Science & Technology

1953-08-01

JOHN A. 1\\lATTAS TIle writer of the following received _his commissioll from Virgillia Polytech- nic Institllte in 1939. Dllrillg "Varld \\Var II he...officer of Leaders Course. Other members of the staff include Lt. Robert G. Mangum, S3 officer, and Lt. Sam H. Biddle , Ad- jutant. Lt. Mangum has the
Alarm Pheromones of the Ant Atta Texana

Treesearch

John C. Moser; R. C. Brownlee; R. Silverstein

1968-01-01

Methyl-3-heptanone (0.59 μg/head) and 2-heptanone (0.14 μg/head) are the main volatile components of the mandibular glands of major workers. In the laboratory, worker ants detected and were attracted by 4-methyl-3-heptanone at a concentration of 5.7 x 10-13 g/cm3 (2.7 x 107 molecules...
Complete excavation and mapping of a Texas leafcutting ant nest

Treesearch

John C. Moser

2006-01-01

A medium-sized nest of the Texas leafcutting ant, Atta texana (Buckley), in northern Louisiana was excavated completely, and a three-dimensional model of its external and subterranean features was constructed. In total, 97 fungus gardens, 27 dormancy cavities, and 45 detritus cavities were located. At the lower center of the funnel-shaped nest was a...
Electronic, structural, and thermodynamic properties of mixed actinide dioxides (U, Pu, Am) O2 from hybrid density functional theory

NASA Astrophysics Data System (ADS)

Ma, Li; Ray, Asok K.

2010-03-01

As a continuation of our studies of pure actinide metals using hybrid density functional theory,footnotetextR. Atta-Fynn and A. K. Ray, Europhysics Letters, 85, 27008-p1- p6 (2009); Chemical Physics Letters, 482, 223-227 (2009). we present here a systematic study of the electronic and geometric structure properties of mixed actinide dioxides, U0.5Pu0.5O2, U0.5Am0.5O2, Pu0.5Am0.5 O2 and U0.8Pu0.2O2. The fraction of exact Hartree-Fock exchange used was 40%. To investigate the effect of spin-orbit coupling on the ground state electronic and geometric structure properties, computations have been carried out at two theoretical levels, one at the scalar-relativistic level with no spin-orbit coupling and one at the fully relativistic level with spin-orbit coupling. Thermodynamic properties have been calculated by a coupling of first-principles calculation and lattice dynamics.
Invertebrate enemies and nest associates of the leaf-cutting ant Atta texana (Buckley) (Formicudae, Attini)

Treesearch

D.A. Waller; John C. Moser

1990-01-01

The complex nests of leaf-cutting ants (Formicidae; Attini) provide rich habitats for ant associates. These mounds consist of interconnected subterranean cavities that average 0.002 m3 in volume (Waler et al. 1938) and extend to depths of 7 m (Moser 1963). Many cavities contain fungus gardens, cultivated on live plant material, frass and debris....
Antennal olfactory responsiveness of the Texas leaf cutting ant (Hymenoptera: Formicidae) to trail pheromone and its two alarm substances

Treesearch

N.A. Andryszak; Thomas L. Payne; J.C. Dickens; John C. Moser; R.W. Fisher

1990-01-01

Electroantennograms (EAGs) were recorded from major workers, queens, and males of the Texas leaf cutting, Atta texana (Buckley) (Hymenoptera: Formicidae) in response to serial dilutions of two alarm substances, 2-heptanone and 4-methyl-3-heptanone, and its trial phermone, 4-methylpyrrole-2-carbonxylate. The lower EAG threshold for major workers...
Toxicological and histopathological effects of boric acid on Atta sexdens rubropilosa (Hymenoptera: Formicidae) workers.

PubMed

Sumida, Simone; Silva-Zacarin, Elaine C M; Decio, Pâmela; Malaspina, Osmar; Bueno, Fabiana C; Bueno, Odair C

2010-06-01

The current study compared the toxicity of different concentrations of boric acid in adult workers of Atta sexdens rubropilosa Forel (Hymenoptera: Formicidae), with toxicological bioassays, and examining the dose-dependent and time-dependent histopathological changes, of the midgut, Malpighian tubules, and postpharyngeal glands. Our results revealed the importance of conducting toxicological bioassays combined with morphological analyses of the organs of ants chronically exposed to insecticides used in commercial ant baits. In vitro bioassays showed that boric acid significantly decreases the survivorship of workers regardless of concentration, whereas the morphological data suggested progressive dose-dependent and time-dependent changes in the organs examined, which were evident in the midgut. The midgut is the first organ to be affected, followed by the postpharyngeal gland and Malpighian tubules. This sequence is in agreement with the absorption pathway of this chemical compound in the midgut, its transference to the hemolymph, possibly reaching the postpharyngeal glands, and excretion by the Malpighian tubules. These progressive changes might be due to the cumulative and delayed effect of boric acid. Our findings provide important information for the understanding of the action of boric acid in ant baits in direct and indirect target organs.
Weapon-Specific Strategic Material Estimation Process (WSSMEP)

DTIC Science & Technology

2014-12-01

Whitley for his insightful review and comments. We also want to thank the editor, Mr. John Everett , and Ms. Barbara Varvaglione for production...Institute for Defense Analyses, 2013. Thomason, Jim, Jim Bell , Eleanor Schwartz, Bob Atwell, Dick Van Atta, Nicholas Karvonides, Zack Rabold, Tiki...sources for more detailed documentation material. 41 Appendix A References Thomason, James S., Robert J. Atwell, D. Sean Burnett, James P. Bell
Town ants: the beginning of John Moser’s remarkable search for knowledge

Treesearch

J.P. Barnett; D.A. Streett; S.R. Blomquist

2016-01-01

John C. Moserâs career spans over 50 years, and his research has focused on understanding the biology of town ants (Atta texana) and phoretic mites and other associates of ants and pine bark beetles. His approach to developing methods for the control of these pests has been to understand more completely the biology of these organisms. This research...
Peterson's Top Colleges for Science: A Guide to Leading Four-Year Programs in the Biological, Chemical, Geological, Mathematical, and Physical Sciences.

ERIC Educational Resources Information Center

Davis-Van Atta, David, Ed.

This guide, published for the first time, provides prospective college students detailed information on 190 United States colleges and universities identified as having very strong track records in the sciences and mathematics. Following a description of how institutions were identified for inclusion by David Davis-Van Atta, and a discussion on…
Chemical releases of social behavior, II. source and specificity of the odor trail substances in four attine genera. (Hymenoptera: Formicidae)

Treesearch

Murray S. Blum; John C. Moser; A.D. Cordero

1964-01-01

The higher members of the tribe Attini characteristically lay persistent and extensive odor trails especially in many neotropical areas. Thus, in Acromyrmex and Atta, long columns of foraging workers are frequently present on the odor trails but in the less specialized attine genera, workers may forage either in files or singly. Weber (1958...
Growth and enzymatic activity of Leucoagaricus gongylophorus, a mutualistic fungus isolated from the leaf-cutting ant Atta mexicana, on cellulose and lignocellulosic biomass.

PubMed

Vigueras, G; Paredes-Hernández, D; Revah, S; Valenzuela, J; Olivares-Hernández, R; Le Borgne, S

2017-08-01

A mutualistic fungus of the leaf-cutting ant Atta mexicana was isolated and identified as Leucoagaricus gongylophorus. This isolate had a close phylogenetic relationship with L. gongylophorus fungi cultivated by other leaf-cutting ants as determined by ITS sequencing. A subcolony started with ~500 A. mexicana workers could process 2 g day -1 of plant material and generate a 135 cm 3 fungus garden in 160 days. The presence of gongylidia structures of ~35 μm was observed on the tip of the hyphae. The fungus could grow without ants on semi-solid cultures with α-cellulose and microcrystalline cellulose and in solid-state cultures with grass and sugarcane bagasse, as sole sources of carbon. The maximum CO 2 production rate on grass (V max = 17·5 mg CO 2 L g -1 day -1 ) was three times higher than on sugarcane bagasse (V max = 6·6 mg CO 2 L g -1 day -1 ). Recoveries of 32·9 mg glucose g biomass -1 and 12·3 mg glucose g biomass -1 were obtained from the fungal biomass and the fungus garden, respectively. Endoglucanase activity was detected on carboxymethylcellulose agar plates. This is the first study reporting the growth of L. gongylophorus from A. mexicana on cellulose and plant material. According to the best of our knowledge, this is the first report about the growth of Leucoagaricus gongylophorus, isolated from the colony of the ant Atta mexicana, on semisolid medium with cellulose and solid-state cultures with lignocellulosic materials. The maximum CO 2 production rate on grass was three times higher than on sugarcane bagasse. Endoglucanase activity was detected and it was possible to recover glucose from the fungal gongylidia. The cellulolytic activity could be used to process lignocellulosic residues and obtain sugar or valuable products, but more work is needed in this direction. © 2017 The Society for Applied Microbiology.

Identification, characterization, and utilization of genome-wide simple sequence repeats to identify a QTL for acidity in apple

PubMed Central

2012-01-01

Background Apple is an economically important fruit crop worldwide. Developing a genetic linkage map is a critical step towards mapping and cloning of genes responsible for important horticultural traits in apple. To facilitate linkage map construction, we surveyed and characterized the distribution and frequency of perfect microsatellites in assembled contig sequences of the apple genome. Results A total of 28,538 SSRs have been identified in the apple genome, with an overall density of 40.8 SSRs per Mb. Di-nucleotide repeats are the most frequent microsatellites in the apple genome, accounting for 71.9% of all microsatellites. AT/TA repeats are the most frequent in genomic regions, accounting for 38.3% of all the G-SSRs, while AG/GA dimers prevail in transcribed sequences, and account for 59.4% of all EST-SSRs. A total set of 310 SSRs is selected to amplify eight apple genotypes. Of these, 245 (79.0%) are found to be polymorphic among cultivars and wild species tested. AG/GA motifs in genomic regions have detected more alleles and higher PIC values than AT/TA or AC/CA motifs. Moreover, AG/GA repeats are more variable than any other dimers in apple, and should be preferentially selected for studies, such as genetic diversity and linkage map construction. A total of 54 newly developed apple SSRs have been genetically mapped. Interestingly, clustering of markers with distorted segregation is observed on linkage groups 1, 2, 10, 15, and 16. A QTL responsible for malic acid content of apple fruits is detected on linkage group 8, and accounts for ~13.5% of the observed phenotypic variation. Conclusions This study demonstrates that di-nucleotide repeats are prevalent in the apple genome and that AT/TA and AG/GA repeats are the most frequent in genomic and transcribed sequences of apple, respectively. All SSR motifs identified in this study as well as those newly mapped SSRs will serve as valuable resources for pursuing apple genetic studies, aiding the apple breeding community in marker-assisted breeding, and for performing comparative genomic studies in Rosaceae. PMID:23039990
The status of the fungi-grower ants (Hymenoptera: Formicidae) in Puerto Rico and adjacent islands

Treesearch

J.A. Torres

1989-01-01

Ants of the tribe Attini (fungus grower) collect different organic materials that are used to grow a fungus. It was thought that the fungus mycelium was the only source of nutrition for these ants, but Quinlan and Cherrett found that Atta cephalotes (L.) squeezes oils from fresh leaves and uses them as food.Â These oils supplement the fungus material eaten by this...
Asynchronous Discrete Control of Continuous Processes.

DTIC Science & Technology

1986-02-24

Input. When 40-lead dual-in-line ceramic packages (D suffix) and in the mode input is high IMOOE=1), the CDPIS54A is 40-lead dual-in-line plastic ...DYNAIC U ThIi. CA~ YRi5iC5 TACDPI8541 CDPI854C DYNAMC LECRICL CARA ERITIC atTA 40 o +UC. DD M W O 1110 VlH’& 7 VDD. VIL, 3 . LIIMTS ’.- CARACTERISTIC
Pathogenic nature of Syncephalastrum in Atta sexdens rubropilosa fungus gardens.

PubMed

Barcoto, Mariana O; Pedrosa, Felipe; Bueno, Odair C; Rodrigues, Andre

2017-05-01

Leaf-cutter ants are considered to be a major herbivore and agricultural pest in the Neotropics. They are often controlled by environmentally persistent insecticides. Biological control using pathogenic fungi is regarded as an alternative for the management of these insects. Here, we assess whether the filamentous fungus Syncephalastrum sp. is a pathogenic microorganism responsible for a characteristic disease in fungus gardens. We also characterise the damage caused by this fungus by evaluating physiological and behavioural responses of Atta sexdens rubropilosa subcolonies infected with Syncephalastrum sp. Syncephalastrum sp. fulfils Koch's postulates characterising it as a pathogenic microorganism. Ant workers recognise the infection and remove contaminated fragments from the fungus garden. Syncephalastrum sp. infection causes an interruption of foraging activity, an increase in ant mortality, subcolony deterioration and an increase in the amount of waste generated, all resulting in subcolony death. Syncephalastrum sp. also inhibits the ant fungal cultivar in vitro. The pathogenic effect of Syncephalastrum sp. does not depend on host morbidity or stress (e.g. worker mortality caused by an entomopathogenic fungus). Syncephalastrum sp. treatment resulted in progressive damage in subcolonies. The interactions among Syncephalastrum sp., fungus garden and ants offer new opportunities in integrated pest management of leaf-cutter ants. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.
Some correlations between the foraging behavior of common nighthawks, Cbordeiles minor (Forester), and the swarming behavior of two species of ants, Atta texana (Buckley) and Iridomyrmex pruinosis (Roger)

Treesearch

Stuart L. Warter; John C. Moser; Murray S. Blum

1962-01-01

At about 5:30 AM, may 24, 1961, four Common Nighthawks, Chordeiles minor, were collected from a group of nearly a dozen feeding at low level along a roadside in Rapides Parish, west of Alexandria, Louisiana. Upon subsequent examination of the distended stomachs of these birds, it was found that approximately 70% of the contents consisted of winged...
Laboratory investigations of the trail-following responses of four species of leaf-cutting ants with notes on the specificity of a trail pheromone of Atta texana (Buckley)

Treesearch

S. W. Robinson; John C. Moser; M. S. Blum; E. Amante

1974-01-01

Interspecific trail following activity of poison sac contents from four species of leaf-cutting ants was investigated. with only one exception, all the species teste followed trails made from each others poison sac contents. however when the ants were given a choice of following one of two separate trails, clear differences were shown in the poison sac contents of the...
Swords & Plowshares: Modifications to the MLRS Family of Munitions

DTIC Science & Technology

2013-04-01

of Dynamic Security (Washington, DC: Infantry Journal Press, 1949), 3. 23 Possony, x. 24 Richard G. Davis, The 31 Initiatives: A Study in Air...York: Dial Press / James Wade, 1979), 40. 28 Andrew G.B. Vallance , The Air Weapon: Doctrines of Air Power Strategy and Operational Art (New York, NY...AL: Air University Press, 1989), 479. 31 Ibid., 480. 32 Richard H. Van Atta and Michael J. Lippitz, Transformation and Transition: DARPA’s Role
Fungal communities in gardens of the leafcutter ant Atta cephalotes in forest and cabruca agrosystems of southern Bahia State (Brazil).

PubMed

Reis, Bárbara Monique Dos Santos; Silva, Aline; Alvarez, Martín Roberto; Oliveira, Tássio Brito de; Rodrigues, Andre

2015-12-01

Leaf-cutting ants interact with several fungi in addition to the fungal symbiont they cultivate for food. Here, we assessed alien fungal communities in colonies of Atta cephalotes. Fungus garden fragments were sampled from colonies in the Atlantic Rainforest and in a cabruca agrosystem in the state of Bahia (Brazil) in two distinct periods to evaluate whether differences in nest habitat influence the diversity of fungi in the ant colonies. We recovered a total of 403 alien fungi isolates from 628 garden fragments. The prevalent taxa found in these samples were Escovopsis sp. (26 %), Escovopsioides nivea (24 %), and Trichoderma spirale (10.9 %). Fungal diversity was similar between the colonies sampled in both areas suggesting that ants focus on reducing loads of alien fungi in the fungus gardens instead of avoiding specific fungi. However, fungal taxa composition differed between colonies sampled in the two areas and between the sampling periods. These differences are likely explained by the availability of plant substrates available for foraging over habitats and periods. Ordination analysis further supported that sampling period was the main attribute for community structuring but also revealed that additional factors may explain the structuring of fungal communities in colonies of A. cephalotes. Copyright © 2015 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.
Radiometric 81Kr dating identifies 120,000-year-old ice at Taylor Glacier, Antarctica

PubMed Central

Buizert, Christo; Baggenstos, Daniel; Jiang, Wei; Purtschert, Roland; Petrenko, Vasilii V.; Lu, Zheng-Tian; Müller, Peter; Kuhl, Tanner; Lee, James; Severinghaus, Jeffrey P.; Brook, Edward J.

2014-01-01

We present successful 81Kr-Kr radiometric dating of ancient polar ice. Krypton was extracted from the air bubbles in four ∼350-kg polar ice samples from Taylor Glacier in the McMurdo Dry Valleys, Antarctica, and dated using Atom Trap Trace Analysis (ATTA). The 81Kr radiometric ages agree with independent age estimates obtained from stratigraphic dating techniques with a mean absolute age offset of 6 ± 2.5 ka. Our experimental methods and sampling strategy are validated by (i) 85Kr and 39Ar analyses that show the samples to be free of modern air contamination and (ii) air content measurements that show the ice did not experience gas loss. We estimate the error in the 81Kr ages due to past geomagnetic variability to be below 3 ka. We show that ice from the previous interglacial period (Marine Isotope Stage 5e, 130–115 ka before present) can be found in abundance near the surface of Taylor Glacier. Our study paves the way for reliable radiometric dating of ancient ice in blue ice areas and margin sites where large samples are available, greatly enhancing their scientific value as archives of old ice and meteorites. At present, ATTA 81Kr analysis requires a 40–80-kg ice sample; as sample requirements continue to decrease, 81Kr dating of ice cores is a future possibility. PMID:24753606
Radiometric 81Kr dating identifies 120,000-year-old ice at Taylor Glacier, Antarctica.

PubMed

Buizert, Christo; Baggenstos, Daniel; Jiang, Wei; Purtschert, Roland; Petrenko, Vasilii V; Lu, Zheng-Tian; Müller, Peter; Kuhl, Tanner; Lee, James; Severinghaus, Jeffrey P; Brook, Edward J

2014-05-13

We present successful (81)Kr-Kr radiometric dating of ancient polar ice. Krypton was extracted from the air bubbles in four ∼350-kg polar ice samples from Taylor Glacier in the McMurdo Dry Valleys, Antarctica, and dated using Atom Trap Trace Analysis (ATTA). The (81)Kr radiometric ages agree with independent age estimates obtained from stratigraphic dating techniques with a mean absolute age offset of 6 ± 2.5 ka. Our experimental methods and sampling strategy are validated by (i) (85)Kr and (39)Ar analyses that show the samples to be free of modern air contamination and (ii) air content measurements that show the ice did not experience gas loss. We estimate the error in the (81)Kr ages due to past geomagnetic variability to be below 3 ka. We show that ice from the previous interglacial period (Marine Isotope Stage 5e, 130-115 ka before present) can be found in abundance near the surface of Taylor Glacier. Our study paves the way for reliable radiometric dating of ancient ice in blue ice areas and margin sites where large samples are available, greatly enhancing their scientific value as archives of old ice and meteorites. At present, ATTA (81)Kr analysis requires a 40-80-kg ice sample; as sample requirements continue to decrease, (81)Kr dating of ice cores is a future possibility.
Paleodistributions and Comparative Molecular Phylogeography of Leafcutter Ants (Atta spp.) Provide New Insight into the Origins of Amazonian Diversity

PubMed Central

Solomon, Scott E.; Bacci, Mauricio; Martins, Joaquim; Vinha, Giovanna Gonçalves; Mueller, Ulrich G.

2008-01-01

The evolutionary basis for high species diversity in tropical regions of the world remains unresolved. Much research has focused on the biogeography of speciation in the Amazon Basin, which harbors the greatest diversity of terrestrial life. The leading hypotheses on allopatric diversification of Amazonian taxa are the Pleistocene refugia, marine incursion, and riverine barrier hypotheses. Recent advances in the fields of phylogeography and species-distribution modeling permit a modern re-evaluation of these hypotheses. Our approach combines comparative, molecular phylogeographic analyses using mitochondrial DNA sequence data with paleodistribution modeling of species ranges at the last glacial maximum (LGM) to test these hypotheses for three co-distributed species of leafcutter ants (Atta spp.). The cumulative results of all tests reject every prediction of the riverine barrier hypothesis, but are unable to reject several predictions of the Pleistocene refugia and marine incursion hypotheses. Coalescent dating analyses suggest that population structure formed recently (Pleistocene-Pliocene), but are unable to reject the possibility that Miocene events may be responsible for structuring populations in two of the three species examined. The available data therefore suggest that either marine incursions in the Miocene or climate changes during the Pleistocene—or both—have shaped the population structure of the three species examined. Our results also reconceptualize the traditional Pleistocene refugia hypothesis, and offer a novel framework for future research into the area. PMID:18648512
The Musharraf Paradox: The Failure of an Economic Success Story

DTIC Science & Technology

2008-01-01

more basic set of issues pre- vailed: People were angry over the fact atta [ flour ] was not avail- able, that food prices were high, and due to this...prices of food items, combined with shortages of sugar, oil and flour , a looming power and gas crisis also worked to dampen the Musharraf economic...resources from the public and private sectors – often to the enrichment of senior officers, both on-duty and retired. The military has come to
Occurrence of killer yeasts in leaf-cutting ant nests.

PubMed

Carreiro, S C; Pagnocca, F C; Bacci, M; Bueno, O C; Hebling, M J A; Middelhoven, W J

2002-01-01

Killer activity was screened in 99 yeast strains isolated from the nests of the leaf-cutting ant Atta sexdens against 6 standard sensitive strains, as well as against each other. Among this yeast community killer activity was widespread since 77 strains (78%) were able to kill or inhibit the growth of at least one standard strain or nest strain. Toxin production was observed in representatives of all the studied genera including Aureobasidium, Rhodotorula, Tremella and Trichosporon, whose killer activity has not yet been described.
Mining and gene ontology based annotation of SSR markers from expressed sequence tags of Humulus lupulus

PubMed Central

Singh, Swati; Gupta, Sanchita; Mani, Ashutosh; Chaturvedi, Anoop

2012-01-01

Humulus lupulus is commonly known as hops, a member of the family moraceae. Currently many projects are underway leading to the accumulation of voluminous genomic and expressed sequence tag sequences in public databases. The genetically characterized domains in these databases are limited due to non-availability of reliable molecular markers. The large data of EST sequences are available in hops. The simple sequence repeat markers extracted from EST data are used as molecular markers for genetic characterization, in the present study. 25,495 EST sequences were examined and assembled to get full-length sequences. Maximum frequency distribution was shown by mononucleotide SSR motifs i.e. 60.44% in contig and 62.16% in singleton where as minimum frequency are observed for hexanucleotide SSR in contig (0.09%) and pentanucleotide SSR in singletons (0.12%). Maximum trinucleotide motifs code for Glutamic acid (GAA) while AT/TA were the most frequent repeat of dinucleotide SSRs. Flanking primer pairs were designed in-silico for the SSR containing sequences. Functional categorization of SSRs containing sequences was done through gene ontology terms like biological process, cellular component and molecular function. PMID:22368382
Selective isolation of dematiaceous fungi from the workers of Atta laevigata (Formicidae: Attini).

PubMed

Guedes, F L A; Attili-Angelis, D; Pagnocca, F C

2012-01-01

Leaf-cutting ants (Formicidae: Attini) are considered pests in agriculture for their impact in human crops, as they utilize leaf fragments to raise their fungal mutualist (Agaricales: Lepiotaceae). Basically, the basidiomycetous fungus is cultivated to supply food to adult workers and broads; in return, the ants protect it against natural enemies. However, recent studies have claimed that other microorganisms are associated to ant nests where a wide range of interactions may take place. To investigate the occurrence of dematiaceous fungi on the cuticle of Atta laevigata ants, 30 workers were sampled from an adult nest located in the surroundings of the Center for the Studies of Social Insects, UNESP-Rio Claro, SP, Brazil. The use of selective techniques to avoid high-sporulation fungi has been recommended and was tested in this study. To favor the isolation of the desired fungi, heads and cuticle scrapings of ant bodies were inoculated on Mycosel agar and incubated for 3 weeks at 35°C. Morphological and molecular methods were used to identify the filamentous fungi recovered. From 56 isolates, 19 were hyaline filamentous species, and among the remaining 37, some are mentioned as phyto-associated fungi like Alternaria arborescens, Bipolaris sorokiniana, Bipolaris eleusines, Bipolaris zeae, Curvularia trifolii, and Paraphaeosphaeria michotii. These species are reported from A. laevigata bodies for the first time. None of the isolation trials revealed the presence of the parasite Escovopsis or entomopathogenic fungi. The possible spread of the fungi in nature by the ants is discussed.
Intramandibular glands in different castes of leaf-cutting ant, Atta laevigata (Fr. Smith, 1858) (Formicidae: Attini).

PubMed

Martins, Luiza Carla Barbosa; Della Lucia, Terezinha Maria Castro; Gonçalves, Wagner Gonzaga; Delabie, Jacques Hubert Charles; Zanuncio, José Cola; Serrão, José Eduardo

2015-07-01

Intramandibular glands have been poorly studied in polymorphic ants, where the differences between castes were unsufficiently scrutinized. Leaf-cutting ants possess one of the most complex systems of communication and labor division, which is polymorphic well as age polyethism, and makes them an ideal model for the study of intramandibular glands. This study has investigated the occurrence of intramandibular glands in female castes and subcastes of Atta laevigata. The mandibles of the queen, medium, and minor workers, and soldiers were submitted to histological, histochemical, ultrastructural, and morphometric analyses. The class-3 gland cells and the epidermal gland with a reservoir were found in all the castes. The queens and soldiers showed a higher number of class-3 gland cells, distributed within the mandible as well as a greater gland size in comparison to the workers. The histochemical tests, periodic acid-Schiff (PAS), mercury-bromophenol, and Nile blue, were similar for the class-3 gland cells and epidermal glands with a reservoir. However, the tests evidenced differences between the castes, with carbohydrates strongly positive in all of them, whereas neutral lipids were found in the queen and soldiers. The protein was weakly positive in the queen, whereas in the soldier, medium, and minor workers these reactions were strongly positive in the intramandibular glands. Our findings in A. laevigata suggest that intramandibular glands are directly involved in labor division and consequently in chemical communication between the castes. © 2015 Wiley Periodicals, Inc.
Effect of Tithonia diversifolia Mulch on Atta cephalotes (Hymenoptera: Formicidae) Nests

PubMed Central

Rodríguez, Jonathan; Montoya-Lerma, James; Calle, Zoraida

2015-01-01

Recent studies have shown an insecticidal effect of Tithonia diversifolia (Hemsl.) Gray (Asterales: Asteraceae) foliage on workers of Atta cephalotes L. and inhibitory effects of this plant on the growth of the symbiotic fungus Leucoagaricus gongylophorus (A. Müler) Singer. To evaluate the potential of T. diversifolia as a biological control treatment of this important pest, we assessed the effect of green manure (mulch) of this plant on natural nests of A. cephalotes, in Cali, Colombia. Three treatments were randomly assigned to 30 nests: 1) green mulch of T. diversifolia, 2) green mulch of Miconia sp., Ruiz & Pav. and 3) unmulched control. Every 2 wk for 6 mo, the surface of the nests was completely covered with leaves. Physical and chemical parameters of nest soil were assessed before the first and after the last application of the mulch. Ant foraging in T. diversifolia-treated nests decreased by 60% after the initial applications of the mulch, while nest surface area decreased by 40%. When the nests covered with T. diversifolia were opened, it was observed that the superficial fungus chambers had been relocated at a greater depth. In addition, microbial activity and soil pH increased by 84% and 12%, respectively, in nests covered with plant residues. In conclusion, the continued use of T. diversifolia mulch reduces foraging activity and negatively affects the internal conditions of the colonies, thereby inducing the ants to relocate the fungus chambers within the nests. PMID:25843585
Artistic creativity and DBS: a case report.

PubMed

Drago, V; Foster, P S; Okun, M S; Haq, I; Sudhyadhom, A; Skidmore, F M; Heilman, K M

2009-01-15

Deep brain stimulation (DBS) is a treatment for patients with Parkinson's disease (PD) who are not adequately controlled with medications. An artist reported changes in her artistic creativity and art appreciation when treated with left DBS. We sought to study her artistic productions and her appreciation of art while both "on" and "off" left DBS. A 69-year-old right-handed woman with an approximate 20-year history of PD was referred to us for management of a left subthalamic region nucleus (STN) DBS placed at another institution 4 years prior. In Experiment 1 we had her rate several dimensions (Evocative Impact, Aesthetics, Novelty, Technique, Closure and Representation) of another artist's paintings. In Experiment 2, we tested her with the Abbreviated Torrance Test (of creativity) for Adults (ATTA). During testing the patient remained on her dopaminergic medication, but was tested on and off left DBS. On the judgment task while "on" left DBS, versus "off" DBS, there were significant reductions in her appreciation of artistic Closure and Technique. When "off" DBS her ATTA creativity index was above average, but when switched "on" her creativity index was below average. These results suggest the possibility that left ventral STN/SNR DBS reduces creativity as well as appreciation of art. The reason for these alterations is not known, but might be related to enhanced activation of the left hemisphere and reciprocal deactivation of the right hemisphere which mediates both visuospatial skills and global attention, both of which are important in artistic creativity and appreciation.
Branch Width and Height Influence the Incorporation of Branches into Foraging Trails and Travel Speed in Leafcutter Ants Atta cephalotes (L.) (Hymenoptera: Formicidae).

PubMed

Freeman, B M; Chaves-Campos, J

2016-06-01

Fallen branches are often incorporated into Atta cephalotes (L.) foraging trails to optimize leaf tissue transport rates and economize trail maintenance. Recent studies in lowlands show laden A. cephalotes travel faster across fallen branches than on ground, but more slowly ascending or descending a branch. The latter is likely because (1) it is difficult to travel up or downhill and (2) bottlenecks occur when branches are narrower than preceding trail. Hence, both branch height and width should determine whether branches decrease net travel times, but no study has evaluated it yet. Laden A. cephalotes were timed in relation to branch width and height across segments preceding, accessing, across, and departing a fallen branch in the highlands of Costa Rica. Ants traveled faster on branches than on cleared segments of trunk-trail, but accelerated when ascending or descending the branch-likely because of the absence of bottlenecks during the day in the highlands. Branch size did not affect ant speed in observed branches; the majority of which (22/24) varied from 11 to 120 mm in both height and width (average 66 mm in both cases). To determine whether ants exclude branches outside this range, ants were offered the choice between branches within this range and branches that were taller/wider than 120 mm. Ants strongly preferred the former. Our results indicate that A. cephalotes can adjust their speed to compensate for the difficulty of traveling on branch slopes. More generally, branch size should be considered when studying ant foraging efficiency.
Underground anemotactic orientation in leaf-cutting ants: perception of airflow and experience-dependent choice of airflow direction during digging

NASA Astrophysics Data System (ADS)

Halboth, Florian; Roces, Flavio

2017-10-01

Air exchange between the large nests of Atta vollenweideri leaf-cutting ants and the environment strongly relies on a passive, wind-induced ventilation mechanism. Air moves through nest tunnels and airflow direction depends on the location of the tunnel openings on the nest mound. We hypothesized that ants might use the direction of airflow along nest tunnels as orientation cue in the context of climate control, as digging workers might prefer to broaden or to close tunnels with inflowing or outflowing air in order to regulate nest ventilation. To investigate anemotactic orientation in Atta vollenweideri, we first tested the ants' ability to perceive air movements by confronting single workers with airflow stimuli in the range 0 to 20 cm/s. Workers responded to airflow velocities ≥ 2 cm/s, and the number of ants reacting to the stimulus increased with increasing airflow speed. Second, we asked whether digging workers use airflow direction as an orientation cue. Workers were exposed to either inflow or outflow of air while digging in the nest and could subsequently choose between two digging sites providing either inflow or outflow of air, respectively. Workers significantly chose the side with the same airflow direction they experienced before. When no airflow was present during initial digging, workers showed no preference for airflow directions. Workers developed preferences for airflow direction only after previous exposure to a given airflow direction. We suggest that experience-modified anemotaxis might help leaf-cutting ants spatially organize their digging activity inside the nest during tasks related to climate control.

Effect of Tithonia diversifolia mulch on Atta cephalotes (Hymenoptera: Formicidae) nests.

PubMed

Rodríguez, Jonathan; Montoya-Lerma, James; Calle, Zoraida

2015-01-01

Recent studies have shown an insecticidal effect of Tithonia diversifolia (Hemsl.) Gray (Asterales: Asteraceae) foliage on workers of Atta cephalotes L. and inhibitory effects of this plant on the growth of the symbiotic fungus Leucoagaricus gongylophorus (A. Müler) Singer. To evaluate the potential of T. diversifolia as a biological control treatment of this important pest, we assessed the effect of green manure (mulch) of this plant on natural nests of A. cephalotes, in Cali, Colombia. Three treatments were randomly assigned to 30 nests: 1) green mulch of T. diversifolia, 2) green mulch of Miconia sp., Ruiz & Pav. and 3) unmulched control. Every 2 wk for 6 mo, the surface of the nests was completely covered with leaves. Physical and chemical parameters of nest soil were assessed before the first and after the last application of the mulch. Ant foraging in T. diversifolia-treated nests decreased by 60% after the initial applications of the mulch, while nest surface area decreased by 40%. When the nests covered with T. diversifolia were opened, it was observed that the superficial fungus chambers had been relocated at a greater depth. In addition, microbial activity and soil pH increased by 84% and 12%, respectively, in nests covered with plant residues. In conclusion, the continued use of T. diversifolia mulch reduces foraging activity and negatively affects the internal conditions of the colonies, thereby inducing the ants to relocate the fungus chambers within the nests. © The Author 2015. Published by Oxford University Press on behalf of the Entomological Society of America.
Underground anemotactic orientation in leaf-cutting ants: perception of airflow and experience-dependent choice of airflow direction during digging.

PubMed

Halboth, Florian; Roces, Flavio

2017-09-19

Air exchange between the large nests of Atta vollenweideri leaf-cutting ants and the environment strongly relies on a passive, wind-induced ventilation mechanism. Air moves through nest tunnels and airflow direction depends on the location of the tunnel openings on the nest mound. We hypothesized that ants might use the direction of airflow along nest tunnels as orientation cue in the context of climate control, as digging workers might prefer to broaden or to close tunnels with inflowing or outflowing air in order to regulate nest ventilation. To investigate anemotactic orientation in Atta vollenweideri, we first tested the ants' ability to perceive air movements by confronting single workers with airflow stimuli in the range 0 to 20 cm/s. Workers responded to airflow velocities ≥ 2 cm/s, and the number of ants reacting to the stimulus increased with increasing airflow speed. Second, we asked whether digging workers use airflow direction as an orientation cue. Workers were exposed to either inflow or outflow of air while digging in the nest and could subsequently choose between two digging sites providing either inflow or outflow of air, respectively. Workers significantly chose the side with the same airflow direction they experienced before. When no airflow was present during initial digging, workers showed no preference for airflow directions. Workers developed preferences for airflow direction only after previous exposure to a given airflow direction. We suggest that experience-modified anemotaxis might help leaf-cutting ants spatially organize their digging activity inside the nest during tasks related to climate control.
The Genome Sequence of the Leaf-Cutter Ant Atta cephalotes Reveals Insights into Its Obligate Symbiotic Lifestyle

PubMed Central

Suen, Garret; Holt, Carson; Abouheif, Ehab; Bornberg-Bauer, Erich; Bouffard, Pascal; Caldera, Eric J.; Cash, Elizabeth; Cavanaugh, Amy; Denas, Olgert; Elhaik, Eran; Favé, Marie-Julie; Gadau, Jürgen; Gibson, Joshua D.; Graur, Dan; Grubbs, Kirk J.; Hagen, Darren E.; Harkins, Timothy T.; Helmkampf, Martin; Hu, Hao; Johnson, Brian R.; Kim, Jay; Marsh, Sarah E.; Moeller, Joseph A.; Muñoz-Torres, Mónica C.; Murphy, Marguerite C.; Naughton, Meredith C.; Nigam, Surabhi; Overson, Rick; Rajakumar, Rajendhran; Reese, Justin T.; Scott, Jarrod J.; Smith, Chris R.; Tao, Shu; Tsutsui, Neil D.; Viljakainen, Lumi; Wissler, Lothar; Yandell, Mark D.; Zimmer, Fabian; Taylor, James; Slater, Steven C.; Clifton, Sandra W.; Warren, Wesley C.; Elsik, Christine G.; Smith, Christopher D.; Weinstock, George M.; Gerardo, Nicole M.; Currie, Cameron R.

2011-01-01

Leaf-cutter ants are one of the most important herbivorous insects in the Neotropics, harvesting vast quantities of fresh leaf material. The ants use leaves to cultivate a fungus that serves as the colony's primary food source. This obligate ant-fungus mutualism is one of the few occurrences of farming by non-humans and likely facilitated the formation of their massive colonies. Mature leaf-cutter ant colonies contain millions of workers ranging in size from small garden tenders to large soldiers, resulting in one of the most complex polymorphic caste systems within ants. To begin uncovering the genomic underpinnings of this system, we sequenced the genome of Atta cephalotes using 454 pyrosequencing. One prediction from this ant's lifestyle is that it has undergone genetic modifications that reflect its obligate dependence on the fungus for nutrients. Analysis of this genome sequence is consistent with this hypothesis, as we find evidence for reductions in genes related to nutrient acquisition. These include extensive reductions in serine proteases (which are likely unnecessary because proteolysis is not a primary mechanism used to process nutrients obtained from the fungus), a loss of genes involved in arginine biosynthesis (suggesting that this amino acid is obtained from the fungus), and the absence of a hexamerin (which sequesters amino acids during larval development in other insects). Following recent reports of genome sequences from other insects that engage in symbioses with beneficial microbes, the A. cephalotes genome provides new insights into the symbiotic lifestyle of this ant and advances our understanding of host–microbe symbioses. PMID:21347285
The Influence of Job Characteristics and the Family on the Propensity to Change Careers: An Expectancy Theory Approach.

DTIC Science & Technology

1976-11-01

tcomes and h i s concep t ions of the i ns trumental ity of the occupation for the atta i nment of these outcomes (Vroorn , 1964). Val ence (V) refers to...increase the research- ers ’ ab ility to predict cho i ce beyond predictions from the va l ence x instrumentality i ndex alone. Hypotheses Because of...i rmen ’s past satisfaction with the job of professor will be positively re— lated to the sum of the products of the va l ences of relevant out— comes
Regulatory interactions between the human HOXB1, HOXB2, and HOXB3 proteins and the upstream sequence of the Otx2 gene in embryonal carcinoma cells.

PubMed

Guazzi, S; Pintonello, M L; Viganò, A; Boncinelli, E

1998-05-01

Vertebrate Hox and Otx genes encode homeodomain-containing transcription factors thought to transduce positional information along the body axis in the segmental portion of the trunk and in the rostral brain, respectively. Moreover, Hox and Otx2 genes show a complementary spatial regulation during embryogenesis. In this report, we show that a 1821-base pair (bp) upstream DNA fragment of the Otx2 gene is positively regulated by co-transfection with expression vectors for the human HOXB1, HOXB2, and HOXB3 proteins in an embryonal carcinoma cell line (NT2/D1) and that a shorter fragment of only 534 bp is able to drive this regulation. We also identified the HOXB1, HOXB2, and HOXB3 DNA-binding region on the 534-bp Otx2 genomic fragment using nuclear extracts from Hox-transfected COS cells and 12.5 days postcoitum mouse embryos or HOXB3 homeodomain-containing bacterial extracts. HOXB1, HOXB3, and nuclear extracts from 12.5 days postcoitum mouse embryos bind to a sequence containing two palindromic TAATTA sites, which bear four copies of the ATTA core sequence, a common feature of most HOM-C/HOX binding sites. HOXB2 protected an adjacent site containing a direct repeat of an ACTT sequence, quite divergent from the ATTA consensus. The region bound by the three homeoproteins is strikingly conserved through evolution and necessary (at least for HOXB1 and HOXB3) to mediate the up-regulation of the Otx2 transcription. Taken together, our data support the hypothesis that anteriorly expressed Hox genes might play a role in the refinement of the Otx2 early expression boundaries in vivo.
Soil moisture and excavation behaviour in the Chaco leaf-cutting ant (Atta vollenweideri): digging performance and prevention of water inflow into the nest.

PubMed

Pielström, Steffen; Roces, Flavio

2014-01-01

The Chaco leaf-cutting ant Atta vollenweideri is native to the clay-heavy soils of the Gran Chaco region in South America. Because of seasonal floods, colonies are regularly exposed to varying moisture across the soil profile, a factor that not only strongly influences workers' digging performance during nest building, but also determines the suitability of the soil for the rearing of the colony's symbiotic fungus. In this study, we investigated the effects of varying soil moisture on behaviours associated with underground nest building in A. vollenweideri. This was done in a series of laboratory experiments using standardised, plastic clay-water mixtures with gravimetric water contents ranging from relatively brittle material to mixtures close to the liquid limit. Our experiments showed that preference and group-level digging rate increased with increasing water content, but then dropped considerably for extremely moist materials. The production of vibrational recruitment signals during digging showed, on the contrary, a slightly negative linear correlation with soil moisture. Workers formed and carried clay pellets at higher rates in moist clay, even at the highest water content tested. Hence, their weak preference and low group-level excavation rate observed for that mixture cannot be explained by any inability to work with the material. More likely, extremely high moistures may indicate locations unsuitable for nest building. To test this hypothesis, we simulated a situation in which workers excavated an upward tunnel below accumulated surface water. The ants stopped digging about 12 mm below the interface soil/water, a behaviour representing a possible adaptation to the threat of water inflow field colonies are exposed to while digging under seasonally flooded soils. Possible roles of soil water in the temporal and spatial pattern of nest growth are discussed.
Evolution Analysis of Simple Sequence Repeats in Plant Genome.

PubMed

Qin, Zhen; Wang, Yanping; Wang, Qingmei; Li, Aixian; Hou, Fuyun; Zhang, Liming

2015-01-01

Simple sequence repeats (SSRs) are widespread units on genome sequences, and play many important roles in plants. In order to reveal the evolution of plant genomes, we investigated the evolutionary regularities of SSRs during the evolution of plant species and the plant kingdom by analysis of twelve sequenced plant genome sequences. First, in the twelve studied plant genomes, the main SSRs were those which contain repeats of 1-3 nucleotides combination. Second, in mononucleotide SSRs, the A/T percentage gradually increased along with the evolution of plants (except for P. patens). With the increase of SSRs repeat number the percentage of A/T in C. reinhardtii had no significant change, while the percentage of A/T in terrestrial plants species gradually declined. Third, in dinucleotide SSRs, the percentage of AT/TA increased along with the evolution of plant kingdom and the repeat number increased in terrestrial plants species. This trend was more obvious in dicotyledon than monocotyledon. The percentage of CG/GC showed the opposite pattern to the AT/TA. Forth, in trinucleotide SSRs, the percentages of combinations including two or three A/T were in a rising trend along with the evolution of plant kingdom; meanwhile with the increase of SSRs repeat number in plants species, different species chose different combinations as dominant SSRs. SSRs in C. reinhardtii, P. patens, Z. mays and A. thaliana showed their specific patterns related to evolutionary position or specific changes of genome sequences. The results showed that, SSRs not only had the general pattern in the evolution of plant kingdom, but also were associated with the evolution of the specific genome sequence. The study of the evolutionary regularities of SSRs provided new insights for the analysis of the plant genome evolution.
Identification and functional characterization of a solute carrier family 15, member 4 gene in Litopenaeus vannamei.

PubMed

Chen, Yong-Gui; Yuan, Kai; Zhang, Ze-Zhi; Yuan, Feng-Hua; Weng, Shao-Ping; Yue, Hai-Tao; He, Jian-Guo; Chen, Yi-Hong

2016-04-01

Innate immunity in shrimp is important in resisting bacterial infection. The NF-κB pathway is pivotal in such an immune response. This study cloned and functionally characterized the solute carrier family (SLC) 15 member A 4 (LvSLC15A4) gene in Litopenaeus vannamei. The open reading frame of LvSLC15A4 is 1, 902 bp long and encodes a putative 633-amino acid protein, which is localized in the plasma membrane and intracellular vesicular compartments. Results of the reporter gene assay showed that LvSLC15A4 upregulated NF-κB target genes, including the immediate-early gene 1 of white spot syndrome virus, as well as several antimicrobial peptide genes, such as pen4, CecA, AttA, and Mtk in S2 cells. Moreover, knocked-down expression of LvSLC15A4 reduced pen4 expression in L. vannamei. LvSLC15A4 down-regulation also increased the cumulative mortality of Vibrio parahemolyticus-infected L. vannamei. Furthermore, LvSLC15A4 expression was induced by unfolded protein response (UPR) in L. vannamei hematocytes. These results suggest that LvSLC15A4 participates in L. vannamei innate immunity via the NF-κB pathway and thus may be related to UPR. Copyright © 2015 Elsevier Ltd. All rights reserved.
Indirect personality assessment of the violent true believer.

PubMed

Meloy, J Reid

2004-04-01

The violent true believer is an individual committed to an ideology or belief system which advances homicide and suicide as a legitimate means to further a particular goal. The author explores useful sources of evidence for an indirect personality assessment of such individuals. He illustrates both idiographic and nomothetic approaches to indirect personality assessment through comparative analyses of Timothy McVeigh, an American who bombed the federal building in Oklahoma City in 1995, and Mohamed Atta, an Egyptian who led the airplane attacks against the World Trade Center and the Pentagon in 2001. The risks of indirect personality assessment and ethical concerns are identified.
The Postpharyngeal Gland: Specialized Organ for Lipid Nutrition in Leaf-Cutting Ants

PubMed Central

Decio, Pâmela; Vieira, Alexsandro Santana; Dias, Nathalia Baptista; Palma, Mario Sergio; Bueno, Odair Correa

2016-01-01

There are several hypotheses about the possible functions of the postpharyngeal gland (PPG) in ants. The proposed functions include roles as cephalic or gastric caeca and diverticulum of the digestive tract, mixing of hydrocarbons, nestmate recognition, feeding larvae, and the accumulation of lipids inside this gland, whose origin is contradictory. The current study aimed to investigate the functions of these glands by examining the protein expression profile of the PPGs of Atta sexdens rubropilosa (Hymenoptera, Formicidae). Mated females received lipid supplementation and their glands were extracted and analyzed using a proteomic approach. The protocol used combined two-dimensional electrophoresis and shotgun strategies, followed by mass spectrometry. We also detected lipid β-oxidation by immunofluorescent marking of acyl-CoA dehydrogenase. Supplying ants with lipids elicited responses in the glandular cells of the PPG; these included increased expression of proteins related to defense mechanisms and signal transduction and reorganization of the cytoskeleton due to cell expansion. In addition, some proteins in PPG were overexpressed, especially those involved in lipid and energy metabolism. Part of the lipids may be reduced, used for the synthesis of fatty alcohol, transported to the hemolymph, or may be used as substrate for the synthesis of acetyl-CoA, which is oxidized to form molecules that drive oxidative phosphorylation and produce energy for cellular metabolic processes. These findings suggest that this organ is specialized for lipid nutrition of adult leaf-cutting ants and characterized like a of diverticulum foregut, with the ability to absorb, store, metabolize, and mobilize lipids to the hemolymph. However, we do not rule out that the PPG may have other functions in other species of ants. PMID:27149618
The Postpharyngeal Gland: Specialized Organ for Lipid Nutrition in Leaf-Cutting Ants.

PubMed

Decio, Pâmela; Vieira, Alexsandro Santana; Dias, Nathalia Baptista; Palma, Mario Sergio; Bueno, Odair Correa

2016-01-01

There are several hypotheses about the possible functions of the postpharyngeal gland (PPG) in ants. The proposed functions include roles as cephalic or gastric caeca and diverticulum of the digestive tract, mixing of hydrocarbons, nestmate recognition, feeding larvae, and the accumulation of lipids inside this gland, whose origin is contradictory. The current study aimed to investigate the functions of these glands by examining the protein expression profile of the PPGs of Atta sexdens rubropilosa (Hymenoptera, Formicidae). Mated females received lipid supplementation and their glands were extracted and analyzed using a proteomic approach. The protocol used combined two-dimensional electrophoresis and shotgun strategies, followed by mass spectrometry. We also detected lipid β-oxidation by immunofluorescent marking of acyl-CoA dehydrogenase. Supplying ants with lipids elicited responses in the glandular cells of the PPG; these included increased expression of proteins related to defense mechanisms and signal transduction and reorganization of the cytoskeleton due to cell expansion. In addition, some proteins in PPG were overexpressed, especially those involved in lipid and energy metabolism. Part of the lipids may be reduced, used for the synthesis of fatty alcohol, transported to the hemolymph, or may be used as substrate for the synthesis of acetyl-CoA, which is oxidized to form molecules that drive oxidative phosphorylation and produce energy for cellular metabolic processes. These findings suggest that this organ is specialized for lipid nutrition of adult leaf-cutting ants and characterized like a of diverticulum foregut, with the ability to absorb, store, metabolize, and mobilize lipids to the hemolymph. However, we do not rule out that the PPG may have other functions in other species of ants.
Troposcatter Antenna Positioner

DTIC Science & Technology

1980-08-01

that ’ Z ’ WecT ie(hu1)s n 1) adue h atta t i vnt id() W= 41TRd(O0) (12) Using (10) twice, we get the second moment . 2S(W)e Wdw -21R 10 (0)( Papoulis...tu 4~e~eawd, deu~entpr,, te~ t and Le~ t ~td acqwiU’On Po4au6m in 4uappo’Lt oj Counand, Conto COuusuwi6 m lantettigexce (01) m40tie.6. Ted*tma and...275 - 7 4.] 󈧕 kL L. d TROPOSCATTER ANTENNA POSITIONR Finalechnical Iep t ." 6Sep 7-_Feb _W1 j( W. P /irkemeier F3 16O2 77-CQl48WpA 9. PERFORMING
Transcriptome analysis and de novo annotation of the critically endangered Amur sturgeon (Acipenser schrenckii).

PubMed

Zhang, X J; Jiang, H Y; Li, L M; Yuan, L H; Chen, J P

2016-06-20

The aim of this study was to provide comprehensive insights into the genetic background of sturgeon by transcriptome study. We performed a de novo assembly of the Amur sturgeon Acipenser schrenckii transcriptome using Illumina Hiseq 2000 sequencing. A total of 148,817 non-redundant unigenes with base length of approximately 121,698,536 bp and ranges from 201 to 26,789 bp were obtained. All the unigenes were classified into 3368 distinct categories and 145,449 singletons by homologous transcript cluster analysis. In all, 46,865 (31.49%) unigenes showed homologous matches with Nr database and 32,214 (21.65%) unigenes were matched to Nt database. In total, 24,862 unigenes were categorized into significantly enriched 52 function groups by GO analysis, and 38,436 unigenes were classified into 25 groups by KOG prediction, as well as 128 enriched KEGG pathways were identified by 45,598 unigenes (P < 0.05). Subsequently, a total of 19,860 SSRs markers were identified with the abundant di-nucleotide type (10,658; 53.67%) and the most AT/TA motif repeats (2689; 13.54%). A total of 1341 conserved lncRNAs were identified by a customized pipeline. Our study provides new sequence and function information for A. schrenckii, which will be the basis for further genetic studies on sturgeon species. The huge number of potential SSRs and putatively conserved lncRNAs isolated by the transcriptome also shed light on research in many fields, including the evolution, conservation management, and biological processes in sturgeon.
Spatio-Temporal Dynamics of Foraging Networks in the Grass-Cutting Ant Atta bisphaerica Forel, 1908 (Formicidae, Attini)

PubMed Central

Lopes, Juliane F. S.; Brugger, Mariana S.; Menezes, Regys B.; Camargo, Roberto S.; Forti, Luiz Carlos; Fourcassié, Vincent

2016-01-01

Foraging networks are a key element for ant colonies because they facilitate the flow of resources from the environment to the nest and they allow the sharing of information among individuals. Here we report the results of an 8-month survey, extending from November 2009 to June 2010, of the foraging networks of four mature colonies of Atta bisphaerica, a species of grass-cutting ant which is considered as a pest in Brazil. We found that the distribution of foraging effort was strongly influenced by the landscape features around the nests, in particular by the permanently wet parts of the pasture in which the nests were located. The foraging networks consisted of underground tunnels which opened on average at 21.5m from the nests and of above-ground physical trails that reached on average 4.70m in length. The use of the foraging networks was highly dynamic, with few sections of the networks used for long periods of time. Three different phases, which could be linked to the seasonal change in the local rainfall regime, could be identified in the construction and use of the foraging networks. The first phase corresponded to the beginning of the rainy season and was characterized by a low foraging activity, as well as a low excavation and physical trail construction effort. The second phase, which began in February and extended up to the end of the humid season at the end of March, was characterized by an intense excavation and trail construction effort, resulting in an expansion of the foraging networks. Finally, in the third phase, which corresponded to the beginning of the dry season, the excavation and trail construction effort leveled off or decreased while foraging activity kept increasing. Our hypothesis is that ants could benefit from the underground tunnels and physical trails built during the humid season to maintain their foraging activity at a high level. PMID:26752413
Recent developments on field gas extraction and sample preparation methods for radiokrypton dating of groundwater

NASA Astrophysics Data System (ADS)

Yokochi, Reika

2016-09-01

Current and foreseen population growths will lead to an increased demand in freshwater, large quantities of which is stored as groundwater. The ventilation age is crucial to the assessment of groundwater resources, complementing the hydrological model approach based on hydrogeological parameters. Ultra-trace radioactive isotopes of Kr (81 Kr and 85 Kr) possess the ideal physical and chemical properties for groundwater dating. The recent advent of atom trap trace analyses (ATTA) has enabled determination of ultra-trace noble gas radioisotope abundances using 5-10 μ L of pure Kr. Anticipated developments will enable ATTA to analyze radiokrypton isotope abundances at high sample throughput, which necessitates simple and efficient sample preparation techniques that are adaptable to various sample chemistries. Recent developments of field gas extraction devices and simple and rapid Kr separation method at the University of Chicago are presented herein. Two field gas extraction devices optimized for different sampling conditions were recently designed and constructed, aiming at operational simplicity and portability. A newly developed Kr purification system enriches Kr by flowing a sample gas through a moderately cooled (138 K) activated charcoal column, followed by a gentle fractionating desorption. This simple process uses a single adsorbent and separates 99% of the bulk atmospheric gases from Kr without significant loss. The subsequent two stages of gas chromatographic separation and a hot Ti sponge getter further purify the Kr-enriched gas. Abundant CH4 necessitates multiple passages through one of the gas chromatographic separation columns. The presented Kr separation system has a demonstrated capability of extracting Kr with > 90% yield and 99% purity within 75 min from 1.2 to 26.8 L STP of atmospheric air with various concentrations of CH4. The apparatuses have successfully been deployed for sampling in the field and purification of groundwater samples.
Soil Moisture and Excavation Behaviour in the Chaco Leaf-Cutting Ant (Atta vollenweideri): Digging Performance and Prevention of Water Inflow into the Nest

PubMed Central

Pielström, Steffen; Roces, Flavio

2014-01-01

The Chaco leaf-cutting ant Atta vollenweideri is native to the clay-heavy soils of the Gran Chaco region in South America. Because of seasonal floods, colonies are regularly exposed to varying moisture across the soil profile, a factor that not only strongly influences workers' digging performance during nest building, but also determines the suitability of the soil for the rearing of the colony's symbiotic fungus. In this study, we investigated the effects of varying soil moisture on behaviours associated with underground nest building in A. vollenweideri. This was done in a series of laboratory experiments using standardised, plastic clay-water mixtures with gravimetric water contents ranging from relatively brittle material to mixtures close to the liquid limit. Our experiments showed that preference and group-level digging rate increased with increasing water content, but then dropped considerably for extremely moist materials. The production of vibrational recruitment signals during digging showed, on the contrary, a slightly negative linear correlation with soil moisture. Workers formed and carried clay pellets at higher rates in moist clay, even at the highest water content tested. Hence, their weak preference and low group-level excavation rate observed for that mixture cannot be explained by any inability to work with the material. More likely, extremely high moistures may indicate locations unsuitable for nest building. To test this hypothesis, we simulated a situation in which workers excavated an upward tunnel below accumulated surface water. The ants stopped digging about 12 mm below the interface soil/water, a behaviour representing a possible adaptation to the threat of water inflow field colonies are exposed to while digging under seasonally flooded soils. Possible roles of soil water in the temporal and spatial pattern of nest growth are discussed. PMID:24748382
How Load-Carrying Ants Avoid Falling Over: Mechanical Stability during Foraging in Atta vollenweideri Grass-Cutting Ants

PubMed Central

Moll, Karin; Roces, Flavio; Federle, Walter

2013-01-01

Background Foraging workers of grass-cutting ants (Atta vollenweideri) regularly carry grass fragments larger than their own body. Fragment length has been shown to influence the ants’ running speed and thereby the colony’s food intake rate. We investigated whether and how grass-cutting ants maintain stability when carrying fragments of two different lengths but identical mass. Principal Findings Ants carried all fragments in an upright, backwards-tilted position, but held long fragments more vertically than short ones. All carrying ants used an alternating tripod gait, where mechanical stability was increased by overlapping stance phases of consecutive steps. The overlap was greatest for ants carrying long fragments, resulting in more legs contacting the ground simultaneously. For all ants, the projection of the total centre of mass (ant and fragment) was often outside the supporting tripod, i.e. the three feet that would be in stance for a non-overlapping tripod gait. Stability was only achieved through additional legs in ground contact. Tripod stability (quantified as the minimum distance of the centre of mass to the edge of the supporting tripod) was significantly smaller for ants with long fragments. Here, tripod stability was lowest at the beginning of each step, when the center of mass was near the posterior margin of the supporting tripod. By contrast, tripod stability was lowest at the end of each step for ants carrying short fragments. Consistently, ants with long fragments mainly fell backwards, whereas ants carrying short fragments mainly fell forwards or to the side. Assuming that transporting ants adjust neither the fragment angle nor the gait, they would be less stable and more likely to fall over. Conclusions In grass-cutting ants, the need to maintain static stability when carrying long grass fragments has led to multiple kinematic adjustments at the expense of a reduced material transport rate. PMID:23300994
Reproductive ecology of phorid parasitoids in relation to the head size of leaf-cutting ants Atta sexdens Forel.

PubMed

Farder-Gomes, C F; Oliveira, M A; Gonçalves, P L; Gontijo, L M; Zanuncio, J C; Bragança, M A L; Pires, E M

2017-08-01

The leaf-cutting ant Atta sexdens Forel (Hymenoptera: Formicidae) is one of the most damaging agricultural pests in the Neotropics. Management strategies predominantly rely on the use of general insecticides. What is needed are more species-specific and environmentally friendly options. Parasitioids such as phorid flies (Diptera: Phoridae) may be one such option, but a greater understanding of the ecology of the flies and their ant hosts is essential to devise biological control strategies. Here we report parasitism rates, ant host size, parasitoid abundance per host and resultant sex ratios of two phorid species Apocephalus attophilus Borgmeier and Eibesfeldtphora tonhascai Brown parasitizing A.sexdens. The two species achieved parasitism rates of 1.48 and 1.46%, respectively and the pupal period was 14.7 ± 1.1 days and 22.1 ± 2.8 days, respectively. There was no significant difference between the head capsule width of ants parasitized by either A. attophilus or E. tonhascai. Likewise, there was no significant effect between the head capsule width of parasitized and unparasitized ants for both species. A significant positive correlation was found between the head capsule width of the parasitized ants and the number of adult parasitoids A. attophilus emerged. Ants parasitized by E. tonhascai survived significantly longer than those parasitized by A. attophilus. There was no significant effect of ant head width on the sex ratio of the offspring of either parasitoid species and no significant difference in the sex ratio (male: female) of their offspring. In summary, these data addressed here are important steps when considering natural enemies for biological control. Studying survival of the parasitized ants, parasitoid offspring sex ratio and host size preference allows for a better understanding of ant natural biological control in the field and can help in rearing of A. attophilus and E. tonhascai in laboratory.
Chemical communication in the dacetine antDaceton armigerum (Hymenoptera: Formicidae).

PubMed

Hölldobler, B; Palmer, J M; Moffett, M W

1990-04-01

Contrary to previous assumptions,Daceton armigerum, the largest ant in the myrmicine tribe Dacetini, employs trail communication. We identified two anatomical sources of trail pheromones: Trails drawn with poison gland contents can last for more than seven days. Trails drawn with the newly discovered sternal glands (in the VIth and VIIth abdominal sternites) are effective but relatively short-lived. In addition, our bioassays revealed that the contents of the mandibular glands elicit alarm behavior, and secretions from the pygidial gland release attraction. When tested with artificial poison gland trails from seven other myrmicine species,Daceton did not exhibit trail following behavior. We confirmed, however, previous findings thatAtta respond toDaceton poison gland trails andSolenopsis followDaceton Dufour's gland trails.
De novo transcriptome of the muga silkworm, Antheraea assamensis (Helfer).

PubMed

Chetia, Hasnahana; Kabiraj, Debajyoti; Singh, Deepika; Mosahari, Ponnala Vimal; Das, Suradip; Sharma, Pragya; Neog, Kartik; Sharma, Swagata; Jayaprakash, P; Bora, Utpal

2017-05-05

Antheraea assamensis (Lepidoptera: Saturniidae), is a semi-domesticated silkworm known to be endemic to Assam and the adjoining hilly areas of Northeast India. It is the only producer of a unique, commercially important variety of golden silk called "muga silk". Herein, we report the de novo transcriptome of A. assamensis reared on Machilus bombycina leaves for the first time. Short reads generated by high throughput sequencing of cDNA libraries from multiple tissues, viz. alimentary canal, silk gland and residual body of the 5 th instar of muga silkworm were assembled into transcripts via a de novo assembly pipeline followed by functional annotation and classification. A total of 1,21,433 transcripts were generated from ~231 million raw reads of which ~74% (89,583) were either allocated a functional annotation or categorized under Pfam/COG/KEGG categories. Identification of differentially expressed transcripts and their comparative sequence analysis revealed candidate genes related to silk synthesis, viz. silk gland factor-1 and 3, sericin-like transcript, etc. with conserved forkhead, homeo- and POU domains. Several candidate anti-microbial peptides which may have potential anti-bacterial, anti-fungal or anti-parasitic activity in A. assamensis were also identified. T/A and AT/TA were predicted to be the most abundant mono- and di-nucleotide simple sequence repeat markers in the transcriptome. Transcriptome validation was carried out by quantitative real-time PCR (qPCR) amplification of eight transcripts. The resources generated by this study will expand the periphery of existing genomic data on A. assamensis facilitating future in-depth studies on its unknown aspects. Copyright © 2017 Elsevier B.V. All rights reserved.

Leaf Cutter Ant (Atta cephalotes) Soil Modification and In Situ CO2 Gas Dynamics in a Neotropical Wet Forest

NASA Astrophysics Data System (ADS)

Fernandez Bou, A. S.; Carrasquillo Quintana, O.; Dierick, D.; Harmon, T. C.; Johnson, S.; Schwendenmann, L.; Zelikova, T. J.

2016-12-01

The goal of this work is to advance our understanding of soil carbon cycling in highly productive neotropical wet forests. More specifically, we are investigating the influence of leaf cutter ants (LCA) on soil CO2 gas dynamics in primary and secondary forest soils at La Selva Biological Station, Costa Rica. LCA are the dominant herbivore in tropical Americas, responsible for as much as 50% of the total herbivory. Their presence is increasing and their range is expanding because of forest fragmentation and other human impacts. We installed gas sampling wells in LCA (Atta cephalotes) nest and control sites (non-nests in the same soil and forest settings). The experimental design encompassed land cover (primary and secondary forest) and soil type (residual and alluvial). We collected gas samples monthly over an 18-month period. Several of the LCA nests were abandoned during this period. Nevertheless, we continued to sample these sites for LCA legacy effects. In several of the sites, we also installed sensors to continuously monitor soil moisture content, temperature, and CO2 levels. Within the 18-month period we conducted a 2-month field campaign to collect soil and nest vent CO2 efflux data from 3 of the nest-control pairs. Integrating the various data sets, we observed that for most of the sites nest and control soils behaved similarly during the tropical dry season. However, during the wet season gas well CO2 concentrations increased in the control sites while levels in the nests remained at dry season levels. This outcome suggests that ants modify soil gas transport properties (e.g., tortuosity). In situ time series and efflux sampling campaign data corroborated these findings. Abandoned nest CO2 levels were similar to those of the active nests, supporting the notion of a legacy effect from LCA manipulations. For this work, the period of abandonment was relatively short (several months to 1 year maximum), which appears to be insufficient for estimating the duration effect. Overall, these results demonstrate that LCA exert a significant effect on carbon cycling in rain forest soils.
Association of polymorphisms in microRNA machinery genes (DROSHA, DICER1, RAN, and XPO5) with risk of idiopathic primary ovarian insufficiency in Korean women.

PubMed

Rah, HyungChul; Jeon, Young Joo; Lee, Bo Eun; Kim, Jung O; Shim, Sung Han; Lee, Woo Sik; Choi, Dong Hee; Kim, Ji Hyang; Kim, Nam Keun

2013-10-01

The aim of our study was to investigate whether polymorphisms in microRNA machinery genes are associated with the risk of primary ovarian insufficiency (POI). We genotyped 136 POI patients and 236 controls among Korean women for nine single nucleotide polymorphisms (SNPs; DROSHA rs6877842 and rs10719; DICER1 rs13078 and rs3742330; RAN rs14035; and XPO5 rs34324334, rs2257082, rs11544382, and rs11077) by polymerase chain reaction-restriction fragment length polymorphism analysis. Differences in genotype frequencies between patients and controls were compared, and odds ratios (ORs) and 95% CIs were determined as measures of the strength of the association between genotype and POI. Of the nine SNPs, XPO5 rs34324334 and rs11544382 were monomorphic and were not analyzed further. The XPO5 rs2257082 CT and CT + TT variant genotypes were more frequent in patients (OR, 2.097; 95% CI, 1.207-3.645) than in controls (OR, 2.030; 95% CI, 1.196-3.445). The combined frequencies of XPO5 rs2257082 CT + TT and rs11077 AC + CC genotypes were higher in patients than in controls (OR, 2.526; 95% CI, 1.088-5.865). An association of POI risk with other polymorphisms was not found. A haplotype-based analysis of seven polymorphisms of the microRNA machinery genes for gene-gene interactions suggests that ***ACTA, ***GCCA, ***G*C*, *T*ATTA, and ***ACT* haplotypes (asterisk indicates SNP locus not included; DROSHA rs6877842 and rs10719, DICER1 rs13078 and rs3742330, RAN rs14035, and XPO5 rs2257082 and rs11077 polymorphisms) are associated with higher POI prevalence, and that ***GCTA, ***ACCA, *C*ATTA, and *C*ATT* haplotypes are associated with lower POI prevalence. Our data demonstrate that the XPO5 rs2257082 T variant allele occurs more frequently in POI patients than in controls, suggesting that this allele may be associated with increased POI risk.
Waterborne Transportation Lines of the United States

DTIC Science & Technology

1988-10-01

C. OUPLANTI! ICO. INC. 3P. C. -0,N 725 I CUNA LA 71161 13 ; 1PrKMNAANE COOP. I2001 MARCUS AVE . ILANE SUCCESS 4Y 1114? 29i APRN TINUI% CU. !ATTN? CAIRN...LANE WEALSO 00 9942. tI I TI 333L06ALj o %EWhSLVA LA ?0114As, Ja3ft4iS p,*v 13 I ATTA, toAL. 1P. 0. -01 Isq3 I A4TIM-1 CA 1I.V31 Al’ hA. II * AV , (1 1...0NM .li. :01 IS. 179 XENTOCVT LIII P3CK CO.. I 1.0 9 170 9~~~ 9 439 14411 9 9 I I -MI "SO,09 -I9**i C W. .IS 13 IT.*92 O L* O4 00111 I I AVE . I
Dating and Tracing Groundwater and Ice with 81Kr and 85Kr

NASA Astrophysics Data System (ADS)

Yang, Guomin; Tong, Amin; Dong, Xize; Gu, Jiqiang; Hu, Shuiming; Jiang, Wei; Lu, Zhengtian; Ritterbusch, Florian

2017-04-01

81Kr (half-life 229kyr) is an ideal tracer for old groundwater and ice in the age range of 105 - 106 years. To meet the increasing demands from the earth science community, a new and improved Atom Trap Trace Analysis (ATTA) apparatus is developed at the University of Science and Technology of China (USTC). This instrument is capable of analyzing over 300 samples per year. Each measurement requirs 1-2 uL STP of krypton gas, which can be extracted from 20-40 kg of water. New sampling and purification systems have also been developed at USTC. With the new portable sampling system, the time for on-site sampling is typically less than one hour. The same sampling and atom-trap apparatuses are also used to analyze 85Kr (half-life 11 yr) to trace young groundwater.
Real & Financial Sectors, ``koq Financenaann..'' & Elbio Dagotto's Interactions

NASA Astrophysics Data System (ADS)

Maksoed, Wh-

2016-10-01

In conjunctions between PMRI/Pendidikan Matematika Realistik Indonesia fom Dr. RK Sembiring to ``ASTRANOMICS'': the New Reality in Business Aviation herewith provided `interaction between real & financial sector' and financialisation from Heinrich Bortis: ``the Real & Financial Sector of a Monetary Production Economy in the perspective of classical-Keynesian political economy'' ever specifies ``sector Riil'' from HE. Mr. Ir. Aburizal Bakrie. Instead describes the context of CMR/Colossal Magnetoresistance cq Carlos SLIM, the richest entrepreneur in the world 2014 also obtaines Dagotto & Tokura: ``Strongly correlated Electronic Materials: Present & Future'',MRS Bulletin, Nov, 2008. Ever existed of UN Secretary General Kofie Atta Annan, for Lih-AT TA-ruh di mana?'' are ```koq Financenaann..?'' in-between conjunctions. CMR are other notions of GiantMagnetoresistance from Fert & Grundberg who awarded with Nobel Prize in Physics, 2007. Heartfelt Gratitudes to HE. Mr. Prof. Ir. HANDOJO.
Uninformed sacrifice: Evidence against long-range alarm transmission in foraging ants exposed to localized abduction

NASA Astrophysics Data System (ADS)

Tejera, F.; Reyes, A.; Altshuler, E.

2016-07-01

It is well established that danger information can be transmitted by ants through relatively small distances, provoking either a state of alarm when they move away from potentially dangerous stimulus, or charge toward it aggressively. There is almost no knowledge if danger information can be transmitted along large distances. In this paper, we abduct leaf cutting ants of the species Atta insularis while they forage in their natural environment at a certain point of the foraging line, so ants make a "U" turn to escape from the danger zone and go back to the nest. Our results strongly suggest that those ants do not transmit "danger information" to other nestmates marching towards the abduction area. The individualistic behavior of the ants returning from the danger zone results in a depression of the foraging activity due to the systematic sacrifice of non-informed individuals.
The Evolutionary Innovation of Nutritional Symbioses in Leaf-Cutter Ants

PubMed Central

Aylward, Frank O.; Currie, Cameron R.; Suen, Garret

2012-01-01

Fungus-growing ants gain access to nutrients stored in plant biomass through their association with a mutualistic fungus they grow for food. This 50 million-year-old obligate mutualism likely facilitated some of these species becoming dominant Neotropical herbivores that can achieve immense colony sizes. Recent culture-independent investigations have shed light on the conversion of plant biomass into nutrients within ant fungus gardens, revealing that this process involves both the fungal cultivar and a symbiotic community of bacteria including Enterobacter, Klebsiella, and Pantoea species. Moreover, the genome sequences of the leaf-cutter ants Atta cephalotes and Acromyrmex echinatior have provided key insights into how this symbiosis has shaped the evolution of these ants at a genetic level. Here we summarize the findings of recent research on the microbial community dynamics within fungus-growing ant fungus gardens and discuss their implications for this ancient symbiosis. PMID:26467948
Sequential soil transport and its influence on the spatial organisation of collective digging in leaf-cutting ants.

PubMed

Pielström, Steffen; Roces, Flavio

2013-01-01

The Chaco leaf-cutting ant Atta vollenweideri (Forel) inhabits large and deep subterranean nests composed of a large number of fungus and refuse chambers. The ants dispose of the excavated soil by forming small pellets that are carried to the surface. For ants in general, the organisation of underground soil transport during nest building remains completely unknown. In the laboratory, we investigated how soil pellets are formed and transported, and whether their occurrence influences the spatial organisation of collective digging. Similar to leaf transport, we discovered size matching between soil pellet mass and carrier mass. Workers observed while digging excavated pellets at a rate of 26 per hour. Each excavator deposited its pellets in an individual cluster, independently of the preferred deposition sites of other excavators. Soil pellets were transported sequentially over 2 m, and the transport involved up to 12 workers belonging to three functionally distinct groups: excavators, several short-distance carriers that dropped the collected pellets after a few centimetres, and long-distance, last carriers that reached the final deposition site. When initiating a new excavation, the proportion of long-distance carriers increased from 18% to 45% within the first five hours, and remained unchanged over more than 20 hours. Accumulated, freshly-excavated pellets significantly influenced the workers' decision where to start digging in a choice experiment. Thus, pellets temporarily accumulated as a result of their sequential transport provide cues that spatially organise collective nest excavation.
Time-gated luminescence imaging of singlet oxygen photoinduced by fluoroquinolones and functionalized graphenes in Daphnia magna.

PubMed

Luo, Tianlie; Chen, Jingwen; Song, Bo; Ma, Hua; Fu, Zhiqiang; Peijnenburg, Willie J G M

2017-10-01

Singlet oxygen ( 1 O 2 ) can be photogenerated by photoactive xenobiotics and is capable of causing adverse effects due to its electrophilicity and its high reactivity with biological molecules. Detection of the production and distribution of 1 O 2 in living organisms is therefore of great importance. In this study, a luminescent probe ATTA-Eu 3+ combined with time-gated luminescence imaging was adopted to detect the distribution and temporal variation of 1 O 2 photoinduced by fluoroquinolone antibiotics and carboxylated/aminated graphenes in Daphnia magna. Results show that the xenobiotics generate 1 O 2 in living daphnids under simulated sunlight irradiation (SSR). The photogeneration of 1 O 2 by carboxylated/aminated graphenes was also confirmed by electron paramagnetic resonance spectroscopy. The strongest luminescence signals of 1 O 2 were observed in the hindgut of daphnids, and the signals in different areas of the daphnids (gut, thoracic legs and post-abdominal claw) displayed a similar trend of enhancement over irradiation time. Mean 1 O 2 concentrations at different regions of daphnids within one hour of SSR irradiation were estimated to be in the range of 0.5∼4.8μM. This study presented an efficient method for visualizing and quantifying the temporal and spatial distribution of 1 O 2 photogenerated by xenobiotics in living organisms, which can be employed for phototoxicity evaluation of xenobiotics. Copyright © 2017 Elsevier B.V. All rights reserved.
The effect of relativity on stability of Copernicium phases, their electronic structure and mechanical properties

NASA Astrophysics Data System (ADS)

Čenčariková, Hana; Legut, Dominik

2018-05-01

The phase stability of the various crystalline structures of the super-heavy element Copernicium was determined based on the first-principles calculations with different levels of the relativistic effects. We utilized the Darwin term, mass-velocity, and spin-orbit interaction with the single electron framework of the density functional theory while treating the exchange and correlation effects using local density approximations. It is found that the spin-orbit coupling is the key component to stabilize the body-centered cubic (bcc) structure over the hexagonal closed packed (hcp) structure, which is in accord with Sol. Stat. Comm. 152 (2012) 530, but in contrast to Atta-Fynn and Ray (2015) [11], Gaston et al. (2007) [10], Papaconstantopoulos (2015) [9]. It seems that the main role here is the correct description of the semi-core relativistic 6p1/2 orbitals. The all other investigated structures, i.e. face-centered cubic (fcc) , simple cubic (sc) as well as rhombohedral (rh) structures are higher in energy. The criteria of mechanical stability were investigated based on the calculated elastic constants, identifying the phase instability of fcc and rh structures, but surprisingly confirm the stability of the energetically higher sc structure. In addition, the pressure-induced structural transition between two stable sc and bcc phases has been detected. The ground-state bcc structure exhibits the highest elastic anisotropy from single elements of the Periodic table. At last, we support the experimental findings that Copernicium is a metal.
Identification, characterization, and functional studies of a Pelle gene in the Chinese mitten crab, Eriocheir sinensis.

PubMed

Huang, Ying; Chen, Yi-Hong; Zhang, Yu-Zhou; Feng, Jin-Ling; Zhao, Ling-Ling; Zhu, Huan-Xi; Wang, Wen; Ren, Qian

2015-08-01

The toll-like receptor/NF-κB signaling pathways play an important role in the innate immune system. In the present study, one Pelle gene (named EsPelle) was identified for the first time from the Chinese mitten crab Eriocheir sinensis. The full-length cDNA of EsPelle is 3797 bp with a 3156 bp-long open reading frame that encodes a 1051 amino acid protein. EsPelle protein contains a death domain at the N-terminal and a serine/threonine kinase domain at the C-terminal. A neighbor joining phylogenetic tree showed that the EsPelle protein, which is closest to those of Scylla paramamosain Pelle and Litopenaeus vannamei Pelle, was clustered to a group of crustacean Pelle proteins. EsPelle was expressed in all tested tissues of normal crabs, and its expression was regulated in hemocytes and hepatopancreas of crabs challenged with lipopolysaccharide, peptidoglycan, Staphyloccocus aureus, Vibrio parahaemolyticus, and Aeromonas hydrophila. Overexpression of EsPelle in Drosophila Schneider 2 cells could upregulate the expression of Drosophila antimicrobial peptides, namely, metchnikowin (Mtk), attacinA (Atta), drosomycin (Drs), and cecropinA (CecA). Moreover, EsPelle silencing by siRNA reduced the transcription of anti-lipopolysaccharide factor 1 and 2, crustin 2, and lysozyme in crabs challenged with V. parahaemolyticus. From the results, we speculated that EsPelle was involved in innate immune defense against V. parahaemolyticus in E. sinensis. Copyright © 2015 Elsevier Ltd. All rights reserved.
Integrated In Situ Sensing and Modeling to Assess Carbon Dioxide Emissions from Tropical Wet Forest Soils: The Role of Leaf Cutter Ant Atta Cepholotes

NASA Astrophysics Data System (ADS)

Harmon, T. C.; Fernandez Bou, A. S.; Dierick, D.; Oberbauer, S. F.; Schwendenmann, L.; Swanson, A. C.; Zelikova, T. J.

2016-12-01

This project focuses on the role of leaf cutter ants (LCA) Atta cepholotes in carbon cycling in neotropical wet forests. LCA are abundant in these forests and workers cut and carry vegetation fragments to their nests, where symbiotic fungi break down the plant material and produce the fungal hyphae on which the ants feed. LCA are the dominant herbivores in tropical forest ecosystems, removing 10-50% of vegetation annually. Their nests can achieve large sizes, extending several meters belowground and covering 50 square meters or more of the forest floor. We monitored soil moisture, temperature, and soil CO2 concentrations continuously in nest and control sites at La Selva Biological Station, Costa Rica. Intermittently, we also assessed soil respiration and LCA nest vent fluxes. Observed soil CO2 concentrations varied markedly with soil moisture conditions, ranging from a few thousand to over 60,000 ppm(v). Accordingly, soil CO2 surface efflux varied temporally by an order of magnitude or more (typical range 0.5 to 5 mmol CO2 m-2 s-1) for the same location as a consequence of soil moisture fluctuations. LCA nest vents equivalent CO2 efflux rates (accounting for vent diameter) can be substantially greater than soil surface values, with observed values ranging from about 1 to 50 mmol m-2 s-1 (it is worth noting that correcting for vent diameters yields equivalent CO2 efflux rates greater than 1000 mmol m-2 s-1). Similar to the soil surface efflux, vent efflux varied temporally by factors of 3 or more, suggesting a potential link between the vent productivity and nest activity, moisture content of surrounding soil, and atmospheric conditions (e.g., air temperature, wind). Using a soil model (Hydrus-1D) to account for unsaturated flow, heat transfer, CO2 production and diffusive transport, we captured moisture and temperature dynamics and the order of magnitude of observed CO2 concentration. Modelled surface fluxes also agreed well with observed soil surface CO2 efflux. These results contribute to our understanding of CO2 production and transport in tropical soils, and the role played by the LCA in the soil carbon cycle.
Generation of high energetic ions from hollow cathode discharge

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

Atta, M.; El Nadai, L.; Lie, Y.T.

1995-12-31

High energetic beams of ions can be produced by using the dense and highly ionized plasma that is generated by the vacuum arc. Ian G. Brown (1993) described the general features and performance characteristics of the ion sources and their use for accelerator injection and ion implantation applications. Atta, at al. (1993) found that the ratio of ion density to electron density has been decreased beside the hollow cathode at different hole diameter due to increasing the ionization degree. Here we have evaluated the ion velocity distribution F(v) = S{Upsilon}(t)/V{sup 2}, where {Upsilon}(t) is the ion flux intensity, S ismore » the distance between the hollow cathode spot and the quadrupole maps spectrometer, and V is the ion velocity. The ion energy (E=mV{sup 2}/2, in is the mass of the ion), and the ion fraction due to the total number of ions for different ion species emitted from graphite and titanium hollow cathode have been determined.« less
A revision of Haematodes Laporte and Weiserianum Bernhauer (Coleoptera: Staphylinidae: Staphylininae: Xanthopygina).

PubMed

Brunke, Adam J; Chatzimanolis, Stylianos

2018-01-01

The species of poorly known but charismatic genera Haematodes Laporte, 1835 and Weiserianum Bernhauer, 1927 are revised. Weiserianum syn. nov. is considered a junior synonym of Haematodes , with Haematodes kuntzeni (Scheerpeltz, 1936) comb. nov. Weiserianum woltersi Bernhauer, 1927 syn. nov. is treated as a synonym of Haematodes tenuipes Kraatz, 1858. Haematodes myteros sp. nov. , is described from Paraguay and Brazil. As the type series of Haematodes bicolor Laporte, 1835 is considered lost, a neotype, selected from the original type locality is designated. We also designate a lectotype for H. tenuipes Kraatz, 1858 to stabilize nomenclature for this species, which is similar to H. myteros . As far as known, Haematodes is restricted to the southern Neotropical region and may be nest parasites within Acromyrmex and Atta ant nests as are species of the related genus Scariphaeus , but no direct observations are yet available. We provide a key to the four known species of Haematodes and illustrate their diagnostic features.
[Creativity and Character Traits of University Students: Transversal Association Study].

PubMed

Santamaría, Hernando; Sánchez, Ricardo

2012-06-01

This study was carried out to assess the relationship between character traits and creativity in a sample of students from a public university in Bogotá. A random sample of 157 students from the Universidad Nacional de Colombia. The two instruments used for measuring character traits and creativity were the International Personality Disorder Examination (IPDE) and the Abbreviated Torrance Test for Adults (ATTA). Additional information about gender, psychopathological antecedents, current academic period and academic average have been recorded. Robust regression methods have been used to analyze the relationship between creativity and character traits. Creativity and narcissistic traits were associated. In a multivariate model, other variables showing a relationship with creativity were found, i.e., male gender, mental illness family antecedents, number of academic periods completed, and a high academic average. Relationship between creativity and narcissistic traits had not been reported in previous. Longitudinal studies using more accurate scales should be undertaken to determine the validity of these findings. Copyright © 2012 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.
Bridging the Gap Between Stationary Homogeneous Isotropic Turbulence and Quantum Mechanics

NASA Astrophysics Data System (ADS)

Sohrab, Siavash

A statistical theory of stationary isotropic turbulence is presented with eddies possessing Gaussian velocity distribution, Maxwell-Boltzmann speed distribution in harmony with perceptions of Heisenberg, and Planck energy distribution in harmony with perceptions of Chandrasekhar and in agreement with experimental observations of Van Atta and Chen. Defining the action S = - mΦ in terms of velocity potential of atomic motion, scale-invariant Schrödinger equation is derivedfrom invariant Bernoulli equation. Thus, the gap between the problems of turbulence and quantum mechanics is closed through connections between Cauchy-Euler-Bernoulli equations of hydrodynamics, Hamilton-Jacobi equation of classical mechanics, and finally Schrödinger equation of quantum mechanics. Transitions of particle (molecular cluster cji) from a small rapidly-oscillating eddy ej (high-energy level-j) to a large slowly-oscillating eddy ei (low energy-level-i) leads to emission of a sub-particle (molecule mji) that carries away the excess energy ɛji = h (νj -νi) in harmony with Bohr theory of atomic spectra. ∖ ∖ NASA Grant No. NAG3-1863.
Why are there few seedlings beneath the myrmecophyte Triplaris americana?

NASA Astrophysics Data System (ADS)

Larrea-Alcázar, Daniel M.; Simonetti, Javier A.

2007-07-01

We compared the relative importance of chemical alellopathy, pruning behaviour of resident ants and other non-related agents to ant-plant mutualism for seedling establishment beneath Triplaris americana L. (Polygonaceae), a myrmecophyte plant. We also included a preliminary analysis of effects of fragmentation on these ecological processes. Seeds and seedlings of Theobroma cacao L. (Sterculiaceae) were used as the target species in all experiments. Leaf-tissue extracts of the myrmecophyte plant did not inhibit germination of cacao seeds. Resident Pseudomyrmex triplarinus Weddell (Pseudomyrmecinae) ants did not remove seeds under the canopy of their host plants. The main seed consumer was the leaf-cutting ant Atta sexdens L. (Myrmicinae). Leaves of cacao seedlings were partially or totally pruned by Pseudomyrmex ants mainly in forest fragments studied. We offer evidence pointing to the possibility that the absence of seedlings beneath Triplaris may result from effects of both ant species. We discuss the benefits of pruning behaviour for the resident ant colony and the effects of ant-ant interactions on seedling establishment beneath this ant-plant system.
Antagonistic interactions between garden yeasts and microfungal garden pathogens of leaf-cutting ants.

PubMed

Rodrigues, Andre; Cable, Rachel N; Mueller, Ulrich G; Bacci, Maurício; Pagnocca, Fernando C

2009-10-01

We investigate the diversity of yeasts isolated in gardens of the leafcutter ant Atta texana. Repeated sampling of gardens from four nests over a 1-year time period showed that gardens contain a diverse assemblage of yeasts. The yeast community in gardens consisted mostly of yeasts associated with plants or soil, but community composition changed between sampling periods. In order to understand the potential disease-suppressing roles of the garden yeasts, we screened isolates for antagonistic effects against known microfungal garden contaminants. In vitro assays revealed that yeasts inhibited the mycelial growth of two strains of Escovopsis (a specialized attine garden parasite), Syncephalastrum racemosum (a fungus often growing in gardens of leafcutter lab nests), and the insect pathogen Beauveria bassiana. These garden yeasts add to the growing list of disease-suppressing microbes in attine nests that may contribute synergistically, together with actinomycetes and Burkholderia bacteria, to protect the gardens and the ants against diseases. Additionally, we suggest that garden immunity against problem fungi may therefore derive not only from the presence of disease-suppressing Pseudonocardia actinomycetes, but from an enrichment of multiple disease-suppressing microorganisms in the garden matrix.
Carbohydrate-rich foods: glycaemic indices and the effect of constituent macronutrients.

PubMed

Widanagamage, Rahal D; Ekanayake, Sagarika; Welihinda, Jayantha

2009-01-01

The glycaemic index (GI) ranks foods according to their acute glycaemic impact and is used in planning meals for patients invoking glycaemic control through diet. Kurakkan (Eleusine coracana) flour roti, rice flour roti, atta flour roti, boiled breadfruit (Artocarpus altilis/Artocarpus communis) and boiled legumes (mungbean, cowpea and chickpea) were categorized as low-GI foods (relative to white bread; Prima Crust Top), and the corresponding GI (+/- standard error of the mean) values were 70+/-8, 69+/-7, 67+/-9, 64+/-7, 57+/-6, 49+/-8 and 29+/-5, respectively. Kurakkan flour pittu and wheat flour roti were classified as medium-GI foods with GI values of 85+/-6 and 72+/-6. Hoppers, rice flour pittu, wheat flour pittu and Olu-milk rice (seeds of Nymphaea lotus) were categorized as high-GI foods, and the corresponding GI (+/- standard error of the mean) values were 120+/-8, 103+/-7, 101+/-8 and 91+/-8, respectively. The GI values significantly (P<0.01) and negatively correlated with the insoluble dietary fibre (rho = - 0.780), soluble dietary fibre (rho = - 0.712) and protein (rho = - 0.738) contents in grams per 100 g digestible starch containing foods.
Essential Oil of Aristolochia trilobata: Synthesis, Routes of Exposure, Acute Toxicity, Binary Mixtures and Behavioral Effects on Leaf-Cutting Ants.

PubMed

de Oliveira, Bruna Maria S; Melo, Carlisson R; Alves, Péricles B; Santos, Abraão A; Santos, Ane Caroline C; Santana, Alisson da S; Araújo, Ana Paula A; Nascimento, Pedro E S; Blank, Arie F; Bacci, Leandro

2017-02-25

Plants of the genus Aristolochia have been frequently reported as important medicinal plants. Despite their high bioactive potential, to date, there are no reports of their effects on leaf-cutting ants. Therefore, the present study aimed to evaluate the insecticidal activity of the essential oil of Aristolochia trilobata and its major components on Atta sexdens and Acromyrmex balzani , two species of leaf-cutting ants. The bioassays were performed regarding routes of exposure, acute toxicity, binary mixtures of the major components and behavioral effects. Twenty-five components were identified in the essential oil of A. trilobata using a gas chromatographic system equipped with a mass spectrometer and a flame ionization detector. The components found in higher proportions were sulcatyl acetate, limonene, p -cymene and linalool. The essential oil of A. trilobata and its individual major components were efficient against A. balzani and A. sexdens workers when applied by fumigation. These components showed fast and efficient insecticidal activity on ants. The components acted synergistically and additively on A. balzani and A. sexdens , respectively, and caused a strong repellency/irritability in the ants. Thus, our results demonstrate the great potential of the essential oil of A. trilobata and its major components for the development of new insecticides.

Essential Oils of Hyptis pectinata Chemotypes: Isolation, Binary Mixtures and Acute Toxicity on Leaf-Cutting Ants.

PubMed

Feitosa-Alcantara, Rosana B; Bacci, Leandro; Blank, Arie F; Alves, Péricles B; Silva, Indira Morgana de A; Soares, Caroline A; Sampaio, Taís S; Nogueira, Paulo Cesar de L; Arrigoni-Blank, Maria de Fátima

2017-04-12

Leaf-cutting ants are pests of great economic importance due to the damage they cause to agricultural and forest crops. The use of organosynthetic insecticides is the main form of control of these insects. In order to develop safer technology, the objective of this work was to evaluate the formicidal activity of the essential oils of two Hyptis pectinata genotypes (chemotypes) and their major compounds on the leaf-cutting ants Acromyrmex balzani Emery and Atta sexdens rubropilosa Forel. Bioassays of exposure pathways (contact and fumigation) and binary mixtures of the major compounds were performed. The major compounds identified in the essential oils of H. pectinata were β-caryophyllene, caryophyllene oxide and calamusenone. The essential oils of H. pectinata were toxic to the ants in both exposure pathways. Essential oils were more toxic than their major compounds alone. The chemotype calamusenone was more toxic to A. balzani in both exposure pathways. A. sexdens rubropilosa was more susceptible to the essential oil of the chemotype β-caryophyllene in both exposure pathways. In general, the binary mixtures of the major compounds resulted in additive effect of toxicity. The essential oils of H. pectinata is a raw material of great potential for the development of new insecticides.
Integrated navigation, flight guidance, and synthetic vision system for low-level flight

NASA Astrophysics Data System (ADS)

Mehler, Felix E.

2000-06-01

Future military transport aircraft will require a new approach with respect to the avionics suite to fulfill an ever-changing variety of missions. The most demanding phases of these mission are typically the low level flight segments, including tactical terrain following/avoidance,payload drop and/or board autonomous landing at forward operating strips without ground-based infrastructure. As a consequence, individual components and systems must become more integrated to offer a higher degree of reliability, integrity, flexibility and autonomy over existing systems while reducing crew workload. The integration of digital terrain data not only introduces synthetic vision into the cockpit, but also enhances navigation and guidance capabilities. At DaimlerChrysler Aerospace AG Military Aircraft Division (Dasa-M), an integrated navigation, flight guidance and synthetic vision system, based on digital terrain data, has been developed to fulfill the requirements of the Future Transport Aircraft (FTA). The fusion of three independent navigation sensors provides a more reliable and precise solution to both the 4D-flight guidance and the display components, which is comprised of a Head-up and a Head-down Display with synthetic vision. This paper will present the system, its integration into the DLR's VFW 614 Advanced Technology Testing Aircraft System (ATTAS) and the results of the flight-test campaign.
Duplication and concerted evolution in a master sex determiner under balancing selection.

PubMed

Privman, Eyal; Wurm, Yannick; Keller, Laurent

2013-05-07

The transformer (tra) gene is a key regulator in the signalling hierarchy controlling all aspects of somatic sexual differentiation in Drosophila and other insects. Here, we show that six of the seven sequenced ants have two copies of tra. Surprisingly, the two paralogues are always more similar within species than among species. Comparative sequence analyses indicate that this pattern is owing to the ongoing concerted evolution after an ancestral duplication rather than independent duplications in each of the six species. In particular, there was strong support for inter-locus recombination between the paralogues of the ant Atta cephalotes. In the five species where the location of paralogues is known, they are adjacent to each other in four cases and separated by only few genes in the fifth case. Because there have been extensive genomic rearrangements in these lineages, this suggests selection acting to conserve their synteny. In three species, we also find a signature of positive selection in one of the paralogues. In three bee species where information is available, the tra gene is also duplicated, the copies are adjacent and in at least one species there was recombination between paralogues. These results suggest that concerted evolution plays an adaptive role in the evolution of this gene family.
Reduced biological control and enhanced chemical pest management in the evolution of fungus farming in ants

PubMed Central

Fernández-Marín, Hermógenes; Zimmerman, Jess K.; Nash, David R.; Boomsma, Jacobus J.; Wcislo, William T.

2009-01-01

To combat disease, most fungus-growing ants (Attini) use antibiotics from mutualistic bacteria (Pseudonocardia) that are cultured on the ants' exoskeletons and chemical cocktails from exocrine glands, especially the metapleural glands (MG). Previous work has hypothesized that (i) Pseudonocardia antibiotics are narrow-spectrum and control a fungus (Escovopsis) that parasitizes the ants' fungal symbiont, and (ii) MG secretions have broad-spectrum activity and protect ants and brood. We assessed the relative importance of these lines of defence, and their activity spectra, by scoring abundance of visible Pseudonocardia for nine species from five genera and measuring rates of MG grooming after challenging ants with disease agents of differing virulence. Atta and Sericomyrmex have lost or greatly reduced the abundance of visible bacteria. When challenged with diverse disease agents, including Escovopsis, they significantly increased MG grooming rates and expanded the range of targets. By contrast, species of Acromyrmex and Trachymyrmex maintain abundant Pseudonocardia. When challenged, these species had lower MG grooming rates, targeted primarily to brood. More elaborate MG defences and reduced reliance on mutualistic Pseudonocardia are correlated with larger colony size among attine genera, raising questions about the efficacy of managing disease in large societies with chemical cocktails versus bacterial antimicrobial metabolites. PMID:19324734
Natural enemies of Atta vollenweideri (Hymenoptera: Formicidae) leaf-cutter ants negatively affected by synthetic pesticides, chlorpyrifos and fipronil.

PubMed

Guillade, Andrea C; Folgarait, Patricia J

2014-02-01

In southern South America, Ada vollenweideri Forel (Hymenoptera: Formicidae) is a significant pest of several crops and forestry, also considered to reduce the carrying capacity of pastures. The most usual control method used in Latin America is the application of synthetic pesticides, mainly chlorpyrifos and fipronil. However, no studies have assessed the effects of these agrochemicals on natural enemies of ants. We aimed to evaluate the efficiency of these pesticides on leaf-cutter ants' control and to test their effect on phorid fly parasitoids. Chlorpyrifos failed to exert complete control over ant colonies in the field and was gravely detrimental to specific parasitoids, reducing their percentage of parasitism, pupal survivorship, and adult longevity. Fipronil, however, exerted complete control over the treated colonies. Laboratory tests using both pesticides, either on ants from foraging trails or on pupariae, showed that chlorpyrifos and fipronil decreased larval and pupal survivorship, as well as adult longevity of parasitoids, in comparison to controls. In conclusion, these pesticides will likely affect parasitoids with regard to their reproductive capacity, leading to the decreased levels of natural parasitism observed in the field after treatments. We discuss why neither pesticide should be taken into account for integrated pest management programs.
Imaging of radiation damage using complementary field ion microscopy and atom probe tomography.

PubMed

Dagan, Michal; Hanna, Luke R; Xu, Alan; Roberts, Steve G; Smith, George D W; Gault, Baptiste; Edmondson, Philip D; Bagot, Paul A J; Moody, Michael P

2015-12-01

Radiation damage in tungsten and a tungsten-tantalum alloy, both of relevance to nuclear fusion research, has been characterized using a combination of field ion microscopy (FIM) imaging and atom probe tomography (APT). While APT provides 3D analytical imaging with sub-nanometer resolution, FIM is capable of imaging the arrangements of single atoms on a crystal lattice and has the potential to provide insights into radiation induced crystal damage, all the way down to its smallest manifestation--a single vacancy. This paper demonstrates the strength of combining these characterization techniques. In ion implanted tungsten, it was found that atomic scale lattice damage is best imaged using FIM. In certain cases, APT reveals an identifiable imprint in the data via the segregation of solute and impurities and trajectory aberrations. In a W-5at%Ta alloy, a combined APT-FIM study was able to determine the atomic distribution of tantalum inside the tungsten matrix. An indirect method was implemented to identify tantalum atoms inside the tungsten matrix in FIM images. By tracing irregularities in the evaporation sequence of atoms imaged with FIM, this method enables the benefit of FIM's atomic resolution in chemical distinction between the two species. Copyright © 2015 Elsevier B.V. All rights reserved.
Molecular-genetic diagnostics of von Hippel-Lindau syndrome (VHL) in Bulgaria: first complex mutation event in the VHL gene.

PubMed

Glushkova, Maria; Dimova, Petia; Yordanova, Iglika; Todorov, Tihomir; Tourtourikov, Ivan; Mitev, Vanyo; Todorova, Albena

2018-02-01

Von Hippel-Lindau syndrome is an autosomal-dominant disease characterized by the formation of various tumours and cysts in many different parts of the body. Von Hippel-Lindau syndrome is caused by VHL gene mutations leading to production of impaired tumor suppressor Von Hippel-Lindau syndrome protein or its complete absence. To study five patients with clinically suspected Von Hippel-Lindau syndrome, who were referred for molecular genetic testing. Sanger sequencing of the coding regions of the VHL gene. Five clinically relevant germline mutations were detected. One of the pathogenic variants has not been previously reported. This novel mutation is a complex mutation event combining a duplication and an indel, rearranging exon 3 of the VHL gene - c. [516_517dupGTCAAGCCT; 532_542delCTGGACATCGTinsATTA], p. (Glu173Serfs*4). Overall, our results showed that the diagnosis of Von Hippel-Lindau syndrome in our country is difficult most probably because of its heterogeneous clinical manifestation and insufficient knowledge on the diagnostic criteria for the disease. From genetic point of view our results add some novel data on the mutation profile of the VHL gene. In order to prove or revise the diagnosis, early genetic testing is strongly recommended in affected patients and their family members to ensure appropriate follow-up and treatment of the malignancies.
Adenine radicals generated in alternating AT duplexes by direct absorption of low-energy UV radiation.

PubMed

Banyasz, Akos; Ketola, Tiia; Martínez-Fernández, Lara; Improta, Roberto; Markovitsi, Dimitra

2018-04-17

There is increasing evidence that the direct absorption of photons with energies that are lower than the ionization potential of nucleobases may result in oxidative damage to DNA. The present work, which combines nanosecond transient absorption spectroscopy and quantum mechanical calculations, studies this process in alternating adenine-thymine duplexes (AT)n. We show that the one-photon ionization quantum yield of (AT)10 at 266 nm (4.66 eV) is (1.5 ± 0.3) × 10-3. According to our PCM/TD-DFT calculations carried out on model duplexes composed of two base pairs, (AT)1 and (TA)1, simultaneous base pairing and stacking does not induce important changes in the absorption spectra of the adenine radical cation and deprotonated radical. The adenine radicals, thus identified in the time-resolved spectra, disappear with a lifetime of 2.5 ms, giving rise to a reaction product that absorbs at 350 nm. In parallel, the fingerprint of reaction intermediates other than radicals, formed directly from singlet excited states and assigned to AT/TA dimers, is detected at shorter wavelengths. PCM/TD-DFT calculations are carried out to map the pathways leading to such species and to characterize their absorption spectra; we find that, in addition to the path leading to the well-known TA* photoproduct, an AT photo-dimerization path may be operative in duplexes.
Density of mushroom body synaptic complexes limits intraspecies brain miniaturization in highly polymorphic leaf-cutting ant workers

PubMed Central

Groh, Claudia; Kelber, Christina; Grübel, Kornelia; Rössler, Wolfgang

2014-01-01

Hymenoptera possess voluminous mushroom bodies (MBs), brain centres associated with sensory integration, learning and memory. The mushroom body input region (calyx) is organized in distinct synaptic complexes (microglomeruli, MG) that can be quantified to analyse body size-related phenotypic plasticity of synaptic microcircuits in these small brains. Leaf-cutting ant workers (Atta vollenweideri) exhibit an enormous size polymorphism, which makes them outstanding to investigate neuronal adaptations underlying division of labour and brain miniaturization. We particularly asked how size-related division of labour in polymorphic workers is reflected in volume and total numbers of MG in olfactory calyx subregions. Whole brains of mini, media and large workers were immunolabelled with anti-synapsin antibodies, and mushroom body volumes as well as densities and absolute numbers of MG were determined by confocal imaging and three-dimensional analyses. The total brain volume and absolute volumes of olfactory mushroom body subdivisions were positively correlated with head widths, but mini workers had significantly larger MB to total brain ratios. Interestingly, the density of olfactory MG was remarkably independent from worker size. Consequently, absolute numbers of olfactory MG still were approximately three times higher in large compared with mini workers. The results show that the maximum packing density of synaptic microcircuits may represent a species-specific limit to brain miniaturization. PMID:24807257
Fluid intake rates in ants correlate with their feeding habits.

PubMed

Paul, J; Roces, F

2003-04-01

This study investigates the techniques of nectar feeding in 11 different ant species, and quantitatively compares fluid intake rates over a wide range of nectar concentrations in four species that largely differ in their feeding habits. Ants were observed to employ two different techniques for liquid food intake, in which the glossa works either as a passive duct-like structure (sucking), or as an up- and downwards moving shovel (licking). The technique employed for collecting fluids at ad libitum food sources was observed to be species-specific and to correlate with the presence or absence of a well-developed crop in the species under scrutiny. Workers of ponerine ants licked fluid food during foraging and transported it as a droplet between their mandibles, whereas workers of species belonging to phylogenetically more advanced subfamilies, with a crop capable of storing liquids, sucked the fluid food, such as formicine ants of the genus Camponotus. In order to evaluate the performance of fluid collection during foraging, intake rates for sucrose solutions of different concentrations were measured in four ant species that differ in their foraging ecology. Scaling functions between fluid intake rates and ant size were first established for the polymorphic species, so as to compare ants of different size across species. Results showed that fluid intake rate depended, as expected and previously reported in the literature, on sugar concentration and the associated fluid viscosity. It also depended on both the species-specific feeding technique and the extent of specialization on foraging on liquid food. For similarly-sized ants, workers of two nectar-feeding ant species, Camponotus rufipes (Formicinae) and Pachycondyla villosa (Ponerinae), collected fluids with the highest intake rates, while workers of the leaf-cutting ant Atta sexdens (Myrmicinae) and a predatory ant from the Rhytidoponera impressa-complex (Ponerinae) did so with the lowest rate. Calculating the energy intake rates in mg sucrose per unit time, licking was shown to be a more advantageous technique at higher sugar concentrations than sucking, whereas sucking provided a higher energy intake rate at lower sugar concentrations.
A small population of hypothalamic neurons govern fertility: the critical role of VAX1 in GnRH neuron development and fertility maintenance.

PubMed

Hoffmann, Hanne M; Mellon, Pamela L

2016-01-01

Fertility depends on the correct maturation and function of approximately 800 gonadotropin-releasing hormone (GnRH) neurons in the brain. GnRH neurons are at the apex of the hypothalamic-pituitary-gonadal axis that regulates fertility. In adulthood, GnRH neurons are scattered throughout the anterior hypothalamic area and project to the median eminence, where GnRH is released into the portal vasculature to stimulate release of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) from the pituitary. LH and FSH then regulate gonadal steroidogenesis and gametogenesis. Absence of GnRH neurons or inappropriate GnRH release leads to infertility. Despite the critical role of GnRH neurons in fertility, we still have a limited understanding of the genes responsible for proper GnRH neuron development and function in adulthood. GnRH neurons originate in the olfactory placode then migrate into the brain. Homeodomain transcription factors expressed within GnRH neurons or along their migratory path are candidate genes for inherited infertility. Using a combined in vitro and in vivo approach, we have identified Ventral Anterior Homeobox 1 ( Vax1 ) as a novel homeodomain transcription factor responsible for GnRH neuron maturation and fertility. GnRH neuron counts in Vax1 knock-out embryos revealed Vax1 to be required for the presence of GnRH-expressing cells at embryonic day 17.5 (E17.5), but not at E13.5. To localize the effects of Vax1 on fertility, we generated Vax1 flox mice and crossed them with Gnrh cre mice to specifically delete Vax1 within GnRH neurons. GnRH staining in Vax1 flox/flox :GnRH cre mice show a total absence of GnRH expression in the adult. We performed lineage tracing in Vax1 flox/flox :GnRH cre :RosaLacZ mice which proved GnRH neurons to be alive, but incapable of expressing GnRH. The absence of GnRH leads to delayed puberty, hypogonadism and complete infertility in both sexes. Finally, using the immortalized model GnRH neuron cell lines, GN11 and GT1-7, we show that VAX1 is a direct regulator of Gnrh1 transcription by binding key ATTA sites within the Gnrh1 promoter. This study identifies VAX1 as a key transcription factor regulating GnRH expression and establishes VAX1 as a novel candidate gene implicated in heritable infertility.
Krypton-81 in groundwater of the Culebra Dolomite near the Waste Isolation Pilot Plant, New Mexico

NASA Astrophysics Data System (ADS)

Sturchio, Neil C.; Kuhlman, Kristopher L.; Yokochi, Reika; Probst, Peter C.; Jiang, Wei; Lu, Zheng-Tian; Mueller, Peter; Yang, Guo-Min

2014-05-01

The Waste Isolation Pilot Plant (WIPP) in New Mexico is the first geologic repository for disposal of transuranic nuclear waste from defense-related programs of the US Department of Energy. It is constructed within halite beds of the Permian-age Salado Formation. The Culebra Dolomite, confined within Rustler Formation evaporites overlying the Salado Formation, is a potential pathway for radionuclide transport from the repository to the accessible environment in the human-disturbed repository scenario. Although extensive subsurface characterization and numerical flow modeling of groundwater has been done in the vicinity of the WIPP, few studies have used natural isotopic tracers to validate the flow models and to better understand solute transport at this site. The advent of Atom-Trap Trace Analysis (ATTA) has enabled routine measurement of cosmogenic 81Kr (half-life 229,000 yr), a near-ideal tracer for long-term groundwater transport. We measured 81Kr in saline groundwater sampled from two Culebra Dolomite monitoring wells near the WIPP site, and compared 81Kr model ages with reverse particle-tracking results of well-calibrated flow models. The 81Kr model ages are ~ 130,000 and ~ 330,000 yr for high-transmissivity and low-transmissivity portions of the formation, respectively. Compared with flow model results which indicate a relatively young mean hydraulic age (~ 32,000 yr), the 81Kr model ages imply substantial physical attenuation of conservative solutes in the Culebra Dolomite and provide limits on the effective diffusivity of contaminants into the confining aquitards.
A Prospective Randomized Controlled Trial to Study the Impact of a Nutrition-Sensitive Intervention on Adult Women With Cancer Cachexia Undergoing Palliative Care in India.

PubMed

Kapoor, Neha; Naufahu, Jane; Tewfik, Sundus; Bhatnagar, Sushma; Garg, Rakesh; Tewfik, Ihab

2017-03-01

Advanced cancer patients with disease progression develop cachexia. Nevertheless, cancer patients at nutritional risk have shown improved body weight and quality of life with oral nutritional supplements. This was a randomized controlled trial in adult female cancer patients (n = 63) attending palliative clinics, with symptoms of cachexia. Eligible patients were randomly distributed into control (n = 33) and intervention (n = 30) groups. Both groups were provided with nutritional and physical activity counseling, but the intervention group received an additional 100 g of Improved Atta (IAtta) for 6 months daily consumption. This study was designed to assess the efficacy of IAtta (with counseling) in enhancing the health status of cachexic patients. Anthropometric measurements, dietary intake, physical activity level and quality of life parameters were assessed at baseline, after 3 months, and at the end of 6 months. Patients in the control group (n = 15) had significantly decreased body weight ( P = .003), mid-upper-arm circumference ( P = .002), and body fat ( P = .002) by the end of intervention. A trend of body weight gain in the intervention group (n = 17; P = .08) and significant increase of body fat ( P = .002) was observed; moreover, patients reported a significant improvement in fatigue ( P = .002) and appetite scores ( P = .006) under quality-of-life domains at the end of intervention. Embedding a nutrition-sensitive intervention ( IAtta ) within Indian palliative care therapy may improve quality of life and stabilize body weight in cancer cachexia patients.
Leucoagaricus gongylophorus Produces Diverse Enzymes for the Degradation of Recalcitrant Plant Polymers in Leaf-Cutter Ant Fungus Gardens

PubMed Central

Aylward, Frank O.; Burnum-Johnson, Kristin E.; Tringe, Susannah G.; Teiling, Clotilde; Tremmel, Daniel M.; Moeller, Joseph A.; Scott, Jarrod J.; Barry, Kerrie W.; Piehowski, Paul D.; Nicora, Carrie D.; Malfatti, Stephanie A.; Monroe, Matthew E.; Purvine, Samuel O.; Goodwin, Lynne A.; Smith, Richard D.; Weinstock, George M.; Gerardo, Nicole M.; Suen, Garret; Lipton, Mary S.

2013-01-01

Plants represent a large reservoir of organic carbon comprised primarily of recalcitrant polymers that most metazoans are unable to deconstruct. Many herbivores gain access to nutrients in this material indirectly by associating with microbial symbionts, and leaf-cutter ants are a paradigmatic example. These ants use fresh foliar biomass as manure to cultivate gardens composed primarily of Leucoagaricus gongylophorus, a basidiomycetous fungus that produces specialized hyphal swellings that serve as a food source for the host ant colony. Although leaf-cutter ants are conspicuous herbivores that contribute substantially to carbon turnover in Neotropical ecosystems, the process through which plant biomass is degraded in their fungus gardens is not well understood. Here we present the first draft genome of L. gongylophorus, and, using genomic and metaproteomic tools, we investigate its role in lignocellulose degradation in the gardens of both Atta cephalotes and Acromyrmex echinatior leaf-cutter ants. We show that L. gongylophorus produces a diversity of lignocellulases in ant gardens and is likely the primary driver of plant biomass degradation in these ecosystems. We also show that this fungus produces distinct sets of lignocellulases throughout the different stages of biomass degradation, including numerous cellulases and laccases that likely play an important role in lignocellulose degradation. Our study provides a detailed analysis of plant biomass degradation in leaf-cutter ant fungus gardens and insight into the enzymes underlying the symbiosis between these dominant herbivores and their obligate fungal cultivar. PMID:23584789
An investigation of small scales of turbulence in a boundary layer at high Reynolds numbers

NASA Technical Reports Server (NTRS)

Wallace, James M.; Ong, L.; Balint, J.-L.

1993-01-01

The assumption that turbulence at large wave-numbers is isotropic and has universal spectral characteristics which are independent of the flow geometry, at least for high Reynolds numbers, has been a cornerstone of closure theories as well as of the most promising recent development in the effort to predict turbulent flows, viz. large eddy simulations. This hypothesis was first advanced by Kolmogorov based on the supposition that turbulent kinetic energy cascades down the scales (up the wave-numbers) of turbulence and that, if the number of these cascade steps is sufficiently large (i.e. the wave-number range is large), then the effects of anisotropies at the large scales are lost in the energy transfer process. Experimental attempts were repeatedly made to verify this fundamental assumption. However, Van Atta has recently suggested that an examination of the scalar and velocity gradient fields is necessary to definitively verify this hypothesis or prove it to be unfounded. Of course, this must be carried out in a flow with a sufficiently high Reynolds number to provide the necessary separation of scales in order unambiguously to provide the possibility of local isotropy at large wave-numbers. An opportunity to use our 12-sensor hot-wire probe to address this issue directly was made available at the 80'x120' wind tunnel at the NASA Ames Research Center, which is normally used for full-scale aircraft tests. An initial report on this high Reynolds number experiment and progress toward its evaluation is presented.
Evolutionary patterns of proteinase activity in attine ant fungus gardens

PubMed Central

2011-01-01

Background Attine ants live in symbiosis with a basidiomycetous fungus that they rear on a substrate of plant material. This indirect herbivory implies that the symbiosis is likely to be nitrogen deprived, so that specific mechanisms may have evolved to enhance protein availability. We therefore hypothesized that fungal proteinase activity may have been under selection for efficiency and that different classes of proteinases might be involved. Results We determined proteinase activity profiles across a wide pH range for fungus gardens of 14 Panamanian species of fungus-growing ants, representing eight genera. We mapped these activity profiles on an independently obtained molecular phylogeny of the symbionts and show that total proteinase activity in lower attine symbionts peaks at ca. pH 6. The higher attine symbionts that have no known free-living relatives had much higher proteinase activities than the lower attine symbionts. Their total in vitro proteinase activity peaked at pH values around 5, which is close to the pH that the ants maintain in their fungus gardens, suggesting that the pH optimum of fungal proteinases may have changed after the irreversible domestication of evolutionary more derived fungal symbionts. This notion is also supported by buffering capacities of fungus gardens at pH 5.2 being remarkably high, and suggests that the fungal symbiont actively helps to maintain garden acidity at this specific level. Metalloproteinases dominated the activity profiles of lower attine gardens and may thus represent the ancestral type of proteinase production, whereas serine proteinase activity dominated the activity profiles of the higher attine gardens reared by Trachymyrmex and Sericomyrmex, suggesting that there may be trade-offs in the production of these enzyme classes. Remarkably, the single symbiont that is shared by species of the crown group of Atta and Acromyrmex leaf-cutting ants mostly showed metalloproteinase activity, suggesting that recurrent changes in enzyme production may have occurred throughout the domestication history of fungus-garden symbionts. Conclusions Proteinase pH optima and buffering capacities of fungal symbionts appear to have evolved remarkable adaptations to living in obligate symbiosis with farming ants. Although the functional roles of serine and metalloproteinases in fungus gardens are unknown, the differential production of these classes of proteolytic enzymes suggest that substrate specificity may be important and that trade-offs may prevent the simultaneous upregulation of both classes of enzymes. PMID:21247468
Leaf-Cutter Ant Fungus Gardens Are Biphasic Mixed Microbial Bioreactors That Convert Plant Biomass to Polyols with Biotechnological Applications

PubMed Central

Somera, Alexandre F.; Lima, Adriel M.; dos Santos-Neto, Álvaro J.; Lanças, Fernando M.

2015-01-01

Leaf-cutter ants use plant matter to culture the obligate mutualistic basidiomycete Leucoagaricus gongylophorus. This fungus mediates ant nutrition on plant resources. Furthermore, other microbes living in the fungus garden might also contribute to plant digestion. The fungus garden comprises a young sector with recently incorporated leaf fragments and an old sector with partially digested plant matter. Here, we show that the young and old sectors of the grass-cutter Atta bisphaerica fungus garden operate as a biphasic solid-state mixed fermenting system. An initial plant digestion phase occurred in the young sector in the fungus garden periphery, with prevailing hemicellulose and starch degradation into arabinose, mannose, xylose, and glucose. These products support fast microbial growth but were mostly converted into four polyols. Three polyols, mannitol, arabitol, and inositol, were secreted by L. gongylophorus, and a fourth polyol, sorbitol, was likely secreted by another, unidentified, microbe. A second plant digestion phase occurred in the old sector, located in the fungus garden core, comprising stocks of microbial biomass growing slowly on monosaccharides and polyols. This biphasic operation was efficient in mediating symbiotic nutrition on plant matter: the microbes, accounting for 4% of the fungus garden biomass, converted plant matter biomass into monosaccharides and polyols, which were completely consumed by the resident ants and microbes. However, when consumption was inhibited through laboratory manipulation, most of the plant polysaccharides were degraded, products rapidly accumulated, and yields could be preferentially switched between polyols and monosaccharides. This feature might be useful in biotechnology. PMID:25911490
Nest architecture, fungus gardens, queen, males and larvae of the fungus-growing ant Mycetagroicus inflatus Brandão & Mayhé-Nunes.

PubMed

Jesovnik, A; Sosa-Calvo, J; Lopes, C T; Vasconcelos, H L; Schultz, T R

2013-01-01

All known fungus-growing ants (tribe Attini) are obligately symbiotic with their cultivated fungi. The fungal cultivars of "lower" attine ants are facultative symbionts, capable of living apart from ants, whereas the fungal cultivars of "higher" attine ants, including leaf-cutting genera Atta and Acromyrmex , are highly specialized, obligate symbionts. Since higher attine ants and fungi are derived from lower attine ants and fungi, understanding the evolutionary transition from lower to higher attine agriculture requires understanding the historical sequence of change in both ants and fungi. The biology of the poorly known ant genus Mycetagroicus is of special interest in this regard because it occupies a phylogenetic position intermediate between lower and higher ant agriculture. Here, based on the excavations of four nests in Pará, Brazil, we report the first biological data for the recently described species Mycetagroicus inflatus , including the first descriptions of Mycetagroicus males and larvae. Like M. cerradensis , the only other species in the genus for which nesting biology is known, the garden chambers of M. inflatus are unusually deep and the garden is most likely relocated vertically in rainy and dry seasons. Due to the proximity of nests to the Araguaia River, it is likely that even the uppermost chambers and nest entrances of M. inflatus are submerged during the rainy season. Most remarkably, all three examined colonies of M. inflatus cultivate the same fungal species as their congener, M. cerradensis , over 1,000 km away, raising the possibility of long-term symbiont fidelity spanning speciation events within the genus.
A Prospective Randomized Controlled Trial to Study the Impact of a Nutrition-Sensitive Intervention on Adult Women With Cancer Cachexia Undergoing Palliative Care in India

PubMed Central

Kapoor, Neha; Naufahu, Jane; Tewfik, Sundus; Bhatnagar, Sushma; Garg, Rakesh; Tewfik, Ihab

2016-01-01

Purpose. Advanced cancer patients with disease progression develop cachexia. Nevertheless, cancer patients at nutritional risk have shown improved body weight and quality of life with oral nutritional supplements. Method. This was a randomized controlled trial in adult female cancer patients (n = 63) attending palliative clinics, with symptoms of cachexia. Eligible patients were randomly distributed into control (n = 33) and intervention (n = 30) groups. Both groups were provided with nutritional and physical activity counseling, but the intervention group received an additional 100 g of Improved Atta (IAtta) for 6 months daily consumption. This study was designed to assess the efficacy of IAtta (with counseling) in enhancing the health status of cachexic patients. Anthropometric measurements, dietary intake, physical activity level and quality of life parameters were assessed at baseline, after 3 months, and at the end of 6 months. Results. Patients in the control group (n = 15) had significantly decreased body weight (P = .003), mid–upper-arm circumference (P = .002), and body fat (P = .002) by the end of intervention. A trend of body weight gain in the intervention group (n = 17; P = .08) and significant increase of body fat (P = .002) was observed; moreover, patients reported a significant improvement in fatigue (P = .002) and appetite scores (P = .006) under quality-of-life domains at the end of intervention. Conclusions. Embedding a nutrition-sensitive intervention ( IAtta ) within Indian palliative care therapy may improve quality of life and stabilize body weight in cancer cachexia patients. PMID:27252077
Recognition of endophytic Trichoderma species by leaf-cutting ants and their potential in a Trojan-horse management strategy

PubMed Central

Rocha, Silma L.; Evans, Harry C.; Jorge, Vanessa L.; Cardoso, Lucimar A. O.; Pereira, Fernanda S. T.; Rocha, Fabiano B.; Barreto, Robert W.; Hart, Adam G.

2017-01-01

Interactions between leaf-cutting ants, their fungal symbiont (Leucoagaricus) and the endophytic fungi within the vegetation they carry into their colonies are still poorly understood. If endophytes antagonistic to Leucoagaricus were found in plant material being carried by these ants, then this might indicate a potential mechanism for plants to defend themselves from leaf-cutter attack. In addition, it could offer possibilities for the management of these important Neotropical pests. Here, we show that, for Atta sexdens rubropilosa, there was a significantly greater incidence of Trichoderma species in the vegetation removed from the nests—and deposited around the entrances—than in that being transported into the nests. In a no-choice test, Trichoderma-infested rice was taken into the nest, with deleterious effects on both the fungal gardens and ant survival. The endophytic ability of selected strains of Trichoderma was also confirmed, following their inoculation and subsequent reisolation from seedlings of eucalyptus. These results indicate that endophytic fungi which pose a threat to ant fungal gardens through their antagonistic traits, such as Trichoderma, have the potential to act as bodyguards of their plant hosts and thus might be employed in a Trojan-horse strategy to mitigate the negative impact of leaf-cutting ants in both agriculture and silviculture in the Neotropics. We posit that the ants would detect and evict such ‘malign’ endophytes—artificially inoculated into vulnerable crops—during the quality-control process within the nest, and, moreover, that the foraging ants may then be deterred from further harvesting of ‘Trichoderma-enriched’ plants. PMID:28484603

Leaf-cutter ant fungus gardens are biphasic mixed microbial bioreactors that convert plant biomass to polyols with biotechnological applications.

PubMed

Somera, Alexandre F; Lima, Adriel M; Dos Santos-Neto, Álvaro J; Lanças, Fernando M; Bacci, Maurício

2015-07-01

Leaf-cutter ants use plant matter to culture the obligate mutualistic basidiomycete Leucoagaricus gongylophorus. This fungus mediates ant nutrition on plant resources. Furthermore, other microbes living in the fungus garden might also contribute to plant digestion. The fungus garden comprises a young sector with recently incorporated leaf fragments and an old sector with partially digested plant matter. Here, we show that the young and old sectors of the grass-cutter Atta bisphaerica fungus garden operate as a biphasic solid-state mixed fermenting system. An initial plant digestion phase occurred in the young sector in the fungus garden periphery, with prevailing hemicellulose and starch degradation into arabinose, mannose, xylose, and glucose. These products support fast microbial growth but were mostly converted into four polyols. Three polyols, mannitol, arabitol, and inositol, were secreted by L. gongylophorus, and a fourth polyol, sorbitol, was likely secreted by another, unidentified, microbe. A second plant digestion phase occurred in the old sector, located in the fungus garden core, comprising stocks of microbial biomass growing slowly on monosaccharides and polyols. This biphasic operation was efficient in mediating symbiotic nutrition on plant matter: the microbes, accounting for 4% of the fungus garden biomass, converted plant matter biomass into monosaccharides and polyols, which were completely consumed by the resident ants and microbes. However, when consumption was inhibited through laboratory manipulation, most of the plant polysaccharides were degraded, products rapidly accumulated, and yields could be preferentially switched between polyols and monosaccharides. This feature might be useful in biotechnology. Copyright © 2015, American Society for Microbiology. All Rights Reserved.
Leucoagaricus gongylophorus Produces Diverse Enzymes for the Degradation of Recalcitrant Plant Polymers in Leaf-Cutter Ant Fungus Gardens

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

Aylward, Frank O.; Burnum-Johnson, Kristin E.; Tringe, Susannah G.

Plants represent a large reservoir of organic carbon comprised largely of recalcitrant polymers that most metazoans are unable to deconstruct. Many herbivores gain access to nutrients in this material indirectly by associating with microbial symbionts, and leaf-cutter ants are a paradigmatic example. These ants use fresh foliar biomass as manure to cultivate fungus gardens composed primarily of Leucoagaricus gongylophorus, a basidiomycetous symbiont that produces specialized hyphal swellings that serve as a food source for the host ant colony. Although leaf-cutter ants are conspicuous herbivores that contribute substantially to carbon turnover in Neotropical ecosystems, the process through which plant biomass ismore » degraded in their fungus gardens is not well understood. Here we present the first draft genome of L. gongylophorus, and using genomic, metaproteomic, and phylogenetic tools we investigate its role in lignocellulose degradation in the fungus gardens of both Atta cephalotes and Acromyrmex echinatior leaf-cutter ants. We show that L. gongylophorus produces a diversity of lignocellulases in fungus gardens, and is likely the primary driver of plant biomass degradation in these ecosystems. We also show that this fungus produces distinct sets of lignocellulases throughout the different stages of biomass degradation, including numerous cellulases and laccases that may be playing an important but previously uncharacterized role in lignocellulose degradation. Our study provides a comprehensive analysis of plant biomass degradation in leaf-cutter ant fungus gardens and provides insight into the molecular dynamics underlying the symbiosis between these dominant herbivores and their obligate fungal cultivar.« less
Krypton-81 in groundwater of the Culebra Dolomite near the Waste Isolation Pilot Plant, New Mexico.

PubMed

Sturchio, Neil C; Kuhlman, Kristopher L; Yokochi, Reika; Probst, Peter C; Jiang, Wei; Lu, Zheng-Tian; Mueller, Peter; Yang, Guo-Min

2014-05-01

The Waste Isolation Pilot Plant (WIPP) in New Mexico is the first geologic repository for disposal of transuranic nuclear waste from defense-related programs of the US Department of Energy. It is constructed within halite beds of the Permian-age Salado Formation. The Culebra Dolomite, confined within Rustler Formation evaporites overlying the Salado Formation, is a potential pathway for radionuclide transport from the repository to the accessible environment in the human-disturbed repository scenario. Although extensive subsurface characterization and numerical flow modeling of groundwater has been done in the vicinity of the WIPP, few studies have used natural isotopic tracers to validate the flow models and to better understand solute transport at this site. The advent of Atom-Trap Trace Analysis (ATTA) has enabled routine measurement of cosmogenic (81)Kr (half-life 229,000 yr), a near-ideal tracer for long-term groundwater transport. We measured (81)Kr in saline groundwater sampled from two Culebra Dolomite monitoring wells near the WIPP site, and compared (81)Kr model ages with reverse particle-tracking results of well-calibrated flow models. The (81)Kr model ages are ~130,000 and ~330,000 yr for high-transmissivity and low-transmissivity portions of the formation, respectively. Compared with flow model results which indicate a relatively young mean hydraulic age (~32,000 yr), the (81)Kr model ages imply substantial physical attenuation of conservative solutes in the Culebra Dolomite and provide limits on the effective diffusivity of contaminants into the confining aquitards. Copyright © 2014 Elsevier B.V. All rights reserved.
ATTA - A New Method of Ultrasensitive Trace-Isotope Analysis

NASA Astrophysics Data System (ADS)

Lu, Z.-T.; Bailey, K.; Chen, C. Y.; Du, X.; Li, Y. M.; O'Connor, T. P.; Young, L.; Winkler, G.

2000-10-01

We have developed a new method of ultrasensitive trace-isotope analysis based upon the technique of laser manipulation of neutral atoms [1]. This new method allows us to count individual 85Kr and 81Kr atoms present in a natural krypton sample with isotopic abundances in the range of 10-11 and 10-13, respectively. Isotope analysis of 81Kr can be used to date polar ice, and 85Kr is a tracer used in monitoring nuclear wastes. In this experiment metastable Kr atoms were produced in a discharge, decelerated via the Zeeman slowing technique, and captured by a Magneto-Optical Trap where the atoms were counted by measuring their fluorescence. At present our system is capable of counting, in average, one 81Kr atom for about 12 minutes with a total efficiency of 2x10-7. We are currently working to improve our system efficiency by applying cryogenic cooling to the Kr atoms in the discharge region and by recirculating the gas in the vacuum system. This method can be used to analyze many other isotope tracers for a wide range of applications including measuring solar neutrino flux, searching for exotic particles, tracing atmospheric and oceanic currents, archeological and geological dating, medical diagnostics, monitoring fission products in the environment for nuclear waste management, etc. This work is supported by the U.S. Department of Energy, Nuclear Physics Division; L.Young is supported by the Office of Basic Energy Sciences, Division of Chemical Sciences (Contract W-31-109-ENG-38). [1] C.Y. Chen et. al., Science 286, 1139 (1999).
Recognition of endophytic Trichoderma species by leaf-cutting ants and their potential in a Trojan-horse management strategy.

PubMed

Rocha, Silma L; Evans, Harry C; Jorge, Vanessa L; Cardoso, Lucimar A O; Pereira, Fernanda S T; Rocha, Fabiano B; Barreto, Robert W; Hart, Adam G; Elliot, Simon L

2017-04-01

Interactions between leaf-cutting ants, their fungal symbiont ( Leucoagaricus ) and the endophytic fungi within the vegetation they carry into their colonies are still poorly understood. If endophytes antagonistic to Leucoagaricus were found in plant material being carried by these ants, then this might indicate a potential mechanism for plants to defend themselves from leaf-cutter attack. In addition, it could offer possibilities for the management of these important Neotropical pests. Here, we show that, for Atta sexdens rubropilosa , there was a significantly greater incidence of Trichoderma species in the vegetation removed from the nests-and deposited around the entrances-than in that being transported into the nests. In a no-choice test, Trichoderma- infested rice was taken into the nest, with deleterious effects on both the fungal gardens and ant survival. The endophytic ability of selected strains of Trichoderma was also confirmed, following their inoculation and subsequent reisolation from seedlings of eucalyptus. These results indicate that endophytic fungi which pose a threat to ant fungal gardens through their antagonistic traits, such as Trichoderma , have the potential to act as bodyguards of their plant hosts and thus might be employed in a Trojan-horse strategy to mitigate the negative impact of leaf-cutting ants in both agriculture and silviculture in the Neotropics. We posit that the ants would detect and evict such 'malign' endophytes-artificially inoculated into vulnerable crops-during the quality-control process within the nest, and, moreover, that the foraging ants may then be deterred from further harvesting of ' Trichoderma -enriched' plants.
Dimeric PROP1 binding to diverse palindromic TAAT sequences promotes its transcriptional activity.

PubMed

Nakayama, Michie; Kato, Takako; Susa, Takao; Sano, Akiko; Kitahara, Kousuke; Kato, Yukio

2009-08-13

Mutations in the Prop1 gene are responsible for murine Ames dwarfism and human combined pituitary hormone deficiency with hypogonadism. Recently, we reported that PROP1 is a possible transcription factor for gonadotropin subunit genes through plural cis-acting sites composed of AT-rich sequences containing a TAAT motif which differs from its consensus binding sequence known as PRDQ9 (TAATTGAATTA). This study aimed to verify the binding specificity and sequence of PROP1 by applying the method of SELEX (Systematic Evolution of Ligands by EXponential enrichment), EMSA (electrophoretic mobility shift assay) and transient transfection assay. SELEX, after 5, 7 and 9 generations of selection using a random sequence library, showed that nucleotides containing one or two TAAT motifs were accumulated and accounted for 98.5% at the 9th generation. Aligned sequences and EMSA demonstrated that PROP1 binds preferentially to 11 nucleotides composed of an inverted TAAT motif separated by 3 nucleotides with variation in the half site of palindromic TAAT motifs and with preferential requirement of T at the nucleotide number 5 immediately 3' to a TAAT motif. Transient transfection assay demonstrated first that dimeric binding of PROP1 to an inverted TAAT motif and its cognates resulted in transcriptional activation, whereas monomeric binding of PROP1 to a single TAAT motif and an inverted ATTA motif did not mediate activation. Thus, this study demonstrated that dimeric binding of PROP1 is able to recognize diverse palindromic TAAT sequences separated by 3 nucleotides and to exhibit its transcriptional activity.
Enrichment and Broad Representation of Plant Biomass-Degrading Enzymes in the Specialized Hyphal Swellings of Leucoagaricus gongylophorus, the Fungal Symbiont of Leaf-Cutter Ants.

PubMed

Aylward, Frank O; Khadempour, Lily; Tremmel, Daniel M; McDonald, Bradon R; Nicora, Carrie D; Wu, Si; Moore, Ronald J; Orton, Daniel J; Monroe, Matthew E; Piehowski, Paul D; Purvine, Samuel O; Smith, Richard D; Lipton, Mary S; Burnum-Johnson, Kristin E; Currie, Cameron R

2015-01-01

Leaf-cutter ants are prolific and conspicuous constituents of Neotropical ecosystems that derive energy from specialized fungus gardens they cultivate using prodigious amounts of foliar biomass. The basidiomycetous cultivar of the ants, Leucoagaricus gongylophorus, produces specialized hyphal swellings called gongylidia that serve as the primary food source of ant colonies. Gongylidia also contain plant biomass-degrading enzymes that become concentrated in ant digestive tracts and are deposited within fecal droplets onto fresh foliar material as ants incorporate it into the fungus garden. Although the enzymes concentrated by L. gongylophorus within gongylidia are thought to be critical to the initial degradation of plant biomass, only a few enzymes present in these hyphal swellings have been identified. Here we use proteomic methods to identify proteins present in the gongylidia of three Atta cephalotes colonies. Our results demonstrate that a diverse but consistent set of enzymes is present in gongylidia, including numerous plant biomass-degrading enzymes likely involved in the degradation of polysaccharides, plant toxins, and proteins. Overall, gongylidia contained over three quarters of all biomass-degrading enzymes identified in the L. gongylophorus genome, demonstrating that the majority of the enzymes produced by this fungus for biomass breakdown are ingested by the ants. We also identify a set of 40 of these enzymes enriched in gongylidia compared to whole fungus garden samples, suggesting that certain enzymes may be particularly important in the initial degradation of foliar material. Our work sheds light on the complex interplay between leaf-cutter ants and their fungal symbiont that allows for the host insects to occupy an herbivorous niche by indirectly deriving energy from plant biomass.
Using 81Kr and noble gases to characterize and date groundwater and brines in the Baltic Artesian Basin on the one-million-year timescale

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

Gerber, Christoph; Vaikmae, Rein; Aeschbach, Werner

Analyses for 81Kr and noble gases on groundwater from the deepest aquifer system of the Baltic Artesian Basin (BAB) were performed to determine groundwater ages and uncover the flow dynamics of the system on a timescale of several hundred thousand years. We find that the system is controlled by mixing of three distinct water masses: Interglacial or recent meteoric water (δ 18O ≈ –10.4‰) with a poorly evolved chemical and noble gas signature, glacial meltwater (δ 18O ≤ –18‰) with elevated noble gas concentrations, and an old, high-salinity brine component (δ 18O ≥ –4.5‰, ≥ 90 g Cl –/L) withmore » strongly depleted atmospheric noble gas concentrations. The 81Kr measurements are interpreted within this mixing framework to estimate the age of the end-members. Deconvoluted 81Kr ages range from 300 ka to 1.3 Ma for interglacial or recent meteoric water and glacial meltwater. For the brine component, ages exceed the dating range of the ATTA-3 instrument of 1.3 Ma. The radiogenic noble gas components 4He* and 40Ar* are less conclusive but also support an age of > 1 Ma for the brine. Based on the chemical and noble gas concentrations and the dating results, we conclude that the brine originates from evaporated seawater that has been modified by later water–rock interaction. Furthermore, as the obtained tracer ages cover several glacial cycles, we discuss the impact of the glacial cycles on flow patterns in the studied aquifer system.« less
Using 81Kr and noble gases to characterize and date groundwater and brines in the Baltic Artesian Basin on the one-million-year timescale

DOE PAGES

Gerber, Christoph; Vaikmae, Rein; Aeschbach, Werner; ...

2017-01-31

Analyses for 81Kr and noble gases on groundwater from the deepest aquifer system of the Baltic Artesian Basin (BAB) were performed to determine groundwater ages and uncover the flow dynamics of the system on a timescale of several hundred thousand years. We find that the system is controlled by mixing of three distinct water masses: Interglacial or recent meteoric water (δ 18O ≈ –10.4‰) with a poorly evolved chemical and noble gas signature, glacial meltwater (δ 18O ≤ –18‰) with elevated noble gas concentrations, and an old, high-salinity brine component (δ 18O ≥ –4.5‰, ≥ 90 g Cl –/L) withmore » strongly depleted atmospheric noble gas concentrations. The 81Kr measurements are interpreted within this mixing framework to estimate the age of the end-members. Deconvoluted 81Kr ages range from 300 ka to 1.3 Ma for interglacial or recent meteoric water and glacial meltwater. For the brine component, ages exceed the dating range of the ATTA-3 instrument of 1.3 Ma. The radiogenic noble gas components 4He* and 40Ar* are less conclusive but also support an age of > 1 Ma for the brine. Based on the chemical and noble gas concentrations and the dating results, we conclude that the brine originates from evaporated seawater that has been modified by later water–rock interaction. Furthermore, as the obtained tracer ages cover several glacial cycles, we discuss the impact of the glacial cycles on flow patterns in the studied aquifer system.« less
Enrichment and broad representation of plant biomass-degrading enzymes in the specialized hyphal swellings of Leucoagaricus gongylophorus, the fungal symbiont of leaf-cutter ants

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

Aylward, Frank O.; Khadempour, Lily; Tremmel, Daniel M.

Leaf-cutter ants are prolific and conspicuous constituents of Neotropical ecosystems that derive energy from specialized fungus gardens they cultivate using prodigious amounts of foliar biomass. The basidiomycetous cultivar of the ants, Leucoagaricus gongylophorus, produces specialized hyphal swellings called gongylidia that serve as the primary food source of ant colonies. Gongylidia also contain plant biomass-degrading enzymes that become concentrated in ant digestive tracts and are deposited within fecal droplets onto fresh foliar material as ants incorporate it into the fungus garden. Although the enzymes concentrated by L. gongylophorus within gongylidia are thought to be critical to the initial degradation of plantmore » biomass, only a few enzymes present in these hyphal swellings have been identified. Here we use proteomic methods to identify proteins present in the gongylidia of three Atta cephalotes colonies. Our results demonstrate that a diverse but consistent set of enzymes is present in gongylidia, including numerous plant biomass-degrading enzymes likely involved in the degradation of polysaccharides, plant toxins, and proteins. Overall, gongylidia contained over three quarters of all biomass-degrading enzymes identified in the L. gongylophorus genome, demonstrating that the majority of the enzymes produced by this fungus for biomass breakdown are ingested by the ants. We also identify a set of 40 of these enzymes enriched in gongylidia compared to whole fungus garden samples, suggesting that certain enzymes may be particularly important in the initial degradation of foliar material. Our work sheds light on the complex interplay between leaf-cutter ants and their fungal symbiont that allows for the host insects to occupy an herbivorous niche by indirectly deriving energy from plant biomass.« less
Enrichment and Broad Representation of Plant Biomass-Degrading Enzymes in the Specialized Hyphal Swellings of Leucoagaricus gongylophorus, the Fungal Symbiont of Leaf-Cutter Ants

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

Aylward, Frank O.; Khadempour, Lily; Tremmel, Daniel

Leaf-cutter ants are prolific and conspicuous Neotropical herbivores that derive energy from specialized fungus gardens they cultivate using foliar biomass. The basidiomycetous cultivar of the ants, Leucoagaricus gongylophorus, produces specialized hyphal swellings called gongylidia that serve as the primary food source of ant colonies. Gongylidia also contain lignocellulases that become concentrated in ant digestive tracts and are deposited within fecal droplets onto fresh foliar material as it is foraged by the ants. Although the enzymes concentrated by L. gongylophorus within gongylidia are thought to be critical to the initial degradation of plant biomass, only a few enzymes present in thesemore » hyphal swellings have been identified. Here we use proteomic methods to identify proteins present in the gongylidia of three Atta cephalotes colonies. Our results demonstrate that a diverse but consistent set of enzymes is present in gongylidia, including numerous lignocellulases likely involved in the degradation of polysaccharides, plant toxins, and proteins. Overall, gongylidia contained over three-quarters of all lignocellulases identified in the L. gongylophorus genome, demonstrating that the majority of the enzymes produced by this fungus for biomass breakdown are ingested by the ants. We also identify a set of 23 lignocellulases enriched in gongylidia compared to whole fungus garden samples, suggesting that certain enzymes may be particularly important in the initial degradation of foliar material. Our work sheds light on the complex interplay between leaf-cutter ants and their fungal symbiont that allows for the host insects to occupy an herbivorous niche by indirectly deriving energy from plant biomass.« less
Efficacy of different fibres and flour mixes in South-Asian flatbreads for reducing post-prandial glucose responses in healthy adults.

PubMed

Boers, Hanny M; MacAulay, Katrina; Murray, Peter; Seijen Ten Hoorn, Jack; Hoogenraad, Anne-Roos; Peters, Harry P F; Vente-Spreeuwenberg, Maria A M; Mela, David J

2017-09-01

Type 2 diabetes (T2DM) is increasing, particularly in South-East Asia. Intake of high-glycaemic foods has been positively associated with T2DM, and feasible routes to reduce the glycaemic response to carbohydrate-rich staple foods are needed. The research question was whether different fibre and legume flour mixes in flatbreads lower postprandial glucose (PPG) responses. Using a balanced incomplete block design, we tested the inclusion of guar gum (GG), konjac mannan (KM) and chickpea flour (CPF) in 10 combinations (2/4/6 g GG; 2/4 g KM; 15 g CPF, and 10 or 15 g CPF plus 2 or 4 g GG) in 100 g total of a control commercial high-fibre flatbread flour mix ("atta") on PPG in 38 normal-weight adults. Self-reported appetite was an additional exploratory outcome. An in vitro digestion assay was adapted for flatbreads and assessed for prediction of in vivo PPG. Flatbreads with 6 g GG, 4 g KM, and 15 g CPF plus 2 or 4 g GG reduced PPG ≥30 % (p < 0.01), while no other combinations differed significantly from the control. A statistical model with four in vitro parameters (rate of digestion, %RDS, AUC, carbohydrate level) was highly predictive of PPG results (adjusted R 2 = 0.89). Test products were similar to the control for appetite-related measures. The results confirm the efficacy of specific additions to flatbread flour mixes for reducing PPG and the value of the in vitro model as a predictive tool with these ingredients and product format. This trial is registered at ClinicalTrials.gov with identifier NCT02671214.
Genome-wide distribution comparative and composition analysis of the SSRs in Poaceae.

PubMed

Wang, Yi; Yang, Chao; Jin, Qiaojun; Zhou, Dongjie; Wang, Shuangshuang; Yu, Yuanjie; Yang, Long

2015-02-15

The Poaceae family is of great importance to human beings since it comprises the cereal grasses which are the main sources for human food and animal feed. With the rapid growth of genomic data from Poaceae members, comparative genomics becomes a convinent method to study genetics of diffierent species. The SSRs (Simple Sequence Repeats) are widely used markers in the studies of Poaceae for their high abundance and stability. In this study, using the genomic sequences of 9 Poaceae species, we detected 11,993,943 SSR loci and developed 6,799,910 SSR primer pairs. The results show that SSRs are distributed on all the genomic elements in grass. Hexamer is the most frequent motif and AT/TA is the most frequent motif in dimer. The abundance of the SSRs has a positive linear relationship with the recombination rate. SSR sequences in the coding regions involve a higher GC content in the Poaceae than that in the other species. SSRs of 70-80 bp in length showed the highest AT/GC base ratio among all of these loci. The result shows the highest polymorphism rate belongs to the SSRs ranged from 30 bp to 40 bp. Using all the SSR primers of Japonica, nineteen universal primers were selected and located on the genome of the grass family. The information of SSR loci, the SSR primers and the tools of mining and analyzing SSR are provided in the PSSRD (Poaceae SSR Database, http://biodb.sdau.edu.cn/pssrd/). Our study and the PSSRD database provide a foundation for the comparative study in the Poaceae and it will accelerate the study on markers application, gene mapping and molecular breeding.
Enrichment and broad representation of plant biomass-degrading enzymes in the specialized hyphal swellings of Leucoagaricus gongylophorus, the fungal symbiont of leaf-cutter ants

DOE PAGES

Aylward, Frank O.; Khadempour, Lily; Tremmel, Daniel M.; ...

2015-08-28

Leaf-cutter ants are prolific and conspicuous constituents of Neotropical ecosystems that derive energy from specialized fungus gardens they cultivate using prodigious amounts of foliar biomass. The basidiomycetous cultivar of the ants, Leucoagaricus gongylophorus, produces specialized hyphal swellings called gongylidia that serve as the primary food source of ant colonies. Gongylidia also contain plant biomass-degrading enzymes that become concentrated in ant digestive tracts and are deposited within fecal droplets onto fresh foliar material as ants incorporate it into the fungus garden. Although the enzymes concentrated by L. gongylophorus within gongylidia are thought to be critical to the initial degradation of plantmore » biomass, only a few enzymes present in these hyphal swellings have been identified. Here we use proteomic methods to identify proteins present in the gongylidia of three Atta cephalotes colonies. Our results demonstrate that a diverse but consistent set of enzymes is present in gongylidia, including numerous plant biomass-degrading enzymes likely involved in the degradation of polysaccharides, plant toxins, and proteins. Overall, gongylidia contained over three quarters of all biomass-degrading enzymes identified in the L. gongylophorus genome, demonstrating that the majority of the enzymes produced by this fungus for biomass breakdown are ingested by the ants. We also identify a set of 40 of these enzymes enriched in gongylidia compared to whole fungus garden samples, suggesting that certain enzymes may be particularly important in the initial degradation of foliar material. Our work sheds light on the complex interplay between leaf-cutter ants and their fungal symbiont that allows for the host insects to occupy an herbivorous niche by indirectly deriving energy from plant biomass.« less
Enrichment and Broad Representation of Plant Biomass-Degrading Enzymes in the Specialized Hyphal Swellings of Leucoagaricus gongylophorus, the Fungal Symbiont of Leaf-Cutter Ants

PubMed Central

Aylward, Frank O.; Khadempour, Lily; Tremmel, Daniel M.; McDonald, Bradon R.; Nicora, Carrie D.; Wu, Si; Moore, Ronald J.; Orton, Daniel J.; Monroe, Matthew E.; Piehowski, Paul D.; Purvine, Samuel O.; Smith, Richard D.; Lipton, Mary S.; Burnum-Johnson, Kristin E.; Currie, Cameron R.

2015-01-01

Leaf-cutter ants are prolific and conspicuous constituents of Neotropical ecosystems that derive energy from specialized fungus gardens they cultivate using prodigious amounts of foliar biomass. The basidiomycetous cultivar of the ants, Leucoagaricus gongylophorus, produces specialized hyphal swellings called gongylidia that serve as the primary food source of ant colonies. Gongylidia also contain plant biomass-degrading enzymes that become concentrated in ant digestive tracts and are deposited within fecal droplets onto fresh foliar material as ants incorporate it into the fungus garden. Although the enzymes concentrated by L. gongylophorus within gongylidia are thought to be critical to the initial degradation of plant biomass, only a few enzymes present in these hyphal swellings have been identified. Here we use proteomic methods to identify proteins present in the gongylidia of three Atta cephalotes colonies. Our results demonstrate that a diverse but consistent set of enzymes is present in gongylidia, including numerous plant biomass-degrading enzymes likely involved in the degradation of polysaccharides, plant toxins, and proteins. Overall, gongylidia contained over three quarters of all biomass-degrading enzymes identified in the L. gongylophorus genome, demonstrating that the majority of the enzymes produced by this fungus for biomass breakdown are ingested by the ants. We also identify a set of 40 of these enzymes enriched in gongylidia compared to whole fungus garden samples, suggesting that certain enzymes may be particularly important in the initial degradation of foliar material. Our work sheds light on the complex interplay between leaf-cutter ants and their fungal symbiont that allows for the host insects to occupy an herbivorous niche by indirectly deriving energy from plant biomass. PMID:26317212
Simple sequence repeat marker development from bacterial artificial chromosome end sequences and expressed sequence tags of flax (Linum usitatissimum L.).

PubMed

Cloutier, Sylvie; Miranda, Evelyn; Ward, Kerry; Radovanovic, Natasa; Reimer, Elsa; Walichnowski, Andrzej; Datla, Raju; Rowland, Gordon; Duguid, Scott; Ragupathy, Raja

2012-08-01

Flax is an important oilseed crop in North America and is mostly grown as a fibre crop in Europe. As a self-pollinated diploid with a small estimated genome size of ~370 Mb, flax is well suited for fast progress in genomics. In the last few years, important genetic resources have been developed for this crop. Here, we describe the assessment and comparative analyses of 1,506 putative simple sequence repeats (SSRs) of which, 1,164 were derived from BAC-end sequences (BESs) and 342 from expressed sequence tags (ESTs). The SSRs were assessed on a panel of 16 flax accessions with 673 (58 %) and 145 (42 %) primer pairs being polymorphic in the BESs and ESTs, respectively. With 818 novel polymorphic SSR primer pairs reported in this study, the repertoire of available SSRs in flax has more than doubled from the combined total of 508 of all previous reports. Among nucleotide motifs, trinucleotides were the most abundant irrespective of the class, but dinucleotides were the most polymorphic. SSR length was also positively correlated with polymorphism. Two dinucleotide (AT/TA and AG/GA) and two trinucleotide (AAT/ATA/TAA and GAA/AGA/AAG) motifs and their iterations, different from those reported in many other crops, accounted for more than half of all the SSRs and were also more polymorphic (63.4 %) than the rest of the markers (42.7 %). This improved resource promises to be useful in genetic, quantitative trait loci (QTL) and association mapping as well as for anchoring the physical/genetic map with the whole genome shotgun reference sequence of flax.
The Transcription Factor AlsR Binds and Regulates the Promoter of the alsSD Operon Responsible for Acetoin Formation in Bacillus subtilis

PubMed Central

Frädrich, Claudia; March, Anika; Fiege, Kerstin; Hartmann, Anja; Jahn, Dieter

2012-01-01

Bacillus subtilis forms acetoin under anaerobic fermentative growth conditions and as a product of the aerobic carbon overflow metabolism. Acetoin formation from pyruvate requires α-acetolactate synthase and acetolactate decarboxylase, both encoded by the alsSD operon. The alsR gene, encoding the LysR-type transcriptional regulator AlsR, was found to be essential for the in vivo expression of alsSD in response to anaerobic acetate accumulation, the addition of acetate, low pH, and the aerobic stationary phase. The expressions of the alsSD operon and the alsR regulatory gene were independent of other regulators of the anaerobic regulatory network, including ResDE, Fnr, and ArfM. A negative autoregulation of alsR was observed. In vitro transcription from the alsSD promoter using purified B. subtilis RNA polymerase required AlsR. DNA binding studies with purified recombinant AlsR in combination with promoter mutagenesis experiments identified a 19-bp high-affinity palindromic binding site (TAAT-N11-ATTA) at positions −76 to −58 (regulatory binding site [RBS]) and a low-affinity site (AT-N11-AT) at positions −41 to −27 (activator binding site [ABS]) upstream of the transcriptional start site of alsSD. The RBS and ABS were found to be essential for in vivo alsSD transcription. AlsR binding to both sites induced the formation of higher-order, transcription-competent complexes. The AlsR protein carrying the S100A substitution at the potential coinducer binding site still bound to the RBS and ABS. However, AlsR(S100A) failed to form the higher-order complex and to initiate in vivo and in vitro transcription. A model for AlsR promoter binding and transcriptional activation was deduced. PMID:22178965
Considerations for Assessing Maximum Critical Temperatures in Small Ectothermic Animals: Insights from Leaf-Cutting Ants

PubMed Central

Ribeiro, Pedro Leite; Camacho, Agustín; Navas, Carlos Arturo

2012-01-01

The thermal limits of individual animals were originally proposed as a link between animal physiology and thermal ecology. Although this link is valid in theory, the evaluation of physiological tolerances involves some problems that are the focus of this study. One rationale was that heating rates shall influence upper critical limits, so that ecological thermal limits need to consider experimental heating rates. In addition, if thermal limits are not surpassed in experiments, subsequent tests of the same individual should yield similar results or produce evidence of hardening. Finally, several non-controlled variables such as time under experimental conditions and procedures may affect results. To analyze these issues we conducted an integrative study of upper critical temperatures in a single species, the ant Atta sexdens rubropiosa, an animal model providing large numbers of individuals of diverse sizes but similar genetic makeup. Our specific aims were to test the 1) influence of heating rates in the experimental evaluation of upper critical temperature, 2) assumptions of absence of physical damage and reproducibility, and 3) sources of variance often overlooked in the thermal-limits literature; and 4) to introduce some experimental approaches that may help researchers to separate physiological and methodological issues. The upper thermal limits were influenced by both heating rates and body mass. In the latter case, the effect was physiological rather than methodological. The critical temperature decreased during subsequent tests performed on the same individual ants, even one week after the initial test. Accordingly, upper thermal limits may have been overestimated by our (and typical) protocols. Heating rates, body mass, procedures independent of temperature and other variables may affect the estimation of upper critical temperatures. Therefore, based on our data, we offer suggestions to enhance the quality of measurements, and offer recommendations to authors aiming to compile and analyze databases from the literature. PMID:22384147
Measurements of Nucleation-Mode Particle Size Distributions in Aircraft Plumes during SULFUR 6

NASA Technical Reports Server (NTRS)

Brock, Charles A.; Bradford, Deborah G.

1999-01-01

This report summarizes the participation of the University of Denver in an airborne measurement program, SULFUR 6, which was undertaken in late September and early October of 1998 by the Deutsches Zentrum fur Luft und Raumfahrt (DLR). Scientific findings from two papers that have been published or accepted and from one manuscript that is in preparation are presented. The SULFUR 6 experiment was designed to investigate the emissions from subsonic aircraft to constrain calculations of possible atmospheric chemical and climatic effects. The University of Denver effort contributed toward the following SULFUR 6 goals: (1) To investigate the relationship between fuel sulfur content (FSC--mass of sulfur per mass of fuel) and particle number and mass emission index (El--quantity emitted per kg of fuel burned); (2) To provide upper and lower limits for the mass conversion efficiency (nu) of fuel sulfur to gaseous and particulate sulfuric acid; (3) To constrain models of volatile particle nucleation and growth by measuring the particle size distribution between 3 and 100 nm at aircraft plume ages ranging from 10(exp -1) to 10(exp 3) s; (4) To determine microphysical and optical properties and bulk chemical composition of soot particles in aircraft exhaust; and (5) To investigate the differences in particle properties between aircraft plumes in contrail and non-contrail situations. The experiment focused on emissions from the ATTAS research aircraft (a well characterized, but older technology turbojet) and from an in-service Boeing 737-300 aircraft provided by Lufthansa, with modem, high-bypass turbofan engines. Measurements were made from the DLR Dassault Falcon 900 aircraft, a modified business jet. The Atmospheric Effects of Aviation Program (AEAP) provided funding to operate an instrument, the nucleation-mode aerosol size spectrometer (N-MASS), during the SULFUR 6 campaign and to analyze the data. The N-MASS was developed at the University of Denver with the support of NOAA's Office of Global Programs and NASA's AEAP and measures particle size distributions in the 4-100 nm range.
Ethnopharmacological survey among migrants living in the Southeast Atlantic Forest of Diadema, São Paulo, Brazil

PubMed Central

2010-01-01

Background Understanding how people of diverse cultural backgrounds have traditionally used plants and animals as medicinal substances during displacements is one of the most important objectives of ethnopharmacological studies. An ethnopharmacological survey conducted among migrants living in the Southeast Atlantic Forest remnants (Diadema, São Paulo, Brazil) is presented herein. Methods Ethnographical methods were used to select and interview the migrants, and botanical and zoological techniques were employed to collect the indicated resources. Results We interviewed five migrants who described knowledge on 12 animals and 85 plants. Only 78 plants were present in Diadema, they belong to 37 taxonomic families; 68 were used exclusively for medicinal purposes, whereas 10 were reported to be toxic and/or presented some restriction of use. These taxa were grouped into 12 therapeutic categories (e.g., gastrointestinal disturbances, inflammatory processes or respiratory problems) based on the 41 individual complaints cited by the migrants. While the twelve animal species were used by the migrants to treat nine complaints; these were divided into six categories, the largest of which related to respiratory problems. None of the animal species and only 57 of the 78 plant species analysed in the present study were previously reported in the pharmacological literature; the popular knowledge concurred with academic findings for 30 of the plants. The seven plants [Impatiens hawkeri W. Bull., Artemisia canphorata Vill., Equisetum arvensis L., Senna pendula (Humb. & Bonpl. ex Willd.) H.S. Irwin & Barneby, Zea mays L., Fevillea passiflora Vell. and Croton fuscescens Spreng)] and the two animals (Atta sexdens and Periplaneta americana) that showed maintenance of use among migrants during their displacement in Brazilian territory, have not been studied by pharmacologists yet. Conclusions Thus, they should be highlighted and focused in further pharmacology and phytochemical studies, since the persistence of their uses can be indicative of bioactive potentials. PMID:21034478

Effects of IL-10 haplotype and atomic bomb radiation exposure on gastric cancer risk.

PubMed

Hayashi, Tomonori; Ito, Reiko; Cologne, John; Maki, Mayumi; Morishita, Yukari; Nagamura, Hiroko; Sasaki, Keiko; Hayashi, Ikue; Imai, Kazue; Yoshida, Kengo; Kajimura, Junko; Kyoizumi, Seishi; Kusunoki, Yoichiro; Ohishi, Waka; Fujiwara, Saeko; Akahoshi, Masazumi; Nakachi, Kei

2013-07-01

Gastric cancer (GC) is one of the cancers that reveal increased risk of mortality and incidence in atomic bomb survivors. The incidence of gastric cancer in the Life Span Study cohort of the Radiation Effects Research Foundation (RERF) increased with radiation dose (gender-averaged excess relative risk per Gy = 0.28) and remains high more than 65 years after exposure. To assess a possible role of gene-environment interaction, we examined the dose response for gastric cancer incidence based on immunosuppression-related IL-10 genotype, in a cohort study with 200 cancer cases (93 intestinal, 96 diffuse and 11 other types) among 4,690 atomic bomb survivors participating in an immunological substudy. Using a single haplotype block composed of four haplotype-tagging SNPs (comprising the major haplotype allele IL-10-ATTA and the minor haplotype allele IL-10-GGCG, which are categorized by IL-10 polymorphisms at -819A>G and -592T>G, +1177T>C and +1589A>G), multiplicative and additive models for joint effects of radiation and this IL-10 haplotyping were examined. The IL-10 minor haplotype allele(s) was a risk factor for intestinal type gastric cancer but not for diffuse type gastric cancer. Radiation was not associated with intestinal type gastric cancer. In diffuse type gastric cancer, the haplotype-specific excess relative risk (ERR) for radiation was statistically significant only in the major homozygote category of IL-10 (ERR = 0.46/Gy, P = 0.037), whereas estimated ERR for radiation with the minor IL-10 homozygotes was close to 0 and nonsignificant. Thus, the minor IL-10 haplotype might act to reduce the radiation related risk of diffuse-type gastric cancer. The results suggest that this IL-10 haplotyping might be involved in development of radiation-associated gastric cancer of the diffuse type, and that IL-10 haplotypes may explain individual differences in the radiation-related risk of gastric cancer. © 2013 by Radiation Research Society
Does the long-range transport of African mineral dust across the Atlantic enhance their hygroscopicity?

NASA Astrophysics Data System (ADS)

Denjean, Cyrielle; Caquineau, Sandrine; Desboeufs, Karine; Laurent, Benoit; Quiñones Rosado, Mariana; Vallejo, Pamela; Mayol-Bracero, Olga; Formenti, Paola

2015-04-01

Influence of mineral dust on radiation balance is largely dependent on their ability to interact with water. While fresh mineral dusts are highly hydrophobic, various transformation processes (coagulation, heterogeneous chemical reaction) can modify the dust physical and chemical properties during long-range transport, which, in turn, can change the dust hygroscopic properties. The model predictions of the radiative effect by mineral dust still suffer of the lack of certainty of dust hygroscopic properties, and their temporal evolution during long-range transport. We present the first direct surface measurements of the hygroscopicity of Saharan dust after long-range transport over the Atlantic Ocean, their relationship with chemical composition, their influence on particle size and shape and implications for optical properties. Particles were collected during the DUST Aging and TransporT from Africa to the Caribbean (Dust-AttaCk) campaign at the Cape San Juan Puerto Rico station in June-July 2012. Environmental scanning electron microscopy (ESEM) was used to analyze the size, shape, chemical composition and hygroscopic properties of individual particles. At different levels of concentrations in summertime, the coarse mode of atmospheric aerosols in Puerto Rico is dominated by Saharan mineral dust. Most of aged dust particles survived atmospheric transport intact with no observed internal mixture with other species and did not show hygroscopic growth up to 94% relative humidity. This is certainly due to the fact that in summertime dust is mostly transported above the marine boundary layer. A minor portion of mineral dust (approximately 19-28% by number) were involved in atmospheric heterogeneous reactions with acidic gases (likely SO2 and HCl) and sea salt aggregation. While sulfate- and chloride-coated dust remained extremely hydrophobic, dust particles in internal mixing with NaCl underwent profound changes in their hygroscopicity, therefore in size and shape. We show that this change in particles size has important implications for their ability to scatter and absorb light. This behavior is also important for cloud properties since the increase of particles size reduces the supersaturating required for cloud droplet activation.
The role of leaf cutter ants on soil organic carbon dynamics in a wet tropical forest

NASA Astrophysics Data System (ADS)

Schwendenmann, L.; Meredyth-Young, M.; Dierick, D.; Allen, M. F.; Harmon, T. C.; Oberbauer, S. F.; Rundel, P.; Trahan, N. A.; Zelikova, T. J.

2016-12-01

Tropical forest ecosystems play an important role in the global carbon (C) cycle. Neotropical forests are significantly influenced by leaf cutter ants (LCA) which are the most important herbivore in these systems. LCA cut fresh leaves and bring large amounts of plant biomass into their nests to grow their fungus gardens. The excavation and continual maintenance of their large nests modifies soil characteristics and biogeochemistry with direct and indirect impacts on soil organic carbon (SOC) dynamics. The aim of this study was to quantify the effects of LCA (Atta cephalotes) on soil C mineralization, carbon degrading enzymes (β-glucosidase and α-glucosidase), and labile soil C (hot water extractable carbon) across a 1 m soil depth profile and comparing between two different soils (residual and alluvial) and forest types (primary and secondary) in a wet tropical rainforest in Costa Rica. We hypothesized that C mineralization rates will be higher inside LCA nests due to continual input of fresh organic matter, as evidenced by higher microbial biomass and carbon degrading enzymes. Similarly, we expected more labile C inside nests. All soil C parameters were highly variable among sites and between nests and controls. Carbon mineralization rates ranged from 0.02 to 0.2 µmol C h-1 g soil-1 during the initial decay phase which lasted approximately 6 days during soil incubation. The highest respiration rates were measured in the top 20 cm of the primary forest residual soil. Contrary to our expectations, C mineralization rates were higher in control soils, where C degrading enzymes were in higher concentrations (around 250 µmol). The labile soil C concentrations were variable across sites (2-25 mg C g soil-1) and higher in the upper soil profiles, but no significant differences were found between controls and nests. Our results indicate greater heterogeneity inside the nests than previously expected. We explain our findings in terms of the removal of leaf and organic matter from the nest surface by LCA, which may have led to a reduction in available carbon substrate for microbial decomposition.
Cytogenetic data on six leafcutter ants of the genus Acromyrmex Mayr, 1865 (Hymenoptera, Formicidae, Myrmicinae): insights into chromosome evolution and taxonomic implications

PubMed Central

Barros, Luísa Antônia Campos; de Aguiar, Hilton Jeferson Alves Cardoso; Mariano, Cléa dos Santos Ferreira; Andrade-Souza, Vanderly; Costa, Marco Antonio; Delabie, Jacques Hubert Charles; Pompolo, Silvia das Graças

2016-01-01

Abstract Cytogenetic data for the genus Acromyrmex Mayr, 1865 are available, to date, for a few species from Brazil and Uruguay, which have uniform chromosome numbers (2n = 38). The recent cytogenetic data of Acromyrmex striatus (Roger, 1863), including its banding patterns, showed a distinct karyotype (2n = 22), similar to earlier studied Atta Fabricius, 1804 species. Karyological data are still scarce for the leafcutter ants and many gaps are still present for a proper understanding of this group. Therefore, this study aimed at increasing cytogenetic knowledge of the genus through the characterization of other six species: Acromyrmex balzani (Emery, 1890), Acromyrmex coronatus Fabricius, 1804, Acromyrmex disciger (Mayr, 1887), Acromyrmex echinatior (Forel, 1899), Acromyrmex niger (Smith, 1858) and Acromyrmex rugosus (Smith, 1858), all of which were collected in Minas Gerais – Brazil, except for Acromyrmex echinatior which was collected in Barro Colorado – Panama. The number and morphology of the chromosomes were studied and the following banding techniques were applied: C-banding, fluorochromes CMA3 and DAPI, as well as the detection of 45S rDNA using FISH technique. All the six species had the same chromosome number observed for already studied species, i.e. 2n = 38. Acromyrmex balzani had a different karyotype compared with other species mainly due to the first metacentric pair. The heterochromatin distribution also showed interspecific variation. Nevertheless, all the studied species had a pair of bands in the short arm of the first subtelocentric pair. The fluorochrome CMA3 visualized bands in the short arm of the first subtelocentric pair for all the six species, while Acromyrmex rugosus and Acromyrmex niger also demonstrated in the other chromosomes. The AT-rich regions with differential staining using DAPI were not observed. 45S ribosomal genes were identified by FISH in the short arm of the first subtelocentric pair in Acromyrmex coronatus, Acromyrmex disciger and Acromyrmex niger. The uniform chromosome number in the genus Acromyrmex (2n = 38) suggests that Acromyrmex striatus (2n = 22) should be transferred to a new genus. Other aspects of the chromosome evolution in ants are also discussed. PMID:27551345
Geochemical and isotopic determination of deep groundwater contributions and salinity to the shallow groundwater and surface water systems, Mesilla Basin, New Mexico, Texas, and Mexico

NASA Astrophysics Data System (ADS)

Robertson, A.; Carroll, K. C.; Kubicki, C.; Purtshert, R.

2017-12-01

The Mesilla Basin/Conejos-Médanos aquifer system, extending from southern New Mexico to Chihuahua, Mexico, is a priority transboundary aquifer under the 2006 United States-Mexico Transboundary Aquifer Assessment Act. Declining water levels, deteriorating water quality, and increasing groundwater use by municipal, industrial, and agricultural users on both sides of the international border raise concerns about long-term aquifer sustainability. Relative contributions of present-day and "paleo" recharge to sustainable fresh groundwater yields has not been determined and evidence suggests that a large source of salinity at the distal end of the Mesilla Basin is saline discharge from deep groundwater flow. The magnitude and distribution of those deep saline flow paths are not determined. The contribution of deep groundwater to discharge and salinity in the shallow groundwater and surface water of the Mesilla Basin will be determined by collecting discrete groundwater samples and analyzing for aqueous geochemical and isotopic tracers, as well as the radioisotopes of argon and krypton. Analytes include major ions, trace elements, the stable isotopes of water, strontium and boron isotopes, uranium isotopes, the carbon isotopes of dissolved inorganic carbon, noble gas concentrations and helium isotope ratios. Dissolved gases are extracted and captured from groundwater wells using membrane contactors in a process known as ultra-trace sampling. Gas samples are analyzed for radioisotope ratios of krypton by the ATTA method and argon by low-level counting. Effectiveness of the ultra-trace sampling device and method was evaluated by comparing results of tritium concentrations to the krypton-85 content. Good agreement between the analyses, especially in samples with undetectable tritium, indicates that the ultra-trace procedure is effective and confirms that introduction of atmospheric air has not occurred. The geochemistry data indicate a complex system of geochemical endmembers, and mixing between these endmembers. Ongoing work seeks to better constrain groundwater ages and mixing models through the coupled use of conventional aqueous geochemical and isotopic analysis and the ultra-trace constituents.
EDITORIAL: A support for prospective nanomaterials A support for prospective nanomaterials

NASA Astrophysics Data System (ADS)

Demming, Anna

2011-01-01

In the early 1990s, scanning probe microscopy was empowering researchers to view nanoscale features, previously the domain of imaginative theorists. Such images undoubtedly sparked the imagination and goaded researchers into ever more creative endeavours to understand nanoscale systems. At the same time, reports on molecular self-assembly were revolutionizing the philosophy behind how such systems could be produced, and promoting genuine bottom-up fabrication technology. The nanoworld was not only available to be gazed at and probed, but could be recreated by imposing the right conditions for the self assembly of complex and controlled structures. Many creative variants of self-assembly processes have been investigated. Researchers in Germany demonstrated that block copolymer micelle nanolithography could be used to generate nanostructured interfaces, where the pattern dimension and geometry is controlled by a combination of the self-assembly of block copolymer micelles with pre-structures formed by photo or electron-beam lithography [1]. The building blocks of life, DNA molecules, have also bred novel synthesis techniques as described in work by researchers in Finland, in a study of two different techniques of 'DNA origami' for the fabrication of complex protein structures [2]. Some fascinating properties have been revealed in self-assembled structures. Researchers in the US demonstrated extraordinary transmission in the infrared using self-assembled monolayers, phospholipid bilayers, and membrane-bound proteins on a subwavelength metallic array [3]. The surface plasmon properties of the arrays are accentuated by stacking them one upon the other, thus enabling extraordinary transmission and providing the basis of a nanospaced capacitive sensor. So-called nanoscaffolds have been used to promote assembly of biological matter in organized forms. A particularly inspiring application of nanoscaffolds has been found in nerve regeneration. Researchers in Singapore demonstrated the potential of biodegradable poly(L-lactide-co-glycolide) nanofibres to guide axon regeneration in vivo [4] and showed that aligned nanofibrous poly(l-lactic acid) scaffolds could be used as a potential cell carrier in neural tissue engineering [5]. In this issue, researchers in Italy demonstrate the use of magnetic bio-hybrid porous scaffolds for nucleating nano-apatite in situ on self-assembling collagen in the presence of magnetite nano-particles [6]. The magnetic nanoparticles provide a sort of crosslinking agent for the collagen, inducing a chemico-physical-mechanical stabilization of the material and allowing control of the porosity of the scaffold network. The work contributes towards developing assistance to bone regeneration guided by an external magnetic field. Another application of nanoscaffolds is in the development of hydrogen storage technology. Scaffolds can be used to help avoid aggregation of hydrogen storage nanoparticles and aid efficient cycling of storage and release [7, 8]. For more on hydrogen storage and other work on developing energy sources using nanotechnology, keep an eye out for our new Energy section to be launched this spring, 2011. The section will consider both the technological aspects and fundamental physics associated with innovations in the energy industry that exploit the properties of nanoscale structures. As we usher in the new year we can be sure that nanotechnology will remain a topic at the forefront of research agendas. There has been much hype over developments in nanotechnology over the years, and without a doubt the smart self-assembling of complex systems and materials has provoked awe of both a positive and negative nature in its time. Great progress has been made in advancing our control over promoting and guiding the self assembly of biological and industrial materials. The benefits available in applications of such research in medicine, renewable energy and many other industries are evident. Richard Feynman, often touted as a pioneer of a 'bottom-up' approach to nanotechnology, once said 'I was born not knowing and have had only a little time to change that here and there'. In a similar sense, what we do not yet know and understand about the ability to create and manipulate nanosystems is apparently infinite, but as can also be acceded in the case of Richard Feynman, the 'little' we have had time learn so far holds more than a little promise. References [1] Glass R, Möller M and Spatz J P 2003 Nanotechnology 14 314 [2] Kuzyk A, Laitinen K T and Törmä P 2009 Nanotechnology 20 235305 [3] Williams S M, Rodriguez K R, Teeters-Kennedy S, Shah S, Rogers T M, Stafford A D and Coe J V 2004 Nanotechnology 15 S495 [4] Bini T B, Gao S, Tan T C, Wang S, Lim, A, Hai L B and Ramakrishna S 2004 Nanotechnology 15 1459 [5] Yang F, Murugan R, Wang S and Ramakrishna S 2005 Biomaterials 26 2603-10 [6] Tampieri A, Landi E, Valentini F, Sandri M, D'Alessandro T, Dediu V and Marcacci M 2011 Nanotechnology 22 015104 [7] Gross A F, Ahn C C, Van Atta S L, Liu P and Vajo J J 2009 Nanotechnology 20 204005 [8] Zhang S, Gross A F, Van Atta S L, Lopez M, Liu P, Ahn C C, Vajo J J and Jensen C M 2009 Nanotechnology 20 204027
How can AN Approach to Steam BE Authentic to both Science and Art?

NASA Astrophysics Data System (ADS)

LaFayette, C. J.; Parke, Ph D., F. I.; Pierce, C.; Nakamura, T.

2015-12-01

A collaborative project engaged a team of geophysicists, engineers, entomologists, and artists to visualize tunnels and chambers of a vast, leafcutting ant colony in rural Texas. Part of the plan was to test the nature of significant outcomes in different domains and contexts. Our team used Ground Penetrating Radar to scan part of the nest, then translate the data into 3D geometry to be experienced on an immersive visualization system. This provided the ability to zoom out of and into the model. The tunnel fragment could appear like a tiny crumb floating in air, or one could move inside it to view details and tunnel architecture. Exterior and interior structure could thus be perceived in a seamless way. The system enabled a kinesthetic sense — one both saw and felt surrounded by the scene. This was the first time GPR had been used to map a living ant colony. Due to this project, entomologists have begun to use GPR with encouraging results. The Atta project inspired in us an enjoyment of experimentation and collaboration. Results were exhibited in international art venues, published in scientific journals, and demonstrated at hybrid venues for art and science. Each form of dissemination was suited to the host. Whether the result can be called art, science, or a blend is determined by its reception in a larger community. Like the species name and the pathway worn from tree to nest, the process of mapping the colony took the form of a palindrome: we pulled something out of the ground, passed it back and forth, and hoisted it out into the world. The role of art in collaboration with science can take many forms. Art can enhance science understanding for non-scientists. Artists and scientists can co-invent new tools for inquiry. Artists are adept at creating ways to experience and understand data or phenomena through multi-modal experiences, for example, aural, haptic, or olfactory. Artists are trained to foreground the process of making as part of the "performance"—"how" one approaches the question is as important as "what tools" one chooses. The end result is always mediated by those choices. The outcome of a work depends on "ways of knowing" inherent in any larger context. Creativity and innovation are not goals in themselves, but means to enable thriving and healthy communities and a sustainable planetary civilization.
Utility of EST-derived SSR in cultivated peanut (Arachis hypogaea L.) and Arachis wild species

PubMed Central

Liang, Xuanqiang; Chen, Xiaoping; Hong, Yanbin; Liu, Haiyan; Zhou, Guiyuan; Li, Shaoxiong; Guo, Baozhu

2009-01-01

Background Lack of sufficient molecular markers hinders current genetic research in peanuts (Arachis hypogaea L.). It is necessary to develop more molecular markers for potential use in peanut genetic research. With the development of peanut EST projects, a vast amount of available EST sequence data has been generated. These data offered an opportunity to identify SSR in ESTs by data mining. Results In this study, we investigated 24,238 ESTs for the identification and development of SSR markers. In total, 881 SSRs were identified from 780 SSR-containing unique ESTs. On an average, one SSR was found per 7.3 kb of EST sequence with tri-nucleotide motifs (63.9%) being the most abundant followed by di- (32.7%), tetra- (1.7%), hexa- (1.0%) and penta-nucleotide (0.7%) repeat types. The top six motifs included AG/TC (27.7%), AAG/TTC (17.4%), AAT/TTA (11.9%), ACC/TGG (7.72%), ACT/TGA (7.26%) and AT/TA (6.3%). Based on the 780 SSR-containing ESTs, a total of 290 primer pairs were successfully designed and used for validation of the amplification and assessment of the polymorphism among 22 genotypes of cultivated peanuts and 16 accessions of wild species. The results showed that 251 primer pairs yielded amplification products, of which 26 and 221 primer pairs exhibited polymorphism among the cultivated and wild species examined, respectively. Two to four alleles were found in cultivated peanuts, while 3–8 alleles presented in wild species. The apparent broad polymorphism was further confirmed by cloning and sequencing of amplified alleles. Sequence analysis of selected amplified alleles revealed that allelic diversity could be attributed mainly to differences in repeat type and length in the microsatellite regions. In addition, a few single base mutations were observed in the microsatellite flanking regions. Conclusion This study gives an insight into the frequency, type and distribution of peanut EST-SSRs and demonstrates successful development of EST-SSR markers in cultivated peanut. These EST-SSR markers could enrich the current resource of molecular markers for the peanut community and would be useful for qualitative and quantitative trait mapping, marker-assisted selection, and genetic diversity studies in cultivated peanut as well as related Arachis species. All of the 251 working primer pairs with names, motifs, repeat types, primer sequences, and alleles tested in cultivated and wild species are listed in Additional File 1. PMID:19309524
Investigation of Deep Ocean Circulation and Mixing Using Ar-39 (Invited)

NASA Astrophysics Data System (ADS)

Smethie, W. M.; Schlosser, P.

2013-12-01

Ar-39 is a radioactive noble gas that forms in the atmosphere by cosmic ray interaction with Ar-40. It has a half-life of 269 years and its production rate in the atmosphere has varied no more than 7% during the past 1000 years. It enters the surface ocean with an average equilibration time of about one month and thus the entire surface ocean, except for ice covered regions at high latitudes, is in quasi-equilibrium with the atmospheric Ar-39:Ar ratio. The well known input to the ocean, radioactive decay constant and chemical inertness make Ar-39 an ideal tracer of circulation and mixing in the deep ocean, where anthropogenic transient tracers such as CFCs and tritium have not yet penetrated. However, due to the difficult measurement, only about 125 oceanic Ar-39 samples have been measured to date. This was done by counting the decays of Ar-39 atoms and required a half liter of argon gas per sample, extracted from about 1500 liters of water. The 125 samples that have been measured provide a glimpse of the information that can be gained from Ar-39 observations. In the Pacific Ocean three vertical profiles show a decrease in Ar-39 from the surface mixed layer through the thermocline to a minimum at intermediate depths and an increase from there to the bottom. This reflects formation of bottom water around the Antarctic continent, spreading of this water northward and upwelling and mixing into intermediate depths. The lowest concentration was 6×4% modern which is equivalent to a 900-1600 year isolation time from the surface. In the Atlantic Ocean newly formed North Atlantic Deep Water has an Ar-39 concentration of about 85% modern compared to 55% modern for newly formed Antarctic Bottom Water and reach values as low as about 40% modern in the interior reflecting the more rapid ventilation of the deep Atlantic Ocean relative to the deep Pacific Ocean. In the Arctic Ocean the mean residence time of deep water in the Nansen, Amundsen and Makarov Basins based on Ar-39 are about 270, 190, and 330 years respectively. Radiocarbon also provides information on circulation and mixing in the deep ocean and thousands of measurements have been made. However, the distributions of Ar-39 and C-14 are different due to the large difference in their half-lives (269 years and 5730 years respectively). Measurement of both tracers provides information on the relative importance of advection and mixing in the deep ocean and provides more accurate transit times than can be obtained with only one of these tracers. In the Atlantic Ocean, where the deep water is roughly a two-end member mixture of northern component and southern component water, the age of the two components can be estimated from simultaneous measurement of Ar-39 and C-14. The few existing measurements suggest that the northern component water has an age range of 40-200 years and the southern component water a range of 60-600 years. Development of the ATTA method for measuring radioactive noble gases offers great potential to dramatically increase the number of samples that can be measured for Ar-39, which could greatly improve our understanding of mixing and circulation in the deep ocean.
A Process to Establish the Common Functions Performed by a Multi-Role Vessel

DTIC Science & Technology

2010-09-01

25 5.9 EPF – Environmental Protection Functions...Functions WFO Offshore Warfighting Functions EPF Environmental Protection Functions EPF .1 Waste Treatment Functions DSTO-TR-2473 16 HSF...Mission Command Function CFV Vessel Command Function EPF Environmental Protection Functions HSF Hotel Services Functions HVAC HVAC Functions
Alternative Proofs for Inequalities of Some Trigonometric Functions

ERIC Educational Resources Information Center

Guo, Bai-Ni; Qi, Feng

2008-01-01

By using an identity relating to Bernoulli's numbers and power series expansions of cotangent function and logarithms of functions involving sine function, cosine function and tangent function, four inequalities involving cotangent function, sine function, secant function and tangent function are established.
Building a reference functional model for EHR systems.

PubMed

Sumita, Yuki; Takata, Mami; Ishitsuka, Keiju; Tominaga, Yasuyuki; Ohe, Kazuhiko

2007-09-01

Our aim was to develop a reference functional model for electric health record systems (RFM). Such a RFM is built from functions using functional descriptive elements (FDEs) and represents the static relationships between them. This paper presents a new format for describing electric health record (EHR) system functions. Questionnaire and field interview survey was conducted in five hospitals in Japan and one in the USA, to collect data on EHR system functions. Based on survey results, a reference functional list (RFL) was created, in which each EHR system function was listed and divided into 13 FDE types. By analyzing the RFL, we built the meta-functional model and the functional model using UML class diagrams. The former defines language for expressing the functional model, while the latter represents functions, FDEs and their static relationships. A total of 385 functions were represented in the RFL. Six patterns were found for the relationships between functions. The meta-functional model was created as a new format for describing functions. Examples of the functional model, which included the six patterns in the relationships between functions and 11 verbs, were created. We present the meta-functional model, which is a new description format for the functional structure and relationships. Although a more detailed description is required to apply the RFM to the semiautomatic generation of functional specification documents, our RFM can visualize functional structures and functional relationships, classify functions using multiple axes and identify the similarities and differences between functions. The RFM will promote not only the standardization of EHR systems, but also communications between system developers and healthcare providers in the EHR system-design processes. 2006 Elsevier Ireland Ltd
Advances in the indirect, descriptive, and experimental approaches to the functional analysis of problem behavior.

PubMed

Wightman, Jade; Julio, Flávia; Virués-Ortega, Javier

2014-05-01

Experimental functional analysis is an assessment methodology to identify the environmental factors that maintain problem behavior in individuals with developmental disabilities and in other populations. Functional analysis provides the basis for the development of reinforcement-based approaches to treatment. This article reviews the procedures, validity, and clinical implementation of the methodological variations of functional analysis and function-based interventions. We present six variations of functional analysis methodology in addition to the typical functional analysis: brief functional analysis, single-function tests, latency-based functional analysis, functional analysis of precursors, and trial-based functional analysis. We also present the three general categories of function-based interventions: extinction, antecedent manipulation, and differential reinforcement. Functional analysis methodology is a valid and efficient approach to the assessment of problem behavior and the selection of treatment strategies.
Generalized Functions for the Fractional Calculus

NASA Technical Reports Server (NTRS)

Lorenzo, Carl F.; Hartley, Tom T.

1999-01-01

Previous papers have used two important functions for the solution of fractional order differential equations, the Mittag-Leffler functionE(sub q)[at(exp q)](1903a, 1903b, 1905), and the F-function F(sub q)[a,t] of Hartley & Lorenzo (1998). These functions provided direct solution and important understanding for the fundamental linear fractional order differential equation and for the related initial value problem (Hartley and Lorenzo, 1999). This paper examines related functions and their Laplace transforms. Presented for consideration are two generalized functions, the R-function and the G-function, useful in analysis and as a basis for computation in the fractional calculus. The R-function is unique in that it contains all of the derivatives and integrals of the F-function. The R-function also returns itself on qth order differ-integration. An example application of the R-function is provided. A further generalization of the R-function, called the G-function brings in the effects of repeated and partially repeated fractional poles.
The relationship of self-rated function and self-rated health to concurrent functional ability, functional decline, and mortality: findings from the Nun Study.

PubMed

Greiner, P A; Snowdon, D A; Greiner, L H

1996-09-01

We investigated the relationship of self-rated function (i.e., the ability to take care of oneself) and self-rated health to concurrent functional ability, functional decline, and mortality in participants in the Nun Study, a longitudinal study of aging and Alzheimer's disease. A total of 629 of the 678 study participants self-rated their function and health and completed an initial functional assessment in 1991-93. Survivors completed a second assessment in 1993-94. Overall, self-rated function had a stronger relationship to functional ability at the first assessment and to functional decline between the first and second assessments than did self-rated health. Self-rated function also had a stronger relationship to mortality than did self-rated health. Self-rated function may be a better marker of global function than is self-rated health and may be a useful addition to clinical assessment and scientific investigation of the relationships among function, health, and disease.
A Revelation: Quantum-Statistics and Classical-Statistics are Analytic-Geometry Conic-Sections and Numbers/Functions: Euler, Riemann, Bernoulli Generating-Functions: Conics to Numbers/Functions Deep Subtle Connections

NASA Astrophysics Data System (ADS)

Descartes, R.; Rota, G.-C.; Euler, L.; Bernoulli, J. D.; Siegel, Edward Carl-Ludwig

2011-03-01

Quantum-statistics Dichotomy: Fermi-Dirac(FDQS) Versus Bose-Einstein(BEQS), respectively with contact-repulsion/non-condensation(FDCR) versus attraction/ condensationBEC are manifestly-demonstrated by Taylor-expansion ONLY of their denominator exponential, identified BOTH as Descartes analytic-geometry conic-sections, FDQS as Elllipse (homotopy to rectangle FDQS distribution-function), VIA Maxwell-Boltzmann classical-statistics(MBCS) to Parabola MORPHISM, VS. BEQS to Hyperbola, Archimedes' HYPERBOLICITY INEVITABILITY, and as well generating-functions[Abramowitz-Stegun, Handbook Math.-Functions--p. 804!!!], respectively of Euler-numbers/functions, (via Riemann zeta-function(domination of quantum-statistics: [Pathria, Statistical-Mechanics; Huang, Statistical-Mechanics]) VS. Bernoulli-numbers/ functions. Much can be learned about statistical-physics from Euler-numbers/functions via Riemann zeta-function(s) VS. Bernoulli-numbers/functions [Conway-Guy, Book of Numbers] and about Euler-numbers/functions, via Riemann zeta-function(s) MORPHISM, VS. Bernoulli-numbers/ functions, visa versa!!! Ex.: Riemann-hypothesis PHYSICS proof PARTLY as BEQS BEC/BEA!!!
Effects of the application of ankle functional rehabilitation exercise on the ankle joint functional movement screen and isokinetic muscular function in patients with chronic ankle sprain.

PubMed

Ju, Sung-Bum; Park, Gi Duck

2017-02-01

[Purpose] This study was conducted to investigate the effects of ankle functional rehabilitation exercise on ankle joint functional movement screen results and isokinetic muscular function in patients with chronic ankle sprain patients. [Subjects and Methods] In this study, 16 patients with chronic ankle sprain were randomized to an ankle functional rehabilitation exercise group (n=8) and a control group (n=8). The ankle functional rehabilitation exercise centered on a proprioceptive sense exercise program, which was applied 12 times for 2 weeks. To verify changes after the application, ankle joint functional movement screen scores and isokinetic muscular function were measured and analyzed. [Results] The ankle functional rehabilitation exercise group showed significant improvements in all items of the ankle joint functional movement screen and in isokinetic muscular function after the exercise, whereas the control group showed no difference after the application. [Conclusion] The ankle functional rehabilitation exercise program can be effectively applied in patients with chronic ankle sprain for the improvement of ankle joint functional movement screen score and isokinetic muscular function.
Effects of the application of ankle functional rehabilitation exercise on the ankle joint functional movement screen and isokinetic muscular function in patients with chronic ankle sprain

PubMed Central

Ju, Sung-Bum; Park, Gi Duck

2017-01-01

[Purpose] This study was conducted to investigate the effects of ankle functional rehabilitation exercise on ankle joint functional movement screen results and isokinetic muscular function in patients with chronic ankle sprain patients. [Subjects and Methods] In this study, 16 patients with chronic ankle sprain were randomized to an ankle functional rehabilitation exercise group (n=8) and a control group (n=8). The ankle functional rehabilitation exercise centered on a proprioceptive sense exercise program, which was applied 12 times for 2 weeks. To verify changes after the application, ankle joint functional movement screen scores and isokinetic muscular function were measured and analyzed. [Results] The ankle functional rehabilitation exercise group showed significant improvements in all items of the ankle joint functional movement screen and in isokinetic muscular function after the exercise, whereas the control group showed no difference after the application. [Conclusion] The ankle functional rehabilitation exercise program can be effectively applied in patients with chronic ankle sprain for the improvement of ankle joint functional movement screen score and isokinetic muscular function. PMID:28265157
New multidimensional functional diversity indices for a multifaceted framework in functional ecology.

PubMed

Villéger, Sébastien; Mason, Norman W H; Mouillot, David

2008-08-01

Functional diversity is increasingly identified as an important driver of ecosystem functioning. Various indices have been proposed to measure the functional diversity of a community, but there is still no consensus on which are most suitable. Indeed, none of the existing indices meets all the criteria required for general use. The main criteria are that they must be designed to deal with several traits, take into account abundances, and measure all the facets of functional diversity. Here we propose three indices to quantify each facet of functional diversity for a community with species distributed in a multidimensional functional space: functional richness (volume of the functional space occupied by the community), functional evenness (regularity of the distribution of abundance in this volume), and functional divergence (divergence in the distribution of abundance in this volume). Functional richness is estimated using the existing convex hull volume index. The new functional evenness index is based on the minimum spanning tree which links all the species in the multidimensional functional space. Then this new index quantifies the regularity with which species abundances are distributed along the spanning tree. Functional divergence is measured using a novel index which quantifies how species diverge in their distances (weighted by their abundance) from the center of gravity in the functional space. We show that none of the indices meets all the criteria required for a functional diversity index, but instead we show that the set of three complementary indices meets these criteria. Through simulations of artificial data sets, we demonstrate that functional divergence and functional evenness are independent of species richness and that the three functional diversity indices are independent of each other. Overall, our study suggests that decomposition of functional diversity into its three primary components provides a meaningful framework for its quantification and for the classification of existing functional diversity indices. This decomposition has the potential to shed light on the role of biodiversity on ecosystem functioning and on the influence of biotic and abiotic filters on the structure of species communities. Finally, we propose a general framework for applying these three functional diversity indices.
Heuristic lipophilicity potential for computer-aided rational drug design: optimizations of screening functions and parameters.

PubMed

Du, Q; Mezey, P G

1998-09-01

In this research we test and compare three possible atom-based screening functions used in the heuristic molecular lipophilicity potential (HMLP). Screening function 1 is a power distance-dependent function, bi/[formula: see text] Ri-r [formula: see text] gamma, screening function 2 is an exponential distance-dependent function, bi exp(-[formula: see text] Ri-r [formula: see text]/d0), and screening function 3 is a weighted distance-dependent function, sign(bi) exp[-xi [formula: see text] Ri-r [formula: see text]/magnitude of bi)]. For every screening function, the parameters (gamma, d0, and xi) are optimized using 41 common organic molecules of 4 types of compounds: aliphatic alcohols, aliphatic carboxylic acids, aliphatic amines, and aliphatic alkanes. The results of calculations show that screening function 3 cannot give chemically reasonable results, however, both the power screening function and the exponential screening function give chemically satisfactory results. There are two notable differences between screening functions 1 and 2. First, the exponential screening function has larger values in the short distance than the power screening function, therefore more influence from the nearest neighbors is involved using screening function 2 than screening function 1. Second, the power screening function has larger values in the long distance than the exponential screening function, therefore screening function 1 is effected by atoms at long distance more than screening function 2. For screening function 1, the suitable range of parameter gamma is 1.0 < gamma < 3.0, gamma = 2.3 is recommended, and gamma = 2.0 is the nearest integral value. For screening function 2, the suitable range of parameter d0 is 1.5 < d0 < 3.0, and d0 = 2.0 is recommended. HMLP developed in this research provides a potential tool for computer-aided three-dimensional drug design.

On computing special functions in marine engineering

NASA Astrophysics Data System (ADS)

Constantinescu, E.; Bogdan, M.

2015-11-01

Important modeling applications in marine engineering conduct us to a special class of solutions for difficult differential equations with variable coefficients. In order to be able to solve and implement such models (in wave theory, in acoustics, in hydrodynamics, in electromagnetic waves, but also in many other engineering fields), it is necessary to compute so called special functions: Bessel functions, modified Bessel functions, spherical Bessel functions, Hankel functions. The aim of this paper is to develop numerical solutions in Matlab for the above mentioned special functions. Taking into account the main properties for Bessel and modified Bessel functions, we shortly present analytically solutions (where possible) in the form of series. Especially it is studied the behavior of these special functions using Matlab facilities: numerical solutions and plotting. Finally, it will be compared the behavior of the special functions and point out other directions for investigating properties of Bessel and spherical Bessel functions. The asymptotic forms of Bessel functions and modified Bessel functions allow determination of important properties of these functions. The modified Bessel functions tend to look more like decaying and growing exponentials.
A statistical mechanical approach to restricted integer partition functions

NASA Astrophysics Data System (ADS)

Zhou, Chi-Chun; Dai, Wu-Sheng

2018-05-01

The main aim of this paper is twofold: (1) suggesting a statistical mechanical approach to the calculation of the generating function of restricted integer partition functions which count the number of partitions—a way of writing an integer as a sum of other integers under certain restrictions. In this approach, the generating function of restricted integer partition functions is constructed from the canonical partition functions of various quantum gases. (2) Introducing a new type of restricted integer partition functions corresponding to general statistics which is a generalization of Gentile statistics in statistical mechanics; many kinds of restricted integer partition functions are special cases of this restricted integer partition function. Moreover, with statistical mechanics as a bridge, we reveal a mathematical fact: the generating function of restricted integer partition function is just the symmetric function which is a class of functions being invariant under the action of permutation groups. Using this approach, we provide some expressions of restricted integer partition functions as examples.
Functional CAR models for large spatially correlated functional datasets.

PubMed

Zhang, Lin; Baladandayuthapani, Veerabhadran; Zhu, Hongxiao; Baggerly, Keith A; Majewski, Tadeusz; Czerniak, Bogdan A; Morris, Jeffrey S

2016-01-01

We develop a functional conditional autoregressive (CAR) model for spatially correlated data for which functions are collected on areal units of a lattice. Our model performs functional response regression while accounting for spatial correlations with potentially nonseparable and nonstationary covariance structure, in both the space and functional domains. We show theoretically that our construction leads to a CAR model at each functional location, with spatial covariance parameters varying and borrowing strength across the functional domain. Using basis transformation strategies, the nonseparable spatial-functional model is computationally scalable to enormous functional datasets, generalizable to different basis functions, and can be used on functions defined on higher dimensional domains such as images. Through simulation studies, we demonstrate that accounting for the spatial correlation in our modeling leads to improved functional regression performance. Applied to a high-throughput spatially correlated copy number dataset, the model identifies genetic markers not identified by comparable methods that ignore spatial correlations.
R-Function Relationships for Application in the Fractional Calculus

NASA Technical Reports Server (NTRS)

Lorenzo, Carl F.; Hartley, Tom T.

2000-01-01

The F-function, and its generalization the R-function, are of fundamental importance in the fractional calculus. It has been shown that the solution of the fundamental linear fractional differential equation may be expressed in terms of these functions. These functions serve as generalizations of the exponential function in the solution of fractional differential equations. Because of this central role in the fractional calculus, this paper explores various intrarelationships of the R-function, which will be useful in further analysis. Relationships of the R-function to the common exponential function, e(t), and its fractional derivatives are shown. From the relationships developed, some important approximations are observed. Further, the inverse relationships of the exponential function, el, in terms of the R-function are developed. Also, some approximations for the R-function are developed.
R-function relationships for application in the fractional calculus.

PubMed

Lorenzo, Carl F; Hartley, Tom T

2008-01-01

The F-function, and its generalization the R-function, are of fundamental importance in the fractional calculus. It has been shown that the solution of the fundamental linear fractional differential equation may be expressed in terms of these functions. These functions serve as generalizations of the exponential function in the solution of fractional differential equations. Because of this central role in the fractional calculus, this paper explores various intrarelationships of the R-function, which will be useful in further analysis. Relationships of the R-function to the common exponential function, et, and its fractional derivatives are shown. From the relationships developed, some important approximations are observed. Further, the inverse relationships of the exponential function, et, in terms of the R-function are developed. Also, some approximations for the R-function are developed.
Development of the Functional Flow Block Diagram for the J-2X Rocket Engine System

NASA Technical Reports Server (NTRS)

White, Thomas; Stoller, Sandra L.; Greene, WIlliam D.; Christenson, Rick L.; Bowen, Barry C.

2007-01-01

The J-2X program calls for the upgrade of the Apollo-era Rocketdyne J-2 engine to higher power levels, using new materials and manufacturing techniques, and with more restrictive safety and reliability requirements than prior human-rated engines in NASA history. Such requirements demand a comprehensive systems engineering effort to ensure success. Pratt & Whitney Rocketdyne system engineers performed a functional analysis of the engine to establish the functional architecture. J-2X functions were captured in six major operational blocks. Each block was divided into sub-blocks or states. In each sub-block, functions necessary to perform each state were determined. A functional engine schematic consistent with the fidelity of the system model was defined for this analysis. The blocks, sub-blocks, and functions were sequentially numbered to differentiate the states in which the function were performed and to indicate the sequence of events. The Engine System was functionally partitioned, to provide separate and unique functional operators. Establishing unique functional operators as work output of the System Architecture process is novel in Liquid Propulsion Engine design. Each functional operator was described such that its unique functionality was identified. The decomposed functions were then allocated to the functional operators both of which were the inputs to the subsystem or component performance specifications. PWR also used a novel approach to identify and map the engine functional requirements to customer-specified functions. The final result was a comprehensive Functional Flow Block Diagram (FFBD) for the J-2X Engine System, decomposed to the component level and mapped to all functional requirements. This FFBD greatly facilitates component specification development, providing a well-defined trade space for functional trades at the subsystem and component level. It also provides a framework for function-based failure modes and effects analysis (FMEA), and a rigorous baseline for the functional architecture.
Tree species diversity promotes aboveground carbon storage through functional diversity and functional dominance.

PubMed

Mensah, Sylvanus; Veldtman, Ruan; Assogbadjo, Achille E; Glèlè Kakaï, Romain; Seifert, Thomas

2016-10-01

The relationship between biodiversity and ecosystem function has increasingly been debated as the cornerstone of the processes behind ecosystem services delivery. Experimental and natural field-based studies have come up with nonconsistent patterns of biodiversity-ecosystem function, supporting either niche complementarity or selection effects hypothesis. Here, we used aboveground carbon (AGC) storage as proxy for ecosystem function in a South African mistbelt forest, and analyzed its relationship with species diversity, through functional diversity and functional dominance. We hypothesized that (1) diversity influences AGC through functional diversity and functional dominance effects; and (2) effects of diversity on AGC would be greater for functional dominance than for functional diversity. Community weight mean (CWM) of functional traits (wood density, specific leaf area, and maximum plant height) were calculated to assess functional dominance (selection effects). As for functional diversity (complementarity effects), multitrait functional diversity indices were computed. The first hypothesis was tested using structural equation modeling. For the second hypothesis, effects of environmental variables such as slope and altitude were tested first, and separate linear mixed-effects models were fitted afterward for functional diversity, functional dominance, and both. Results showed that AGC varied significantly along the slope gradient, with lower values at steeper sites. Species diversity (richness) had positive relationship with AGC, even when slope effects were considered. As predicted, diversity effects on AGC were mediated through functional diversity and functional dominance, suggesting that both the niche complementarity and the selection effects are not exclusively affecting carbon storage. However, the effects were greater for functional diversity than for functional dominance. Furthermore, functional dominance effects were strongly transmitted by CWM of maximum plant height, reflecting the importance of forest vertical stratification for diversity-carbon relationship. We therefore argue for stronger complementary effects that would be induced also by complementary light-use efficiency of tree and species growing in the understory layer.
Cognitive Performance and Long-Term Social Functioning in Psychotic Disorder: A Three-Year Follow-Up Study

PubMed Central

Simons, Claudia J. P.; Bartels-Velthuis, Agna A.; Pijnenborg, Gerdina H. M.

2016-01-01

Objective Studies have linked cognitive functioning to everyday social functioning in psychotic disorders, but the nature of the relationships between cognition, social cognition, symptoms, and social functioning remains unestablished. Modelling the contributions of non-social and social cognitive ability in the prediction of social functioning may help in more clearly defining therapeutic targets to improve functioning. Method In a sample of 745 patients with a non-affective psychotic disorder, the associations between cognition and social cognition at baseline on the one hand, and self-reported social functioning three years later on the other, were analysed. First, case-control comparisons were conducted; associations were subsequently further explored in patients, investigating the potential mediating role of symptoms. Analyses were repeated in a subsample of 233 patients with recent-onset psychosis. Results Information processing speed and immediate verbal memory were stronger associated with social functioning in patients than in healthy controls. Most cognition variables significantly predicted social functioning at follow-up, whereas social cognition was not associated with social functioning. Symptoms were robustly associated with follow-up social functioning, with negative symptoms fully mediating most associations between cognition and follow-up social functioning. Illness duration did not moderate the strength of the association between cognitive functioning and follow-up social functioning. No associations were found between (social) cognition and follow-up social functioning in patients with recent-onset psychosis. Conclusions Although cognitive functioning is associated with later social functioning in psychotic disorder, its role in explaining social functioning outcome above negative symptoms appears only modest. In recent-onset psychosis, cognition may have a negligible role in predicting later social functioning. Moreover, social cognition tasks may not predict self-reported social functioning. PMID:27082629
Assessing the relationships between phylogenetic and functional singularities in sharks (Chondrichthyes).

PubMed

Cachera, Marie; Le Loc'h, François

2017-08-01

The relationships between diversity and ecosystem functioning have become a major focus of science. A crucial issue is to estimate functional diversity, as it is intended to impact ecosystem dynamics and stability. However, depending on the ecosystem, it may be challenging or even impossible to directly measure ecological functions and thus functional diversity. Phylogenetic diversity was recently under consideration as a proxy for functional diversity. Phylogenetic diversity is indeed supposed to match functional diversity if functions are conservative traits along evolution. However, in case of adaptive radiation and/or evolutive convergence, a mismatch may appear between species phylogenetic and functional singularities. Using highly threatened taxa, sharks, this study aimed to explore the relationships between phylogenetic and functional diversities and singularities. Different statistical computations were used in order to test both methodological issue (phylogenetic reconstruction) and overall a theoretical questioning: the predictive power of phylogeny for function diversity. Despite these several methodological approaches, a mismatch between phylogeny and function was highlighted. This mismatch revealed that (i) functions are apparently nonconservative in shark species, and (ii) phylogenetic singularity is not a proxy for functional singularity. Functions appeared to be not conservative along the evolution of sharks, raising the conservational challenge to identify and protect both phylogenetic and functional singular species. Facing the current rate of species loss, it is indeed of major importance to target phylogenetically singular species to protect genetic diversity and also functionally singular species in order to maintain particular functions within ecosystem.
Heuristic lipophilicity potential for computer-aided rational drug design: Optimizations of screening functions and parameters

NASA Astrophysics Data System (ADS)

Du, Qishi; Mezey, Paul G.

1998-09-01

In this research we test and compare three possible atom-basedscreening functions used in the heuristic molecular lipophilicity potential(HMLP). Screening function 1 is a power distance-dependent function, b_{{i}} /| {R_{{i}}- r} |^γ, screening function 2is an exponential distance-dependent function, biexp(-| {R_i- r} |/d_0 , and screening function 3 is aweighted distance-dependent function, {{sign}}( {b_i } ){{exp}}ξ ( {| {R_i- r} |/| {b_i } |} )For every screening function, the parameters (γ ,d0, and ξ are optimized using 41 common organic molecules of 4 types of compounds:aliphatic alcohols, aliphatic carboxylic acids, aliphatic amines, andaliphatic alkanes. The results of calculations show that screening function3 cannot give chemically reasonable results, however, both the powerscreening function and the exponential screening function give chemicallysatisfactory results. There are two notable differences between screeningfunctions 1 and 2. First, the exponential screening function has largervalues in the short distance than the power screening function, thereforemore influence from the nearest neighbors is involved using screeningfunction 2 than screening function 1. Second, the power screening functionhas larger values in the long distance than the exponential screeningfunction, therefore screening function 1 is effected by atoms at longdistance more than screening function 2. For screening function 1, thesuitable range of parameter d0 is 1.5 < d0 < 3.0, and d0 = 2.0 is recommended. HMLP developed in this researchprovides a potential tool for computer-aided three-dimensional drugdesign.
Functional Relationships for Investigating Cognitive Processes

PubMed Central

Wright, Anthony A.

2013-01-01

Functional relationships (from systematic manipulation of critical variables) are advocated for revealing fundamental processes of (comparative) cognition—through examples from my work in psychophysics, learning, and memory. Functional relationships for pigeon wavelength (hue) discrimination revealed best discrimination at the spectral points of hue transition for pigeons—a correspondence (i.e., functional relationship) similar to that for humans. Functional relationships for learning revealed: Item-specific or relational learning in matching to sample as a function of the pigeons’ sample-response requirement, and same/different abstract-concept learning as a function of the training set size for rhesus monkeys, capuchin monkeys, and pigeons. Functional relationships for visual memory revealed serial position functions (a 1st order functional relationship) that changed systematically with retention delay (a 2nd order relationship) for pigeons, capuchin monkeys, rhesus monkeys, and humans. Functional relationships for rhesus-monkey auditory memory also revealed systematic changes in serial position functions with delay, but these changes were opposite to those for visual memory. Functional relationships for proactive interference revealed interference that varied as a function of a ratio of delay times. Functional relationships for change detection memory revealed (qualitative) similarities and (quantitative) differences in human and monkey visual short term memory as a function of the number of memory items. It is concluded that these findings were made possible by varying critical variables over a substantial portion of the manipulable range to generate functions and derive relationships. PMID:23174335
Brain Connectivity and Functional Recovery in Patients With Ischemic Stroke.

PubMed

Almeida, Sara Regina Meira; Vicentini, Jessica; Bonilha, Leonardo; De Campos, Brunno M; Casseb, Raphael F; Min, Li Li

2017-01-01

Brain mapping studies have demonstrated that functional poststroke brain reorganization is associated with recovery of motor function. Nonetheless, the specific mechanisms associated with functional reorganization leading to motor recovery are still partly unknown. In this study, we performed a cross-sectional evaluation of poststroke subjects with the following goals: (1) To assess intra- and interhemispheric functional brain activation patterns associated with motor function in poststroke patients with variable degrees of recovery; (2) to investigate the involvement of other nonmotor functional networks in relationship with recovery. We studied 59 individuals: 13 patients with function Rankin > 1 and Barthel < 100; 19 patients with preserved function with Rankin 0-1 and Barthel = 100; and 27 healthy controls. All subjects underwent structural and functional magnetic resonance imaging (3T Philips Achieva, Holland) using the same protocol (TR = 2 seconds, TE = 30 ms, FOV = 240 × 240 × 117, slice = 39). Resting state functional connectivity was used by in-house software, based on SPM12. Among patients with and without preserved function, the functional connectivity between the primary motor region (M1) and the contralateral hemisphere was increased compared with controls. Nonetheless, only patients with decreased function exhibited decreased functional connectivity between executive control, sensorimotor and visuospatial networks. Functional recovery after stroke is associated with preserved functional connectivity of motor to nonmotor networks. Copyright © 2016 by the American Society of Neuroimaging.
Functional chest pain responds to biofeedback treatment but functional heartburn does not: what is the difference?

PubMed

Shapiro, Michael; Shanani, Ram; Taback, Hanna; Abramowich, Dov; Scapa, Eitan; Broide, Efrat

2012-06-01

Patients with functional esophageal disorders represent a challenging treatment group. The purpose of this study was to evaluate the role of biofeedback in the treatment of patients with functional esophageal disorders. In this prospective study, patients with typical/atypical symptoms of gastroesophageal reflux disease underwent upper endoscopy and 24-h pH monitoring. All patients filled out gastroesophageal Reflux Disease Symptom, Hospital Anxiety and Depression, and Symptom Stress Rating questionnaires. Patients with functional heartburn and those with functional chest pain were offered biofeedback treatment. A global assessment questionnaire was filled out at the end of treatment and then 2.8 (range 1-4) years later. From January 2006 to December 2009, 22 patients with functional esophageal diseases were included in the study. Thirteen had functional heartburn and nine had functional chest pain. Six patients from each group received biofeedback treatment. After treatment for 1-4 years, patients with functional chest pain showed significant improvements in symptoms compared with those who were not treated. Patients with functional heartburn showed no improvement. Patients with functional chest pain had a longer time of esophageal acid exposure than those with functional heartburn. Patients with functional chest pain have different central and intraesophageal factors associated with symptom generation in comparison with patients with functional heartburn. Biofeedback is a useful tool in the treatment of patients with functional chest pain, but not for those with functional heartburn.
Concomitant prediction of function and fold at the domain level with GO-based profiles.

PubMed

Lopez, Daniel; Pazos, Florencio

2013-01-01

Predicting the function of newly sequenced proteins is crucial due to the pace at which these raw sequences are being obtained. Almost all resources for predicting protein function assign functional terms to whole chains, and do not distinguish which particular domain is responsible for the allocated function. This is not a limitation of the methodologies themselves but it is due to the fact that in the databases of functional annotations these methods use for transferring functional terms to new proteins, these annotations are done on a whole-chain basis. Nevertheless, domains are the basic evolutionary and often functional units of proteins. In many cases, the domains of a protein chain have distinct molecular functions, independent from each other. For that reason resources with functional annotations at the domain level, as well as methodologies for predicting function for individual domains adapted to these resources are required.We present a methodology for predicting the molecular function of individual domains, based on a previously developed database of functional annotations at the domain level. The approach, which we show outperforms a standard method based on sequence searches in assigning function, concomitantly predicts the structural fold of the domains and can give hints on the functionally important residues associated to the predicted function.
Ecosystem Functions across Trophic Levels Are Linked to Functional and Phylogenetic Diversity

PubMed Central

Thompson, Patrick L.; Davies, T. Jonathan; Gonzalez, Andrew

2015-01-01

In experimental systems, it has been shown that biodiversity indices based on traits or phylogeny can outperform species richness as predictors of plant ecosystem function. However, it is unclear whether this pattern extends to the function of food webs in natural ecosystems. Here we tested whether zooplankton functional and phylogenetic diversity explains the functioning of 23 natural pond communities. We used two measures of ecosystem function: (1) zooplankton community biomass and (2) phytoplankton abundance (Chl a). We tested for diversity-ecosystem function relationships within and across trophic levels. We found a strong correlation between zooplankton diversity and ecosystem function, whereas local environmental conditions were less important. Further, the positive diversity-ecosystem function relationships were more pronounced for measures of functional and phylogenetic diversity than for species richness. Zooplankton and phytoplankton biomass were best predicted by different indices, suggesting that the two functions are dependent upon different aspects of diversity. Zooplankton community biomass was best predicted by zooplankton trait-based functional richness, while phytoplankton abundance was best predicted by zooplankton phylogenetic diversity. Our results suggest that the positive relationship between diversity and ecosystem function can extend across trophic levels in natural environments, and that greater insight into variation in ecosystem function can be gained by combining functional and phylogenetic diversity measures. PMID:25693188
Relationship between cardiac autonomic function and cognitive function in Alzheimer's disease.

PubMed

Nonogaki, Zen; Umegaki, Hiroyuki; Makino, Taeko; Suzuki, Yusuke; Kuzuya, Masafumi

2017-01-01

Alzheimer's disease (AD) affects many central nervous structures and neurotransmitter systems. These changes affect not only cognitive function, but also cardiac autonomic function. However, the functional relationship between cardiac autonomic function and cognition in AD has not yet been investigated. The objective of the present study was to evaluate the association between cardiac autonomic function measured by heart rate variability and cognitive function in AD. A total of 78 AD patients were recruited for this study. Cardiac autonomic function was evaluated using heart rate variability analysis. Multiple linear regression analysis was used to model the association between heart rate variability and cognitive function (global cognitive function, memory, executive function and processing speed), after adjustment for covariates. Global cognitive function was negatively associated with sympathetic modulation (low-to-high frequency power ratio). Memory performance was positively associated with parasympathetic modulation (high frequency power) and negatively associated with sympathetic modulation (low-to-high frequency power ratio). These associations were independent of age, sex, educational years, diabetes, hypertension and cholinesterase inhibitor use. Cognitive function, especially in the areas of memory, is associated with cardiac autonomic function in AD. Specifically, lower cognitive performance was found to be associated with significantly higher cardiac sympathetic and lower parasympathetic function in AD. Geriatr Gerontol Int 2017; 17: 92-98. © 2015 Japan Geriatrics Society.
Combining Density Functional Theory and Green's Function Theory: Range-Separated, Nonlocal, Dynamic, and Orbital-Dependent Hybrid Functional.

PubMed

Kananenka, Alexei A; Zgid, Dominika

2017-11-14

We present a rigorous framework which combines single-particle Green's function theory with density functional theory based on a separation of electron-electron interactions into short- and long-range components. Short-range contribution to the total energy and exchange-correlation potential is provided by a density functional approximation, while the long-range contribution is calculated using an explicit many-body Green's function method. Such a hybrid results in a nonlocal, dynamic, and orbital-dependent exchange-correlation functional of a single-particle Green's function. In particular, we present a range-separated hybrid functional called srSVWN5-lrGF2 which combines the local-density approximation and the second-order Green's function theory. We illustrate that similarly to density functional approximations, the new functional is weakly basis-set dependent. Furthermore, it offers an improved description of the short-range dynamic correlation. The many-body contribution to the functional mitigates the many-electron self-interaction error present in many density functional approximations and provides a better description of molecular properties. Additionally, we illustrate that the new functional can be used to scale down the self-energy and, therefore, introduce an additional sparsity to the self-energy matrix that in the future can be exploited in calculations for large molecules or periodic systems.
Ecosystem functions across trophic levels are linked to functional and phylogenetic diversity.

PubMed

Thompson, Patrick L; Davies, T Jonathan; Gonzalez, Andrew

2015-01-01

In experimental systems, it has been shown that biodiversity indices based on traits or phylogeny can outperform species richness as predictors of plant ecosystem function. However, it is unclear whether this pattern extends to the function of food webs in natural ecosystems. Here we tested whether zooplankton functional and phylogenetic diversity explains the functioning of 23 natural pond communities. We used two measures of ecosystem function: (1) zooplankton community biomass and (2) phytoplankton abundance (Chl a). We tested for diversity-ecosystem function relationships within and across trophic levels. We found a strong correlation between zooplankton diversity and ecosystem function, whereas local environmental conditions were less important. Further, the positive diversity-ecosystem function relationships were more pronounced for measures of functional and phylogenetic diversity than for species richness. Zooplankton and phytoplankton biomass were best predicted by different indices, suggesting that the two functions are dependent upon different aspects of diversity. Zooplankton community biomass was best predicted by zooplankton trait-based functional richness, while phytoplankton abundance was best predicted by zooplankton phylogenetic diversity. Our results suggest that the positive relationship between diversity and ecosystem function can extend across trophic levels in natural environments, and that greater insight into variation in ecosystem function can be gained by combining functional and phylogenetic diversity measures.
Restoring function in major depressive disorder: A systematic review.

PubMed

Sheehan, David V; Nakagome, Kazuyuki; Asami, Yuko; Pappadopulos, Elizabeth A; Boucher, Matthieu

2017-06-01

Functional impairment contributes to significant disability and economic burden in major depressive disorder (MDD). Treatment response is measured by improvement in depressive symptoms, but functional improvement often lags behind symptomatic improvement. Residual deficits are associated with relapse of depressive symptoms. A literature search was conducted using the following terms: "major depressive disorder," "functional impairment," "functional outcomes," "recovery of function," "treatment outcome," "outcome assessment," "social functioning," "presenteeism," "absenteeism," "psychiatric status rating scales," and "quality of life." Search limits included publication date (January 1, 1995 to August 31, 2016), English language, and human clinical trials. Controlled, acute-phase, nonrecurrent MDD treatment studies in adults were included if a functional outcome was measured at baseline and endpoint. The qualitative analysis included 35 controlled studies. The Sheehan Disability Scale was the most commonly used functional assessment. Antidepressant treatments significantly improved functional outcomes. Early treatment response predicted functional improvement, while baseline disease severity did not. Clinical studies utilized various methodologies and assessments for functional impairment, and were not standardized or adequately powered. The lack of synchronicity between symptomatic and functional improvement highlights an unmet need for MDD. Treatment guided by routine monitoring of symptoms and functionality may minimize residual functional impairments. Copyright © 2017. Published by Elsevier B.V.
42 CFR 476.86 - Correlation of Title XI functions with Title XVIII functions.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 42 Public Health 4 2011-10-01 2011-10-01 false Correlation of Title XI functions with Title XVIII functions. 476.86 Section 476.86 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF...) Qio Review Functions § 476.86 Correlation of Title XI functions with Title XVIII functions. (a...

Automated prediction of protein function and detection of functional sites from structure.

PubMed

Pazos, Florencio; Sternberg, Michael J E

2004-10-12

Current structural genomics projects are yielding structures for proteins whose functions are unknown. Accordingly, there is a pressing requirement for computational methods for function prediction. Here we present PHUNCTIONER, an automatic method for structure-based function prediction using automatically extracted functional sites (residues associated to functions). The method relates proteins with the same function through structural alignments and extracts 3D profiles of conserved residues. Functional features to train the method are extracted from the Gene Ontology (GO) database. The method extracts these features from the entire GO hierarchy and hence is applicable across the whole range of function specificity. 3D profiles associated with 121 GO annotations were extracted. We tested the power of the method both for the prediction of function and for the extraction of functional sites. The success of function prediction by our method was compared with the standard homology-based method. In the zone of low sequence similarity (approximately 15%), our method assigns the correct GO annotation in 90% of the protein structures considered, approximately 20% higher than inheritance of function from the closest homologue.
Exploring the evolution of protein function in Archaea.

PubMed

Goncearenco, Alexander; Berezovsky, Igor N

2012-05-30

Despite recent progress in studies of the evolution of protein function, the questions what were the first functional protein domains and what were their basic building blocks remain unresolved. Previously, we introduced the concept of elementary functional loops (EFLs), which are the functional units of enzymes that provide elementary reactions in biochemical transformations. They are presumably descendants of primordial catalytic peptides. We analyzed distant evolutionary connections between protein functions in Archaea based on the EFLs comprising them. We show examples of the involvement of EFLs in new functional domains, as well as reutilization of EFLs and functional domains in building multidomain structures and protein complexes. Our analysis of the archaeal superkingdom yields the dominating mechanisms in different periods of protein evolution, which resulted in several levels of the organization of biochemical function. First, functional domains emerged as combinations of prebiotic peptides with the very basic functions, such as nucleotide/phosphate and metal cofactor binding. Second, domain recombination brought to the evolutionary scene the multidomain proteins and complexes. Later, reutilization and de novo design of functional domains and elementary functional loops complemented evolution of protein function.
The relationship between motor function, cognition, independence and quality of life in myelomeningocele patients.

PubMed

Luz, Carolina Lundberg; Moura, Maria Clara Drummond Soares de; Becker, Karine Kyomi; Teixeira, Rosani Aparecida Antunes; Voos, Mariana Callil; Hasue, Renata Hydee

2017-08-01

Motor function, cognition, functional independence and quality of life have been described in myelomeningocele patients, but no study has investigated their relationships. We aimed to investigate the relationships between motor function, cognition, functional independence, quality of life, age, and lesion level in myelomeningocele patients, and investigate the influence of hydrocephalus on these variables. We assessed 47 patients with the Gross Motor Function Measure (motor function), Raven's Colored Progressive Matrices (cognition), Pediatric Evaluation of Disability Inventory (functional independence) and the Autoquestionnaire Qualité de vie Enfant Imagé (quality of life). Spearman's correlation tests determined relationships between the variables. The Friedman ANOVAs determined the influence of hydrocephalus. Motor function was strongly related to mobility and lesion level, and moderately related to cognition, self-care and social function. Cognition and quality of life were moderately related to functional independence. Age correlated moderately with functional independence and quality of life. Hydrocephalus resulted in poorer motor/cognitive outcomes and lower functional independence.
Self-Interaction Error in Density Functional Theory: An Appraisal.

PubMed

Bao, Junwei Lucas; Gagliardi, Laura; Truhlar, Donald G

2018-05-03

Self-interaction error (SIE) is considered to be one of the major sources of error in most approximate exchange-correlation functionals for Kohn-Sham density-functional theory (KS-DFT), and it is large with all local exchange-correlation functionals and with some hybrid functionals. In this work, we consider systems conventionally considered to be dominated by SIE. For these systems, we demonstrate that by using multiconfiguration pair-density functional theory (MC-PDFT), the error of a translated local density-functional approximation is significantly reduced (by a factor of 3) when using an MCSCF density and on-top density, as compared to using KS-DFT with the parent functional; the error in MC-PDFT with local on-top functionals is even lower than the error in some popular KS-DFT hybrid functionals. Density-functional theory, either in MC-PDFT form with local on-top functionals or in KS-DFT form with some functionals having 50% or more nonlocal exchange, has smaller errors for SIE-prone systems than does CASSCF, which has no SIE.
Distance-Based Functional Diversity Measures and Their Decomposition: A Framework Based on Hill Numbers

PubMed Central

Chiu, Chun-Huo; Chao, Anne

2014-01-01

Hill numbers (or the “effective number of species”) are increasingly used to characterize species diversity of an assemblage. This work extends Hill numbers to incorporate species pairwise functional distances calculated from species traits. We derive a parametric class of functional Hill numbers, which quantify “the effective number of equally abundant and (functionally) equally distinct species” in an assemblage. We also propose a class of mean functional diversity (per species), which quantifies the effective sum of functional distances between a fixed species to all other species. The product of the functional Hill number and the mean functional diversity thus quantifies the (total) functional diversity, i.e., the effective total distance between species of the assemblage. The three measures (functional Hill numbers, mean functional diversity and total functional diversity) quantify different aspects of species trait space, and all are based on species abundance and species pairwise functional distances. When all species are equally distinct, our functional Hill numbers reduce to ordinary Hill numbers. When species abundances are not considered or species are equally abundant, our total functional diversity reduces to the sum of all pairwise distances between species of an assemblage. The functional Hill numbers and the mean functional diversity both satisfy a replication principle, implying the total functional diversity satisfies a quadratic replication principle. When there are multiple assemblages defined by the investigator, each of the three measures of the pooled assemblage (gamma) can be multiplicatively decomposed into alpha and beta components, and the two components are independent. The resulting beta component measures pure functional differentiation among assemblages and can be further transformed to obtain several classes of normalized functional similarity (or differentiation) measures, including N-assemblage functional generalizations of the classic Jaccard, Sørensen, Horn and Morisita-Horn similarity indices. The proposed measures are applied to artificial and real data for illustration. PMID:25000299
Distance-based functional diversity measures and their decomposition: a framework based on Hill numbers.

PubMed

Chiu, Chun-Huo; Chao, Anne

2014-01-01

Hill numbers (or the "effective number of species") are increasingly used to characterize species diversity of an assemblage. This work extends Hill numbers to incorporate species pairwise functional distances calculated from species traits. We derive a parametric class of functional Hill numbers, which quantify "the effective number of equally abundant and (functionally) equally distinct species" in an assemblage. We also propose a class of mean functional diversity (per species), which quantifies the effective sum of functional distances between a fixed species to all other species. The product of the functional Hill number and the mean functional diversity thus quantifies the (total) functional diversity, i.e., the effective total distance between species of the assemblage. The three measures (functional Hill numbers, mean functional diversity and total functional diversity) quantify different aspects of species trait space, and all are based on species abundance and species pairwise functional distances. When all species are equally distinct, our functional Hill numbers reduce to ordinary Hill numbers. When species abundances are not considered or species are equally abundant, our total functional diversity reduces to the sum of all pairwise distances between species of an assemblage. The functional Hill numbers and the mean functional diversity both satisfy a replication principle, implying the total functional diversity satisfies a quadratic replication principle. When there are multiple assemblages defined by the investigator, each of the three measures of the pooled assemblage (gamma) can be multiplicatively decomposed into alpha and beta components, and the two components are independent. The resulting beta component measures pure functional differentiation among assemblages and can be further transformed to obtain several classes of normalized functional similarity (or differentiation) measures, including N-assemblage functional generalizations of the classic Jaccard, Sørensen, Horn and Morisita-Horn similarity indices. The proposed measures are applied to artificial and real data for illustration.
Changes in Bird Functional Diversity across Multiple Land Uses: Interpretations of Functional Redundancy Depend on Functional Group Identity

PubMed Central

Luck, Gary W.; Carter, Andrew; Smallbone, Lisa

2013-01-01

Examinations of the impact of land-use change on functional diversity link changes in ecological community structure driven by land modification with the consequences for ecosystem function. Yet, most studies have been small-scale, experimental analyses and primarily focussed on plants. There is a lack of research on fauna communities and at large-scales across multiple land uses. We assessed changes in the functional diversity of bird communities across 24 land uses aligned along an intensification gradient. We tested the hypothesis that functional diversity is higher in less intensively used landscapes, documented changes in diversity using four diversity metrics, and examined how functional diversity varied with species richness to identify levels of functional redundancy. Functional diversity, measured using a dendogram-based metric, increased from high to low intensity land uses, but observed values did not differ significantly from randomly-generated expected values. Values for functional evenness and functional divergence did not vary consistently with land-use intensification, although higher than expected values were mostly recorded in high intensity land uses. A total of 16 land uses had lower than expected values for functional dispersion and these were mostly low intensity native vegetation sites. Relations between functional diversity and bird species richness yielded strikingly different patterns for the entire bird community vs. particular functional groups. For all birds and insectivores, functional evenness, divergence and dispersion showed a linear decline with increasing species richness suggesting substantial functional redundancy across communities. However, for nectarivores, frugivores and carnivores, there was a significant hump-shaped or non-significant positive linear relationship between these functional measures and species richness indicating less redundancy. Hump-shaped relationships signify that the most functionally diverse communities occur at intermediate levels of species richness. Interpretations of redundancy thus vary for different functional groups and related ecosystem functions (e.g. pollination), and can be substantially different to relationships involving entire ecological communities. PMID:23696844
A Study of the Thermal Environment Developed by a Traveling Slipper at High Velocity

DTIC Science & Technology

2013-03-01

Power Partition Function The next partition function takes the same formulation as the powered function but now the exponent is squared. The...function and note the squared term in the exponent . 66 Equation 4.27 (4.36) Thus far the three partition functions each give a predicted...hypothesized that the function would fall somewhere between the first exponential decay function and the power function. However, by squaring the exponent
Identity effects dominate the impacts of multiple species extinctions on the functioning of complex food webs.

PubMed

Harvey, Eric; Séguin, Annie; Nozais, Christian; Archambault, Philippe; Gravel, Dominique

2013-01-01

Understanding the impacts of species extinctions on the functioning of food webs is a challenging task because of the complexity of ecological interactions. We report the impacts of experimental species extinctions on the functioning of two food webs of freshwater and marine systems. We used a linear model to partition the variance among the multiple components of the diversity effect (linear group richness, nonlinear group richness, and identity). The identity of each functional group was the best explaining variable of ecosystem functioning for both systems. We assessed the contribution of each functional group in multifunctional space and found that, although the effect of functional group varied across ecosystem functions, some functional groups shared common effects on functions. This study is the first experimental demonstration that functional identity dominates the effects of extinctions on ecosystem functioning, suggesting that generalizations are possible despite the inherent complexity of interactions.
Nonlocal kinetic energy functionals by functional integration.

PubMed

Mi, Wenhui; Genova, Alessandro; Pavanello, Michele

2018-05-14

Since the seminal studies of Thomas and Fermi, researchers in the Density-Functional Theory (DFT) community are searching for accurate electron density functionals. Arguably, the toughest functional to approximate is the noninteracting kinetic energy, T s [ρ], the subject of this work. The typical paradigm is to first approximate the energy functional and then take its functional derivative, δT s [ρ]δρ(r), yielding a potential that can be used in orbital-free DFT or subsystem DFT simulations. Here, this paradigm is challenged by constructing the potential from the second-functional derivative via functional integration. A new nonlocal functional for T s [ρ] is prescribed [which we dub Mi-Genova-Pavanello (MGP)] having a density independent kernel. MGP is constructed to satisfy three exact conditions: (1) a nonzero "Kinetic electron" arising from a nonzero exchange hole; (2) the second functional derivative must reduce to the inverse Lindhard function in the limit of homogenous densities; (3) the potential is derived from functional integration of the second functional derivative. Pilot calculations show that MGP is capable of reproducing accurate equilibrium volumes, bulk moduli, total energy, and electron densities for metallic (body-centered cubic, face-centered cubic) and semiconducting (crystal diamond) phases of silicon as well as of III-V semiconductors. The MGP functional is found to be numerically stable typically reaching self-consistency within 12 iterations of a truncated Newton minimization algorithm. MGP's computational cost and memory requirements are low and comparable to the Wang-Teter nonlocal functional or any generalized gradient approximation functional.
Executive Function Subcomponents and their Relations to Everyday Functioning in Healthy Older Adults

PubMed Central

McAlister, Courtney; Schmitter-Edgecombe, Maureen

2016-01-01

Everyday functioning and its executive functioning cognitive correlates (i.e., switching, inhibition, and updating) were investigated in healthy older adults (HOAs) using multiple methods of functional status. In addition to whether computerized experimental tasks would better dissociate these subcomponents than neuropsychological measures of executive functioning, we were also interested in the contributions of both experimental and neuropsychological measures of executive function subcomponents to functional abilities. Seventy HOAs (45 young-old and 25 old-old) and 70 younger adults completed executive function and neuropsychological tests. In addition to self- and informant questionnaires of functional abilities, HOAs completed two performance-based measures. An aging effect was found on all executive function measures. Old-old older adults and their informants did not report more functional difficulties but demonstrated more difficulties on performance-based measures relative to young-old participants. For the HOAs, after controlling for age and education, the neuropsychological measures of executive functioning, but not experimental measures, explained a significant amount of variance in the informant-report and both performance-based measures. Updating measures differentially predicted performance-based measures, while switching was important for questionnaire and performance-based measures. The contribution of executive functioning to functional status when measured with experimental measures specifically designed to isolate the executive subcomponent was not as strong as hypothesized. Further research examining the value of isolating executive function subcomponents in neuropsychological assessment and the prediction of functional abilities in older adults is warranted. PMID:27206842
Executive function subcomponents and their relations to everyday functioning in healthy older adults.

PubMed

McAlister, Courtney; Schmitter-Edgecombe, Maureen

2016-10-01

Everyday functioning and its executive functioning cognitive correlates (i.e., switching, inhibition, and updating) were investigated in healthy older adults (HOAs) using multiple methods of functional status. In addition to whether computerized experimental tasks would better dissociate these subcomponents than neuropsychological measures of executive functioning, we were also interested in the contributions of both experimental and neuropsychological measures of executive function subcomponents to functional abilities. Seventy HOAs (45 young-old and 25 old-old) and 70 younger adults completed executive function and neuropsychological tests. In addition to self- and informant questionnaires of functional abilities, HOAs completed two performance-based measures. An aging effect was found on all executive function measures. Old-old older adults and their informants did not report more functional difficulties but demonstrated more difficulties on performance-based measures than did young-old participants. For the HOAs, after controlling for age and education, the neuropsychological measures of executive functioning, but not experimental measures, explained a significant amount of variance in the informant-report and both performance-based measures. Updating measures differentially predicted performance-based measures, while switching was important for questionnaire and performance-based measures. The contribution of executive functioning to functional status when measured with experimental measures specifically designed to isolate the executive subcomponent was not as strong as hypothesized. Further research examining the value of isolating executive function subcomponents in neuropsychological assessment and the prediction of functional abilities in older adults is warranted.
Nonlocal kinetic energy functionals by functional integration

NASA Astrophysics Data System (ADS)

Mi, Wenhui; Genova, Alessandro; Pavanello, Michele

2018-05-01

Since the seminal studies of Thomas and Fermi, researchers in the Density-Functional Theory (DFT) community are searching for accurate electron density functionals. Arguably, the toughest functional to approximate is the noninteracting kinetic energy, Ts[ρ], the subject of this work. The typical paradigm is to first approximate the energy functional and then take its functional derivative, δ/Ts[ρ ] δ ρ (r ) , yielding a potential that can be used in orbital-free DFT or subsystem DFT simulations. Here, this paradigm is challenged by constructing the potential from the second-functional derivative via functional integration. A new nonlocal functional for Ts[ρ] is prescribed [which we dub Mi-Genova-Pavanello (MGP)] having a density independent kernel. MGP is constructed to satisfy three exact conditions: (1) a nonzero "Kinetic electron" arising from a nonzero exchange hole; (2) the second functional derivative must reduce to the inverse Lindhard function in the limit of homogenous densities; (3) the potential is derived from functional integration of the second functional derivative. Pilot calculations show that MGP is capable of reproducing accurate equilibrium volumes, bulk moduli, total energy, and electron densities for metallic (body-centered cubic, face-centered cubic) and semiconducting (crystal diamond) phases of silicon as well as of III-V semiconductors. The MGP functional is found to be numerically stable typically reaching self-consistency within 12 iterations of a truncated Newton minimization algorithm. MGP's computational cost and memory requirements are low and comparable to the Wang-Teter nonlocal functional or any generalized gradient approximation functional.
Sampling functions for geophysics

NASA Technical Reports Server (NTRS)

Giacaglia, G. E. O.; Lunquist, C. A.

1972-01-01

A set of spherical sampling functions is defined such that they are related to spherical-harmonic functions in the same way that the sampling functions of information theory are related to sine and cosine functions. An orderly distribution of (N + 1) squared sampling points on a sphere is given, for which the (N + 1) squared spherical sampling functions span the same linear manifold as do the spherical-harmonic functions through degree N. The transformations between the spherical sampling functions and the spherical-harmonic functions are given by recurrence relations. The spherical sampling functions of two arguments are extended to three arguments and to nonspherical reference surfaces. Typical applications of this formalism to geophysical topics are sketched.
The Gaussian-Lorentzian Sum, Product, and Convolution (Voigt) functions in the context of peak fitting X-ray photoelectron spectroscopy (XPS) narrow scans

NASA Astrophysics Data System (ADS)

Jain, Varun; Biesinger, Mark C.; Linford, Matthew R.

2018-07-01

X-ray photoelectron spectroscopy (XPS) is arguably the most important vacuum technique for surface chemical analysis, and peak fitting is an indispensable part of XPS data analysis. Functions that have been widely explored and used in XPS peak fitting include the Gaussian, Lorentzian, Gaussian-Lorentzian sum (GLS), Gaussian-Lorentzian product (GLP), and Voigt functions, where the Voigt function is a convolution of a Gaussian and a Lorentzian function. In this article we discuss these functions from a graphical perspective. Arguments based on convolution and the Central Limit Theorem are made to justify the use of functions that are intermediate between pure Gaussians and pure Lorentzians in XPS peak fitting. Mathematical forms for the GLS and GLP functions are presented with a mixing parameter m. Plots are shown for GLS and GLP functions with mixing parameters ranging from 0 to 1. There are fundamental differences between the GLS and GLP functions. The GLS function better follows the 'wings' of the Lorentzian, while these 'wings' are suppressed in the GLP. That is, these two functions are not interchangeable. The GLS and GLP functions are compared to the Voigt function, where the GLS is shown to be a decent approximation of it. Practically, both the GLS and the GLP functions can be useful for XPS peak fitting. Examples of the uses of these functions are provided herein.
Microbial Functional Gene Diversity Predicts Groundwater Contamination and Ecosystem Functioning.

PubMed

He, Zhili; Zhang, Ping; Wu, Linwei; Rocha, Andrea M; Tu, Qichao; Shi, Zhou; Wu, Bo; Qin, Yujia; Wang, Jianjun; Yan, Qingyun; Curtis, Daniel; Ning, Daliang; Van Nostrand, Joy D; Wu, Liyou; Yang, Yunfeng; Elias, Dwayne A; Watson, David B; Adams, Michael W W; Fields, Matthew W; Alm, Eric J; Hazen, Terry C; Adams, Paul D; Arkin, Adam P; Zhou, Jizhong

2018-02-20

Contamination from anthropogenic activities has significantly impacted Earth's biosphere. However, knowledge about how environmental contamination affects the biodiversity of groundwater microbiomes and ecosystem functioning remains very limited. Here, we used a comprehensive functional gene array to analyze groundwater microbiomes from 69 wells at the Oak Ridge Field Research Center (Oak Ridge, TN), representing a wide pH range and uranium, nitrate, and other contaminants. We hypothesized that the functional diversity of groundwater microbiomes would decrease as environmental contamination (e.g., uranium or nitrate) increased or at low or high pH, while some specific populations capable of utilizing or resistant to those contaminants would increase, and thus, such key microbial functional genes and/or populations could be used to predict groundwater contamination and ecosystem functioning. Our results indicated that functional richness/diversity decreased as uranium (but not nitrate) increased in groundwater. In addition, about 5.9% of specific key functional populations targeted by a comprehensive functional gene array (GeoChip 5) increased significantly ( P < 0.05) as uranium or nitrate increased, and their changes could be used to successfully predict uranium and nitrate contamination and ecosystem functioning. This study indicates great potential for using microbial functional genes to predict environmental contamination and ecosystem functioning. IMPORTANCE Disentangling the relationships between biodiversity and ecosystem functioning is an important but poorly understood topic in ecology. Predicting ecosystem functioning on the basis of biodiversity is even more difficult, particularly with microbial biomarkers. As an exploratory effort, this study used key microbial functional genes as biomarkers to provide predictive understanding of environmental contamination and ecosystem functioning. The results indicated that the overall functional gene richness/diversity decreased as uranium increased in groundwater, while specific key microbial guilds increased significantly as uranium or nitrate increased. These key microbial functional genes could be used to successfully predict environmental contamination and ecosystem functioning. This study represents a significant advance in using functional gene markers to predict the spatial distribution of environmental contaminants and ecosystem functioning toward predictive microbial ecology, which is an ultimate goal of microbial ecology. Copyright © 2018 He et al.
Identification of Novel Ovarian Cancer Oncogenes that Function by Regulating Exosome Function

DTIC Science & Technology

2017-09-01

Novel Ovarian Cancer Oncogenes that Function by Regulating Exosome Function September 2017 x 1Sep2016...31Aug2017 Email: mbirrer@partners.org 6 Identification of Novel Ovarian Cancer Oncogenes that Function by Regulating Exosome Function xx
Potential Representation - Global vs. Local Trial Functions

NASA Astrophysics Data System (ADS)

Michel, Volker

2014-05-01

Many systems of trial functions are available for representing potential fields on the sphere or parts of the sphere. We distinguish global trial functions (such as spherical harmonics) from localized trial functions (such as spline basis functions, scaling functions, wavelets, and Slepian functions). All these systems have their own pros and cons. We discuss the advantages and disadvantages of several selected systems of trial functions and propose criteria for their applicability. Moreover, we present an algorithm which is able to combine different types of trial functions. This yields a sparser solution which combines the features of the different basis systems which are used.
Elucidation of spin echo small angle neutron scattering correlation functions through model studies.

PubMed

Shew, Chwen-Yang; Chen, Wei-Ren

2012-02-14

Several single-modal Debye correlation functions to approximate part of the overall Debey correlation function of liquids are closely examined for elucidating their behavior in the corresponding spin echo small angle neutron scattering (SESANS) correlation functions. We find that the maximum length scale of a Debye correlation function is identical to that of its SESANS correlation function. For discrete Debye correlation functions, the peak of SESANS correlation function emerges at their first discrete point, whereas for continuous Debye correlation functions with greater width, the peak position shifts to a greater value. In both cases, the intensity and shape of the peak of the SESANS correlation function are determined by the width of the Debye correlation functions. Furthermore, we mimic the intramolecular and intermolecular Debye correlation functions of liquids composed of interacting particles based on a simple model to elucidate their competition in the SESANS correlation function. Our calculations show that the first local minimum of a SESANS correlation function can be negative and positive. By adjusting the spatial distribution of the intermolecular Debye function in the model, the calculated SESANS spectra exhibit the profile consistent with that of hard-sphere and sticky-hard-sphere liquids predicted by more sophisticated liquid state theory and computer simulation. © 2012 American Institute of Physics
Unexpected high vulnerability of functions in wilderness areas: evidence from coral reef fishes.

PubMed

D'agata, Stéphanie; Vigliola, Laurent; Graham, Nicholas A J; Wantiez, Laurent; Parravicini, Valeriano; Villéger, Sébastien; Mou-Tham, Gerard; Frolla, Philippe; Friedlander, Alan M; Kulbicki, Michel; Mouillot, David

2016-12-14

High species richness is thought to support the delivery of multiple ecosystem functions and services under changing environments. Yet, some species might perform unique functional roles while others are redundant. Thus, the benefits of high species richness in maintaining ecosystem functioning are uncertain if functions have little redundancy, potentially leading to high vulnerability of functions. We studied the natural propensity of assemblages to be functionally buffered against loss prior to fishing activities, using functional trait combinations, in coral reef fish assemblages across unfished wilderness areas of the Indo-Pacific: Chagos Archipelago, New Caledonia and French Polynesia. Fish functional diversity in these wilderness areas is highly vulnerable to fishing, explained by species- and abundance-based redundancy packed into a small combination of traits, leaving most other trait combinations (60%) sensitive to fishing, with no redundancy. Functional vulnerability peaks for mobile and sedentary top predators, and large species in general. Functional vulnerability decreases for certain functional entities in New Caledonia, where overall functional redundancy was higher. Uncovering these baseline patterns of functional vulnerability can offer early warning signals of the damaging effects from fishing, and may serve as baselines to guide precautionary and even proactive conservation actions. © 2016 The Author(s).

Unexpected high vulnerability of functions in wilderness areas: evidence from coral reef fishes

PubMed Central

Vigliola, Laurent; Graham, Nicholas A. J.; Wantiez, Laurent; Parravicini, Valeriano; Villéger, Sébastien; Mou-Tham, Gerard; Frolla, Philippe; Friedlander, Alan M.; Kulbicki, Michel; Mouillot, David

2016-01-01

High species richness is thought to support the delivery of multiple ecosystem functions and services under changing environments. Yet, some species might perform unique functional roles while others are redundant. Thus, the benefits of high species richness in maintaining ecosystem functioning are uncertain if functions have little redundancy, potentially leading to high vulnerability of functions. We studied the natural propensity of assemblages to be functionally buffered against loss prior to fishing activities, using functional trait combinations, in coral reef fish assemblages across unfished wilderness areas of the Indo-Pacific: Chagos Archipelago, New Caledonia and French Polynesia. Fish functional diversity in these wilderness areas is highly vulnerable to fishing, explained by species- and abundance-based redundancy packed into a small combination of traits, leaving most other trait combinations (60%) sensitive to fishing, with no redundancy. Functional vulnerability peaks for mobile and sedentary top predators, and large species in general. Functional vulnerability decreases for certain functional entities in New Caledonia, where overall functional redundancy was higher. Uncovering these baseline patterns of functional vulnerability can offer early warning signals of the damaging effects from fishing, and may serve as baselines to guide precautionary and even proactive conservation actions. PMID:27928042
Properties of field functionals and characterization of local functionals

NASA Astrophysics Data System (ADS)

Brouder, Christian; Dang, Nguyen Viet; Laurent-Gengoux, Camille; Rejzner, Kasia

2018-02-01

Functionals (i.e., functions of functions) are widely used in quantum field theory and solid-state physics. In this paper, functionals are given a rigorous mathematical framework and their main properties are described. The choice of the proper space of test functions (smooth functions) and of the relevant concept of differential (Bastiani differential) are discussed. The relation between the multiple derivatives of a functional and the corresponding distributions is described in detail. It is proved that, in a neighborhood of every test function, the support of a smooth functional is uniformly compactly supported and the order of the corresponding distribution is uniformly bounded. Relying on a recent work by Dabrowski, several spaces of functionals are furnished with a complete and nuclear topology. In view of physical applications, it is shown that most formal manipulations can be given a rigorous meaning. A new concept of local functionals is proposed and two characterizations of them are given: the first one uses the additivity (or Hammerstein) property, the second one is a variant of Peetre's theorem. Finally, the first step of a cohomological approach to quantum field theory is carried out by proving a global Poincaré lemma and defining multi-vector fields and graded functionals within our framework.
Tai Chi Chuan optimizes the functional organization of the intrinsic human brain architecture in older adults

PubMed Central

Wei, Gao-Xia; Dong, Hao-Ming; Yang, Zhi; Luo, Jing; Zuo, Xi-Nian

2014-01-01

Whether Tai Chi Chuan (TCC) can influence the intrinsic functional architecture of the human brain remains unclear. To examine TCC-associated changes in functional connectomes, resting-state functional magnetic resonance images were acquired from 40 older individuals including 22 experienced TCC practitioners (experts) and 18 demographically matched TCC-naïve healthy controls, and their local functional homogeneities across the cortical mantle were compared. Compared to the controls, the TCC experts had significantly greater and more experience-dependent functional homogeneity in the right post-central gyrus (PosCG) and less functional homogeneity in the left anterior cingulate cortex (ACC) and the right dorsal lateral prefrontal cortex. Increased functional homogeneity in the PosCG was correlated with TCC experience. Intriguingly, decreases in functional homogeneity (improved functional specialization) in the left ACC and increases in functional homogeneity (improved functional integration) in the right PosCG both predicted performance gains on attention network behavior tests. These findings provide evidence for the functional plasticity of the brain’s intrinsic architecture toward optimizing locally functional organization, with great implications for understanding the effects of TCC on cognition, behavior and health in aging population. PMID:24860494
What North America's skeleton crew of megafauna tells us about community disassembly

PubMed Central

2017-01-01

Functional trait diversity is increasingly used to model future changes in community structure despite a poor understanding of community disassembly's effects on functional diversity. By tracking the functional diversity of the North American large mammal fauna through the End-Pleistocene megafaunal extinction and up to the present, I show that contrary to expectations, functionally unique species are no more likely to go extinct than functionally redundant species. This makes total functional richness loss no worse than expected given similar taxonomic richness declines. However, where current species sit in functional space relative to pre-anthropogenic baselines is not random and likely explains ecosystem functional changes better than total functional richness declines. Prehistoric extinctions have left many extant species functionally isolated and future extinctions will cause even more rapid drops in functional richness. PMID:28077767
18 CFR 376.104 - Functions.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Functions. 376.104... OF ENERGY REVISED GENERAL RULES ORGANIZATION, MISSION, AND FUNCTIONS; OPERATIONS DURING EMERGENCY CONDITIONS Organization, Mission, and Functions § 376.104 Functions. The functions of the Commission include...
Endogenous sex hormones and cognitive function in the elderly.

PubMed

Boss, Lisa; Kang, Duck-Hee; Bergstrom, Nancy; Leasure, J Leigh

2015-08-01

Estrogen and testosterone may influence cognitive function in the older adult, but the relationship between sex hormones and cognitive function is complex. To examine associations of sex hormones and cognitive function among older adults ≥65 years old. Using a cross-sectional research design, data were collected once from 71 elderly (mean age 86.4 years). Global cognitive function and executive function were measured with standardized instruments, and saliva samples were collected for salivary estradiol and testosterone. Estradiol was significantly and positively correlated with global cognitive function in men only (r = 0.54, p < 0.05). Testosterone was not significantly correlated with global cognitive function or executive function in either gender. Associations between sex hormones and cognitive function were mostly non-significant. However, higher estradiol was significantly correlated with better global cognitive function in men, suggesting gender-specific differences. Along with sex hormones, other comorbidity may need to be assessed together in relation to cognitive function in the elderly. Accordingly, clinicians play an important role in educating and promoting beneficial actions to preserve cognitive function.
Contours of a causal feedback mechanism between adaptive personality and psychosocial function in patients with personality disorders: a secondary analysis from a randomized clinical trial.

PubMed

Klungsøyr, Ole; Antonsen, Bjørnar; Wilberg, Theresa

2017-06-05

Patients with personality disorders commonly exhibit impairment in psychosocial function that persists over time even with diagnostic remission. Further causal knowledge may help to identify and assess factors with a potential to alleviate this impairment. Psychosocial function is associated with personality functioning which describes personality disorder severity in DSM-5 (section III) and which can reportedly be improved by therapy. The reciprocal association between personality functioning and psychosocial function was assessed, in 113 patients with different personality disorders, in a secondary longitudinal analysis of data from a randomized clinical trial, over six years. Personality functioning was represented by three domains of the Severity Indices of Personality Problems: Relational Capacity, Identity Integration, and Self-control. Psychosocial function was measured by Global Assessment of Functioning. The marginal structural model was used for estimation of causal effects of the three personality functioning domains on psychosocial function, and vice versa. The attractiveness of this model lies in the ability to assess an effect of a time - varying exposure on an outcome, while adjusting for time - varying confounding. Strong causal effects were found. A hypothetical intervention to increase Relational Capacity by one standard deviation, both at one and two time-points prior to assessment of psychosocial function, would increase psychosocial function by 3.5 standard deviations (95% CI: 2.0, 4.96). Significant effects of Identity Integration and Self-control on psychosocial function, and from psychosocial function on all three domains of personality functioning, although weaker, were also found. This study indicates that persistent impairment in psychosocial function can be addressed through a causal pathway of personality functioning, with interventions of at least 18 months duration.
Analysis of structure-function network decoupling in the brain systems of spastic diplegic cerebral palsy.

PubMed

Lee, Dongha; Pae, Chongwon; Lee, Jong Doo; Park, Eun Sook; Cho, Sung-Rae; Um, Min-Hee; Lee, Seung-Koo; Oh, Maeng-Keun; Park, Hae-Jeong

2017-10-01

Manifestation of the functionalities from the structural brain network is becoming increasingly important to understand a brain disease. With the aim of investigating the differential structure-function couplings according to network systems, we investigated the structural and functional brain networks of patients with spastic diplegic cerebral palsy with periventricular leukomalacia compared to healthy controls. The structural and functional networks of the whole brain and motor system, constructed using deterministic and probabilistic tractography of diffusion tensor magnetic resonance images and Pearson and partial correlation analyses of resting-state functional magnetic resonance images, showed differential embedding of functional networks in the structural networks in patients. In the whole-brain network of patients, significantly reduced global network efficiency compared to healthy controls were found in the structural networks but not in the functional networks, resulting in reduced structural-functional coupling. On the contrary, the motor network of patients had a significantly lower functional network efficiency over the intact structural network and a lower structure-function coupling than the control group. This reduced coupling but reverse directionality in the whole-brain and motor networks of patients was prominent particularly between the probabilistic structural and partial correlation-based functional networks. Intact (or less deficient) functional network over impaired structural networks of the whole brain and highly impaired functional network topology over the intact structural motor network might subserve relatively preserved cognitions and impaired motor functions in cerebral palsy. This study suggests that the structure-function relationship, evaluated specifically using sparse functional connectivity, may reveal important clues to functional reorganization in cerebral palsy. Hum Brain Mapp 38:5292-5306, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.
Defining Function in the Functional Medicine Model.

PubMed

Bland, Jeffrey

2017-02-01

In the functional medicine model, the word function is aligned with the evolving understanding that disease is an endpoint and function is a process. Function can move both forward and backward. The vector of change in function through time is, in part, determined by the unique interaction of an individual's genome with their environment, diet, and lifestyle. The functional medicine model for health care is concerned less with what we call the dysfunction or disease , and more about the dynamic processes that resulted in the person's dysfunction. The previous concept of functional somatic syndromes as psychosomatic in origin has now been replaced with a new concept of function that is rooted in the emerging 21st-century understanding of systems network-enabled biology.
Defining Function in the Functional Medicine Model

PubMed Central

Bland, Jeffrey

2017-01-01

In the functional medicine model, the word function is aligned with the evolving understanding that disease is an endpoint and function is a process. Function can move both forward and backward. The vector of change in function through time is, in part, determined by the unique interaction of an individual’s genome with their environment, diet, and lifestyle. The functional medicine model for health care is concerned less with what we call the dysfunction or disease, and more about the dynamic processes that resulted in the person’s dysfunction. The previous concept of functional somatic syndromes as psychosomatic in origin has now been replaced with a new concept of function that is rooted in the emerging 21st-century understanding of systems network-enabled biology. PMID:28223904
Protein Function Prediction: Problems and Pitfalls.

PubMed

Pearson, William R

2015-09-03

The characterization of new genomes based on their protein sets has been revolutionized by new sequencing technologies, but biologists seeking to exploit new sequence information are often frustrated by the challenges associated with accurately assigning biological functions to newly identified proteins. Here, we highlight some of the challenges in functional inference from sequence similarity. Investigators can improve the accuracy of function prediction by (1) being conservative about the evolutionary distance to a protein of known function; (2) considering the ambiguous meaning of "functional similarity," and (3) being aware of the limitations of annotations in functional databases. Protein function prediction does not offer "one-size-fits-all" solutions. Prediction strategies work better when the idiosyncrasies of function and functional annotation are better understood. Copyright © 2015 John Wiley & Sons, Inc.
Generalized -deformed correlation functions as spectral functions of hyperbolic geometry

NASA Astrophysics Data System (ADS)

Bonora, L.; Bytsenko, A. A.; Guimarães, M. E. X.

2014-08-01

We analyze the role of vertex operator algebra and 2d amplitudes from the point of view of the representation theory of infinite-dimensional Lie algebras, MacMahon and Ruelle functions. By definition p-dimensional MacMahon function, with , is the generating function of p-dimensional partitions of integers. These functions can be represented as amplitudes of a two-dimensional c = 1 CFT, and, as such, they can be generalized to . With some abuse of language we call the latter amplitudes generalized MacMahon functions. In this paper we show that generalized p-dimensional MacMahon functions can be rewritten in terms of Ruelle spectral functions, whose spectrum is encoded in the Patterson-Selberg function of three-dimensional hyperbolic geometry.
Description of an α-cluster tail in 8Be and 20Ne: Delocalization of the α cluster by quantum penetration

NASA Astrophysics Data System (ADS)

Kanada-En'yo, Yoshiko

2014-10-01

We analyze the α-cluster wave functions in cluster states of ^8Be and ^{20}Ne by comparing the exact relative wave function obtained by the generator coordinate method (GCM) with various types of trial functions. For the trial functions, we adopt the fixed range shifted Gaussian of the Brink-Bloch (BB) wave function, the spherical Gaussian with the adjustable range parameter of the spherical Tohsaki-Horiuchi-Schuck-Röpke (sTHSR), the deformed Gaussian of the deformed THSR (dTHSR), and a function with the Yukawa tail (YT). The quality of the description of the exact wave function with a trial function is judged by the squared overlap between the trial function and the GCM wave function. A better result is obtained with the sTHSR wave function than the BB wave function, and further improvement can be made with the dTHSR wave function because these wave functions can describe the outer tail better. The YT wave function gives almost an equal quality to or even better quality than the dTHSR wave function, indicating that the outer tail of α-cluster states is characterized by the Yukawa-like tail rather than the Gaussian tail. In weakly bound α-cluster states with small α separation energy and the low centrifugal and Coulomb barriers, the outer tail part is the slowly damping function described well by the quantum penetration through the effective barrier. This outer tail characterizes the almost zero-energy free α gas behavior, i.e., the delocalization of the cluster.
Loss of functional diversity of ant assemblages in secondary tropical forests.

PubMed

Bihn, Jochen H; Gebauer, Gerhard; Brandl, Roland

2010-03-01

Secondary forests and plantations increasingly dominate the tropical wooded landscape in place of primary forests. The expected reduction of biodiversity and its impact on ecological functions provided by these secondary forests are of major concern to society and ecologists. The potential effect of biodiversity loss on ecosystem functioning depends largely on the associated loss in the functional diversity of animal and plant assemblages, i.e., the degree of functional redundancy among species. However, the relationship between species and functional diversity is still poorly documented for most ecosystems. Here, we analyze how changes in the species diversity of ground-foraging ant assemblages translate into changes of functional diversity along a successional gradient of secondary forests in the Atlantic Forest of Brazil. Our analysis uses continuous measures of functional diversity and is based on four functional traits related to resource use of ants: body size, relative eye size, relative leg length, and trophic position. We find a strong relationship between species and functional diversity, independent of the functional traits used, with no evidence for saturation in this relationship. Recovery of species richness and diversity of ant assemblages in tropical secondary forests was accompanied by a proportional increase of functional richness and diversity of assemblages. Moreover, our results indicate that the increase in functional diversity along the successional gradient of secondary forests is primarily driven by rare species, which are functionally unique. The observed loss of both species and functional diversity in secondary forests offers no reason to believe that the ecological functions provided by secondary forests are buffered against species loss through functional redundancy.
Functional Requirements Document for HALE UAS Operations in the NAS: Step 1. Version 3

NASA Technical Reports Server (NTRS)

2006-01-01

The purpose of this Functional Requirements Document (FRD) is to compile the functional requirements needed to achieve the Access 5 Vision of "operating High Altitude, Long Endurance (HALE) Unmanned Aircraft Systems (UAS) routinely, safely, and reliably in the national airspace system (NAS)" for Step 1. These functional requirements could support the development of a minimum set of policies, procedures and standards by the Federal Aviation Administration (FAA) and various standards organizations. It is envisioned that this comprehensive body of work will enable the FAA to establish and approve regulations to govern safe operation of UAS in the NAS on a routine or daily "file and fly" basis. The approach used to derive the functional requirements found within this FRD was to decompose the operational requirements and objectives identified within the Access 5 Concept of Operations (CONOPS) into the functions needed to routinely and safely operate a HALE UAS in the NAS. As a result, four major functional areas evolved to enable routine and safe UAS operations for an on-demand basis in the NAS. These four major functions are: Aviate, Navigate, Communicate, and Avoid Hazards. All of the functional requirements within this document can be directly traceable to one of these four major functions. Some functions, however, are traceable to several, or even all, of these four major functions. These cross-cutting functional requirements support the "Command / Control: function as well as the "Manage Contingencies" function. The requirements associated to these high-level functions and all of their supporting low-level functions are addressed in subsequent sections of this document.
Functional Communication Profiles in Children with Cerebral Palsy in Relation to Gross Motor Function and Manual and Intellectual Ability.

PubMed

Choi, Ja Young; Park, Jieun; Choi, Yoon Seong; Goh, Yu Ra; Park, Eun Sook

2018-07-01

The aim of the present study was to investigate communication function using classification systems and its association with other functional profiles, including gross motor function, manual ability, intellectual functioning, and brain magnetic resonance imaging (MRI) characteristics in children with cerebral palsy (CP). This study recruited 117 individuals with CP aged from 4 to 16 years. The Communication Function Classification System (CFCS), Viking Speech Scale (VSS), Speech Language Profile Groups (SLPG), Gross Motor Function Classification System (GMFCS), Manual Ability Classification System (MACS), and intellectual functioning were assessed in the children along with brain MRI categorization. Very strong relationships were noted among the VSS, CFCS, and SLPG, although these three communication systems provide complementary information, especially for children with mid-range communication impairment. These three communication classification systems were strongly related with the MACS, but moderately related with the GMFCS. Multiple logistic regression analysis indicated that manual ability and intellectual functioning were significantly related with VSS and CFCS function, whereas only intellectual functioning was significantly related with SLPG functioning in children with CP. Communication function in children with a periventricular white matter lesion (PVWL) varied widely. In the cases with a PVWL, poor functioning was more common on the SLPG, compared to the VSS and CFCS. Very strong relationships were noted among three communication classification systems that are closely related with intellectual ability. Compared to gross motor function, manual ability seemed more closely related with communication function in these children. © Copyright: Yonsei University College of Medicine 2018.
Neuropsychological Characteristics and Their Association with Higher-Level Functional Capacity in Parkinson's Disease

PubMed Central

Miura, Kayoko; Matsui, Mie; Takashima, Shutaro; Tanaka, Kortaro

2015-01-01

Background/Aims Little is known about the relationship between cognitive functions and higher-level functional capacity (e.g. intellectual activity, social role, and social participation) in Parkinson's disease (PD). The purpose of this study was to clarify neuropsychological characteristics and their association with higher-level functional capacity in PD patients. Methods Participants were 31 PD patients and 23 demographically matched healthy controls. Neuropsychological tests were conducted. One year later, a questionnaire survey evaluated higher-level functional capacity in daily living. Results The PD group scored significantly lower than the control group in all cognitive domains, particularly executive function and processing. Executive function, processing speed, language, and memory were significantly correlated with higher-level functional capacity in PD patients. Stepwise regression showed that only executive function (Trail Making Test-B), together with disease severity (HY stage), predicted the higher-level functional capacity. Conclusion Our findings provide evidence of a relationship between executive function and higher-level functional capacity in patients with PD. PMID:26273243
A systematic review of vascular and endothelial function: effects of fruit, vegetable and potassium intake.

PubMed

Blanch, N; Clifton, P M; Keogh, J B

2015-03-01

To review the relationships between: 1) Potassium and endothelial function; 2) Fruits and vegetables and endothelial function; 3) Potassium and other measures of vascular function; 4) Fruits and vegetables and other measures of vascular function. An electronic search for intervention trials investigating the effect of potassium, fruits and vegetables on vascular function was performed in MEDLINE, EMBASE and the Cochrane Library. Potassium appears to improve endothelial function with a dose of >40 mmol/d, however the mechanisms for this effect remain unclear. Potassium may improve measures of vascular function however this effect may be dependent on the effect of potassium on blood pressure. The effect of fruit and vegetables on endothelial function independent of confounding variables is less clear. Increased fruit and vegetable intake may improve vascular function only in high risk populations. Increasing dietary potassium appears to improve vascular function but the effect of increasing fruit and vegetable intake per se on vascular function is less clear. Copyright © 2014 Elsevier B.V. All rights reserved.
[Nostalgia and the functions of autobiographical memory].

PubMed

Wolf, T

2014-11-01

Current research on autobiographical memory distinguishes between a self function, a directive function, and a social function of autobiographical memory. From a lifespan perspective, the use of autobiographical memory for these functions is expected to decrease with age. The present study extended these functions by the function of nostalgia: Often triggered by negative emotions, remembering personal and positive experiences might, among others, enhance positive effects. This emotion-regulating function is expected to become more important in old age. In the present study 273 adults (aged between 19 and 90 years) completed the Thinking About Life Experiences Questionnaire (TALE) as well as 11 newly developed items to assess the nostalgia function. Exploratory and confirmatory factor analyses supported a four-factor model reflecting the presumed self, directive, social, and nostalgia functions of autobiographical memory. The results showed a decrease in the use of autobiographical memory for self, directive and social functions with increasing age, whereas the nostalgia function followed a U-shaped pattern.
Systematic Characterization and Analysis of the Taxonomic Drivers of Functional Shifts in the Human Microbiome.

PubMed

Manor, Ohad; Borenstein, Elhanan

2017-02-08

Comparative analyses of the human microbiome have identified both taxonomic and functional shifts that are associated with numerous diseases. To date, however, microbiome taxonomy and function have mostly been studied independently and the taxonomic drivers of functional imbalances have not been systematically identified. Here, we present FishTaco, an analytical and computational framework that integrates taxonomic and functional comparative analyses to accurately quantify taxon-level contributions to disease-associated functional shifts. Applying FishTaco to several large-scale metagenomic cohorts, we show that shifts in the microbiome's functional capacity can be traced back to specific taxa. Furthermore, the set of taxa driving functional shifts and their contribution levels vary markedly between functions. We additionally find that similar functional imbalances in different diseases are driven by both disease-specific and shared taxa. Such integrated analysis of microbiome ecological and functional dynamics can inform future microbiome-based therapy, pinpointing putative intervention targets for manipulating the microbiome's functional capacity. Copyright © 2017 Elsevier Inc. All rights reserved.

The Implicit Function Theorem and Non-Existence of Limit of Functions of Several Variables

ERIC Educational Resources Information Center

dos Santos, A. L. C.; da Silva, P. N.

2008-01-01

We use the Implicit Function Theorem to establish a result of non-existence of limit to a certain class of functions of several variables. We consider functions given by quotients such that both the numerator and denominator functions are null at the limit point. We show that the non-existence of the limit of such function is related with the…
Neurocognition and psychosocial functioning in adolescents with bipolar disorder.

PubMed

Best, Michael W; Bowie, Christopher R; Naiberg, Melanie R; Newton, Dwight F; Goldstein, Benjamin I

2017-01-01

Adults with bipolar disorder demonstrate significantly poorer psychosocial functioning and neurocognition compared to controls. In adult bipolar disorder neurocognition predicts a substantial portion of variance in functioning. Adolescents with bipolar disorder have reducedpsychosocial functioning, but less is known about neurocognitive impairments, and no studies have examined the relationship between neurocognition and functioning in an adolescent sample. 38 adolescents with bipolar disorder and 49 healthy controls under 20 years of age completed assessments of psychosocial functioning, neurocognitive ability, and psychiatric symptoms. Adolescents with bipolar disorder had significantly poorer psychosocial functioning in domains of daily activities, social functioning, and satisfaction with functioning, ps<.006, compared to healthy controls. They also had poorer general neurocognitive functioning than controls, p=.004, with the greatest impairment on a test of sustained attention. Neurocognition was not a significant predictor of psychosocial functioning in this sample, but depressive symptoms significantly predicted functioning in all domains, p<.033. Limited sample size did not allow for complex statistical analyses. Differences in demographic characteristics of the clinical and control groups may limit generalization of these results. This adolescent sample with bipolar disorder experiences significantly poorer neurocognitive and psychosocial functioning compared to controls; however, psychosocial functioning appears to be more strongly related to mood symptoms than to neurocognition. Future work is needed to delineate the time course of neurocognitive functioning and its relation to psychosocial functioning across the course of illness. Adolescence may provide an ideal time for cognitive enhancement and intensive psychosocial intervention. Copyright © 2016 Elsevier B.V. All rights reserved.
GO-based functional dissimilarity of gene sets.

PubMed

Díaz-Díaz, Norberto; Aguilar-Ruiz, Jesús S

2011-09-01

The Gene Ontology (GO) provides a controlled vocabulary for describing the functions of genes and can be used to evaluate the functional coherence of gene sets. Many functional coherence measures consider each pair of gene functions in a set and produce an output based on all pairwise distances. A single gene can encode multiple proteins that may differ in function. For each functionality, other proteins that exhibit the same activity may also participate. Therefore, an identification of the most common function for all of the genes involved in a biological process is important in evaluating the functional similarity of groups of genes and a quantification of functional coherence can helps to clarify the role of a group of genes working together. To implement this approach to functional assessment, we present GFD (GO-based Functional Dissimilarity), a novel dissimilarity measure for evaluating groups of genes based on the most relevant functions of the whole set. The measure assigns a numerical value to the gene set for each of the three GO sub-ontologies. Results show that GFD performs robustly when applied to gene set of known functionality (extracted from KEGG). It performs particularly well on randomly generated gene sets. An ROC analysis reveals that the performance of GFD in evaluating the functional dissimilarity of gene sets is very satisfactory. A comparative analysis against other functional measures, such as GS2 and those presented by Resnik and Wang, also demonstrates the robustness of GFD.
[Effects of functional electrical therapy on upper extremity functional motor recovery in patients after stroke--our experience and future directions].

PubMed

Plavsić, Aleksandra; Svirtlih, Laslo; Stefanović, Aleksandra; Jović, Stevan; Durović, Aleksandar; Popović, Mirjana

2011-01-01

New neurorehabilitation together with conventional techniques provide methods and technologies for maximizing what is preserved from the sensory motor system after cerebrovascular insult. The rehabilitation technique named functional electrical therapy was investigated in more than 60 patients in acute, subacute and chronic phase after cerebrovascular insult. The functional sensory information generated by functional electrical therapy was hypothesized to result in the intensive functional brain training of the activities performed. Functional electrical therapy is a combination of functional exercise and electrical therapy. The functional electrical therapy protocol comprises voluntary movement of the paretic arm in synchrony with the electrically assisted hand functions in order to perform typical daily activities. The daily treatment of 30 minutes lasts three weeks. The outcome measures include several tests for the evaluation of arm/hand functionality: upper extremity function test, drawing test, modified Aschworth scale, motor activity log and passive range of movement. Results from our several clinical studies showed that functional electrical therapy, if applied in acute and subacute stroke patients, leads to faster and greater improvement of functioning of the hemiplegic arm/hand compared to the control group. The outcomes were significantly superior at all times after the treatment for the higher functioning group. Additional well-planned clinical studies are needed to determine the adequate dose of treatment (timing, duration, intensity) with functional electrical therapy regarding the patient's status. A combination with other techniques should be further investigated.
Functional Task Test: Data Review

NASA Technical Reports Server (NTRS)

Cromwell, Ronita

2014-01-01

After space flight there are changes in multiple physiological systems including: Cardiovascular function; Sensorimotor function; and Muscle function. How do changes in these physiological system impact astronaut functional performance?
Stretched hydrogen molecule from a constrained-search density-functional perspective

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

Valone, Steven M; Levy, Mel

2009-01-01

Constrained-search density functional theory gives valuable insights into the fundamentals of density functional theory. It provides exact results and bounds on the ground- and excited-state density functionals. An important advantage of the theory is that it gives guidance in the construction of functionals. Here they engage constrained search theory to explore issues associated with the functional behavior of 'stretched bonds' in molecular hydrogen. A constrained search is performed with familiar valence bond wavefunctions ordinarily used to describe molecular hydrogen. The effective, one-electron hamiltonian is computed and compared to the corresponding uncorrelated, Hartree-Fock effective hamiltonian. Analysis of the functional suggests themore » need to construct different functionals for the same density and to allow a competition among these functions. As a result the correlation energy functional is composed explicitly of energy gaps from the different functionals.« less
The Functional Classification of Brain Damage-Related Vision Loss

ERIC Educational Resources Information Center

Colenbrander, August

2009-01-01

This article provides a terminological framework to show the relationships among different types of visual deficits. It distinguishes between visual functions, which describe how the eye and the lower visual system function, and functional vision, which describes how a person functions. When visual functions are disturbed, the term "visual…
Compressed Continuous Computation v. 12/20/2016

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

Gorodetsky, Alex

2017-02-17

A library for performing numerical computation with low-rank functions. The (C3) library enables performing continuous linear and multilinear algebra with multidimensional functions. Common tasks include taking "matrix" decompositions of vector- or matrix-valued functions, approximating multidimensional functions in low-rank format, adding or multiplying functions together, integrating multidimensional functions.
Assessing and Treating Stereotypical Behaviors in Classrooms Using a Functional Approach

ERIC Educational Resources Information Center

Bruhn, Allison L.; Balint-Langel, Kinga; Troughton, Leonard; Langan, Sean; Lodge, Kelsey; Kortemeyer, Sara

2015-01-01

For years, the assumption has been that stereotypical behaviors functioned only to provide sensory or automatic reinforcement. However, these behaviors also may serve social functions. Given the unsettled debate, functional behavior assessment and functional analysis can be used to identify the exact function of stereotypical behavior and design…
20 CFR 667.220 - What Workforce Investment Act title I functions and activities constitute the costs of...

Code of Federal Regulations, 2010 CFR

2010-04-01

... cash management functions; (ii) Procurement and purchasing functions; (iii) Property management functions; (iv) Personnel management functions; (v) Payroll functions; (vi) Coordinating the resolution of... for official business in carrying out administrative activities or the overall management of the WIA...
Functional Analysis of HIV/AIDS Stigma: Consensus or Divergence?

ERIC Educational Resources Information Center

Hosseinzadeh, Hassan; Hossain, Syeda Zakia

2011-01-01

Functional theory proposes that attitudes may serve a variety of purposes for individuals. This study aimed to determine whether stigmatized attitudes toward HIV/AIDS serve the same function for all (consensus function) or serve different functions for different individuals (divergence function) by assessing various aspects of HIV/AIDS stigma…
Age and Adaptive Functioning in Children and Adolescents with ASD: The Effects of Intellectual Functioning and ASD Symptom Severity.

PubMed

Hill, Trenesha L; Gray, Sarah A O; Kamps, Jodi L; Enrique Varela, R

2015-12-01

The present study examined the moderating effects of intellectual functioning and ASD symptom severity on the relation between age and adaptive functioning in 220 youth with autism spectrum disorder (ASD). Regression analysis indicated that intellectual functioning and ASD symptom severity moderated the relation between age and adaptive functioning. For younger children with lower intellectual functioning, higher ASD symptom severity was associated with better adaptive functioning than that of those with lower ASD symptom severity. Similarly, for older children with higher intellectual functioning, higher ASD symptom severity was associated with better adaptive functioning than that of those with lower ASD symptom severity. Analyses by subscales suggest that this pattern is driven by the Conceptual subscale. Clinical and research implications are discussed.
Age and Adaptive Functioning in Children and Adolescents with ASD: The Effects of Intellectual Functioning and ASD Symptom Severity

PubMed Central

Hill, Trenesha L.; Gray, Sarah A. O.; Kamps, Jodi L.; Varela, R. Enrique

2016-01-01

The present study examined the moderating effects of intellectual functioning and ASD symptom severity on the relation between age and adaptive functioning in 220 youth with autism spectrum disorder (ASD). Regression analysis indicated that intellectual functioning and ASD symptom severity moderated the relation between age and adaptive functioning. For younger children with lower intellectual functioning, higher ASD symptom severity was associated with better adaptive functioning than that of those with lower ASD symptom severity. Similarly, for older children with higher intellectual functioning, higher ASD symptom severity was associated with better adaptive functioning than that of those with lower ASD symptom severity. Analyses by subscales suggest that this pattern is driven by the Conceptual subscale. Clinical and research implications are discussed. PMID:26174048
Proteins with neomorphic moonlighting functions in disease.

PubMed

Jeffery, Constance J

2011-07-01

One gene can encode multiple protein functions because of RNA splice variants, gene fusions during evolution, promiscuous enzyme activities, and moonlighting protein functions. In addition to these types of multifunctional proteins, in which both functions are considered "normal" functions of a protein, some proteins have been described in which a mutation or conformational change imparts a second function on a protein that is not a "normal" function of the protein. We propose to call these new functions "neomorphic moonlighting functions". The most common examples of neomorphic moonlighting functions are due to conformational changes that impart novel protein-protein interactions resulting in the formation of protein aggregates in Alzheimers, Parkinsons disease, and the systemic amyloidoses. Other changes that can result in a neomorphic moonlighting function include a mutation in SMAD4 that causes the protein to bind to new promoters and thereby alter gene transcription patterns, mutations in two isocitrate dehydrogenase isoforms that impart a new catalytic activity, and mutations in dihydrolipoamide dehydrogenase that activate a hidden protease activity. These neomorphic moonlighting functions were identified because of their connection to disease. In the cases described herein, the new functions cause cancers or severe neurological impairment, although in most cases the mechanism by which the new function leads to disease is unknown. Copyright © 2011 Wiley Periodicals, Inc.
Combined Henyey-Greenstein and Rayleigh phase function.

PubMed

Liu, Quanhua; Weng, Fuzhong

2006-10-01

The phase function is an important parameter that affects the distribution of scattered radiation. In Rayleigh scattering, a scatterer is approximated by a dipole, and its phase function is analytically related to the scattering angle. For the Henyey-Greenstein (HG) approximation, the phase function preserves only the correct asymmetry factor (i.e., the first moment), which is essentially important for anisotropic scattering. When the HG function is applied to small particles, it produces a significant error in radiance. In addition, the HG function is applied only for an intensity radiative transfer. We develop a combined HG and Rayleigh (HG-Rayleigh) phase function. The HG phase function plays the role of modulator extending the application of the Rayleigh phase function for small asymmetry scattering. The HG-Rayleigh phase function guarantees the correct asymmetry factor and is valid for a polarization radiative transfer. It approaches the Rayleigh phase function for small particles. Thus the HG-Rayleigh phase function has wider applications for both intensity and polarimetric radiative transfers. For microwave radiative transfer modeling in this study, the largest errors in the brightness temperature calculations for weak asymmetry scattering are generally below 0.02 K by using the HG-Rayleigh phase function. The errors can be much larger, in the 1-3 K range, if the Rayleigh and HG functions are applied separately.
Monitoring of Total and Regional Liver Function after SIRT.

PubMed

Bennink, Roelof J; Cieslak, Kasia P; van Delden, Otto M; van Lienden, Krijn P; Klümpen, Heinz-Josef; Jansen, Peter L; van Gulik, Thomas M

2014-01-01

Selective internal radiation therapy (SIRT) is a promising treatment modality for advanced hepatocellular carcinoma or metastatic liver cancer. SIRT is usually well tolerated. However, in most patients, SIRT will result in a (temporary) decreased liver function. Occasionally patients develop radioembolization-induced liver disease (REILD). In case of a high tumor burden of the liver, it could be beneficial to perform SIRT in two sessions enabling the primary untreated liver segments to guarantee liver function until function in the treated segments has recovered or functional hypertrophy has occurred. Clinically used liver function tests provide evidence of only one of the many liver functions, though all of them lack the possibility of assessment of segmental (regional) liver function. Hepatobiliary scintigraphy (HBS) has been validated as a tool to assess total and regional liver function in liver surgery. It is also used to assess segmental liver function before and after portal vein embolization. HBS is considered as a valuable quantitative liver function test enabling assessment of segmental liver function recovery after regional intervention and determination of future remnant liver function. We present two cases in which HBS was used to monitor total and regional liver function in a patient after repeated whole liver SIRT complicated with REILD and a patient treated unilaterally without complications.
Adaptive functioning following pediatric traumatic brain injury: Relationship to executive function and processing speed.

PubMed

Shultz, Emily L; Hoskinson, Kristen R; Keim, Madelaine C; Dennis, Maureen; Taylor, H Gerry; Bigler, Erin D; Rubin, Kenneth H; Vannatta, Kathryn; Gerhardt, Cynthia A; Stancin, Terry; Yeates, Keith Owen

2016-10-01

Pediatric traumatic brain injury (TBI) may affect children's ability to perform everyday tasks (i.e., adaptive functioning). Guided by the American Association for Intellectual and Developmental Disabilities (AAIDD) model, we explored the association between TBI and adaptive functioning at increasing levels of specificity (global, AAIDD domains, and subscales). We also examined the contributions of executive function and processing speed as mediators of TBI's effects on adaptive functioning. Children (ages 8-13) with severe TBI (STBI; n = 19), mild-moderate TBI (MTBI; n = 50), or orthopedic injury (OI; n = 60) completed measures of executive function (TEA-Ch) and processing speed (WISC-IV) an average of 2.7 years postinjury (SD = 1.2; range: 1-5.3). Parents rated children's adaptive functioning (ABAS-II, BASC-2, CASP). STBI had lower global adaptive functioning (η2 = .04-.08) than the MTBI and OI groups, which typically did not differ. Deficits in the STBI group were particularly evident in the social domain, with specific deficits in social participation, leisure, and social adjustment (η2 = .06-.09). Jointly, executive function and processing speed were mediators of STBI's effects on global adaptive functioning and in conceptual and social domains. In the STBI group, executive function mediated social functioning, and processing speed mediated social participation. Children with STBI experience deficits in adaptive functioning, particularly in social adjustment, with less pronounced deficits in conceptual and practical skills. Executive function and processing speed may mediate the effects of STBI on adaptive functioning. Targeting adaptive functioning and associated cognitive deficits for intervention may enhance quality of life for pediatric TBI survivors. (PsycINFO Database Record (c) 2016 APA, all rights reserved).
Adaptive functioning following pediatric traumatic brain injury: Relationship to executive function and processing speed

PubMed Central

Shultz, Emily; Robinson, Kristen E.; Keim, Madelaine; Dennis, Maureen; Taylor, H. Gerry; Bigler, Erin D.; Rubin, Kenneth H.; Vannatta, Kathryn; Gerhardt, Cynthia A.; Stancin, Terry; Yeates, Keith Owen

2016-01-01

Objective Pediatric traumatic brain injury (TBI) may affect children’s ability to perform everyday tasks (i.e., adaptive functioning). Guided by the American Association for Intellectual and Developmental Disabilities (AAIDD) model, we explored the association between TBI and adaptive functioning at increasing levels of specificity (global, AAIDD domains, and subscales). We also examined the contributions of executive function and processing speed as mediators of TBI’s effects on adaptive functioning. Method Children (ages 8–13) with severe TBI (STBI; n=19), mild-moderate TBI (MTBI; n=50), or orthopedic injury (OI; n=60) completed measures of executive function (TEA-Ch) and processing speed (WISC-IV) an average of 2.7 years post-injury (SD = 1.2; range: 1–5.3). Parents rated children’s adaptive functioning (ABAS-II, BASC-2, CASP). Results STBI had lower global adaptive functioning (η2 = .04–.08) than the MTBI and OI groups, which typically did not differ. Deficits in the STBI group were particularly evident in the social domain, with specific deficits in social participation, leisure, and social adjustment (η2 = .06–.09). Jointly, executive function and processing speed were mediators of STBI’s effects on global adaptive functioning and in conceptual and social domains. In the STBI group, executive function mediated social functioning, and processing speed mediated social participation. Conclusions Children with STBI experience deficits in adaptive functioning, particularly in social adjustment, with less pronounced deficits in conceptual and practical skills. Executive function and processing speed may mediate the effects of STBI on adaptive functioning. Targeting adaptive functioning and associated cognitive deficits for intervention may enhance quality of life for pediatric TBI survivors. PMID:27182708
Relation between hand function and gross motor function in full term infants aged 4 to 8 months.

PubMed

Nogueira, Solange F; Figueiredo, Elyonara M; Gonçalves, Rejane V; Mancini, Marisa C

2015-01-01

In children, reaching emerges around four months of age, which is followed by rapid changes in hand function and concomitant changes in gross motor function, including the acquisition of independent sitting. Although there is a close functional relationship between these domains, to date they have been investigated separately. To investigate the longitudinal profile of changes and the relationship between the development of hand function (i.e. reaching for and manipulating an object) and gross motor function in 13 normally developing children born at term who were evaluated every 15 days from 4 to 8 months of age. The number of reaches and the period (i.e. time) of manipulation to an object were extracted from video synchronized with the Qualisys(r) movement analysis system. Gross motor function was measured using the Alberta Infant Motor Scale. ANOVA for repeated measures was used to test the effect of age on the number of reaches, the time of manipulation and gross motor function. Hierarchical regression models were used to test the associations of reaching and manipulation with gross motor function. RESULTS revealed a significant increase in the number of reaches (p<0.001), the time of manipulation (p<0.001) and gross motor function (p<0.001) over time, as well as associations between reaching and gross motor function (R2=0.84; p<0.001) and manipulation and gross motor function (R2=0.13; p=0.02) from 4 to 6 months of age. Associations from 6 to 8 months of age were not significant. The relationship between hand function and gross motor function was not constant, and the age span from 4 to 6 months was a critical period of interdependency of hand function and gross motor function development.
Hydrodynamics-based functional forms of activity metabolism: a case for the power-law polynomial function in animal swimming energetics.

PubMed

Papadopoulos, Anthony

2009-01-01

The first-degree power-law polynomial function is frequently used to describe activity metabolism for steady swimming animals. This function has been used in hydrodynamics-based metabolic studies to evaluate important parameters of energetic costs, such as the standard metabolic rate and the drag power indices. In theory, however, the power-law polynomial function of any degree greater than one can be used to describe activity metabolism for steady swimming animals. In fact, activity metabolism has been described by the conventional exponential function and the cubic polynomial function, although only the power-law polynomial function models drag power since it conforms to hydrodynamic laws. Consequently, the first-degree power-law polynomial function yields incorrect parameter values of energetic costs if activity metabolism is governed by the power-law polynomial function of any degree greater than one. This issue is important in bioenergetics because correct comparisons of energetic costs among different steady swimming animals cannot be made unless the degree of the power-law polynomial function derives from activity metabolism. In other words, a hydrodynamics-based functional form of activity metabolism is a power-law polynomial function of any degree greater than or equal to one. Therefore, the degree of the power-law polynomial function should be treated as a parameter, not as a constant. This new treatment not only conforms to hydrodynamic laws, but also ensures correct comparisons of energetic costs among different steady swimming animals. Furthermore, the exponential power-law function, which is a new hydrodynamics-based functional form of activity metabolism, is a special case of the power-law polynomial function. Hence, the link between the hydrodynamics of steady swimming and the exponential-based metabolic model is defined.

Residual symptoms and specific functional impairments in euthymic patients with bipolar disorder.

PubMed

Samalin, Ludovic; de Chazeron, Ingrid; Vieta, Eduard; Bellivier, Frank; Llorca, Pierre-Michel

2016-03-01

The aims of the present study were to confirm the impact of residual symptoms on overall functioning in a large sample of euthymic patients with bipolar disorder in real-life conditions and to explore the relationship between residual symptoms and specific areas of functional impairment. This was a multicenter, cross-sectional, non-interventional study of euthymic outpatients with bipolar disorder. The Functioning Assessment Short Test was used to assess overall and specific domains of functioning (autonomy, occupational functioning, cognitive functioning, financial issues, interpersonal relationships, and leisure time). Various residual symptoms were assessed (residual mood symptoms, emotional dysregulation, sleep and sexual disorders, stigma, and perceived cognitive impairment). Logistic regression was used to determine the best model of association between functional domains and residual symptoms. Almost half of the 468 patients included (42%) had poor overall functioning. Residual depressive symptoms appeared to have an impact on overall functioning and in nearly all areas of functioning. In addition, specific residual symptoms had significantly more negative effects on some domains of functioning in euthymic patients with bipolar disorder (residual manic symptoms and occupational stigma on autonomy, emotional inhibition on occupational functioning, residual manic symptoms on financial issues, family stigma on interpersonal relationships, and sexual function and occupational stigma on leisure time). Our findings highlight the importance of evaluating overall functioning in clinical practice as well as functional domains. They also indicate that some residuals symptoms in patients with bipolar disorder should be targeted in personalized treatment plans, in order to improve functioning in the domains in which the patient is most impaired. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
Functional vision in children with perinatal brain damage.

PubMed

Alimović, Sonja; Jurić, Nikolina; Bošnjak, Vlatka Mejaški

2014-09-01

Many authors have discussed the effects of visual stimulations on visual functions, but there is no research about the effects on using vision in everyday activities (i.e. functional vision). Children with perinatal brain damage can develop cerebral visual impairment with preserved visual functions (e.g. visual acuity, contrast sensitivity) but poor functional vision. Our aim was to discuss the importance of assessing and stimulating functional vision in children with perinatal brain damage. We assessed visual functions (grating visual acuity, contrast sensitivity) and functional vision (the ability of maintaining visual attention and using vision in communication) in 99 children with perinatal brain damage and visual impairment. All children were assessed before and after the visual stimulation program. Our first assessment results showed that children with perinatal brain damage had significantly more problems in functional vision than in basic visual functions. During the visual stimulation program both variables of functional vision and contrast sensitivity improved significantly, while grating acuity improved only in 2.7% of children. We also found that improvement of visual attention significantly correlated to improvement on all other functions describing vision. Therefore, functional vision assessment, especially assessment of visual attention is indispensable in early monitoring of child with perinatal brain damage.
Relationship between theory of mind and functional independence is mediated by executive function.

PubMed

Ahmed, Fayeza S; Miller, L Stephen

2013-06-01

Theory of mind (ToM) is the ability to comprehend another person's perspective. Although there is much literature of ToM in children, there is a limited and somewhat inconclusive amount of studies examining ToM in a geriatric population. This study examined ToM's relationship to functional independence. Two tests of ToM, tests of executive function, and a measure of functional ability were administered to cognitively intact older adults. Results showed that 1 test of ToM (Strange Stories test) significantly accounted for variance in functional ability, whereas the other did not (Faux Pas test). In addition, Strange Stories test performance was partially driven by a verbal abstraction-based executive function: proverb interpretation. A multiple mediation model was employed to examine whether executive functions explained the relationship between the Strange Stories test and functional ability. Results showed that both the combined and individual indirect effects of the executive function measures mediated the relationship. We argue that, although components of ToM are associated with functional independence, ToM does not appear to account for additional variance in functional independence beyond executive function measures. PsycINFO Database Record (c) 2013 APA, all rights reserved.
Robust, Adaptive Functional Regression in Functional Mixed Model Framework.

PubMed

Zhu, Hongxiao; Brown, Philip J; Morris, Jeffrey S

2011-09-01

Functional data are increasingly encountered in scientific studies, and their high dimensionality and complexity lead to many analytical challenges. Various methods for functional data analysis have been developed, including functional response regression methods that involve regression of a functional response on univariate/multivariate predictors with nonparametrically represented functional coefficients. In existing methods, however, the functional regression can be sensitive to outlying curves and outlying regions of curves, so is not robust. In this paper, we introduce a new Bayesian method, robust functional mixed models (R-FMM), for performing robust functional regression within the general functional mixed model framework, which includes multiple continuous or categorical predictors and random effect functions accommodating potential between-function correlation induced by the experimental design. The underlying model involves a hierarchical scale mixture model for the fixed effects, random effect and residual error functions. These modeling assumptions across curves result in robust nonparametric estimators of the fixed and random effect functions which down-weight outlying curves and regions of curves, and produce statistics that can be used to flag global and local outliers. These assumptions also lead to distributions across wavelet coefficients that have outstanding sparsity and adaptive shrinkage properties, with great flexibility for the data to determine the sparsity and the heaviness of the tails. Together with the down-weighting of outliers, these within-curve properties lead to fixed and random effect function estimates that appear in our simulations to be remarkably adaptive in their ability to remove spurious features yet retain true features of the functions. We have developed general code to implement this fully Bayesian method that is automatic, requiring the user to only provide the functional data and design matrices. It is efficient enough to handle large data sets, and yields posterior samples of all model parameters that can be used to perform desired Bayesian estimation and inference. Although we present details for a specific implementation of the R-FMM using specific distributional choices in the hierarchical model, 1D functions, and wavelet transforms, the method can be applied more generally using other heavy-tailed distributions, higher dimensional functions (e.g. images), and using other invertible transformations as alternatives to wavelets.
Robust, Adaptive Functional Regression in Functional Mixed Model Framework

PubMed Central

Zhu, Hongxiao; Brown, Philip J.; Morris, Jeffrey S.

2012-01-01

Functional data are increasingly encountered in scientific studies, and their high dimensionality and complexity lead to many analytical challenges. Various methods for functional data analysis have been developed, including functional response regression methods that involve regression of a functional response on univariate/multivariate predictors with nonparametrically represented functional coefficients. In existing methods, however, the functional regression can be sensitive to outlying curves and outlying regions of curves, so is not robust. In this paper, we introduce a new Bayesian method, robust functional mixed models (R-FMM), for performing robust functional regression within the general functional mixed model framework, which includes multiple continuous or categorical predictors and random effect functions accommodating potential between-function correlation induced by the experimental design. The underlying model involves a hierarchical scale mixture model for the fixed effects, random effect and residual error functions. These modeling assumptions across curves result in robust nonparametric estimators of the fixed and random effect functions which down-weight outlying curves and regions of curves, and produce statistics that can be used to flag global and local outliers. These assumptions also lead to distributions across wavelet coefficients that have outstanding sparsity and adaptive shrinkage properties, with great flexibility for the data to determine the sparsity and the heaviness of the tails. Together with the down-weighting of outliers, these within-curve properties lead to fixed and random effect function estimates that appear in our simulations to be remarkably adaptive in their ability to remove spurious features yet retain true features of the functions. We have developed general code to implement this fully Bayesian method that is automatic, requiring the user to only provide the functional data and design matrices. It is efficient enough to handle large data sets, and yields posterior samples of all model parameters that can be used to perform desired Bayesian estimation and inference. Although we present details for a specific implementation of the R-FMM using specific distributional choices in the hierarchical model, 1D functions, and wavelet transforms, the method can be applied more generally using other heavy-tailed distributions, higher dimensional functions (e.g. images), and using other invertible transformations as alternatives to wavelets. PMID:22308015
Research on Bounded Rationality of Fuzzy Choice Functions

PubMed Central

Wu, Xinlin; Zhao, Yong

2014-01-01

The rationality of a fuzzy choice function is a hot research topic in the study of fuzzy choice functions. In this paper, two common fuzzy sets are studied and analyzed in the framework of the Banerjee choice function. The complete rationality and bounded rationality of fuzzy choice functions are defined based on the two fuzzy sets. An assumption is presented to study the fuzzy choice function, and especially the fuzzy choice function with bounded rationality is studied combined with some rationality conditions. Results show that the fuzzy choice function with bounded rationality also satisfies some important rationality conditions, but not vice versa. The research gives supplements to the investigation in the framework of the Banerjee choice function. PMID:24782677
Research on bounded rationality of fuzzy choice functions.

PubMed

Wu, Xinlin; Zhao, Yong

2014-01-01

The rationality of a fuzzy choice function is a hot research topic in the study of fuzzy choice functions. In this paper, two common fuzzy sets are studied and analyzed in the framework of the Banerjee choice function. The complete rationality and bounded rationality of fuzzy choice functions are defined based on the two fuzzy sets. An assumption is presented to study the fuzzy choice function, and especially the fuzzy choice function with bounded rationality is studied combined with some rationality conditions. Results show that the fuzzy choice function with bounded rationality also satisfies some important rationality conditions, but not vice versa. The research gives supplements to the investigation in the framework of the Banerjee choice function.
Characterization of Strength and Function in Ambulatory Adults With GNE Myopathy.

PubMed

Argov, Zohar; Bronstein, Faye; Esposito, Alicia; Feinsod-Meiri, Yael; Florence, Julaine M; Fowler, Eileen; Greenberg, Marcia B; Malkus, Elizabeth C; Rebibo, Odelia; Siener, Catherine S; Caraco, Yoseph; Kolodny, Edwin H; Lau, Heather A; Pestronk, Alan; Shieh, Perry; Skrinar, Alison M; Mayhew, Jill E

2017-09-01

To characterize the pattern and extent of muscle weakness and impact on physical functioning in adults with GNEM. Strength and function were assessed in GNEM subjects (n = 47) using hand-held dynamometry, manual muscle testing, upper and lower extremity functional capacity tests, and the GNEM-Functional Activity Scale (GNEM-FAS). Profound upper and lower muscle weakness was measured using hand-held dynamometry in a characteristic pattern, previously described. Functional tests and clinician-reported outcomes demonstrated the consequence of muscle weakness on physical functioning. The characteristic pattern of upper and lower muscle weakness associated with GNEM and the resulting functional limitations can be reliably measured using these clinical outcome assessments of muscle strength and function.
Wave function for harmonically confined electrons in time-dependent electric and magnetostatic fields.

PubMed

Zhu, Hong-Ming; Chen, Jin-Wang; Pan, Xiao-Yin; Sahni, Viraht

2014-01-14

We derive via the interaction "representation" the many-body wave function for harmonically confined electrons in the presence of a magnetostatic field and perturbed by a spatially homogeneous time-dependent electric field-the Generalized Kohn Theorem (GKT) wave function. In the absence of the harmonic confinement - the uniform electron gas - the GKT wave function reduces to the Kohn Theorem wave function. Without the magnetostatic field, the GKT wave function is the Harmonic Potential Theorem wave function. We further prove the validity of the connection between the GKT wave function derived and the system in an accelerated frame of reference. Finally, we provide examples of the application of the GKT wave function.
Rice functional genomics research in China.

PubMed

Han, Bin; Xue, Yongbiao; Li, Jiayang; Deng, Xing-Wang; Zhang, Qifa

2007-06-29

Rice functional genomics is a scientific approach that seeks to identify and define the function of rice genes, and uncover when and how genes work together to produce phenotypic traits. Rapid progress in rice genome sequencing has facilitated research in rice functional genomics in China. The Ministry of Science and Technology of China has funded two major rice functional genomics research programmes for building up the infrastructures of the functional genomics study such as developing rice functional genomics tools and resources. The programmes were also aimed at cloning and functional analyses of a number of genes controlling important agronomic traits from rice. National and international collaborations on rice functional genomics study are accelerating rice gene discovery and application.
Pulmonary function and the risk of functional limitation in chronic obstructive pulmonary disease.

PubMed

Eisner, Mark D; Iribarren, Carlos; Yelin, Edward H; Sidney, Stephen; Katz, Patricia P; Ackerson, Lynn; Lathon, Phenius; Tolstykh, Irina; Omachi, Theodore; Byl, Nancy; Blanc, Paul D

2008-05-01

The authors' objective was to analyze the impact of respiratory impairment on the risk of physical functional limitations among adults with chronic obstructive pulmonary disease (COPD). They hypothesized that greater pulmonary function decrement would result in a broad array of physical functional limitations involving organ systems remote from the lung, a key step in the pathway leading to overall disability. The authors used baseline data from the Function, Living, Outcomes, and Work (FLOW) study, a prospective cohort study of adults with COPD recruited from northern California in 2005-2007. They studied the impact of pulmonary function impairment on the risk of functional limitations using validated measures: lower extremity function (Short Physical Performance Battery), submaximal exercise performance (6-Minute Walk Test), standing balance (Functional Reach Test), skeletal muscle strength (manual muscle testing with dynamometry), and self-reported functional limitation (standardized item battery). Multiple variable analysis was used to control for confounding by age, sex, race, height, educational attainment, and cigarette smoking. Greater pulmonary function impairment, as evidenced by lower forced expiratory volume in 1 second (FEV(1)), was associated with poorer Short Physical Performance Battery scores and less distance walked during the 6-Minute Walk Test. Lower forced expiratory volume in 1 second was also associated with weaker muscle strength and with a greater risk of self-reported functional limitation (p < 0.05). In conclusion, pulmonary function impairment is associated with multiple manifestations of physical functional limitation among COPD patients. Longitudinal follow-up can delineate the impact of these functional limitations on the prospective risk of disability, guiding preventive strategies that could attenuate the disablement process.
The norms and variances of the Gabor, Morlet and general harmonic wavelet functions

NASA Astrophysics Data System (ADS)

Simonovski, I.; Boltežar, M.

2003-07-01

This paper deals with certain properties of the continuous wavelet transform and wavelet functions. The norms and the spreads in time and frequency of the common Gabor and Morlet wavelet functions are presented. It is shown that the norm of the Morlet wavelet function does not satisfy the normalization condition and that the normalized Morlet wavelet function is identical to the Gabor wavelet function with the parameter σ=1. The general harmonic wavelet function is developed using frequency modulation of the Hanning and Hamming window functions. Several properties of the general harmonic wavelet function are also presented and compared to the Gabor wavelet function. The time and frequency spreads of the general harmonic wavelet function are only slightly higher than the time and frequency spreads of the Gabor wavelet function. However, the general harmonic wavelet function is simpler to use than the Gabor wavelet function. In addition, the general harmonic wavelet function can be constructed in such a way that the zero average condition is truly satisfied. The average value of the Gabor wavelet function can approach a value of zero but it cannot reach it. When calculating the continuous wavelet transform, errors occur at the start- and the end-time indexes. This is called the edge effect and is caused by the fact that the wavelet transform is calculated from a signal of finite length. In this paper, we propose a method that uses signal mirroring to reduce the errors caused by the edge effect. The success of the proposed method is demonstrated by using a simulated signal.
START: an advanced radiation therapy information system.

PubMed

Cocco, A; Valentini, V; Balducci, M; Mantello, G

1996-01-01

START is an advanced radiation therapy information system (RTIS) which connects direct information technology present in the devices with indirect information technology for clinical, administrative, information management integrated with the hospital information system (HIS). The following objectives are pursued: to support decision making in treatment planning and functional and information integration with the rest of the hospital; to enhance organizational efficiency of a Radiation Therapy Department; to facilitate the statistical evaluation of clinical data and managerial performance assessment; to ensure the safety and confidentiality of used data. For its development a working method based on the involvement of all operators of the Radiation Therapy Department, was applied. Its introduction in the work activity was gradual, trying to reuse and integrate the existing information applications. The START information flow identifies four major phases: admission, visit of admission, planning, therapy. The system main functionalities available to the radiotherapist are: clinical history/medical report linking function; folder function; planning function; tracking function; electronic mail and banner function; statistical function; management function. Functions available to the radiotherapy technician are: the room daily list function; management function: to the nurse the following functions are available: patient directing function; management function. START is a departmental client (pc-windows)-server (unix) developed on an integrated database of all information of interest (clinical, organizational and administrative) coherent with the standard and with a modular architecture which can evolve with additional functionalities in subsequent times. For a more thorough evaluation of its impact on the daily activity of a radiation therapy facility, a prolonged clinical validation is in progress.
Self-Critical, and Robust, Procedures for the Analysis of Multivariate Normal Data.

DTIC Science & Technology

1982-06-01

Influence Functions The influence function is the most important tt of qual- itative zobustness since many other robustness characteristics of an estimator...may be derived from it. The influence function characterizes the (asymptotic) response of an estimator to an additional observation as a function of...the influence function be bounded. It is also advantageous, in our opinion, if the influence functions are re-descending to zero. The influence function for
Relationships between the decoupled and coupled transfer functions: Theoretical studies and experimental validation

NASA Astrophysics Data System (ADS)

Wang, Zengwei; Zhu, Ping; Liu, Zhao

2018-01-01

A generalized method for predicting the decoupled transfer functions based on in-situ transfer functions is proposed. The method allows predicting the decoupled transfer functions using coupled transfer functions, without disassembling the system. Two ways to derive relationships between the decoupled and coupled transfer functions are presented. Issues related to immeasurability of coupled transfer functions are also discussed. The proposed method is validated by numerical and experimental case studies.
Auditory Weighting Functions and TTS/PTS Exposure Functions for Marine Mammals Exposed to Underwater Noise

DTIC Science & Technology

2016-12-01

weighting functions utilized the “M-weighting” functions at lower frequencies, where no TTS existed at that time . Since derivation of the Phase 2...resulting shapes of the weighting functions (left) and exposure functions (right). The arrows indicate the direction of change when the designated parameter...thresholds are in dB re 1 μPa ..................................... iv 1. Species group designations for Navy Phase 3 auditory weighting functions
Functional performance testing for power and return to sports.

PubMed

Manske, Robert; Reiman, Michael

2013-05-01

Functional performance testing of athletes can determine physical limitations that may affect sporting activities. Optimal functional performance testing simulates the athlete's activity. A Medline search from 1960 to 2012 was implemented with the keywords functional testing, functional impairment testing, and functional performance testing in the English language. Each author also undertook independent searches of article references. Functional performance tests can bridge the gap between general physical tests and full, unrestricted athletic activity.
Transforming Functions by Rescaling Axes

ERIC Educational Resources Information Center

Ferguson, Robert

2017-01-01

Students are often asked to plot a generalised parent function from their knowledge of a parent function. One approach is to sketch the parent function, choose a few points on the parent function curve, transform and plot these points, and use the transformed points as a guide to sketching the generalised parent function. Another approach is to…
45 CFR 155.705 - Functions of a SHOP.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 45 Public Welfare 1 2014-10-01 2014-10-01 false Functions of a SHOP. 155.705 Section 155.705... Functions: Small Business Health Options Program (SHOP) § 155.705 Functions of a SHOP. (a) Exchange functions that apply to SHOP. The SHOP must carry out all the required functions of an Exchange described in...
On computing closed forms for summations. [polynomials and rational functions

NASA Technical Reports Server (NTRS)

Moenck, R.

1977-01-01

The problem of finding closed forms for a summation involving polynomials and rational functions is considered. A method closely related to Hermite's method for integration of rational functions derived. The method expresses the sum of a rational function as a rational function part and a transcendental part involving derivatives of the gamma function.

Trial-Based Functional Analysis and Functional Communication Training in an Early Childhood Setting

ERIC Educational Resources Information Center

Lambert, Joseph M.; Bloom, Sarah E.; Irvin, Jennifer

2012-01-01

Problem behavior is common in early childhood special education classrooms. Functional communication training (FCT; Carr & Durand, 1985) may reduce problem behavior but requires identification of its function. The trial-based functional analysis (FA) is a method that can be used to identify problem behavior function in schools. We conducted…
Facilitating the Genesis of Functional Working Spaces in Guided Explorations

ERIC Educational Resources Information Center

Miranda, Vicente Carrión; Pluvinage, François; Adjiage, Robert

2016-01-01

Approximating given real-valued functions by affine functions is among the most basic activities with functions. In this study we examine two contexts in which two such approximations are performed. The first involves a microscopic representation of functions for the study of tangents; the second a macroscopic representation of functions for the…
Challenging Stereotypes: Sexual Functioning of Single Adults with High Functioning Autism Spectrum Disorder

ERIC Educational Resources Information Center

Byers, E. Sandra; Nichols, Shana; Voyer, Susan D.

2013-01-01

This study examined the sexual functioning of single adults (61 men, 68 women) with high functioning autism and Asperger syndrome living in the community with and without prior relationship experience. Participants completed an on-line questionnaire assessing autism symptoms, psychological functioning, and various aspects of sexual functioning. In…
Multiconfiguration Pair-Density Functional Theory Outperforms Kohn-Sham Density Functional Theory and Multireference Perturbation Theory for Ground-State and Excited-State Charge Transfer.

PubMed

Ghosh, Soumen; Sonnenberger, Andrew L; Hoyer, Chad E; Truhlar, Donald G; Gagliardi, Laura

2015-08-11

The correct description of charge transfer in ground and excited states is very important for molecular interactions, photochemistry, electrochemistry, and charge transport, but it is very challenging for Kohn-Sham (KS) density functional theory (DFT). KS-DFT exchange-correlation functionals without nonlocal exchange fail to describe both ground- and excited-state charge transfer properly. We have recently proposed a theory called multiconfiguration pair-density functional theory (MC-PDFT), which is based on a combination of multiconfiguration wave function theory with a new type of density functional called an on-top density functional. Here we have used MC-PDFT to study challenging ground- and excited-state charge-transfer processes by using on-top density functionals obtained by translating KS exchange-correlation functionals. For ground-state charge transfer, MC-PDFT performs better than either the PBE exchange-correlation functional or CASPT2 wave function theory. For excited-state charge transfer, MC-PDFT (unlike KS-DFT) shows qualitatively correct behavior at long-range with great improvement in predicted excitation energies.
The advantages of deep ocean water for the development of functional fermentation food.

PubMed

Lee, Chun-Lin

2015-03-01

Deep ocean water (DOW) is obtained from 600 m below the sea surface. In recent years, DOW has been applied in the development of fermentation biotechnologies and functional foods. DOW is rich in trace minerals, comprises multiple physiological and health functions, and is able to promote microbe growth; therefore, the application of DOW directly benefits the development of the fermentation industry and functional foods. This study integrated the current health functions and applications of DOW with the latest results from studies related to fermentation biotechnology. Subsequently, the influence of applying DOW in fermented functional food development and the effects in health function improvements were summarized. According to the previous studies, the main reasons for the increased effect of fermented functional foods through the application of DOW are increased generation of functional metabolite contents in the microbes, intrinsic health functions of DOW, and the microbial use of mechanisms of converting the absorbed inorganic ions into highly bioavailable organic ions for the human body. These combined advantages not only enhance the health functions of fermentation products but also provide fermentation products with the intrinsic health functions of DOW.
Inhomogeneity induced and appropriately parameterized semilocal exchange and correlation energy functionals in two-dimensions.

PubMed

Patra, Abhilash; Jana, Subrata; Samal, Prasanjit

2018-04-07

The construction of meta generalized gradient approximations based on the density matrix expansion (DME) is considered as one of the most accurate techniques to design semilocal exchange energy functionals in two-dimensional density functional formalism. The exchange holes modeled using DME possess unique features that make it a superior entity. Parameterized semilocal exchange energy functionals based on the DME are proposed. The use of different forms of the momentum and flexible parameters is to subsume the non-uniform effects of the density in the newly constructed semilocal functionals. In addition to the exchange functionals, a suitable correlation functional is also constructed by working upon the local correlation functional developed for 2D homogeneous electron gas. The non-local effects are induced into the correlation functional by a parametric form of one of the newly constructed exchange energy functionals. The proposed functionals are applied to the parabolic quantum dots with a varying number of confined electrons and the confinement strength. The results obtained with the aforementioned functionals are quite satisfactory, which indicates why these are suitable for two-dimensional quantum systems.
Inhomogeneity induced and appropriately parameterized semilocal exchange and correlation energy functionals in two-dimensions

NASA Astrophysics Data System (ADS)

Patra, Abhilash; Jana, Subrata; Samal, Prasanjit

2018-04-01

The construction of meta generalized gradient approximations based on the density matrix expansion (DME) is considered as one of the most accurate techniques to design semilocal exchange energy functionals in two-dimensional density functional formalism. The exchange holes modeled using DME possess unique features that make it a superior entity. Parameterized semilocal exchange energy functionals based on the DME are proposed. The use of different forms of the momentum and flexible parameters is to subsume the non-uniform effects of the density in the newly constructed semilocal functionals. In addition to the exchange functionals, a suitable correlation functional is also constructed by working upon the local correlation functional developed for 2D homogeneous electron gas. The non-local effects are induced into the correlation functional by a parametric form of one of the newly constructed exchange energy functionals. The proposed functionals are applied to the parabolic quantum dots with a varying number of confined electrons and the confinement strength. The results obtained with the aforementioned functionals are quite satisfactory, which indicates why these are suitable for two-dimensional quantum systems.
On One-Dimensional Stretching Functions for Finite-Difference Calculations

NASA Technical Reports Server (NTRS)

Vinokur, M.

1980-01-01

The class of one dimensional stretching function used in finite difference calculations is studied. For solutions containing a highly localized region of rapid variation, simple criteria for a stretching function are derived using a truncation error analysis. These criteria are used to investigate two types of stretching functions. One is an interior stretching function, for which the location and slope of an interior clustering region are specified. The simplest such function satisfying the criteria is found to be one based on the inverse hyperbolic sine. The other type of function is a two sided stretching function, for which the arbitrary slopes at the two ends of the one dimensional interval are specified. The simplest such general function is found to be one based on the inverse tangent. The general two sided function has many applications in the construction of finite difference grids.
A survey of functional programming language principles

NASA Technical Reports Server (NTRS)

Holloway, C. M.

1986-01-01

Research in the area of functional programming languages has intensified in the 8 years since John Backus' Turing Award Lecture on the topic was published. The purpose of this paper is to present a survey of the ideas of functional programming languages. The paper assumes the reader is comfortable with mathematics and has knowledge of the basic principles of traditional programming languages, but does not assume any prior knowledge of the ideas of functional languages. A simple functional language is defined and used to illustrate the basic ideas. Topics discussed include the reasons for developing functional languages, methods of expressing concurrency, the algebra of functional programming languages, program transformation techniques, and implementations of functional languages. Existing functional languages are also mentioned. The paper concludes with the author's opinions as to the future of functional languages. An annotated bibliography on the subject is also included.
Treatment of Functional Impairment in Patients with Bipolar Disorder.

PubMed

Sanchez-Moreno, Jose; Martinez-Aran, Anabel; Vieta, Eduard

2017-01-01

Traditionally, functional impairment has received little attention in bipolar disorder, despite the fact that many patients experience significant impairments in daily life. In the last decade, research has changed its focus from clinical remission to functional recovery in bipolar patients as a priority. A literature review of this topic will allow us provide an overview of the relevance of functional impairment as well as the potential factors that can predict or contribute to low functioning in bipolar disorder (BD). Treatment approaches should consider not only euthymia as a goal but also cognitive and functional improvement of patients with such a complex disorder. Functional remediation and psychoeducation among psychological interventions may help to enhance functioning. The combination of cognitive enhancers and cognitive/functional remediation programs may help in improving cognitive and functional impairments. Early interventions are essential to prevent cognitive deficits and disability.
No direct association among respiratory function, disease control and family functioning in a sample of Mexican children with intermittent asthma.

PubMed

Rodriguez-Orozco, Alain Raimundo; Núñez-Tapia, Rosa María; Ramírez-Silva, Armando; Gómez-Alonso, Carlos

2013-05-15

Asthma has been linked to family disfunctioning and poor control of the disease.This study was conducted to analyze the interactions between the level of intermittent asthma control, family functioning and respiratory function and between quality of life of asthmatic patients and their caregivers.7 to 15 years old children with intermittent asthma were included. Asthma Control Test Questionnaire, Pediatric Asthma Quality of Life Questionnaire (PAQLQ) test, and flowmetry were applied to children and Pediatric Asthma Caregiver´s Quatily of Life Questionnaire (PAQCLQ) and the Family Functioning Perception Test (FF-SIL) were applied to their parents.The most affected areas of family functioning in dysfunctional families were adaptability and permeability. A medium to high strength of association was founded between the emotional function of parents and the emotional function of children, R2=0.552. The most remarkable associations were among parents' limitation of activities and parents' emotional function (r=0.837), parents' limitation of activities and child's emotional function (r=0.722), parents' emotional role and limitation of activities (r=0.837), parents' emotional role and emotional functioning of children with asthma (r=0.743) and the limitation of activities of children with asthma and the emotional function of children with asthma (r=0.870).No direct associations were founded among respiratory function, disease control and family functioning in Mexican children with intermittent asthma and emotional function of parents and children were associated in both groups.
Self-assessment in schizophrenia: Accuracy of evaluation of cognition and everyday functioning.

PubMed

Gould, Felicia; McGuire, Laura Stone; Durand, Dante; Sabbag, Samir; Larrauri, Carlos; Patterson, Thomas L; Twamley, Elizabeth W; Harvey, Philip D

2015-09-01

Self-assessment deficits, often referred to as impaired insight or unawareness of illness, are well established in people with schizophrenia. There are multiple levels of awareness, including awareness of symptoms, functional deficits, cognitive impairments, and the ability to monitor cognitive and functional performance in an ongoing manner. The present study aimed to evaluate the comparative predictive value of each aspect of awareness on the levels of everyday functioning in people with schizophrenia. We examined multiple aspects of self-assessment of functioning in 214 people with schizophrenia. We also collected information on everyday functioning rated by high contact clinicians and examined the importance of self-assessment for the prediction of real-world functional outcomes. The relative impact of performance-based measures of cognition, functional capacity, and metacognitive performance on everyday functioning was also examined. Misestimation of ability emerged as the strongest predictor of real-world functioning and exceeded the influences of cognitive performance, functional capacity performance, and performance-based assessment of metacognitive monitoring. The relative contribution of the factors other than self-assessment varied according to which domain of everyday functioning was being examined, but, in all cases, accounted for less predictive variance. These results underscore the functional impact of misestimating one's current functioning and relative level of ability. These findings are consistent with the use of insight-focused treatments and compensatory strategies designed to increase self-awareness in multiple functional domains. (c) 2015 APA, all rights reserved).
Self Assessment in Schizophrenia: Accuracy of Evaluation of Cognition and Everyday Functioning

PubMed Central

Gould, Felicia; McGuire, Laura Stone; Durand, Dante; Sabbag, Samir; Larrauri, Carlos; Patterson, Thomas L.; Twamley, Elizabeth W.; Harvey, Philip D.

2015-01-01

Objective Self-assessment deficits, often referred to as impaired insight or unawareness of illness, are well established in people with schizophrenia. There are multiple levels of awareness, including awareness of symptoms, functional deficits, cognitive impairments, and the ability to monitor cognitive and functional performance in an ongoing manner. The present study aimed to evaluate the comparative predictive value of each aspect of awareness on the levels of everyday functioning in people with schizophrenia. Method We examined multiple aspects of self-assessment of functioning in 214 people with schizophrenia. We also collected information on everyday functioning rated by high contact clinicians and examined the importance of self-assessment for the prediction of real world functional outcomes. The relative impact of performance based measures of cognition, functional capacity, and metacognitive performance on everyday functioning was also examined. Results Misestimation of ability emerged as the strongest predictor of real world functioning and exceeded the influences of cognitive performance, functional capacity performance, and performance-based assessment of metacognitive monitoring. The relative contribution of the factors other than self-assessment varied according to which domain of everyday functioning was being examined, but in all cases, accounted for less predictive variance. Conclusions These results underscore the functional impact of misestimating one’s current functioning and relative level of ability. These findings are consistent with the use of insight-focused treatments and compensatory strategies designed to increase self-awareness in multiple functional domains. PMID:25643212
Functional food awareness and perceptions in relation to information sources in older adults.

PubMed

Vella, Meagan N; Stratton, Laura M; Sheeshka, Judy; Duncan, Alison M

2014-05-17

The functional food industry has experienced innovative and economic expansion, yet research into consumer perceptions of functional foods and their associated health claims is limited. Among consumers, older adults could benefit from functional foods due to age-related issues pertaining to food and health. The purpose of this research was to identify the need for information related to functional foods among older adults (≥60 years old) and to assess awareness and perceptions of health claims on functional food packages. Community-dwelling older adults (n = 200) completed a researcher administered questionnaire designed to collect information about functional foods including current consumption, motivating factors for consumption, perceived need for information, sources of information for functional foods and awareness of health claims. Prevalence of functional food consumption among participants was 93.0%. Increased awareness and knowledge was the most commonly reported factor that would promote functional food consumption (85.5%) and 63.5% of participants wanted more information about functional foods with preferred sources being newspapers/magazines/books (68.5%) and food labels (66.1%). Participants were predominately (93.5%) aware of health claims on functional foods and those with more education were more likely to report being aware of health claims (p = 0.045). Although functional food consumption among older adults in this sample is high, there is a need for further information regarding functional foods. These results inform stakeholders regarding the potential for information to influence functional food acceptance among older adult consumers.
Solute-solvent cavity and bridge functions. I. Varying size of the solute

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

Vyalov, I., E-mail: ivan.vyalov@iit.it; Chuev, G., E-mail: genchuev@rambler.ru; Georgi, N., E-mail: georgi@mis.mpg.de

2014-08-21

In this work we present the results of the extensive molecular simulations of solute-solvent cavity and bridge functions. The mixtures of Lennard-Jones solvent with Lennard-Jones solute at infinite dilution are considered for different solute-solvent size ratios—up to 4:1. The Percus-Yevick and hypernetted chain closures deviate substantially from simulation results in the investigated temperature and density ranges. We also find that the behavior of the indirect and cavity correlation functions is non-monotonous within the hard-core region, but the latter can be successfully approximated by mean-field theory if the solute-solvent interaction energy is divided into repulsive and attractive contribution, according to Weeks-Chandler-Andersenmore » theory. Furthermore, in spite of the non-monotonous behavior of logarithm of the cavity function and the indirect correlation function, their difference, i.e., the bridge function remains constant within the hard-core region. Such behavior of the bridge and indirect correlation functions at small distances and for small values of indirect correlation function is well known from the Duh-Haymet plots, where the non-unique relationship results in loops of the bridge function vs. indirect correlation function graphs. We show that the same pathological behavior appears also when distance is small and indirect correlation function is large. We further show that the unique functional behavior of the bridge function can be established when bridge is represented as a function of the renormalized, repulsive indirect correlation function.« less
Efficient Bayesian hierarchical functional data analysis with basis function approximations using Gaussian-Wishart processes.

PubMed

Yang, Jingjing; Cox, Dennis D; Lee, Jong Soo; Ren, Peng; Choi, Taeryon

2017-12-01

Functional data are defined as realizations of random functions (mostly smooth functions) varying over a continuum, which are usually collected on discretized grids with measurement errors. In order to accurately smooth noisy functional observations and deal with the issue of high-dimensional observation grids, we propose a novel Bayesian method based on the Bayesian hierarchical model with a Gaussian-Wishart process prior and basis function representations. We first derive an induced model for the basis-function coefficients of the functional data, and then use this model to conduct posterior inference through Markov chain Monte Carlo methods. Compared to the standard Bayesian inference that suffers serious computational burden and instability in analyzing high-dimensional functional data, our method greatly improves the computational scalability and stability, while inheriting the advantage of simultaneously smoothing raw observations and estimating the mean-covariance functions in a nonparametric way. In addition, our method can naturally handle functional data observed on random or uncommon grids. Simulation and real studies demonstrate that our method produces similar results to those obtainable by the standard Bayesian inference with low-dimensional common grids, while efficiently smoothing and estimating functional data with random and high-dimensional observation grids when the standard Bayesian inference fails. In conclusion, our method can efficiently smooth and estimate high-dimensional functional data, providing one way to resolve the curse of dimensionality for Bayesian functional data analysis with Gaussian-Wishart processes. © 2017, The International Biometric Society.
DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Hesheng, E-mail: hesheng@umich.edu; Feng, Mary; Jackson, Andrew

Purpose: To develop a local and global function model in the liver based on regional and organ function measurements to support individualized adaptive radiation therapy (RT). Methods and Materials: A local and global model for liver function was developed to include both functional volume and the effect of functional variation of subunits. Adopting the assumption of parallel architecture in the liver, the global function was composed of a sum of local function probabilities of subunits, varying between 0 and 1. The model was fit to 59 datasets of liver regional and organ function measures from 23 patients obtained before, during, andmore » 1 month after RT. The local function probabilities of subunits were modeled by a sigmoid function in relating to MRI-derived portal venous perfusion values. The global function was fitted to a logarithm of an indocyanine green retention rate at 15 minutes (an overall liver function measure). Cross-validation was performed by leave-m-out tests. The model was further evaluated by fitting to the data divided according to whether the patients had hepatocellular carcinoma (HCC) or not. Results: The liver function model showed that (1) a perfusion value of 68.6 mL/(100 g · min) yielded a local function probability of 0.5; (2) the probability reached 0.9 at a perfusion value of 98 mL/(100 g · min); and (3) at a probability of 0.03 [corresponding perfusion of 38 mL/(100 g · min)] or lower, the contribution to global function was lost. Cross-validations showed that the model parameters were stable. The model fitted to the data from the patients with HCC indicated that the same amount of portal venous perfusion was translated into less local function probability than in the patients with non-HCC tumors. Conclusions: The developed liver function model could provide a means to better assess individual and regional dose-responses of hepatic functions, and provide guidance for individualized treatment planning of RT.« less
Association between pulmonary function and renal function: findings from China and Australia.

PubMed

Yu, Dahai; Chen, Tao; Cai, Yamei; Zhao, Zhanzheng; Simmons, David

2017-05-01

The relationship between obstructive lung function and impaired renal function is unclear. This study investigated the dose-response relationship between obstructive lung function and impaired renal function. Two independent cross-sectional studies with representative sampling were applied. 1454 adults from rural Victoria, Australia (1298 with normal renal function, 156 with impaired renal function) and 5824 adults from Nanjing, China (4313 with normal renal function, 1511 with impaired renal function). Pulmonary function measurements included forced expiratory volume in one second (FEV1) and forced vital capacity (FVC). Estimated glomerular filtration rate (eGFR), and impaired renal function marked by eGFR <60 mL/min/1.73m 2 were used as outcome. eGFR increased linearly with FEV1 in Chinese participants and with FVC in Australians. A non-linear relationship with peaked eGFR was found for FEV1 at 2.65 L among Australians and for FVC at 2.78 L among Chinese participants, respectively. A non-linear relationship with peaked eGFR was found for the predicted percentage value of forced expiratory volume in 1 s (PFEV1) at 81-82% and for the predicted percentage value of forced vital capacity (PFVC) at 83-84% among both Chinese and Australian participants, respectively. The non-linear dose-response relationships between lung capacity measurements (both for FEV1 and FVC) and risk of impaired renal function were consistently identified in both Chinese and Australian participants. An increased risk of impaired renal function was found below 3.05 L both for FEV1 and FVC, respectively. The non-linear relationship between PFEV and PVC and the risk of impaired renal function were consistently identified in both Chinese and Australian participants. An increased risk of impaired renal function was found below 76-77% for PFEV1 and 79-80% for PFVC, respectively. In both Australian and Chinese populations, the risk of impaired renal function increased both with FEV1 and FVC below 3.05 L, with PFEV1 below 76-77% or with PFVC below 79-80%, respectively. Obstructive lung function was associated with increased risk of reduced renal function. The screen for impaired renal function in patients with obstructive lung disease might be useful to ensure there was no impaired renal function before the commencement of potentially nephrotoxic medication where indicated (eg diuretics).
Modified Gaussian influence function of deformable mirror actuators.

PubMed

Huang, Linhai; Rao, Changhui; Jiang, Wenhan

2008-01-07

A new deformable mirror influence function based on a Gaussian function is introduced to analyze the fitting capability of a deformable mirror. The modified expressions for both azimuthal and radial directions are presented based on the analysis of the residual error between a measured influence function and a Gaussian influence function. With a simplex search method, we further compare the fitting capability of our proposed influence function to fit the data produced by a Zygo interferometer with that of a Gaussian influence function. The result indicates that the modified Gaussian influence function provides much better performance in data fitting.
Linear and quadratic static response functions and structure functions in Yukawa liquids.

PubMed

Magyar, Péter; Donkó, Zoltán; Kalman, Gabor J; Golden, Kenneth I

2014-08-01

We compute linear and quadratic static density response functions of three-dimensional Yukawa liquids by applying an external perturbation potential in molecular dynamics simulations. The response functions are also obtained from the equilibrium fluctuations (static structure factors) in the system via the fluctuation-dissipation theorems. The good agreement of the quadratic response functions, obtained in the two different ways, confirms the quadratic fluctuation-dissipation theorem. We also find that the three-point structure function may be factorizable into two-point structure functions, leading to a cluster representation of the equilibrium triplet correlation function.

Wigner functions defined with Laplace transform kernels.

PubMed

Oh, Se Baek; Petruccelli, Jonathan C; Tian, Lei; Barbastathis, George

2011-10-24

We propose a new Wigner-type phase-space function using Laplace transform kernels--Laplace kernel Wigner function. Whereas momentum variables are real in the traditional Wigner function, the Laplace kernel Wigner function may have complex momentum variables. Due to the property of the Laplace transform, a broader range of signals can be represented in complex phase-space. We show that the Laplace kernel Wigner function exhibits similar properties in the marginals as the traditional Wigner function. As an example, we use the Laplace kernel Wigner function to analyze evanescent waves supported by surface plasmon polariton. © 2011 Optical Society of America
Slice regular functions of several Clifford variables

NASA Astrophysics Data System (ADS)

Ghiloni, R.; Perotti, A.

2012-11-01

We introduce a class of slice regular functions of several Clifford variables. Our approach to the definition of slice functions is based on the concept of stem functions of several variables and on the introduction on real Clifford algebras of a family of commuting complex structures. The class of slice regular functions include, in particular, the family of (ordered) polynomials in several Clifford variables. We prove some basic properties of slice and slice regular functions and give examples to illustrate this function theory. In particular, we give integral representation formulas for slice regular functions and a Hartogs type extension result.
Methods of Constructing a Blended Performance Function Suitable for Formation Flight

NASA Technical Reports Server (NTRS)

Ryan, John J.

2017-01-01

This paper presents two methods for constructing an approximate performance function of a desired parameter using correlated parameters. The methods are useful when real-time measurements of a desired performance function are not available to applications such as extremum-seeking control systems. The first method approximates an a priori measured or estimated desired performance function by combining real-time measurements of readily available correlated parameters. The parameters are combined using a weighting vector determined from a minimum-squares optimization to form a blended performance function. The blended performance function better matches the desired performance function mini- mum than single-measurement performance functions. The second method expands upon the first by replacing the a priori data with near-real-time measurements of the desired performance function. The resulting blended performance function weighting vector is up- dated when measurements of the desired performance function are available. Both methods are applied to data collected during formation- flight-for-drag-reduction flight experiments.
Assessing physical function and physical activity in patients with CKD.

PubMed

Painter, Patricia; Marcus, Robin L

2013-05-01

Patients with CKD are characterized by low levels of physical functioning, which, along with low physical activity, predict poor outcomes in those treated with dialysis. The hallmark of clinical care in geriatric practice and geriatric research is the orientation to and assessment of physical function and functional limitations. Although there is increasing interest in physical function and physical activity in patients with CKD, the nephrology field has not focused on this aspect of care. This paper provides an in-depth review of the measurement of physical function and physical activity. It focuses on physiologic impairments and physical performance limitations (impaired mobility and functional limitations). The review is based on established frameworks of physical impairment and functional limitations that have guided research in physical function in the aging population. Definitions and measures for physiologic impairments, physical performance limitations, self-reported function, and physical activity are presented. On the basis of the information presented, recommendations for incorporating routine assessment of physical function and encouragement for physical activity in clinical care are provided.
Upper-limb motor and sensory function in patients with hip fracture: Comparison with community-dwelling older adults.

PubMed

Hayashi, Hiroyuki; Nakashima, Daiki; Matsuoka, Hiroka; Iwai, Midori; Nakamura, Shugo; Kubo, Ayumi; Tomiyama, Naoki

2017-11-06

Upper-limb function is important in patients with hip fracture so they can perform activities of daily living and participate in leisure activities. Upper-limb function of these patients, however, has not been thoroughly investigated. The aim of this study was to evaluate the upper-limb motor and sensory functions in patients with hip fracture by comparing these functions with those of community-dwelling older adults (control group). We compared the results of motor and sensory function tests of upper-limb function - range of motion, strength, sensibility, finger dexterity, comprehensive hand function - between patients with hip fracture (n= 32) and the control group (n= 32). Patients with hip fracture had significantly reduced grip strength, pinch strength, finger dexterity, and comprehensive hand function compared with the control group. Most upper-limb functions are impaired in the patients with hip fracture. Thus, upper-limb function of patients with hip fracture should be considered during treatment.
Spin-Multiplet Components and Energy Splittings by Multistate Density Functional Theory.

PubMed

Grofe, Adam; Chen, Xin; Liu, Wenjian; Gao, Jiali

2017-10-05

Kohn-Sham density functional theory has been tremendously successful in chemistry and physics. Yet, it is unable to describe the energy degeneracy of spin-multiplet components with any approximate functional. This work features two contributions. (1) We present a multistate density functional theory (MSDFT) to represent spin-multiplet components and to determine multiplet energies. MSDFT is a hybrid approach, taking advantage of both wave function theory and density functional theory. Thus, the wave functions, electron densities and energy density-functionals for ground and excited states and for different components are treated on the same footing. The method is illustrated on valence excitations of atoms and molecules. (2) Importantly, a key result is that for cases in which the high-spin components can be determined separately by Kohn-Sham density functional theory, the transition density functional in MSDFT (which describes electronic coupling) can be defined rigorously. The numerical results may be explored to design and optimize transition density functionals for configuration coupling in multiconfigurational DFT.
Exotic species enhance response diversity to land-use change but modify functional composition.

PubMed

Stavert, Jamie R; Pattemore, David E; Gaskett, Anne C; Beggs, Jacqueline R; Bartomeus, Ignasi

2017-08-16

Two main mechanisms may buffer ecosystem functions despite biodiversity loss. First, multiple species could share similar ecological roles, thus providing functional redundancy. Second, species may respond differently to environmental change (response diversity). However, ecosystem function would be best protected when functionally redundant species also show response diversity. This linkage has not been studied directly, so we investigated whether native and exotic pollinator species with similar traits (functional redundancy) differed in abundance (response diversity) across an agricultural intensification gradient. Exotic pollinator species contributed most positive responses, which partially stabilized overall abundance of the pollinator community. However, although some functionally redundant species exhibited response diversity, this was not consistent across functional groups and aggregate abundances within each functional group were rarely stabilized. This shows functional redundancy and response diversity do not always operate in concert. Hence, despite exotic species becoming increasingly dominant in human-modified systems, they cannot replace the functional composition of native species. © 2017 The Author(s).
Evaluation of Language Function under Awake Craniotomy

PubMed Central

KANNO, Aya; MIKUNI, Nobuhiro

2015-01-01

Awake craniotomy is the only established way to assess patients’ language functions intraoperatively and to contribute to their preservation, if necessary. Recent guidelines have enabled the approach to be used widely, effectively, and safely. Non-invasive brain functional imaging techniques, including functional magnetic resonance imaging and diffusion tensor imaging, have been used preoperatively to identify brain functional regions corresponding to language, and their accuracy has increased year by year. In addition, the use of neuronavigation that incorporates this preoperative information has made it possible to identify the positional relationships between the lesion and functional regions involved in language, conduct functional brain mapping in the awake state with electrical stimulation, and intraoperatively assess nerve function in real time when resecting the lesion. This article outlines the history of awake craniotomy, the current state of pre- and intraoperative evaluation of language function, and the clinical usefulness of such functional evaluation. When evaluating patients’ language functions during awake craniotomy, given the various intraoperative stresses involved, it is necessary to carefully select the tasks to be undertaken, quickly perform all examinations, and promptly evaluate the results. As language functions involve both input and output, they are strongly affected by patients’ preoperative cognitive function, degree of intraoperative wakefulness and fatigue, the ability to produce verbal articulations and utterances, as well as perform synergic movement. Therefore, it is essential to appropriately assess the reproducibility of language function evaluation using awake craniotomy techniques. PMID:25925758
Functional MRI registration with tissue-specific patch-based functional correlation tensors.

PubMed

Zhou, Yujia; Zhang, Han; Zhang, Lichi; Cao, Xiaohuan; Yang, Ru; Feng, Qianjin; Yap, Pew-Thian; Shen, Dinggang

2018-06-01

Population studies of brain function with resting-state functional magnetic resonance imaging (rs-fMRI) rely on accurate intersubject registration of functional areas. This is typically achieved through registration using high-resolution structural images with more spatial details and better tissue contrast. However, accumulating evidence has suggested that such strategy cannot align functional regions well because functional areas are not necessarily consistent with anatomical structures. To alleviate this problem, a number of registration algorithms based directly on rs-fMRI data have been developed, most of which utilize functional connectivity (FC) features for registration. However, most of these methods usually extract functional features only from the thin and highly curved cortical grey matter (GM), posing great challenges to accurate estimation of whole-brain deformation fields. In this article, we demonstrate that additional useful functional features can also be extracted from the whole brain, not restricted to the GM, particularly the white-matter (WM), for improving the overall functional registration. Specifically, we quantify local anisotropic correlation patterns of the blood oxygenation level-dependent (BOLD) signals using tissue-specific patch-based functional correlation tensors (ts-PFCTs) in both GM and WM. Functional registration is then performed by integrating the features from different tissues using the multi-channel large deformation diffeomorphic metric mapping (mLDDMM) algorithm. Experimental results show that our method achieves superior functional registration performance, compared with conventional registration methods. © 2018 Wiley Periodicals, Inc.
Evaluation of Language Function under Awake Craniotomy.

PubMed

Kanno, Aya; Mikuni, Nobuhiro

2015-01-01

Awake craniotomy is the only established way to assess patients' language functions intraoperatively and to contribute to their preservation, if necessary. Recent guidelines have enabled the approach to be used widely, effectively, and safely. Non-invasive brain functional imaging techniques, including functional magnetic resonance imaging and diffusion tensor imaging, have been used preoperatively to identify brain functional regions corresponding to language, and their accuracy has increased year by year. In addition, the use of neuronavigation that incorporates this preoperative information has made it possible to identify the positional relationships between the lesion and functional regions involved in language, conduct functional brain mapping in the awake state with electrical stimulation, and intraoperatively assess nerve function in real time when resecting the lesion. This article outlines the history of awake craniotomy, the current state of pre- and intraoperative evaluation of language function, and the clinical usefulness of such functional evaluation. When evaluating patients' language functions during awake craniotomy, given the various intraoperative stresses involved, it is necessary to carefully select the tasks to be undertaken, quickly perform all examinations, and promptly evaluate the results. As language functions involve both input and output, they are strongly affected by patients' preoperative cognitive function, degree of intraoperative wakefulness and fatigue, the ability to produce verbal articulations and utterances, as well as perform synergic movement. Therefore, it is essential to appropriately assess the reproducibility of language function evaluation using awake craniotomy techniques.
A global characterization and identification of multifunctional enzymes.

PubMed

Cheng, Xian-Ying; Huang, Wei-Juan; Hu, Shi-Chang; Zhang, Hai-Lei; Wang, Hao; Zhang, Jing-Xian; Lin, Hong-Huang; Chen, Yu-Zong; Zou, Quan; Ji, Zhi-Liang

2012-01-01

Multi-functional enzymes are enzymes that perform multiple physiological functions. Characterization and identification of multi-functional enzymes are critical for communication and cooperation between different functions and pathways within a complex cellular system or between cells. In present study, we collected literature-reported 6,799 multi-functional enzymes and systematically characterized them in structural, functional, and evolutionary aspects. It was found that four physiochemical properties, that is, charge, polarizability, hydrophobicity, and solvent accessibility, are important for characterization of multi-functional enzymes. Accordingly, a combinational model of support vector machine and random forest model was constructed, based on which 6,956 potential novel multi-functional enzymes were successfully identified from the ENZYME database. Moreover, it was observed that multi-functional enzymes are non-evenly distributed in species, and that Bacteria have relatively more multi-functional enzymes than Archaebacteria and Eukaryota. Comparative analysis indicated that the multi-functional enzymes experienced a fluctuation of gene gain and loss during the evolution from S. cerevisiae to H. sapiens. Further pathway analyses indicated that a majority of multi-functional enzymes were well preserved in catalyzing several essential cellular processes, for example, metabolisms of carbohydrates, nucleotides, and amino acids. What's more, a database of known multi-functional enzymes and a server for novel multi-functional enzyme prediction were also constructed for free access at http://bioinf.xmu.edu.cn/databases/MFEs/index.htm.
Using a Multi-Trait Approach to Manipulate Plant Functional Diversity in a Biodiversity-Ecosystem Function Experiment

PubMed Central

Schittko, Conrad; Hawa, Mahmoud; Wurst, Susanne

2014-01-01

A frequent pattern emerging from biodiversity-ecosystem function studies is that functional group richness enhances ecosystem functions such as primary productivity. However, the manipulation of functional group richness goes along with major disadvantages like the transformation of functional trait data into categories or the exclusion of functional differences between organisms in the same group. In a mesocosm study we manipulated plant functional diversity based on the multi-trait Functional Diversity (FD)-approach of Petchey and Gaston by using database data of seven functional traits and information on the origin of the species in terms of being native or exotic. Along a gradient ranging from low to high FD we planted 40 randomly selected eight-species mixtures under controlled conditions. We found a significant positive linear correlation of FD with aboveground productivity and a negative correlation with invasibility of the plant communities. Based on community-weighted mean calculations for each functional trait, we figured out that the traits N-fixation and species origin, i.e. being native or exotic, played the most important role for community productivity. Our results suggest that the identification of the impact of functional trait diversity and the relative contributions of relevant traits is essential for a mechanistic understanding of the role of biodiversity for ecosystem functions such as aboveground biomass production and resistance against invasion. PMID:24897501
Q (Alpha) Function and Squeezing Effect

NASA Technical Reports Server (NTRS)

Yunjie, Xia; Xianghe, Kong; Kezhu, Yan; Wanping, Chen

1996-01-01

The relation of squeezing and Q(alpha) function is discussed in this paper. By means of Q function, the squeezing of field with gaussian Q(alpha) function or negative P(a)function is also discussed in detail.
Discrete-Trial Functional Analysis and Functional Communication Training with Three Adults with Intellectual Disabilities and Problem Behavior

ERIC Educational Resources Information Center

Chezan, Laura C.; Drasgow, Erik; Martin, Christian A.

2014-01-01

We conducted a sequence of two studies on the use of discrete-trial functional analysis and functional communication training. First, we used discrete-trial functional analysis (DTFA) to identify the function of problem behavior in three adults with intellectual disabilities and problem behavior. Results indicated clear patterns of problem…
Functional Thinking Ways in Relation to Linear Function Tables of Elementary School Students

ERIC Educational Resources Information Center

Tanisli, Dilek

2011-01-01

One of the basic components of algebraic thinking is functional thinking. Functional thinking involves focusing on the relationship between two (or more) varying quantities and such thinking facilitates the studies on both algebra and the notion of function. The development of functional thinking of students should start in the early grades and it…
Characterization of Strength and Function in Ambulatory Adults With GNE Myopathy

PubMed Central

Argov, Zohar; Bronstein, Faye; Esposito, Alicia; Feinsod-Meiri, Yael; Florence, Julaine M.; Fowler, Eileen; Greenberg, Marcia B.; Malkus, Elizabeth C.; Rebibo, Odelia; Siener, Catherine S.; Caraco, Yoseph; Kolodny, Edwin H.; Lau, Heather A.; Pestronk, Alan; Shieh, Perry; Mayhew, Jill E.

2017-01-01

Abstract Objective: To characterize the pattern and extent of muscle weakness and impact on physical functioning in adults with GNEM. Methods: Strength and function were assessed in GNEM subjects (n = 47) using hand-held dynamometry, manual muscle testing, upper and lower extremity functional capacity tests, and the GNEM-Functional Activity Scale (GNEM-FAS). Results: Profound upper and lower muscle weakness was measured using hand-held dynamometry in a characteristic pattern, previously described. Functional tests and clinician-reported outcomes demonstrated the consequence of muscle weakness on physical functioning. Conclusions: The characteristic pattern of upper and lower muscle weakness associated with GNEM and the resulting functional limitations can be reliably measured using these clinical outcome assessments of muscle strength and function. PMID:28827485
Challenging stereotypes: sexual functioning of single adults with high functioning autism spectrum disorder.

PubMed

Byers, E Sandra; Nichols, Shana; Voyer, Susan D

2013-11-01

This study examined the sexual functioning of single adults (61 men, 68 women) with high functioning autism and Asperger syndrome living in the community with and without prior relationship experience. Participants completed an on-line questionnaire assessing autism symptoms, psychological functioning, and various aspects of sexual functioning. In general participants reported positive sexual functioning. Participants without prior relationship experience were significantly younger and more likely to be male and identify as heterosexual. They reported significantly higher sexual anxiety, lower sexual arousability, lower dyadic desire, and fewer positive sexual cognitions. The men reported better sexual function than did the women in a number of areas. These results counter negative societal perceptions about the sexuality of high functioning individuals on the autism spectrum.
Functional Rarity: The Ecology of Outliers.

PubMed

Violle, Cyrille; Thuiller, Wilfried; Mouquet, Nicolas; Munoz, François; Kraft, Nathan J B; Cadotte, Marc W; Livingstone, Stuart W; Mouillot, David

2017-05-01

Rarity has been a central topic for conservation and evolutionary biologists aiming to determine the species characteristics that cause extinction risk. More recently, beyond the rarity of species, the rarity of functions or functional traits, called functional rarity, has gained momentum in helping to understand the impact of biodiversity decline on ecosystem functioning. However, a conceptual framework for defining and quantifying functional rarity is still lacking. We introduce 12 different forms of functional rarity along gradients of species scarcity and trait distinctiveness. We then highlight the potential key role of functional rarity in the long-term and large-scale maintenance of ecosystem processes, as well as the necessary linkage between functional and evolutionary rarity. Copyright © 2017 Elsevier Ltd. All rights reserved.
Functional diversity of home gardens and their agrobiodiversity conservation benefits in Benin, West Africa.

PubMed

Gbedomon, Rodrigue Castro; Salako, Valère Kolawolé; Fandohan, Adandé Belarmain; Idohou, Alix Frank Rodrigue; Glèlè Kakaї, Romain; Assogbadjo, Achille Ephrem

2017-11-25

Understanding the functional diversity of home gardens and their socio-ecological determinants is essential for mainstreaming these agroforestry practices into agrobiodiversity conservation strategies. This paper analyzed functional diversity of home gardens, identified the socio-ecological drivers of functions assigned to them, and assessed the agrobiodiversity benefits of home gardens functions. Using data on occurring species in home garden (HG) and functions assigned to each species by the gardeners, the study combined clustering and discriminant canonical analyses to explore the functional diversity of 360 home gardens in Benin, West Africa. Next, multinomial logistic models and chi-square tests were used to analyze the effect of socio-demographic characteristics of gardeners (age, gender, and education level), agro-ecological zones (humid, sub-humid, and semi-arid), and management regime (single and multiple managers) on the possession of a functional type of home gardens. Generalized linear models were used to assess the effect of the functions of home gardens and the determinant factor on their potential in conserving agrobiodiversity. Seven functional groups of home gardens, four with specific functions (food, medicinal, or both food and medicinal) and three with multiple functions (more than two main functions), were found. Women owned most of home gardens with primarily food plant production purpose while men owned most of home gardens with primarily medicinal plant production purposes. Finding also showed that multifunctional home gardens had higher plant species diversity. Specifically, crops and crop wild relatives occurred mainly in home gardens with food function while wild plant species were mostly found in home gardens with mainly medicinal function. Home gardening is driven by functions beyond food production. These functions are mostly related to direct and extractive values of home gardens. Functions of home gardens were gendered, with women mostly involved in home food gardens, and contribute to maintenance of crops and crop wild relatives while men were mostly home medicinal gardeners and contribute to the maintenance of wild plant species in home gardens. Although multiple functional home gardens were related to higher plant diversity, there was no guarantee for long-term maintenance of plant species in home gardens.
Resolving protein structure-function-binding site relationships from a binding site similarity network perspective.

PubMed

Mudgal, Richa; Srinivasan, Narayanaswamy; Chandra, Nagasuma

2017-07-01

Functional annotation is seldom straightforward with complexities arising due to functional divergence in protein families or functional convergence between non-homologous protein families, leading to mis-annotations. An enzyme may contain multiple domains and not all domains may be involved in a given function, adding to the complexity in function annotation. To address this, we use binding site information from bound cognate ligands and catalytic residues, since it can help in resolving fold-function relationships at a finer level and with higher confidence. A comprehensive database of 2,020 fold-function-binding site relationships has been systematically generated. A network-based approach is employed to capture the complexity in these relationships, from which different types of associations are deciphered, that identify versatile protein folds performing diverse functions, same function associated with multiple folds and one-to-one relationships. Binding site similarity networks integrated with fold, function, and ligand similarity information are generated to understand the depth of these relationships. Apart from the observed continuity in the functional site space, network properties of these revealed versatile families with topologically different or dissimilar binding sites and structural families that perform very similar functions. As a case study, subtle changes in the active site of a set of evolutionarily related superfamilies are studied using these networks. Tracing of such similarities in evolutionarily related proteins provide clues into the transition and evolution of protein functions. Insights from this study will be helpful in accurate and reliable functional annotations of uncharacterized proteins, poly-pharmacology, and designing enzymes with new functional capabilities. Proteins 2017; 85:1319-1335. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Structural equation modeling of motor impairment, gross motor function, and the functional outcome in children with cerebral palsy.

PubMed

Park, Eun-Young; Kim, Won-Ho

2013-05-01

Physical therapy intervention for children with cerebral palsy (CP) is focused on reducing neurological impairments, improving strength, and preventing the development of secondary impairments in order to improve functional outcomes. However, relationship between motor impairments and functional outcome has not been proved definitely. This study confirmed the construct of motor impairment and performed structural equation modeling (SEM) between motor impairment, gross motor function, and functional outcomes of regarding activities of daily living in children with CP. 98 children (59 boys, 39 girls) with CP participated in this cross-sectional study. Mean age was 11 y 5 mo (SD 1 y 9 mo). The Manual Muscle Test (MMT), the Modified Ashworth Scale (MAS), range of motion (ROM) measurement, and the selective motor control (SMC) scale were used to assess motor impairments. Gross motor function and functional outcomes were measured using the Gross Motor Function Measure (GMFM) and the Functional Skills domain of the Pediatric Evaluation of Disability Inventory (PEDI) respectively. Measurement of motor impairment was consisted of strength, spasticity, ROM, and SMC. The construct of motor impairment was confirmed though an examination of a measurement model. The proposed SEM model showed good fit indices. Motor impairment effected gross motor function (β=-.0869). Gross motor function and motor impairment affected functional outcomes directly (β=0.890) and indirectly (β=-0.773) respectively. We confirmed that the construct of motor impairment consist of strength, spasticity, ROM, and SMC and it was identified through measurement model analysis. Functional outcomes are best predicted by gross motor function and motor impairments have indirect effects on functional outcomes. Copyright © 2013 Elsevier Ltd. All rights reserved.
Negative Impacts of Human Land Use on Dung Beetle Functional Diversity

PubMed Central

Barragán, Felipe; Moreno, Claudia E.; Escobar, Federico; Halffter, Gonzalo; Navarrete, Dario

2011-01-01

The loss of biodiversity caused by human activity is assumed to alter ecosystem functioning. However our understanding of the magnitude of the effect of these changes on functional diversity and their impact on the dynamics of ecological processes is still limited. We analyzed the functional diversity of copro-necrophagous beetles under different conditions of land use in three Mexican biosphere reserves. In Montes Azules pastures, forest fragments and continuous rainforest were analyzed, in Los Tuxtlas rainforest fragments of different sizes were analyzed and in Barranca de Metztitlán two types of xerophile scrub with different degrees of disturbance from grazing were analyzed. We assigned dung beetle species to functional groups based on food relocation, beetle size, daily activity period and food preferences, and as measures of functional diversity we used estimates based on multivariate methods. In Montes Azules functional richness was lower in the pastures than in continuous rainforest and rainforest fragments, but fragments and continuous forest include functionally redundant species. In small rainforest fragments (<5 ha) in Los Tuxtlas, dung beetle functional richness was lower than in large rainforest fragments (>20 ha). Functional evenness and functional dispersion did not vary among habitat types or fragment size in these reserves. In contrast, in Metztitlán, functional richness and functional dispersion were different among the vegetation types, but differences were not related to the degree of disturbance by grazing. More redundant species were found in submontane than in crassicaule scrub. For the first time, a decrease in the functional diversity in communities of copro-necrophagous beetles resulting from changes in land use is documented, the potential implications for ecosystem functioning are discussed and a series of variables that could improve the evaluation of functional diversity for this biological group is proposed. PMID:21448292
Density functional study of double ionization energies

NASA Astrophysics Data System (ADS)

Chong, D. P.

2008-02-01

In this paper, double ionization energies (DIEs) of gas-phase atoms and molecules are calculated by energy difference method with density functional theory. To determine the best functional for double ionization energies, we first study 24 main group atoms in the second, third, and fourth periods. An approximation is used in which the electron density is first obtained from a density functional computation with the exchange-correlation potential Vxc known as statistical average of orbital potentials, after which the energy is computed from that density with 59 different exchange-correlation energy functionals Exc. For the 24 atoms, the two best Exc functional providing DIEs with average absolute deviation (AAD) of only 0.25eV are the Perdew-Burke-Ernzerhof functional modified by Hammer et al. [Phys. Rev. B 59, 6413 (1999)] and one known as the Krieger-Chen-Iafrate-Savin functional modified by Krieger et al. (unpublished). Surprisingly, none of the 20 available hybrid functionals is among the top 15 functionals for the DIEs of the 24 atoms. A similar procedure is then applied to molecules, with opposite results: Only hybrid functionals are among the top 15 functionals for a selection of 29molecules. The best Exc functional for the 29molecules is found to be the Becke 1997 functional modified by Wilson et al. [J. Chem. Phys. 115, 9233 (2001)]. With that functional, the AAD from experiment for DIEs of 29molecules is just under 0.5eV. If the two suspected values for C2H2 and Fe(CO)5 are excluded, the AAD improves to 0.32eV. Many other hybrid functionals perform almost as well.
Trajectories of change in cognitive function in people with chronic obstructive pulmonary disease.

PubMed

Park, Soo Kyung

2018-04-01

To describe changes in cognitive function, as measured by the trail making test; to identify distinct patterns of change in cognitive function; and to examine predictors of change in cognitive function in people with severe chronic obstructive pulmonary disease. How cognitive function changes in people with chronic obstructive pulmonary disease and what factors influence those changes over time is not well known, despite the fact that it declines rapidly in this population and significantly impacts functional decline in healthy older adults. A secondary analysis and longitudinal study with a follow-up period of 3 years. A data set from the National Emphysema Treatment Trial provided participant data. Patients with severe chronic obstructive pulmonary disease (n = 307) were recruited at a clinical site. Several demographic and clinical measures were assessed at baseline. Trail making test scores were measured at baseline, 1, 2 and 3 years. Cognitive function was stable for 3 years in people with chronic obstructive pulmonary disease. However, four distinct patterns of change in cognitive function were identified. Age, education, 6-min walk distance and cognitive impairment scores at baseline on the trail making test Part B were significant predictors of worsening cognitive function and below-average cognitive function over 3 years. These findings suggest that increasing exercise capacity improves cognitive function and delays deterioration of cognitive function in people with COPD. Understanding the trajectories of change in cognitive function and predictors of change in cognitive function over 3 years may enable health care providers to identify patients at greatest risk of developing mental deterioration and those who might benefit from interventions to improve cognitive function. Health care providers should periodically assess and frequently screen people with COPD for cognitive function. © 2018 John Wiley & Sons Ltd.
[Effects of Square-Stepping Exercise inducing activation of the brain's cognitive function in community-dwelling older Japanese females--Focus on the baseline cognitive function level and age].

PubMed

Abe, Takumi; Tsuji, Taishi; Kitano, Naruki; Muraki, Toshiaki; Hotta, Kazushi; Okura, Tomohiro

2015-01-01

The purpose of this study was to investigate whether the degree of improvement in cognitive function achieved with an exercise intervention in community-dwelling older Japanese women is affected by the participant's baseline cognitive function and age. Eighty-eight women (mean age: 70.5±4.2 years) participated in a prevention program for long-term care. They completed the Square-Stepping Exercise (SSE) program once a week, 120 minutes/session, for 11 weeks. We assessed participants' cognitive function using 5 cognitive tests (5-Cog) before and after the intervention. We defined cognitive function as the 5-Cog total score and defined the change in cognitive function as the 5-cog post-score minus the pre-score. We divided participants into four groups based on age (≤69 years or ≥70 years) and baseline cognitive function level (above vs. below the median cognitive function level). We conducted two-way analysis of variance. All 4 groups improved significantly in cognitive function after the intervention. There were no baseline cognitive function level×age interactions and no significant main effects of age, although significant main effects of baseline cognitive function level (P=0.004, η(2)=0.09) were observed. Square-Stepping Exercise is an effective exercise for improving cognitive function. These results suggest that older adults with cognitive decline are more likely to improve their cognitive function with exercise than if they start the intervention with high cognitive function. Furthermore, during an exercise intervention, baseline cognitive function level may have more of an effect than a participant's age on the degree of cognitive improvement.
Use of the rVV10 Nonlocal Correlation Functional in the B97M-V Density Functional: Defining B97M-rV and Related Functionals [On the Use of the rVV10 Nonlocal Correlation Functional in the B97M-V Density Functional: Defining B97M-rV and Related Functionals

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

Mardirossian, Narbe; Ruiz Pestana, Luis; Womack, James C.

The VV10 and rVV10 nonlocal correlation functionals are consistently implemented and assessed, with the goal of determining if the rVV10 nonlocal correlation functional can replace the VV10 nonlocal correlation functional in the recently developed B97M-V density functional, to give the B97M-rV density functional. Along the way, four density functionals are simultaneously tested: VV10, rVV10, B97M-V, and B97M-rV. An initial assessment is carried out across the S22 data set, and the short-range damping variable, b, is varied for all four density functionals in order to determine the sensitivity of the functionals to the empirical parameter. The results of this test indicatemore » that a value of b = 6 (fortuitously the same as that in B97M-V) is suitable for B97M-rV. The functionals are then compared across an extensive database of interaction energies, and it is demonstrated that B97M-rV either matches or outperforms B97M-V for all of the tests considered. Finally, the optimization of b across the S22 data set is extended to two range-separated hybrid density functionals, ωB97X-V and ωB97M-V, and a value of b = 6.2 is recommended for both ωB97X-rV and ωB97M-rV.« less
Extended screened exchange functional derived from transcorrelated density functional theory.

PubMed

Umezawa, Naoto

2017-09-14

We propose a new formulation of the correlation energy functional derived from the transcorrelated method in use in density functional theory (TC-DFT). An effective Hamiltonian, H TC , is introduced by a similarity transformation of a many-body Hamiltonian, H, with respect to a complex function F: H TC =1FHF. It is proved that an expectation value of H TC for a normalized single Slater determinant, D n , corresponds to the total energy: E[n] = ⟨Ψ n |H|Ψ n ⟩/⟨Ψ n |Ψ n ⟩ = ⟨D n |H TC |D n ⟩ under the two assumptions: (1) The electron density nr associated with a trial wave function Ψ n = D n F is v-representable and (2) Ψ n and D n give rise to the same electron density nr. This formulation, therefore, provides an alternative expression of the total energy that is useful for the development of novel correlation energy functionals. By substituting a specific function for F, we successfully derived a model correlation energy functional, which resembles the functional form of the screened exchange method. The proposed functional, named the extended screened exchange (ESX) functional, is described within two-body integrals and is parametrized for a numerically exact correlation energy of the homogeneous electron gas. The ESX functional does not contain any ingredients of (semi-)local functionals and thus is totally free from self-interactions. The computational cost for solving the self-consistent-field equation is comparable to that of the Hartree-Fock method. We apply the ESX functional to electronic structure calculations for a solid silicon, H - ion, and small atoms. The results demonstrate that the TC-DFT formulation is promising for the systematic improvement of the correlation energy functional.
Concordance and discordance between taxonomic and functional homogenization: responses of soil mite assemblages to forest conversion.

PubMed

Mori, Akira S; Ota, Aino T; Fujii, Saori; Seino, Tatsuyuki; Kabeya, Daisuke; Okamoto, Toru; Ito, Masamichi T; Kaneko, Nobuhiro; Hasegawa, Motohiro

2015-10-01

The compositional characteristics of ecological assemblages are often simplified; this process is termed "biotic homogenization." This process of biological reorganization occurs not only taxonomically but also functionally. Testing both aspects of homogenization is essential if ecosystem functioning supported by a diverse mosaic of functional traits in the landscape is concerned. Here, we aimed to infer the underlying processes of taxonomic/functional homogenization at the local scale, which is a scale that is meaningful for this research question. We recorded species of litter-dwelling oribatid mites along a gradient of forest conversion from a natural forest to a monoculture larch plantation in Japan (in total 11 stands), and collected data on the functional traits of the recorded species to quantify functional diversity. We calculated the taxonomic and functional β-diversity, an index of biotic homogenization. We found that both the taxonomic and functional β-diversity decreased with larch dominance (stand homogenization). After further deconstructing β-diversity into the components of turnover and nestedness, which reflect different processes of community organization, a significant decrease in the response to larch dominance was observed only for the functional turnover. As a result, there was a steeper decline in the functional β-diversity than the taxonomic β-diversity. This discordance between the taxonomic and functional response suggests that species replacement occurs between species that are functionally redundant under environmental homogenization, ultimately leading to the stronger homogenization of functional diversity. The insights gained from community organization of oribatid mites suggest that the functional characteristics of local assemblages, which support the functionality of ecosystems, are of more concern in human-dominated forest landscapes.
Negative impacts of human land use on dung beetle functional diversity.

PubMed

Barragán, Felipe; Moreno, Claudia E; Escobar, Federico; Halffter, Gonzalo; Navarrete, Dario

2011-03-23

The loss of biodiversity caused by human activity is assumed to alter ecosystem functioning. However our understanding of the magnitude of the effect of these changes on functional diversity and their impact on the dynamics of ecological processes is still limited. We analyzed the functional diversity of copro-necrophagous beetles under different conditions of land use in three Mexican biosphere reserves. In Montes Azules pastures, forest fragments and continuous rainforest were analyzed, in Los Tuxtlas rainforest fragments of different sizes were analyzed and in Barranca de Metztitlán two types of xerophile scrub with different degrees of disturbance from grazing were analyzed. We assigned dung beetle species to functional groups based on food relocation, beetle size, daily activity period and food preferences, and as measures of functional diversity we used estimates based on multivariate methods. In Montes Azules functional richness was lower in the pastures than in continuous rainforest and rainforest fragments, but fragments and continuous forest include functionally redundant species. In small rainforest fragments (<5 ha) in Los Tuxtlas, dung beetle functional richness was lower than in large rainforest fragments (>20 ha). Functional evenness and functional dispersion did not vary among habitat types or fragment size in these reserves. In contrast, in Metztitlán, functional richness and functional dispersion were different among the vegetation types, but differences were not related to the degree of disturbance by grazing. More redundant species were found in submontane than in crassicaule scrub. For the first time, a decrease in the functional diversity in communities of copro-necrophagous beetles resulting from changes in land use is documented, the potential implications for ecosystem functioning are discussed and a series of variables that could improve the evaluation of functional diversity for this biological group is proposed.
Wave-function functionals

NASA Astrophysics Data System (ADS)

Pan, Xiao-Yin; Slamet, Marlina; Sahni, Viraht

2010-04-01

We extend our prior work on the construction of variational wave functions ψ that are functionals of functions χ:ψ=ψ[χ] rather than simply being functions. In this manner, the space of variations is expanded over those of traditional variational wave functions. In this article we perform the constrained search over the functions χ chosen such that the functional ψ[χ] satisfies simultaneously the constraints of normalization and the exact expectation value of an arbitrary single- or two-particle Hermitian operator, while also leading to a rigorous upper bound to the energy. As such the wave function functional is accurate not only in the region of space in which the principal contributions to the energy arise but also in the other region of the space represented by the Hermitian operator. To demonstrate the efficacy of these ideas, we apply such a constrained search to the ground state of the negative ion of atomic hydrogen H-, the helium atom He, and its positive ions Li+ and Be2+. The operators W whose expectations are obtained exactly are the sum of the single-particle operators W=∑irin,n=-2,-1,1,2, W=∑iδ(ri), W=-(1)/(2)∑i∇i2, and the two-particle operators W=∑nun,n=-2,-1,1,2, where u=|ri-rj|. Comparisons with the method of Lagrangian multipliers and of other constructions of wave-function functionals are made. Finally, we present further insights into the construction of wave-function functionals by studying a previously proposed construction of functionals ψ[χ] that lead to the exact expectation of arbitrary Hermitian operators. We discover that analogous to the solutions of the Schrödinger equation, there exist ψ[χ] that are unphysical in that they lead to singular values for the expectations. We also explain the origin of the singularity.
Physiological and biochemical basis of clinical liver function tests: a review.

PubMed

Hoekstra, Lisette T; de Graaf, Wilmar; Nibourg, Geert A A; Heger, Michal; Bennink, Roelof J; Stieger, Bruno; van Gulik, Thomas M

2013-01-01

To review the literature on the most clinically relevant and novel liver function tests used for the assessment of hepatic function before liver surgery. Postoperative liver failure is the major cause of mortality and morbidity after partial liver resection and develops as a result of insufficient remnant liver function. Therefore, accurate preoperative assessment of the future remnant liver function is mandatory in the selection of candidates for safe partial liver resection. A MEDLINE search was performed using the key words "liver function tests," "functional studies in the liver," "compromised liver," "physiological basis," and "mechanistic background," with and without Boolean operators. Passive liver function tests, including biochemical parameters and clinical grading systems, are not accurate enough in predicting outcome after liver surgery. Dynamic quantitative liver function tests, such as the indocyanine green test and galactose elimination capacity, are more accurate as they measure the elimination process of a substance that is cleared and/or metabolized almost exclusively by the liver. However, these tests only measure global liver function. Nuclear imaging techniques ((99m)Tc-galactosyl serum albumin scintigraphy and (99m)Tc-mebrofenin hepatobiliary scintigraphy) can measure both total and future remnant liver function and potentially identify patients at risk for postresectional liver failure. Because of the complexity of liver function, one single test does not represent overall liver function. In addition to computed tomography volumetry, quantitative liver function tests should be used to determine whether a safe resection can be performed. Presently, (99m)Tc-mebrofenin hepatobiliary scintigraphy seems to be the most valuable quantitative liver function test, as it can measure multiple aspects of liver function in, specifically, the future remnant liver.
Starting a new conversation: Engaging Veterans with spinal cord injury in discussions of what function means to them, the barriers/facilitators they encounter, and the adaptations they use to optimize function.

PubMed

Hill, Jennifer N; Balbale, Salva; Lones, Keshonna; LaVela, Sherri L

2017-01-01

Assessments of function in persons with spinal cord injury (SCI) often utilize pre-defined constructs and measures without consideration of patient context, including how patients define function and what matters to them. We utilized photovoice to understand how individuals define function, facilitators and barriers to function, and adaptations to support functioning. Veterans with SCI were provided with cameras and guidelines to take photographs of things that: (1) help with functioning, (2) are barriers to function, and (3) represent adaptations used to support functioning. Interviews to discuss photographs followed and were audio-recorded, transcribed, and analyzed using grounded-thematic coding. Nvivo 8 was used to store and organize data. Participants (n = 9) were male (89%), Caucasian (67%), had paraplegia (75%), averaged 64 years of age, and were injured, on average, for 22 years. Function was described in several ways: the concept of 'normalcy,' aspects of daily living, and ability to be independent. Facilitators included: helpful tools, physical therapy/therapists, transportation, and caregivers. Barriers included: wheelchair-related issues and interior/exterior barriers both in the community and in the hospital. Examples of adaptations included: traditional examples like ramps, and also creative examples like the use of rubber bands on a can to help with grip. Patient-perspectives elicited in-depth information that expanded the common definition of function by highlighting the concept of "normality," facilitators and barriers to function, and adaptations to optimize function. These insights emphasize function within a patient-context, emphasizing a holistic definition of function that can be used to develop personalized, patient-driven care plans. Published by Elsevier Inc.
Use of the rVV10 Nonlocal Correlation Functional in the B97M-V Density Functional: Defining B97M-rV and Related Functionals [On the Use of the rVV10 Nonlocal Correlation Functional in the B97M-V Density Functional: Defining B97M-rV and Related Functionals

DOE PAGES

Mardirossian, Narbe; Ruiz Pestana, Luis; Womack, James C.; ...

2016-12-06

The VV10 and rVV10 nonlocal correlation functionals are consistently implemented and assessed, with the goal of determining if the rVV10 nonlocal correlation functional can replace the VV10 nonlocal correlation functional in the recently developed B97M-V density functional, to give the B97M-rV density functional. Along the way, four density functionals are simultaneously tested: VV10, rVV10, B97M-V, and B97M-rV. An initial assessment is carried out across the S22 data set, and the short-range damping variable, b, is varied for all four density functionals in order to determine the sensitivity of the functionals to the empirical parameter. The results of this test indicatemore » that a value of b = 6 (fortuitously the same as that in B97M-V) is suitable for B97M-rV. The functionals are then compared across an extensive database of interaction energies, and it is demonstrated that B97M-rV either matches or outperforms B97M-V for all of the tests considered. Finally, the optimization of b across the S22 data set is extended to two range-separated hybrid density functionals, ωB97X-V and ωB97M-V, and a value of b = 6.2 is recommended for both ωB97X-rV and ωB97M-rV.« less
Evaluation of measurement equivalence of the Family Satisfaction with the End-of-Life Care in an ethnically diverse cohort: Tests of differential item functioning

PubMed Central

Teresi, Jeanne A; Ocepek-Welikson, Katja; Ramirez, Mildred; Kleinman, Marjorie; Ornstein, Katherine; Siu, Albert

2016-01-01

Background The Family Satisfaction with End-of-Life Care is an internationally used measure of satisfaction with cancer care. However, the Family Satisfaction with End-of-Life Care has not been studied for equivalence of item endorsement across different socio-demographic groups using differential item functioning. Aims The aims of this secondary data analysis were (1) to examine potential differential item functioning in the family satisfaction item set with respect to type of caregiver, race, and patient age, gender, and education and (2) to provide parameters and documentation of differential item functioning for an item bank. Design A mixed qualitative and quantitative analysis was conducted. A priori hypotheses regarding potential group differences in item response were established. Item response theory and Wald tests were used for the analyses of differential item functioning, accompanied by magnitude and impact measures. Results Very little significant differential item functioning was observed for patient's age and gender. For race, 13 items showed differential item functioning after multiple comparison adjustment, 10 with non-uniform differential item functioning. No items evidenced differential item functioning of high magnitude, and the impact was negligible. For education, 5 items evidenced uniform differential item functioning after adjustment, none of high magnitude. Differential item functioning impact was trivial. One item evidenced differential item functioning for the caregiver relationship variable. Conclusion Differential item functioning was observed primarily for race and education. No differential item functioning of high magnitude was observed for any item, and the overall impact of differential item functioning was negligible. One item, satisfaction with “the patient's pain relief,” might be singled out for further study, given that this item was both hypothesized and observed to show differential item functioning for race and education. PMID:25160692
FunShift: a database of function shift analysis on protein subfamilies

PubMed Central

Abhiman, Saraswathi; Sonnhammer, Erik L. L.

2005-01-01

Members of a protein family normally have a general biochemical function in common, but frequently one or more subgroups have evolved a slightly different function, such as different substrate specificity. It is important to detect such function shifts for a more accurate functional annotation. The FunShift database described here is a compilation of function shift analysis performed between subfamilies in protein families. It consists of two main components: (i) subfamilies derived from protein domain families and (ii) pairwise subfamily comparisons analyzed for function shift. The present release, FunShift 12, was derived from Pfam 12 and consists of 151 934 subfamilies derived from 7300 families. We carried out function shift analysis by two complementary methods on families with up to 500 members. From a total of 179 210 subfamily pairs, 62 384 were predicted to be functionally shifted in 2881 families. Each subfamily pair is provided with a markup of probable functional specificity-determining sites. Tools for searching and exploring the data are provided to make this database a valuable resource for protein function annotation. Knowledge of these functionally important sites will be useful for experimental biologists performing functional mutation studies. FunShift is available at http://FunShift.cgb.ki.se. PMID:15608176
Contrasting biodiversity-ecosystem functioning relationships in phylogenetic and functional diversity.

PubMed

Steudel, Bastian; Hallmann, Christine; Lorenz, Maike; Abrahamczyk, Stefan; Prinz, Kathleen; Herrfurth, Cornelia; Feussner, Ivo; Martini, Johannes W R; Kessler, Michael

2016-10-01

It is well known that ecosystem functioning is positively influenced by biodiversity. Most biodiversity-ecosystem functioning experiments have measured biodiversity based on species richness or phylogenetic relationships. However, theoretical and empirical evidence suggests that ecosystem functioning should be more closely related to functional diversity than to species richness. We applied different metrics of biodiversity in an artificial biodiversity-ecosystem functioning experiment using 64 species of green microalgae in combinations of two to 16 species. We found that phylogenetic and functional diversity were positively correlated with biomass overyield, driven by their strong correlation with species richness. At low species richness, no significant correlation between overyield and functional and phylogenetic diversity was found. However, at high species richness (16 species), we found a positive relationship of overyield with functional diversity and a negative relationship with phylogenetic diversity. We show that negative phylogenetic diversity-ecosystem functioning relationships can result from interspecific growth inhibition. The opposing performances of facilitation (functional diversity) and inhibition (phylogenetic diversity) we observed at the 16 species level suggest that phylogenetic diversity is not always a good proxy for functional diversity and that results from experiments with low species numbers may underestimate negative species interactions. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.
Microbial Functional Gene Diversity Predicts Groundwater Contamination and Ecosystem Functioning

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

He, Zhili; Zhang, Ping; Wu, Linwei

Contamination from anthropogenic activities has significantly impacted Earth’s biosphere. However, knowledge about how environmental contamination affects the biodiversity of groundwater microbiomes and ecosystem functioning remains very limited. Here, we used a comprehensive functional gene array to analyze groundwater microbiomes from 69 wells at the Oak Ridge Field Research Center (Oak Ridge, TN), representing a wide pH range and uranium, nitrate, and other contaminants. We hypothesized that the functional diversity of groundwater microbiomes would decrease as environmental contamination (e.g., uranium or nitrate) increased or at low or high pH, while some specific populations capable of utilizing or resistant to those contaminantsmore » would increase, and thus, such key microbial functional genes and/or populations could be used to predict groundwater contamination and ecosystem functioning. Our results indicated that functional richness/diversity decreased as uranium (but not nitrate) increased in groundwater. In addition, about 5.9% of specific key functional populations targeted by a comprehensive functional gene array (GeoChip 5) increased significantly (P < 0.05) as uranium or nitrate increased, and their changes could be used to successfully predict uranium and nitrate contamination and ecosystem functioning. Here, this study indicates great potential for using microbial functional genes to predict environmental contamination and ecosystem functioning.« less
Functional integrative levels in the human interactome recapitulate organ organization.

PubMed

Souiai, Ouissem; Becker, Emmanuelle; Prieto, Carlos; Benkahla, Alia; De las Rivas, Javier; Brun, Christine

2011-01-01

Interactome networks represent sets of possible physical interactions between proteins. They lack spatio-temporal information by construction. However, the specialized functions of the differentiated cell types which are assembled into tissues or organs depend on the combinatorial arrangements of proteins and their physical interactions. Is tissue-specificity, therefore, encoded within the interactome? In order to address this question, we combined protein-protein interactions, expression data, functional annotations and interactome topology. We first identified a subnetwork formed exclusively of proteins whose interactions were observed in all tested tissues. These are mainly involved in housekeeping functions and are located at the topological center of the interactome. This 'Largest Common Interactome Network' represents a 'functional interactome core'. Interestingly, two types of tissue-specific interactions are distinguished when considering function and network topology: tissue-specific interactions involved in regulatory and developmental functions are central whereas tissue-specific interactions involved in organ physiological functions are peripheral. Overall, the functional organization of the human interactome reflects several integrative levels of functions with housekeeping and regulatory tissue-specific functions at the center and physiological tissue-specific functions at the periphery. This gradient of functions recapitulates the organization of organs, from cells to organs. Given that several gradients have already been identified across interactomes, we propose that gradients may represent a general principle of protein-protein interaction network organization.
Global functional diversity of freshwater fish is concentrated in the Neotropics while functional vulnerability is widespread.

PubMed

Toussaint, A; Charpin, N; Brosse, S; Villéger, S

2016-03-16

Worldwide biodiversity assessments have mainly focused on species richness but little is known about the diversity of species roles, i.e. functional diversity, while this is a key facet to understanding the consequences of global changes on the ecosystem services to human societies. Here, we report the world pattern of functional diversity of freshwater fish using a database encompassing morphological characteristics of more than 9,000 species. The Neotropical realm hosts more than 75% of global functional diversity while other realms each host less than 25%. This discrepancy is mediated by high functional uniqueness in some diversified Neotropical fish orders. Surprisingly, functional diversity patterns were weakly related to functional vulnerability. In the Neotropics the loss of threatened species will cause a limited loss of functional diversity (<10%) whereas in the Nearctic and Palearctic realms, decline of the functional diversity will reach 43% and 33%, respectively, conferring a high functional vulnerability to these realms. Conservation of the Neotropical fish diversity is a key target to maintain world fish functional diversity, but this should not hide the pressing need to conserve the vulnerable fish faunas of the rest of the world, in which functional diversity is to a large extent supported by threatened species.
Microbial Functional Gene Diversity Predicts Groundwater Contamination and Ecosystem Functioning

PubMed Central

Zhang, Ping; Wu, Linwei; Rocha, Andrea M.; Shi, Zhou; Wu, Bo; Qin, Yujia; Wang, Jianjun; Yan, Qingyun; Curtis, Daniel; Ning, Daliang; Van Nostrand, Joy D.; Wu, Liyou; Watson, David B.; Adams, Michael W. W.; Alm, Eric J.; Adams, Paul D.; Arkin, Adam P.

2018-01-01

ABSTRACT Contamination from anthropogenic activities has significantly impacted Earth’s biosphere. However, knowledge about how environmental contamination affects the biodiversity of groundwater microbiomes and ecosystem functioning remains very limited. Here, we used a comprehensive functional gene array to analyze groundwater microbiomes from 69 wells at the Oak Ridge Field Research Center (Oak Ridge, TN), representing a wide pH range and uranium, nitrate, and other contaminants. We hypothesized that the functional diversity of groundwater microbiomes would decrease as environmental contamination (e.g., uranium or nitrate) increased or at low or high pH, while some specific populations capable of utilizing or resistant to those contaminants would increase, and thus, such key microbial functional genes and/or populations could be used to predict groundwater contamination and ecosystem functioning. Our results indicated that functional richness/diversity decreased as uranium (but not nitrate) increased in groundwater. In addition, about 5.9% of specific key functional populations targeted by a comprehensive functional gene array (GeoChip 5) increased significantly (P < 0.05) as uranium or nitrate increased, and their changes could be used to successfully predict uranium and nitrate contamination and ecosystem functioning. This study indicates great potential for using microbial functional genes to predict environmental contamination and ecosystem functioning. PMID:29463661

Microbial Functional Gene Diversity Predicts Groundwater Contamination and Ecosystem Functioning

DOE PAGES

He, Zhili; Zhang, Ping; Wu, Linwei; ...

2018-02-20

Contamination from anthropogenic activities has significantly impacted Earth’s biosphere. However, knowledge about how environmental contamination affects the biodiversity of groundwater microbiomes and ecosystem functioning remains very limited. Here, we used a comprehensive functional gene array to analyze groundwater microbiomes from 69 wells at the Oak Ridge Field Research Center (Oak Ridge, TN), representing a wide pH range and uranium, nitrate, and other contaminants. We hypothesized that the functional diversity of groundwater microbiomes would decrease as environmental contamination (e.g., uranium or nitrate) increased or at low or high pH, while some specific populations capable of utilizing or resistant to those contaminantsmore » would increase, and thus, such key microbial functional genes and/or populations could be used to predict groundwater contamination and ecosystem functioning. Our results indicated that functional richness/diversity decreased as uranium (but not nitrate) increased in groundwater. In addition, about 5.9% of specific key functional populations targeted by a comprehensive functional gene array (GeoChip 5) increased significantly (P < 0.05) as uranium or nitrate increased, and their changes could be used to successfully predict uranium and nitrate contamination and ecosystem functioning. Here, this study indicates great potential for using microbial functional genes to predict environmental contamination and ecosystem functioning.« less
Resonant nonlinear ultrasound spectroscopy

DOEpatents

Johnson, Paul A.; TenCate, James A.; Guyer, Robert A.; Van Den Abeele, Koen E. A.

2001-01-01

Components with defects are identified from the response to strains applied at acoustic and ultrasound frequencies. The relative resonance frequency shift .vertline..DELTA..function./.function..sub.0.vertline., is determined as a function of applied strain amplitude for an acceptable component, where .function..sub.0 is the frequency of the resonance peak at the lowest amplitude of applied strain and .DELTA..function. is the frequency shift of the resonance peak of a selected mode to determine a reference relationship. Then, the relative resonance frequency shift .vertline..DELTA..function./.function..sub.0 is determined as a function of applied strain for a component under test, where fo .function..sub.0 the frequency of the resonance peak at the lowest amplitude of applied strain and .DELTA..function. is the frequency shift of the resonance peak to determine a quality test relationship. The reference relationship is compared with the quality test relationship to determine the presence of defects in the component under test.
A study of accurate exchange-correlation functionals through adiabatic connection

NASA Astrophysics Data System (ADS)

Singh, Rabeet; Harbola, Manoj K.

2017-10-01

A systematic way of improving exchange-correlation energy functionals of density functional theory has been to make them satisfy more and more exact relations. Starting from the initial generalized gradient approximation (GGA) functionals, this has culminated into the recently proposed SCAN (strongly constrained and appropriately normed) functional that satisfies several known constraints and is appropriately normed. The ultimate test for the functionals developed is the accuracy of energy calculated by employing them. In this paper, we test these exchange-correlation functionals—the GGA hybrid functionals B3LYP and PBE0 and the meta-GGA functional SCAN—from a different perspective. We study how accurately these functionals reproduce the exchange-correlation energy when electron-electron interaction is scaled as αVee with α varying between 0 and 1. Our study reveals interesting comparison between these functionals and the associated difference Tc between the interacting and the non-interacting kinetic energy for the same density.
Nonparametric Bayesian models for a spatial covariance.

PubMed

Reich, Brian J; Fuentes, Montserrat

2012-01-01

A crucial step in the analysis of spatial data is to estimate the spatial correlation function that determines the relationship between a spatial process at two locations. The standard approach to selecting the appropriate correlation function is to use prior knowledge or exploratory analysis, such as a variogram analysis, to select the correct parametric correlation function. Rather that selecting a particular parametric correlation function, we treat the covariance function as an unknown function to be estimated from the data. We propose a flexible prior for the correlation function to provide robustness to the choice of correlation function. We specify the prior for the correlation function using spectral methods and the Dirichlet process prior, which is a common prior for an unknown distribution function. Our model does not require Gaussian data or spatial locations on a regular grid. The approach is demonstrated using a simulation study as well as an analysis of California air pollution data.
Clinical interpretation of the Spinal Cord Injury Functional Index (SCI-FI).

PubMed

Fyffe, Denise; Kalpakjian, Claire Z; Slavin, Mary; Kisala, Pamela; Ni, Pengsheng; Kirshblum, Steven C; Tulsky, David S; Jette, Alan M

2016-09-01

To provide validation of functional ability levels for the Spinal Cord Injury - Functional Index (SCI-FI). Cross-sectional. Inpatient rehabilitation hospital and community settings. A sample of 855 individuals with traumatic spinal cord injury enrolled in 6 rehabilitation centers participating in the National Spinal Cord Injury Model Systems Network. Not Applicable. Spinal Cord Injury-Functional Index (SCI-FI). Cluster analyses identified three distinct groups that represent low, mid-range and high SCI-FI functional ability levels. Comparison of clusters on personal and other injury characteristics suggested some significant differences between groups. These results strongly support the use of SCI-FI functional ability levels to document the perceived functional abilities of persons with SCI. Results of the cluster analysis suggest that the SCI-FI functional ability levels capture function by injury characteristics. Clinical implications regarding tracking functional activity trajectories during follow-up visits are discussed.
Effects of Functional-Task Training on Older Adults With Alzheimer's Disease.

PubMed

Pedroso, Renata V; Ayán, Carlos; Fraga, Francisco J; da Silva, Thays M V; Cancela, José M; Santos-Galduròz, Ruth F

2018-01-01

The aim of this study was to verify the effects of functional-task training on cognitive function, activities of daily living (ADL) performance, and functional fitness in community-dwelling older adults with diagnosis of Alzheimer's disease (AD). A total of 57 participants (22 functional-task training group [FTG], 21 social gathering group [SGG], 14 control group [CG]) were recruited. Participants in both intervention groups carried out three 1-hr sessions per week of a functional-task program and social gathering activities for 12 weeks. Significant improvements were observed in executive functions (TMT, t-test, p = .03) in the SGG and in upper limb strength (arm curl, t-test, p = .01) in the FTG. Functional-task training has no significant effect on cognitive function, ADL, and functional fitness among people with AD, although it may contribute to slowing down the process of deterioration this illness causes.
Bayesian function-on-function regression for multilevel functional data.

PubMed

Meyer, Mark J; Coull, Brent A; Versace, Francesco; Cinciripini, Paul; Morris, Jeffrey S

2015-09-01

Medical and public health research increasingly involves the collection of complex and high dimensional data. In particular, functional data-where the unit of observation is a curve or set of curves that are finely sampled over a grid-is frequently obtained. Moreover, researchers often sample multiple curves per person resulting in repeated functional measures. A common question is how to analyze the relationship between two functional variables. We propose a general function-on-function regression model for repeatedly sampled functional data on a fine grid, presenting a simple model as well as a more extensive mixed model framework, and introducing various functional Bayesian inferential procedures that account for multiple testing. We examine these models via simulation and a data analysis with data from a study that used event-related potentials to examine how the brain processes various types of images. © 2015, The International Biometric Society.
Classical Testing in Functional Linear Models.

PubMed

Kong, Dehan; Staicu, Ana-Maria; Maity, Arnab

2016-01-01

We extend four tests common in classical regression - Wald, score, likelihood ratio and F tests - to functional linear regression, for testing the null hypothesis, that there is no association between a scalar response and a functional covariate. Using functional principal component analysis, we re-express the functional linear model as a standard linear model, where the effect of the functional covariate can be approximated by a finite linear combination of the functional principal component scores. In this setting, we consider application of the four traditional tests. The proposed testing procedures are investigated theoretically for densely observed functional covariates when the number of principal components diverges. Using the theoretical distribution of the tests under the alternative hypothesis, we develop a procedure for sample size calculation in the context of functional linear regression. The four tests are further compared numerically for both densely and sparsely observed noisy functional data in simulation experiments and using two real data applications.
A cumulant functional for static and dynamic correlation

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

Hollett, Joshua W., E-mail: j.hollett@uwinnipeg.ca; Department of Chemistry, University of Manitoba, Winnipeg, Manitoba R3T 2N2; Hosseini, Hessam

A functional for the cumulant energy is introduced. The functional is composed of a pair-correction and static and dynamic correlation energy components. The pair-correction and static correlation energies are functionals of the natural orbitals and the occupancy transferred between near-degenerate orbital pairs, rather than the orbital occupancies themselves. The dynamic correlation energy is a functional of the statically correlated on-top two-electron density. The on-top density functional used in this study is the well-known Colle-Salvetti functional. Using the cc-pVTZ basis set, the functional effectively models the bond dissociation of H{sub 2}, LiH, and N{sub 2} with equilibrium bond lengths and dissociationmore » energies comparable to those provided by multireference second-order perturbation theory. The performance of the cumulant functional is less impressive for HF and F{sub 2}, mainly due to an underestimation of the dynamic correlation energy by the Colle-Salvetti functional.« less
Classical Testing in Functional Linear Models

PubMed Central

Kong, Dehan; Staicu, Ana-Maria; Maity, Arnab

2016-01-01

We extend four tests common in classical regression - Wald, score, likelihood ratio and F tests - to functional linear regression, for testing the null hypothesis, that there is no association between a scalar response and a functional covariate. Using functional principal component analysis, we re-express the functional linear model as a standard linear model, where the effect of the functional covariate can be approximated by a finite linear combination of the functional principal component scores. In this setting, we consider application of the four traditional tests. The proposed testing procedures are investigated theoretically for densely observed functional covariates when the number of principal components diverges. Using the theoretical distribution of the tests under the alternative hypothesis, we develop a procedure for sample size calculation in the context of functional linear regression. The four tests are further compared numerically for both densely and sparsely observed noisy functional data in simulation experiments and using two real data applications. PMID:28955155
Multi-subject Manifold Alignment of Functional Network Structures via Joint Diagonalization.

PubMed

Nenning, Karl-Heinz; Kollndorfer, Kathrin; Schöpf, Veronika; Prayer, Daniela; Langs, Georg

2015-01-01

Functional magnetic resonance imaging group studies rely on the ability to establish correspondence across individuals. This enables location specific comparison of functional brain characteristics. Registration is often based on morphology and does not take variability of functional localization into account. This can lead to a loss of specificity, or confounds when studying diseases. In this paper we propose multi-subject functional registration by manifold alignment via coupled joint diagonalization. The functional network structure of each subject is encoded in a diffusion map, where functional relationships are decoupled from spatial position. Two-step manifold alignment estimates initial correspondences between functionally equivalent regions. Then, coupled joint diagonalization establishes common eigenbases across all individuals, and refines the functional correspondences. We evaluate our approach on fMRI data acquired during a language paradigm. Experiments demonstrate the benefits in matching accuracy achieved by coupled joint diagonalization compared to previously proposed functional alignment approaches, or alignment based on structural correspondences.
Inter-species activity correlations reveal functional correspondences between monkey and human brain areas

PubMed Central

Mantini, Dante; Hasson, Uri; Betti, Viviana; Perrucci, Mauro G.; Romani, Gian Luca; Corbetta, Maurizio; Orban, Guy A.; Vanduffel, Wim

2012-01-01

Evolution-driven functional changes in the primate brain are typically assessed by aligning monkey and human activation maps using cortical surface expansion models. These models use putative homologous areas as registration landmarks, assuming they are functionally correspondent. In cases where functional changes have occurred in an area, this assumption prohibits to reveal whether other areas may have assumed lost functions. Here we describe a method to examine functional correspondences across species. Without making spatial assumptions, we assess similarities in sensory-driven functional magnetic resonance imaging responses between monkey (Macaca mulatta) and human brain areas by means of temporal correlation. Using natural vision data, we reveal regions for which functional processing has shifted to topologically divergent locations during evolution. We conclude that substantial evolution-driven functional reorganizations have occurred, not always consistent with cortical expansion processes. This novel framework for evaluating changes in functional architecture is crucial to building more accurate evolutionary models. PMID:22306809
An exploration of function analysis and function allocation in the commercial flight domain

NASA Technical Reports Server (NTRS)

Mcguire, James C.; Zich, John A.; Goins, Richard T.; Erickson, Jeffery B.; Dwyer, John P.; Cody, William J.; Rouse, William B.

1991-01-01

The applicability is explored of functional analysis methods to support cockpit design. Specifically, alternative techniques are studied for ensuring an effective division of responsibility between the flight crew and automation. A functional decomposition is performed of the commercial flight domain to provide the information necessary to support allocation decisions and demonstrate methodology for allocating functions to flight crew or to automation. The function analysis employed 'bottom up' and 'top down' analyses and demonstrated the comparability of identified functions, using the 'lift off' segment of the 'take off' phase as a test case. The normal flight mission and selected contingencies were addressed. Two alternative methods for using the functional description in the allocation of functions between man and machine were investigated. The two methods were compared in order to ascertain their relative strengths and weaknesses. Finally, conclusions were drawn regarding the practical utility of function analysis methods.
Scaling within the spectral function approach

NASA Astrophysics Data System (ADS)

Sobczyk, J. E.; Rocco, N.; Lovato, A.; Nieves, J.

2018-03-01

Scaling features of the nuclear electromagnetic response functions unveil aspects of nuclear dynamics that are crucial for interpreting neutrino- and electron-scattering data. In the large momentum-transfer regime, the nucleon-density response function defines a universal scaling function, which is independent of the nature of the probe. In this work, we analyze the nucleon-density response function of 12C, neglecting collective excitations. We employ particle and hole spectral functions obtained within two distinct many-body methods, both widely used to describe electroweak reactions in nuclei. We show that the two approaches provide compatible nucleon-density scaling functions that for large momentum transfers satisfy first-kind scaling. Both methods yield scaling functions characterized by an asymmetric shape, although less pronounced than that of experimental scaling functions. This asymmetry, only mildly affected by final state interactions, is mostly due to nucleon-nucleon correlations, encoded in the continuum component of the hole spectral function.
The invariant of the stiffness filter function with the weight filter function of the power function form

NASA Astrophysics Data System (ADS)

Shang, Zhen; Sui, Yun-Kang

2012-12-01

Based on the independent, continuous and mapping (ICM) method and homogenization method, a research model is constructed to propose and deduce a theorem and corollary from the invariant between the weight filter function and the corresponding stiffness filter function of the form of power function. The efficiency in searching for optimum solution will be raised via the choice of rational filter functions, so the above mentioned results are very important to the further study of structural topology optimization.
Luigi Gatteschi's work on asymptotics of special functions and their zeros

NASA Astrophysics Data System (ADS)

Gautschi, Walter; Giordano, Carla

2008-12-01

A good portion of Gatteschi's research publications-about 65%-is devoted to asymptotics of special functions and their zeros. Most prominently among the special functions studied figure classical orthogonal polynomials, notably Jacobi polynomials and their special cases, Laguerre polynomials, and Hermite polynomials by implication. Other important classes of special functions dealt with are Bessel functions of the first and second kind, Airy functions, and confluent hypergeometric functions, both in Tricomi's and Whittaker's form. This work is reviewed here, and organized along methodological lines.
Functional Performance Testing for Power and Return to Sports

PubMed Central

Manske, Robert; Reiman, Michael

2013-01-01

Context: Functional performance testing of athletes can determine physical limitations that may affect sporting activities. Optimal functional performance testing simulates the athlete’s activity. Evidence Acquisition: A Medline search from 1960 to 2012 was implemented with the keywords functional testing, functional impairment testing, and functional performance testing in the English language. Each author also undertook independent searches of article references. Conclusion: Functional performance tests can bridge the gap between general physical tests and full, unrestricted athletic activity. PMID:24427396
Flight Crew Workload Evaluation Based on the Workload Function Distribution Method.

PubMed

Zheng, Yiyuan; Lu, Yanyu; Jie, Yuwen; Fu, Shan

2017-05-01

The minimum flight crew on the flight deck should be established according to the workload for individual crewmembers. Typical workload measures consist of three types: subjective rating scale, task performance, and psychophysiological measures. However, all these measures have their own limitations. To reflect flight crew workload more specifically and comprehensively within the flight environment, and more directly comply with airworthiness regulations, the Workload Function Distribution Method, which combined the basic six workload functions, was proposed. The analysis was based on the different conditions of workload function numbers. Each condition was analyzed from two aspects, which were overall proportion and effective proportion. Three types of approach tasks were used in this study and the NASA-TLX scale was implemented for comparison. Neither the one-function condition nor the two-function condition had the same results with NASA-TLX. However, both the three-function and the four- to six- function conditions were identical with NASA-TLX. Further, the significant differences were different on four to six conditions. The overall proportion was insignificant, while the effective proportions were significant. The results show that the conditions with one function and two functions seemed to have no influence on workload, while executing three functions and four to six functions had an impact on workload. Besides, effective proportions of workload functions were more precisely compared with the overall proportions to indicate workload, especially in the conditions with multiple functions.Zheng Y, Lu Y, Jie Y, Fu S. Flight crew workload evaluation based on the workload function distribution method. Aerosp Med Hum Perform. 2017; 88(5):481-486.
Functional food awareness and perceptions in relation to information sources in older adults

PubMed Central

2014-01-01

Background The functional food industry has experienced innovative and economic expansion, yet research into consumer perceptions of functional foods and their associated health claims is limited. Among consumers, older adults could benefit from functional foods due to age-related issues pertaining to food and health. The purpose of this research was to identify the need for information related to functional foods among older adults (≥60 years old) and to assess awareness and perceptions of health claims on functional food packages. Methods Community-dwelling older adults (n = 200) completed a researcher administered questionnaire designed to collect information about functional foods including current consumption, motivating factors for consumption, perceived need for information, sources of information for functional foods and awareness of health claims. Results Prevalence of functional food consumption among participants was 93.0%. Increased awareness and knowledge was the most commonly reported factor that would promote functional food consumption (85.5%) and 63.5% of participants wanted more information about functional foods with preferred sources being newspapers/magazines/books (68.5%) and food labels (66.1%). Participants were predominately (93.5%) aware of health claims on functional foods and those with more education were more likely to report being aware of health claims (p = 0.045). Conclusions Although functional food consumption among older adults in this sample is high, there is a need for further information regarding functional foods. These results inform stakeholders regarding the potential for information to influence functional food acceptance among older adult consumers. PMID:24886306
The association between alcohol drinking and self-reported mental and physical functioning: a prospective cohort study among City of Helsinki employees.

PubMed

Salonsalmi, Aino; Rahkonen, Ossi; Lahelma, Eero; Laaksonen, Mikko

2017-05-04

Alcohol drinking is associated with ill health but less is known about its contribution to overall functioning. We aimed to examine whether alcohol drinking predicts self-reported mental and physical functioning 5-7 years later. A prospective cohort study. Helsinki, Finland. 40-year-old to 60-year-old employees of the City of Helsinki (5301 women and 1230 men) who participated in a postal survey in 2000-2002 and a follow-up survey in 2007. Mental and physical functioning measured by the Short Form 36 Health Survey. Alcohol drinking was differently associated with mental and physical functioning. Heavy average drinking, binge drinking and problem drinking were all associated with subsequent poor mental functioning except for heavy average drinking among men, whereas only problem drinking was associated with poor physical functioning. Also, non-drinking was associated with poor physical functioning. Problem drinking was the drinking habit showing most widespread and strongest associations with health functioning. The associations between problem drinking and poor mental functioning and with poor physical functioning among women remained after adjusting for baseline mental functioning, sociodemographic factors, working conditions and other health behaviours. Alcohol drinking is associated especially with poor mental functioning. Problem drinking was the drinking habit strongest associated with poor health functioning. The results call for early recognition and prevention of alcohol problems in order to improve health functioning among employees. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Topology-function conservation in protein-protein interaction networks.

PubMed

Davis, Darren; Yaveroğlu, Ömer Nebil; Malod-Dognin, Noël; Stojmirovic, Aleksandar; Pržulj, Nataša

2015-05-15

Proteins underlay the functioning of a cell and the wiring of proteins in protein-protein interaction network (PIN) relates to their biological functions. Proteins with similar wiring in the PIN (topology around them) have been shown to have similar functions. This property has been successfully exploited for predicting protein functions. Topological similarity is also used to guide network alignment algorithms that find similarly wired proteins between PINs of different species; these similarities are used to transfer annotation across PINs, e.g. from model organisms to human. To refine these functional predictions and annotation transfers, we need to gain insight into the variability of the topology-function relationships. For example, a function may be significantly associated with specific topologies, while another function may be weakly associated with several different topologies. Also, the topology-function relationships may differ between different species. To improve our understanding of topology-function relationships and of their conservation among species, we develop a statistical framework that is built upon canonical correlation analysis. Using the graphlet degrees to represent the wiring around proteins in PINs and gene ontology (GO) annotations to describe their functions, our framework: (i) characterizes statistically significant topology-function relationships in a given species, and (ii) uncovers the functions that have conserved topology in PINs of different species, which we term topologically orthologous functions. We apply our framework to PINs of yeast and human, identifying seven biological process and two cellular component GO terms to be topologically orthologous for the two organisms. © The Author 2015. Published by Oxford University Press.
Ensemble density variational methods with self- and ghost-interaction-corrected functionals

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

Pastorczak, Ewa; Pernal, Katarzyna, E-mail: pernalk@gmail.com

2014-05-14

Ensemble density functional theory (DFT) offers a way of predicting excited-states energies of atomic and molecular systems without referring to a density response function. Despite a significant theoretical work, practical applications of the proposed approximations have been scarce and they do not allow for a fair judgement of the potential usefulness of ensemble DFT with available functionals. In the paper, we investigate two forms of ensemble density functionals formulated within ensemble DFT framework: the Gross, Oliveira, and Kohn (GOK) functional proposed by Gross et al. [Phys. Rev. A 37, 2809 (1988)] alongside the orbital-dependent eDFT form of the functional introducedmore » by Nagy [J. Phys. B 34, 2363 (2001)] (the acronym eDFT proposed in analogy to eHF – ensemble Hartree-Fock method). Local and semi-local ground-state density functionals are employed in both approaches. Approximate ensemble density functionals contain not only spurious self-interaction but also the so-called ghost-interaction which has no counterpart in the ground-state DFT. We propose how to correct the GOK functional for both kinds of interactions in approximations that go beyond the exact-exchange functional. Numerical applications lead to a conclusion that functionals free of the ghost-interaction by construction, i.e., eDFT, yield much more reliable results than approximate self- and ghost-interaction-corrected GOK functional. Additionally, local density functional corrected for self-interaction employed in the eDFT framework yields excitations energies of the accuracy comparable to that of the uncorrected semi-local eDFT functional.« less
Influence of CT-based depth correction of renal scintigraphy in evaluation of living kidney donors on side selection and postoperative renal function: is it necessary to know the relative renal function?

PubMed

Weinberger, Sarah; Klarholz-Pevere, Carola; Liefeldt, Lutz; Baeder, Michael; Steckhan, Nico; Friedersdorff, Frank

2018-03-22

To analyse the influence of CT-based depth correction in the assessment of split renal function in potential living kidney donors. In 116 consecutive living kidney donors preoperative split renal function was assessed using the CT-based depth correction. Influence on donor side selection and postoperative renal function of the living kidney donors were analyzed. Linear regression analysis was performed to identify predictors of postoperative renal function. A left versus right kidney depth variation of more than 1 cm was found in 40/114 donors (35%). 11 patients (10%) had a difference of more than 5% in relative renal function after depth correction. Kidney depth variation and changes in relative renal function after depth correction would have had influence on side selection in 30 of 114 living kidney donors. CT depth correction did not improve the predictability of postoperative renal function of the living kidney donor. In general, it was not possible to predict the postoperative renal function from preoperative total and relative renal function. In multivariate linear regression analysis, age and BMI were identified as most important predictors for postoperative renal function of the living kidney donors. Our results clearly indicate that concerning the postoperative renal function of living kidney donors, the relative renal function of the donated kidney seems to be less important than other factors. A multimodal assessment with consideration of all available results including kidney size, location of the kidney and split renal function remains necessary.
The mediating role of metacognition in the relationship between executive function and self-regulated learning.

PubMed

Follmer, D Jake; Sperling, Rayne A

2016-12-01

Researchers have demonstrated significant relations among executive function, metacognition, and self-regulated learning. However, prior research emphasized the use of indirect measures of executive function and did not evaluate how specific executive functions are related to participants' self-regulated learning. The primary goals of the current study were to examine and test the relations among executive function, metacognition, and self-regulated learning as well as to examine how self-regulated learning is informed by executive function. The sample comprised 117 undergraduate students attending a large, Mid-Atlantic research university in the United States. Participants were individually administered direct and indirect measures of executive function, metacognition, and self-regulated learning. A mediation model specifying the relations among the regulatory constructs was proposed. In multiple linear regression analyses, executive function predicted metacognition and self-regulated learning. Direct measures of inhibition and shifting accounted for a significant amount of the variance in metacognition and self-regulated learning beyond an indirect measure of executive functioning. Separate mediation analyses indicated that metacognition mediated the relationship between executive functioning and self-regulated learning as well as between specific executive functions and self-regulated learning. The findings of this study are supported by previous research documenting the relations between executive function and self-regulated learning, and extend prior research by examining the manner in which executive function and self-regulated learning are linked. The findings provide initial support for executive functions as key processes, mediated by metacognition, that predict self-regulated learning. Implications for the contribution of executive functions to self-regulated learning are discussed. © 2016 The British Psychological Society.
T59. VIRTUAL REALTY ASSESSMENT OF FUNCTIONAL CAPACITY IN EARLY SCHIZOPHRENIA: ASSOCIATIONS WITH NEUROCOGNITION, FUNCTIONAL CAPACITY PERFORMANCE, AND DAILY FUNCTIONING

PubMed Central

Ventura, Joseph; Welikson, Tamara; Subotnik, Kenneth L; Ered, Arielle; Keefe, Richard; Hellemann, Gerhard H; Nuechterlein, Keith H

2018-01-01

Abstract Background Research using virtual reality assessment of functional capacity has shown promise as a reliable and valid way to assess treatment response in patients with established schizophrenia. There has been little work on virtual reality based assessments of functional capacity for patients in the early phase of schizophrenia. We examined whether virtual reality based assessment methods reveal functional capacity deficits in young patients and relevant relationships with established measures of neurocognition, functional capacity performance, and daily functioning. Methods The sample consisted of UCLA Aftercare Research Program patients (n=42) who were diagnosed by trained raters administering the SCID and who met criteria for schizophrenia, schizoaffective disorder, or schizophreniform disorder, and screened normal control subjects (n=13). Patients were within 2 years of their first psychotic episode upon clinic entry, were an average of 23.2 years old, and had an average of 12.9 years of education. The Virtual Reality Functional Capacity Assessment Tool (VRFCAT) was the computer-based measure of functional capacity. We used the MATRICS Consensus Cognitive Battery (MCCB) as an objective measure of neurocognition and the UCSD Performance-Based Skills Assessment (UPSA) to assess functional capacity performance. The Global Functioning Scale: Role and Social, and the Role Functioning Scale were used to assess work and school performance, familial interactions, and social functioning. Results We were able to confirm that the deficit in functional capacity performance measured using VRFCAT is present in the early course of schizophrenia in that the patients were slower and committed more errors (M=830.41) as compared with normal controls (M=716.84; t=3.0, p<.01). Virtual reality based assessment of functional capacity was correlated with objective measures of neurocognition (MCCB Overall Composite), r=-.71, p=<.01, standard approaches to functional capacity assessment (UPSA), r=-.66, p=<.01, work and school functioning (r=-.52, p<.01), and level of social relationships (r=-.43, p=<.03), but not familial relationships (r=-.03, p=.87). Interestingly, neither neurocognition (MCCB) nor functional capacity performance (UPSA) were correlated with the level of familial relationships. Discussion We extend previous findings in that even patients in the early course of schizophrenia showed virtual reality based functional capacity performance deficits when compared with normal control subjects. Virtual reality based performance was correlated with neurocognition, suggesting that it may be sensitive to changes in cognition. Furthermore, correlations with everyday work/school and social functioning indicate promise as a co-primary measure to index change in functioning in response to treatment. Interestingly, none of our measures of functional capacity or neurocognition were correlated with familial relationships indicating that the determinates of family interactions might be driven by factors other than cognitive capacities.
20 CFR 641.856 - What functions and activities constitute costs of administration?

Code of Federal Regulations, 2010 CFR

2010-04-01

..., including: (i) Accounting, budgeting, financial, and cash management functions; (ii) Procurement and purchasing functions; (iii) Property management functions; (iv) Personnel management functions; (v) Payroll... example, personnel, procurement, purchasing, property management, accounting, and payroll systems...
Connected Functional Working Spaces: A Framework for the Teaching and Learning of Functions at Upper Secondary Level

ERIC Educational Resources Information Center

Minh, Tran Kiem; Lagrange, Jean-Baptiste

2016-01-01

This paper aims at contributing to remedy the narrow treatment of functions at upper secondary level. Assuming that students make sense of functions by working on functional situations in distinctive settings, we propose to consider functional working spaces inspired by geometrical working spaces. We analyse a classroom situation based on a…
Direct connection between the different QCD orders for parton distribution and fragmentation functions

NASA Astrophysics Data System (ADS)

Shevchenko, O. Yu.

2013-06-01

The formulas directly connecting parton distribution functions and fragmentation functions at the next-to-leading-order QCD with the same quantities at the leading order are derived. These formulas are universal, i.e., have the same form for all kinds of parton distribution functions and fragmentation functions, differing only in the respective splitting functions entering there.
A Comparison of Experimental Functional Analysis and the Questions about Behavioral Function (QABF) in the Assessment of Challenging Behavior of Individuals with Autism

ERIC Educational Resources Information Center

Healy, Olive; Brett, Denise; Leader, Geraldine

2013-01-01

We compared two functional behavioral assessment methods: the Questions About Behavioral Function (QABF; a standardized test) and experimental functional analysis (EFA) to identify behavioral functions of aggressive/destructive behavior, self-injurious behavior and stereotypy in 32 people diagnosed with autism. Both assessments found that self…
Functional Analyses and Treatment of Precursor Behavior

PubMed Central

Najdowski, Adel C; Wallace, Michele D; Ellsworth, Carrie L; MacAleese, Alicia N; Cleveland, Jackie M

2008-01-01

Functional analysis has been demonstrated to be an effective method to identify environmental variables that maintain problem behavior. However, there are cases when conducting functional analyses of severe problem behavior may be contraindicated. The current study applied functional analysis procedures to a class of behavior that preceded severe problem behavior (precursor behavior) and evaluated treatments based on the outcomes of the functional analyses of precursor behavior. Responding for all participants was differentiated during the functional analyses, and individualized treatments eliminated precursor behavior. These results suggest that functional analysis of precursor behavior may offer an alternative, indirect method to assess the operant function of severe problem behavior. PMID:18468282
Functional fixedness in a technologically sparse culture.

PubMed

German, Tim P; Barrett, H Clark

2005-01-01

Problem solving can be inefficient when the solution requires subjects to generate an atypical function for an object and the object's typical function has been primed. Subjects become "fixed" on the design function of the object, and problem solving suffers relative to control conditions in which the object's function is not demonstrated. In the current study, such functional fixedness was demonstrated in a sample of adolescents (mean age of 16 years) among the Shuar of Ecuadorian Amazonia, whose technologically sparse culture provides limited access to large numbers of artifacts with highly specialized functions. This result suggests that design function may universally be the core property of artifact concepts in human semantic memory.
Approximate formulas for elasticity of the Tornquist functions and some their advantages

NASA Astrophysics Data System (ADS)

Issin, Meyram

2017-09-01

In this article functions of demand for prime necessity, second necessity and luxury goods depending on the income are considered. These functions are called Tornquist functions. By means of the return model the demand for prime necessity goods and second necessity goods are approximately described. Then on the basis of a method of the smallest squares approximate formulas for elasticity of these Tornquist functions are received. To receive an approximate formula for elasticity of function of demand for luxury goods, the linear asymptotic formula is constructed for this function. Some benefits of approximate formulas for elasticity of Tornquist functions are specified.
Orbital-dependent density functionals: Theory and applications

NASA Astrophysics Data System (ADS)

Kümmel, Stephan; Kronik, Leeor

2008-01-01

This review provides a perspective on the use of orbital-dependent functionals, which is currently considered one of the most promising avenues in modern density-functional theory. The focus here is on four major themes: the motivation for orbital-dependent functionals in terms of limitations of semilocal functionals; the optimized effective potential as a rigorous approach to incorporating orbital-dependent functionals within the Kohn-Sham framework; the rationale behind and advantages and limitations of four popular classes of orbital-dependent functionals; and the use of orbital-dependent functionals for predicting excited-state properties. For each of these issues, both formal and practical aspects are assessed.
Value function in economic growth model

NASA Astrophysics Data System (ADS)

Bagno, Alexander; Tarasyev, Alexandr A.; Tarasyev, Alexander M.

2017-11-01

Properties of the value function are examined in an infinite horizon optimal control problem with an unlimited integrand index appearing in the quality functional with a discount factor. Optimal control problems of such type describe solutions in models of economic growth. Necessary and sufficient conditions are derived to ensure that the value function satisfies the infinitesimal stability properties. It is proved that value function coincides with the minimax solution of the Hamilton-Jacobi equation. Description of the growth asymptotic behavior for the value function is provided for the logarithmic, power and exponential quality functionals and an example is given to illustrate construction of the value function in economic growth models.
Differential Gender Effects in the Relationship between Perceived Immune Functioning and Autistic Traits.

PubMed

Mackus, Marlou; Kruijff, Deborah de; Otten, Leila S; Kraneveld, Aletta D; Garssen, Johan; Verster, Joris C

2017-04-12

Altered immune functioning has been demonstrated in individuals with autism spectrum disorder (ASD). The current study explores the relationship between perceived immune functioning and experiencing ASD traits in healthy young adults. N = 410 students from Utrecht University completed a survey on immune functioning and autistic traits. In addition to a 1-item perceived immune functioning rating, the Immune Function Questionnaire (IFQ) was completed to assess perceived immune functioning. The Dutch translation of the Autism-Spectrum Quotient (AQ) was completed to examine variation in autistic traits, including the domains "social insights and behavior", "difficulties with change", "communication", "phantasy and imagination", and "detail orientation". The 1-item perceived immune functioning score did not significantly correlate with the total AQ score. However, a significant negative correlation was found between perceived immune functioning and the AQ subscale "difficulties with change" (r = -0.119, p = 0.019). In women, 1-item perceived immune functioning correlated significantly with the AQ subscales "difficulties with change" (r = -0.149, p = 0.029) and "communication" (r = -0.145, p = 0.032). In men, none of the AQ subscales significantly correlated with 1-item perceived immune functioning. In conclusion, a modest relationship between perceived immune functioning and several autistic traits was found.
Multitrophic functional diversity predicts ecosystem functioning in experimental assemblages of estuarine consumers.

PubMed

Lefcheck, Jonathan S; Duffy, J Emmett

2015-11-01

The use of functional traits to explain how biodiversity affects ecosystem functioning has attracted intense interest, yet few studies have a priori altered functional diversity, especially in multitrophic communities. Here, we manipulated multivariate functional diversity of estuarine grazers and predators within multiple levels of species richness to test how species richness and functional diversity predicted ecosystem functioning in a multitrophic food web. Community functional diversity was a better predictor than species richness for the majority of ecosystem properties, based on generalized linear mixed-effects models. Combining inferences from eight traits into a single multivariate index increased prediction accuracy of these models relative to any individual trait. Structural equation modeling revealed that functional diversity of both grazers and predators was important in driving final biomass within trophic levels, with stronger effects observed for predators. We also show that different species drove different ecosystem responses, with evidence for both sampling effects and complementarity. Our study extends experimental investigations of functional trait diversity to a multilevel food web, and demonstrates that functional diversity can be more accurate and effective than species richness in predicting community biomass in a food web context.
Cognitive predictors of everyday functioning in older adults: results from the ACTIVE Cognitive Intervention Trial.

PubMed

Gross, Alden L; Rebok, George W; Unverzagt, Frederick W; Willis, Sherry L; Brandt, Jason

2011-09-01

The present study sought to predict changes in everyday functioning using cognitive tests. Data from the Advanced Cognitive Training for Independent and Vital Elderly trial were used to examine the extent to which competence in different cognitive domains--memory, inductive reasoning, processing speed, and global mental status--predicts prospectively measured everyday functioning among older adults. Coefficients of determination for baseline levels and trajectories of everyday functioning were estimated using parallel process latent growth models. Each cognitive domain independently predicts a significant proportion of the variance in baseline and trajectory change of everyday functioning, with inductive reasoning explaining the most variance (R2 = .175) in baseline functioning and memory explaining the most variance (R2 = .057) in changes in everyday functioning. Inductive reasoning is an important determinant of current everyday functioning in community-dwelling older adults, suggesting that successful performance in daily tasks is critically dependent on executive cognitive function. On the other hand, baseline memory function is more important in determining change over time in everyday functioning, suggesting that some participants with low baseline memory function may reflect a subgroup with incipient progressive neurologic disease.
Functional Parallel Factor Analysis for Functions of One- and Two-dimensional Arguments.

PubMed

Choi, Ji Yeh; Hwang, Heungsun; Timmerman, Marieke E

2018-03-01

Parallel factor analysis (PARAFAC) is a useful multivariate method for decomposing three-way data that consist of three different types of entities simultaneously. This method estimates trilinear components, each of which is a low-dimensional representation of a set of entities, often called a mode, to explain the maximum variance of the data. Functional PARAFAC permits the entities in different modes to be smooth functions or curves, varying over a continuum, rather than a collection of unconnected responses. The existing functional PARAFAC methods handle functions of a one-dimensional argument (e.g., time) only. In this paper, we propose a new extension of functional PARAFAC for handling three-way data whose responses are sequenced along both a two-dimensional domain (e.g., a plane with x- and y-axis coordinates) and a one-dimensional argument. Technically, the proposed method combines PARAFAC with basis function expansion approximations, using a set of piecewise quadratic finite element basis functions for estimating two-dimensional smooth functions and a set of one-dimensional basis functions for estimating one-dimensional smooth functions. In a simulation study, the proposed method appeared to outperform the conventional PARAFAC. We apply the method to EEG data to demonstrate its empirical usefulness.
Impact of vocational rehabilitation on social functioning, cognitive functioning, and psychopathology in patients with chronic schizophrenia

PubMed Central

Suresh Kumar, P. N.

2008-01-01

Aim: To assess the impact of vocational rehabilitation on psychopathology, social functioning and cognitive functioning in schizophrenia Materials and Methods: 34 patients with DSM IV diagnosis of chronic schizophrenia were compared 40 patients with same diagnosis but not attending vocational rehabilitation using PANSS, SCARF social functioning Index and MMSE. Results and Discussion: Basic psycho-socio-demographic data were comparable in both groups except more hospitalization in the no rehabilitation group. Comparison of social functioning, cognitive functioning and psychopathology showed significant improvement in rehabilitated patients. Cognitive functioning had positive correlation with occupational role in the rehabilitated group and negative correlation in the rehabilitated group. Social functioning had negative correlation with positive and negative symptoms, general psychopathology and total PANSS score and cognitive symptoms in patients without rehabilitation. Conclusion: The present concludes that there is a definite limitation in the domains of social functioning, cognitive functioning and psychopathology in chronic schizophrenia patients who had no rehabilitation. However vocational rehabilitation significantly improves these limitations, which in turn help these patients to integrate into the society so as to function efficiently in their roles as parents, home makers and social beings. PMID:19823610
Psychosocial functioning in the context of diagnosis: assessment and theoretical issues.

PubMed

Ro, Eunyoe; Clark, Lee Anna

2009-09-01

Psychosocial functioning is an important focus of attention in the revision of the Diagnostic and Statistical Manual of Mental Disorders. Researchers and clinicians are converging upon the opinion that psychometrically strong, comprehensive assessment of individuals' functioning is needed to characterize disorder fully. Also shared is the realization that existing theory and research in this domain have critical shortcomings. The authors urge that the field reexamine the empirical evidence and address theoretical issues to guide future development of the construct and its measurement. The authors first discuss several theoretical issues relevant to the conceptualization and assessment of functioning: (a) definitions of functioning, (b) the role of functioning in defining disorder, and (c) understanding functioning within environmental contexts. The authors then present data regarding empirical domains of psychosocial functioning and their interrelations. Self-reported data on multiple domains of psychosocial functioning were collected from 429 participants. Factor-analytic results (promax rotation) suggest a 4-factor structure of psychosocial functioning: Well-Being, Basic Functioning, Self-Mastery, and Interpersonal and Social Relationships. Finally, the authors propose an integration of theory and empirical findings, which they believe will better incorporate psychosocial functioning into future diagnostic systems. Copyright 2009 APA, all rights reserved.

Exchange Energy Density Functionals that reproduce the Linear Response Function of the Free Electron Gas

NASA Astrophysics Data System (ADS)

García-Aldea, David; Alvarellos, J. E.

2009-03-01

We present several nonlocal exchange energy density functionals that reproduce the linear response function of the free electron gas. These nonlocal functionals are constructed following a similar procedure used previously for nonlocal kinetic energy density functionals by Chac'on-Alvarellos-Tarazona, Garc'ia-Gonz'alez et al., Wang-Govind-Carter and Garc'ia-Aldea-Alvarellos. The exchange response function is not known but we have used the approximate response function developed by Utsumi and Ichimaru, even we must remark that the same ansatz can be used to reproduce any other response function with the same scaling properties. We have developed two families of new nonlocal functionals: one is constructed with a mathematical structure based on the LDA approximation -- the Dirac functional for the exchange - and for the second one the structure of the second order gradient expansion approximation is took as a model. The functionals are constructed is such a way that they can be used in localized systems (using real space calculations) and in extended systems (using the momentum space, and achieving a quasilinear scaling with the system size if a constant reference electron density is defined).
Functional recovery in patients with schizophrenia: recommendations from a panel of experts.

PubMed

Lahera, Guillermo; Gálvez, José L; Sánchez, Pedro; Martínez-Roig, Miguel; Pérez-Fuster, J V; García-Portilla, Paz; Herrera, Berta; Roca, Miquel

2018-06-05

The management of schizophrenia is evolving towards a more comprehensive model based on functional recovery. The concept of functional recovery goes beyond clinical remission and encompasses multiple aspects of the patient's life, making it difficult to settle on a definition and to develop reliable assessment criteria. In this consensus process based on a panel of experts in schizophrenia, we aimed to provide useful insights on functional recovery and its involvement in clinical practice and clinical research. After a literature review of functional recovery in schizophrenia, a scientific committee of 8 members prepared a 75-item questionnaire, including 6 sections: (I) the concept of functional recovery (9 items), (II) assessment of functional recovery (23 items), (III) factors influencing functional recovery (16 items), (IV) psychosocial interventions and functional recovery (8 items), (V) pharmacological treatment and functional recovery (14 items), and (VI) the perspective of patients and their relatives on functional recovery (5 items). The questionnaire was sent to a panel of 53 experts, who rated each item on a 9-point Likert scale. Consensus was achieved in a 2-round Delphi dynamics, using the median (interquartile range) scores to consider consensus in either agreement (scores 7-9) or disagreement (scores 1-3). Items not achieving consensus in the first round were sent back to the experts for a second consideration. After the two recursive rounds, consensus was achieved in 64 items (85.3%): 61 items (81.3%) in agreement and 3 (4.0%) in disagreement, all of them from section II (assessment of functional recovery). Items not reaching consensus were related to the concepts of functional recovery (1 item, 1.3%), functional assessment (5 items, 6.7%), factors influencing functional recovery (3 items, 4.0%), and psychosocial interventions (2 items, 5.6%). Despite the lack of a well-defined concept of functional recovery, we identified a trend towards a common archetype of the definition and factors associated with functional recovery, as well as its applicability in clinical practice and clinical research.
Extension of many-body theory and approximate density functionals to fractional charges and fractional spins.

PubMed

Yang, Weitao; Mori-Sánchez, Paula; Cohen, Aron J

2013-09-14

The exact conditions for density functionals and density matrix functionals in terms of fractional charges and fractional spins are known, and their violation in commonly used functionals has been shown to be the root of many major failures in practical applications. However, approximate functionals are designed for physical systems with integer charges and spins, not in terms of the fractional variables. Here we develop a general framework for extending approximate density functionals and many-electron theory to fractional-charge and fractional-spin systems. Our development allows for the fractional extension of any approximate theory that is a functional of G(0), the one-electron Green's function of the non-interacting reference system. The extension to fractional charge and fractional spin systems is based on the ensemble average of the basic variable, G(0). We demonstrate the fractional extension for the following theories: (1) any explicit functional of the one-electron density, such as the local density approximation and generalized gradient approximations; (2) any explicit functional of the one-electron density matrix of the non-interacting reference system, such as the exact exchange functional (or Hartree-Fock theory) and hybrid functionals; (3) many-body perturbation theory; and (4) random-phase approximations. A general rule for such an extension has also been derived through scaling the orbitals and should be useful for functionals where the link to the Green's function is not obvious. The development thus enables the examination of approximate theories against known exact conditions on the fractional variables and the analysis of their failures in chemical and physical applications in terms of violations of exact conditions of the energy functionals. The present work should facilitate the calculation of chemical potentials and fundamental bandgaps with approximate functionals and many-electron theories through the energy derivatives with respect to the fractional charge. It should play an important role in developing accurate approximate density functionals and many-body theory.
Relation between hand function and gross motor function in full term infants aged 4 to 8 months

PubMed Central

Nogueira, Solange F.; Figueiredo, Elyonara M.; Gonçalves, Rejane V.; Mancini, Marisa C.

2015-01-01

Background: In children, reaching emerges around four months of age, which is followed by rapid changes in hand function and concomitant changes in gross motor function, including the acquisition of independent sitting. Although there is a close functional relationship between these domains, to date they have been investigated separately. Objective: To investigate the longitudinal profile of changes and the relationship between the development of hand function (i.e. reaching for and manipulating an object) and gross motor function in 13 normally developing children born at term who were evaluated every 15 days from 4 to 8 months of age. Method: The number of reaches and the period (i.e. time) of manipulation to an object were extracted from video synchronized with the Qualisys(r) movement analysis system. Gross motor function was measured using the Alberta Infant Motor Scale. ANOVA for repeated measures was used to test the effect of age on the number of reaches, the time of manipulation and gross motor function. Hierarchical regression models were used to test the associations of reaching and manipulation with gross motor function. Results: Results revealed a significant increase in the number of reaches (p<0.001), the time of manipulation (p<0.001) and gross motor function (p<0.001) over time, as well as associations between reaching and gross motor function (R2=0.84; p<0.001) and manipulation and gross motor function (R2=0.13; p=0.02) from 4 to 6 months of age. Associations from 6 to 8 months of age were not significant. Conclusion: The relationship between hand function and gross motor function was not constant, and the age span from 4 to 6 months was a critical period of interdependency of hand function and gross motor function development. PMID:25714437
From data to function: functional modeling of poultry genomics data.

PubMed

McCarthy, F M; Lyons, E

2013-09-01

One of the challenges of functional genomics is to create a better understanding of the biological system being studied so that the data produced are leveraged to provide gains for agriculture, human health, and the environment. Functional modeling enables researchers to make sense of these data as it reframes a long list of genes or gene products (mRNA, ncRNA, and proteins) by grouping based upon function, be it individual molecular functions or interactions between these molecules or broader biological processes, including metabolic and signaling pathways. However, poultry researchers have been hampered by a lack of functional annotation data, tools, and training to use these data and tools. Moreover, this lack is becoming more critical as new sequencing technologies enable us to generate data not only for an increasingly diverse range of species but also individual genomes and populations of individuals. We discuss the impact of these new sequencing technologies on poultry research, with a specific focus on what functional modeling resources are available for poultry researchers. We also describe key strategies for researchers who wish to functionally model their own data, providing background information about functional modeling approaches, the data and tools to support these approaches, and the strengths and limitations of each. Specifically, we describe methods for functional analysis using Gene Ontology (GO) functional summaries, functional enrichment analysis, and pathways and network modeling. As annotation efforts begin to provide the fundamental data that underpin poultry functional modeling (such as improved gene identification, standardized gene nomenclature, temporal and spatial expression data and gene product function), tool developers are incorporating these data into new and existing tools that are used for functional modeling, and cyberinfrastructure is being developed to provide the necessary extendibility and scalability for storing and analyzing these data. This process will support the efforts of poultry researchers to make sense of their functional genomics data sets, and we provide here a starting point for researchers who wish to take advantage of these tools.
Structural Brain Connectivity Constrains within-a-Day Variability of Direct Functional Connectivity

PubMed Central

Park, Bumhee; Eo, Jinseok; Park, Hae-Jeong

2017-01-01

The idea that structural white matter connectivity constrains functional connectivity (interactions among brain regions) has widely been explored in studies of brain networks; studies have mostly focused on the “average” strength of functional connectivity. The question of how structural connectivity constrains the “variability” of functional connectivity remains unresolved. In this study, we investigated the variability of resting state functional connectivity that was acquired every 3 h within a single day from 12 participants (eight time sessions within a 24-h period, 165 scans per session). Three different types of functional connectivity (functional connectivity based on Pearson correlation, direct functional connectivity based on partial correlation, and the pseudo functional connectivity produced by their difference) were estimated from resting state functional magnetic resonance imaging data along with structural connectivity defined using fiber tractography of diffusion tensor imaging. Those types of functional connectivity were evaluated with regard to properties of structural connectivity (fiber streamline counts and lengths) and types of structural connectivity such as intra-/inter-hemispheric edges and topological edge types in the rich club organization. We observed that the structural connectivity constrained the variability of direct functional connectivity more than pseudo-functional connectivity and that the constraints depended strongly on structural connectivity types. The structural constraints were greater for intra-hemispheric and heterologous inter-hemispheric edges than homologous inter-hemispheric edges, and feeder and local edges than rich club edges in the rich club architecture. While each edge was highly variable, the multivariate patterns of edge involvement, especially the direct functional connectivity patterns among the rich club brain regions, showed low variability over time. This study suggests that structural connectivity not only constrains the strength of functional connectivity, but also the within-a-day variability of functional connectivity and connectivity patterns, particularly the direct functional connectivity among brain regions. PMID:28848416
Simulating evolution of protein complexes through gene duplication and co-option.

PubMed

Haarsma, Loren; Nelesen, Serita; VanAndel, Ethan; Lamine, James; VandeHaar, Peter

2016-06-21

We present a model of the evolution of protein complexes with novel functions through gene duplication, mutation, and co-option. Under a wide variety of input parameters, digital organisms evolve complexes of 2-5 bound proteins which have novel functions but whose component proteins are not independently functional. Evolution of complexes with novel functions happens more quickly as gene duplication rates increase, point mutation rates increase, protein complex functional probability increases, protein complex functional strength increases, and protein family size decreases. Evolution of complexity is inhibited when the metabolic costs of making proteins exceeds the fitness gain of having functional proteins, or when point mutation rates get so large the functional proteins undergo deleterious mutations faster than new functional complexes can evolve. Copyright © 2016 Elsevier Ltd. All rights reserved.
First Principles Study of Chemically Functionalized Graphene

NASA Astrophysics Data System (ADS)

Jha, Sanjiv; Vasiliev, Igor

2015-03-01

The electronic, structural and vibrational properties of carbon nanomaterials can be affected by chemical functionalization. We applied ab initio computational methods based on density functional theory to study the covalent functionalization of graphene with benzyne, carboxyl groups and tetracyanoethylene oxide (TCNEO). Our calculations were carried out using the SIESTA and Quantum-ESPRESSO electronic structure codes combined with the local density and generalized gradient approximations for the exchange correlation functional and norm-conserving Troullier-Martins pseudopotentials. The simulated Raman and infrared spectra of graphene functionalized with carboxyl groups and TCNEO were consistent with the available experimental results. The computed vibrational spectra of graphene functionalized with carboxyl groups showed that the presence of point defects near the functionalization site affects the Raman and infrared spectroscopic signatures of functionalized graphene. Supported by NSF CHE-1112388.
Density functional theory for d- and f-electron materials and compounds

DOE PAGES

Mattson, Ann E.; Wills, John M.

2016-02-12

Here, the fundamental requirements for a computationally tractable Density Functional Theory-based method for relativistic f- and (nonrelativistic) d-electron materials and compounds are presented. The need for basing the Kohn–Sham equations on the Dirac equation is discussed. The full Dirac scheme needs exchange-correlation functionals in terms of four-currents, but ordinary functionals, using charge density and spin-magnetization, can be used in an approximate Dirac treatment. The construction of a functional that includes the additional confinement physics needed for these materials is illustrated using the subsystem-functional scheme. If future studies show that a full Dirac, four-current based, exchange-correlation functional is needed, the subsystemmore » functional scheme is one of the few schemes that can still be used for constructing functional approximations.« less
On one-dimensional stretching functions for finite-difference calculations. [computational fluid dynamics

NASA Technical Reports Server (NTRS)

Vinokur, M.

1979-01-01

The class of one-dimensional stretching functions used in finite-difference calculations is studied. For solutions containing a highly localized region of rapid variation, simple criteria for a stretching function are derived using a truncation error analysis. These criteria are used to investigate two types of stretching functions. One is an interior stretching function, for which the location and slope of an interior clustering region are specified. The simplest such function satisfying the criteria is found to be one based on the inverse hyperbolic sine. The other type of function is a two-sided stretching function, for which the arbitrary slopes at the two ends of the one-dimensional interval are specified. The simplest such general function is found to be one based on the inverse tangent.
FAST TRACK COMMUNICATION: Preferential functionalization on zigzag graphene nanoribbons: first-principles calculations

NASA Astrophysics Data System (ADS)

Lee, Hoonkyung

2010-09-01

We investigate the functionalization of functional groups to graphene nanoribbons with zigzag and armchair edges using first-principles calculations. We find that the formation energy for the configuration of the functional groups functionalized to the zigzag edge is ~ 0.2 eV per functional group lower than that to the armchair edge. The formation energy difference arises from a structural deformation on the armchair edge by the functionalization whereas there is no structural deformation on the zigzag edge. Selective functionalization on the zigzag edge takes place at a condition of the temperature and the pressure of ~ 25 °C and 10 - 5 atm. Our findings show that selective functionalization can offer the opportunity for an approach to the separation of zigzag graphene nanoribbons with their solubility change.
Ecological Functions of Landscapes

NASA Astrophysics Data System (ADS)

Kiryushin, V. I.

2018-01-01

Ecological functions of landscapes are considered a system of processes ensuring the development, preservation, and evolution of ecosystems and the biosphere as a whole. The concept of biogeocenosis can be considered a model that integrates biotic and environmental functions. The most general biogeocenotic functions specify the biodiversity, biotic links, self-organization, and evolution of ecosystems. Close interaction between biocenosis and the biotope (ecotope) is ensured by the continuous exchange of matter, energy, and information. Ecotope determines the biocenosis. The group of ecotopic functions includes atmospheric (gas exchange, heat exchange, hydroatmospheric, climate-forming), lithospheric (geodynamic, geophysical, and geochemical), hydrologic and hydrogeologic functions of landscape and ecotopic functions of soils. Bioecological functions emerge as a result of the biotope and ecotope interaction; these are the bioproductive, destructive, organoaccumulative, biochemical (gas, concentration, redox, biochemical, biopedological), pedogenetic, and energy functions
The assessment of function. Part II: clinical perspective of a javelin thrower with low back and groin pain

PubMed Central

Reiman, Michael P; Manske, Robert C

2012-01-01

Assessment of an individual’s functional ability can be complex. This assessment should also be individualized and adaptable to changes in functional status. In the first article of this series, we operationally defined function, discussed the construct of function, examined the evidence as it relates to assessment methods of various aspects of function, and explored the multi-dimensional nature of the concept of function. In this case report, we aim to demonstrate the utilization of a multi-dimensional assessment method (functional performance testing) as it relates to a high-level athlete presenting with pain in the low back and groin. It is our intent to demonstrate how the clinician should continually adapt their assessment dependent on the current functional abilities of the patients. PMID:23633887
Everyday psychological functioning in children with unilateral cerebral palsy: does executive functioning play a role?

PubMed

Whittingham, Koa; Bodimeade, Harriet L; Lloyd, Owen; Boyd, Roslyn N

2014-06-01

To identify whether executive functioning mediates the effect of having unilateral cerebral palsy (CP) on executive functioning in everyday life, psychological functioning, and social functioning. A cross-sectional cohort of 46 children with unilateral CP (25 males, 21 females; mean age 11y 1mo, SD 2y 5mo; 24 right-sided, 22 left-sided) and 20 children with typical development (nine males, 11 females; mean age 10y 10mo, SD 2y 4mo). Cognitive executive functioning was tested using a neuropsychological battery. Executive functioning in everyday life was measured with the Behavior Rating Inventory of Executive Function (BRIEF; teacher and parent reports) and psychological and social functioning by the Strengths and Difficulties Questionnaire (SDQ). Analysis included analysis of covariance and bootstrapping. Children with unilateral CP were found to have significantly decreased functioning, compared with children with typical development, on the BRIEF Behavioral Regulation Index, the BRIEF Metacognition Index, and on the SDQ emotion, conduct, hyperactivity, and peer problems subscales. Group differences were mediated by cognitive executive functioning for the BRIEF Metacognition Index (teacher and parent report), the BRIEF Behavioral Regulation Index (parent report only), the SDQ conduct subscale, and the SDQ hyperactivity subscale. This study suggests that the increased risk of children with unilateral CP experiencing executive functioning difficulties in everyday life, conduct problems, and hyperactivity can be partly explained by decreased cognitive executive functioning abilities relative to children with typical development. © 2014 Mac Keith Press.
Diffeomorphic functional brain surface alignment: Functional demons.

PubMed

Nenning, Karl-Heinz; Liu, Hesheng; Ghosh, Satrajit S; Sabuncu, Mert R; Schwartz, Ernst; Langs, Georg

2017-08-01

Aligning brain structures across individuals is a central prerequisite for comparative neuroimaging studies. Typically, registration approaches assume a strong association between the features used for alignment, such as macro-anatomy, and the variable observed, such as functional activation or connectivity. Here, we propose to use the structure of intrinsic resting state fMRI signal correlation patterns as a basis for alignment of the cortex in functional studies. Rather than assuming the spatial correspondence of functional structures between subjects, we have identified locations with similar connectivity profiles across subjects. We mapped functional connectivity relationships within the brain into an embedding space, and aligned the resulting maps of multiple subjects. We then performed a diffeomorphic alignment of the cortical surfaces, driven by the corresponding features in the joint embedding space. Results show that functional alignment based on resting state fMRI identifies functionally homologous regions across individuals with higher accuracy than alignment based on the spatial correspondence of anatomy. Further, functional alignment enables measurement of the strength of the anatomo-functional link across the cortex, and reveals the uneven distribution of this link. Stronger anatomo-functional dissociation was found in higher association areas compared to primary sensory- and motor areas. Functional alignment based on resting state features improves group analysis of task based functional MRI data, increasing statistical power and improving the delineation of task-specific core regions. Finally, a comparison of the anatomo-functional dissociation between cohorts is demonstrated with a group of left and right handed subjects. Copyright © 2017 Elsevier Inc. All rights reserved.
Biodiversity increases functional and compositional resistance, but decreases resilience in phytoplankton communities.

PubMed

Baert, Jan M; De Laender, Frederik; Sabbe, Koen; Janssen, Colin R

2016-12-01

There is now ample evidence that biodiversity stabilizes aggregated ecosystem functions, such as primary production, in changing environments. In primary producer systems, this stabilizing effect is found to be driven by higher functional resistance (i.e., reduced changes in functions by environmental changes) rather than through higher functional resilience (i.e., rapid recovery following environmental changes) in more diverse systems. The stability of aggregated ecosystem functions directly depends on changes in species composition and by consequence their functional contributions to ecosystem functions. Still, it remains only theoretically explored how biodiversity can stabilize ecosystem functions by affecting compositional stability. Here, we demonstrate how biodiversity effects on compositional stability drive biodiversity effects on functional stability in diatom communities. In a microcosm experiment, we exposed 39 communities of five different levels of species richness (1, 2, 4, 6, and 8 species) to three concentrations of a chemical stressor (0, 25, and 250 μg/L atrazine) for four weeks, after which all communities were transferred to atrazine-free medium for three more weeks. Biodiversity simultaneously increased, increasing functional and compositional resistance, but decreased functional and compositional resilience. These results confirm the theoretically proposed link between biodiversity effects on functional and compositional stability in primary producer systems, and provide a mechanistic underpinning for observed biodiversity-stability relationships. Finally, we discuss how higher compositional stability can be expected to become increasingly important in stabilizing ecosystem functions under field conditions when multiple environmental stressors fluctuate simultaneously. © 2016 by the Ecological Society of America.
Revealing protein functions based on relationships of interacting proteins and GO terms.

PubMed

Teng, Zhixia; Guo, Maozu; Liu, Xiaoyan; Tian, Zhen; Che, Kai

2017-09-20

In recent years, numerous computational methods predicted protein function based on the protein-protein interaction (PPI) network. These methods supposed that two proteins share the same function if they interact with each other. However, it is reported by recent studies that the functions of two interacting proteins may be just related. It will mislead the prediction of protein function. Therefore, there is a need for investigating the functional relationship between interacting proteins. In this paper, the functional relationship between interacting proteins is studied and a novel method, called as GoDIN, is advanced to annotate functions of interacting proteins in Gene Ontology (GO) context. It is assumed that the functional difference between interacting proteins can be expressed by semantic difference between GO term and its relatives. Thus, the method uses GO term and its relatives to annotate the interacting proteins separately according to their functional roles in the PPI network. The method is validated by a series of experiments and compared with the concerned method. The experimental results confirm the assumption and suggest that GoDIN is effective on predicting functions of protein. This study demonstrates that: (1) interacting proteins are not equal in the PPI network, and their function may be same or similar, or just related; (2) functional difference between interacting proteins can be measured by their degrees in the PPI network; (3) functional relationship between interacting proteins can be expressed by relationship between GO term and its relatives.
Causal effect of disconnection lesions on interhemispheric functional connectivity in rhesus monkeys

PubMed Central

O’Reilly, Jill X.; Croxson, Paula L.; Jbabdi, Saad; Sallet, Jerome; Noonan, MaryAnn P.; Mars, Rogier B.; Browning, Philip G.F.; Wilson, Charles R. E.; Mitchell, Anna S.; Miller, Karla L.; Rushworth, Matthew F. S.; Baxter, Mark G.

2013-01-01

In the absence of external stimuli or task demands, correlations in spontaneous brain activity (functional connectivity) reflect patterns of anatomical connectivity. Hence, resting-state functional connectivity has been used as a proxy measure for structural connectivity and as a biomarker for brain changes in disease. To relate changes in functional connectivity to physiological changes in the brain, it is important to understand how correlations in functional connectivity depend on the physical integrity of brain tissue. The causal nature of this relationship has been called into question by patient data suggesting that decreased structural connectivity does not necessarily lead to decreased functional connectivity. Here we provide evidence for a causal but complex relationship between structural connectivity and functional connectivity: we tested interhemispheric functional connectivity before and after corpus callosum section in rhesus monkeys. We found that forebrain commissurotomy severely reduced interhemispheric functional connectivity, but surprisingly, this effect was greatly mitigated if the anterior commissure was left intact. Furthermore, intact structural connections increased their functional connectivity in line with the hypothesis that the inputs to each node are normalized. We conclude that functional connectivity is likely driven by corticocortical white matter connections but with complex network interactions such that a near-normal pattern of functional connectivity can be maintained by just a few indirect structural connections. These surprising results highlight the importance of network-level interactions in functional connectivity and may cast light on various paradoxical findings concerning changes in functional connectivity in disease states. PMID:23924609
Brain functional network abnormality extends beyond the sensorimotor network in brachial plexus injury patients.

PubMed

Feng, Jun-Tao; Liu, Han-Qiu; Hua, Xu-Yun; Gu, Yu-Dong; Xu, Jian-Guang; Xu, Wen-Dong

2016-12-01

Brachial plexus injury (BPI) is a type of severe peripheral nerve trauma that leads to central remodeling in the brain, as revealed by functional MRI analysis. However, previously reported remodeling is mostly restricted to sensorimotor areas of the brain. Whether this disturbance in the sensorimotor network leads to larger-scale functional remodeling remains unknown. We sought to explore the higher-level brain functional abnormality pattern of BPI patients from a large-scale network function connectivity dimension in 15 right-handed BPI patients. Resting-state functional MRI data were collected and analyzed using independent component analysis methods. Five components of interest were recognized and compared between patients and healthy subjects. Patients showed significantly altered brain local functional activities in the bilateral fronto-parietal network (FPN), sensorimotor network (SMN), and executive-control network (ECN) compared with healthy subjects. Moreover, functional connectivity between SMN and ECN were significantly less in patients compared with healthy subjects, and connectivity strength between ECN and SMN was negatively correlated with patients' residual function of the affected limb. Functional connectivity between SMN and right FPN were also significantly less than in controls, although connectivity between ECN and default mode network (DMN) was greater than in controls. These data suggested that brain functional disturbance in BPI patients extends beyond the sensorimotor network and cascades serial remodeling in the brain, which significantly correlates with residual hand function of the paralyzed limb. Furthermore, functional remodeling in these higher-level functional networks may lead to cognitive alterations in complex tasks.
High intraspecific variability in the functional niche of a predator is associated with ontogenetic shift and individual specialization

PubMed Central

Zhao, Tian; Villéger, Sébastien; Lek, Sovan; Cucherousset, Julien

2014-01-01

Investigations on the functional niche of organisms have primarily focused on differences among species and tended to neglect the potential effects of intraspecific variability despite the fact that its potential ecological and evolutionary importance is now widely recognized. In this study, we measured the distribution of functional traits in an entire population of largemouth bass (Micropterus salmoides) to quantify the magnitude of intraspecific variability in functional traits and niche (size, position, and overlap) between age classes. Stable isotope analyses (δ13C and δ15N) were also used to determine the association between individual trophic ecology and intraspecific functional trait variability. We observed that functional traits were highly variable within the population (mean coefficient variation: 15.62% ± 1.78% SE) and predominantly different between age classes. In addition, functional and trophic niche overlap between age classes was extremely low. Differences in functional niche between age classes were associated with strong changes in trophic niche occurring during ontogeny while, within age classes, differences among individuals were likely driven by trophic specialization. Each age class filled only a small portion of the total functional niche of the population and age classes occupied distinct portions in the functional space, indicating the existence of ontogenetic specialists with different functional roles within the population. The high amplitude of intraspecific variability in functional traits and differences in functional niche position among individuals reported here supports the recent claims for an individual-based approach in functional ecology. PMID:25558359

RATGRAPH: Computer Graphing of Rational Functions.

ERIC Educational Resources Information Center

Minch, Bradley A.

1987-01-01

Presents an easy-to-use Applesoft BASIC program that graphs rational functions and any asymptotes that the functions might have. Discusses the nature of rational functions, graphing them manually, employing a computer to graph rational functions, and describes how the program works. (TW)
Alphabet Soup

ERIC Educational Resources Information Center

Rebholz, Joachim A.

2017-01-01

Graphing functions is an important topic in algebra and precalculus high school courses. The functions that are usually discussed include polynomials, rational, exponential, and trigonometric functions along with their inverses. These functions can be used to teach different aspects of function theory: domain, range, monotonicity, inverse…
Stability and the Evolvability of Function in a Model Protein

PubMed Central

Bloom, Jesse D.; Wilke, Claus O.; Arnold, Frances H.; Adami, Christoph

2004-01-01

Functional proteins must fold with some minimal stability to a structure that can perform a biochemical task. Here we use a simple model to investigate the relationship between the stability requirement and the capacity of a protein to evolve the function of binding to a ligand. Although our model contains no built-in tradeoff between stability and function, proteins evolved function more efficiently when the stability requirement was relaxed. Proteins with both high stability and high function evolved more efficiently when the stability requirement was gradually increased than when there was constant selection for high stability. These results show that in our model, the evolution of function is enhanced by allowing proteins to explore sequences corresponding to marginally stable structures, and that it is easier to improve stability while maintaining high function than to improve function while maintaining high stability. Our model also demonstrates that even in the absence of a fundamental biophysical tradeoff between stability and function, the speed with which function can evolve is limited by the stability requirement imposed on the protein. PMID:15111394
Performance of wave function and density functional methods for water hydrogen bond spin-spin coupling constants.

PubMed

García de la Vega, J M; Omar, S; San Fabián, J

2017-04-01

Spin-spin coupling constants in water monomer and dimer have been calculated using several wave function and density functional-based methods. CCSD, MCSCF, and SOPPA wave functions methods yield similar results, specially when an additive approach is used with the MCSCF. Several functionals have been used to analyze their performance with the Jacob's ladder and a set of functionals with different HF exchange were tested. Functionals with large HF exchange appropriately predict 1 J O H , 2 J H H and 2h J O O couplings, while 1h J O H is better calculated with functionals that include a reduced fraction of HF exchange. Accurate functionals for 1 J O H and 2 J H H have been tested in a tetramer water model. The hydrogen bond effects on these intramolecular couplings are additive when they are calculated by SOPPA(CCSD) wave function and DFT methods. Graphical Abstract Evaluation of the additive effect of the hydrogen bond on spin-spin coupling constants of water using WF and DFT methods.
Exploration of functional food consumption in older adults in relation to food matrices, bioactive ingredients, and health.

PubMed

Vella, Meagan N; Stratton, Laura M; Sheeshka, Judy; Duncan, Alison M

2013-01-01

The functional food industry is expanding, yet research into consumer perceptions of functional foods is limited. Older adults could benefit from functional foods due to age-related food and health issues. This research gathered information about functional foods from community-dwelling older adults (n = 200) who completed a researcher-administered questionnaire about consumption, food matrices, bioactive ingredients, and health areas addressed through functional foods. Overall prevalence of functional food consumption was found to be 93.0%. Commonly consumed foods included yogurt with probiotics (56.0%), eggs with omega-3 fatty acids (37.0%), and bread with fiber (35.5%). Functional food matrices primarily consumed were yogurt (51.5%), bread (44.0%), and cereal (40.0%). The primary functional food bioactive consumed was dietary fiber (79.5%). Most participants (86.2%) indicated that they consume functional foods to improve health, and the major areas specified were osteoporosis/bone health (67.5%), heart disease (61.0%), and arthritis (55.0%). These results inform health professionals regarding the potential of functional foods to support health among older adults.
Effects of change in physical activity on physical function limitations in older women: mediating roles of physical function performance and self-efficacy.

PubMed

McAuley, Edward; Morris, Katherine S; Doerksen, Shawna E; Motl, Robert W; Liang, Hu; White, Siobhan M; Wójcicki, Thomas R; Rosengren, Karl

2007-12-01

To examine the hypothesis that changes in self-efficacy and functional performance mediate, in part, the beneficial effect of physical activity on functional limitations over time. Prospective, observational study. Community-based. Two hundred forty-nine community-dwelling older women. Participants completed measures of self-reported physical activity, functional limitations, and self-efficacy. Four measures of physical function performance were also assessed. Measures were completed at baseline and 24 months. Data were analyzed using a panel model within a covariance modeling framework. Results indicated that increases in physical activity over time were associated with greater improvements in self-efficacy, which was associated in turn with improved physical function performance, both of which mediated the association between physical activity and functional limitations. Fewer functional limitations at baseline were also associated with higher levels of self-efficacy at 24 months. Age, race, and health status covariates did not significantly change these relationships. The findings support the mediating roles of self-efficacy and physical function performance in the relationship between longitudinal changes in physical activity and functional limitations in older women.
Is intelligence equivalent to executive functions?

PubMed

Ardila, Alfredo

2018-05-01

Since the mid 19th century, cognitive and behavioral neurosciences have attempted to find the neurological bases of intellectual abilities. During the early 20th century the psychometric concept of "intelligence" was coined; and toward the end of the 20th century the neuropsychological concept of "executive functions" was introduced. Controversies, however, remain about the unity or heterogeneity of so-called executive functions. It is proposed that two major executive functions could be separated: metacognitive -or intelectual- and emotional/motivational. A similar distinction has been suggested by several authors. Standard definitions of intelligence implicitly assume that executive functions represent the fundamental components of intelligence. Research has demonstrated that, if considered as a whole, executive functions only partially correspond to the psychometric concept of intelligence; whereas some specific executive functions clearly correspond to intelligence, some others do not involve intelligence. If using a major distinction between metacognitive -or simply "intellectual"-executive functions, and emotional/ motivational -or simply non-intellectual-executive functions, it becomes evident that general intelligence can be equated with metacognitive executive functions but not with emotional/ motivational executive functions.
The Role of Cortical Plasticity in Recovery of Function Following Allogeneic Hand Transplantation

DTIC Science & Technology

2015-10-01

transplantation, functional magnetic resonance imaging, hand replantation, cortical reorganization, functional recovery 16. SECURITY CLASSIFICATION OF: U...functional magnetic resonance imaging (fMRI) data suggest that areas of the sensory and motor cortex devoted to representing the hand prior to...function, recovery, functional magnetic resonance imaging 3. Accomplishments Major Goals Achieved: Year Two My lab is relocated to Washington University
Functional profiles reveal unique ecological roles of various biological soil crust organisms

USGS Publications Warehouse

Bowker, M.A.; Mau, R.L.; Maestre, F.T.; Escolar, C.; Castillo-Monroy, A. P.

2011-01-01

1. At the heart of the body of research on biodiversity effects on ecosystem function is the debate over whether different species tend to be functionally singular or redundant. When we consider ecosystem multi-function, the provision of multiple ecosystem functions simultaneously, we may find that seemingly redundant species may in fact play unique roles in ecosystems. 2. Over the last few decades, the significance of biological soil crusts (BSCs) as ecological boundaries and ecosystem engineers, and their multi-functional nature, has become increasingly well documented. We compiled 'functional profiles' of the organisms in this understudied community, to determine whether functional singularity emerges when multiple ecosystem functions are considered. 3. In two data sets, one representing multiple sites around the semi-arid regions of Spain (regional scale), and another from a single site in central Spain (local scale), we examined correlations between the abundance or frequency of BSC species in a community, and multiple surrogates of ecosystem functioning. There was a wide array of apparent effects of species on specific functions. 4. Notably, in gypsiferous soils and at regional scale, we found that indicators of carbon (C) and phosphorus cycling were apparently suppressed and promoted by the lichens Diploschistes diacapsis and Squamarina lentigera, respectively. The moss Pleurochaete squarrosa appears to promote C cycling in calcareous soils at this spatial scale. At the local scale in gypsiferous soils, D. diacapsis positively correlated with carbon cycling, but negatively with nitrogen cycling, whereas numerous lichens exhibited the opposite profile. 5. We found a high degree of functional singularity, i.e. that species were highly individualistic in their effects on multiple functions. Many functional attributes were not easily predictable from existing functional grouping systems based primarily on morphology. 6. Our results suggest that maintaining species-rich BSC communities is crucial to maintain the overall functionality of ecosystems dominated by these organisms, and that dominance and the outcome of competition could be highly influential in the determination of such functionality. ?? 2011 The Authors. Functional Ecology ?? 2011 British Ecological Society.
[Range of Hip Joint Motion and Weight of Lower Limb Function under 3D Dynamic Marker].

PubMed

Xia, Q; Zhang, M; Gao, D; Xia, W T

2017-12-01

To explore the range of reasonable weight coefficient of hip joint in lower limb function. When the hip joints of healthy volunteers under normal conditions or fixed at three different positions including functional, flexed and extension positions, the movements of lower limbs were recorded by LUKOtronic motion capture and analysis system. The degree of lower limb function loss was calculated using Fugl-Meyer lower limb function assessment form when the hip joints were fixed at the aforementioned positions. One-way analysis of variance and Tamhane's T2 method were used to proceed statistics analysis and calculate the range of reasonable weight coefficient of hip joint. There were significant differences between the degree of lower limb function loss when the hip joints fixed at flexed and extension positions and at functional position. While the differences between the degree of lower limb function loss when the hip joints fixed at flexed position and extension position had no statistical significance. In 95% confidence interval, the reasonable weight coefficient of hip joint in lower limb function was between 61.05% and 73.34%. Expect confirming the reasonable weight coefficient, the effects of functional and non-functional positions on the degree of lower limb function loss should also be considered for the assessment of hip joint function loss. Copyright© by the Editorial Department of Journal of Forensic Medicine
Psychometrics of Multiple Choice Questions with Non-Functioning Distracters: Implications to Medical Education.

PubMed

Deepak, Kishore K; Al-Umran, Khalid Umran; AI-Sheikh, Mona H; Dkoli, B V; Al-Rubaish, Abdullah

2015-01-01

The functionality of distracters in a multiple choice question plays a very important role. We examined the frequency and impact of functioning and non-functioning distracters on psychometric properties of 5-option items in clinical disciplines. We analyzed item statistics of 1115 multiple choice questions from 15 summative assessments of undergraduate medical students and classified the items into five groups by their number of non-functioning distracters. We analyzed the effect of varying degree of non-functionality ranging from 0 to 4, on test reliability, difficulty index, discrimination index and point biserial correlation. The non-functionality of distracters inversely affected the test reliability and quality of items in a predictable manner. The non-functioning distracters made the items easier and lowered the discrimination index significantly. Three non-functional distracters in a 5-option MCQ significantly affected all psychometric properties (p < 0.5). The corrected point biserial correlation revealed that the items with 3 functional options were psychometrically as effective as 5-option items. Our study reveals that a multiple choice question with 3 functional options provides lower most limit of item format that has adequate psychometric property. The test containing items with less number of functioning options have significantly lower reliability. The distracter function analysis and revision of nonfunctioning distracters can serve as important methods to improve the psychometrics and reliability of assessment.
Nurses' perspectives on how operational leaders influence function-focused care for hospitalised older people.

PubMed

Fox, Mary T; Butler, Jeffrey I

2016-11-01

To explore nurses' perspectives on how leaders influence function-focused care, defined as care that preserves and restores older people's functional abilities. Hospitalised older people are at risk of functional decline. Although leaders have the potential to influence function-focused care, few studies have explored nurses' perspectives on how leaders influence function-focused care. Thirteen focus groups were held with 57 acute care nurses. Semi-structured questions prompted discussion on nurses' perspectives, needs and strategies to meet their needs. Data were thematically analysed. Three themes were identified: (1) the emphasis in hospitals is on moving older people quickly through the system, not supporting their functioning; (2) leaders are generally seen as too disconnected from practice to design system efficiency initiatives that support older people's functioning and nurses' provisioning of function-focused care; and (3) leadership strategies to better support nurses in providing function-focused care to older people in the context of system efficiency. Leaders should connect with practice to devise age-sensitive efficiency initiatives that support function-focused care. Nurses need support from leaders in four areas to provide function-focused care to older people in the current hospital context. The findings provide direction on how leaders can facilitate function-focused care in the current health-care environment emphasising system efficiency. © 2016 John Wiley & Sons Ltd.
Random matrix theory for analyzing the brain functional network in attention deficit hyperactivity disorder

NASA Astrophysics Data System (ADS)

Wang, Rong; Wang, Li; Yang, Yong; Li, Jiajia; Wu, Ying; Lin, Pan

2016-11-01

Attention deficit hyperactivity disorder (ADHD) is the most common childhood neuropsychiatric disorder and affects approximately 6 -7 % of children worldwide. Here, we investigate the statistical properties of undirected and directed brain functional networks in ADHD patients based on random matrix theory (RMT), in which the undirected functional connectivity is constructed based on correlation coefficient and the directed functional connectivity is measured based on cross-correlation coefficient and mutual information. We first analyze the functional connectivity and the eigenvalues of the brain functional network. We find that ADHD patients have increased undirected functional connectivity, reflecting a higher degree of linear dependence between regions, and increased directed functional connectivity, indicating stronger causality and more transmission of information among brain regions. More importantly, we explore the randomness of the undirected and directed functional networks using RMT. We find that for ADHD patients, the undirected functional network is more orderly than that for normal subjects, which indicates an abnormal increase in undirected functional connectivity. In addition, we find that the directed functional networks are more random, which reveals greater disorder in causality and more chaotic information flow among brain regions in ADHD patients. Our results not only further confirm the efficacy of RMT in characterizing the intrinsic properties of brain functional networks but also provide insights into the possibilities RMT offers for improving clinical diagnoses and treatment evaluations for ADHD patients.
Functional Integrative Levels in the Human Interactome Recapitulate Organ Organization

PubMed Central

Prieto, Carlos; Benkahla, Alia; De Las Rivas, Javier; Brun, Christine

2011-01-01

Interactome networks represent sets of possible physical interactions between proteins. They lack spatio-temporal information by construction. However, the specialized functions of the differentiated cell types which are assembled into tissues or organs depend on the combinatorial arrangements of proteins and their physical interactions. Is tissue-specificity, therefore, encoded within the interactome? In order to address this question, we combined protein-protein interactions, expression data, functional annotations and interactome topology. We first identified a subnetwork formed exclusively of proteins whose interactions were observed in all tested tissues. These are mainly involved in housekeeping functions and are located at the topological center of the interactome. This ‘Largest Common Interactome Network’ represents a ‘functional interactome core’. Interestingly, two types of tissue-specific interactions are distinguished when considering function and network topology: tissue-specific interactions involved in regulatory and developmental functions are central whereas tissue-specific interactions involved in organ physiological functions are peripheral. Overall, the functional organization of the human interactome reflects several integrative levels of functions with housekeeping and regulatory tissue-specific functions at the center and physiological tissue-specific functions at the periphery. This gradient of functions recapitulates the organization of organs, from cells to organs. Given that several gradients have already been identified across interactomes, we propose that gradients may represent a general principle of protein-protein interaction network organization. PMID:21799769
Measuring Work Functioning: Validity of a Weighted Composite Work Functioning Approach.

PubMed

Boezeman, Edwin J; Sluiter, Judith K; Nieuwenhuijsen, Karen

2015-09-01

To examine the construct validity of a weighted composite work functioning measurement approach. Workers (health-impaired/healthy) (n = 117) completed a composite measure survey that recorded four central work functioning aspects with existing scales: capacity to work, quality of work performance, quantity of work, and recovery from work. Previous derived weights reflecting the relative importance of these aspects of work functioning were used to calculate the composite weighted work functioning score of the workers. Work role functioning, productivity, and quality of life were used for validation. Correlations were calculated and norms applied to examine convergent and divergent construct validity. A t test was conducted and a norm applied to examine discriminative construct validity. Overall the weighted composite work functioning measure demonstrated construct validity. As predicted, the weighted composite score correlated (p < .001) strongly (r > .60) with work role functioning and productivity (convergent construct validity), and moderately (.30 < r < .60) with physical quality of life and less strongly than work role functioning and productivity with mental quality of life (divergent validity). Further, the weighted composite measure detected that health-impaired workers show with a large effect size (Cohen's d > .80) significantly worse work functioning than healthy workers (discriminative validity). The weighted composite work functioning measurement approach takes into account the relative importance of the different work functioning aspects and demonstrated good convergent, fair divergent, and good discriminative construct validity.
Visualizing bacterial tRNA identity determinants and antideterminants using function logos and inverse function logos

PubMed Central

Freyhult, Eva; Moulton, Vincent; Ardell, David H.

2006-01-01

Sequence logos are stacked bar graphs that generalize the notion of consensus sequence. They employ entropy statistics very effectively to display variation in a structural alignment of sequences of a common function, while emphasizing its over-represented features. Yet sequence logos cannot display features that distinguish functional subclasses within a structurally related superfamily nor do they display under-represented features. We introduce two extensions to address these needs: function logos and inverse logos. Function logos display subfunctions that are over-represented among sequences carrying a specific feature. Inverse logos generalize both sequence logos and function logos by displaying under-represented, rather than over-represented, features or functions in structural alignments. To make inverse logos, a compositional inverse is applied to the feature or function frequency distributions before logo construction, where a compositional inverse is a mathematical transform that makes common features or functions rare and vice versa. We applied these methods to a database of structurally aligned bacterial tDNAs to create highly condensed, birds-eye views of potentially all so-called identity determinants and antideterminants that confer specific amino acid charging or initiator function on tRNAs in bacteria. We recovered both known and a few potentially novel identity elements. Function logos and inverse logos are useful tools for exploratory bioinformatic analysis of structure–function relationships in sequence families and superfamilies. PMID:16473848
Validation of the Early Functional Abilities scale: An assessment of four dimensions in early recovery after traumatic brain injury.

PubMed

Poulsen, Ingrid; Kreiner, Svend; Engberg, Aase W

2018-02-13

The Early Functional Abilities scale assesses the restoration of brain function after brain injury, based on 4 dimensions. The primary objective of this study was to evaluate the validity, objectivity, reliability and measurement precision of the Early Functional Abilities scale by Rasch model item analysis. A secondary objective was to examine the relationship between the Early Functional Abilities scale and the Functional Independence Measurement™, in order to establish the criterion validity of the Early Functional Abilities scale and to compare the sensitivity of measurements using the 2 instruments. The Rasch analysis was based on the assessment of 408 adult patients at admission to sub-acute rehabilitation in Copenhagen, Denmark after traumatic brain injury. The Early Functional Abilities scale provides valid and objective measurement of vegetative (autonomic), facio-oral, sensorimotor and communicative/cognitive functions. Removal of one item from the sensorimotor scale confirmed unidimensionality for each of the 4 subscales, but not for the entire scale. The Early Functional Abilities subscales are sensitive to differences between patients in ranges in which the Functional Independence Measurement™ has a floor effect. The Early Functional Abilities scale assesses the early recovery of important aspects of brain function after traumatic brain injury, but is not unidimensional. We recommend removal of the "standing" item and calculation of summary subscales for the separate dimensions.
18 CFR 358.5 - Independent functioning rule.

Code of Federal Regulations, 2010 CFR

2010-04-01

... its marketing function employees. (b) Separation of functions. (1) A transmission provider is prohibited from permitting its marketing function employees to: (i) Conduct transmission functions; or (ii... differs in any way from the access available to other transmission customers. (2) A transmission provider...
Museums and Their Functions.

ERIC Educational Resources Information Center

Osborne, Harold

1985-01-01

Historical background concerning the nature and function of museums is provided, and the aesthetic functions of museums are discussed. The first major aesthetic function of museums is to preserve the artistic heritage of mankind and to make it widely available. The second major function is patronage. (RM)
Using the structure-function linkage database to characterize functional domains in enzymes.

PubMed

Brown, Shoshana; Babbitt, Patricia

2014-12-12

The Structure-Function Linkage Database (SFLD; http://sfld.rbvi.ucsf.edu/) is a Web-accessible database designed to link enzyme sequence, structure, and functional information. This unit describes the protocols by which a user may query the database to predict the function of uncharacterized enzymes and to correct misannotated functional assignments. The information in this unit is especially useful in helping a user discriminate functional capabilities of a sequence that is only distantly related to characterized sequences in publicly available databases. Copyright © 2014 John Wiley & Sons, Inc.

Multiple utility constrained multi-objective programs using Bayesian theory

NASA Astrophysics Data System (ADS)

Abbasian, Pooneh; Mahdavi-Amiri, Nezam; Fazlollahtabar, Hamed

2018-03-01

A utility function is an important tool for representing a DM's preference. We adjoin utility functions to multi-objective optimization problems. In current studies, usually one utility function is used for each objective function. Situations may arise for a goal to have multiple utility functions. Here, we consider a constrained multi-objective problem with each objective having multiple utility functions. We induce the probability of the utilities for each objective function using Bayesian theory. Illustrative examples considering dependence and independence of variables are worked through to demonstrate the usefulness of the proposed model.
Some properties of the Catalan-Qi function related to the Catalan numbers.

PubMed

Qi, Feng; Mahmoud, Mansour; Shi, Xiao-Ting; Liu, Fang-Fang

2016-01-01

In the paper, the authors find some properties of the Catalan numbers, the Catalan function, and the Catalan-Qi function which is a generalization of the Catalan numbers. Concretely speaking, the authors present a new expression, asymptotic expansions, integral representations, logarithmic convexity, complete monotonicity, minimality, logarithmically complete monotonicity, a generating function, and inequalities of the Catalan numbers, the Catalan function, and the Catalan-Qi function. As by-products, an exponential expansion and a double inequality for the ratio of two gamma functions are derived.
Recent developments in LIBXC - A comprehensive library of functionals for density functional theory

NASA Astrophysics Data System (ADS)

Lehtola, Susi; Steigemann, Conrad; Oliveira, Micael J. T.; Marques, Miguel A. L.

2018-01-01

LIBXC is a library of exchange-correlation functionals for density-functional theory. We are concerned with semi-local functionals (or the semi-local part of hybrid functionals), namely local-density approximations, generalized-gradient approximations, and meta-generalized-gradient approximations. Currently we include around 400 functionals for the exchange, correlation, and the kinetic energy, spanning more than 50 years of research. Moreover, LIBXC is by now used by more than 20 codes, not only from the atomic, molecular, and solid-state physics, but also from the quantum chemistry communities.
A case study in bifurcation theory

NASA Astrophysics Data System (ADS)

Khmou, Youssef

This short paper is focused on the bifurcation theory found in map functions called evolution functions that are used in dynamical systems. The most well-known example of discrete iterative function is the logistic map that puts into evidence bifurcation and chaotic behavior of the topology of the logistic function. We propose a new iterative function based on Lorentizan function and its generalized versions, based on numerical study, it is found that the bifurcation of the Lorentzian function is of second-order where it is characterized by the absence of chaotic region.
[The relationship between executive functions, physical and functional capability in people over 60 years old].

PubMed

Rajtar-Zembaty, Anna; Sałakowski, Andrzej; Rajtar-Zembaty, Jakub

Nowadays it is believed that cognitive decline may contribute to the formation of gait disturbance and increased risk of falls. Currently the importance of executive functions to maintain proper control of gait is emphasized. The aim of the study was to assess the relationship between the level of executive function, functional and physical capability in patients over 60 years of age. The study included 300 patients (199 women and 101 men) aged 60-88 years. In order to screening for cognitive function Mini-Mental State Examination (MMSE) was used. The following researchers tools were used to conduct functional assessment: a) Short Physical Performance Battery (SPPB), b) Timed “Up and Go” (TUG) and c) Fast Walking Test. To assess executive fucntion Trail Making Test (TMT) was selected. The relationship between the speed of information processing (part A, TMT), executive functions (Part B, TMT), level of functional and physical capability was observed. The strongest positive correlation was noted between the time of TUG test and TMT part B (r=0.32; p<0.01), and also between Fast Gait Test and TMT part A (r=0.27; p<0.01). It has been proven that the level of executive function is related to the level of functional capability (β=0.18; p=0.001). It was found that 15% of variation in the level of the TUG test was explained by age, TMT- B, GDS and BMI. There is a relationship between level of executive functions, functional and physical capability in patients over 60 years of age. Cognitive processes play an important role in the control of motor functions therefore it is important to incorporate examination of cognitive functions in the early geriatric diagnosis.
Network-based function prediction and interactomics: the case for metabolic enzymes.

PubMed

Janga, S C; Díaz-Mejía, J Javier; Moreno-Hagelsieb, G

2011-01-01

As sequencing technologies increase in power, determining the functions of unknown proteins encoded by the DNA sequences so produced becomes a major challenge. Functional annotation is commonly done on the basis of amino-acid sequence similarity alone. Long after sequence similarity becomes undetectable by pair-wise comparison, profile-based identification of homologs can often succeed due to the conservation of position-specific patterns, important for a protein's three dimensional folding and function. Nevertheless, prediction of protein function from homology-driven approaches is not without problems. Homologous proteins might evolve different functions and the power of homology detection has already started to reach its maximum. Computational methods for inferring protein function, which exploit the context of a protein in cellular networks, have come to be built on top of homology-based approaches. These network-based functional inference techniques provide both a first hand hint into a proteins' functional role and offer complementary insights to traditional methods for understanding the function of uncharacterized proteins. Most recent network-based approaches aim to integrate diverse kinds of functional interactions to boost both coverage and confidence level. These techniques not only promise to solve the moonlighting aspect of proteins by annotating proteins with multiple functions, but also increase our understanding on the interplay between different functional classes in a cell. In this article we review the state of the art in network-based function prediction and describe some of the underlying difficulties and successes. Given the volume of high-throughput data that is being reported the time is ripe to employ these network-based approaches, which can be used to unravel the functions of the uncharacterized proteins accumulating in the genomic databases. © 2010 Elsevier Inc. All rights reserved.
Linking social anxiety and adolescent romantic relationship functioning: indirect effects and the importance of peers.

PubMed

Hebert, Karen R; Fales, Jessica; Nangle, Douglas W; Papadakis, Alison A; Grover, Rachel L

2013-11-01

Peer relationships undergo dramatic shifts in form and function during adolescence, at the same time the incidence of socially evaluative fears sharply rises. Despite well-established links between social anxiety and broader interpersonal functioning, there is a dearth of research evaluating the impact of social anxiety on functioning in close relationships during this developmental stage. The present study examines the impact of social anxiety on functioning in close friendships and romantic relationships during adolescence. From a developmental psychopathology perspective, it was expected that social anxiety would influence functioning (quality, length, satisfaction) in romantic relationships through its influence on functioning in same- and other-sex friendships. Participants included 314 adolescents (60.5% female, 14-19 years of age) with a prior or current history of romantic relationship involvement. Structural equation modeling was used to test a mediation model positing an indirect pathway from social anxiety to romantic relationship functioning through functioning in close same- and other-sex friendships. Given known gender differences in social anxiety and relationship functioning, gender also was explored as a potential moderator. Results supported the hypothesized indirect pathway whereby social anxiety was associated with impairment in same-sex friendships; functioning in same-sex friendships was associated with functioning in other-sex friendships, which was associated, in turn, with functioning in romantic relationships. While the hypothesized indirect pathway was significant among both boys and girls, there was greater continuity of functioning between same- and other-sex friendships for girls. These findings highlight the importance of examining the multiple downstream effects of social anxiety on perceived social functioning in adolescence, and suggest that continuity may exist for maladaptive patterns of socialization, particularly across developmentally salient close relationships.
Cognitive Assessment Interview (CAI): Validity as a co-primary measure of cognition across phases of schizophrenia.

PubMed

Ventura, Joseph; Subotnik, Kenneth L; Ered, Arielle; Hellemann, Gerhard S; Nuechterlein, Keith H

2016-04-01

Progress has been made in developing interview-based measures for the assessment of cognitive functioning, such as the Cognitive Assessment Interview (CAI), as co-primary measures that compliment objective neurocognitive assessments and daily functioning. However, a few questions remain, including whether the relationships with objective cognitive measures and daily functioning are high enough to justify the CAI as an co-primary measure and whether patient-only assessments are valid. Participants were first-episode schizophrenia patients (n=60) and demographically-similar healthy controls (n=35), chronic schizophrenia patients (n=38) and demographically similar healthy controls (n=19). Participants were assessed at baseline with an interview-based measure of cognitive functioning (CAI), a test of objective cognitive functioning, functional capacity, and role functioning at baseline, and in the first episode patients again 6 months later (n=28). CAI ratings were correlated with objective cognitive functioning, functional capacity, and functional outcomes in first-episode schizophrenia patients at similar magnitudes as in chronic patients. Comparisons of first-episode and chronic patients with healthy controls indicated that the CAI sensitively detected deficits in schizophrenia. The relationship of CAI Patient-Only ratings with objective cognitive functioning, functional capacity, and daily functioning were comparable to CAI Rater scores that included informant information. These results confirm in an independent sample the relationship of the CAI ratings with objectively measured cognition, functional capacity, and role functioning. Comparison of schizophrenia patients with healthy controls further validates the CAI as an co-primary measure of cognitive deficits. Also, CAI change scores were strongly related to objective cognitive change indicating sensitivity to change. Copyright © 2016 Elsevier B.V. All rights reserved.
Examining the association between social cognition and functioning in individuals at ultra-high risk for psychosis.

PubMed

Cotter, Jack; Bartholomeusz, Cali; Papas, Alicia; Allott, Kelly; Nelson, Barnaby; Yung, Alison R; Thompson, Andrew

2017-01-01

Social and role functioning are compromised for the majority of individuals at ultra-high risk of psychosis, and it is important to identify factors that contribute to this functional decline. This study aimed to investigate social cognitive abilities, which have previously been linked to functioning in schizophrenia, as potential factors that impact social, role and global functioning in ultra-high risk patients. A total of 30 ultra-high risk patients were recruited from an established at-risk clinical service in Melbourne, Australia, and completed a battery of social cognitive, neurocognitive, clinical and functioning measures. We examined the relationships between all four core domains of social cognition (emotion recognition, theory of mind, social perception and attributional style), neurocognitive, clinical and demographic variables with three measures of functioning (the Global Functioning Social and Role scales and the Social and Occupational Functioning Assessment Scale) using correlational and multiple regression analyses. Performance on a visual theory of mind task (visual jokes task) was significantly correlated with both concurrent role ( r = 0.425, p = 0.019) and global functioning ( r = 0.540, p = 0.002). In multivariate analyses, it also accounted for unique variance in global, but not role functioning after adjusting for negative symptoms and stress. Social functioning was not associated with performance on any of the social cognition tasks. Among specific social cognitive abilities, only a test of theory of mind was associated with functioning in our ultra-high risk sample. Further longitudinal research is needed to examine the impact of social cognitive deficits on long-term functional outcome in the ultra-high risk group. Identifying social cognitive abilities that significantly impact functioning is important to inform the development of targeted intervention programmes for ultra-high risk individuals.
The relationships between sex hormones and sexual function in middle-aged and older European men.

PubMed

O'Connor, Daryl B; Lee, David M; Corona, Giovanni; Forti, Gianni; Tajar, Abdelouahid; O'Neill, Terence W; Pendleton, Neil; Bartfai, Gyorgy; Boonen, Steven; Casanueva, Felipe F; Finn, Joseph D; Giwercman, Aleksander; Han, Thang S; Huhtaniemi, Ilpo T; Kula, Krzysztof; Labrie, Fernand; Lean, Michael E J; Punab, Margus; Silman, Alan J; Vanderschueren, Dirk; Wu, Frederick C W

2011-10-01

Limited data are available exploring the associations between sex hormones, multiple domains of sexual functioning, and sexual function-related distress in nonpatient samples in Europe. The aim of the study was to investigate the relationships between serum testosterone (T), estradiol (E2), and dihydrotestosterone (DHT) and sexual function in a multicenter population-based study of aging in men. Using stratified random sampling, 2838 men aged 40-79 yr completed the European Male Ageing Study-Sexual Function Questionnaire and provided a blood sample for hormone measurements. T, E2, and DHT were measured using gas chromatography-mass spectrometry. We conducted a community-based population survey in eight European centers. Self-reported sexual function (overall sexual function, sexual function-related distress, erectile dysfunction, masturbation) was measured. Total and free T, but not E2 or DHT, was associated with overall sexual function in middle-aged and older men. E2 was the only hormone associated with sexual function-related distress such that higher levels were related to greater distress. Free T levels were associated with masturbation frequency and erectile dysfunction in the fully adjusted models, such that higher T was associated with less dysfunction and greater frequency. Moreover, there was a T threshold for the relationship between total T, sexual function, and erectile dysfunction. At T concentrations of 8 nmol/liter or less, T was associated with worse sexual functioning, whereas at T levels over 8 nmol/liter, the relationship came to a plateau. These findings suggest that different hormonal mechanisms may regulate sexual functioning (T) vs. the psychological aspects (E2) of male sexual behavior. Moreover, there was a T threshold for overall sexual function such that at levels greater than 8 nmol/liter the relationship between T and sexual function did not become stronger.
On the detection of functionally coherent groups of protein domains with an extension to protein annotation

PubMed Central

McLaughlin, William A; Chen, Ken; Hou, Tingjun; Wang, Wei

2007-01-01

Background Protein domains coordinate to perform multifaceted cellular functions, and domain combinations serve as the functional building blocks of the cell. The available methods to identify functional domain combinations are limited in their scope, e.g. to the identification of combinations falling within individual proteins or within specific regions in a translated genome. Further effort is needed to identify groups of domains that span across two or more proteins and are linked by a cooperative function. Such functional domain combinations can be useful for protein annotation. Results Using a new computational method, we have identified 114 groups of domains, referred to as domain assembly units (DASSEM units), in the proteome of budding yeast Saccharomyces cerevisiae. The units participate in many important cellular processes such as transcription regulation, translation initiation, and mRNA splicing. Within the units the domains were found to function in a cooperative manner; and each domain contributed to a different aspect of the unit's overall function. The member domains of DASSEM units were found to be significantly enriched among proteins contained in transcription modules, defined as genes sharing similar expression profiles and presumably similar functions. The observation further confirmed the functional coherence of DASSEM units. The functional linkages of units were found in both functionally characterized and uncharacterized proteins, which enabled the assessment of protein function based on domain composition. Conclusion A new computational method was developed to identify groups of domains that are linked by a common function in the proteome of Saccharomyces cerevisiae. These groups can either lie within individual proteins or span across different proteins. We propose that the functional linkages among the domains within the DASSEM units can be used as a non-homology based tool to annotate uncharacterized proteins. PMID:17937820
Impact of blood products on platelet function in patients with traumatic injuries: a translational study.

PubMed

Henriksen, Hanne Hee; Grand, Alexandra G; Viggers, Sandra; Baer, Lisa A; Solbeck, Sacha; Cotton, Bryan A; Matijevic, Nena; Ostrowski, Sisse R; Stensballe, Jakob; Fox, Erin E; Chen, Tzu-An; Holcomb, John B; Johansson, Pär I; Cardenas, Jessica C; Wade, Charles E

2017-06-15

Reductions in platelet (PLT) count and function are associated with poor outcomes in trauma patients. We proposed to determine if patients expected to receive blood products have a decrease in PLT function higher than expected based on the reduction in PLT count, and if the reduction in function could be associated with the donor plasma/supernatant received. PLT count and function were measured on admission to the emergency department and intensive care unit in severely injured patients expected to receive a transfusion. PLT function was measured by Multiplate aggregometry in response to five agonists. Function was corrected for alterations in count. In vitro studies were conducted in the blood of normal subjects to assess the effect of dilutions with AB donor plasma on PLT function. Forty-six patients were enrolled, with 87% requiring a transfusion. Median Injury Severity Score was 23 (13, 29) and mortality 15%. PLT count and function were decreased from emergency department to intensive care unit admission by 25% and 58%, respectively. Decreases in function persisted after adjustment for count. Patients requiring large volumes of blood products had reductions in function that were disproportionately greater. Reductions in PLT function were greatest after transfusion of PLTs. In in vitro studies with a 30% dilution by autologous plasma caused a relational reduction in function, whereas allogenic plasma resulted in greater decreases that were highly variable between donors. Within hours of injury a decrease in both PLT count and function occurs, that is aggravated with the administration of blood products, with transfusion of PLTs showing the greatest effect. The effect on PLT function of allogenic transfused plasma appears to be highly donor related. Copyright © 2017 Elsevier Inc. All rights reserved.
The assessment of function: How is it measured? A clinical perspective

PubMed Central

Reiman, Michael P; Manske, Robert C

2011-01-01

Testing for outcome or performance can take many forms; including multiple iterations of self-reported measures of function (an assessment of the individual’s perceived dysfunction) and/or clinical special tests (which are primarily assessments of impairments). Typically absent within these testing mechanisms is whether or not one can perform a specific task associated with function. The paper will operationally define function, discuss the construct of function within the disablement model, will overview the multi-dimensional nature of ‘function’ as a concept, will examine the current evidence for functional testing methods, and will propose a functional testing continuum. Limitations of functional performance testing will be discussed including recommendations for future research. PMID:22547919
Functional analysis screening for multiple topographies of problem behavior.

PubMed

Bell, Marlesha C; Fahmie, Tara A

2018-04-23

The current study evaluated a screening procedure for multiple topographies of problem behavior in the context of an ongoing functional analysis. Experimenters analyzed the function of a topography of primary concern while collecting data on topographies of secondary concern. We used visual analysis to predict the function of secondary topographies and a subsequent functional analysis to test those predictions. Results showed that a general function was accurately predicted for five of six (83%) secondary topographies. A specific function was predicted and supported for a subset of these topographies. The experimenters discuss the implication of these results for clinicians who have limited time for functional assessment. © 2018 Society for the Experimental Analysis of Behavior.
Grid Integrated Distributed PV (GridPV) Version 2.

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

Reno, Matthew J.; Coogan, Kyle

2014-12-01

This manual provides the documentation of the MATLAB toolbox of functions for using OpenDSS to simulate the impact of solar energy on the distribution system. The majority of the functio ns are useful for interfacing OpenDSS and MATLAB, and they are of generic use for commanding OpenDSS from MATLAB and retrieving information from simulations. A set of functions is also included for modeling PV plant output and setting up the PV plant in th e OpenDSS simulation. The toolbox contains functions for modeling the OpenDSS distribution feeder on satellite images with GPS coordinates. Finally, example simulations functions are included tomore » show potential uses of the toolbox functions. Each function i n the toolbox is documented with the function use syntax, full description, function input list, function output list, example use, and example output.« less
A continued role for signaling functions in the early evolution of feathers.

PubMed

Ruxton, Graeme D; Persons Iv, W Scott; Currie, Philip J

2017-03-01

Persons and Currie (2015) argued against either flight, thermoregulation, or signaling as a functional benefit driving the earliest evolution of feathers; rather, they favored simple feathers having an initial tactile sensory function, which changed to a thermoregulatory function as density increased. Here, we explore the relative merits of early simple feathers that may have originated as tactile sensors progressing instead toward a signaling, rather than (or in addition to) a thermoregulatory function. We suggest that signaling could act in concert with a sensory function more naturally than could thermoregulation. As such, the dismissal of a possible signaling function and the presumption that an initial sensory function led directly to a thermoregulatory function (implicit in the title "bristles before down") are premature. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.
On one-dimensional stretching functions for finite-difference calculations. [computational fluid dynamics

NASA Technical Reports Server (NTRS)

Vinokur, M.

1983-01-01

The class of one-dimensional stretching functions used in finite-difference calculations is studied. For solutions containing a highly localized region of rapid variation, simple criteria for a stretching function are derived using a truncation error analysis. These criteria are used to investigate two types of stretching functions. One an interior stretching function, for which the location and slope of an interior clustering region are specified. The simplest such function satisfying the criteria is found to be one based on the inverse hyperbolic sine. The other type of function is a two-sided stretching function, for which the arbitrary slopes at the two ends of the one-dimensional interval are specified. The simplest such general function is found to be one based on the inverse tangent. Previously announced in STAR as N80-25055
Production Functions for Water Delivery Systems: Analysis and Estimation Using Dual Cost Function and Implicit Price Specifications

NASA Astrophysics Data System (ADS)

Teeples, Ronald; Glyer, David

1987-05-01

Both policy and technical analysis of water delivery systems have been based on cost functions that are inconsistent with or are incomplete representations of the neoclassical production functions of economics. We present a full-featured production function model of water delivery which can be estimated from a multiproduct, dual cost function. The model features implicit prices for own-water inputs and is implemented as a jointly estimated system of input share equations and a translog cost function. Likelihood ratio tests are performed showing that a minimally constrained, full-featured production function is a necessary specification of the water delivery operations in our sample. This, plus the model's highly efficient and economically correct parameter estimates, confirms the usefulness of a production function approach to modeling the economic activities of water delivery systems.
Electromagnetic scaling functions within the Green's function Monte Carlo approach

DOE PAGES

Rocco, N.; Alvarez-Ruso, L.; Lovato, A.; ...

2017-07-24

We have studied the scaling properties of the electromagnetic response functions of 4He and 12C nuclei computed by the Green's function Monte Carlo approach, retaining only the one-body current contribution. Longitudinal and transverse scaling functions have been obtained in the relativistic and nonrelativistic cases and compared to experiment for various kinematics. The characteristic asymmetric shape of the scaling function exhibited by data emerges in the calculations in spite of the nonrelativistic nature of the model. The results are mostly consistent with scaling of zeroth, first, and second kinds. Our analysis reveals a direct correspondence between the scaling and the nucleon-densitymore » response functions. In conclusion, the scaling function obtained from the proton-density response displays scaling of the first kind, even more evidently than the longitudinal and transverse scaling functions« less
Electromagnetic scaling functions within the Green's function Monte Carlo approach

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

Rocco, N.; Alvarez-Ruso, L.; Lovato, A.

We have studied the scaling properties of the electromagnetic response functions of 4He and 12C nuclei computed by the Green's function Monte Carlo approach, retaining only the one-body current contribution. Longitudinal and transverse scaling functions have been obtained in the relativistic and nonrelativistic cases and compared to experiment for various kinematics. The characteristic asymmetric shape of the scaling function exhibited by data emerges in the calculations in spite of the nonrelativistic nature of the model. The results are mostly consistent with scaling of zeroth, first, and second kinds. Our analysis reveals a direct correspondence between the scaling and the nucleon-densitymore » response functions. In conclusion, the scaling function obtained from the proton-density response displays scaling of the first kind, even more evidently than the longitudinal and transverse scaling functions« less

Alterations to Functional Analysis Methodology to Clarify the Functions of Low Rate, High Intensity Problem Behavior

PubMed Central

Davis, Barbara J; Schmidt, Jonathan; Bowman, Lynn G; Boelter, Eric W

2012-01-01

Current research provides few suggestions for modifications to functional analysis procedures to accommodate low rate, high intensity problem behavior. This study examined the results of the extended duration functional analysis procedures of Kahng, Abt, and Schonbachler (2001) with six children admitted to an inpatient hospital for the treatment of severe problem behavior. Results of initial functional analyses (Iwata, Dorsey, Slifer, Bauman, & Richman, 1982/1994) were inconclusive for all children because of low levels of responding. The altered functional analyses, which changed multiple variables including the duration of the functional analysis (i.e., 6 or 7 hrs), yielded clear behavioral functions for all six participants. These results add additional support for the utility of an altered analysis of low rate, high intensity problem behavior when standard functional analyses do not yield differentiated results. PMID:23326628
Alterations to functional analysis methodology to clarify the functions of low rate, high intensity problem behavior.

PubMed

Davis, Barbara J; Kahng, Sungwoo; Schmidt, Jonathan; Bowman, Lynn G; Boelter, Eric W

2012-01-01

Current research provides few suggestions for modifications to functional analysis procedures to accommodate low rate, high intensity problem behavior. This study examined the results of the extended duration functional analysis procedures of Kahng, Abt, and Schonbachler (2001) with six children admitted to an inpatient hospital for the treatment of severe problem behavior. Results of initial functional analyses (Iwata, Dorsey, Slifer, Bauman, & Richman, 1982/1994) were inconclusive for all children because of low levels of responding. The altered functional analyses, which changed multiple variables including the duration of the functional analysis (i.e., 6 or 7 hrs), yielded clear behavioral functions for all six participants. These results add additional support for the utility of an altered analysis of low rate, high intensity problem behavior when standard functional analyses do not yield differentiated results.
15 CFR 2001.3 - Functions.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 15 Commerce and Foreign Trade 3 2010-01-01 2010-01-01 false Functions. 2001.3 Section 2001.3... TRADE REPRESENTATIVE CREATION, ORGANIZATION, AND FUNCTIONS § 2001.3 Functions. (a) The Trade... agreements, and other matters which are related to the trade agreements program; (4) Performs the functions...
Functional Multiple-Set Canonical Correlation Analysis

ERIC Educational Resources Information Center

Hwang, Heungsun; Jung, Kwanghee; Takane, Yoshio; Woodward, Todd S.

2012-01-01

We propose functional multiple-set canonical correlation analysis for exploring associations among multiple sets of functions. The proposed method includes functional canonical correlation analysis as a special case when only two sets of functions are considered. As in classical multiple-set canonical correlation analysis, computationally, the…
21 CFR 870.3640 - Indirect pacemaker generator function analyzer.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Indirect pacemaker generator function analyzer... Indirect pacemaker generator function analyzer. (a) Identification. An indirect pacemaker generator function analyzer is an electrically powered device that is used to determine pacemaker function or...
21 CFR 870.3640 - Indirect pacemaker generator function analyzer.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Indirect pacemaker generator function analyzer... Indirect pacemaker generator function analyzer. (a) Identification. An indirect pacemaker generator function analyzer is an electrically powered device that is used to determine pacemaker function or...
21 CFR 870.3640 - Indirect pacemaker generator function analyzer.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Indirect pacemaker generator function analyzer... Indirect pacemaker generator function analyzer. (a) Identification. An indirect pacemaker generator function analyzer is an electrically powered device that is used to determine pacemaker function or...
21 CFR 870.3640 - Indirect pacemaker generator function analyzer.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Indirect pacemaker generator function analyzer... Indirect pacemaker generator function analyzer. (a) Identification. An indirect pacemaker generator function analyzer is an electrically powered device that is used to determine pacemaker function or...
Building an Understanding of Functions: A Series of Activities for Pre-Calculus

ERIC Educational Resources Information Center

Carducci, Olivia M.

2008-01-01

Building block toys can be used to illustrate various concepts connected with functions including graphs and rates of change of linear and exponential functions, piecewise functions, and composition of functions. Five brief activities suitable for a pre-calculus course are described.
A Primer on Functional Analysis

ERIC Educational Resources Information Center

Yoman, Jerome

2008-01-01

This article presents principles and basic steps for practitioners to complete a functional analysis of client behavior. The emphasis is on application of functional analysis to adult mental health clients. The article includes a detailed flow chart containing all major functional diagnoses and behavioral interventions, with functional assessment…
Functional Additive Mixed Models

PubMed Central

Scheipl, Fabian; Staicu, Ana-Maria; Greven, Sonja

2014-01-01

We propose an extensive framework for additive regression models for correlated functional responses, allowing for multiple partially nested or crossed functional random effects with flexible correlation structures for, e.g., spatial, temporal, or longitudinal functional data. Additionally, our framework includes linear and nonlinear effects of functional and scalar covariates that may vary smoothly over the index of the functional response. It accommodates densely or sparsely observed functional responses and predictors which may be observed with additional error and includes both spline-based and functional principal component-based terms. Estimation and inference in this framework is based on standard additive mixed models, allowing us to take advantage of established methods and robust, flexible algorithms. We provide easy-to-use open source software in the pffr() function for the R-package refund. Simulations show that the proposed method recovers relevant effects reliably, handles small sample sizes well and also scales to larger data sets. Applications with spatially and longitudinally observed functional data demonstrate the flexibility in modeling and interpretability of results of our approach. PMID:26347592
Effects of Fishing and Regional Species Pool on the Functional Diversity of Fish Communities

PubMed Central

Martins, Gustavo M.; Arenas, Francisco; Neto, Ana I.; Jenkins, Stuart R.

2012-01-01

The potential population and community level impacts of fishing have received considerable attention, but little is known about how fishing influences communities’ functional diversity at regional scales. We examined how estimates of functional diversity differed among 25 regions of variable richness and investigated the functional consequences of removing species targeted by commercial fisheries. Our study shows that fishing leads to substantial losses in functional diversity. The magnitude of such loss was, however, reduced in the more speciose regions. Moreover, the removal of commercially targeted species caused a much larger reduction in functional diversity than expected by random species deletions, which was a consequence of the selective nature of fishing for particular species traits. Results suggest that functional redundancy is spatially variable, that richer biotas provide some degree of insurance against the impact of fishing on communities’ functional diversity and that fishing predominantly selects for particular species traits. Understanding how fishing impacts community functional diversity is key to predict its effects for biodiversity as well as ecosystem functioning. PMID:22952950
Clinical interpretation of the Spinal Cord Injury Functional Index (SCI-FI)

PubMed Central

Fyffe, Denise; Kalpakjian, Claire Z.; Slavin, Mary; Kisala, Pamela; Ni, Pengsheng; Kirshblum, Steven C.; Tulsky, David S.; Jette, Alan M.

2016-01-01

Objective: To provide validation of functional ability levels for the Spinal Cord Injury – Functional Index (SCI-FI). Design: Cross-sectional. Setting: Inpatient rehabilitation hospital and community settings. Participants: A sample of 855 individuals with traumatic spinal cord injury enrolled in 6 rehabilitation centers participating in the National Spinal Cord Injury Model Systems Network. Interventions: Not Applicable. Main Outcome Measures: Spinal Cord Injury-Functional Index (SCI-FI). Results: Cluster analyses identified three distinct groups that represent low, mid-range and high SCI-FI functional ability levels. Comparison of clusters on personal and other injury characteristics suggested some significant differences between groups. Conclusions: These results strongly support the use of SCI-FI functional ability levels to document the perceived functional abilities of persons with SCI. Results of the cluster analysis suggest that the SCI-FI functional ability levels capture function by injury characteristics. Clinical implications regarding tracking functional activity trajectories during follow-up visits are discussed. PMID:26781769
On a method for generating inequalities for the zeros of certain functions

NASA Astrophysics Data System (ADS)

Gatteschi, Luigi; Giordano, Carla

2007-10-01

In this paper we describe a general procedure which yields inequalities satisfied by the zeros of a given function. The method requires the knowledge of a two-term approximation of the function with bound for the error term. The method was successfully applied many years ago [L. Gatteschi, On the zeros of certain functions with application to Bessel functions, Nederl. Akad. Wetensch. Proc. Ser. 55(3)(1952), Indag. Math. 14(1952) 224-229] and more recently too [L. Gatteschi and C. Giordano, Error bounds for McMahon's asymptotic approximations of the zeros of the Bessel functions, Integral Transform Special Functions, 10(2000) 41-56], to the zeros of the Bessel functions of the first kind. Here, we present the results of the application of the method to get inequalities satisfied by the zeros of the derivative of the function . This function plays an important role in the asymptotic study of the stationary points of the solutions of certain differential equations.
Functional Additive Mixed Models.

PubMed

Scheipl, Fabian; Staicu, Ana-Maria; Greven, Sonja

2015-04-01

We propose an extensive framework for additive regression models for correlated functional responses, allowing for multiple partially nested or crossed functional random effects with flexible correlation structures for, e.g., spatial, temporal, or longitudinal functional data. Additionally, our framework includes linear and nonlinear effects of functional and scalar covariates that may vary smoothly over the index of the functional response. It accommodates densely or sparsely observed functional responses and predictors which may be observed with additional error and includes both spline-based and functional principal component-based terms. Estimation and inference in this framework is based on standard additive mixed models, allowing us to take advantage of established methods and robust, flexible algorithms. We provide easy-to-use open source software in the pffr() function for the R-package refund. Simulations show that the proposed method recovers relevant effects reliably, handles small sample sizes well and also scales to larger data sets. Applications with spatially and longitudinally observed functional data demonstrate the flexibility in modeling and interpretability of results of our approach.
A Functional Varying-Coefficient Single-Index Model for Functional Response Data

PubMed Central

Li, Jialiang; Huang, Chao; Zhu, Hongtu

2016-01-01

Motivated by the analysis of imaging data, we propose a novel functional varying-coefficient single index model (FVCSIM) to carry out the regression analysis of functional response data on a set of covariates of interest. FVCSIM represents a new extension of varying-coefficient single index models for scalar responses collected from cross-sectional and longitudinal studies. An efficient estimation procedure is developed to iteratively estimate varying coefficient functions, link functions, index parameter vectors, and the covariance function of individual functions. We systematically examine the asymptotic properties of all estimators including the weak convergence of the estimated varying coefficient functions, the asymptotic distribution of the estimated index parameter vectors, and the uniform convergence rate of the estimated covariance function and their spectrum. Simulation studies are carried out to assess the finite-sample performance of the proposed procedure. We apply FVCSIM to investigating the development of white matter diffusivities along the corpus callosum skeleton obtained from Alzheimer’s Disease Neuroimaging Initiative (ADNI) study. PMID:29200540
A Functional Varying-Coefficient Single-Index Model for Functional Response Data.

PubMed

Li, Jialiang; Huang, Chao; Zhu, Hongtu

2017-01-01

Motivated by the analysis of imaging data, we propose a novel functional varying-coefficient single index model (FVCSIM) to carry out the regression analysis of functional response data on a set of covariates of interest. FVCSIM represents a new extension of varying-coefficient single index models for scalar responses collected from cross-sectional and longitudinal studies. An efficient estimation procedure is developed to iteratively estimate varying coefficient functions, link functions, index parameter vectors, and the covariance function of individual functions. We systematically examine the asymptotic properties of all estimators including the weak convergence of the estimated varying coefficient functions, the asymptotic distribution of the estimated index parameter vectors, and the uniform convergence rate of the estimated covariance function and their spectrum. Simulation studies are carried out to assess the finite-sample performance of the proposed procedure. We apply FVCSIM to investigating the development of white matter diffusivities along the corpus callosum skeleton obtained from Alzheimer's Disease Neuroimaging Initiative (ADNI) study.
Effects of fishing and regional species pool on the functional diversity of fish communities.

PubMed

Martins, Gustavo M; Arenas, Francisco; Neto, Ana I; Jenkins, Stuart R

2012-01-01

The potential population and community level impacts of fishing have received considerable attention, but little is known about how fishing influences communities' functional diversity at regional scales. We examined how estimates of functional diversity differed among 25 regions of variable richness and investigated the functional consequences of removing species targeted by commercial fisheries. Our study shows that fishing leads to substantial losses in functional diversity. The magnitude of such loss was, however, reduced in the more speciose regions. Moreover, the removal of commercially targeted species caused a much larger reduction in functional diversity than expected by random species deletions, which was a consequence of the selective nature of fishing for particular species traits. Results suggest that functional redundancy is spatially variable, that richer biotas provide some degree of insurance against the impact of fishing on communities' functional diversity and that fishing predominantly selects for particular species traits. Understanding how fishing impacts community functional diversity is key to predict its effects for biodiversity as well as ecosystem functioning.
Spectroscopic studies on sidewall carboxylic acid functionalization of multi-walled carbon nanotubes with valine

NASA Astrophysics Data System (ADS)

Deborah, M.; Jawahar, A.; Mathavan, T.; Dhas, M. Kumara; Benial, A. Milton Franklin

2015-03-01

The valine functionalized multi-walled carbon nanotubes (MWCNTS) were prepared and characterized by using XRD, UV-Vis, FT-IR, EPR, SEM, and EDX, spectroscopic techniques. The enhanced XRD peak (0 0 2) intensity was observed for valine functionalized MWCNTs compared with oxidized MWCNTs, which is likely due to sample purification by acid washing. UV-Vis study shows the formation of valine functionalized MWCNTs. FT-IR study confirms the presence of functional groups of oxidized MWCNTs and valine functionalized MWCNTs. The ESR line shape analysis indicates that the observed EPR line shape is a Gaussian line shape. The g-values indicate that the systems are isotropic in nature. The morphology study was carried out for oxidized MWCNTs and valine functionalized MWCNTs by using SEM. The EDX spectra revealed that the high purity of oxidized MWCNTs and valine functionalized MWCNTs. The functionalization has been chosen because, functionalization of CNTs with amino acids makes them soluble and biocompatible. Thus, they have potential applications in the field of biosensors and targeted drug delivery.
Leaf bacterial diversity mediates plant diversity and ecosystem function relationships.

PubMed

Laforest-Lapointe, Isabelle; Paquette, Alain; Messier, Christian; Kembel, Steven W

2017-06-01

Research on biodiversity and ecosystem functioning has demonstrated links between plant diversity and ecosystem functions such as productivity. At other trophic levels, the plant microbiome has been shown to influence host plant fitness and function, and host-associated microbes have been proposed to influence ecosystem function through their role in defining the extended phenotype of host organisms However, the importance of the plant microbiome for ecosystem function has not been quantified in the context of the known importance of plant diversity and traits. Here, using a tree biodiversity-ecosystem functioning experiment, we provide strong support for the hypothesis that leaf bacterial diversity is positively linked to ecosystem productivity, even after accounting for the role of plant diversity. Our results also show that host species identity, functional identity and functional diversity are the main determinants of leaf bacterial community structure and diversity. Our study provides evidence of a positive correlation between plant-associated microbial diversity and terrestrial ecosystem productivity, and a new mechanism by which models of biodiversity-ecosystem functioning relationships can be improved.

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