The influence of fire-coral colony size and agonistic behaviour of territorial damselfish on associated coral reef fish communities.

PubMed

Leal, Isabela Carolina Silva; de Araújo, Maria Elisabeth; da Cunha, Simone Rabelo; Pereira, Pedro Henrique Cipresso

2015-07-01

Branching hydrocorals from the genus Millepora play an important ecological role in South Atlantic reefs, where branching scleractinian corals are absent. Previous studies have shown a high proportion of reef fish species using branching fire-coral colonies as shelter, breeding, and feeding sites. However, the effects of Millepora spp. colony size and how the agonistic behaviour of a competitive damselfish affect the associated reef fish community are still unknown. The present study examined how fire-coral colony volume and the presence of a highly territorial and aggressive damselfish (Brazilian endemic Stegastes fuscus) affects the reef fish community associated with the fire-coral Millepora alcicornis. M. alcicornis colonies were surveyed from September 2012 to April 2013 at Tamandaré Reefs off Northeast Brazil. Our results show that the abundance and richness of coral associated fish was positively correlated with M. alcicornis coral colony volume. Additionally, behaviour of S. fuscus, the most abundant reef fish species found associated with fire-coral colonies (almost 57% of the fish community), was also influenced by fire-coral colony volume. There was a clear trend of increased agonistic behaviour and feeding on coral polyps as colony volume increased. This trend was reversed for the non-occupational swimming category, which decreased as M. alcicornis colony volume increased. Behavioural ontogenetic changes were also detected for S. fuscus individuals. Juveniles mainly showed two distinct behaviours: sheltered on coral branches and feeding on coral polyps. In contrast, adults presented greater equitability among the behavioural categories, mostly non-occupational swimming around coral colonies and agonistic behaviour. Lastly, S. fuscus individuals actively defended fire-coral colonies from intruders. A large number of agonistic interactions occurred against potential food competitors, which were mainly roving herbivores, omnivores, and sessile invertebrate feeders. To our knowledge, the present study provides the first evidence that through habitat competition, the presence of S. fuscus may affect reef fish communities associated with M. alcicornis coral colonies. Our findings also indicate that S. fuscus uses M. alcicornis coral colonies as part of their territory for shelter and foraging. In conclusion, M. alcicornis fire-coral colonies are extremely important habitats for reef fishes and the size and presence of a territorial damselfish are relevant variables for associated reef fish community. Copyright © 2015 Elsevier Ltd. All rights reserved.

Indirect effects of species interactions on habitat provisioning.

PubMed

Holbrook, Sally J; Schmitt, Russell J; Brooks, Andrew J

2011-07-01

Species that shelter in a biogenic habitat can influence their refugia and, in turn, play an essential role in shaping local patterns of biodiversity. Here we explore a positive feedback loop between the provisioning rate of habitat-forming branching corals and their associated fishes and show how interactions between two groups of fish--the planktivorous damselfish and predatory hawkfish--altered the feedback. A field experiment confirmed that skeletal growth of branching coral (genus Pocillopora) increased substantially with increasing numbers (biomass) of resident fishes, likely because they greatly increased the interstitial concentrations of nutrients. Because there is a positive relationship between colony size and number (biomass) of associated fishes (primarily damselfishes in the Family Pomacentridae), a structure-function feedback loop exists in which increasing numbers of damselfish enhance coral growth and larger corals host greater abundances (and species richness) of fish. However, interactions between damselfishes and arc-eye hawkfish, Paracirrhites arcatus, a largely solitary resident, can disrupt this positive feedback loop. Field surveys revealed a marked pattern of fish occupancy related to coral size: Pocillopora colonies of sufficient size to host fish (>40 cm circumference) had either groups of damselfish or an arc-eye hawkfish; only larger colonies (>75 cm) were occupied by both the damselfish and hawkfish. Subsequent short- and long-term experiments revealed that on intermediate-sized Pocillopora colonies, arc-eye hawkfish prevented the establishment of damselfish by suppressing their recruitment. The demographic consequences to the host coral were substantial; in a 1-year-long experiment, intermediate-size Pocillopora occupied by hawkfish grew at half the rate of corals that hosted groups of damselfish. These findings indicate that: (1) species which occupy a biogenic habitat can enhance the provisioning rate of their habitat; (2) such positive feedbacks between community structure and ecosystem function can be disrupted by a strong interactor; (3) even substantial consequences on ecosystem processes that arise can be difficult to discern.

Effects of coral bleaching on the obligate coral-dwelling crab Trapezia cymodoce

NASA Astrophysics Data System (ADS)

Stella, J. S.; Munday, P. L.; Jones, G. P.

2011-09-01

Corals are an essential and threatened habitat for a diverse range of reef-associated animals. Episodes of coral bleaching are predicted to increase in frequency and intensity over coming decades, yet the effects of coral-host bleaching on the associated animal communities remain poorly understood. The present study investigated the effects of host-colony bleaching on the obligate coral-dwelling crab, Trapezia cymodoce, during a natural bleaching event in the lagoon of Lizard Island, Australia. Branching corals, which harbour the highest diversity of coral associates, comprised 13% of live coral cover at the study site, with 83% affected by bleaching. Crabs on healthy and bleached colonies of Pocillopora damicornis were monitored over a 5-week period to determine whether coral bleaching affected crab density and movement patterns. All coral colonies initially contained one breeding pair of crabs. There was a significant decline in crab density on bleached corals after 5 weeks, with many corals losing one or both crabs, yet all healthy colonies retained a mating pair. Fecundity of crabs collected from bleached and healthy colonies of P. damicornis was also compared. The size of egg clutches of crabs collected from bleached hosts was 40% smaller than those from healthy hosts, indicating a significant reduction in fecundity. A laboratory experiment on movement patterns found that host-colony bleaching also prompted crabs to emigrate in search of more suitable colonies. Emigrant crabs engaged in aggressive interactions with occupants of healthy hosts, with larger crabs always usurping occupants of a smaller size. Decreased densities and clutch sizes, along with increased competitive interactions, could potentially result in a population decline of these important coral associates with cascading effects on coral health.

A new computational approach to simulate pattern formation in Paenibacillus dendritiformis bacterial colonies

NASA Astrophysics Data System (ADS)

Tucker, Laura Jane

Under the harsh conditions of limited nutrient and hard growth surface, Paenibacillus dendritiformis in agar plates form two classes of patterns (morphotypes). The first class, called the dendritic morphotype, has radially directed branches. The second class, called the chiral morphotype, exhibits uniform handedness. The dendritic morphotype has been modeled successfully using a continuum model on a regular lattice; however, a suitable computational approach was not known to solve a continuum chiral model. This work details a new computational approach to solving the chiral continuum model of pattern formation in P. dendritiformis. The approach utilizes a random computational lattice and new methods for calculating certain derivative terms found in the model.

The effects of nutrient chemotaxis on bacterial aggregation patterns with non-linear degenerate cross diffusion

NASA Astrophysics Data System (ADS)

Leyva, J. Francisco; Málaga, Carlos; Plaza, Ramón G.

2013-11-01

This paper studies a reaction-diffusion-chemotaxis model for bacterial aggregation patterns on the surface of thin agar plates. It is based on the non-linear degenerate cross diffusion model proposed by Kawasaki et al. (1997) [5] and it includes a suitable nutrient chemotactic term compatible with such type of diffusion, as suggested by Ben-Jacob et al. (2000) [20]. An asymptotic estimation predicts the growth velocity of the colony envelope as a function of both the nutrient concentration and the chemotactic sensitivity. It is shown that the growth velocity is an increasing function of the chemotactic sensitivity. High resolution numerical simulations using Graphic Processing Units (GPUs), which include noise in the diffusion coefficient for the bacteria, are presented. The numerical results verify that the chemotactic term enhances the velocity of propagation of the colony envelope. In addition, the chemotaxis seems to stabilize the formation of branches in the soft-agar, low-nutrient regime.

DISSECTING COLONY DEVELOPMENT OF NEUROSPORA CRASSA USING mRNA PROFILING AND COMPARTATIVE GENOMICS APPROACHES

USDA-ARS?s Scientific Manuscript database

Colony development, which includes hyphal extension, branching, anastomosis and asexual sporulation are fundamental aspects of the lifecycle of filamentous fungi; genetic mechanisms underlying these phenomena are poorly understood. We conducted transcriptional profiling during colony development of...

Re-evaluation of characters in Apolemiidae (Siphonophora), with description of two new species from Monterey Bay, California.

PubMed

Siebert, Stefan; Pugh, Phil R; Haddock, Steven H D; Dunn, Casey W

2013-01-01

Siphonophores are polymorphic planktonic marine Cnidarians. The family Apolemiidae is sister to all other species of physonect and calycophoran siphonophores. Although this enigmatic group arguably includes the longest animal species on the planet, their colony-level organization and growth patterns are not well understood. Here we describe two new apolemiid species: Apolemia lanosa sp. nov. and A. rubriversa sp. nov. We provide detailed descriptions of zooid budding and the organization of mature zooids within the siphosome. Our findings reveal that at least two distinct general patterns of siphosomal organization are found in different Apolemia species. In the first pattern, dispersed organization, zooids independently attach directly to the siphosomal stem. In the second pattern, pedunculate organization, only the gastrozooid is attached directly to the stem, and the other zooids of the cormidium branch from its peduncle. This diversity within Apolemia indicates that fundamental aspects of zooid budding and organization are homoplastic within Siphonophora, as both patterns are also found in other siphonophores. The observations presented here greatly clarify the interpretation of diagnostic characters within Apolemiidae, bear on the status of the three previously described species, provide critical detail for understanding the diversity of colony-level organization in siphonophores, and establish a foundation for the description of additional apolemiid species.

Diversity and abundance of invertebrate epifaunal assemblages associated with gorgonians are driven by colony attributes

NASA Astrophysics Data System (ADS)

Cúrdia, João; Carvalho, Susana; Pereira, Fábio; Guerra-García, José Manuel; Santos, Miguel N.; Cunha, Marina R.

2015-06-01

The present study aimed to explicitly quantify the link between the attributes of shallow-water gorgonian colonies (Octocorallia: Alcyonacea) and the ecological patterns of associated non-colonial epifaunal invertebrates. Based on multiple regression analysis, we tested the contribution of several attributes (colony height, width, and area, fractal dimension as a measure of colony complexity, lacunarity as a measure of the heterogeneity, and "colonial" epibiont cover) to abundance and taxonomic richness of associated assemblages. The results highlight the variation in the response of epifaunal assemblages to the gorgonian colony characteristics. The nature and intensity of the relationships were gorgonian species-dependent and varied from one taxonomic group to another. For both gorgonian species analyzed, the strongest predictor of species richness and abundance of the epifaunal assemblages was "colonial" epibiont cover, possibly due to a trophic effect (direct or indirect enhancement of food availability) combined with the surface available for colonization (species-area effect). Although structural complexity is usually indicated as the main driver for rich and abundant coral-associated assemblages, no significant relationship was observed between fractal dimension and the community descriptors; lacunarity, which reflects the sizes of the inter-branch spaces, was only linked to taxonomic richness in the assemblages associated with Leptogorgia lusitanica. The validity of the paradigm that structural complexity enhances biodiversity may be scale-dependent. In the case of gorgonians, the effect of complexity at the "garden" level may be more relevant than at the individual colony level. This reinforces the need for the conservation of gorgonian aggregation areas as a whole in order to preserve host diversity and size structure.

Learning and discrimination of cuticular hydrocarbons in a social insect

PubMed Central

van Wilgenburg, Ellen; Felden, Antoine; Choe, Dong-Hwan; Sulc, Robert; Luo, Jun; Shea, Kenneth J.; Elgar, Mark A.; Tsutsui, Neil D.

2012-01-01

Social insect cuticular hydrocarbon (CHC) mixtures are among the most complex chemical cues known and are important in nest-mate, caste and species recognition. Despite our growing knowledge of the nature of these cues, we have very little insight into how social insects actually perceive and discriminate among these chemicals. In this study, we use the newly developed technique of differential olfactory conditioning to pure, custom-designed synthetic colony odours to analyse signal discrimination in Argentine ants, Linepithema humile. Our results show that tri-methyl alkanes are more easily learned than single-methyl or straight-chain alkanes. In addition, we reveal that Argentine ants can discriminate between hydrocarbons with different branching patterns and the same chain length, but not always between hydrocarbons with the same branching patterns but different chain length. Our data thus show that biochemical characteristics influence those compounds that ants can discriminate between, and which thus potentially play a role in chemical signalling and nest-mate recognition. PMID:21831880

A branching process model for the analysis of abortive colony size distributions in carbon ion-irradiated normal human fibroblasts.

PubMed

Sakashita, Tetsuya; Hamada, Nobuyuki; Kawaguchi, Isao; Hara, Takamitsu; Kobayashi, Yasuhiko; Saito, Kimiaki

2014-05-01

A single cell can form a colony, and ionizing irradiation has long been known to reduce such a cellular clonogenic potential. Analysis of abortive colonies unable to continue to grow should provide important information on the reproductive cell death (RCD) following irradiation. Our previous analysis with a branching process model showed that the RCD in normal human fibroblasts can persist over 16 generations following irradiation with low linear energy transfer (LET) γ-rays. Here we further set out to evaluate the RCD persistency in abortive colonies arising from normal human fibroblasts exposed to high-LET carbon ions (18.3 MeV/u, 108 keV/µm). We found that the abortive colony size distribution determined by biological experiments follows a linear relationship on the log-log plot, and that the Monte Carlo simulation using the RCD probability estimated from such a linear relationship well simulates the experimentally determined surviving fraction and the relative biological effectiveness (RBE). We identified the short-term phase and long-term phase for the persistent RCD following carbon-ion irradiation, which were similar to those previously identified following γ-irradiation. Taken together, our results suggest that subsequent secondary or tertiary colony formation would be invaluable for understanding the long-lasting RCD. All together, our framework for analysis with a branching process model and a colony formation assay is applicable to determination of cellular responses to low- and high-LET radiation, and suggests that the long-lasting RCD is a pivotal determinant of the surviving fraction and the RBE.

Cellular Fatty Acid Composition, Soluble-Protein Profile, and Antimicrobial Resistance Pattern of Eubacterium lentum

PubMed Central

Mosca, Adriana; Summanen, Paula; Finegold, Sydney M.; De Michele, Giampiero; Miragliotta, Giuseppe

1998-01-01

Phenotypic heterogeneity among isolates of Eubacterium lentum has been recognized for many years. To better delineate their taxonomic relatedness, 29 clinical isolates of E. lentum were examined for soluble-protein content, cellular fatty acid profile, and antimicrobial resistance pattern in order to ascertain whether differences in these characteristics could be correlated with differences in biochemical activities. Among 29 isolates we could identify 6 that were different from all the others. These strains were coccobacilli with translucent colonies; they were catalase and H2S negative, not fluorescent under UV light, and susceptible to beta-lactam drugs; growth was not stimulated by arginine; and fatty acid analysis revealed the presence of straight-chain fatty acids. The remainder of the strains, including the type species, were pleomorphic bacilli with speckled colonies and were catalase and H2S positive; all but two were fluorescent under UV light; they were resistant to beta-lactam antibiotics; growth was greatly stimulated by arginine; and they demonstrated saturated branched-chain fatty acids. Our data suggest that E. lentum can be further differentiated into different types. PMID:9508307

Fragmentation in the branching coral Acropora palmata (Lamarck): growth, survivorship, and reproduction of colonies and fragments.

PubMed

Lirman

2000-08-23

Acropora palmata, a branching coral abundant on shallow reef environments throughout the Caribbean, is susceptible to physical disturbance caused by storms. Accordingly, the survivorship and propagation of this species are tied to its capability to recover after fragmentation. Fragments of A. palmata comprised 40% of ramets within populations that had experienced recent storms. While the survivorship of A. palmata fragments was not directly related to the size of fragments, removal of fragments from areas where they settled was influenced by size. Survivorship of fragments was also affected by type of substratum; the greatest mortality (58% loss within the first month) was observed on sand, whereas fragments placed on top of live colonies of A. palmata fused to the underlying tissue and did not experience any losses. Fragments created by Hurricane Andrew on a Florida reef in August 1992 began developing new growth (proto-branches) 7 months after the storm. The number of proto-branches on fragments was dependent on size, but growth was not affected by the size of fragments. Growth-rates of proto-branches increased exponentially with time (1.7 cm year(-1) for 1993-1994, 2.7 cm year(-1) for 1994-1995, 4.2 cm year(-1) for 1995-1996, and 6.5 cm year(-1) for 1996-1997), taking over 4 years for proto-branches to achieve rates comparable to those of adult colonies on the same reef (6.9 cm year(-1)). In addition to the initial mortality and reduced growth-rates, fragmentation resulted in a loss of reproductive potential. Neither colonies that experienced severe fragmentation nor fragments contained gametes until 4 years after the initial damage. Although A. palmata may survive periodic fragmentation, the long-term effects of this process will depend ultimately on the balance between the benefits and costs of this process.

[Spatial distribution pattern of Pontania dolichura larvae and sampling technique].

PubMed

Zhang, Feng; Chen, Zhijie; Zhang, Shulian; Zhao, Huiyan

2006-03-01

In this paper, the spatial distribution pattern of Pontania dolichura larvae was analyzed with Taylor's power law, Iwao's distribution function, and six aggregation indexes. The results showed that the spatial distribution pattern of P. dolichura larvae was of aggregated, and the basic component of the distribution was individual colony, with the aggregation intensity increased with density. On branches, the aggregation was caused by the adult behavior of laying eggs and the spatial position of leaves, while on leaves, the aggregation was caused by the spatial position of news leaves in spring when m < 2.37, and by the spatial position of news leaves in spring and the behavior of eclosion and laying eggs when m > 2.37. By using the parameters alpha and beta in Iwao's m * -m regression equation, the optimal and sequential sampling numbers were determined.

Size-dependent physiological responses of the branching coral Pocillopora verrucosa to elevated temperature and PCO2.

PubMed

Edmunds, Peter J; Burgess, Scott C

2016-12-15

Body size has large effects on organism physiology, but these effects remain poorly understood in modular animals with complex morphologies. Using two trials of a ∼24 day experiment conducted in 2014 and 2015, we tested the hypothesis that colony size of the coral Pocillopora verrucosa affects the response of calcification, aerobic respiration and gross photosynthesis to temperature (∼26.5 and ∼29.7°C) and P CO 2  (∼40 and ∼1000 µatm). Large corals calcified more than small corals, but at a slower size-specific rate; area-normalized calcification declined with size. Whole-colony and area-normalized calcification were unaffected by temperature, P CO 2 , or the interaction between the two. Whole-colony respiration increased with colony size, but the slopes of these relationships differed between treatments. Area-normalized gross photosynthesis declined with colony size, but whole-colony photosynthesis was unaffected by P CO 2 , and showed a weak response to temperature. When scaled up to predict the response of large corals, area-normalized metrics of physiological performance measured using small corals provide inaccurate estimates of the physiological performance of large colonies. Together, these results demonstrate the importance of colony size in modulating the response of branching corals to elevated temperature and high P CO 2 . © 2016. Published by The Company of Biologists Ltd.

The effect of local hydrodynamics on the spatial extent and morphology of cold-water coral habitats at Tisler Reef, Norway

NASA Astrophysics Data System (ADS)

De Clippele, L. H.; Huvenne, V. A. I.; Orejas, C.; Lundälv, T.; Fox, A.; Hennige, S. J.; Roberts, J. M.

2018-03-01

This study demonstrates how cold-water coral morphology and habitat distribution are shaped by local hydrodynamics, using high-definition video from Tisler Reef, an inshore reef in Norway. A total of 334 video frames collected on the north-west (NW) and south-east (SE) side of the reef were investigated for Lophelia pertusa coral cover and morphology and for the cover of the associated sponges Mycale lingua and Geodia sp. Our results showed that the SE side was a better habitat for L. pertusa (including live and dead colonies). Low cover of Geodia sp. was found on both sides of Tisler Reef. In contrast, Mycale lingua had higher percentage cover, especially on the NW side of the reef. Bush-shaped colonies of L. pertusa with elongated branches were the most abundant coral morphology on Tisler Reef. The highest abundance and density of this morphology were found on the SE side of the reef, while a higher proportion of cauliflower-shaped corals with short branches were found on the NW side. The proportion of very small L. pertusa colonies was also significantly higher on the SE side of the reef. The patterns in coral spatial distribution and morphology were related to local hydrodynamics—there were more frequent periods of downwelling currents on the SE side—and to the availability of suitable settling substrates. These factors make the SE region of Tisler Reef more suitable for coral growth. Understanding the impact of local hydrodynamics on the spatial extent and morphology of coral, and their relation to associated organisms such as sponges, is key to understanding the past and future development of the reef.

Stabilization of growth of a pearlite colony because of interaction between carbon and lattice dilatations

NASA Astrophysics Data System (ADS)

Razumov, I. K.

2017-10-01

The previously proposed model of pearlite transformation develops taking into account the possible interaction between carbon and lattice dilatations arising in austenite near the pearlite colony. The normal stresses caused by the colony stimulate autocatalysis of plates, and tangential stresses promote the stabilization of the transformation front. The mechanism of ferrite branching, which can play an important role in the kinetics of pearlite and bainite transformations, is discussed.

Divergent branches of mitochondrial signaling regulate specific genes and the viability of specialized cell types of differentiated yeast colonies.

PubMed

Podholová, Kristýna; Plocek, Vítězslav; Rešetárová, Stanislava; Kučerová, Helena; Hlaváček, Otakar; Váchová, Libuše; Palková, Zdena

2016-03-29

Mitochondrial retrograde signaling mediates communication from altered mitochondria to the nucleus and is involved in many normal and pathophysiological changes, including cell metabolic reprogramming linked to cancer development and progression in mammals. The major mitochondrial retrograde pathway described in yeast includes three activators, Rtg1p, Rtg2p and Rtg3p, and repressors, Mks1p and Bmh1p/Bmh2p. Using differentiated yeast colonies, we show that Mks1p-Rtg pathway regulation is complex and includes three branches that divergently regulate the properties and fate of three specifically localized cell subpopulations via signals from differently altered mitochondria. The newly identified RTG pathway-regulated genes ATO1/ATO2 are expressed in colonial upper (U) cells, the cells with active TORC1 that metabolically resemble tumor cells, while CIT2 is a typical target induced in one subpopulation of starving lower (L) cells. The viability of the second L cell subpopulation is strictly dependent on RTG signaling. Additional co-activators of Rtg1p-Rtg3p specific to particular gene targets of each branch are required to regulate cell differentiation.

Expression and Functional Role of Sprouty-2 in Breast Morphogenesis

PubMed Central

Hilmarsdottir, Bylgja; Gustafsdottir, Sigrun M.; Franzdottir, Sigridur Rut; Arason, Ari Jon; Steingrimsson, Eirikur; Magnusson, Magnus K.; Gudjonsson, Thorarinn

2013-01-01

Branching morphogenesis is a mechanism used by many species for organogenesis and tissue maintenance. Receptor tyrosine kinases (RTKs), including epidermal growth factor receptor (EGFR) and the sprouty protein family are believed to be critical regulators of branching morphogenesis. The aim of this study was to analyze the expression of Sprouty-2 (SPRY2) in the mammary gland and study its role in branching morphogenesis. Human breast epithelial cells, breast tissue and mouse mammary glands were used for expression studies using immunoblotting, real rime PCR and immunohistochemistry. Knockdown of SPRY2 in the breast epithelial stem cell line D492 was done by lentiviral transduction of shRNA constructs targeting SPRY2. Three dimensional culture of D492 with or without endothelial cells was done in reconstituted basement membrane matrix. We show that in the human breast, SPRY2 is predominantly expressed in the luminal epithelial cells of both ducts and lobuli. In the mouse mammary gland, SPRY2 expression is low or absent in the virgin state, while in the pregnant mammary gland SPRY2 is expressed at branching epithelial buds with increased expression during lactation. This expression pattern is closely associated with the activation of the EGFR pathway. Using D492 which generates branching structures in three-dimensional (3D) culture, we show that SPRY2 expression is low during initiation of branching with subsequent increase throughout the branching process. Immunostaining locates expression of phosphorylated SPRY2 and EGFR at the tip of lobular-like, branching ends. SPRY2 knockdown (KD) resulted in increased migration, increased pERK and larger and more complex branching structures indicating a loss of negative feedback control during branching morphogenesis. In D492 co-cultures with endothelial cells, D492 SPRY2 KD generates spindle-like colonies that bear hallmarks of epithelial to mesenchymal transition. These data indicate that SPRY2 is an important regulator of branching morphogenesis and epithelial to mesenchymal transition in the mammary gland. PMID:23573284

Expression and functional role of sprouty-2 in breast morphogenesis.

PubMed

Sigurdsson, Valgardur; Ingthorsson, Saevar; Hilmarsdottir, Bylgja; Gustafsdottir, Sigrun M; Franzdottir, Sigridur Rut; Arason, Ari Jon; Steingrimsson, Eirikur; Magnusson, Magnus K; Gudjonsson, Thorarinn

2013-01-01

Branching morphogenesis is a mechanism used by many species for organogenesis and tissue maintenance. Receptor tyrosine kinases (RTKs), including epidermal growth factor receptor (EGFR) and the sprouty protein family are believed to be critical regulators of branching morphogenesis. The aim of this study was to analyze the expression of Sprouty-2 (SPRY2) in the mammary gland and study its role in branching morphogenesis. Human breast epithelial cells, breast tissue and mouse mammary glands were used for expression studies using immunoblotting, real rime PCR and immunohistochemistry. Knockdown of SPRY2 in the breast epithelial stem cell line D492 was done by lentiviral transduction of shRNA constructs targeting SPRY2. Three dimensional culture of D492 with or without endothelial cells was done in reconstituted basement membrane matrix. We show that in the human breast, SPRY2 is predominantly expressed in the luminal epithelial cells of both ducts and lobuli. In the mouse mammary gland, SPRY2 expression is low or absent in the virgin state, while in the pregnant mammary gland SPRY2 is expressed at branching epithelial buds with increased expression during lactation. This expression pattern is closely associated with the activation of the EGFR pathway. Using D492 which generates branching structures in three-dimensional (3D) culture, we show that SPRY2 expression is low during initiation of branching with subsequent increase throughout the branching process. Immunostaining locates expression of phosphorylated SPRY2 and EGFR at the tip of lobular-like, branching ends. SPRY2 knockdown (KD) resulted in increased migration, increased pERK and larger and more complex branching structures indicating a loss of negative feedback control during branching morphogenesis. In D492 co-cultures with endothelial cells, D492 SPRY2 KD generates spindle-like colonies that bear hallmarks of epithelial to mesenchymal transition. These data indicate that SPRY2 is an important regulator of branching morphogenesis and epithelial to mesenchymal transition in the mammary gland.

Morphological Diversity of the Colony Produced by Bacteria Proteus mirabilis

NASA Astrophysics Data System (ADS)

Nakahara, Akio; Shimada, Yuji; Wakita, Jun-ichi; Matsushita, Mitsugu; Matsuyama, Tohey

1996-08-01

Morphological changes of colonies have been investigatedfor a bacterial strain of Proteus mirabilis, which is a famous speciesfor producing concentric-ring-like colonies. It was found that colony patterns can be classified into three types,i.e., cyclic spreading, diffusion-limited growth (DLA-like)and three-dimensional growth (inside the agar medium) patterns. Cyclic spreading patterns can further be classifiedinto three subgroups, i.e., concentric-ring, homogeneous and spatiotemporal patterns. These subgroups were classified by examining the development of colony structure after colonies spread all over petri-dishes. Comparison of the results with thoseof another bacterial species Bacillus subtilis is also discussed.

Turing mechanism underlying a branching model for lung morphogenesis.

PubMed

Xu, Hui; Sun, Mingzhu; Zhao, Xin

2017-01-01

The mammalian lung develops through branching morphogenesis. Two primary forms of branching, which occur in order, in the lung have been identified: tip bifurcation and side branching. However, the mechanisms of lung branching morphogenesis remain to be explored. In our previous study, a biological mechanism was presented for lung branching pattern formation through a branching model. Here, we provide a mathematical mechanism underlying the branching patterns. By decoupling the branching model, we demonstrated the existence of Turing instability. We performed Turing instability analysis to reveal the mathematical mechanism of the branching patterns. Our simulation results show that the Turing patterns underlying the branching patterns are spot patterns that exhibit high local morphogen concentration. The high local morphogen concentration induces the growth of branching. Furthermore, we found that the sparse spot patterns underlie the tip bifurcation patterns, while the dense spot patterns underlies the side branching patterns. The dispersion relation analysis shows that the Turing wavelength affects the branching structure. As the wavelength decreases, the spot patterns change from sparse to dense, the rate of tip bifurcation decreases and side branching eventually occurs instead. In the process of transformation, there may exists hybrid branching that mixes tip bifurcation and side branching. Since experimental studies have reported that branching mode switching from side branching to tip bifurcation in the lung is under genetic control, our simulation results suggest that genes control the switch of the branching mode by regulating the Turing wavelength. Our results provide a novel insight into and understanding of the formation of branching patterns in the lung and other biological systems.

Growth pattern of the surface of fungus Aspergillus colony

NASA Astrophysics Data System (ADS)

Matsuura, Shu; Miyazima, Sasuke

1992-05-01

Aspergillus oryzae colonies were grown under various glucose concentrations, temperatures, and agar concentrations, and the effects on the pattern were investigated. Patterns of colony were found to vary from uniform to diffusion-limited aggregation type.

Geographic and habitat partitioning of genetically distinct zooxanthellae (Symbiodinium) in Acropora corals on the Great Barrier Reef.

PubMed

Ulstrup, K E; Van Oppen, M J H

2003-12-01

Intra- and intercolony diversity and distribution of zooxanthellae in acroporid corals is largely uncharted. In this study, two molecular methods were applied to determine the distribution of zooxanthellae in the branching corals Acropora tenuis and A. valida at several reef locations in the central section of the Great Barrier Reef. Sun-exposed and shaded parts of all colonies were examined. Single-stranded conformational polymorphism analysis showed that individual colonies of A. tenuis at two locations harbour two strains of Symbiodinium belonging to clade C (C1 and C2), whereas conspecific colonies at two other reefs harboured a single zooxanthella strain. A. valida was found to simultaneously harbour strains belonging to two distinct phylogenetic clades (C and D) at all locations sampled. A novel method with improved sensitivity (quantitative polymerase chain reaction using Taqman fluorogenic probes) was used to map the relative abundance distribution of the two zooxanthella clades. At two of the five sampling locations both coral species were collected. At these two locations, composition of the zooxanthella communities showed the same pattern in both coral species, i.e. correlation with ambient light in Pioneer Bay and an absence thereof in Nelly Bay. The results show that the distribution of genetically distinct zooxanthellae is correlated with light regime and possibly temperature in some (but not all) colonies of A. tenuis and A. valida and at some reef locations, which we interpret as acclimation to local environmental conditions.

Origins and relationships of colonial Heliophyllum in the upper Middle Devonian (Givetian) of New York

USGS Publications Warehouse

Oliver, W.A.

1997-01-01

Heliophyllum halli Milne-Edwards and Haime is common to abundant in many Lower and Middle Devonian stratigraphic units in New York. Most Heliophyllum are solitary, but both branching and massive colonies are known. Four 'populations' of colonial Heliophyllum in the Givetian part of the sequence are distinct, as is a fifth form that occurs through the section. Each of the colonial forms is interpreted as an independent derivative of solitary forms of H. halli. The relationships appear to range from infrasubspecific to specific, and it is suggested that the complex should be recognized as the Heliophyllum halli species group.

Colony patterning and collective hyphal growth of filamentous fungi

NASA Astrophysics Data System (ADS)

Matsuura, Shu

2002-11-01

Colony morphology of wild and mutant strains of Aspergillus nidulans at various nutrient and agar levels was investigated. Two types of colony patterning were found for these strains. One type produced uniform colonies at all nutrient and agar levels tested, and the other exhibited morphological change into disordered ramified colonies at low nutrient levels. Both types showed highly condensed compact colonies at high nutrient levels on low agar media that was highly diffusive. Disordered colonies were found to develop with low hyphal extension rates at low nutrient levels. To understand basic pattern selection rules, a colony model with three parameters, i.e., the initial nutrient level and the step length of nutrient random walk as the external parameters, and the frequency of nutrient uptake as an internal parameter, was constructed. At low nutrient levels, with decreasing nutrient uptake frequency under diffusive conditions, the model colony exhibited onsets of disordered ramification. Further, in the growth process of A. nidulans, reduction of hyphal extension rate due to a population effect of hyphae was found when hyphae form three-dimensional dense colonies, as compared to the case in which hyphal growth was restricted into two-dimensional space. A hyphal population effect was introduced in the colony model. Thickening of colony periphery due to the population effect became distinctive as the nutrient diffusion effect was raised at high nutrient levels with low hyphal growth rate. It was considered that colony patterning and onset of disorder were strongly governed by the combination of nutrient diffusion and hyphal growth rate.

Environmental influences on the Indo–Pacific octocoral Isis hippuris Linnaeus 1758 (Alcyonacea: Isididae): genetic fixation or phenotypic plasticity?

PubMed Central

Pochon, Xavier; Watling, Les

2015-01-01

As conspicuous modular components of benthic marine habitats, gorgonian (sea fan) octocorals have perplexed taxonomists for centuries through their shear diversity, particularly throughout the Indo–Pacific. Phenotypic incongruence within and between seemingly unitary lineages across contrasting environments can provide the raw material to investigate processes of disruptive selection. Two distinct phenotypes of the Isidid Isis hippuris Linnaeus, 1758 partition between differing reef environments: long-branched bushy colonies on degraded reefs, and short-branched multi/planar colonies on healthy reefs within the Wakatobi Marine National Park (WMNP), Indonesia. Multivariate analyses reveal phenotypic traits between morphotypes were likely integrated primarily at the colony level with increased polyp density and consistently smaller sclerite dimensions at the degraded site. Sediment load and turbidity, hence light availability, primarily influenced phenotypic differences between the two sites. This distinct morphological dissimilarity between the two sites is a reliable indicator of reef health; selection primarily acting on colony morphology, porosity through branching structure, as well as sclerite diversity and size. ITS2 sequence and predicted RNA secondary structure further revealed intraspecific variation between I. hippuris morphotypes relative to such environments (ΦST = 0.7683, P < 0.001). This evidence suggests—but does not confirm—that I. hippuris morphotypes within the WMNP are two separate species; however, to what extent and taxonomic assignment requires further investigation across its full geographic distribution. Incongruence between colonies present in the WMNP with tenuously described Isis alternatives (Isis reticulata Nutting, 1910, Isis minorbrachyblasta Zou, Huang & Wang, 1991), questions the validity of such assignments. Furthermore, phylogenetic analyses confirm early taxonomic suggestion that the characteristic jointed axis of the Isididae is in fact a convergent trait. Thus the polyphyletic nature of the Isididae lies in its type species I. hippuris, being unrelated to the rest of its family members. PMID:26312170

Environmental influences on the Indo-Pacific octocoral Isis hippuris Linnaeus 1758 (Alcyonacea: Isididae): genetic fixation or phenotypic plasticity?

PubMed

Rowley, Sonia J; Pochon, Xavier; Watling, Les

2015-01-01

As conspicuous modular components of benthic marine habitats, gorgonian (sea fan) octocorals have perplexed taxonomists for centuries through their shear diversity, particularly throughout the Indo-Pacific. Phenotypic incongruence within and between seemingly unitary lineages across contrasting environments can provide the raw material to investigate processes of disruptive selection. Two distinct phenotypes of the Isidid Isis hippurisLinnaeus, 1758 partition between differing reef environments: long-branched bushy colonies on degraded reefs, and short-branched multi/planar colonies on healthy reefs within the Wakatobi Marine National Park (WMNP), Indonesia. Multivariate analyses reveal phenotypic traits between morphotypes were likely integrated primarily at the colony level with increased polyp density and consistently smaller sclerite dimensions at the degraded site. Sediment load and turbidity, hence light availability, primarily influenced phenotypic differences between the two sites. This distinct morphological dissimilarity between the two sites is a reliable indicator of reef health; selection primarily acting on colony morphology, porosity through branching structure, as well as sclerite diversity and size. ITS2 sequence and predicted RNA secondary structure further revealed intraspecific variation between I. hippuris morphotypes relative to such environments (ΦST = 0.7683, P < 0.001). This evidence suggests-but does not confirm-that I. hippuris morphotypes within the WMNP are two separate species; however, to what extent and taxonomic assignment requires further investigation across its full geographic distribution. Incongruence between colonies present in the WMNP with tenuously described Isis alternatives (Isis reticulataNutting, 1910, Isis minorbrachyblastaZou, Huang & Wang, 1991), questions the validity of such assignments. Furthermore, phylogenetic analyses confirm early taxonomic suggestion that the characteristic jointed axis of the Isididae is in fact a convergent trait. Thus the polyphyletic nature of the Isididae lies in its type species I. hippuris, being unrelated to the rest of its family members.

Construction of high-density bacterial colony arrays and patterns by the ink-jet method.

PubMed

Xu, Tao; Petridou, Sevastioni; Lee, Eric H; Roth, Elizabeth A; Vyavahare, Narendra R; Hickman, James J; Boland, Thomas

2004-01-05

We have developed a method for fabricating bacterial colony arrays and complex patterns using commercially available ink-jet printers. Bacterial colony arrays with a density of 100 colonies/cm(2) were obtained by directly ejecting Escherichia coli (E. coli) onto agar-coated substrates at a rapid arraying speed of 880 spots per second. Adjusting the concentration of bacterial suspensions allowed single colonies of viable bacteria to be obtained. In addition, complex patterns of viable bacteria as well as bacteria density gradients were constructed using desktop printers controlled by a simple software program. Copyright 2003 Wiley Periodicals, Inc.

Novel Perspectives on the Characterization of Species-Dependent Optical Signatures of Bacterial Colonies by Digital Holography.

PubMed

Buzalewicz, Igor; Kujawińska, Małgorzata; Krauze, Wojciech; Podbielska, Halina

2016-01-01

The use of light diffraction for the microbiological diagnosis of bacterial colonies was a significant breakthrough with widespread implications for the food industry and clinical practice. We previously confirmed that optical sensors for bacterial colony light diffraction can be used for bacterial identification. This paper is focused on the novel perspectives of this method based on digital in-line holography (DIH), which is able to reconstruct the amplitude and phase properties of examined objects, as well as the amplitude and phase patterns of the optical field scattered/diffracted by the bacterial colony in any chosen observation plane behind the object from single digital hologram. Analysis of the amplitude and phase patterns inside a colony revealed its unique optical properties, which are associated with the internal structure and geometry of the bacterial colony. Moreover, on a computational level, it is possible to select the desired scattered/diffracted pattern within the entire observation volume that exhibits the largest amount of unique, differentiating bacterial features. These properties distinguish this method from the already proposed sensing techniques based on light diffraction/scattering of bacterial colonies. The reconstructed diffraction patterns have a similar spatial distribution as the recorded Fresnel patterns, previously applied for bacterial identification with over 98% accuracy, but they are characterized by both intensity and phase distributions. Our results using digital holography provide new optical discriminators of bacterial species revealed in one single step in form of new optical signatures of bacterial colonies: digital holograms, reconstructed amplitude and phase patterns, as well as diffraction patterns from all observation space, which exhibit species-dependent features. To the best of our knowledge, this is the first report on bacterial colony analysis via digital holography and our study represents an innovative approach to the subject.

Novel Perspectives on the Characterization of Species-Dependent Optical Signatures of Bacterial Colonies by Digital Holography

PubMed Central

Buzalewicz, Igor; Kujawińska, Małgorzata; Krauze, Wojciech; Podbielska, Halina

2016-01-01

The use of light diffraction for the microbiological diagnosis of bacterial colonies was a significant breakthrough with widespread implications for the food industry and clinical practice. We previously confirmed that optical sensors for bacterial colony light diffraction can be used for bacterial identification. This paper is focused on the novel perspectives of this method based on digital in-line holography (DIH), which is able to reconstruct the amplitude and phase properties of examined objects, as well as the amplitude and phase patterns of the optical field scattered/diffracted by the bacterial colony in any chosen observation plane behind the object from single digital hologram. Analysis of the amplitude and phase patterns inside a colony revealed its unique optical properties, which are associated with the internal structure and geometry of the bacterial colony. Moreover, on a computational level, it is possible to select the desired scattered/diffracted pattern within the entire observation volume that exhibits the largest amount of unique, differentiating bacterial features. These properties distinguish this method from the already proposed sensing techniques based on light diffraction/scattering of bacterial colonies. The reconstructed diffraction patterns have a similar spatial distribution as the recorded Fresnel patterns, previously applied for bacterial identification with over 98% accuracy, but they are characterized by both intensity and phase distributions. Our results using digital holography provide new optical discriminators of bacterial species revealed in one single step in form of new optical signatures of bacterial colonies: digital holograms, reconstructed amplitude and phase patterns, as well as diffraction patterns from all observation space, which exhibit species-dependent features. To the best of our knowledge, this is the first report on bacterial colony analysis via digital holography and our study represents an innovative approach to the subject. PMID:26943121

Element patterns in feathers of nestling Black-Crowned Night-Herons, Nycticorax nycticorax L., from four colonies in Delaware, Maryland, and Minnesota

USGS Publications Warehouse

Custer, Thomas W.; Golden, Nancy H.; Rattner, Barnett A.

2008-01-01

The pattern of elements in nestling black-crowned night-heron feathers from a rural Minnesota colony differed from colonies in industrialized regions of Maryland and Delaware. Except for chromium, however, the differences did not reflect the elements associated with waters and sediments of the Maryland and Delaware colonies. Therefore, elements in water and sediment do not necessarily bioaccumulate in night-heron feathers in relation to potential exposure. Although trace element patterns in feathers indicated differences among geographical locations, they did not separate all locations well and their usefulness as an indicator of natal colony location may be limited.

Habitat Selectivity and Reliance on Live Corals for Indo-Pacific Hawkfishes (Family: Cirrhitidae).

PubMed

Coker, Darren J; Hoey, Andrew S; Wilson, Shaun K; Depczynski, Martial; Graham, Nicholas A J; Hobbs, Jean-Paul A; Holmes, Thomas H; Pratchett, Morgan S

2015-01-01

Hawkfishes (family: Cirrhitidae) are small conspicuous reef predators that commonly perch on, or shelter within, the branches of coral colonies. This study examined habitat associations of hawkfishes, and explicitly tested whether hawkfishes associate with specific types of live coral. Live coral use and habitat selectivity of hawkfishes was explored at six locations from Chagos in the central Indian Ocean extending east to Fiji in the Pacific Ocean. A total of 529 hawkfishes from seven species were recorded across all locations with 63% of individuals observed perching on, or sheltering within, live coral colonies. Five species (all except Cirrhitus pinnulatus and Cirrhitichthys oxycephalus) associated with live coral habitats. Cirrhitichthys falco selected for species of Pocillopora while Paracirrhites arcatus and P. forsteri selected for both Pocillopora and Acropora, revealing that these habitats are used disproportionately more than expected based on the local cover of these coral genera. Habitat selection was consistent across geographic locations, and species of Pocillopora were the most frequently used and most consistently selected even though this coral genus never comprised more than 6% of the total coral cover at any of the locations. Across locations, Paracirrhites arcatus and P. forsteri were the most abundant species and variation in their abundance corresponded with local patterns of live coral cover and abundance of Pocilloporid corals, respectively. These findings demonstrate the link between small predatory fishes and live coral habitats adding to the growing body of literature highlighting that live corals (especially erect branching corals) are critically important for sustaining high abundance and diversity of fishes on coral reefs.

Three ancient hormonal cues co-ordinate shoot branching in a moss.

PubMed

Coudert, Yoan; Palubicki, Wojtek; Ljung, Karin; Novak, Ondrej; Leyser, Ottoline; Harrison, C Jill

2015-03-25

Shoot branching is a primary contributor to plant architecture, evolving independently in flowering plant sporophytes and moss gametophytes. Mechanistic understanding of branching is largely limited to flowering plants such as Arabidopsis, which have a recent evolutionary origin. We show that in gametophytic shoots of Physcomitrella, lateral branches arise by re-specification of epidermal cells into branch initials. A simple model co-ordinating the activity of leafy shoot tips can account for branching patterns, and three known and ancient hormonal regulators of sporophytic branching interact to generate the branching pattern- auxin, cytokinin and strigolactone. The mode of auxin transport required in branch patterning is a key divergence point from known sporophytic pathways. Although PIN-mediated basipetal auxin transport regulates branching patterns in flowering plants, this is not so in Physcomitrella, where bi-directional transport is required to generate realistic branching patterns. Experiments with callose synthesis inhibitors suggest plasmodesmal connectivity as a potential mechanism for transport.

Laser-induced speckle scatter patterns in Bacillus colonies

PubMed Central

Kim, Huisung; Singh, Atul K.; Bhunia, Arun K.; Bae, Euiwon

2014-01-01

Label-free bacterial colony phenotyping technology called BARDOT (Bacterial Rapid Detection using Optical scattering Technology) provided successful classification of several different bacteria at the genus, species, and serovar level. Recent experiments with colonies of Bacillus species provided strikingly different characteristics of elastic light scatter (ELS) patterns, which were comprised of random speckles compared to other bacteria, which are dominated by concentric rings and spokes. Since this laser-based optical sensor interrogates the whole volume of the colony, 3-D information of micro- and macro-structures are all encoded in the far-field scatter patterns. Here, we present a theoretical model explaining the underlying mechanism of the speckle formation by the colonies from Bacillus species. Except for Bacillus polymyxa, all Bacillus spp. produced random bright spots on the imaging plane, which presumably dependent on the cellular and molecular organization and content within the colony. Our scatter model-based analysis revealed that colony spread resulting in variable surface roughness can modify the wavefront of the scatter field. As the center diameter of the Bacillus spp. colony grew from 500 to 900 μm, average speckles area decreased two-fold and the number of small speckles increased seven-fold. In conclusion, as Bacillus colony grows, the average speckle size in the scatter pattern decreases and the number of smaller speckle increases due to the swarming growth characteristics of bacteria within the colony. PMID:25352840

Development of bacterial colony phenotyping instrument using reflected scatter light

NASA Astrophysics Data System (ADS)

Doh, Iyll-Joon

Bacterial rapid detection using optical scattering technology (BARDOT) involves in differentiating elastic scattering pattern of bacterial colony. This elastic light scatter technology has shown promising label-free classification rate. However, there is limited success in certain circumstances where either a growth media or a colony has higher opacity. This situation is due to the physical principles of the current BARDOT which mainly relies on optical patterns generated by transmitted signals. Incoming light is obstructed and cannot be transmitted through the dense bacterial colonies, such as Lactobacillus, Yeast, mold and soil bacteria. Moreover, a blood agar, widely used in clinical field, is an example of an opaque media that does not allow light to be transmitted through. Therefore, in this research, a newly designed reflection type scatterometer is presented. The reflection type scatterometer measures the elastic scattering pattern generated by reflected signal. A theoretical model to study the optical pattern characteristic with respect to bacterial colony morphology is presented. Both theoretical and experiment results show good agreement that the size of backward scattering pattern has positive correlation to colony aspect ratio, a colony elevation to diameter ratio. Four pathogenic bacteria on blood agar, Escherichia coli K12, Listeria innocua, Salmonella Typhimurium, and Staphylococcus aureus, are tested and measured with proposed instrument. The measured patterns are analyzed with a classification software, and high classification rate can be achieved.

[Application and analysis of abdominal aortic branch malperfusion pattern in thoracic endovascular aortic repair for Stanford B aortic dissection].

PubMed

Han, X F; Guo, X; Li, T Z; Liu, G R; Huang, L J

2017-12-18

To evaluate the efficiency of thoracic endovascular aortic repair (TEVAR) in dealing with abdominal aortic branch malperfusion based on the analysis of aortic computed tomography angiography (CTA) images in pre- and post-TEVAR. Retrospective analysis from September 2015 to March 2016 in single institution to 32 patients, diagnosed as Stanford B aortic dissection with abdominal aortic branch malperfusion, CTA images in pre- and post-TEVAR were collected. Based on the aortic branch malperfusion pattern redefined by Nagamine, we identified and characterized branch malperfusion pattern for four abdominal aortic branches (celiac trunk, superior mesenteric artery, bilateral renal artery) in statistical analysis. In the four abdominal aortic branches (total 128 branches), 86 branches (67.2%) expressed with Class I patterns, in which subtype I-b presented with 0.8%, subtype I-c with 5.5%; 14 branches (10.9%) expressed with Class II patterns, in which subtype II-b-1 with 3.9%, subtype II-b-2 with 3.1%; 16 branches (12.5%) expressed with Class III patterns, all with subtype III-a, no subtype III-b and III-c presented. The remaining 12 branches were normal. The 100% successful rate of TEVAR obtained in 32 patients performed. The mean following-up was 4 months. Aortic CTA showed that among the 14 "high-risk" abdominal aortic branch malperfusion, 13 (92.9%) with obvious branch malperfusion in post-TEVAR were observed to improve, and the remaining one branch malperfusion (7.1%) was observed to change from subtype I-b to I-c. Few ratios in abdominal aortic branches suffered with obvious malperfusion complicated by Stanford B aortic dissection. For branches with "high-risk" malperfusion pattern, optimal changes were observed in abdominal aortic branch without revascularization in post-TEVAR, as well other branches with non-"high-risk" pattern perfusion were mostly stable in post-TEVAR. It could be of profound benefit to extend branch malperfusion patterns redefined by Nagamine in clinical practice to assess aortic dissection and in further guide for revascularization or not.

Three ancient hormonal cues co-ordinate shoot branching in a moss

PubMed Central

Coudert, Yoan; Palubicki, Wojtek; Ljung, Karin; Novak, Ondrej; Leyser, Ottoline; Harrison, C Jill

2015-01-01

Shoot branching is a primary contributor to plant architecture, evolving independently in flowering plant sporophytes and moss gametophytes. Mechanistic understanding of branching is largely limited to flowering plants such as Arabidopsis, which have a recent evolutionary origin. We show that in gametophytic shoots of Physcomitrella, lateral branches arise by re-specification of epidermal cells into branch initials. A simple model co-ordinating the activity of leafy shoot tips can account for branching patterns, and three known and ancient hormonal regulators of sporophytic branching interact to generate the branching pattern- auxin, cytokinin and strigolactone. The mode of auxin transport required in branch patterning is a key divergence point from known sporophytic pathways. Although PIN-mediated basipetal auxin transport regulates branching patterns in flowering plants, this is not so in Physcomitrella, where bi-directional transport is required to generate realistic branching patterns. Experiments with callose synthesis inhibitors suggest plasmodesmal connectivity as a potential mechanism for transport. DOI: http://dx.doi.org/10.7554/eLife.06808.001 PMID:25806686

Burkholderia pseudomallei Colony Morphotypes Show a Synchronized Metabolic Pattern after Acute Infection

PubMed Central

Steinmetz, Ivo; Lalk, Michael

2016-01-01

Background Burkholderia pseudomallei is a water and soil bacterium and the causative agent of melioidosis. A characteristic feature of this bacterium is the formation of different colony morphologies which can be isolated from environmental samples as well as from clinical samples, but can also be induced in vitro. Previous studies indicate that morphotypes can differ in a number of characteristics such as resistance to oxidative stress, cellular adhesion and intracellular replication. Yet the metabolic features of B. pseudomallei and its different morphotypes have not been examined in detail so far. Therefore, this study aimed to characterize the exometabolome of B. pseudomallei morphotypes and the impact of acute infection on their metabolic characteristics. Methods and Principal Findings We applied nuclear magnetic resonance spectroscopy (1H-NMR) in a metabolic footprint approach to compare nutrition uptake and metabolite secretion of starvation induced morphotypes of the B. pseudomallei strains K96243 and E8. We observed gluconate production and uptake in all morphotype cultures. Our study also revealed that among all morphotypes amino acids could be classified with regard to their fast and slow consumption. In addition to these shared metabolic features, the morphotypes varied highly in amino acid uptake profiles, secretion of branched chain amino acid metabolites and carbon utilization. After intracellular passage in vitro or murine acute infection in vivo, we observed a switch of the various morphotypes towards a single morphotype and a synchronization of nutrient uptake and metabolite secretion. Conclusion To our knowledge, this study provides first insights into the basic metabolism of B. pseudomallei and its colony morphotypes. Furthermore, our data suggest, that acute infection leads to the synchronization of B. pseudomallei colony morphology and metabolism through yet unknown host signals and bacterial mechanisms. PMID:26943908

The causes of spatial patterning of mounds of a fungus-cultivating termite: results from nearest-neighbour analysis and ecological studies.

PubMed

Korb, Judith; Linsenmair, Karl Eduard

2001-05-01

Little is known about processes regulating population dynamics in termites. We investigated the distribution of mound-colonies of the fungus-cultivating termite Macrotermes bellicosus (Smeathman) in two habitats in the Comoé National Park (Côte d'Ivoire) with nearest-neighbour analysis differentiating between different age classes. These results were compared with ecological data on processes influencing population dynamics. High mound densities were recorded in shrub savannah while only a few mounds were found in gallery forest. Mounds were distributed randomly in both habitats when all mounds were considered together, and when inhabited and uninhabited mounds were treated separately. However, distinctive non-random patterns were revealed in the savannah when we distinguished between different age classes. Small, young colonies were aggregated when they coexisted with larger, older colonies, which were more regularly distributed. This indicates that the distribution of older colonies is influenced by intraspecific competition whereas that of younger colonies is influenced by opposing factors that lead to aggregation. This is in accordance with ecological data. Food is a limiting resource for large colonies, while patchily distributed appropriate microclimatic conditions seem to be more important for young colonies. Colonies that had formerly coexisted (i.e. living colonies and recently dead colonies) showed aggregated, random and regular distribution patterns, suggesting several causes of mortality. Colonies that had never had contact with each other were randomly distributed and no specific regulation mechanism was implicated. These results show that different age classes seem to be regulated by different processes and that separation between age classes is necessary to reveal indicative spatial patterns in nearest-neighbour analysis.

Automated branching pattern report generation for laparoscopic surgery assistance

NASA Astrophysics Data System (ADS)

Oda, Masahiro; Matsuzaki, Tetsuro; Hayashi, Yuichiro; Kitasaka, Takayuki; Misawa, Kazunari; Mori, Kensaku

2015-05-01

This paper presents a method for generating branching pattern reports of abdominal blood vessels for laparoscopic gastrectomy. In gastrectomy, it is very important to understand branching structure of abdominal arteries and veins, which feed and drain specific abdominal organs including the stomach, the liver and the pancreas. In the real clinical stage, a surgeon creates a diagnostic report of the patient anatomy. This report summarizes the branching patterns of the blood vessels related to the stomach. The surgeon decides actual operative procedure. This paper shows an automated method to generate a branching pattern report for abdominal blood vessels based on automated anatomical labeling. The report contains 3D rendering showing important blood vessels and descriptions of branching patterns of each vessel. We have applied this method for fifty cases of 3D abdominal CT scans and confirmed the proposed method can automatically generate branching pattern reports of abdominal arteries.

Growth Dynamics of the Threatened Caribbean Staghorn Coral Acropora cervicornis: Influence of Host Genotype, Symbiont Identity, Colony Size, and Environmental Setting

PubMed Central

Lirman, Diego; Schopmeyer, Stephanie; Galvan, Victor; Drury, Crawford; Baker, Andrew C.; Baums, Iliana B.

2014-01-01

Background The drastic decline in the abundance of Caribbean acroporid corals (Acropora cervicornis, A. palmata) has prompted the listing of this genus as threatened as well as the development of a regional propagation and restoration program. Using in situ underwater nurseries, we documented the influence of coral genotype and symbiont identity, colony size, and propagation method on the growth and branching patterns of staghorn corals in Florida and the Dominican Republic. Methodology/Principal Findings Individual tracking of> 1700 nursery-grown staghorn fragments and colonies from 37 distinct genotypes (identified using microsatellites) in Florida and the Dominican Republic revealed a significant positive relationship between size and growth, but a decreasing rate of productivity with increasing size. Pruning vigor (enhanced growth after fragmentation) was documented even in colonies that lost 95% of their coral tissue/skeleton, indicating that high productivity can be maintained within nurseries by sequentially fragmenting corals. A significant effect of coral genotype was documented for corals grown in a common-garden setting, with fast-growing genotypes growing up to an order of magnitude faster than slow-growing genotypes. Algal-symbiont identity established using qPCR techniques showed that clade A (likely Symbiodinium A3) was the dominant symbiont type for all coral genotypes, except for one coral genotype in the DR and two in Florida that were dominated by clade C, with A- and C-dominated genotypes having similar growth rates. Conclusion/Significance The threatened Caribbean staghorn coral is capable of extremely fast growth, with annual productivity rates exceeding 5 cm of new coral produced for every cm of existing coral. This species benefits from high fragment survivorship coupled by the pruning vigor experienced by the parent colonies after fragmentation. These life-history characteristics make A. cervicornis a successful candidate nursery species and provide optimism for the potential role that active propagation can play in the recovery of this keystone species. PMID:25268812

Predation by feeding aggregations of Drupella spp. inhibits the recovery of reefs damaged by a mass bleaching event

NASA Astrophysics Data System (ADS)

Bruckner, Andrew W.; Coward, Georgia; Bimson, Kathyrn; Rattanawongwan, Tipwimon

2017-12-01

High densities of two corallivorous gastropods, Drupella cornus and D. rugosa, may delay the recovery of coral reefs impacted by mass bleaching events by aggregating on the remaining corals. Following severe bleaching in April/May 2016 that resulted in the loss of up to 80% of the living coral cover from reefs in South Malé, Maldives, aggregations of up to 250 Drupella per coral were recorded on surviving colonies. The distribution of snails was not random; larger aggregations were seen on reefs with fewer remaining live corals and also on the largest corals. Branching, digitate and tabular corals, especially species of Acropora and Pocillopora, sustained the highest mortality from the bleaching. Remaining colonies of these taxa exhibited the highest occurrence of snails and the most extensive snail predation, although less-preferred taxa such as Montipora, Porites, Astreopora, Cyphastrea and Pachyseris were also targeted. Drupella also concentrated on broken Acropora branches and overturned colonies; on some reefs, these were the only surviving acroporids, and many of them did not bleach. Continued predation pressure from Drupella may eliminate formerly dominant corals, including genets that are resistant to higher sea water temperatures.

Isolation of a Bacterial Strain Able To Degrade Branched Nonylphenol

PubMed Central

Tanghe, Tom; Dhooge, Willem; Verstraete, Willy

1999-01-01

Conventional enrichment of microorganisms on branched nonylphenol (NP) as only carbon and energy source yielded mixed cultures able to grow on the organic compound. However, plating yielded no single colonies capable, alone or in combination with other isolates, of degrading the NP in liquid culture. Therefore, a special approach was used, referred to as “serial dilution-plate resuspension,” to reduce culture complexity. In this way, one isolate, TTNP3, tentatively identified as a Sphingomonas sp., was found to be able to grow on NP in liquid culture. Remarkably, this isolate was able to be filtered through a 0.45-μm-pore-diameter filter. Moreover, isolate TTNP3 did not form visible colonies on mineral medium with NP, and it formed visible colonies on R2A agar only after a prolonged incubation of 1 week. High-performance liquid chromatography and gas chromatography-mass spectroscopy analysis of the culture media indicated that the strain starts the degradation of NP with a fission of the phenol ring and preferably uses the para isomer of NP and not the ortho isomer. No distinct accumulation of an intermediary product could be observed. PMID:9925611

Spatio-Temporal Patterns in Colonies of Rod-Shaped Bacteria

NASA Astrophysics Data System (ADS)

Kitsunezaki, S.

In incubation experiments of bacterial colonies of Proteus Mirabilis, macroscopic spatio-temporal patterns, such as turbulent and unidirectional spiral patterns, appear in colonies. Considering only kinetic propeties of rod-shaped bacteria, we propose a phenomenological model for the directional and positional distributions. As the average density increases, homogeneous states bifurcate sub-critically into nonuniform states exhibiting localized collective motion, and spiral patterns appear for sufficiently large density. These patterns result from interactions between the local bacteria densities and the order parameter representing collective motion. Our model can be described by reduced equations using a perturbative method for large density. The unidirectionality of sprial rotation is also discussed.

Concentrative nitrogen allocation to sun-lit branches and the effects on whole-plant growth under heterogeneous light environments.

PubMed

Sugiura, D; Tateno, M

2013-08-01

We investigated the nitrogen and carbohydrate allocation patterns of trees under heterogeneous light environments using saplings of the devil maple tree (Acer diabolicum) with Y-shaped branches. Different branch groups were created: all branches of a sapling exposed to full light (L-branches), all branches exposed to full shade (S-branches), and half of the branches of a sapling exposed to light (HL-branches) and the other half exposed to shade (HS-branches). Throughout the growth period, nitrogen was preferentially allocated to HL-branches, whereas nitrogen allocation to HS-branches was suppressed compared to L- and S-branches. HL-branches with the highest leaf nitrogen content (N(area)) also had the highest rates of growth, and HS-branches with the lowest N(area) had the lowest observed growth rates. In addition, net nitrogen assimilation, estimated using a photosynthesis model, was strongly correlated with branch growth and whole-plant growth. In contrast, patterns of photosynthate allocation to branches and roots were not affected by the light conditions of the other branch. These observations suggest that tree canopies develop as a result of resource allocation patterns, where the growth of sun-lit branches is favoured over shaded branches, which leads to enhanced whole-plant growth in heterogeneous light environments. Our results indicate that whole-plant growth is enhanced by the resource allocation patterns created for saplings in heterogeneous light environments.

Redox signaling in the growth and development of colonial hydroids.

PubMed

Blackstone, Neil W

2003-02-01

Redox signaling provides a quick and efficient mechanism for clonal or colonial organisms to adapt their growth and development to aspects of the environment, e.g. the food supply. A 'signature' of mitochondrial redox signaling, particularly as mediated by reactive oxygen species (ROS), can be elucidated by experimental manipulation of the electron transport chain. The major sites of ROS formation are found at NADH dehydrogenase of complex I and at the interface between coenzyme Q and complex III. Inhibitors of complex III should thus upregulate ROS from both sites; inhibitors of complex I should upregulate ROS from the first but not the second site, while uncouplers of oxidative phosphorylation should downregulate ROS from both sites. To investigate the possibility of such redox signaling, perturbations of colony growth and development were carried out using the hydroid Podocoryna carnea. Oxygen uptake of colonies was measured to determine comparable physiological doses of antimycin A(1) (an inhibitor of complex III), rotenone (an inhibitor of complex I) and carbonyl cyanide m-chlorophenylhydrazone (CCCP; an uncoupler of oxidative phosphorylation). Using these doses, clear effects on colony growth and development were obtained. Treatment with antimycin A(1) results in 'runner-like' colony growth, with widely spaced polyps and stolon branches, while treatment with CCCP results in 'sheet-like' growth, with closely spaced polyps and stolon branches. Parallel results have been obtained previously with azide, an inhibitor of complex IV, and dinitrophenol, another uncoupler of oxidative phosphorylation. Perhaps surprisingly, rotenone produced effects on colony development similar to those of CCCP. Assays of peroxides using 2',7'-dichlorofluorescin diacetate and fluorescent microscopy suggest a moderate difference in ROS formation between the antimycin and rotenone treatments. The second site of ROS formation (the interface between coenzyme Q and complex III) may thus predominate in the signaling that regulates colony development. The fat-rich, brine shrimp diet of these hydroids may be relevant in this context. Acyl CoA dehydrogenase, which catalyzes the first step in the mitochondrial beta-oxidation of fatty acids, carries electrons to coenzyme Q, thus bypassing complex I. These results support a role for redox signaling, mediated by ROS, in colony development. Nevertheless, other redox sensors between complexes I and III may yet be found.

Demography and life history characteristics of two honey bee races (Apis mellifera).

PubMed

Winston, Mark L; Dropkin, Jennifer A; Taylor, Orley R

1981-03-01

Intra-colony demography and life history characteristics of neotropical Africanized and temperate European honey bearaces were compared under simulated feral conditions. Major differences in colony demography were found which nevertheless resulted in some similar reproductive characteristics. European colonies were larger than Africanized colonies, had more rapid initral growth rates of worker populations, showed better survivorship of brood and adult workers, and differed in patterns of worker age distribution. However, both races were similar in the brood and adult populations when colonies swarmed, the frequency and timing of swarming, and the number of workers in prime swarms. The factors most important in determining these colony growth and reproductive patterns were likely worker mortality rates, climate, and resource availability.

Limits to physiological plasticity of the coral Pocillopora verrucosa from the central Red Sea

NASA Astrophysics Data System (ADS)

Ziegler, Maren; Roder, Cornelia M.; Büchel, Claudia; Voolstra, Christian R.

2014-12-01

Many coral species display changing distribution patterns across coral reef depths. While changes in the underwater light field and the ability to associate with different photosynthetic symbionts of the genus Symbiodinium explain some of the variation, the limits to physiological plasticity are unknown for most corals. In the central Red Sea, colonies of the branching coral Pocillopora verrucosa are most abundant in shallow high light environments and become less abundant in water depths below 10 m. To further understand what determines this narrow distribution, we conducted a cross-depths transplant experiment looking at physiological plasticity and acclimation in regard to depth. Colonies from 5, 10, and 20 m were collected, transplanted to all depths, and re-investigated after 30 and 210 d. All coral colonies transplanted downward from shallow to deep water displayed an increase in photosynthetic light-harvesting pigments, which resulted in higher photosynthetic efficiency. Shallow-water specimens transplanted to deeper water showed a significant decrease in total protein content after 30 and 210 d under low light conditions compared to specimens transplanted to shallow and medium depths. Stable isotope data suggest that heterotrophic input of carbon was not increased under low light, and consequently, decreasing protein levels were symptomatic of decreasing photosynthetic rates that could not be compensated for through higher light-harvesting efficiency. Our results provide insights into the physiological plasticity of P. verrucosa in changing light regimes and explain the observed depth distribution pattern. Despite its high abundance in shallow reef waters, P. verrucosa possesses limited heterotrophic acclimation potential, i.e., the ability to support its mainly photoautotrophic diet through heterotrophic feeding. We conclude that P. verrucosa might be a species vulnerable to sudden changes in underwater light fields resulting from processes such as increased turbidity caused by coastal development along the Saudi Arabian Red Sea coast.

Rapid detection of malignant bio-species using digital holographic pattern recognition and nano-photonics

NASA Astrophysics Data System (ADS)

Sarkisov, Sergey S.; Kukhtareva, Tatiana; Kukhtarev, Nickolai V.; Curley, Michael J.; Edwards, Vernessa; Creer, Marylyn

2013-03-01

There is a great need for rapid detection of bio-hazardous species particularly in applications to food safety and biodefense. It has been recently demonstrated that the colonies of various bio-species could be rapidly detected using culture-specific and reproducible patterns generated by scattered non-coherent light. However, the method heavily relies on a digital pattern recognition algorithm, which is rather complex, requires substantial computational power and is prone to ambiguities due to shift, scale, or orientation mismatch between the analyzed pattern and the reference from the library. The improvement could be made, if, in addition to the intensity of the scattered optical wave, its phase would be also simultaneously recorded and used for the digital holographic pattern recognition. In this feasibility study the research team recorded digital Gabor-type (in-line) holograms of colonies of micro-organisms, such as Salmonella with a laser diode as a low-coherence light source and a lensless high-resolution (2.0x2.0 micron pixel pitch) digital image sensor. The colonies were grown in conventional Petri dishes using standard methods. The digitally recorded holograms were used for computational reconstruction of the amplitude and phase information of the optical wave diffracted on the colonies. Besides, the pattern recognition of the colony fragments using the cross-correlation between the digital hologram was also implemented. The colonies of mold fungi Altenaria sp, Rhizophus, sp, and Aspergillus sp have been also generating nano-colloidal silver during their growth in specially prepared matrices. The silver-specific plasmonic optical extinction peak at 410-nm was also used for rapid detection and growth monitoring of the fungi colonies.

The effect of allometric scaling in coral thermal microenvironments

PubMed Central

Ong, Robert H.; Kaandorp, Jaap A.; Mullins, Benjamin J.; Caley, M. Julian

2017-01-01

A long-standing interest in marine science is in the degree to which environmental conditions of flow and irradiance, combined with optical, thermal and morphological characteristics of individual coral colonies, affects their sensitivity of thermal microenvironments and susceptibility to stress-induced bleaching within and/or among colonies. The physiological processes in Scleractinian corals tend to scale allometrically as a result of physical and geometric constraints on body size and shape. There is a direct relationship between scaling to thermal stress, thus, the relationship between allometric scaling and rates of heating and cooling in coral microenvironments is a subject of great interest. The primary aim of this study was to develop an approximation that predicts coral thermal microenvironments as a function of colony morphology (shape and size), light or irradiance, and flow velocity or regime. To do so, we provided intuitive interpretation of their energy budgets for both massive and branching colonies, and then quantified the heat-size exponent (b*) and allometric constant (m) using logarithmic linear regression. The data demonstrated a positive relationship between thermal rates and changes in irradiance, A/V ratio, and flow, with an interaction where turbulent regime had less influence on overall stress which may serve to ameliorate the effects of temperature rise compared to the laminar regime. These findings indicated that smaller corals have disproportionately higher stress, however they can reach thermal equilibrium quicker. Moreover, excellent agreements between the predicted and simulated microscale temperature values with no significant bias were observed for both the massive and branching colonies, indicating that the numerical approximation should be within the accuracy with which they could be measured. This study may assist in estimating the coral microscale temperature under known conditions of water flow and irradiance, in particular when examining the intra- and inter-colony variability found during periods of bleaching conditions. PMID:29023468

Investigation of multimodal forward scatter phenotyping from bacterial colonies

NASA Astrophysics Data System (ADS)

Kim, Huisung

A rapid, label-free, and elastic light scattering (ELS) based bacterial colony phenotyping technology, bacterial rapid detection using optical scattering technology (BARDOT) provides a successful classification of several bacterial genus and species. For a thorough understanding of the phenomena and overcoming the limitations of the previous design, five additional modalities from a bacterial colony: 3D morphology, spatial optical density (OD) distribution, spectral forward scattering pattern, spectral OD, and surface backward reflection pattern are proposed to enhance the classification/identification ratio, and the feasibilities of each modality are verified. For the verification, three different instruments: integrated colony morphology analyzer (ICMA), multi-spectral BARDOT (MS-BARDOT) , and multi-modal BARDOT (MM-BARDOT) are proposed and developed. The ICMA can measure 3D morphology and spatial OD distribution of the colony simultaneously. A commercialized confocal displacement meter is used to measure the profiles of the bacterial colonies, together with a custom built optical density measurement unit to interrogate the biophysics behind the collective behavior of a bacterial colony. The system delivers essential information related to the quantitative growth dynamics (height, diameter, aspect ratio, optical density) of the bacterial colony, as well as, a relationship in between the morphological characteristics of the bacterial colony and its forward scattering pattern. Two different genera: Escherichia coli O157:H7 EDL933, and Staphylococcus aureus ATCC 25923 are selected for the analysis of the spatially resolved growth dynamics, while, Bacillus spp. such as B. subtilis ATCC 6633, B. cereus ATCC 14579, B. thuringiensis DUP6044, B. polymyxa B719W, and B. megaterium DSP 81319, are interrogated since some of the Bacillus spp. provides strikingly different characteristics of ELS patterns, and the origin of the speckle patterns are successfully correlated with the 2-D spatial density map from the ICMA. The MS-BARDOT can measure multispectral elastic-light-scatter patterns of the bacterial colony and its spectral OD to overcome the inherent limits of the single-wavelength BARDOT. A theoretical model for spectral forward scatter patterns from a bacterial colony based on elastic light scatter is presented. The spectral forward scatter patterns are computed by scalar diffraction theory, and compared with experimental results of three discrete wavelengths (405 nm, 635 nm, and 904 nm). Both model and experiment results show an excellent agreement; a longer wavelength induces a wider ring width, a wider ring gap, a smaller pattern size, and smaller numbers of rings. Further analysis using spatial fast Fourier transform (SFFT) shows a good agreement; the spatial frequencies are increasing towards the inward direction, and the slope is inversely proportional to the incoming wavelength. Four major pathogenic bacterial genera (Escherichia coli O157:H7 EDL933, Listeria monocytogenes F4244, Salmonella enterica serovar Enteritidis PT21, and Staphylococcus aureus ATCC 25923) and the seven major Escherichia coli serovar (O26, O45, O103, O111, O121, O145, and O157) with 3-4 strains each are measured and analyzed with the proposed instrument and algorithm. The MM-BARDOT can measure six different modalities: 1) light microscopy, 2) 3D morphology map from confocal microscopy, 3) 3D optical density map, 4) spectral forward scattering pattern, 5) spectral OD, 6) surface backward reflection pattern, and 7) fluorescence of a bacterial colony without moving the specimen. A custom-built confocal microscope with a controller which can be easily attached to an infinity-corrected commercial microscope is designed and built. Since the current BARDOT needs additional information from a bacterial colony to enhance the identification/classification ratio for a lower hierarchy of bacterial taxonomy such as serovar or strain level, the approach can offer a series of coordinates matched and correlated bio-optical characteristics of a colony and enhance the classification accuracy of the previously introduced BARDOT system. Four major pathogenic bacterial genera: Escherichia coli O157:H7 EDL933, Listeria monocytogenes F4244, Salmonella enterica serovar Enteritidis PT21, and Staphylococcus aureus ATCC 25923 are measured and analyzed with the proposed instrument and algorithm. Also, a feasibility test for a smaller colony (up to 500 mum) classification utilizing a surface backward reflection pattern from the measurement is done, and shows a potential as an additional modality for the bacterial phenotyping.

Uniform modeling of bacterial colony patterns with varying nutrient and substrate

NASA Astrophysics Data System (ADS)

Schwarcz, Deborah; Levine, Herbert; Ben-Jacob, Eshel; Ariel, Gil

2016-04-01

Bacteria develop complex patterns depending on growth condition. For example, Bacillus subtilis exhibit five different patterns depending on substrate hardness and nutrient concentration. We present a unified integro-differential model that reproduces the entire experimentally observed morphology diagram at varying nutrient concentrations and substrate hardness. The model allows a comprehensive and quantitative comparison between experimental and numerical variables and parameters, such as colony growth rate, nutrient concentration and diffusion constants. As a result, the role of the different physical mechanisms underlying and regulating the growth of the colony can be evaluated.

Extreme plasticity in thermoregulatory behaviors of free-ranging black-tailed prairie dogs

USGS Publications Warehouse

Lehmer, E.M.; Savage, L.T.; Antolin, M.F.; Biggins, D.E.

2006-01-01

In the natural environment, hibernating sciurids generally remain dormant during winter and enter numerous deep torpor bouts from the time of first immergence in fall until emergence in spring. In contrast, black-tailed prairie dogs (Cynomys ludovicianus) remain active throughout winter but periodically enter short and shallow bouts of torpor. While investigating body temperature (Tb) patterns of black-tailed prairie dogs from six separate colonies in northern Colorado, we observed one population that displayed torpor patterns resembling those commonly seen in hibernators. Five individuals in this population experienced multiple torpor bouts in immediate succession that increased in length and depth as winter progressed, whereas 16 prairie dogs in five neighboring colonies remained euthermic for the majority of winter and entered shallow bouts of torpor infrequently. Our results suggest that these differences in torpor patterns did not result from differences in the physiological indicators that we measured because the prairie dogs monitored had similar body masses and concentrations of stored lipids across seasons. Likewise, our results did not support the idea that differences in overwinter Tb patterns between prairie dogs in colonies with differing torpor patterns resulted from genetic differences between populations; genetic analyses of prairie dog colonies revealed high genetic similarity between the populations and implied that individuals regularly disperse between colonies. Local environmental conditions probably played a role in the unusual T b patterns experienced by prairie dogs in the colony where hibernation-like patterns were observed; this population received significantly less rainfall than neighboring colonies during the summer growing seasons before, during, and after the year of the winter in which they hibernated. Our study provides a rare example of extreme plasticity in thermoregulatory behaviors of free-ranging prairie dogs and provides evidence contrary to models that propose a clear delineation between homeothermy, facultative torpor, and hibernation. ?? 2006 by The University of Chicago. All rights reserved.

Periodic Pattern Formation of Bacterial Colonies

NASA Astrophysics Data System (ADS)

Itoh, Hiroto; Wakita, Jun-ichi; Matsuyama, Tohey; Matsushita, Mitsugu

1999-04-01

We have experimentally investigated pattern formation of colonies ofbacterial species Proteus mirabilis, which is famous forforming concentric-ring-like colonies.The colony grows cyclically with the interface repeating an advance anda stop alternately on a surface of a solid agar medium.We distinguish three phases (initial lag phase, the followingmigration and consolidation phases that appear alternately) for the colony growth.When we cut a colony just behind a migrating front shortly after the migrationstarted, the migration ended earlier and the following consolidationlasted longer.However, the following cycles were not influenced by the cut, i.e., thephases of the migration and consolidation were not affected.Global chemical signals governing the colony formation from thecenter were not found to exist.We also quantitatively checked phase entrainment by letting two coloniescollide with each other and found that it does not take place in macroscopic scales.All these experimental results suggest that the most important factorfor the migration is the cell population density.

Development of a microbial high-throughput screening instrument based on elastic light scatter patterns

NASA Astrophysics Data System (ADS)

Bae, Euiwon; Patsekin, Valery; Rajwa, Bartek; Bhunia, Arun K.; Holdman, Cheryl; Davisson, V. Jo; Hirleman, E. Daniel; Robinson, J. Paul

2012-04-01

A microbial high-throughput screening (HTS) system was developed that enabled high-speed combinatorial studies directly on bacterial colonies. The system consists of a forward scatterometer for elastic light scatter (ELS) detection, a plate transporter for sample handling, and a robotic incubator for automatic incubation. To minimize the ELS pattern-capturing time, a new calibration plate and correction algorithms were both designed, which dramatically reduced correction steps during acquisition of the circularly symmetric ELS patterns. Integration of three different control software programs was implemented, and the performance of the system was demonstrated with single-species detection for library generation and with time-resolved measurement for understanding ELS colony growth correlation, using Escherichia coli and Listeria. An in-house colony-tracking module enabled researchers to easily understand the time-dependent variation of the ELS from identical colony, which enabled further analysis in other biochemical experiments. The microbial HTS system provided an average scan time of 4.9 s per colony and the capability of automatically collecting more than 4000 ELS patterns within a 7-h time span.

Growth-mediated autochemotactic pattern formation in self-propelling bacteria

NASA Astrophysics Data System (ADS)

Mukherjee, Mrinmoy; Ghosh, Pushpita

2018-01-01

Bacteria, while developing a multicellular colony or biofilm, can undergo pattern formation by diverse intricate mechanisms. One such route is directional movement or chemotaxis toward or away from self-secreted or externally employed chemicals. In some bacteria, the self-produced signaling chemicals or autoinducers themselves act as chemoattractants or chemorepellents and thereby regulate the directional movements of the cells in the colony. In addition, bacteria follow a certain growth kinetics which is integrated in the process of colony development. Here, we study the interplay of bacterial growth dynamics, cell motility, and autochemotactic motion with respect to the self-secreted diffusive signaling chemicals in spatial pattern formation. Using a continuum model of motile bacteria, we show growth can act as a crucial tuning parameter in determining the spatiotemporal dynamics of a colony. In action of growth dynamics, while chemoattraction toward autoinducers creates arrested phase separation, pattern transitions and suppression can occur for a fixed chemorepulsive strength.

Biology and ecology of the hydrocoral millepora on coral reefs.

PubMed

Lewis, John B

2006-01-01

Millepores are colonial polypoidal hydrozoans secreting an internal calcareous skeleton of an encrusting or upright form, often of considerable size. Defensive polyps protruding from the skeleton are numerous and highly toxic and for this reason millepores are popularly known as "stinging corals" or "fire corals." In shallow tropical seas millepore colonies are conspicuous on coral reefs and may be locally abundant and important reef-framework builders. The history of systematic research on the Milleporidae and the sister family Stylasteridae is rich and full with the works of early naturalists beginning with Linnaeus. Seventeen living millepore species are recognised. Marked phenotypic variation in form and structure of colonies is characteristic of the genus Millepora. The first published descriptions of the anatomy and histology of millepores were by H. N. Moseley in one of the Challenger Expedition reports. These original, detailed accounts by Moseley remain valid and, except for recent descriptions of the ultrastructure of the skeleton and skeletogenic tissues, have not needed much modification. Millepores occur worldwide on coral reefs at depths of between 1 and 40 m and their distribution on reefs is generally zoned in response to physical factors. Colonies may be abundant locally on coral reefs but usually comprise <10% of the overall surface cover. Growth rates of colonies are similar to the measured rates of branching and platelike scleractinian corals. Millepores are voracious zooplankton feeders and they obtain part of their nutrition from autotrophic sources, photosynthetic production by symbiotic zooxanthellae. Reproduction in millepores is characterised by alternation of generations with a well-developed polypoid stage that buds off planktonic medusae. Sexual reproduction is seasonal for known species and the medusae have a brief planktonic life. Asexual production is achieved by sympodial growth, the production of new skeleton and soft tissue along a growing edge or branch tip, and by the reattachment, regeneration and repair of damaged or broken colony fragments. The physiological and ecological responses of species of millepores are similar to those of the species of scleractinian corals over a broad range of natural and anthropogenic disturbances. Severe damage to colonies may occur during major storms. Delicately branching species are more susceptible than massive and bladed species. The ability of broken fragments to regenerate can ameliorate the extent of damage. Widespread bleaching and mortality of millepores has been reported during mass bleaching events that have affected many coral reefs. Millepores are often the first to recover after short-term bleaching events. Harmful effects of oil spills, chronic oil pollution and oil-spill detergents have been widely reported for millepores. Although the hydrozoan coenosarc, with its fiercely stinging zooids, does not appear to be an attractive substratum for attachment and settlement of epizooans, a number of sessile and errant forms commonly occur on millepores. These include barnacles, amphipods, tanaid and alpheid crustaceans, polychaetes and gastropods. Burrowing molluscs, polychaetes and crustacea also abound. Many of these species or their close relatives also occur on scleractinian corals. A variety of predators, grazers and fouling organisms occur on millepores. These include errant polychaetes, several coral-feeding fish and a gastropod mollusc. Various invasive green, red and brown algae are widespread, growing on dead branches of millepores and overgrowing live coral tissue. Various "band diseases" associated with microorganisms that appear to cause lesions on millepores and loss of tissue have been documented but are not of widespread occurrence. Infestations of endolithic algae and fungi growing within the skeletons have been reported in a number of millepore species.

Spatio-temporal differentiation and sociality in spiders.

PubMed

Purcell, Jessica; Vasconcellos-Neto, João; Gonzaga, Marcelo O; Fletcher, Jeffrey A; Avilés, Leticia

2012-01-01

Species that differ in their social system, and thus in traits such as group size and dispersal timing, may differ in their use of resources along spatial, temporal, or dietary dimensions. The role of sociality in creating differences in habitat use is best explored by studying closely related species or socially polymorphic species that differ in their social system, but share a common environment. Here we investigate whether five sympatric Anelosimus spider species that range from nearly solitary to highly social differ in their use of space and in their phenology as a function of their social system. By studying these species in Serra do Japi, Brazil, we find that the more social species, which form larger, longer-lived colonies, tend to live inside the forest, where sturdier, longer lasting vegetation is likely to offer better support for their nests. The less social species, which form single-family groups, in contrast, tend to occur on the forest edge where the vegetation is less robust. Within these two microhabitats, species with longer-lived colonies tend to occupy the potentially more stable positions closer to the core of the plants, while those with smaller and shorter-lived colonies build their nests towards the branch tips. The species further separate in their use of common habitat due to differences in the timing of their reproductive season. These patterns of habitat use suggest that the degree of sociality can enable otherwise similar species to differ from one another in ways that may facilitate their co-occurrence in a shared environment, a possibility that deserves further consideration.

Spatio-Temporal Differentiation and Sociality in Spiders

PubMed Central

Purcell, Jessica; Vasconcellos-Neto, João; Gonzaga, Marcelo O.; Fletcher, Jeffrey A.; Avilés, Leticia

2012-01-01

Species that differ in their social system, and thus in traits such as group size and dispersal timing, may differ in their use of resources along spatial, temporal, or dietary dimensions. The role of sociality in creating differences in habitat use is best explored by studying closely related species or socially polymorphic species that differ in their social system, but share a common environment. Here we investigate whether five sympatric Anelosimus spider species that range from nearly solitary to highly social differ in their use of space and in their phenology as a function of their social system. By studying these species in Serra do Japi, Brazil, we find that the more social species, which form larger, longer–lived colonies, tend to live inside the forest, where sturdier, longer lasting vegetation is likely to offer better support for their nests. The less social species, which form single-family groups, in contrast, tend to occur on the forest edge where the vegetation is less robust. Within these two microhabitats, species with longer-lived colonies tend to occupy the potentially more stable positions closer to the core of the plants, while those with smaller and shorter-lived colonies build their nests towards the branch tips. The species further separate in their use of common habitat due to differences in the timing of their reproductive season. These patterns of habitat use suggest that the degree of sociality can enable otherwise similar species to differ from one another in ways that may facilitate their co-occurrence in a shared environment, a possibility that deserves further consideration. PMID:22545086

Spatiotemporal Patterns Produced by Bacteria

NASA Astrophysics Data System (ADS)

Shimada, Yuji; Nakahara, Akio; Matsushita, Mitsugu; Matsuyama, Tohey

1995-06-01

Spatiotemporal patterns formed by a bacterial colony of Proteus mirabilis on an agar plate were observed. About half or one hour after the colony spread over the entire surface of the agar medium in a petridish, various patterns including target and spiral patterns appeared. They are very similar to those seen in other dissipative systems, such as chemical oscillations and electrohydrodynamic convective systems. Microscopic observations revealed that the collective motion of bacterial cells is responsible for the formation of these spatiotemporal patterns.

An individual-based modeling approach to simulate the effects of cellular nutrient competition on Escherichia coli K-12 MG1655 colony behavior and interactions in aerobic structured food systems.

PubMed

Tack, Ignace L M M; Logist, Filip; Noriega Fernández, Estefanía; Van Impe, Jan F M

2015-02-01

Traditional kinetic models in predictive microbiology reliably predict macroscopic dynamics of planktonically-growing cell cultures in homogeneous liquid food systems. However, most food products have a semi-solid structure, where microorganisms grow locally in colonies. Individual colony cells exhibit strongly different and non-normally distributed behavior due to local nutrient competition. As a result, traditional models considering average population behavior in a homogeneous system do not describe colony dynamics in full detail. To incorporate local resource competition and individual cell differences, an individual-based modeling approach has been applied to Escherichia coli K-12 MG1655 colonies, considering the microbial cell as modeling unit. The first contribution of this individual-based model is to describe single colony growth under nutrient-deprived conditions. More specifically, the linear and stationary phase in the evolution of the colony radius, the evolution from a disk-like to branching morphology, and the emergence of a starvation zone in the colony center are simulated and compared to available experimental data. These phenomena occur earlier at more severe nutrient depletion conditions, i.e., at lower nutrient diffusivity and initial nutrient concentration in the medium. Furthermore, intercolony interactions have been simulated. Higher inoculum densities lead to stronger intercolony interactions, such as colony merging and smaller colony sizes, due to nutrient competition. This individual-based model contributes to the elucidation of characteristic experimentally observed colony behavior from mechanistic information about cellular physiology and interactions. Copyright © 2014 Elsevier Ltd. All rights reserved.

Intraspecific variations in responses to ocean acidification in two branching coral species.

PubMed

Sekizawa, Ayami; Uechi, Hikaru; Iguchi, Akira; Nakamura, Takashi; Kumagai, Naoki H; Suzuki, Atsushi; Sakai, Kazuhiko; Nojiri, Yukihiro

2017-09-15

Ocean acidification is widely recognised to have a negative impact on marine calcifying organisms by reducing calcifications, but controversy remains over whether such organisms could cope with ocean acidification within a range of phenotypic plasticity and/or adapt to future acidifying ocean. We performed a laboratory rearing experiment using clonal fragments of the common branching corals Montipora digitata and Porites cylindrica under control and acidified seawater (lower pH) conditions (approximately 400 and 900μatm pCO 2 , respectively) and evaluated the intraspecific variations in their responses to ocean acidification. Intra- and interspecific variations in calcification and photosynthetic efficiency were evident according to both pCO 2 conditions and colony, indicating that responses to acidification may be individually variable at the colony level. Our results suggest that some corals may cope with ocean acidification within their present genotypic composition by adaptation through phenotypic plasticity, while others may be placed under selective pressures resulting in population alteration. Copyright © 2017 Elsevier Ltd. All rights reserved.

Hepatic Arterial Configuration in Relation to the Segmental Anatomy of the Liver; Observations on MDCT and DSA Relevant to Radioembolization Treatment

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

Hoven, Andor F. van den, E-mail: a.f.vandenhoven@umcutrecht.nl; Leeuwen, Maarten S. van, E-mail: m.s.vanleeuwen@umcutrecht.nl; Lam, Marnix G. E. H., E-mail: m.lam@umcutrecht.nl

PurposeCurrent anatomical classifications do not include all variants relevant for radioembolization (RE). The purpose of this study was to assess the individual hepatic arterial configuration and segmental vascularization pattern and to develop an individualized RE treatment strategy based on an extended classification.MethodsThe hepatic vascular anatomy was assessed on MDCT and DSA in patients who received a workup for RE between February 2009 and November 2012. Reconstructed MDCT studies were assessed to determine the hepatic arterial configuration (origin of every hepatic arterial branch, branching pattern and anatomical course) and the hepatic segmental vascularization territory of all branches. Aberrant hepatic arteries weremore » defined as hepatic arterial branches that did not originate from the celiac axis/CHA/PHA. Early branching patterns were defined as hepatic arterial branches originating from the celiac axis/CHA.ResultsThe hepatic arterial configuration and segmental vascularization pattern could be assessed in 110 of 133 patients. In 59 patients (54 %), no aberrant hepatic arteries or early branching was observed. Fourteen patients without aberrant hepatic arteries (13 %) had an early branching pattern. In the 37 patients (34 %) with aberrant hepatic arteries, five also had an early branching pattern. Sixteen different hepatic arterial segmental vascularization patterns were identified and described, differing by the presence of aberrant hepatic arteries, their respective vascular territory, and origin of the artery vascularizing segment four.ConclusionsThe hepatic arterial configuration and segmental vascularization pattern show marked individual variability beyond well-known classifications of anatomical variants. We developed an individualized RE treatment strategy based on an extended anatomical classification.« less

A total extinction confidently hoped for: the destruction of Cape San society under Dutch colonial rule, 1700-1795.

PubMed

Adhikari, Mohamed

2010-01-01

San (Bushman) society in the Cape Colony was almost completely annihilated during the eighteenth and nineteenth centuries as a result of land confiscation, massacre, forced labour and cultural suppression that accompanied colonial rule. Whereas similar obliterations of indigenous peoples in other parts of the world have resulted in major public controversies and heated debate amongst academics about the genocidal nature of these episodes, in South Africa the issue has effectively been ignored aside from passing, often polemical, references to it as genocide. Even recent studies that have approached the mass killing of the Cape San with sensitivity and insight do not address it as a case of genocide. This article sets out to redress this imbalance in part by analysing the dynamic of frontier conflict between San and settler under Dutch colonial rule as genocide. It demonstrates both the exterminatory intent underlying settler violence as well as the complicity of a weak colonial state in these depredations, including its sanctioning of the root-and-branch eradication of the San.

Model Simulation of Diurnal Vertical Migration Patterns of Different-Sized Colonies of Microcystis Employing a Particle Trajectory Approach.

PubMed

Chien, Yu Ching; Wu, Shian Chee; Chen, Wan Ching; Chou, Chih Chung

2013-04-01

Microcystis , a genus of potentially harmful cyanobacteria, is known to proliferate in stratified freshwaters due to its capability to change cell density and regulate buoyancy. In this study, a trajectory model was developed to simulate the cell density change and spatial distribution of Microcystis cells with nonuniform colony sizes. Simulations showed that larger colonies migrate to the near-surface water layer during the night to effectively capture irradiation and become heavy enough to sink during daytime. Smaller-sized colonies instead took a longer time to get to the surface. Simulation of the diurnally varying Microcystis population profile matched the observed pattern in the field when the radii of the multisized colonies were in a beta distribution. This modeling approach is able to take into account the history of cells by keeping track of their positions and properties, such as cell density and the sizes of colonies. It also serves as the basis for further developmental modeling of phytoplanktons that are forming colonies and changing buoyancy.

Modelled drift patterns of fish larvae link coastal morphology to seabird colony distribution.

PubMed

Sandvik, Hanno; Barrett, Robert T; Erikstad, Kjell Einar; Myksvoll, Mari S; Vikebø, Frode; Yoccoz, Nigel G; Anker-Nilssen, Tycho; Lorentsen, Svein-Håkon; Reiertsen, Tone K; Skarðhamar, Jofrid; Skern-Mauritzen, Mette; Systad, Geir Helge

2016-05-13

Colonial breeding is an evolutionary puzzle, as the benefits of breeding in high densities are still not fully explained. Although the dynamics of existing colonies are increasingly understood, few studies have addressed the initial formation of colonies, and empirical tests are rare. Using a high-resolution larval drift model, we here document that the distribution of seabird colonies along the Norwegian coast can be explained by variations in the availability and predictability of fish larvae. The modelled variability in concentration of fish larvae is, in turn, predicted by the topography of the continental shelf and coastline. The advection of fish larvae along the coast translates small-scale topographic characteristics into a macroecological pattern, viz. the spatial distribution of top-predator breeding sites. Our findings provide empirical corroboration of the hypothesis that seabird colonies are founded in locations that minimize travel distances between breeding and foraging locations, thereby enabling optimal foraging by central-place foragers.

Mathematical Modeling the Geometric Regularity in Proteus Mirabilis Colonies

NASA Astrophysics Data System (ADS)

Zhang, Bin; Jiang, Yi; Minsu Kim Collaboration

Proteus Mirabilis colony exhibits striking spatiotemporal regularity, with concentric ring patterns with alternative high and low bacteria density in space, and periodicity for repetition process of growth and swarm in time. We present a simple mathematical model to explain the spatiotemporal regularity of P. Mirabilis colonies. We study a one-dimensional system. Using a reaction-diffusion model with thresholds in cell density and nutrient concentration, we recreated periodic growth and spread patterns, suggesting that the nutrient constraint and cell density regulation might be sufficient to explain the spatiotemporal periodicity in P. Mirabilis colonies. We further verify this result using a cell based model.

Prediction of the light scattering patterns from bacteria colonies by a time-resolved reaction-diffusion model and the scalar diffraction theory

NASA Astrophysics Data System (ADS)

Bae, Euiwon; Bai, Nan; Aroonnual, Amornrat; Bhunia, Arun K.; Robinson, J. Paul; Hirleman, E. Daniel

2009-05-01

In order to maximize the utility of the optical scattering technology in the area of bacterial colony identification, it is necessary to have a thorough understanding of how bacteria species grow into different morphological aggregation and subsequently function as distinctive optical amplitude and phase modulators to alter the incoming Gaussian laser beam. In this paper, a 2-dimentional reaction-diffusion (RD) model with nutrient concentration, diffusion coefficient, and agar hardness as variables is investigated to explain the correlation between the various environmental parameters and the distinctive morphological aggregations formed by different bacteria species. More importantly, the morphological change of the bacterial colony against time is demonstrated by this model, which is able to characterize the spatio-temporal patterns formed by the bacteria colonies over their entire growth curve. The bacteria population density information obtained from the RD model is mathematically converted to the amplitude/phase modulation factor used in the scalar diffraction theory which predicts the light scattering patterns for bacterial colonies. The conclusions drawn from the RD model combined with the scalar diffraction theory are useful in guiding the design of the optical scattering instrument aiming at bacteria colony detection and classification.

Ecology of Rabies Virus Exposure in Colonies of Brazilian Free-Tailed Bats (Tadarida brasiliensis) at Natural and Man-Made Roosts in Texas

PubMed Central

Allen, Louise C.; Jackson, Felix R.; Kunz, Thomas H.; Rupprecht, Charles E.; McCracken, Gary F.

2010-01-01

Abstract Previous studies have investigated rabies virus (RABV) epizootiology in Brazilian free-tailed bats (Tadarida brasiliensis) in natural cave roosts. However, little is known about geographic variation in RABV exposure, or if the use of man-made roosts by this species affects enzootic RABV infection dynamics within colonies. We sampled rabies viral neutralizing antibodies in bats at three bridge and three cave roosts at multiple time points during the reproductive season to investigate temporal and roost variation in RABV exposure. We report seropositive bats in all age and sex classes with minimal geographic variation in RABV seroprevalence among Brazilian free-tailed bat colonies in south-central Texas. While roost type was not a significant predictor of RABV seroprevalence, it was significantly associated with seasonal fluctuations, suggesting patterns of exposure that differ between roosts. Temporal patterns suggest increased RABV seroprevalence after parturition in cave colonies, potentially related to an influx of susceptible young, in contrast to more uniform seroprevalence in bridge colonies. This study highlights the importance of life history and roost ecology in understanding patterns of RABV seroprevalence in colonies of the Brazilian free-tailed bat. PMID:19492942

Computer-based classification of bacteria species by analysis of their colonies Fresnel diffraction patterns

NASA Astrophysics Data System (ADS)

Suchwalko, Agnieszka; Buzalewicz, Igor; Podbielska, Halina

2012-01-01

In the presented paper the optical system with converging spherical wave illumination for classification of bacteria species, is proposed. It allows for compression of the observation space, observation of Fresnel patterns, diffraction pattern scaling and low level of optical aberrations, which are not possessed by other optical configurations. Obtained experimental results have shown that colonies of specific bacteria species generate unique diffraction signatures. Analysis of Fresnel diffraction patterns of bacteria colonies can be fast and reliable method for classification and recognition of bacteria species. To determine the unique features of bacteria colonies diffraction patterns the image processing analysis was proposed. Classification can be performed by analyzing the spatial structure of diffraction patterns, which can be characterized by set of concentric rings. The characteristics of such rings depends on the bacteria species. In the paper, the influence of basic features and ring partitioning number on the bacteria classification, is analyzed. It is demonstrated that Fresnel patterns can be used for classification of following species: Salmonella enteritidis, Staplyococcus aureus, Proteus mirabilis and Citrobacter freundii. Image processing is performed by free ImageJ software, for which a special macro with human interaction, was written. LDA classification, CV method, ANOVA and PCA visualizations preceded by image data extraction were conducted using the free software R.

Harvesting Effects, Recovery Mechanisms, and Management Strategies for a Long-Lived and Structural Precious Coral

PubMed Central

Montero-Serra, Ignasi; Linares, Cristina; García, Marina; Pancaldi, Francesca; Frleta-Valić, Maša; Ledoux, Jean-Baptiste; Zuberer, Frederic; Merad, Djamel; Drap, Pierre; Garrabou, Joaquim

2015-01-01

Overexploitation is a major threat for the integrity of marine ecosystems. Understanding the ecological consequences of different extractive practices and the mechanisms underlying the recovery of populations is essential to ensure sustainable management plans. Precious corals are long-lived structural invertebrates, historically overfished, and their conservation is currently a worldwide concern. However, the processes underlying their recovery are poorly known. Here, we examined harvesting effects and recovery mechanisms of red coral Corallium rubrum by analyzing long-term photographic series taken on two populations that were harvested. We compared the relative importance of reproduction and re-growth as drivers of resilience. Harvesting heavily impacted coral populations causing large decreases in biomass and strong size-class distribution shifts towards populations dominated by small colonies. At the end of the study (after 4 and 7 years) only partial recovery was observed. The observed general pattern of low recruitment and high mortality of new recruits demonstrated limited effects of reproduction on population recovery. Adversely, low mortality of partially harvested adults and a large proportion of colonies showing new branches highlighted the importance of re-growth in the recovery process. The demographic projections obtained through stochastic models confirmed that the recovery rates of C. rubrum can be strongly modulated depending on harvesting procedures. Thus, leaving the basal section of the colonies when harvesting to avoid total mortality largely enhances the resilience of C. rubrum populations and quickens their recovery. On the other hand, the high survival of harvested colonies and the significant biomass reduction indicated that abundance may not be an adequate metric to assess the conservation status of clonal organisms because it can underestimate harvesting effects. This study highlights the unsustainability of current harvesting practices of C. rubrum and provides urgently needed data to improve management practices that are still largely based on untested assumptions. PMID:25706556

Cold-Water Corals and Anthropogenic Impacts in La Fonera Submarine Canyon Head, Northwestern Mediterranean Sea

PubMed Central

Canals, Miquel; Ballesteros, Enric; Gili, Josep-Maria; Sanchez-Vidal, Anna

2016-01-01

We assess the occurrence and extent of cold-water coral (CWC) species Madrepora oculata and Dendrophyllia cornigera, as well as gorgonian red coral Corallium rubrum, in La Fonera canyon head (Northwestern Mediterranean Sea), as well as human impacts taking place in their habitats. Occurrence is assessed based on Remotely Operated Vehicle (ROV) video imaging. Terrain classification techniques are applied to high-resolution swath bathymetric data to obtain semi-automatic interpretative maps to identify the relationship between coral distribution patterns and canyon environments. A total of 21 ROV immersions were carried out in different canyon environments at depths ranging between 79 and 401 m. Large, healthy colonies of M. oculata occur on abrupt, protected, often overhanging, rocky sections of the canyon walls, especially in Illa Negra branch. D. cornigera is sparser and evenly distributed at depth, on relatively low sloping areas, in rocky but also partially sedimented areas. C. rubrum is most frequent between 100 and 160 m on highly sloping rocky areas. The probable extent of CWC habitats is quantified by applying a maximum entropy model to predict habitat suitability: 0.36 km2 yield M. oculata occurrence probabilities over 70%. Similar predictive models have been produced for D. cornigera and C. rubrum. All ROV transects document either the presence of litter on the seafloor or pervasive trawling marks. Nets and longlines are imaged entangled on coral colonies. Coral rubble is observed at the foot of impacted colonies. Some colonies are partially covered by sediment that could be the result of the resuspension generated by bottom trawling on neighbouring fishing grounds, which has been demonstrated to be responsible of daily increases in sediment fluxes within the canyon. The characteristics of the CWC community in La Fonera canyon are indicative that it withstands high environmental stress of both natural and human origin. PMID:27182776

Patterns of split sex ratio in ants have multiple evolutionary causes based on different within-colony conflicts

PubMed Central

Kümmerli, Rolf; Keller, Laurent

2009-01-01

Split sex ratio—a pattern where colonies within a population specialize in either male or queen production—is a widespread phenomenon in ants and other social Hymenoptera. It has often been attributed to variation in colony kin structure, which affects the degree of queen–worker conflict over optimal sex allocation. However, recent findings suggest that split sex ratio is a more diverse phenomenon, which can evolve for multiple reasons. Here, we provide an overview of the main conditions favouring split sex ratio. We show that each split sex-ratio type arises due to a different combination of factors determining colony kin structure, queen or worker control over sex ratio and the type of conflict between colony members. PMID:19457886

Intraspecific competitive networks in the Red Sea coral Stylophora pistillata

NASA Astrophysics Data System (ADS)

Rinkevich, B.; Loya, Y.

1983-09-01

Intraspecific competitive interactions were studied underwater in the Red Sea coral Stylophora pistillata during 1976 1981, through a series of field observations (FO) and field experiments (FE). The FO series were conducted on more than 200 pairs of colonies (with a gap of 1 3 cm between the nearest branches in a pair), which were checked monthly for possible interactions, during approximately five years. The FE series consisted of allografts, isografts and colony to colony attachements. S. pistillata exhibits two basic colour morphs, in which purple colonics are found to be superior to yellow morphs and competitively exculde them, even when they are not physically touching. When differences in size between the competing colonies were in the range of 2 3 orders of magnitude, a significant superiority of big colonies over little ones was recorded, irrespective of colour morphs. Five major schematic routes of intraspecific interactions are drawn and discussed. The outcome of interactions between two competing colonies is the synergistic effect of different aggressive forms, such as nematocyst discharge, overgrowth on branches or basal plates, a “retreat growth” phenomenon (possibly caused by pheromones), formation of border lines, abnormal growth forms and others. SEM observations indicate the existance of a gap (up to 30 μm) between allografts that appeared to be fused in naked-eye observations and the appearance of plasmic (?) filaments immediately above and within the contact zones. In contrast to the FE series the FO were free from any stress caused by experimental procedures and provided the opportunity to record additional forms of aggression, which were not observed in the FE series. In many cases, the duration of processes and the final outcome of interactions were much faster in FE than in FO. It is concluded that intraspecific interactions involve significant energetic expenditures that otherwise would be channelled into other metabolic requirements such as reproduction and growth. Self-recognition mechanisms and the role of immunological processes are discussed. The FO series indicate that in the vast majority of interactions no physical contact (cell to cell) is needed for self-identification.

Dynamical Properties of Transient Spatio-Temporal Patterns in Bacterial Colony of Proteus mirabilis

NASA Astrophysics Data System (ADS)

Watanabe, Kazuhiko; Wakita, Jun-ichi; Itoh, Hiroto; Shimada, Hirotoshi; Kurosu, Sayuri; Ikeda, Takemasa; Yamazaki, Yoshihiro; Matsuyama, Tohey; Matsushita, Mitsugu

2002-02-01

Spatio-temporal patterns emerged inside a colony of bacterial species Proteus mirabilis on the surface of nutrient-rich semisolid agar medium have been investigated. We observed various patterns composed of the following basic types: propagating stripe, propagating stripe with fixed dislocation, expanding and shrinking target, and rotating spiral. The remarkable point is that the pattern changes immediately when we alter the position for observation, but it returns to the original if we restore the observing position within a few minutes. We further investigated mesoscopic and microscopic properties of the spatio-temporal patterns. It turned out that whenever the spatio-temporal patterns are observed in a colony, the areas are composed of two superimposed monolayers of elongated bacterial cells. In each area they are aligned almost parallel with each other like a two-dimensional nematic liquid crystal, and move collectively and independently of another layer. It has been found that the observed spatio-temporal patterns are explained as the moiré effect.

Colony attendance patterns by mated Forster's Terns Sterna forsteri using an automated data-logging receiver system

USGS Publications Warehouse

Bluso-Demers, Jill D.; Ackerman, Joshua T.; Takekawa, John Y.

2010-01-01

In order to examine 24-hour colony attendance patterns by mated Forster's Terns Sterna forsteri in South San Francisco Bay, California, during incubation and chick-rearing stages, we radio-marked 10 individuals consisting of five pairs and recorded colony attendance using an automated data-logging receiver system. We calculated and analyzed five variables: the total attendance time by pairs and individuals, the duration of individual attendance bouts, and the duration both members of a pair either overlapped in colony attendance or were both absent from the colony. The percentage of time spent on the colony by at least one individual of a pair was highest during incubation and declined during chick rearing. Overall, male terns spent a greater proportion of time diurnally attending the colony than females. Females spent a greater proportion of time on colony at night, and without these nocturnal records, we would have reported overall female colony attendance rates as being much lower. Despite sex-specific differences in attendance rates, the length of attendance bouts did not differ between the sexes. Simultaneous colony attendance by both members of a pair was high at night, but during the day, pairs infrequently overlapped in their colony attendance and both members were frequently absent. Our datalogging system functioned well, and our data illustrates the importance of collecting 24-hour records when considering attendance rates.

Fractal patterns of fracture in sandwich composite materials under biaxial tension

NASA Astrophysics Data System (ADS)

Fang, Jing; Yao, Xuefeng; Qi, Jia

1996-04-01

The paper presents a successful experiment to generate a fractal pattern of branching cracks in a brittle material sandwiched in ductile plates. A glass sheet bonded between two polycarbonate plates was heated at different levels of temperatures and the stress field due to the difference of thermal coefficients of the materials was solved by combining the results from isochromatic fringes and thermal stress analysis. At a critical degree of temperature, a crack was initiated at a point and soon produced crack branches to release the stored energy. A tree—like fractal patterns of the branch cracks was then developed with the growth of the branches that subsequently produced more branches on their ways of propagation. The fractal dimension of the fracture pattern was evaluated and the mechanism of the fragmentation was analyzed with the help of the residual stress field of isochromatic and isoclinic patterns.

Vascular anatomy of the medial sural artery perforator flap: a new classification system of intra-muscular branching patterns.

PubMed

Dusseldorp, Joseph R; Pham, Quy J; Ngo, Quan; Gianoutsos, Mark; Moradi, Pouria

2014-09-01

The medial sural artery perforator (MSAP) flap is a versatile fasciocutaneous flap. The main difficulty encountered when raising the MSAP flap is in obtaining adequate pedicle length during intra-muscular dissection. The objective of this study was to determine the pattern of intra-muscular course of the MSAP flap pedicle. 14 cadaveric specimens were dissected and CT angiograms of 84 legs were examined. The intra-muscular branching pattern and depths of the medial sural artery branches were analyzed. The number of perforators, position of the dominant perforator and both intra-muscular and total pedicle length were also recorded and compared to existing anatomical data. Three types of arterial branching pattern were identified within the medial gastrocnemius, demonstrating one (31%), two (59%) or three or more (10%) main branches. A dominant perforator from the medial sural artery was present in 92% of anatomical specimens (13/14). Vertically, the location of the perforator from the popliteal crease was on average 13 cm (±2 cm). Transversely, the perforator originated 2.5 cm (±1 cm) from the posterior midline. Using CT angiography it was possible in 10 consecutive patients to identify a more superficial intra-muscular branch and determine the leg with the optimal branching pattern type for flap harvest. This study is the first to describe the variability of the intra-muscular arterial anatomy of the medial head of gastrocnemius muscle. Surgeons utilizing the MSAP flap option should be aware of the possible branching pattern types and consequently the differing perforator distribution and depths of intra-muscular branches. Routine use of pre-operative CT angiogram may help determine which leg has the most favorable branching pattern type and intra-muscular course for flap harvest. Copyright © 2014 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Pattern Formation of Bacterial Colonies by Escherichia coli

NASA Astrophysics Data System (ADS)

Tokita, Rie; Katoh, Takaki; Maeda, Yusuke; Wakita, Jun-ichi; Sano, Masaki; Matsuyama, Tohey; Matsushita, Mitsugu

2009-07-01

We have studied the morphological diversity and change in bacterial colonies, using the bacterial species Escherichia coli, as a function of both agar concentration Ca and nutrient concentration Cn. We observed various colony patterns, classified them into four types by pattern characteristics and established a morphological diagram by dividing it into four regions. They are regions A [diffusion-limited aggregation (DLA)-like], B (Eden-like), C (concentric-ring), and D (fluid-spreading). In particular, we have observed a concentric-ring colony growth for E. coli. We focused on the periodic growth in region C and obtained the following results: (i) A colony grows cyclically with the growing front repeating an advance (migration phase) and a momentary rest (consolidation phase) alternately. (ii) The growth width L and the bulge width W in one cycle decrease asymptotically to certain values, when Ca is increased. (iii) L does not depend on Cn, while W is an increasing function of Cn. Plausible mechanisms are proposed to explain the experimental results, by comparing them with those obtained for other bacterial species such as Proteus mirabilis and Bacillus subtilis.

Control of the pattern of perithecium development in Sordaria fimicola on agar medium.

PubMed

Pollock, R T

1975-06-01

In a Sordaria fimicola (Rob.) Ces. and de Not. colony grown on agar medium in a petri plate, perithecia developed in a narrow band around the plate edge after the colony margin reached the edge. Physical wounding of the colony carried out shortly before or during the time perithecia were developing around the plate edge stimulated perithecium development in the wound area. Diffusion barriers were created by cutting small trenches in the agar parallel to the plate edge. The trenches were made at several different positions between the plate center and edge using cultures of several different ages, and the resultant distribution of perithecia along the trench edges suggested that the colony center and periphery produce diffusible inhibitors of perithecium development. These inhibitors may be responsible, in part, for the observed pattern of perithecium development in the colony.

Incomplete Homogenization of Chemical Recognition Labels Between Formica sanguinea and Formica rufa Ants (Hymenoptera: Formicidae) Living in a Mixed Colony

PubMed Central

Włodarczyk, Tomasz; Szczepaniak, Lech

2014-01-01

Abstract Formica sanguinea Latreille (Hymenoptera: Formicidae) is a slave-making species, i.e., it raids colonies of host species and pillages pupae, which are taken to develop into adult workers in a parasite colony. However, it has been unclear if the coexistence of F. sanguinea with slave workers requires uniformity of cuticular hydrocarbons (CHCs), among which those other than n -alkanes are believed to be the principal nestmate recognition cues utilized by ants. In this study, a mixed colony (MC) of F. sanguinea and Formica rufa L. as a slave species was used to test the hypothesis that CHCs are exchanged between the species. Chemical analysis of hexane extracts from ants’ body surfaces provided evidence for interspecific exchange of alkenes and methyl-branched alkanes. This result was confirmed by behavioral tests during which ants exhibited hostility toward conspecific individuals from the MC but not toward ones from homospecific colonies of their own species. However, it seems that species-specific differences in chemical recognition labels were not eliminated completely because ants from the MC were treated differently depending on whether they were con- or allospecific to the individuals whose behavioral reactions were tested. These findings are discussed in the context of mechanisms of colony's odor formation and effective integration of slaves into parasite colony. PMID:25502026

Evaluation of popliteal artery branching patterns and a new subclassification of the 'usual' branching pattern.

PubMed

Celtikci, Pinar; Ergun, Onur; Durmaz, Hasan Ali; Conkbayir, Isik; Hekimoglu, Baki

2017-09-01

To determine the frequency of popliteal artery branching variations in a wide study cohort and to investigate the relationship between these variations and infrapopliteal peripheral arterial disease (PAD). A subclassification was proposed for the most encountered type I-A, utilizing tibio-fibular trunk (TFT) length. A total number of 1184 lower extremity digital subtraction angiography (DSA) studies of 669 patients were evaluated. Following exclusion, 863 lower extremity DSA studies (431 right, 432 left) of 545 patients were enrolled. Popliteal artery branching type, patency of anterior tibial artery (ATA), fibular artery (FA) and posterior tibial artery (PTA) in each extremity and TFT length for type I-A extremities were recorded. Percentages of branching patterns, mean length and cut-off value of TFT and incidence of PAD in different types of branching were calculated. Type I-A was the most common type of branching (81.3%). Frequency of branching pattern variation was 18.7%, the most common variation category was category III (12.2%) and the most common variation type was type III-A (5.6%). ATA and PTA had higher percentages of PAD in extremities with variant branching types. Cut-off value of 3 cm for TFT length was proposed in order to subclassify type I-A. Our study cohort presents a higher incidence of popliteal artery branching variations. Some branching variations might have effect on the involvement pattern of the infrapopliteal arteries by PAD. We propose a subclassification for type I-A; type I-A-S (TFT < 3 cm) and type I-A-L (TFT ≥ 3 cm) which might have impact on interventional procedures.

The Branching Pattern of the Brachiocephalic Trunk in the Donkey (Equus asinus).

PubMed

Akbari, G; Asadiahranjani, B; Goodarzi, N; Shokrollahi, S

2017-08-01

Donkeys are a member of the horse family (Equidae) and share a common ancestor. However, in morphological terms, donkeys and horses are regarded as two separate subgenus. Given variations in the branching pattern of the brachiocephalic trunk (BCT) in different species of animals and the use of donkeys in anatomy courses at colleges of veterinary medicine, we conducted this study in order to investigate the branching patterns of BCT and to describe detailed morphological information regarding donkeys. Seventeen mature donkeys were examined following euthanasia by exsanguination from the common carotid artery under general anaesthesia. Thirteen donkeys were embalmed and injected with coloured latex from BCT origin for better visualization of vessels. Four other donkeys were freshly studied without the embalming procedure. In all cases, the BCT was the only branch of the aortic arch and branched into the left subclavian (LSb) artery, the right costocervical trunk, the right subclavian (RSb) artery and the bicarotid trunk. The main branching pattern of the RSb was the costocervical trunk, the vertebral artery, the internal thoracic artery and the superficial cervical artery. The deep cervical artery branched from the costocervical trunk. The major branching pattern of the LSb was the vertebral artery, the internal thoracic artery and the superficial cervical artery. In donkeys, the external thoracic artery branches from the internal thoracic artery. Results obtained from this study indicate that BCT branching in donkeys has some similarities and differences as compared to that in horses and in the Caspian miniature horse. © 2017 Blackwell Verlag GmbH.

Methods and measurement variance for field estimations of coral colony planar area using underwater photographs and semi-automated image segmentation.

PubMed

Neal, Benjamin P; Lin, Tsung-Han; Winter, Rivah N; Treibitz, Tali; Beijbom, Oscar; Kriegman, David; Kline, David I; Greg Mitchell, B

2015-08-01

Size and growth rates for individual colonies are some of the most essential descriptive parameters for understanding coral communities, which are currently experiencing worldwide declines in health and extent. Accurately measuring coral colony size and changes over multiple years can reveal demographic, growth, or mortality patterns often not apparent from short-term observations and can expose environmental stress responses that may take years to manifest. Describing community size structure can reveal population dynamics patterns, such as periods of failed recruitment or patterns of colony fission, which have implications for the future sustainability of these ecosystems. However, rapidly and non-invasively measuring coral colony sizes in situ remains a difficult task, as three-dimensional underwater digital reconstruction methods are currently not practical for large numbers of colonies. Two-dimensional (2D) planar area measurements from projection of underwater photographs are a practical size proxy, although this method presents operational difficulties in obtaining well-controlled photographs in the highly rugose environment of the coral reef, and requires extensive time for image processing. Here, we present and test the measurement variance for a method of making rapid planar area estimates of small to medium-sized coral colonies using a lightweight monopod image-framing system and a custom semi-automated image segmentation analysis program. This method demonstrated a coefficient of variation of 2.26% for repeated measurements in realistic ocean conditions, a level of error appropriate for rapid, inexpensive field studies of coral size structure, inferring change in colony size over time, or measuring bleaching or disease extent of large numbers of individual colonies.

Globalization as Continuing Colonialism: Critical Global Citizenship Education in an Unequal World

ERIC Educational Resources Information Center

Mikander, Pia

2016-01-01

In an unequal world, education about global inequality can be seen as a controversial but necessary topic for social science to deal with. Even though the world no longer consists of colonies and colonial powers, many aspects of the global economy follow the same patterns as during colonial times, with widening gaps between the world's richest and…

Abundance and reproductive patterns of the excavating sponge Cliona vermifera: a threat to Pacific coral reefs?

NASA Astrophysics Data System (ADS)

Bautista-Guerrero, Eric; Carballo, José Luis; Maldonado, Manuel

2014-03-01

Cliona vermifera is a common excavating sponge in coral reefs from the East Pacific. Abundance and reproductive patterns of the sponge in a Mexican Pacific coral reef over a 4-year period are herein described. Sponge abundance was estimated along three transects 50 m long which were randomly placed on the reef, and along each one, a piece of coral rubble and a branch of a live coral from the Pocillopora spp. coral colony closest to the transect were collected at random, approximately every 2 m, yielding 25 pieces of each category per transect (and 75 pieces total of each category). A 2-way ANOVA revealed that invasion was significantly higher in living coral colonies (34.8 %) than in rubble (13.7 %). It also indicated that the abundance in both coralline substrates showed a temporal variation without a clear pattern of increase over the years. It was estimated that 60-85 % of sponges in the population reproduced sexually every year. The sponge proved gonochoristic, with a sex ratio strongly departing from parity (1 male: 3 females). Over the 4-year study period, at least two cohorts of oocytes with densities of up to 3.5 oocytes per mm2 tissue were observed. Spermatogenesis lasted about a month, but often producing more than a pulse from July to November, coupled with peaks of oocyte maturation. Fertilization occurred internally to produce encapsulated zygotes that were released in one or more spawning events from July to November. In the following months (December to February), which were the periods of lowest temperature (~18.5-20 °C), no gametic activity occurred in the sponges. Because anomalous temperature rises that are detrimental to corals do not appear to negatively affect the reproduction and abundance of C. vermifera, it is likely that the excavating activity of this sponge may be compromising the health of those coral reefs that are recurrently affected by episodes of thermal stress.

Facial patterns in a tropical social wasp correlate with colony membership

NASA Astrophysics Data System (ADS)

Baracchi, David; Turillazzi, Stefano; Chittka, Lars

2016-10-01

Social insects excel in discriminating nestmates from intruders, typically relying on colony odours. Remarkably, some wasp species achieve such discrimination using visual information. However, while it is universally accepted that odours mediate a group level recognition, the ability to recognise colony members visually has been considered possible only via individual recognition by which wasps discriminate `friends' and `foes'. Using geometric morphometric analysis, which is a technique based on a rigorous statistical theory of shape allowing quantitative multivariate analyses on structure shapes, we first quantified facial marking variation of Liostenogaster flavolineata wasps. We then compared this facial variation with that of chemical profiles (generated by cuticular hydrocarbons) within and between colonies. Principal component analysis and discriminant analysis applied to sets of variables containing pure shape information showed that despite appreciable intra-colony variation, the faces of females belonging to the same colony resemble one another more than those of outsiders. This colony-specific variation in facial patterns was on a par with that observed for odours. While the occurrence of face discrimination at the colony level remains to be tested by behavioural experiments, overall our results suggest that, in this species, wasp faces display adequate information that might be potentially perceived and used by wasps for colony level recognition.

Nest signature changes throughout colony cycle and after social parasite invasion in social wasps

PubMed Central

Blancato, Giuliano; Picchi, Laura; Lucas, Christophe

2017-01-01

Social insects recognize their nestmates by means of a cuticular hydrocarbon signature shared by colony members, but how nest signature changes across time has been rarely tested in longitudinal studies and in the field. In social wasps, the chemical signature is also deposited on the nest surface, where it is used by newly emerged wasps as a reference to learn their colony odor. Here, we investigate the temporal variations of the chemical signature that wasps have deposited on their nests. We followed the fate of the colonies of the social paper wasp Polistes biglumis in their natural environment from colony foundation to decline. Because some colonies were invaded by the social parasite Polistes atrimandibularis, we also tested the effects of social parasites on the nest signature. We observed that, as the season progresses, the nest signature changed; the overall abundance of hydrocarbons as well as the proportion of longer-chain and branched hydrocarbons increased. Where present, social parasites altered the host-nest signature qualitatively (adding parasite-specific alkenes) and quantitatively (by interfering with the increase in overall hydrocarbon abundance). Our results show that 1) colony odor is highly dynamic both in colonies controlled by legitimate foundresses and in those controlled by social parasites; 2) emerged offspring contribute little to colony signature, if at all, in comparison to foundresses; and 3) social parasites, that later mimic host signature, initially mark host nests with species-specific hydrocarbons. This study implies that important updating of the neural template used in nestmate recognition should occur in social insects. PMID:29261775

Modelled drift patterns of fish larvae link coastal morphology to seabird colony distribution

PubMed Central

Sandvik, Hanno; Barrett, Robert T.; Erikstad, Kjell Einar; Myksvoll, Mari S.; Vikebø, Frode; Yoccoz, Nigel G.; Anker-Nilssen, Tycho; Lorentsen, Svein-Håkon; Reiertsen, Tone K.; Skarðhamar, Jofrid; Skern-Mauritzen, Mette; Systad, Geir Helge

2016-01-01

Colonial breeding is an evolutionary puzzle, as the benefits of breeding in high densities are still not fully explained. Although the dynamics of existing colonies are increasingly understood, few studies have addressed the initial formation of colonies, and empirical tests are rare. Using a high-resolution larval drift model, we here document that the distribution of seabird colonies along the Norwegian coast can be explained by variations in the availability and predictability of fish larvae. The modelled variability in concentration of fish larvae is, in turn, predicted by the topography of the continental shelf and coastline. The advection of fish larvae along the coast translates small-scale topographic characteristics into a macroecological pattern, viz. the spatial distribution of top-predator breeding sites. Our findings provide empirical corroboration of the hypothesis that seabird colonies are founded in locations that minimize travel distances between breeding and foraging locations, thereby enabling optimal foraging by central-place foragers. PMID:27173005

Changes in scleractinian coral Seriatopora hystrix morphology and its endocellular Symbiodinium characteristics along a bathymetric gradient from shallow to mesophotic reef

NASA Astrophysics Data System (ADS)

Nir, O.; Gruber, D. F.; Einbinder, S.; Kark, S.; Tchernov, D.

2011-12-01

The algae living endosymbiotically within coral are thought to increase algal pigmentation with increasing depth to capture the diminishing light. Here, we follow distribution of the hermatypic coral Seriatopora hystrix along a 60-m bathymetric gradient in the Gulf of Eilat, Red Sea, to study coral ecophysiology and response to light regimes. Combining work on coral morphology, pigment content and genotyping of the photosymbiont, we found that total chlorophyll concentration per zooxanthellae cell and the dark- and light-acclimated quantum yield of photosystem II did not vary significantly along the 60-m gradient. However, the chlorophyll a/c ratio increased with depth. This suggests that the symbiotic algae in S. hystrix possess a mechanism for acclimatization or adaptation that differs from previously described pathways. The accepted photoacclimatory process involves an increase in chlorophyll content per alga as light intensity decreases. Based on corallite and branch morphology, this research suggests that S. hystrix has two depth-dependent ecophenotypes. Above 10 m depth, S. hystrix exhibits sturdier colony configurations with thick branches, while below 30 m depth, colonies are characterized by thin branches and the presence of a larger polyp area. Between 10 and 30 m depth, both ecophenotypes are present, suggesting that corallite morphology may act as another axis of photoacclimation with depth.

Parasites modulate within-colony activity and accelerate the temporal polyethism schedule of a social insect, the honey bee.

PubMed

Natsopoulou, Myrsini E; McMahon, Dino P; Paxton, Robert J

Task allocation in social insect colonies is generally organised into an age-related division of labour, termed the temporal polyethism schedule, which may in part have evolved to reduce infection of the colony's brood by pests and pathogens. The temporal polyethism schedule is sensitive to colony perturbations that may lead to adaptive changes in task allocation, maintaining colony homeostasis. Though social insects can be infected by a range of parasites, little is known of how these parasites impact within-colony behaviour and the temporal polyethism schedule. We use honey bees ( Apis mellifera ) experimentally infected by two of their emerging pathogens, Deformed wing virus (DWV), which is relatively understudied concerning its behavioural impact on its host, and the exotic microsporidian Nosema ceranae . We examined parasite effects on host temporal polyethism and patterns of activity within the colony. We found that pathogens accelerated the temporal polyethism schedule, but without reducing host behavioural repertoire. Infected hosts exhibited increased hyperactivity, allocating more time to self-grooming and foraging-related tasks. The strength of behavioural alterations we observed was found to be pathogen specific; behavioural modifications were more pronounced in virus-treated hosts versus N. ceranae -treated hosts, with potential benefits for the colony in terms of reducing within-colony transmission. Investigating the effects of multiple pathogens on behavioural patterns of social insects could play a crucial role in understanding pathogen spread within a colony and their effects on colony social organisation.

Fish corallivory on a pocilloporid reef and experimental coral responses to predation

NASA Astrophysics Data System (ADS)

Palacios, M. M.; Muñoz, C. G.; Zapata, F. A.

2014-09-01

This study examined the effects of the Guineafowl pufferfish ( Arothron meleagris), a major corallivore in the Eastern Pacific, on pocilloporid corals on a reef at Gorgona Island, Colombia. Pufferfish occurred at a density of 171.2 individuals ha-1 and fed at a rate of 1.8 bites min-1, which produced a standing bite density of 366.2 bites m-2. We estimate that approximately 15.6 % of the annual pocilloporid carbonate production is removed by the pufferfish population. Examination of the predation effect on individual pocilloporid colonies revealed that although nubbins exposed to corallivory had lower linear growth, they gained similar weight and became thicker than those protected from it. Additionally, colonies with simulated predation injuries (on up to 75 % of branch tips) healed successfully and maintained growth rates similar to those of uninjured colonies. Despite the high corallivore pressure exerted by pufferfish on this reef, we conclude that they have a low destructive impact on Pocillopora colonies as corals can maintain their carbonate production rate while effectively recovering from partial predation. Due to its influence on colony morphology, pufferfish predation may increase environmentally induced morphological variability in Pocillopora.

Design of Mini Latissimus Dorsi Flap Based on Thoracodorsal Vascular Patterns.

PubMed

Elzawawy, Ehab Mostafa; Kelada, Melad Naim; Al Karmouty, Ahmed Farouk

2018-06-01

Latissimus dorsi (LD) flap has been used for reconstructive purposes in oncoplastic breast surgery. Using large part of the muscle as a flap leads to a residual functional loss. Muscle sparing and mini LD flaps can be used with no functional sequelae. However, the design of such flap presents a challenge. Twenty cadavers were dissected on both sides to identify the different vascular patterns of the thoracodorsal (TD) pedicle. The vessels were counted, and the following measurements were taken: diameter, length, distance from inferior angel of scapula, and vertebral level. Data were collected and entered into the personal computer. Statistical analysis was done using (SPSS/version 20) software. Five vascular patterns of TD pedicle were found. Type 1: a long vertically descending pedicle giving 3 to 4 transverse medial branches to LD in 40%. Type 2: a short pedicle terminating into 1 to 2 serratus anterior collaterals and 1 to 2 transverse lateral branches to LD in 10%. Type 3: a long vertically descending pedicle giving 2 to 3 small lateral branches to upper part of LD and terminating into medial and lateral branches in the lower part of LD in 10%. Type 4: a short pedicle that gives 4 to 5 terminal branches to LD, one of them is a long vertically descending branch to lower part of LD in 20%. Type 5: a short pedicle that terminates into a transverse medial and a long vertical branch to LD in 20%. The classically described pattern of TD pedicle (type 5) was found in 20% of cases, whereas the most commonly found pattern was type 1. This means that the pattern of TD branching is unpredictable, and a preoperative ultrasound is essential to define the existing pattern and plan the best LD flap design for each patient. In types 1 and 5, the flap can be designed using the transverse medial branch or branches. In type 2, one of the lateral transverse branches can be used. In types 3, 4, and 5, the long descending vertical branch can be used. It has a sizeable diameter (1.80.23 mm), length (12.31.64 cm), and can be located 6.50.96 cm below the inferior angle of scapula.

Locally accelerated growth is part of the innate immune response and repair mechanisms in reef-building corals as detected by green fluorescent protein (GFP)-like pigments

NASA Astrophysics Data System (ADS)

D'Angelo, C.; Smith, E. G.; Oswald, F.; Burt, J.; Tchernov, D.; Wiedenmann, J.

2012-12-01

Homologs of the green fluorescent protein (GFP) are a prevalent group of host pigments responsible for the green, red and purple-blue colours of many reef-building corals. They have been suggested to contribute to the striking coloration changes of different corals species in response to wounding and infestation with epibionts/parasites. In order to elucidate the physiological processes underlying the potentially disease-related colour changes, we have analysed spatial and temporal expression patterns of GFP-like proteins and other biomarkers in corals from the Red Sea, the Arabian/Persian Gulf and Fiji both in their natural habitat and under specific laboratory conditions. The expression of distinct GFP-like proteins and the growth marker proliferating cell nuclear antigen was upregulated in growing branch tips and margins of healthy coral colonies as well as in disturbed colony parts. Furthermore, phenoloxidase activity increased in these proliferating tissues. It is thus demonstrated that locally accelerated growth is part of the innate immune response and repair mechanisms in reef-building corals and, moreover, these processes can be detected utilizing the excellent biomarker properties of GFP-like proteins. Finally, the results of this work suggest an additional vulnerability of corals in predicted future scenarios of increased ocean acidification, warming and eutrophication that are anticipated to reduce coral growth capacity.

Multi-Affinity for Growing Rough Interfaces of Bacterial Colonies

NASA Astrophysics Data System (ADS)

Kobayashi, N.; Ozawa, T.; Saito, K.; Yamazaki, Y.; Matsuyama, T.; Matsushita, M.

We have examined whether rough interfaces of bacterial colonies are multi-affine. We have used the bacterial species called textit{Bacillus subtilis}, which has been found to exhibit a variety of colony patterns when varying both the concentration of nutrient and solidity of agar medium. Consequently, we have found that the colony interface on a nutrient-rich, solid agar medium is multi-affine. On the other hand, the colony interface on a nutrient-rich, semi-solid agar medium is self-affine.

Aggregation Dynamics Using Phase Wave Signals and Branching Patterns

NASA Astrophysics Data System (ADS)

Sakaguchi, Hidetsugu; Kusagaki, Takuma

2016-09-01

The aggregation dynamics of slime mold is studied using coupled equations of phase ϕ and cell concentration n. Phase waves work as tactic signals for aggregation. Branching structures appear during the aggregation. A stationary branching pattern appears like a river network, if cells are uniformly supplied into the system.

Variability in the Branching Pattern of the Internal Iliac Artery in Indian Population and Its Clinical Importance

PubMed Central

Sivanandan, Anandarani; Sendiladibban, Sakthivelavan; Felicia Jebakani, Christilda

2014-01-01

Internal iliac artery (IIA) is one of the terminal branches of the common iliac artery and is the prime artery of pelvis. The artery has many parietal and visceral branches and hence the variations are frequently noted. The larger branches, namely, the inferior gluteal artery, the superior gluteal artery, and the internal pudendal artery, show sufficient regularity in their patterns of origin to allow typing. The variability of the IIA and its branching pattern were studied by dissecting sixty-eight male pelvic halves (34 right and 34 left) and forty-eight female pelvic halves (24 right and 24 left sides). In significant number of specimens, IIA terminated without dividing into 2 trunks as against the usual description. There was also considerable interchange of branches between the 2 terminal divisions. The patterns of branching noted were grouped as per Adachi's classification. The incidence was noted to be as follows: type Ia in 60.6%, type Ib in 2.6%, type IIa in 15.8%, and type III in 21%. The other types were not observed in this study. Conclusion. Interventions in the pelvic region must take into account the variability of the IIA and its branches that can modify the expected relations and may lead to undesired hemorrhagic or embolic accidents. PMID:25580296

The pivotal role of aristaless in development and evolution of diverse antennal morphologies in moths and butterflies.

PubMed

Ando, Toshiya; Fujiwara, Haruhiko; Kojima, Tetsuya

2018-01-25

Antennae are multi-segmented appendages and main odor-sensing organs in insects. In Lepidoptera (moths and butterflies), antennal morphologies have diversified according to their ecological requirements. While diurnal butterflies have simple, rod-shaped antennae, nocturnal moths have antennae with protrusions or lateral branches on each antennal segment for high-sensitive pheromone detection. A previous study on the Bombyx mori (silk moth) antenna, forming two lateral branches per segment, during metamorphosis has revealed the dramatic change in expression of antennal patterning genes to segmentally reiterated, branch-associated pattern and abundant proliferation of cells contributing almost all the dorsal half of the lateral branch. Thus, localized cell proliferation possibly controlled by the branch-associated expression of antennal patterning genes is implicated in lateral branch formation. Yet, actual gene function in lateral branch formation in Bombyx mori and evolutionary mechanism of various antennal morphologies in Lepidoptera remain elusive. We investigated the function of several genes and signaling specifically in lateral branch formation in Bombyx mori by the electroporation-mediated incorporation of siRNAs or morpholino oligomers. Knock down of aristaless, a homeobox gene expressed specifically in the region of abundant cell proliferation within each antennal segment, during metamorphosis resulted in missing or substantial shortening of lateral branches, indicating its importance for lateral branch formation. aristaless expression during metamorphosis was lost by knock down of Distal-less and WNT signaling but derepressed by knock down of Notch signaling, suggesting the strict determination of the aristaless expression domain within each antennal segment by the combinatorial action of them. In addition, analyses of pupal aristaless expression in antennae with various morphologies of several lepidopteran species revealed that the aristaless expression pattern has a striking correlation with antennal shapes, whereas the segmentally reiterated expression pattern was observed irrespective of antennal morphologies. Our results presented here indicate the significance of aristaless function in lateral branch formation in B. mori and imply that the diversification in the aristaless expression pattern within each antennal segment during metamorphosis is one of the significant determinants of antennal morphologies. According to these findings, we propose a mechanism underlying development and evolution of lepidopteran antennae with various morphologies.

Studies in the differentiation between Microsporum ferrugineum Ota and Trichophyton soudanense Joyeux.

PubMed

Weitzman, I; Rosenthal, S

1984-02-15

A study, conducted with 20 isolates of Microsporum ferrugineum and 12 isolates of Trichophyton soudanense, revealed that some of the discrepancies in the literature regarding their characteristics and differentiation were due to methodology, strain variation and the use of an insufficient number of isolates. We found all isolates of T. soudanense to be urease negative and gelatinase positive (usually by the first week); to produce brown to black colonies on Lowenstein-Jensen medium; to rapidly decompose casein and more slowly tyrosine; to grow well or better at 37 degrees C as compared to room temperature; to produce reflexive branching on cornmeal Tween agar and abundant microconidia on casero medium and to exhibit no sexual reaction with either mating type of arthroderma simii. All but one isolate demonstrated restricted growth on lactose agar and only three isolates perforated hair. In contrast, we found 18 of 20 isolates of M. ferrugineum to be urease positive in urea broth (most isolates were negative on urea agar); all produced light-colored colonies on Lowenstein-Jensen medium; spreading colonies on lactose agar and failed to perforate hair in vitro or to produce reflexive branching. Most isolates manifested poorer to no growth at 37 degrees C compared to room temperature and all but one failed to decompose casein and tyrosine. A few strains produced macroconidia and/or microconidia on casero medium and some reacted sexually with A. simii (a) (-) mating type. Gelatin hydrolysis was variable.(ABSTRACT TRUNCATED AT 250 WORDS)

Colony geometry and structural complexity of the endangered species Acropora cervicornis partly explains the structure of their associated fish assemblage.

PubMed

Agudo-Adriani, Esteban A; Cappelletto, Jose; Cavada-Blanco, Francoise; Croquer, Aldo

2016-01-01

In the past decade, significant efforts have been made to describe fish-habitat associations. However, most studies have oversimplified actual connections between fish assemblages and their habitats by using univariate correlations. The purpose of this study was to identify the features of habitat forming corals that facilitate and influences assemblages of associated species such as fishes. For this we developed three-dimensional models of colonies of Acropora cervicornis to estimate geometry (length and height), structural complexity (i.e., volume, density of branches, etc.) and biological features of the colonies (i.e., live coral tissue, algae). We then correlated these colony characteristics with the associated fish assemblage using multivariate analyses. We found that geometry and complexity were better predictors of the structure of fish community, compared to other variables such as percentage of live coral tissue or algae. Combined, the geometry of each colony explained 40% of the variability of the fish assemblage structure associated with this coral species; 61% of the abundance and 69% of fish richness, respectively. Our study shows that three-dimensional reconstructions of discrete colonies of Acropora cervicornis provides a useful description of the colonial structural complexity and may explain a great deal of the variance in the structure of the associated coral reef fish community. This demonstration of the strongly trait-dependent ecosystem role of this threatened species has important implications for restoration and conservation efforts.

Colony geometry and structural complexity of the endangered species Acropora cervicornis partly explains the structure of their associated fish assemblage

PubMed Central

Cappelletto, Jose; Cavada-Blanco, Francoise; Croquer, Aldo

2016-01-01

In the past decade, significant efforts have been made to describe fish-habitat associations. However, most studies have oversimplified actual connections between fish assemblages and their habitats by using univariate correlations. The purpose of this study was to identify the features of habitat forming corals that facilitate and influences assemblages of associated species such as fishes. For this we developed three-dimensional models of colonies of Acropora cervicornis to estimate geometry (length and height), structural complexity (i.e., volume, density of branches, etc.) and biological features of the colonies (i.e., live coral tissue, algae). We then correlated these colony characteristics with the associated fish assemblage using multivariate analyses. We found that geometry and complexity were better predictors of the structure of fish community, compared to other variables such as percentage of live coral tissue or algae. Combined, the geometry of each colony explained 40% of the variability of the fish assemblage structure associated with this coral species; 61% of the abundance and 69% of fish richness, respectively. Our study shows that three-dimensional reconstructions of discrete colonies of Acropora cervicornis provides a useful description of the colonial structural complexity and may explain a great deal of the variance in the structure of the associated coral reef fish community. This demonstration of the strongly trait-dependent ecosystem role of this threatened species has important implications for restoration and conservation efforts. PMID:27069801

Perfluorinated Compounds and Polybrominated Diphenyl Ethers in Great Blue Heron Eggs from Three Colonies on the Mississippi River, Minnesota

USGS Publications Warehouse

Custer, T.W.; Kannan, K.; Tao, L.; Yun, S.-H.; Trowbridge, A.

2010-01-01

Archived Great Blue Heron (Ardea herodias) eggs (N = 16) collected in 1993 from three colonies on the Mississippi River in Minnesota were analyzed in 2007 for perfluorinated compounds (PFCs) and polybrominated diphenyl ethers (PBDEs). One of the three colonies, Pig's Eye, was located near a presumed source of PFCs. Based on a multivariate analysis, the pattern of nine PFC concentrations differed significantly between Pig's Eye and the upriver (P = 0.002) and downriver (P = 0.02) colonies; but not between the upriver and downriver colonies (P = 0.25). Mean concentrations of perfluorooctane sulfonate (PFOS), a major PFC compound, were significantly higher at the Pig's Eye colony (geometric mean = 940 ng/g wet weight) than at upriver (60 ng/g wet weight) and downriver (131 ng/g wet weight) colonies. Perfluorooctane sulfonate concentrations from the Pig's Eye colony are among the highest reported in bird eggs. Concentrations of PFOS in Great Blue Heron eggs from Pig's Eye were well below the toxicity thresholds estimated for Bobwhite Quail (Colinus virginianus) and Mallards (Anas platyrhynchos), but within the toxicity threshold estimated for White Leghorn Chickens (Gallus domesticus). The pattern of six PBDE congener concentrations did not differ among the three colonies (P = 0.08). Total PBDE concentrations, however, were significantly greater (P = 0.03) at Pig's Eye (geometric mean = 142 ng/g wet weight) than the upriver colony (13 ng/g wet weight). Polybrominated diphenyl ether concentrations in two of six Great Blue Heron eggs from the Pig's Eye colony were within levels associated with altered reproductive behavior in American Kestrels (Falco sparverius).

4D Biofabrication of Branching Multicellular Structures: A Morphogenesis Simulation Based on Turing’s Reaction-Diffusion Dynamics

NASA Astrophysics Data System (ADS)

Zhu, Xiaolu; Yang, Hao

2017-12-01

The recently emerged four-dimensional (4D) biofabrication technique aims to create dynamic three-dimensional (3D) biological structures that can transform their shapes or functionalities with time when an external stimulus is imposed or when cell postprinting self-assembly occurs. The evolution of 3D pattern of branching geometry via self-assembly of cells is critical for 4D biofabrication of artificial organs or tissues with branched geometry. However, it is still unclear that how the formation and evolution of these branching pattern are biologically encoded. We study the 4D fabrication of lung branching structures utilizing a simulation model on the reaction-diffusion mechanism, which is established using partial differential equations of four variables, describing the reaction and diffusion process of morphogens with time during the development process of lung branching. The simulation results present the forming process of 3D branching pattern, and also interpret the behaviors of side branching and tip splitting as the stalk growing, through 3D visualization of numerical simulation.

Is there a role for termite alates in colony expansion in Wisconsin?

Treesearch

Frederick Green III; Rachel A. Arango; Glenn R. Esenther; Thomas G. Shelton

2014-01-01

Termite colonies in Wisconsin tend to be large and widely spread out geographically, and separated by distances up to 1342km. We recently completed a study to determine the genetic diversity and population substructure of thirteen existing colonies of Reticulitermes flavipes using amplified fragment length polymorphism to determine patterns of...

Polyclonality of Staphylococcus epidermidis residing on the healthy ocular surface.

PubMed

Ueta, Mayumi; Iida, Tetsuya; Sakamoto, Masako; Sotozono, Chie; Takahashi, Junko; Kojima, Kentaro; Okada, Kazuhisa; Chen, Xiuhao; Kinoshita, Shigeru; Honda, Takeshi

2007-01-01

Staphylococcus epidermidis is part of the normal bacterial flora on the ocular surface. The chromosomal DNA of bacterial isolates obtained from the conjunctival sac, upper and lower lid margins, and upper and lower Meibomian glands of healthy volunteers was subjected to SmaI digestion and PFGE to study the genetic diversity of the organisms. Multiple colonies were also examined of S. epidermidis derived from the conjunctival sac of the same subjects. Lastly, commensal bacteria were harvested from the ocular surfaces of four healthy subjects once a month for 6 months, and the genetic background of the S. epidermidis isolates was analysed. It was found that bacterial strains not only from different subjects but also from multiple ocular surface sites of the same subject exhibited different PFGE patterns. In five of 42 subjects multiple colonies of S. epidermidis were isolated from the conjunctival sac; three harboured multiple colonies with different PFGE patterns, and two manifested multiple colonies with identical PFGE patterns. S. epidermidis isolated from the conjunctival sac of the same subjects over a 6-month period exhibited varying PFGE patterns. The data demonstrate the polyclonality of S. epidermidis on the healthy ocular surface.

The endangered pondberry (Lindera melissifolia [Walt] Blume, Lauraceae)

Treesearch

Margaret S. Devall

2013-01-01

Pondberry (Lindera melissifolia) is an endangered plant species that occurs in seven southern states. It is a rhizomatous, clonal shrub that usually grows in colonies and has numerous stems with few branches and drooping leaves that give off a spicy odor when crushed. Pondberry is dioecious, with small yellow flowers that bloom in spring and have scarlet drupes that...

Right bundle branch block pattern during right ventricular permanent pacing: Is it safe or not?

PubMed Central

Erdogan, Okan; Aksu, Feyza

2007-01-01

The present case report describes a patient with dual chamber pacemaker whose surface ECG demonstrated paced right bundle branch block pattern suggesting a malpositioned ventricular lead in the left ventricle. However, diagnostic work-up revealed that the lead was appropriately located in the right ventricular apex. Diagnostic maneuvers and clues for differentiating safe right bundle branch block pattern during permanent pacing are thoroughly revisited and discussed within the article. PMID:17684578

Automated numerical simulation of biological pattern formation based on visual feedback simulation framework

PubMed Central

Sun, Mingzhu; Xu, Hui; Zeng, Xingjuan; Zhao, Xin

2017-01-01

There are various fantastic biological phenomena in biological pattern formation. Mathematical modeling using reaction-diffusion partial differential equation systems is employed to study the mechanism of pattern formation. However, model parameter selection is both difficult and time consuming. In this paper, a visual feedback simulation framework is proposed to calculate the parameters of a mathematical model automatically based on the basic principle of feedback control. In the simulation framework, the simulation results are visualized, and the image features are extracted as the system feedback. Then, the unknown model parameters are obtained by comparing the image features of the simulation image and the target biological pattern. Considering two typical applications, the visual feedback simulation framework is applied to fulfill pattern formation simulations for vascular mesenchymal cells and lung development. In the simulation framework, the spot, stripe, labyrinthine patterns of vascular mesenchymal cells, the normal branching pattern and the branching pattern lacking side branching for lung branching are obtained in a finite number of iterations. The simulation results indicate that it is easy to achieve the simulation targets, especially when the simulation patterns are sensitive to the model parameters. Moreover, this simulation framework can expand to other types of biological pattern formation. PMID:28225811

Automated numerical simulation of biological pattern formation based on visual feedback simulation framework.

PubMed

Sun, Mingzhu; Xu, Hui; Zeng, Xingjuan; Zhao, Xin

2017-01-01

There are various fantastic biological phenomena in biological pattern formation. Mathematical modeling using reaction-diffusion partial differential equation systems is employed to study the mechanism of pattern formation. However, model parameter selection is both difficult and time consuming. In this paper, a visual feedback simulation framework is proposed to calculate the parameters of a mathematical model automatically based on the basic principle of feedback control. In the simulation framework, the simulation results are visualized, and the image features are extracted as the system feedback. Then, the unknown model parameters are obtained by comparing the image features of the simulation image and the target biological pattern. Considering two typical applications, the visual feedback simulation framework is applied to fulfill pattern formation simulations for vascular mesenchymal cells and lung development. In the simulation framework, the spot, stripe, labyrinthine patterns of vascular mesenchymal cells, the normal branching pattern and the branching pattern lacking side branching for lung branching are obtained in a finite number of iterations. The simulation results indicate that it is easy to achieve the simulation targets, especially when the simulation patterns are sensitive to the model parameters. Moreover, this simulation framework can expand to other types of biological pattern formation.

Variations in the branching pattern of posterior division of mandibular nerve: a case report.

PubMed

Muraleedharan, Aparna; Veeramani, Raveendranath; Chand, Parkash

2014-11-01

Abnormal communications among the branches of mandibular nerve especially the posterior division are significant due to various procedures undertaken in this region. These variations are worth reporting as they pose serious implications in several interventions in this region, and may even lead to false diagnosis. During routine dissection, the mandibular nerve and its branches were dissected in the infratemporal fossa. The branches from the posterior division of the mandibular nerve namely the inferior alveolar and auriculotemporal nerves were carefully dissected, and their abnormal branching pattern was noted. There was a communicating branch between left inferior alveolar and auriculotemporal nerve. There was also a variant recurrent branch from the left inferior alveolar nerve that supplied the lateral pterygoid muscle. Such variant branches and communications between the branches of mandibular nerve as seen in this case have an embryological basis and are clinically important in this region especially for dental surgeries and anesthesia.

Universality in Bacterial Colonies

NASA Astrophysics Data System (ADS)

Bonachela, Juan A.; Nadell, Carey D.; Xavier, João B.; Levin, Simon A.

2011-07-01

The emergent spatial patterns generated by growing bacterial colonies have been the focus of intense study in physics during the last twenty years. Both experimental and theoretical investigations have made possible a clear qualitative picture of the different structures that such colonies can exhibit, depending on the medium on which they are growing. However, there are relatively few quantitative descriptions of these patterns. In this paper, we use a mechanistically detailed simulation framework to measure the scaling exponents associated with the advancing fronts of bacterial colonies on hard agar substrata, aiming to discern the universality class to which the system belongs. We show that the universal behavior exhibited by the colonies can be much richer than previously reported, and we propose the possibility of up to four different sub-phases within the medium-to-high nutrient concentration regime. We hypothesize that the quenched disorder that characterizes one of these sub-phases is an emergent property of the growth and division of bacteria competing for limited space and nutrients.

Branching Patterns and Stepped Leaders in an Electric-Circuit Model for Creeping Discharge

NASA Astrophysics Data System (ADS)

Hidetsugu Sakaguchi,; Sahim M. Kourkouss,

2010-06-01

We construct a two-dimensional electric circuit model for creeping discharge. Two types of discharge, surface corona and surface leader, are modeled by a two-step function of conductance. Branched patterns of surface leaders surrounded by the surface corona appear in numerical simulation. The fractal dimension of branched discharge patterns is calculated by changing voltage and capacitance. We find that surface leaders often grow stepwise in time, as is observed in lightning leaders of thunder.

vasa-related genes and their expression in stem cells of colonial parasitic rhizocephalan barnacle Polyascus polygenea (Arthropoda: Crustacea: Cirripedia: Rhizocephala).

PubMed

Shukalyuk, Andrey I; Golovnina, Kseniya A; Baiborodin, Sergei I; Gunbin, Konstantin V; Blinov, Alexander G; Isaeva, Valeria V

2007-02-01

vasa (vas)-related genes are members of the DEAD-box protein family and are expressed in the germ cells of many Metazoa. We cloned vasa-related genes (PpVLG, CpVLG) and other DEAD-box family related genes (PpDRH1, PpDRH2, CpDRH, AtDRHr) from the colonial parasitic rhizocephalan barnacle Polyascus polygenea, the non-colonial Clistosaccus paguri (Crustacea: Cirripedia: Rhizocephala), and the parasitic isopodan Athelgis takanoshimensis (Crustacea: Isopoda). The colonial Polyascus polygenea, a parasite of the coastal crabs Hemigrapsus sanguineus and Hemigrapsus longitarsis was used as a model object for further detailed investigations. Phylogenetic analysis suggested that PpVLG and CpVLG are closely related to vasa-like genes of other Arthropoda. The rest of the studied genes form their own separate branch on the phylogenetic tree and have a common ancestry with the p68 and PL10 subfamilies. We suppose this group may be a new subfamily of the DEAD-box RNA helicases that is specific for parasitic Crustacea. We found PpVLG and PpDRH1 expression products in stem cells from stolons and buds of internae, during asexual reproduction of colonial P. polygenea, and in germ cells from sexually reproducing externae, including male spermatogenic cells and female oogenic cells.

Extending Jak2V617F and MplW515 mutation analysis to single hematopoietic colonies and B and T lymphocytes.

PubMed

Pardanani, Animesh; Lasho, Terra L; Finke, Christy; Mesa, Ruben A; Hogan, William J; Ketterling, Rhett P; Gilliland, Dwight Gary; Tefferi, Ayalew

2007-09-01

JAK2V617F and MPLW515L/K are myeloproliferative disorder (MPD)-associated mutations. We genotyped 552 individual hematopoietic colonies obtained by CD34+ cell culture from 16 affected patients (13 JAK2V617F and 3 MPLW515L/K) to determine (a) the proportion of colonies harboring a particular mutation in the presence or absence of cytokines, (b) the lineage distribution of endogenous colonies for each mutation, and (c) the differences (if any) in the pattern of mutation among the various MPDs, as established by genotyping of individual colonies. Genotyping analysis revealed cohabitation of mutation-negative and mutation-positive endogenous colonies in polycythemia vera as well as other MPDs. Culture of progenitor cells harboring MPLW515L/K yielded virtually no endogenous erythroid colonies in contrast to JAK2V617F-harboring progenitor cells. The mutation pattern (i.e., relative distribution of homozygous, heterozygous, or wild-type colonies) was not a distinguishing feature among the MPDs, and MPLW515 mutations were detected in B and/or T lymphocytes in all three patients tested. These observations suggest that clonal myelopoiesis antedates acquisition of JAK2V617F or MPLW515L/K mutations and that the latter is acquired in a lympho-myeloid progenitor cell.

[Angiographic evaluation of branching pattern and anatomy of the aortic arch].

PubMed

Ergun, Onur; Tatar, İdil Güneş; Birgi, Erdem; Durmaz, Hasan Ali; Akçalar, Seray; Kurt, Aydın; Hekimoğlu, Baki

2015-04-01

The study aimed to investigate anatomical variations in branching pattern and anatomy of the aortic arch, and the prevalence of each type. Between September 2011 and November 2013, angiographic studies of 270 patients (144 male, 126 female) were analyzed retrospectively for variations in branching pattern and anatomy of the aortic arch. Patient mean age was 59.8 years (range, 13-88). Branching variations were found and divided into subtypes. Patients were also classified according to arch anatomy. Incidence of variations and types of aortic arch were statistically analysed. Analysis of the 270 patients revealed six types of branching pattern. Type I, classical pattern arch with three branches (TB, LCC, LS), was observed in 198 cases (73.3%). Type II (bovine arch), the most commonly observed variation, in which LCC originates from TB, was observed in 58 cases (21.5%). Type III, in which the left vertebral artery arises from the arch, was seen in seven cases (2.6%). Type IV, a combination of types II and III, was observed in three cases (1.1%). Type V, common origin of common carotids, LS and aberrant RS, was found in three cases (1.1%). Type VI (avian type), arch with only two branches, was observed in one case (0.4%). When patients were classified according to aortic arch anatomy, Type 1, Type 2 and Type 3 were observed in 195, 40 and 35 patients respectively. Knowledge of the variations and anatomy of the aortic arch is essential during interventional procedures and neck-thorax surgery.

Seabird, fisheries, marine mammal, and oceanographic investigations around Kasatochi, Koniuji, and Ulak Islands, August 1996 (SMMOCI 96-3)

USGS Publications Warehouse

Drew, Gary S.; Piatt, John F.; Byrd, G. Vernon; Dragoo, Donald E.

2003-01-01

Although islands in the Aleutians are known to support some of the highest densities of seabirds in the world, their remoteness has limited systematic research on the at-sea distribution of seabirds near these colonies.  Kasatochi, Koniuji, and Ulak islands, in the central Aleutian Islands, together comprise one of nine ecological sites monitored once every 5 years on an annual rotation since 1996 by the Alaska Maritime National Wildlife Refuge (AMNWR).  To supplement annual colony monitoring and examine seabird distribution away from colony sites, the AMNWR personnel in conjunction with U.S. Geological Survey (USGS) researchers, conducted a pelagic survey of the waters around these 3 islands in 1996.Previous research in this area has focused on the seabird colony sites located on Kasatochi, Koniuji, and Ulak islands.  Although boat-based circumnavigations have been used to evaluate colony populations (Early et al. 1981; Bailey and Trapp 1986; Byrd and Williams 1994; Byrd 1995a, 1995b), wide ranging pelagic surveys to examine foraging patterns had not previously been conducted near the islands.  The goal of this survey was to examine foraging patterns of the seabirds nesting in the study area and identify factors that may explain seabird distribution patterns.

Breeding synchrony in colonial birds: from local stress to global harmony.

PubMed

Jovani, Roger; Grimm, Volker

2008-07-07

Why and how birds in colonies often breed in striking synchrony is an unsolved question. In colonies, conspecific birds often destroy eggs and kill chicks, either intentionally or not. We propose that social tranquillity at the time of laying can be achieved if a bird's stress level is partly determined by the agitation of its neighbours. Moreover, we propose that this local process, together with environmental cues, can synchronize breeding between neighbours and through a whole colony. We tested our hypotheses using a generic individual-based model where the breeding predisposition of females was updated daily depending on an increase in the photoperiod (positively) and the stress level of neighbours: negatively if they were agitated, and positively otherwise. A female laid her eggs when her stress level fell to a critical value. Even giving only a low relevance to the neighbour's stress level was enough to synchronize the laying date of neighbours and also of a huge colony. Moreover, females bred in a safer environment, which is known from field studies to increase fitness. Our study highlights the power of local adaptive (individual) behaviour to create global (colony) patterns. We argue that collective patterns such as breeding synchrony in colonial birds could have simple adaptive individual-level explanations.

Characterization of viral siRNA populations in honey bee colony collapse disorder.

PubMed

Chejanovsky, Nor; Ophir, Ron; Schwager, Michal Sharabi; Slabezki, Yossi; Grossman, Smadar; Cox-Foster, Diana

2014-04-01

Colony Collapse Disorder (CCD), a special case of collapse of honey bee colonies, has resulted in significant losses for beekeepers. CCD-colonies show abundance of pathogens which suggests that they have a weakened immune system. Since honey bee viruses are major players in colony collapse and given the important role of viral RNA interference (RNAi) in combating viral infections we investigated if CCD-colonies elicit an RNAi response. Deep-sequencing analysis of samples from CCD-colonies from US and Israel revealed abundant small interfering RNAs (siRNA) of 21-22 nucleotides perfectly matching the Israeli acute paralysis virus (IAPV), Kashmir virus and Deformed wing virus genomes. Israeli colonies showed high titers of IAPV and a conserved RNAi-pattern of matching the viral genome. That was also observed in sample analysis from colonies experimentally infected with IAPV. Our results suggest that CCD-colonies set out a siRNA response that is specific against predominant viruses associated with colony losses. Copyright © 2014 Elsevier Inc. All rights reserved.

Effects of Wintering Environment and Parasite–Pathogen Interactions on Honey Bee Colony Loss in North Temperate Regions

PubMed Central

Currie, Robert W.

2016-01-01

Extreme winter losses of honey bee colonies are a major threat to beekeeping but the combinations of factors underlying colony loss remain debatable. We monitored colonies in two environments (colonies wintered indoors or outdoors) and characterized the effects of two parasitic mites, seven viruses, and Nosema on honey bee colony mortality and population loss over winter. Samples were collected from two locations within hives in fall, mid-winter and spring of 2009/2010. Although fall parasite and pathogen loads were similar in outdoor and indoor-wintered colonies, the outdoor-wintered colonies had greater relative reductions in bee population score over winter. Seasonal patterns in deformed wing virus (DWV), black queen cell virus (BQCV), and Nosema level also differed with the wintering environment. DWV and Nosema levels decreased over winter for indoor-wintered colonies but BQCV did not. Both BQCV and Nosema concentration increased over winter in outdoor-wintered colonies. The mean abundance of Varroa decreased and concentration of Sacbrood virus (SBV), Kashmir bee virus (KBV), and Chronic bee paralysis virus (CBPV) increased over winter but seasonal patterns were not affected by wintering method. For most viruses, either entrance or brood area samples were reasonable predictors of colony virus load but there were significant season*sample location interactions for Nosema and BQCV, indicating that care must be taken when selecting samples from a single location. For Nosema spp., the fall entrance samples were better predictors of future infestation levels than were fall brood area samples. For indoor-wintered colonies, Israeli acute paralysis virus IAPV concentration was negatively correlated with spring population size. For outdoor-wintered hives, spring Varroa abundance and DWV concentration were positively correlated with bee loss and negatively correlated with spring population size. Multivariate analyses for fall collected samples indicated higher DWV was associated with colony death as did high SBV for spring-collected samples. PMID:27448049

Loss of live coral compromises predator-avoidance behaviour in coral reef damselfish.

PubMed

Boström-Einarsson, Lisa; Bonin, Mary C; Munday, Philip L; Jones, Geoffrey P

2018-05-17

Tropical reefs have experienced an unprecedented loss of live coral in the past few decades and the biodiversity of coral-dependent species is under threat. Many reef fish species decline in abundance as coral cover is lost, yet the mechanisms responsible for these losses are largely unknown. A commonly hypothesised cause of fish decline is the loss of shelter space between branches as dead corals become overgrown by algae. Here we tested this hypothesis by quantifying changes in predator-avoidance behaviour of a common damselfish, Pomacentrus moluccensis, before and after the death of their coral colony. Groups of P. moluccensis were placed on either healthy or degraded coral colonies, startled using a visual stimulus and their sheltering responses compared over a 7-week period. P. moluccensis stopped sheltering amongst the coral branches immediately following the death of the coral, despite the presence of ample shelter space. Instead, most individuals swam away from the dead coral, potentially increasing their exposure to predators. It appears that the presence of live coral rather than shelter per se is the necessary cue that elicits the appropriate behavioural response to potential predators. The disruption of this link poses an immediate threat to coral-associated fishes on degrading reefs.

Structure and anticancer activity of native and modified polysaccharides from brown alga Dictyota dichotoma.

PubMed

Usoltseva, Roza V; Shevchenko, Natalia M; Malyarenko, Olesya S; Ishina, Irina A; Ivannikova, Svetlana I; Ermakova, Svetlana P

2018-01-15

The laminaran DdL and fucoidan DdF were obtained from the brown alga Dictyota dichotoma. DdF was a sulfated (28.9%) and acetylated heteropolysaccharide containing fucose, galactose, mannose and glucose (57.9, 20.4, 12.4 and 9.2mol%, respectively). DdL was a 1,3;1,6-β-d-glucan with the main chain built from 1,3-linked glucose residues and single glucose residue in branches at C6 (one branch on three glucose residues of the main chain). Sulfated (43.7%) laminaran DdLs was obtained from DdL by sulfation. It was determined that sulfates occur at C2, C4 and C6 of glucose residues. The anticancer effect of DdF, DdL, and DdLs (200μg/mL) was studied in vitro on colon cancer cells HCT-116, HT-29, and DLD-1. The effect of polysaccharides (40μg/mL) on colony formation of DLD-1 cancer cells after irradiation (4Gy) was investigated first. All polysaccharides showed a synergistic effect with X-ray irradiation against cancer cells, decreasing the amount and size of cancer cells colonies. Copyright © 2017 Elsevier Ltd. All rights reserved.

Anatomy of psoas muscle innervation: Cadaveric study.

PubMed

Mahan, Mark A; Sanders, Luke E; Guan, Jian; Dailey, Andrew T; Taylor, William; Morton, David A

2017-05-01

Hip flexion weakness is relatively common after lateral transpsoas surgery. Persistent weakness may result from injury to the innervation of the psoas major muscles (PMMs); however, anatomical texts have conflicting descriptions of this innervation, and the branching pattern of the nerves within the psoas major, particularly relative to vertebral anatomy, has not been described. The authors dissected human cadavers to describe the branching pattern of nerves supplying the PMMs. Sixteen embalmed cadavers were dissected, and the fine branching pattern of the innervation to the PMM was studied in 24 specimens. The number of branches and width and length of each branch of nerves to the PMMs were quantified. Nerve branches innervating the PMMs arose from spinal nerve levels L1-L4, with an average of 6.3 ± 1.1 branches per muscle. The L1 nerve branch was the least consistently present, whereas L2 and L3 branches were the most robust, the most numerous, and always present. The nerve branches to the psoas major commonly crossed the intervertebral (IV) disc obliquely prior to ramification within the muscle; 76%, 80%, and 40% of specimens had a branch to the PMM cross the midportion of the L2-3, L3-4, and L4-5 IV discs, respectively. The PMMs are segmentally innervated from the L2-L4 ventral rami branches, where these branches course obliquely across the L2-3, L3-4, and L4-5 IV discs. Knowledge of the mapping of nerve branches to the PMMs may reduce injury and the incidence of persistent weak hip flexion during lateral transpsoas surgery. Clin. Anat. 30:479-486, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Holotransformations of bacterial colonies and genome cybernetics

NASA Astrophysics Data System (ADS)

Ben-Jacob, Eshel; Tenenbaum, Adam; Shochet, Ofer; Avidan, Orna

1994-01-01

We present a study of colony transformations during growth of Bacillus subtilis under adverse environmental conditions. It is a continuation of our pilot study of “Adaptive self-organization during growth of bacterial colonies” (Physica A 187 (1992) 378). First we identify and describe the transformations pathway, i.e. the excitation of the branching modes from Bacillus subtilis 168 (grown under diffusion limited conditions) and the phase transformations between the tip-splitting phase (phase T) and the chiral phase (phase C) which belong to the same mode. This pathway shows the evolution of complexity as the bacteria are exposed to adverse growth conditions. We present the morphology diagram of phases T and C as a function of agar concentration and pepton level. As expected, the growth of phase T is ramified (fractal-like or DLA-like) at low pepton level (about 1 g/1) and turns compact at high pepton level (about 10 g/1). The growth of phase C is also ramified at low pepton level and turns denser and finally compact as the pepton level increases. Generally speaking, the colonies develop more complex patterns and higher micro-level organization for more adverse environments. We use the growth velocity as a response function to describe the growth. At low agar concentration (and low pepton level) phase C grows faster than phase T, and for a high agar concentration (about 2%) phase T grows faster. We observe colony transformations between the two phases (phase transformations). They are found to be consistent with the “fastest growing morphology” selection principle adopted from azoic systems. The transformations are always from the slower phase to the faster one. Hence, we observe T→ C transformations at low agar concentrations and C→ T transformations at high agar concentrations. We have observed both localized and extended transformations. Usually, the transformations are localized for more adverse growth conditions, and extended for growth conditions close to the boundaries between morphologies. We have observed also transformations between different branching modes, as well as transformations via virtual states. Motivated by the contemporary knowledge about phages and plasmids, we postulate a theoretical framework to comply with our experimental findings. We explain our observations using these assumptions as well as our proposal of co-mutations and auto-catalytic mutations as presented in the above mentioned pilot paper. This theoretical framework is a part of the new evolving picture of genome cybernetics. We also discuss the concept of adaptive genome changes which are based on pre-existing knowledge as well as the concept of genetic learning. i.e. changes (in response to a new problem) which develop the potential for adaptive genome changes. These concepts follow naturally if the picture of genome cybernetics is accepted. We conclude with a discussion of the implications and with further predictions (to be tested experimentally) derived from our assumptions.

Molecular variants of human papillomavirus type 16 from four continents suggest ancient pandemic spread of the virus and its coevolution with humankind.

PubMed

Chan, S Y; Ho, L; Ong, C K; Chow, V; Drescher, B; Dürst, M; ter Meulen, J; Villa, L; Luande, J; Mgaya, H N

1992-04-01

We have amplified by the polymerase chain reaction, cloned, and sequenced genomic segments of 118 human papillomavirus type 16 (HPV-16) isolates from 76 cervical biopsy, 14 cervical smear, 3 vulval biopsy, 2 penile biopsy, 2 anal biopsy, and 1 vaginal biopsy sample and two cell lines. The specimens were taken from patients in four countries--Singapore, Brazil, Tanzania, and Germany. The sequence of a 364-bp fragment of the long control region of the virus revealed 38 variants, most of which differed by one or several point mutations. Phylogenetic trees were constructed by distance matrix methods and a transformation series approach. The trees based on the long control region were supported by another set based on the complete E5 protein-coding region. Both sets had two main branches. Nearly all of the variants from Tanzania were assigned to one (African) branch, and all of the German and most of the Singaporean variants were assigned to the other (Eurasian) branch. While some German and Singaporean variants were identical, each group also contained variants that formed unique branches. In contrast to the group-internal homogeneity of the Singaporean, German, and Tanzanian variants, the Brazilian variants were clearly divided between the two branches. Exceptions to this were the seven Singaporean isolates with mutational patterns typical of the Tanzanian isolates. The data suggest that HPV-16 evolved separately for a long period in Africa and Eurasia. Representatives of both branches may have been transferred to Brazil via past colonial immigration. The comparable efficiencies of transfer of the African and the Eurasian variants to the New World suggest pandemic spread of HPV-16 in past centuries. Representatives of the African branch were possibly transferred to the Far East along old Arab and Indonesian sailing routes. Our data also support the view that HPV-16 is a well-defined virus type, since the variants show only a maximal genomic divergence of about 5%. The small amount of divergence in any one geographic location and the lack of marked divergence between the Tanzanian and Brazilian African genome variants two centuries after their likely introduction into the New World suggest a very slow rate of viral evolution. The phylogenetic tree therefore probably represents a minimum of several centuries of evolution, if not an age equal to that of the respective human races.

Outcome and management of pregnancies in severe chronic neutropenia patients by the European Branch of the Severe Chronic Neutropenia International Registry

PubMed Central

Zeidler, Cornelia; Grote, Ulrike A.H.; Nickel, Anna; Brand, Beate; Carlsson, Göran; Cortesão, Emília; Dufour, Carlo; Duhem, Caroline; Notheis, Gundula; Papadaki, Helen A.; Tamary, Hannah; Tjønnfjord, Geir E.; Tucci, Fabio; Van Droogenbroeck, Jan; Vermylen, Christiane; Voglova, Jaroslava; Xicoy, Blanca; Welte, Karl

2014-01-01

Long-term granulocyte-colony stimulating factor treatment has been shown to be safe and effective in severe chronic neutropenia patients. However, data on its use during pregnancy are limited. To address this issue, we analyzed all pregnancies reported to the European branch of the Severe Chronic Neutropenia International Registry since 1994. A total of 38 pregnancies in 21 women with chronic neutropenia (16 pregnancies in 10 women with congenital, 10 in 6 women with cyclic, 12 in 5 women with idiopathic neutropenia) were reported. Granulocyte-colony stimulating factor was administered throughout pregnancy in 16 women and for at least one trimester in a further 5 women. No major differences were seen between treated and untreated women with respect to pregnancy outcome, newborn complications and infections. In addition, we evaluated the genetic transmission of known or suspected genetic defects in 16 mothers having 22 newborns as well as in 8 men fathering 15 children. As a proof of inheritance, neutropenia was passed on to the newborn in 58% from female and in 62% from male patients with ELANE mutations, but also to some newborns from parents with unknown gene mutation. Based on our results, granulocyte-colony stimulating factor therapy has been shown to be safe for mothers throughout pregnancies and for newborns without any signs of teratogenicity. With an increasing number of adult patients, genetic counseling prior to conception and supportive care of mothers during pregnancy are crucial. The acceptance of having affected children may reflect the high quality of life obtained due to this treatment. PMID:24997149

Synthetic Arabinomannan Heptasaccharide Glycolipids Inhibit Biofilm Growth and Augment Isoniazid Effects in Mycobacterium smegmatis.

PubMed

Maiti, Krishnagopal; Syal, Kirtimaan; Chatterji, Dipankar; Jayaraman, Narayanaswamy

2017-10-05

Biofilm formation, involving attachment to an adherent surface, is a critical survival strategy of mycobacterial colonies in hostile environmental conditions. Here we report the synthesis of heptasaccharide glycolipids based on mannopyranoside units anchored on to a branched arabinofuranoside core. Two types of glycolipids-2,3-branched and 2,5-branched-were synthesized and evaluated for their efficacies in inhibiting biofilm growth by the non-pathogenic mycobacterium variant Mycobacterium smegmatis. Biofilm formation was inhibited at a minimum biofilm growth inhibition concentration (MBIC) of 100 μg mL -1 in the case of the 2,5-branched heptasaccharide glycolipid. Further, we were able to ascertain that a combination of the drug isoniazid with the branched heptasaccharide glycolipid (50 μg mL -1 ) potentiates the drug, making it three times more effective, with an improved MBIC of 30 μg mL -1 . These studies establish that synthetic glycolipids not only act as inhibitors of biofilm growth, but also provide a synergistic effect when combined with significantly lowered concentrations of isoniazid to disrupt the biofilm structures of the mycobacteria. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Directing the Branching Growth of Cuprous Oxide by OH- Ions

NASA Astrophysics Data System (ADS)

Chen, Kunfeng; Si, Yunfei; Xue, Dongfeng

The effect of OH- ions on the branching growth of cuprous oxide microcrystals was systematically studied by a reduction route, where copper-citrate complexes were reduced by glucose under alkaline conditions. Different copper salts including Cu(NO3)2, CuCl2, CuSO4, and Cu(Ac)2 were used in this work. The results indicate that the Cu2O branching growth habit is closely correlated to the concentration of OH- ions, which plays an important role in directing the diffusion-limited branching growth of Cu2O and influencing the reduction power of glucose. A variety of Cu2O branching patterns including 6-pod, 8-pod and 24-pod branches, have been achieved without using template and surfactant. The current method can provide a good platform for studying the growth mechanism of microcrystal branching patterns.

Diurnal patterns of branch movement in a desert shrub (Larrea tridentata) track hydraulic stress

NASA Astrophysics Data System (ADS)

Hallmark, A.

2016-12-01

Near-surface, repeat digital photography has emerged as a powerful tool to collect continuous observations of plant traits of individuals and communities across daily, seasonal, and annual time scales. To date, this technology has largely been used to detect patterns of vegetative phenology or "canopy greenness." Little work has been done to use digital photographs to quantify changes in canopy structure or shifts in canopy function on shorter time scales. In this study, we tracked the position of creosote (Larrea tridentata) branches using a timeseries of photos taken in a creosote-dominated shrubland in central New Mexico, USA where radiation, temperature, humidity, soil water content, soil water potential, and stem water potential were also measured. We found that both living and dead woody branches displayed dramatic diurnal patterns of movement, with shrubs only 1-2 m in height sometimes undergoing vertical shifts in branch position of over 0.25 m and changes in branch angle of over 20 degrees. Although circadian rhythms in plants are often attributed to cyclical patterns of photoperiod or temperature, we found that creosote branch movements were best correlated with diurnal changes in stem water potential and atmospheric humidity and that this correlation was stronger under wetter soil conditions. Branches were straighter and oriented in higher positions in times of low hydraulic stress, possibly preparing the creosote to better capture moisture via stemflow. Branches were oriented lower to the ground in times of high hydraulic stress, possibly providing more shade and reducing soil evaporation beneath the base of the shrub. To our knowledge, this is the first study to describe diurnal patterns of branch movements in creosote and is the most extensive dataset of observations of diurnal movements in any woody plant. It provides more knowledge about the biology of a desert shrub, but also offers novel methods for using repeat digital photography to gain inferences about plant form and function.

Outlier analyses to test for local adaptation to breeding grounds in a migratory arctic seabird.

PubMed

Tigano, Anna; Shultz, Allison J; Edwards, Scott V; Robertson, Gregory J; Friesen, Vicki L

2017-04-01

Investigating the extent (or the existence) of local adaptation is crucial to understanding how populations adapt. When experiments or fitness measurements are difficult or impossible to perform in natural populations, genomic techniques allow us to investigate local adaptation through the comparison of allele frequencies and outlier loci along environmental clines. The thick-billed murre ( Uria lomvia ) is a highly philopatric colonial arctic seabird that occupies a significant environmental gradient, shows marked phenotypic differences among colonies, and has large effective population sizes. To test whether thick-billed murres from five colonies along the eastern Canadian Arctic coast show genomic signatures of local adaptation to their breeding grounds, we analyzed geographic variation in genome-wide markers mapped to a newly assembled thick-billed murre reference genome. We used outlier analyses to detect loci putatively under selection, and clustering analyses to investigate patterns of differentiation based on 2220 genomewide single nucleotide polymorphisms (SNPs) and 137 outlier SNPs. We found no evidence of population structure among colonies using all loci but found population structure based on outliers only, where birds from the two northernmost colonies (Minarets and Prince Leopold) grouped with birds from the southernmost colony (Gannet), and birds from Coats and Akpatok were distinct from all other colonies. Although results from our analyses did not support local adaptation along the latitudinal cline of breeding colonies, outlier loci grouped birds from different colonies according to their non-breeding distributions, suggesting that outliers may be informative about adaptation and/or demographic connectivity associated with their migration patterns or nonbreeding grounds.

Effect of genotype and environment on branching in weedy green millet (Setaria viridis) and domesticated foxtail millet (Setaria italica) (Poaceae).

PubMed

Doust, Andrew N; Kellogg, Elizabeth A

2006-04-01

Many domesticated crops are derived from species whose life history includes weedy characteristics, such as the ability to vary branching patterns in response to environmental conditions. However, domesticated crop plants are characterized by less variable plant architecture, as well as by a general reduction in vegetative branching compared to their progenitor species. Here we examine weedy green millet and its domesticate foxtail millet that differ in the number of tillers (basal branches) and axillary branches along each tiller. Branch number in F(2:3) progeny of a cross between the two species varies with genotype, planting density, and other environmental variables, with significant genotype-environment interactions (GEI). This is shown by a complex pattern of reaction norms and by variation in the pattern of significant quantitative trait loci (QTL) amongst trials. Individual and joint analyses of high and low density trials indicate that most QTL have significant GEI. Dominance and epistasis also explain some variation in branching. Likely candidate genes underlying the QTL (based on map position and phenotypic effect) include teosinte branched1 and barren stalk1. Phytochrome B, which has been found to affect response to shading in other plants, explains little or no variation. Much variation in branching is explained by QTL that do not have obvious candidate genes from maize or rice.

Developmental plasticity of bacterial colonies and consortia in germ-free and gnotobiotic settings

PubMed Central

2012-01-01

Background Bacteria grown on semi-solid media can build two types of multicellular structures, depending on the circumstances. Bodies (colonies) arise when a single clone is grown axenically (germ-free), whereas multispecies chimeric consortia contain monoclonal microcolonies of participants. Growth of an axenic colony, mutual interactions of colonies, and negotiation of the morphospace in consortial ecosystems are results of intricate regulatory and metabolic networks. Multicellular structures developed by Serratia sp. are characteristically shaped and colored, forming patterns that reflect their growth conditions (in particular medium composition and the presence of other bacteria). Results Building on our previous work, we developed a model system for studying ontogeny of multicellular bacterial structures formed by five Serratia sp. morphotypes of two species grown in either "germ-free" or "gnotobiotic" settings (i.e. in the presence of bacteria of other conspecific morphotype, other Serratia species, or E. coli). Monoclonal bodies show regular and reproducible macroscopic appearance of the colony, as well as microscopic pattern of its growing margin. Standard development can be modified in a characteristic and reproducible manner in close vicinity of other bacterial structures (or in the presence of their products). Encounters of colonies with neighbors of a different morphotype or species reveal relationships of dominance, cooperation, or submission; multiple interactions can be summarized in "rock – paper – scissors" network of interrelationships. Chimerical (mixed) plantings consisting of two morphotypes usually produced a “consortium” whose structure is consistent with the model derived from interaction patterns observed in colonies. Conclusions Our results suggest that development of a bacterial colony can be considered analogous to embryogenesis in animals, plants, or fungi: to proceed, early stages require thorough insulation from the rest of the biosphere. Only later, the newly developing body gets connected to the ecological interactions in the biosphere. Mixed “anlagen” cannot accomplish the first, germ-free phase of development; hence, they will result in the consortium of small colonies. To map early development and subsequent interactions with the rest of the biospheric web, simplified gnotobiotic systems described here may turn to be of general use, complementing similar studies on developing multicellular eukaryots under germ-free or gnotobiotic conditions. PMID:22894147

Sex differences in the branching position of the nerve to the abductor digiti minimi muscle: an anatomical study of cadavers.

PubMed

Mizuno, Daisuke; Naito, Munekazu; Hayashi, Shogo; Ohmichi, Yusuke; Ohmichi, Mika; Nakano, Takashi

2015-01-01

The nerve to the abductor digiti minimi muscle (ADMM nerve) is the first branch of the lateral plantar nerve or originates directly from the posterior tibial nerve. Damage to the ADMM nerve is a cause of heel pain and eventually results in ADMM atrophy. It is known that ADMM atrophy occurs more often in females than in males, and the reason remains unclear. This study aimed to explore sex differences in the branching pattern, position, and angle of the ADMM nerve. Forty-two cadavers (20 males, 22 females) were dissected at Aichi Medical University between 2011 and 2015. Cases of foot deformity or atrophy were excluded and 67 ft (30 male, 37 female) were examined to assess the branching pattern, position, and angle of the ADMM nerve. The branching positions of the ADMM nerve were superior to the malleolar-calcaneal axis (MCA) in 37 ft (55 %), on the MCA in 10 ft (15 %), and inferior to the MCA in 20 ft (30 %). There was no case among male feet in which the ADMM nerve branched inferior to the MCA, whereas this pattern was observed in 19 of 37 female feet (51 %). The branching position of the ADMM nerve was significantly closer to the MCA in female feet than in male feet. There were no significant sex differences in the branching pattern and angle of the ADMM nerve. The ADMM nerve sometimes branches off inferior to the MCA in females, but not in males. This difference may be the reason for the more frequent occurrence of ADMM atrophy in females than in males.

Influence of condition of growth of bacterial colonies on fractal dimension of bacterial speckle patterns

NASA Astrophysics Data System (ADS)

Ulyanov, Alexander S.; Lyapina, Anna M.; Ulianova, Onega V.; Feodorova, Valentina A.

2010-10-01

New field of application of fractal dimensions is proposed. A technique, based on the calculation of fractal dimension, was used for express-diagnostics and identification of bacteria of the vaccine strain Yersinia pestis EV line NIIEG. Purpose of this study was the experimental investigation of properties of speckle patterns, formed under laser illumination of a single colony of the strain that was grown on different agars.

Influence of condition of growth of bacterial colonies on fractal dimension of bacterial speckle patterns

NASA Astrophysics Data System (ADS)

Ulyanov, Alexander S.; Lyapina, Anna M.; Ulianova, Onega V.; Feodorova, Valentina A.

2011-03-01

New field of application of fractal dimensions is proposed. A technique, based on the calculation of fractal dimension, was used for express-diagnostics and identification of bacteria of the vaccine strain Yersinia pestis EV line NIIEG. Purpose of this study was the experimental investigation of properties of speckle patterns, formed under laser illumination of a single colony of the strain that was grown on different agars.

Circatrigintan instead of lunar periodicity of larval release in a brooding coral species.

PubMed

Linden, Bart; Huisman, Jef; Rinkevich, Baruch

2018-04-04

Larval release by brooding corals is often assumed to display lunar periodicity. Here, we show that larval release of individual Stylophora pistillata colonies does not comply with the assumed tight entrainment by the lunar cycle, and can better be classified as a circatrigintan pattern. The colonies exhibited three distinct reproductive patterns, characterized by short intervals, long intervals and no periodicity between reproductive peaks, respectively. Cross correlation between the lunar cycle and larval release of the periodic colonies revealed an approximately 30-day periodicity with a variable lag of 5 to 10 days after full moon. The observed variability indicates that the lunar cycle does not provide a strict zeitgeber. Other factors such as water temperature and solar radiation did not correlate significantly with the larval release. The circatrigintan patterns displayed by S. pistillata supports the plasticity of corals and sheds new light on discussions on the fecundity of brooding coral species.

Reflected scatterometry for noninvasive interrogation of bacterial colonies

NASA Astrophysics Data System (ADS)

Kim, Huisung; Doh, Iyll-Joon; Sturgis, Jennifer; Bhunia, Arun K.; Robinson, J. Paul; Bae, Euiwon

2016-10-01

A phenotyping of bacterial colonies on agar plates using forward-scattering diffraction-pattern analysis provided promising classification of several different bacteria such as Salmonella, Vibrio, Listeria, and E. coli. Since the technique is based on forward-scattering phenomena, light transmittance of both the colony and the medium is critical to ensure quality data. However, numerous microorganisms and their growth media allow only limited light penetration and render the forward-scattering measurement a challenging task. For example, yeast, Lactobacillus, mold, and several soil bacteria form colorful and dense colonies that obstruct most of the incoming light passing through them. Moreover, blood agar, which is widely utilized in the clinical field, completely blocks the incident coherent light source used in forward scatterometry. We present a newly designed reflection scatterometer and validation of the resolving power of the instrument. The reflectance-type instrument can acquire backward elastic scatter patterns for both highly opaque media and colonies and has been tested with three different bacterial genera grown on blood agar plates. Cross-validation results show a classification rate above 90% for four genera.

Bleaching, disease and recovery in the threatened scleractinian coral Acropora palmata in St. John, US Virgin Islands: 2003-2010

NASA Astrophysics Data System (ADS)

Rogers, C. S.; Muller, E. M.

2012-09-01

A long-term study of the scleractinian coral Acropora palmata in the US Virgin Islands (USVI) showed that diseases, particularly white pox, are limiting the recovery of this threatened species. Colonies of A. palmata in Haulover Bay, within Virgin Islands National Park, St. John, were examined monthly in situ for signs of disease and other stressors from January 2003 through December 2009. During the study, 89.9 % of the colonies ( n = 69) exhibited disease, including white pox (87 %), white band (13 %), and unknown (9 %). Monthly disease prevalence ranged from 0 to 57 %, and disease was the most significant cause of complete colony mortality ( n = 17). A positive correlation was found between water temperature and disease prevalence, but not incidence. Annual average disease prevalence and incidence remained constant during the study. Colonies generally showed an increase in the estimated amount of total living tissue from growth, but 25 (36.2 %) of the colonies died. Acropora palmata bleached in the USVI for the first time during the 2005 Caribbean bleaching event. Only one of the 23 colonies that bleached appeared to die directly from bleaching. In 2005, corals that bleached had greater disease prevalence than those that did not bleach. Just over half (52 %) of the colonies incurred some physical damage. Monitoring of fragments (broken branches) that were generated by physical damage through June 2007 showed that 46.1 % died and 28.4 % remained alive; the fragments that attached to the substrate survived longer than those that did not. Recent surveys showed an increase in the total number of colonies within the reef area, formed from both asexual and sexual reproduction. Genotype analysis of 48 of the originally monitored corals indicated that 43 grew from sexual recruits supporting the conclusion that both asexual and sexual reproduction are contributing to an increase in colony density at this site.

Bleaching, disease and recovery in the threatened scleractinian coral Acropora palmata in St. John, US Virgin Islands: 2003-2010

USGS Publications Warehouse

Rogers, C.S.; Muller, E.M.

2012-01-01

A long-term study of the scleractinian coral Acropora palmata in the US Virgin Islands (USVI) showed that diseases, particularly white pox, are limiting the recovery of this threatened species. Colonies of A. palmata in Haulover Bay, within Virgin Islands National Park, St. John, were examined monthly in situ for signs of disease and other stressors from January 2003 through December 2009. During the study, 89.9 % of the colonies (n = 69) exhibited disease, including white pox (87 %), white band (13 %), and unknown (9 %). Monthly disease prevalence ranged from 0 to 57 %, and disease was the most significant cause of complete colony mortality (n = 17). A positive correlation was found between water temperature and disease prevalence, but not incidence. Annual average disease prevalence and incidence remained constant during the study. Colonies generally showed an increase in the estimated amount of total living tissue from growth, but 25 (36.2 %) of the colonies died. Acropora palmata bleached in the USVI for the first time during the 2005 Caribbean bleaching event. Only one of the 23 colonies that bleached appeared to die directly from bleaching. In 2005, corals that bleached had greater disease prevalence than those that did not bleach. Just over half (52 %) of the colonies incurred some physical damage. Monitoring of fragments (broken branches) that were generated by physical damage through June 2007 showed that 46.1 % died and 28.4 % remained alive; the fragments that attached to the substrate survived longer than those that did not. Recent surveys showed an increase in the total number of colonies within the reef area, formed from both asexual and sexual reproduction. Genotype analysis of 48 of the originally monitored corals indicated that 43 grew from sexual recruits supporting the conclusion that both asexual and sexual reproduction are contributing to an increase in colony density at this site.

The Intersection of the Extrinsic Hedgehog and WNT/Wingless Signals with the Intrinsic Hox Code Underpins Branching Pattern and Tube Shape Diversity in the Drosophila Airways

PubMed Central

Matsuda, Ryo; Hosono, Chie; Saigo, Kaoru; Samakovlis, Christos

2015-01-01

The tubular networks of the Drosophila respiratory system and our vasculature show distinct branching patterns and tube shapes in different body regions. These local variations are crucial for organ function and organismal fitness. Organotypic patterns and tube geometries in branched networks are typically controlled by variations of extrinsic signaling but the impact of intrinsic factors on branch patterns and shapes is not well explored. Here, we show that the intersection of extrinsic hedgehog(hh) and WNT/wingless (wg) signaling with the tube-intrinsic Hox code of distinct segments specifies the tube pattern and shape of the Drosophila airways. In the cephalic part of the airways, hh signaling induces expression of the transcription factor (TF) knirps (kni) in the anterior dorsal trunk (DTa1). kni represses the expression of another TF spalt major (salm), making DTa1 a narrow and long tube. In DTa branches of more posterior metameres, Bithorax Complex (BX-C) Hox genes autonomously divert hh signaling from inducing kni, thereby allowing DTa branches to develop as salm-dependent thick and short tubes. Moreover, the differential expression of BX-C genes is partly responsible for the anterior-to-posterior gradual increase of the DT tube diameter through regulating the expression level of Salm, a transcriptional target of WNT/wg signaling. Thus, our results highlight how tube intrinsic differential competence can diversify tube morphology without changing availabilities of extrinsic factors. PMID:25615601

Quantitative spectral light scattering polarimetry for monitoring fractal growth pattern of Bacillus thuringiensis bacterial colonies

NASA Astrophysics Data System (ADS)

Banerjee, Paromita; Soni, Jalpa; Ghosh, Nirmalya; Sengupta, Tapas K.

2013-02-01

It is of considerable current interest to develop various methods which help to understand and quantify the cellular association in growing bacterial colonies and is also important in terms of detection and identification of a bacterial species. A novel approach is used here to probe the morphological structural changes occurring during the growth of the bacterial colony of Bacillus thuringiensis under different environmental conditions (in normal nutrient agar, in presence of glucose - acting as additional nutrient and additional 3mM arsenate as additional toxic material). This approach combines the quantitative Mueller matrix polarimetry to extract intrinsic polarization properties and inverse analysis of the polarization preserving part of the light scattering spectra to determine the fractal parameter H (Hurst exponent) using Born approximation. Interesting differences are observed in the intrinsic polarization parameters and also in the Hurst exponent, which is a measurement of the fractality of a pattern formed by bacteria while growing as a colony. These findings are further confirmed with optical microscopic studies of the same sample and the results indicate a very strong and distinct dependence on the environmental conditions during growth, which can be exploited to quantify different bacterial species and their growth patterns.

Branch and foliage morphological plasticity in old-growth Thuja plicata.

PubMed

Edelstein, Zoe R; Ford, E David

2003-07-01

At the Wind River Canopy Crane Facility in southeastern Washington State, USA, we examined phenotypic variation between upper- and lower-canopy branches of old-growth Thuja plicata J. Donn ex D. Don (western red cedar). Lower-canopy branches were longer, sprouted fewer daughter branches per unit stem length and were more horizontal than upper-canopy branches. Thuja plicata holds its foliage in fronds, and these had less projected area per unit mass, measured by specific frond area, and less overlap, measured by silhouette to projected area ratio (SPARmax), in the lower canopy than in the upper canopy. The value of SPARmax, used as an indicator of sun and shade foliage in needle-bearing species, did not differ greatly between upper- and lower-canopy branches. We suggest that branching patterns, as well as frond structure, are important components of morphological plasticity in T. plicata. Our results imply that branches of old-growth T. plicata trees have a guerilla growth pattern, responding to changes in solar irradiance in a localized manner.

Development of a multispectral light-scatter sensor for bacterial colonies

USDA-ARS?s Scientific Manuscript database

We report a multispectral elastic-light-scatter instrument that can simultaneously detect three-wavelength scatter patterns and associated optical densities from individual bacterial colonies, overcoming the limits of the single-wavelength predecessor. Absorption measurements on liquid bacterial sam...

Reflected scatterometry for noninvasive interrogation of bacterial colonies

USDA-ARS?s Scientific Manuscript database

A phenotyping of bacterial colonies on agar plates using forward-scattering diffraction-pattern analysis provided promising classification of several different bacteria such as Salmonella, Vibrio, Listeria, and E. coli. Since the technique is based on forward-scattering phenomena, light transmittanc...

Branches of the Facial Artery.

PubMed

Hwang, Kun; Lee, Geun In; Park, Hye Jin

2015-06-01

The aim of this study is to review the name of the branches, to review the classification of the branching pattern, and to clarify a presence percentage of each branch of the facial artery, systematically. In a PubMed search, the search terms "facial," AND "artery," AND "classification OR variant OR pattern" were used. The IBM SPSS Statistics 20 system was used for statistical analysis. Among the 500 titles, 18 articles were selected and reviewed systematically. Most of the articles focused on "classification" according to the "terminal branch." Several authors classified the facial artery according to their terminal branches. Most of them, however, did not describe the definition of "terminal branch." There were confusions within the classifications. When the inferior labial artery was absent, 3 different types were used. The "alar branch" or "nasal branch" was used instead of the "lateral nasal branch." The angular branch was used to refer to several different branches. The presence as a percentage of each branch according to the branches in Gray's Anatomy (premasseteric, inferior labial, superior labial, lateral nasal, and angular) varied. No branch was used with 100% consistency. The superior labial branch was most frequently cited (95.7%, 382 arteries in 399 hemifaces). The angular branch (53.9%, 219 arteries in 406 hemifaces) and the premasseteric branch were least frequently cited (53.8%, 43 arteries in 80 hemifaces). There were significant differences among each of the 5 branches (P < 0.05) except between the angular branch and the premasseteric branch and between the superior labial branch and the inferior labial branch. The authors believe identifying the presence percentage of each branch will be helpful for surgical procedures.

Bud structure, position and fate generate various branching patterns along shoots of closely related Rosaceae species: a review

PubMed Central

Costes, Evelyne; Crespel, Laurent; Denoyes, Béatrice; Morel, Philippe; Demene, Marie-Noëlle; Lauri, Pierre-Eric; Wenden, Bénédicte

2014-01-01

Branching in temperate plants is closely linked to bud fates, either floral or vegetative. Here, we review how the fate of meristematic tissues contained in buds and their position along a shoot imprint specific branching patterns which differ among species. Through examples chosen in closely related species in different genera of the Rosaceae family, a panorama of patterns is apparent. Patterns depend on whether vegetative and floral buds are borne individually or together in mixed buds, develop as the shoot grows or after a rest period, and are located in axillary or terminal positions along the parent shoot. The resulting branching patterns are conserved among varieties in a given species but progressively change with the parent shoot length during plant ontogeny. They can also be modulated by agronomic and environmental conditions. The existence of various organizations in the topology and fate of meristematic tissues and their appendages in closely related species questions the between-species conservation of physiological and molecular mechanisms leading to bud outgrowth vs. quiescence and to floral induction vs. vegetative development. PMID:25520729

Restricted mating dispersal and strong breeding group structure in a mid-sized marsupial mammal (Petrogale penicillata).

PubMed

Hazlitt, S L; Sigg, D P; Eldridge, M D B; Goldizen, A W

2006-09-01

Ecological genetic studies have demonstrated that spatial patterns of mating dispersal, the dispersal of gametes through mating behaviour, can facilitate inbreeding avoidance and strongly influence the structure of populations, particularly in highly philopatric species. Elements of breeding group dynamics, such as strong structuring and sex-biased dispersal among groups, can also minimize inbreeding and positively influence levels of genetic diversity within populations. Rock-wallabies are highly philopatric mid-sized mammals whose strong dependence on rocky terrain has resulted in series of discreet, small colonies in the landscape. Populations show no signs of inbreeding and maintain high levels of genetic diversity despite strong patterns of limited gene flow within and among colonies. We used this species to investigate the importance of mating dispersal and breeding group structure to inbreeding avoidance within a 'small' population. We examined the spatial patterns of mating dispersal, the extent of kinship within breeding groups, and the degree of relatedness among brush-tailed rock-wallaby breeding pairs within a colony in southeast Queensland. Parentage data revealed remarkably restricted mating dispersal and strong breeding group structuring for a mid-sized mammal. Breeding groups showed significant levels of female kinship with evidence of male dispersal among groups. We found no evidence for inbreeding avoidance through mate choice; however, anecdotal data suggest the importance of life history traits to inbreeding avoidance between first-degree relatives. We suggest that the restricted pattern of mating dispersal and strong breeding group structuring facilitates inbreeding avoidance within colonies. These results provide insight into the population structure and maintenance of genetic diversity within colonies of the threatened brush-tailed rock-wallaby.

Pre-colonial Ethnic Institutions and Contemporary African Development*

PubMed Central

Michalopoulos, Stelios; Papaioannou, Elias

2013-01-01

We investigate the role of deeply-rooted pre-colonial ethnic institutions in shaping comparative regional development within African countries. We combine information on the spatial distribution of ethnicities before colonization with regional variation in contemporary economic performance, as proxied by satellite images of light density at night. We document a strong association between pre-colonial ethnic political centralization and regional development. This pattern is not driven by differences in local geographic features or by other observable ethnic-specific cultural and economic variables. The strong positive association between pre-colonial political complexity and contemporary development obtains also within pairs of adjacent ethnic homelands with different legacies of pre-colonial political institutions. PMID:25089052

Spatial structure and nest demography reveal the influence of competition, parasitism and habitat quality on slavemaking ants and their hosts

PubMed Central

2011-01-01

Background Natural communities are structured by intra-guild competition, predation or parasitism and the abiotic environment. We studied the relative importance of these factors in two host-social parasite ecosystems in three ant communities in Europe (Bavaria) and North America (New York, West Virginia). We tested how these factors affect colony demography, life-history and the spatial pattern of colonies, using a large sample size of more than 1000 colonies. The strength of competition was measured by the distance to the nearest competitor. Distance to the closest social parasite colony was used as a measure of parasitism risk. Nest sites (i.e., sticks or acorns) are limited in these forest ecosystems and we therefore included nest site quality as an abiotic factor in the analysis. In contrast to previous studies based on local densities, we focus here on the positioning and spatial patterns and we use models to compare our predictions to random expectations. Results Colony demography was universally affected by the size of the nest site with larger and more productive colonies residing in larger nest sites of higher quality. Distance to the nearest competitor negatively influenced host demography and brood production in the Bavarian community, pointing to an important role of competition, while social parasitism was less influential in this community. The New York community was characterized by the highest habitat variability, and productive colonies were clustered in sites of higher quality. Colonies were clumped on finer spatial scales, when we considered only the nearest neighbors, but more regularly distributed on coarser scales. The analysis of spatial positioning within plots often produced different results compared to those based on colony densities. For example, while host and slavemaker densities are often positively correlated, slavemakers do not nest closer to potential host colonies than expected by random. Conclusions The three communities are differently affected by biotic and abiotic factors. Some of the differences can be attributed to habitat differences and some to differences between the two slavemaking-host ecosystems. The strong effect of competition in the Bavarian community points to the scarcity of resources in this uniform habitat compared to the other more diverse sites. The decrease in colony aggregation with scale indicates fine-scale resource hotspots: colonies are locally aggregated in small groups. Our study demonstrates that species relationships vary across scales and spatial patterns can provide important insights into species interactions. These results could not have been obtained with analyses based on local densities alone. Previous studies focused on social parasitism and its effect on host colonies. The broader approach taken here, considering several possible factors affecting colony demography and not testing each one in isolation, shows that competition and environmental variability can have a similar strong impact on demography and life-history of hosts. We conclude that the effects of parasites or predators should be studied in parallel to other ecological influences. PMID:21443778

Spatial structure and nest demography reveal the influence of competition, parasitism and habitat quality on slavemaking ants and their hosts.

PubMed

Scharf, Inon; Fischer-Blass, Birgit; Foitzik, Susanne

2011-03-28

Natural communities are structured by intra-guild competition, predation or parasitism and the abiotic environment. We studied the relative importance of these factors in two host-social parasite ecosystems in three ant communities in Europe (Bavaria) and North America (New York, West Virginia). We tested how these factors affect colony demography, life-history and the spatial pattern of colonies, using a large sample size of more than 1000 colonies. The strength of competition was measured by the distance to the nearest competitor. Distance to the closest social parasite colony was used as a measure of parasitism risk. Nest sites (i.e., sticks or acorns) are limited in these forest ecosystems and we therefore included nest site quality as an abiotic factor in the analysis. In contrast to previous studies based on local densities, we focus here on the positioning and spatial patterns and we use models to compare our predictions to random expectations. Colony demography was universally affected by the size of the nest site with larger and more productive colonies residing in larger nest sites of higher quality. Distance to the nearest competitor negatively influenced host demography and brood production in the Bavarian community, pointing to an important role of competition, while social parasitism was less influential in this community. The New York community was characterized by the highest habitat variability, and productive colonies were clustered in sites of higher quality. Colonies were clumped on finer spatial scales, when we considered only the nearest neighbors, but more regularly distributed on coarser scales. The analysis of spatial positioning within plots often produced different results compared to those based on colony densities. For example, while host and slavemaker densities are often positively correlated, slavemakers do not nest closer to potential host colonies than expected by random. The three communities are differently affected by biotic and abiotic factors. Some of the differences can be attributed to habitat differences and some to differences between the two slavemaking-host ecosystems. The strong effect of competition in the Bavarian community points to the scarcity of resources in this uniform habitat compared to the other more diverse sites. The decrease in colony aggregation with scale indicates fine-scale resource hotspots: colonies are locally aggregated in small groups. Our study demonstrates that species relationships vary across scales and spatial patterns can provide important insights into species interactions. These results could not have been obtained with analyses based on local densities alone. Previous studies focused on social parasitism and its effect on host colonies. The broader approach taken here, considering several possible factors affecting colony demography and not testing each one in isolation, shows that competition and environmental variability can have a similar strong impact on demography and life-history of hosts. We conclude that the effects of parasites or predators should be studied in parallel to other ecological influences.

Probing the fractal pattern and organization of Bacillus thuringiensis bacteria colonies growing under different conditions using quantitative spectral light scattering polarimetry

NASA Astrophysics Data System (ADS)

Banerjee, Paromita; Soni, Jalpa; Purwar, Harsh; Ghosh, Nirmalya; Sengupta, Tapas K.

2013-03-01

Development of methods for quantification of cellular association and patterns in growing bacterial colony is of considerable current interest, not only to help understand multicellular behavior of a bacterial species but also to facilitate detection and identification of a bacterial species in a given space and under a given set of condition(s). We have explored quantitative spectral light scattering polarimetry for probing the morphological and structural changes taking place during colony formations of growing Bacillus thuringiensis bacteria under different conditions (in normal nutrient agar representing favorable growth environment, in the presence of 1% glucose as an additional nutrient, and 3 mM sodium arsenate as toxic material). The method is based on the measurement of spectral 3×3 Mueller matrices (which involves linear polarization measurements alone) and its subsequent analysis via polar decomposition to extract the intrinsic polarization parameters. Moreover, the fractal micro-optical parameter, namely, the Hurst exponent H, is determined via fractal-Born approximation-based inverse analysis of the polarization-preserving component of the light scattering spectra. Interesting differences are noted in the derived values for the H parameter and the intrinsic polarization parameters (linear diattenuation d, linear retardance δ, and linear depolarization Δ coefficients) of the growing bacterial colonies under different conditions. The bacterial colony growing in presence of 1% glucose exhibit the strongest fractality (lowest value of H), whereas that growing in presence of 3 mM sodium arsenate showed the weakest fractality. Moreover, the values for δ and d parameters are found to be considerably higher for the colony growing in presence of glucose, indicating more structured growth pattern. These findings are corroborated further with optical microscopic studies conducted on the same samples.

Temporal patterns in appearance of sooty blotch and flyspeck fungi on apples.

PubMed

Batzer, J C; Sisson, A J; Harrington, T C; Mayfield, D A; Gleason, M L

2012-11-01

Sooty blotch and flyspeck (SBFS) is a complex of about 80 fungal species that blemish the surface of apple fruit in humid regions worldwide. The dark colonies become visible in mid- to late summer, reducing the value of fresh fruit. Although many SBFS species can co-occur in the same orchard and even on the same apple, little is known about temporal patterns of these species, including the timing of colony appearance. To test the hypothesis that colonies of SBFS species appear on apples at characteristic times during the growing season, 50 apples were monitored weekly at three Iowa orchards in 2006 and six orchards in 2007 and 2008. However, a mean of 24.3 apples per orchard was assessed at harvest because of apple drop throughout the season. Colonies were marked with colored pens as they appeared. After harvest and after storage of apples at 2 °C for 3 months, SBFS colonies on each fruit were counted and classified by morphology, and a representative subset of colonies was excised from the fruit and preserved on dried peels for species identification using rDNA. Seventeen species were identified. Stomiopeltis spp. RS1 and RS2 appeared on apples 10 to 14 days before other SBFS taxa. Dissoconium aciculare was generally the last species to appear on apple fruit, and it continued to appear during postharvest storage. The most prevalent taxa in Iowa orchards were also the most abundant. Diversity of SBFS fungi in an orchard was positively correlated with cumulative hours of surface wetness hours due to rainfall or dew, which is believed to favor growth of SBFS fungi. Species-specific information about temporal patterns of appearance on apple fruit may lead to improved SBFS management strategies.

Growth of the Antarctic octocoral Primnoella scotiae and predation by the anemone Dactylanthus antarcticus

NASA Astrophysics Data System (ADS)

Peck, Lloyd S.; Brockington, Simon

2013-08-01

Growth rates in Antarctic marine ectotherms have been demonstrated to be slowed by two to five times compared to shallow-water temperate species, with no previous reports for octocorals. Here growth rates were estimated in the single axis, non-branching Antarctic octocoral Primnoella scotiae using repeated in situ length measures covering both summer and winter periods, for tagged colonies from three sites at Signy Island over a two year period. Mean rates of length increase at the different sites ranged from 0.96 mm yr-1 to 55.3 mm yr-1. The fastest individual colony growth rate at any site ranged from 2.55 mm yr-1 to 175.6 mm yr-1. The mean of the fastest growth rates across all sites was 33.0 mm yr-1±14.7 (s.e.). Growth was significantly different between sites, and also between seasons and years. The mean overall increase in diameter of the average sized colony in the study (222.5 mm in axis length) was 0.053 mm yr-1. This is the slowest reported growth rate of any octocoral to date, and is five times slower than growth in most cold water octocorals. During the study it was noted that colonies were being attacked and consumed by the anemone Dactylanthus antarcticus. At one of the sites studied, between 5% and 8% of colonies surveyed were attacked each month. Anemone dispersal was via whole body inflation and drifting to new prey colonies that were attached to using tentacle-like column protuberances.

Sociogenomics of Cooperation and Conflict during Colony Founding in the Fire Ant Solenopsis invicta

PubMed Central

Manfredini, Fabio; Riba-Grognuz, Oksana; Wurm, Yannick; Keller, Laurent; Shoemaker, DeWayne; Grozinger, Christina M.

2013-01-01

One of the fundamental questions in biology is how cooperative and altruistic behaviors evolved. The majority of studies seeking to identify the genes regulating these behaviors have been performed in systems where behavioral and physiological differences are relatively fixed, such as in the honey bee. During colony founding in the monogyne (one queen per colony) social form of the fire ant Solenopsis invicta, newly-mated queens may start new colonies either individually (haplometrosis) or in groups (pleometrosis). However, only one queen (the “winner”) in pleometrotic associations survives and takes the lead of the young colony while the others (the “losers”) are executed. Thus, colony founding in fire ants provides an excellent system in which to examine the genes underpinning cooperative behavior and how the social environment shapes the expression of these genes. We developed a new whole genome microarray platform for S. invicta to characterize the gene expression patterns associated with colony founding behavior. First, we compared haplometrotic queens, pleometrotic winners and pleometrotic losers. Second, we manipulated pleometrotic couples in order to switch or maintain the social ranks of the two cofoundresses. Haplometrotic and pleometrotic queens differed in the expression of genes involved in stress response, aging, immunity, reproduction and lipid biosynthesis. Smaller sets of genes were differentially expressed between winners and losers. In the second experiment, switching social rank had a much greater impact on gene expression patterns than the initial/final rank. Expression differences for several candidate genes involved in key biological processes were confirmed using qRT-PCR. Our findings indicate that, in S. invicta, social environment plays a major role in the determination of the patterns of gene expression, while the queen's physiological state is secondary. These results highlight the powerful influence of social environment on regulation of the genomic state, physiology and ultimately, social behavior of animals. PMID:23950725

Outcome and management of pregnancies in severe chronic neutropenia patients by the European Branch of the Severe Chronic Neutropenia International Registry.

PubMed

Zeidler, Cornelia; Grote, Ulrike A H; Nickel, Anna; Brand, Beate; Carlsson, Göran; Cortesão, Emília; Dufour, Carlo; Duhem, Caroline; Notheis, Gundula; Papadaki, Helen A; Tamary, Hannah; Tjønnfjord, Geir E; Tucci, Fabio; Van Droogenbroeck, Jan; Vermylen, Christiane; Voglova, Jaroslava; Xicoy, Blanca; Welte, Karl

2014-08-01

Long-term granulocyte-colony stimulating factor treatment has been shown to be safe and effective in severe chronic neutropenia patients. However, data on its use during pregnancy are limited. To address this issue, we analyzed all pregnancies reported to the European branch of the Severe Chronic Neutropenia International Registry since 1994. A total of 38 pregnancies in 21 women with chronic neutropenia (16 pregnancies in 10 women with congenital, 10 in 6 women with cyclic, 12 in 5 women with idiopathic neutropenia) were reported. Granulocyte-colony stimulating factor was administered throughout pregnancy in 16 women and for at least one trimester in a further 5 women. No major differences were seen between treated and untreated women with respect to pregnancy outcome, newborn complications and infections. In addition, we evaluated the genetic transmission of known or suspected genetic defects in 16 mothers having 22 newborns as well as in 8 men fathering 15 children. As a proof of inheritance, neutropenia was passed on to the newborn in 58% from female and in 62% from male patients with ELANE mutations, but also to some newborns from parents with unknown gene mutation. Based on our results, granulocyte-colony stimulating factor therapy has been shown to be safe for mothers throughout pregnancies and for newborns without any signs of teratogenicity. With an increasing number of adult patients, genetic counseling prior to conception and supportive care of mothers during pregnancy are crucial. The acceptance of having affected children may reflect the high quality of life obtained due to this treatment. Copyright© Ferrata Storti Foundation.

Occurrence of Six Honeybee Viruses in Diseased Austrian Apiaries

PubMed Central

Berényi, Olga; Bakonyi, Tamás; Derakhshifar, Irmgard; Köglberger, Hemma; Nowotny, Norbert

2006-01-01

The occurrence, prevalence, and distribution patterns of acute bee paralysis virus (ABPV), black queen cell virus (BQCV), chronic bee paralysis virus (CBPV), deformed wing virus (DWV), Kashmir bee virus (KBV), and sacbrood virus (SBV) were investigated in 90 Austrian honeybee colonies suffering from symptoms of depopulation, sudden collapse, paralysis, or dark coloring by employing reverse transcription-PCR. Infestation with parasites was also recorded. The samples originated from all parts of Austria. The most prevalent virus was DWV, present in 91% of samples, followed by ABPV, SBV, and BQCV (68%, 49%, and 30%, respectively). CBPV was detected in 10% of colonies, while KBV was not present in any sample. In most samples, more than one virus was identified. The distribution pattern of ABPV, BQCV, CBPV, and SBV varied considerably in the different geographic regions investigated, while DWV was widespread in all Austrian federal states. In bees that showed dark coloring and disorientation, CBPV was always detected. Simultaneous infections of DWV and ABPV were most frequently observed in colonies suffering from weakness, depopulation, and sudden collapse. Bees obtained from apparently healthy colonies within the same apiaries showed a similar distribution pattern of viruses; however, the relative virus load was 10 to 126 times lower than in bees from diseased colonies. A limited number of bee samples from surrounding central European countries (Germany, Poland, Hungary, and Slovenia) were also tested for the presence of the above viruses. Variances were found in the distribution of BQCV and SBV. PMID:16597939

General view of Buildings No. 62, 18, and 19 from ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

General view of Buildings No. 62, 18, and 19 from the west. These Colonial Revival duplex officers' quarters were built in 1922, 1921, and 1916, respectively. This grouping is located on the northwest side of the historic campus near the cemetery. These structures continue to be used as housing. - National Home for Disabled Volunteer Soldiers, Northwestern Branch, Officers' Quarters, 5000 West National Avenue, Milwaukee, Milwaukee County, WI

Prejudice and Politics.

ERIC Educational Resources Information Center

Taft, Charles P.; Felknor, Bruce L.

This monograph, written in 1960, examines the part prejudice played in politics throughout our national history. Part I of the monograph discusses "The Colonial Era." The immigrants that populated the new nation brought with them varied cultural heritages and different religious faiths. Soon the colonial pattern of religious prejudice reflected…

Differentiation of bacterial colonies and temporal growth patterns using hyperspectral imaging

NASA Astrophysics Data System (ADS)

Mehrübeoglu, Mehrube; Buck, Gregory W.; Livingston, Daniel W.

2014-09-01

Detection and identification of bacteria are important for health and safety. Hyperspectral imaging offers the potential to capture unique spectral patterns and spatial information from bacteria which can then be used to detect and differentiate bacterial species. Here, hyperspectral imaging has been used to characterize different bacterial colonies and investigate their growth over time. Six bacterial species (Pseudomonas fluorescens, Escherichia coli, Serratia marcescens, Salmonella enterica, Staphylococcus aureus, Enterobacter aerogenes) were grown on tryptic soy agar plates. Hyperspectral data were acquired immediately after, 24 hours after, and 96 hours after incubation. Spectral signatures from bacterial colonies demonstrated repeatable measurements for five out of six species. Spatial variations as well as changes in spectral signatures were observed across temporal measurements within and among species at multiple wavelengths due to strengthening or weakening reflectance signals from growing bacterial colonies based on their pigmentation. Between-class differences and within-class similarities were the most prominent in hyperspectral data collected 96 hours after incubation.

Correlates of nest-defense behavior of common terns

USGS Publications Warehouse

Erwin, R.M.

1988-01-01

Nest-defense behavior was studied at seven Common Tern (Sterna hirundo) colonies in southern coastal New Jersey during June and July 1981. Data were collected weekly on numbers of adults, nests, eggs, and young in relation to the frequency and intensity of dive attacks on a human intruder by nesting terns. I explored the relationships between attack behavior and colony size/density, seasonality, and brood survival. The results provide little support for social facilitation since neither colony size (range 30-250 nests) nor density was related to mean attack frequency; however, in larger colonies, fewer birds participated in dive attacks. Although the intensity of attacks was strongly seasonal, patterns were very different among colonies and peak attack rates did not always coincide with peak hatching periods. Defense levels declined late in the season in most colonies regardless of whether brood survival was high or low. Colonies with individuals that attacked early in the season had higher overall nesting success than in colonies where individuals showed little early season aggression.

Spatiotemporal dynamics of black-tailed prairie dog colonies affected by plague

USGS Publications Warehouse

Augustine, D.J.; Matchett, M.R.; Toombs, T.P.; Cully, J.F.; Johnson, T.L.; Sidle, John G.

2008-01-01

Black-tailed prairie dogs (Cynomys ludovicianus) are a key component of the disturbance regime in semi-arid grasslands of central North America. Many studies have compared community and ecosystem characteristics on prairie dog colonies to grasslands without prairie dogs, but little is known about landscape-scale patterns of disturbance that prairie dog colony complexes may impose on grasslands over long time periods. We examined spatiotemporal dynamics in two prairie dog colony complexes in southeastern Colorado (Comanche) and northcentral Montana (Phillips County) that have been strongly influenced by plague, and compared them to a complex unaffected by plague in northwestern Nebraska (Oglala). Both plague-affected complexes exhibited substantial spatiotemporal variability in the area occupied during a decade, in contrast to the stability of colonies in the Oglala complex. However, the plague-affected complexes differed in spatial patterns of colony movement. Colonies in the Comanche complex in shortgrass steppe shifted locations over a decade. Only 10% of the area occupied in 1995 was still occupied by prairie dogs in 2006. In 2005 and 2006 respectively, 74 and 83% of the total area of the Comanche complex occurred in locations that were not occupied in 1995, and only 1% of the complex was occupied continuously over a decade. In contrast, prairie dogs in the Phillips County complex in mixed-grass prairie and sagebrush steppe primarily recolonized previously occupied areas after plague-induced colony declines. In Phillips County, 62% of the area occupied in 1993 was also occupied by prairie dogs in 2004, and 12% of the complex was occupied continuously over a decade. Our results indicate that plague accelerates spatiotemporal movement of prairie dog colonies, and have significant implications for landscape-scale effects of prairie dog disturbance on grassland composition and productivity. These findings highlight the need to combine landscape-scale measures of habitat suitability with long-term measures of colony locations to understand the role of plague-affected prairie dogs as a grassland disturbance process. ?? 2007 Springer Science+Business Media B.V.

Population trends and distribution of Common Murre Uria aalge colonies in Washington, 1996-2015

USGS Publications Warehouse

Thomas, Susan M; Lyons, James E.

2017-01-01

Periodic assessments of population trends and changes in spatial distribution are valuable for managing marine birds and their breeding habitats, particularly when evaluating long-term response to threats such as oil spills, predation pressure, and changing ocean conditions. We evaluated recent trends in abundance and distribution of the Common Murre Uria aalge within Copalis, Quillayute Needles, and Flattery Rocks National Wildlife Refuges, which include all murre colonies in Washington except one, off-refuge, on Tatoosh Island. In 1996-2001 and 2010-2015, aerial photographic surveys were conducted during the incubation phase (mid-June through mid-July) each year. Using images from film (1996-2001) and digital (2010-2015) cameras that included all parts of each colony, we manually counted murres. We estimated population trend as annual percent change in whole-colony counts using an overdispersed Poisson regression model. Overall, numbers of murres counted at breeding colonies in Washington increased by 8.8% per year (95% CI 3.0%-14.9%) during 1996–2015. The overall statewide increase was driven by an increase at colonies in northern Washington of approximately 11% per year (95% CI 4.5%-17.8%). Despite an increasing trend, abundance remains lower than levels in the late 1970s, and the spatial distribution has changed. Colonies in southern Washington - where murres were historically the most abundant - are no longer active, or only minimally so, whereas colonies in the north - which were rarely active in the early 1970s - are now the largest. There was high variability in spatial distribution among years, a pattern that indicates a need for coordinated monitoring and movement studies throughout the California Current System to understand dispersal and colonization. Our results indicate that future management of refuge islands could protect both current and historic colony locations, given the patterns of colony dynamics and the uncertainty about long-term effects of a changing ocean ecosystem and predation pressure on the status of murres.

Rapid assessment of the bryozoan, Zoobotryon verticillatum (Delle Chiaje, 1822) in marinas, Canary Islands.

PubMed

Minchin, Dan

2012-10-01

A rapid assessment, using the abundance and distribution range method, was used to evaluate the status of a large branching bryozoan, Zoobotryon verticillatum attached to the immersed part of marina pontoons in the Canary Islands. Colonies were also found attached to the hulls of leisure craft berthed alongside pontoons at three marinas in Lanzarote during 2012. Low levels of abundance and distribution of the bryozoan occurred in marinas with a freshwater influence whereas in a sheltered marina lacking direct freshwater inputs colonies occurred at ∼2 per metre of combined pontoon length. While the occurrence of this bryozoan is recent it may be expected to occur elsewhere in Macaronesia most probably spread by leisure craft. Copyright © 2012 Elsevier Ltd. All rights reserved.

Intracolonial genetic variation in the scleractinian coral Seriatopora hystrix

NASA Astrophysics Data System (ADS)

Maier, E.; Buckenmaier, A.; Tollrian, R.; Nürnberger, B.

2012-06-01

In recent years, increasing numbers of studies revealed intraorganismal genetic variation, primarily in modular organisms like plants or colonial marine invertebrates. Two underlying mechanisms are distinguished: Mosaicism is caused by somatic mutation, whereas chimerism originates from allogeneic fusion. We investigated the occurrence of intracolonial genetic variation at microsatellite loci in five natural populations of the scleractinian coral Seriatopora hystrix on the Great Barrier Reef. This coral is a widely distributed, brooding species that is at present a target of intensive population genetic research on reproduction and dispersal patterns. From each of 155 S. hystrix colonies, either two or three samples were genotyped at five or six loci. Twenty-seven (~17%) genetically heterogeneous colonies were found. Statistical analyses indicated the occurrence of both mosaicism and chimerism. In most cases, intracolonial variation was found only at a single allele. Our analyses suggest that somatic mutations present a major source of genetic heterogeneity within a single colony. Moreover, we observed large, apparently stable chimeric colonies that harbored clearly distinct genotypes and contrast these findings with the patterns typically observed in laboratory-based experiments. We discuss the error that mosaicism and chimerism introduce into population genetic analyses.

Calibration of a Modified Andersen Bacterial Aerosol Sampler

PubMed Central

May, K. R.

1964-01-01

A study of the flow regime in the commercial Andersen sampler revealed defects in the sampling of the larger airborne particles. Satisfactory sampling was obtained by redesigning the hole pattern of the top stages and adding one more stage to extend the range of the instrument. A new, rational hole pattern is suggested for the lower stages. With both patterns a special colony-counting mask can be used to facilitate the assay. A calibration of the modified system is presented which enables particle size distribution curves to be drawn from the colony counts. Images FIG. 2 FIG. 3 FIG. 4 FIG. 5 FIG. 6 FIG. 7 FIG. 8 PMID:14106938

Time-Lapse Analysis of Human Embryonic Stem Cells Reveals Multiple Bottlenecks Restricting Colony Formation and Their Relief upon Culture Adaptation

PubMed Central

Barbaric, Ivana; Biga, Veronica; Gokhale, Paul J.; Jones, Mark; Stavish, Dylan; Glen, Adam; Coca, Daniel; Andrews, Peter W.

2014-01-01

Summary Using time-lapse imaging, we have identified a series of bottlenecks that restrict growth of early-passage human embryonic stem cells (hESCs) and that are relieved by karyotypically abnormal variants that are selected by prolonged culture. Only a minority of karyotypically normal cells divided after plating, and these were mainly cells in the later stages of cell cycle at the time of plating. Furthermore, the daughter cells showed a continued pattern of cell death after division, so that few formed long-term proliferating colonies. These colony-forming cells showed distinct patterns of cell movement. Increasing cell density enhanced cell movement facilitating cell:cell contact, which resulted in increased proportion of dividing cells and improved survival postplating of normal hESCs. In contrast, most of the karyotypically abnormal cells reentered the cell cycle on plating and gave rise to healthy progeny, without the need for cell:cell contacts and independent of their motility patterns. PMID:25068128

Wind-Induced Reconfigurations in Flexible Branched Trees

NASA Astrophysics Data System (ADS)

Ojo, Oluwafemi; Shoele, Kourosh

2017-11-01

Wind induced stresses are the major mechanical cause of failure in trees. We know that the branching mechanism has an important effect on the stress distribution and stability of a tree in the wind. Eloy in PRL 2011, showed that Leonardo da Vinci's original observation which states the total cross section of branches is conserved across branching nodes is the best configuration for resisting wind-induced fracture in rigid trees. However, prediction of the fracture risk and pattern of a tree is also a function of their reconfiguration capabilities and how they mitigate large wind-induced stresses. In this studies through developing an efficient numerical simulation of flexible branched trees, we explore the role of the tree flexibility on the optimal branching. Our results show that the probability of a tree breaking at any point depends on both the cross-section changes in the branching nodes and the level of tree flexibility. It is found that the branching mechanism based on Leonardo da Vinci's original observation leads to a uniform stress distribution over a wide range of flexibilities but the pattern changes for more flexible systems.

[Posttraumatic primary cutaneous aspergillosis with Candida guilliermondii infection in a healthy host].

PubMed

Türkşen, Zeynep; Yağcı, Server; Karadağ, Ayşe Serap; Tezer, Ayla; Taner, Omer Faruk; Tekin, Fatih; Arıkan Akdağlı, Sevtap

2010-10-01

Opportunistic fungal infections are usually seen in immunocompromised patients. While Candida is the most prevalent agent in such infections, Aspergillus is at the second order. Primary cutaneous aspergillosis is most common in immunocompromised patients but can rarely be seen in healthy hosts as well. We report a case of posttraumatic primary cutaneous aspergillosis and Candida guilliermondii coinfection in a 70-years-old healthy man. The patient had an ulcerous lesion which developed in the site of a trauma on the middle finger of the right hand. Histopathological examination of the biopsy specimens revealed septate hyphae with dichotomous branching small circular blastospores. The cultures of the biopsy specimen yielded yellow-green colored, granular mold colonies and creamy white yeast colonies. Microscopic examination of the lactophenol cotton blue stained mold colonies indicated long conidiophores with vesicles surrounded by uniseriate phialides, compatible with Aspergillus flavus. Yeast colonies were identified as Candida guilliermondii by ID32C (BioMerieux, France) and by their microscopical morphology detected in corn meal-Tween 80 agar incubated at 25°C for 72 hours. The patient was treated properly with surgical debridement and itraconazole therapy. Since the immune system is compressed as a consequence of aging, cutaneous opportunistic fungal infections should be considered in the differential diagnosis of posttraumatic necrotic ulcers and black eschar in aged patients.

Cultivation of a Synergistetes strain representing a previously uncultivated lineage

PubMed Central

Vartoukian, S R; Palmer, R M; Wade, W G

2010-01-01

Subgingival plaque samples obtained from human subjects with periodontitis, shown to include previously uncultivable members of the phylum Synergistetes, were used to inoculate Cooked Meat Medium (CMM). The presence of Cluster A (uncultivable) Synergistetes was monitored by fluorescent in situ hybridization (FISH) and quantitative PCR (Q-PCR). Cluster A Synergistetes were found to grow in CMM in co-culture with other plaque bacteria and growth was stimulated by the addition of mucin and serum. Plaque samples were also used to inoculate Blood Agar (BA) plates and growth of Cluster A Synergistetes was revealed after anaerobic incubation, by colony hybridization with specific probes. Surface growth on the plates in regions identified by colony hybridization was harvested and used to inoculate fresh plates, thus enriching for Cluster A Synergistetes. Cross-streaks of other plaque bacteria were also used to stimulate Synergistetes growth. In the early passages, no discrete Synergistetes colonies were seen, but after eight passages and the use of cross-streaks of other bacteria present in the enriched community, colonies arose, which consisted solely of Cluster A Synergistetes cells, as determined by 16S rRNA gene PCR and cloning. This is the first report of the successful culture of a member of the uncultivable branch of this phylum. PMID:20074237

Land use in the Northern Great Plains region of the U.S. influences the survival and productivity of honey bee colonies

USGS Publications Warehouse

Smart, Matthew; Pettis, Jeff S.; Euliss, Ned H. Jr.; Spivak, Marla S.

2016-01-01

The Northern Great Plains region of the US annually hosts a large portion of commercially managed U.S. honey bee colonies each summer. Changing land use patterns over the last several decades have contributed to declines in the availability of bee forage across the region, and the future sustainability of the region to support honey bee colonies is unclear. We examined the influence of varying land use on the survivorship and productivity of honey bee colonies located in six apiaries within the Northern Great Plains state of North Dakota, an area of intensive agriculture and high density of beekeeping operations. Land use surrounding the apiaries was quantified over three years, 2010–2012, and survival and productivity of honey bee colonies were determined in response to the amount of bee forage land within a 3.2-km radius of each apiary. The area of uncultivated forage land (including pasture, USDA conservation program fields, fallow land, flowering woody plants, grassland, hay land, and roadside ditches) exerted a positive impact on annual apiary survival and honey production. Taxonomic diversity of bee-collected pollen and pesticide residues contained therein varied seasonally among apiaries, but overall were not correlated to large-scale land use patterns or survival and honey production. The predominant flowering plants utilized by honey bee colonies for pollen were volunteer species present in unmanaged (for honey bees), and often ephemeral, lands; thus placing honey bee colonies in a precarious situation for acquiring forage and nutrients over the entire growing season. We discuss the implications for land management, conservation, and beekeeper site selection in the Northern Great Plains to adequately support honey bee colonies and insure long term security for pollinator-dependent crops across the entire country.

Role of endothelial permeability hotspots and endothelial mitosis in determining age-related patterns of macromolecule uptake by the rabbit aortic wall near branch points.

PubMed

Chooi, K Yean; Comerford, Andrew; Cremers, Stephanie J; Weinberg, Peter D

2016-07-01

Transport of macromolecules between plasma and the arterial wall plays a key role in atherogenesis. Scattered hotspots of elevated endothelial permeability to macromolecules occur in the aorta; a fraction of them are associated with dividing cells. Hotspots occur particularly frequently downstream of branch points, where lesions develop in young rabbits and children. However, the pattern of lesions varies with age, and can be explained by similar variation in the pattern of macromolecule uptake. We investigated whether patterns of hotspots and mitosis also change with age. Evans' Blue dye-labeled albumin was injected intravenously into immature or mature rabbits and its subsequent distribution in the aortic wall around intercostal branch ostia examined by confocal microscopy and automated image analysis. Mitosis was detected by immunofluorescence after adding 5-bromo-2-deoxiuridine to drinking water. Hotspots were most frequent downstream of branches in immature rabbits, but a novel distribution was observed in mature rabbits. Neither pattern was explained by mitosis. Hotspot uptake correlated spatially with the much greater non-hotspot uptake (p < 0.05), and the same pattern was seen when only the largest hotspots were considered. The pattern of hotspots changes with age. The data are consistent with there being a continuum of local permeabilities rather than two distinct mechanisms. The distribution of the dye, which binds to elastin and collagen, was similar to that of non-binding tracers and to lesions apart from a paucity at the lateral margins of branches that can be explained by lower levels of fibrous proteins in those regions. Copyright © 2016. Published by Elsevier Ireland Ltd.

The black coral fauna (Cnidaria: Antipatharia) of Bermuda with new records.

PubMed

Wagner, Daniel; Shuler, Andrew

2017-11-07

The black coral fauna of Bermudan waters is poorly known, in large part due to the logistical challenges of surveying deep-water (>50 m) environments where most species occur. In 2016, the Nekton Expedition sought to survey the deep-water biodiversity around Bermuda using manned submersibles and mixed-gas technical SCUBA. A total of 28 black coral specimens were collected, and these were examined based on skeletal spine morphology, polyp morphology, colony branching pattern and in situ photographs. The specimens were assigned to seven species in three families and four genera, including (1) Antipathes atlantica Gray, 1857, (2) Antipathes furcata Gray, 1857, (3) Stichopathes pourtalesi Brook, 1889, (4) Stichopathes sp., (5) Distichopathes filix (Pourtales, 1867), (6) Tanacetipathes hirta (Gray, 1857), and (7) Tanacetipathes tanacetum (Pourtales, 1867). Of these, three species (Stichopathes sp., S. pourtalesi, and D. filix), one genus (Distichopathes) and one family (Aphanipathidae) are reported from Bermudan waters for the first time, thereby increasing the known black coral diversity of Bermuda to twelve species, five genera and four families. The diagnostic characters of the taxa identified as part of this study are illustrated and described.

Structure of a human pulmonary acinus.

PubMed

Berend, N; Rynell, A C; Ward, H E

1991-02-01

The structure of the human pulmonary acinus has been described infrequently. The aim of the study was to determine the branching pattern of respiratory bronchioles and alveolar ducts in a human acinus from the peripheral part of the lung, where space constraints may have affected airway branching patterns. The lungs were obtained from an 18 year old victim of a motor vehicle accident and fixed in inflation under a pressure of 25 cm H2O. A block was cut from the lower edge of the right lower lobe and embedded in plastic. Serial sections were cut and the branching pattern of airways subtended by a terminal bronchiole were followed. The acinus was bounded on two sides by pleura and on the remaining sides by connective tissue septa. The terminal bronchiole divided into two respiratory bronchioles, each of which gave rise to four systems of alveolar ducts. Between successive systems of alveolar ducts the respiratory bronchioles continued as single airways, becoming progressively more alveolated towards the periphery but not subtending further branches of respiratory bronchioles. The duct systems became less complex towards the periphery, near to the edge of the lung. The total volume of the acinus was similar to that found in previous studies. This branching pattern has not been described previously in a human acinus.

Differential action and differential expression of DNA polymerase I during Escherichia coli colony development.

PubMed Central

Shapiro, J A

1992-01-01

A mini-Tn10 insertion in the polA cistron (polA2099) was isolated in a search for mutations that affect patterned Mudlac replication in colonies. The polA2099 mutation had a dramatic effect on cell morphogenesis during the first few hours of microcolony development. Abnormal microcolonies containing filamentous cells were produced as a result of SOS induction. Despite gross abnormalities in early microcolonies, mature polA2099 colonies after 2 to 4 days were morphologically indistinguishable from Pol+ colonies, and 44-h polA2099 colonies displayed a cell size distribution very similar to that of Pol+ colonies. These results suggested the involvement of a protective factor produced during colony growth that compensated for the polA deficiency. The action of a diffusible substance that stimulates growth of polA2099 microcolonies was shown by spotting dilute polA2099 cultures next to established colonies. Differential transcription of polA during colony development was visualized by growing colonies containing polA-lacZ fusions on beta-galactosidase indicator agar. When polA-lacZ colonies were inoculated next to established colonies, a diffusible factor was seen to inhibit polA transcription during the earliest stages of colony development. These results show that a basic housekeeping function, DNA polymerase I, is subject to multicellular control by the changing conditions which the bacteria create as they proliferate on agar. Images PMID:1331025

Isolation of Escherichia coli mutants defective in enzymes of membrane lipid synthesis.

PubMed Central

Raetz, C R

1975-01-01

A new method has been developed which permits the rapid screening of E. coli colonies for mutants with defective enzymes of phospholipid metabolism. In this procedure, a disc of filter paper is pressed down on an agar plate containing several hundred colonies of mutagen-treated cells, after which the paper is lifted off. In the process the colonies are transferred to the paper, giving rise to a replica print of the master plate. The few cells from each colony left on the master keep growing in the original pattern. The pattern of colonies is also retained on the filter paper, even after the cells are rendered permeable with lysozyme and EDTA. Colonies treated in this manner remain absorbed to the paper, where they can convert sn-(U-14-C)glycero-3-P to phosphatidyl(U-14-C)glycerophosphate, dependent on added CDP-diglyceride. Unrelated reactions of sn-(U-14-C)glycero-3-P that may obscure the synthesis of phosphatidyl-glycerophosphate are inhibited by the addition of reagents poisoning energy generation. The radioactive phospholipid that forms around each colony on the paper is precipitated in situ with trichloroacetic acid, and unreacted sn-(U-14-C)glycero-3-P is washed away. After autoradiography, the colonies on the filter paper are stained with Coomassie blue. When the autoradiogram is superimposed on the strained paper, mutants are identified as blue colonies lacking a black halo. With this method, 20,000 colonies were screened in several days. Four mutants were identified with low levels of CDP-diglyceride:snglycero-3-P phosphatidyl transferase (EC 2.7.8.5, GLYCEROL-PHOSPHATE PHOSPHATIDYLTRANSFERASE, PHOSPHATIDYLGLYCEROPHOSPHATE SYNTHETASE) IN EXTRACTS. With a similar assay, 10,000 additional colonies were screened for mutants with altered CDP-diglyceride:L-serine O-phosphatidyltransferase (EC 2.7.8.8, phosphatidylserine synthetase), and four strains were found in which the enzyme is thermolabile. The screening technique described here is termed replica printing and should be applicable not only to studies of phospholipid metabolism but also to nucleic acid and protein synthesis. Images PMID:49056

Security During Nigeria’s 2015 National Elections: What Should We Expect From the Police?

DTIC Science & Technology

2015-03-01

of Transition Initiatives PDP Peoples Democratic Party PSC Police Service Commission SSS State Security Service USAID United States Agency for...enforcement powers. State Security Service ( SSS ) The SSS , Nigeria’s internal intelligence agency, was established by military decree in 1986, although...its origins can be traced to the colonial-era police Special Branch. The remit of the SSS is considerable and includes the prevention, detection, and

An (almost) solvable model for bacterial pattern formation

NASA Astrophysics Data System (ADS)

Grammaticos, B.; Badoual, M.; Aubert, M.

2007-10-01

We present a simple model for the description of ring-like concentric structures in bacterial colonies. We model the differences between Bacillus subtilis and Proteus mirabilis colonies by using a different dependence of the duration of the consolidation phase on the concentration of agar. We compare our results to experimental data from these two bacterial species colonies and obtain a good agreement. Based on this analysis, we formulate a hypothesis on the connection of the diffusion constant that appears in the model to the experimental agar concentration.

Programmable assembly of pressure sensors using pattern-forming bacteria.

PubMed

Cao, Yangxiaolu; Feng, Yaying; Ryser, Marc D; Zhu, Kui; Herschlag, Gregory; Cao, Changyong; Marusak, Katherine; Zauscher, Stefan; You, Lingchong

2017-11-01

Biological systems can generate microstructured materials that combine organic and inorganic components and possess diverse physical and chemical properties. However, these natural processes in materials fabrication are not readily programmable. Here, we use a synthetic-biology approach to assemble patterned materials. We demonstrate programmable fabrication of three-dimensional (3D) materials by printing engineered self-patterning bacteria on permeable membranes that serve as a structural scaffold. Application of gold nanoparticles to the colonies creates hybrid organic-inorganic dome structures. The dynamics of the dome structures' response to pressure is determined by their geometry (colony size, dome height, and pattern), which is easily modified by varying the properties of the membrane (e.g., pore size and hydrophobicity). We generate resettable pressure sensors that process signals in response to varying pressure intensity and duration.

Recombinant Clone Heterogeneity in ESCHERICHIA COLI Conjunction: Effect of Ph and Partially Replicated Recipient Deoxyribonucleic Acid

PubMed Central

Ou, Jonathan T.

1975-01-01

At pH 6.8, a substantial fraction of recombinant colonies obtained from conjugation with an HfrH donor contained multiple recombinant classes in a single colony (polygenotypic colony). In contrast, when the conjugation was performed at pH 7.6, the number of polygenotypic colonies was drastically reduced, and the recombinant colonies were predominantly monogenotypic or digenotypic. Genetic analysis revealed that the digenotypic recombinants differ in those donor markers near the origin of DNA replication but share those donor markers near the terminus. This integration pattern suggests that the formation of digenotypic recombinants involves recombination of a single copy of the exogenome with a partially replicated recipient DNA molecule. This suggestion was supported by examination of the genotype of recombinant colonies recovered from crosses with an HfrKL96 donor which was derived from HfrH but transfers its chromosome in the reverse direction. PMID:8360

Colony size as a buffer against seasonality: Bergmann's rule in social insects

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

Kaspari, M.; Vargo, E.

1994-06-01

In eusocial species, the size of the superorganism is the summed sizes of its component individuals. Bergmann's rule, the cline of decreasing size with decreasing latitude, applies to colony size in ants. Using data from the literature and our own collections, we show that colony sizes of tropical ant species are on average 1/10th the size of temperate species. The patterns holds for 5 of 6 subfamilies and 15 of 16 genera tested. What causes this trend Larger colonies of the fire ant, Solenopsis invicta, are better able to protect the queen (the colony's reproductive tissue) against food shortage, likelymore » by sacrificing workers (it's somatic tissue). Days of queen survival follows the allometry M[sup 0.25]. We propose that the shorter growing seasons in temperate latitudes cull small-colony species through over-wintering starvation.« less

Ground-nesting waterbirds and mammalian carnivores in the Virginia barrier island region: Running out of options

USGS Publications Warehouse

Erwin, R.M.; Truitt, B.R.; Jimenez, J.E.

2001-01-01

We examined changing patterns of distribution of two large mammalian predators, the raccoon (Procyon lotor) and red fox (Vulpes vulpes), and beach-nesting terns and Black Skimmers (Rynchops niger) along ca. 80 km of the Virginia barrier island landscape between the periods 1975-1977 and 1998. Based on evidence from trapping, scent stations, den observations and sightings of the two predators, there has been a marked increase in their island ranges. In 1975-77, only 6 of the 11 surveyed barrier islands definitely harbored at least one of the two mammals, but by 1998, 11 of 14 islands showed evidence of one or both during the spring and summer. Concurrently, annual beach-nesting bird surveys have been conducted since the mid 1970s during June. From 1977 to 1998, the number of colonies of terns [Common (Sterna hirundo), Gull-billed (S. nilotica), Least (S. antillarum), Royal (S. maxima), and Sandwich (S. sandvicensis)] and Black Skimmers declined from 23 colonies on 11 barrier islands to 13 colonies on 10 islands. In addition, the populations decreased dramatically for all species except the marginal Sandwich Tern and Least Tern. This pattern suggests that mammalian predation may be a major factor in colony site selection or success, although we have no data on success at most locations. The only consistently large colony over the years has been the Royal Tern colony on Fisherman Island, one of the few with no resident large mammals. Because these declining waterbirds appear to be running out of options for safe colony sites in coastal Virginia, we discuss the prospects of conducting limited predator removals on certain islands. In addition, considerations of strict management and enforcement of protection at critical manmade colony sites that now attract large numbers of certain species, are timely. Lastly, where dredged material disposal projects are planned, providing nesting sites for these colonial species and roosting sites for migrant birds may be appropriate.

Colony size and brood investment of Myrmica rubra ant colonies in habitats invaded by goldenrods.

PubMed

Grześ, I M; Ślipiński, P; Babik, H; Moroń, D; Walter, B; Trigos Peral, G; Maak, I; Witek, M

2018-01-01

Ant richness and abundance are negatively affected by the invasion of alien goldenrods ( Solidago sp.). However, little is known about the mechanisms standing behind the impact of the invaders on ant life history, such as colony investments in growth and reproduction. We examined this problem of the investments of Myrmica rubra ant colonies living in different grasslands invaded and non-invaded by goldenrods. Altogether, 47 colonies were analysed; and for each colony, we calculated the number of queens, workers and the production of young workers, gynes, and males. We found that colonies from invaded meadows are smaller in size, but have a similar number of adult queens compared to colonies from non-invaded sites. We also found different brood investments among colonies from invaded and non-invaded meadows-colonies from non-invaded meadows produce more young workers and invest more in growth, whereas colonies from invaded meadows invest more in reproduction through higher gyne production. Male production was at a similar level in colonies from both habitat types. The observed patterns may be explained by the effect of various environmental factors occurring in both grassland types, such as stress in changed habitats, higher competition among gynes in non-invaded grasslands, or finally, by the adaptive colony-level response of ants to stress. The higher production of gynes observed in the invaded grasslands may support dispersal and enhance the probability of establishing a colony in a more favourable location.

Variance-based selection may explain general mating patterns in social insects.

PubMed

Rueppell, Olav; Johnson, Nels; Rychtár, Jan

2008-06-23

Female mating frequency is one of the key parameters of social insect evolution. Several hypotheses have been suggested to explain multiple mating and considerable empirical research has led to conflicting results. Building on several earlier analyses, we present a simple general model that links the number of queen matings to variance in colony performance and this variance to average colony fitness. The model predicts selection for multiple mating if the average colony succeeds in a focal task, and selection for single mating if the average colony fails, irrespective of the proximate mechanism that links genetic diversity to colony fitness. Empirical support comes from interspecific comparisons, e.g. between the bee genera Apis and Bombus, and from data on several ant species, but more comprehensive empirical tests are needed.

Comparison of bacterial counts obtained from naturally contaminated foods by means of Stomacher and blender.

PubMed

Purvis, U; Sharpe, A N; Bergener, D M; Lachapelle, G; Milling, M; Spiring, F

1987-01-01

Four Regional Health Protection Branch laboratories each compared aerobic colony counts obtained after "stomaching" and blending, for a minimum of 10 samples in each of the seven food groups: dry pastas; chocolate and cocoa powders; frozen entrees (macaroni and cheese, chow mein, chop suey, fried rice, seafood casseroles, and Salisbury steak); nonfat dry milk; shrimp and crabmeats; spices; and breakfast sausages. Overall, counts obtained after using the Stomacher were equivalent to or higher than counts obtained after using the blender in 73% of the comparisons (alpha = 0.05). Where differences existed, counts obtained after using the Stomacher tended to be higher than counts obtained after using the blender from milk powder and lower from sausage. Aerobic colony counts from these foods are not unacceptably biased when obtained by Stomacher.

Both natural selection and isolation by distance explain phenotypic divergence in bill size and body mass between South Australian little penguin colonies.

PubMed

Colombelli-Négrel, Diane

2016-11-01

Morphological variation between populations of the same species can arise as a response to genetic variation, local environmental conditions, or a combination of both. In this study, I examined small-scale geographic variation in bill size and body mass in little penguins ( Eudyptula minor ) across five breeding colonies in South Australia separated by <150 km. To help understand patterns driving the differences, I investigated these variations in relation to environmental parameters (air temperature, sea surface temperature, and water depth) and geographic distances between the colonies. I found substantial morphological variation among the colonies for body mass and bill measurements (except bill length). Colonies further located from each other showed greater morphological divergence overall than adjacent colonies. In addition, phenotypic traits were somewhat correlated to environmental parameters. Birds at colonies surrounded by hotter sea surface temperatures were heavier with longer and larger bills. Birds with larger and longer bills were also found at colonies surrounded by shallower waters. Overall, the results suggest that both environmental factors (natural selection) and interpopulation distances (isolation by distance) are causes of phenotypic differentiation between South Australian little penguin colonies.

Tree Branching: Leonardo da Vinci's Rule versus Biomechanical Models

PubMed Central

Minamino, Ryoko; Tateno, Masaki

2014-01-01

This study examined Leonardo da Vinci's rule (i.e., the sum of the cross-sectional area of all tree branches above a branching point at any height is equal to the cross-sectional area of the trunk or the branch immediately below the branching point) using simulations based on two biomechanical models: the uniform stress and elastic similarity models. Model calculations of the daughter/mother ratio (i.e., the ratio of the total cross-sectional area of the daughter branches to the cross-sectional area of the mother branch at the branching point) showed that both biomechanical models agreed with da Vinci's rule when the branching angles of daughter branches and the weights of lateral daughter branches were small; however, the models deviated from da Vinci's rule as the weights and/or the branching angles of lateral daughter branches increased. The calculated values of the two models were largely similar but differed in some ways. Field measurements of Fagus crenata and Abies homolepis also fit this trend, wherein models deviated from da Vinci's rule with increasing relative weights of lateral daughter branches. However, this deviation was small for a branching pattern in nature, where empirical measurements were taken under realistic measurement conditions; thus, da Vinci's rule did not critically contradict the biomechanical models in the case of real branching patterns, though the model calculations described the contradiction between da Vinci's rule and the biomechanical models. The field data for Fagus crenata fit the uniform stress model best, indicating that stress uniformity is the key constraint of branch morphology in Fagus crenata rather than elastic similarity or da Vinci's rule. On the other hand, mechanical constraints are not necessarily significant in the morphology of Abies homolepis branches, depending on the number of daughter branches. Rather, these branches were often in agreement with da Vinci's rule. PMID:24714065

Tree branching: Leonardo da Vinci's rule versus biomechanical models.

PubMed

Minamino, Ryoko; Tateno, Masaki

2014-01-01

This study examined Leonardo da Vinci's rule (i.e., the sum of the cross-sectional area of all tree branches above a branching point at any height is equal to the cross-sectional area of the trunk or the branch immediately below the branching point) using simulations based on two biomechanical models: the uniform stress and elastic similarity models. Model calculations of the daughter/mother ratio (i.e., the ratio of the total cross-sectional area of the daughter branches to the cross-sectional area of the mother branch at the branching point) showed that both biomechanical models agreed with da Vinci's rule when the branching angles of daughter branches and the weights of lateral daughter branches were small; however, the models deviated from da Vinci's rule as the weights and/or the branching angles of lateral daughter branches increased. The calculated values of the two models were largely similar but differed in some ways. Field measurements of Fagus crenata and Abies homolepis also fit this trend, wherein models deviated from da Vinci's rule with increasing relative weights of lateral daughter branches. However, this deviation was small for a branching pattern in nature, where empirical measurements were taken under realistic measurement conditions; thus, da Vinci's rule did not critically contradict the biomechanical models in the case of real branching patterns, though the model calculations described the contradiction between da Vinci's rule and the biomechanical models. The field data for Fagus crenata fit the uniform stress model best, indicating that stress uniformity is the key constraint of branch morphology in Fagus crenata rather than elastic similarity or da Vinci's rule. On the other hand, mechanical constraints are not necessarily significant in the morphology of Abies homolepis branches, depending on the number of daughter branches. Rather, these branches were often in agreement with da Vinci's rule.

Using within-day hive weight changes to measure environmental effects on honey bee colonies

USDA-ARS?s Scientific Manuscript database

Patterns in within-day hive weight data from two independent datasets in Arizona and California were modeled using piecewise regression, and analyzed with respect to honey bee colony behavior and landscape effects. The regression analysis yielded information on the start and finish of a colony’s dai...

CD1c presentation of synthetic glycolipid antigens with foreign alkyl branching motifs

PubMed Central

de Jong, Annemieke; Arce, Eva Casas; Cheng, Tan-Yun; van Summeren, Ruben P.; Feringa, Ben L.; Dudkin, Vadim; Crich, David; Matsunaga, Isamu; Minnaard, Adriaan J.; Moody, D. Branch

2009-01-01

Summary Human CD1c is a protein that activates αβ T cells by presenting self antigens, synthetic mannosyl phosphodolichols and mycobacterial mannosyl phosphopolyketides. To determine which molecular structures of antigens mediate a T cell response, we measured activation by structurally divergent M. tuberculosis mannosyl-β1-phosphomycoketides as well as by synthetic analogs produced by two methods that yield either stereorandom or stereospecific methyl branching patterns. T cell responses required both a phosphate and a β-linked mannose unit, and showed preference for C30–34 lipid units with methyl branches in the S-configuration. Thus, in all cases T cell responses were strongest for synthetic compounds that mimicked the natural branched lipids produced by mycobacterial polyketide synthase 12. Incorporation of methylmalonate to form branched lipids is a common bacterial lipid synthesis pathway that is absent in vertebrates, so the preferential recognition of branched lipids may represent a new type of lipid-based pathogen associated molecular pattern (PAMP). PMID:18022562

Feeding habitats of nesting wading birds: Spatial use and social influences

USGS Publications Warehouse

Erwin, R. Michael

1983-01-01

In an effort to relate social interactions to feeding-habitat use, I observed six species of wading birds near a major colony site in coastal North Carolina. Three spatial scales of habitat use were considered: the general orientation to and from the colony (coarsest level), the habitat "patch," and (at the finest level) the microhabitat. Departure-arrival directions of Great Egrets (Casmerodius albus), Snowy Egrets (Egretta thula), Cattle Egrets (Bubulcus ibis), Little Blue Herons (Egretta caerulea), Tricolored Herons (Egretta tricolor), and Glossy Ibises (Plegadis falcinellus) were monitored at the colony site to document coarse patterns of feeding-habitat use. Added to these data were observations made at five different wetland sites to monitor between-habitat and within-habitat patterns for the five aquatic-feeding species. The results indicated a broad and variable use of feeding habitat over time. At the coarsest scale (i.e. orientation at the colony), diffuse patterns, influenced little by either inter- or intraspecific social interaction, were found for all species. At the next level (habitat "patch"), only one of five wetland sites was relatively consistent in attracting feeding birds, and its use increased from May to June. Few groups were seen at four of the five sites. At the one "attractive" site, the within-habitat patterns again were spatially variable over time, except for those of the abundant Snowy Egret, whose microhabitat preference was fairly consistent. Glossy Ibises and Snowy Egrets frequently formed mixed-species groups, Little Blue Herons were the least social, and Great Egrets and Tricolored Herons generally occurred in groups of less than 10 birds but rarely in groups larger than 30. The close association between Snowy Egrets and Glossy Ibises appeared to be based on a "beater-follower" relationship, wherein the probing, nonvisually feeding ibises make prey more available to the followers. In the study area, local enhancement appeared to play a more important role than did any "information-sharing" at the colony.

Disruptive selection as a driver of evolutionary branching and caste evolution in social insects.

PubMed

Planqué, R; Powell, S; Franks, N R; van den Berg, J B

2016-11-01

Theory suggests that evolutionary branching via disruptive selection may be a relatively common and powerful force driving phenotypic divergence. Here, we extend this theory to social insects, which have novel social axes of phenotypic diversification. Our model, built around turtle ant (Cephalotes) biology, is used to explore whether disruptive selection can drive the evolutionary branching of divergent colony phenotypes that include a novel soldier caste. Soldier evolution is a recurrent theme in social insect diversification that is exemplified in the turtle ants. We show that phenotypic mutants can gain competitive advantages that induce disruptive selection and subsequent branching. A soldier caste does not generally appear before branching, but can evolve from subsequent competition. The soldier caste then evolves in association with specialized resource preferences that maximize defensive performance. Overall, our model indicates that resource specialization may occur in the absence of morphological specialization, but that when morphological specialization evolves, it is always in association with resource specialization. This evolutionary coupling of ecological and morphological specialization is consistent with recent empirical evidence, but contrary to predictions of classical caste theory. Our model provides a new theoretical understanding of the ecology of caste evolution that explicitly considers the process of adaptive phenotypic divergence and diversification. © 2016 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2016 European Society For Evolutionary Biology.

ramosa2 encodes a LATERAL ORGAN BOUNDARY domain protein that determines the fate of stem cells in branch meristems of maize.

PubMed

Bortiri, Esteban; Chuck, George; Vollbrecht, Erik; Rocheford, Torbert; Martienssen, Rob; Hake, Sarah

2006-03-01

Genetic control of grass inflorescence architecture is critical given that cereal seeds provide most of the world's food. Seeds are borne on axillary branches, which arise from groups of stem cells in axils of leaves and whose branching patterns dictate most of the variation in plant form. Normal maize (Zea mays) ears are unbranched, and tassels have long branches only at their base. The ramosa2 (ra2) mutant of maize has increased branching with short branches replaced by long, indeterminate ones. ra2 was cloned by chromosome walking and shown to encode a LATERAL ORGAN BOUNDARY domain transcription factor. ra2 is transiently expressed in a group of cells that predicts the position of axillary meristem formation in inflorescences. Expression in different mutant backgrounds places ra2 upstream of other genes that regulate branch formation. The early expression of ra2 suggests that it functions in the patterning of stem cells in axillary meristems. Alignment of ra2-like sequences reveals a grass-specific domain in the C terminus that is not found in Arabidopsis thaliana. The ra2-dm allele suggests this domain is required for transcriptional activation of ra1. The ra2 expression pattern is conserved in rice (Oryza sativa), barley (Hordeum vulgare), sorghum (Sorghum bicolor), and maize, suggesting that ra2 is critical for shaping the initial steps of grass inflorescence architecture.

Cranial Arterial Patterning in Greyhounds: Another Case of Internal Intraspecific Variation.

PubMed

Pols, S; Henneberg, M; Norris, R

2016-06-01

The greyhound is a dog breed highly specialized to run fast (17 m/s) over short distances (Usherwood and Wilson, 2005). As a result, there are many anatomical structures correlated with this sprinting function. The branching patterns of vasculature supplying blood to the head, forelimbs and thorax (subclavian arteries and its branches) were described in 34 adult greyhound cadavers (22 male, 12 female) (donated with owner consent and used under a memorandum of understanding with the University of Adelaide Animal Ethics Committee) from silicone casts of the arch of the aorta and the cranial arteries. Chi-squared analysis was used to test for pattern frequency differences, and t-tests were used to analyse the differences between sex and symmetry. All measurements were scaled to a fixed measure, the Open Thorax Length (OTL), to correct for size variation between individuals. Significant differences were found between the left and right subclavian arteries in the greyhound. The length to the first branch as a percentage of the OTL was greater in the right subclavian artery than the left subclavian artery (P < 0.001). The interval between the first and last branches (branching interval) as a percentage of the OTL was larger in the left subclavian artery than the right subclavian artery (P < 0.001). The reason for these differences remains unclear. Nonetheless, intraspecific variations of the branching patterns of the subclavian arteries have been described in the greyhound, thus suggesting that breed-specific variations in the cardiovascular system are likely to occur throughout domestic dogs. © 2015 Blackwell Verlag GmbH.

Physical-chemical mechanisms of pattern formation during gastrulation

NASA Astrophysics Data System (ADS)

Bozorgui, Behnaz; Kolomeisky, Anatoly B.; Teimouri, Hamid

2018-03-01

Gastrulation is a fundamental phase during the biological development of most animals when a single layer of identical embryo cells is transformed into a three-layer structure, from which the organs start to develop. Despite a remarkable progress in quantifying the gastrulation processes, molecular mechanisms of these processes remain not well understood. Here we theoretically investigate early spatial patterning in a geometrically confined colony of embryonic stem cells. Using a reaction-diffusion model, a role of Bone-Morphogenetic Protein 4 (BMP4) signaling pathway in gastrulation is specifically analyzed. Our results show that for slow diffusion rates of BMP4 molecules, a new length scale appears, which is independent of the size of the system. This length scale separates the central region of the colony with uniform low concentrations of BMP molecules from the region near the colony edge where the concentration of signaling molecules is elevated. The roles of different components of the signaling pathway are also explained. Theoretical results are consistent with recent in vitro experiments, providing microscopic explanations for some features of early embryonic spatial patterning. Physical-chemical mechanisms of these processes are discussed.

Competitive interactions between corals and turf algae depend on coral colony form.

PubMed

Swierts, Thomas; Vermeij, Mark Ja

2016-01-01

Turf algae are becoming more abundant on coral reefs worldwide, but their effects on other benthic organisms remain poorly described. To describe the general characteristics of competitive interactions between corals and turf algae, we determined the occurrence and outcomes of coral-turf algal interactions among different coral growth forms (branching, upright, massive, encrusting, plating, and solitary) on a shallow reef in Vietnam. In total, the amount of turf algal interaction, i.e., the proportion of the coral boundary directly bordering turf algae, was quantified for 1,276 coral colonies belonging to 27 genera and the putative outcome of each interaction was noted. The amount of turf algal interaction and the outcome of these interactions differed predictably among the six growth forms. Encrusting corals interacted most often with turf algae, but also competed most successfully against turf algae. The opposite was observed for branching corals, which rarely interacted with turf algae and rarely won these competitive interactions. Including all other growth forms, a positive relationship was found between the amount of competitive interactions with neighboring turf algae and the percentage of such interaction won by the coral. This growth form dependent ability to outcompete turf algae was not only observed among coral species, but also among different growth forms in morphologically plastic coral genera (Acropora, Favia, Favites, Montastrea, Montipora, Porites) illustrating the general nature of this relationship.

Competitive interactions between corals and turf algae depend on coral colony form

PubMed Central

Vermeij, Mark JA

2016-01-01

Turf algae are becoming more abundant on coral reefs worldwide, but their effects on other benthic organisms remain poorly described. To describe the general characteristics of competitive interactions between corals and turf algae, we determined the occurrence and outcomes of coral–turf algal interactions among different coral growth forms (branching, upright, massive, encrusting, plating, and solitary) on a shallow reef in Vietnam. In total, the amount of turf algal interaction, i.e., the proportion of the coral boundary directly bordering turf algae, was quantified for 1,276 coral colonies belonging to 27 genera and the putative outcome of each interaction was noted. The amount of turf algal interaction and the outcome of these interactions differed predictably among the six growth forms. Encrusting corals interacted most often with turf algae, but also competed most successfully against turf algae. The opposite was observed for branching corals, which rarely interacted with turf algae and rarely won these competitive interactions. Including all other growth forms, a positive relationship was found between the amount of competitive interactions with neighboring turf algae and the percentage of such interaction won by the coral. This growth form dependent ability to outcompete turf algae was not only observed among coral species, but also among different growth forms in morphologically plastic coral genera (Acropora, Favia, Favites, Montastrea, Montipora, Porites) illustrating the general nature of this relationship. PMID:27190707

Evolution of altruism in spatial prisoner's dilemma: Intra- and inter-cellular interactions

NASA Astrophysics Data System (ADS)

Yokoi, Hiroki; Uehara, Takashi; Sakata, Tomoyuki; Naito, Hiromi; Morita, Satoru; Tainaka, Kei-ichi

2014-12-01

Iterated prisoner's dilemma game is carried out on lattice with “colony” structure. Each cell is regarded as a colony which contains plural players with an identical strategy. Both intra- and inter-cellular interactions are assumed. In the former a player plays with all other players in the same colony, while in the latter he plays with one player each from adjacent colonies. Spatial patterns among four typical strategies exhibit various dynamics and winners. Both theory and simulation reveal that All Cooperation (AC) wins, when the members of colony or the intensity of noise increases. This result explains the evolution of altruism in animal societies, even though errors easily occur in animal communications.

Fecal-indicator bacteria in the Newfound Creek watershed, western North Carolina, during a high and low streamflow condition, 2003

USGS Publications Warehouse

Giddings, Elise M.; Oblinger, Carolyn J.

2004-01-01

Water quality in the Newfound Creek watershed has been shown to be affected by bacteria, sediment, and nutrients. In this study, Escherichia coli (E. coli) bacteria were sampled at five sites in Newfound Creek and five tributary sites during low flow on May 28, 2003, and high flow on November 19, 2003. In addition, a subset of five sites was sampled for fecal coliform bacteria, E. coli bacteria in streambed sediments (low flow only), and coliphage virus for serotyping. Coliphage virus serotyping has been used to identify human and animal sources of bacterial contamination. A streamflow gage was installed and operated to support ongoing water-quality studies in the watershed. Fecal coliform densities ranged from 92 to 27,000 colony-forming units per 100 milliliters of water for E. coli and 140 to an estimated 29,000 colony-forming units per 100 milliliters of water for fecal coliform during the two sampling visits. Ninety percent of the E. coli and fecal coliform samples exceeded corresponding U.S. Environmental Protection Agency or North Carolina water-quality criteria for recreational and ambient waters. During low flow, the middle part of the Newfound Creek watershed and the Dix Creek tributary had the highest densities of E. coli bacteria. During the high-flow sampling, all tributaries contained high densities of E. coli bacteria, although Dix Creek and Round Hill Branch were the largest contributors of these bacteria to Newfound Creek. Coliphage virus serotyping results were inconclusive because most samples did not contain the male-specific RNA coliphage needed for serotyping. Positive results indicated, however, that during low flow, non-human sources of bacteria were present in Sluder Branch, and during high flow, human sources of bacteria were present in Round Hill Branch. Sampling of bacteria in streambed sediments during low flow indicated that sediments do not appear to be a substantial source of bacteria relative to the water column, with the exception of an area near the confluence of Sluder Branch and Newfound Creek.

Communication-based regulated freedom of response in bacterial colonies

NASA Astrophysics Data System (ADS)

Ben-Jacob, Eshel; Shapira, Yoash; Becker, Israela; Raichman, Nadav; Volman, Vladislav; Hulata, Eyal; Baruchi, Itay

2003-12-01

Bacteria have developed intricate communication capabilities on all levels-the genome, the individual bacteria, the colony, and multi-colonial eco-systems of different bacterial species. All manner of biochemical messages are utilized for communication, including simple and complex abiotic molecules, peptides, proteins and even genetic sequences. These communication capabilities are required for bacterial cooperative self-organization into multicellular hierarchically structured colonies with complex spatio-temporal patterning. A colonial higher complexity is required for better colonial adaptability in a dynamic environment. The communication-based cooperative self-organization goes hand in hand with changes in cell structure and behavior. We identify two classes of such changes: (1) automatic and predetermined changes, which are triggered by inducive messages. (2) Regulated “decision-making” changes, which represent cellular regulated freedom of response to informative (semantic) messages. Each bacterium has internal degrees of freedom and informatics capabilities (storage, processing and interpretation of information). These features are required for the freedom of response in self-alteration (self-plasticity). Additionally, the cell can send messages to alter other bacteria in a self-regulated manner. To convert the above seemingly blurred notions into testable concepts we present the first steps towards quantification of colonial features associated with “regulated freedom”. For this we extract a binary representation of the observed patterns to show the existence of Lévy distributions with parameters that range from near the Cauchy limit to the Gaussian limit. The assumption about bacterial “regulated freedom” or “decision-making” appears in contradict the fundamental principle of time causality. We propose, that this apparent difficulty might be resolved by applying the recent understandings of biotic and abiotic self-organization, to the dynamics of the cells’ internal biochemical gel.

Programmable assembly of pressure sensors using pattern-forming bacteria

PubMed Central

Cao, Yangxiaolu; Feng, Yaying; Ryser, Marc D.; Zhu, Kui; Herschlag, Gregory; Cao, Changyong; Marusak, Katherine; Zauscher, Stefan; You, Lingchong

2017-01-01

Biological systems can generate microstructured materials that combine organic and inorganic components and possess diverse physical and chemical properties. However, these natural processes in materials fabrication are not readily programmable. Here, we use a synthetic-biology approach to mimic such natural processes to assemble patterned materials.. We demonstrate programmable fabrication of three-dimensional (3D) materials by printing engineered self-patterning bacteria on permeable membranes that serve as a structural scaffold. Application of gold nanoparticles to the colonies creates hybrid organic-inorganic dome structures. The dynamics of the dome structures' response to pressure is determined by their geometry (colony size, dome height and pattern), which is easily modified by varying the properties of the membrane (e.g., pore size and hydrophobicity). We generate resettable pressure sensors that process signals in response to varying pressure intensity and duration. PMID:28991268

Nocturnal activity patterns of northern myotis (Myotis septentrionalis) during the maternity season in West Virginia (USA)

USGS Publications Warehouse

Johnson, J.B.; Edwards, J.W.; Ford, W.M.

2011-01-01

Nocturnal activity patterns of northern myotis (Myotis septentrionalis) at diurnal roost trees remain largely uninvestigated. For example, the influence of reproductive status, weather, and roost tree and surrounding habitat characteristics on timing of emergence, intra-night activity, and entrance at their roost trees is poorly known. We examined nocturnal activity patterns of northern myotis maternity colonies during pregnancy and lactation at diurnal roost trees situated in areas that were and were not subjected to recent prescribed fires at the Fernow Experimental Forest, West Virginia from 2007 to 2009. According to exit counts and acoustic data, northern myotis colony sizes were similar between reproductive periods and roost tree settings. However, intra-night activity patterns differed slightly between reproductive periods and roost trees in burned and non-burned areas. Weather variables poorly explained variation in activity patterns during pregnancy, but precipitation and temperature were negatively associated with activity patterns during lactation. ?? Museum and Institute of Zoology PAS.

Behavioral ecology of black-legged kittiwakes during chick rearing in a failing colony

USGS Publications Warehouse

Roberts, Bay D.; Hatch, Scott A.

1993-01-01

Compared with their Atlantic counterparts, Black-legged Kittiwakes (Rissa tridactyla) in North Pacific colonies are notably unproductive. A large colony on Middleton Island, Alaska, has in most years since 1981 seen complete breeding failure and the population has declined by half. We compared parent-offspring behaviors in this colony during two years that differed in overall breeding success. Potential indicators of food stress included parental attendance at the nest, foraging trip lengths, chick feeding and begging rates, and sibling aggression. Whereas chick feeding and begging rates were strongly correlated with overall breeding performance, patterns of time allocation by adults (nest attendance and foraging trips) were not. Contrasts between years and comparisons with data from other colonies in and outside Alaska point to food shortage as the likely cause of recurrent breeding failure on Middleton.

Wood Storks of the Birdsville Colony and swamps of the Savannah River Plant: 1985 annual report

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

Coulter, M.C.

1986-05-01

Our objectives in 1985 were to determine the location of foraging sites of Wood Storks from their Birdsville colony; to characterize the habitat, vegetation, water quality and prey density/biomass at these sites; to examine seasonal changes in prey density at foraging sites and to relate this to the stork use of the foraging sites; to observe the breeding birds to determine times when food demands at the colony are greatest; to determine the breeding success of the storks at the Birdsville rookery; to examine the movement of storks from the rookery to foraging sites; to continue to evaluate the importancemore » of the SRSS to foraging Wood Storks; to examine the movements of individual birds to determine the generality of the observed patterns; and to compare the 1985 patterns with those observed in previous years.« less

Endemic circulation of European bat lyssavirus type 1 in serotine bats, Spain.

PubMed

Vázquez-Morón, Sonia; Juste, Javier; Ibáñez, Carlos; Ruiz-Villamor, Eduardo; Avellón, Ana; Vera, Manuel; Echevarría, Juan E

2008-08-01

To determine the presence of European bat lyssavirus type 1 in southern Spain, we studied 19 colonies of serotine bats (Eptesicus isabellinus), its main reservoir, during 1998-2003. Viral genome and antibodies were detected in healthy bats, which suggests subclinical infection. The different temporal patterns of circulation found in each colony indicate independent endemic circulation.

Swarm intelligence in bioinformatics: methods and implementations for discovering patterns of multiple sequences.

PubMed

Cui, Zhihua; Zhang, Yi

2014-02-01

As a promising and innovative research field, bioinformatics has attracted increasing attention recently. Beneath the enormous number of open problems in this field, one fundamental issue is about the accurate and efficient computational methodology that can deal with tremendous amounts of data. In this paper, we survey some applications of swarm intelligence to discover patterns of multiple sequences. To provide a deep insight, ant colony optimization, particle swarm optimization, artificial bee colony and artificial fish swarm algorithm are selected, and their applications to multiple sequence alignment and motif detecting problem are discussed.

Marking individual ants for behavioral sampling in a laboratory colony.

PubMed

Holbrook, C Tate

2009-07-01

Ant societies are tractable and malleable, two features that make them ideal models for probing the organization of complex biological systems. The ability to identify specific individuals while they function as part of a colony permits an integrative analysis of social complexity, including self-organizational processes (i.e., how individual-level properties and social interactions give rise to emergent, colony-level attributes such as division of labor and collective decision making). Effects of genotype, nutrition, and physiology on individual behavior and the organization of work also can be investigated in this manner, through correlative and manipulative approaches. Moreover, aspects of colony demography (e.g., colony size, and age and size distributions of workers) can be altered experimentally to examine colony development and regulatory mechanisms underlying colony homeostasis and resiliency. This protocol describes how to sample the behavior of ants living in a colony under laboratory conditions. Specifically, it outlines how to identify and observe individuals within a colony, an approach that can be used to quantify individual- and colony-level patterns of behavior. When a lower-resolution measure of overall group behavior is desired, individual identities might not be required. Given the diversity of ants and their study, this protocol provides a very general methodology; the details can be modified according to the body size, colony size, and ecology of the focal species, as well as to specific research aims. These basic techniques can also be extended to more advanced experimental designs such as manipulation of colony demography and hormone treatment.

Inheritance of resistance to Acarapis woodi (Acari: Tarsonemidae) in crosses between selected resistant Russian and selected susceptible u.s. honey bees (Hymenoptera: Apidae).

PubMed

Villa, José D; Rinderer, Thomas E

2008-12-01

The pattern of inheritance of tracheal mite resistance in selected Russian bees was determined in bioassays and in samples from field colonies. Resistant colonies of Russian origin and colonies selected for high susceptibility in the United States were used to generate divergent parental populations. Seven groups of F1 colonies were produced by crossing queens and drones from these selected resistant Russian and selected susceptible populations. In a series of bioassays with young workers exposed in infested colonies, average mite abundance (female mites per worker) in F1 colonies was intermediate (1.04 +/- 0.13 [mean +/- SE]) and significantly different from that of both resistant Russian (0.74 +/- 0.13) and selected susceptible (1.57 +/- 0.13) colonies. Colonies representing the three populations were established in two apiaries in July 2005. Colonies surviving with original queens after 10 mo had mite prevalences supporting the findings of the bioassay. All three resistant colonies had undetectable mite levels, whereas prevalences in four F1 colonies ranged from 0 to 53%, and in 10 susceptible colonies ranged from 0 to 90%. Tracheal mite resistance in Russian bees is likely polygenic, but there may be a number of genes with major dominance interacting with minor genes. Use of selected Russian queens mated with Russian drones or with drones from unknown sources is beneficial for beekeeping in areas with persistent problems with tracheal mite infestation.

Between-group transmission dynamics of the swallow bug, Oeciacus vicarius.

PubMed

Brown, Charles R; Brown, Mary Bomberger

2005-06-01

The parasitic cimicid swallow bug, Oeciacus vicarius, is the principal invertebrate vector for Buggy Creek virus (BCRV) and has also been associated with Venezuelan equine encephalitis virus. To help understand the spread of this vector, we experimentally measured the transmission of O. vicarius between groups (colonies) of its main host, the cliff swallow (Petrochelidonpyrrhonota), in the field. Transmission of bugs between colonies varied significantly with year, size of the colony, and week within the season. Bug immigration into sites tended to peak in mid-summer. Swallow nests in larger colonies had more consistent rates of bug introduction than did nests in small colonies, but within a colony a given nest's weekly immigrant-bug count varied widely across the season. Transmission of O. vicarius between host social groups follows broadly predictable seasonal patterns, but there is nevertheless temporal and spatial heterogeneity in bug transmission. By understanding how long-distance movement by this vector varies in time and space, we can better predict where and when BCRV epizootics may occur.

Upper Miocene reef complex of Mallorca, Balearic Islands, Spain

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

Pomar, L.

1988-02-01

The late Tortonian-Messinian coral reef platform of south Mallorca onlaps a folded middle late Miocene carbonate platform on which progradation of up to 20 km occurs. Vertical sea cliffs (up to 100 m high) superbly show the last 5 km of this progradation and complement the numerous water-well cores from the island interior. The Mallorca reef presents the most complete facies zonation of the Miocene reefs of the western Mediterranean. The reef wall framework is up to 20 m thick and shows (1) erosional reef flat with reef breccia and small corals; (2) spur-and-grove zone with large, massive corals; (3)more » deep buttresses and pinnacles with terraces of branching corals; and (4) deep reef wall with flat, laminar coral colonies, branching red algae, and Halimeda sands.« less

A microsampling method for genotyping coral symbionts

NASA Astrophysics Data System (ADS)

Kemp, D. W.; Fitt, W. K.; Schmidt, G. W.

2008-06-01

Genotypic characterization of Symbiodinium symbionts in hard corals has routinely involved coring, or the removal of branches or a piece of the coral colony. These methods can potentially underestimate the complexity of the Symbiodinium community structure and may produce lesions. This study demonstrates that microscale sampling of individual coral polyps provided sufficient DNA for identifying zooxanthellae clades by RFLP analyses, and subclades through the use of PCR amplification of the ITS-2 region of rDNA and denaturing-gradient gel electrophoresis. Using this technique it was possible to detect distinct ITS-2 types of Symbiodinium from two or three adjacent coral polyps. These methods can be used to intensely sample coral-symbiont population/communities while causing minimal damage. The effectiveness and fine scale capabilities of these methods were demonstrated by sampling and identifying phylotypes of Symbiodinium clades A, B, and C that co-reside within a single Montastraea faveolata colony.

Colony site dynamics and habitat use in Atlantic coast seabirds

USGS Publications Warehouse

Erwin, R.M.; Galli, J.; Burger, J.

1981-01-01

Seabird colony sizes and movements were documented in the DelMarVa coastal region in 1976-1977 and in New Jersey in 1978-1979. Most colonies were found on marsh and dredge deposition islands and on barrier island beaches. For the "traditionally" beach-nesting Herring Gull, Common Tern, and Black Skimmer, larger, more stable colonies were found on barrier beaches than on marsh islands. In marsh habitats, rates of colony-site change of marsh-nesting Forster's Tern and Laughing Gulls were similar to those of the former beach nesters. Several adaptations have evolved in marsh specialists to cope with a high risk of reproductive failure due to flooding, but both Herring Gulls and Common Terns also appear to be very adaptable in nesting under various habitat conditions.New colonies and those abandoned between years may be pioneering attempts by younger or inexperienced birds, because they are often smaller than persistent colonies, although patterns differ among areas and habitats. Colony-site dynamics are complex and result from many selective factors including competition, predation, physical changes in site structure, and flooding. The invasion of Herring Gulls into marshes along the mid-Atlantic coast has had an impact on new colony-site choice by associated seabirds.Calculating colony-site turnover rates allows for comparisons among species, habitats, and regions and may give useful insights into habitat quality and change and alternative nesting strategies.

Convection-driven aggregation of micron sized capsules

NASA Astrophysics Data System (ADS)

Shklyaev, Oleg; Shum, Henry; Balazs, Anna

Collective dynamics of microcapsules often serve as a model for understanding behavior observed in colonies of biological cells. Using computer simulations, we explore the capability of chemically generated convection to assemble microcapsules into a colony with neighbors close enough to facilitate chemical communication. The microcapsules are assumed to carry a supply of chemical fuel. When this fuel, leaking out of the capsules, reacts at enzyme-covered sites of the chamber, the reaction generates fluid density variations driving flows. These flows carry the microcapsules, which tend to aggregate into colonies on and near the enzyme-covered sites. This aggregation continues until the reagent has been depleted and convection stops. We show that capsule colonies of predesigned shapes can be assembled by patterning the enzyme-covered surface.

Experimental investigation of the dynamics of spontaneous pattern formation during dendritic ice crystal growth

NASA Astrophysics Data System (ADS)

Tirmizi, Shakeel H.; Gill, William N.

1989-06-01

The dynamics of spontaneous pattern formation are studied experimentally by observing and recording the evolution of ice crystal patterns which grow freely in a supercooled melt. The sequence of evolution to dendrites is recorded in real time using cine-micrography. In the range of subcoolings from 0.06 to 0.29°C, all the patterns evolved as follows: Smooth disk → Perturbed disk → Disk dendrite → Partially developed dendrite → Fully developed dendrite. The initial smooth disk, the main branch and the side branches all developed perturbations beyond a critical size which depends on the subcooling. The combined effect of the destabilizing thermal gradients ahead of the growing crystal and the stabilizing Gibbs-Thompson capillarity effect dictates the critical size of the unstable structures in terms of the mean curvature of the interface. Detailed analysis of the evolving patterns was done using digital image analysis on the PRIME computer to determine both the manner in which the dendritic growth process replicates itself and the role which the shape and the movement of the interface play in the pattern formation process. Total arc length ST, total area A and the complexity ratio ξ = ST⧸√ A of evolving patterns were computed as a function of time and undercooling for each crystal image. These results permitted us to make some comparisons with theoretical models on pattern evolution. Three distinct phases of evolution were identified: the initial phase when the crystal structure is smooth and free of any perturbations and the complexity ratio is almost a constant, an intermediate phase when the crystal structure develops perturbations which grow quickly in number and in size and the complexity ratio increases rapidly and a final phase when the pattern approaches that of a fully developed dendrite which, on a global scale grows in a shape-perserving manner and has a slowly increasing complexity ratio which seems to approach an asymptote. Two factors were found to be responsible for the symmetric dendritic patterns. These are: first, hexagonal symmetry due to the hexagonal closed packed structure, leads to strong anisotropy in molecular attachment kinetics and in surface free energy; second, the competition among side branches causes smaller side branches to melt when they are trapped between larger ones which generate latent heat and prevent the small branches from gaining access to the fresh cold fluid ahead of them. These two factors lead to a channelling effect which prevents the growth of perturbations from occurring randomly and thus directs the evolving crystal structure into patterns which are regular and reproducible. Theoretical models which are local in nature fail to take into account side branch competition, and this is one of their major weaknesses.

Extreme multiplicity in cylindrical Rayleigh-Bénard convection. II. Bifurcation diagram and symmetry classification

NASA Astrophysics Data System (ADS)

Borońska, Katarzyna; Tuckerman, Laurette S.

2010-03-01

A large number of flows with distinctive patterns have been observed in experiments and simulations of Rayleigh-Bénard convection in a water-filled cylinder whose radius is twice the height. We have adapted a time-dependent pseudospectral code, first, to carry out Newton’s method and branch continuation and, second, to carry out the exponential power method and Arnoldi iteration to calculate leading eigenpairs and determine the stability of the steady states. The resulting bifurcation diagram represents a compromise between the tendency in the bulk toward parallel rolls and the requirement imposed by the boundary conditions that primary bifurcations be toward states whose azimuthal dependence is trigonometric. The diagram contains 17 branches of stable and unstable steady states. These can be classified geometrically as roll states containing two, three, and four rolls; axisymmetric patterns with one or two tori; threefold-symmetric patterns called Mercedes, Mitsubishi, marigold, and cloverleaf; trigonometric patterns called dipole and pizza; and less symmetric patterns called CO and asymmetric three rolls. The convective branches are connected to the conductive state and to each other by 16 primary and secondary pitchfork bifurcations and turning points. In order to better understand this complicated bifurcation diagram, we have partitioned it according to azimuthal symmetry. We have been able to determine the bifurcation-theoretic origin from the conductive state of all the branches observed at high Rayleigh number.

Multi-jet propulsion organized by clonal development in a colonial siphonophore

PubMed Central

Costello, John H.; Colin, Sean P.; Gemmell, Brad J.; Dabiri, John O.; Sutherland, Kelly R.

2015-01-01

Physonect siphonophores are colonial cnidarians that are pervasive predators in many neritic and oceanic ecosystems. Physonects employ multiple, clonal medusan individuals, termed nectophores, to propel an aggregate colony. Here we show that developmental differences between clonal nectophores of the physonect Nanomia bijuga produce a division of labour in thrust and torque production that controls direction and magnitude of whole-colony swimming. Although smaller and less powerful, the position of young nectophores near the apex of the nectosome allows them to dominate torque production for turning, whereas older, larger and more powerful individuals near the base of the nectosome contribute predominantly to forward thrust production. The patterns we describe offer insight into the biomechanical success of an ecologically important and widespread colonial animal group, but, more broadly, provide basic physical understanding of a natural solution to multi-engine organization that may contribute to the expanding field of underwater-distributed propulsion vehicle design. PMID:26327286

Multi-jet propulsion organized by clonal development in a colonial siphonophore

NASA Astrophysics Data System (ADS)

Costello, John; Colin, Sean; Gemmell, Brad; Dabiri, John; Sutherland, Kelly

2015-11-01

Physonect siphonophores are colonial cnidarians that are pervasive predators in many neritic and oceanic ecosystems. Physonects employ multiple, clonal medusan individuals, termed nectophores, to propel an aggregate colony. Here we show that developmental differences between clonal nectophores of the physonect Nanomia bijuga produce a division of labor in thrust and torque production that controls direction and magnitude of whole colony swimming. Although smaller and less powerful, the position of young nectophores near the apex of the nectosome allows them to dominate torque production for turning whereas older, larger and more powerful individuals near the base of the nectosome contribute predominantly to forward thrust production. The patterns we describe offer insight into the biomechanical success of an ecologically important and widespread colonial animal group, but more broadly, provide basic physical understanding of a natural solution to multi-engine organization that may contribute to the expanding field of underwater distributed propulsion vehicle design.

Multi-jet propulsion organized by clonal development in a colonial siphonophore.

PubMed

Costello, John H; Colin, Sean P; Gemmell, Brad J; Dabiri, John O; Sutherland, Kelly R

2015-09-01

Physonect siphonophores are colonial cnidarians that are pervasive predators in many neritic and oceanic ecosystems. Physonects employ multiple, clonal medusan individuals, termed nectophores, to propel an aggregate colony. Here we show that developmental differences between clonal nectophores of the physonect Nanomia bijuga produce a division of labour in thrust and torque production that controls direction and magnitude of whole-colony swimming. Although smaller and less powerful, the position of young nectophores near the apex of the nectosome allows them to dominate torque production for turning, whereas older, larger and more powerful individuals near the base of the nectosome contribute predominantly to forward thrust production. The patterns we describe offer insight into the biomechanical success of an ecologically important and widespread colonial animal group, but, more broadly, provide basic physical understanding of a natural solution to multi-engine organization that may contribute to the expanding field of underwater-distributed propulsion vehicle design.

Colony genetic organization and breeding pattern of subterranean termite (Reticulitermes flavipes) over the three field seasons in Nebraska, USA

USDA-ARS?s Scientific Manuscript database

In this study, we repeated sampling from eight individual colonies from Wilderness Park, Lincoln, Nebraska, separated by at least 200 meters over a 3-year period and during seasonal change (fall-winter) from 2009 to 2011. Ten workers from each site were genotyped at seven microsatellite loci. The re...

An unusual branch of celiac trunk feeding suprarenal gland - a case report.

PubMed

Sarkar, Munmun; Mukherjee, Pranab; Roy, Hironmoy; Sengupta, Sandip Kumar; Sarkar, Amarendra Nath

2014-04-01

During routine dissection, variation in branching pattern of coeliac trunk has been observed in adult 54-year-old male cadaver. Instead of normal three branches an additional branch i.e., Left inferior phrenic artery originated from it as fourth branch. Then it divided into two branches, one directly supplied the diaphragm and other branch divided into three sub-branches. First and second branch entered into the left suprarenal gland at its upper and middle pole and third one finally terminated by supplying to the diaphragm. There is no separate middle suprarenal artery on the left side, but inferior suprarenal artery was as usual. No variations have been found on right side in the lateral branches of abdominal aorta. Such a quadrifurcation of celiac trunk to supply suprarenal gland is quiet unique so far searched in literature.

Bilateral Neuroretinitis and a Unilateral Superior Hemivein Occlusion with Frosted Branch Angiitis Pattern Presenting Simultaneously in Behçet's Disease.

PubMed

Schwartz, Roy; Borok, Sara; Goldstein, Michaella; Kesler, Anat; Regev, Keren; Elkayam, Ori; Habot-Wilner, Zohar

2016-01-01

To report a unique case of Behçet's disease that presented with atypical ocular manifestations. Case report. A 23-year-old homosexual male presented with bilateral anterior uveitis, vitritis, neuroretinitis and a unilateral superior hemivein occlusion with frosted branch angiitis pattern. These were accompanied by systemic findings of recurrent oral aphthous ulcers, erythema nodosum, and neurological and gastrointestinal involvement. A positive HLA-B51 examination supported the diagnosis of Behçet's disease. Neuroretinitis and frosted branch angiitis may be the clinical manifestations of Behçet's disease and may present simultaneously.

Bilateral Neuroretinitis and a Unilateral Superior Hemivein Occlusion with Frosted Branch Angiitis Pattern Presenting Simultaneously in Behçet's Disease

PubMed Central

Schwartz, Roy; Borok, Sara; Goldstein, Michaella; Kesler, Anat; Regev, Keren; Elkayam, Ori; Habot-Wilner, Zohar

2016-01-01

Purpose To report a unique case of Behçet's disease that presented with atypical ocular manifestations. Methods Case report. Results A 23-year-old homosexual male presented with bilateral anterior uveitis, vitritis, neuroretinitis and a unilateral superior hemivein occlusion with frosted branch angiitis pattern. These were accompanied by systemic findings of recurrent oral aphthous ulcers, erythema nodosum, and neurological and gastrointestinal involvement. A positive HLA-B51 examination supported the diagnosis of Behçet's disease. Conclusion Neuroretinitis and frosted branch angiitis may be the clinical manifestations of Behçet's disease and may present simultaneously. PMID:27065852

YAP is essential for mechanical force production and epithelial cell proliferation during lung branching morphogenesis

PubMed Central

Lin, Chuwen; Yao, Erica; Zhang, Kuan; Jiang, Xuan; Croll, Stacey; Thompson-Peer, Katherine; Chuang, Pao-Tien

2017-01-01

Branching morphogenesis is a fundamental program for tissue patterning. We show that active YAP, a key mediator of Hippo signaling, is distributed throughout the murine lung epithelium and loss of epithelial YAP severely disrupts branching. Failure to branch is restricted to regions where YAP activity is removed. This suggests that YAP controls local epithelial cell properties. In support of this model, mechanical force production is compromised and cell proliferation is reduced in Yap mutant lungs. We propose that defective force generation and insufficient epithelial cell number underlie the branching defects. Through genomic analysis, we also uncovered a feedback control of pMLC levels, which is critical for mechanical force production, likely through the direct induction of multiple regulators by YAP. Our work provides a molecular pathway that could control epithelial cell properties required for proper morphogenetic movement and pattern formation. DOI: http://dx.doi.org/10.7554/eLife.21130.001 PMID:28323616

Individual variation in staging and timing of spring migration of Pacific common eiders in Alaska

USGS Publications Warehouse

Petersen, Margaret R.

2005-01-01

Timing of migration and characterization of migration patterns of birds are usually based on dates of peak migration to and from staging, wintering, and breeding areas used by the bulk of a species. For Pacific common eiders (Somateria mollissima v-nigrum), as well as other species, the timing of migration into and through the Beaufort Sea is based on counts of birds past land or ice-based sites and radar observations, and arrival dates to colonies determined by influxes of birds seen by ground observers. With the continued and proposed development of nearshore and offshore waters of the Beaufort Sea, there is an expanding need to manage local populations. Observations of individual Pacific common eiders can provide a more complete understanding of local populations as well as variability among populations. This study was designed to determine factors influencing migration patterns of individuals nesting in the western Beaufort Sea from their wintering locations along the Chukotka Peninsula, through the eastern Chukchi and western Beaufort seas, until their arrival to their nesting area. The Simpson Lagoon/Maguire Island nesting colonies are 1300-1400 km from the primary winter area. Eiders enter the Beaufort Sea at Point Barrow then move east 300-350 km to their nesting colonies. Nesting adult females were marked with satellite transmitters during summer then followed the next spring and early summer. Transmitters were programmed to provide location data every 3 days (2001, n = 12) or daily (2002 and 2004, n = 7 and 18, respectively) beginning 15 April. I expected the dates of arrival to the colony to vary with weather during migration (Point. Barrow to the colony) and general conditions in spring (early or late year based on differences in temperatures from the long term norm for April, May, and June). All individuals returned to the colony area they were marked the previous year. Data were consistent with other “short” distance migrants. There were no correlations of the dates of arrival to the dates birds left the wintering area, the total days spent staging, wind speed or direction, temperature, weather, or seasonal differences in temperature from the long term average, a plethora of non-significant results. However, two patterns emerged: some birds migrated about 550 km and staged in the eastern Chukchi Sea before migrating to the colonies, while others went directly either to the colony area (1300 km) or elsewhere within the western  Beaufort. I will present preliminary analysis and several hypotheses regarding these two strategies. 

Circadian Clock Gene Expression in the Coral Favia fragum over Diel and Lunar Reproductive Cycles

PubMed Central

Hoadley, Kenneth D.; Szmant, Alina M.; Pyott, Sonja J.

2011-01-01

Natural light cycles synchronize behavioral and physiological cycles over varying time periods in both plants and animals. Many scleractinian corals exhibit diel cycles of polyp expansion and contraction entrained by diel sunlight patterns, and monthly cycles of spawning or planulation that correspond to lunar moonlight cycles. The molecular mechanisms for regulating such cycles are poorly understood. In this study, we identified four molecular clock genes (cry1, cry2, clock and cycle) in the scleractinian coral, Favia fragum, and investigated patterns of gene expression hypothesized to be involved in the corals' diel polyp behavior and lunar reproductive cycles. Using quantitative PCR, we measured fluctuations in expression of these clock genes over both diel and monthly spawning timeframes. Additionally, we assayed gene expression and polyp expansion-contraction behavior in experimental corals in normal light:dark (control) or constant dark treatments. Well-defined and reproducible diel patterns in cry1, cry2, and clock expression were observed in both field-collected and the experimental colonies maintained under control light:dark conditions, but no pattern was observed for cycle. Colonies in the control light:dark treatment also displayed diel rhythms of tentacle expansion and contraction. Experimental colonies in the constant dark treatment lost diel patterns in cry1, cry2, and clock expression and displayed a diminished and less synchronous pattern of tentacle expansion and contraction. We observed no pattern in cry1, cry2, clock, or cycle expression correlated with monthly spawning events suggesting these genes are not involved in the entrainment of reproductive cycles to lunar light cycles in F. fragum. Our results suggest a molecular clock mechanism, potentially similar to that in described in fruit flies, exists within F. fragum. PMID:21573070

Local texture and strongly linked conduction in spray-pyrolyzed TlBa2Ca2Cu3O(8+x) deposits

NASA Astrophysics Data System (ADS)

Kroeger, D. M.; Goyal, A.; Specht, E. D.; Wang, Z. L.; Tkaczyk, J. E.; Sutliff, J. A.; Deluca, J. A.

Local texture in polycrystalline TlBa2Ca2 Cu3O(8+x) deposits has been determined from transmission electron microscopy, electron backscatter diffraction patterns and x-ray diffraction. The small-grained deposits had excellent c-axis alignment and contained colonies of grains with similar but not identical a-axis orientations. Most grain boundaries within a colony have small misorientation angles and should not be weak links. It is proposed that long range conduction utilizes a percolative network of small angle grain boundaries at colony intersections.

Computational and Experimental Evaluation of a Complex Inlet Swirl Pattern Generation System (POSTPRINT)

DTIC Science & Technology

2016-08-01

Sanders, Chase A. Nessler, William W. Copenhaver, Michael G. List, and Timothy J. Janczewski Turbomachinery Branch Turbine Engine Division AUGUST...Branch Turbine Engine Division Turbine Engine Division Aerospace Systems Directorate //Signature// ROBERT D. HANCOCK Principal Scientist Turbine ...ORGANIZATION Turbomachinery Branch Turbine Engine Division Air Force Research Laboratory, Aerospace Systems Directorate Wright-Patterson Air Force

Population genetic evidence for sex-specific dispersal in an inbred social spider.

PubMed

Smith, Deborah R; Su, Yong-Chao; Berger-Tal, Reut; Lubin, Yael

2016-08-01

Dispersal in most group-living species ensures gene flow among groups, but in cooperative social spiders, juvenile dispersal is suppressed and colonies are highly inbred. It has been suggested that such inbred sociality is advantageous in the short term, but likely to lead to extinction or reduced speciation rates in the long run. In this situation, very low levels of dispersal and gene flow among colonies may have unusually important impacts on fitness and persistence of social spiders. We investigated sex-specific differences in dispersal and gene flow among colonies, as reflected in the genetic structure within colonies and populations of the African social spider Stegodyphus dumicola Pocock, 1898 (Eresidae). We used DNA fingerprinting and mtDNA sequence data along with spatial mapping of colonies to compare male and female patterns of relatedness within and among colonies at three study sites. Samples were collected during and shortly after the mating season to detect sex-specific dispersal. Distribution of mtDNA haplotypes was consistent with proliferation of social nests by budding and medium- to long-distance dispersal by ballooning females. Analysis of molecular variance and spatial autocorrelation analyses of AFLPs showed high levels of genetic similarity within colonies, and STRUCTURE analyses revealed that the number of source populations contributing to colonies ranged from one to three. We also showed significant evidence of male dispersal among colonies at one site. These results support the hypothesis that in social spiders, genetic cohesion among populations is maintained by long-distance dispersal of female colony founders. Genetic diversity within colonies is maintained by colony initiation by multiple dispersing females, and adult male dispersal over short distances. Male dispersal may be particularly important in maintaining gene flow among colonies in local populations.

Growth dynamics of cancer cell colonies and their comparison with noncancerous cells

NASA Astrophysics Data System (ADS)

Huergo, M. A. C.; Pasquale, M. A.; González, P. H.; Bolzán, A. E.; Arvia, A. J.

2012-01-01

The two-dimensional (2D) growth dynamics of HeLa (cervix cancer) cell colonies was studied following both their growth front and the pattern morphology evolutions utilizing large population colonies exhibiting linearly and radially spreading fronts. In both cases, the colony profile fractal dimension was df=1.20±0.05 and the growth fronts displaced at the constant velocity 0.90±0.05 μm min-1. Colonies showed changes in both cell morphology and average size. As time increased, the formation of large cells at the colony front was observed. Accordingly, the heterogeneity of the colony increased and local driving forces that set in began to influence the dynamics of the colony front. The dynamic scaling analysis of rough colony fronts resulted in a roughness exponent α = 0.50±0.05, a growth exponent β = 0.32±0.04, and a dynamic exponent z=1.5±0.2. The validity of this set of scaling exponents extended from a lower cutoff lc≈60 μm upward, and the exponents agreed with those predicted by the standard Kardar-Parisi-Zhang continuous equation. HeLa data were compared with those previously reported for Vero cell colonies. The value of df and the Kardar-Parisi-Zhang-type 2D front growth dynamics were similar for colonies of both cell lines. This indicates that the cell colony growth dynamics is independent of the genetic background and the tumorigenic nature of the cells. However, one can distinguish some differences between both cell lines during the growth of colonies that may result from specific cooperative effects and the nature of each biosystem.

Contrasting patterns of connectivity among endemic and widespread fire coral species ( Millepora spp.) in the tropical Southwestern Atlantic

NASA Astrophysics Data System (ADS)

de Souza, Júlia N.; Nunes, Flávia L. D.; Zilberberg, Carla; Sanchez, Juan A.; Migotto, Alvaro E.; Hoeksema, Bert W.; Serrano, Xaymara M.; Baker, Andrew C.; Lindner, Alberto

2017-09-01

Fire corals are the only branching corals in the South Atlantic and provide an important ecological role as habitat-builders in the region. With three endemic species ( Millepora brazilensis, M. nitida and M. laboreli) and one amphi-Atlantic species ( M. alcicornis), fire coral diversity in the Brazilian Province rivals that of the Caribbean Province. Phylogenetic relationships and patterns of population genetic structure and diversity were investigated in all four fire coral species occurring in the Brazilian Province to understand patterns of speciation and biogeography in the genus. A total of 273 colonies from the four species were collected from 17 locations spanning their geographic ranges. Sequences from the 16S ribosomal DNA (rDNA) were used to evaluate phylogenetic relationships. Patterns in genetic diversity and connectivity were inferred by measures of molecular diversity, analyses of molecular variance, pairwise differentiation, and by spatial analyses of molecular variance. Morphometrics of the endemic species M. braziliensis and M. nitida were evaluated by discriminant function analysis; macro-morphological characters were not sufficient to distinguish the two species. Genetic analyses showed that, although they are closely related, each species forms a well-supported clade. Furthermore, the endemic species characterized a distinct biogeographic barrier: M. braziliensis is restricted to the north of the São Francisco River, whereas M. nitida occurs only to the south. Millepora laboreli is restricted to a single location and has low genetic diversity. In contrast, the amphi-Atlantic species M. alcicornis shows high genetic connectivity within the Brazilian Province, and within the Caribbean Province (including Bermuda), despite low levels of gene flow between these populations and across the tropical Atlantic. These patterns reflect the importance of the Amazon-Orinoco Plume and the Mid-Atlantic Barrier as biogeographic barriers, and suggest that, while M. alcicornis is capable of long-distance dispersal, the three endemics have restricted ranges and more limited dispersal capabilities.

Temporal consistency in background mortality of four dominant coral taxa along Australia's Great Barrier Reef

NASA Astrophysics Data System (ADS)

Pisapia, C.; Anderson, K. D.; Pratchett, M. S.

2016-09-01

Studies on the population and community dynamics of scleractinian corals typically focus on catastrophic mortality associated with acute disturbances (e.g., coral bleaching and outbreaks of crown-of-thorns starfish), though corals are subject to high levels of background mortality and injuries caused by routine and chronic processes. This study quantified prevalence (proportion of colonies with injuries) and severity (areal extent of injuries on individual colonies) of background mortality and injuries for four common coral taxa (massive Porites, encrusting Montipora, Acropora hyacinthus and branching Pocillopora) on the Great Barrier Reef, Australia. Sampling was conducted over three consecutive years during which there were no major acute disturbances. A total of 2276 adult colonies were surveyed across 27 sites, within nine reefs and three distinct latitudinal sectors. The prevalence of injuries was very high (>83%) across all four taxa, but highest for Porites (91%) and Montipora (85%). For these taxa ( Montipora and Pocillopora), there was also significant temporal and spatial variation in prevalence of partial mortality. The severity of injuries ranged from 3% to more than 80% and varied among coral taxa, but was fairly constant spatially and temporally. This shows that some injuries have considerable longevity and that corals may invest relatively little in regenerating tissue over sites of previous injuries. Inter-colony variation in the severity of injury also had no apparent effect on the realized growth of individual colonies, suggesting that energy diverted to regeneration has a limited bearing on overall energetic allocation, or impacts on other life-history processes (e.g., reproduction) rather than growth. Establishing background levels of injury and regeneration is important for understanding energy investment and life-history consequences for reef-building corals as well as for predicting susceptibility to, and capacity to recover from, acute disturbances.

Computational modeling and experimental characterization of bacterial microcolonies for rapid detection using light scattering

NASA Astrophysics Data System (ADS)

Bai, Nan

A label-free and nondestructive optical elastic forward light scattering method has been extended for the analysis of microcolonies for food-borne bacteria detection and identification. To understand the forward light scattering phenomenon, a model based on the scalar diffraction theory has been employed: a bacterial colony is considered as a biological spatial light modulator with amplitude and phase modulation to the incoming light, which continues to propagate to the far-field to form a distinct scattering 'fingerprint'. Numerical implementation via angular spectrum method (ASM) and Fresnel approximation have been carried out through Fast Fourier Transform (FFT) to simulate this optical model. Sampling criteria to achieve unbiased and un-aliased simulation results have been derived and the effects of violating these conditions have been studied. Diffraction patterns predicted by these two methods (ASM and Fresnel) have been compared to show their applicability to different simulation settings. Through the simulation work, the correlation between the colony morphology and its forward scattering pattern has been established to link the number of diffraction rings and the half cone angle with the diameter and the central height of the Gaussian-shaped colonies. In order to experimentally prove the correlation, a colony morphology analyzer has been built and used to characterize the morphology of different bacteria genera and investigate their growth dynamics. The experimental measurements have demonstrated the possibility of differentiating bacteria Salmonella, Listeria, Escherichia in their early growth stage (100˜500 µm) based on their phenotypic characteristics. This conclusion has important implications in microcolony detection, as most bacteria of our interest need much less incubation time (8˜12 hours) to grow into this size range. The original forward light scatterometer has been updated to capture scattering patterns from microcolonies. Experiments have been performed to reveal the time dependent nature of scattering patterns. The experimental work has been compared with simulation results and demonstrated the feasibility of extending this technique for microcolony identification. Lastly, a quantitative phase imaging technique based on the phase gradient driven intensity variation has been studied and implemented to render the 2D phase map of the colony sample.

Intramuscular communicating branches in the flexor digitorum profundus: dissection and Sihler's staining.

PubMed

Won, Sung-Yoon; Choi, Da-Yae; Lee, Jae-Gi; Yoon, Kwan-Hyun; Kwak, Hyun-Ho; Hu, Kyung-Seok; Kim, Hee-Jin

2010-03-01

This study was designed to clarify the anatomy of the intramuscular communicating branch (ICb) between the median and ulnar nerves in the flexor digitorum profundus (FDP), and morphologically demonstrate the location of connection. Twenty Korean cadavers were dissected and a further 8 were subjected to modified Sihler's staining to investigate the pattern of innervation of the ICb and the location of its communicating points in muscle. The median and ulnar nerves divided into small branches before entering FDP muscle. Of these small branches, one or two met inside the muscle. This communicating pattern could be classified into three types: type I, communicating branches in both the proximal and distal regions; type II, at least one communicating branch in the proximal region; type III, at least one communicating branch in the distal region. Of 20 dissected specimens, no case of type I was observed, but 3 cases of type II and 15 cases of type III were found. No ICbs at all were found in two of the dissected specimens. In eight stained specimens, one was classified as type I, two as type II, and five as type III. The proximal communicating branches were located at 34.1% from the interepicondylar line, inside the third muscle bundle. The distal communicating branches were located at 66.0% from the interepicondylar line, between third and fourth muscle bundles. These findings could provide critical anatomical information regarding the nerve distribution of FDP focused on the ICbs.

A Type II Arabinogalactan from Anoectochilus formosanus for G-CSF Production in Macrophages and Leukopenia Improvement in CT26-Bearing Mice Treated with 5-Fluorouracil.

PubMed

Yang, Li-Chan; Lu, Ting-Jang; Lin, Wen-Chuan

2013-01-01

Anoectochilus formosanus is an herb well known in Asian countries. The polysaccharide isolated from A. formosanus consists of type II arabinogalactan (AGAF), with branched 3,6-Gal as the major moiety. In this study, AGAF was examined for the granulocyte colony-stimulating factor (G-CSF) production and related protein expression in RAW 264.7 murine macrophages. The signaling pathway of G-CSF production involves AGAF and mitogen-activated protein kinases (MAPKs) inhibitors and pattern-recognition receptor antibodies. AGAF was evaluated to ease the leukopenia in CT26-colon-cancer-bearing mice treated with 5-fluorouracil (5-FU). The results of this study showed that AGAF was a stimulant for Toll-like receptor 2 and Dectin-1 and that it induced G-CSF production, through p38 and ERK MAPK, and NF- κ B pathways. In vivo examination showed that the oral administration of AGAF mitigated the side effects of leukopenia caused by 5-FU in colon-cancer-bearing mice. In conclusion, the botanic type II AGAF in this study was a potent G-CSF inducer in vivo and in vitro.

Quasi-chemostat behavior in the leading edge of B. subtilis biofilms

NASA Astrophysics Data System (ADS)

Srinivasan, Siddarth; Mahadevan, Lakshminarayanan; Rubinstein, Shmuel

2015-11-01

Bacillus subtilis is a gram positive bacterium that is a model system commonly used to study biofilm formation. By performing wide-field time-lapse microscopy on a fluorescently labeled B. subtilis strain, we observe a well defined steady boundary layer at the edge of a biofilm growing on an nutrient infused agar gel substrate, within which the outward radial expansion growth predominantly occurs. Using distinct fluorescent protein markers as proxies of gene expression, we quantitatively measure how the width, velocity and ratio of motile cell to matrix cell phenotypes within this boundary layer responds to changes in environmental conditions (such as substrate agar percentage & temperature). We further propose that the steady state at the leading edge can be interpreted as a quasi-chemostat which may enable well controlled response experiments on a colony scale. Finally, we show that for low agar concentration (0.5 wt%), the cells exhibit swarming behavior, whose dynamics and swimming velocities are characterized using differential dynamic microscopy. We show the swarming state is associated with an unstable front which gives rise to fingering and branching growth patterns, illustrating the varied morphological response of the biofilm to environmental conditions

The Influence of Microgravity on Invasive Growth in Saccharomyces cerevisiae

NASA Astrophysics Data System (ADS)

Van Mulders, Sebastiaan E.; Stassen, Catherine; Daenen, Luk; Devreese, Bart; Siewers, Verena; van Eijsden, Rudy G. E.; Nielsen, Jens; Delvaux, Freddy R.; Willaert, Ronnie

2011-01-01

This study investigates the effects of microgravity on colony growth and the morphological transition from single cells to short invasive filaments in the model eukaryotic organism Saccharomyces cerevisiae. Two-dimensional spreading of the yeast colonies grown on semi-solid agar medium was reduced under microgravity in the Σ1278b laboratory strain but not in the CMBSESA1 industrial strain. This was supported by the Σ1278b proteome map under microgravity conditions, which revealed upregulation of proteins linked to anaerobic conditions. The Σ1278b strain showed a reduced invasive growth in the center of the yeast colony. Bud scar distribution was slightly affected, with a switch toward more random budding. Together, microgravity conditions disturb spatially programmed budding patterns and generate strain-dependent growth differences in yeast colonies on semi-solid medium.

Specializing on vulnerable habitat: Acropora selectivity among damselfish recruits and the risk of bleaching-induced habitat loss

NASA Astrophysics Data System (ADS)

Bonin, M. C.

2012-03-01

Coral reef habitats are increasingly being degraded and destroyed by a range of disturbances, most notably climate-induced coral bleaching. Habitat specialists, particularly those associated with susceptible coral species, are clearly among the most vulnerable to population decline or extinction. However, the degree of specialization on coral microhabitats is still unclear for one of the most ubiquitous, abundant and well studied of coral reef fish families—the damselfishes (Pomacentridae). Using high taxonomic resolution surveys of microhabitat use and availability, this study provides the first species-level description of patterns of Acropora selectivity among recruits of 10 damselfish species in order to determine their vulnerability to habitat degradation. In addition, surveys of the bleaching susceptibility of 16 branching coral species revealed which preferred recruitment microhabitats are at highest risk of decline as a result of chronic coral bleaching. Four species (i.e., Chrysiptera parasema, Pomacentrus moluccensis, Dascyllus melanurus and Chromis retrofasciata) were identified as highly vulnerable because they used only branching hard corals as recruitment habitat and primarily associated with only 2-4 coral species. The bleaching surveys revealed that five species of Acropora were highly susceptible to bleaching, with more than 50% of colonies either severely bleached or already dead. These highly susceptible corals included two of the preferred microhabitats of the specialist C. parasema and represented a significant proportion of its total recruitment microhabitat. In contrast, highly susceptible corals were rarely used by another specialist, P. moluccensis, suggesting that this species faces a lower risk of bleaching-induced habitat loss compared to C. parasema. As degradation to coral reef habitats continues, specialists will increasingly be forced to use alternative recruitment microhabitats, and this is likely to reduce population replenishment. Future research should focus on examining the fitness costs of using these alternative microhabitats.

The ras/mitogen-activated protein kinase pathway inhibitor and likely tumor suppressor proteins, sprouty 1 and sprouty 2 are deregulated in breast cancer.

PubMed

Lo, Ting Ling; Yusoff, Permeen; Fong, Chee Wai; Guo, Ke; McCaw, Ben J; Phillips, Wayne A; Yang, He; Wong, Esther Sook Miin; Leong, Hwei Fen; Zeng, Qi; Putti, Thomas Choudary; Guy, Graeme R

2004-09-01

Sprouty (Spry) proteins were found to be endogenous inhibitors of the Ras/mitogen-activated protein kinase pathway that play an important role in the remodeling of branching tissues. We investigated Spry expression levels in various cancers and found that Spry1 and Spry2 were down-regulated consistently in breast cancers. Such prevalent patterns of down-regulation may herald the later application of these isoforms as tumor markers that are breast cancer specific and more profound than currently characterized markers. Spry1 and 2 were expressed specifically in the luminal epithelial cells of breast ducts, with higher expression during stages of tissue remodeling when the epithelial ducts are forming and branching. These findings suggest that Sprys might be involved as a modeling counterbalance and surveillance against inappropriate epithelial expansion. The abrogation of endogenous Spry activity in MCF-7 cells by the overexpression of a previously characterized dominant-negative mutant of Spry, hSpry2Y55F resulted in enhanced cell proliferation in vitro. The hSpry2Y55F stably expressing cells also formed larger and greater number of colonies in the soft-agar assay. An in vivo nude mice assay showed a dramatic increase in the tumorigenic potential of hSpry2Y55F stable cells. The consistent down-regulation of Spry1 and 2 in breast cancer and the experimental evidence using a dominant-negative hSpry2Y55F indicate that Spry proteins may actively maintain tissue integrity that runs amok when their expression is decreased below normal threshold levels. This alludes to a previously unrecognized role for Sprys in cancer development.

Persistence of black-tailed prairie-dog populations affected by plague in northern Colorado, USA.

PubMed

George, Dylan B; Webb, Colleen T; Pepin, Kim M; Savage, Lisa T; Antolini, Michael F

2013-07-01

The spatial distribution of prairie dog (Cynomys ludovicianus) colonies in North America has changed from large, contiguous populations to small, isolated colonies in metapopulations. One factor responsible for this drastic change in prairie-dog population structure is plague (caused by the bacterium Yersinia pestis). We fit stochastic patch occupancy models to 20 years of prairie-dog colony occupancy data from two discrete metapopulations (west and east) in the Pawnee National Grassland in Colorado, USA, that differ in connectivity among suitable habitat patches. We conducted model selection between two hypothesized modes of plague movement: independent of prairie-dog dispersal (colony-area) vs. plague movement consistent with prairie-dog dispersal (connectivity to extinct colonies). The best model, which fit the data well (area under the curve [AUC]: 0.94 west area; 0.79 east area), revealed that over time the proportion of extant colonies was better explained by colony size than by connectivity to extinct (plagued) colonies. The idea that prairie dogs are not likely to be the main vector that spreads Y. pestis across the landscape is supported by the observation that colony extinctions are primarily caused by plague, prairie-dog dispersal is short range, and connectivity to extinct colonies was not selected as a factor in the models. We also conducted simulations with the best model to examine long-term patterns of colony occupancy and persistence of prairie-dog metapopulations. In the case where the metapopulations persist, our model predicted that the western metapopulation would have a colony occupancy rate approximately 2.5 times higher than that of the eastern metapopulation (-50% occupied colonies vs. 20%) in 50 years, but that the western metapopulation has -80% chance of extinction in 100 years while the eastern metapopulation has a less than 25% chance. Extinction probability of individual colonies depended on the frequency with which colonies of the same size class occurred in the metapopulation. Thus, the long-term persistence of prairie-dog metapopulations depended on specific details of the metapopulation.

Similar patterns of frequency-dependent selection on animal personalities emerge in three species of social spiders.

PubMed

Lichtenstein, J L L; Pruitt, J N

2015-06-01

Frequency-dependent selection is thought to be a major contributor to the maintenance of phenotypic variation. We tested for frequency-dependent selection on contrasting behavioural strategies, termed here 'personalities', in three species of social spiders, each thought to represent an independent evolutionary origin of sociality. The evolution of sociality in the spider genus Anelosimus is consistently met with the emergence of two temporally stable discrete personality types: an 'aggressive' or 'docile' form. We assessed how the foraging success of each phenotype changes as a function of its representation within a colony. We did this by creating experimental colonies of various compositions (six aggressives, three aggressives and three dociles, one aggressive and five dociles, six dociles), maintaining them in a common garden for 3 weeks, and tracking the mass gained by individuals of either phenotype. We found that both the docile and aggressive phenotypes experienced their greatest mass gain in mixed colonies of mostly docile individuals. However, the performance of both phenotypes decreased as the frequency of the aggressive phenotype increased. Nearly identical patterns of phenotype-specific frequency dependence were recovered in all three species. Naturally occurring colonies of these spiders exhibit mixtures dominated by the docile phenotype, suggesting that these spiders may have evolved mechanisms to maintain the compositions that maximize the success of the colony without compromising the expected reproductive output of either phenotype. © 2015 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2015 European Society For Evolutionary Biology.

Nutrient Distribution and Absorption in the Colonial Hydroid Podocoryna carnea Is Sequentially Diffusive and Directional.

PubMed

Buss, Leo W; Anderson, Christopher P; Perry, Elena K; Buss, Evan D; Bolton, Edward W

2015-01-01

The distribution and absorption of ingested protein was characterized within a colony of Podocoryna carnea when a single polyp was fed. Observations were conducted at multiple spatial and temporal scales at three different stages of colony ontogeny with an artificial food item containing Texas Red conjugated albumin. Food pellets were digested and all tracer absorbed by digestive cells within the first 2-3 hours post-feeding. The preponderance of the label was located in the fed polyp and in a transport-induced diffusion pattern surrounding the fed polyp. After 6 hours post-feeding particulates re-appeared in the gastrovascular system and their absorption increased the area over which the nutrients were distributed, albeit still in a pattern that was centered on the fed polyp. At later intervals, tracer became concentrated in some stolon tips, but not in others, despite the proximity of these stolons either to the fed polyp or to adjacent stolons receiving nutrients. Distribution and absorption of nutrients is sequentially diffusive and directional.

Investigation of Age Polyethism in Food Processing of the Fungus-Growing Termite Odontotermes formosanus (Blattodea: Termitidae) Using a Laboratory Artificial Rearing System.

PubMed

Li, Hongjie; Yang, Mengyi; Chen, Yonger; Zhu, Na; Lee, Chow-Yang; Wei, Ji-Qian; Mo, Jianchu

2015-02-01

Laboratory rearing systems are useful models for studying Rhinotermitid behavior. Information on the biology of fungus-growing termites, however, is limited because of the difficulty of rearing colonies in the laboratory settings. The physical structure of termite nests makes it impossible to photograph or to observe colonies in the field. In this study, an artificial rearing system for field-collected colonies of the fungus-growing termite Odontotermes formosanus (Shiraki) was developed to facilitate observation in the laboratory. We recorded colony activity within the artificial rearing system and documented a variety of social behaviors that occurred throughout the food processing of the colony. This complex miniature ecosystem was cooperatively organized via division of labor in the foraging and processing of plant materials, and the observed patterns largely resembled the caste and age-based principles present in Macrotermes colonies. This work extends our insights into polyethism in the subfamily Macrotermitinae. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Patterns of surface burrow plugging in a colony of black-tailed prairie dogs occupied by black-footed ferrets

USGS Publications Warehouse

Eads, David E.; Biggins, Dean E.

2012-01-01

Black-tailed prairie dogs (Cynomys ludovicianus) can surface-plug openings to a burrow occupied by a black-footed ferret (Mustela nigripes). At a coarse scale, surface plugs are more common in colonies of prairie dogs occupied by ferrets than in colonies without ferrets. However, little is known about spatial and temporal patterns of surface plugging in a colony occupied by ferrets. In a 452-ha colony of black-tailed prairie dogs in South Dakota, we sampled burrow openings for surface plugs and related those data to locations of ferrets observed during spotlight surveys. Of 67,574 burrow openings in the colony between June and September 2007, 3.7% were plugged. In a colony-wide grid of 80 m × 80 m cells, the occurrence of surface plugging (≥1 opening plugged) was greater in cells used by ferrets (93.3% of cells) than in cells not observably used by ferrets (70.6%). Rates of surface plugging (percentages of openings plugged) were significantly higher in cells used by ferrets (median = 3.7%) than in cells without known ferret use (median = 3.2%). Also, numbers of ferret locations in cells correlated positively with numbers of mapped surface plugs in the cells. To investigate surface plugging at finer temporal and spatial scales, we compared rates of surface plugging in 20-m-radius circle-plots centered on ferret locations and in random plots 1–4 days after observing a ferret (Jun–Oct 2007 and 2008). Rates of surface plugging were greater in ferret-plots (median = 12.0%) than in random plots (median = 0%). For prairie dogs and their associates, the implications of surface plugging could be numerous. For instance, ferrets must dig to exit or enter plugged burrows (suggesting energetic costs), and surface plugs might influence microclimates in burrows and consequently influence species that cannot excavate soil (e.g., fleas that transmit the plague bacterium Yersinia pestis).

Role of Microbial Immigration in the Colonization of Apple Leaves by Aureobasidium pullulans▿

PubMed Central

McGrath, Molly J.; Andrews, John H.

2007-01-01

The role of microbial immigration in the veinal colonization pattern of Aureobasidium pullulans on the adaxial surface of apple leaves was investigated in two experiments at two periods (early and late seasons) in 2004 by applying green fluorescent protein (GFP)-tagged blastospores to the foliage of orchard trees. Individual leaves were resampled by a semidestructive method immediately after inoculation (t0) and about 1 (t1), 2 (t2), and 3 (t3) weeks later. At t0, there were no significant (P ≤ 0.05) differences in densities (cells/mm2) on veinal (excluding midvein) sites and those on interveinal sites, but at all points thereafter, densities were significantly higher on veins. GFP-tagged A. pullulans cells remained primarily as singletons on interveinal regions (≥90% at all points), while ≥20% of cells over veins at t3 were in colonies of ≥4 cells. The colonies that developed from single cells placed on midveins and other veins were significantly larger than those that developed on interveinal regions of detached field and seedling leaves incubated under controlled conditions. Colonies primarily developed linearly along veins, reaching average colony sizes (72 h) of 24.4 ± 12.7 (mean ± standard deviation) cells. In contrast, colonies on interveinal regions tended to average only 2.9 ± 1.3 cells, with less linearity. To examine the potential role of A. pullulans growth-inhibiting factors associated with interveinal features, single GFP-tagged A. pullulans cells in droplets previously incubated on interveinal sites were placed on midveins and compared to midvein colonies derived from cells in a water-only suspension. No differences in colony size resulted. Our results indicate that immigration limitation and growth-inhibiting factors are not the primary factors responsible for A. pullulans veinal colonization patterns in the field. Rather, indirect evidence suggests that growth-promoting substances occur locally in the veinal areas. PMID:17142367

Whey protein supplementation does not alter plasma branched-chained amino acid profiles but results in unique metabolomics patterns in obese women enrolled in an 8-week weight loss trial

USDA-ARS?s Scientific Manuscript database

Background. Elevations of plasma concentrations of branched-chain amino acids (BCAA) are correlated with insulin resistance. Reduction in the activity of branched-chain ketoacid dehydrogenase complex (BCKDC) activity and impaired complete mitochondrial BCAA catabolism may contribute to this phenoty...

Convergence of leaf display and photosynthetic characteristics of understory Abies amabilis and Tsuga Heterophylla in an old-growth forest in southwestern Washington State, USA

Treesearch

Hiroaki Ishii; Ken-Ichi Yoshimura; Akira Mori

2009-01-01

The branching pattern of A. amabilis was regular (normal shoot-length distribution, less variable branching angle and bifurcation ratio), whereas that of T. heterophylla was more plastic (positively skewed shoot-length distribution, more variable branching angle and bifurcation ratio). The two species had similar shoot...

Intimal cushions and endothelial nuclear elongation around mouse aortic branches and their spatial correspondence with patterns of lipid deposition

PubMed Central

Bond, Andrew R.; Ni, Chih-Wen; Jo, Hanjoong

2010-01-01

Spatial variation in hemodynamic stresses acting on the arterial wall may explain the nonuniform distribution of atherosclerosis. In thoracic aortas of LDL receptor/apolipoprotein E double knockout mice, lesions develop preferentially around the entire circumference of intercostal branch ostia, regardless of age, with the highest prevalence occurring upstream. Additional chevron-shaped lesions occur further upstream of the ostia. This pattern differs from the age-related ones occurring in people and rabbits. In the present study, patterns of near-wall blood flow around intercostal ostia in wild-type mice were estimated from the morphology of endothelial nuclei, which were shown in vitro to elongate in response to elevated shear stress and to align with the flow, and wall structure was assessed from confocal and scanning electron microscopy. A triangular intimal cushion surrounded the upstream part of most ostia. Nuclear length-to-width ratios were lowest over this cushion and highest at the sides of branches, regardless of age. Nuclear orientations were consistent with flow diverging around the branch. The pattern of nuclear morphology differed from the age-related ones observed in rabbits. The intimal cushion and the distribution of shear stress inferred from these observations can partly account for the pattern of lesions observed in knockout mice. Nuclear elongation in nonbranch regions was approximately constant across animals of different size, demonstrating the existence of a mechanism by which endothelial cells compensate for the dependence of mean aortic wall shear stress on body mass. PMID:19933414

Variation in age composition among colony sizes in Cliff Swallows.

PubMed

Brown, Charles R; Roche, Erin A; Brown, Mary Bomberger

2014-09-01

Variation in group size is characteristic of most social species. The extent to which individuals sort among group sizes based on age may yield insight into why groups vary in size and the age-specific costs and benefits of different social environments. We investigated the age composition of Cliff Swallow ( Petrochelidon pyrrhonota ) colonies of different sizes over 18 years at a long-term study site in western Nebraska, USA. Using years elapsed since banding as a relative measure of age for over 194,000 birds, we found that the proportion of age-class-1 swallows (birds banded as nestlings or juveniles or adults in the year of banding) of both sexes increased in larger colonies and at colony sites becoming active later in the summer. Age composition was unrelated to how often a particular colony site was used. The effect of colony size most likely reflected the fact that older birds return to the same colony site in successive years even when the colony size there decreases, and that yearlings and immigrants benefit more from larger colonies than do older, more experienced individuals. The date effect probably resulted in part from later spring arrival by younger and/or immigrant swallows. At fumigated sites where ectoparasitic swallow bugs ( Oeciacus vicarius ) had been removed, age composition did not vary with either colony size or colony initiation date. The patterns reported here appear to be driven partially by the presence of ectoparasites and suggest that the hematophagous bugs influence variation in Cliff Swallow group composition. Our results are consistent with the hypothesis that variation in colony size reflects, in part, age-based sorting of individuals among groups.

Plasticity first: molecular signatures of a complex morphological trait in filamentous cyanobacteria.

PubMed

Koch, Robin; Kupczok, Anne; Stucken, Karina; Ilhan, Judith; Hammerschmidt, Katrin; Dagan, Tal

2017-08-31

Filamentous cyanobacteria that differentiate multiple cell types are considered the peak of prokaryotic complexity and their evolution has been studied in the context of multicellularity origins. Species that form true-branching filaments exemplify the most complex cyanobacteria. However, the mechanisms underlying the true-branching morphology remain poorly understood despite of several investigations that focused on the identification of novel genes or pathways. An alternative route for the evolution of novel traits is based on existing phenotypic plasticity. According to that scenario - termed genetic assimilation - the fixation of a novel phenotype precedes the fixation of the genotype. Here we show that the evolution of transcriptional regulatory elements constitutes a major mechanism for the evolution of new traits. We found that supplementation with sucrose reconstitutes the ancestral branchless phenotype of two true-branching Fischerella species and compared the transcription start sites (TSSs) between the two phenotypic states. Our analysis uncovers several orthologous TSSs whose transcription level is correlated with the true-branching phenotype. These TSSs are found in genes that encode components of the septosome and elongasome (e.g., fraC and mreB). The concept of genetic assimilation supplies a tenable explanation for the evolution of novel traits but testing its feasibility is hindered by the inability to recreate and study the evolution of present-day traits. We present a novel approach to examine transcription data for the plasticity first route and provide evidence for its occurrence during the evolution of complex colony morphology in true-branching cyanobacteria. Our results reveal a route for evolution of the true-branching phenotype in cyanobacteria via modification of the transcription level of pre-existing genes. Our study supplies evidence for the 'plasticity-first' hypothesis and highlights the importance of transcriptional regulation in the evolution of novel traits.

Bud Composition, Branching Patterns and Leaf Phenology in Cerrado Woody Species

PubMed Central

DAMASCOS, M. A.; PRADO, C. H. B. A.; RONQUIM, C. C.

2005-01-01

• Background and Aims Plants have complex mechanisms of aerial biomass exposition, which depend on bud composition, the period of the year in which shoot extension occurs, branching pattern, foliage persistence, herbivory and environmental conditions. • Methods The influence of water availability and temperature on shoot growth, the bud composition, the leaf phenology, and the relationship between partial leaf fall and branching were evaluated over 3 years in Cerrado woody species Bauhinia rufa (BR), Leandra lacunosa (LL) and Miconia albicans (MA). • Key Results Deciduous BR preformed organs in buds and leaves flush synchronously at the transition from the dry to the wet season. The expansion time of leaves is <1 month. Main shoots (first-order axis, A1 shoots) extended over 30 d and they did not branch. BR budding and foliage unfolds were brought about independently of inter-annual rainfall variations. By contrast, in LL and MA evergreen species, the shoot extension rate and the neoformation of aerial organs depended on rainfall. Leaf emergence was continuous for 2–6 months and lamina expansion took place over 1–4 months. The leaf life span was 5–20 months and the main A1 shoot extension happened over 122–177 d. Both evergreen species allocated biomass to shoots, leaves or flowers continuously during the year, branching in the middle of the wet season to form second-order (A2 shoots) and third-order (A3 shoots) axis in LL and A2 shoots in MA. Partial shed of A1 shoot leaves would facilitate a higher branching intensity A2 shoot production in LL than in MA. MA presented a longer leaf life span, produced a lower percentage of A2 shoots but had a higher meristem persistence on A1 and A2 shoots than LL. • Conclusions It was possible to identify different patterns of aerial growth in Cerrado woody species defined by shoot-linked traits such as branching pattern, bud composition, meristem persistence and leaf phenology. These related traits must be considered over and above leaf deciduousness for searching functional guilds in a Cerrado woody community. For the first time a relationship between bud composition, shoot growth and leaf production pattern is found in savanna woody plants. PMID:16157631

BRANCHING PATTERNS OF INDIVIDUAL SYMPATHETIC NEURONS IN CULTURE

PubMed Central

Bray, D.

1973-01-01

The growth of single sympathetic neurons in tissue culture was examined with particular regard to the way in which the patterns of axonal or dendritic processes (here called nerve fibers), were formed. The tips of the fibers were seen to advance in straight lines and to grow at rates that did not vary appreciably with time, with their position in the cell outgrowth, or with the fiber diameter. Most of the branch points were formed by the bifurcation of a fiber tip (growth cone), apparently at random, and thereafter remained at about the same distance from the cell body. It seemed that the final shape of a neuron was the result of the reiterated and largely autonomous activities of the growth cones. The other parts of the cell played a supportive role but, apart from this, had no obvious influence on the final pattern of branches formed. PMID:4687915

Image-based quantification and mathematical modeling of spatial heterogeneity in ESC colonies.

PubMed

Herberg, Maria; Zerjatke, Thomas; de Back, Walter; Glauche, Ingmar; Roeder, Ingo

2015-06-01

Pluripotent embryonic stem cells (ESCs) have the potential to differentiate into cells of all three germ layers. This unique property has been extensively studied on the intracellular, transcriptional level. However, ESCs typically form clusters of cells with distinct size and shape, and establish spatial structures that are vital for the maintenance of pluripotency. Even though it is recognized that the cells' arrangement and local interactions play a role in fate decision processes, the relations between transcriptional and spatial patterns have not yet been studied. We present a systems biology approach which combines live-cell imaging, quantitative image analysis, and multiscale, mathematical modeling of ESC growth. In particular, we develop quantitative measures of the morphology and of the spatial clustering of ESCs with different expression levels and apply them to images of both in vitro and in silico cultures. Using the same measures, we are able to compare model scenarios with different assumptions on cell-cell adhesions and intercellular feedback mechanisms directly with experimental data. Applying our methodology to microscopy images of cultured ESCs, we demonstrate that the emerging colonies are highly variable regarding both morphological and spatial fluorescence patterns. Moreover, we can show that most ESC colonies contain only one cluster of cells with high self-renewing capacity. These cells are preferentially located in the interior of a colony structure. The integrated approach combining image analysis with mathematical modeling allows us to reveal potential transcription factor related cellular and intercellular mechanisms behind the emergence of observed patterns that cannot be derived from images directly. © 2015 International Society for Advancement of Cytometry.

Distribution and morphology of growth anomalies in Acropora from the Indo-Pacific

USGS Publications Warehouse

Work, Thierry M.; Aeby, Greta S.; Coles, Steve L.

2008-01-01

We assessed the distribution and prevalence of growth anomalies (GAs) in Acropora from French Frigate Shoals (Hawaii, USA), Johnston Atoll and Tutuila (American Samoa), developed a nomenclature for gross morphology, characterized GAs at the cellular level and obtained preliminary indices of their spatial patterns and progression within coral colonies. Acropora GAs were found in all 3 regions, but the distribution, variety and prevalence of Acropora GAs was highest in American Samoa. GAs were grouped into 7 gross morphologies (exophytic, bosselated, crateriform, nodular, vermiform, fimbriate or annular). On histology, GAs consisted of hyperplastic basal body wall (calicodermis, mesoglea and gastrodermis apposed to skeleton) with 3 distinct patterns of necrosis. There was no evidence of anaplasia or mitotic figures (common but not necessarily required morphologic indicators of neoplasia). Compared to normal tissues, GAs had significantly fewer polyps, zooxanthellae within the gastrodermis of the coenenchyme, mesenterial filaments and gonads but significantly more necrosis. On 2 colonies with GAs monitored at 2 points over 11 mo, numbers of GAs per colony increased from 0.9 to 3 times the original number seen, and significant clustering of GAs occurred within colonies. The evidence of GAs being true neoplasias (tumors) is mixed, so a cautionary approach is urged in use of morphologic terminology.

Sexual systems in scleractinian corals: an unusual pattern in the reef-building species Diploastrea heliopora

NASA Astrophysics Data System (ADS)

Guest, J. R.; Baird, A. H.; Goh, B. P. L.; Chou, L. M.

2012-09-01

The sexual system in corals refers to the spatial and temporal pattern of sexual function within an individual coral polyp, colony or population. Although information on sexual systems now exists for over 400 scleractinian species, data are still lacking for some important reef-building taxa. The vast majority of scleractinians are either simultaneous hermaphrodites or gonochoric with other sexual systems rarely occurring. Diploastrea heliopora is one of the most ubiquitous and easily recognised reef-building species in the Indo-West Pacific; however, surprisingly little is known about its reproductive biology. The aim of the present study was to examine the reproductive biology of D. heliopora colonies on chronically impacted, equatorial reefs south of Singapore. Here we show that in Singapore, D. heliopora is a broadcast spawner with predominantly gonochoric polyps. Colonies, however, contained male, female and a low proportion of cosexual polyps during the 14-month sampling period. The most plausible explanation for this is that polyps switch sexes with oogenic and spermatogenic cycles occasionally overlapping. This leads to colony level alternation of sex function within and between breeding seasons. While this sexual system is atypical for scleractinians, it supports molecular evidence that D. heliopora is phylogenetically distinct from species formerly in the family Faviidae.

Distribution and morphology of growth anomalies in Acropora from the Indo-Pacific.

PubMed

Work, Thierry M; Aeby, Greta S; Coles, Steve L

2008-01-24

We assessed the distribution and prevalence of growth anomalies (GAs) in Acropora from French Frigate Shoals (Hawaii, USA), Johnston Atoll and Tutuila (American Samoa), developed a nomenclature for gross morphology, characterized GAs at the cellular level and obtained preliminary indices of their spatial patterns and progression within coral colonies. Acropora GAs were found in all 3 regions, but the distribution, variety and prevalence of Acropora GAs was highest in American Samoa. GAs were grouped into 7 gross morphologies (exophytic, bosselated, crateriform, nodular, vermiform, fimbriate or annular). On histology, GAs consisted of hyperplastic basal body wall (calicodermis, mesoglea and gastrodermis apposed to skeleton) with 3 distinct patterns of necrosis. There was no evidence of anaplasia or mitotic figures (common but not necessarily required morphologic indicators of neoplasia). Compared to normal tissues, GAs had significantly fewer polyps, zooxanthellae within the gastrodermis of the coenenchyme, mesenterial filaments and gonads but significantly more necrosis. On 2 colonies with GAs monitored at 2 points over 11 mo, numbers of GAs per colony increased from 0.9 to 3 times the original number seen, and significant clustering of GAs occurred within colonies. The evidence of GAs being true neoplasias (tumors) is mixed, so a cautionary approach is urged in use of morphologic terminology.

Cold Shock Response of Bacillus subtilis: Isoleucine-Dependent Switch in the Fatty Acid Branching Pattern for Membrane Adaptation to Low Temperatures†

PubMed Central

Klein, Wolfgang; Weber, Michael H. W.; Marahiel, Mohamed A.

1999-01-01

Bacillus subtilis has developed sophisticated mechanisms to withstand fluctuations in temperature. Membrane fatty acids are the major determinants for a sufficiently fluid membrane state to ensure the membrane’s function at all temperatures. The fatty acid profile of B. subtilis is characterized by a high content of branched fatty acids irrespective of the growth medium. Here, we report on the importance of isoleucine for B. subtilis to survive cold shock from 37 to 15°C. Cold shock experiments with strain JH642 revealed a cold-protective function for all intermediates of anteiso-branched fatty acid biosynthesis. Metabolites related to iso-branched or straight-chain fatty acid biosynthesis were not protective. Fatty acid profiles of different B. subtilis wild-type strains proved the altered branching pattern by an increase in the anteiso-branched fatty acid content and a concomitant decrease of iso-branched species during cold shock. There were no significant changes in the fatty acid saturation or acyl chain length. The cold-sensitive phenotype of isoleucine-deficient strains in the absence of isoleucine correlated with their inability to synthesize more anteiso-branched fatty acids, as shown by the fatty acid profile. The switch to a fatty acid profile dominated by anteiso-C15:0 and C17:0 at low temperatures and the cold-sensitive phenotype of isoleucine-deficient strains in the absence of isoleucine focused our attention on the critical role of anteiso-branched fatty acids in the growth of B. subtilis in the cold. PMID:10464205

Foraging ecology of the endangered wood stork recorded in the stable isotope signature of feathers.

PubMed

Romanek, C S; Gaines, K F; Bryan, A L; Brisbin, I L

2000-12-01

Down feathers and regurgitant were collected from nestling wood storks (Mycteria americana) from two inland and two coastal breeding colonies in Georgia. The stable isotopic ratios of carbon ( 13 C/ 12 C) and nitrogen ( 15 N/ 14 N) in these materials were analyzed to gain insights into the natal origins of juvenile storks and the foraging activities of adults. Down feathers differed in δ 13 C between inland and coastal colonies, having average isotopic values that reflected the sources of carbon fixed in biomass at the base of the food web. Feathers from the inland colonies differed between colonies in δ 15 N, while those from the coastal colonies did not. These patterns primarily reflected the foraging activities of parent storks, with individuals capturing differing percentages of prey of distinct trophic status at each colony. Collectively, the carbon and nitrogen isotopic signatures of feather keratin were used to distinguish nestlings from each colony, except for instances where storks from different colonies foraged in common wetlands. The stable isotopic composition of food items in regurgitant was used to reconstruct the trophic structure of the ecosystems in which wood storks foraged. Predicted foraging activities based on the isotopic composition of keratin were generally consistent with the percentage of prey types (freshwater vs. saltwater and lower trophic level vs. upper trophic level consumer) observed in regurgitant, except for the coastal colony at St. Simons Island, where the δ 13 C of feathers strongly suggested that freshwater prey were a significant component of the diet. This inconsistency was resolved by aerial tracking of adults during foraging excursions using a fixed-wing aircraft. Observed foraging activities supported interpretations based on the stable isotope content of feathers, suggesting that the latter provided a better record of overall foraging activity than regurgitant analysis alone. Observed foraging patterns were compared to the predictions of a statistical model that determined habitat utilization based on habitat availability using a geographic information system (GIS) database. Observed foraging activities and those predicted from feathers both suggested that some adult storks preferred to feed their young freshwater prey, even when saltwater resources were more accessible in the local environment. This conclusion supports the contention that wood stork populations are sensitive to changes in the distribution of freshwater habitats along the southeastern coastal plain of the United States.

Patterns of Storm Injury and Tree Response

Treesearch

Kevin Smith; Walter Shortle; Kenneth Dudzik

2001-01-01

The ice storm of January 1998 in the northeastern United States and adjacent Canada was an extreme example of severe weather that injures trees every year. Broken branches, split branch forks, and snapped stems are all examples of storm injury.

Sediment and discharge yields within a minimally disturbed, headwater watershed in North Central Pennsylvania, USA, with an emphasis on Superstorm Sandy

USGS Publications Warehouse

Maloney, Kelly O.; Shull, Dustin R.

2015-01-01

We estimated discharge and suspended sediment (SS) yield in a minimally disturbed watershed in North Central Pennsylvania, USA, and compared a typical storm (September storm, 4.80 cm) to a large storm (Superstorm Sandy, 7.47 cm rainfall). Depending on branch, Sandy contributed 9.7–19.9 times more discharge and 11.5–37.4 times more SS than the September storm. During the September storm, the upper two branches accounted for 60.6% of discharge and 88.8% of SS at Lower Branch; during Sandy these percentages dropped to 36.1% for discharge and 30.1% for SS. The branch with close proximity roads had over two-three times per area SS yield than the branch without such roads. Hysteresis loops showed typical clockwise patterns for the September storm and more complicated patterns for Sandy, reflecting the multipeak event. Estimates of SS and hysteresis in minimally disturbed watersheds provide useful information that can be compared spatially and temporally to facilitate management.

Artificial bee colony in neuro - Symbolic integration

NASA Astrophysics Data System (ADS)

Kasihmuddin, Mohd Shareduwan Mohd; Sathasivam, Saratha; Mansor, Mohd. Asyraf

2017-08-01

Swarm intelligence is a research area that models the population of the swarm based on natural computation. Artificial bee colony (ABC) algorithm is a swarm based metaheuristic algorithm introduced by Karaboga to optimize numerical problem. Pattern-SAT is a pattern reconstruction paradigm that utilized 2SAT logical rule in representing the behavior of the desired pattern. The information of the desired pattern in terms of 2SAT logic is embedded to Hopfield neural network (HNN-P2SAT) and the desired pattern is reconstructed during the retrieval phase. Since the performance of HNN-P2SAT in Pattern-SAT deteriorates when the number of 2SAT clause increased, newly improved ABC is used to reduce the computation burden during the learning phase of HNN-P2SAT (HNN-P2SATABC). The aim of this study is to investigate the performance of Pattern-SAT produced by ABC incorporated with HNN-P2SAT and compare it with conventional standalone HNN. The comparison is examined by using Microsoft Visual Basic C++ 2013 software. The detailed comparison in doing Pattern-SAT is discussed based on global Pattern-SAT, ratio of activated clauses and computation time. The result obtained from computer simulation indicates the beneficial features of HNN-P2SATABC in doing Pattern-SAT. This finding is expected to result in a significant implication on the choice of searching method used to do Pattern-SAT.

The effect of species and colony size on the bleaching response of reef-building corals in the Florida Keys during the 2005 mass bleaching event

NASA Astrophysics Data System (ADS)

Brandt, M. E.

2009-12-01

Understanding the variation in coral bleaching response is necessary for making accurate predictions of population changes and the future state of reefs in a climate of increasing thermal stress events. Individual coral colonies, belonging to inshore patch reef communities of the Florida Keys, were followed through the 2005 mass bleaching event. Overall, coral bleaching patterns followed an index of accumulated thermal stress more closely than in situ temperature measurements. Eight coral species ( Colpophyllia natans, Diploria strigosa, Montastraea cavernosa, M. faveolata, Porites astreoides, P. porites, Siderastrea siderea, and Stephanocoenia intersepta), representing >90% of the coral colonies studied, experienced intense levels of bleaching, but responses varied. Bleaching differed significantly among species: Colpophyllia natans and Diploria strigosa were most susceptible to thermal stress, while Stephanocoenia intersepta was the most tolerant. For colonies of C. natans, M. faveolata, and S. siderea, larger colonies experienced more extensive bleaching than smaller colonies. The inshore patch reef communities of the Florida Keys have historically been dominated by large colonies of Montastraea sp. and Colpophyllia natans. These results provide evidence that colony-level differences can affect bleaching susceptibility in this habitat and suggest that the impact of future thermal stress events may be biased toward larger colonies of dominant reef-building species. Predicted increases in the frequency of mass bleaching and subsequent mortality may therefore result in significant structural shifts of these ecologically important communities.

Extralaryngeal branching of the recurrent laryngeal nerve: a meta-analysis of 28,387 nerves.

PubMed

Henry, Brandon Michael; Vikse, Jens; Graves, Matthew J; Sanna, Silvia; Sanna, Beatrice; Tomaszewska, Iwona M; Tubbs, R Shane; Tomaszewski, Krzysztof A

2016-11-01

The recurrent laryngeal nerves (RLN) are branches of the vagus nerve that go on to innervate most of the intrinsic muscles of the larynx. Historically, the RLN has been considered to branch after it enters the larynx, but numerous studies have demonstrated that it often branches before. The wide variability of this extralaryngeal branching (ELB) has significant implications for the risk of iatrogenic injury. We aimed to assess the anatomical characteristics of ELB comprehensively. Articles on the ELB of the RLN were identified by a comprehensive database search. Relevant data were extracted and pooled into a meta-analysis of the prevalence of branching, branching pattern, distance of ELB point from the larynx, and presence of positive motor signals in anterior and posterior ELB branches. A total of 69 articles (n = 28,387 nerves) from both intraoperative and cadaveric modalities were included in the meta-analysis. The overall pooled prevalence of ELB was 60.0 % (95 % CI 52.0-67.7). Cadaveric and intraoperative subgroups differed with prevalence rates of 73.3 % (95 % CI 61.0-84.0) and 39.2 % (95 % CI 29.0-49.9), respectively. Cadavers most often presented with a ELB pattern of bifurcation, with a prevalence of 61.1 %, followed by no branching at 23.4 %. Branching of the RLN occurred most often at a distance of 1-2 cm (74.8 % of cases) prior to entering the larynx. A positive motor signal was most often noted in anterior RLN branches (99.9 %) but only in 1.5 % of posterior branches. The anatomy of the RLN is highly variable, and ELB is likely to have been underreported in intraoperative studies. Because of its high likelihood, the possibility of ELB needs to be assessed in patients to prevent iatrogenic injury and long-term postoperative complications.

Use of a series of chemostat cultures to isolate 'improved' variants of the Quorn mycoprotein fungus, Fusarium graminearum A3/5.

PubMed

Wiebe, M G; Robson, G D; Oliver, S G; Trinci, A P

1994-11-01

Variants (designated A23-S and A24-S) of the Quorn myco-protein fungus, Fusarium graminearum A3/5 were isolated from a series of glucose-limited cultures grown at a dilution rate of 0.18 h-1 for a combined total of 109 d. These variants had unchanged mycelial morphologies but, when grown in mixed culture with the parental strain (A3/5) in glucose-limited chemostat culture at 0.18 h-1, A23-S and A24-S had selection coefficients of 0.013 and 0.017 h-1, respectively, and supplanted A3/5. When a monoculture of A23-S was grown in a glucose-limited culture at a dilution rate of 0.18 h-1, the appearance of highly branched (so-called colonial) mutants was delayed compared with their appearance in chemostat cultures of the parental strain. Furthermore, when a monoculture of A24-S was grown in glucose-limited culture at 0.18 h-1, the appearance of colonial mutants was delayed even further. Thus, it is possible to isolate advantageous (relative to A3/5) variants of F. graminearum A3/5 which have unchanged mycelial morphologies, but in which the appearance of colonial mutants is delayed.

Evidence for density dependence in foraging and migratory behavior of a subtropical nearshore seabird

USGS Publications Warehouse

Lamb, Juliet S.; Satgé, Yvan G.; Jodice, Patrick G. R.

2017-01-01

Density-dependent competition for food resources influences both foraging ecology and reproduction in a variety of animals. The relationship between colony size, local prey depletion, and reproductive output in colonial central-place foragers has been extensively studied in seabirds; however, most studies have focused on effects of intraspecific competition during the breeding season, while little is known about whether density-dependent resource depletion influences individual migratory behavior outside the breeding season. Using breeding colony size as a surrogate for intraspecific resource competition, we tested for effects of colony size on breeding home range, nestling health, and migratory patterns of a nearshore colonial seabird, the brown pelican (Pelecanus occidentalis), originating from seven breeding colonies of varying sizes in the subtropical northern Gulf of Mexico. We found evidence for density-dependent effects on foraging behavior during the breeding season, as individual foraging areas increased linearly with the number of breeding pairs per colony. Contrary to our predictions, however, nestlings from more numerous colonies with larger foraging ranges did not experience either decreased condition or increased stress. During nonbreeding, individuals from larger colonies were more likely to migrate, and traveled longer distances, than individuals from smaller colonies, indicating that the influence of density-dependent effects on distribution persists into the nonbreeding period. We also found significant effects of individual physical condition, particularly body size, on migratory behavior, which in combination with colony size suggesting that dominant individuals remain closer to breeding sites during winter. We conclude that density-dependent competition may be an important driver of both the extent of foraging ranges and the degree of migration exhibited by brown pelicans. However, the effects of density-dependent competition on breeding success and population regulation remain uncertain in this system.

Patterns of pollen and nectar foraging specialization by bumblebees over multiple timescales using RFID

PubMed Central

Russell, Avery L.; Morrison, Sarah J.; Moschonas, Eleni H.; Papaj, Daniel R.

2017-01-01

The ecological success of social insects is frequently ascribed to improvements in task performance due to division of labour amongst workers. While much research has focused on improvements associated with lifetime task specialization, members of colonies can specialize on a given task over shorter time periods. Eusocial bees in particular must collect pollen and nectar rewards to survive, but most workers appear to mix collection of both rewards over their lifetimes. We asked whether bumblebees specialize over timescales shorter than their lifetime. We also explored factors that govern such patterns, and asked whether reward specialists made more foraging bouts than generalists. In particular, we described antennal morphology and size of all foragers in a single colony and related these factors to each forager’s complete foraging history, obtained using radio frequency identification (RFID). Only a small proportion of foragers were lifetime specialists; nevertheless, >50% of foragers specialized daily on a given reward. Contrary to expectations, daily and lifetime reward specialists were not better foragers (being neither larger nor making more bouts); larger bees with more antennal olfactory sensilla made more bouts, but were not more specialized. We discuss causes and functions of short and long-term patterns of specialization for bumblebee colonies. PMID:28181584

Low colony counts of asymptomatic group B streptococcus bacteriuria: a survey of practice patterns.

PubMed

Aungst, Matthew; King, Jeremy; Steele, Andrew; Gordon, Michael

2004-10-01

The purpose of this study was to survey expert opinion on the management of low colony counts (< 100,000 colony forming units/mL) of asymptomatic group B streptococcus (GBS) bacteriuria discovered in the first trimester. A survey was sent to the 241 senior obstetricians affiliated with each of the Obstetrics and Gynecology training programs in the United States on July 10, 2002. Surveys received by the deadline (September 1, 2002) were included in the dataset. Eighty-five completed surveys were returned for a response rate of 35%. Seventy-seven percent reported treating low colony counts of asymptomatic GBS bacteriuria in the first trimester at the time of diagnosis, whereas 23% stated they did not treat prior to labor (margin of error 7.5% with 95% confidence). Nine percent stated that their institution had a written protocol for the treatment of low colony counts of asymptomatic GBS bacteriuria. Two physicians indicated that they screened for asymptomatic GBS bacteriuria at 28 weeks. Currently, no generally accepted protocol for the management of low colony counts of asymptomatic GBS bacteriuria exists. This survey indicates that most of the responding senior obstetricians at United States training programs treat low colony counts of asymptomatic GBS bacteriuria in the first trimester.

Gene flow in a Yersinia pestis vector, Oropsylla hirsuta, during a plague epizootic.

PubMed

Jones, Philip H; Washburn, Leigh R; Britten, Hugh B

2011-09-01

Appreciating how Yersinia pestis, the etiological agent of plague, spreads among black - tailed prairie dog (Cynomys ludovicianus) colonies (BTPD), is vital to wildlife conservation programs in North American grasslands. A little - studied aspect of the system is the role of Y. pestis vectors, i.e. fleas, play in the spreading of plague in natural settings. We investigated the genetic structure and variability of a common prairie dog flea (Oropsylla hirsuta) in BTPD colonies in order to examine dispersal patterns. Given that this research took place during a widespread plague epizootic, there was the added advantage of gaining information on the dynamics of sylvatic plague. Oropsylla hirsuta were collected from BTPD burrows in nine colonies from May 2005 to July 2005, and eight polymorphic microsatellite markers were used to generate genotypic data from them. Gene flow estimates revealed low genetic differentiation among fleas sampled from different colonies. NestedPCR plague assays confirmed the presence of Y. pestis with the average Y. pestis prevalence across all nine colonies at 12%. No significant correlations were found between the genetic variability and gene flow of O. hirsuta and Y. pestis prevalence on a per -colony basis. Oropsylla hirsuta dispersal among BTPD colonies was high, potentially explaining the rapid spread of Y. pestis in our study area in 2005 and 2006.

Expression and functional analyses of a Kinesin gene GhKIS13A1 from cotton (Gossypium hirsutum) fiber.

PubMed

Li, Yan-Jun; Zhu, Shou-Hong; Zhang, Xin-Yu; Liu, Yong-Chang; Xue, Fei; Zhao, Lan-Jie; Sun, Jie

2017-06-12

Cotton fiber, a natural fiber widely used in the textile industry, is differentiated from single cell of ovule epidermis. A large number of genes are believed to be involved in fiber formation, but so far only a few fiber genes have been isolated and functionally characterized in this developmental process. The Kinesin13 subfamily was found to play key roles during cell division and cell elongation, and was considered to be involved in the regulation of cotton fiber development. The full length of coding sequence of GhKIS13A1 was cloned using cDNA from cotton fiber for functional characterization. Expression pattern analysis showed that GhKIS13A1 maintained a lower expression level during cotton fiber development. Biochemical assay showed that GhKIS13A1 has microtubule binding activity and basal ATPase activity that can be activated significantly by the presence of microtubules. Overexpression of GhKIS13A1 in Arabidopsis reduced leaf trichomes and the percentage of three-branch trichomes, and increased two-branch and shriveled trichomes compared to wild-type. Additionally, the expression of GhKIS13A1 in the Arabidopsis Kinesin-13a-1 mutant rescued the defective trichome branching pattern of the mutant, making its overall trichome branching pattern back to normal. Our results suggested that GhKIS13A1 is functionally compatible with AtKinesin-13A regarding their role in regulating the number and branching pattern of leaf trichomes. Given the developmental similarities between cotton fibers and Arabidopsis trichomes, it is speculated that GhKIS13A1 may also be involved in the regulation of cotton fiber development.

Developmental Morphology of the Shoot in Weddellina squamulosa and Implications for Shoot Evolution in the Podostemaceae

PubMed Central

Koi, Satoshi; Kato, Masahiro

2007-01-01

Background and Aims In angiosperms, the shoot apical meristem produces a shoot system composed of stems, leaves and axillary buds. Podostemoideae, one of three subfamilies of the river-weed family Podostemaceae, have a unique ‘shoot’ that lacks a shoot apical meristem and is composed only of leaves. Tristichoideae have been interpreted to have a shoot apical meristem, although its branching pattern is uncertain. The shoot developmental pattern in Weddellinoideae has not been investigated with a focus on the meristem. Weddellinoideae are in a phylogenetically key position to reveal the process of shoot evolution in Podostemaceae. Methods The shoot development of Weddellina squamulosa, the sole species of Weddellinoideae, was investigated using scanning electron microscopy and semi-thin serial sections. Key Results The shoot of W. squamulosa has a tunica–corpus-organized apical meristem. It is determinate and successively initiates a new branch extra-axillarily at the base of an immediately older branch, resulting in a sympodial, approximately plane branching pattern. Large scaly leaves initiate acropetally on the flanks of the apical meristem, as is usual in angiosperms, whereas small scaly leaves scattered on the stem initiate basipetally in association with the elongation of internodes. Conclusions Weddellinoideae, like Tristichoideae, have a shoot apical meristem, leading to the hypothesis that the meristem was lost in Podostemoideae. The patterns of leaf formation in Podostemoideae and shoot branching in Weddellinoideae are similar in that these organs arise at the bases of older organs. This similarity leads to another hypothesis that the ‘branch’ in Weddellinoideae (and possibly Tristichoideae) and the ‘leaf’ in Podostemoideae are comparable, and that the shoot apical meristem disappeared in the early evolution of Podostemaceae. PMID:17468112

Mapping sleeping bees within their nest: spatial and temporal analysis of worker honey bee sleep.

PubMed

Klein, Barrett Anthony; Stiegler, Martin; Klein, Arno; Tautz, Jürgen

2014-01-01

Patterns of behavior within societies have long been visualized and interpreted using maps. Mapping the occurrence of sleep across individuals within a society could offer clues as to functional aspects of sleep. In spite of this, a detailed spatial analysis of sleep has never been conducted on an invertebrate society. We introduce the concept of mapping sleep across an insect society, and provide an empirical example, mapping sleep patterns within colonies of European honey bees (Apis mellifera L.). Honey bees face variables such as temperature and position of resources within their colony's nest that may impact their sleep. We mapped sleep behavior and temperature of worker bees and produced maps of their nest's comb contents as the colony grew and contents changed. By following marked bees, we discovered that individuals slept in many locations, but bees of different worker castes slept in different areas of the nest relative to position of the brood and surrounding temperature. Older worker bees generally slept outside cells, closer to the perimeter of the nest, in colder regions, and away from uncapped brood. Younger worker bees generally slept inside cells and closer to the center of the nest, and spent more time asleep than awake when surrounded by uncapped brood. The average surface temperature of sleeping foragers was lower than the surface temperature of their surroundings, offering a possible indicator of sleep for this caste. We propose mechanisms that could generate caste-dependent sleep patterns and discuss functional significance of these patterns.

Local behavioral rules sustain the cell allocation pattern in the combs of honey bee colonies (Apis mellifera).

PubMed

Montovan, Kathryn J; Karst, Nathaniel; Jones, Laura E; Seeley, Thomas D

2013-11-07

In the beeswax combs of honey bees, the cells of brood, pollen, and honey have a consistent spatial pattern that is sustained throughout the life of a colony. This spatial pattern is believed to emerge from simple behavioral rules that specify how the queen moves, where foragers deposit honey/pollen and how honey/pollen is consumed from cells. Prior work has shown that a set of such rules can explain the formation of the allocation pattern starting from an empty comb. We show that these rules cannot maintain the pattern once the brood start to vacate their cells, and we propose new, biologically realistic rules that better sustain the observed allocation pattern. We analyze the three resulting models by performing hundreds of simulation runs over many gestational periods and a wide range of parameter values. We develop new metrics for pattern assessment and employ them in analyzing pattern retention over each simulation run. Applied to our simulation results, these metrics show alteration of an accepted model for honey/pollen consumption based on local information can stabilize the cell allocation pattern over time. We also show that adding global information, by biasing the queen's movements towards the center of the comb, expands the parameter regime over which pattern retention occurs. © 2013 Published by Elsevier Ltd. All rights reserved.

The Cult of Order: In Search of Underlying Patterns of the Colonial and Neo-Colonial "Grammar of Educationalisation" in the Belgian Congo. Exported School Rituals and Routines?

ERIC Educational Resources Information Center

Van Ruyskensvelde, Sarah; Hulstaert, Karen; Depaepe, Marc

2017-01-01

An analysis of the history of primary education in Belgium by Depaepe et al. in 2000 has demonstrated how the idea of "order" structured classroom reality in the course of the nineteenth and twentieth centuries. This "order" is not only visible in the internal organisation of schooling (e.g. division into year classes, a…

Analysis of the therapeutic gain in the treatment of human osteosarcoma microcolonies in vitro with 211At-labelled monoclonal antibody.

PubMed

Larsen, R H; Bruland, O S; Hoff, P; Alstad, J; Rofstad, E K

1994-06-01

Microcolonies were obtained by culturing cells of two human osteosarcoma lines (OHS and KPDX) and one human melanoma line (WIX-c) for either 24 or 72 h. The microcolonies were treated with either alpha-particle radiation emitted by the 211At-labelled monoclonal antibody (MAb) TP-3 or external beam X-rays. Survival of microcolonies was assayed by colony formation. Therapeutic gain factor (TGF) values were calculated for two survival levels, 50% and 20% microcolony regeneration (i.e. at least one cell in 50% or 20% of the colonies survived the treatments). The TGF values were affected by the specific activity of the 211At-MAb conjugate, the antigen expression of the cells and the size and growth pattern of the microcolonies. Treatment with 211At-TP-3 gave TGF values that varied from 1.3 +/- 0.4 to 4.5 +/- 0.7 (mean +/- s.e.). The antigen-rich OHS cell line had on average 1.6 times higher TGF than the antigen-poor KPDX cell line. The TGF increased significantly with colony size for the densely packed colonies of the KPDX cell line but not for the OHS cell line, which had colonies with cells growing in a more scattered pattern. Control experiments with the two non-specific 211At forms, free 211At and 211At-labelled bovine serum albumin, gave TGF values from 0.6 +/- 0.1 to 1.0 +/- 0.3. This study suggests that in vivo evaluation of 211At-MAbs using relevant tumour models is desirable.

Analysis of the therapeutic gain in the treatment of human osteosarcoma microcolonies in vitro with 211At-labelled monoclonal antibody.

PubMed Central

Larsen, R. H.; Bruland, O. S.; Hoff, P.; Alstad, J.; Rofstad, E. K.

1994-01-01

Microcolonies were obtained by culturing cells of two human osteosarcoma lines (OHS and KPDX) and one human melanoma line (WIX-c) for either 24 or 72 h. The microcolonies were treated with either alpha-particle radiation emitted by the 211At-labelled monoclonal antibody (MAb) TP-3 or external beam X-rays. Survival of microcolonies was assayed by colony formation. Therapeutic gain factor (TGF) values were calculated for two survival levels, 50% and 20% microcolony regeneration (i.e. at least one cell in 50% or 20% of the colonies survived the treatments). The TGF values were affected by the specific activity of the 211At-MAb conjugate, the antigen expression of the cells and the size and growth pattern of the microcolonies. Treatment with 211At-TP-3 gave TGF values that varied from 1.3 +/- 0.4 to 4.5 +/- 0.7 (mean +/- s.e.). The antigen-rich OHS cell line had on average 1.6 times higher TGF than the antigen-poor KPDX cell line. The TGF increased significantly with colony size for the densely packed colonies of the KPDX cell line but not for the OHS cell line, which had colonies with cells growing in a more scattered pattern. Control experiments with the two non-specific 211At forms, free 211At and 211At-labelled bovine serum albumin, gave TGF values from 0.6 +/- 0.1 to 1.0 +/- 0.3. This study suggests that in vivo evaluation of 211At-MAbs using relevant tumour models is desirable. PMID:8198960

Sall1-dependent signals affect Wnt signaling and ureter tip fate to initiate kidney development.

PubMed

Kiefer, Susan M; Robbins, Lynn; Stumpff, Kelly M; Lin, Congxing; Ma, Liang; Rauchman, Michael

2010-09-01

Development of the metanephric kidney depends on precise control of branching of the ureteric bud. Branching events represent terminal bifurcations that are thought to depend on unique patterns of gene expression in the tip compared with the stalk and are influenced by mesenchymal signals. The metanephric mesenchyme-derived signals that control gene expression at the ureteric bud tip are not well understood. In mouse Sall1 mutants, the ureteric bud grows out and invades the metanephric mesenchyme, but it fails to initiate branching despite tip-specific expression of Ret and Wnt11. The stalk-specific marker Wnt9b and the beta-catenin downstream target Axin2 are ectopically expressed in the mutant ureteric bud tips, suggesting that upregulated canonical Wnt signaling disrupts ureter branching in this mutant. In support of this hypothesis, ureter arrest is rescued by lowering beta-catenin levels in the Sall1 mutant and is phenocopied by ectopic expression of a stabilized beta-catenin in the ureteric bud. Furthermore, transgenic overexpression of Wnt9b in the ureteric bud causes reduced branching in multiple founder lines. These studies indicate that Sall1-dependent signals from the metanephric mesenchyme are required to modulate ureteric bud tip Wnt patterning in order to initiate branching.

Growth and development of Frankia spp. strain CcI3 at the single-hypha level in liquid culture.

PubMed

Huang, Ying; Benson, David R

2012-01-01

Filamentous actinobacteria from the genus Frankia grow by hyphal tip extension and branching. The growth kinetics and branching pattern of Frankia are not well studied, especially at the early stages of mycelial development. Here, we compare the growth of Frankia sp. strain CcI3 in liquid cultures with and without proteose peptone #3 (PP3) using time-lapse photomicrography and image analysis. Individual hyphae showed a pseudolinear increase in length at early stages of development, whereas at the mycelial level, the aggregate length of hyphae described an exponential rate before slowing. Growth based on optical density or microscopic observations was similar in medium with or without PP3. However, PP3 altered the pattern of mycelial development by increasing branching. Distances between the hyphal apex and first branches were on average shorter in PP3-containing media. The final interbranch distances were also shorter in PP3 medium indicating that hyphae tended to branch earlier and more often when supplemented with PP3 to give a more compact mycelium. Vesicle development in nitrogen-fixing cultures limited cell expansion as a result of vesicles truncating growth on new branches. The results provide some explanation for the growth kinetics of Frankia and some indication of how growth rates may be improved.

Morphometric differences and fluctuating asymmetry in Melipona subnitida Ducke 1910 (Hymenoptera: Apidae) in different types of housing.

PubMed

Lima, C B S; Nunes, L A; Carvalho, C A L; Ribeiro, M F; Souza, B A; Silva, C S B

2016-01-01

A geometric morphometrics approach was applied to evaluate differences in forewing patterns of the Jandaira bee (Melipona subnitida Ducke). For this, we studied the presence of fluctuating asymmetry (FA) in forewing shape and size of colonies kept in either rational hive boxes or natural tree trunks. We detected significant FA for wing size as well as wing shape independent of the type of housing (rational box or tree trunks), indicating the overall presence of stress during the development of the studied specimens. FA was also significant (p < 0.01) between rational boxes, possibly related to the use of various models of rational boxes used for keeping stingless bees. In addition, a Principal Component Analysis indicated morphometric variation between bee colonies kept in either rational hive boxes or in tree trunks, that may be related to the different origins of the bees: tree trunk colonies were relocated natural colonies while rational box colonies originated from multiplying other colonies. We conclude that adequate measures should be taken to reduce the amount of stress during bee handling by using standard models of rational boxes that cause the least disruption.

Linking ice accretion and crown structure: towards a model of the effect of freezing rain on tree canopies

PubMed Central

Nock, Charles A.; Lecigne, Bastien; Taugourdeau, Olivier; Greene, David F.; Dauzat, Jean; Delagrange, Sylvain; Messier, Christian

2016-01-01

Background and Aims Despite a longstanding interest in variation in tree species vulnerability to ice storm damage, quantitative analyses of the influence of crown structure on within-crown variation in ice accretion are rare. In particular, the effect of prior interception by higher branches on lower branch accumulation remains unstudied. The aim of this study was to test the hypothesis that intra-crown ice accretion can be predicted by a measure of the degree of sheltering by neighbouring branches. Methods Freezing rain was artificially applied to Acer platanoides L., and in situ branch-ice thickness was measured directly and from LiDAR point clouds. Two models of freezing rain interception were developed: ‘IceCube’, which uses point clouds to relate ice accretion to a voxel-based index (sheltering factor; SF) of the sheltering effect of branch elements above a measurement point; and ‘IceTree’, a simulation model for in silico evaluation of the interception pattern of freezing rain in virtual tree crowns. Key Results Intra-crown radial ice accretion varied strongly, declining from the tips to the bases of branches and from the top to the base of the crown. SF for branches varied strongly within the crown, and differences among branches were consistent for a range of model parameters. Intra-crown variation in ice accretion on branches was related to SF (R2 = 0·46), with in silico results from IceTree supporting empirical relationships from IceCube. Conclusions Empirical results and simulations confirmed a key role for crown architecture in determining intra-crown patterns of ice accretion. As suspected, the concentration of freezing rain droplets is attenuated by passage through the upper crown, and thus higher branches accumulate more ice than lower branches. This is the first step in developing a model that can provide a quantitative basis for investigating intra-crown and inter-specific variation in freezing rain damage. PMID:27107412

Analysis of the role of the Spitzenkörper in fungal morphogenesis by computer simulation of apical branching in Aspergillus niger

PubMed Central

Reynaga-Peña, Cristina G.; Gierz, Gerhard; Bartnicki-Garcia, Salomon

1997-01-01

High-resolution video microscopy, image analysis, and computer simulation were used to study the role of the Spitzenkörper (Spk) in apical branching of ramosa-1, a temperature-sensitive mutant of Aspergillus niger. A shift to the restrictive temperature led to a cytoplasmic contraction that destabilized the Spk, causing its disappearance. After a short transition period, new Spk appeared where the two incipient apical branches emerged. Changes in cell shape, growth rate, and Spk position were recorded and transferred to the fungus simulator program to test the hypothesis that the Spk functions as a vesicle supply center (VSC). The simulation faithfully duplicated the elongation of the main hypha and the two apical branches. Elongating hyphae exhibited the growth pattern described by the hyphoid equation. During the transition phase, when no Spk was visible, the growth pattern was nonhyphoid, with consecutive periods of isometric and asymmetric expansion; the apex became enlarged and blunt before the apical branches emerged. Video microscopy images suggested that the branch Spk were formed anew by gradual condensation of vesicle clouds. Simulation exercises where the VSC was split into two new VSCs failed to produce realistic shapes, thus supporting the notion that the branch Spk did not originate by division of the original Spk. The best computer simulation of apical branching morphogenesis included simulations of the ontogeny of branch Spk via condensation of vesicle clouds. This study supports the hypothesis that the Spk plays a major role in hyphal morphogenesis by operating as a VSC—i.e., by regulating the traffic of wall-building vesicles in the manner predicted by the hyphoid model. PMID:9256441

Detection of fungi colony growth on bones by dynamic speckle

NASA Astrophysics Data System (ADS)

Vincitorio, F. M.; Budini, N.; Mulone, C.; Spector, M.; Freyre, C.; López Díaz, A. J.; Ramil, A.

2013-11-01

In this work we have studied the dynamic speckle patterns of mucor fungi colonies, which were inoculated on different samples. We were interested in analyzing the development of fungi colonies in bones, since during the last two years, a series of infections by mucor fungi have been reported on patients from different hospitals in Argentina. Coincidentally, all of these infections appeared on patients that were subjected to a surgical intervention for implantation of a titanium prosthesis. Apparently, the reason of the infection was a deficient sterilization process in conjunction with an accidental contamination. We observed that fungi growth, activity and death can be distinguished by means of the dynamic speckle technique.

Antiviral Defense Mechanisms in Honey Bees

PubMed Central

Brutscher, Laura M.; Daughenbaugh, Katie F.; Flenniken, Michelle L.

2015-01-01

Honey bees are significant pollinators of agricultural crops and other important plant species. High annual losses of honey bee colonies in North America and in some parts of Europe have profound ecological and economic implications. Colony losses have been attributed to multiple factors including RNA viruses, thus understanding bee antiviral defense mechanisms may result in the development of strategies that mitigate colony losses. Honey bee antiviral defense mechanisms include RNA-interference, pathogen-associated molecular pattern (PAMP) triggered signal transduction cascades, and reactive oxygen species generation. However, the relative importance of these and other pathways is largely uncharacterized. Herein we review the current understanding of honey bee antiviral defense mechanisms and suggest important avenues for future investigation. PMID:26273564

Linear and branched perfluorooctane sulfonate (PFOS) isomer patterns differ among several tissues and blood of polar bears.

PubMed

Greaves, Alana K; Letcher, Robert J

2013-09-01

Perfluorooctane sulfonate (PFOS) is a globally distributed persistent organic pollutant that has been found to bioaccumulate and biomagnify in aquatic food webs. Although principally in its linear isomeric configuration, 21-35% of the PFOS manufactured via electrochemical fluorination is produced as a branched structural isomer. PFOS isomer patterns were investigated in multiple tissues of polar bears (Ursus maritimus) from East Greenland. The liver (n = 9), blood (n = 19), brain (n = 16), muscle (n = 5), and adipose (n = 5) were analyzed for linear PFOS (n-PFOS), as well as multiple mono- and di-trifluoromethyl-substituted branched isomers. n-PFOS accounted for 93.0 ± 0.5% of Σ-PFOS isomer concentrations in the liver, whereas the proportion was significantly lower (p<0.05) in the blood (85.4 ± 0.5%). Branched isomers were quantifiable in the liver and blood, but not in the brain, muscle, or adipose. In both the liver and blood, 6-perfluoromethylheptane sulfonate (P6MHpS) was the dominant branched isomer (2.61 ± 0.10%, and 3.26 ± 0.13% of Σ-PFOS concentrations, respectively). No di-trifluoromethyl-substituted isomers were detectable in any of the tissues analyzed. These tissue-specific isomer patterns suggest isomer-specific pharmacokinetics, perhaps due to differences in protein affinities, and thus differences in protein interactions, as well transport, absorption, and/or metabolism in the body. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

Sulfation pattern of fucose branches affects the anti-hyperlipidemic activities of fucosylated chondroitin sulfate.

PubMed

Wu, Nian; Zhang, Yu; Ye, Xingqian; Hu, Yaqin; Ding, Tian; Chen, Shiguo

2016-08-20

Fucosylated chondroitin sulfates (fCSs) are glycosaminoglycans extracted from sea cucumbers, consisting of chondroitin sulfate E (CSE) backbones and sulfated fucose branches. The biological properties of fCSs could be affected by the sulfation pattern of their fucose branches. In the present study, two fCSs were isolated from sea cucumbers Isostichopus badionotus (fCS-Ib) and Pearsonothuria graeffei (fCS-Pg). Their monosaccharide compositions of glucuronic acid (GlcA), N-acetylgalactosamine (GalNAc), fucose (Fuc) and sulfate were at similar molar ratio with 1.0/0.7/0.9/3.1 for fCS-Ib and 1.0/0.8/1.5/2.6 for fCS-Pg. The two fCSs have different sulfation patterns on their fucose branches, fCS-Pg with 3,4-O-disulfation while fCS-Ib with 2,4-O-disulfation. Their antihyperlipidemic effects were compared using a high-fat high-fructose diet (HFFD)-fed C57BL/6J mice model. Both fCS-Ib and fCS-Pg had significant effects on lipid profile improvement, liver protection, blood glucose diminution and hepatic glycogen synthesis. Specifically, fCS-Pg with 3,4-O-disulfation fucose branches was more effective in reduction of blood cholesterol (TC), low density lipoprotein (LDL) and atherogenic index (AI). Our results indicate that both fCSs, especially fCS-Pg, could be used as a potential anti-hyperlipidemic drug. Copyright © 2016. Published by Elsevier Ltd.

Detailed Anatomy of the Cranial Cervical Ganglion in the Dromedary Camel (Camelus dromedarius).

PubMed

Nourinezhad, Jamal; Mazaheri, Yazdan; Biglari, Zahra

2015-08-01

The detailed morphology and topography of the cranial cervical ganglion (CCG) with its surrounding structures were studied in 10 sides of five heads of adult one-humped camel to determine its general arrangement as well as its differences and similarities to other animals. The following detailed descriptions were obtained: (1) the bilateral CCG was constantly present caudal to cranial base at the rostroventral border of the occipital condyle over the caudolateral part of nasopharynx; (2) the CCG was always in close relations medially with the longus capitis muscle, rostrolaterally with the internal carotid artery, and caudally with the vagus nerve; and (3) the branches of the CCG were the internal carotid and external carotid nerves, jugular nerve, cervical interganglionic branch, laryngopharyngeal branch, carotid sinus branch and communicating branches to the vagus, and first spinal nerves. In conclusion, there was no variation regarding topography of dromedary CCG among the specimens, in spite of typical variations in number, and mainly in origin of nerve branches ramifying from the CCG. In comparative anatomy aspect, the close constant relations, and presence of major nerves (internal/external carotid and jugular nerves) of dromedary CCG exhibited a typical reported animal's pattern. However, the shape, structures lateral to the CCG, the origin and course pattern of external carotid and jugular nerves, the number of the major nerves branches, the communicating branches of the CCG to the spinal and cranial nerves, and the separation of most rostral parts of vagosympathetic trunk of dromedary were different from those of most reported animals. © 2015 Wiley Periodicals, Inc.

The Similarity and Appropriate Usage of Three Honey Bee (Hymenoptera: Apidae) Datasets for Longitudinal Studies.

PubMed

Highland, Steven; James, R R

2016-04-01

Honey bee (Apis mellifera L., Hymenoptera: Apidae) colonies have experienced profound fluctuations, especially declines, in the past few decades. Long-term datasets on honey bees are needed to identify the most important environmental and cultural factors associated with these changes. While a few such datasets exist, scientists have been hesitant to use some of these due to perceived shortcomings in the data. We compared data and trends for three datasets. Two come from the US Department of Agriculture's National Agricultural Statistics Service (NASS), Agricultural Statistics Board: one is the annual survey of honey-producing colonies from the Annual Bee and Honey program (ABH), and the other is colony counts from the Census of Agriculture conducted every five years. The third dataset we developed from the number of colonies registered annually by some states. We compared the long-term patterns of change in colony numbers among the datasets on a state-by-state basis. The three datasets often showed similar hive numbers and trends varied by state, with differences between datasets being greatest for those states receiving a large number of migratory colonies. Dataset comparisons provide a method to estimate the number of colonies in a state used for pollination versus honey production. Some states also had separate data for local and migratory colonies, allowing one to determine whether the migratory colonies were typically used for pollination or honey production. The Census of Agriculture should provide the most accurate long-term data on colony numbers, but only every five years. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Stoichiometry patterns in the androdioecious Acer tegmentosum

PubMed Central

Zhang, Xinna; Yao, Jie; Fan, Chunyu; Tan, Lingzhao; Zhang, Chunyu; Wang, Juan; Zhao, Xiuhai; von Gadow, Klaus

2016-01-01

This study evaluates stoichiometry patterns in the androdioecious Acer tegmentosum, a species characterized by a rare reproductive system where males and hermaphrodites coexist. Altogether 31 hermaphrodites and 29 male plants were harvested and samples of leaves, current-year shoots, branches and coarse roots were analyzed to explore gender differences in biomass, C, N and P concentrations of these four components. The nitrogen to phosphorus relationship of each component was examined using SMA estimates. Males had significantly greater amounts of leaf and coarse root dry matter content than hermaphrodites. C, N and P stoichiometry differed significantly between genders, especially in the newly emerging vegetative components (leaves and shoots). Males had higher C/N and C/P ratios in current-year shoots and lower C/P ratios in leaves and branches. Hermaphrodites had higher N/P ratios in the leaves and branches. Males had higher rates of increase in leaf P content than hermaphrodites. This study suggests that stoichiometry patterns may be significantly affected by gender. PMID:27725739

Guidance of vascular development: lessons from the nervous system.

PubMed

Larrivée, Bruno; Freitas, Catarina; Suchting, Steven; Brunet, Isabelle; Eichmann, Anne

2009-02-27

The vascular system of vertebrates consists of an organized, branched network of arteries, veins, and capillaries that penetrates all the tissues of the body. One of the most striking features of the vascular system is that its branching pattern is highly stereotyped, with major and secondary branches forming at specific sites and developing highly conserved organ-specific vascular patterns. The factors controlling vascular patterning are not yet completely understood. Recent studies have highlighted the anatomic and structural similarities between blood vessels and nerves. The 2 networks are often aligned, with nerve fibers and blood vessels following parallel routes. Furthermore, both systems require precise control over their guidance and growth. Several molecules with attractive and repulsive properties have been found to modulate the proper guidance of both nerves and blood vessels. These include the Semaphorins, the Slits, and the Netrins and their receptors. In this review, we describe the molecular mechanisms by which blood vessels and axons achieve proper path finding and the molecular cues that are involved in their guidance.

Phylogeography of colonially nesting seabirds, with special reference to global matrilineal patterns in the sooty tern (Sterna fuscata).

PubMed

Avise, J C; Nelson, W S; Bowen, B W; Walker, D

2000-11-01

Sooty tern (Sterna fuscata) rookeries are scattered throughout the tropical oceans. When not nesting, individuals wander great distances across open seas, but, like many other seabirds, they tend to be site-faithful to nesting locales in successive years. Here we examine the matrilineal history of sooty terns on a global scale. Assayed colonies within an ocean are poorly differentiated in mitochondrial DNA sequence, a result indicating tight historical ties. However, a shallow genealogical partition distinguishes Atlantic from Indo-Pacific rookeries. Phylogeographic patterns in the sooty tern are compared to those in other colonially nesting seabirds, as well as in the green turtle (Chelonia mydas), an analogue of tropical seabirds in some salient aspects of natural history. Phylogeographic structure within an ocean is normally weak in seabirds, unlike the pronounced matrilineal structure in green turtles. However, the phylogeographic partition between Atlantic and Indo-Pacific rookeries in sooty terns mirrors, albeit in shallower evolutionary time, the major matrilineal subdivision in green turtles. Thus, global geology has apparently influenced historical gene movements in these two circumtropical species.

Polydomy in the ant Ectatomma opaciventre

PubMed Central

Tofolo, Viviane C.; Giannotti, Edilberto; Neves, Erika F.; Andrade, Luis H. C.; M. Lima, Sandro; Súarez, Yzel R.; Antonialli-Junior, William F.

2014-01-01

Abstract Tropical ants commonly exhibit a hyper-dispersed pattern of spatial distribution of nests. In polydomous species, nests may be satellites, that is, secondary structures of the main nest, where the queen is found. In order to evaluate whether the ant Ectatomma opaciventre Roger (Formicidae: Ectatomminae) uses the strategy of building polydomous nests, the spatial distribution pattern of 33 nests in a 1,800 m 2 degraded area located in Rio Claro, SP, Brazil, were investigated using the nearest neighbor method. To complement the results of this investigation, the cuticular chemical profile of eight colonies was analyzed using Fourier transform infrared photoacoustic spectrosco-py (FTIR-PAS). The nests of E. opaciventre presented a hyper-dispersed or regular distribution, which is the most common in ants. The analysis of the cuticular hydrocarbons apparently con-firmed the hypothesis that this species is polydomous, since the chemical profiles of all studied colonies with nests at different sites were very similar to the chemical signature of the single found queen and were also different from those of colonies used as control. PMID:25373168

Genetic control of rhizomes and genomic localization of a major-effect growth habit QTL in perennial wildrye

USDA-ARS?s Scientific Manuscript database

Subterranean rhizome branches facilitate vegetative dispersal, survival, and regrowth of perennial grasses. Developmental differences between upright, prostrate, and subterranean stem branching patterns may involve auxin-mediated responses to gravity or light, but genetic mechanisms controlling the...

Sensory Neuron Fates Are Distinguished by a Transcriptional Switch that Regulates Dendrite Branch Stabilization

PubMed Central

Smith, Cody J.; O’Brien, Timothy; Chatzigeorgiou, Marios; Spencer, W. Clay; Feingold-Link, Elana; Husson, Steven J.; Hori, Sayaka; Mitani, Shohei; Gottschalk, Alexander; Schafer, William R.; Miller, David M.

2013-01-01

SUMMARY Sensory neurons adopt distinct morphologies and functional modalities to mediate responses to specific stimuli. Transcription factors and their downstream effectors orchestrate this outcome but are incompletely defined. Here, we show that different classes of mechanosensory neurons in C. elegans are distinguished by the combined action of the transcription factors MEC-3, AHR-1, and ZAG-1. Low levels of MEC-3 specify the elaborate branching pattern of PVD nociceptors, whereas high MEC-3 is correlated with the simple morphology of AVM and PVM touch neurons. AHR-1 specifies AVM touch neuron fate by elevating MEC-3 while simultaneously blocking expression of nociceptive genes such as the MEC-3 target, the claudin-like membrane protein HPO-30, that promotes the complex dendritic branching pattern of PVD. ZAG-1 exercises a parallel role to prevent PVM from adopting the PVD fate. The conserved dendritic branching function of the Drosophila AHR-1 homolog, Spineless, argues for similar pathways in mammals. PMID:23889932

Point pattern analysis of FIA data

Treesearch

Chris Woodall

2002-01-01

Point pattern analysis is a branch of spatial statistics that quantifies the spatial distribution of points in two-dimensional space. Point pattern analysis was conducted on stand stem-maps from FIA fixed-radius plots to explore point pattern analysis techniques and to determine the ability of pattern descriptions to describe stand attributes. Results indicate that the...

Coming out of the woods: do termites need a specialized worker caste to search for new food sources?

NASA Astrophysics Data System (ADS)

Rupf, Thomas; Roisin, Yves

2008-09-01

Most small-colony termites live confined within a single piece of wood on which they feed and do not possess permanent workers: Tasks are done by developmentally flexible immatures (pseudergates). By contrast, large-colony termites possess a specialized (true) worker caste and forage outside their nest for food. To shed light on possible transitional steps between these contrasting patterns of social organization, we studied an atypical Rhinotermitidae, Prorhinotermes inopinatus. In this species, despite the absence of a true worker caste, soldiers, pseudergates, and neotenic reproductives may leave the nest and explore their surroundings. Although evidence presented in this study indicates that termites recognize unknown areas, there is no directional recruitment toward them. The discovery of a food source, i.e., a piece of wood, is followed by the establishment of a long-lasting trail between the nest and the food source. A large fraction of the colony, including neotenic reproductives, ultimately migrates into the piece of wood. Our results thus demonstrate that multiple features of external foraging behavior can evolve independently of the existence of a true worker caste in termites. We suggest that large colonies with true workers, like those of most Rhinotermitidae, may easily have evolved from a Prorhinotermes-like pattern if submitted to increasing selective pressures for worker efficiency in a stable environment.

Manipulation of colony environment modulates honey bee aggression and brain gene expression.

PubMed

Rittschof, C C; Robinson, G E

2013-11-01

The social environment plays an essential role in shaping behavior for most animals. Social effects on behavior are often linked to changes in brain gene expression. In the honey bee (Apis mellifera L.), social modulation of individual aggression allows colonies to adjust the intensity with which they defend their hive in response to predation threat. Previous research has showed social effects on both aggression and aggression-related brain gene expression in honey bees, caused by alarm pheromone and unknown factors related to colony genotype. For example, some bees from less aggressive genetic stock reared in colonies with genetic predispositions toward increased aggression show both increased aggression and more aggressive-like brain gene expression profiles. We tested the hypothesis that exposure to a colony environment influenced by high levels of predation threat results in increased aggression and aggressive-like gene expression patterns in individual bees. We assessed gene expression using four marker genes. Experimentally induced predation threats modified behavior, but the effect was opposite of our predictions: disturbed colonies showed decreased aggression. Disturbed colonies also decreased foraging activity, suggesting that they did not habituate to threats; other explanations for this finding are discussed. Bees in disturbed colonies also showed changes in brain gene expression, some of which paralleled behavioral findings. These results show that bee aggression and associated molecular processes are subject to complex social influences. © 2013 John Wiley & Sons Ltd and International Behavioural and Neural Genetics Society.

Resilience of honeybee colonies via common stomach: A model of self-regulation of foraging

PubMed Central

Schmickl, Thomas

2017-01-01

We propose a new regulation mechanism based on the idea of the “common stomach” to explain several aspects of the resilience and homeostatic regulation of honeybee colonies. This mechanism exploits shared pools of substances (pollen, nectar, workers, brood) that modulate recruitment, abandonment and allocation patterns at the colony-level and enable bees to perform several survival strategies to cope with difficult circumstances: Lack of proteins leads to reduced feeding of young brood, to early capping of old brood and to regaining of already spent proteins through brood cannibalism. We modeled this system by linear interaction terms and mass-action law. To test the predictive power of the model of this regulatory mechanism we compared our model predictions to experimental data of several studies. These comparisons show that the proposed regulation mechanism can explain a variety of colony level behaviors. Detailed analysis of the model revealed that these mechanisms could explain the resilience, stability and self-regulation observed in honeybee colonies. We found that manipulation of material flow and applying sudden perturbations to colony stocks are quickly compensated by a resulting counter-acting shift in task selection. Selective analysis of feedback loops allowed us to discriminate the importance of different feedback loops in self-regulation of honeybee colonies. We stress that a network of simple proximate mechanisms can explain significant colony-level abilities that can also be seen as ultimate reasoning of the evolutionary trajectory of honeybees. PMID:29161278

Assessing the living and dead proportions of cold-water coral colonies: implications for deep-water Marine Protected Area monitoring in a changing ocean.

PubMed

Vad, Johanne; Orejas, Covadonga; Moreno-Navas, Juan; Findlay, Helen S; Roberts, J Murray

2017-01-01

Coral growth patterns result from an interplay of coral biology and environmental conditions. In this study colony size and proportion of live and dead skeletons in the cold-water coral (CWC) Lophelia pertusa (Linnaeus, 1758) were measured using video footage from Remotely Operated Vehicle (ROV) transects conducted at the inshore Mingulay Reef Complex (MRC) and at the offshore PISCES site (Rockall Bank) in the NE Atlantic. The main goal of this paper was to explore the development of a simple method to quantify coral growth and its potential application as an assessment tool of the health of these remote habitats. Eighteen colonies were selected and whole colony and dead/living layer size were measured. Live to dead layer ratios for each colony were then determined and analysed. The age of each colony was estimated using previously published data. Our paper shows that: (1) two distinct morphotypes can be described: at the MRC, colonies displayed a 'cauliflower-shaped' morphotype whereas at the PISCES site, colonies presented a more flattened 'bush-shaped' morphotype; (2) living layer size was positively correlated with whole colony size; (3) live to dead layer ratio was negatively correlated to whole colony size; (4) live to dead layer ratio never exceeded 0.27. These results suggest that as a colony develops and its growth rate slows down, the proportion of living polyps in the colony decreases. Furthermore, at least 73% of L. pertusa colonies are composed of exposed dead coral skeleton, vulnerable to ocean acidification and the associated shallowing of the aragonite saturation horizon, with significant implications for future deep-sea reef framework integrity. The clear visual contrast between white/pale living and grey/dark dead portions of the colonies also gives a new way by which they can be visually monitored over time. The increased use of marine autonomous survey vehicles offers an important new platform from which such a surveying technique could be applied to monitor deep-water marine protected areas in the future.

Variant anatomy of renal arteries in a Kenyan population.

PubMed

Ogeng'o, Julius A; Masaki, Charles O; Sinkeet, Simeon R; Muthoka, Johnstone M; Murunga, Acleus K

2010-01-01

Variant anatomy of renal arteries is important in renal transplant, vascular reconstruction, and uroradiological procedures. The variations show ethnic and population differences. Data from Africans are scarce and altogether absent for Kenyans. To describe patterns of origin, trajectories and branching of renal arteries in a Kenyan population. Descriptive cross-sectional study conducted in the Department of Human Anatomy, University of Nairobi. Three hundred and fifty six kidneys from 178 cadavers and postmortem specimens were used in the study. Aorta, renal arteries and kidneys were exposed by dissection. Number, trajectories, level of branching, number of branches and point of entry into the kidney were recorded. Data was analyzed using SPSS version 16.0, and presented using macrographs, tables, and bar charts. Additional arteries occurred in 14.3% of the cases. In 82.4% of these, there was one additional artery. Fifty nine point five per cent of the double renal arteries were parallel and 7.1% crossed. Of the 305 single arteries, 76.4% showed hilar, 21.6% prehilar and 2% intraparenchymal branching. In the hilar branching, ladder type was present in 65% and fork type in 35%. Bifurcation and trifurcation were present in 59.6% and 33.1% respectively. Polar arteries were present in 16.9% cases. Over 14% of the Kenyan population may have additional renal arteries while more than 20% show early branching. Several trajectories and hilar branching patterns exist which renal transplant surgeons and radiologists should be aware of to avoid inadvertent vascular injury.

Dynamics of vascular branching morphogenesis: The effect of blood and tissue flow

NASA Astrophysics Data System (ADS)

Nguyen, Thi-Hanh; Eichmann, Anne; Le Noble, Ferdinand; Fleury, Vincent

2006-06-01

Vascularization of embryonic organs or tumors starts from a primitive lattice of capillaries. Upon perfusion, this lattice is remodeled into branched arteries and veins. Adaptation to mechanical forces is implied to play a major role in arterial patterning. However, numerical simulations of vessel adaptation to haemodynamics has so far failed to predict any realistic vascular pattern. We present in this article a theoretical modeling of vascular development in the yolk sac based on three features of vascular morphogenesis: the disconnection of side branches from main branches, the reconnection of dangling sprouts (“dead ends”), and the plastic extension of interstitial tissue, which we have observed in vascular morphogenesis. We show that the effect of Poiseuille flow in the vessels can be modeled by aggregation of random walkers. Solid tissue expansion can be modeled by a Poiseuille (parabolic) deformation, hence by deformation under hits of random walkers. Incorporation of these features, which are of a mechanical nature, leads to realistic modeling of vessels, with important biological consequences. The model also predicts the outcome of simple mechanical actions, such as clamping of vessels or deformation of tissue by the presence of obstacles. This study offers an explanation for flow-driven control of vascular branching morphogenesis.

The making of a branching annelid: an analysis of complete mitochondrial genome and ribosomal data of Ramisyllis multicaudata.

PubMed

Aguado, M Teresa; Glasby, Christopher J; Schroeder, Paul C; Weigert, Anne; Bleidorn, Christoph

2015-07-17

Ramisyllis multicaudata is a member of Syllidae (Annelida, Errantia, Phyllodocida) with a remarkable branching body plan. Using a next-generation sequencing approach, the complete mitochondrial genomes of R. multicaudata and Trypanobia sp. are sequenced and analysed, representing the first ones from Syllidae. The gene order in these two syllids does not follow the order proposed as the putative ground pattern in Errantia. The phylogenetic relationships of R. multicaudata are discerned using a phylogenetic approach with the nuclear 18S and the mitochondrial 16S and cox1 genes. Ramisyllis multicaudata is the sister group of a clade containing Trypanobia species. Both genera, Ramisyllis and Trypanobia, together with Parahaplosyllis, Trypanosyllis, Eurysyllis, and Xenosyllis are located in a long branched clade. The long branches are explained by an accelerated mutational rate in the 18S rRNA gene. Using a phylogenetic backbone, we propose a scenario in which the postembryonic addition of segments that occurs in most syllids, their huge diversity of reproductive modes, and their ability to regenerate lost parts, in combination, have provided an evolutionary basis to develop a new branching body pattern as realised in Ramisyllis.

Occurrence of fecal-indicator bacteria and protocols for identification of fecal-contamination sources in selected reaches of the West Branch Brandywine Creek, Chester County, Pennsylvania

USGS Publications Warehouse

Cinotto, Peter J.

2005-01-01

The presence of fecal-indicator bacteria indicates the potential presence of pathogens originating from the fecal matter of warm-blooded animals. These pathogens are responsible for numerous human diseases ranging from common diarrhea to meningitis and polio. The detection of fecal-indicator bacteria and interpretation of the resultant data are, therefore, of great importance to water-resource managers. Current (2005) techniques used to assess fecal contamination within the fluvial environment primarily assess samples collected from the water column, either as grab samples or as depth- and (or) width-integrated samples. However, current research indicates approximately 99 percent of all bacteria within nature exist as attached, or sessile, bacteria. Because of this condition, most current techniques for the detection of fecal contamination, which utilize bacteria, assess only about 1 percent of the total bacteria within the fluvial system and are, therefore, problematic. Evaluation of the environmental factors affecting the occurrence and distribution of bacteria within the fluvial system, as well as the evaluation and modification of alternative approaches that effectively quantify the larger population of sessile bacteria within fluvial sediments, will present water-resource managers with more effective tools to assess, prevent, and (or) eliminate sources of fecal contamination within pristine and impaired watersheds. Two stream reaches on the West Branch Brandywine Creek in the Coatesville, Pa., region were studied between September 2002 and August 2003. The effects of sediment particle size, climatic conditions, aquatic growth, environmental chemistry, impervious surfaces, sediment and soil filtration, and dams on observed bacteria concentrations were evaluated. Alternative approaches were assessed to better detect geographic sources of fecal contamination including the use of turbidity as a surrogate for bacteria, the modification and implementation of sandbag bacteria samplers, and the use of optical brighteners. For the purposes of this report, sources of bacteria were defined as geographic locations where elevated concentrations of bacteria are observed within, or expected to enter, the main branch of the West Branch Brandywine Creek. Biologic sources (for example, waterfowl) were noted where applicable; however, no specific study of biologic sources (such as bacterial source tracking) was conducted. Data indicated that specific bacterial populations within fluvial sediments could be related to specific particle-size ranges. This relation is likely the result of the reduced porosity and permeability associated with finer sediments and the ability of specific bacteria to tolerate particular environments. Escherichia coli (E. coli) showed a higher median concentration (2,160 colonies per gram of saturated sediment) in the 0.125 to 0.5-millimeter size range of natural sediments than in other ranges, and enterococcus bacteria showed a higher median concentration (61,830 colonies per gram of saturated sediment) in the 0.062 to 0.25-millimeter size range of natural sediments than in other ranges. There were insufficient data to assess the particle-size relation to fecal coliform bacteria and (or) fecal streptococcus bacteria. Climatic conditions were shown to affect bacteria concentrations in both the water column and fluvial sediments. Drought conditions in 2002 resulted in lower overall bacteria concentrations than the more typically wet year of 2003. E. coli concentrations in fluvial sediment along the Coatesville study reach in 2002 had a median concentration of 92 colonies per gram of saturated sediment; in 2003, the median concentration had risen to 4,752 colonies per gram of saturated sediment. Symbiotic relations between bacteria and aquatic growth were likely responsible for increased bacteria concentrations observed within an impoundment area on the Coatesville study reach. This reach showed evidence of

Role of TCP Gene BRANCHED1 in the Control of Shoot Branching in Arabidopsis.

PubMed

Poza-Carrión, César; Aguilar-Martínez, José Antonio; Cubas, Pilar

2007-11-01

Branching patterns are major determinants of plant architecture. They depend both on leaf phillotaxy (branch primordia are formed in the axils of leaves) and on the decision of buds to grow out to give a branch or to remain dormant. In Arabidopsis, several genes involved in the long-distance signalling of the control of branch outgrowth have been identified. However, the genes acting inside the buds to cause growth arrest remained unknown until now. In the February issue of Plant Cell we have described the function of BRANCHED1 (BRC1), an Arabidopsis gene coding for a plant-specific transcription factor of the TCP family that is expressed in the buds and prevents their development. Loss of BRC1 function leads to accelerated AM initiation, precocious progression of bud development and excess of shoot branching. BRC1 transcription is affected by endogenous and environmental signals controlling branching and we have shown that BRC1 function mediates the response to these stimuli. Therefore we have proposed that BRC1 function represents the point at which signals controlling branching are integrated within axillary buds.

Elimination of Coptotermes lacteus (Froggatt) (Blattodea: Rhinotemitidae) Colonies Using Bistrifluron Bait Applied through In-Ground Bait Stations Surrounding Mounds.

PubMed

Webb, Garry

2017-09-12

The efficacy of bistrifluron termite bait was evaluated using in-ground bait stations placed around Coptotermes lacteus mounds in south-eastern Australia during late summer and autumn (late February to late May 2012). Four in-ground bait stations containing timber billets were placed around each of twenty mounds. Once sufficient numbers of in-ground stations were infested by termites, mounds were assigned to one of four groups (one, two, three or four 120 g bait canisters or 120 to 480 g bait in total per mound) and bait canisters installed. One mound, nominally assigned treatment with two canisters ultimately had no termite interception in any of the four in-ground stations and not treated. Eighteen of the remaining 19 colonies were eliminated by 12 weeks after bait placement, irrespective of bait quantity removed (range 43 to 480 g). Measures of colony decline-mound repair capability and internal core temperature-did not accurately reflect the colony decline, as untreated colonies showed a similar pattern of decline in both repair capability and internal mound core temperature. However, during the ensuing spring-summer period, capacity to repair the mound was restored in untreated colonies and the internal core temperature profile was similar to the previous spring-summer period which indicated that these untreated colonies remained healthy.

Innervation pattern of the suprascapular nerve within supraspinatus: a three-dimensional computer modeling study.

PubMed

Hermenegildo, J A; Roberts, S L; Kim, S Y

2014-05-01

The relationship between the innervation pattern of the suprascapular nerve (SSN) and the muscle architecture of supraspinatus has not been thoroughly investigated. The supraspinatus is composed of two architecturally distinct regions: anterior and posterior. Each of these regions is further subdivided into three parts: superficial, middle and deep. The purpose of this study was to investigate the course of the SSN throughout the volume of supraspinatus and to relate the intramuscular branches to the distinct regions and parts of the supraspinatus. The SSN was dissected in thirty formalin embalmed cadaveric specimens and digitized throughout the muscle volume in six of those specimens. The digitized data were modeled using Autodesk(®) Maya(®) 2011. The three-dimensional (3D) models were used to relate the intramuscular innervation pattern to the muscle and tendon architecture defined by Kim et al. (2007, Clin Anat 20:648-655). The SSN bifurcated into two main trunks: medial and lateral. All parts of the anterior region were predominantly innervated by the medial trunk and its proximal and medial branches, whereas all parts of the posterior region predominantly by the lateral trunk and its posterolateral and/or posteromedial branches. The posterior region also received innervation from the proximal branch of the medial trunk in half of the specimens. These findings provide evidence that the anterior and posterior regions are distinct with respect to their innervation. The 3D map of the innervation pattern will aid in planning future clinical studies investigating muscle activation patterns and provide insight into possible injury of the nerve with supraspinatus pathology and surgical techniques. Copyright © 2013 Wiley Periodicals, Inc.

Edgecliff reefs - Devonian temperate water carbonate deposition

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

Wolosz, T.H.

1991-03-01

The Middle Devonian Edgecliff Member of the Onondaga Formation in New York and Ontario, Canada, is a coral-rich, reefy,' crinoidal grainstone/packstone. The reefs contain only rare stromatoporoids and are devoid of algae, having been constructed by a fauna of mound and thicket-forming branching colonial rugosans, and large sheet favositids that populated grainstone/packstone flank beds and banks. Despite the restricted fauna, the reefs display a variety of growth patterns. Rugosan mounds range in size from 2-3 m diameter by 1 m thick, up to 230 m diameter by 15 m thick. Composite structures consist of interbedded rugosan buildups and packstone/grainstone flanks,more » ranging from shield-shaped reefs (240 m diameter by 6 m thick) in which the rugosans occur only as thickets, to pinnacle reefs (up to 3 km diameter by 60 m thick) in which rugosan mounds are interbedded with crinoidal flanks. Geographic distribution of these reef types and analysis of surrounding facies suggests that reef growth pattern was controlled by water depth and local rate of subsidence. Despite superfacial resemblance to modern deep water ahermatypic coral mounds and thickets, abundant coral breakage and overturning, and erosion of at least one reef core during an intermediate stage of reef growth supports a shallow water origin of these reefs. It is suggested that the Edgecliff and its reefs represent an example of Devonian cool water carbonate deposition, a hypothesis supported by a trend of increasing stromatoporoid abundance westwards across New York (in the direction of the paleo-equator).« less

Host–symbiont recombination versus natural selection in the response of coral–dinoflagellate symbioses to environmental disturbance

PubMed Central

LaJeunesse, Todd C.; Smith, Robin; Walther, Mariana; Pinzón, Jorge; Pettay, Daniel T.; McGinley, Michael; Aschaffenburg, Matthew; Medina-Rosas, Pedro; Cupul-Magaña, Amilcar L.; Pérez, Andrés López; Reyes-Bonilla, Hector; Warner, Mark E.

2010-01-01

Mutualisms between reef-building corals and endosymbiotic dinoflagellates are particularly sensitive to environmental stress, yet the ecosystems they construct have endured major oscillations in global climate. During the winter of 2008, an extreme cold-water event occurred in the Gulf of California that bleached corals in the genus Pocillopora harbouring a thermally ‘sensitive’ symbiont, designated Symbiodinium C1b-c, while colonies possessing Symbiodinium D1 were mostly unaffected. Certain bleached colonies recovered quickly while others suffered partial or complete mortality. In most colonies, no appreciable change was observed in the identity of the original symbiont, indicating that these partnerships are stable. During the initial phases of recovery, a third species of symbiont B1Aiptasia, genetically identical to that harboured by the invasive anemone, Aiptasia sp., grew opportunistically and was visible as light-yellow patches on the branch tips of several colonies. However, this symbiont did not persist and was displaced in all cases by C1b-c several months later. Colonies with D1 were abundant at inshore habitats along the continental eastern Pacific, where seasonal turbidity is high relative to offshore islands. Environmental conditions of the central and southern coasts of Mexico were not sufficient to explain the exclusivity of D1 Pocillopora in these regions. It is possible that mass mortalities associated with major thermal disturbances during the 1997–1998 El Niño Southern Oscillation eliminated C1b-c holobionts from these locations. The differential loss of Pocillopora holobionts in response to thermal stress suggests that natural selection on existing variation can cause rapid and significant shifts in the frequency of particular coral–algal partnerships. However, coral populations may take decades to recover following episodes of severe selection, thereby raising considerable uncertainty about the long-term viability of these communities. PMID:20444713

Host-symbiont recombination versus natural selection in the response of coral-dinoflagellate symbioses to environmental disturbance.

PubMed

LaJeunesse, Todd C; Smith, Robin; Walther, Mariana; Pinzón, Jorge; Pettay, Daniel T; McGinley, Michael; Aschaffenburg, Matthew; Medina-Rosas, Pedro; Cupul-Magaña, Amilcar L; Pérez, Andrés López; Reyes-Bonilla, Hector; Warner, Mark E

2010-10-07

Mutualisms between reef-building corals and endosymbiotic dinoflagellates are particularly sensitive to environmental stress, yet the ecosystems they construct have endured major oscillations in global climate. During the winter of 2008, an extreme cold-water event occurred in the Gulf of California that bleached corals in the genus Pocillopora harbouring a thermally 'sensitive' symbiont, designated Symbiodinium C1b-c, while colonies possessing Symbiodinium D1 were mostly unaffected. Certain bleached colonies recovered quickly while others suffered partial or complete mortality. In most colonies, no appreciable change was observed in the identity of the original symbiont, indicating that these partnerships are stable. During the initial phases of recovery, a third species of symbiont B1(Aiptasia), genetically identical to that harboured by the invasive anemone, Aiptasia sp., grew opportunistically and was visible as light-yellow patches on the branch tips of several colonies. However, this symbiont did not persist and was displaced in all cases by C1b-c several months later. Colonies with D1 were abundant at inshore habitats along the continental eastern Pacific, where seasonal turbidity is high relative to offshore islands. Environmental conditions of the central and southern coasts of Mexico were not sufficient to explain the exclusivity of D1 Pocillopora in these regions. It is possible that mass mortalities associated with major thermal disturbances during the 1997-1998 El Niño Southern Oscillation eliminated C1b-c holobionts from these locations. The differential loss of Pocillopora holobionts in response to thermal stress suggests that natural selection on existing variation can cause rapid and significant shifts in the frequency of particular coral-algal partnerships. However, coral populations may take decades to recover following episodes of severe selection, thereby raising considerable uncertainty about the long-term viability of these communities.

Lineage sorting in multihost parasites: Eidmanniella albescens and Fregatiella aurifasciata on seabirds from the Galapagos Islands.

PubMed

Rivera-Parra, Jose L; Levin, Iris I; Johnson, Kevin P; Parker, Patricia G

2015-08-01

Parasites comprise a significant percentage of the biodiversity of the planet and are useful systems to test evolutionary and ecological hypotheses. In this study, we analyze the effect of host species identity and the immediate local species assemblage within mixed species colonies of nesting seabirds on patterns of genetic clustering within two species of multihost ectoparasitic lice. We use three genetic markers (one mitochondrial, COI, and two nuclear, EF1-α and wingless) and maximum likelihood phylogenetic trees to test whether (1) parasites show lineage sorting based on their host species; and (2) switching of lineages to the alternate host species depends on the immediate local species assemblage of individual hosts within a colony. Specifically, we examine the genetic structure of two louse species: Eidmanniella albescens, infecting both Nazca (Sula granti) and blue-footed boobies (Sula nebouxii), and Fregatiella aurifasciata, infecting both great (Fregata minor) and magnificent frigatebirds (Fregata magnificens). We found that host species identity was the only factor explaining the patterns of genetic structure in both parasites. In both cases, there is evident genetic differentiation depending on the host species. Thus, a revision of the taxonomy of these louse species is needed. One possible explanation of this pattern is extremely low louse migration rates between host species, perhaps influenced by fine-scale spatial separation of host species within mixed colonies, and low parasite infrapopulation numbers.

Lineage sorting in multihost parasites: Eidmanniella albescens and Fregatiella aurifasciata on seabirds from the Galapagos Islands

PubMed Central

Rivera-Parra, Jose L; Levin, Iris I; Johnson, Kevin P; Parker, Patricia G

2015-01-01

Parasites comprise a significant percentage of the biodiversity of the planet and are useful systems to test evolutionary and ecological hypotheses. In this study, we analyze the effect of host species identity and the immediate local species assemblage within mixed species colonies of nesting seabirds on patterns of genetic clustering within two species of multihost ectoparasitic lice. We use three genetic markers (one mitochondrial, COI, and two nuclear, EF1-α and wingless) and maximum likelihood phylogenetic trees to test whether (1) parasites show lineage sorting based on their host species; and (2) switching of lineages to the alternate host species depends on the immediate local species assemblage of individual hosts within a colony. Specifically, we examine the genetic structure of two louse species: Eidmanniella albescens, infecting both Nazca (Sula granti) and blue-footed boobies (Sula nebouxii), and Fregatiella aurifasciata, infecting both great (Fregata minor) and magnificent frigatebirds (Fregata magnificens). We found that host species identity was the only factor explaining the patterns of genetic structure in both parasites. In both cases, there is evident genetic differentiation depending on the host species. Thus, a revision of the taxonomy of these louse species is needed. One possible explanation of this pattern is extremely low louse migration rates between host species, perhaps influenced by fine-scale spatial separation of host species within mixed colonies, and low parasite infrapopulation numbers. PMID:26380662

Spanish Surnamed American Employment in the Southwest.

ERIC Educational Resources Information Center

Schmidt, Fred H.

This report provides statistical data on the job patterns that prevail for Spanish Americans in Arizona, California, Colorado, New Mexico, and Texas. The Southwest once represented an internal colonial empire to the United States, and the inhabitants were treated as such. Present employment patterns must be viewed in this light. The data show that…

Shifting Patterns of Transnational Academic Mobility: A Comparative and Historical Approach

ERIC Educational Resources Information Center

Kim, Terri

2009-01-01

This article is an initial attempt to illustrate how patterns of academic mobility in the history of universities have been framed by the international politics of particular time periods. The article briefly looks at "the medieval period" and then at the emergent colonial and nationalist periods, including the ways that institutions as…

SEASONAL AND DIURNAL ACTIVITY PATTERNS IN ANT (HYMENOPTERA: FORMICIDAE) COMMUNITIES IN A VEGETATION TRANSITION REGION OF SOUTHEASTERN NEW MEXICO

EPA Science Inventory

The densities of active ant colonies were estimated in three habitats: creosotebush shrubland, grassland, and shinnery-oak mesquite dunes. Diurnal foraging patterns were studied at bait boards. Species richness of ant communities in this transitional region (8-12 species) was co...

Anastomosis behavior differs between asymbiotic and symbiotic hyphae of Rhizophagus clarus.

PubMed

Purin, Sonia; Morton, Joseph B

2013-01-01

The life history of arbuscular mycorrhizal fungi (AMF, Glomeromycota) consists of a short asymbiotic phase when spores germinate and a longer symbiotic phase where hyphae form a network within roots and subsequently in the rhizosphere. Hyphal anastomosis contributes to colony formation, yet this process has been studied mostly in the asymbiotic phase rather than in mycorrhizal plants because of methodological limitations. We sought to compare patterns of anastomosis during each phase of fungal growth by measuring hyphal fusions in genetically identical and different single spore isolates of Rhizophagus clarus from different environments and geographic locations. These isolates were genotyped with two anonymous markers of microsatellite-flanking regions. Anastomosis of hyphae from germinating spores was examined in axenic Petri dishes. A rhizohyphatron consisting of agar-coated glass slides bridging single or paired mycorrhizal sorghum plants allowed evaluation of anastomosis of symbiotic hyphae. Anastomosis of hyphae within a colony, defined here as a mycelium from an individual germinating spore or from mycorrhizal roots of one plant, occurred with similar frequencies (8-38%). However, anastomosis between paired colonies was observed in germinating spores from either genetically identical or different isolates, but it was never detected in symbiotic hyphae. The frequency of anastomosis in asymbiotic hyphae from paired interactions was low, occurring in fewer than 6% of hyphal contacts. These data suggest that anastomosis is relatively unconstrained when interactions occur within a colony but is confined to asymbiotic hyphae when interactions occur between paired colonies. This pattern of behavior suggests that asymbiotic and symbiotic phases of mycelium development by R. clarus may differ in function. Anastomosis in the asymbiotic phase may provide brief opportunities for gene flow between populations of this and possibly other AMF species.

Streptomycin Induced Stress Response in Salmonella enterica Serovar Typhimurium Shows Distinct Colony Scatter Signature

PubMed Central

Singh, Atul K.; Drolia, Rishi; Bai, Xingjian; Bhunia, Arun K.

2015-01-01

We investigated the streptomycin-induced stress response in Salmonella enterica serovars with a laser optical sensor, BARDOT (bacterial rapid detection using optical scattering technology). Initially, the top 20 S. enterica serovars were screened for their response to streptomycin at 100 μg/mL. All, but four S. enterica serovars were resistant to streptomycin. The MIC of streptomycin-sensitive serovars (Enteritidis, Muenchen, Mississippi, and Schwarzengrund) varied from 12.5 to 50 μg/mL, while streptomycin-resistant serovar (Typhimurium) from 125–250 μg/mL. Two streptomycin-sensitive serovars (Enteritidis and Mississippi) were grown on brain heart infusion (BHI) agar plates containing sub-inhibitory concentration of streptomycin (1.25–5 μg/mL) and a streptomycin-resistant serovar (Typhimurium) was grown on BHI containing 25–50 μg/mL of streptomycin and the colonies (1.2 ± 0.1 mm diameter) were scanned using BARDOT. Data show substantial qualitative and quantitative differences in the colony scatter patterns of Salmonella grown in the presence of streptomycin than the colonies grown in absence of antibiotic. Mass-spectrometry identified overexpression of chaperonin GroEL, which possibly contributed to the observed differences in the colony scatter patterns. Quantitative RT-PCR and immunoassay confirmed streptomycin-induced GroEL expression while, aminoglycoside adenylyltransferase (aadA), aminoglycoside efflux pump (aep), multidrug resistance subunit acrA, and ribosomal protein S12 (rpsL), involved in streptomycin resistance, were unaltered. The study highlights suitability of the BARDOT as a non-invasive, label-free tool for investigating stress response in Salmonella in conjunction with the molecular and immunoassay methods. PMID:26252374

Evolutionary Determinants of Morphological Polymorphism in Colonial Animals.

PubMed

Simpson, Carl; Jackson, Jeremy B C; Herrera-Cubilla, Amalia

2017-07-01

Colonial animals commonly exhibit morphologically polymorphic modular units that are phenotypically distinct and specialize in specific functional tasks. But how and why these polymorphic modules have evolved is poorly understood. Across colonial invertebrates, there is wide variation in the degree of polymorphism, from none in colonial ascidians to extreme polymorphism in siphonophores, such as the Portuguese man-of-war. Bryozoa are a phylum of exclusively colonial invertebrates that uniquely exhibit almost the entire range of polymorphism, from monomorphic species to others that rival siphonophores in their polymorphic complexity. Previous approaches to understanding the evolution of polymorphism have been based on analyses of (1) the functional role of polymorphs or (2) presumed evolutionary costs and benefits based on evolutionary theory that postulates polymorphism should be evolutionarily sustainable only in more stable environments because polymorphism commonly leads to the loss of feeding and sexual competence. Here we use bryozoans from opposite shores of the Isthmus of Panama to revisit the environmental hypothesis by comparison of faunas from distinct oceanographic provinces that differ greatly in environmental variability, and we then examine the correlations between the extent of polymorphism in relation to patterns of ecological succession and variation in life histories. We find no support for the environmental hypothesis. Distributions of the incidence of polymorphism in the oceanographically unstable Eastern Pacific are indistinguishable from those in the more stable Caribbean. In contrast, the temporal position of species in a successional sequence is collinear with the degree of polymorphism because species with fewer types of polymorphs are competitively replaced by species with higher numbers of polymorphs on the same substrata. Competitively dominant species also exhibit patterns of growth that increase their competitive ability. The association between degrees of polymorphism and variations in life histories is fundamental to understanding of the macroevolution of polymorphism.

Extracellular matrix and growth factors in branching morphogenesis

NASA Technical Reports Server (NTRS)

Hardman, P.; Spooner, B. S.

1993-01-01

The unifying hypothesis of the NSCORT in gravitational biology postulates that the ECM and growth factors are key interrelated components of a macromolecular regulatory system. The ECM is known to be important in growth and branching morphogenesis of embryonic organs. Growth factors have been detected in the developing embryo, and often the pattern of localization is associated with areas undergoing epithelial-mesenchymal interactions. Causal relationships between these components may be of fundamental importance in control of branching morphogenesis.

Human liver segments: role of cryptic liver lobes and vascular physiology in the development of liver veins and left-right asymmetry.

PubMed

Hikspoors, Jill P J M; Peeters, Mathijs M J P; Kruepunga, Nutmethee; Mekonen, Hayelom K; Mommen, Greet M C; Köhler, S Eleonore; Lamers, Wouter H

2017-12-07

Couinaud based his well-known subdivision of the liver into (surgical) segments on the branching order of portal veins and the location of hepatic veins. However, both segment boundaries and number remain controversial due to an incomplete understanding of the role of liver lobes and vascular physiology on hepatic venous development. Human embryonic livers (5-10 weeks of development) were visualized with Amira 3D-reconstruction and Cinema 4D-remodeling software. Starting at 5 weeks, the portal and umbilical veins sprouted portal-vein branches that, at 6.5 weeks, had been pruned to 3 main branches in the right hemi-liver, whereas all (>10) persisted in the left hemi-liver. The asymmetric branching pattern of the umbilical vein resembled that of a "distributing" vessel, whereas the more symmetric branching of the portal trunk resembled a "delivering" vessel. At 6 weeks, 3-4 main hepatic-vein outlets drained into the inferior caval vein, of which that draining the caudate lobe formed the intrahepatic portion of the caval vein. More peripherally, 5-6 major tributaries drained both dorsolateral regions and the left and right ventromedial regions, implying a "crypto-lobar" distribution. Lobar boundaries, even in non-lobated human livers, and functional vascular requirements account for the predictable topography and branching pattern of the liver veins, respectively.

Mapping Sleeping Bees within Their Nest: Spatial and Temporal Analysis of Worker Honey Bee Sleep

PubMed Central

Klein, Barrett Anthony; Stiegler, Martin; Klein, Arno; Tautz, Jürgen

2014-01-01

Patterns of behavior within societies have long been visualized and interpreted using maps. Mapping the occurrence of sleep across individuals within a society could offer clues as to functional aspects of sleep. In spite of this, a detailed spatial analysis of sleep has never been conducted on an invertebrate society. We introduce the concept of mapping sleep across an insect society, and provide an empirical example, mapping sleep patterns within colonies of European honey bees (Apis mellifera L.). Honey bees face variables such as temperature and position of resources within their colony's nest that may impact their sleep. We mapped sleep behavior and temperature of worker bees and produced maps of their nest's comb contents as the colony grew and contents changed. By following marked bees, we discovered that individuals slept in many locations, but bees of different worker castes slept in different areas of the nest relative to position of the brood and surrounding temperature. Older worker bees generally slept outside cells, closer to the perimeter of the nest, in colder regions, and away from uncapped brood. Younger worker bees generally slept inside cells and closer to the center of the nest, and spent more time asleep than awake when surrounded by uncapped brood. The average surface temperature of sleeping foragers was lower than the surface temperature of their surroundings, offering a possible indicator of sleep for this caste. We propose mechanisms that could generate caste-dependent sleep patterns and discuss functional significance of these patterns. PMID:25029445

Transient left septal and anterior fascicular block associated with type 1 electrocardiographic Brugada pattern.

PubMed

Pérez-Riera, Andrés Ricardo; Barbosa-Barros, Raimundo; Penachini da Costa de Rezende Barbosa, Marianne; Daminello-Raimundo, Rodrigo; de Abreu, Luiz Carlos

The left septal fascicular block (LSFB) or blockage of the middle fibers of the left bundle branch is probably caused mainly by - in the developed world - the proximal obstruction of the left anterior descending artery (LAD) before its first anterior septal perforator branch (S 1 ). The association of transient LSFB and left anterior fascicular block (LAFB) - left bifascicular block - and the electrocardiographic type 1 Brugada pattern (BrP) has not been described in the literature yet. Copyright © 2017 Elsevier Inc. All rights reserved.

Gordonia westfalica sp. nov., a novel rubber-degrading actinomycete.

PubMed

Linos, Alexandros; Berekaa, Mahmoud M; Steinbüchel, Alexander; Kim, Kwang Kyu; Sproer, Cathrin; Kroppenstedt, Reiner M

2002-07-01

A cis-1,4-polyisoprene-degrading bacterium (strain Kb2T) was isolated from foul water taken from the inside of a deteriorated automobile tyre found on a farmer's field in Westfalia, Germany. The strain was aerobic, Gram-positive, exhibited orange smooth and rough colonies on complex nutrient agar, produced elementary branching hyphae that fragmented into rod/coccus-like elements and showed chemotaxonomic markers which were consistent with its classification within the genus Gordonia, i.e. the presence of mesodiaminopimelic acid, arabinose and galactose in whole-cell hydrolysates (cell-wall chemotype IV), N-glycolylmuramic acid in the peptidoglycan wall, a fatty-acid pattern composed of unbranched saturated and monounsaturated fatty acids plus tuberculostearic acid, mycolic acids comprising 56-60 carbon atoms and MK-9(H2) as the only menaquinone. The 16S rDNA sequence of strain Kb2T was found to be most similar to the 16S rDNA sequences of the type strains of Gordonia alkanivorans (DSM 44369T) and Gordonia nitida (KCTC 0605BPT). However, DNA-DNA relatedness data showed that strain Kb2T ( =DSM 44215T NRRL B-24152T) could be distinguished from these two species and represented a new species within the genus Gordonia, for which the name Gordonia westfalica is proposed.

Benefiting from a migratory prey: spatio-temporal patterns in allochthonous subsidization of an Arctic predator.

PubMed

Giroux, Marie-Andrée; Berteaux, Dominique; Lecomte, Nicolas; Gauthier, Gilles; Szor, Guillaume; Bêty, Joël

2012-05-01

1. Flows of nutrients and energy across ecosystem boundaries have the potential to subsidize consumer populations and modify the dynamics of food webs, but how spatio-temporal variations in autochthonous and allochthonous resources affect consumers' subsidization remains largely unexplored. 2. We studied spatio-temporal patterns in the allochthonous subsidization of a predator living in a relatively simple ecosystem. We worked on Bylot Island (Nunavut, Canada), where arctic foxes (Vulpes lagopus L.) feed preferentially on lemmings (Lemmus trimucronatus and Dicrostonyx groenlandicus Traill), and alternatively on colonial greater snow geese (Anser caerulescens atlanticus L.). Geese migrate annually from their wintering grounds (where they feed on farmlands and marshes) to the Canadian Arctic, thus generating a strong flow of nutrients and energy across ecosystem boundaries. 3. We examined the influence of spatial variations in availability of geese on the diet of fox cubs (2003-2005) and on fox reproductive output (1996-2005) during different phases of the lemming cycle. 4. Using stable isotope analysis and a simple statistical routine developed to analyse the outputs of a multisource mixing model (SIAR), we showed that the contribution of geese to the diet of arctic fox cubs decreased with distance from the goose colony. 5. The probability that a den was used for reproduction by foxes decreased with distance from the subsidized goose colony and increased with lemming abundance. When lemmings were highly abundant, the effect of distance from the colony disappeared. The goose colony thus generated a spatial patterning of reproduction probability of foxes, while the lemming cycle generated a strong temporal variation of reproduction probability of foxes. 6. This study shows how the input of energy owing to the large-scale migration of prey affects the functional and reproductive responses of an opportunistic consumer, and how this input is spatially and temporally modulated through the foraging behaviour of the consumer. Thus, perspectives of both landscape and foraging ecology are needed to fully resolve the effects of subsidies on animal demographic processes and population dynamics. © 2012 The Authors. Journal of Animal Ecology © 2012 British Ecological Society.

Regulation of branching dynamics by axon-intrinsic asymmetries in Tyrosine Kinase Receptor signaling

PubMed Central

Zschätzsch, Marlen; Oliva, Carlos; Langen, Marion; De Geest, Natalie; Özel, Mehmet Neset; Williamson, W Ryan; Lemon, William C; Soldano, Alessia; Munck, Sebastian; Hiesinger, P Robin; Sanchez-Soriano, Natalia; Hassan, Bassem A

2014-01-01

Axonal branching allows a neuron to connect to several targets, increasing neuronal circuit complexity. While axonal branching is well described, the mechanisms that control it remain largely unknown. We find that in the Drosophila CNS branches develop through a process of excessive growth followed by pruning. In vivo high-resolution live imaging of developing brains as well as loss and gain of function experiments show that activation of Epidermal Growth Factor Receptor (EGFR) is necessary for branch dynamics and the final branching pattern. Live imaging also reveals that intrinsic asymmetry in EGFR localization regulates the balance between dynamic and static filopodia. Elimination of signaling asymmetry by either loss or gain of EGFR function results in reduced dynamics leading to excessive branch formation. In summary, we propose that the dynamic process of axon branch development is mediated by differential local distribution of signaling receptors. DOI: http://dx.doi.org/10.7554/eLife.01699.001 PMID:24755286

Plasticity in skeletal characteristics of nursery-raised staghorn coral, Acropora cervicornis

USGS Publications Warehouse

Kuffner, Ilsa B.; Bartels, Erich; Stathakopoulos, Anastasios; Enochs, Ian C.; Kolodziej, Graham; Toth, Lauren; Manzello, Derek P.

2017-01-01

Staghorn coral, Acropora cervicornis, is a threatened species and the primary focus of western Atlantic reef restoration efforts to date. We compared linear extension, calcification rate, and skeletal density of nursery-raised A. cervicornis branches reared for 6 months either on blocks attached to substratum or hanging from PVC trees in the water column. We demonstrate that branches grown on the substratum had significantly higher skeletal density, measured using computerized tomography, and lower linear extension rates compared to water-column fragments. Calcification rates determined with buoyant weighing were not statistically different between the two grow-out methods, but did vary among coral genotypes. Whereas skeletal density and extension rates were plastic traits that depended on grow-out method, calcification rate was conserved. Our results show that the two rearing methods generate the same amount of calcium carbonate skeleton but produce colonies with different skeletal characteristics and suggest that there is genetically based variability in coral calcification performance.

Plasticity in skeletal characteristics of nursery-raised staghorn coral, Acropora cervicornis

NASA Astrophysics Data System (ADS)

Kuffner, Ilsa B.; Bartels, Erich; Stathakopoulos, Anastasios; Enochs, Ian C.; Kolodziej, G.; Toth, Lauren T.; Manzello, Derek P.

2017-09-01

Staghorn coral, Acropora cervicornis, is a threatened species and the primary focus of western Atlantic reef restoration efforts to date. We compared linear extension, calcification rate, and skeletal density of nursery-raised A. cervicornis branches reared for 6 months either on blocks attached to substratum or hanging from PVC trees in the water column. We demonstrate that branches grown on the substratum had significantly higher skeletal density, measured using computerized tomography, and lower linear extension rates compared to water-column fragments. Calcification rates determined with buoyant weighing were not statistically different between the two grow-out methods, but did vary among coral genotypes. Whereas skeletal density and extension rates were plastic traits that depended on grow-out method, calcification rate was conserved. Our results show that the two rearing methods generate the same amount of calcium carbonate skeleton but produce colonies with different skeletal characteristics and suggest that there is genetically based variability in coral calcification performance.

Spatial Arrangement of Branches in Relation to Slope and Neighbourhood Competition

PubMed Central

SUMIDA, AKIHIRO; TERAZAWA, IKUE; TOGASHI, ASAKO; KOMIYAMA, AKIRA

2002-01-01

To gain a better understanding of the effects of spatial structure on patterns of neighbourhood competition among hardwood trees, the three‐dimensional extension of primary branches was surveyed for ten community‐grown Castanea crenata (Fagaceae) trees with respect to the positioning of neighbouring branches and the slope of the forest floor. There were significantly more branches extending towards the lower side of the slope than towards the upper side, but structural properties such as branch length and vertical angle were not affected by slope. When horizontal extension of a branch towards its neighbour was compared for a C. crenata branch and a neighbouring heterospecific, the former was significantly narrower than the latter when the inter‐branch distance (horizontal distance between the base positions of two neighbouring branches) was short (< approx. 5 m). Castanea crenata branches tended to extend in a direction avoiding neighbouring branches of heterospecifics when the inter‐branch distance was short. Furthermore, for an inter‐branch distance <3 m, the horizontal extension of a C. crenata branch was less when it was neighbouring a heterospecific branch than when neighbouring a conspecific branch. These results suggest that horizontal extension of C. crenata branches is more prone to spatial invasion by nearby neighbouring branches of heterospecifics, and that the invasion can be lessened when C. crenata trees are spatially aggregated. The reason why such an arrangement occurs is discussed in relation to the later leaf‐flush of C. crenata compared with that of other species in the forest. PMID:12096742

Origin of Pareto-like spatial distributions in ecosystems.

PubMed

Manor, Alon; Shnerb, Nadav M

2008-12-31

Recent studies of cluster distribution in various ecosystems revealed Pareto statistics for the size of spatial colonies. These results were supported by cellular automata simulations that yield robust criticality for endogenous pattern formation based on positive feedback. We show that this patch statistics is a manifestation of the law of proportionate effect. Mapping the stochastic model to a Markov birth-death process, the transition rates are shown to scale linearly with cluster size. This mapping provides a connection between patch statistics and the dynamics of the ecosystem; the "first passage time" for different colonies emerges as a powerful tool that discriminates between endogenous and exogenous clustering mechanisms. Imminent catastrophic shifts (such as desertification) manifest themselves in a drastic change of the stability properties of spatial colonies.

The path for long range conduction in high J(sub c) TlBa2Ca2Cu3O(8+x) spray-pyrolyzed deposits

NASA Astrophysics Data System (ADS)

Kroeger, D. M.; Goyal, A.; Specht, E. D.; Wang, Z. L.; Tkaczyk, J. E.; Sutliff, J. A.; Deluca, J. A.

Grain boundary misorientations and local texture in polycrystalline TlBa2Ca2Cu3O(8+x) deposits prepared by thallination of spray-pyrolyzed precursor deposits on yttria-stabilized zirconia have been determined from transmission electron microscopy, electron backscatter diffraction patterns, and x ray diffraction. The deposits were polycrystalline, had small grains, and excellent c-axis alignment. The deposits contained colonies of grains with similar but not identical a-axis orientations. Most grain boundaries within a colony have small misorientation angles and should not be weak links. It is proposed that long range current flow occurs through a percolative network of small angle grain boundaries at colony intersections.

Crown development in a pioneer tree, Rhus trichocarpa, in relation to the structure and growth of individual branches.

PubMed

Osada, Noriyuki

2006-01-01

Based on an allometric reconstruction, the structure and biomass-allocation patterns of branches and current-year shoots were investigated in branches of various heights in the pioneer tree Rhus trichocarpa, to evaluate how crown development is achieved and limited in association with height. Path analysis was conducted to explore the effects of light availability, basal height and size of individual branches on branch structure and growth. Branch angle was affected by basal height, whereas branch mass was influenced primarily by light availability. This result suggests that branch structure is strongly constrained by basal height, and that trees mediate such constraints under different light environments. Previous-year leaf area and light availability showed positive effects on current-year stem mass. In contrast, branch basal height and mass negatively affected current-year stem mass. Moreover, the length of stems of a given diameter decreased with increasing branch height. Therefore the cost of biomass investment for a unit growth in length is greater for branches of larger size and at upper positions. Vertical growth rate in length decreased with increasing height. Height-dependent changes in stem allometry and angle influenced the reduction in vertical growth rate to a similar degree.

Terminal branching pattern of the right coronary artery in left-dominant hearts: a cadaveric study.

PubMed

Gupta, Tulika; Saini, Abhimanyu; Sahni, Daisy

2013-01-01

Left coronary dominance has been reported to be associated with increased mortality and severity in case of myocardial ischemia involving left coronary artery. The present cadaveric study was proposed to objectively study and document the termination and branching pattern of the right coronary artery in left-coronary-dominant hearts in relation to the blood supply to the posterior surface of the right ventricle. Seventy-five cadaveric hearts were studied. The coronary vessels were injected with colored cellulose acetate butyrate and dissected. The coronary dominance was determined. In left-dominant hearts, branches and termination of the right coronary artery were studied. Left coronary dominance was found in 13% of the specimens. The number of ventricular branches was found to be present as 0, 1, 2, and 4 in two, four, two, and two of the cases, respectively. The average length of the ventricular branch was 12.7 mm with a range of 5-35 mm. The atrial branch was found in 50% of hearts, varying from 2 to 3 mm in length. In three hearts, the acute marginal artery did not give any posterior ventricular branch, while two, three, and five posterior ventricular branches were seen in four, two, and one heart(s), respectively. The length of the posterior ventricular arteries was between 5 and 15 mm. The RCA is an inconstant and unreliable source of posterior right ventricular perfusion in a significant percentage of population with left-coronary-dominant hearts. This might be the reason for the increased morbidity and mortality seen in the event of left coronary ischemia. Copyright © 2013 Elsevier Inc. All rights reserved.

Bioethanol strains of Saccharomyces cerevisiae characterised by microsatellite and stress resistance.

PubMed

Reis, Vanda Renata; Antonangelo, Ana Teresa Burlamaqui Faraco; Bassi, Ana Paula Guarnieri; Colombi, Débora; Ceccato-Antonini, Sandra Regina

Strains of Saccharomyces cerevisiae may display characteristics that are typical of rough-type colonies, made up of cells clustered in pseudohyphal structures and comprised of daughter buds that do not separate from the mother cell post-mitosis. These strains are known to occur frequently in fermentation tanks with significant lower ethanol yield when compared to fermentations carried out by smooth strains of S. cerevisiae that are composed of dispersed cells. In an attempt to delineate genetic and phenotypic differences underlying the two phenotypes, this study analysed 10 microsatellite loci of 22 S. cerevisiae strains as well as stress resistance towards high concentrations of ethanol and glucose, low pH and cell sedimentation rates. The results obtained from the phenotypic tests by Principal-Component Analysis revealed that unlike the smooth colonies, the rough colonies of S. cerevisiae exhibit an enhanced resistance to stressful conditions resulting from the presence of excessive glucose and ethanol and high sedimentation rate. The microsatellite analysis was not successful to distinguish between the colony phenotypes as phenotypic assays. The relevant industrial strain PE-2 was observed in close genetic proximity to rough-colony although it does not display this colony morphology. A unique genetic pattern specific to a particular phenotype remains elusive. Copyright © 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

Endoparasitism in colonial hosts: patterns and processes.

PubMed

Hill, S L L; Okamura, B

2007-06-01

This study begins to redress our lack of knowledge of the interactions between colonial hosts and their parasites by focusing on a novel host-parasite system. Investigations of freshwater bryozoan populations revealed that infection by myxozoan parasites is widespread. Covert infections were detected in all 5 populations studied and were often at high prevalence while overt infections were observed in only 1. Infections were persistent in populations subject to temporal sampling. Negative effects of infection were identified but virulence was low. Infection did not induce mortality in the environmental conditions studied. However, the production of statoblasts (dormant propagules) was greatly reduced in bryozoans with overt infections in comparison to uninfected bryozoans. Overtly-infected bryozoans also grew more slowly and had low fission rates relative to colonies lacking overt infection. Bryozoans with covert infections were smaller than uninfected bryozoans. High levels of vertical transmission were achieved through colony fission and the infection of statoblasts. Increased fission rates may be a strategy for hosts to escape from parasites but the parasite can also exploit the fragmentation of colonial hosts to gain vertical transmission and dispersal. Our study provides evidence that opportunities and constraints for host-parasite co-evolution can be highly dependent on organismal body plans and that low virulence may be associated with exploitation of colonial hosts by endoparasites.

Idiopathic brood disease syndrome and queen events as precursors of colony mortality in migratory beekeeping operations in the eastern United States.

PubMed

vanEngelsdorp, Dennis; Tarpy, David R; Lengerich, Eugene J; Pettis, Jeffery S

2013-02-01

Using standard epidemiological methods, this study set out to quantify the risk associated with exposure to easily diagnosed factors on colony mortality and morbidity in three migratory beekeeping operations. Fifty-six percent of all colonies monitored during the 10-month period died. The relative risk (RR) that a colony would die over the short term (∼50 days) was appreciably increased in colonies diagnosed with Idiopathic Brood Disease Syndrome (IBDS), a condition where brood of different ages appear molten on the bottom of cells (RR=3.2), or with a "queen event" (e.g., evidence of queen replacement or failure; RR=3.1). We also found that several risk factors-including the incidence of a poor brood pattern, chalkbood (CB), deformed wing virus (DWV), sacbrood virus (SBV), and exceeding the threshold of 5 Varroa mites per 100 bees-were differentially expressed in different beekeeping operations. Further, we found that a diagnosis of several factors were significantly more or less likely to be associated with a simultaneous diagnosis of another risk factor. These finding support the growing consensus that the causes of colony mortality are multiple and interrelated. Copyright © 2012 Elsevier B.V. All rights reserved.

Seabird colonies as relevant sources of pollutants in Antarctic ecosystems: Part 1 - Trace elements.

PubMed

Cipro, C V Z; Bustamante, P; Petry, M V; Montone, R C

2018-08-01

Global distillation is classically pointed as the biggest responsible for contaminant inputs in Polar ecosystems. Mercury (Hg) and other trace elements (TEs) also present natural sources, whereas the biologically mediated input is typically ignored. However, bioaccumulation and biomagnification combined with the fact that seabirds gather in large numbers into large colonies and excrete on land might represent an important local TEs input. A previous work suggested these colonies as sources of not only nutrients, but also organic contaminants. To evaluate a similar hypothesis for TEs, samples of lichen (n = 55), mosses (n = 58) and soil (n = 37) were collected in 13 locations within the South Shetlands Archipelago during the austral summers of 2013-14 and 2014-15. They were divided in: "colony" (within the colony itself for soil and bordering it for vegetation) and "control" (at least 50 m away from colony interference), analysed for TEs (As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, V, and Zn) and stable isotopes (C and N). In most cases, soil seems the best matrix to assess colonies as TEs sources, as it presented more differences between control/colony sites than vegetation. Colonies are clearly local sources of organic matter, Cd, Hg and likely of As, Se and Zn. Conversely, Co, Cr, Ni and Pb come presumably from other sources, natural or anthropogenic. In general, isotopes were more useful for interpreting vegetation data due to fractionation of absorbed animal-derived organic matter. Other local Hg sources could be inferred from high levels in control sites, location and wind patterns. Copyright © 2018 Elsevier Ltd. All rights reserved.

Task partitioning in a ponerine ant.

PubMed

Theraulaz, Guy; Bonabeau, Eric; Sole, Ricard V; Schatz, Bertrand; Deneubourg, Jean-Louis

2002-04-21

This paper reports a study of the task partitioning observed in the ponerine ant Ectatomma ruidum, where prey-foraging behaviour can be subdivided into two categories: stinging and transporting. Stingers kill live prey and transporters carry prey corpses back to the nest. Stinging and transporting behaviours are released by certain stimuli through response thresholds; the respective stimuli for stinging and transporting appear to be the number of live prey and the number of prey corpses. A response threshold model, the parameters of which are all measured empirically, reproduces a set of non-trivial colony-level dynamical patterns observed in the experiments. This combination of modelling and empirical work connects explicitly the level of individual behaviour with colony-level patterns of work organization. Copyright 2002 Elsevier Science Ltd. All rights reserved.

Distinct Bacterial Communities Associated with Massive and Branching Scleractinian Corals and Potential Linkages to Coral Susceptibility to Thermal or Cold Stress

PubMed Central

Liang, Jiayuan; Yu, Kefu; Wang, Yinghui; Huang, Xueyong; Huang, Wen; Qin, Zhenjun; Pan, Ziliang; Yao, Qiucui; Wang, Wenhuan; Wu, Zhengchao

2017-01-01

It is well known that different coral species have different tolerances to thermal or cold stress, which is presumed to be related to the density of Symbiodinium. However, the intrinsic factors between stress-tolerant characteristics and coral-associated bacteria are rarely studied. In this study, 16 massive coral and 9 branching coral colonies from 6 families, 10 genera, and 18 species were collected at the same time and location (Xinyi Reef) in the South China Sea to investigate the bacterial communities. The results of an alpha diversity analysis showed that bacterial diversities associated with massive corals were generally higher than those with branching corals at different taxonomic levels (phylum, class, order, and so on). In addition, hierarchical clustering tree and PCoA analyses showed that coral species were clustered into two large groups according to the similarity of bacterial communities. Group I consisted of massive Goniastrea, Plesiastrea, Leptastrea, Platygyra, Echinopora, Porites, and Leptoria, and group II consisted of branching Acropora and Pocillopora. These findings suggested that both massive corals and branching corals have their own preference for the choice of associated bacteria, which may be involved in observed differences in thermal/cold tolerances. Further analysis found that 55 bacterial phyla, including 43 formally described phyla and 12 candidate phyla, were detected in these coral species. Among them, 52 phyla were recovered from the massive coral group, and 46 phyla were recovered from the branching coral group. Formally described coral pathogens have not been detected in these coral species, suggesting that they are less likely to be threatened by disease in this geographic area. This study highlights a clear relationship between the high complexity of bacterial community associated with coral, skeletal morphology of coral and potentially tolerances to thermal or cold stress. PMID:28642738

Cellulolytic Protist Numbers Rise and Fall Dramatically in Termite Queens and Kings during Colony Foundation

PubMed Central

Shimada, Keisuke; Lo, Nathan; Kitade, Osamu; Wakui, Akane

2013-01-01

Among the best-known examples of mutualistic symbioses is that between lower termites and the cellulolytic flagellate protists in their hindguts. Although the symbiosis in worker termites has attracted much attention, there have been only a few studies of protists in other castes. We have performed the first examination of protist population dynamics in queens and kings during termite colony foundation. Protist numbers, as well as measurements of hindgut and reproductive tissue sizes, were undertaken at five time points over 400 days in incipient colonies of Reticulitermes speratus, as well as in other castes of mature colonies of this species. We found that protist numbers increased dramatically in both queens and kings during the first 50 days of colony foundation but began to decrease by day 100, eventually disappearing by day 400. Hindgut width followed a pattern similar to that of protist numbers, while ovary and testis widths increased significantly only at day 400. Kings were found to contain higher numbers of protists than queens in incipient colonies, which may be linked to higher levels of nutrient transfer from kings to queens than vice versa, as is known in some other termite species. Protists were found to be abundant in soldiers from mature colonies but absent in neotenics. This probably reflects feeding of soldiers by workers via proctodeal trophallaxis and of reproductives via stomodeal trophallaxis. The results reveal the dynamic nature of protist numbers during colony foundation and highlight the trade-offs that exist between reproduction and parental care during this critical phase of the termite life cycle. PMID:23376945

Periodic Colony Formation of Bacteria Due to their Cell Reproduction and Movement

NASA Astrophysics Data System (ADS)

Itoh, H.; Wakita, J.; Watanabe, K.; Matsuyama, T.; Matsushita, M.

We have experimentally investigated periodic pattern formation produced by bacterial species Proteus mirabilis, which forms concentric-ring-like colonies by repeating migration and rest alternately on the surface of a solid agar medium. We distinguish three phases (initial lag phase, the following migration and consolidation phases that appear alternately) for the colony growth. Here we mainly used physical approaches in order to try to understand the formation of concentric-ring-like colonies, such as cutting the part of a colony during its growth. Global chemical signals governing the colony formation from the center were not found. We also checked phase entrainment quantitatively by letting two colonies collide with each other and confirmed that it does not take place in macroscopic scales. When we cut a colony just behind the migrating front shortly after the migration started, the migration ended earlier and the following consolidation lasted longer. However, the following cycles were not influenced by the cut, i.e., the following migration and consolidation phases were both found to return normal. The cut results in the stop of supply of cell population to the migrating front by internal waves. In fact the cell population on the new terrace during the first migration after the cut was less than that without cut. Furthermore, the cell population density was found to be recovered to the ordinary value by the end of the consolidation. All these experimental results suggest that the most important factor for the repetition of migration and consolidation phases is the cell population density.

Phase transition of traveling waves in bacterial colony pattern

NASA Astrophysics Data System (ADS)

Wakano, Joe Yuichiro; Komoto, Atsushi; Yamaguchi, Yukio

2004-05-01

Depending on the growth condition, bacterial colonies can exhibit different morphologies. Many previous studies have used reaction diffusion equations to reproduce spatial patterns. They have revealed that nonlinear reaction term can produce diverse patterns as well as nonlinear diffusion coefficient. Typical reaction term consists of nutrient consumption, bacterial reproduction, and sporulation. Among them, the functional form of sporulation rate has not been biologically investigated. Here we report experimentally measured sporulation rate. Then, based on the result, a reaction diffusion model is proposed. One-dimensional simulation showed the existence of traveling wave solution. We study the wave form as a function of the initial nutrient concentration and find two distinct types of solution. Moreover, transition between them is very sharp, which is analogous to phase transition. The velocity of traveling wave also shows sharp transition in nonlinear diffusion model, which is consistent with the previous experimental result. The phenomenon can be explained by separatrix in reaction term dynamics. Results of two-dimensional simulation are also shown and discussed.

Societies drifting apart? Behavioural, genetic and chemical differentiation between supercolonies in the yellow crazy ant Anoplolepis gracilipes.

PubMed

Drescher, Jochen; Blüthgen, Nico; Schmitt, Thomas; Bühler, Jana; Feldhaar, Heike

2010-10-22

In populations of most social insects, gene flow is maintained through mating between reproductive individuals from different colonies in periodic nuptial flights followed by dispersal of the fertilized foundresses. Some ant species, however, form large polygynous supercolonies, in which mating takes place within the maternal nest (intranidal mating) and fertilized queens disperse within or along the boundary of the supercolony, leading to supercolony growth (colony budding). As a consequence, gene flow is largely confined within supercolonies. Over time, such supercolonies may diverge genetically and, thus, also in recognition cues (cuticular hydrocarbons, CHC's) by a combination of genetic drift and accumulation of colony-specific, neutral mutations. We tested this hypothesis for six supercolonies of the invasive ant Anoplolepis gracilipes in north-east Borneo. Within supercolonies, workers from different nests tolerated each other, were closely related and showed highly similar CHC profiles. Between supercolonies, aggression ranged from tolerance to mortal encounters and was negatively correlated with relatedness and CHC profile similarity. Supercolonies were genetically and chemically distinct, with mutually aggressive supercolony pairs sharing only 33.1%±17.5% (mean ± SD) of their alleles across six microsatellite loci and 73.8%±11.6% of the compounds in their CHC profile. Moreover, the proportion of alleles that differed between supercolony pairs was positively correlated to the proportion of qualitatively different CHC compounds. These qualitatively differing CHC compounds were found across various substance classes including alkanes, alkenes and mono-, di- and trimethyl-branched alkanes. We conclude that positive feedback between genetic, chemical and behavioural traits may further enhance supercolony differentiation through genetic drift and neutral evolution, and may drive colonies towards different evolutionary pathways, possibly including speciation.

Decay pattern of the Pygmy Dipole Resonance in 140Ce

NASA Astrophysics Data System (ADS)

Isaak, J.; Löher, B.; Savran, D.; Aumann, T.; Beller, J.; Cooper, N.; Derya, V.; Duchêne, M.; Endres, J.; Fiori, E.; Kelley, J. H.; Knörzer, M.; Pietralla, N.; Ponomarev, V. Yu.; Romig, C.; Scheck, M.; Scheit, H.; Silva, J.; Tonchev, A. P.; Tornow, W.; Weller, H. R.; Werner, V.; Zilges, A.; Zweidinger, M.

2015-05-01

The decay behavior of low-lying dipole states in 140Ce was investigated exploiting the γ3-setup at the HIγS facility using quasi-monochromatic photon beams. Branching ratios of individual excited states as well as average branching ratios to low-lying states have been extracted using γ - γ coincidence measurements. The comparison of the average branching ratios to QPM calculations shows a remarkable agreement between experiment and theory in the energy range from 5.0 to 8.5 MeV.

Distinct 3-O-Sulfated Heparan Sulfate Modification Patterns Are Required for kal-1−Dependent Neurite Branching in a Context-Dependent Manner in Caenorhabditis elegans

PubMed Central

Tecle, Eillen; Diaz-Balzac, Carlos A.; Bülow, Hannes E.

2013-01-01

Heparan sulfate (HS) is an unbranched glycosaminoglycan exhibiting substantial molecular diversity due to multiple, nonuniformly introduced modifications, including sulfations, epimerization, and acetylation. HS modifications serve specific and instructive roles in neuronal development, leading to the hypothesis of a HS code that regulates nervous system patterning. Although the in vivo roles of many of the HS modifications have been investigated, very little is known about the function of HS 3-O-sulfation in vivo. By examining patterning of the Caenorhabditis elegans nervous system in loss of function mutants of the two 3-O-sulfotransferases, hst-3.1 and hst-3.2, we found HS 3-O-sulfation to be largely dispensable for overall neural development. However, generation of stereotypical neurite branches in hermaphroditic-specific neurons required hst-3.1, hst-3.2, as well as an extracellular cell adhesion molecule encoded by kal-1, the homolog of Kallmann Syndrome associated gene 1/anosmin-1. In contrast, kal-1−dependent neurite branching in AIY neurons required catalytic activity of hst-3.2 but not hst-3.1. The context-dependent requirement for hst-3.2 and hst-3.1 indicates that both enzymes generate distinct types of HS modification patterns in different cell types, which regulate kal-1 to promote neurite branching. We conclude that HS 3-O-sulfation does not play a general role in establishing the HS code in C. elegans but rather plays a specialized role in a context-dependent manner to establish defined aspects of neuronal circuits. PMID:23451335

Linking ice accretion and crown structure: towards a model of the effect of freezing rain on tree canopies.

PubMed

Nock, Charles A; Lecigne, Bastien; Taugourdeau, Olivier; Greene, David F; Dauzat, Jean; Delagrange, Sylvain; Messier, Christian

2016-06-01

Despite a longstanding interest in variation in tree species vulnerability to ice storm damage, quantitative analyses of the influence of crown structure on within-crown variation in ice accretion are rare. In particular, the effect of prior interception by higher branches on lower branch accumulation remains unstudied. The aim of this study was to test the hypothesis that intra-crown ice accretion can be predicted by a measure of the degree of sheltering by neighbouring branches. Freezing rain was artificially applied to Acer platanoides L., and in situ branch-ice thickness was measured directly and from LiDAR point clouds. Two models of freezing rain interception were developed: 'IceCube', which uses point clouds to relate ice accretion to a voxel-based index (sheltering factor; SF) of the sheltering effect of branch elements above a measurement point; and 'IceTree', a simulation model for in silico evaluation of the interception pattern of freezing rain in virtual tree crowns. Intra-crown radial ice accretion varied strongly, declining from the tips to the bases of branches and from the top to the base of the crown. SF for branches varied strongly within the crown, and differences among branches were consistent for a range of model parameters. Intra-crown variation in ice accretion on branches was related to SF (R(2) = 0·46), with in silico results from IceTree supporting empirical relationships from IceCube. Empirical results and simulations confirmed a key role for crown architecture in determining intra-crown patterns of ice accretion. As suspected, the concentration of freezing rain droplets is attenuated by passage through the upper crown, and thus higher branches accumulate more ice than lower branches. This is the first step in developing a model that can provide a quantitative basis for investigating intra-crown and inter-specific variation in freezing rain damage. © The Author 2016. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Side-branch technique for difficult guidewire placement in coronary bifurcation lesion.

PubMed

He, Xingwei; Gao, Bo; Liu, Yujian; Li, Zhuxi; Zeng, Hesong

2016-01-01

Despite tremendous advances in technology and skills, percutaneous coronary intervention (PCI) of bifurcation lesion (BL) remains a particular challenge for the interventionalist. During bifurcation PCI, safe guidewire placement in the main branch (MB) and the side branch (SB) is the first step for successful procedure. However, in certain cases, the complex pattern of vessel anatomy and the mix of plaque distribution may make target vessel wiring highly challenging. Therefore, specific techniques are required for solving this problem. Hereby, we describe a new use of side-branch technique for difficult guidewire placement in BL. Copyright © 2015 Elsevier Inc. All rights reserved.

Historic land use and grazing patterns in northern New Mexico

Treesearch

Carol Raish

1996-01-01

The entrance of the Spanish into what is now New Mexico in the 1500s permanently altered aboriginal land use and subsistence patterns by the introduction of domesticated animals such as horses, cattle. sheep, goats, and pigs. During the Spanish Colonial and Mexican periods, both the Puebloan groups and the Hispanic settlers practiced mixed farming featuring small...

The Preference for Symmetry in Flower-Naive and Not-so-Naive Bumblebees

ERIC Educational Resources Information Center

Plowright, C. M. S.; Evans, S. A.; Leung, J. Chew; Collin, C. A.

2011-01-01

Truly flower-naive bumblebees, with no prior rewarded experience for visits on any visual patterns outside the colony, were tested for their choice of bilaterally symmetric over asymmetric patterns in a radial-arm maze. No preference for symmetry was found. Prior training with rewarded black and white disks did, however, lead to a significant…

Travelling Careers: Overseas Migration Patterns in the Professional Lives of Women Attending Girton and Newnham before 1939

ERIC Educational Resources Information Center

Goodman, Joyce; Jacobs, Andrea; Kisby, Fiona; Loader, Helen

2011-01-01

This paper explores the migration patterns of women who studied at Girton and Newnham prior to 1939 through whom dissemination of knowledge and values flowed from Cambridge overseas. It also considers organisations that fostered women's mobility in empire, particularly the Colonial Intelligence League for Educated Women and the International…

Analysis of the arterial anatomical variations of thyroid gland: anatomic guide for surgical neck dissection.

PubMed

Ray, B; Pugazhandhi, B; D'Souza, A S; Saran, S; Fasil, M; Srinivasa, R S

2012-01-01

Aim of this study was to establish preliminary data on the variations of arterial supply of thyroid gland in Karnataka population. The anterior triangles in the neck of formalin fixed cadavers were dissected. The length, branching pattern, number and length of branches of superior thyroid artery (STA) were noted. We measured the length of inferior thyroid artery (ITA) from its point of emergence from thyrocervical trunk (TCT) to lower pole of thyroid gland. The length of the external carotid artery (ECA), TCT from the point of its emergence to the point of its branching was noted. We noted the number of branches from ITA and TCT. Presence of any additional artery supplying the thyroid gland was searched for. Difference in the length of STA and ITA between the two sexes and sides were noted. Statistical analysis was done by Student's t-test. In our study the maximum length of STA was 5.34cm and that of ITA was 5.07cm and there were no statistically significant side-to-side differences in level of bifurcation. Observations of the present study on the course and branching pattern of arteries around thyroid gland will help in easier approach during thyroid surgeries and interventional techniques (Tab. 1, Fig. 3, Ref. 38).

A new banding technique for nesting adult purple martins

USGS Publications Warehouse

Klimkiewicz, M.K.; Jung, P.D.

1977-01-01

Mery (1966) showed an almost equal sex ratio, males returned more frequently than females, over 50% of returns paired with other returns, an adult return rate of 20%, and no pair bonds maintained for more than one season. Her study lasted 13 years. Our study has shown that the return rate of locals to parent colonies is 4.1%, sex ratios are nearly equal (combination of banding and observation), return rate of locals to nearby colonies is 0.9,one pair maintained the pair bond for two years, SY females lay fewer eggs than ASY's, SY adults occasionally do not feed frequently enough to maintain the normal growth pattern of the young, SY adults often build poorly constructed nests with little or no mud, overall nest success is lower in SY adults, adults do indeed return to the same colony (19.6%) box and/or compartment, sexes are balanced in a stable colony, males or females are sometimes in excess in a new colony, SY adults are predominate in a new colony, the limiting factor in colony size is most likely the number of boxes and/or compartments available for nesting and,finally, adults and young do indeed use the boxes for roosting after nesting and fledging is complete (even boxes not their own). All of our results are tentative and subject to change after f rther study. Much additional study will be required before we can come up with conclusive answers to many of these questions about the Purple Martin.

Ants regulate colony spatial organization using multiple chemical road-signs

PubMed Central

Heyman, Yael; Shental, Noam; Brandis, Alexander; Hefetz, Abraham; Feinerman, Ofer

2017-01-01

Communication provides the basis for social life. In ant colonies, the prevalence of local, often chemically mediated, interactions introduces strong links between communication networks and the spatial distribution of ants. It is, however, unknown how ants identify and maintain nest chambers with distinct functions. Here, we combine individual tracking, chemical analysis and machine learning to decipher the chemical signatures present on multiple nest surfaces. We present evidence for several distinct chemical ‘road-signs' that guide the ants' movements within the dark nest. These chemical signatures can be used to classify nest chambers with different functional roles. Using behavioural manipulations, we demonstrate that at least three of these chemical signatures are functionally meaningful and allow ants from different task groups to identify their specific nest destinations, thus facilitating colony coordination and stabilization. The use of multiple chemicals that assist spatiotemporal guidance, segregation and pattern formation is abundant in multi-cellular organisms. Here, we provide a rare example for the use of these principles in the ant colony. PMID:28569746

A Study on Intraspecific Resource Partitioning in the Stingless bee Scaptotrigona mexicana Guérin (Apidae, Meliponini) Using Behavioral and Molecular Techniques.

PubMed

Sánchez, D; Solórzano-Gordillo, E; Vandame, R

2016-10-01

As a general rule, within an ecological guild, there is one species that is dominant and is commonly the most abundant. The aim of this work was to investigate if such pattern occurs intraspecifically, among colonies of the stingless bee Scaptotrigona mexicana Guérin. Through behavioral and molecular techniques, we found preliminary evidence that apparently colonies of this species do not monopolize resources, instead they seem to share food; however, some colonies had more foragers in a food patch or in a feeder, so some type of exclusion could be at work, though we could not determine the final output of such interaction, i.e., if underrepresented colonies were eventually excluded, developed slower or were overrepresented in other food patches. Our results give evidence that resource partitioning within this species occurs peacefully; however, further studies are necessary to determine if threatening behavior or aggressions appear when resources are scarce and competition becomes harsher.

Ants regulate colony spatial organization using multiple chemical road-signs.

PubMed

Heyman, Yael; Shental, Noam; Brandis, Alexander; Hefetz, Abraham; Feinerman, Ofer

2017-06-01

Communication provides the basis for social life. In ant colonies, the prevalence of local, often chemically mediated, interactions introduces strong links between communication networks and the spatial distribution of ants. It is, however, unknown how ants identify and maintain nest chambers with distinct functions. Here, we combine individual tracking, chemical analysis and machine learning to decipher the chemical signatures present on multiple nest surfaces. We present evidence for several distinct chemical 'road-signs' that guide the ants' movements within the dark nest. These chemical signatures can be used to classify nest chambers with different functional roles. Using behavioural manipulations, we demonstrate that at least three of these chemical signatures are functionally meaningful and allow ants from different task groups to identify their specific nest destinations, thus facilitating colony coordination and stabilization. The use of multiple chemicals that assist spatiotemporal guidance, segregation and pattern formation is abundant in multi-cellular organisms. Here, we provide a rare example for the use of these principles in the ant colony.

Redox state, reactive oxygen species and adaptive growth in colonial hydroids.

PubMed

Blackstone, N W

2001-06-01

Colonial metazoans often encrust surfaces over which the food supply varies in time or space. In such an environment, adaptive colony development entails adjusting the timing and spacing of feeding structures and gastrovascular connections to correspond to this variable food supply. To investigate the possibility of such adaptive growth, within-colony differential feeding experiments were carried out using the hydroid Podocoryna carnea. Indeed, such colonies strongly exhibited adaptive growth, developing dense arrays of polyps (feeding structures) and gastrovascular connections in areas that were fed relative to areas that were starved, and this effect became more consistent over time. To investigate mechanisms of signaling between the food supply and colony development, measurements were taken of metabolic parameters that have been implicated in signal transduction in other systems, particularly redox state and levels of reactive oxygen species. Utilizing fluorescence microscopy of P. carnea cells in vivo, simultaneous measurements of redox state [using NAD(P)H] and hydrogen peroxide (using 2',7'-dichlorofluorescin diacetate) were taken. Both measures focused on polyp epitheliomuscular cells, since these exhibit the greatest metabolic activity. Colonies 3-5h after feeding were relatively oxidized, with low levels of peroxide, while colonies 24h after feeding were relatively reduced, with high levels of peroxide. The functional role of polyps in feeding and generating gastrovascular flow probably produced this dichotomy. Polyps 3-5h after feeding contract maximally, and this metabolic demand probably shifts the redox state in the direction of oxidation and diminishes levels of reactive oxygen species. In contrast, 24h after feeding, polyps are quiescent, and this lack of metabolic demand probably shifts the redox state in the direction of reduction and increases levels of reactive oxygen species. Within-colony differential feeding experiments were carried out on colonies 24h after the usual, colony-wide feeding. At this time, a single polyp was fed, and this polyp was compared with an otherwise similar polyp from the same colony. A pattern similar to the whole-colony experiments was obtained: the just-fed polyp, as it begins contracting shortly after feeding, appears to be relatively oxidized, with low levels of peroxide compared with the polyp that was not fed. These data are consistent with the hypothesis that adaptive colony development in response to a variable food supply is mediated by redox state or reactive oxygen species or both, although alternative hypotheses are also discussed.

A quantitative test of population genetics using spatiogenetic patterns in bacterial colonies.

PubMed

Korolev, Kirill S; Xavier, João B; Nelson, David R; Foster, Kevin R

2011-10-01

It is widely accepted that population-genetics theory is the cornerstone of evolutionary analyses. Empirical tests of the theory, however, are challenging because of the complex relationships between space, dispersal, and evolution. Critically, we lack quantitative validation of the spatial models of population genetics. Here we combine analytics, on- and off-lattice simulations, and experiments with bacteria to perform quantitative tests of the theory. We study two bacterial species, the gut microbe Escherichia coli and the opportunistic pathogen Pseudomonas aeruginosa, and show that spatiogenetic patterns in colony biofilms of both species are accurately described by an extension of the one-dimensional stepping-stone model. We use one empirical measure, genetic diversity at the colony periphery, to parameterize our models and show that we can then accurately predict another key variable: the degree of short-range cell migration along an edge. Moreover, the model allows us to estimate other key parameters, including effective population size (density) at the expansion frontier. While our experimental system is a simplification of natural microbial community, we argue that it constitutes proof of principle that the spatial models of population genetics can quantitatively capture organismal evolution.

Portable bacterial identification system based on elastic light scatter patterns.

PubMed

Bae, Euiwon; Ying, Dawei; Kramer, Donald; Patsekin, Valery; Rajwa, Bartek; Holdman, Cheryl; Sturgis, Jennifer; Davisson, V Jo; Robinson, J Paul

2012-08-28

Conventional diagnosis and identification of bacteria requires shipment of samples to a laboratory for genetic and biochemical analysis. This process can take days and imposes significant delay to action in situations where timely intervention can save lives and reduce associated costs. To enable faster response to an outbreak, a low-cost, small-footprint, portable microbial-identification instrument using forward scatterometry has been developed. This device, weighing 9 lb and measuring 12 × 6 × 10.5 in., utilizes elastic light scatter (ELS) patterns to accurately capture bacterial colony characteristics and delivers the classification results via wireless access. The overall system consists of two CCD cameras, one rotational and one translational stage, and a 635-nm laser diode. Various software algorithms such as Hough transform, 2-D geometric moments, and the traveling salesman problem (TSP) have been implemented to provide colony count and circularity, centering process, and minimized travel time among colonies. Experiments were conducted with four bacteria genera using pure and mixed plate and as proof of principle a field test was conducted in four different locations where the average classification rate ranged between 95 and 100%.

Recent worldwide expansion of Nosema ceranae (Microsporidia) in Apis mellifera populations inferred from multilocus patterns of genetic variation.

PubMed

Gómez-Moracho, T; Bartolomé, C; Bello, X; Martín-Hernández, R; Higes, M; Maside, X

2015-04-01

Nosema ceranae has been found infecting Apismellifera colonies with increasing frequency and it now represents a major threat to the health and long-term survival of these honeybees worldwide. However, so far little is known about the population genetics of this parasite. Here, we describe the patterns of genetic variation at three genomic loci in a collection of isolates from all over the world. Our main findings are: (i) the levels of genetic polymorphism (πS≈1%) do not vary significantly across its distribution range, (ii) there is substantial evidence for recombination among haplotypes, (iii) the best part of the observed genetic variance corresponds to differences within bee colonies (up to 88% of the total variance), (iv) parasites collected from Asian honeybees (Apis cerana and Apis florea) display significant differentiation from those obtained from Apismellifera (8-16% of the total variance, p<0.01) and (v) there is a significant excess of low frequency variants over neutral expectations among samples obtained from A. mellifera, but not from Asian honeybees. Overall these results are consistent with a recent colonization and rapid expansion of N. ceranae throughout A. mellifera colonies. Copyright © 2015 Elsevier B.V. All rights reserved.

Trends in the Breeding Population of Adélie Penguins in the Ross Sea, 1981–2012: A Coincidence of Climate and Resource Extraction Effects

PubMed Central

Lyver, Phil O’B.; Barron, Mandy; Barton, Kerry J.; Ainley, David G.; Pollard, Annie; Gordon, Shulamit; McNeill, Stephen; Ballard, Grant; Wilson, Peter R.

2014-01-01

Measurements of the size of Adélie penguin (Pygoscelis adeliae) colonies of the southern Ross Sea are among the longest biologic time series in the Antarctic. We present an assessment of recent annual variation and trends in abundance and growth rates of these colonies, adding to the published record not updated for more than two decades. High angle oblique aerial photographic surveys of colonies were acquired and penguins counted for the breeding seasons 1981–2012. In the last four years the numbers of Adélie penguins in the Ross and Beaufort Island colonies (southern Ross Sea metapopulation) reached their highest levels since aerial counts began in 1981. Results indicated that 855,625 pairs of Adélie penguins established breeding territories in the western Ross Sea, with just over a quarter (28%) of those in the southern portion, constituting a semi-isolated metapopulation (three colonies on Ross Island, one on nearby Beaufort Island). The southern population had a negative per capita growth rate of −0.019 during 1981–2000, followed by a positive per capita growth rate of 0.067 for 2001–2012. Colony growth rates for this metapopulation showed striking synchrony through time, indicating that large-scale factors influenced their annual growth. In contrast to the increased colony sizes in the southern population, the patterns of change among colonies of the northern Ross Sea were difficult to characterize. Trends were similar to southern colonies until the mid-1990s, after which the signal was lost owing to significantly reduced frequency of surveys. Both climate factors and recovery of whale populations likely played roles in the trends among southern colonies until 2000, after which depletion of another trophic competitor, the Antarctic toothfish (Dissostichus mawsoni), may explain the sharp increasing trend evident since then. PMID:24621601

Branched poly(ethyleneimine): a versatile scaffold for patterning polymer brushes by means of remote photocatalytic lithography

NASA Astrophysics Data System (ADS)

Panzarasa, Guido; Dübner, Matthias; Soliveri, Guido; Edler, Matthias; Griesser, Thomas

2017-09-01

Patterning of functional surfaces is one of the cornerstones of nanotechnology as it allows the fabrication of sensors and lab-on-a-chip devices. Here, the patterning of self-assembled monolayers of branched poly(ethyleneimine) (bPEI) on silica was achieved by means of remote photocatalytic lithography. Moreover, when 2-bromoisobutyryl-modified bPEI was used, the resulting pattern could be amplified by grafting polymer brushes by means of surface-initiated atom transfer radical polymerization. In contrast to previous reports for the patterning of bPEI, the present approach can be conducted in minutes instead of hours, reducing the exposure time to UV radiation and enhancing the overall efficiency. Furthermore, our approach is much more user-friendly, allowing a facile fabrication of patterned initiator-modified surfaces and the use of inexpensive instrumentation such as a low-power UV source and a simple photomask. Considering the versatility of bPEI as a scaffold for the development of biosensors, patterning by means of remote photocatalytic lithography will open new opportunities in a broad field of applications.

Streamflow, sediment-transport, and water-temperature characteristics of the three small watersheds in the Alsea River basin, Oregon

USGS Publications Warehouse

Harris, David Dell; Williams, Robert Charles

1971-01-01

Data collected during the prelogging period 1959-65 indicate an average annual runoff for Needle Branch and Deer and Flynn Creeks of 74.2, 75.1, and 77.7 inches, respectively. The measured precipitation at Flynn Creek of 92.9 inches was 5 inches less than at either Needle Branch or Deer Creek. Unit flood runoff during the prelogging period was found to be lowest on Flynn Creek and highest on Needle Branch. On Needle Branch, there appear to be two distinct low-flow patterns, one for a saturated and one for an unsaturated soil condition. The average annual sediment yield was highest on Flynn Creek, 321 tons per square mile, and lowest on Needle Branch, 166 tons per square mile. Maximum water temperatures were 62?F on Flynn Creek and 61?F on Needle Branch and Deer Creek.

Fenestration of axillary vein by a variant axillary artery.

PubMed

Hadimani, S; Desai, S D; Bagoji, I B; Patil, B S

2013-01-01

Variations of venous pattern in the arm are common. In this case report, we present a variation of axillary artery and vein. During routine educational dissections of axillary region, it was observed that a fenestrated axillary vein was perforated by a variant axillary artery in right arm of an old male cadaver. The axillary artery which was fenestrated through axillary vein had only two branches arising from its second part and no branches from its remaining distal parts. The branches are thoraco-acromial (usual) and another large collateral (unusual) branch. This collateral branch is the origin of several important arteries as the subscapular, circumflex scapular, posterior circumflex humeral and lateral thoracic arteries. We propose to name this artery as collateral axillary arterial trunk. The course of this collateral axillary arterial trunk and its branches and also clinical significance of this variation are discussed in the paper.

Honey bee success predicted by landscape composition in Ohio, USA.

PubMed

Sponsler, D B; Johnson, R M

2015-01-01

Foraging honey bees (Apis mellifera L.) can routinely travel as far as several kilometers from their hive in the process of collecting nectar and pollen from floral patches within the surrounding landscape. Since the availability of floral resources at the landscape scale is a function of landscape composition, apiculturists have long recognized that landscape composition is a critical determinant of honey bee colony success. Nevertheless, very few studies present quantitative data relating colony success metrics to local landscape composition. We employed a beekeeper survey in conjunction with GIS-based landscape analysis to model colony success as a function of landscape composition in the State of Ohio, USA, a region characterized by intensive cropland, urban development, deciduous forest, and grassland. We found that colony food accumulation and wax production were positively related to cropland and negatively related to forest and grassland, a pattern that may be driven by the abundance of dandelion and clovers in agricultural areas compared to forest or mature grassland. Colony food accumulation was also negatively correlated with urban land cover in sites dominated by urban and agricultural land use, which does not support the popular opinion that the urban environment is more favorable to honey bees than cropland.

Inoculation density and nutrient level determine the formation of mushroom-shaped structures in Pseudomonas aeruginosa biofilms

NASA Astrophysics Data System (ADS)

Ghanbari, Azadeh; Dehghany, Jaber; Schwebs, Timo; Müsken, Mathias; Häussler, Susanne; Meyer-Hermann, Michael

2016-09-01

Pseudomonas aeruginosa often colonises immunocompromised patients and the lungs of cystic fibrosis patients. It exhibits resistance to many antibiotics by forming biofilms, which makes it hard to eliminate. P. aeruginosa biofilms form mushroom-shaped structures under certain circumstances. Bacterial motility and the environment affect the eventual mushroom morphology. This study provides an agent-based model for the bacterial dynamics and interactions influencing bacterial biofilm shape. Cell motility in the model relies on recently published experimental data. Our simulations show colony formation by immotile cells. Motile cells escape from a single colony by nutrient chemotaxis and hence no mushroom shape develops. A high number density of non-motile colonies leads to migration of motile cells onto the top of the colonies and formation of mushroom-shaped structures. This model proposes that the formation of mushroom-shaped structures can be predicted by parameters at the time of bacteria inoculation. Depending on nutrient levels and the initial number density of stalks, mushroom-shaped structures only form in a restricted regime. This opens the possibility of early manipulation of spatial pattern formation in bacterial colonies, using environmental factors.

Inoculation density and nutrient level determine the formation of mushroom-shaped structures in Pseudomonas aeruginosa biofilms.

PubMed

Ghanbari, Azadeh; Dehghany, Jaber; Schwebs, Timo; Müsken, Mathias; Häussler, Susanne; Meyer-Hermann, Michael

2016-09-09

Pseudomonas aeruginosa often colonises immunocompromised patients and the lungs of cystic fibrosis patients. It exhibits resistance to many antibiotics by forming biofilms, which makes it hard to eliminate. P. aeruginosa biofilms form mushroom-shaped structures under certain circumstances. Bacterial motility and the environment affect the eventual mushroom morphology. This study provides an agent-based model for the bacterial dynamics and interactions influencing bacterial biofilm shape. Cell motility in the model relies on recently published experimental data. Our simulations show colony formation by immotile cells. Motile cells escape from a single colony by nutrient chemotaxis and hence no mushroom shape develops. A high number density of non-motile colonies leads to migration of motile cells onto the top of the colonies and formation of mushroom-shaped structures. This model proposes that the formation of mushroom-shaped structures can be predicted by parameters at the time of bacteria inoculation. Depending on nutrient levels and the initial number density of stalks, mushroom-shaped structures only form in a restricted regime. This opens the possibility of early manipulation of spatial pattern formation in bacterial colonies, using environmental factors.

A new device for monitoring individual activity rhythms of honey bees reveals critical effects of the social environment on behavior.

PubMed

Beer, Katharina; Steffan-Dewenter, Ingolf; Härtel, Stephan; Helfrich-Förster, Charlotte

2016-08-01

Chronobiological studies of individual activity rhythms in social insects can be constrained by the artificial isolation of individuals from their social context. We present a new experimental set-up that simultaneously measures the temperature rhythm in a queen-less but brood raising mini colony and the walking activity rhythms of singly kept honey bees that have indirect social contact with it. Our approach enables monitoring of individual bees in the social context of a mini colony under controlled laboratory conditions. In a pilot experiment, we show that social contact with the mini colony improves the survival of monitored young individuals and affects locomotor activity patterns of young and old bees. When exposed to conflicting Zeitgebers consisting of a light-dark (LD) cycle that is phase-delayed with respect to the mini colony rhythm, rhythms of young and old bees are socially synchronized with the mini colony rhythm, whereas isolated bees synchronize to the LD cycle. We conclude that the social environment is a stronger Zeitgeber than the LD cycle and that our new experimental set-up is well suited for studying the mechanisms of social entrainment in honey bees.

Abscisic acid signaling is controlled by a BRANCHED1/HD-ZIP I cascade in Arabidopsis axillary buds.

PubMed

González-Grandío, Eduardo; Pajoro, Alice; Franco-Zorrilla, José M; Tarancón, Carlos; Immink, Richard G H; Cubas, Pilar

2017-01-10

Shoot-branching patterns determine key aspects of plant life and are important targets for crop breeding. However, we are still largely ignorant of the genetic networks controlling locally the most important decision during branch development: whether the axillary bud, or branch primordium, grows out to give a lateral shoot or remains dormant. Here we show that, inside the buds, the TEOSINTE BRANCHED1, CYCLOIDEA, PCF (TCP) transcription factor BRANCHED1 (BRC1) binds to and positively regulates the transcription of three related Homeodomain leucine zipper protein (HD-ZIP)-encoding genes: HOMEOBOX PROTEIN 21 (HB21), HOMEOBOX PROTEIN 40 (HB40), and HOMEOBOX PROTEIN 53 (HB53). These three genes, together with BRC1, enhance 9-CIS-EPOXICAROTENOID DIOXIGENASE 3 (NCED3) expression, lead to abscisic acid accumulation, and trigger hormone response, thus causing suppression of bud development. This TCP/HD-ZIP genetic module seems to be conserved in dicot and monocotyledonous species to prevent branching under light-limiting conditions.

Fibrillatory conduction in branching atrial tissue--Insight from volumetric and monolayer computer models.

PubMed

Wieser, L; Fischer, G; Nowak, C N; Tilg, B

2007-05-01

Increased local load in branching atrial tissue (muscle fibers and bundle insertions) influences wave propagation during atrial fibrillation (AF). This computer model study reveals two principal phenomena: if the branching is distant from the driving rotor (>19 mm), the load causes local slowing of conduction or wavebreaks. If the driving rotor is close to the branching, the increased load causes first a slow drift of the rotor towards the branching. Finally, the rotor anchors, and a stable, repeatable pattern of activation can be observed. Variation of the bundle geometry from a cylindrical, volumetric structure to a flat strip of a comparable load in a monolayer model changed the local activation sequence in the proximity of the bundle. However, the global behavior and the basic effects are similar in all models. Wavebreaks in branching tissue contribute to the chaotic nature of AF (fibrillatory conduction). The stabilization (anchoring) of driving rotors by branching tissue might contribute to maintain sustained AF.

The morphology and classification of α ganglion cells in the rat retinae: a fractal analysis study.

PubMed

Jelinek, Herbert F; Ristanović, Dušan; Milošević, Nebojša T

2011-09-30

Rat retinal ganglion cells have been proposed to consist of a varying number of subtypes. Dendritic morphology is an essential aspect of classification and a necessary step toward understanding structure-function relationships of retinal ganglion cells. This study aimed at using a heuristic classification procedure in combination with the box-counting analysis to classify the alpha ganglion cells in the rat retinae based on the dendritic branching pattern and to investigate morphological changes with retinal eccentricity. The cells could be divided into two groups: cells with simple dendritic pattern (box dimension lower than 1.390) and cells with complex dendritic pattern (box dimension higher than 1.390) according to their dendritic branching pattern complexity. Both were further divided into two subtypes due to the stratification within the inner plexiform layer. In the present study we have shown that the alpha rat RCGs can be classified further by their dendritic branching complexity and thus extend those of previous reports that fractal analysis can be successfully used in neuronal classification, particularly that the fractal dimension represents a robust and sensitive tool for the classification of retinal ganglion cells. A hypothesis of possible functional significance of our classification scheme is also discussed. Copyright © 2011 Elsevier B.V. All rights reserved.

Use of artificial bee colonies algorithm as numerical approximation of differential equations solution

NASA Astrophysics Data System (ADS)

Fikri, Fariz Fahmi; Nuraini, Nuning

2018-03-01

The differential equation is one of the branches in mathematics which is closely related to human life problems. Some problems that occur in our life can be modeled into differential equations as well as systems of differential equations such as the Lotka-Volterra model and SIR model. Therefore, solving a problem of differential equations is very important. Some differential equations are difficult to solve, so numerical methods are needed to solve that problems. Some numerical methods for solving differential equations that have been widely used are Euler Method, Heun Method, Runge-Kutta and others. However, some of these methods still have some restrictions that cause the method cannot be used to solve more complex problems such as an evaluation interval that we cannot change freely. New methods are needed to improve that problems. One of the method that can be used is the artificial bees colony algorithm. This algorithm is one of metaheuristic algorithm method, which can come out from local search space and do exploration in solution search space so that will get better solution than other method.

Fucosylated chondroitin sulfate oligosaccharides exert anticoagulant activity by targeting at intrinsic tenase complex with low FXII activation: Importance of sulfation pattern and molecular size.

PubMed

Li, Junhui; Li, Shan; Yan, Lufeng; Ding, Tian; Linhardt, Robert J; Yu, Yanlei; Liu, Xinyue; Liu, Donghong; Ye, Xingqian; Chen, Shiguo

2017-10-20

Fucosylated chondroitin sulfates (fCSs) are structurally unusual glycosaminoglycans isolated from sea cucumbers that exhibit potent anticoagulant activity. These fCSs were isolated from sea cucumber, Isostichopus badionotus and Pearsonothuria graeffei. Fenton reaction followed by gel filtration chromatography afforded fCS oligosaccharides, with different sulfation patterns identified by mass and NMR spectroscopy, and these were used to clarify the relationship between the structures and the anticoagulant activities of fCSs. In vitro activities were measured by activated partial thromboplastin time (APTT), thrombin time (TT), thrombin and factor Xa inhibition, and activation of FXII. The results showed that free radicals preferentially acted on GlcA residues affording oligosaccharides that were purified from both fCSs. The inhibition of thrombin and factor X activities, mediated through antithrombin III and heparin cofactor II of fCSs oligosaccharides were affected by their molecular weight and fucose branches. Oligosaccharides with different sulfation patterns of the fucose branching had a similar ability to inhibit the FXa by the intrinsic factor Xase (factor IXa-VIIIa complex). Oligosaccharides with 2,4-O-sulfo fucose branches from fCS-Ib showed higher activities than ones with 3,4-O-disulfo branches obtained from fCS-Pg. Furthermore, a heptasaccharide is the minimum size oligosaccharide required for anticoagulation and FXII activation. This activity was absent for fCS oligosaccharides smaller than nonasaccharides. Molecular size and fucose branch sulfation are important for anticoagulant activity and reduction of size can reverse the activation of FXII caused by native fCSs. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Development, Regeneration, and Evolution of Feathers

PubMed Central

Chen, Chih-Feng; Foley, John; Tang, Pin-Chi; Li, Ang; Jiang, Ting Xin; Wu, Ping; Widelitz, Randall B.; Chuong, Cheng Ming

2017-01-01

The feather is a complex ectodermal organ with hierarchical branching patterns. It provides functions in endothermy, communication, and flight. Studies of feather growth, cycling, and health are of fundamental importance to avian biology and poultry science. In addition, feathers are an excellent model for morphogenesis studies because of their accessibility, and their distinct patterns can be used to assay the roles of specific molecular pathways. Here we review the progress in aspects of development, regeneration, and evolution during the past three decades. We cover the development of feather buds in chicken embryos, regenerative cycling of feather follicle stem cells, formation of barb branching patterns, emergence of intrafeather pigmentation patterns, interplay of hormones and feather growth, and the genetic identification of several feather variants. The discovery of feathered dinosaurs redefines the relationship between feathers and birds. Inspiration from biomaterials and flight research further fuels biomimetic potential of feathers as a multidisciplinary research focal point. PMID:25387232

Threshold effect with stochastic fluctuation in bacteria-colony-like proliferation dynamics as analyzed through a comparative study of reaction-diffusion equations and cellular automata

NASA Astrophysics Data System (ADS)

Odagiri, Kenta; Takatsuka, Kazuo

2009-02-01

We report a comparative study on pattern formation between the methods of cellular automata (CA) and reaction-diffusion equations (RD) applying to a morphology of bacterial colony formation. To do so, we began the study with setting an extremely simple model, which was designed to realize autocatalytic proliferation of bacteria (denoted as X ) fed with nutrition (N) and their inactive state (prespore state) P1 due to starvation: X+N→2X and X→P1 , respectively. It was found numerically that while the CA could successfully generate rich patterns ranging from the circular fat structure to the viscous-finger-like complicated one, the naive RD reproduced only the circular pattern but failed to give a finger structure. Augmenting the RD equations by adding two physical factors, (i) a threshold effect in the dynamics of X+N→2X (breaking the continuity limit of RD) and (ii) internal noise with onset threshold (breaking the inherent symmetry of RD), we have found that the viscous-finger-like realistic patterns are indeed recovered by thus modified RD. This highlights the important difference between CA and RD, and at the same time, clarifies the necessary factors for the complicated patterns to emerge in such a surprisingly simple model system.

Recurrent catheter-related infection caused by a single clone of Mycobacterium chelonae with two colonial morphotypes.

PubMed

Hsueh, P R; Teng, L J; Yang, P C; Chen, Y C; Ho, S W; Luh, K T

1998-05-01

We describe herein a recurrent catheter-related (Port-A-Cath; Smiths Industries Medical Systems [SIMS] Deltec, Inc., St. Paul, Minn.) infection caused by multidrug-resistant Mycobacterium chelonae with two colonial morphotypes in a 53-year-old woman with gastric adenocarcinoma. Four isolates recovered from this patient within a 3-month period were found to belong to a single clone on the basis of the isolates' identical antibiotypes as determined by the E test and their identical random amplified polymorphic DNA patterns.

Waddling on the Dark Side: Ambient Light Affects Attendance Behavior of Little Penguins.

PubMed

Rodríguez, Airam; Chiaradia, André; Wasiak, Paula; Renwick, Leanne; Dann, Peter

2016-04-01

Visible light on Earth largely comes from the sun, including light reflected from the moon. Predation risk is strongly determined by light conditions, and some animals are nocturnal to reduce predation. Artificial lights and its consequent light pollution may disrupt this natural behavior. Here, we used 13 years of attendance data to study the effects of sun, moon, and artificial light on the attendance pattern of a nocturnal seabird, the little penguin Eudyptula minor at Phillip Island, Australia. The little penguin is the smallest and the only penguin species whose activity on land is strictly nocturnal. Automated monitoring systems recorded individually marked penguins every time they arrived (after sunset) at or departed (before sunrise) from 2 colonies under different lighting conditions: natural night skylight and artificial lights (around 3 lux) used to enhance penguin viewing for ecotourism around sunset. Sunlight had a strong effect on attendance as penguins arrived on average around 81 min after sunset and departed around 92 min before sunrise. The effect of moonlight was also strong, varying according to moon phase. Fewer penguins came ashore during full moon nights. Moon phase effect was stronger on departure than arrival times. Thus, during nights between full moon and last quarter, arrival times (after sunset) were delayed, even though moonlight levels were low, while departure times (before sunrise) were earlier, coinciding with high moonlight levels. Cyclic patterns of moon effect were slightly out of phase but significantly between 2 colonies, which could be due to site-specific differences or presence/absence of artificial lights. Moonlight could be overridden by artificial light at our artificially lit colony, but the similar amplitude of attendance patterns between colonies suggests that artificial light did not mask the moonlight effect. Further research is indeed necessary to understand how seabirds respond to the increasing artificial night light levels. © 2016 The Author(s).

Focal high cell density generates a gradient of patterns in self-organizing vascular mesenchymal cells.

PubMed

Cheng, Henry; Reddy, Aneela; Sage, Andrew; Lu, Jinxiu; Garfinkel, Alan; Tintut, Yin; Demer, Linda L

2012-01-01

In embryogenesis, structural patterns, such as vascular branching, may form via a reaction-diffusion mechanism in which activator and inhibitor morphogens guide cells into periodic aggregates. We previously found that vascular mesenchymal cells (VMCs) spontaneously aggregate into nodular structures and that morphogen pairs regulate the aggregation into patterns of spots and stripes. To test the effect of a focal change in activator morphogen on VMC pattern formation, we created a focal zone of high cell density by plating a second VMC layer within a cloning ring over a confluent monolayer. After 24 h, the ring was removed and pattern formation monitored by phase-contrast microscopy. At days 2-8, the patterns progressed from uniform distributions to swirl, labyrinthine and spot patterns. Within the focal high-density zone (HDZ) and a narrow halo zone, cells aggregated into spot patterns, whilst in the outermost zone of the plate, cells formed a labyrinthine pattern. The area occupied by aggregates was significantly greater in the outermost zone than in the HDZ or halo. The rate of pattern progression within the HDZ increased as a function of its plating density. Thus, focal differences in cell density may drive pattern formation gradients in tissue architecture, such as vascular branching. Copyright © 2012 S. Karger AG, Basel.

Negative Feedback Enables Fast and Flexible Collective Decision-Making in Ants

PubMed Central

Grüter, Christoph; Schürch, Roger; Czaczkes, Tomer J.; Taylor, Keeley; Durance, Thomas; Jones, Sam M.; Ratnieks, Francis L. W.

2012-01-01

Positive feedback plays a major role in the emergence of many collective animal behaviours. In many ants pheromone trails recruit and direct nestmate foragers to food sources. The strong positive feedback caused by trail pheromones allows fast collective responses but can compromise flexibility. Previous laboratory experiments have shown that when the environment changes, colonies are often unable to reallocate their foragers to a more rewarding food source. Here we show both experimentally, using colonies of Lasius niger, and with an agent-based simulation model, that negative feedback caused by crowding at feeding sites allows ant colonies to maintain foraging flexibility even with strong recruitment to food sources. In a constant environment, negative feedback prevents the frequently found bias towards one feeder (symmetry breaking) and leads to equal distribution of foragers. In a changing environment, negative feedback allows a colony to quickly reallocate the majority of its foragers to a superior food patch that becomes available when foraging at an inferior patch is already well underway. The model confirms these experimental findings and shows that the ability of colonies to switch to a superior food source does not require the decay of trail pheromones. Our results help to resolve inconsistencies between collective foraging patterns seen in laboratory studies and observations in the wild, and show that the simultaneous action of negative and positive feedback is important for efficient foraging in mass-recruiting insect colonies. PMID:22984518

Estimating the density of honeybee colonies across their natural range to fill the gap in pollinator decline censuses.

PubMed

Jaffé, Rodolfo; Dietemann, Vincent; Allsopp, Mike H; Costa, Cecilia; Crewe, Robin M; Dall'olio, Raffaele; DE LA Rúa, Pilar; El-Niweiri, Mogbel A A; Fries, Ingemar; Kezic, Nikola; Meusel, Michael S; Paxton, Robert J; Shaibi, Taher; Stolle, Eckart; Moritz, Robin F A

2010-04-01

Although pollinator declines are a global biodiversity threat, the demography of the western honeybee (Apis mellifera) has not been considered by conservationists because it is biased by the activity of beekeepers. To fill this gap in pollinator decline censuses and to provide a broad picture of the current status of honeybees across their natural range, we used microsatellite genetic markers to estimate colony densities and genetic diversity at different locations in Europe, Africa, and central Asia that had different patterns of land use. Genetic diversity and colony densities were highest in South Africa and lowest in Northern Europe and were correlated with mean annual temperature. Confounding factors not related to climate, however, are also likely to influence genetic diversity and colony densities in honeybee populations. Land use showed a significantly negative influence over genetic diversity and the density of honeybee colonies over all sampling locations. In Europe honeybees sampled in nature reserves had genetic diversity and colony densities similar to those sampled in agricultural landscapes, which suggests that the former are not wild but may have come from managed hives. Other results also support this idea: putative wild bees were rare in our European samples, and the mean estimated density of honeybee colonies on the continent closely resembled the reported mean number of managed hives. Current densities of European honeybee populations are in the same range as those found in the adverse climatic conditions of the Kalahari and Saharan deserts, which suggests that beekeeping activities do not compensate for the loss of wild colonies. Our findings highlight the importance of reconsidering the conservation status of honeybees in Europe and of regarding beekeeping not only as a profitable business for producing honey, but also as an essential component of biodiversity conservation.

BEEHAVE: a systems model of honeybee colony dynamics and foraging to explore multifactorial causes of colony failure

PubMed Central

Becher, Matthias A; Grimm, Volker; Thorbek, Pernille; Horn, Juliane; Kennedy, Peter J; Osborne, Juliet L

2014-01-01

A notable increase in failure of managed European honeybee Apis mellifera L. colonies has been reported in various regions in recent years. Although the underlying causes remain unclear, it is likely that a combination of stressors act together, particularly varroa mites and other pathogens, forage availability and potentially pesticides. It is experimentally challenging to address causality at the colony scale when multiple factors interact. In silico experiments offer a fast and cost-effective way to begin to address these challenges and inform experiments. However, none of the published bee models combine colony dynamics with foraging patterns and varroa dynamics. We have developed a honeybee model, BEEHAVE, which integrates colony dynamics, population dynamics of the varroa mite, epidemiology of varroa-transmitted viruses and allows foragers in an agent-based foraging model to collect food from a representation of a spatially explicit landscape. We describe the model, which is freely available online (www.beehave-model.net). Extensive sensitivity analyses and tests illustrate the model's robustness and realism. Simulation experiments with various combinations of stressors demonstrate, in simplified landscape settings, the model's potential: predicting colony dynamics and potential losses with and without varroa mites under different foraging conditions and under pesticide application. We also show how mitigation measures can be tested. Synthesis and applications. BEEHAVE offers a valuable tool for researchers to design and focus field experiments, for regulators to explore the relative importance of stressors to devise management and policy advice and for beekeepers to understand and predict varroa dynamics and effects of management interventions. We expect that scientists and stakeholders will find a variety of applications for BEEHAVE, stimulating further model development and the possible inclusion of other stressors of potential importance to honeybee colony dynamics. PMID:25598549

BEEHAVE: a systems model of honeybee colony dynamics and foraging to explore multifactorial causes of colony failure.

PubMed

Becher, Matthias A; Grimm, Volker; Thorbek, Pernille; Horn, Juliane; Kennedy, Peter J; Osborne, Juliet L

2014-04-01

A notable increase in failure of managed European honeybee Apis mellifera L. colonies has been reported in various regions in recent years. Although the underlying causes remain unclear, it is likely that a combination of stressors act together, particularly varroa mites and other pathogens, forage availability and potentially pesticides. It is experimentally challenging to address causality at the colony scale when multiple factors interact. In silico experiments offer a fast and cost-effective way to begin to address these challenges and inform experiments. However, none of the published bee models combine colony dynamics with foraging patterns and varroa dynamics.We have developed a honeybee model, BEEHAVE, which integrates colony dynamics, population dynamics of the varroa mite, epidemiology of varroa-transmitted viruses and allows foragers in an agent-based foraging model to collect food from a representation of a spatially explicit landscape.We describe the model, which is freely available online (www.beehave-model.net). Extensive sensitivity analyses and tests illustrate the model's robustness and realism. Simulation experiments with various combinations of stressors demonstrate, in simplified landscape settings, the model's potential: predicting colony dynamics and potential losses with and without varroa mites under different foraging conditions and under pesticide application. We also show how mitigation measures can be tested. Synthesis and applications . BEEHAVE offers a valuable tool for researchers to design and focus field experiments, for regulators to explore the relative importance of stressors to devise management and policy advice and for beekeepers to understand and predict varroa dynamics and effects of management interventions. We expect that scientists and stakeholders will find a variety of applications for BEEHAVE, stimulating further model development and the possible inclusion of other stressors of potential importance to honeybee colony dynamics.

Multi-scale imaging and informatics pipeline for in situ pluripotent stem cell analysis.

PubMed

Gorman, Bryan R; Lu, Junjie; Baccei, Anna; Lowry, Nathan C; Purvis, Jeremy E; Mangoubi, Rami S; Lerou, Paul H

2014-01-01

Human pluripotent stem (hPS) cells are a potential source of cells for medical therapy and an ideal system to study fate decisions in early development. However, hPS cells cultured in vitro exhibit a high degree of heterogeneity, presenting an obstacle to clinical translation. hPS cells grow in spatially patterned colony structures, necessitating quantitative single-cell image analysis. We offer a tool for analyzing the spatial population context of hPS cells that integrates automated fluorescent microscopy with an analysis pipeline. It enables high-throughput detection of colonies at low resolution, with single-cellular and sub-cellular analysis at high resolutions, generating seamless in situ maps of single-cellular data organized by colony. We demonstrate the tool's utility by analyzing inter- and intra-colony heterogeneity of hPS cell cycle regulation and pluripotency marker expression. We measured the heterogeneity within individual colonies by analyzing cell cycle as a function of distance. Cells loosely associated with the outside of the colony are more likely to be in G1, reflecting a less pluripotent state, while cells within the first pluripotent layer are more likely to be in G2, possibly reflecting a G2/M block. Our multi-scale analysis tool groups colony regions into density classes, and cells belonging to those classes have distinct distributions of pluripotency markers and respond differently to DNA damage induction. Lastly, we demonstrate that our pipeline can robustly handle high-content, high-resolution single molecular mRNA FISH data by using novel image processing techniques. Overall, the imaging informatics pipeline presented offers a novel approach to the analysis of hPS cells that includes not only single cell features but also colony wide, and more generally, multi-scale spatial configuration.

Isolation and Characterization of Isogenic Pairs of Domed Hemolytic and Flat Nonhemolytic Colony Types of Bordetella pertussis

PubMed Central

Peppler, Mark S.

1982-01-01

Four different serotype strains of Bordetella pertussis, 3779BL2S4, Tohama I, 353/Z, and 2753, were plated on Bordet-Gengou agar, where they grew as domed, hemolytic (D+H+) wild-type colonies. Cloned D+H+ colony types of all four strains were passed onto modified Stainer-Scholte medium solidified with 1% Noble Agar. Colonies were selected from Stainer-Scholte agar, and these subsequently grew as flat, nonhemolytic (D−H−) colonies when transferred back onto Bordet-Gengou agar. The frequency of D−H− organisms within a population of cloned D+H+ was determined to be between 5 × 10−5 and 5 × 10−6. The D−H− colony types maintained their flat, nonhemolytic characteristics for over 80 single-colony passages on Bordet-Gengou agar. The isogenic pairs of D+H+ and D−H− colony types from the four strains were compared for hemagglutination titer, lymphocytosis-promoting activity, adenylate cyclase activity, and presence of agglutinogens by agglutination. In all cases the D−H− colony types showed reduced activities or amounts of antigen compared with their D+H+ parents. Freely diffusible antigens were markedly different between the two phenotypes as noted by double diffusion of antisera added to plates on which colonies of the variants were growing. Antigens solubilized from the two colony types by Triton X-100 were also markedly different as judged by radial immunodiffusion with antifimbrial hemagglutinin, antilymphocytosis-promoting factor, and anti-353/Z adsorbed with autoclaved 353/Z. In addition, autoradiographs of 125I-surface-labeled whole cells separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed unique banding patterns for each colony type. Since all organisms, regardless of colony type, were grown on Bordet-Gengou agar, the differences reported could not be due to medium composition. Differences between phenotypes were also independent of passage number on Bordet-Gengou agar. By analogy to previous studies, the D−H− organisms appear to fulfill the criteria for phase III or phase IV in the system of Leslie and Gardner (P. H. Leslie and A. D. Gardner, J. Hyg. 31:423-434, 1931) or phase III in the system of Kasuga et al. (T. Kasuga, Y. Nakase, K. Ukishima, and K. Takatsu, Kitasato Arch. Exp. Med. 26:121-134, 1954). Images PMID:6279517

Rabbit hepatic arterial anatomy variations: implications on experimental design.

PubMed

Tam, Alda L; Melancon, Marites P; Ensor, Joe; Liu, Yang; Dixon, Katherine; McWatters, Amanda; Gupta, Sanjay

2014-12-01

The VX2 rabbit model of liver cancer is commonly used to evaluate the efficacy of locoregional anticancer therapy and knowledge of the hepatic arterial anatomy in the rabbit is important for catheter-directed experiments. To describe the normal anatomy and anatomic variations of the celiac axis and hepatic artery in the rabbit. Angiograms of 222 rabbits were retrospectively reviewed. The branching pattern of the celiac axis was classified and the diameters of the major branches were measured. Paired t-tests were used to compare the difference between the average sizes of arteries. Variant celiac axis or hepatic artery anatomy was noted in 25.9% of angiograms, with the gastric branches arising from the proper hepatic artery in 23.3% of cases. The celiac axis could be successfully classified into one of five distinct branching patterns in 193 (86.9%) cases. The mean diameters of the right and left hepatic arteries were 0.67 mm (95% CI [0.64, 0.7]) and 1.25 mm (95% CI [1.19, 1.31]), respectively. The mean diameters of the medial and lateral branches of the left hepatic artery were 0.63 mm (95% CI [0.6, 0.67]) and 0.91 mm (95% CI [0.86, 0.96]), respectively. The right hepatic artery was significantly smaller than the left hepatic artery and the lateral branch of the left hepatic artery (all P values <0.0001). Arterial variants in the rabbit are not uncommon. The proper hepatic artery often gives origin to gastric artery branches. To facilitate superselective intra-arterial intervention, the left lateral lobe of the liver should be targeted for tumor implantation because of the significant size difference between the right and left hepatic arteries. © The Foundation Acta Radiologica 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Training Spiking Neural Models Using Artificial Bee Colony

PubMed Central

Vazquez, Roberto A.; Garro, Beatriz A.

2015-01-01

Spiking neurons are models designed to simulate, in a realistic manner, the behavior of biological neurons. Recently, it has been proven that this type of neurons can be applied to solve pattern recognition problems with great efficiency. However, the lack of learning strategies for training these models do not allow to use them in several pattern recognition problems. On the other hand, several bioinspired algorithms have been proposed in the last years for solving a broad range of optimization problems, including those related to the field of artificial neural networks (ANNs). Artificial bee colony (ABC) is a novel algorithm based on the behavior of bees in the task of exploring their environment to find a food source. In this paper, we describe how the ABC algorithm can be used as a learning strategy to train a spiking neuron aiming to solve pattern recognition problems. Finally, the proposed approach is tested on several pattern recognition problems. It is important to remark that to realize the powerfulness of this type of model only one neuron will be used. In addition, we analyze how the performance of these models is improved using this kind of learning strategy. PMID:25709644

Do Ants Need to Estimate the Geometrical Properties of Trail Bifurcations to Find an Efficient Route? A Swarm Robotics Test Bed

PubMed Central

Garnier, Simon; Combe, Maud; Jost, Christian; Theraulaz, Guy

2013-01-01

Interactions between individuals and the structure of their environment play a crucial role in shaping self-organized collective behaviors. Recent studies have shown that ants crossing asymmetrical bifurcations in a network of galleries tend to follow the branch that deviates the least from their incoming direction. At the collective level, the combination of this tendency and the pheromone-based recruitment results in a greater likelihood of selecting the shortest path between the colony's nest and a food source in a network containing asymmetrical bifurcations. It was not clear however what the origin of this behavioral bias is. Here we propose that it results from a simple interaction between the behavior of the ants and the geometry of the network, and that it does not require the ability to measure the angle of the bifurcation. We tested this hypothesis using groups of ant-like robots whose perceptual and cognitive abilities can be fully specified. We programmed them only to lay down and follow light trails, avoid obstacles and move according to a correlated random walk, but not to use more sophisticated orientation methods. We recorded the behavior of the robots in networks of galleries presenting either only symmetrical bifurcations or a combination of symmetrical and asymmetrical bifurcations. Individual robots displayed the same pattern of branch choice as individual ants when crossing a bifurcation, suggesting that ants do not actually measure the geometry of the bifurcations when travelling along a pheromone trail. Finally at the collective level, the group of robots was more likely to select one of the possible shorter paths between two designated areas when moving in an asymmetrical network, as observed in ants. This study reveals the importance of the shape of trail networks for foraging in ants and emphasizes the underestimated role of the geometrical properties of transportation networks in general. PMID:23555202

Exact coherent structures in an asymptotically reduced description of parallel shear flows

NASA Astrophysics Data System (ADS)

Beaume, Cédric; Knobloch, Edgar; Chini, Gregory P.; Julien, Keith

2015-02-01

A reduced description of shear flows motivated by the Reynolds number scaling of lower-branch exact coherent states in plane Couette flow (Wang J, Gibson J and Waleffe F 2007 Phys. Rev. Lett. 98 204501) is constructed. Exact time-independent nonlinear solutions of the reduced equations corresponding to both lower and upper branch states are found for a sinusoidal, body-forced shear flow. The lower branch solution is characterized by fluctuations that vary slowly along the critical layer while the upper branch solutions display a bimodal structure and are more strongly focused on the critical layer. The reduced equations provide a rational framework for investigations of subcritical spatiotemporal patterns in parallel shear flows.

Geodermatophilus, a New Genus of the Dermatophilaceae (Actinomycetales)

PubMed Central

Luedemann, George M.

1968-01-01

Organisms having a complex life cycle similar to the animal pathogen Dermatophilus congolensis have been isolated from soils of the United States. The soil isolates grow readily on agar media producing a black, friable, or sooty colony; in broth, the isolates produce a thick sediment with a clear supernatant fluid and occasionally a black surface pellicle. The generic taxon Geodermatophilus is proposed for these soil isolates. Geodermatophilus differs morphologically from Dermatophilus in thallus shape, ensheathment, and branching, and physiologically in respect to blood hemolysis, casein hydrolysis, carbohydrate utilization, acid production, and media requirements. The type species proposed is G. obscurus. Three subspecies are recognized. Images PMID:5726312

Universal scaling in the branching of the tree of life.

PubMed

Herrada, E Alejandro; Tessone, Claudio J; Klemm, Konstantin; Eguíluz, Víctor M; Hernández-García, Emilio; Duarte, Carlos M

2008-07-23

Understanding the patterns and processes of diversification of life in the planet is a key challenge of science. The Tree of Life represents such diversification processes through the evolutionary relationships among the different taxa, and can be extended down to intra-specific relationships. Here we examine the topological properties of a large set of interspecific and intraspecific phylogenies and show that the branching patterns follow allometric rules conserved across the different levels in the Tree of Life, all significantly departing from those expected from the standard null models. The finding of non-random universal patterns of phylogenetic differentiation suggests that similar evolutionary forces drive diversification across the broad range of scales, from macro-evolutionary to micro-evolutionary processes, shaping the diversity of life on the planet.

Three-dimensional reconstruction of prostate cancer architecture with serial immunohistochemical sections: hallmarks of tumour growth, tumour compartmentalisation, and implications for grading and heterogeneity.

PubMed

Tolkach, Yuri; Thomann, Stefan; Kristiansen, Glen

2018-05-01

Conventional morphology of prostate cancer considers only the two-dimensional (2D) architecture of the tumour. Our aim was to examine the feasibility of three-dimensional (3D) reconstruction of tumour morphology based on multiple consecutive histological sections and to decipher relevant features of prostate cancer architecture. Seventy-five consecutive histological sections (5 μm) of a typical prostate adenocarcinoma (Gleason score of 3 + 4 = 7) were immunostained (pan-cytokeratin) and scanned for further 3D reconstructions with fiji/imagej software. The main findings related to the prostate cancer architecture in this case were: (i) continuity of all glands, with the tumour being an integrated system, even in Gleason pattern 4 with poorly formed glands-no short-range migration of cells by Gleason pattern 4 (poorly formed glands); (ii) no repeated interconnections between the glands, with a tumour building a tree-like branched structure with very 'plastic' branches (maximal depth of investigation 375 μm); (iii) very stark compartmentalisation of the tumour related to extensive branching, the coexistence of independent terminal units of such branches in one 2D slice explaining intratumoral heterogeneity; (iv) evidence of a craniocaudal growth direction in interglandular regions of the prostate and for a lateromedial growth direction in subcapsular posterolateral regions; and (v) a 3D architecture-based description of Gleason pattern 4 with poorly formed glands, and its continuum with Gleason pattern 3. Consecutive histological sections provide high-quality material for 3D reconstructions of the tumour architecture, with excellent resolution. The reconstruction of multiple regions in this typical case of a Gleason score 3 + 4 = 7 tumour provides insights into relevant aspects of tumour growth, the continuity of Gleason patterns 3 and 4, and tumour heterogeneity. © 2018 John Wiley & Sons Ltd.

Seasonal patterns of reserve and soluble carbohydrates in mature sugar maple (Acer saccharum)

Treesearch

B.L. Wong; K.L. Baggett; A.H. Rye

2003-01-01

Sugar maple (Acer saccharum Marsh.) trees exhibit seasonal patterns of production, accumulation, and utilization of nonstructural carbohydrates that are closely correlated with phenological events and (or) physiological processes. The simultaneous seasonal patterns of both reserve and soluble carbohydrates in the leaves, twigs, branches, and trunks of healthy mature...

Hyperinnervation improves Xenopus laevis limb regeneration.

PubMed

Mitogawa, Kazumasa; Makanae, Aki; Satoh, Akira

2018-01-15

Xenopus laevis (an anuran amphibian) shows limb regeneration ability between that of urodele amphibians and that of amniotes. Xenopus frogs can initiate limb regeneration but fail to form patterned limbs. Regenerated limbs mainly consist of cone-shaped cartilage without any joints or branches. These pattern defects are thought to be caused by loss of proper expressions of patterning-related genes. This study shows that hyperinnervation surgery resulted in the induction of a branching regenerate. The hyperinnervated blastema allows the identification and functional analysis of the molecules controlling this patterning of limb regeneration. This paper focuses on the nerve affects to improve Xenopus limb patterning ability during regeneration. The nerve molecules, which regulate limb patterning, were also investigated. Blastemas grown in a hyperinnervated forelimb upregulate limb patterning-related genes (shh, lmx1b, and hoxa13). Nerves projecting their axons to limbs express some growth factors (bmp7, fgf2, fgf8, and shh). Inputs of these factors to a blastema upregulated some limb patterning-related genes and resulted in changes in the cartilage patterns in the regenerates. These results indicate that additional nerve factors enhance Xenopus limb patterning-related gene expressions and limb regeneration ability, and that bmp, fgf, and shh are candidate nerve substitute factors. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Trematodes with a reproductive division of labour: heterophyids also have a soldier caste and early infections reveal how colonies become structured.

PubMed

Garcia-Vedrenne, Ana E; Quintana, Anastasia C E; DeRogatis, Andrea M; Dover, Christina M; Lopez, Maribel; Kuris, Armand M; Hechinger, Ryan F

2017-01-01

Recent findings have extended the documentation of complex sociality to the Platyhelminthes, describing the existence of a reproductive division of labour involving a soldier caste among the parthenitae of trematode parasites. However, all species examined to date occupy high positions in trematode interspecific dominance hierarchies and belong to two closely related families, the Echinostomatidae and the Philophthalmidae (Superfamily Echinostomatoidea). Further, the two species documented as lacking soldiers also belong to the Echinostomatidae. Here, we examine four species of intermediate dominance, all belonging to the family Heterophyidae (Superfamily Opisthorchioidea): Euhaplorchis californiensis, Phocitremoides ovale, Pygidiopsoides spindalis and Stictodora hancocki, all of which infect the California horn snail, Cerithideopsis californica (=Cerithidea californica). We quantify morphology, distribution and behaviour of rediae from fully developed colonies. We also provide information on colony structure for three developing heterophyid colonies to better understand colony development. We discuss the implications of our findings, particularly with respect to how they suggest alternatives to the conclusions of other researchers concerning the nature of trematode sociality. Our analyses of morphological, distributional and behavioural patterns of developed colonies indicate that these heterophyid trematodes have a non-reproductive caste whose function is defence of the colony from invading trematodes. Hence, a soldier caste occurs for species lower in dominance hierarchies than previously known, and is present in at least two superfamilies of digenean trematodes, suggesting that selection for a soldier caste may be much more common among the Trematoda than previously recognised. Copyright © 2016 Australian Society for Parasitology. Published by Elsevier Ltd. All rights reserved.

Epithelial-mesenchymal transition in colonies of rhesus monkey embryonic stem cells: a model for processes involved in gastrulation.

PubMed

Behr, Rüdiger; Heneweer, Carola; Viebahn, Christoph; Denker, Hans-Werner; Thie, Michael

2005-01-01

Rhesus monkey embryonic stem (rhES) cells were grown on mouse embryonic fibroblast (MEF) feeder layers for up to 10 days to form multilayered colonies. Within this period, stem cell colonies differentiated transiently into complex structures with a disc-like morphology. These complex colonies were characterized by morphology, immunohistochemistry, and marker mRNA expression to identify processes of epithelialization as well as epithelial-mesenchymal transition (EMT) and pattern formation. Typically, differentiated colonies were comprised of an upper and a lower ES cell layer, the former growing on top of the layer of MEF cells whereas the lower ES cell layer spread out underneath the MEF cells. Interestingly, in the central part of the colonies, a roundish pit developed. Here the feeder layer disappeared, and upper layer cells seemed to ingress and migrate through the pit downward to form the lower layer while undergoing a transition from the epithelial to the mesenchymal phenotype, which was indicated by the loss of the marker proteins E-cadherin and ZO-1 in the lower layer. In support of this, we found a concomitant 10-fold upregulation of the gene Snail2, which is a key regulator of the EMT process. Conversion of epiblast to mesoderm was also indicated by the regulated expression of the mesoderm marker Brachyury. An EMT is a characteristic process of vertebrate gastrulation. Thus, these rhES cell colonies may be an interesting model for studies on some basic processes involved in early primate embryogenesis and may open new ways to study the regulation of EMT in vitro.

Murre eggs (Uria aalge and Uria lomvia) as indicators of mercury contamination in the Alaskan marine environment

USGS Publications Warehouse

Day, Russel D.; Vander Pol, Stacy S.; Christopher, Steven J.; Davis, W.C.; Pugh, Rebecca S.; Simac, K.S.; Roseneau, David G.; Becker, P.R.

2006-01-01

Sixty common murre (Uria aalge) and 27 thick-billed murre (Uria lomvia) eggs collected by the Seabird Tissue Archival and Monitoring Project (STAMP) in 1999−2001 from two Gulf of Alaska and three Bering Sea nesting colonies were analyzed for total mercury (Hg) using isotope dilution cold vapor inductively coupled mass spectrometry. Hg concentrations (wet mass) ranged from 0.011 μg/g to 0.357 μg/g (relative standard deviation = 76%), while conspecifics from the same colonies and years had an average relative standard deviation of 33%. Hg levels in eggs from the Gulf of Alaska (0.166 μg/g ± 0.011 μg/g) were significantly higher (p < 0.0001) than in the Bering Sea (0.047 μg/g ± 0.004 μg/g). Within the Bering Sea, Hg was significantly higher (p = 0.0007) in eggs from Little Diomede Island near the arctic than at the two more southern colonies. Although thick-billed and common murres are ecologically similar, there were significant species differences in egg Hg concentrations within each region (p < 0.0001). In the Bering Sea, eggs from thick-billed murres had higher Hg concentrations than eggs from common murres, while in the Gulf of Alaska, common murre eggs had higher concentrations than those of thick-billed murres. A separate one-way analysis of variance on the only time−trend data currently available for a colony (St. Lazaria Island in the Gulf of Alaska) found significantly lower Hg concentrations in common murre eggs collected in 2001 compared to 1999 (p = 0.017). Results from this study indicate that murre eggs may be effective monitoring units for detecting geographic, species, and temporal patterns of Hg contamination in marine food webs. The relatively small intracolony variation in egg Hg levels and the ability to consistently obtain adequate sample sizes both within and among colonies over a large geographic range means that monitoring efforts using murre eggs will have suitable statistical power for detecting environmental patterns of Hg contamination. The potential influences of trophic effects, physical transport patterns, and biogeochemical processes on these monitoring efforts are discussed, and future plans to investigate the sources of the observed variability are presented.

Anatomic Variation in Intrahepatic Bile Ducts: an Analysis of Intraoperative Cholangiograms in 300 Consecutive Donors for Living Donor Liver Transplantation

PubMed Central

Choi, Jin Woo; Kim, Kyoung Won; Kim, Ah Young; Kim, Pyo Nyun; Ha, Hyun Kwon; Lee, Moon-Gyu

2003-01-01

Objective To describe the anatomical variation occurring in intrahepatic bile ducts (IHDs) in terms of their branching patterns, and to determine the frequency of each variation. Materials and Methods The study group consisted of 300 consecutive donors for liver transplantation who underwent intraoperative cholangiography. Anatomical variation in IHDs was classified according to the branching pattern of the right anterior and right posterior segmental duct (RASD and RPSD, respectively), and the presence or absence of the first-order branch of the left hepatic duct (LHD), and of an accessory hepatic duct. Results The anatomy of the intrahepatic bile ducts was typical in 63% of cases (n=188), showed triple confluence in 10% (n=29), anomalous drainage of the RPSD into the LHD in 11% (n=34), anomalous drainage of the RPSD into the common hepatic duct (CHD) in 6% (n=19), anomalous drainage of the RPSD into the cystic duct in 2% (n=6), drainage of the right hepatic duct (RHD) into the cystic duct (n=1), the presence of an accessory duct leading to the CHD or RHD in 5% (n=16), individual drainage of the LHD into the RHD or CHD in 1% (n=4), and unclassified or complex variation in 1% (n=3). Conclusion The branching pattern of IHDs was atypical in 37% of cases. The two most common variations were drainage of the RPSD into the LHD (11%) and triple confluence of the RASD, RPSD and LHD (10%). PMID:12845303

Anatomic variations in intrahepatic bile ducts in a north Indian population.

PubMed

Sharma, Vijay; Saraswat, Vivek Anand; Baijal, Sanjay Saran; Choudhuri, Gourdas

2008-07-01

In the present study, we described the anatomical variations in the branching patterns of intrahepatic bile ducts (IHD) and determined the frequency of each variation in north Indian patients. There are no data from India. The study group consisted of 253 consecutive patients (131 women) undergoing endoscopic retrograde cholangiograms for different indications. Anatomical variations in IHD were classified according to the branching pattern of the right anterior segmental duct (RASD) and the right posterior segmental duct (RPSD), presence or absence of first-order branch of left hepatic duct (LHD) and of an accessory hepatic duct. Anatomy of the IHD was typical in 52.9% of cases (n = 134), showing triple confluence in 11.46% (n = 29), anomalous drainage of the RPSD into the LHD in 18.2% (n = 46), anomalous drainage of the RPSD into the common hepatic duct (CHD) in 7.1% (n = 18), drainage of the right hepatic duct (RHD) into the cystic duct 0.4% (n = 1), presence of an accessory duct leading to the CHD or RHD in 4.7% (n = 12), individual drainage of the LHD into the RHD or CHD in 2.4% (n = 6), and unclassified or complex variations in 2.7% (n = 7). None had anomalous drainage of RPSD into the cystic duct. The branching pattern of IHD was atypical in 47% patients. The two most common variations were drainage of the RPSD into the LHD (18.2%) and triple confluence of the RASD, RPSD, and LHD (11.5%).

Branching patterns of root systems: quantitative analysis of the diversity among dicotyledonous species

PubMed Central

Pagès, Loïc

2014-01-01

Background and Aims Root branching, and in particular acropetal branching, is a common and important developmental process for increasing the number of growing tips and defining the distribution of their meristem size. This study presents a new method for characterizing the results of this process in natura from scanned images of young, branched parts of excavated roots. The method involves the direct measurement or calculation of seven different traits. Methods Young plants of 45 species of dicots were sampled from fields and gardens with uniform soils. Roots were separated, scanned and then measured using ImageJ software to determine seven traits related to root diameter and interbranch distance. Results The traits exhibited large interspecific variations, and covariations reflecting trade-offs. For example, at the interspecies level, the spacing of lateral roots (interbranch distance along the parent root) was strongly correlated to the diameter of the finest roots found in the species, and showed a continuum between two opposite strategies: making dense and fine lateral roots, or thick and well-spaced laterals. Conclusions A simple method is presented for classification of branching patterns in roots that allows relatively quick sampling and measurements to be undertaken. The feasibilty of the method is demonstrated for dicotyledonous species and it has the potential to be developed more broadly for other species and a wider range of enivironmental conditions. PMID:25062886

Post-breeding movements of Ancient Murrelet Synthliboramphus antiquus family groups, subsequent migration of adults and implications for management.

PubMed

Gaston, Anthony J; Hashimoto, Yuriko; Wilson, Laurie

2017-01-01

Increased shipping in British Columbia (BC) waters poses risks for marine birds from marine oil spills. Ancient Murrelets (Synthliboramphus antiquus), small marine diving birds of which half of the world's population breeds in BC, are especially susceptible to oiling immediately after departing from their breeding colonies, as their offspring are flightless, constraining their parents to remain with them. In 2014 we deployed geolocator loggers on Ancient Murrelets at four breeding colonies, two on the east and two on the west coast of Haida Gwaii to investigate patterns of post-breeding dispersal and subsequent migratory movements. Birds from east coast colonies moved south and east after leaving their colonies, remaining in Queen Charlotte Sound and adjacent waters for 4-6 weeks, whereas those from west coast colonies moved steadily north and west, so that they left BC waters earlier than those from east coast colonies. These movements were consistent with being driven by surface currents. In June, all birds moved rapidly to the eastern Aleutians, SE Bering Sea, and waters off Kamchatka, where they probably moulted. In August, most moved north, some passing through Bering Straits into the Chukchi Sea. In October-November some birds returned to waters off western N America (33%) and the remainder carried on westwards to waters off Japan, Korea and NE China. For the former group the movement to the Bering Sea in June constituted a moult migration and, as such, is the first described for an auk. Those birds wintering in Asia began moving east in February and arrived off BC in March, when observations at colonies show that burrow visits begin in Haida Gwaii. Our data suggest that, immediately after colony departure, birds from the east coast colonies (about half the population of Haida Gwaii) are at higher risk from potential oil spills in northern British Columbia waters than those breeding on the west coast.

Environmental correlates of temporary emigration for female Weddell seals and consequences for recruitment

USGS Publications Warehouse

Stauffer, Glenn E.; Rotella, Jay J.; Garrott, Robert A.; Kendall, William L.

2014-01-01

In colonial-breeding species, prebreeders often emigrate temporarily from natal reproductive colonies then subsequently return for one or more years before producing young. Variation in attendance–nonattendance patterns can have implications for subsequent recruitment. We used open robust-design multistate models and 28 years of encounter data for prebreeding female Weddell seals (Leptonychotes weddellii [Lesson]) to evaluate hypotheses about (1) the relationships of temporary emigration (TE) probabilities to environmental and population size covariates and (2) motivations for attendance and consequences of nonattendance for subsequent probability of recruitment to the breeding population. TE probabilities were density dependent (βˆBPOP = 0.66,  = 0.17; estimated effects [β] and standard errors of population size in the previous year) and increased when the fast-ice edge was distant from the breeding colonies (βˆDIST = 0.75,  = 0.04; estimated effects and standard errors of distance to the sea-ice edge in the current year on TE probability in the current year) and were strongly age and state dependent. These results suggest that trade-offs between potential benefits and costs of colony attendance vary annually and might influence motivation to attend colonies. Recruitment probabilities were greatest for seals that consistently attended colonies in two or more years (e.g.,  = 0.56, SD = 0.17) and lowest for seals that never or inconsistently attended prior to recruitment (e.g.,  = 0.32, SD = 0.15), where denotes the mean recruitment probability (over all years) for 10-year-old seals for the specified prebreeder state. In colonial-breeding seabirds, repeated colony attendance increases subsequent probability of recruitment to the adult breeding population; our results suggest similar implications for a marine mammal and are consistent with the hypothesis that prebreeders were motivated to attend reproductive colonies to gain reproductive skills or perhaps to optimally synchronize estrus through close association with mature breeding females.

Hematological Analysis of the Ascidian Botrylloides leachii (Savigny, 1816) During Whole-Body Regeneration.

PubMed

Blanchoud, Simon; Zondag, Lisa; Lamare, Miles D; Wilson, Megan J

2017-06-01

Whole-body regeneration (WBR)-the formation of an entire adult from only a small fragment of its own tissue-is extremely rare among chordates. Exceptionally, in the colonial ascidian Botrylloides leachii (Savigny, 1816) a fully functional adult is formed from their common vascular system after ablation of all adults from the colony in just 10 d, thanks to their high blastogenetic potential. While previous studies have identified key genetic markers and morphological changes, no study has yet focused on the hematological aspects of regeneration despite the major involvement of the remaining vascular system and the contained hemocytes in this process. To dissect this process, we analyzed colony blood flow patterns using time-lapse microscopy to obtain a quantitative description of the velocity, reversal pattern, and average distance traveled by hemocytes. We also observed that flows present during regeneration are powered by temporally and spatially synchronized contractions of the terminal ampullae. In addition, we revised previous studies of B. leachii hematology as well as asexual development using histological sectioning and compared the role played by hemocytes during WBR. We found that regeneration starts with a rapid healing response characterized by hemocyte aggregation and infiltration of immunocytes, followed by increased activity of hemoblasts, recruitment of macrophage-like cells for clearing the tissues of debris, and their subsequent disappearance from the circulation concomitant with the maturation of a single regenerated adult. Overall, we provide a detailed account of the hematological properties of regenerating B. leachii colonies, providing novel lines of inquiry toward the decipherment of regeneration in chordates.

Microbial biomass, community structure and metal tolerance of a naturally Pb-enriched forest soil.

PubMed

Bååth, E; Díaz-Raviña, M; Bakken, L R

2005-11-01

The effect of long-term elevated soil Pb levels on soil microbiota was studied at a forest site in Norway, where the soil has been severely contaminated with Pb since the last period of glaciation (several thousand years). Up to 10% Pb (total amount, w/w) has been found in the top layer. The microbial community was drastically affected, as judged from changes in the phospholipid fatty acid (PLFA) pattern. Specific PLFAs that were high in Pb-enriched soil were branched (especially br17:0 and br18:0), whereas PLFAs common in eukaryotic organisms such as fungi (18:2omega6,9 and 20:4) were low compared with levels at adjacent, uncontaminated sites. Congruent changes in the PLFA pattern were found upon analyzing the culturable part of the bacterial community. The high Pb concentrations in the soil resulted in increased tolerance to Pb of the bacterial community, measured using both thymidine incorporation and plate counts. Furthermore, changes in tolerance were correlated to changes in the community structure. The bacterial community of the most contaminated soils showed higher specific activity (thymidine and leucine incorporation rates) and higher culturability than that of control soils. Fungal colony forming units (CFUs) were 10 times lower in the most Pb-enriched soils, the species composition was widely different from that in control soils, and the isolated fungi had high Pb tolerance. The most commonly isolated fungus in Pb-enriched soils was Tolypocladium inflatum. Comparison of isolates from Pb-enriched soil and isolates from unpolluted soils showed that T. inflatum was intrinsically Pb-tolerant, and that the prolonged conditions with high Pb had not selected for any increased tolerance.

Behavioral Patterns of Women Who Employ Their Leisure Time in Sports Activities: An Application of the Football Branch

ERIC Educational Resources Information Center

Eroglu, Yeser; Özsoy, Selami

2017-01-01

This study is conducted to reveal the role of gender in attending leisure time activities and to determine gender perceptions about sports branches. For this purpose, an application was performed with the participation of 7 female students from Abant Izzet Baysal University School of Physical Education and Sport. For 8 weeks, volunteer…

An annual pattern of native embolism in upper branches of four tall conifer species

Treesearch

Katherine A. McCulloh; Daniel M. Johnson; Frederick C. Meinzer; Barbara Lachenbruch

2011-01-01

The Pacific Northwest of North America experiences relatively mild winters and dry summers. For the tall coniferous trees that grow in this region, we predicted that loss in the hydraulic conductivity of uppermost branches would be avoided because of difficulty reversing accumulated emboli in xylem that is always under negative pressure. To test this hypothesis, we...

Neurovascular patterning cues and implications for central and peripheral neurological disease

PubMed Central

Gamboa, Nicholas T.; Taussky, Philipp; Park, Min S.; Couldwell, William T.; Mahan, Mark A.; Kalani, M. Yashar S.

2017-01-01

The highly branched nervous and vascular systems run along parallel trajectories throughout the human body. This stereotyped pattern of branching shared by the nervous and vascular systems stems from a common reliance on specific cues critical to both neurogenesis and angiogenesis. Continually emerging evidence supports the notion of later-evolving vascular networks co-opting neural molecular mechanisms to ensure close proximity and adequate delivery of oxygen and nutrients to nervous tissue. As our understanding of these biologic pathways and their phenotypic manifestations continues to advance, identification of where pathways go awry will provide critical insight into central and peripheral nervous system pathology. PMID:28966815

Nerve supply of the subscapularis during anterior shoulder surgery: definition of a potential risk area.

PubMed

Leschinger, Tim; Hackl, Michael; Zeifang, Felix; Scaal, Martin; Müller, Lars Peter; Wegmann, Kilian

2017-01-01

The purpose of the study was to evaluate the position of the subscapular nerves relative to surgical landmarks during exposure and to analyze the pattern of innervation of the subscapularis to avoid injury during anterior shoulder surgery. 20 embalmed human cadaveric shoulder specimens were used in the study. The muscular insertions of the subscapular nerves were marked and their closest branches to the musculotendinous junction and the coracoid process were measured in horizontal and vertical distances. In addition, the innervation pattern of each specimen was documented. 14/20 specimens showed an innervation of the subscapularis with an upper, middle and lower subscapular nerve branch. Even though the nerve branches were in average more than 2 cm medial to the musculotendinous junction, minimal distances of 1.1-1.3 cm were found. The mean vertical distance as measured from the medial base of the coracoid to the nerve innervation point into the muscle was 0.7 cm for the upper nerve branch, 2.2 cm for the middle nerve branch and 4.4 cm for the lower nerve branch. The subscapularis has a variable nerve supply, which increases the risk of muscle denervation during open shoulder surgery. Dissection or release should be avoided at the anterior aspect of the subscapularis muscle more than 1 cm medial to the musculotendinous junction. In approaches with a horizontal incision of the subscapularis, splitting should be performed at a vertical distance of 3.2-3.6 cm to the coracoid base to avoid iatrogenic subscapular nerve injuries.

Genetic structure of brown pelicans (Pelecanus occidentalis) in the northern Gulf of Mexico in the context of human management and disturbance

PubMed Central

Longest, Susan M.; Ottewell, Kym; Lantz, Samantha M.; Walter, Scott T.

2017-01-01

Environmental disturbances, both natural and anthropogenic, have the capacity to substantially impact animal behavior and abundance, which can in turn influence patterns of genetic diversity and gene flow. However, little empirical information is available on the nature and degree of such changes due to the relative rarity of longitudinal genetic sampling of wild populations at appropriate intervals. Addressing this knowledge gap is therefore of interest to evolutionary biologists, policy makers, and managers. In the past half century, populations of the brown pelican (Pelecanus occidentalis) in the southeastern United States have been exposed to regional extirpations, translocations, colony losses, and oil spills, but potential impacts on genetic diversity and population structure remain unknown. To investigate the cumulative impacts of recent disturbances and management actions, we analyzed seven microsatellite loci using genetic samples collected from 540 nestlings across twelve pelican colonies from two time periods, corresponding to before (n = 305) and after (n = 235) the 2010 Deepwater Horizon oil spill. Pre-2010 populations in Texas were significantly differentiated from Louisiana, Alabama, and Florida populations to the east, with reintroduced populations in southeastern Louisiana having less genetic diversity than sites in Texas, consistent with a recent bottleneck. In contrast, there was no evidence of a geographic component to genetic structure among colonies sampled after the spill, consistent with increased dispersal among sites following the event. This pattern may be associated with reduced philopatry in response to colony abandonment in the areas most heavily impacted by the Deepwater Horizon event, though other factors (e.g., rehabilitation and translocation of oiled birds or colony loss due to erosion and tropical storms) were likely also involved. Future monitoring is necessary to determine if bottlenecks and loss of genetic variation are associated with the oil spill over time, and is recommended for other systems in which disturbance effects may be inferred via repeated genetic sampling. PMID:28977003

Genetic structure of brown pelicans (Pelecanus occidentalis) in the northern Gulf of Mexico in the context of human management and disturbance.

PubMed

Geary, Brock; Longest, Susan M; Ottewell, Kym; Lantz, Samantha M; Walter, Scott T; Karubian, Jordan; Leberg, Paul L

2017-01-01

Environmental disturbances, both natural and anthropogenic, have the capacity to substantially impact animal behavior and abundance, which can in turn influence patterns of genetic diversity and gene flow. However, little empirical information is available on the nature and degree of such changes due to the relative rarity of longitudinal genetic sampling of wild populations at appropriate intervals. Addressing this knowledge gap is therefore of interest to evolutionary biologists, policy makers, and managers. In the past half century, populations of the brown pelican (Pelecanus occidentalis) in the southeastern United States have been exposed to regional extirpations, translocations, colony losses, and oil spills, but potential impacts on genetic diversity and population structure remain unknown. To investigate the cumulative impacts of recent disturbances and management actions, we analyzed seven microsatellite loci using genetic samples collected from 540 nestlings across twelve pelican colonies from two time periods, corresponding to before (n = 305) and after (n = 235) the 2010 Deepwater Horizon oil spill. Pre-2010 populations in Texas were significantly differentiated from Louisiana, Alabama, and Florida populations to the east, with reintroduced populations in southeastern Louisiana having less genetic diversity than sites in Texas, consistent with a recent bottleneck. In contrast, there was no evidence of a geographic component to genetic structure among colonies sampled after the spill, consistent with increased dispersal among sites following the event. This pattern may be associated with reduced philopatry in response to colony abandonment in the areas most heavily impacted by the Deepwater Horizon event, though other factors (e.g., rehabilitation and translocation of oiled birds or colony loss due to erosion and tropical storms) were likely also involved. Future monitoring is necessary to determine if bottlenecks and loss of genetic variation are associated with the oil spill over time, and is recommended for other systems in which disturbance effects may be inferred via repeated genetic sampling.

The Home Network: Identity and Materiality in Early Modern and Modern Ulster

NASA Astrophysics Data System (ADS)

Whalen, Kathryn M.

This dissertation looks at three categories of ceramics and the creation of a hybrid culture during the Early Modern and Modern period in Ireland. During these time periods Ireland was a part of the English global colonial enterprises, and was the site of many legal and cultural changes due to its subordinate position in the hierarchy of socio-political and economic phenomenon that characterize the pinnacle of British global power. This study looks to understand how these powers articulated with England's one European colony, Ireland, and if that articulation has similarities to other colonial cultures across time and space. To study the possibility of hybridity between the Irish and English inhabitants of Ireland during the Post-Medieval Period, three categories of ceramics have been analyzed. Fine earthenwares in the form of tablewares and tea sets were macroscopically analyzed for patterns, age, and place of origin. Coarse earthenwares were subjected to X-ray florescence to look for patterns in the spectral data to see if a point of origin could be ascribed to them. And lastly, white ball clay pipe fragments were both macroscopically analyzed for makers' marks and subjected to X-ray florescence to verify their point of origin. The relationship between where these artifacts come from- if they are local productions or imports- and where they were disposed of- either across the landscaper or only associated with households of particular ethnicities- says something about how people negotiate their ethnic identities in colonial settings. As people in Ireland adopt the English style of tea drinking and start to use English mass-produced fine earthenwares, it disrupts the local cottage industry of coarse earthenware manufacturing. What this study seeks to know is if there is a difference in the adoption of English tea drinking, and if the purchasing of certain types of ceramic vessels contributes to the performance of ethnic identity in a colonial setting.

Association mapping in sunflower (Helianthus annuus L.) reveals independent control of apical vs. basal branching.

PubMed

Nambeesan, Savithri U; Mandel, Jennifer R; Bowers, John E; Marek, Laura F; Ebert, Daniel; Corbi, Jonathan; Rieseberg, Loren H; Knapp, Steven J; Burke, John M

2015-03-11

Shoot branching is an important determinant of plant architecture and influences various aspects of growth and development. Selection on branching has also played an important role in the domestication of crop plants, including sunflower (Helianthus annuus L.). Here, we describe an investigation of the genetic basis of variation in branching in sunflower via association mapping in a diverse collection of cultivated sunflower lines. Detailed phenotypic analyses revealed extensive variation in the extent and type of branching within the focal population. After correcting for population structure and kinship, association analyses were performed using a genome-wide collection of SNPs to identify genomic regions that influence a variety of branching-related traits. This work resulted in the identification of multiple previously unidentified genomic regions that contribute to variation in branching. Genomic regions that were associated with apical and mid-apical branching were generally distinct from those associated with basal and mid-basal branching. Homologs of known branching genes from other study systems (i.e., Arabidopsis, rice, pea, and petunia) were also identified from the draft assembly of the sunflower genome and their map positions were compared to those of associations identified herein. Numerous candidate branching genes were found to map in close proximity to significant branching associations. In sunflower, variation in branching is genetically complex and overall branching patterns (i.e., apical vs. basal) were found to be influenced by distinct genomic regions. Moreover, numerous candidate branching genes mapped in close proximity to significant branching associations. Although the sunflower genome exhibits localized islands of elevated linkage disequilibrium (LD), these non-random associations are known to decay rapidly elsewhere. The subset of candidate genes that co-localized with significant associations in regions of low LD represents the most promising target for future functional analyses.

Fish tag recovery from Anaho Island nesting colony, Pyramid Lake, Nevada

USGS Publications Warehouse

Scoppettone, G. Gary; Fabes, Mark C.; Rissler, Peter H.; Withers, Donna

2016-01-06

In 2001, tags applied to the federally endangered species cui-ui (Chasmistes cujus) to study their population dynamics were discovered strewn throughout the American White Pelican (Pelecanus erythrorhynchos) nesting colony on Anaho Island, Pyramid Lake, Nevada. Cui-ui are endemic to Pyramid Lake, and Anaho Island harbors one of North America’s largest nesting colonies of American White Pelican. Cui-ui are consumed by pelicans during the fish’s spring migration into the Truckee River to reproduce. The predatory success of pelican has been validated by determining the odds of finding a tag from a predated cui-ui within the Anaho Island nesting colony. It is unknown how many cui-ui tags are eliminated by birds before arrival to the colony versus how many are brought to the colony but never recovered. The focus of this study was to improve the estimate of the chances of collecting a tag from a predated adult cui-ui in the pelican nesting colony by feeding dead tagged Lahontan cutthroat trout (Oncorhynchus clarkii henshawi) and common carp (Cyprinus carpio) to pelican and subsequently searching for these tags within the colony. We also randomly deployed 1,000 dispersal tags throughout the nesting colony, searching for these after one and two breeding seasons. After adding 1,027 fed fish to 547 previously fed fish, we estimated 5.3 percent of the tagged cui-ui taken by pelican were recovered during tag searches. A study of dispersal tags randomly deployed within the pelican nesting colony showed that 51.5 percent would be expected to be recovered after at least one breeding season after being deployed. Results of our studies indicate that more than 90 percent of tags from adult cui-ui are eliminated by birds outside the pelican nesting colony. Tags recovered from other species and the site at which they were tagged are also reported. Most notable were recovered Lahontan cutthroat trout tags, which were the highest in number, but their proximity to double-crested cormorant (Phalacrocorax auritus) nests suggests this species to be the primary predator. Tags from other species of fish came from as far as the Columbia River, Washington (about 600 kilometers). This study provides an important baseline for future tag recovery from the pelican nesting colony on Anaho Island and opens new questions to American White Pelican movement patterns.

Influence of climate change on productivity of American White Pelicans, Pelecanus erythrorhynchos

USGS Publications Warehouse

Sovada, Marsha A.; Igl, Lawrence D.; Pietz, Pamela J.; Bartos, Alisa J.

2014-01-01

In the past decade, severe weather and West Nile virus were major causes of chick mortality at American white pelican (Pelecanus erythrorhynchos) colonies in the northern plains of North America. At one of these colonies, Chase Lake National Wildlife Refuge in North Dakota, spring arrival by pelicans has advanced approximately 16 days over a period of 44 years (1965–2008). We examined phenology patterns of pelicans and timing of inclement weather through the 44-year period, and evaluated the consequence of earlier breeding relative to weather-related chick mortality. We found severe weather patterns to be random through time, rather than concurrently shifting with the advanced arrival of pelicans. In recent years, if nest initiations had followed the phenology patterns of 1965 (i.e., nesting initiated 16 days later), fewer chicks likely would have died from weather-related causes. That is, there would be fewer chicks exposed to severe weather during a vulnerable transition period that occurs between the stage when chicks are being brooded by adults and the stage when chicks from multiple nests become part of a thermally protective crèche.

Standing variation in spatially growing populations

NASA Astrophysics Data System (ADS)

Fusco, Diana; Gralka, Matti; Kayser, Jona; Hallatschek, Oskar

Patterns of genetic diversity not only reflect the evolutionary history of a species but they can also determine the evolutionary response to environmental change. For instance, the standing genetic diversity of a microbial population can be key to rescue in the face of an antibiotic attack. While genetic diversity is in general shaped by both demography and evolution, very little is understood when both factors matter, as e.g. for biofilms with pronounced spatial organization. Here, we quantitatively explore patterns of genetic diversity by using microbial colonies and well-mixed test tube populations as antipodal model systems with extreme and very little spatial structure, respectively. We find that Eden model simulations and KPZ theory can remarkably reproduce the genetic diversity in microbial colonies obtained via population sequencing. The excellent agreement allows to draw conclusions on the resilience of spatially-organized populations and to uncover new strategies to contain antibiotic resistance.

Circadian consequences of social organization in the ant species Camponotus compressus

NASA Astrophysics Data System (ADS)

Sharma, Vijay Kumar; Lone, Shahnaz Rahman; Goel, Anubhuthi; Chandrashekaran, M. K.

The locomotor activity rhythm of different castes of the ant species Camponotus compressus was monitored individually under laboratory light/dark (LD) cycles, and under continuous darkness (DD). The colony of this ant species comprises two sexual castes, the queens and the males, and three worker castes, namely the major, media, and minor workers. The virgin males and virgin queens display rhythmic activity patterns, but the mated queens were arrhythmic while laying eggs, with the rhythmicity resuming soon after egg-laying. Under the LD regime, major workers showed nocturnal patterns, while about 75% of the media workers displayed nocturnal patterns and about 25% showed diurnal patterns. Under the DD regime, most major workers exhibited circadian rhythm of activity with a single steady state, whereas media workers displayed two types of activity patterns, with activity patterns changing after 6-9 days in DD (turn-arounds). The pre-turn-around τ of the ants that showed nocturnal activity patterns during LD entrainment was <24 h after release into DD, which then became >24 h, after 6-9 days. On the other hand, the pre-turn-around τ of those ants that exhibited diurnal patterns during LD entrainment was first >24 h after release into DD, and then became <24 h, after 6-9 days. The activity of the minor workers neither entrained to LD cycles nor showed any sign of free-run in DD. It appears that the circadian clocks of the ant species C. compressus are flexible, and may perhaps depend upon the tasks assigned to them in the colony.

Multi-scale modelling of the dynamics of cell colonies: insights into cell-adhesion forces and cancer invasion from in silico simulations.

PubMed

Schlüter, Daniela K; Ramis-Conde, Ignacio; Chaplain, Mark A J

2015-02-06

Studying the biophysical interactions between cells is crucial to understanding how normal tissue develops, how it is structured and also when malfunctions occur. Traditional experiments try to infer events at the tissue level after observing the behaviour of and interactions between individual cells. This approach assumes that cells behave in the same biophysical manner in isolated experiments as they do within colonies and tissues. In this paper, we develop a multi-scale multi-compartment mathematical model that accounts for the principal biophysical interactions and adhesion pathways not only at a cell-cell level but also at the level of cell colonies (in contrast to the traditional approach). Our results suggest that adhesion/separation forces between cells may be lower in cell colonies than traditional isolated single-cell experiments infer. As a consequence, isolated single-cell experiments may be insufficient to deduce important biological processes such as single-cell invasion after detachment from a solid tumour. The simulations further show that kinetic rates and cell biophysical characteristics such as pressure-related cell-cycle arrest have a major influence on cell colony patterns and can allow for the development of protrusive cellular structures as seen in invasive cancer cell lines independent of expression levels of pro-invasion molecules.

Multi-scale modelling of the dynamics of cell colonies: insights into cell-adhesion forces and cancer invasion from in silico simulations

PubMed Central

Schlüter, Daniela K.; Ramis-Conde, Ignacio; Chaplain, Mark A. J.

2015-01-01

Studying the biophysical interactions between cells is crucial to understanding how normal tissue develops, how it is structured and also when malfunctions occur. Traditional experiments try to infer events at the tissue level after observing the behaviour of and interactions between individual cells. This approach assumes that cells behave in the same biophysical manner in isolated experiments as they do within colonies and tissues. In this paper, we develop a multi-scale multi-compartment mathematical model that accounts for the principal biophysical interactions and adhesion pathways not only at a cell–cell level but also at the level of cell colonies (in contrast to the traditional approach). Our results suggest that adhesion/separation forces between cells may be lower in cell colonies than traditional isolated single-cell experiments infer. As a consequence, isolated single-cell experiments may be insufficient to deduce important biological processes such as single-cell invasion after detachment from a solid tumour. The simulations further show that kinetic rates and cell biophysical characteristics such as pressure-related cell-cycle arrest have a major influence on cell colony patterns and can allow for the development of protrusive cellular structures as seen in invasive cancer cell lines independent of expression levels of pro-invasion molecules. PMID:25519994

Morphogen and community effects determine cell fates in response to BMP4 signaling in human embryonic stem cells.

PubMed

Nemashkalo, Anastasiia; Ruzo, Albert; Heemskerk, Idse; Warmflash, Aryeh

2017-09-01

Paracrine signals maintain developmental states and create cell fate patterns in vivo and influence differentiation outcomes in human embryonic stem cells (hESCs) in vitro Systematic investigation of morphogen signaling is hampered by the difficulty of disentangling endogenous signaling from experimentally applied ligands. Here, we grow hESCs in micropatterned colonies of 1-8 cells ('µColonies') to quantitatively investigate paracrine signaling and the response to external stimuli. We examine BMP4-mediated differentiation in µColonies and standard culture conditions and find that in µColonies, above a threshold concentration, BMP4 gives rise to only a single cell fate, contrary to its role as a morphogen in other developmental systems. Under standard culture conditions BMP4 acts as a morphogen but this requires secondary signals and particular cell densities. We find that a 'community effect' enforces a common fate within µColonies, both in the state of pluripotency and when cells are differentiated, and that this effect allows a more precise response to external signals. Using live cell imaging to correlate signaling histories with cell fates, we demonstrate that interactions between neighbors result in sustained, homogenous signaling necessary for differentiation. © 2017. Published by The Company of Biologists Ltd.

Burrow Dusting or Oral Vaccination Prevents Plague-Associated Prairie Dog Colony Collapse.

PubMed

Tripp, Daniel W; Rocke, Tonie E; Runge, Jonathan P; Abbott, Rachel C; Miller, Michael W

2017-09-01

Plague impacts prairie dogs (Cynomys spp.), the endangered black-footed ferret (Mustela nigripes) and other sensitive wildlife species. We compared efficacy of prophylactic treatments (burrow dusting with deltamethrin or oral vaccination with recombinant "sylvatic plague vaccine" [RCN-F1/V307]) to placebo treatment in black-tailed prairie dog (C. ludovicianus) colonies. Between 2013 and 2015, we measured prairie dog apparent survival, burrow activity and flea abundance on triplicate plots ("blocks") receiving dust, vaccine or placebo treatment. Epizootic plague affected all three blocks but emerged asynchronously. Dust plots had fewer fleas per burrow (P < 0.0001), and prairie dogs captured on dust plots had fewer fleas (P < 0.0001) than those on vaccine or placebo plots. Burrow activity and prairie dog density declined sharply in placebo plots when epizootic plague emerged. Patterns in corresponding dust and vaccine plots were less consistent and appeared strongly influenced by timing of treatment applications relative to plague emergence. Deltamethrin or oral vaccination enhanced apparent survival within two blocks. Applying insecticide or vaccine prior to epizootic emergence blunted effects of plague on prairie dog survival and abundance, thereby preventing colony collapse. Successful plague mitigation will likely entail strategic combined uses of burrow dusting and oral vaccination within large colonies or colony complexes.

Burrow dusting or oral vaccination prevents plague-associated prairie dog colony collapse

USGS Publications Warehouse

Tripp, Daniel W.; Rocke, Tonie E.; Runge, Jonathan P.; Abbott, Rachel C.; Miller, Michael W.

2017-01-01

Plague impacts prairie dogs (Cynomys spp.), the endangered black-footed ferret (Mustela nigripes) and other sensitive wildlife species. We compared efficacy of prophylactic treatments (burrow dusting with deltamethrin or oral vaccination with recombinant “sylvatic plague vaccine” [RCN-F1/V307]) to placebo treatment in black-tailed prairie dog (C. ludovicianus) colonies. Between 2013 and 2015, we measured prairie dog apparent survival, burrow activity and flea abundance on triplicate plots (“blocks”) receiving dust, vaccine or placebo treatment. Epizootic plague affected all three blocks but emerged asynchronously. Dust plots had fewer fleas per burrow (P < 0.0001), and prairie dogs captured on dust plots had fewer fleas (P < 0.0001) than those on vaccine or placebo plots. Burrow activity and prairie dog density declined sharply in placebo plots when epizootic plague emerged. Patterns in corresponding dust and vaccine plots were less consistent and appeared strongly influenced by timing of treatment applications relative to plague emergence. Deltamethrin or oral vaccination enhanced apparent survival within two blocks. Applying insecticide or vaccine prior to epizootic emergence blunted effects of plague on prairie dog survival and abundance, thereby preventing colony collapse. Successful plague mitigation will likely entail strategic combined uses of burrow dusting and oral vaccination within large colonies or colony complexes.

Environmental and Genetic Determinants of Colony Morphology in Yeast

PubMed Central

Granek, Joshua A.; Magwene, Paul M.

2010-01-01

Nutrient stresses trigger a variety of developmental switches in the budding yeast Saccharomyces cerevisiae. One of the least understood of such responses is the development of complex colony morphology, characterized by intricate, organized, and strain-specific patterns of colony growth and architecture. The genetic bases of this phenotype and the key environmental signals involved in its induction have heretofore remained poorly understood. By surveying multiple strain backgrounds and a large number of growth conditions, we show that limitation for fermentable carbon sources coupled with a rich nitrogen source is the primary trigger for the colony morphology response in budding yeast. Using knockout mutants and transposon-mediated mutagenesis, we demonstrate that two key signaling networks regulating this response are the filamentous growth MAP kinase cascade and the Ras-cAMP-PKA pathway. We further show synergistic epistasis between Rim15, a kinase involved in integration of nutrient signals, and other genes in these pathways. Ploidy, mating-type, and genotype-by-environment interactions also appear to play a role in the controlling colony morphology. Our study highlights the high degree of network reuse in this model eukaryote; yeast use the same core signaling pathways in multiple contexts to integrate information about environmental and physiological states and generate diverse developmental outputs. PMID:20107600

In vitro reconstruction of branched tubular structures from lung epithelial cells in high cell concentration gradient environment.

PubMed

Hagiwara, Masaya; Peng, Fei; Ho, Chih-Ming

2015-01-27

We have succeeded in developing hollow branching structure in vitro commonly observed in lung airway using primary lung airway epithelial cells. Cell concentration gradient is the key factor that determines production of the branching cellular structures, as optimization of this component removes the need for heterotypic culture. The higher cell concentration leads to the more production of morphogens and increases the growth rate of cells. However, homogeneous high cell concentration does not make a branching structure. Branching requires sufficient space in which cells can grow from a high concentration toward a low concentration. Simulation performed using a reaction-diffusion model revealed that long-range inhibition prevents cells from branching when they are homogeneously spread in culture environments, while short-range activation from neighboring cells leads to positive feedback. Thus, a high cell concentration gradient is required to make branching structures. Spatial distributions of morphogens, such as BMP-4, play important roles in the pattern formation. This simple yet robust system provides an optimal platform for the further study and understanding of branching mechanisms in the lung airway, and will facilitate chemical and genetic studies of lung morphogenesis programs.

The international migration of nurses in long-term care.

PubMed

Redfoot, Donald L; Houser, Ari N

2008-01-01

This article describes five major factors that are affecting patterns of international migration among nurses who work in long-term care settings: DEMOGRAPHIC DRIVERS: The aging of the populations in developed countries and the low to negative growth in the working-age population will increase the demand for international workers to provide long-term care services. GENDER AND RACE: A dual labor market of long-term care workers, increasingly made up of women of color, is becoming internationalized by the employment of migrating nurses from developing countries. CREDENTIALING: The process of credentialing skilled workers creates barriers to entry for migrating nurses and leads to "decredentialing" where registered nurses work as licensed practical nurses or aides. COLONIAL HISTORY AND GEOGRAPHY: The colonial histories of many European countries and the United States have increased migration from former colonies in developing countries to former colonial powers. WORKER RECRUITMENT: Efforts to limit the recruitment of health care workers from some developing countries have had little effect on migration, in part because much of the recruitment comes through informal channels of family and friends.

Complex colony-level organization of the deep-sea siphonophore Bargmannia elongata (Cnidaria, Hydrozoa) is directionally asymmetric and arises by the subdivision of pro-buds.

PubMed

Dunn, Casey W

2005-12-01

Siphonophores are free-swimming colonial hydrozoans (Cnidaria) composed of asexually produced multicellular zooids. These zooids, which are homologous to solitary animals, are functionally specialized and arranged in complex species-specific patterns. The coloniality of siphonophores provides an opportunity to study the major transitions in evolution that give rise to new levels of biological organization, but siphonophores are poorly known because they are fragile and live in the open ocean. The organization and development of the deep-sea siphonophore Bargmannia elongata is described here using specimens collected with a remotely operated underwater vehicle. Each bud gives rise to a precise, directionally asymmetric sequence of zooids through a stereotypical series of subdivisions, rather than to a single zooid as in most other hydrozoans. This initial description of development in a deep-sea siphonophore provides an example of how precise colony-level organization can arise, and illustrates that the morphological complexity of cnidarians is greater than is often assumed. Copyright 2005 Wiley-Liss, Inc.

'ENVIRONMENTAL AKALISM' AND THE WAR ON FILTH: THE PERSONIFICATION OF SANITATION IN URBAN NIGERIA.

PubMed

Manton, John

2013-11-01

In Nigerian cities, as across much of Africa, sanitation practices at zone, ward and street levels inscribe - in patterns of circulation and interaction around waste - not only the hopes and fears of urban residents and managers, but also the aspirations and failures encoded in colonial and post-colonial national and regional histories. Adjusting to numerous challenges - the interplay of racist colonial zoning strategies, rapid post-colonial urban expansion, the withdrawal of public services amid the liberalization programmes of the 1980s, the increasingly abject character of the social contract, and the ongoing tenuousness of economic life and activity - urban environmental sanitation in Nigeria has long struggled to keep pace with the historical dynamics of the country's emergent metropolises. Following the activities of a cohort of inspectors and volunteers at the Ministry of Environment and Water Resources, Oyo State, this article examines the politics of performance and coercion surrounding the monthly observance of Environmental Sanitation Day in Ibadan amid the heightened political tensions of the electoral season in 2011.

Social and Population Structure in the Ant Cataglyphis emmae

PubMed Central

Jowers, Michael J.; Leniaud, Laurianne; Cerdá, Xim; Alasaad, Samer; Caut, Stephane; Amor, Fernando; Aron, Serge; Boulay, Raphaël R.

2013-01-01

Dispersal has consequences not only for individual fitness, but also for population dynamics, population genetics and species distribution. Social Hymenoptera show two contrasting colony reproductive strategies, dependent and independent colony foundation modes, and these are often associated to the population structures derived from inter and intra-population gene flow processes conditioned by alternative dispersal strategies. Here we employ microsatellite and mitochondrial markers to investigate the population and social genetic structure and dispersal patterns in the ant Cataglyphis emmae at both, local and regional scales. We find that C. emmae is monogynous and polyandrous. Lack of detection of any population viscosity and population structure with nuclear markers at the local scale suggests efficient dispersal, in agreement with a lack of inbreeding. Contrasting demographic differences before and during the mating seasons suggest that C. emmae workers raise sexuals in peripheric nest chambers to reduce intracolonial conflicts. The high genetic differentiation recovered from the mtDNA haplotypes, together with the significant correlation of such to geographic distance, and presence of new nuclear alleles between areas (valleys) suggest long-term historical isolation between these regions, indicative of limited dispersal at the regional scale. Our findings on the ecological, social and population structure of this species increases our understanding of the patterns and processes involved under independent colony foundation. PMID:24039827

Noninvasive forward-scattering system for rapid detection, characterization, and identification of Listeria colonies: image processing and data analysis

NASA Astrophysics Data System (ADS)

Rajwa, Bartek; Bayraktar, Bulent; Banada, Padmapriya P.; Huff, Karleigh; Bae, Euiwon; Hirleman, E. Daniel; Bhunia, Arun K.; Robinson, J. Paul

2006-10-01

Bacterial contamination by Listeria monocytogenes puts the public at risk and is also costly for the food-processing industry. Traditional methods for pathogen identification require complicated sample preparation for reliable results. Previously, we have reported development of a noninvasive optical forward-scattering system for rapid identification of Listeria colonies grown on solid surfaces. The presented system included application of computer-vision and patternrecognition techniques to classify scatter pattern formed by bacterial colonies irradiated with laser light. This report shows an extension of the proposed method. A new scatterometer equipped with a high-resolution CCD chip and application of two additional sets of image features for classification allow for higher accuracy and lower error rates. Features based on Zernike moments are supplemented by Tchebichef moments, and Haralick texture descriptors in the new version of the algorithm. Fisher's criterion has been used for feature selection to decrease the training time of machine learning systems. An algorithm based on support vector machines was used for classification of patterns. Low error rates determined by cross-validation, reproducibility of the measurements, and robustness of the system prove that the proposed technology can be implemented in automated devices for detection and classification of pathogenic bacteria.

Anatomy of the cystic artery arising from the gastroduodenal artery and its choledochal branch—a case report

PubMed Central

SARKAR, A. K.; ROY, T. S.

2000-01-01

Variations in the branching pattern of the common hepatic artery often occur and may be encountered during cholecystectomy. Variants of the cystic artery, its branches and relations with the biliary structures and blood vessels emphasise the importance of arterial dissection in biliary surgery. In this study, a rare variant of the cystic artery and its choledochal branch is described. The cystic artery arose from the gastroduodenal artery, passed anterior to structures in the free margin of lesser omentum and travelled a long distance before supplying the gall bladder. A long choledochal branch was noted accompanying the common bile duct. Surgical implications of this variation of the cystic and choledochal arteries are discussed. PMID:11117634

Computational models of airway branching morphogenesis.

PubMed

Varner, Victor D; Nelson, Celeste M

2017-07-01

The bronchial network of the mammalian lung consists of millions of dichotomous branches arranged in a highly complex, space-filling tree. Recent computational models of branching morphogenesis in the lung have helped uncover the biological mechanisms that construct this ramified architecture. In this review, we focus on three different theoretical approaches - geometric modeling, reaction-diffusion modeling, and continuum mechanical modeling - and discuss how, taken together, these models have identified the geometric principles necessary to build an efficient bronchial network, as well as the patterning mechanisms that specify airway geometry in the developing embryo. We emphasize models that are integrated with biological experiments and suggest how recent progress in computational modeling has advanced our understanding of airway branching morphogenesis. Copyright © 2016 Elsevier Ltd. All rights reserved.

Evaluation of the optimal visceral branch configuration in open thoracoabdominal aortic repair by computed tomography.

PubMed

Kamohara, Keiji; Furukawa, Kojiro; Itoh, Manabu; Morokuma, Hiroyuki; Tanaka, Hideya; Hayashi, Nagi; Morita, Shigeki

2015-01-01

In thoracoabdominal aneurysm (TAAA) repair, our technical modification of visceral reconstruction using longer cut pre-sewn side branches has provided good surgical outcomes. Here, we assessed the long-term durability and patency of revascularized branches using computed tomography (CT) to confirm the validity of our approach. Early and late CT evaluations were performed in 11 TAAA patients (males: 5; mean age: 60.6 years) using the Coselli graft to evaluate the position of main graft and the diverging pattern and patency of side branches. Seven of 11 were sutured in an extra-anatomical fashion using longer cut side branches. In Anatomical (n = 4) and Extra-anatomical (n = 7) groups, the early patency of side branches was not significantly different. Although the late patency of right renal artery (RA) was 100% in both groups, the one of left RA was 60% in Extra-anatomical, while 100% in Anatomical. Furthermore, the main graft in Extra-anatomical was significantly posterior and leftward to the spine with left RA side branch diverging at an acute angle. When a pre-sewn branched graft designed for TAAA is used, the graft should be sutured in a fashion similar to normal patient anatomy to minimize the possibility of kinking of RA side branch for the patency.

Changes in transcript abundance relating to colony collapse disorder in honey bees (Apis mellifera).

PubMed

Johnson, Reed M; Evans, Jay D; Robinson, Gene E; Berenbaum, May R

2009-09-01

Colony collapse disorder (CCD) is a mysterious disappearance of honey bees that has beset beekeepers in the United States since late 2006. Pathogens and other environmental stresses, including pesticides, have been linked to CCD, but a causal relationship has not yet been demonstrated. Because the gut acts as a primary interface between the honey bee and its environment as a site of entry for pathogens and toxins, we used whole-genome microarrays to compare gene expression between guts of bees from CCD colonies originating on both the east and west coasts of the United States and guts of bees from healthy colonies sampled before the emergence of CCD. Considerable variation in gene expression was associated with the geographical origin of bees, but a consensus list of 65 transcripts was identified as potential markers for CCD status. Overall, elevated expression of pesticide response genes was not observed. Genes involved in immune response showed no clear trend in expression pattern despite the increased prevalence of viruses and other pathogens in CCD colonies. Microarray analysis revealed unusual ribosomal RNA fragments that were conspicuously more abundant in the guts of CCD bees. The presence of these fragments may be a possible consequence of picorna-like viral infection, including deformed wing virus and Israeli acute paralysis virus, and may be related to arrested translation. Ribosomal fragment abundance and presence of multiple viruses may prove to be useful diagnostic markers for colonies afflicted with CCD.

Changes in transcript abundance relating to colony collapse disorder in honey bees (Apis mellifera)

PubMed Central

Johnson, Reed M.; Evans, Jay D.; Robinson, Gene E.; Berenbaum, May R.

2009-01-01

Colony collapse disorder (CCD) is a mysterious disappearance of honey bees that has beset beekeepers in the United States since late 2006. Pathogens and other environmental stresses, including pesticides, have been linked to CCD, but a causal relationship has not yet been demonstrated. Because the gut acts as a primary interface between the honey bee and its environment as a site of entry for pathogens and toxins, we used whole-genome microarrays to compare gene expression between guts of bees from CCD colonies originating on both the east and west coasts of the United States and guts of bees from healthy colonies sampled before the emergence of CCD. Considerable variation in gene expression was associated with the geographical origin of bees, but a consensus list of 65 transcripts was identified as potential markers for CCD status. Overall, elevated expression of pesticide response genes was not observed. Genes involved in immune response showed no clear trend in expression pattern despite the increased prevalence of viruses and other pathogens in CCD colonies. Microarray analysis revealed unusual ribosomal RNA fragments that were conspicuously more abundant in the guts of CCD bees. The presence of these fragments may be a possible consequence of picorna-like viral infection, including deformed wing virus and Israeli acute paralysis virus, and may be related to arrested translation. Ribosomal fragment abundance and presence of multiple viruses may prove to be useful diagnostic markers for colonies afflicted with CCD. PMID:19706391

Multiscale habitat selection by burrowing owls in black-tailed prairie dog colonies

USGS Publications Warehouse

Lantz, S.J.; Conway, C.J.; Anderson, S.H.

2007-01-01

Some populations of western burrowing owls (Athene cunicularia hypugaea) have declined in recent decades. To design and implement effective recovery efforts, we need a better understanding of how distribution and demographic traits are influenced by habitat quality. To this end, we measured spatial patterns of burrowing owl breeding habitat selection within black-tailed prairie dog (Cynomys ludovicianus) colonies in northeastern Wyoming, USA. We compared burrow-, site-, colony-, and landscape-scale habitat parameters between burrowing owl nest burrows (n = 105) and unoccupied burrows (n = 85). We sampled 4 types of prairie dog colonies: 1) owl-occupied, active with prairie dogs (n = 16); 2) owl-occupied, inactive (n = 13); 3) owl-unoccupied, active (n = 14); and 4) owl-unoccupied, inactive (n = 14). We used an information-theoretic approach to examine a set of candidate models of burrowing owl nest-site selection. The model with the most support included variables at all 4 spatial scales, and results were consistent among the 4 types of prairie dog colonies. Nest burrows had longer tunnels, more available burrows within 30 m, and less shrub cover within 30 m, more prairie dog activity within 100 m, and were closer to water than unoccupied burrows. The model correctly classified 76% of cases, all model coefficients were stable, and the model had high predictive ability. Based on our results, we recommend actions to ensure persistence of the remaining prairie dog colonies as an important management strategy for burrowing owl conservation in the Great Plains of North America.

Transgene-free iPSCs generated from small volume peripheral blood nonmobilized CD34+ cells

PubMed Central

Merling, Randall K.; Sweeney, Colin L.; Choi, Uimook; De Ravin, Suk See; Myers, Timothy G.; Otaizo-Carrasquero, Francisco; Pan, Jason; Linton, Gilda; Chen, Lifeng; Koontz, Sherry; Theobald, Narda L.; Malech, Harry L.

2013-01-01

A variety of somatic cells can be reprogrammed to induced pluripotent stem cells (iPSCs), but CD34+ hematopoietic stem cells (HSCs) present in nonmobilized peripheral blood (PB) would be a convenient target. We report a method for deriving iPSC from PB HSCs using immunobead purification and 2- to 4-day culture to enrich CD34+ HSCs to 80% ± 9%, followed by reprogramming with loxP-flanked polycistronic (human Oct4, Klf4, Sox2, and c-Myc) STEMCCA-loxP lentivector, or with Sendai vectors. Colonies arising with STEMCCA-loxP were invariably TRA-1-60+, yielding 5.3 ± 2.8 iPSC colonies per 20 mL PB (n = 17), where most colonies had single-copy STEMCCA-loxP easily excised by transient Cre expression. Colonies arising with Sendai were variably reprogrammed (10%-80% TRA-1-60+), with variable yield (6 to >500 TRA-1-60+ iPSC colonies per 10 mL blood; n = 6). Resultant iPSC clones expressed pluripotent cell markers and generated teratomas. Genomic methylation patterns of STEMCCA-loxP–reprogrammed clones closely matched embryonic stem cells. Furthermore, we showed that iPSCs are derived from the nonmobilized CD34+ HSCs enriched from PB rather than from any lymphocyte or monocyte contaminants because they lack somatic rearrangements typical of T or B lymphocytes and because purified CD14+ monocytes do not yield iPSC colonies under these reprogramming conditions. PMID:23386128

Social behavior of bacteria: from physics to complex organization

NASA Astrophysics Data System (ADS)

Ben-Jacob, E.

2008-10-01

I describe how bacteria develop complex colonial patterns by utilizing intricate communication capabilities, such as quorum sensing, chemotactic signaling and exchange of genetic information (plasmids) Bacteria do not store genetically all the information required for generating the patterns for all possible environments. Instead, additional information is cooperatively generated as required for the colonial organization to proceed. Each bacterium is, by itself, a biotic autonomous system with its own internal cellular informatics capabilities (storage, processing and assessments of information). These afford the cell certain plasticity to select its response to biochemical messages it receives, including self-alteration and broadcasting messages to initiate alterations in other bacteria. Hence, new features can collectively emerge during self-organization from the intra-cellular level to the whole colony. Collectively bacteria store information, perform decision make decisions (e.g. to sporulate) and even learn from past experience (e.g. exposure to antibiotics)-features we begin to associate with bacterial social behavior and even rudimentary intelligence. I also take Schrdinger’s’ “feeding on negative entropy” criteria further and propose that, in addition organisms have to extract latent information embedded in the environment. By latent information we refer to the non-arbitrary spatio-temporal patterns of regularities and variations that characterize the environmental dynamics. In other words, bacteria must be able to sense the environment and perform internal information processing for thriving on latent information embedded in the complexity of their environment. I then propose that by acting together, bacteria can perform this most elementary cognitive function more efficiently as can be illustrated by their cooperative behavior.

Life history strategy of the honey bee, Apis mellifera.

PubMed

Seeley, Thomas D

1978-01-01

The feral honey bee queens (colonies) of central New York State (USA) show a K-type life history strategy. Their demographic characteristics include low early life mortality, low reproductive rate, long lifespan, high population stability and repeated reproductions. Identifying the life history strategy of these bees reveals the general pattern of selection for competitive ability, rather than productivity, which has shaped their societies. Selection for competitive power explains the adaptiveness (compared with alternatives found in many other insect societies) of the large perennial colonies, infrequent but expensive offspring, and efficient foraging which characterize the social organization of these bees.

Finding the optimal lengths for three branches at a junction.

PubMed

Woldenberg, M J; Horsfield, K

1983-09-21

This paper presents an exact analytical solution to the problem of locating the junction point between three branches so that the sum of the total costs of the branches is minimized. When the cost per unit length of each branch is known the angles between each pair of branches can be deduced following reasoning first introduced to biology by Murray. Assuming the outer ends of each branch are fixed, the location of the junction and the length of each branch are then deduced using plane geometry and trigonometry. The model has applications in determining the optimal cost of a branch or branches at a junction. Comparing the optimal to the actual cost of a junction is a new way to compare cost models for goodness of fit to actual junction geometry. It is an unambiguous measure and is superior to comparing observed and optimal angles between each daughter and the parent branch. We present data for 199 junctions in the pulmonary arteries of two human lungs. For the branches at each junction we calculated the best fitting value of x from the relationship that flow alpha (radius)x. We found that the value of x determined whether a junction was best fitted by a surface, volume, drag or power minimization model. While economy of explanation casts doubt that four models operate simultaneously, we found that optimality may still operate, since the angle to the major daughter is less than the angle to the minor daughter. Perhaps optimality combined with a space filling branching pattern governs the branching geometry of the pulmonary artery.

The Organization of Foraging in the Fire Ant, Solenopsis invicta

PubMed Central

Tschinkel, Walter R.

2011-01-01

Although natural selection in ants acts most strongly at the colony, or superorganismal level, foraging patterns have rarely been studied at that level, focusing instead on the behavior of individual foragers or groups of foragers. The experiments and observations in this paper reveal in broad strokes how colonies of the fire ant, Solenopsis invicta Buren (Hymenoptera: Formicidae), allocate their available labor to foraging, how they disperse that force within their territory, and how this force changes with colony size, season and worker age. Territory area is positively related to colony size and the number of foragers, more so during the spring than fall. Changes of colony size and territory area are driven by seasonal variation of sexual and worker production, which in turn drive seasonal variation of worker age-distribution. During spring sexual production, colonies shrink because worker production falls below replacement. This loss is proportional to colony size, causing forager density in the spring to be negatively related to colony and territory size. In the fall, colonies emphasize worker production, bringing colony size back up. However, because smaller colonies curtailed spring worker production less than larger ones, their fall forager populations are proportionally greater, causing them to gain territory at the expense of large colonies. Much variation of territory area remains unexplained and can probably be attributed to pressure from neighboring colonies. Boundaries between territories are characterized by “no ants' zones” mostly devoid of fire ants. The forager population can be divided into a younger group of recruitable workers that wait for scouts to activate them to help retrieve large food finds. About one-third of the recruits wait near openings in the foraging tunnels that underlie the entire territory, while two-thirds wait in the nest. Recruitment to food is initially very rapid and local from the foraging tunnels, while sustained recruitment gradually involves the recruits waiting in the nest. As recruits age, they become scouts searching for food on the surface, and die about two weeks later. Foraging tunnels decrease in cross-sectional area with distance from the nest, in keeping with the gradual bleeding off of workers to the surface with distance. Foragers lack route-faithfulness, and having been marked and released at one point within the territory, they can be recaptured at any other point a day later. The size of the territory actually occupied may be limited during dry weather, resulting in very large no-ants' zones. PMID:21529150

Whey protein supplementation does not alter plasma branched-chained amino acid profiles but results in unique metabolomics patterns in obese women enrolled in an 8-week weight loss trial

USDA-ARS?s Scientific Manuscript database

Background: It has been suggested that perturbations in branched-chain amino acid (BCAA) catabolism are associated with insulin resistance and contribute to elevated systemic BCAAs. Evidence in rodents suggests dietary protein rich in BCAAs can increase BCAA catabolism, but there is limited evidence...

Asymmetric Branching in Biological Resource Distribution Networks

NASA Astrophysics Data System (ADS)

Brummer, Alexander Byers

There is a remarkable relationship between an organism's metabolic rate (resting power consumption) and the organism's mass. It may be a universal law of nature that an organism's resting metabolic rate is proportional to its mass to the power of 3/4. This relationship, known as Kleiber's Law, appears to be valid for both plants and animals. This law is important because it implies that larger organisms are more efficient than smaller organisms, and knowledge regarding metabolic rates are essential to a multitude of other fields in ecology and biology. This includes modeling the interactions of many species across multiple trophic levels, distributions of species abundances across large spatial landscapes, and even medical diagnostics for respiratory and cardiovascular pathologies. Previous models of vascular networks that seek to identify the origin of metabolic scaling have all been based on the unrealistic assumption of perfectly symmetric branching. In this dissertation I will present a theory of asymmetric branching in self-similar vascular networks (published by Brummer et al. in [9]). The theory shows that there can exist a suite of vascular forms that result in the often observed 3/4 metabolic scaling exponent of Kleiber's Law. Furthermore, the theory makes predictions regarding major morphological features related to vascular branching patterns and their relationships to metabolic scaling. These predictions are suggestive of evolutionary convergence in vascular branching. To test these predictions, I will present an analysis of real mammalian and plant vascular data that shows: (i) broad patterns in vascular networks across entire animal kingdoms and (ii) within these patterns, plant and mammalian vascular networks can be uniquely distinguished from one another (publication in preparation by Brummer et al.). I will also present results from a computational study in support of point (i). Namely, that asymmetric branching may be the optimal strategy to balance the simultaneous demands of maximizing the number of nutrient exchange sites (capillaries or leaves) versus hydraulic resistance to resource transport (publication in preparation by Brummer et al.). Finally, I report on improved methods of estimating whole organism metabolism based solely on measurements of vasculature.

Quantification of dimethylsulfoniopropionate (DMSP) in Acropora spp. of reef-building coral using mass spectrometry with deuterated internal standard.

PubMed

Swan, Hilton B; Deschaseaux, Elisabeth S M; Jones, Graham B; Eyre, Bradley D

2017-03-01

Dimethylsulfoniopropionate (DMSP) in scleractinian coral is usually analysed indirectly as dimethylsulfide (DMS) using gas chromatography (GC) with a sulfur-specific detector. We developed a headspace GC method for mass spectral analysis of DMSP in branching coral where hexa-deuterated DMSP (d 6 -DMSP) was added to samples and standards to optimise the analytical precision and quantitative accuracy. Using this indirect HS-GC-MS method, we show that common coral sample handling techniques did not alter DMSP concentrations in Acropora aspera and that endogenous DMS was insignificant compared to the store of DMSP in A. aspera. Field application of the indirect HS-GC-MS method in all seasons over a 5-year period at Heron Island in the southern Great Barrier Reef indicated that healthy colonies of A. aspera ordinarily seasonally conserve their branch tip store of DMSP; however, this store increased to a higher concentration under extended thermal stress conditions driven by a strong El Niño Southern Oscillation event. A liquid chromatography mass spectral method (LC-MS) was subsequently developed for direct analysis of DMSP in branching coral, also utilising the d 6 -DMSP internal standard. The quantitative comparison of DMSP in four species of Acropora coral by indirect HS-GC-MS and direct LC-MS analyses gave equivalent concentrations in A. aspera only; in the other three species, HS-GC-MS gave consistently higher concentrations, indicating that indirect analysis of DMSP may lead to artificially high values for some coral species. Graphical Abstract Dimethylsulfoniopropionate (DMSP) was quantified in Acropora spp. of branching coral using deuterated stable isotope dilution mass spectrometry.

Squirmers with swirl: a model for Volvox swimming.

PubMed

Pedley, T J; Brumley, D R; Goldstein, R E

2016-07-10

Colonies of the green alga Volvox are spheres that swim through the beating of pairs of flagella on their surface somatic cells. The somatic cells themselves are mounted rigidly in a polymeric extracellular matrix, fixing the orientation of the flagella so that they beat approximately in a meridional plane, with axis of symmetry in the swimming direction, but with a roughly [Formula: see text] azimuthal offset which results in the eponymous rotation of the colonies about a body-fixed axis. Experiments on colonies of Volvox carteri held stationary on a micropipette show that the beating pattern takes the form of a symplectic metachronal wave (Brumley  et al.   Phys. Rev. Lett. , vol. 109, 2012, 268102). Here we extend the Lighthill/Blake axisymmetric, Stokes-flow model of a free-swimming spherical squirmer (Lighthill  Commun. Pure Appl. Maths , vol. 5, 1952, pp. 109-118; Blake  J. Fluid Mech. , vol. 46, 1971 b , pp. 199-208) to include azimuthal swirl. The measured kinematics of the metachronal wave for 60 different colonies are used to calculate the coefficients in the eigenfunction expansions and hence predict the mean swimming speeds and rotation rates, proportional to the square of the beating amplitude, as functions of colony radius. As a test of the squirmer model, the results are compared with measurements (Drescher  et al.   Phys. Rev. Lett. , vol. 102, 2009, 168101) of the mean swimming speeds and angular velocities of a different set of 220 colonies, also given as functions of colony radius. The predicted variation with radius is qualitatively correct, but the model underestimates both the mean swimming speed and the mean angular velocity unless the amplitude of the flagellar beat is taken to be larger than previously thought. The reasons for this discrepancy are discussed.

Aberration-free superresolution imaging via binary speckle pattern encoding and processing

NASA Astrophysics Data System (ADS)

Ben-Eliezer, Eyal; Marom, Emanuel

2007-04-01

We present an approach that provides superresolution beyond the classical limit as well as image restoration in the presence of aberrations; in particular, the ability to obtain superresolution while extending the depth of field (DOF) simultaneously is tested experimentally. It is based on an approach, recently proposed, shown to increase the resolution significantly for in-focus images by speckle encoding and decoding. In our approach, an object multiplied by a fine binary speckle pattern may be located anywhere along an extended DOF region. Since the exact magnification is not known in the presence of defocus aberration, the acquired low-resolution image is electronically processed via a parallel-branch decoding scheme, where in each branch the image is multiplied by the same high-resolution synchronized time-varying binary speckle but with different magnification. Finally, a hard-decision algorithm chooses the branch that provides the highest-resolution output image, thus achieving insensitivity to aberrations as well as DOF variations. Simulation as well as experimental results are presented, exhibiting significant resolution improvement factors.

Branching pattern in natural drainage network

NASA Astrophysics Data System (ADS)

Hooshyar, M.; Singh, A.; Wang, D.

2017-12-01

The formation and growth of river channels and their network evolution are governed by the erosional and depositional processes operating on the landscape due to movement of water. The branching structure of drainage network is an important feature related to the network topology and contain valuable information about the forming mechanisms of the landscape. We studied the branching patterns in natural drainage networks, extracted from 1 m Digital Elevation Models (DEMs) of 120 catchments with minimal human impacts across the United States. We showed that the junction angles have two distinct modes an the observed modes are physically explained as the optimal angles that result in minimum energy dissipation and are linked to the exponent characterizing slope-area curve. Our findings suggest that the flow regimes, debris-flow dominated or fluvial, have distinct characteristic angles which are functions of the scaling exponent of the slope-area curve. These findings enable us to understand the geomorphological signature of hydrological processes on drainage networks and develop more refined landscape evolution models.

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

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.

Group A streptococcus colonies from a single throat swab can have heterogeneous antimicrobial susceptibility patterns.

PubMed

Vandevoorde, Aurélie; Ascenzo, Sabrina; Miendje Deyi, Veronique Yvette; Mascart, Georges; Mansbach, Anne-Laure; Landsberg, Marguerite; Dreze, Pierre; Steer, Andrew C; Van Melderen, Laurence; Smeesters, Pierre R

2013-03-01

This study describes for the first time heterogeneity of antibiotic resistance profiles among group A Streptococcus isolates originating from a single throat swab in patients with acute pharyngitis. For each throat swab, 10 group A Streptococcus colonies were randomly selected from the primary plate and subcultured to a secondary plate. These isolates were characterized by various phenotypic and genotypic methods. Our results demonstrated that differing antibiotic resistance profiles were present in 19% of pediatric patients with acute pharyngitis before antimicrobial treatment. This heterogeneity likely resulted from horizontal gene transfer among streptococcal isolates sharing the same genetic background. As only a minority of colonies displayed antibiotic resistance among these heterogeneous samples, a classical diagnostic antibiogram would have classified them in most instances as "susceptible," although therapeutic failure could be caused by the proliferation of resistant strains after initiation of antibiotic treatment.

San Antonio, Texas, USA

NASA Image and Video Library

1992-07-09

This sharp, cloud free view of San Antonio, Texas (29.5N, 98.5W) illustrates the classic pattern of western cities. The city has a late nineteenth century Anglo grid pattern overlaid onto an earlier, less regular Hispanic settlement. A well marked central business district having streets laid out north/south and east/west is surrounded by blocks of suburban homes and small businesses set between the older colonial radial transportation routes.

Response of coral assemblages to thermal stress: are bleaching intensity and spatial patterns consistent between events?

PubMed

Penin, Lucie; Vidal-Dupiol, Jeremie; Adjeroud, Mehdi

2013-06-01

Mass bleaching events resulting in coral mortality are among the greatest threats to coral reefs, and are projected to increase in frequency and intensity with global warming. Achieving a better understanding of the consistency of the response of coral assemblages to thermal stress, both spatially and temporally, is essential to determine which reefs are more able to tolerate climate change. We compared variations in spatial and taxonomic patterns between two bleaching events at the scale of an island (Moorea Island, French Polynesia). Despite similar thermal stress and light conditions, bleaching intensity was significantly lower in 2007 (approximately 37 % of colonies showed signs of bleaching) than in 2002, when 55 % of the colonies bleached. Variations in the spatial patterns of bleaching intensity were consistent between the two events. Among nine sampling stations at three locations and three depths, the stations at which the bleaching response was lowest in 2002 were those that showed the lowest levels of bleaching in 2007. The taxonomic patterns of susceptibility to bleaching were also consistent between the two events. These findings have important implications for conservation because they indicate that corals are capable of acclimatization and/or adaptation and that, even at small spatial scales, some areas are consistently more susceptible to bleaching than others.

Self-organization of human embryonic stem cells on micropatterns

PubMed Central

Deglincerti, Alessia; Etoc, Fred; Guerra, M. Cecilia; Martyn, Iain; Metzger, Jakob; Ruzo, Albert; Simunovic, Mijo; Yoney, Anna; Brivanlou, Ali H.; Siggia, Eric; Warmflash, Aryeh

2018-01-01

Fate allocation in the gastrulating embryo is spatially organized as cells differentiate to specialized cell types depending on their positions with respect to the body axes. There is a need for in vitro protocols that allow the study of spatial organization associated with this developmental transition. While embryoid bodies and organoids can exhibit some spatial organization of differentiated cells, these methods do not yield consistent and fully reproducible results. Here, we describe a micropatterning approach where human embryonic stem cells are confined to disk-shaped, sub-millimeter colonies. After 42 hours of BMP4 stimulation, cells form self-organized differentiation patterns in concentric radial domains, which express specific markers associated with the embryonic germ layers, reminiscent of gastrulating embryos. Our protocol takes 3 days; it uses commercial microfabricated slides (CYTOO), human laminin-521 (LN-521) as extra-cellular matrix coating, and either conditioned or chemically-defined medium (mTeSR). Differentiation patterns within individual colonies can be determined by immunofluorescence and analyzed with cellular resolution. Both the size of the micropattern and the type of medium affect the patterning outcome. The protocol is appropriate for personnel with basic stem cell culture training. This protocol describes a robust platform for quantitative analysis of the mechanisms associated with pattern formation at the onset of gastrulation. PMID:27735934

Selective sweeps in growing microbial colonies

NASA Astrophysics Data System (ADS)

Korolev, Kirill S.; Müller, Melanie J. I.; Karahan, Nilay; Murray, Andrew W.; Hallatschek, Oskar; Nelson, David R.

2012-04-01

Evolutionary experiments with microbes are a powerful tool to study mutations and natural selection. These experiments, however, are often limited to the well-mixed environments of a test tube or a chemostat. Since spatial organization can significantly affect evolutionary dynamics, the need is growing for evolutionary experiments in spatially structured environments. The surface of a Petri dish provides such an environment, but a more detailed understanding of microbial growth on Petri dishes is necessary to interpret such experiments. We formulate a simple deterministic reaction-diffusion model, which successfully predicts the spatial patterns created by two competing species during colony expansion. We also derive the shape of these patterns analytically without relying on microscopic details of the model. In particular, we find that the relative fitness of two microbial strains can be estimated from the logarithmic spirals created by selective sweeps. The theory is tested with strains of the budding yeast Saccharomyces cerevisiae for spatial competitions with different initial conditions and for a range of relative fitnesses. The reaction-diffusion model also connects the microscopic parameters like growth rates and diffusion constants with macroscopic spatial patterns and predicts the relationship between fitness in liquid cultures and on Petri dishes, which we confirmed experimentally. Spatial sector patterns therefore provide an alternative fitness assay to the commonly used liquid culture fitness assays.

Multi-center randomized controlled trial of cognitive treatment, placebo, oxybutynin, bladder training, and pelvic floor training in children with functional urinary incontinence.

PubMed

van Gool, Jan D; de Jong, Tom P V M; Winkler-Seinstra, Pauline; Tamminen-Möbius, Tytti; Lax, Hildegard; Hirche, Herbert; Nijman, Rien J M; Hjälmås, Kelm; Jodal, Ulf; Bachmann, Hannsjörg; Hoebeke, Piet; Walle, Johan Vande; Misselwitz, Joachim; John, Ulrike; Bael, An

2014-06-01

Functional urinary incontinence causes considerable morbidity in 8.4% of school-age children, mainly girls. To compare oxybutynin, placebo, and bladder training in overactive bladder (OAB), and cognitive treatment and pelvic floor training in dysfunctional voiding (DV), a multi-center controlled trial was designed, the European Bladder Dysfunction Study. Seventy girls and 27 boys with clinically diagnosed OAB and urge incontinence were randomly allocated to placebo, oxybutynin, or bladder training (branch I), and 89 girls and 16 boys with clinically diagnosed DV to either cognitive treatment or pelvic floor training (branch II). All children received standardized cognitive treatment, to which these interventions were added. The main outcome variable was daytime incontinence with/without urinary tract infections. Urodynamic studies were performed before and after treatment. In branch I, the 15% full response evolved to cure rates of 39% for placebo, 43% for oxybutynin, and 44% for bladder training. In branch II, the 25% full response evolved to cure rates of 52% for controls and 49% for pelvic floor training. Before treatment, detrusor overactivity (OAB) or pelvic floor overactivity (DV) did not correlate with the clinical diagnosis. After treatment these urodynamic patterns occurred de novo in at least 20%. The mismatch between urodynamic patterns and clinical symptoms explains why cognitive treatment was the key to success, not the added interventions. Unpredictable changes in urodynamic patterns over time, the response to cognitive treatment, and the gender-specific prevalence suggest social stress might be a cause for the symptoms, mediated by corticotropin-releasing factor signaling pathways. © 2013 Wiley Periodicals, Inc.

Anatomical Relationship Between the Kidney Collecting System and the Intrarenal Arteries in the Sheep: Contribution for a New Urological Model.

PubMed

Buys-Gonçalves, Gabriela Faria; De Souza, Diogo Benchimol; Sampaio, Francisco José Barcellos; Pereira-Sampaio, Marco Aurélio

2016-04-01

Previous studies have demonstrated that the pig collecting system heals after partial nephrectomy without closure. Recently, a study in sheep showed that partial nephrectomy without closure of the collecting system resulted in urinary leakage and urinoma. The aim of this study was to present detailed anatomical findings on the intrarenal anatomy of the sheep. Forty two kidneys were used to produce tridimensional endocasts of the collecting system together with the intrarenal arteries. A renal pelvis which displayed 11-19 (mean of 16) renal recesses was present. There were no calices present. The renal artery was singular in each kidney and gave two primary branches one to the dorsal surface and one to ventral surface. Dorsal and ventral branches of the renal artery were classified based on the relationship between their branching pattern and the collecting system as: type I (cranial and caudal segmental arteries), type II (cranial, middle and caudal segmental arteries) or type III (cranial, cranial middle, caudal middle, and caudal segmental arteries). Type I was the most common branching pattern for the dorsal and ventral branches of the renal artery. The arterial supply of the caudal pole of the sheep kidney supports its use as an experimental model due to the similarity to the human kidney. However, the lack of a retropelvic artery discourages the use of the cranial pole in experiments in which the arteries are an important aspect to be considered. © 2016 Wiley Periodicals, Inc.

High temperature stress and its effect on pollen development and morphological components of harvest index in the C3 model grass Brachypodium distachyon

PubMed Central

Harsant, Jeffrey; Pavlovic, Lazar; Chiu, Greta; Sultmanis, Stefanie; Sage, Tammy L.

2013-01-01

The effect of high temperatures on harvest index (HI) and morphological components that contribute to HI was investigated in two lines (Bd21 and Bd21-3) of Brachypodium distachyon, a C3 grass recognized as a tractable plant, to address critical issues associated with enhancing cereal crop yields in the presence of global climate change. The results demonstrated that temperatures ≥32 °C eliminated HI. Reductions in yield at 32 °C were due primarily to declines in pollen viability, retention of pollen in anthers, and pollen germination, while abortion of microspores by the uninucleate stage that was correlated with abnormal tapetal development resulted in yield failure at 36 °C. Increasing temperatures from 24 to 32 °C resulted in reductions in tiller numbers but had no impact on axillary branch numbers per tiller. Grain developed at 24 and 28 °C primarily in tiller spikes, although spikes on axillary branches also formed grain. Grain quantity decreased in tiller spikes but increased in axillary branch spikes as temperatures rose from 24 to 28 °C. Differential patterns of axillary branching and floret development within spikelets between Bd21 and Bd21-3 resulted in higher grain yield in axillary branches of Bd21-3 at 28 °C. The response of male reproductive development and tiller branching patterns in B. distachyon to increasing temperatures mirrors that in other cereal crops, providing support for the use of this C3 grass in assessing the molecular control of HI in the presence of global warming. PMID:23771979

Isolating isomers of perfluorocarboxylates in polar bears (Ursus maritimus) from two geographical locations.

PubMed

De Silva, Amila O; Mabury, Scott A

2004-12-15

The source of involatile, anthropogenic perfluorocarboxylate anions (PFCAs) in biota from remote regions is of heightened interest due to the persistence, toxicity, and bioaccumulation of these materials. Large-scale production of fluorinated compounds is carried out primarily by one of two methods: electrochemical fluorination (ECF) and telomerization. Products of the two processes may be distinguished based on constitutional isomer pattern as ECF products are characteristically comprised of a variety of constitutional isomers. The objective of this research was to develop a method for identifying the constitutional isomer profile of PFCAs in environmental samples and to apply the method to polar bear livers from two different locations. Resolution of constitutional isomers of derivatized PFCAs (8-13 carbons) was accomplished via GC-MS. Seven isomers of an authentic ECF perfluorooctanoate (PFOA) standard were separated. The linear isomer comprised 78% of this standard. Isomer profiles of PFCAs in liver samples of 15 polar bears (Ursus maritimus) from the Canadian Arctic and eastern Greenland were determined by GC-MS. The PFOA isomer pattern in Greenland polar bear samples showed a variety of branched isomers while only the linear PFOA isomer was determined in Canadian samples. Samples of both locations had primarily (>99%) linear isomers of perfluorononanoate and perfluorotridecanoate. Branched isomers of perfluorodecanoate, perfluoroundecanoate, and perfluorododecanoate were determined in the polar bear samples. Unlike the PFOA isomer signature, only a single branched isomer peak on the chromatograms was observed for these longer chain PFCAs. The presence of branched isomers suggests some contribution from ECF sources. However, in comparison to the amount of branched isomers in the ECF PFOA standard, such minor percentages of branched PFCAs may suggest additional input from an exclusively linear isomer source.

Nosema ceranae Infection Promotes Proliferation of Yeasts in Honey Bee Intestines.

PubMed

Ptaszyńska, Aneta A; Paleolog, Jerzy; Borsuk, Grzegorz

2016-01-01

Nosema ceranae infection not only damages honey bee (Apis melifera) intestines, but we believe it may also affect intestinal yeast development and its seasonal pattern. In order to check our hypothesis, infection intensity versus intestinal yeast colony forming units (CFU) both in field and cage experiments were studied. Field tests were carried out from March to October in 2014 and 2015. N. ceranae infection intensity decreased more than 100 times from 7.6 x 108 in March to 5.8 x 106 in October 2014. A similar tendency was observed in 2015. Therefore, in the European eastern limit of its range, N. ceranae infection intensity showed seasonality (spring peak and subsequent decline in the summer and fall), however, with an additional mid-summer peak that had not been recorded in other studies. Due to seasonal changes in the N. ceranae infection intensity observed in honey bee colonies, we recommend performing studies on new therapeutics during two consecutive years, including colony overwintering. A natural decrease in N. ceranae spore numbers observed from March to October might be misinterpreted as an effect of Nosema spp. treatment with new compounds. A similar seasonal pattern was observed for intestinal yeast population size in field experiments. Furthermore, cage experiments confirmed the size of intestinal yeast population to increase markedly together with the increase in the N. ceranae infection intensity. Yeast CFUs amounted to respectively 2,025 (CV = 13.04) and 11,150 (CV = 14.06) in uninfected and N. ceranae-infected workers at the end of cage experiments. Therefore, honey bee infection with N. ceranae supported additional opportunistic yeast infections, which may have resulted in faster colony depopulations.

Water level dynamics in wetlands and nesting success of Black Terns in Maine

USGS Publications Warehouse

Gilbert, A.T.; Servello, F.A.

2005-01-01

The Black Tern (Chlidonias niger) nests in freshwater wetlands that are prone to water level fluctuations, and nest losses to flooding are common. We examined temporal patterns in water levels at six sites with Black Tern colonies in Maine and determined probabilities of flood events and associated nest loss at Douglas Pond, the location of the largest breeding colony. Daily precipitation data from weather stations and water flow data from a flow gauge below Douglas Pond were obtained for 1960-1999. Information on nest losses from three floods at Douglas Pond in 1997-1999 were used to characterize small (6% nest loss), medium (56% nest loss) and large (94% nest loss) flood events, and we calculated probabilities of these three levels of flooding occurring at Douglas Pond using historic water levels data. Water levels generally decreased gradually during the nesting season at colony sites, except at Douglas Pond where water levels fluctuated substantially in response to rain events. Annual probabilities of small, medium, and large flood events were 68%, 35%, and 13% for nests initiated during 23 May-12 July, with similar probabilities for early (23 May-12 June) and late (13 June-12 July) periods. An index of potential nest loss indicated that medium floods at Douglas Pond had the greatest potential effect on nest success because they occurred relatively frequently and inundated large proportions of nests. Nest losses at other colonies were estimated to be approximately 30% of those at Douglas Pond. Nest losses to flooding appear to be common for the Black Tern in Maine and related to spring precipitation patterns, but ultimate effects on breeding productivity are uncertain.

Performance of Copan WASP for Routine Urine Microbiology

PubMed Central

Quiblier, Chantal; Jetter, Marion; Rominski, Mark; Mouttet, Forouhar; Böttger, Erik C.; Keller, Peter M.

2015-01-01

This study compared a manual workup of urine clinical samples with fully automated WASPLab processing. As a first step, two different inocula (1 and 10 μl) and different streaking patterns were compared using WASP and InoqulA BT instrumentation. Significantly more single colonies were produced with the10-μl inoculum than with the 1-μl inoculum, and automated streaking yielded significantly more single colonies than manual streaking on whole plates (P < 0.001). In a second step, 379 clinical urine samples were evaluated using WASP and the manual workup. Average numbers of detected morphologies, recovered species, and CFUs per milliliter of all 379 urine samples showed excellent agreement between WASPLab and the manual workup. The percentage of urine samples clinically categorized as positive or negative did not differ between the automated and manual workflow, but within the positive samples, automated processing by WASPLab resulted in the detection of more potential pathogens. In summary, the present study demonstrates that (i) the streaking pattern, i.e., primarily the number of zigzags/length of streaking lines, is critical for optimizing the number of single colonies yielded from primary cultures of urine samples; (ii) automated streaking by the WASP instrument is superior to manual streaking regarding the number of single colonies yielded (for 32.2% of the samples); and (iii) automated streaking leads to higher numbers of detected morphologies (for 47.5% of the samples), species (for 17.4% of the samples), and pathogens (for 3.4% of the samples). The results of this study point to an improved quality of microbiological analyses and laboratory reports when using automated sample processing by WASP and WASPLab. PMID:26677255

Accessory branch of median nerve supplying the brachialis muscle: a case report and clinical significance.

PubMed

Paraskevas, George; Anastasopoulos, Nikolaos; Nitsa, Zoi; Kitsoulis, Panagiotis; Spyridakis, Ioannis

2014-12-01

A very rare case of an accessory branch of the median nerve taking its origin in the region of the right arm was observed to supply the infero-medial portion of the brachialis muscle in a male cadaver. Simultaneously, the ipsilateral musculocutaneous nerve was innervating the muscles of the anterior compartment of the arm. Such an aberrant muscular branch of the median nerve for the brachialis muscle is very rarely reported in the literature. Lesion of the median nerve proximal to the branch's origin site could induce weak flexion of the elbow, whereas injury of the musculocutaneous nerve could lead to misinterpretation of symptoms. We discuss the patterns of brachialis muscle innervation as well as the clinical applications of such a variant.

Risk factors for the presence of Deformed wing virus and Acute bee paralysis virus under temperate and subtropical climate in Argentinian bee colonies.

PubMed

Molineri, Ana; Giacobino, Agostina; Pacini, Adriana; Bulacio Cagnolo, Natalia; Fondevila, Norberto; Ferrufino, Cecilia; Merke, Julieta; Orellano, Emanuel; Bertozzi, Ezequiel; Masciángelo, Germán; Pietronave, Hernán; Signorini, Marcelo

2017-05-01

Beekeepers all across the world are suffering important losses of their colonies, and the parasitic mites Varroa destructor and Nosema sp, as well as several bee viruses, are being pointed out as the possible causes of these losses, generally associated with environmental and management factors. The objective of the present study was to evaluate the presence of seven virus species (Deformed wing virus -DWV-, Acute bee paralysis virus -ABPV-, Chronic bee paralysis virus -CBPV-, Black queen cell virus -BQCV-, Kashmir bee virus -KBV-, Israeli acute bee paralysis virus -IAPV-, and Sacbrood bee virus -SBV), as well as the prevalence of Nosema sp. and Varroa destructor, and their possible associated factors, under temperate and subtropical climate conditions in Argentinean colonies. A total of 385 colonies distributed in five Argentinean eco-regions were examined after honey harvest. The final multivariable model revealed only one variable associated with the presence of DWV and two with the presence of ABPV. The apiary random effect was significant in both cases (P=0.018; P=0.006, respectively). Colonies with a Varroa infestation rate >3% showed higher presence of DWV than colonies with <3% of Varroa infestation level (OR=1.91; 95% CI: 1.02-3.57; P<0.044). The same pattern was observed for the presence of ABPV (OR=2.23; 95% CI: 1.04-4.77; P<0.039). Also, colonies where replacement of old combs was not a common practice had higher presence of ABPV (OR=6.02; 95% CI: 1.16-31.25; P<0.033). Regardless of the location of the colonies, virus presence was strongly associated with V. destructor level. Therefore, all the factors that directly or indirectly influence the levels of mites will be also influencing the presence of the viruses. Copyright © 2017 Elsevier B.V. All rights reserved.

Bio-physical modeling of time-resolved forward scattering by Listeria colonies

NASA Astrophysics Data System (ADS)

Bae, Euiwon; Banada, Padmapriya P.; Bhunia, Arun K.; Hirleman, E. Daniel

2006-10-01

We have developed a detection system and associated protocol based on optical forward scattering where the bacterial colonies of various species and strains growing on solid nutrient surfaces produced unique scatter signatures. The aim of the present investigation was to develop a bio-physical model for the relevant phenomena. In particular, we considered time-varying macroscopic morphological properties of the growing colonies and modeled the scattering using scalar diffraction theory. For the present work we performed detailed studies with three species of Listeria; L. innocua, L. monocytogenes, and L. ivanovii. The baseline experiments involved cultures grown on brain heart infusion (BHI) agar and the scatter images were captured every six hours for an incubation period of 42 hours. The morphologies of the colonies were studied by phase contrast microscopy, including measurement of the diameter of the colony. Growth curves, represented by colony diameter as a function of time, were compared with the time-evolution of scattering signatures. Similar studies were carried out with L. monocytogenes grown on different substrates. Non-dimensionalizing incubation time in terms of the time to reach stationary phase was effective in reducing the dimensionality of the model. Bio-physical properties of the colony such as diameter, bacteria density variation, surface curvature/profile, and transmission coefficient are important parameters in predicting the features of the forward scattering signatures. These parameters are included in a baseline model that treats the colony as a concentric structure with radial variations in phase modulation. In some cases azimuthal variations and random phase inclusions were included as well. The end result is a protocol (growth media, incubation time and conditions) that produces reproducible and distinguishable scatter patterns for a variety of harmful food borne pathogens in a short period of time. Further, the bio-physical model we developed is very effective in predicting the dominant features of the scattering signatures required by the identification process and will be effective for informing further improvements in the instrumentation.

Evaluating the Role of Drone-Produced Chemical Signals in Mediating Social Interactions in Honey Bees (Apis mellifera).

PubMed

Villar, Gabriel; Wolfson, Megan D; Hefetz, Abraham; Grozinger, Christina M

2018-01-01

Pheromones play a critical role in shaping societies of social insects, including honey bees, Apis mellifera. While diverse functions have been ascribed to queen- and worker-produced compounds, few studies have explored the identity and function of male-produced (drone) compounds. However, several lines of evidence suggest that drones engage in a variety of social interactions inside and outside of the colony. Here we elucidate the chemical composition of extracts of the drone mandibular gland, and test the hypothesis that compounds produced in these glands, or a synthetic blend consisting of the six main compounds, mediate drone social interactions in and out of the colony. Drone mandibular glands primarily produce a blend of saturated, unsaturated and methyl branched fatty acids ranging in chain length from nonanoic to docosanoic acids, and both gland extracts and synthetic blends of these chemicals serve to attract drones outside of the hive, but do not attract workers inside the hive. These studies shed light on the role drones and drone-produced chemicals have on mediating social interactions with other drones and highlight their potential importance in communicating with other castes.

[Lee Jungsook, a Korean independence activist and a nurse during the Japanese colonial period].

PubMed

Kim, Sook Young

2015-04-01

This article examines the life of Lee Jungsook, a Korean nurse, as a independence activist during the Japanese colonial period. Lee Jungsook(1896-1950) was born in Bukchung in Hamnam province. She studied at Chungshin girl's high school and worked at Severance hospital. The characteristics and culture of her educational background and work place were very important factors which influenced greatly the life of Lee Jungsook. She learned independent spirit and nationalism from Chungshin girls' high school and worked as nurse at the Severance hospital which were full of intense aspiration for Korea's independence. Many of doctors, professors and medical students were participated in the 3.1 Independence Movement. Lee Jungsook was a founding member of Hyulsungdan who tried to help the independence activists in prison and their families and worked as a main member of Korean Women's Association for Korean Independece and Kyungsung branch of the Korean Red Cross. She was sent to jail by the Japanese government for her independence activism. After being released after serving two years confinement, she worked for the Union for Women's Liberation as a founding member. Lee Joungsook was a great independence activist who had a nursing care spirit as a nurse.

Predation and aggressiveness in host plant protection: a generalization using ants from the genus Azteca

NASA Astrophysics Data System (ADS)

Dejean, Alain; Grangier, Julien; Leroy, Céline; Orivel, Jerôme

2009-01-01

In studying the ant genus Azteca, a Neotropical group of arboreal species, we aimed to determine the extent to which the ants use predation and/or aggressiveness to protect their host plants from defoliating insects. We compared a territorially dominant, carton-nester, Azteca chartifex, and three plant-ant species. Azteca alfari and Azteca ovaticeps are associated with the myrmecophyte Cecropia (Cecropiaceae) and their colonies shelter in its hollow branches; whereas Azteca bequaerti is associated with Tococa guianensis (Melastomataceae) and its colonies shelter in leaf pouches situated at the base of the laminas. Whereas A. bequaerti workers react to the vibrations transmitted by the lamina when an alien insect lands on a leaf making it unnecessary for them to patrol their plant, the workers of the three other species rather discover prey by contact. The workers of all four species use a predatory behaviour involving spread-eagling alien insects after recruiting nestmates at short range, and, in some cases, at long range. Because A. alfari and A. ovaticeps discard part of the insects they kill, we deduced that the workers’ predatory behaviour and territorial aggressiveness combine in the biotic defence of their host tree.

Predation and aggressiveness in host plant protection: a generalization using ants from the genus Azteca.

PubMed

Dejean, Alain; Grangier, Julien; Leroy, Céline; Orivel, Jerôme

2009-01-01

In studying the ant genus Azteca, a Neotropical group of arboreal species, we aimed to determine the extent to which the ants use predation and/or aggressiveness to protect their host plants from defoliating insects. We compared a territorially dominant, carton-nester, Azteca chartifex, and three plant-ant species. Azteca alfari and Azteca ovaticeps are associated with the myrmecophyte Cecropia (Cecropiaceae) and their colonies shelter in its hollow branches; whereas Azteca bequaerti is associated with Tococa guianensis (Melastomataceae) and its colonies shelter in leaf pouches situated at the base of the laminas. Whereas A. bequaerti workers react to the vibrations transmitted by the lamina when an alien insect lands on a leaf making it unnecessary for them to patrol their plant, the workers of the three other species rather discover prey by contact. The workers of all four species use a predatory behaviour involving spread-eagling alien insects after recruiting nestmates at short range, and, in some cases, at long range. Because A. alfari and A. ovaticeps discard part of the insects they kill, we deduced that the workers' predatory behaviour and territorial aggressiveness combine in the biotic defence of their host tree.

Granulocyte-macrophage colony-stimulating factor (GM-CSF) regulates cytokine induction by 1,3-beta-D-glucan SCG in DBA/2 mice in vitro.

PubMed

Harada, Toshie; Miura, Noriko N; Adachi, Yoshiyuki; Nakajima, Mitsuhiro; Yadomae, Toshiro; Ohno, Naohito

2004-08-01

Sparassis crispa Fr. is an edible/medicinal mushroom that recently became cultivable in Japan. SCG is a major 6-branched 1,3-beta-D-glucan in S. crispa showing antitumor activity. We recently found that the splenocytes from naive DBA/1 and DBA/2 mice strongly react with SCG to produce interferon-gamma (IFN-gamma). In this study, cytokines induced by SCG were screened and found to be IFN-gamma, tumor necrosis factor-alpha (TNF-alpha), granulocyte-macrophage colony-stimulating factor (GM-CSF), and interleukin-12 (IL-12p70). The addition of recombinant murine GM-CSF (rMuGM-CSF) to spleen cell cultures from various strains of mice synergistically enhanced IFN-gamma, TNF-alpha and IL-12p70 in the presence of SCG. In contrast, neutralizing GM-CSF using anti-GM-CSF monoclonal antibody (mAb) significantly inhibited IFN-gamma, TNF-alpha, and IL-12p70 elicited by SCG. We conclude that GM-CSF is a key molecule for cytokine induction by beta-glucan, and GM-CSF induction by SCG is the specific step in DBA/2 mice in vitro.

Regulation and control of intracellular algae (= zooxanthellae) in hard corals

PubMed Central

Jones, R. J.; Yellowlees, D.

1997-01-01

To examine algal (= zooxanthellae) regulation and control, and the factors determining algal densities in hard corals, the zooxanthellae mitotic index and release rates were regularly determined in branch tips from a colony of a staghorn coral, Acropora formosa, recovering from a coral 'bleaching' event (the stress-related dissociation of the coral–algal symbiosis). Mathematical models based upon density-dependent decreases in the algal division frequency and increases in algal release rates during the post-bleaching recovery period accurately predict the observed recovery period (ca. 20 weeks). The models suggest that (i) the colony recovered its algal population from the division of the remaining zooxanthellae, and (ii) the continual loss of zooxanthellae significantly slowed the recovery of the coral. Possible reasons for the 'paradoxical' loss of healthy zooxanthellae from the bleached coral are discussed in terms of endodermal processes occurring in the recovering coral and the redistribution of newly formed zooxanthellae to aposymbiotic host cells. At a steady-state algal density of 2.1 x 106 zooxanthellae cm-2 at the end of the recovery period, the zooxanthellae would have to form a double layer of cells in the coral tissues, consistent with microscopic observations. Neighbouring colonies of A. formosa with inherently higher algal densities possess proportionately smaller zooxanthellae. Results suggest that space availability and the size of the algal symbionts determines the algal densities in the coral colonies. The large increases in the algal densities reported in corals exposed to elevated nutrient concentrations (i.e between a two- and five-fold increase in the algal standing stock) are not consistent with this theory. We suggest that increases of this magnitude are a product of the experimental conditions: reasons for this statement are discussed. We propose that the stability of the coral–algal symbiosis under non-stress conditions, and the constancy of zooxanthellae densities in corals reported across growth form, depth and geographic range, are related to space availability limiting algal densities. However, at these densities, zooxanthellae have attributes consistent with nutrient limitation.

Shoot development in grapevine (Vitis vinifera) is affected by the modular branching pattern of the stem and intra- and inter-shoot trophic competition.

PubMed

Lebon, Eric; Pellegrino, Anne; Tardieu, Francois; Lecoeur, Jeremie

2004-03-01

Shoot architecture variability in grapevine (Vitis vinifera) was analysed using a generic modelling approach based on thermal time developed for annual herbaceous species. The analysis of shoot architecture was based on various levels of shoot organization, including pre-existing and newly formed parts of the stem, and on the modular structure of the stem, which consists of a repeated succession of three phytomers (P0-P1-P2). Four experiments were carried out using the cultivar 'Grenache N': two on potted vines (one of which was carried out in a glasshouse) and two on mature vines in a vineyard. These experiments resulted in a broad diversity of environmental conditions, but none of the plants experienced soil water deficit. Development of the main axis was highly dependent on air temperature, being linearly related to thermal time for all stages of leaf development from budbreak to veraison. The stable progression of developmental stages along the main stem resulted in a thermal-time based programme of leaf development. Leaf expansion rate varied with trophic competition (shoot and cluster loads) and environmental conditions (solar radiation, VPD), accounting for differences in final leaf area. Branching pattern was highly variable. Classification of the branches according to ternary modular structure increased the accuracy of the quantitative analysis of branch development. The rate and duration of leaf production were higher for branches derived from P0 phytomers than for branches derived from P1 or P2 phytomers. Rates of leaf production, expressed as a -function of thermal time, were not stable and depended on trophic competition and environmental conditions such as solar radiation or VPD. The application to grapevine of a generic model developed in annual plants made it possible to identify constants in main stem development and to determine the hierarchical structure of branches with respect to the modular structure of the stem in response to intra- and inter-shoot trophic competition.

Growth of modern branched columnar stromatolites in Lake Joyce, Antarctica.

PubMed

Mackey, T J; Sumner, D Y; Hawes, I; Jungblut, A D; Andersen, D T

2015-07-01

Modern decimeter-scale columnar stromatolites from Lake Joyce, Antarctica, show a change in branching pattern during a period of lake level rise. Branching patterns correspond to a change in cyanobacterial community composition as preserved in authigenic calcite crystals. The transition in stromatolite morphology is preserved by mineralized layers that contain microfossils and cylindrical molds of cyanobacterial filaments. The molds are composed of two populations with different diameters. Large diameter molds (>2.8 μm) are abundant in calcite forming the oldest stromatolite layers, but are absent from younger layers. In contrast, <2.3 μm diameter molds are common in all stromatolites layers. Loss of large diameter molds corresponds to the transition from smooth-sided stromatolitic columns to branched and irregular columns. Mold diameters are similar to trichome diameters of the four most abundant living cyanobacteria morphotypes in Lake Joyce: Phormidium autumnale morphotypes have trichome diameters >3.5 μm, whereas Leptolyngbya antarctica, L. fragilis, and Pseudanabaena frigida morphotypes have diameters <2.3 μm. P. autumnale morphotypes were only common in mats at <12 m depth. Mats containing abundant P. autumnale morphotypes were smooth, whereas mats with few P. autumnale morphotypes contained small peaks and protruding bundles of filaments, suggesting that the absence of P. autumnale morphotypes allowed small-scale topography to develop on mats. Comparisons of living filaments and mold diameters suggest that P. autumnale morphotypes were present early in stromatolite growth, but disappeared from the community through time. We hypothesize that the mat-smoothing behavior of P. autumnale morphotypes inhibited nucleation of stromatolite branches. When P. autumnale morphotypes were excluded from the community, potentially reflecting a rise in lake level, short-wavelength roughness provided nuclei for stromatolite branches. This growth history provides a conceptual model for initiation of branched stromatolite growth resulting from a change in microbial community composition. © 2015 John Wiley & Sons Ltd.

The ureteric bud epithelium: morphogenesis and roles in metanephric kidney patterning.

PubMed

Nagalakshmi, Vidya K; Yu, Jing

2015-03-01

The mammalian metanephric kidney is composed of two epithelial components, the collecting duct system and the nephron epithelium, that differentiate from two different tissues -the ureteric bud epithelium and the nephron progenitors, respectively-of intermediate mesoderm origin. The collecting duct system is generated through reiterative ureteric bud branching morphogenesis, whereas the nephron epithelium is formed in a process termed nephrogenesis, which is initiated with the mesenchymal-epithelial transition of the nephron progenitors. Ureteric bud branching morphogenesis is regulated by nephron progenitors, and in return, the ureteric bud epithelium regulates nephrogenesis. The metanephric kidney is physiologically divided along the corticomedullary axis into subcompartments that are enriched with specific segments of these two epithelial structures. Here, we provide an overview of the major molecular and cellular processes underlying the morphogenesis and patterning of the ureteric bud epithelium and its roles in the cortico-medullary patterning of the metanephric kidney. © 2015 Wiley Periodicals, Inc.

Pattern formation and collective effects in populations of magnetic microswimmers

NASA Astrophysics Data System (ADS)

Vach, Peter J.; Walker, Debora; Fischer, Peer; Fratzl, Peter; Faivre, Damien

2017-03-01

Self-propelled particles are one prototype of synthetic active matter used to understand complex biological processes, such as the coordination of movement in bacterial colonies or schools of fishes. Collective patterns such as clusters were observed for such systems, reproducing features of biological organization. However, one limitation of this model is that the synthetic assemblies are made of identical individuals. Here we introduce an active system based on magnetic particles at colloidal scales. We use identical but also randomly-shaped magnetic micropropellers and show that they exhibit dynamic and reversible pattern formation.

Branch pattern of starch internal structure influences the glucogenesis by mucosal Nt-maltase-glucoamylase.

PubMed

Lin, Amy Hui-Mei; Ao, Zihua; Quezada-Calvillo, Roberto; Nichols, Buford L; Lin, Chi-Tien; Hamaker, Bruce R

2014-10-13

To produce sufficient amounts of glucose from food starch, both α-amylase and mucosal α-glucosidases are required. We found previously that the digestion rate of starch is influenced by its susceptibility to mucosal α-glucosidases. In the present study, six starches and one glycogen were pre-hydrolyzed by α-amylase for various time periods, and then further hydrolyzed with the mucosal α-glucosidase, the N-terminal subunit of maltase-glucoamylase (Nt-MGAM), to generate free glucose. Results showed that α-amylase amplified the Nt-MGAM glucogenesis, and that the amplifications differed in various substrates. The amount of branches within α-amylase hydrolysate substrates was highly related to the rate of Nt-MGAM glucogenesis. After de-branching, the hydrolysates showed three fractions, Fraction 1, 2, and 3, in size exclusion chromatographs. We found that the α-amylase hydrolysates with higher quantity of the Fraction 3 (molecules with relatively short chain-length) and shorter average chain-length of this fraction had lower rates of Nt-MGAM glucogenesis. This study revealed that the branch pattern of α-amylase hydrolysates modulates glucose release by Nt-MGAM. It further supported the hypothesis that the internal structure of starch affects its digestibility at the mucosal α-glucosidase level. Published by Elsevier Ltd.

Developmental Programming of Branching Morphogenesis in the Kidney

PubMed Central

Schneider, Laura; Al-Awqati, Qais

2015-01-01

The kidney developmental program encodes the intricate branching and organization of approximately 1 million functional units (nephrons). Branching regulation is poorly understood, as is the source of a 10-fold variation in nephron number. Notably, low nephron count increases the risk for developing hypertension and renal failure. To better understand the source of this variation, we analyzed the complete gestational trajectory of mouse kidney development. We constructed a computerized architectural map of the branching process throughout fetal life and found that organogenesis is composed of two distinct developmental phases, each with stage-specific rate and morphologic parameters. The early phase is characterized by a rapid acceleration in branching rate and by branching divisions that repeat with relatively reproducible morphology. The latter phase, however, is notable for a significantly decreased yet constant branching rate and the presence of nonstereotyped branching events that generate progressive variability in tree morphology until birth. Our map identifies and quantitates the contribution of four developmental mechanisms that guide organogenesis: growth, patterning, branching rate, and nephron induction. When applied to organs that developed under conditions of malnutrition or in the setting of growth factor mutation, our normative map provided an essential link between kidney architecture and the fundamental morphogenetic mechanisms that guide development. This morphogenetic map is expected to find widespread applications and help identify modifiable targets to prevent developmental programming of common diseases. PMID:25644110

Developmental Programming of Branching Morphogenesis in the Kidney.

PubMed

Sampogna, Rosemary V; Schneider, Laura; Al-Awqati, Qais

2015-10-01

The kidney developmental program encodes the intricate branching and organization of approximately 1 million functional units (nephrons). Branching regulation is poorly understood, as is the source of a 10-fold variation in nephron number. Notably, low nephron count increases the risk for developing hypertension and renal failure. To better understand the source of this variation, we analyzed the complete gestational trajectory of mouse kidney development. We constructed a computerized architectural map of the branching process throughout fetal life and found that organogenesis is composed of two distinct developmental phases, each with stage-specific rate and morphologic parameters. The early phase is characterized by a rapid acceleration in branching rate and by branching divisions that repeat with relatively reproducible morphology. The latter phase, however, is notable for a significantly decreased yet constant branching rate and the presence of nonstereotyped branching events that generate progressive variability in tree morphology until birth. Our map identifies and quantitates the contribution of four developmental mechanisms that guide organogenesis: growth, patterning, branching rate, and nephron induction. When applied to organs that developed under conditions of malnutrition or in the setting of growth factor mutation, our normative map provided an essential link between kidney architecture and the fundamental morphogenetic mechanisms that guide development. This morphogenetic map is expected to find widespread applications and help identify modifiable targets to prevent developmental programming of common diseases. Copyright © 2015 by the American Society of Nephrology.

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

PubMed

Lehoux, Caroline; Cloutier, Richard

2015-11-01

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

Dynamics of spacing adjustment and recovery mechanisms of ABAC-type growth pattern in ternary eutectic systems

NASA Astrophysics Data System (ADS)

Mohagheghi, Samira; Şerefoğlu, Melis

2017-07-01

In directionally solidified 2D samples at ternary eutectic compositions, the stable three-phase pattern is established to be lamellar structure with ABAC stacking, where A, B, and C are crystalline phases. Beyond the stability limits of the ABAC pattern, the system uses various spacing adjustment mechanisms to revert to the stable regime. In this study, the dynamics of spacing adjustment and recovery mechanisms of isotropic ABAC patterns were investigated using three-phase In-Bi-Sn alloy. Unidirectional solidification experiments were performed on 23.0 and 62.7 μm-thick samples, where solidification front was monitored in real-time from both sides of the sample using a particular microscopy system. At these thicknesses, the pattern was found to be 2D during steady-state growth, i.e. both top and bottom microstructures were the same. However, during spacing adjustment and recovery mechanisms, 3D features were observed. Dynamics of two major instabilities, lamellae branching and elimination, were quantified. After these instabilities, two key ABAC pattern recovery mechanisms, namely, phase invasion and phase exchange processes, were identified and analyzed. After elimination, ABAC pattern is recovered by either continuous eliminations of all phases or by phase exchange. After branching, the recovery mechanisms are established to be phase invasion and phase exchange.

Immune defense in leaf-cutting ants: a cross-fostering approach.

PubMed

Armitage, Sophie A O; Broch, Jens F; Marín, Hermogenes Fernández; Nash, David R; Boomsma, Jacobus J

2011-06-01

To ameliorate the impact of disease, social insects combine individual innate immune defenses with collective social defenses. This implies that there are different levels of selection acting on investment in immunity, each with their own trade-offs. We present the results of a cross-fostering experiment designed to address the influences of genotype and social rearing environment upon individual and social immune defenses. We used a multiply mating leaf-cutting ant, enabling us to test for patriline effects within a colony, as well as cross-colony matriline effects. The worker's father influenced both individual innate immunity (constitutive antibacterial activity) and the size of the metapleural gland, which secretes antimicrobial compounds and functions in individual and social defense, indicating multiple mating could have important consequences for both defense types. However, the primarily social defense, a Pseudonocardia bacteria that helps to control pathogens in the ants' fungus garden, showed a significant colony of origin by rearing environment interaction, whereby ants that acquired the bacteria of a foster colony obtained a less abundant cover of bacteria: one explanation for this pattern would be co-adaptation between host colonies and their vertically transmitted mutualist. These results illustrate the complexity of the selection pressures that affect the expression of multilevel immune defenses. © 2011 The Author(s). Evolution© 2011 The Society for the Study of Evolution.

Microtubule nucleation and organization in dendrites

PubMed Central

Delandre, Caroline; Amikura, Reiko; Moore, Adrian W.

2016-01-01

ABSTRACT Dendrite branching is an essential process for building complex nervous systems. It determines the number, distribution and integration of inputs into a neuron, and is regulated to create the diverse dendrite arbor branching patterns characteristic of different neuron types. The microtubule cytoskeleton is critical to provide structure and exert force during dendrite branching. It also supports the functional requirements of dendrites, reflected by differential microtubule architectural organization between neuron types, illustrated here for sensory neurons. Both anterograde and retrograde microtubule polymerization occur within growing dendrites, and recent studies indicate that branching is enhanced by anterograde microtubule polymerization events in nascent branches. The polarities of microtubule polymerization events are regulated by the position and orientation of microtubule nucleation events in the dendrite arbor. Golgi outposts are a primary microtubule nucleation center in dendrites and share common nucleation machinery with the centrosome. In addition, pre-existing dendrite microtubules may act as nucleation sites. We discuss how balancing the activities of distinct nucleation machineries within the growing dendrite can alter microtubule polymerization polarity and dendrite branching, and how regulating this balance can generate neuron type-specific morphologies. PMID:27097122

Fault Branching and Long-Term Earthquake Rupture Scenario for Strike-Slip Earthquake

NASA Astrophysics Data System (ADS)

Klinger, Y.; CHOI, J. H.; Vallage, A.

2017-12-01

Careful examination of surface rupture for large continental strike-slip earthquakes reveals that for the majority of earthquakes, at least one major branch is involved in the rupture pattern. Often, branching might be either related to the location of the epicenter or located toward the end of the rupture, and possibly related to the stopping of the rupture. In this work, we examine large continental earthquakes that show significant branches at different scales and for which ground surface rupture has been mapped in great details. In each case, rupture conditions are described, including dynamic parameters, past earthquakes history, and regional stress orientation, to see if the dynamic stress field would a priori favor branching. In one case we show that rupture propagation and branching are directly impacted by preexisting geological structures. These structures serve as pathways for the rupture attempting to propagate out of its shear plane. At larger scale, we show that in some cases, rupturing a branch might be systematic, hampering possibilities for the development of a larger seismic rupture. Long-term geomorphology hints at the existence of a strong asperity in the zone where the rupture branched off the main fault. There, no evidence of throughgoing rupture could be seen along the main fault, while the branch is well connected to the main fault. This set of observations suggests that for specific configurations, some rupture scenarios involving systematic branching are more likely than others.

A systematic review and meta-analysis of variations in branching patterns of the adult aortic arch.

PubMed

Popieluszko, Patrick; Henry, Brandon Michael; Sanna, Beatrice; Hsieh, Wan Chin; Saganiak, Karolina; Pękala, Przemysław A; Walocha, Jerzy A; Tomaszewski, Krzysztof A

2018-07-01

The aortic arch (AA) is the main conduit of the left side of the heart, providing a blood supply to the head, neck, and upper limbs. As it travels through the thorax, the pattern in which it gives off the branches to supply these structures can vary. Variations of these branching patterns have been studied; however, a study providing a comprehensive incidence of these variations has not yet been conducted. The objective of this study was to perform a meta-analysis of all the studies that report prevalence data on AA variants and to provide incidence data on the most common variants. A systematic search of online databases including PubMed, Embase, Scopus, ScienceDirect, Web of Science, SciELO, BIOSIS, and CNKI was performed for literature describing incidence of AA variations in adults. Studies including prevalence data on adult patients or cadavers were collected and their data analyzed. A total of 51 articles were included (N = 23,882 arches). Seven of the most common variants were analyzed. The most common variants found included the classic branching pattern, defined as a brachiocephalic trunk, a left common carotid, and a left subclavian artery (80.9%); the bovine arch variant (13.6%); and the left vertebral artery variant (2.8%). Compared by geographic data, bovine arch variants were noted to have a prevalence as high as 26.8% in African populations. Although patients who have an AA variant are often asymptomatic, they compose a significant portion of the population of patients and pose a greater risk of hemorrhage and ischemia during surgery in the thorax. Because of the possibility of encountering such variants, it is prudent for surgeons to consider potential variations in planning procedures, especially of an endovascular nature, in the thorax. Copyright © 2017 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

Relationship of Caspian tern foraging ecology to nesting success in the Columbia River estuary, Oregon, USA

NASA Astrophysics Data System (ADS)

Anderson, Scott K.; Roby, Daniel D.; Lyons, Donald E.; Collis, Ken

2007-07-01

The prevalence of juvenile salmonids ( Oncorhynchus spp.) and marine forage fishes in the diet of Caspian terns ( Hydroprogne caspia) nesting in the Columbia River estuary has been established, but the relationship between diet composition, foraging distribution, and productivity of these birds has received little attention. We used radio-telemetry and on-colony observations to relate changes in off-colony distribution to patterns of colony attendance, diet composition, and productivity of adult terns nesting on East Sand Island during two years of different river and prey conditions. Average distance from the East Sand Island colony (located in the marine zone of the estuary) was 38% (6.6 km) greater in 2000 compared to 2001, associated with lower availability of marine forage fish near East Sand Island and lower prevalence of marine prey in tern diets. Colony attendance was much lower (37.0% vs. 62.5% of daylight hours), average trip duration was 40% longer (38.9 min), and nesting success was much lower (0.57 young fledged pair -1 vs. 1.40 young fledged pair -1) in 2000 compared to 2001. Higher proportions of juvenile salmonids in the diet were associated with relatively high use of the freshwater zone of the estuary by radio-tagged terns, which occurred prior to chick-rearing and when out-migrating salmonid smolts were relatively abundant. Lower availability of marine prey in 2000 apparently limited Caspian tern nesting success by markedly reducing colony attendance and lengthening foraging trips by nesting terns, thereby increasing chick mortality rates from predation, exposure, and starvation.

Relationship of Caspian tern foraging ecology to nesting success in the Columbia River estuary, Oregon, USA

USGS Publications Warehouse

Anderson, Scott K.; Roby, D.D.; Lyons, Donald E.; Collis, K.

2007-01-01

The prevalence of juvenile salmonids (Oncorhynchus spp.) and marine forage fishes in the diet of Caspian terns (Hydroprogne caspia) nesting in the Columbia River estuary has been established, but the relationship between diet composition, foraging distribution, and productivity of these birds has received little attention. We used radio-telemetry and on-colony observations to relate changes in off-colony distribution to patterns of colony attendance, diet composition, and productivity of adult terns nesting on East Sand Island during two years of different river and prey conditions. Average distance from the East Sand Island colony (located in the marine zone of the estuary) was 38% (6.6 km) greater in 2000 compared to 2001, associated with lower availability of marine forage fish near East Sand Island and lower prevalence of marine prey in tern diets. Colony attendance was much lower (37.0% vs. 62.5% of daylight hours), average trip duration was 40% longer (38.9 min), and nesting success was much lower (0.57 young fledged pair-1 vs. 1.40 young fledged pair-1) in 2000 compared to 2001. Higher proportions of juvenile salmonids in the diet were associated with relatively high use of the freshwater zone of the estuary by radio-tagged terns, which occurred prior to chick-rearing and when out-migrating salmonid smolts were relatively abundant. Lower availability of marine prey in 2000 apparently limited Caspian tern nesting success by markedly reducing colony attendance and lengthening foraging trips by nesting terns, thereby increasing chick mortality rates from predation, exposure, and starvation. ?? 2007 Elsevier Ltd. All rights reserved.

Variation in spatial scale of competing polydomous twig-nesting ants in coffee agroecosystems

PubMed Central

Mathis, Kaitlyn A.; Philpott, Stacy M.; Ramirez, Santiago R.

2016-01-01

Arboreal ants are both highly diverse and ecologically dominant in the tropics. This ecologically important group is particularly useful in ongoing efforts to understand processes that regulate species diversity and coexistence. Our study addresses how polydomy can influence patterns of nest occupation in competing arboreal ants. We examined the spatial structure of nest occupation (nest distance, abundance and density) in three polydomous co-occurring twig-nesting ant species (Pseudomyrmex simplex, P. ejectus and P. PSW-53) by mapping twigs occupied by ants from each species within plots in our study site. We then used two colony structure estimators (intraspecific aggression and cuticular hydrocarbon variation) to determine the relative degree of polydomy for each species. All work was conducted in coffee agroforests in Chiapas, Mexico. Our results revealed that the two species with highest abundance and nest density were also highly polydomous, where both species had either single or multiple non-aggressive colonies occupying nests on a large spatial scale (greater than the hectare level). Our results also indicate that the species with the lowest abundance and density is less polydomous, occupying several overlapping and territorial colonies at the hectare level in which multiple colonies never co-occur on the same host plant. These results contribute evidence that successful coexistence and highly polydomous colony structure may allow ants, through reduced intraspecific aggression, to successfully occupy more nests more densely than ant species that have multiple territorial colonies. Furthermore our study highlights the importance of considering intraspecific interactions when examining community assembly of ants. PMID:27795573

Colony-level variation in pollen collection and foraging preferences among wild-caught bumble bees (Hymenoptera: Apidae).

PubMed

Saifuddin, Mustafa; Jha, Shalene

2014-04-01

Given that many pollinators have exhibited dramatic declines related to habitat destruction, an improved understanding of pollinator resource collection across human-altered landscapes is essential to conservation efforts. Despite the importance of bumble bees (Bombus spp.) as global pollinators, little is known regarding how pollen collection patterns vary between individuals, colonies, and landscapes. In this study, Vosnesensky bumble bees (Bombus vosnesenskii Radoszkowski) were collected from a range of human-altered and natural landscapes in northern California. Extensive vegetation surveys and Geographic Information System (GIS)-based habitat classifications were conducted at each site, bees were genotyped to identify colony mates, and pollen loads were examined to identify visited plants. In contrast to predictions based on strong competitive interactions, pollen load composition was significantly more similar for bees captured in a shared study region compared with bees throughout the research area but was not significantly more similar for colony mates. Preference analyses revealed that pollen loads were not composed of the most abundant plant species per study region. The majority of ranked pollen preference lists were significantly correlated for pairwise comparisons of colony mates and individuals within a study region, whereas the majority of pairwise comparisons of ranked pollen preference lists between individuals located at separate study regions were uncorrelated. Results suggest that pollen load composition and foraging preferences are similar for bees throughout a shared landscape regardless of colony membership. The importance of native plant species in pollen collection is illustrated through preference analyses, and we suggest prioritization of specific rare native plant species for enhanced bumble bee pollen collection.

A Strain of Bacillus sphaericus Causes Slower Development of Resistance in Culex quinquefasciatus

PubMed Central

Pei, Guofeng; Oliveira, Cláudia M. F.; Yuan, Zhiming; Nielsen-LeRoux, Christina; Silva-Filha, Maria Helena; Yan, Jianpin; Regis, Lêda

2002-01-01

Two field-collected Culex quinquefasciatus colonies were subjected to selection pressure by three strains of Bacillus sphaericus, C3-41, 2362, and IAB59, under laboratory conditions. After 13 and 18 generations of exposure to high concentrations of C3-41 and IAB59, a field-collected low-level-resistant colony developed >144,000- and 46.3-fold resistance to strains C3-41 and IAB59, respectively. A field-collected susceptible colony was selected with 2362 and IAB59 for 46 and 12 generations and attained >162,000- and 5.7-fold resistance to the two agents, respectively. The pattern of resistance evolution in mosquitoes depended on continuous selection pressure, and the stronger the selection pressure, the more quickly resistance developed. The resistant colonies obtained after selection with B. sphaericus C3-41 and 2362 showed very high levels of cross-resistance to B. sphaericus 2362 and C3-41, respectively, but they displayed only low-level cross-resistance to IAB59. On the other hand, the IAB59-selected colonies had high cross-resistance to both strains C3-41 and 2362. Additionally, the slower evolution of resistance against strain IAB59 may be explained by the presence of another larvicidal factor. This is in agreement with the nontoxicity of the cloned and purified binary toxin (Bin1) of IAB59 for 2362-resistant larvae. We also verified that all the B. sphaericus-selected colonies showed no cross-resistance to Bacillus thuringiensis subsp. israelensis, suggesting that it would be a promising alternative in managing resistance to B. sphaericus in C. quinquefasciatus larvae. PMID:12039761

Pteridine levels and head weights are correlated with age and colony task in the honey bee, Apis mellifera

PubMed Central

Rinkevich, Frank D.; Margotta, Joseph W.; Pittman, Jean M.; Ottea, James A.

2016-01-01

Background. The age of an insect strongly influences many aspects of behavior and reproduction. The interaction of age and behavior is epitomized in the temporal polyethism of honey bees in which young adult bees perform nurse and maintenance duties within the colony, while older bees forage for nectar and pollen. Task transition is dynamic and driven by colony needs. However, an abundance of precocious foragers or overage nurses may have detrimental effects on the colony. Additionally, honey bee age affects insecticide sensitivity. Therefore, determining the age of a set of individual honey bees would be an important measurement of colony health. Pteridines are purine-based pigment molecules found in many insect body parts. Pteridine levels correlate well with age, and wild caught insects may be accurately aged by measuring pteridine levels. The relationship between pteridines and age varies with a number of internal and external factors among many species. Thus far, no studies have investigated the relationship of pteridines with age in honey bees. Methods. We established single-cohort colonies to obtain age-matched nurse and forager bees. Bees of known ages were also sampled from colonies with normal demographics. Nurses and foragers were collected every 3–5 days for up to 42 days. Heads were removed and weighed before pteridines were purified and analyzed using previously established fluorometric methods. Results. Our analysis showed that pteridine levels significantly increased with age in a linear manner in both single cohort colonies and colonies with normal demography. Pteridine levels were higher in foragers than nurses of the same age in bees from single cohort colonies. Head weight significantly increased with age until approximately 28-days of age and then declined for both nurse and forager bees in single cohort colonies. A similar pattern of head weight in bees from colonies with normal demography was observed but head weight was highest in 8-day old nurse bees and there was no relationship of head weight with age of foragers. Discussion. Although the relationship between pteridine levels and age was significant, variation in the data yielded a +4-day range in age estimation. This allows an unambiguous method to determine whether a bee may be a young nurse or old forager in colonies with altered demographics as in the case of single cohort colonies. Pteridine levels in bees do not correlate with age as well as in other insects. However, most studies used insects reared under tightly controlled laboratory conditions, while we used free-living bees. The dynamics of head weight change with age is likely to be due to growth and atrophy of the hypopharyngeal glands. Taken together, these methods represent a useful tool for assessing the age of an insect. Future studies utilizing these methods will provide a more holistic view of colony health. PMID:27413635

Reconnaissance of the hydrology, water quality, and sources of bacterial and nutrient contamination in the Ozark Plateaus aquifer system and Cave Springs Branch of Honey Creek, Delaware County, Oklahoma, March 1999-March 2000

USGS Publications Warehouse

Schlottmann, Jamie L.; Tanner, Ralph S.; Samadpour, Mansour

2000-01-01

A reconnaissance investigation of hydrology and water quality was conducted to evaluate possible sources of bacteria and nutrient contamination in the Cave Springs Branch basin and the underlying karstic Ozark Plateau aquifer system. Objectives were to: (1) determine the directions of ground-water flow in the basin and determine whether Cave Springs Branch interacts with ground water, (2) compare water quality in Cave Springs Branch with water quality in nearby wells to determine whether the stream is contaminating nearby wells, and (3) determine sources of fecal coliform bacteria and nitrate contamination in Cave Springs Branch and ground water. Potential sources of bacteria and nitrate in the area include cultivated agriculture, cow and horse on pasture, poultry production, households, and wildlife. Presence of fecal coliform and fecal streptococcal bacteria directly indicate fecal contamination and the potential for the presence of other pathogenic organisms in a water supply. Nitrate in drinking water poses health risks and may indicate the presence of additional contaminants. Fecal coliform bacteria colony counts were least in wells, intermediate in the poultry-processing plant wastewater outfall and Honey Creek above the confluence with Cave Springs Branch, and greatest in Cave Springs Branch. Bacteria strains and resistance to antibiotics by some bacteria indicate that livestock may have been sources of some bacteria in the water samples. Multiple antibiotic resistances were not present in the isolates from the water samples, indicating that the bacteria may not be from human or poultry sources. Ribotyping indicates that Escherichia coli bacteria in water samples from the basin were from bird, cow, horse, dog, deer, and human sources. The presence of multiple ribotypes from each type of animal source except bird indicates that most of the bacteria are from multiple populations of source animals. Identifiable sources of bacteria in Cave Springs Branch at the state line were dominantly cow and horse with one ribotype from bird. Escherichia coli was detected in only one well sample. Bacterial ribotypes in water from that upgradient well indicated human and dog feces as sources for bacteria, and that on site wastewater treatment may not always be adequate in these highly permeable soils. Greater concentrations of nitrate in Cave Springs Branch and O'Brien Spring relative to the poultry-processing plant wastewater outfall may be due, in part, to conversion of ammonia from poultry processing plant wastewater. The poultry-processing plant wastewater outfall sample collected in March 2000 contained greater concentrations of ammonia and total organic nitrogen plus ammonia than the spring, stream, and well samples collected during August 1999. Cave Springs Branch and Honey Creek contributed approximately equal loads of nitrogen to Honey Creek below the confluence and the greatest loads of nitrogen were introduced to Cave Springs Branch by the poultry processing plant wastewater outfall and O'Brien Spring. Nitrate concentrations in upgradient well samples ranged from 0.38 to 4.60 milligrams per liter, indicating that there are sources of ground-water nitrogen other than Cave Springs Branch, such as animal waste, fertilizer, or human waste. Nitrogen compounds in water from wells downgradient of Cave Springs Branch may be from Cave Springs Branch, fertilizers, animal waste, or human waste.

A discrete artificial bee colony algorithm for detecting transcription factor binding sites in DNA sequences.

PubMed

Karaboga, D; Aslan, S

2016-04-27

The great majority of biological sequences share significant similarity with other sequences as a result of evolutionary processes, and identifying these sequence similarities is one of the most challenging problems in bioinformatics. In this paper, we present a discrete artificial bee colony (ABC) algorithm, which is inspired by the intelligent foraging behavior of real honey bees, for the detection of highly conserved residue patterns or motifs within sequences. Experimental studies on three different data sets showed that the proposed discrete model, by adhering to the fundamental scheme of the ABC algorithm, produced competitive or better results than other metaheuristic motif discovery techniques.