Science.gov

Sample records for leper colonies

  1. Colonial America.

    ERIC Educational Resources Information Center

    Web Feet K-8, 2001

    2001-01-01

    Presents resources for grades K-8, on the subject of Colonial America. Describes Web sites; CD-ROMs and software; videos; books; audios; magazines; and professional resources. Includes two articles, "Native Americans in the Colonies," and "The Golden Age of Pirates," which also highlight resources. Presents a Web activity focusing on daily life in…

  2. The Amana Colonies.

    ERIC Educational Resources Information Center

    Lilja, Marilyn

    Designed for use in Iowa elementary schools, this unit introduces students to Iowa's Amana Colonies. Four lessons cover the history and cultural heritage of the colonies, daily life in historical times, daily life in modern times, and the colonies as a corporate museum. Throughout the lessons, emphasis is placed on the values and organization of…

  3. Murre Colony, Inset Detail

    USGS Multimedia Gallery

    This inset of the associated murre colony photo shows evidence of nesting and chick-feeding in a California common murre colony on Prince Island off San Miguel Island off Southern California. Ecologists Josh Adams and Jonathan Felis of the USGS Western Ecological Research Center shot this and other ...

  4. Registration of Colony Switchgrass

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Colony (Reg. No. __________, PI 658520) is a lowland cytotype of switchgrass (Panicum virgatum L.) developed and released by the USDA-ARS and North Carolina Agricultural Research Service. Colony was developed from three cycles of selection with random cross pollination occurring in cycle 0, index se...

  5. Chlamydomonas (Chlorophyceae) colony PCR.

    PubMed

    Cao, Muqing; Fu, Yu; Guo, Yan; Pan, Junmin

    2009-03-01

    The ease and effectiveness of colony polymerase chain reaction (PCR) has allowed rapid amplification of DNA fragments and screening of large number of colonies of interest including transformants and mutants with genetic manipulations. Here, we evaluated colony PCR in Chlamydomonas. Individual colonies were treated with 10 mM ethylenediaminetetraacetic acid (EDTA) or Chelex-100 and the resulting clear cell lysate was used for PCR reaction. Either genomic DNA or plasmid DNA incorporated into the genome was equally amplified. We found that the Chelex method is superior to EDTA method in certain cases. This colony PCR technique will bypass the tedious process of isolating genomic DNA for PCR reaction and will make it possible for rapid amplification of genomic DNA fragments as well as rapid large-scale screening of transformants. PMID:19242652

  6. Robotic space colonies

    NASA Technical Reports Server (NTRS)

    Schenker, P.; Easter, R.; Rodriguez, G.

    2001-01-01

    This paper reviews recent advances in these technologies, with a particular focus on experimental state-of-the-art robot work crew system demonstrations at JPL, that are being conducted now to begin to realize the futuristic robotic colony vision.

  7. Growth of Bacterial Colonies

    NASA Astrophysics Data System (ADS)

    Warren, Mya; Hwa, Terence

    2013-03-01

    On hard agar gel, there is insufficient surface hydration for bacteria to swim or swarm. Instead, growth occurs in colonies of close-packed cells, which expand purely due to repulsive interactions: individual bacteria push each other out of the way through the force of their growth. In this way, bacterial colonies represent a new type of ``active'' granular matter. In this study, we investigate the physical, biochemical, and genetic elements that determine the static and dynamic aspects of this mode of bacterial growth for E. coli. We characterize the process of colony expansion empirically, and use discrete and continuum models to examine the extent to which our observations can be explained by the growth characteristics of non-communicating cells, coupled together by physical forces, nutrients, and waste products. Our results challenge the commonly accepted modes of bacterial colony growth and provide insight into sources of growth limitation in crowded bacterial communities.

  8. Plymouth Colony, Massachusetts, USA

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Site of the original Plymouth Colony in Massachusetts (42.0N, 70.5), This detailed photo is rich in early American history. Plymouth Rock, the Pilgrims first stepping stone on North America and site of Plymouth Colony is located just behind the natural breakwater on the south shore of Plymouth Bay seen in the middle of the photo. The through canal to the south is part of the Intercoastal Canal system. Cape Cod is just south of the canal.

  9. [Visiting the Amana Colonies.

    ERIC Educational Resources Information Center

    Ohrn, Deborah Gore, Ed.

    1992-01-01

    This issue of "The Goldfinch: Iowa History for Young People" focuses upon the Amana Colonies, which were home to many German immigrants in the 19th century, and which retain much of their ethnic heritage today. The articles and activities included in this issue are "Amana Today"; "No Black Buggies in Amana"; "Visiting Tante Marie and Onkel…

  10. Sailing to the Colonies.

    ERIC Educational Resources Information Center

    Carter, Dorothy S.

    1990-01-01

    Presents a class activity designed to foster an understanding of rules, develop analytical skills, and introduce students to early colonial history. Divides the class into groups who are sailing to the New World, and presents them with ethical and practical problems to be solved on board the ship. (RW)

  11. Colonial American Astronomy

    NASA Astrophysics Data System (ADS)

    Yeomans, Donald K.

    2007-12-01

    While a foundation of German scientific methods enabled the rapid growth of North American Astronomy in the nineteenth century, during the seventeenth and most of the eighteenth centuries, the colonial men of science looked only to the English mother country for scientific patronage and guidance. An essay on fundamental astronomy appeared in one of the annual colonial almanacs as early as 1656, telescopic observations were made about 1660 and the first original colonial astronomical work was published by Thomas Danforth on the comet of 1664. By 1671 the Copernican ideas were so espoused at Harvard College that a physics class refused to read a Ptolemaic textbook when it was assigned to them by a senior instructor. At least in the Cambridge-Boston area, contemporary colonialist had access to the most recent scientific publications from the mother country. Observations of the great comet of 1680 by the Almanac maker, John Foster, reached Isaac Newton and were used and gratefully acknowledged in his Principia. During the seventeenth century the colonial interest in astronomy was more intense than it was for other sciences but colonists still occupied a position in the scientific backwater when compared with contemporary European scientists. Nevertheless, the science of astronomy was successfully transplanted from England to North America in the seventeenth century.

  12. [The rehabilitation cares at the lepers].

    PubMed

    De Brier, G; Jouvion, A; Mercier, J; Trappier, T; Urseau, I; Thefenne, L

    2011-12-01

    Leprosy elimination (<1/100 000) is almost reached all around the world, although, but disabled people are still a lot, and they need rehabilitation as soon as possible. The different lesions (neurological, dermatologic and joint) must be treated in order to protect from handicap. Physical rehabilitation medicine can help with a global and polyvalent coverage. Therapeutic education and reinsertion are an important part. PMID:22393618

  13. Growing yeast into cylindrical colonies.

    PubMed

    Vulin, Clément; Di Meglio, Jean-Marc; Lindner, Ariel B; Daerr, Adrian; Murray, Andrew; Hersen, Pascal

    2014-05-20

    Microorganisms often form complex multicellular assemblies such as biofilms and colonies. Understanding the interplay between assembly expansion, metabolic yield, and nutrient diffusion within a freely growing colony remains a challenge. Most available data on microorganisms are from planktonic cultures, due to the lack of experimental tools to control the growth of multicellular assemblies. Here, we propose a method to constrain the growth of yeast colonies into simple geometric shapes such as cylinders. To this end, we designed a simple, versatile culture system to control the location of nutrient delivery below a growing colony. Under such culture conditions, yeast colonies grow vertically and only at the locations where nutrients are delivered. Colonies increase in height at a steady growth rate that is inversely proportional to the cylinder radius. We show that the vertical growth rate of cylindrical colonies is not defined by the single-cell division rate, but rather by the colony metabolic yield. This contrasts with cells in liquid culture, in which the single-cell division rate is the only parameter that defines the population growth rate. This method also provides a direct, simple method to estimate the metabolic yield of a colony. Our study further demonstrates the importance of the shape of colonies on setting their expansion. We anticipate that our approach will be a starting point for elaborate studies of the population dynamics, evolution, and ecology of microbial colonies in complex landscapes. PMID:24853750

  14. Growing Yeast into Cylindrical Colonies

    PubMed Central

    Vulin, Clément; Di Meglio, Jean-Marc; Lindner, Ariel B.; Daerr, Adrian; Murray, Andrew; Hersen, Pascal

    2014-01-01

    Microorganisms often form complex multicellular assemblies such as biofilms and colonies. Understanding the interplay between assembly expansion, metabolic yield, and nutrient diffusion within a freely growing colony remains a challenge. Most available data on microorganisms are from planktonic cultures, due to the lack of experimental tools to control the growth of multicellular assemblies. Here, we propose a method to constrain the growth of yeast colonies into simple geometric shapes such as cylinders. To this end, we designed a simple, versatile culture system to control the location of nutrient delivery below a growing colony. Under such culture conditions, yeast colonies grow vertically and only at the locations where nutrients are delivered. Colonies increase in height at a steady growth rate that is inversely proportional to the cylinder radius. We show that the vertical growth rate of cylindrical colonies is not defined by the single-cell division rate, but rather by the colony metabolic yield. This contrasts with cells in liquid culture, in which the single-cell division rate is the only parameter that defines the population growth rate. This method also provides a direct, simple method to estimate the metabolic yield of a colony. Our study further demonstrates the importance of the shape of colonies on setting their expansion. We anticipate that our approach will be a starting point for elaborate studies of the population dynamics, evolution, and ecology of microbial colonies in complex landscapes. PMID:24853750

  15. Colony image acquisition and genetic segmentation algorithm and colony analyses

    NASA Astrophysics Data System (ADS)

    Wang, W. X.

    2012-01-01

    Colony anaysis is used in a large number of engineerings such as food, dairy, beverages, hygiene, environmental monitoring, water, toxicology, sterility testing. In order to reduce laboring and increase analysis acuracy, many researchers and developers have made efforts for image analysis systems. The main problems in the systems are image acquisition, image segmentation and image analysis. In this paper, to acquire colony images with good quality, an illumination box was constructed. In the box, the distances between lights and dishe, camra lens and lights, and camera lens and dishe are adjusted optimally. In image segmentation, It is based on a genetic approach that allow one to consider the segmentation problem as a global optimization,. After image pre-processing and image segmentation, the colony analyses are perfomed. The colony image analysis consists of (1) basic colony parameter measurements; (2) colony size analysis; (3) colony shape analysis; and (4) colony surface measurements. All the above visual colony parameters can be selected and combined together, used to make a new engineeing parameters. The colony analysis can be applied into different applications.

  16. Iberian colonial science.

    PubMed

    Cañĩzares-Esguerra, Jorge

    2005-03-01

    The Portuguese and Spanish empires were both global and long lasting. This essay focuses on colonial Spanish America, particularly on the practices of natural history. It also suggests that chivalric-epic ideologies permeated early modem epistemologies, including those of the French and the British. The essay criticizes the application of nineteenth-century models of empire to the understanding of the early modern composite monarchies in the New World. Finally, it explores the ways metropolitan natural philosophy was transformed in the New World kingdoms to bolster patriotic identities. PMID:16114801

  17. Colony image acquisition and segmentation

    NASA Astrophysics Data System (ADS)

    Wang, W. X.

    2007-12-01

    For counting of both colonies and plaques, there is a large number of applications including food, dairy, beverages, hygiene, environmental monitoring, water, toxicology, sterility testing, AMES testing, pharmaceuticals, paints, sterile fluids and fungal contamination. Recently, many researchers and developers have made efforts for this kind of systems. By investigation, some existing systems have some problems. The main problems are image acquisition and image segmentation. In order to acquire colony images with good quality, an illumination box was constructed as: the box includes front lightning and back lightning, which can be selected by users based on properties of colony dishes. With the illumination box, lightning can be uniform; colony dish can be put in the same place every time, which make image processing easy. The developed colony image segmentation algorithm consists of the sub-algorithms: (1) image classification; (2) image processing; and (3) colony delineation. The colony delineation algorithm main contain: the procedures based on grey level similarity, on boundary tracing, on shape information and colony excluding. In addition, a number of algorithms are developed for colony analysis. The system has been tested and satisfactory.

  18. Student Discipline in Colonial America.

    ERIC Educational Resources Information Center

    Petry, John R.

    The basis for the severe discipline imposed on school children in colonial America, especially in the Puritan colonies, was the belief in original sin. The child was regarded as being born in sin and thus depraved and prone to sin. The purpose of education was to enable children to read the Bible and thus change the behavior which otherwise would…

  19. Colony collapse disorder in Europe.

    PubMed

    Dainat, Benjamin; Vanengelsdorp, Dennis; Neumann, Peter

    2012-02-01

    Colony collapse disorder (CCD) is a condition of honey bees, which has contributed in part to the recent major losses of honey bee colonies in the USA. Here we report the first CCD case from outside of the USA. We suggest that more standardization is needed for the case definition to diagnose CCD and to compare data on a global scale. PMID:23757238

  20. Post-Colonial Theory and Action Research

    ERIC Educational Resources Information Center

    Parsons, Jim B.; Harding, Kelly J.

    2011-01-01

    This essay explores connections between post-colonial theory and action research. Post-colonial theory is committed to addressing the plague of colonialism. Action research, at its core, promises to problematize uncontested "colonial" hegemonies of any form. Both post-colonial theory and action research engage dialogic, critically reflective and…

  1. Genetic diversity affects colony survivorship in commercial honey bee colonies

    NASA Astrophysics Data System (ADS)

    Tarpy, David R.; vanEngelsdorp, Dennis; Pettis, Jeffrey S.

    2013-08-01

    Honey bee ( Apis mellifera) queens mate with unusually high numbers of males (average of approximately 12 drones), although there is much variation among queens. One main consequence of such extreme polyandry is an increased diversity of worker genotypes within a colony, which has been shown empirically to confer significant adaptive advantages that result in higher colony productivity and survival. Moreover, honey bees are the primary insect pollinators used in modern commercial production agriculture, and their populations have been in decline worldwide. Here, we compare the mating frequencies of queens, and therefore, intracolony genetic diversity, in three commercial beekeeping operations to determine how they correlate with various measures of colony health and productivity, particularly the likelihood of queen supersedure and colony survival in functional, intensively managed beehives. We found the average effective paternity frequency ( m e ) of this population of honey bee queens to be 13.6 ± 6.76, which was not significantly different between colonies that superseded their queen and those that did not. However, colonies that were less genetically diverse (headed by queens with m e ≤ 7.0) were 2.86 times more likely to die by the end of the study when compared to colonies that were more genetically diverse (headed by queens with m e > 7.0). The stark contrast in colony survival based on increased genetic diversity suggests that there are important tangible benefits of increased queen mating number in managed honey bees, although the exact mechanism(s) that govern these benefits have not been fully elucidated.

  2. Genetic diversity affects colony survivorship in commercial honey bee colonies.

    PubMed

    Tarpy, David R; Vanengelsdorp, Dennis; Pettis, Jeffrey S

    2013-08-01

    Honey bee (Apis mellifera) queens mate with unusually high numbers of males (average of approximately 12 drones), although there is much variation among queens. One main consequence of such extreme polyandry is an increased diversity of worker genotypes within a colony, which has been shown empirically to confer significant adaptive advantages that result in higher colony productivity and survival. Moreover, honey bees are the primary insect pollinators used in modern commercial production agriculture, and their populations have been in decline worldwide. Here, we compare the mating frequencies of queens, and therefore, intracolony genetic diversity, in three commercial beekeeping operations to determine how they correlate with various measures of colony health and productivity, particularly the likelihood of queen supersedure and colony survival in functional, intensively managed beehives. We found the average effective paternity frequency (m e ) of this population of honey bee queens to be 13.6 ± 6.76, which was not significantly different between colonies that superseded their queen and those that did not. However, colonies that were less genetically diverse (headed by queens with m e  ≤ 7.0) were 2.86 times more likely to die by the end of the study when compared to colonies that were more genetically diverse (headed by queens with m e  > 7.0). The stark contrast in colony survival based on increased genetic diversity suggests that there are important tangible benefits of increased queen mating number in managed honey bees, although the exact mechanism(s) that govern these benefits have not been fully elucidated. PMID:23728203

  3. Indian Education in Colonial Peru

    ERIC Educational Resources Information Center

    Martin, Luis

    1973-01-01

    The Spaniards who dedicated themselves to the education of the American Indians in colonial Peru were firm believers in intellectual capabilities of the Indians and in the need to approach them through their own Quechua language. (FF)

  4. Cost effectiveness of colony lysis and colony PCR methods for screening of recombinant Escherichia coli colonies--a comparative study.

    PubMed

    Azhahianambi, P; Ghosh, S; Ashok Kumar, C; Suryanarayana, V V S

    2008-10-01

    Economizing the research protocols by using low cost technologies is the need of laboratories of developing world. Screening of recombinant E. coli colonies is the crucial step in gene cloning and expression studies. In the present study, the cost effectiveness of colony lysis method and colony PCR method in the screening of recombinant E. coli colonies was compared. The colony lysis method was 20 two times more cost effective and less time consuming and can be used to screen the recombinant E. coli colonies in large scale instead of colony PCR method. PMID:19024172

  5. Colonialism in Africa: A Critical Look!

    ERIC Educational Resources Information Center

    Gage, Susan

    Using text, activities, cartoons, and prose, the publication encourages junior and senior secondary students to examine the history of colonialism in Africa and the importance of colonialism in Africa today. Chapter 1 provides an overview of 500 years of colonialism. Chapter 2 describes pre-colonial Africa from the year 1000 to 1442. The focus of…

  6. Periodic growth of bacterial colonies

    NASA Astrophysics Data System (ADS)

    Yamazaki, Yoshihiro; Ikeda, Takemasa; Shimada, Hirotoshi; Hiramatsu, Fumiko; Kobayashi, Naoki; Wakita, Jun-ichi; Itoh, Hiroto; Kurosu, Sayuri; Nakatsuchi, Michio; Matsuyama, Tohey; Matsushita, Mitsugu

    2005-06-01

    The formation of concentric ring colonies by bacterial species Bacillus subtilis and Proteus mirabilis has been investigated experimentally, focusing our attention on the dependence of local cell density upon the bacterial motility. It has been confirmed that these concentric ring colonies reflect the periodic change of the bacterial motility between motile cell state and immotile cell state. We conclude that this periodic change is macroscopically determined neither by biological factors (i.e., biological clock) nor by chemical factors (chemotaxis as inhibitor). And our experimental results strongly suggest that the essential factor for the change of the bacterial motility during concentric ring formation is the local cell density.

  7. Colonial and post-colonial aspects of Australian identity.

    PubMed

    Tranter, Bruce; Donoghue, Jed

    2007-06-01

    Since the 1988 Bicentennial and the 2001 centenary of federation celebrations colonial images have flourished in Australia, highlighting the roles of convicts and free settlers during early colonization. Old sites, such as Port Arthur have been re-invigorated, and in 2004 Tasmanians celebrated the bicentenary of 'white' settlement. However, social scientists have given little attention to the role of colonial and post-colonial figures and myths as aspects of Australian national identity. We seek to address this issue by examining how convicts, free settlers, bushrangers and ANZACs are associated with contemporary identity in Australia. We examine evidence from the 2003 Australian Survey of Social Attitudes and find that historical figures such as the ANZACs and post-World War II immigrants comprise important aspects of national identity. A substantial majority of Australians judged ANZACs to be important, countering recent claims of the 'demise of the digger'. Sporting heroes are also at the core of Australian identity. Colonial figures appear to be far less important, although views on national identity vary according to social location. In particular, left-wing, university educated, younger, postmaterialist Australians view convicts and bushrangers as relatively important, indicating the salience of the larrikin in Australian identity. PMID:17610618

  8. Genetic diversity affects colony survivorship in commercial honey bee colonies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Honey bee (Apis mellifera) queens mate with unusually high numbers of males (average of approximately 12 drones), although there is much variation among queens. One main consequence of such extreme polyandry is an increased diversity of worker genotypes within a colony, which has been shown empirica...

  9. Chronic sublethal stress causes bee colony failure

    PubMed Central

    Bryden, John; Gill, Richard J; Mitton, Robert A A; Raine, Nigel E; Jansen, Vincent A A; Hodgson, David

    2013-01-01

    Current bee population declines and colony failures are well documented yet poorly understood and no single factor has been identified as a leading cause. The evidence is equivocal and puzzling: for instance, many pathogens and parasites can be found in both failing and surviving colonies and field pesticide exposure is typically sublethal. Here, we investigate how these results can be due to sublethal stress impairing colony function. We mathematically modelled stress on individual bees which impairs colony function and found how positive density dependence can cause multiple dynamic outcomes: some colonies fail while others thrive. We then exposed bumblebee colonies to sublethal levels of a neonicotinoid pesticide. The dynamics of colony failure, which we observed, were most accurately described by our model. We argue that our model can explain the enigmatic aspects of bee colony failures, highlighting an important role for sublethal stress in colony declines. PMID:24112478

  10. Chronic sublethal stress causes bee colony failure.

    PubMed

    Bryden, John; Gill, Richard J; Mitton, Robert A A; Raine, Nigel E; Jansen, Vincent A A

    2013-12-01

    Current bee population declines and colony failures are well documented yet poorly understood and no single factor has been identified as a leading cause. The evidence is equivocal and puzzling: for instance, many pathogens and parasites can be found in both failing and surviving colonies and field pesticide exposure is typically sublethal. Here, we investigate how these results can be due to sublethal stress impairing colony function. We mathematically modelled stress on individual bees which impairs colony function and found how positive density dependence can cause multiple dynamic outcomes: some colonies fail while others thrive. We then exposed bumblebee colonies to sublethal levels of a neonicotinoid pesticide. The dynamics of colony failure, which we observed, were most accurately described by our model. We argue that our model can explain the enigmatic aspects of bee colony failures, highlighting an important role for sublethal stress in colony declines. PMID:24112478

  11. Murre Colony on Prince Island

    USGS Multimedia Gallery

    A breeding colony of California common murres (Uria aalge californica) on Prince Island off San Miguel Island off Southern California. Ecologists Josh Adams and Jonathan Felis of the USGS Western Ecological Research Center shot this and other high-resolution digital telephotos from a research vessel...

  12. The Vine and Olive Colony.

    ERIC Educational Resources Information Center

    Albinski, Nan Bowman

    1985-01-01

    Traces the historical sources of "Some Plant Olive Trees," a utopian novel by Emma Gelders Sterne, which offers a fictional account of the Vine and Olive colony, one of the most colorful yet least known utopian communities of the nineteenth century. (AYC)

  13. Allorecognition between compound ascidian colonies.

    PubMed

    Harada, Yoshito

    2013-09-01

    The compound ascidian Botryllus schlosseri reproduces asexually, and forms colonies to adhere to matrices such as rocks. This species has developed a mechanism to distinguish between self stem cells and invasive parasitizing nonself cells from other individuals of the same species, probably as a defense against parasitism. It is highly likely that such adult colony histocompatibility is controlled differently from its gametic allorecognition during fertilization. Allorecognition in adults is controlled by a single fusion/histocompatibility (FuHC) locus. In 2005, a candidate gene responsible for the phenotype associated with this genetic locus, named cFuHC, was reported; however, this proposal was subsequently refuted, and the actual determinant may exist elsewhere within the FuHC locus. Given that its is unlikely that a single gene could produce the diversity of FuHC alleles needed to determine individual identity and to distinguish self from nonself colonies, it is possible that the FuHC locus consists of a cluster of multiple determinants aligned in tandem. PMID:24004073

  14. Exploration adjustment by ant colonies

    PubMed Central

    2016-01-01

    How do animals in groups organize their work? Division of labour, i.e. the process by which individuals within a group choose which tasks to perform, has been extensively studied in social insects. Variability among individuals within a colony seems to underpin both the decision over which tasks to perform and the amount of effort to invest in a task. Studies have focused mainly on discrete tasks, i.e. tasks with a recognizable end. Here, we study the distribution of effort in nest seeking, in the absence of new nest sites. Hence, this task is open-ended and individuals have to decide when to stop searching, even though the task has not been completed. We show that collective search effort declines when colonies inhabit better homes, as a consequence of a reduction in the number of bouts (exploratory events). Furthermore, we show an increase in bout exploration time and a decrease in bout instantaneous speed for colonies inhabiting better homes. The effect of treatment on bout effort is very small; however, we suggest that the organization of work performed within nest searching is achieved both by a process of self-selection of the most hard-working ants and individual effort adjustment. PMID:26909180

  15. Exploration adjustment by ant colonies.

    PubMed

    Doran, Carolina; Stumpe, Martin C; Sendova-Franks, Ana; Franks, Nigel R

    2016-01-01

    How do animals in groups organize their work? Division of labour, i.e. the process by which individuals within a group choose which tasks to perform, has been extensively studied in social insects. Variability among individuals within a colony seems to underpin both the decision over which tasks to perform and the amount of effort to invest in a task. Studies have focused mainly on discrete tasks, i.e. tasks with a recognizable end. Here, we study the distribution of effort in nest seeking, in the absence of new nest sites. Hence, this task is open-ended and individuals have to decide when to stop searching, even though the task has not been completed. We show that collective search effort declines when colonies inhabit better homes, as a consequence of a reduction in the number of bouts (exploratory events). Furthermore, we show an increase in bout exploration time and a decrease in bout instantaneous speed for colonies inhabiting better homes. The effect of treatment on bout effort is very small; however, we suggest that the organization of work performed within nest searching is achieved both by a process of self-selection of the most hard-working ants and individual effort adjustment. PMID:26909180

  16. Nest- and colony-mate recognition in polydomous colonies of meat ants ( Iridomyrmex purpureus)

    NASA Astrophysics Data System (ADS)

    van Wilgenburg, E.; Ryan, D.; Morrison, P.; Marriott, P. J.; Elgar, M. A.

    2006-07-01

    Workers of polydomous colonies of social insects must recognize not only colony-mates residing in the same nest but also those living in other nests. We investigated the impact of a decentralized colony structure on colony- and nestmate recognition in the polydomous Australian meat ant ( Iridomyrmex purpureus). Field experiments showed that ants of colonies with many nests were less aggressive toward alien conspecifics than those of colonies with few nests. In addition, while meat ants were almost never aggressive toward nestmates, they were frequently aggressive when confronted with an individual from a different nest within the same colony. Our chemical analysis of the cuticular hydrocarbons of workers using a novel comprehensive two-dimensional gas chromatography technique that increases the number of quantifiable compounds revealed both colony- and nest-specific patterns. Combined, these data indicate an incomplete transfer of colony odor between the nests of polydomous meat ant colonies.

  17. Intracolonial genetic variation affects reproductive skew and colony productivity during colony foundation in a parthenogenetic termite

    PubMed Central

    2014-01-01

    Background In insect societies, intracolonial genetic variation is predicted to affect both colony efficiency and reproductive skew. However, because the effects of genetic variation on these two colony characteristics have been tested independently, it remains unclear whether they are affected by genetic variation independently or in a related manner. Here we test the effect of genetic variation on colony efficiency and reproductive skew in a rhinotermitid termite, Reticulitermes speratus, a species in which female-female pairs can facultatively found colonies. We established colonies using two types of female-female pairs: colonies founded by sisters (i.e., sister-pair colonies) and those founded by females from different colonies (i.e., unrelated-pair colonies). Colony growth and reproductive skew were then compared between the two types of incipient colonies. Results At 15 months after colony foundation, unrelated-pair colonies were larger than sister-pair colonies, although the caste ratio between workers and nymphs, which were alternatively differentiated from young larvae, did not differ significantly. Microsatellite DNA analyses of both founders and their parthenogenetically produced offspring indicated that, in both sister-pair and unrelated-pair colonies, there was no significant skew in the production of eggs, larvae, workers and soldiers. Nymph production, however, was significantly more skewed in the sister-pair colonies than in unrelated-pair colonies. Because nymphs can develop into winged adults (alates) or nymphoid reproductives, they have a higher chance of direct reproduction than workers in this species. Conclusions Our results support the idea that higher genetic variation among colony members could provide an increase in colony productivity, as shown in hymenopteran social insects. Moreover, this study suggests that low genetic variation (high relatedness) between founding females increases reproductive skew via one female preferentially channeling her relatives along the reproductive track. This study thus demonstrated that, in social insects, intracolonial genetic variation can simultaneously affect both colony efficiency and reproductive skew. PMID:25123355

  18. Deadly competition between sibling bacterial colonies

    NASA Astrophysics Data System (ADS)

    Be'Er, Avraham

    2011-03-01

    As a result of stress due to nutrient limitation or antibiotics, competing individual bacteria within a single colony may lyse sibling cells to release nutrients (cannibalism) or DNA (fratricide). However, we have recently shown that competition is not limited to individuals, but can occur at the colony level [A. Be'er et al., PNAS 106, 428 (2009); A. Be'er et al., PNAS 107, 6258 (2010).] In response to the presence of an encroaching sibling colony, Paenibacillus dendritiformis bacteria secrete a lethal protein, lysing cells at the interface between the colonies. Analysis of the proteins secreted by these competing sibling colonies, combined with a mathematical model, shows how colonies maintain their growth by self-regulating the secretion of two proteins: subtilisin (a well-known growth promoter), and Slf (a previously unknown protein, which is lethal). The results also explain why a single colony is not inhibited by its own secretions.

  19. Granulocyte colony-stimulating factor.

    PubMed

    Tabbara, I A

    1993-03-01

    Recombinant human granulocyte colony-stimulating factor (G-CSF) is a nonglycosylated protein produced in Escherichia coli using recombinant DNA technology. G-CSF was first defined in vitro as a relatively selective stimulator of pure granulocyte colonies from normal marrow and as a factor that induces differentiation of leukemic cell lines. Additional studies have shown that it has significant effects on primitive marrow stem cells as well as on the differentiated cells of the granulocyte-macrophage pathway enhancing phagocytosis, superoxide release, antibody-dependent cellular cytotoxicity, and migration of both neutrophils and monocytes. The most extensively studied clinical application of G-CSF has been in chemotherapy-induced myelosuppression, where it was shown to reduce the duration of severe neutropenia, the incidence of febrile neutropenic episodes, the overall duration of intravenous antibiotic therapy, and the length of hospitalization. G-CSF has also been shown to correct primary and acquired forms of neutropenia, to accelerate neutrophil recovery after bone marrow transplantation, and to mobilize stem cells in peripheral blood or hemopoietic rescue. G-CSF is well tolerated, mild to moderate bone pain being the most frequently reported adverse side effect. The clinical applications of G-CSF are likely to expand as more information emerges from continuing clinical trials. PMID:7680827

  20. Conceptual design of a lunar colony

    NASA Technical Reports Server (NTRS)

    Dalton, C. (Editor); Hohmann, E. (Editor)

    1972-01-01

    A systems engineering study is presented for a proposed lunar colony. The lunar colony was to grow from an existent, 12-man, earth-dependent lunar surface base and was to utilize lunar resources, becoming as earth-independent as possible. An in-depth treatment of some of the aspects of the lunar colony was given. We have found that the use of lunar resources is feasible for oxygen production (both for breathing and for space tug fuel), food production, and building materials. A program is outlined for recycling waste materials developed at the colony as well as a full program for growth and research activity of the colony to a level of 180 colonists. Recommendations for the lunar colony are given.

  1. Sequential events in bacterial colony morphogenesis

    NASA Astrophysics Data System (ADS)

    Shapiro, James A.; Trubatch, David

    1991-04-01

    Bacterial colonies are organized, differentiated multicellular communities expressing genetically controlled patterns. These patterns can be seen in mature colonies by staining for differential gene expression, by visualization of surface textures, and by microscopic examination of cellular morphologies and multicellular arrays. Colony morphogenesis involves many sequential processes of cellular growth, differentiation and movement which are regulated, at least in part, by cell-cell interactions and communication between groups of cells. These morphogenetic processes can be followed by periodic microscopic examination of developing colonies and by time-lapse video recordings. Since the final colony structure is the integrated product of many steps, pattern formation cannot realistically be explained by assumptions about autonomous cell behaviors. Instead, colony growth is best viewed as a developmental process in which the cells interact and adjust their individual and collective behaviors as morphogenesis proceeds.

  2. Organizer regions in marine colonial hydrozoans.

    PubMed

    Mayorova, Tatiana; Kosevich, Igor; Dulin, Nickolai; Savina, Elizaveta; Kraus, Yulia

    2015-04-01

    Organizers are specific tissue regions of developing organisms that provide accuracy and robustness to the body plan formation. Hydrozoan cnidarians (both solitary and colonial) require organizer regions for maintaining the regular body patterning during continuous tissue dynamics during asexual reproduction and growth. While the hypostomal organizer of the solitary Hydra has been studied relatively well, our knowledge of organizers in colonial hydrozoans remains fragmentary and incomplete. As colonial hydrozoans demonstrate an amazing diversity of morphological and life history traits, it is of special interest to investigate the organizers specific for particular ontogenetic stages and particular types of colonies. In the present study we aimed to assess the inductive capacities of several candidate organizer regions in hydroids with different colony organization. We carried out grafting experiments on colonial hydrozoans belonging to Leptothecata and Anthoathecata. We confirmed that the hypostome tip is an organizer in the colonial Anthoathecata as it is in the solitary polyp Hydra. We also found that the posterior tip of the larva is an organizer in hydroids regardless of the peculiarities of their metamorphosis mode and colony structure. We show for the first time that the shoot growing tip, which can be considered a key evolutionary novelty of Leptothecata, is an organizer region. Taken together, our data demonstrate that organizers function throughout the larval and polypoid stages in colonial hydroids. PMID:25749284

  3. Recruitment Strategies and Colony Size in Ants

    PubMed Central

    Planqué, Robert; van den Berg, Jan Bouwe; Franks, Nigel R.

    2010-01-01

    Ants use a great variety of recruitment methods to forage for food or find new nests, including tandem running, group recruitment and scent trails. It has been known for some time that there is a loose correlation across many taxa between species-specific mature colony size and recruitment method. Very small colonies tend to use solitary foraging; small to medium sized colonies use tandem running or group recruitment whereas larger colonies use pheromone recruitment trails. Until now, explanations for this correlation have focused on the ants' ecology, such as food resource distribution. However, many species have colonies with a single queen and workforces that grow over several orders of magnitude, and little is known about how a colony's organization, including recruitment methods, may change during its growth. After all, recruitment involves interactions between ants, and hence the size of the colony itself may influence which recruitment method is used—even if the ants' behavioural repertoire remains unchanged. Here we show using mathematical models that the observed correlation can also be explained by recognizing that failure rates in recruitment depend differently on colony size in various recruitment strategies. Our models focus on the build up of recruiter numbers inside colonies and are not based on optimality arguments, such as maximizing food yield. We predict that ant colonies of a certain size should use only one recruitment method (and always the same one) rather than a mix of two or more. These results highlight the importance of the organization of recruitment and how it is affected by colony size. Hence these results should also expand our understanding of ant ecology. PMID:20694195

  4. [Notes about other epidemics in Colonial Chile].

    PubMed

    Laval, Enrique

    2015-10-01

    In chronicles or in the historiography of the Colony in Chile there are few references about epidemics different to smallpox; like typhus, typhoid fever, dysentery, etc. Almost all, fast spreading in the country and some with high lethality, which led to overflowing the capacity of hospitals in the Chilean colonial period. PMID:26633117

  5. Pathogen webs in collapsing honey bee colonies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recent losses in honey bee colonies are unusual in their severity, geographical distribution, and, in some cases, failure to present recognized symptoms of known disease. Domesticated honey bees face numerous pests and pathogens, tempting hypotheses that colony collapses arise from exposure to new o...

  6. Colony Collapse Disorder: A descriptive studey

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Over the last two winters, there have been large-scale, unexplained losses of managed honey bee (Apis mellifera L.) colonies in the United States. In the absence of a known cause, this syndrome was named Colony Collapse Disorder (CCD) because the main trait was a rapid loss of adult worker bees. We ...

  7. Colonial America: A Course of Study.

    ERIC Educational Resources Information Center

    Bennett, Sondra; Stephens, Mark

    This illustrated unit of study can be incorporated into regular social studies courses in elementary classrooms. The unit focuses on life in the 13 original colonies from the settlement period to the Revolutionary War. Activities are provided to help students learn the names and locations of the colonies. A highlight of the unit is a study of the…

  8. Colonial American Literature: A Guide to Resources.

    ERIC Educational Resources Information Center

    Van Noate, Judith, Comp.

    This handout is a guide to library resources in the J. Murrey Atkins Library at the University of North Carolina-Charlotte for the study of colonial American literature. The guide is intended to help readers find sources of criticism on colonial and revolutionary literature. It explains important reference sources in the Atkins library reference…

  9. Predictive markers of honey bee colony collapse

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Managed honey bee colonies are currently affected by abrupt depopulation during winter and many factors are suspected to be involved, either alone or in combination. Pathogens are considered as principal actors, contributing to weaken colony health and leaving room for secondary infections. In parti...

  10. Education in Colonial Africa: The German Experience

    ERIC Educational Resources Information Center

    vanderPloeg, Arie J.

    1977-01-01

    Examines the introduction and growth of state-supported schools in two German colonies in Africa, Kamerun and Deutsch Ostafrika, describes African reaction to and utilization of them, assesses, from the colonial perspective, why such schools were introduced and what they were intended to accomplish, and examines the reasons for their differential…

  11. Hegemony and Accommodation in the History Curriculum in Colonial Botswana

    ERIC Educational Resources Information Center

    Mafela, Lily

    2014-01-01

    A reanalysis of colonial education is necessary in order to highlight its multifaceted and hybrid nature in specific colonial contexts. Although in general, colonial education served the socio-political needs of the colonial machinery, the colonial government's hegemonic authority over the school curriculum did not operate as a totalising…

  12. Predictive Markers of Honey Bee Colony Collapse

    PubMed Central

    Dainat, Benjamin; Evans, Jay D.; Chen, Yan Ping; Gauthier, Laurent; Neumann, Peter

    2012-01-01

    Across the Northern hemisphere, managed honey bee colonies, Apis mellifera, are currently affected by abrupt depopulation during winter and many factors are suspected to be involved, either alone or in combination. Parasites and pathogens are considered as principal actors, in particular the ectoparasitic mite Varroa destructor, associated viruses and the microsporidian Nosema ceranae. Here we used long term monitoring of colonies and screening for eleven disease agents and genes involved in bee immunity and physiology to identify predictive markers of honeybee colony losses during winter. The data show that DWV, Nosema ceranae, Varroa destructor and Vitellogenin can be predictive markers for winter colony losses, but their predictive power strongly depends on the season. In particular, the data support that V. destructor is a key player for losses, arguably in line with its specific impact on the health of individual bees and colonies. PMID:22384162

  13. Formation and dissolution of bacterial colonies.

    PubMed

    Weber, Christoph A; Lin, Yen Ting; Biais, Nicolas; Zaburdaev, Vasily

    2015-09-01

    Many organisms form colonies for a transient period of time to withstand environmental pressure. Bacterial biofilms are a prototypical example of such behavior. Despite significant interest across disciplines, physical mechanisms governing the formation and dissolution of bacterial colonies are still poorly understood. Starting from a kinetic description of motile and interacting cells we derive a hydrodynamic equation for their density on a surface, where most of the kinetic coefficients are estimated from experimental data for N. gonorrhoeae bacteria. We use it to describe the formation of multiple colonies with sizes consistent with experimental observations. Finally, we show how the changes in the cell-to-cell interactions lead to the dissolution of the bacterial colonies. The successful application of kinetic theory to a complex far from equilibrium system such as formation and dissolution of living bacterial colonies potentially paves the way for the physical quantification of the initial stages of biofilm formation. PMID:26465495

  14. Formation and dissolution of bacterial colonies

    NASA Astrophysics Data System (ADS)

    Weber, Christoph A.; Lin, Yen Ting; Biais, Nicolas; Zaburdaev, Vasily

    2015-09-01

    Many organisms form colonies for a transient period of time to withstand environmental pressure. Bacterial biofilms are a prototypical example of such behavior. Despite significant interest across disciplines, physical mechanisms governing the formation and dissolution of bacterial colonies are still poorly understood. Starting from a kinetic description of motile and interacting cells we derive a hydrodynamic equation for their density on a surface, where most of the kinetic coefficients are estimated from experimental data for N. gonorrhoeae bacteria. We use it to describe the formation of multiple colonies with sizes consistent with experimental observations. Finally, we show how the changes in the cell-to-cell interactions lead to the dissolution of the bacterial colonies. The successful application of kinetic theory to a complex far from equilibrium system such as formation and dissolution of living bacterial colonies potentially paves the way for the physical quantification of the initial stages of biofilm formation.

  15. Predictive markers of honey bee colony collapse.

    PubMed

    Dainat, Benjamin; Evans, Jay D; Chen, Yan Ping; Gauthier, Laurent; Neumann, Peter

    2012-01-01

    Across the Northern hemisphere, managed honey bee colonies, Apis mellifera, are currently affected by abrupt depopulation during winter and many factors are suspected to be involved, either alone or in combination. Parasites and pathogens are considered as principal actors, in particular the ectoparasitic mite Varroa destructor, associated viruses and the microsporidian Nosema ceranae. Here we used long term monitoring of colonies and screening for eleven disease agents and genes involved in bee immunity and physiology to identify predictive markers of honeybee colony losses during winter. The data show that DWV, Nosema ceranae, Varroa destructor and Vitellogenin can be predictive markers for winter colony losses, but their predictive power strongly depends on the season. In particular, the data support that V. destructor is a key player for losses, arguably in line with its specific impact on the health of individual bees and colonies. PMID:22384162

  16. Form and metabolic scaling in colonial animals.

    PubMed

    Hartikainen, Hanna; Humphries, Stuart; Okamura, Beth

    2014-03-01

    Benthic colonial organisms exhibit a wide variation in size and shape and provide excellent model systems for testing the predictions of models that describe the scaling of metabolic rate with organism size. We tested the hypothesis that colony form will influence metabolic scaling and its derivatives by characterising metabolic and propagule production rates in three species of freshwater bryozoans that vary in morphology and module organisation and which demonstrate two- and three-dimensional growth forms. The results were evaluated with respect to predictions from two models for metabolic scaling. Isometric metabolic scaling in two-dimensional colonies supported predictions of a model based on dynamic energy budget theory (DEB) and not those of a model based on fractally branching supply networks. This metabolic isometry appears to be achieved by equivalent energy budgets of edge and central modules, in one species (Cristatella mucedo) via linear growth and in a second species (Lophopus crystallinus) by colony fission. Allometric scaling characterised colonies of a three-dimensional species (Fredericella sultana), also providing support for the DEB model. Isometric scaling of propagule production rates for C. mucedo and F. sultana suggests that the number of propagules produced in colonies increases in direct proportion with the number of modules within colonies. Feeding currents generated by bryozoans function in both food capture and respiration, thus linking metabolic scaling with dynamics of self-shading and resource capture. Metabolic rates fundamentally dictate organismal performance (e.g. growth, reproduction) and, as we show here, are linked with colony form. Metabolic profiles and associated variation in colony form should therefore influence the outcome of biotic interactions in habitats dominated by colonial animals and may drive patterns of macroevolution. PMID:24265433

  17. Public health developments in colonial Malaya: colonialism and the politics of prevention.

    PubMed Central

    Manderson, L

    1999-01-01

    In both African and Asian colonies until the late 19th century, colonial medicine operated pragmatically to meet the medical needs first of colonial officers and troops, immigrant settlers, and laborers responsible for economic development, then of indigenous populations when their ill health threatened the well-being of the expatriate population. Since the turn of the century, however, the consequences of colonial expansion and development for indigenous people's health had become increasingly apparent, and disease control and public health programs were expanded in this light. These programs increased government surveillance of populations at both community and household levels. As a consequence, colonial states extended institutional oversight and induced dependency through public health measures. Drawing on my own work on colonial Malaya, I illustrate developments in public health and their links to the moral logic of colonialism and its complementarity to the political economy. PMID:9987478

  18. Automated counting of mammalian cell colonies.

    PubMed

    Barber, P R; Vojnovic, B; Kelly, J; Mayes, C R; Boulton, P; Woodcock, M; Joiner, M C

    2001-01-01

    Investigating the effect of low-dose radiation exposure on cells using assays of colony-forming ability requires large cell samples to maintain statistical accuracy. Manually counting the resulting colonies is a laborious task in which consistent objectivity is hard to achieve. This is true especially with some mammalian cell lines which form poorly defined or 'fuzzy' colonies, typified by glioma or fibroblast cell lines. A computer-vision-based automated colony counter is presented in this paper. It utilizes novel imaging and image-processing methods involving a modified form of the Hough transform. The automated counter is able to identify less-discrete cell colonies typical of these cell lines. The results of automated colony counting are compared with those from four manual (human) colony counts for the cell lines HT29, A172, U118 and IN1265. The results from the automated counts fall well within the distribution of the manual counts for all four cell lines with respect to surviving fraction (SF) versus dose curves, SF values at 2 Gy (SF2) and total area under the SF curve (Dbar). From the variation in the counts, it is shown that the automated counts are generally more consistent than the manual counts. PMID:11197679

  19. Automated counting of mammalian cell colonies

    NASA Astrophysics Data System (ADS)

    Barber, Paul R.; Vojnovic, Borivoj; Kelly, Jane; Mayes, Catherine R.; Boulton, Peter; Woodcock, Michael; Joiner, Michael C.

    2001-01-01

    Investigating the effect of low-dose radiation exposure on cells using assays of colony-forming ability requires large cell samples to maintain statistical accuracy. Manually counting the resulting colonies is a laborious task in which consistent objectivity is hard to achieve. This is true especially with some mammalian cell lines which form poorly defined or `fuzzy' colonies, typified by glioma or fibroblast cell lines. A computer-vision-based automated colony counter is presented in this paper. It utilizes novel imaging and image-processing methods involving a modified form of the Hough transform. The automated counter is able to identify less-discrete cell colonies typical of these cell lines. The results of automated colony counting are compared with those from four manual (human) colony counts for the cell lines HT29, A172, U118 and IN1265. The results from the automated counts fall well within the distribution of the manual counts for all four cell lines with respect to surviving fraction (SF) versus dose curves, SF values at 2 Gy (SF2) and total area under the SF curve (Dbar). From the variation in the counts, it is shown that the automated counts are generally more consistent than the manual counts.

  20. Colony image acquisition system and segmentation algorithms

    NASA Astrophysics Data System (ADS)

    Wang, Weixing

    2011-12-01

    This paper presents a novel colony analysis system including an adjustable image acquisition subsystem and a wavelet-watershed-based image segmentation algorithm. An illumination box was constructed--both front lightning and back lightning illuminations can be chosen by users based on the properties of Petri dishes. In the illumination box, the lightning is uniform, which makes image processing easy. A digital camera at the top of the box is connected to a PC computer; all the camera functions are controlled by the developed computer software in this study. As usual, in the image processing part, the hardest task is image segmentation which is carried out by the four different algorithms: 1. recursive image segmentation on gray similarity; 2. canny edge detection-based segmentation; 3. the combination of 1 and 2, and 4. colony delineation on wavelet and watershed. The first three algorithms can obtain good results for ordinary colony images, and for the images including a lot of small (tiny) colonies and dark colonies and overlapping (or touching) colonies, the algorithm 4 can obtain better results than the others. The algorithms are tested by using a large number of different colony images, and the testing results are satisfactory.

  1. Colony Foundation in an Oceanic Seabird

    PubMed Central

    Munilla, Ignacio; Genovart, Meritxell; Paiva, Vitor H.; Velando, Alberto

    2016-01-01

    Seabirds are colonial vertebrates that despite their great potential for long-range dispersal and colonization are reluctant to establish in novel locations, often recruiting close to their natal colony. The foundation of colonies is therefore a rare event in most seabird species and little is known about the colonization process in this group. The Cory’s shearwater (Calonectris diomedea) is a pelagic seabird that has recently established three new colonies in Galicia (NE Atlantic) thus expanding its distribution range 500 km northwards. This study aimed to describe the establishment and early progress of the new Galician populations and to determine the genetic and morphometric characteristics of the individuals participating in these foundation events. Using 10 microsatellite loci, we tested the predictions supported by different seabird colonization models. Possibly three groups of non-breeders, adding up to around 200 birds, started visiting the Galician colonies in the mid 2000’s and some of them eventually laid eggs and reproduced, thus establishing new breeding colonies. The Galician populations showed a high genetic diversity and a frequency of private alleles similar to or even higher than some of the large historical populations. Most individuals were assigned to several Atlantic populations and a few (if any) to Mediterranean colonies. Our study suggests that a large and admixed population is settling in Galicia, in agreement with predictions from island metapopulation models of colonization. Multiple source colonies imply that some birds colonizing Galicia were dispersing from very distant colonies (> 1500 km). Long-distance colonizations undertaken by relatively large and admixed groups of colonizers can help to explain the low levels of genetic structure over vast areas that are characteristic of most oceanic seabird species. PMID:26909694

  2. Colony Foundation in an Oceanic Seabird.

    PubMed

    Munilla, Ignacio; Genovart, Meritxell; Paiva, Vitor H; Velando, Alberto

    2016-01-01

    Seabirds are colonial vertebrates that despite their great potential for long-range dispersal and colonization are reluctant to establish in novel locations, often recruiting close to their natal colony. The foundation of colonies is therefore a rare event in most seabird species and little is known about the colonization process in this group. The Cory's shearwater (Calonectris diomedea) is a pelagic seabird that has recently established three new colonies in Galicia (NE Atlantic) thus expanding its distribution range 500 km northwards. This study aimed to describe the establishment and early progress of the new Galician populations and to determine the genetic and morphometric characteristics of the individuals participating in these foundation events. Using 10 microsatellite loci, we tested the predictions supported by different seabird colonization models. Possibly three groups of non-breeders, adding up to around 200 birds, started visiting the Galician colonies in the mid 2000's and some of them eventually laid eggs and reproduced, thus establishing new breeding colonies. The Galician populations showed a high genetic diversity and a frequency of private alleles similar to or even higher than some of the large historical populations. Most individuals were assigned to several Atlantic populations and a few (if any) to Mediterranean colonies. Our study suggests that a large and admixed population is settling in Galicia, in agreement with predictions from island metapopulation models of colonization. Multiple source colonies imply that some birds colonizing Galicia were dispersing from very distant colonies (> 1500 km). Long-distance colonizations undertaken by relatively large and admixed groups of colonizers can help to explain the low levels of genetic structure over vast areas that are characteristic of most oceanic seabird species. PMID:26909694

  3. GENERAL VIEW LOOKING EAST ALONG THE RAILROAD TRACKS TOWARDS COLONIAL ...

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

    GENERAL VIEW LOOKING EAST ALONG THE RAILROAD TRACKS TOWARDS COLONIAL WAREHOUSE TO THE RIGHT - Minneapolis Warehouse District, Colonial Warehouse, 200 Third Avenue North, Minneapolis, Hennepin County, MN

  4. Bacterial colony counting by Convolutional Neural Networks.

    PubMed

    Ferrari, Alessandro; Lombardi, Stefano; Signoroni, Alberto

    2015-08-01

    Counting bacterial colonies on microbiological culture plates is a time-consuming, error-prone, nevertheless fundamental task in microbiology. Computer vision based approaches can increase the efficiency and the reliability of the process, but accurate counting is challenging, due to the high degree of variability of agglomerated colonies. In this paper, we propose a solution which adopts Convolutional Neural Networks (CNN) for counting the number of colonies contained in confluent agglomerates, that scored an overall accuracy of the 92.8% on a large challenging dataset. The proposed CNN-based technique for estimating the cardinality of colony aggregates outperforms traditional image processing approaches, becoming a promising approach to many related applications. PMID:26738016

  5. Application of continuous monitoring of honeybee colonies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Monitoring physical variables associated with honey bee colonies, including weight, temperature, humidity, respiratory gases, vibration, acoustics and forager traffic, in a continuous manner is becoming feasible for most researchers as the cost and size of electronic sensors and dataloggers decrease...

  6. Identification of a Colonial Chordate Histocompatibility Gene

    PubMed Central

    Voskoboynik, Ayelet; Newman, Aaron M.; Corey, Daniel M.; Sahoo, Debashis; Pushkarev, Dmitry; Neff, Norma F.; Passarelli, Benedetto; Koh, Winston; Ishizuka, Katherine J.; Palmeri, Karla J.; Dimov, Ivan K.; Keasar, Chen; Fan, H. Christina; Mantalas, Gary L.; Sinha, Rahul; Penland, Lolita; Quake, Stephen R.; Weissman, Irving L.

    2013-01-01

    Histocompatibility is the basis by which multicellular organisms of the same species distinguish self from non-self. Relatively little is known about the mechanisms underlying histocompatibility reactions in lower organisms. Botryllus schlosseri is a colonial urochordate, a sister group of vertebrates, that exhibits a genetically determined natural transplantation reaction, whereby self-recognition between colonies leads to formation of parabionts with a common vasculature, whereas rejection occurs between incompatible colonies. Using genetically defined lines, whole-transcriptome sequencing, and genomics, we identified a single gene that encodes self/non-self and determines “graft” outcomes in this organism. This gene is significantly upregulated in colonies poised to undergo fusion or rejection, is highly expressed in the vasculature, and is functionally linked to histocompatibility outcomes. These findings establish a platform for advancing the science of allorecognition. PMID:23888037

  7. Optical image acquisition system for colony analysis

    NASA Astrophysics Data System (ADS)

    Wang, Weixing; Jin, Wenbiao

    2006-02-01

    For counting of both colonies and plaques, there is a large number of applications including food, dairy, beverages, hygiene, environmental monitoring, water, toxicology, sterility testing, AMES testing, pharmaceuticals, paints, sterile fluids and fungal contamination. Recently, many researchers and developers have made efforts for this kind of systems. By investigation, some existing systems have some problems since they belong to a new technology product. One of the main problems is image acquisition. In order to acquire colony images with good quality, an illumination box was constructed as: the box includes front lightning and back lightning, which can be selected by users based on properties of colony dishes. With the illumination box, lightning can be uniform; colony dish can be put in the same place every time, which make image processing easy. A digital camera in the top of the box connected to a PC computer with a USB cable, all the camera functions are controlled by the computer.

  8. Pathogen Webs in Collapsing Honey Bee Colonies

    PubMed Central

    Cornman, R. Scott; Tarpy, David R.; Chen, Yanping; Jeffreys, Lacey; Lopez, Dawn; Pettis, Jeffery S.; vanEngelsdorp, Dennis; Evans, Jay D.

    2012-01-01

    Recent losses in honey bee colonies are unusual in their severity, geographical distribution, and, in some cases, failure to present recognized characteristics of known disease. Domesticated honey bees face numerous pests and pathogens, tempting hypotheses that colony collapses arise from exposure to new or resurgent pathogens. Here we explore the incidence and abundance of currently known honey bee pathogens in colonies suffering from Colony Collapse Disorder (CCD), otherwise weak colonies, and strong colonies from across the United States. Although pathogen identities differed between the eastern and western United States, there was a greater incidence and abundance of pathogens in CCD colonies. Pathogen loads were highly covariant in CCD but not control hives, suggesting that CCD colonies rapidly become susceptible to a diverse set of pathogens, or that co-infections can act synergistically to produce the rapid depletion of workers that characterizes the disorder. We also tested workers from a CCD-free apiary to confirm that significant positive correlations among pathogen loads can develop at the level of individual bees and not merely as a secondary effect of CCD. This observation and other recent data highlight pathogen interactions as important components of bee disease. Finally, we used deep RNA sequencing to further characterize microbial diversity in CCD and non-CCD hives. We identified novel strains of the recently described Lake Sinai viruses (LSV) and found evidence of a shift in gut bacterial composition that may be a biomarker of CCD. The results are discussed with respect to host-parasite interactions and other environmental stressors of honey bees. PMID:22927991

  9. Pathogen webs in collapsing honey bee colonies.

    PubMed

    Cornman, R Scott; Tarpy, David R; Chen, Yanping; Jeffreys, Lacey; Lopez, Dawn; Pettis, Jeffery S; vanEngelsdorp, Dennis; Evans, Jay D

    2012-01-01

    Recent losses in honey bee colonies are unusual in their severity, geographical distribution, and, in some cases, failure to present recognized characteristics of known disease. Domesticated honey bees face numerous pests and pathogens, tempting hypotheses that colony collapses arise from exposure to new or resurgent pathogens. Here we explore the incidence and abundance of currently known honey bee pathogens in colonies suffering from Colony Collapse Disorder (CCD), otherwise weak colonies, and strong colonies from across the United States. Although pathogen identities differed between the eastern and western United States, there was a greater incidence and abundance of pathogens in CCD colonies. Pathogen loads were highly covariant in CCD but not control hives, suggesting that CCD colonies rapidly become susceptible to a diverse set of pathogens, or that co-infections can act synergistically to produce the rapid depletion of workers that characterizes the disorder. We also tested workers from a CCD-free apiary to confirm that significant positive correlations among pathogen loads can develop at the level of individual bees and not merely as a secondary effect of CCD. This observation and other recent data highlight pathogen interactions as important components of bee disease. Finally, we used deep RNA sequencing to further characterize microbial diversity in CCD and non-CCD hives. We identified novel strains of the recently described Lake Sinai viruses (LSV) and found evidence of a shift in gut bacterial composition that may be a biomarker of CCD. The results are discussed with respect to host-parasite interactions and other environmental stressors of honey bees. PMID:22927991

  10. ColonyArea: an ImageJ plugin to automatically quantify colony formation in clonogenic assays.

    PubMed

    Guzmán, Camilo; Bagga, Manish; Kaur, Amanpreet; Westermarck, Jukka; Abankwa, Daniel

    2014-01-01

    The clonogenic or colony formation assay is a widely used method to study the number and size of cancer cell colonies that remain after irradiation or cytotoxic agent administration and serves as a measure for the anti-proliferative effect of these treatments. Alternatively, this assay is used to quantitate the transforming potential of cancer associated genes and chemical agents. Therefore, there is a need for a simplified and standardized analysis of colony formation assays for both routine laboratory use and for parallelized automated analysis. Here we describe the freely available ImageJ-plugin "ColonyArea", which is optimized for rapid and quantitative analysis of focus formation assays conducted in 6- to 24-well dishes. ColonyArea processes image data of multi-well dishes, by separating, concentrically cropping and background correcting well images individually, before colony formation is quantitated. Instead of counting the number of colonies, ColonyArea determines the percentage of area covered by crystal violet stained cell colonies, also taking the intensity of the staining and therefore cell density into account. We demonstrate that these parameters alone or in combination allow for robust quantification of IC50 values of the cytotoxic effect of two staurosporines, UCN-01 and staurosporine (STS) on human glioblastoma cells (T98G). The relation between the potencies of the two compounds compared very well with that obtained from an absorbance based method to quantify colony growth and to published data. The ColonyArea ImageJ plugin provides a simple and efficient analysis routine to quantitate assay data of one of the most commonly used cellular assays. The bundle is freely available for download as supporting information. We expect that ColonyArea will be of broad utility for cancer biologists, as well as clinical radiation scientists. PMID:24647355

  11. Development of streptococcal L-form colonies.

    PubMed

    Bibel, D J; Lawson, J W

    1972-10-01

    The development and architecture of L-form agar colonies produced from protoplasts and L-phase bodies were studied by both light and scanning electron microscopy. Agar blocks containing L-phase microcolonies of group A Streptococcus strains ADA and GL8 and group D Streptococcus strain F24 as well as longitudinal sections of mature colonies were used as samples. Initially, granules of about 0.5 mum in diameter were produced by multiple condensation and fragmentation of protoplasts and large bodies. Surface growth by granules ensued and infiltration into agar occurred only after 10 to 11 hr of incubation at 37 C. Club-shaped granules were noted and division seemed to take place by simple fission. The configuration of large bodies and granules in mature colonies suggested budding as another means of replication. Acellular spaces inside the colonies appeared to have been formed by lysis of large bodies or by the envelopment of space by the extending growth of minute granules. Whereas no significant strain variation was noted in colonies of less than 24 hr of incubation, fully mature colonies were differentiated on uniform media. PMID:5079075

  12. 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.

  13. Colony Collapse Disorder: A Descriptive Study

    PubMed Central

    vanEngelsdorp, Dennis; Evans, Jay D.; Saegerman, Claude; Mullin, Chris; Haubruge, Eric; Nguyen, Bach Kim; Frazier, Maryann; Frazier, Jim; Cox-Foster, Diana; Chen, Yanping; Underwood, Robyn; Tarpy, David R.; Pettis, Jeffery S.

    2009-01-01

    Background Over the last two winters, there have been large-scale, unexplained losses of managed honey bee (Apis mellifera L.) colonies in the United States. In the absence of a known cause, this syndrome was named Colony Collapse Disorder (CCD) because the main trait was a rapid loss of adult worker bees. We initiated a descriptive epizootiological study in order to better characterize CCD and compare risk factor exposure between populations afflicted by and not afflicted by CCD. Methods and Principal Findings Of 61 quantified variables (including adult bee physiology, pathogen loads, and pesticide levels), no single measure emerged as a most-likely cause of CCD. Bees in CCD colonies had higher pathogen loads and were co-infected with a greater number of pathogens than control populations, suggesting either an increased exposure to pathogens or a reduced resistance of bees toward pathogens. Levels of the synthetic acaricide coumaphos (used by beekeepers to control the parasitic mite Varroa destructor) were higher in control colonies than CCD-affected colonies. Conclusions/Significance This is the first comprehensive survey of CCD-affected bee populations that suggests CCD involves an interaction between pathogens and other stress factors. We present evidence that this condition is contagious or the result of exposure to a common risk factor. Potentially important areas for future hypothesis-driven research, including the possible legacy effect of mite parasitism and the role of honey bee resistance to pesticides, are highlighted. PMID:19649264

  14. Parasitism and phenotypic change in colonial hosts.

    PubMed

    Hartikainen, Hanna; Fontes, Inês; Okamura, Beth

    2013-09-01

    Changes in host phenotype are often attributed to manipulation that enables parasites to complete trophic transmission cycles. We characterized changes in host phenotype in a colonial host–endoparasite system that lacks trophic transmission (the freshwater bryozoan Fredericella sultana and myxozoan parasite Tetracapsuloides bryosalmonae). We show that parasitism exerts opposing phenotypic effects at the colony and module levels. Thus, overt infection (the development of infectious spores in the host body cavity) was linked to a reduction in colony size and growth rate, while colony modules exhibited a form of gigantism. Larger modules may support larger parasite sacs and increase metabolite availability to the parasite. Host metabolic rates were lower in overtly infected relative to uninfected hosts that were not investing in propagule production. This suggests a role for direct resource competition and active parasite manipulation (castration) in driving the expression of the infected phenotype. The malformed offspring (statoblasts) of infected colonies had greatly reduced hatching success. Coupled with the severe reduction in statoblast production this suggests that vertical transmission is rare in overtly infected modules. We show that although the parasite can occasionally infect statoblasts during overt infections, no infections were detected in the surviving mature offspring, suggesting that during overt infections, horizontal transmission incurs a trade-off with vertical transmission. PMID:23965820

  15. Quantitative analysis of colony morphology in yeast

    PubMed Central

    Ruusuvuori, Pekka; Lin, Jake; Scott, Adrian C.; Tan, Zhihao; Sorsa, Saija; Kallio, Aleksi; Nykter, Matti; Yli-Harja, Olli; Shmulevich, Ilya; Dudley, Aimée M.

    2014-01-01

    Microorganisms often form multicellular structures such as biofilms and structured colonies that can influence the organism’s virulence, drug resistance, and adherence to medical devices. Phenotypic classification of these structures has traditionally relied on qualitative scoring systems that limit detailed phenotypic comparisons between strains. Automated imaging and quantitative analysis have the potential to improve the speed and accuracy of experiments designed to study the genetic and molecular networks underlying different morphological traits. For this reason, we have developed a platform that uses automated image analysis and pattern recognition to quantify phenotypic signatures of yeast colonies. Our strategy enables quantitative analysis of individual colonies, measured at a single time point or over a series of time-lapse images, as well as the classification of distinct colony shapes based on image-derived features. Phenotypic changes in colony morphology can be expressed as changes in feature space trajectories over time, thereby enabling the visualization and quantitative analysis of morphological development. To facilitate data exploration, results are plotted dynamically through an interactive Yeast Image Analysis web application (YIMAA; http://yimaa.cs.tut.fi) that integrates the raw and processed images across all time points, allowing exploration of the image-based features and principal components associated with morphological development. PMID:24447135

  16. Genetic Analysis of Termite Colonies in Wisconsin.

    PubMed

    Arango, R A; Marschalek, D A; Green, F; Raffa, K F; Berres, M E

    2015-06-01

    The objective of this study was to document current areas of subterranean termite activity in Wisconsin and to evaluate genetic characteristics of these northern, peripheral colonies. Here, amplified fragment-length polymorphism was used to characterize levels of inbreeding, expected heterozygosity, and percent polymorphism within colonies as well as genetic structure among populations sampled. Genetic analysis revealed two species of termites occur in Wisconsin, Reticulitermes flavipes (Kollar) and Reticulitermes tibialis Banks, both found in the southern half of the state. Colonies of both species in Wisconsin are thought to represent the northern boundary of their current distributions. Measurements of within colony genetic variation showed the proportion of polymorphic loci to be between 52.9-63.9% and expected heterozygosity to range from 0.122-0.189. Consistent with geographical isolation, strong intercolony genetic differences were observed, with over 50% of FST values above 0.25 and the remaining showing moderate levels of genetic differentiation. Combined with low levels of inbreeding in most collection locations (FIS 0.042-0.123), we hypothesize termites were introduced numerous times in the state, likely by anthropogenic means. We discuss the potential effects of these genetic characteristics on successful colony establishment of termites along the northern boundary compared with termites in the core region of their distribution. PMID:26313996

  17. Ant colony optimization algorithm for continuous domains based on position distribution model of ant colony foraging.

    PubMed

    Liu, Liqiang; Dai, Yuntao; Gao, Jinyu

    2014-01-01

    Ant colony optimization algorithm for continuous domains is a major research direction for ant colony optimization algorithm. In this paper, we propose a distribution model of ant colony foraging, through analysis of the relationship between the position distribution and food source in the process of ant colony foraging. We design a continuous domain optimization algorithm based on the model and give the form of solution for the algorithm, the distribution model of pheromone, the update rules of ant colony position, and the processing method of constraint condition. Algorithm performance against a set of test trials was unconstrained optimization test functions and a set of optimization test functions, and test results of other algorithms are compared and analyzed to verify the correctness and effectiveness of the proposed algorithm. PMID:24955402

  18. Early Developmental Program Shapes Colony Morphology in Bacteria

    PubMed Central

    Mamou, Gideon; Malli Mohan, Ganesh Babu; Rouvinski, Alex; Rosenberg, Alex; Ben-Yehuda, Sigal

    2016-01-01

    Summary When grown on a solid surface, bacteria form highly organized colonies, yet little is known about the earliest stages of colony establishment. Following Bacillus subtilis colony development from a single progenitor cell, a sequence of highly ordered spatiotemporal events was revealed. Colony was initiated by the formation of leading-cell chains, deriving from the colony center and extending in multiple directions, typically in a “Y-shaped” structure. By eradicating particular cells during these early stages, we could influence the shape of the resulting colony and demonstrate that Y-arm extension defines colony size. A mutant in ymdB encoding a phosphodiesterase displayed unordered developmental patterns, indicating a role in guiding these initial events. Finally, we provide evidence that intercellular nanotubes contribute to proper colony formation. In summary, we reveal a “construction plan” for building a colony and provide the initial molecular basis for this process. PMID:26904951

  19. Early Developmental Program Shapes Colony Morphology in Bacteria.

    PubMed

    Mamou, Gideon; Malli Mohan, Ganesh Babu; Rouvinski, Alex; Rosenberg, Alex; Ben-Yehuda, Sigal

    2016-03-01

    When grown on a solid surface, bacteria form highly organized colonies, yet little is known about the earliest stages of colony establishment. Following Bacillus subtilis colony development from a single progenitor cell, a sequence of highly ordered spatiotemporal events was revealed. Colony was initiated by the formation of leading-cell chains, deriving from the colony center and extending in multiple directions, typically in a "Y-shaped" structure. By eradicating particular cells during these early stages, we could influence the shape of the resulting colony and demonstrate that Y-arm extension defines colony size. A mutant in ymdB encoding a phosphodiesterase displayed unordered developmental patterns, indicating a role in guiding these initial events. Finally, we provide evidence that intercellular nanotubes contribute to proper colony formation. In summary, we reveal a "construction plan" for building a colony and provide the initial molecular basis for this process. PMID:26904951

  20. Predicting Honeybee Colony Failure: Using the BEEHAVE Model to Simulate Colony Responses to Pesticides

    PubMed Central

    2015-01-01

    To simulate effects of pesticides on different honeybee (Apis mellifera L.) life stages, we used the BEEHAVE model to explore how increased mortalities of larvae, in-hive workers, and foragers, as well as reduced egg-laying rate, could impact colony dynamics over multiple years. Stresses were applied for 30 days, both as multiples of the modeled control mortality and as set percentage daily mortalities to assess the sensitivity of the modeled colony both to small fluctuations in mortality and periods of low to very high daily mortality. These stresses simulate stylized exposure of the different life stages to nectar and pollen contaminated with pesticide for 30 days. Increasing adult bee mortality had a much greater impact on colony survival than mortality of bee larvae or reduction in egg laying rate. Importantly, the seasonal timing of the imposed mortality affected the magnitude of the impact at colony level. In line with the LD50, we propose a new index of “lethal imposed stress”: the LIS50 which indicates the level of stress on individuals that results in 50% colony mortality. This (or any LISx) is a comparative index for exploring the effects of different stressors at colony level in model simulations. While colony failure is not an acceptable protection goal, this index could be used to inform the setting of future regulatory protection goals. PMID:26444386

  1. Monoclonal origin of B lymphocyte colony-forming cells in spleen colonies formed by multipotential hemopoietic stem cells

    PubMed Central

    Lala, PK; Johnson, GR

    1978-01-01

    Spleen colonies produced by transplanting lethally irradiated mice with either 12 day fetal liver or adult bone marrow cells were found to contain B- lymphocyte colony-forming cells (BL-CFC) . The proportion of BL-CFC positive spleen colonies did not increase substantially between 8 and 14 days after transplantation, the range being 18-45 percent. However, the absolute number of BL-CFC per spleen colony varied considerably (between 1 and 10,318), although the majority of colonies contained less than 200 BL-CFC. Irrespective of the time after transplantation, smaller spleen colonies were found to have a higher frequency of BL-CFC than larger spleen colonies. To determine the possible clonal origin of BL-CFC from spleen colony- forming unit (CFU-S), CBA mice were injected with equal numbers of CBA and CBA T(6)/T(6) fetal liver or adult bone marrow cells. Analysis of 7-15-day spleen colonies demonstrated that 90 percent were either exclusively T(6) positive or T(6) negative and approximately equal numbers ofboth colony types were observed. B-lymphocyte colonies were grown and successfully karyotyped from 19 spleen colonies. When compared with the original spleen colony karyotype the B-lymphocyte colony cells karyotype was identical in all 19 cases. In 3 of the 19 colonies analyzed a mixture of T(6) positive and T(6) negative karyotypes was present and identical proportions of the karyotypes were present in the pooled B-lymphocyte colony cells and spleen colony cells. The data indicate that the B-lymphocyte colony-forming cells detected in spleen colonies are genuine members of the hemopoietic clone derived from the initiating hemopoietic stem cell (CFU-S). PMID:309918

  2. Branching instability in expanding bacterial colonies

    PubMed Central

    Giverso, Chiara; Verani, Marco; Ciarletta, Pasquale

    2015-01-01

    Self-organization in developing living organisms relies on the capability of cells to duplicate and perform a collective motion inside the surrounding environment. Chemical and mechanical interactions coordinate such a cooperative behaviour, driving the dynamical evolution of the macroscopic system. In this work, we perform an analytical and computational analysis to study pattern formation during the spreading of an initially circular bacterial colony on a Petri dish. The continuous mathematical model addresses the growth and the chemotactic migration of the living monolayer, together with the diffusion and consumption of nutrients in the agar. The governing equations contain four dimensionless parameters, accounting for the interplay among the chemotactic response, the bacteria–substrate interaction and the experimental geometry. The spreading colony is found to be always linearly unstable to perturbations of the interface, whereas branching instability arises in finite-element numerical simulations. The typical length scales of such fingers, which align in the radial direction and later undergo further branching, are controlled by the size parameters of the problem, whereas the emergence of branching is favoured if the diffusion is dominant on the chemotaxis. The model is able to predict the experimental morphologies, confirming that compact (resp. branched) patterns arise for fast (resp. slow) expanding colonies. Such results, while providing new insights into pattern selection in bacterial colonies, may finally have important applications for designing controlled patterns. PMID:25652464

  3. Buckling instability in ordered bacterial colonies

    PubMed Central

    Boyer, Denis; Mather, William; Mondragón-Palomino, Octavio; Orozco-Fuentes, Sirio; Danino, Tal; Hasty, Jeff; Tsimring, Lev S

    2013-01-01

    Bacterial colonies often exhibit complex spatio-temporal organization. This collective behavior is affected by a multitude of factors ranging from the properties of individual cells (shape, motility, membrane structure) to chemotaxis and other means of cell–cell communication. One of the important but often overlooked mechanisms of spatio-temporal organization is direct mechanical contact among cells in dense colonies such as biofilms. While in natural habitats all these different mechanisms and factors act in concert, one can use laboratory cell cultures to study certain mechanisms in isolation. Recent work demonstrated that growth and ensuing expansion flow of rod-like bacteria Escherichia coli in confined environments leads to orientation of cells along the flow direction and thus to ordering of cells. However, the cell orientational ordering remained imperfect. In this paper we study one mechanism responsible for the persistence of disorder in growing cell populations. We demonstrate experimentally that a growing colony of nematically ordered cells is prone to the buckling instability. Our theoretical analysis and discrete-element simulations suggest that the nature of this instability is related to the anisotropy of the stress tensor in the ordered cell colony. PMID:21358041

  4. Education and Evangelism in the English Colonies

    ERIC Educational Resources Information Center

    Watras, Joseph

    2008-01-01

    This article considers two related educational endeavors of the Massachusetts colony. The first is the colonists' efforts to pass their religious traditions to their children. The second is the effort of missionaries to spread the Christian faith to Native Americans. In both cases, the colonists wanted their children and the American Indians to…

  5. Colonial Newspaper Reaction to the Somerset Decision.

    ERIC Educational Resources Information Center

    Bradley, Patricia

    To examine colonial American press coverage of the British court decision to free American slave James Somerset, a study was conducted to clarify why the decision worked as a victory for British abolitionists but was usually cited even in post-Revolution America in the passage of increasingly oppressive slave legislation. Twenty-three of the…

  6. Policing native pleasures: a colonial history.

    PubMed

    Jabbar, Naheem

    2012-12-01

    The moral modality of colonial power is still with us when it comes to the recreation of sexual norms of traditional or feudal society. We can examine the emergent properties of colonial knowledge anew by exploring how the colonial regime's strategic attention of regulating brothels in India differed from the analytic of power Foucault described for sexuality in European society. It turns out that amongst other things, public anxieties about the failure of adaptation by South Asians are incapable of leaving sexuality aside as a key interpretive device for their culture. The British preoccupation with reproducing the dynamics of the bourgeois matrimonial market on foreign soil in the mid-nineteenth century similarly necessitated a sociological pretext for racial purity. However, the kind of knowledge a typical traveller and employee of the East India Company brought to the Victorian public from his own researches in the brothels and streets of colonial India, which revealed how popular prostitution was as a vice amongst the officer class, was also more than a welcome imaginary relief from Christian morality; it was an alternative vision of modernity. PMID:23240839

  7. English Literatures in Post-Colonial Singapore

    ERIC Educational Resources Information Center

    Dass, Rozita

    2015-01-01

    The emergence of a vibrant literary, culture and arts scene promotes Singapore's claims as a hub for arts and culture in the Asian region, and as a global arts city by the 21st century. The richness and variety of Singapore literature from the early post-colonial years are evident in the evolution of a Singapore literary culture. The diaspora of…

  8. English Literatures in Post-Colonial Singapore

    ERIC Educational Resources Information Center

    Dass, Rozita

    2015-01-01

    The emergence of a vibrant literary, culture and arts scene promotes Singapore's claims as a hub for arts and culture in the Asian region, and as a global arts city by the 21st century. The richness and variety of Singapore literature from the early post-colonial years are evident in the evolution of a Singapore literary culture. The diaspora of…

  9. Branching instability in expanding bacterial colonies.

    PubMed

    Giverso, Chiara; Verani, Marco; Ciarletta, Pasquale

    2015-03-01

    Self-organization in developing living organisms relies on the capability of cells to duplicate and perform a collective motion inside the surrounding environment. Chemical and mechanical interactions coordinate such a cooperative behaviour, driving the dynamical evolution of the macroscopic system. In this work, we perform an analytical and computational analysis to study pattern formation during the spreading of an initially circular bacterial colony on a Petri dish. The continuous mathematical model addresses the growth and the chemotactic migration of the living monolayer, together with the diffusion and consumption of nutrients in the agar. The governing equations contain four dimensionless parameters, accounting for the interplay among the chemotactic response, the bacteria-substrate interaction and the experimental geometry. The spreading colony is found to be always linearly unstable to perturbations of the interface, whereas branching instability arises in finite-element numerical simulations. The typical length scales of such fingers, which align in the radial direction and later undergo further branching, are controlled by the size parameters of the problem, whereas the emergence of branching is favoured if the diffusion is dominant on the chemotaxis. The model is able to predict the experimental morphologies, confirming that compact (resp. branched) patterns arise for fast (resp. slow) expanding colonies. Such results, while providing new insights into pattern selection in bacterial colonies, may finally have important applications for designing controlled patterns. PMID:25652464

  10. A Bicentennial Without a Puerto Rican Colony

    ERIC Educational Resources Information Center

    Thomas, Piri

    1975-01-01

    The United States revolution of 1776 is said to lose validity in light of Puerto Rico's colonial situation under American rule. The plight of the Puerto Rican people is compared to that of the Euro-American settlers under the thumb-screw of British imperialism. (Author/AM)

  11. Colonial Continuities and Educational Inequalities in Indonesia.

    ERIC Educational Resources Information Center

    Carpenter, Harold F., Jr.

    This paper explores the effect of 350 years of Dutch colonial rule upon Indonesian educational policies and the resulting regional inequalities in education. It was Dutch policy not to educate most of the children from the poorer social classes, but to use education to maintain and strengthen the existing social structure. Education was also used…

  12. Detection of Campylobacter Colonies using Hyperspectral Imaging

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Isolation and detection of Campylobacter in foods via direct plating involves lengthy laboratory procedures including enrichments and microaerobic incubations, which take several days to a week. The incubation time for growing Campylobacter colonies in agar media is typically 24 hours to 48 hours. F...

  13. Project Final Report: HPC-Colony II

    SciTech Connect

    Jones, Terry R; Kale, Laxmikant V; Moreira, Jose

    2013-11-01

    This report recounts the HPC Colony II Project which was a computer science effort funded by DOE's Advanced Scientific Computing Research office. The project included researchers from ORNL, IBM, and the University of Illinois at Urbana-Champaign. The topic of the effort was adaptive system software for extreme scale parallel machines. A description of findings is included.

  14. Women in Colonial and Revolutionary America.

    ERIC Educational Resources Information Center

    Eisenberg, Bonnie; And Others

    Designed as a supplemental teaching tool for upper elementary and middle school use, this unit contains information on the circumstances under which women of various cultures lived in the United States during the colonial and revolutionary periods and presents a perspective that is seldom included in textbooks. The unit includes biographies of ten…

  15. Education and Evangelism in the English Colonies

    ERIC Educational Resources Information Center

    Watras, Joseph

    2008-01-01

    This article considers two related educational endeavors of the Massachusetts colony. The first is the colonists' efforts to pass their religious traditions to their children. The second is the effort of missionaries to spread the Christian faith to Native Americans. In both cases, the colonists wanted their children and the American Indians to…

  16. Considerations for lunar colony communications systems

    NASA Technical Reports Server (NTRS)

    Dowling, Richard P.

    1992-01-01

    This paper addresses system aspects of communications for a lunar colony. Human factors are particularly noted. The practical aspects of communications infrastructure are emphasized rather than specific technologies. Communications needs for mission support and morale are discussed along with potential means of satisfying them. Problem areas are identified and some possible solutions are considered.

  17. Colony Fusion in a Parthenogenetic Ant, Pristomyrmex punctatus

    PubMed Central

    Satow, Show; Satoh, Toshiyuki; Hirota, Tadao

    2013-01-01

    In the ant Pristomyrmex punctatus Smith (Hymenoptera: Formicidae), all young workers lay a small number of eggs parthenogenetically. Some colonies consist of monoclonal individuals that provide high inclusive fitness, according to the kin selection theory. However, in some populations, a majority of the colonies contain multiple lineages. Intracolonial genetic variation of parthenogenetic ants cannot be explained by the multiple mating of single founderesses or by the foundation of a colony by multiple foundresses, which are the usual causes of genetically diverse colonies in social insects. Here, we hypothesized that the fusion of established colonies might facilitate the formation of multiclonal colonies. Colony fusion decreases indirect benefits because of the reduction in intracolonial relatedness. However, when suitable nesting places for overwintering are scarce, colony fusion provides a strategy for the survival of colonies. Here, ants derived from different colonies were allowed to encounter one another in a container with just one nesting place. Initially, high aggression was observed; however, after several days, no aggression was observed and the ants shared the nest. When the fused colonies were allowed to transfer to two alternative nests, ants from different colonies occupied the same nest. This study highlights the importance of limiting the number of nesting places in order to understand the genetic diversity of parthenogenetic ant colonies. PMID:23895053

  18. Nest-size and colony characteristics of wading birds in selected Atlantic Coast colonies

    USGS Publications Warehouse

    Beaver, D.L.; Osborn, R.G.; Custer, T.W.

    1980-01-01

    Nests of 5 species of wading birds were identified and marked during the breeding season at 6 locations from Massachusetts to North Carolina. At the end of the breeding season 12 characteristics of nest-site location were measured. Nest locations were mapped to examine dispersion and nearest neighbor relationships. Multivariate analyses were used to describe and compare sites and species.....We found that variations in nest-sites between colonies were greater than between species; colonies differed mainly in the variety and size of vegetation; birds preferred to nest in vegetation that offered relatively stable nest-sites; and the dispersion of nests in the colonies was related to vegetative patterns. The interaction of these factors with the number of bird species and the abundance of birds in the colony seemed to determine whether nest-sites were stratified, segregated or randomly distributed.

  19. Nest site and colony characteristics of wading birds in selected atlantic coast colonies

    USGS Publications Warehouse

    Beaver, D.L.; Osborn, R.G.; Custer, T.W.

    1980-01-01

    Nests of 5 spp. of wading birds [Egretta thula, Plegadis falcinellus, Florida caerulea, casmerodius albus and Hydranassa tricolor] were identified and marked during the breeding season at 6 locations from Maccachusetts [USA] to North Carolina [USA]. At the end of the breeding season, 12 characteristics of nest-site location were measured. Nest locations were mapped to examine dispersion and nearest neighbor relationships. Multivariate analysis were used to describe and compare sites and species. Variations in nest-sites between colonies were greater than between species; colonies differed mainly in the variety and size of vegetation. Birds preferred to nest in vegetation that offered relatively stable nest sites, and the dispersion of nests in the colonies was related to vegetative patterns. The interaction of these factors with the number of bird species and the abundance of birds in the colony determined whether nest sites were stratified, segregated or randomly distributed.

  20. A quantitative model of honey bee colony population dynamics.

    PubMed

    Khoury, David S; Myerscough, Mary R; Barron, Andrew B

    2011-01-01

    Since 2006 the rate of honey bee colony failure has increased significantly. As an aid to testing hypotheses for the causes of colony failure we have developed a compartment model of honey bee colony population dynamics to explore the impact of different death rates of forager bees on colony growth and development. The model predicts a critical threshold forager death rate beneath which colonies regulate a stable population size. If death rates are sustained higher than this threshold rapid population decline is predicted and colony failure is inevitable. The model also predicts that high forager death rates draw hive bees into the foraging population at much younger ages than normal, which acts to accelerate colony failure. The model suggests that colony failure can be understood in terms of observed principles of honey bee population dynamics, and provides a theoretical framework for experimental investigation of the problem. PMID:21533156

  1. Influence of task switching costs on colony homeostasis

    NASA Astrophysics Data System (ADS)

    Jeanson, Raphaël; Lachaud, Jean-Paul

    2015-06-01

    In social insects, division of labour allows colonies to optimise the allocation of workers across all available tasks to satisfy colony requirements. The maintenance of stable conditions within colonies (homeostasis) requires that some individuals move inside the nest to monitor colony needs and execute unattended tasks. We developed a simple theoretical model to explore how worker mobility inside the nest and task switching costs influence the maintenance of stable levels of task-associated stimuli. Our results indicate that worker mobility in large colonies generates important task switching costs and is detrimental to colony homeostasis. Our study suggests that the balance between benefits and costs associated with the mobility of workers patrolling inside the nest depends on colony size. We propose that several species of ants with diverse life-history traits should be appropriate to test the prediction that the proportion of mobile workers should vary during colony ontogeny.

  2. A Quantitative Model of Honey Bee Colony Population Dynamics

    PubMed Central

    Khoury, David S.; Myerscough, Mary R.; Barron, Andrew B.

    2011-01-01

    Since 2006 the rate of honey bee colony failure has increased significantly. As an aid to testing hypotheses for the causes of colony failure we have developed a compartment model of honey bee colony population dynamics to explore the impact of different death rates of forager bees on colony growth and development. The model predicts a critical threshold forager death rate beneath which colonies regulate a stable population size. If death rates are sustained higher than this threshold rapid population decline is predicted and colony failure is inevitable. The model also predicts that high forager death rates draw hive bees into the foraging population at much younger ages than normal, which acts to accelerate colony failure. The model suggests that colony failure can be understood in terms of observed principles of honey bee population dynamics, and provides a theoretical framework for experimental investigation of the problem. PMID:21533156

  3. Influence of task switching costs on colony homeostasis.

    PubMed

    Jeanson, Raphaël; Lachaud, Jean-Paul

    2015-06-01

    In social insects, division of labour allows colonies to optimise the allocation of workers across all available tasks to satisfy colony requirements. The maintenance of stable conditions within colonies (homeostasis) requires that some individuals move inside the nest to monitor colony needs and execute unattended tasks. We developed a simple theoretical model to explore how worker mobility inside the nest and task switching costs influence the maintenance of stable levels of task-associated stimuli. Our results indicate that worker mobility in large colonies generates important task switching costs and is detrimental to colony homeostasis. Our study suggests that the balance between benefits and costs associated with the mobility of workers patrolling inside the nest depends on colony size. We propose that several species of ants with diverse life-history traits should be appropriate to test the prediction that the proportion of mobile workers should vary during colony ontogeny. PMID:26040241

  4. Oversea Education and British Colonial Education 1929-63.

    ERIC Educational Resources Information Center

    Whitehead, Clive

    2003-01-01

    Focuses on an early twentieth century journal called "Oversea Education," designed to increase communication among British colonies, particularly for education, based on William Ormsby Gore's travels among the colonies. Describes Frank Ward's editorial work that championed the rights of colonial subjects to have better educational policy. (KDR)

  5. The Genesis of Public Relations in British Colonial Practice.

    ERIC Educational Resources Information Center

    Smyth, Rosaleen

    2001-01-01

    Demonstrates how the British Colonial Office employed public relations strategies as they administered the British colony of Northern Rhodesia before, during, and after World War II. Demonstrates how civil servants in London and colonial officials implemented public relations policies, strategies, and tactics on an ad hoc basis, covering political…

  6. Deformed Wing Virus Implicated in Overwintering Honeybee Colony Losses ?

    PubMed Central

    Highfield, Andrea C.; El Nagar, Aliya; Mackinder, Luke C. M.; Noël, Laure M.-L. J.; Hall, Matthew J.; Martin, Stephen J.; Schroeder, Declan C.

    2009-01-01

    The worldwide decline in honeybee colonies during the past 50 years has often been linked to the spread of the parasitic mite Varroa destructor and its interaction with certain honeybee viruses. Recently in the United States, dramatic honeybee losses (colony collapse disorder) have been reported; however, there remains no clear explanation for these colony losses, with parasitic mites, viruses, bacteria, and fungal diseases all being proposed as possible candidates. Common characteristics that most failing colonies share is a lack of overt disease symptoms and the disappearance of workers from what appears to be normally functioning colonies. In this study, we used quantitative PCR to monitor the presence of three honeybee viruses, deformed wing virus (DWV), acute bee paralysis virus (ABPV), and black queen cell virus (BQCV), during a 1-year period in 15 asymptomatic, varroa mite-positive honeybee colonies in Southern England, and 3 asymptomatic colonies confirmed to be varroa mite free. All colonies with varroa mites underwent control treatments to ensure that mite populations remained low throughout the study. Despite this, multiple virus infections were detected, yet a significant correlation was observed only between DWV viral load and overwintering colony losses. The long-held view has been that DWV is relatively harmless to the overall health status of honeybee colonies unless it is in association with severe varroa mite infestations. Our findings suggest that DWV can potentially act independently of varroa mites to bring about colony losses. Therefore, DWV may be a major factor in overwintering colony losses. PMID:19783750

  7. Before 1776: The Massachusetts Bay Colony from Founding to Revolution.

    ERIC Educational Resources Information Center

    Gruenbaum, Thelma

    Designed for use at 4th-through-10th-grade level, this short history of the Massachusetts Bay Colony provides a view of colonial life style and culture prior to the American Revolution. The first sections discuss the Puritan migration and early settlement around Boston. Descriptions of colonial housing, furniture, food, clothing, clothing styles,…

  8. Deformed wing virus implicated in overwintering honeybee colony losses.

    PubMed

    Highfield, Andrea C; El Nagar, Aliya; Mackinder, Luke C M; Noël, Laure M-L J; Hall, Matthew J; Martin, Stephen J; Schroeder, Declan C

    2009-11-01

    The worldwide decline in honeybee colonies during the past 50 years has often been linked to the spread of the parasitic mite Varroa destructor and its interaction with certain honeybee viruses. Recently in the United States, dramatic honeybee losses (colony collapse disorder) have been reported; however, there remains no clear explanation for these colony losses, with parasitic mites, viruses, bacteria, and fungal diseases all being proposed as possible candidates. Common characteristics that most failing colonies share is a lack of overt disease symptoms and the disappearance of workers from what appears to be normally functioning colonies. In this study, we used quantitative PCR to monitor the presence of three honeybee viruses, deformed wing virus (DWV), acute bee paralysis virus (ABPV), and black queen cell virus (BQCV), during a 1-year period in 15 asymptomatic, varroa mite-positive honeybee colonies in Southern England, and 3 asymptomatic colonies confirmed to be varroa mite free. All colonies with varroa mites underwent control treatments to ensure that mite populations remained low throughout the study. Despite this, multiple virus infections were detected, yet a significant correlation was observed only between DWV viral load and overwintering colony losses. The long-held view has been that DWV is relatively harmless to the overall health status of honeybee colonies unless it is in association with severe varroa mite infestations. Our findings suggest that DWV can potentially act independently of varroa mites to bring about colony losses. Therefore, DWV may be a major factor in overwintering colony losses. PMID:19783750

  9. The Genesis of Public Relations in British Colonial Practice.

    ERIC Educational Resources Information Center

    Smyth, Rosaleen

    2001-01-01

    Demonstrates how the British Colonial Office employed public relations strategies as they administered the British colony of Northern Rhodesia before, during, and after World War II. Demonstrates how civil servants in London and colonial officials implemented public relations policies, strategies, and tactics on an ad hoc basis, covering political…

  10. Brazilian Higher Education from a Post-Colonial Perspective

    ERIC Educational Resources Information Center

    Leite, Denise

    2010-01-01

    This article examines Brazilian higher education (HE) politics from a post-colonial perspective. The term "post-colonial" originally referred to a historical period of colonial empires established by European nations. Nowadays, the term commonly distinguishes a field of contemporary studies of "defamiliarisation of the imperial North" made up of…

  11. French colonial medicine in Cambodia: reflections of governmentality.

    PubMed

    Trankell, Ing-Britt; Ovesen, Jan

    2004-04-01

    Studies of colonial medicine, mostly from former British colonies, have shown that colonial medical interventions mostly benefited the European colonisers and often had very little positive effects on the health of the native populations at large. A common assumption is that this was also the case for French colonial medicine in general, and for colonial medicine in Cambodia in particular, and that the unsatisfactory contemporary state of the medical services in the country may be partly explained by its colonial past. As a way to test this assumption, this paper presents an ethnography of colonial medicine in Cambodia in the first decades of the twentieth century. Documents in the Cambodian National Archives provided the primary sources, and their significance was assessed against the background of the authors' experience of medical anthropological research in contemporary Cambodia. Michel Foucault's concept of governmentality is used as the interpretative frame. Elements of colonial governmentality in the medical field included the promotion of modern medicine through the free dispensing of medicines and medical treatment and rudimentary medical training of members of the local population, as well as compulsory vaccinations and surveillance of the colonial subjects. It is concluded that both the idea of medicine as a 'tool of empire' and that of the colonial physician as a humanitarian hero are equally incomplete as general descriptions, and that specific ethnographies of medical policies and practices should be undertaken for particular colonial settings. This paper provides the first anthropological account of colonial medicine in Cambodia. PMID:26868101

  12. Colony Rheology: Active Arthropods Generate Flows

    NASA Astrophysics Data System (ADS)

    Daniels, Karen; Mann, Michael; Charbonneau, Patrick

    2015-03-01

    Hydrodynamic-like flows are observed in biological systems as varied as bacteria, insects, birds, fish, and mammals. Both the phenomenology (e.g. front instabilities, milling motions) and the interaction types (hydrodynamic, direct contact, psychological, excluded-volume) strongly vary between systems, but a question common to all of them is to understand the role of particle-scale fluctuations in controlling large-scale rheological behaviors. We will address these questions through experiments on a new system, Tyrolichus casei (cheese mites), which live in dense, self-mixing colonies composed of a mixture of living mites and inert flour/detritus. In experiments performed in a Hele-Shaw geometry, we observe that the rheology of a colony is strongly dependent on the relative concentration of active and inactive particles. In addition to spreading flows, we also observe that the system can generate convective circulation and auto-compaction.

  13. FY005 Accomplishments for Colony Project

    SciTech Connect

    Jones, T; Kale, L; Moreira, J; Mendes, C; Chakravorty, S; Inglett, T; Tauferner, A

    2005-07-05

    The Colony Project is developing operating system and runtime system technology to enable efficient general purpose environments on tens of thousands of processors. To accomplish this, we are investigating memory management techniques, fault management strategies, and parallel resource management schemes. Recent results show promising findings for scalable strategies based on processor virtualization, in-memory checkpointing, and parallel aware modifications to full featured operating systems.

  14. The Development of Politics in Extraterrestrial Colonies

    NASA Astrophysics Data System (ADS)

    Sivier, D. J.

    The existence of feudal or totalitarian interplanetary empires has been a favourite theme in Science Fiction. Although the vast distances between the stars make the emergence of an interstellar empire impossible without the creation of a faster than light drive, this is not necessarily true for the other worlds within our solar system. Environmental constraints on the off-world colonies themselves, and repressive, hierarchical and feudalistic social and commercial institutions and customs inherited from the parent cultures on Earth and a tradition of military rule descending from the foundation of these colonies may all work to bring about a new feudal or totalitarian social order on humanity's extraterrestrial colonies. There are encouraging signs that this may not be the case, however. Already the debate over the projected colonisation of Mars is a factor influencing present controversies over repressive institutions and customs. Nevertheless, those wishing for a free, democratic, and politically, socially and technologically innovative and vigorous human society spreading throughout the solar system should not become complacent.

  15. Aging in the colonial chordate, Botryllus schlosseri

    PubMed Central

    Munday, Roma; Rodriguez, Delany; Di Maio, Alessandro; Kassmer, Susannah; Braden, Brian; Taketa, Daryl A.; Langenbacher, Adam; De Tomaso, Anthony

    2015-01-01

    What mechanisms underlie aging? One theory, the wear-and-tear model, attributes aging to progressive deterioration in the molecular and cellular machinery which eventually lead to death through the disruption of physiological homeostasis. The second suggests that life span is genetically programmed, and aging may be derived from intrinsic processes which enforce a non-random, terminal time interval for the survivability of the organism. We are studying an organism that demonstrates both properties: the colonial ascidian, Botryllus schlosseri. Botryllus is a member of the Tunicata, the sister group to the vertebrates, and has a number of life history traits which make it an excellent model for studies on aging. First, Botryllus has a colonial life history, and grows by a process of asexual reproduction during which entire bodies, including all somatic and germline lineages, regenerate every week, resulting in a colony of genetically identical individuals. Second, previous studies of lifespan in genetically distinct Botryllus lineages suggest that a direct, heritable basis underlying mortality exists that is unlinked to reproductive effort and other life history traits. Here we will review recent efforts to take advantage of the unique life history traits of B. schlosseri and develop it into a robust model for aging research. PMID:26136620

  16. 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.

  17. Swarming Ring Patterns in Bacterial Colonies Exposed to Ultraviolet Radiation

    SciTech Connect

    Delprato, Anna M.; Samadani, Azadeh; Kudrolli, A.; Tsimring, L. S.

    2001-10-08

    We report a novel morphological transition in a Bacillus subtilis colony initially growing under ambient conditions, after ultraviolet radiation exposure. The bacteria in the central regions of the colonies are observed to migrate towards the colony edge forming a ring during uniform spatial exposure. When the radiation is switched off, the colonies were observed to grow both inward into the evacuated regions as well as outward indicating that the pattern is not formed due to depletion of nutrients at the center of the colony. We also propose a reaction-diffusion model in which waste-limited chemotaxis initiated by the UV radiation leads to the observed phenomenology.

  18. Rapid behavioral maturation accelerates failure of stressed honey bee colonies.

    PubMed

    Perry, Clint J; Søvik, Eirik; Myerscough, Mary R; Barron, Andrew B

    2015-03-17

    Many complex factors have been linked to the recent marked increase in honey bee colony failure, including pests and pathogens, agrochemicals, and nutritional stressors. It remains unclear, however, why colonies frequently react to stressors by losing almost their entire adult bee population in a short time, resulting in a colony population collapse. Here we examine the social dynamics underlying such dramatic colony failure. Bees respond to many stressors by foraging earlier in life. We manipulated the demography of experimental colonies to induce precocious foraging in bees and used radio tag tracking to examine the consequences of precocious foraging for their performance. Precocious foragers completed far fewer foraging trips in their life, and had a higher risk of death in their first flights. We constructed a demographic model to explore how this individual reaction of bees to stress might impact colony performance. In the model, when forager death rates were chronically elevated, an increasingly younger forager force caused a positive feedback that dramatically accelerated terminal population decline in the colony. This resulted in a breakdown in division of labor and loss of the adult population, leaving only brood, food, and few adults in the hive. This study explains the social processes that drive rapid depopulation of a colony, and we explore possible strategies to prevent colony failure. Understanding the process of colony failure helps identify the most effective strategies to improve colony resilience. PMID:25675508

  19. Rapid behavioral maturation accelerates failure of stressed honey bee colonies

    PubMed Central

    Perry, Clint J.; Myerscough, Mary R.; Barron, Andrew B.

    2015-01-01

    Many complex factors have been linked to the recent marked increase in honey bee colony failure, including pests and pathogens, agrochemicals, and nutritional stressors. It remains unclear, however, why colonies frequently react to stressors by losing almost their entire adult bee population in a short time, resulting in a colony population collapse. Here we examine the social dynamics underlying such dramatic colony failure. Bees respond to many stressors by foraging earlier in life. We manipulated the demography of experimental colonies to induce precocious foraging in bees and used radio tag tracking to examine the consequences of precocious foraging for their performance. Precocious foragers completed far fewer foraging trips in their life, and had a higher risk of death in their first flights. We constructed a demographic model to explore how this individual reaction of bees to stress might impact colony performance. In the model, when forager death rates were chronically elevated, an increasingly younger forager force caused a positive feedback that dramatically accelerated terminal population decline in the colony. This resulted in a breakdown in division of labor and loss of the adult population, leaving only brood, food, and few adults in the hive. This study explains the social processes that drive rapid depopulation of a colony, and we explore possible strategies to prevent colony failure. Understanding the process of colony failure helps identify the most effective strategies to improve colony resilience. PMID:25675508

  20. Developmental Instability in Incipient Colonies of Social Insects

    PubMed Central

    Chouvenc, Thomas; Basille, Mathieu; Li, Hou-Feng; Su, Nan-Yao

    2014-01-01

    Social insect colonies can provide homeostatic conditions that buffer the incidence of environmental fluctuations on individuals, which have contributed to their ecological success. Coptotermes (Isoptera: Rhinotermitidae) is a highly invasive termite genus and several species have important economic impact in many areas of the world. Mature Coptotermes colonies with millions of individuals can provide optimal environmental condition and nurturing capacity for the developing brood. However, it was previously suggested that contrary to mature colonies, incipient colonies may be exposed to critical stress, which may explain for the low success rate of establishment within the first year of the life of a termite colony. We here investigated the stress imposed on individuals of incipient colonies by comparing the developmental instability of individuals between incipient and mature colonies of two Coptotermes species, C. formosanus Shiraki and C. gestroi (Wasmann). We assessed the developmental instability by measuring the asymmetry of morphological traits from the head capsule of the soldier caste. Soldiers from incipient colonies of both species displayed strong asymmetrical traits in comparison to soldiers from mature colonies. We suggest that homeostatic conditions for optimal development are reached as the colony matures, and confirmed that the incipient colony remains a critical bottleneck where individuals are exposed to high developmental stress. PMID:25423502

  1. Scanning electron microscopy of intact colonies of microorganisms.

    PubMed

    Whittaker, D K; Drucker, D B

    1970-11-01

    Colonies of S. mutans OMZ61, Streptococcus sp. D182, Staphylococcus aureus Oxford NCTC 6571, and Candida albicans type A, MRL 3153 were grown on various media. Cubes of agar bearing two to three colonies were excised and processed for scanning electron microscopy. The characteristic shape of the colonies was seen when examined at low magnifications. At a magnification of 2,000 diameters, the arrangement of individual organisms within the colonies was observed. Plano-convex colonies consisted of uniformly distributed organisms, whereas S. mutans colonies presented a more complex arrangement possibly associated with the production of extracellular polysaccharides. Certain colonies were totally or partially covered by an adherent film through which the outline of the organisms could be distinguished. PMID:5489440

  2. Intraspecific Variation among Social Insect Colonies: Persistent Regional and Colony-Level Differences in Fire Ant Foraging Behavior

    PubMed Central

    Bockoven, Alison A.; Wilder, Shawn M.; Eubanks, Micky D.

    2015-01-01

    Individuals vary within a species in many ecologically important ways, but the causes and consequences of such variation are often poorly understood. Foraging behavior is among the most profitable and risky activities in which organisms engage and is expected to be under strong selection. Among social insects there is evidence that within-colony variation in traits such as foraging behavior can increase colony fitness, but variation between colonies and the potential consequences of such variation are poorly documented. In this study, we tested natural populations of the red imported fire ant, Solenopsis invicta, for the existence of colony and regional variation in foraging behavior and tested the persistence of this variation over time and across foraging habitats. We also reared single-lineage colonies in standardized environments to explore the contribution of colony lineage. Fire ants from natural populations exhibited significant and persistent colony and regional-level variation in foraging behaviors such as extra-nest activity, exploration, and discovery of and recruitment to resources. Moreover, colony-level variation in extra-nest activity was significantly correlated with colony growth, suggesting that this variation has fitness consequences. Lineage of the colony had a significant effect on extra-nest activity and exploratory activity and explained approximately half of the variation observed in foraging behaviors, suggesting a heritable component to colony-level variation in behavior. PMID:26197456

  3. Intraspecific Variation among Social Insect Colonies: Persistent Regional and Colony-Level Differences in Fire Ant Foraging Behavior.

    PubMed

    Bockoven, Alison A; Wilder, Shawn M; Eubanks, Micky D

    2015-01-01

    Individuals vary within a species in many ecologically important ways, but the causes and consequences of such variation are often poorly understood. Foraging behavior is among the most profitable and risky activities in which organisms engage and is expected to be under strong selection. Among social insects there is evidence that within-colony variation in traits such as foraging behavior can increase colony fitness, but variation between colonies and the potential consequences of such variation are poorly documented. In this study, we tested natural populations of the red imported fire ant, Solenopsis invicta, for the existence of colony and regional variation in foraging behavior and tested the persistence of this variation over time and across foraging habitats. We also reared single-lineage colonies in standardized environments to explore the contribution of colony lineage. Fire ants from natural populations exhibited significant and persistent colony and regional-level variation in foraging behaviors such as extra-nest activity, exploration, and discovery of and recruitment to resources. Moreover, colony-level variation in extra-nest activity was significantly correlated with colony growth, suggesting that this variation has fitness consequences. Lineage of the colony had a significant effect on extra-nest activity and exploratory activity and explained approximately half of the variation observed in foraging behaviors, suggesting a heritable component to colony-level variation in behavior. PMID:26197456

  4. Enhanced ant colony optimization for multiscale problems

    NASA Astrophysics Data System (ADS)

    Hu, Nan; Fish, Jacob

    2016-01-01

    The present manuscript addresses the issue of computational complexity of optimizing nonlinear composite materials and structures at multiple scales. Several solutions are detailed to meet the enormous computational challenge of optimizing nonlinear structures at multiple scales including: (i) enhanced sampling procedure that provides superior performance of the well-known ant colony optimization algorithm, (ii) a mapping-based meshing of a representative volume element that unlike unstructured meshing permits sensitivity analysis on coarse meshes, and (iii) a multilevel optimization procedure that takes advantage of possible weak coupling of certain scales. We demonstrate the proposed optimization procedure on elastic and inelastic laminated plates involving three scales.

  5. Josephine Baker: psychoanalysis and the colonial fetish.

    PubMed

    Cheng, Anne Anlin

    2006-01-01

    This paper traces an intricate path connecting racial fantasy, aesthetic judgment, and the larger cultural problem of inter-subjective recognition. In particular, the author examines the theme of fetishism, both sexual and racial, in a Western historical, colonial context, in order to unravel a set of disturbances that cohere around the racial fetish then and now. Taking the figure of an entertainment icon of the 1920s, Josephine Baker, as a case study, the author shows how the imagination of the colonizing white male was both articulated and disrupted by Baker as a ready-made representation of the cultural, racial, and sexual other. PMID:16482962

  6. Intercellular Genomics of Subsurface Microbial Colonies

    SciTech Connect

    Ortoleva, Peter; Tuncay, Kagan; Gannon, Dennis; Meile, Christof

    2007-02-14

    This report summarizes progress in the second year of this project. The objective is to develop methods and software to predict the spatial configuration, properties and temporal evolution of microbial colonies in the subsurface. To accomplish this, we integrate models of intracellular processes, cell-host medium exchange and reaction-transport dynamics on the colony scale. At the conclusion of the project, we aim to have the foundations of a predictive mathematical model and software that captures the three scales of these systems – the intracellular, pore, and colony wide spatial scales. In the second year of the project, we refined our transcriptional regulatory network discovery (TRND) approach that utilizes gene expression data along with phylogenic similarity and gene ontology analyses and applied it successfully to E.coli, human B cells, and Geobacter sulfurreducens. We have developed a new Web interface, GeoGen, which is tailored to the reconstruction of microbial TRNs and solely focuses on Geobacter as one of DOE’s high priority microbes. Our developments are designed such that the frameworks for the TRND and GeoGen can readily be used for other microbes of interest to the DOE. In the context of modeling a single bacterium, we are actively pursuing both steady-state and kinetic approaches. The steady-state approach is based on a flux balance that uses maximizing biomass growth rate as its objective, subjected to various biochemical constraints, for the optimal values of reaction rates and uptake/release of metabolites. For the kinetic approach, we use Karyote, a rigorous cell model developed by us for an earlier DOE grant and the DARPA BioSPICE Project. We are also investigating the interplay between bacterial colonies and environment at both pore and macroscopic scales. The pore scale models use detailed representations for realistic porous media accounting for the distribution of grain size whereas the macroscopic models employ the Darcy-type flow equations and up-scaled advective-diffusive transport equations for chemical species. We are rigorously testing the relationship between these two scales by evaluating macroscopic parameters using the volume averaging methodology applied to pore scale model results.

  7. Spatiotemporal evolution of bacterial biofilm colonies

    NASA Astrophysics Data System (ADS)

    Wilking, James; Koehler, Stephan; Sinha, Naveen; Seminara, Agnese; Brenner, Michael; Weitz, David

    2014-03-01

    Many bacteria on earth live in surface-attached communities known as biofilms. Gene expression in a biofilm is typically varied, resulting in a variety of phenotypes within a single film. These phenotypes play a critical role in biofilm physiology and development. We use time-resolved, wide-field fluorescence microscopy to image triple-labeled fluorescent Bacillus Subtilis colonies grown on agar to determine in a non-invasive fashion the evolving phenotypes. We infer their transition rates from the resulting spatiotemporal maps of gene expression. Moreover, we correlate these transition rates with local measurements of nutrient concentration to determine the influence of extracellular signals on gene expression.

  8. Combined Final Report for Colony II Project

    SciTech Connect

    Kale, Laxmikant; Jones, Terry; Moreira, Jose

    2013-10-23

    (This report was originally submmited by the lead PI (Terry Jones, ORNL) on October 22, 2013 to the program manager, Lucy Nowell. It is being submitted from University of Illinois in accordance with instructions). HPC Colony II seeks to provide portable performance for leadership class machines. Our strategy is based on adaptive system software that aims to make the intelligent decisions necessary to allow domain scientists to safely focus on their task at hand and allow the system software stack to adapt their application to the underlying architecture. This report describes the research undertaken towards these objectives and the results obtained over the performance period of the project.

  9. The Contemporary Reality of Canadian Imperialism: Settler Colonialism and the Hybrid Colonial State

    ERIC Educational Resources Information Center

    Barker, Adam J.

    2009-01-01

    The author's fundamental contention is this: Canadian society remains driven by the logic of imperialism and engages in concerted colonial action against Indigenous peoples whose claims to land and self-determination continue to undermine the legitimacy of Canadian authority and hegemony. The imperial ambitions of the Canadian state and its…

  10. Entombed pollen: A new condition in honey bee colonies associated with increased risk of colony mortality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Here we describe a new phenomenon, entombed pollen, which is highly associated with increased colony mortality. Entombed pollen appears as sunken, wax-covered cells amidst “normal”, uncapped cells of stored pollen, and the pollen contained within these cells is brick red in color. There appears to b...

  11. Disrupting the Coloniality of Being: Toward De-Colonial Ontologies in Philosophy of Education

    ERIC Educational Resources Information Center

    Richardson, Troy A.

    2012-01-01

    This essay works to bridge conversations in philosophy of education with decolonial theory. The author considers Margonis' (1999, 2011a, b) use of Rousseau (1979) and Heidegger (1962) in developing an ontological attitude that counters social hierarchies and promotes anti-colonial relations. While affirming this effort, the essay outlines a…

  12. Stable isotope enrichment in laboratory ant colonies: effects of colony age, metamorphosis, diet, and fat storage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ecologists use stable isotopes to infer diets and trophic levels of animals in food webs, yet some assumptions underlying these inferences have not been thoroughly tested. We used laboratory-reared colonies of Solenopsis invicta Buren (Formicidae: Solenopsidini) to test the effects of metamorphosis,...

  13. Genetic Diversity in Laboratory Colonies of Western Corn Rootworm (Coleoptera: Chrysomelidae) including a Nondiapause Colony

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Laboratory-reared western corn rootworms, Diabrotica virgifera virgifera, from colonies maintained at the North Central Agricultural Research Laboratory (NCARL) in Brookings, SD, are used extensively by many researchers in studies of the biology, ecology, behavior, and genetics of this major insect ...

  14. The regulation of British colonial lunatic asylums and the origins of colonial psychiatry, 1860-1864.

    PubMed

    Swartz, Sally

    2010-05-01

    In this paper I outline a brief period in the history of the British Empire, during which colonial lunatic asylum policy began to be formulated. I begin with a scandal that erupted in Jamaica and suggest that this set in motion processes that led to critical changes in asylum administration. The first of these processes was an audit of hospitals and asylums in the colonies. The results of the audit and the policy that emerged from it marked the beginning of systematic regulation of lunatic asylum practice across the British Empire. It revealed a formulation of policy that was intended to cut across the self-governing regimes that had up to this point been allowed to evolve. Drawing on the work of Michel Foucault and Nikolas Rose, I argue that the policy and the practices associated with it contribute to an understanding of the emergence of the psy-sciences in colonial settings. They illustrate the establishment of a panoptic gaze on previously neglected insane spaces. Systematic surveillance constituted government at a distance and made colonial lunacy administration a governable discursive space. The regulation of the medical officers, lunatic attendants, and hospital boards began the process of creating a professional psychiatric workforce. I conclude with a discussion of the implications and the mixed impact of this policy change for the mentally ill across the empire, over the ensuing decades. PMID:20533769

  15. Disrupting the Coloniality of Being: Toward De-Colonial Ontologies in Philosophy of Education

    ERIC Educational Resources Information Center

    Richardson, Troy A.

    2012-01-01

    This essay works to bridge conversations in philosophy of education with decolonial theory. The author considers Margonis' (1999, 2011a, b) use of Rousseau (1979) and Heidegger (1962) in developing an ontological attitude that counters social hierarchies and promotes anti-colonial relations. While affirming this effort, the essay outlines a…

  16. First recorded loss of an emperor penguin colony in the recent period of Antarctic regional warming: implications for other colonies.

    PubMed

    Trathan, Philip N; Fretwell, Peter T; Stonehouse, Bernard

    2011-01-01

    In 1948, a small colony of emperor penguins Aptenodytes forsteri was discovered breeding on Emperor Island (67° 51' 52″ S, 68° 42' 20″ W), in the Dion Islands, close to the West Antarctic Peninsula (Stonehouse 1952). When discovered, the colony comprised approximately 150 breeding pairs; these numbers were maintained until 1970, after which time the colony showed a continuous decline. By 1999 there were fewer than 20 pairs, and in 2009 high-resolution aerial photography revealed no remaining trace of the colony. Here we relate the decline and loss of the Emperor Island colony to a well-documented rise in local mean annual air temperature and coincident decline in seasonal sea ice duration. The loss of this colony provides empirical support for recent studies (Barbraud & Weimerskirch 2001; Jenouvrier et al 2005, 2009; Ainley et al 2010; Barber-Meyer et al 2005) that have highlighted the vulnerability of emperor penguins to changes in sea ice duration and distribution. These studies suggest that continued climate change is likely to impact upon future breeding success and colony viability for this species. Furthermore, a recent circumpolar study by Fretwell & Trathan (2009) highlighted those Antarctic coastal regions where colonies appear most vulnerable to such changes. Here we examine which other colonies might be at risk, discussing various ecological factors, some previously unexplored, that may also contribute to future declines. The implications of this are important for future modelling work and for understanding which colonies actually are most vulnerable. PMID:21386883

  17. Playback of colony sound alters the breeding schedule and clutch size in zebra finch (Taeniopygia guttata) colonies

    PubMed Central

    Waas, Joseph R.; Colgan, Patrick W.; Boag, Peter T.

    2005-01-01

    The hypothesis that social stimulation, derived from the presence and activities of conspecifics, can hasten and synchronize breeding in colonies of birds was tested. A modified playback/recorder system was used to continuously exaggerate the amount of colony sound available to zebra finches throughout their courtship period. Males that heard ‘sound supplements’ generated from their own colony sang more than males in control colonies that did not receive playback; males that heard samples from a different colony, sang at an intermediate level. Females that were exposed to the vocalizations of their mate and playback from a colony other than their own, laid eggs earlier and more synchronously than females in control colonies. Females that heard the vocalizations of their mate along with playback samples generated from their own colony, laid eggs more synchronously but not earlier than control females. Both acoustic treatments caused females to lay larger clutches. Social stimulation influences the breeding schedule and clutch size in zebra finch colonies. If there are advantages associated with these effects, social stimulation may contribute to the maintenance of colonial breeding systems. PMID:15734692

  18. First Recorded Loss of an Emperor Penguin Colony in the Recent Period of Antarctic Regional Warming: Implications for Other Colonies

    PubMed Central

    Trathan, Philip N.; Fretwell, Peter T.; Stonehouse, Bernard

    2011-01-01

    In 1948, a small colony of emperor penguins Aptenodytes forsteri was discovered breeding on Emperor Island (67° 51′ 52″ S, 68° 42′ 20″ W), in the Dion Islands, close to the West Antarctic Peninsula (Stonehouse 1952). When discovered, the colony comprised approximately 150 breeding pairs; these numbers were maintained until 1970, after which time the colony showed a continuous decline. By 1999 there were fewer than 20 pairs, and in 2009 high-resolution aerial photography revealed no remaining trace of the colony. Here we relate the decline and loss of the Emperor Island colony to a well-documented rise in local mean annual air temperature and coincident decline in seasonal sea ice duration. The loss of this colony provides empirical support for recent studies (Barbraud & Weimerskirch 2001; Jenouvrier et al 2005, 2009; Ainley et al 2010; Barber-Meyer et al 2005) that have highlighted the vulnerability of emperor penguins to changes in sea ice duration and distribution. These studies suggest that continued climate change is likely to impact upon future breeding success and colony viability for this species. Furthermore, a recent circumpolar study by Fretwell & Trathan (2009) highlighted those Antarctic coastal regions where colonies appear most vulnerable to such changes. Here we examine which other colonies might be at risk, discussing various ecological factors, some previously unexplored, that may also contribute to future declines. The implications of this are important for future modelling work and for understanding which colonies actually are most vulnerable. PMID:21386883

  19. Antennal cropping during colony foundation in termites

    PubMed Central

    Nalepa, Christine A.; Evans, Theodore A.; Lenz, Michael

    2011-01-01

    Abstract The literature on pairing and mating behavior in termites indicates that a number of distal antennal segments in dealates of both sexes are often removed during colony foundation, with terms such as amputation, mutilation and cannibalism typically employed to report the phenomenon. Here we propose the use of the phrase ‘antennal cropping’ to describe the behavior, and assess naturally occurring levels of its occurrence by comparing the number of antennal segments in museum specimens of alates and dealates in 16 species of Australian termites (four families), supplemented by analyzing published data on Coptotermes gestroi. Dealates had significantly fewer antennal segments than alates in 14 of the 16 termite species, with both exceptions belonging to the family Termitidae. Levels of antennal cropping were not significantly different between the sexes but did vary by family. Dealates in the Kalotermitidae removed the most segments (41.3%) and those in the Termitidae removed the fewest (8.9%). We discuss the biological significance of this phylogenetically widespread termite behavior, and suggest that controlled antennal cropping is not only a normal part of their behavioral repertoire but also a key influence that changes the conduct and physiology of the royal pair during the initial stages of colony foundation. PMID:22287897

  20. A catalog of Louisiana's nesting seabird colonies

    USGS Publications Warehouse

    Fontenot, William R.; Cardiff, Steve W.; DeMay, Richard A.; Dittmann, Donna L.; Hartley, Stephen B.; Jeske, Clinton W.; Lorenz, Nicole; Michot, Thomas C.; Purrington, Robert Dan; Seymour, Michael; Vermillion, William G.

    2012-01-01

    collective habitats which comprise Louisiana's now fragile coastal zone have taken major hits from commercial/residential, oil & gas, and other industrial development, primarily in the form of coastal erosion exacerbated by these and other factors (Portnoy 1978, Spendelow and Patton 1988, Martin and Lester 1990, Green, et al. 2006). Moreover, during this same period, both geologic subsidence rates (Tornqvist et al. 2008) and mean sea-level (Tornqvist et al. 2002) have increased, along with significant tropical storm activity; all of which have combined to impact available marsh, barrier island, beach, and dredge spoil nesting habitat for waterbirds, especially seabirds, throughout the coastal zone of Louisiana. The primary objective of this publication is to detail those coastal Louisiana colonial seabird nesting sites for which we have reasonably accurate data, in a tabular, site-by-site format. All major survey (1976-2008) data of site-by-site seabird species counts, as well as several smaller data sets, referred to in the site history tables as “miscellaneous observations” obtained during the May-June seabird breeding period, are included. It is our hope that these data will provide a dependable foundation from which future colonial seabird nesting surveys might be planned and carried out, as well as showcase the importance of coastal Louisiana's seabird rookeries, and contribute to their conservation.

  1. Image feature extraction based multiple ant colonies cooperation

    NASA Astrophysics Data System (ADS)

    Zhang, Zhilong; Yang, Weiping; Li, Jicheng

    2015-05-01

    This paper presents a novel image feature extraction algorithm based on multiple ant colonies cooperation. Firstly, a low resolution version of the input image is created using Gaussian pyramid algorithm, and two ant colonies are spread on the source image and low resolution image respectively. The ant colony on the low resolution image uses phase congruency as its inspiration information, while the ant colony on the source image uses gradient magnitude as its inspiration information. These two ant colonies cooperate to extract salient image features through sharing a same pheromone matrix. After the optimization process, image features are detected based on thresholding the pheromone matrix. Since gradient magnitude and phase congruency of the input image are used as inspiration information of the ant colonies, our algorithm shows higher intelligence and is capable of acquiring more complete and meaningful image features than other simpler edge detectors.

  2. Colonial mentality: a review and recommendation for Filipino American psychology.

    PubMed

    David, E J R; Okazaki, Sumie

    2006-01-01

    Colonial mentality is a term used widely by ethnic studies scholars and by the Filipino American community to refer to a form of internalized oppression among Filipinos and Filipino Americans. The authors propose that colonial mentality is a construct that is central to the understanding of the psychology of contemporary Filipino Americans. Drawing on larger scholarship from postcolonial studies and psychological research on oppression, the authors review the historical and sociological contexts in which to understand the significance of the colonial mentality concept for the Filipino American population. The authors also review the existing literature on colonial mentality and provide specific recommendations for incorporating this construct into research and practice with Filipino Americans. It is argued, through this illustrative example of colonial mentality among Filipino Americans, that examining the psychological impact of colonialism is a way to incorporate larger historical and sociological contextual variables into ethnic minority research and practice. PMID:16594851

  3. Varroa-Virus Interaction in Collapsing Honey Bee Colonies

    PubMed Central

    Francis, Roy M.; Nielsen, Steen L.; Kryger, Per

    2013-01-01

    Varroa mites and viruses are the currently the high-profile suspects in collapsing bee colonies. Therefore, seasonal variation in varroa load and viruses (Acute-Kashmir-Israeli complex (AKI) and Deformed Wing Virus (DWV)) were monitored in a year-long study. We investigated the viral titres in honey bees and varroa mites from 23 colonies (15 apiaries) under three treatment conditions: Organic acids (11 colonies), pyrethroid (9 colonies) and untreated (3 colonies). Approximately 200 bees were sampled every month from April 2011 to October 2011, and April 2012. The 200 bees were split to 10 subsamples of 20 bees and analysed separately, which allows us to determine the prevalence of virus-infected bees. The treatment efficacy was often low for both treatments. In colonies where varroa treatment reduced the mite load, colonies overwintered successfully, allowing the mites and viruses to be carried over with the bees into the next season. In general, AKI and DWV titres did not show any notable response to the treatment and steadily increased over the season from April to October. In the untreated control group, titres increased most dramatically. Viral copies were correlated to number of varroa mites. Most colonies that collapsed over the winter had significantly higher AKI and DWV titres in October compared to survivors. Only treated colonies survived the winter. We discuss our results in relation to the varroa-virus model developed by Stephen Martin. PMID:23526946

  4. 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 marshnesting 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

  5. Improved Ant Colony Clustering Algorithm and Its Performance Study

    PubMed Central

    Gao, Wei

    2016-01-01

    Clustering analysis is used in many disciplines and applications; it is an important tool that descriptively identifies homogeneous groups of objects based on attribute values. The ant colony clustering algorithm is a swarm-intelligent method used for clustering problems that is inspired by the behavior of ant colonies that cluster their corpses and sort their larvae. A new abstraction ant colony clustering algorithm using a data combination mechanism is proposed to improve the computational efficiency and accuracy of the ant colony clustering algorithm. The abstraction ant colony clustering algorithm is used to cluster benchmark problems, and its performance is compared with the ant colony clustering algorithm and other methods used in existing literature. Based on similar computational difficulties and complexities, the results show that the abstraction ant colony clustering algorithm produces results that are not only more accurate but also more efficiently determined than the ant colony clustering algorithm and the other methods. Thus, the abstraction ant colony clustering algorithm can be used for efficient multivariate data clustering. PMID:26839533

  6. Hierarchy length in orphaned colonies of the ant Temnothorax nylanderi

    NASA Astrophysics Data System (ADS)

    Heinze, J.

    2008-08-01

    Workers of the ant Temnothorax nylanderi form dominance orders in orphaned colonies in which only one or a few top-ranking workers begin to produce males from unfertilized eggs. Between one and 11 individuals initiated 80% of all aggression in 14 queenless colonies. As predicted from inclusive fitness models (Molet M, van Baalen M, Monnin T, Insectes Soc 52:247 256, 2005), hierarchy length was found to first increase with colony size and then to level off at larger worker numbers. The frequency and skew of aggression decreased with increasing size, indicating that rank orders are less pronounced in larger colonies.

  7. 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

  8. Varroa-virus interaction in collapsing honey bee colonies.

    PubMed

    Francis, Roy M; Nielsen, Steen L; Kryger, Per

    2013-01-01

    Varroa mites and viruses are the currently the high-profile suspects in collapsing bee colonies. Therefore, seasonal variation in varroa load and viruses (Acute-Kashmir-Israeli complex (AKI) and Deformed Wing Virus (DWV)) were monitored in a year-long study. We investigated the viral titres in honey bees and varroa mites from 23 colonies (15 apiaries) under three treatment conditions: Organic acids (11 colonies), pyrethroid (9 colonies) and untreated (3 colonies). Approximately 200 bees were sampled every month from April 2011 to October 2011, and April 2012. The 200 bees were split to 10 subsamples of 20 bees and analysed separately, which allows us to determine the prevalence of virus-infected bees. The treatment efficacy was often low for both treatments. In colonies where varroa treatment reduced the mite load, colonies overwintered successfully, allowing the mites and viruses to be carried over with the bees into the next season. In general, AKI and DWV titres did not show any notable response to the treatment and steadily increased over the season from April to October. In the untreated control group, titres increased most dramatically. Viral copies were correlated to number of varroa mites. Most colonies that collapsed over the winter had significantly higher AKI and DWV titres in October compared to survivors. Only treated colonies survived the winter. We discuss our results in relation to the varroa-virus model developed by Stephen Martin. PMID:23526946

  9. Efficient Division and Sampling of Cell Colonies Using Microcup Arrays

    PubMed Central

    Pai, Jeng-Hao; Kluckman, Kimberly; Cowley, Dale O.; Bortner, Donna M.; Sims, Christopher E.; Allbritton, Nancy L.; Allbritton, Nancy L.

    2012-01-01

    A microengineered array to sample clonal colonies is described. The cells were cultured on an array of individually releasable elements until the colonies expanded to cover multiple elements. Single elements were released using a laser-based system and collected to sample cells from individual colonies. A greater than an 85% rate in splitting and collecting colonies was achieved using a 3-dimensional cup-like design or “microcup”. Surface modification using patterned titanium deposition of the glass substrate improved the stability of microcup adhesion to the glass while enabling minimization of the laser energy for splitting the colonies. Smaller microcup dimensions and slotting the microcup walls reduced the time needed for colonies to expand into multiple microcups. The stem cell colony retained on the array and the collected fraction within released microcups remained undifferentiated and viable. The colony samples were characterized by both reporter gene expression and a destructive assay (PCR) to identify target colonies. The platform is envisioned as a means to rapidly establish cell lines using a destructive assay to identify desired clones. PMID:23099535

  10. Dynamics of the presence of israeli acute paralysis virus in honey bee colonies with colony collapse disorder.

    PubMed

    Hou, Chunsheng; Rivkin, Hadassah; Slabezki, Yossi; Chejanovsky, Nor

    2014-05-01

    The determinants of Colony Collapse Disorder (CCD), a particular case of collapse of honey bee colonies, are still unresolved. Viruses including the Israeli acute paralysis virus (IAPV) were associated with CCD. We found an apiary with colonies showing typical CCD characteristics that bore high loads of IAPV, recovered some colonies from collapse and tested the hypothesis if IAPV was actively replicating in them and infectious to healthy bees. We found that IAPV was the dominant pathogen and it replicated actively in the colonies: viral titers decreased from April to September and increased from September to December. IAPV extracted from infected bees was highly infectious to healthy pupae: they showed several-fold amplification of the viral genome and synthesis of the virion protein VP3. The health of recovered colonies was seriously compromised. Interestingly, a rise of IAPV genomic copies in two colonies coincided with their subsequent collapse. Our results do not imply IAPV as the cause of CCD but indicate that once acquired and induced to replication it acts as an infectious factor that affects the health of the colonies and may determine their survival. This is the first follow up outside the US of CCD-colonies bearing IAPV under natural conditions. PMID:24800677

  11. Dynamics of the Presence of Israeli Acute Paralysis Virus in Honey Bee Colonies with Colony Collapse Disorder

    PubMed Central

    Hou, Chunsheng; Rivkin, Hadassah; Slabezki, Yossi; Chejanovsky, Nor

    2014-01-01

    The determinants of Colony Collapse Disorder (CCD), a particular case of collapse of honey bee colonies, are still unresolved. Viruses including the Israeli acute paralysis virus (IAPV) were associated with CCD. We found an apiary with colonies showing typical CCD characteristics that bore high loads of IAPV, recovered some colonies from collapse and tested the hypothesis if IAPV was actively replicating in them and infectious to healthy bees. We found that IAPV was the dominant pathogen and it replicated actively in the colonies: viral titers decreased from April to September and increased from September to December. IAPV extracted from infected bees was highly infectious to healthy pupae: they showed several-fold amplification of the viral genome and synthesis of the virion protein VP3. The health of recovered colonies was seriously compromised. Interestingly, a rise of IAPV genomic copies in two colonies coincided with their subsequent collapse. Our results do not imply IAPV as the cause of CCD but indicate that once acquired and induced to replication it acts as an infectious factor that affects the health of the colonies and may determine their survival. This is the first follow up outside the US of CCD-colonies bearing IAPV under natural conditions. PMID:24800677

  12. Colonial Zapotec Calendars and Calendrical Astronomy

    NASA Astrophysics Data System (ADS)

    Justeson, John

    A great deal is known about colonial Zapotec calendar systems. Every pan-Mesoamerican system was in use: the divinatory/sacred calendar of 260 days, together with its partition into 13- and 20-day subdivisions; the civil year of 365 days and its subdivision into eighteen 20-day months plus a final period of 5 days; and the cycle of 52 years, a permutation of the divinatory and civil calendars. A surprising amount is known about the activities and professional tools and practices of the calendar specialists, and about the ways that calendrical knowledge was transmitted. We have scant information on Zapotec astronomical knowledge and practices, believed to have been in their hands, but an understanding of the timing of eclipses was among their applications of calendrical constructs.

  13. Modelling the morphology of migrating bacterial colonies

    NASA Astrophysics Data System (ADS)

    Nishiyama, A.; Tokihiro, T.; Badoual, M.; Grammaticos, B.

    2010-08-01

    We present a model which aims at describing the morphology of colonies of Proteus mirabilis and Bacillus subtilis. Our model is based on a cellular automaton which is obtained by the adequate discretisation of a diffusion-like equation, describing the migration of the bacteria, to which we have added rules simulating the consolidation process. Our basic assumption, following the findings of the group of Chuo University, is that the migration and consolidation processes are controlled by the local density of the bacteria. We show that it is possible within our model to reproduce the morphological diagrams of both bacteria species. Moreover, we model some detailed experiments done by the Chuo University group, obtaining a fine agreement.

  14. Histiocytic typhlocolitis in two colony Beagle dogs.

    PubMed

    Carvallo, Francisco R; Kerlin, Roy; Fredette, Claudine; Pisharath, Harshan; DebRoy, Chitrita; Kariyawasam, Subhashinie; Pardo, Ingrid D

    2015-02-01

    Two young female Beagle dogs in a laboratory colony with clinical signs of loose stools and fecal blood were confirmed to have histiocytic ulcerative colitis by histologic evaluation. This syndrome is well recognized in other dog breeds such as Boxers and related French Bulldogs, Mastiffs, Alaskan malamutes and Doberman Pinschers. Formalin-fixed paraffin sections of large intestine from one dog demonstrated the presence of Escherichia coli strain LF82 by immunohistochemistry and 16S ribosomal RNA gene sequencing. E coli strain LF82 has been implicated in the pathogenesis of Crohn's disease and similar bacteria have been cultured from cases of histiocytic ulcerative colitis in Boxer dogs. Spontaneous histiocytic ulcerative colitis must be differentiated from test article-related findings in nonclinical toxicity studies in Beagle dogs. PMID:25467750

  15. 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.

  16. Microtubules viewed as molecular ant colonies.

    PubMed

    Tabony, James

    2006-10-01

    Populations of ants and other social insects self-organize and develop 'emergent' properties through stigmergy in which individual ants communicate with one another via chemical trails of pheromones that attract or repulse other ants. In this way, sophisticated properties and functions develop. Under appropriate conditions, in vitro microtubule preparations, initially comprised of only tubulin and GTP, behave in a similar manner. They self-organize and develop other higher-level emergent phenomena by a process where individual microtubules are coupled together by the chemical trails they produce by their own reactive growing and shrinking. This behaviour is described and compared with the behaviour of ant colonies. Viewing microtubules as populations of molecular ants may provide new insights as to how the cytoskeleton may spontaneously develop high-level functions. It is plausible that such processes occur during the early stages of embryogenesis and in cells. PMID:16968217

  17. Optic disc detection using ant colony optimization

    NASA Astrophysics Data System (ADS)

    Dias, Marcy A.; Monteiro, Fernando C.

    2012-09-01

    The retinal fundus images are used in the treatment and diagnosis of several eye diseases, such as diabetic retinopathy and glaucoma. This paper proposes a new method to detect the optic disc (OD) automatically, due to the fact that the knowledge of the OD location is essential to the automatic analysis of retinal images. Ant Colony Optimization (ACO) is an optimization algorithm inspired by the foraging behaviour of some ant species that has been applied in image processing for edge detection. Recently, the ACO was used in fundus images to detect edges, and therefore, to segment the OD and other anatomical retinal structures. We present an algorithm for the detection of OD in the retina which takes advantage of the Gabor wavelet transform, entropy and ACO algorithm. Forty images of the retina from DRIVE database were used to evaluate the performance of our method.

  18. Ant Colonies Do Not Trade-Off Reproduction against Maintenance

    PubMed Central

    Scheuerlein, Alexander; Heinze, Jürgen

    2015-01-01

    The question on how individuals allocate resources into maintenance and reproduction is one of the central questions in life history theory. Yet, resource allocation into maintenance on the organismic level can only be measured indirectly. This is different in a social insect colony, a “superorganism” where workers represent the soma and the queen the germ line of the colony. Here, we investigate whether trade-offs exist between maintenance and reproduction on two levels of biological organization, queens and colonies, by following single-queen colonies of the ant Cardiocondyla obscurior throughout the entire lifespan of the queen. Our results show that maintenance and reproduction are positively correlated on the colony level, and we confirm results of an earlier study that found no trade-off on the individual (queen) level. We attribute this unexpected outcome to the existence of a positive feedback loop where investment into maintenance (workers) increases the rate of resource acquisition under laboratory conditions. Even though food was provided ad libitum, variation in productivity among the colonies suggests that resources can only be utilized and invested into additional maintenance and reproduction by the colony if enough workers are available. The resulting relationship between per-capita and colony productivity in our study fits well with other studies conducted in the field, where decreasing per-capita productivity and the leveling off of colony productivity have been linked to density dependent effects due to competition among colonies. This suggests that the absence of trade-offs in our laboratory study might also be prevalent under natural conditions, leading to a positive association of maintenance, (= growth) and reproduction. In this respect, insect colonies resemble indeterminate growing organisms. PMID:26383861

  19. Medicine in colonial Australia, 1788-1900.

    PubMed

    Lewis, Milton J

    2014-07-01

    For the first five decades of European settlement in Australia, medical care for convicts and free settlers was provided by the Colonial Medical Service. After about 1850, as population and wealth grew markedly, there was significant professional development based on private practice. Except in Victoria, medical societies and journals did not become solidly established until late in the 19th century. The advent of local British Medical Association branches was an important factor in this consolidation. In the first few years of the colony, mortality was very high, but the common childhood infections were absent until the 1830s. From the 1880s, there was a sustained decline in mortality from communicable diseases, and therefore in aggregate mortality, while maternal mortality remained high. Australian practitioners quickly took up advances in practice from overseas, such as antisepsis and diphtheria antitoxin. They shared in the international growth in the status of medicine, which was conferred by the achievements of bacteriology in particular. From 1813, students were apprenticed in Sydney and Hobart and then travelled to Britain to obtain corporate qualifications. Medical schools were ultimately opened in the new universities in Melbourne (in 1862), Sydney (1883) and Adelaide (1885). The first female student was admitted to medicine in Sydney in 1885. Medical politics were intense. The outlawing of practice by unorthodox practitioners proved to be an unattainable goal. In the latter half of the 19th century, doctors saw chemists as unfair competitors for patients. The main medicopolitical struggle was with the mutual-aid friendly societies, which funded basic medical care for a significant proportion of the population until well into the 20th century. The organised profession set out to overcome the power of the lay-controlled societies in imposing an unacceptable contract system on doctors, even if, historically, the guaranteed income was a sine qua non of practice in poorer areas. PMID:25047777

  20. Bacterial Colony: First Report of Donut Colony Morphology among Diphtheroids Isolated in Blood

    PubMed Central

    2015-01-01

    Isolation of diphtheroids in human clinical specimens is not uncommon. Several studies have highlighted the significance of these bacteria in human infection, which morphologically resemble Corynebacterium diphtheriae. Previous studies have noted that occurrence of these bacteria in specimens like the blood should not be ignored as they can result in serious infections like endocarditis and sepsis among debilitated individuals, including the neonates. We report isolation of diphtheroid bacterium in blood from a case of septicaemia showing donut colony morphology. PMID:26677424

  1. Model Specification Searches Using Ant Colony Optimization Algorithms

    ERIC Educational Resources Information Center

    Marcoulides, George A.; Drezner, Zvi

    2003-01-01

    Ant colony optimization is a recently proposed heuristic procedure inspired by the behavior of real ants. This article applies the procedure to model specification searches in structural equation modeling and reports the results. The results demonstrate the capabilities of ant colony optimization algorithms for conducting automated searches.

  2. The Political Economy of Colonial Education: Mozambique, 1930-1975.

    ERIC Educational Resources Information Center

    Cross, Michael

    1987-01-01

    Under colonial fascism and during the revolutionary period leading to independence, the schooling of the African majority in Mozambique had no direct link with the economy, was more a mechanism of social control than of labor reproduction, and (in contrast to other African colonies) did not produce an African middle class supportive of the…

  3. How natural infection by Nosema ceranae causes honeybee colony collapse.

    PubMed

    Higes, Mariano; Martín-Hernández, Raquel; Botías, Cristina; Bailón, Encarna Garrido; González-Porto, Amelia V; Barrios, Laura; Del Nozal, M Jesús; Bernal, José L; Jiménez, Juan J; Palencia, Pilar García; Meana, Aránzazu

    2008-10-01

    In recent years, honeybees (Apis mellifera) have been strangely disappearing from their hives, and strong colonies have suddenly become weak and died. The precise aetiology underlying the disappearance of the bees remains a mystery. However, during the same period, Nosema ceranae, a microsporidium of the Asian bee Apis cerana, seems to have colonized A. mellifera, and it's now frequently detected all over the world in both healthy and weak honeybee colonies. For first time, we show that natural N. ceranae infection can cause the sudden collapse of bee colonies, establishing a direct correlation between N. ceranae infection and the death of honeybee colonies under field conditions. Signs of colony weakness were not evident until the queen could no longer replace the loss of the infected bees. The long asymptomatic incubation period can explain the absence of evident symptoms prior to colony collapse. Furthermore, our results demonstrate that healthy colonies near to an infected one can also become infected, and that N. ceranae infection can be controlled with a specific antibiotic, fumagillin. Moreover, the administration of 120 mg of fumagillin has proven to eliminate the infection, but it cannot avoid reinfection after 6 months. We provide Koch's postulates between N. ceranae infection and a syndrome with a long incubation period involving continuous death of adult bees, non-stop brood rearing by the bees and colony loss in winter or early spring despite the presence of sufficient remaining pollen and honey. PMID:18647336

  4. Modeling cell-matrix traction forces in Keratinocyte colonies

    NASA Astrophysics Data System (ADS)

    Banerjee, Shiladitya

    2013-03-01

    Crosstalk between cell-cell and cell-matrix adhesions plays an essential role in the mechanical function of tissues. The traction forces exerted by cohesive keratinocyte colonies with strong cell-cell adhesions are mostly concentrated at the colony periphery. In contrast, for weak cadherin-based intercellular adhesions, individual cells in a colony interact with their matrix independently, with a disorganized distribution of traction forces extending throughout the colony. In this talk I will present a minimal physical model of the colony as contractile elastic media linked by springs and coupled to an elastic substrate. The model captures the spatial distribution of traction forces seen in experiments. For cell colonies with strong cell-cell adhesions, the total traction force of the colony measured in experiments is found to scale with the colony's geometrical size. This scaling suggests the emergence of an effective surface tension of magnitude comparable to that measured for non-adherent, three-dimensional cell aggregates. The physical model supports the scaling and indicates that the surface tension may be controlled by acto-myosin contractility. Supported by the NSF through grant DMR-1004789. This work was done in collaboration with Aaron F. Mertz, Eric R. Dufresne and Valerie Horsley (Yale University) and M. Cristina Marchetti (Syracuse University).

  5. The Education of Indentured Servants in Colonial America

    ERIC Educational Resources Information Center

    Snyder, Mark R.

    2007-01-01

    This article serves as a foundation for understanding the earliest form of technical instruction in colonial America. It is a synthesis of historical studies that have addresses the education of indentured servants and apprentices in colonial America. It defines indentured servitude and contrasts it with apprenticeship--a form of indentured…

  6. Discover for Yourself: An Optimal Control Model in Insect Colonies

    ERIC Educational Resources Information Center

    Winkel, Brian

    2013-01-01

    We describe the enlightening path of self-discovery afforded to the teacher of undergraduate mathematics. This is demonstrated as we find and develop background material on an application of optimal control theory to model the evolutionary strategy of an insect colony to produce the maximum number of queen or reproducer insects in the colony at…

  7. Education and National Personae in Portugal's Colonial and Postcolonial Transition.

    ERIC Educational Resources Information Center

    Errante, Antoinette

    1998-01-01

    Traces the evolution of Portuguese national identity, 1926-74, in relation to its African colonies, particularly Mozambique, to demonstrate that colonialism enforces values, identities, and "hierarchies of domination" within the colonizing society as well as between colonizers and colonized peoples. Examines the role of education in shaping and…

  8. Idiocy and the Law in Colonial New England.

    ERIC Educational Resources Information Center

    Wickham, Parnel

    2001-01-01

    A review of laws and records of the courts of colonial New England indicates early laws of Massachusetts extended certain rights to idiots: they authorized the transfer of property, exonerated idiots who committed capital crimes, and extended relief to impoverished idiots. The relationship between colonial laws and present legislation is examined.…

  9. Slave Advertising in the Colonial Newspaper: Mirror to the Dilemma.

    ERIC Educational Resources Information Center

    Bradley, Patricia

    To explore racial attitudes from the colonial period of the United States, a study examined advertising practices regarding announcements dealing with black slaves in colonial newspapers in Massachusetts, New York, Pennsylvania, Maryland, Virginia, and South Carolina. Careful scrutiny revealed no relationship between the editorial stance of a…

  10. The Sioux on the Reservations: The American Colonial Problem.

    ERIC Educational Resources Information Center

    Hagen, E.E.; Schaw, Louis C.

    A study conducted by the Massachusetts Institute of Technology examined problems surrounding the socioeconomic and cultural status of the Sioux on the Pine Ridge and Rosebud Indian reservations. Study of economic status revealed the similarity of Indian problems to those faced by emerging underdeveloped colonial or ex-colonial peoples around the…

  11. 21 CFR 866.2180 - Manual colony counter.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Manual colony counter. 866.2180 Section 866.2180 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2180 Manual colony...

  12. 21 CFR 866.2180 - Manual colony counter.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Manual colony counter. 866.2180 Section 866.2180 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2180 Manual colony...

  13. 21 CFR 866.2180 - Manual colony counter.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Manual colony counter. 866.2180 Section 866.2180 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2180 Manual colony...

  14. Patterns of gene expression in Bacillus subtilis colonies.

    PubMed Central

    Salhi, B; Mendelson, N H

    1993-01-01

    Bacillus subtilis 5:7, a derivative of macrofiber-producing strain FJ7, carries the lacZ reporter gene within Tn917 at an unknown location in the host genome. Expression of the host gene carrying lacZ within colonies of 5:7 was observed by examining growth under different conditions in the presence of 5-bromo-4-chloro-3-indolyl-beta-D-galactopyranoside (X-Gal). At a high plating density small colonies arose that expressed the host gene early and throughout the colony, whereas at a low density large colonies were produced that expressed the host gene late in development and only in cells forming a ring pattern close to the colony periphery. A highly regulated spatial and temporal gene expression pattern was observed in growth from cross-streaks, suggesting that gene expression is responsive to concentration gradient fields established by neighboring growth. Colonies cultured on agar blocks revealed that expression was governed by depletion of a medium component and also by the geometry of the substrate upon which the colonies grew. At least three factors influenced the control of expression: (i) the concentration of a diffusible component of the medium exhausted by cell growth, (ii) a spatial-temporal factor related to growth within the colony, and (iii) the geometry of the growth substrate. Images PMID:8349543

  15. COLONIAL GROWTH OF ANAEROBIC SPIROCHETES ON SOLID MEDIA

    PubMed Central

    Hardy, Paul H.; Lee, Young C.; Nell, E. Ellen

    1963-01-01

    Hardy, Paul H., Jr. (The Johns Hopkins University School of Medicine, Baltimore, Md.), Young C. Lee, and E. Ellen Nell. Colonial growth of anaerobic spirochetes on solid media. J. Bacteriol. 86:616–626. 1963.—A total of 14 strains of treponemes and one of Borrelia vincentii were cultivated as colonies on agar plates inoculated under ordinary atmospheric conditions, but incubated anaerobically. Every spirochete strain produced diffuse colonies with growth located primarily in the agar; in addition, eight treponeme strains also produced discrete colonies with surface growth. These represented stable colonial variants in several strains, and in one the spirochetes in the surface colonies showed permanently altered cellular morphology. Sufficient variation in colonial morphology was noted between strains to suggest that this may have some value in further classification of this group of microorganisms. Several conditions contributed to the successful growth of all strains as colonies, the most important of which was the use of a firm jelling agar preparation, Ionagar No. 2, that permitted preparation of plates with a final agar concentration of 0.7%. Agar concentrations of 0.9%, or above, in media inhibited treponeme growth. Images PMID:14066453

  16. Bacterial interference with coliform colony sheen production on membrane filters.

    PubMed

    Burlingame, G A; McElhaney, J; Bennett, M; Pipes, W O

    1984-01-01

    The membrane filter (MF) method for detection and enumeration of coliform bacteria in drinking water requires that the coliforms both grow and produce a green metallic sheen when the filter is incubated on modified Endo medium at 35 degrees C for 22 h. Large numbers of noncoliform bacteria, which are enumerated by the standard plate count (SPC) technique, can interfere with the detection of coliforms on MF. This paper presents quantitative evidence from laboratory experiments on the interference of specific SPC bacteria on coliform colony sheen production on MF. Pseudomonas aeruginosa and Aeromonas hydrophila caused significant reductions in Escherichia coli sheen colony counts when present at 3,000 and 220 per filter, respectively. The Flavobacterium sp. and Bacillus sp. selected for this study from SPC did not interfere with coliform colony sheen production. Excessive crowding of E. coli and Enterobacter cloacae colonies on MF also caused a reduction in the number of colonies that produced sheen. Even when there was no crowding (14 colonies per filter), only a fraction of the E. cloacae colonies produced sheen colonies on modified Endo medium. PMID:6696423

  17. Estimating 3-dimensional colony surface area of field corals

    EPA Science Inventory

    Colony surface area is a critical descriptor for biological and physical attributes of reef-building (scleractinian, stony) corals. The three-dimensional (3D) size and structure of corals are directly related to many ecosystem values and functions. Most methods to estimate colony...

  18. Colonialism, Education and Rural Buddhist Communities in Bangladesh

    ERIC Educational Resources Information Center

    Barua, Bijoy

    2007-01-01

    This paper will excavate pre-independence (British/Pakistan) and post-independence colonial education interventions into Buddhist culture and education with the view to expose the nature and shape of colonial domination and related Buddhist efforts at cultural and educational decolonization. This will be accomplished by (a) considering a brief…

  19. 21 CFR 866.2180 - Manual colony counter.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Manual colony counter. 866.2180 Section 866.2180 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2180 Manual colony...

  20. 21 CFR 866.2180 - Manual colony counter.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Manual colony counter. 866.2180 Section 866.2180 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2180 Manual colony...

  1. Discover for Yourself: An Optimal Control Model in Insect Colonies

    ERIC Educational Resources Information Center

    Winkel, Brian

    2013-01-01

    We describe the enlightening path of self-discovery afforded to the teacher of undergraduate mathematics. This is demonstrated as we find and develop background material on an application of optimal control theory to model the evolutionary strategy of an insect colony to produce the maximum number of queen or reproducer insects in the colony at…

  2. Colonial Education: A History of Education in Belize.

    ERIC Educational Resources Information Center

    Lewis, Karla

    This paper discusses the education in Belize (formerly known as British Honduras) during the colonial era and the lasting impact of the educational foundation of the country. The paper examines the influence the British colonial educational system continues to have in Belize, 20 years after independence. It gives an overview of the history of…

  3. Space Colonies. Citations from the International Aerospace Abstracts data base

    NASA Technical Reports Server (NTRS)

    Zollars, G. F.

    1979-01-01

    Approximately 204 citations to the international literature concerning various aspects of space colonies are presented. Topics include the design and construction of space colonies, the effects on humans of long term life in a variety of spaceborne environments, and the potential uses of orbital space stations and lunar bases.

  4. Countering Coloniality in Educational Research: From Ownership to Answerability

    ERIC Educational Resources Information Center

    Patel, Lisa

    2014-01-01

    In this theoretical article, I argue for a relational stance on learning as a way of reckoning with educational research as part of the settler colonial structure of the United States. Because of my geopolitical location to the United States as a settler colony, I begin by contrasting the stances of anticolonial and decolonial. I then analyze the…

  5. Allee effects and colony collapse disorder in honey bees

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We propose a mathematical model to quantify the hypothesis that a major ultimate cause of Colony Collapse Disorder (CCD) in honey bees is the presence of an Allee effect in the growth dynamics of honey bee colonies. In the model, both recruitment of adult bees as well as mortality of adult bees have...

  6. Nonrelatives inherit colony resources in a primitive termite

    PubMed Central

    Johns, Philip M.; Howard, Kenneth J.; Breisch, Nancy L.; Rivera, Anahi; Thorne, Barbara L.

    2009-01-01

    The evolution of eusociality, especially how selection would favor sterility or subfertility of most individuals within a highly social colony, is an unresolved paradox. Eusociality evolved independently in diverse taxa, including insects (all ants and termites; some bees, wasps, thrips, and beetles), snapping shrimp, and naked mole rats. Termites have received comparatively less focus than the haplodiploid Hymenoptera (ants, bees, and wasps); however, they are the only diploid group with highly complex colonies and an extraordinary diversity of castes. In this study we staged encounters between unrelated colonies of primitive dampwood termites, Zootermopsis nevadensis, mimicking natural meetings that occur under bark. During encounters, kings and/or queens were killed and surviving members merged into one colony. After encounters, members of both unrelated colonies cooperated as a single social unit. We determined the colony of origin of replacement reproductives that emerged after death of kings and/or queens. Here, we document that replacement reproductives developed from workers in either or both original colonies, inherited the merged resources of the colony, and sometimes interbred. Because this species shares many characteristics with ancestral termites, these findings demonstrate how ecological factors could have promoted the evolution of eusociality by accelerating and enhancing direct fitness opportunities of helper offspring, rendering relatedness favoring kin selection less critical. PMID:19805058

  7. Women in Sports and Games in the Colonial Period.

    ERIC Educational Resources Information Center

    Howell, Reet A.

    The physical activities of women in the colonial period in the United States were limited. Social attitudes differed between the northern and southern colonies on appropriate activities for women. In the north it was not considered unseemly for women to participate in ice skating, while in the south women were encouraged to become good…

  8. Automatic counting and classification of bacterial colonies using hyperspectral imaging

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Detection and counting of bacterial colonies on agar plates is a routine microbiology practice to get a rough estimate of the number of viable cells in a sample. There have been a variety of different automatic colony counting systems and software algorithms mainly based on color or gray-scale pictu...

  9. Education "Reform" in Latino Detroit: Achievement Gap or Colonial Legacy?

    ERIC Educational Resources Information Center

    Gonzales, Sandra M.; Shields, Carolyn M.

    2015-01-01

    Using critical theory and an analysis of missionary reports and documentation describing education in colonial Puerto Rico and Mexico, the authors cross borders and time periods to socially and historically situate Spanish colonial educational methodologies and their contemporary use in one low-income Latino community in urban Detroit, Michigan.…

  10. Evaluation of counting error due to colony masking in bioaerosol sampling.

    PubMed Central

    Chang, C W; Hwang, Y H; Grinshpun, S A; Macher, J M; Willeke, K

    1994-01-01

    Colony counting error due to indistinguishable colony overlap (i.e., masking) was evaluated theoretically and experimentally. A theoretical model to predict colony masking was used to determine colony counting efficiency by Monte Carlo computer simulation of microorganism collection and development into CFU. The computer simulation was verified experimentally by collecting aerosolized Bacillus subtilis spores and examining micro- and macroscopic colonies. Colony counting efficiency decreased (i) with increasing density of collected culturable microorganisms, (ii) with increasing colony size, and (iii) with decreasing ability of an observation system to distinguish adjacent colonies as separate units. Counting efficiency for 2-mm colonies, at optimal resolution, decreased from 98 to 85% when colony density increased from 1 to 10 microorganisms cm-2, in contrast to an efficiency decrease from 90 to 45% for 5-mm colonies. No statistically significant difference (alpha = 0.05) between experimental and theoretical results was found when colony shape was used to estimate the number of individual colonies in a CFU. Experimental colony counts were 1.2 times simulation estimates when colony shape was not considered, because of nonuniformity of actual colony size and the better discrimination ability of the human eye relative to the model. Colony surface densities associated with high counting accuracy were compared with recommended upper plate count limits and found to depend on colony size and an observation system's ability to identify overlapped colonies. Correction factors were developed to estimate the actual number of collected microorganisms from observed colony counts.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7986046

  11. Large area magnetic micropallet arrays for cell colony sorting.

    PubMed

    Cox-Muranami, Wesley A; Nelson, Edward L; Li, G P; Bachman, Mark

    2015-12-15

    A new micropallet array platform for adherent cell colony sorting has been developed. The platform consisted of thousands of square plastic pallets, 270 μm by 270 μm on each side, large enough to hold a single colony of cells. Each pallet included a magnetic core, allowing them to be collected with a magnet after being released using a microscope mounted laser system. The micropallets were patterned from 1002F epoxy resist and were fabricated on translucent, gold coated microscope slides. The gold layer was used as seed for electroplating the ferromagnetic cores within every individual pallet. The gold layer also facilitated the release of each micropallet during laser release. This array allows for individual observation, sorting and collection of isolated cell colonies for biological cell colony research. In addition to consistent release and recovery of individual colonies, we demonstrated stable biocompatibility and minimal loss in imaging quality compared to previously developed micropallet arrays. PMID:26606460

  12. Leisure, economy and colonial urbanism: Darjeeling, 1835-1930.

    PubMed

    Bhattacharya, Nandini

    2013-08-01

    This article posits that the hill station of Darjeeling was a unique form of colonial urbanism. It shifts historiographical interest from major urban centres in colonial India (such as Bombay or Calcutta) and instead attempts a greater understanding of smaller urban centres. In the process, it also interrogates the category of hill stations, which have been understood as exotic and scenic sites rather than as towns that were integral to the colonial economy. In arguing that hill stations, particularly Darjeeling, were not merely the scenic and healthy 'other' of the clamorous, dirty and diseased plains of India, it refutes suggestions that the 'despoiling' or overcrowding of Darjeeling was incremental to the purposes of its establishment. Instead, it suggests that Darjeeling was part of the colonial mainstream; its urbanization and inclusion into the greater colonial economy was effected from the time of its establishment. Therefore, a constant tension between its exotic and its functional elements persisted throughout. PMID:24273391

  13. An ant colony algorithm on continuous searching space

    NASA Astrophysics Data System (ADS)

    Xie, Jing; Cai, Chao

    2015-12-01

    Ant colony algorithm is heuristic, bionic and parallel. Because of it is property of positive feedback, parallelism and simplicity to cooperate with other method, it is widely adopted in planning on discrete space. But it is still not good at planning on continuous space. After a basic introduction to the basic ant colony algorithm, we will propose an ant colony algorithm on continuous space. Our method makes use of the following three tricks. We search for the next nodes of the route according to fixed-step to guarantee the continuity of solution. When storing pheromone, it discretizes field of pheromone, clusters states and sums up the values of pheromone of these states. When updating pheromone, it makes good resolutions measured in relative score functions leave more pheromone, so that ant colony algorithm can find a sub-optimal solution in shorter time. The simulated experiment shows that our ant colony algorithm can find sub-optimal solution in relatively shorter time.

  14. Leisure, economy and colonial urbanism: Darjeeling, 1835–1930

    PubMed Central

    BHATTACHARYA, NANDINI

    2013-01-01

    This article posits that the hill station of Darjeeling was a unique form of colonial urbanism. It shifts historiographical interest from major urban centres in colonial India (such as Bombay or Calcutta) and instead attempts a greater understanding of smaller urban centres. In the process, it also interrogates the category of hill stations, which have been understood as exotic and scenic sites rather than as towns that were integral to the colonial economy. In arguing that hill stations, particularly Darjeeling, were not merely the scenic and healthy ‘other’ of the clamorous, dirty and diseased plains of India, it refutes suggestions that the ‘despoiling’ or overcrowding of Darjeeling was incremental to the purposes of its establishment. Instead, it suggests that Darjeeling was part of the colonial mainstream; its urbanization and inclusion into the greater colonial economy was effected from the time of its establishment. Therefore, a constant tension between its exotic and its functional elements persisted throughout. PMID:24273391

  15. Iridovirus and Microsporidian Linked to Honey Bee Colony Decline

    PubMed Central

    Bromenshenk, Jerry J.; Henderson, Colin B.; Wick, Charles H.; Stanford, Michael F.; Zulich, Alan W.; Jabbour, Rabih E.; Deshpande, Samir V.; McCubbin, Patrick E.; Seccomb, Robert A.; Welch, Phillip M.; Williams, Trevor; Firth, David R.; Skowronski, Evan; Lehmann, Margaret M.; Bilimoria, Shan L.; Gress, Joanna; Wanner, Kevin W.; Cramer, Robert A.

    2010-01-01

    Background In 2010 Colony Collapse Disorder (CCD), again devastated honey bee colonies in the USA, indicating that the problem is neither diminishing nor has it been resolved. Many CCD investigations, using sensitive genome-based methods, have found small RNA bee viruses and the microsporidia, Nosema apis and N. ceranae in healthy and collapsing colonies alike with no single pathogen firmly linked to honey bee losses. Methodology/Principal Findings We used Mass spectrometry-based proteomics (MSP) to identify and quantify thousands of proteins from healthy and collapsing bee colonies. MSP revealed two unreported RNA viruses in North American honey bees, Varroa destructor-1 virus and Kakugo virus, and identified an invertebrate iridescent virus (IIV) (Iridoviridae) associated with CCD colonies. Prevalence of IIV significantly discriminated among strong, failing, and collapsed colonies. In addition, bees in failing colonies contained not only IIV, but also Nosema. Co-occurrence of these microbes consistently marked CCD in (1) bees from commercial apiaries sampled across the U.S. in 2006–2007, (2) bees sequentially sampled as the disorder progressed in an observation hive colony in 2008, and (3) bees from a recurrence of CCD in Florida in 2009. The pathogen pairing was not observed in samples from colonies with no history of CCD, namely bees from Australia and a large, non-migratory beekeeping business in Montana. Laboratory cage trials with a strain of IIV type 6 and Nosema ceranae confirmed that co-infection with these two pathogens was more lethal to bees than either pathogen alone. Conclusions/Significance These findings implicate co-infection by IIV and Nosema with honey bee colony decline, giving credence to older research pointing to IIV, interacting with Nosema and mites, as probable cause of bee losses in the USA, Europe, and Asia. We next need to characterize the IIV and Nosema that we detected and develop management practices to reduce honey bee losses. PMID:20949138

  16. Spatial Distribution of Bacterial Colonies in a Model Cheese ▿

    PubMed Central

    Jeanson, S.; Chadœuf, J.; Madec, M. N.; Aly, S.; Floury, J.; Brocklehurst, T. F.; Lortal, S.

    2011-01-01

    In most ripened cheeses, bacteria are responsible for the ripening process. Immobilized in the cheese matrix, they grow as colonies. Therefore, their distribution as well as the distance between them are of major importance for ripening steps since metabolites diffuse within the cheese matrix. No data are available to date about the spatial distribution of bacterial colonies in cheese. This is the first study to model the distribution of bacterial colonies in a food-type matrix using nondestructive techniques. We compared (i) the mean theoretical three-dimensional (3D) distances between colonies calculated on the basis of inoculation levels and considering colony distribution to be random and (ii) experimental measurements using confocal microscopy photographs of fluorescent colonies of a Lactococcus lactis strain producing green fluorescent protein (GFP) inoculated, at different levels, into a model cheese made by ultrafiltration (UF). Enumerations showed that the final numbers of cells were identical whatever the inoculation level (104 to 107 CFU/g). Bacterial colonies were shown to be randomly distributed, fitting Poisson's model. The initial inoculation level strongly influenced the mean distances between colonies (from 25 μm to 250 μm) and also their mean diameters. The lower the inoculation level, the larger the colonies were and the further away from each other. Multiplying the inoculation level by 50 multiplied the interfacial area of exchange with the cheese matrix by 7 for the same cell biomass. We finally suggested that final cell numbers should be discussed together with inoculation levels to take into account the distribution and, consequently, the interfacial area of colonies, which can have a significant influence on the cheese-ripening process on a microscopic scale. PMID:21169438

  17. Growth Rate Consequences of Coloniality in a Harmful Phytoplankter

    PubMed Central

    Wilson, Alan E.; Kaul, RajReni B.; Sarnelle, Orlando

    2010-01-01

    Background Allometric studies have shown that individual growth rate is inversely related to body size across a broad spectrum of organisms that vary greatly in size. Fewer studies have documented such patterns within species. No data exist directly documenting the influence of colony size on growth rate for microscopic, colonial organisms. Methodology/Principal Findings To determine if similar negative relationships between growth rate and size hold for colonial organisms, we developed a technique for measuring the growth of individual colonies of a bloom-forming, toxic cyanobacterium, Microcystis aeruginosa using microscopy and digital image analysis. For five out of six genotypes of M. aeruginosa isolated from lakes in Michigan and Alabama, we found significant negative relationships between colony size and growth rate. We found large intraspecific variation in both the slope of these relationships and in the growth rate of colonies at a standard size. In addition, growth rate estimates for individual colonies were generally consistent with population growth rates measured using standard batch culture. Conclusions/Significance Given that colony size varies widely within populations, our results imply that natural populations of colonial phytoplankton exist as a mosaic of individuals with widely varying ecological attributes (since size strongly affects growth rate, grazing mortality, and migration speed). Quantifying the influence of colony size on growth rate will permit development of more accurate, predictive models of ecological interactions (e.g., competition, herbivory) and their role in the proliferation of harmful algal blooms, in addition to increasing our understanding about why these interactions vary in strength within and across environments. PMID:20084114

  18. Observations on colony formation by the cosmopolitan phytoplankton genus Phaeocystis

    NASA Astrophysics Data System (ADS)

    Verity, Peter G.; Medlin, Linda K.

    2003-12-01

    Few marine phytoplankton have heteromorphic life cycles and also often dominate the ecosystems in which they occur. The class Prymnesiophyceae contains a notable exception: the genus Phaeocystis includes three species that form gelatinous colonies but also occur within their ranges as solitary cells. Phaeocystis antarctica and P. pouchetii are exclusively high latitude taxa, and are notable for regionally tremendous blooms of the colony stage. P. globosa occurs circumglobally, yet its colony blooms primarily are confined to colder waters within its range. Three additional species are warm water forms that have been reported only as solitary cells or loose aggregations that bear little resemblance to the organized colonies of the other taxa. Interpretation of existing data indicates that resource availability (light, temperature and nutrients) by itself is not sufficient to explain this distinction between cold-water colony-forming taxa and warm water solitary cell taxa, nor why colony development in P. globosa is essentially a spatially restricted phenomenon within a much broader geographic range. Colony development by P. globosa in situ has been observed at temperatures ?20 °C, but only rarely and generally under conditions of seasonally or anthropogenically elevated nutrient supply. Data presented here demonstrate colony development at 20-22 °C in natural plankton communities from oligotrophic waters that were pre-screened through 63 ?m mesh (i.e. lacking mesozooplankton and large microzooplankton), but not in unscreened communities containing microzooplankton and >63 ?m zooplankton. Reduction of colony proliferation at higher temperatures by mesozooplankton grazing remains as an intriguing possibility that is consistent with available evidence to help explain differences in latitudinal extent of in situ colony development. These data are interpreted within a theoretical framework regarding the potential advantages and disadvantages of the two life cycle stages.

  19. The Importance of Microbes in Nutrition and Health of Honey Bee Colonies Part-2: Factors Affecting the Microbial Community in Honey Bee Colonies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Honey bee colonies have innumerable symbiotic bacteria and fungi that are essential to the health of the colony. In the first part of this series, we discussed the importance of microbes in maintaining the health of honey bee colonies. The bacteria, yeasts and molds that live in a healthy colony a...

  20. [Japan's Oriental medicine policy in colonial Korea].

    PubMed

    Park, Yunjae

    2008-06-01

    During its colonization of Korea, the Japanese Empire used the Western medicine as a tool for advertising its advanced culture. However, the medical workforce available in Korea was insufficient. The Rule for Uisaeng (Oriental medicine practitioner) was an ordinance decreed in 1913 with a purpose of supplementing the medical workforce. As the Oriental medicine practitioners became official medical workforce, the Japanese Empire could mobilize them in a hygienic administration such as prevention of epidemics. The Uisaengs also tried to adapt themselves to the colonial environment by studying Western medicines. However, the distrust of the Japanese Empire in Oriental medicine continued until 1920s. Manchurian Incident in 1931 brought a change. As the relationship with China aggravated, the provision of medical herb became unstable and the Japanese Empire began to encourage using Oriental medical herb following the Movement for Improving Rural Region Economy. An attempt of the Japanese Empire to utilize the medical herb resulted in a plan to make the Oriental medical herb officinal. The goal was to organize and standardize the Oriental medical herb through a research by the Medical Herb Investigation Committee. However, the medical herb on the table was the one verified by the Western medicine. That is, it was not a traditional medical herb that uses the original theory of Oriental medicine. There was a minority opinion arguing that they should study the Oriental medicine itself. However, that argument was also based on the theory and principles of the Western medicine. Even though an attempt to make full use of Uisaengs expanded as the war continued, the major medical workforce that the Japanese Empire relied on was those trained in Western medicine. In other words, the Japanese Empire did not give a full credit to the Oriental medicine during the colonial era. During the colonization, Japanese Empire used Oriental medicine under the nominal reason of lack of medical workforces. In early 1930s, a policy supporting usage of Oriental medical herb was selected. However, it does not mean that the change in policy encouraged Oriental medicine since the medical herb that the Japanese Empire supported was those that were organized and categorized according to the principles in Western medicine. PMID:19008655

  1. Compositional analysis of Spanish Colonial ceramics

    SciTech Connect

    James, W.D.; Carlson, S.B.; Carlson, D.L.

    1994-12-31

    Ceramic shards found in Spanish Colonial missions in Texas consist of broken remnants of wares either brought from Mexico or manufactured locally by 18th century Native Americans. A few are thought to be of European or Asian manufacture, but these consist of only a few percent of the ceramic assemblages available for study now. Certain types of ceramics are consistently found in these sites, including local Native American wares and Mexican slipped or glazed wares. In addition, undecorated lead-glazed coarse earthenwares occur in great frequency, but their place of origin is unknown. Speculation has been that these lead-glazed wares, which range in color from yellow to olive-green and occur in both coiled and wheel-thrown constructions, were locally made by Native Americans using Spanish technology or that they were imported from Mexico. Compositional analysis of these wares was undertaken to clarify their source of manufacture. The sample included 102 ceramics from four Texas mission sites: Mission San Lorenzo de la Santa Cruz in Real County, Mission San Juan Capistrano in Bexar County, Mission Rosario in Goliad County, and Mission Dolores de los Ais in San Augustine County. A larger goal of the study was to examine the supply system to these well-dispersed mission sites and how it was affected by Spain`s economic climate during the l8th century.

  2. How Can Bee Colony Algorithm Serve Medicine?

    PubMed Central

    Salehahmadi, Zeinab; Manafi, Amir

    2014-01-01

    Healthcare professionals usually should make complex decisions with far reaching consequences and associated risks in health care fields. As it was demonstrated in other industries, the ability to drill down into pertinent data to explore knowledge behind the data can greatly facilitate superior, informed decisions to ensue the facts. Nature has always inspired researchers to develop models of solving the problems. Bee colony algorithm (BCA), based on the self-organized behavior of social insects is one of the most popular member of the family of population oriented, nature inspired meta-heuristic swarm intelligence method which has been proved its superiority over some other nature inspired algorithms. The objective of this model was to identify valid novel, potentially useful, and understandable correlations and patterns in existing data. This review employs a thematic analysis of online series of academic papers to outline BCA in medical hive, reducing the response and computational time and optimizing the problems. To illustrate the benefits of this model, the cases of disease diagnose system are presented. PMID:25489530

  3. 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.

  4. How can bee colony algorithm serve medicine?

    PubMed

    Salehahmadi, Zeinab; Manafi, Amir

    2014-07-01

    Healthcare professionals usually should make complex decisions with far reaching consequences and associated risks in health care fields. As it was demonstrated in other industries, the ability to drill down into pertinent data to explore knowledge behind the data can greatly facilitate superior, informed decisions to ensue the facts. Nature has always inspired researchers to develop models of solving the problems. Bee colony algorithm (BCA), based on the self-organized behavior of social insects is one of the most popular member of the family of population oriented, nature inspired meta-heuristic swarm intelligence method which has been proved its superiority over some other nature inspired algorithms. The objective of this model was to identify valid novel, potentially useful, and understandable correlations and patterns in existing data. This review employs a thematic analysis of online series of academic papers to outline BCA in medical hive, reducing the response and computational time and optimizing the problems. To illustrate the benefits of this model, the cases of disease diagnose system are presented. PMID:25489530

  5. Was Fundamental Education Another Form Of Colonialism?

    NASA Astrophysics Data System (ADS)

    Watras, Joseph

    2007-01-01

    A description of the work of Pedro Tamesis Orata provides an opportunity to investigate the conflicts that can occur when educators seek to reduce poverty while trying to respect indigenous cultures. A native of the Philippines, Orata completed his doctoral studies at the Ohio State University in 1927. During US President Franklin Roosevelt's New Deal, he accepted the position of school principal for the US Bureau of Indian Affairs. After World War II, he directed the spread of fundamental education through the United Nations Educational, Scientific and Cultural Organization (UNESCO). In his final years, he returned to the Philippines where he began a movement to spread what were called self-help high schools. In these activities, Orata taught people to follow John Dewey's five steps of thinking while working to improve their standards of living. In the 1970s, educators, such as Paulo Freire, complained that problem-solving methods, similar to those Orata favored, reinforced the oppressive aspects of formerly colonial societies. While Freire may have been overly critical, conflicts among cultural orientations appear to be unavoidable. The hope behind this investigation is that the difficulties can be reduced when people understand the different forces that persist.

  6. Interpopulational allogeneic reactions in the colonial protochordate Botryllus schlosseri.

    PubMed

    Rinkevich, B; Weissman, I L

    1991-12-01

    Botryllus schlosseri is a cosmopolitan encrusting colonial tunicate which undergoes a natural transplantation reaction. When the growing edges of two colonies come into direct contact by interaction between their extracorporeal blood vessel termini, the ampullae, they either reject each other or fuse. This phenomenon is controlled by a single gene locus (Fu/HC) with multiple codominantly expressed alleles. Rejecting colonies share no alleles. Here we analyze allogeneic responses of Monterey (Mon), California, versus Woods Hole (WH), Massachusetts, colonies. Of 42 Mon x WH pairs tested, allogeneic rejection reactions occurred in all. Necrotic lesions (points of rejection, PORs) were produced and developed only by Woods Hole ampullae, either within the Woods Hole tunic, in the borderline between the paired colonies, or within the Monterey tunic. Four types of PORs were characterized. All types involved reactions of blood cells and vessels, including infiltration, hemorrhage formation, retraction and ampullae amputation. These findings were observed in single WH x Mon pairs, in multiple subclones of WH x Mon from two parental colonies (seven independent colony pairs were assayed), and on multiple repeats of interactions from pairs that had already undergone a rejection reaction. In all cases, the range of reaction types, the location of PORs, and the timing of the responses could be found in primary as well as repeat reactions. PMID:1777421

  7. The colonial context of Filipino American immigrants' psychological experiences.

    PubMed

    David, E J R; Nadal, Kevin L

    2013-07-01

    Because of the long colonial history of Filipinos and the highly Americanized climate of postcolonial Philippines, many scholars from various disciplines have speculated that colonialism and its legacies may play major roles in Filipino emigration to the United States. However, there are no known empirical studies in psychology that specifically investigate whether colonialism and its effects have influenced the psychological experiences of Filipino American immigrants prior to their arrival in the United States. Further, there is no existing empirical study that specifically investigates the extent to which colonialism and its legacies continue to influence Filipino American immigrants' mental health. Thus, using interviews (N = 6) and surveys (N = 219) with Filipino American immigrants, two studies found that colonialism and its consequences are important factors to consider when conceptualizing the psychological experiences of Filipino American immigrants. Specifically, the findings suggest that (a) Filipino American immigrants experienced ethnic and cultural denigration in the Philippines prior to their U.S. arrival, (b) ethnic and cultural denigration in the Philippines and in the United States may lead to the development of colonial mentality (CM), and (c) that CM may have negative mental health consequences among Filipino American immigrants. The two studies' findings suggest that the Filipino American immigration experience cannot be completely captured by the voluntary immigrant narrative, as they provide empirical support to the notion that the Filipino American immigration experience needs to be understood in the context of colonialism and its most insidious psychological legacy- CM. PMID:23875854

  8. Ecological Conditions Favoring Budding in Colonial Organisms under Environmental Disturbance

    PubMed Central

    Nakamaru, Mayuko; Takada, Takenori; Ohtsuki, Akiko; Suzuki, Sayaki U.; Miura, Kanan; Tsuji, Kazuki

    2014-01-01

    Dispersal is a topic of great interest in ecology. Many organisms adopt one of two distinct dispersal tactics at reproduction: the production of small offspring that can disperse over long distances (such as seeds and spawned eggs), or budding. The latter is observed in some colonial organisms, such as clonal plants, corals and ants, in which (super)organisms split their body into components of relatively large size that disperse to a short distance. Contrary to the common dispersal viewpoint, short-dispersal colonial organisms often flourish even in environments with frequent disturbances. In this paper, we investigate the conditions that favor budding over long-distance dispersal of small offspring, focusing on the life history of the colony growth and the colony division ratio. These conditions are the relatively high mortality of very small colonies, logistic growth, the ability of dispersers to peacefully seek and settle unoccupied spaces, and small spatial scale of environmental disturbance. If these conditions hold, budding is advantageous even when environmental disturbance is frequent. These results suggest that the demography or life history of the colony underlies the behaviors of the colonial organisms. PMID:24621824

  9. A View of Future Human Colonies on Mars

    NASA Astrophysics Data System (ADS)

    Gustafson, Robert J.; Rice, Eric E.; Gramer, Daniel J.; White, Brant C.

    2003-01-01

    In a recent feasibility study, ORBITEC conceptualized systems and an evolving architecture for producing and utilizing Mars-based in-situ resources utilization (ISRU) propellant combinations. The propellants will be used to support the propulsion and power systems for ground and flight vehicles that would be part of Mars exploration and colonization. The key aspect of the study was to show the benefits of ISRU, develop an analysis methodology, as well as provide some guidance to future propellant system choices based upon what is known today about Mars. The study time frame included an early unmanned and manned exploration period (now to 2040) and a colonization period that occurs from 2040 to 2090. As part of this feasibility study, ORBITEC developed two different Mars colonization scenarios, namely a low case that ends with a 100-person colony and a high case that ends with a 10.000-person colony. A population growth model, mission traffic model, and infrastructure model was developed for each scenario to better understand the requirements of future Mars colonies. This paper outlines the characteristics of the Mars colonies that ORBITEC envisions under both colonization scenarios. This includes a discussion of the flow of people and materials between the Earth and Mars, the infrastructure requirements of the colonies, potential colony configurations, and the mission requirements of the colonies.

  10. Impacts of inbreeding on bumblebee colony fitness under field conditions

    PubMed Central

    Whitehorn, Penelope R; Tinsley, Matthew C; Brown, Mark JF; Darvill, Ben; Goulson, Dave

    2009-01-01

    Background Inbreeding and the loss of genetic diversity are known to be significant threats to small, isolated populations. Hymenoptera represent a special case regarding the impact of inbreeding. Haplodiploidy may permit purging of deleterious recessive alleles in haploid males, meaning inbreeding depression is reduced relative to diploid species. In contrast, the impact of inbreeding may be exacerbated in Hymenopteran species that have a single-locus complementary sex determination system, due to the production of sterile or inviable diploid males. We investigated the costs of brother-sister mating in the bumblebee Bombus terrestris. We compared inbred colonies that produced diploid males and inbred colonies that did not produce diploid males with outbred colonies. Mating, hibernation and colony founding took place in the laboratory. Once colonies had produced 15 offspring they were placed in the field and left to forage under natural conditions. Results The diploid male colonies had a significantly reduced fitness compared to regular inbred and outbred colonies; they had slower growth rates in the laboratory, survived for a shorter time period under field conditions and produced significantly fewer offspring overall. No differences in success were found between non-diploid male inbred colonies and outbred colonies. Conclusion Our data illustrate that inbreeding exacts a considerable cost in Bombus terrestris through the production of diploid males. We suggest that diploid males may act as indicators of the genetic health of populations, and that their detection could be used as an informative tool in hymenopteran conservation. We conclude that whilst haplodiploids may suffer less inbreeding depression than diploid species, they are still highly vulnerable to population fragmentation and reduced genetic diversity due to the extreme costs imposed by the production of diploid males. PMID:19573223

  11. Increased Inter-Colony Fusion Rates Are Associated with Reduced COI Haplotype Diversity in an Invasive Colonial Ascidian Didemnum vexillum

    PubMed Central

    Smith, Kirsty F.; Stefaniak, Lauren; Saito, Yasunori; Gemmill, Chrissen E. C.; Cary, S. Craig; Fidler, Andrew E.

    2012-01-01

    Considerable progress in our understanding of the population genetic changes associated with biological invasions has been made over the past decade. Using selectively neutral loci, it has been established that reductions in genetic diversity, reflecting founder effects, have occurred during the establishment of some invasive populations. However, some colonial organisms may actually gain an ecological advantage from reduced genetic diversity because of the associated reduction in inter-colony conflict. Here we report population genetic analyses, along with colony fusion experiments, for a highly invasive colonial ascidian, Didemnum vexillum. Analyses based on mitochondrial cytochrome oxidase I (COI) partial coding sequences revealed two distinct D. vexillum clades. One COI clade appears to be restricted to the probable native region (i.e., north-west Pacific Ocean), while the other clade is present in widely dispersed temperate coastal waters around the world. This clade structure was supported by 18S ribosomal DNA (rDNA) sequence data, which revealed a one base-pair difference between the two clades. Recently established populations of D. vexillum in New Zealand displayed greatly reduced COI genetic diversity when compared with D. vexillum in Japan. In association with this reduction in genetic diversity was a significantly higher inter-colony fusion rate between randomly paired New Zealand D. vexillum colonies (80%, standard deviation ±18%) when compared with colonies found in Japan (27%, standard deviation ±15%). The results of this study add to growing evidence that for colonial organisms reductions in population level genetic diversity may alter colony interaction dynamics and enhance the invasive potential of newly colonizing species. PMID:22303442

  12. Transits of Venus and Colonial India

    NASA Astrophysics Data System (ADS)

    Kochhar, Rajesh

    2012-09-01

    Astronomical expeditions during the colonial period had a political and national significance also. Measuring the earth and mapping the sky were activities worthy of powerful and power- seeking nations. Such was the sanctity of global astronomical activity that many other agendas could be hidden under it. An early astronomy-related expedition turned out to be extremely beneficial, to botany. The expedition sent by the French Government in 1735 to South America under the leadership of Charles Marie de la Condamine (1701--1774) ostensibly for the measurement of an arc of the meridian at Quito in Ecuador surreptitiously collected data that enabled Linnaeus to describe the genus cinchona in 1742. When the pair of transits of Venus occurred in 1761 and 1769, France and England were engaged in a bitter rivalry for control of India. The observation of the transits became a part of the rivalry. A telescope presented by the British to a South Indian King as a decorative toy was borrowed back for actual use. Scientifically the transit observations were a wash out, but the exercise introduced Europe to details of living Indian tradition of eclipse calculations. More significantly, it led to the institutionalization of modern astronomy in India under the auspices of the English East India Company (1787). The transits of Venus of 1874 and 1882 were important not so much for the study of the events as for initiating systematic photography of the Sun. By this, Britain owned most of the world's sunshine, and was expected to help European solar physicists get data from its vast Empire on a regular basis. This and the then genuinely held belief that a study of the sun would help predict failure of monsoons led to the institutionalization of solar physics studies in India (1899). Of course, when the solar physicists learnt that solar activity did not quite determine rainfall in India, they forgot to inform the Government.

  13. Metatranscriptomic analyses of honey bee colonies.

    PubMed

    Tozkar, Cansu Ö; Kence, Meral; Kence, Aykut; Huang, Qiang; Evans, Jay D

    2015-01-01

    Honey bees face numerous biotic threats from viruses to bacteria, fungi, protists, and mites. Here we describe a thorough analysis of microbes harbored by worker honey bees collected from field colonies in geographically distinct regions of Turkey. Turkey is one of the World's most important centers of apiculture, harboring five subspecies of Apis mellifera L., approximately 20% of the honey bee subspecies in the world. We use deep ILLUMINA-based RNA sequencing to capture RNA species for the honey bee and a sampling of all non-endogenous species carried by bees. After trimming and mapping these reads to the honey bee genome, approximately 10% of the sequences (9-10 million reads per library) remained. These were then mapped to a curated set of public sequences containing ca. Sixty megabase-pairs of sequence representing known microbial species associated with honey bees. Levels of key honey bee pathogens were confirmed using quantitative PCR screens. We contrast microbial matches across different sites in Turkey, showing new country recordings of Lake Sinai virus, two Spiroplasma bacterium species, symbionts Candidatus Schmidhempelia bombi, Frischella perrara, Snodgrassella alvi, Gilliamella apicola, Lactobacillus spp.), neogregarines, and a trypanosome species. By using metagenomic analysis, this study also reveals deep molecular evidence for the presence of bacterial pathogens (Melissococcus plutonius, Paenibacillus larvae), Varroa destructor-1 virus, Sacbrood virus, and fungi. Despite this effort we did not detect KBV, SBPV, Tobacco ringspot virus, VdMLV (Varroa Macula like virus), Acarapis spp., Tropilaeleps spp. and Apocephalus (phorid fly). We discuss possible impacts of management practices and honey bee subspecies on microbial retinues. The described workflow and curated microbial database will be generally useful for microbial surveys of healthy and declining honey bees. PMID:25852743

  14. Metatranscriptomic analyses of honey bee colonies

    PubMed Central

    Tozkar, Cansu Ö.; Kence, Meral; Kence, Aykut; Huang, Qiang; Evans, Jay D.

    2015-01-01

    Honey bees face numerous biotic threats from viruses to bacteria, fungi, protists, and mites. Here we describe a thorough analysis of microbes harbored by worker honey bees collected from field colonies in geographically distinct regions of Turkey. Turkey is one of the World's most important centers of apiculture, harboring five subspecies of Apis mellifera L., approximately 20% of the honey bee subspecies in the world. We use deep ILLUMINA-based RNA sequencing to capture RNA species for the honey bee and a sampling of all non-endogenous species carried by bees. After trimming and mapping these reads to the honey bee genome, approximately 10% of the sequences (9–10 million reads per library) remained. These were then mapped to a curated set of public sequences containing ca. Sixty megabase-pairs of sequence representing known microbial species associated with honey bees. Levels of key honey bee pathogens were confirmed using quantitative PCR screens. We contrast microbial matches across different sites in Turkey, showing new country recordings of Lake Sinai virus, two Spiroplasma bacterium species, symbionts Candidatus Schmidhempelia bombi, Frischella perrara, Snodgrassella alvi, Gilliamella apicola, Lactobacillus spp.), neogregarines, and a trypanosome species. By using metagenomic analysis, this study also reveals deep molecular evidence for the presence of bacterial pathogens (Melissococcus plutonius, Paenibacillus larvae), Varroa destructor-1 virus, Sacbrood virus, and fungi. Despite this effort we did not detect KBV, SBPV, Tobacco ringspot virus, VdMLV (Varroa Macula like virus), Acarapis spp., Tropilaeleps spp. and Apocephalus (phorid fly). We discuss possible impacts of management practices and honey bee subspecies on microbial retinues. The described workflow and curated microbial database will be generally useful for microbial surveys of healthy and declining honey bees. PMID:25852743

  15. Chemotaxis migration and morphogenesis of living colonies.

    PubMed

    Ben Amar, Martine

    2013-06-01

    Development of forms in living organisms is complex and fascinating. Morphogenetic theories that investigate these shapes range from discrete to continuous models, from the variational elasticity to time-dependent fluid approach. Here a mixture model is chosen to describe the mass transport in a morphogenetic gradient: it gives a mathematical description of a mixture involving several constituents in mechanical interactions. This model, which is highly flexible can incorporate many biological processes but also complex interactions between cells as well as between cells and their environment. We use this model to derive a free-boundary problem easier to handle analytically. We solve it in the simplest geometry: an infinite linear front advancing with a constant velocity. In all the cases investigated here as the 3 D diffusion, the increase of mitotic activity at the border, nonlinear laws for the uptake of morphogens or for the mobility coefficient, a planar front exists above a critical threshold for the mobility coefficient but it becomes unstable just above the threshold at long wavelengths due to the existence of a Goldstone mode. This explains why sparsely bacteria exhibit dendritic patterns experimentally in opposition to other colonies such as biofilms and epithelia which are more compact. In the most unstable situation, where all the laws: diffusion, chemotaxis driving and chemoattractant uptake are linear, we show also that the system can recover a dynamic stability. A second threshold for the mobility exists which has a lower value as the ratio between diffusion coefficients decreases. Within the framework of this model where the biomass is treated mainly as a viscous and diffusive fluid, we show that the multiplicity of independent parameters in real biologic experimental set-up may explain varieties of observed patterns. PMID:23807468

  16. Hindu Responses to Darwinism: Assimilation and Rejection in a Colonial and Post-Colonial Context

    NASA Astrophysics Data System (ADS)

    MacKenzie Brown, C.

    2010-06-01

    Hindu responses to Darwinism, like Christian, have run the gamut from outright rejection to fairly robust but limited accommodations of the Darwinian perspective. Despite certain features of Hindu thought such as the enormous time-scales of traditional cosmogonies that may suggest considerable affinity with modern notions of organic evolution, more often than not traditional assumptions have worked against deep engagement with Darwinism, allowing only for superficial assimilation at best. Three fundamental factors have affected Hindu responses to Darwinism: the great diversity within the tradition spanning evolutionist and creationist perspectives, the encounter with Darwinism in the late nineteenth century as part of an alien culture, and the fact that this encounter occurred within a colonial context. This essay explores the complex interactions of these three factors, beginning with the diversity within the ancient and classical cosmological traditions, followed by consideration of colonial developments and the emergence of four representative Hindu approaches to Darwinism: Modern Vedic Evolutionism, Anthropic Vedic Evolutionism, Reactionary Vedic Evolutionism, and Modern Vedic Creationism. The essay concludes by discussing various epistemological issues in the attempts of modern Hindu apologists to legitimize Vedic world views. These issues include the appeal to modern science to confirm traditional ideals and values, while simultaneously subordinating scientific method to spiritual means of knowledge, or rejecting scientific methodology with its inbuilt skepticism entirely.

  17. Taverns and Coffee Houses: Adult Educational Institutions In Colonial America.

    ERIC Educational Resources Information Center

    Long, Huey B.

    1981-01-01

    Presents the concept of colonial taverns and coffee houses as adult education institutions. They were of great importance in the development of impressions, opinions, attitudes, and knowledge about agriculture, business, shipping, economics, community and world affairs, and recreation. (CT)

  18. Honeybee colony collapse due to Nosema ceranae in professional apiaries.

    PubMed

    Higes, Mariano; Martín-Hernández, Raquel; Garrido-Bailón, Encarna; González-Porto, Amelia V; García-Palencia, Pilar; Meana, Aranzazu; Del Nozal, María J; Mayo, R; Bernal, José L

    2009-04-01

    Honeybee colony collapse is a sanitary and ecological worldwide problem. The features of this syndrome are an unexplained disappearance of adult bees, a lack of brood attention, reduced colony strength, and heavy winter mortality without any previous evident pathological disturbances. To date there has not been a consensus about its origins. This report describes the clinical features of two professional bee-keepers affecting by this syndrome. Anamnesis, clinical examination and analyses support that the depopulation in both cases was due to the infection by Nosema ceranae (Microsporidia), an emerging pathogen of Apis mellifera. No other significant pathogens or pesticides (neonicotinoids) were detected and the bees had not been foraging in corn or sunflower crops. The treatment with fumagillin avoided the loss of surviving weak colonies. This is the first case report of honeybee colony collapse due to N. ceranae in professional apiaries in field conditions reported worldwide. PMID:23765741

  19. A non-policing honey bee colony (Apis mellifera capensis)

    NASA Astrophysics Data System (ADS)

    Beekman, Madeleine; Good, Gregory; Allsopp, Mike; Radloff, Sarah; Pirk, Chris; Ratnieks, Francis

    2002-09-01

    In the Cape honey bee Apis mellifera capensis, workers lay female eggs without mating by thelytokous parthenogenesis. As a result, workers are as related to worker-laid eggs as they are to queen-laid eggs and therefore worker policing is expected to be lower, or even absent. This was tested by transferring worker- and queen-laid eggs into three queenright A. m. capensis discriminator colonies and monitoring their removal. Our results show that worker policing is variable in A. m. capensis and that in one colony worker-laid eggs were not removed. This is the first report of a non-policing queenright honey bee colony. DNA microsatellite and morphometric analysis suggests that the racial composition of the three discriminator colonies was different. The variation in policing rates could be explained by differences in degrees of hybridisation between A. m. capensis and A. m. scutellata, although a larger survey is needed to confirm this.

  20. 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

  1. View from beneath archway (note Windmill & Colonial House in ...

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

    View from beneath archway (note Windmill & Colonial House in background) - National Park Seminary, Bounded by Capitol Beltway (I-495), Linden Lane, Woodstove Avenue, & Smith Drive, Silver Spring, Montgomery County, MD

  2. Colony size as a species character in massive reef corals

    NASA Astrophysics Data System (ADS)

    Soong, Keryea

    1993-07-01

    In a study of seven massive, Caribbean corals, I have found major differences in reproductive behavior between species with large maximum colony sizes and species with smaller maximum colony sizes. Four species ( Diploria clivosa, D. strigosa, Montastrea cavernosa, Siderastrea siderea) which are large (<1000 cm2 in surface area) broadcast gametes during a short spawning season. Their puberty size is relatively large (>100 cm2, except M. cavernosa). In contrast, two small massive species (<100 cm2, Favia fragum and S. radians), and one medium-sized (100 1000 cm2, Porites astreoides) massive species, brood larvae during an extended season (year-round in Panama). The puberty size of the small species is only 2 4 cm2. Given these close associations between maximum colony sizes and a number of fundamental reproductive attributes, greater attention should be given to the colony size distributions of different species of reef corals in nature, since many important life history and population characters may be inferred.

  3. Modelling Food and Population Dynamics in Honey Bee Colonies

    PubMed Central

    Khoury, David S.; Barron, Andrew B.; Myerscough, Mary R.

    2013-01-01

    Honey bees (Apis mellifera) are increasingly in demand as pollinators for various key agricultural food crops, but globally honey bee populations are in decline, and honey bee colony failure rates have increased. This scenario highlights a need to understand the conditions in which colonies flourish and in which colonies fail. To aid this investigation we present a compartment model of bee population dynamics to explore how food availability and bee death rates interact to determine colony growth and development. Our model uses simple differential equations to represent the transitions of eggs laid by the queen to brood, then hive bees and finally forager bees, and the process of social inhibition that regulates the rate at which hive bees begin to forage. We assume that food availability can influence both the number of brood successfully reared to adulthood and the rate at which bees transition from hive duties to foraging. The model predicts complex interactions between food availability and forager death rates in shaping colony fate. Low death rates and high food availability results in stable bee populations at equilibrium (with population size strongly determined by forager death rate) but consistently increasing food reserves. At higher death rates food stores in a colony settle at a finite equilibrium reflecting the balance of food collection and food use. When forager death rates exceed a critical threshold the colony fails but residual food remains. Our model presents a simple mathematical framework for exploring the interactions of food and forager mortality on colony fate, and provides the mathematical basis for more involved simulation models of hive performance. PMID:23667418

  4. Detection of hemolytic Listeria monocytogenes by using DNA colony hybridization

    SciTech Connect

    Datta, A.R.; Wentz, B.A.; Hill, W.E.

    1987-09-01

    A fragment of about 500 base pairs of the beta-hemolysin gene from Listeria monocytogenes was used to screen different bacterial strains by DNA colony hybridization. The cells in the colonies were lysed by microwaves in the presence of sodium hydroxide. Of 52 different strains of Listeria species screened, only the DNA from beta-hemolytic (CAMP-positive) strains of L. monocytogenes hybridized with this probe.

  5. Individual Variability of Nosema ceranae Infections in Apis mellifera Colonies

    PubMed Central

    Mulholland, Grace E.; Traver, Brenna E.; Johnson, Nels G.; Fell, Richard D.

    2012-01-01

    Since 2006, beekeepers have reported increased losses of Apis mellifera colonies, and one factor that has been potentially implicated in these losses is the microsporidian Nosema ceranae. Since N. ceranae is a fairly recently discovered parasite, there is little knowledge of the variation in infection levels among individual workers within a colony. In this study we examined the levels of infection in individual bees from five colonies over three seasons using both spore counting and quantitative real-time PCR. The results show considerable intra-colony variation in infection intensity among individual workers with a higher percentage of low-level infections detected by PCR than by spore counting. Colonies generally had the highest percentage of infected bees in early summer (June) and the lowest levels in the fall (September). Nosema apis was detected in only 16/705 bees (2.3%) and always as a low-level co-infection with N. ceranae. The results also indicate that intra-colony variation in infection levels could influence the accuracy of Nosema diagnosis. PMID:26466731

  6. No intracolonial nepotism during colony fissioning in honey bees

    PubMed Central

    Rangel, Juliana; Mattila, Heather R.; Seeley, Thomas D.

    2009-01-01

    Most species of social insects have singly mated queens, but in some species each queen mates with numerous males to create a colony whose workers belong to multiple patrilines. This colony genetic structure creates a potential for intracolonial nepotism. One context with great potential for such nepotism arises in species, like honey bees, whose colonies reproduce by fissioning. During fissioning, workers might nepotistically choose between serving a young (sister) queen or the old (mother) queen, preferring the former if she is a full-sister but the latter if the young queen is only a half-sister. We examined three honeybee colonies that swarmed, and performed paternity analyses on the young (immature) queens and samples of workers who either stayed with the young queens in the nest or left with the mother queen in the swarm. For each colony, we checked whether patrilines represented by immature queens had higher proportions of staying workers than patrilines not represented by immature queens. We found no evidence of this. The absence of intracolonial nepotism during colony fissioning could be because the workers cannot discriminate between full-sister and half-sister queens when they are immature, or because the costs of behaving nepotistically outweigh the benefits. PMID:19692398

  7. Appearance of colonies of Prototheca on CHROMagar Candida medium.

    PubMed

    Casal, M; Linares, M J; Solís, F; Rodríguez, F C

    1997-01-01

    The microorganisms capable of producing opportunist infections include the yeast-like organisms of the genus Candida, and the unicellular algae of the genus Prototheca, which share common features and can, therefore, lead to confusion. Their colonies are almost identical and they grow in the same culture media used routinely in mycology. CHROMagar Candida is a new chromogenic differential isolation medium that facilitates the presumptive differentiation of some of the most clinically important yeast-like organisms. To our knowledge, the use of CHROMagar Candida with Prototheca spp. has not been reported in the literature. This report describes the growth of 151 strains of Prototheca on CHROMagar Candida compared to the growth of a total of 326 well-characterized yeast organisms of the genera Candida, Cryptococcus, Trichosporon, Geotrichum, and Saccharomyces. It is clinically relevant to note that algae of the genus Prototheca (P. wickerhamii, P. zopfii, and P. stagnora) and of the genus Candida parapsilosis produced similar cream-colored colonies on CHROMagar Candida medium. Based on their growth on CHROMagar, a new species of Candida is described, C. zeylanoides, which has blue-green colonies. The colonies of two species of Trichosporon are also differentiated: the blue-green colonies of T. beigelii and the pink colonies of T. capitatum. PMID:9335150

  8. Theoretical size controls of the giant Phaeocystis globosa colonies

    NASA Astrophysics Data System (ADS)

    Liu, Xiao; Smith, Walker O.; Tang, Kam W.; Doan, Nhu Hai; Nguyen, Ngoc Lam

    2015-06-01

    An unusual characteristic of the cosmopolitan haptophyte Phaeocystis globosa is its ability to form colonies of strikingly large size-up to 3 cm in diameter. The large size and the presence of a mucoid envelope are believed to contribute to the formation of dense blooms in Southeast Asia. We collected colonies of different sizes in shallow coastal waters of Viet Nam and conducted a series of measurements and experiments on individual colonies. Using these empirical data, we developed a simple carbon-based model to predict the growth and maximal size of P. globosa colonies. Our model suggests that growth of a colony from 0.2 cm to 1.4 cm (the maximal size in our samples) would take 16 days. This number, however, is strongly influenced by the maximal photosynthetic rate and other physiological parameters used in the model. The model also returns a specific growth rate of 0.30 d-1 for colonial cells, comparable to satellite estimates, but lower than have been measured for unicellular P. globosa in batch culture at similar temperatures. We attribute this low growth rate to not only the model uncertainties, but factors such as self-shading and diffusive limitation of nutrient uptake.

  9. Specific pathogen free macaque colonies: a review of principles and recent advances for viral testing and colony management.

    PubMed

    Yee, JoAnn L; Vanderford, Thomas H; Didier, Elizabeth S; Gray, Stanton; Lewis, Anne; Roberts, Jeffrey; Taylor, Kerry; Bohm, Rudolf P

    2016-04-01

    Specific pathogen free (SPF) macaques provide valuable animal models for biomedical research. In 1989, the National Center for Research Resources [now Office of Research Infrastructure Programs (ORIP)] of the National Institutes of Health initiated experimental research contracts to establish and maintain SPF colonies. The derivation and maintenance of SPF macaque colonies is a complex undertaking requiring knowledge of the biology of the agents for exclusion and normal physiology and behavior of macaques, application of the latest diagnostic technology, facilitiy management, and animal husbandry. This review provides information on the biology of the four viral agents targeted for exclusion in ORIP SPF macaque colonies, describes current state-of-the-art viral diagnostic algorithms, presents data from proficiency testing of diagnostic assays between laboratories at institutions participating in the ORIP SPF program, and outlines management strategies for maintaining the integrity of SPF colonies using results of diagnostic testing as a guide to decision making. PMID:26932456

  10. Social interactions in the central nest of Coptotermes formosanus juvenile colonies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Juvenile colonies of Coptotermes formosanus Shiraki were investigated to determine the social interactions among all individuals near the central nest of a colony. The behavioral repertoire of whole colonies of subterranean termites has yet to be identified because of their cryptic nests. Colonies ...

  11. A metagenomic survey of microbes in honey bee colony collapse disorder

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In Colony Collapse Disorder (CCD), honey bee colonies inexplicably lose all of their workers. CCD has resulted in a loss of 50-90% of colonies in beekeeping operations across the United States. The observation that irradiated combs from affected colonies can be repopulated with naïve bees suggests a...

  12. Spread of plague among black-tailed prairie dogs is associated with colony spatial characteristics

    USGS Publications Warehouse

    Johnson, T.L.; Cully, J.F., Jr.; Collinge, S.K.; Ray, C.; Frey, C.M.; Sandercock, B.K.

    2011-01-01

    Sylvatic plague (Yersinia pestis) is an exotic pathogen that is highly virulent in black-tailed prairie dogs (Cynomys ludovicianus) and causes widespread colony losses and individual mortality rates >95%. We investigated colony spatial characteristics that may influence inter-colony transmission of plague at 3 prairie dog colony complexes in the Great Plains. The 4 spatial characteristics we considered include: colony size, Euclidean distance to nearest neighboring colony, colony proximity index, and distance to nearest drainage (dispersal) corridor. We used multi-state mark-recapture models to determine the relationship between these colony characteristics and probability of plague transmission among prairie dog colonies. Annual mapping of colonies and mark-recapture analyses of disease dynamics in natural colonies led to 4 main results: 1) plague outbreaks exhibited high spatial and temporal variation, 2) the site of initiation of epizootic plague may have substantially influenced the subsequent inter-colony spread of plague, 3) the long-term effect of plague on individual colonies differed among sites because of how individuals and colonies were distributed, and 4) colony spatial characteristics were related to the probability of infection at all sites although the relative importance and direction of relationships varied among sites. Our findings suggest that conventional prairie dog conservation management strategies, including promoting large, highly connected colonies, may need to be altered in the presence of plague. ?? 2011 The Wildlife Society.

  13. Colonie Interim Storage Site annual site environmental report for calendar year 1989, Colonie, New York

    SciTech Connect

    Not Available

    1990-05-01

    IN 1984, Congress assigned the cleanup of the National Lead (NL) Industries site in Colonie, New York, to the Department of Energy (DOE) as part of a decontamination research and development project under the 1984 Energy and Water Appropriations Act. DOE then included the site in the Formerly Utilized Sites Remedial Action Program (FUSRAP), an existing DOE program to decontaminate or otherwise control sites where residual radioactive materials remain for the early years of the nation's atomic energy program. DOE instituted an environmental monitoring program at the site in 1984. Results are presented annually in reports such as this. Under FUSRAP, the first environmental monitoring report for this site presented data for calendar year 1984. This report presents the findings of the environmental monitoring program conducted during calendar year 1989. 16 refs., 17 figs., 14 tabs.

  14. Measurement of ammonia emissions from tropical seabird colonies

    NASA Astrophysics Data System (ADS)

    Riddick, S. N.; Blackall, T. D.; Dragosits, U.; Daunt, F.; Braban, C. F.; Tang, Y. S.; MacFarlane, W.; Taylor, S.; Wanless, S.; Sutton, M. A.

    2014-06-01

    The excreta (guano) of seabirds at their breeding colonies represents a notable source of ammonia (NH3) emission to the atmosphere, with effects on surrounding ecosystems through nitrogen compounds being thereby transported from sea to land. Previous measurements in temperate UK conditions quantified emission hotspots and allowed preliminary global upscaling. However, thermodynamic processes and water availability limit NH3 formation from guano, which suggests that the proportion of excreted nitrogen that volatilizes as NH3 may potentially be higher at tropical seabird colonies than similar colonies in temperate or sub-polar regions. To investigate such differences, we measured NH3 concentrations and environmental conditions at two tropical seabird colonies during the breeding season: a colony of 20,000 tern spp. and noddies on Michaelmas Cay, Great Barrier Reef, and a colony of 200,000 Sooty terns on Ascension Island, Atlantic Ocean. At both sites time-integrated NH3 concentrations and meteorological parameters were measured. In addition, at Ascension Island, semi-continuous hourly NH3 concentrations and micrometeorological parameters were measured throughout the campaign. Ammonia emissions, quantified using a backwards Lagrangian atmospheric dispersion model, were estimated at 21.8 μg m-2 s-1 and 18.9 μg m-2 s-1 from Michaelmas Cay and Ascension Island, respectively. High temporal resolution NH3 data at Ascension Island estimated peak hourly emissions up to 377 μg NH3 m2 s-1. The estimated percentage fraction of total guano nitrogen volatilized was 67% at Michaelmas Cay and 32% at Ascension Island, with the larger value at the former site attributed to higher water availability. These values are much larger than published data for sub-polar locations, pointing to a substantial climatic dependence on emission of atmospheric NH3 from seabird colonies.

  15. California gull chicks raised near colony edges have elevated stress levels

    USGS Publications Warehouse

    Herring, Garth; Ackerman, Joshua T.

    2011-01-01

    Coloniality in nesting birds represents an important life history strategy for maximizing reproductive success. Birds nesting near the edge of colonies tend to have lower reproductive success than individuals nesting near colony centers, and offspring of edge-nesting parents may be impaired relative to those of central-nesting parents. We used fecal corticosterone metabolites in California gull chicks (Larus californicus) to examine whether colony size or location within the colony influenced a chick's physiological condition. We found that chicks being raised near colony edges had higher fecal corticosterone metabolite concentrations than chicks raised near colony centers, but that colony size (ranging from 150 to 11,554 nests) had no influence on fecal corticosterone levels. Fecal corticosterone metabolite concentrations also increased with chick age. Our results suggest that similarly aged California gull chicks raised near colony edges may be more physiologically stressed, as indicated by corticosterone metabolites, than chicks raised near colony centers.

  16. Predatory drill holes and partial mortality in Devonian colonial metazoans

    NASA Astrophysics Data System (ADS)

    Wilson, Mark A.; Taylor, Paul D.

    2006-07-01

    Elliptical holes ˜0.2 0.3 mm in diameter with beveled edges have been found penetrating the zooids of encrusting hederellids (colonial metazoans of uncertain affinity) from several localities in the Middle Devonian (Givetian) of North America. These are the first known predatory drill holes in pre-Cretaceous colonial animals and a key addition to the record of Paleozoic predation. Some drill holes were subsequently patched from within by new skeletal material, proving that the drilling occurred during the life of the colony. These drill holes are analogous to predatory drill holes in some modern cheilostome bryozoans, which can be similarly patched, in this case by the intramural budding of a new zooid into the empty chamber of the old zooid. A drilling predator of unknown affinity evidently consumed hederellid zooids one at a time, inflicting partial mortality on the colonies. The mode of drilling suggests that the predator specialized in this type of colonial prey, and the repaired drill holes show that the hederellids had a response to such damage. Reports of small circular holes interpreted as predatory drill holes are becoming more common in noncolonial shelled invertebrates from the Paleozoic, notably brachiopods, bivalves, and crinoids. These drill holes are far less frequent than in post-Paleozoic shells (where most are the work of gastropods), and many are of questionable origin, with some representing the traces of parasites and others postmortem domichnia.

  17. Colony size predicts division of labour in attine ants.

    PubMed

    Ferguson-Gow, Henry; Sumner, Seirian; Bourke, Andrew F G; Jones, Kate E

    2014-10-22

    Division of labour is central to the ecological success of eusocial insects, yet the evolutionary factors driving increases in complexity in division of labour are little known. The size-complexity hypothesis proposes that, as larger colonies evolve, both non-reproductive and reproductive division of labour become more complex as workers and queens act to maximize inclusive fitness. Using a statistically robust phylogenetic comparative analysis of social and environmental traits of species within the ant tribe Attini, we show that colony size is positively related to both non-reproductive (worker size variation) and reproductive (queen-worker dimorphism) division of labour. The results also suggested that colony size acts on non-reproductive and reproductive division of labour in different ways. Environmental factors, including measures of variation in temperature and precipitation, had no significant effects on any division of labour measure or colony size. Overall, these results support the size-complexity hypothesis for the evolution of social complexity and division of labour in eusocial insects. Determining the evolutionary drivers of colony size may help contribute to our understanding of the evolution of social complexity. PMID:25165765

  18. Ant Colonies Prefer Infected over Uninfected Nest Sites

    PubMed Central

    Pontieri, Luigi; Vojvodic, Svjetlana; Graham, Riley; Pedersen, Jes Søe; Linksvayer, Timothy A.

    2014-01-01

    During colony relocation, the selection of a new nest involves exploration and assessment of potential sites followed by colony movement on the basis of a collective decision making process. Hygiene and pathogen load of the potential nest sites are factors worker scouts might evaluate, given the high risk of epidemics in group-living animals. Choosing nest sites free of pathogens is hypothesized to be highly efficient in invasive ants as each of their introduced populations is often an open network of nests exchanging individuals (unicolonial) with frequent relocation into new nest sites and low genetic diversity, likely making these species particularly vulnerable to parasites and diseases. We investigated the nest site preference of the invasive pharaoh ant, Monomorium pharaonis, through binary choice tests between three nest types: nests containing dead nestmates overgrown with sporulating mycelium of the entomopathogenic fungus Metarhizium brunneum (infected nests), nests containing nestmates killed by freezing (uninfected nests), and empty nests. In contrast to the expectation pharaoh ant colonies preferentially (84%) moved into the infected nest when presented with the choice of an infected and an uninfected nest. The ants had an intermediate preference for empty nests. Pharaoh ants display an overall preference for infected nests during colony relocation. While we cannot rule out that the ants are actually manipulated by the pathogen, we propose that this preference might be an adaptive strategy by the host to “immunize” the colony against future exposure to the same pathogenic fungus. PMID:25372856

  19. Colony size predicts division of labour in attine ants

    PubMed Central

    Ferguson-Gow, Henry; Sumner, Seirian; Bourke, Andrew F. G.; Jones, Kate E.

    2014-01-01

    Division of labour is central to the ecological success of eusocial insects, yet the evolutionary factors driving increases in complexity in division of labour are little known. The size–complexity hypothesis proposes that, as larger colonies evolve, both non-reproductive and reproductive division of labour become more complex as workers and queens act to maximize inclusive fitness. Using a statistically robust phylogenetic comparative analysis of social and environmental traits of species within the ant tribe Attini, we show that colony size is positively related to both non-reproductive (worker size variation) and reproductive (queen–worker dimorphism) division of labour. The results also suggested that colony size acts on non-reproductive and reproductive division of labour in different ways. Environmental factors, including measures of variation in temperature and precipitation, had no significant effects on any division of labour measure or colony size. Overall, these results support the size–complexity hypothesis for the evolution of social complexity and division of labour in eusocial insects. Determining the evolutionary drivers of colony size may help contribute to our understanding of the evolution of social complexity. PMID:25165765

  20. Active mechanics and geometry of adherent cells and cell colonies

    NASA Astrophysics Data System (ADS)

    Banerjee, Shiladitya

    2014-03-01

    Measurements of traction stresses exerted by adherent cells or cell colonies on elastic substrates have yielded new insight on how the mechanical and geometrical properties of the substrate regulate cellular force distribution, mechanical energy, spreading, morphology or stress ber architecture. We have developed a generic mechanical model of adherent cells as an active contractile gel mechanically coupled to an elastic substrate and to neighboring cells in a tissue. The contractile gel model accurately predicts the distribution of cellular and traction stresses as observed in single cell experiments, and captures the dependence of cell shape, traction stresses and stress ber polarization on the substrate's mechanical and geometrical properties. The model further predicts that the total strain energy of an adherent cell is solely regulated by its spread area, in agreement with recent experiments on micropatterned substrates with controlled geometry. When used to describe the behavior of colonies of adherent epithelial cells, the model demonstrates the crucial role of the mechanical cross-talk between intercellular and extracellular adhesion in regulating traction force distribution. Strong intercellular mechanical coupling organizes traction forces to the colony periphery, whereas weaker intercellular coupling leads to the build up of traction stresses at intercellular junctions. Furthermore, in agreement with experiments on large cohesive keratinocyte colonies, the model predicts a linear scaling of traction forces with the colony size. This scaling suggests the emergence of an effective surface tension as a scale-free material property of the adherent tissue, originating from actomyosin contractility.

  1. Colony dynamics of the Formosan subterranean termite in a frequently disturbed urban landscape.

    PubMed

    Aluko, Gabriel A; Husseneder, Claudia

    2007-08-01

    The success of evaluating areawide control of the Formosan subterranean termite, Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae), in urban landscapes hinges on detailed understanding of colony movement and plasticity of the breeding system. Most previous studies of colony affiliation and breeding systems of C. formosanus have been conducted in relatively undisturbed park-like areas. However, disturbance in the form of landscaping, construction, and nearby treatment may impact termite colony dynamics in urban habitats. Therefore, we used microsatellite genotyping to identify the number of colonies, assess colony movement, and investigate the breeding structure of colonies surrounding the Supreme Court Building in New Orleans, LA. During 4 yr, 18 distinct colonies were identified in the study area. In contrast to earlier studies in park-like areas, which indicated stable foraging areas, colonies in this study moved frequently into and out of inground stations. Five colonies were simple families; two of these colonies were headed by inbred nestmate pairs, and three of these colonies were headed by outbred unrelated pairs. Thirteen colonies were extended families headed by fewer than five neotenic reproductives. During the study, the predominant breeding system shifted; simple family colonies either moved or were eliminated, and they were replaced with new extended family colonies. In one case, a generation turnover within a colony from simple to extended family was observed. PMID:17849849

  2. Trichuris trichiura in a post-Colonial Brazilian mummy

    PubMed Central

    Bianucci, Rafaella; Torres, Eduardo J Lopes; Santiago, Juliana MF Dutra; Ferreira, Luis F; Nerlich, Andreas G; de Souza, Sheila Maria Mendonça; Giuffra, Valentina; Chieffi, Pedro Paulo; Bastos, Otilio Machado; Travassos, Renata; de Souza, Wanderley; Araújo, Adauto

    2015-01-01

    Trichuris trichiura is a soil-transmitted helminth which is prevalent in warm, moist, tropical and subtropical regions of the world with poor sanitation. Heavy whipworm can result either in Trichuris dysenteric syndrome - especially in children - or in a chronic colitis. In heavy infections, worms can spread proximally and may cause ileitis. Here we provide first microscopic evidence for a T. trichiura adult worm embedded in the rectum of a post-Colonial Brazilian adult mummy. During Colonial and post-Colonial times, many European chroniclers described a parasitic disease named Maculo whose symptomatology coincides with heavy helminthiasis. Based on our findings and on comparison of ancient textual evidence with modern description of heavy whipworm, we feel confident in considering that the two syndromes are expressions of the same pathological condition. PMID:25742276

  3. Alexander von Humboldt's perceptions of colonial Spanish America.

    PubMed

    Rebok, Sandra

    2009-01-01

    This study presents an in-depth analysis of Alexander von Humboldt's descriptions and critical comments on the colonial society of the different regions he visited during his well-known expedition through the Americas (1799-1804). The criticisms of colonialism that he expressed, reflecting his personal convictions, have already been the focal point of many studies, but Humboldt also was able to offer a more differentiated assessment through comparisons of regional and local traditions and developments. This essay focuses on his personal diaries, which offer many interesting comments on colonial societies. These considerations and impressions made during the expedition are of particular scholarly value since they were not subject to censorship of any kind. PMID:19852391

  4. Trichuris trichiura in a post-Colonial Brazilian mummy.

    PubMed

    Bianucci, Rafaella; Torres, Eduardo J Lopes; Santiago, Juliana M F Dutra; Ferreira, Luis F; Nerlich, Andreas G; Souza, Sheila Maria Mendonça de; Giuffra, Valentina; Chieffi, Pedro Paulo; Bastos, Otilio Maria; Travassos, Renata; Souza, Wanderley de; Araújo, Adauto

    2015-02-01

    Trichuris trichiura is a soil-transmitted helminth which is prevalent in warm, moist, tropical and subtropical regions of the world with poor sanitation. Heavy whipworm can result either in Trichuris dysenteric syndrome - especially in children - or in a chronic colitis. In heavy infections, worms can spread proximally and may cause ileitis. Here we provide first microscopic evidence for a T. trichiura adult worm embedded in the rectum of a post-Colonial Brazilian adult mummy. During Colonial and post-Colonial times, many European chroniclers described a parasitic disease named Maculo whose symptomatology coincides with heavy helminthiasis. Based on our findings and on comparison of ancient textual evidence with modern description of heavy whipworm, we feel confident in considering that the two syndromes are expressions of the same pathological condition. PMID:25742276

  5. Amplification of emerging viruses in a bat colony.

    PubMed

    Drexler, Jan Felix; Corman, Victor Max; Wegner, Tom; Tateno, Adriana Fumie; Zerbinati, Rodrigo Melim; Gloza-Rausch, Florian; Seebens, Antje; Müller, Marcel A; Drosten, Christian

    2011-03-01

    Bats host noteworthy viral pathogens, including coronaviruses, astroviruses, and adenoviruses. Knowledge on the ecology of reservoir-borne viruses is critical for preventive approaches against zoonotic epidemics. We studied a maternity colony of Myotis myotis bats in the attic of a private house in a suburban neighborhood in Rhineland-Palatinate, Germany, during 2008, 2009, and 2010. One coronavirus, 6 astroviruses, and 1 novel adenovirus were identified and monitored quantitatively. Strong and specific amplification of RNA viruses, but not of DNA viruses, occurred during colony formation and after parturition. The breeding success of the colony was significantly better in 2010 than in 2008, in spite of stronger amplification of coronaviruses and astroviruses in 2010, suggesting that these viruses had little pathogenic influence on bats. However, the general correlation of virus and bat population dynamics suggests that bats control infections similar to other mammals and that they may well experience epidemics of viruses under certain circumstances. PMID:21392436

  6. Energetic basis of colonial living in social insects

    PubMed Central

    Hou, Chen; Kaspari, Michael; Vander Zanden, Hannah B.; Gillooly, James F.

    2010-01-01

    Understanding the ecology and evolution of insect societies requires greater knowledge of how sociality affects the performance of whole colonies. Metabolic scaling theory, based largely on the body mass scaling of metabolic rate, has successfully predicted many aspects of the physiology and life history of individual (or unitary) organisms. Here we show, using a diverse set of social insect species, that this same theory predicts the size dependence of basic features of the physiology (i.e., metabolic rate, reproductive allocation) and life history (i.e., survival, growth, and reproduction) of whole colonies. The similarity in the size dependence of these features in unitary organisms and whole colonies points to commonalities in functional organization. Thus, it raises an important question of how such evolutionary convergence could arise through the process of natural selection. PMID:20133582

  7. Idiocy and the law in colonial New England.

    PubMed

    Wickham, P

    2001-04-01

    A review of the laws and records of the courts of colonial New England indicate some ways the early settlers thought about and responded to idiocy. Early Massachusetts laws extended certain rights to idiots: They authorized the transfer of property, exonerated idiots who committed capital crimes, and extended relief to idiots who were impoverished. There is no documentation of the implementation of these laws nor is there direct reference to idiocy in court proceedings. Nevertheless, the court records identify certain individuals with incompetence and atypical behavior suggestive of idiocy. Most of the colonial laws as well as the colonists' ways of thinking about idiocy originated in English common law and custom. The New England colonial laws and records of the courts offer insights into contemporary issues regarding mental retardation. PMID:11340960

  8. Amplification of Emerging Viruses in a Bat Colony

    PubMed Central

    Drexler, Jan Felix; Corman, Victor Max; Wegner, Tom; Tateno, Adriana Fumie; Zerbinati, Rodrigo Melim; Gloza-Rausch, Florian; Seebens, Antje; Müller, Marcel A.

    2011-01-01

    Bats host noteworthy viral pathogens, including coronaviruses, astroviruses, and adenoviruses. Knowledge on the ecology of reservoir-borne viruses is critical for preventive approaches against zoonotic epidemics. We studied a maternity colony of Myotis myotis bats in the attic of a private house in a suburban neighborhood in Rhineland-Palatinate, Germany, during 2008, 2009, and 2010. One coronavirus, 6 astroviruses, and 1 novel adenovirus were identified and monitored quantitatively. Strong and specific amplification of RNA viruses, but not of DNA viruses, occurred during colony formation and after parturition. The breeding success of the colony was significantly better in 2010 than in 2008, in spite of stronger amplification of coronaviruses and astroviruses in 2010, suggesting that these viruses had little pathogenic influence on bats. However, the general correlation of virus and bat population dynamics suggests that bats control infections similar to other mammals and that they may well experience epidemics of viruses under certain circumstances. PMID:21392436

  9. Telomerase deficiency in a colonial ascidian after prolonged asexual propagation.

    PubMed

    Sköld, Helen Nilsson; Asplund, Maria E; Wood, Christine A; Bishop, John D D

    2011-06-15

    In organisms that propagate by agametic cloning, the parental body is the reproductive unit and fitness increases with clonal size, so that colonial metazoans, despite lack of experimental data, have been considered potentially immortal. Using asexual propagation rate as a measure of somatic performance, and telomerase activity and relative telomere length as molecular markers of senescence, old (7-12 years) asexual strains of a colonial ascidian, Diplosoma listerianum, were compared with their recent sexually produced progeny. We report for the first time evidence for long-term molecular senescence in asexual lineages of a metazoan, and that only passage between sexual generations provides total rejuvenation permitting indefinite propagation and growth. Thus, this colonial ascidian has not fully escaped ageing. The possibility of somatic replicative senescence also potentially helps to explain why metazoans, with the capacity for asexual propagation through agametic cloning, commonly undergo cycles of sexual reproduction in the wild. PMID:21548077

  10. Modeling colony collapse disorder in honeybees as a contagion.

    PubMed

    Kribs-Zaleta, Christopher M; Mitchell, Christopher

    2014-12-01

    Honeybee pollination accounts annually for over $14 billion in United States agriculture alone. Within the past decade there has been a mysterious mass die-off of honeybees, an estimated 10 million beehives and sometimes as much as 90% of an apiary. There is still no consensus on what causes this phenomenon, called Colony Collapse Disorder, or CCD. Several mathematical models have studied CCD by only focusing on infection dynamics. We created a model to account for both healthy hive dynamics and hive extinction due to CCD, modeling CCD via a transmissible infection brought to the hive by foragers. The system of three ordinary differential equations accounts for multiple hive population behaviors including Allee effects and colony collapse. Numerical analysis leads to critical hive sizes for multiple scenarios and highlights the role of accelerated forager recruitment in emptying hives during colony collapse. PMID:25365602

  11. Artificial Bee Colony Optimization for Short-Term Hydrothermal Scheduling

    NASA Astrophysics Data System (ADS)

    Basu, M.

    2014-12-01

    Artificial bee colony optimization is applied to determine the optimal hourly schedule of power generation in a hydrothermal system. Artificial bee colony optimization is a swarm-based algorithm inspired by the food foraging behavior of honey bees. The algorithm is tested on a multi-reservoir cascaded hydroelectric system having prohibited operating zones and thermal units with valve point loading. The ramp-rate limits of thermal generators are taken into consideration. The transmission losses are also accounted for through the use of loss coefficients. The algorithm is tested on two hydrothermal multi-reservoir cascaded hydroelectric test systems. The results of the proposed approach are compared with those of differential evolution, evolutionary programming and particle swarm optimization. From numerical results, it is found that the proposed artificial bee colony optimization based approach is able to provide better solution.

  12. Neonicotinoid pesticide reduces bumble bee colony growth and queen production.

    PubMed

    Whitehorn, Penelope R; O'Connor, Stephanie; Wackers, Felix L; Goulson, Dave

    2012-04-20

    Growing evidence for declines in bee populations has caused great concern because of the valuable ecosystem services they provide. Neonicotinoid insecticides have been implicated in these declines because they occur at trace levels in the nectar and pollen of crop plants. We exposed colonies of the bumble bee Bombus terrestris in the laboratory to field-realistic levels of the neonicotinoid imidacloprid, then allowed them to develop naturally under field conditions. Treated colonies had a significantly reduced growth rate and suffered an 85% reduction in production of new queens compared with control colonies. Given the scale of use of neonicotinoids, we suggest that they may be having a considerable negative impact on wild bumble bee populations across the developed world. PMID:22461500

  13. Estimating reproductive success in colonial waterbirds: An evaluation

    USGS Publications Warehouse

    Erwin, R.M.; Custer, T.W.

    1982-01-01

    To estimate reproductive success in a population one ideally would like to determine the number of young fledged per nesting female. However, this is difficult because often (1) the adults are not individually marked, (2) the colony is not visited daily, and (3) the investigator is unable to monitor all young until they fledge. If adults are unmarked and successful renesting occurs, reproductive success will be underestimated. If a colony is not visited daily and nests are initiated and lost between visits, reproductive success will be overestimated. The Mayfield method is one approach to overcoming this latter problem. Finally, nestling colonial birds are often able to move away from the nest site well before fledging and thus avoid being detected. To overcome this problem capture-recapture methods and enclosures have been used. In this paper we discuss these limitations and evaluate methods of dealing with them.

  14. Rebel girls? Unplanned pregnancy and colonialism in highlands Papua, Indonesia.

    PubMed

    Butt, Leslie; Munro, Jenny

    2007-01-01

    In highlands Papua, Indonesia, rapid social change under a colonial system of governance has created novel sexual opportunities for young indigenous women. Recent scholarship has viewed similar youthful sexual practices that challenge the status quo as expressions of personal agency. By looking at how young women and their families cope with unplanned pregnancies, we suggest that a more viable analytic approach would be to view sexuality, pregnancy and childbirth as a single unit of analysis. From this perspective, young women's experiences are primarily ones of constraint. Case studies offer insights into the ways a political context of colonial domination limits options and choices for young women who have children born out of wedlock. In particular, this paper describes how the 'settler gaze' - omnipresent colonial norms and judgments - creates regulatory effects in the realm of reproduction. PMID:17963098

  15. Effects of introducing foxes and raccoons on herring gull colonies

    USGS Publications Warehouse

    Kadlec, J.A.

    1971-01-01

    Red foxes (Vulpes fulva) and raccoons (Procyon lotor) released at colonies of herring gulls (Larus argentatus) on islands off the Massachusetts coast effectively eliminated the production of young gulls. Annual predator introductions for 2-4 years caused major reductions in colony size and occasionally total abandonment of the island as a colony site. Observations of the experimental islands for 2 years after cessation of predator introductions showed slow repopulation of the islands and lower breeding success than on control islands. The size of the regional population was reduced largely because of the movements of gulls off the experimental islands. The introduced predators are, in most cases, difficult to maintain on the islands; this restricts their utility in population management.

  16. Colony differences in response to trapping in roseate terns

    USGS Publications Warehouse

    Burger, J.; Nisbet, I.C.T.; Zingo, J.M.; Spendelow, J.A.; Safina, C.; Gochfeld, M.

    1995-01-01

    Both members of seabird pairs are normally required to fledge young. Seabirds that nest in sites accessible to predators usually have one parent in attendance during the egg/chick phase. Time devoted to foraging can vary with individual skill and age, prey availability and abundance (Seamy 1978), and distance to foraging grounds (Safina 1990). Although average skill of similar-aged individuals should not vary from colony to colony (Ryder 1980), prey availability and abundance, and spatial distribution of foraging grounds may vary. Thus, the percent of time both members of a pair are present at the nest site may vary in different colonies. In this paper, we examine parental behavior in response to trapping in Roseate Terns (Sterna dougallii) nesting in three of the six major colonies in the northeastern United States: Cedar Beach, New York, Falkner Island, Connecticut; and Bird Island, Massachusetts. Roseate Terns were listed on the United States? Endangered Species List in 1987. We were interested in differences among colonies in how often both parents were present, how soon a mate returned to the nest if one parent was temporarily removed, how soon a trapped bird returned to the nest after release, and the time during which the nest was left unguarded. We feel it is important to recognize and make management decisions based on colony differences where they exist. Our study follows directly from earlier work at Cedar Beach on trapping vulnerability of Common Terns (Sterna hirundo) and Roseate Terns. Nisbet reported that Roseate Terns at Bird Island required about three hours to return to the nest after trapping.

  17. 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.

  18. 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.

  19. Indigenous knowledge in the science curriculum: avoiding neo-colonialism

    NASA Astrophysics Data System (ADS)

    Ryan, Ann

    2008-09-01

    Science education in Papua New Guinea has been influenced by neo-colonial practices that have significantly contributed to the silencing of the Papua New Guinea voice. This silencing has led to the production of science curriculum documents that are irrelevant to the students for whom they are written. To avoid being caught up in neo-colonial practices, Western science educators ought to consider the notion of cultural mediators. This position, I argue, infers an obligation to take responsibility for their actions and to consider postcolonial discourses as a way of understanding the relationships and dialogue between different ways of knowing.

  20. Female immigrants and labor in colonial Malaya: 1860-1947.

    PubMed

    Lee, S M

    1989-01-01

    "The role of Chinese and Indian women as immigrants and workers in colonial Malaya is examined using data from censuses, immigration records, official reports and secondary sources. The article discusses the main types of work of female immigrants and their contribution to the economic development of colonial Malaya during the late nineteenth and early twentieth centuries in an attempt to redress the neglect of female immigrants' economic role in Malaya's history. Comparisons between male and female immigrants' labor and between Chinese and Indian immigrants, are drawn to highlight the different conditions of migration and labor for the different groups of immigrants." PMID:12315959

  1. Simulation study of bacterial colonies formed by the twitching motility: The effect of slingshot-like motions of bacteria on the colony edge

    NASA Astrophysics Data System (ADS)

    Morikawa, Ryota; Miyakawa, Takeshi; Tamakoshi, Masatada; Takasu, Masako

    2013-02-01

    Statistical properties and patterns of bacterial colony formed by the twitching motility are studied from the viewpoint of both computer simulations and experimental examinations. Models of four kinds of bacterial motion are proposed and the growing bacterial colonies due to the models are simulated by means of Monte Carlo method. Macroscopic patterns of the bacterial colonies and orientational order parameters of the bacteria are analyzed. By comparing the simulation results with the colony pattern formed by Thermus thermophilus, we suggest that wriggling edge of the colony is caused by slingshot-like motions of bacteria.

  2. Edges of human embryonic stem cell colonies display distinct mechanical properties and differentiation potential.

    PubMed

    Rosowski, Kathryn A; Mertz, Aaron F; Norcross, Samuel; Dufresne, Eric R; Horsley, Valerie

    2015-01-01

    In order to understand the mechanisms that guide cell fate decisions during early human development, we closely examined the differentiation process in adherent colonies of human embryonic stem cells (hESCs). Live imaging of the differentiation process reveals that cells on the outer edge of the undifferentiated colony begin to differentiate first and remain on the perimeter of the colony to eventually form a band of differentiation. Strikingly, this band is of constant width in all colonies, independent of their size. Cells at the edge of undifferentiated colonies show distinct actin organization, greater myosin activity and stronger traction forces compared to cells in the interior of the colony. Increasing the number of cells at the edge of colonies by plating small colonies can increase differentiation efficiency. Our results suggest that human developmental decisions are influenced by cellular environments and can be dictated by colony geometry of hESCs. PMID:26391588

  3. Edges of human embryonic stem cell colonies display distinct mechanical properties and differentiation potential

    PubMed Central

    Rosowski, Kathryn A.; Mertz, Aaron F.; Norcross, Samuel; Dufresne, Eric R.; Horsley, Valerie

    2015-01-01

    In order to understand the mechanisms that guide cell fate decisions during early human development, we closely examined the differentiation process in adherent colonies of human embryonic stem cells (hESCs). Live imaging of the differentiation process reveals that cells on the outer edge of the undifferentiated colony begin to differentiate first and remain on the perimeter of the colony to eventually form a band of differentiation. Strikingly, this band is of constant width in all colonies, independent of their size. Cells at the edge of undifferentiated colonies show distinct actin organization, greater myosin activity and stronger traction forces compared to cells in the interior of the colony. Increasing the number of cells at the edge of colonies by plating small colonies can increase differentiation efficiency. Our results suggest that human developmental decisions are influenced by cellular environments and can be dictated by colony geometry of hESCs. PMID:26391588

  4. Why join a neighbour: fitness consequences of colony fusions in termites.

    PubMed

    Korb, Judith; Roux, E A

    2012-11-01

    The evolution of life is characterized by major evolutionary transitions during which independent units cooperated and formed a new level of selection. Relatedness is a common mechanism that reduces conflict in such cooperative associations. One of the latest transitions is the evolution of social insect colonies. As expected, they are composed of kin and mechanisms have evolved that prevent the intrusion of nonrelatives. Yet, there are exceptions an extreme case is the fusion of unrelated colonies. What are the advantages of fusions that have colonies with a high potential for conflict as a consequence? Here, we investigated fitness costs and benefits of colony fusions in a lower termite species, Cryptotermes secundus, in which more than 25% of all colonies in the field are fused. We found two benefits of colony fusion depending on colony size: very small colonies had an increased probability of survival when they fused, yet for most colony sizes mainly a few workers profit from colony fusions as their chance to become reproductives increased. This individual benefit was often costly for other colony members: colony growth was reduced and the current reproductives had an increased chance of dying when fusions were aggressive. Our study suggests that fusion of colonies often is the result of 'selfish' worker interests to become reproductives, and this might have been important for the termites' social evolution. Our results uniquely shows that selfish interests among related colony members can lead to the formation of groups with increased potential for conflict among less related members. PMID:22998731

  5. Bumble bee colony dynamics: quantifying the importance of land use and floral resources for colony growth and queen production.

    PubMed

    Crone, Elizabeth E; Williams, Neal M

    2016-04-01

    Bumble bee (Bombus) species are ecologically and economically important pollinators, and many species are in decline. In this article, we develop a mechanistic model to analyse growth trajectories of Bombus vosnesenskii colonies in relation to floral resources and land use. Queen production increased with floral resources and was higher in semi-natural areas than on conventional farms. However, the most important parameter for queen production was the colony growth rate per flower, as opposed to the average number of available flowers. This result indicates the importance of understanding mechanisms of colony growth, in order to predict queen production and enhance bumble bee population viability. Our work highlights the importance of interpreting bumble bee conservation efforts in the context of overall population dynamics and provides a framework for doing so. PMID:26913696

  6. 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

  7. Isolation of a murine osteoclast colony-stimulating factor.

    PubMed Central

    Lee, M Y; Eyre, D R; Osborne, W R

    1991-01-01

    Cultures of a cell line derived from a murine mammary carcinoma that induces hypercalcemia were examined for soluble products that could induce osteoclasts to differentiate from murine bone marrow cells. The serum-free culture supernatant of this cell line stimulated growth of colonies from bone marrow cells that exhibited tartrate-resistant acid phosphatase (TRAPase) activity. These TRAPase-positive cells demonstrated essential features of osteoclasts when cultured with mineralized bone or dentin. The culture period required for colony development and the frequency of colony-forming cells indicated that relatively primitive marrow progenitors were stimulated by a tumor-derived factor(s) to form immature osteoclasts. Other colony-stimulating factors (CSFs), including granulocyte CSF, macrophage CSF, granulocyte-macrophage CSF and interleukin 3, were ruled out as the source of the activity produced by the tumor cells. The biological activity was successfully purified by gel filtration chromatography and reverse-phase HPLC. By SDS/PAGE, the activity was traced to a protein of approximately 17 kDa. Functional and biochemical studies of the purified factor suggest that it is distinct from any known CSF of myeloid cells. This protein appears to be a CSF for the osteoclast lineage, osteoclast CSF (O-CSF). Images PMID:1924309

  8. American Colonial Life as Experienced through Daniel Defoe's "Moll Flanders."

    ERIC Educational Resources Information Center

    Traubitz, Nancy

    1999-01-01

    Presents an interdisciplinary unit for high school students in which the students examine life in the American colonies. Focuses on "Moll Flanders" because the students find her to be a fascinating guide to the past, bringing history alive. Gives resources, a handout, and two timed writing assignments. (CMK)

  9. Female First Nations Chiefs and the Colonial Legacy in Canada

    ERIC Educational Resources Information Center

    Voyageur, Cora J.

    2011-01-01

    The social, economic, and political regulation of Canada's First Nations was codified in the Indian Act. Rooted in colonialism and paternalism, the Indian Act was created by the government of Canada to fulfill three functions: (1) to define who was and was not an Indian; (2) to civilize the Indian; and (3) to manage the Indian people and their…

  10. Converting insect colony waste into a potting susbstrate.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rearing insect generates both a solid and semisolid waste that is generally discarded in landfills. A study was initiated to determine if the semi-solid insect colony waste product and vermiculite used in insect rearing could be combined and used as a growth substrate for plants. The semi-solid larv...

  11. The View from the Veranda: Understanding Today's Colonial Student

    ERIC Educational Resources Information Center

    Ogden, Anthony

    2008-01-01

    Like the steady stream of colonial families of decades past traveling to their country's dominions abroad, contemporary education abroad students are similar passengers on a powerful steamship bound for lands of new sounds, sights and wonders. Although their studies may be challenging and demanding, students are exhilarated with thoughts of new…

  12. Surrendering a Colonial Domain: Educating North India, 1854-1890

    ERIC Educational Resources Information Center

    Allender, Tim

    2007-01-01

    Postcolonial research has often assumed that colonial education fell victim to the forces of nationalism, like other areas of Raj governance in the early twentieth century. However, European-led education that aspired to reach the general population had already failed a generation earlier, at least in north India. This was after highly imaginative…

  13. The Primary School Curriculum in a Colonial Society

    ERIC Educational Resources Information Center

    Bacus, M. Kazim

    1974-01-01

    A history of primary school curriculum in Guyana, a former British colony, points out social determinates of curriculum. Ruling groups emphasized agriculture and manual arts in public education to maintain class distinctions while the masses fought for academic education as a key to financial and social success. (JH)

  14. 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.

  15. Assessment of density in enriched colony cages: Egg quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Enriched colony cage production systems are becoming more prevalent in the US. A study was undertaken to determine the impact of housing density on hen health, well-being, egg production and quality. Six densities were examined with 8 housing replicates per density. Egg quality was assessed at hen a...

  16. Female First Nations Chiefs and the Colonial Legacy in Canada

    ERIC Educational Resources Information Center

    Voyageur, Cora J.

    2011-01-01

    The social, economic, and political regulation of Canada's First Nations was codified in the Indian Act. Rooted in colonialism and paternalism, the Indian Act was created by the government of Canada to fulfill three functions: (1) to define who was and was not an Indian; (2) to civilize the Indian; and (3) to manage the Indian people and their…

  17. Recent Literature on Slavery in Colonial North America.

    ERIC Educational Resources Information Center

    Wright, Donald R.

    2003-01-01

    Provides a review of literature published on slavery in colonial North America, focusing on how this literature has changed over the years. Includes literature in topical areas, such as the Atlantic slave trade, African American culture, and race. Includes a bibliography. (CMK)

  18. Microsatellite loci for the invasive colonial hydrozoan Cordylophora caspia

    EPA Science Inventory

    Cordylophora caspia, a colonial hydrozoan native to the Ponto-Caspian region, has become a common invader of both fresh and brackish water ecosystems of North America and Europe. Here we describe 11 polymorphic microsatellite loci for this species. Preliminary analyses indicate ...

  19. Existential Thoughts in Fanon's Post-Colonialism Discourse

    ERIC Educational Resources Information Center

    Yeh, Chuan-Rong

    2013-01-01

    Frantz Fanon, a pioneer of post-colonial theory, attempted to seek some unbeknown possibilities through a Sartrean existentialism thought toward ethnic liberation and the fighting against imperialism. This article tries to enter Fanon's short life that was full of humanism and existentialist thought and to explore the hidden theoretical context…

  20. Colony forming cell assays for human hematopoietic progenitor cells.

    PubMed

    Wognum, Bert; Yuan, Ning; Lai, Becky; Miller, Cindy L

    2013-01-01

    Hematopoietic stem cells (HSCs) present in small numbers in adult bone marrow (BM), peripheral blood (PB) and umbilical cord blood (CB) produce a heterogeneous pool of progenitors that can be detected in vitro using colony forming cell (CFC) assays. Hematopoietic progenitor cells proliferate and differentiate to produce colonies of maturing cells when cultured in a semisolid methylcellulose-based medium that is supplemented with suitable growth factors and other supplements. The colonies are then classified and enumerated in situ by light microscopy or an automated imaging instrument. CFC assays are important tools in basic hematology research but are also used by clinical cell processing laboratories to measure the progenitor cell content of BM, CB and mobilized PB (MPB) preparations used for cell transplantation. Standard CFC assays for human progenitor cells require a culture period of at least 14 days to enable optimal outgrowth and differentiation of the maximum number of CFCs in a cell preparation. In this chapter protocols are described for the detection and enumeration of myeloid multipotential progenitors and committed progenitors of the erythroid, monocyte, and granulocyte lineages in samples from human PB, MPB, BM, and CB. In addition protocols are described for a modified version of the CFC-assay that allows accurate enumeration of total CFC numbers in CB or MPB after a culture period of only 7 days, but without distinction of colony types. PMID:23179838

  1. Ezekiel Cheever (1614-1708), New England Colonial Teacher.

    ERIC Educational Resources Information Center

    Parker, Franklin; Parker, Betty J.

    This paper narrates the life of Ezekiel Cheever, the most famous colonial New England Latin grammar teacher of his time. Cheever came from middle class Puritan roots in England, receiving a classical education before emigrating to Boston (Massachusetts). His remarkably long teaching career of 70 years in four New England towns and the esteem shown…

  2. 21 CFR 866.2170 - Automated colony counter.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Automated colony counter. 866.2170 Section 866.2170 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2170 Automated...

  3. 21 CFR 866.2170 - Automated colony counter.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Automated colony counter. 866.2170 Section 866.2170 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2170 Automated...

  4. 21 CFR 866.2170 - Automated colony counter.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Automated colony counter. 866.2170 Section 866.2170 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2170 Automated...

  5. From Savage to Citizen: Education, Colonialism and Idiocy

    ERIC Educational Resources Information Center

    Simpson, Murray K.

    2007-01-01

    In constructing a framework for the participation and inclusion in political life of subjects, the Enlightenment also produced a series of systematic exclusions for those who did not qualify: including "idiots" and "primitive races". "Idiocy" emerged as part of wider strategies of governance in Europe and its colonies. This opened up the…

  6. Pilgrims: A Simulation of the First Year at Plymouth Colony.

    ERIC Educational Resources Information Center

    Flint, Myron

    This simulation allows students to learn about the struggle of daily life in Plymouth Colony. Students experience the hardships of life in the New World as they make decisions and face consequences as the Pilgrims did nearly 400 years ago. The unit is divided into nine phases with each phase taking approximately one hour of class time. Students…

  7. Urban Economics, Conduit-Colonialism and Public Policy

    ERIC Educational Resources Information Center

    Hamilton, Charles V.

    1972-01-01

    Considerable amounts of money already come into the cities and the black communities, but go right out as payments to absentee landlords, exploitative merchants, credit gougers, and loan sharks, as well as in support of the colonial management system. (Author/JM)

  8. Outbreaks of Pneumocystis carinii pneumonia in colonies of immunodeficient mice.

    PubMed Central

    Walzer, P D; Kim, C K; Linke, M J; Pogue, C L; Huerkamp, M J; Chrisp, C E; Lerro, A V; Wixson, S K; Hall, E; Shultz, L D

    1989-01-01

    Outbreaks of Pneumocystis carinii pneumonia occurred in colonies of nu/nu and scid/scid mice at four different institutions. The disease, which was characterized by chronic wasting and respiratory insufficiency, was more severe in older mice and in animals housed in cages with special protective tops. Histopathologic features included alveolar filling with the typical foamy honeycomb material and a mild, nonspecific host inflammatory response. Immunofluorescence and immunoblotting studies suggested the P. carinii isolate was of mouse rather than of rat or human origin, and the outbreaks could be related to each other by common vendor or source of breeding animals. Once P. carinii became established in a mouse colony, the organism tended to persist for long periods of time. The principal control measure was depopulation of the colony, although limited experience with the administration of trimethoprim-sulfamethoxazole was encouraging. Thus, outbreaks of pneumocystosis are a serious problem among colonies of immunodeficient mice, with important implications for the use of these animals in biomedical research. Data obtained by studying these outbreaks should enhance understanding of the pathogenesis of P. carinii pneumonia and be helpful in formulating improved methods of detection and control. Images PMID:2642471

  9. The Transatlantic Slave Trade and Colonial Chesapeake Slavery.

    ERIC Educational Resources Information Center

    Walsh, Lorena S.

    2003-01-01

    Explores the slave trade system that brought slaves to the Chesapeake Bay area during the eighteenth century colonial United States. Uses information from the "Trans-Atlantic Slave Trade: A Database on CD-ROM" to examine slave routes. Provides information on the origins and distribution of slaves in the Chesapeake Bay region and the experiences of…

  10. Making Thirteen Colonies. A History of US. Book Two.

    ERIC Educational Resources Information Center

    Hakim, Joy

    This history volume traces the development of the American colonies from the arrival of the first English settlers in North America to the establishment of the United States and the beginning of the westward expansion. The profusely illustrated text includes sidebars elaborating upon significant points. Maps help students locate and visualize…

  11. Honeybee Colony Vibrational Measurements to Highlight the Brood Cycle.

    PubMed

    Bencsik, Martin; Le Conte, Yves; Reyes, Maritza; Pioz, Maryline; Whittaker, David; Crauser, Didier; Simon Delso, Noa; Newton, Michael I

    2015-01-01

    Insect pollination is of great importance to crop production worldwide and honey bees are amongst its chief facilitators. Because of the decline of managed colonies, the use of sensor technology is growing in popularity and it is of interest to develop new methods which can more accurately and less invasively assess honey bee colony status. Our approach is to use accelerometers to measure vibrations in order to provide information on colony activity and development. The accelerometers provide amplitude and frequency information which is recorded every three minutes and analysed for night time only. Vibrational data were validated by comparison to visual inspection data, particularly the brood development. We show a strong correlation between vibrational amplitude data and the brood cycle in the vicinity of the sensor. We have further explored the minimum data that is required, when frequency information is also included, to accurately predict the current point in the brood cycle. Such a technique should enable beekeepers to reduce the frequency with which visual inspections are required, reducing the stress this places on the colony and saving the beekeeper time. PMID:26580393

  12. Massive diversification in aging colonies of Escherichia coli.

    PubMed

    Saint-Ruf, Claude; Garfa-Traoré, Meriem; Collin, Valérie; Cordier, Corinne; Franceschi, Christine; Matic, Ivan

    2014-09-01

    The evolutionary success of bacteria depends greatly on their capacity to continually generate phenotypic diversity. Structured environments are particularly favorable for diversification because of attenuated clonal interference, which renders selective sweeps nearly impossible and enhances opportunities for adaptive radiation. We examined at the microscale level the emergence and the spatial and temporal dynamics of phenotypic diversity and their underlying causes in Escherichia coli colonies. An important dynamic heterogeneity in the growth, metabolic activity, morphology, gene expression patterns, stress response induction, and death patterns among cells within colonies was observed. Genetic analysis indicated that the phenotypic variation resulted mostly from mutations and that indole production, oxidative stress, and the RpoS-regulated general stress response played an important role in the generation of diversity. We observed the emergence and persistence of phenotypic variants within single colonies that exhibited variable fitness compared to the parental strain. Some variants showed improved capacity to produce biofilms, whereas others were able to use different nutrients or to tolerate antibiotics or oxidative stress. Taken together, our data show that bacterial colonies provide an ecological opportunity for the generation and maintenance of vast phenotypic diversity, which may increase the probability of population survival in unpredictable environments. PMID:24982303

  13. The colony environment modulates sleep in honey bee workers.

    PubMed

    Eban-Rothschild, Ada; Bloch, Guy

    2015-02-01

    One of the most important and evolutionarily conserved roles of sleep is the processing and consolidation of information acquired during wakefulness. In both insects and mammals, environmental and social stimuli can modify sleep physiology and behavior, yet relatively little is known about the specifics of the wake experiences and their relative contribution to experience-dependent modulation of sleep. Honey bees provide an excellent model system in this regard because their behavioral repertoire is well characterized and the environment they experience during the day can be manipulated while keeping an ecologically and sociobiologically relevant context. We examined whether social experience modulates sleep in honey bees, and evaluated the relative contribution of different social signals. We exposed newly emerged bees to different components of their natural social environment and then monitored their sleep behavior in individual cages in a constant lab environment. We found that rich waking experience modulates subsequent sleep. Bees that experienced the colony environment for 1 or 2 days slept more than same-age sister bees that were caged individually or in small groups in the lab. Furthermore, bees placed in mesh-enclosures in the colony, that prevented direct contact with nestmates, slept similarly to bees freely moving in the colony. These results suggest that social signals that do not require direct or close distance interactions between bees are sufficiently rich to encompass almost the entire effect of the colony on sleep. Our findings provide a remarkable example of social experience-dependent modulation of an essential biological process. PMID:25524987

  14. The Transatlantic Slave Trade and Colonial Chesapeake Slavery.

    ERIC Educational Resources Information Center

    Walsh, Lorena S.

    2003-01-01

    Explores the slave trade system that brought slaves to the Chesapeake Bay area during the eighteenth century colonial United States. Uses information from the "Trans-Atlantic Slave Trade: A Database on CD-ROM" to examine slave routes. Provides information on the origins and distribution of slaves in the Chesapeake Bay region and the experiences of…

  15. 6. AERIAL OBLIQUE FROM EAST, SHOWING QUONSET POINT SUMMER COLONY ...

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

    6. AERIAL OBLIQUE FROM EAST, SHOWING QUONSET POINT SUMMER COLONY IN FOREGROUND, NEUTRALITY PATROL HANGAR (BLDG. 2) ON LEFT, RHODE ISLAND NATIONAL GUARD FACILITIES IN CENTER. NATIONAL GUARD DISPENSARY SURVIVES AS BLDG. 435. USN PHOTO, C. MARCH, 1940. - Quonset Point Naval Air Station, Roger Williams Way, North Kingstown, Washington County, RI

  16. Women's Educational Experience under Colonialism: Toward a Diachronic Model.

    ERIC Educational Resources Information Center

    Barthel, Diane

    1985-01-01

    Introduces a three-stage historical model of female education in Africa during and since the colonial period. Suggests an historical tendency to educate only males, then an attempt to educate a limited number of females for "modern" roles. Contemporary situation presents educational opportunities for more women, but with subtle sexism from earlier…

  17. Massive Diversification in Aging Colonies of Escherichia coli

    PubMed Central

    Saint-Ruf, Claude; Garfa-Traoré, Meriem; Collin, Valérie; Cordier, Corinne; Franceschi, Christine

    2014-01-01

    The evolutionary success of bacteria depends greatly on their capacity to continually generate phenotypic diversity. Structured environments are particularly favorable for diversification because of attenuated clonal interference, which renders selective sweeps nearly impossible and enhances opportunities for adaptive radiation. We examined at the microscale level the emergence and the spatial and temporal dynamics of phenotypic diversity and their underlying causes in Escherichia coli colonies. An important dynamic heterogeneity in the growth, metabolic activity, morphology, gene expression patterns, stress response induction, and death patterns among cells within colonies was observed. Genetic analysis indicated that the phenotypic variation resulted mostly from mutations and that indole production, oxidative stress, and the RpoS-regulated general stress response played an important role in the generation of diversity. We observed the emergence and persistence of phenotypic variants within single colonies that exhibited variable fitness compared to the parental strain. Some variants showed improved capacity to produce biofilms, whereas others were able to use different nutrients or to tolerate antibiotics or oxidative stress. Taken together, our data show that bacterial colonies provide an ecological opportunity for the generation and maintenance of vast phenotypic diversity, which may increase the probability of population survival in unpredictable environments. PMID:24982303

  18. Art Education in Colonial India: Implementation and Imposition

    ERIC Educational Resources Information Center

    Kantawala, Ami

    2012-01-01

    Historical inquiry in art education forms the basis of any research undertaken in the field. It is on this path that we discover ignored moments and personalities and clarify challenging ideas, thus approaching history from multiple perspectives. This historical study attempts to reframe the past of colonial Indian art education within the broader…

  19. Ectoparasitism shortens the breeding season in a colonial bird

    PubMed Central

    Brown, Charles R.; Brown, Mary Bomberger

    2015-01-01

    When blood-feeding parasites increase seasonally, their deleterious effects may prevent some host species, especially those living in large groups where parasites are numerous, from reproducing later in the summer. Yet the role of parasites in regulating the length of a host's breeding season—and thus the host's opportunity for multiple brooding—has not been systematically investigated. The highly colonial cliff swallow (Petrochelidon pyrrhonota), a temperate-latitude migratory songbird in the western Great Plains, USA, typically has a relatively short (eight to nine week) breeding season, with birds rarely nesting late in the summer. Colonies at which ectoparasitic swallow bugs (Oeciacus vicarius) were experimentally removed by fumigation were over 45 times more likely to have birds undertake a second round of nesting than were colonies exposed to parasites. Late nesting approximately doubled the length of the breeding season, with some birds raising two broods. Over a 27 year period the percentage of birds engaging in late nesting each year increased at a colony site where parasites were removed annually. This trend could not be explained by changes in group size, climate or nesting phenology during the study. The results suggest that ectoparasitism shortens the cliff swallow's breeding season and probably prevents many individuals from multiple brooding. When this constraint is removed, selection may rapidly favour late nesting. PMID:26064606

  20. 21 CFR 866.2170 - Automated colony counter.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Automated colony counter. 866.2170 Section 866.2170 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2170 Automated...

  1. 21 CFR 866.2170 - Automated colony counter.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Automated colony counter. 866.2170 Section 866.2170 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2170 Automated...

  2. The Heritage of Mexico. Volume 2: The Colonial Period.

    ERIC Educational Resources Information Center

    Burton, Paul C.

    The colonial period in Mexican history, from 1519 to the Revolution of 1910, is the subject of the second in a series of three bilingual (Spanish-English) books designed to aid teachers in presenting the historical and cultural background of the Mexican people. The series, which lends itself to the Inquiry Method of teaching, includes illustrated…

  3. [Landscape influence on the Grey Herons colonies distribution].

    PubMed

    Boisteau, Benjamin; Marion, Loïc

    2006-03-01

    We analysed the spatial relationship between the location and the size of the 112 grey heron colonies existing in 1994 in the two refuge areas after their decline of the species in the 19th century in France: South Brittany (Loire-Atlantique and Morbihan), and eastern France (Haute-Saône, Saône-et-Loire, Meurthe-et-Moselle, Vosges). We tested 35 variables describing the hydrographical network surrounding the colonies from a local to a regional scale using a Geographic Information System. The results show that, whatever the scale, the distribution of the breeding colonies was not governed by the same elements of the hydrographical network in the different areas. Two strategies of spatial utilization were observed between the western and the eastern parts of France. Moreover, two quite distinct situations were also distinguished between Morbihan and Loire-Atlantique. This study stresses that the type and the spatial organization of the hydrographical elements, but also of the history of the populations, are important in the distribution of the Grey Heron colonies. PMID:16545763

  4. Genetic Stock Identification Of Production Colonies Of Russian Honey Bees

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The prevalence of Nosema ceranae in managed honey bee colonies has increased dramatically in the past 10 – 20 years worldwide. A variety of genetic testing methods for species identification and prevalence are now available. However sample size and preservation method of samples prior to testing hav...

  5. Existential Thoughts in Fanon's Post-Colonialism Discourse

    ERIC Educational Resources Information Center

    Yeh, Chuan-Rong

    2013-01-01

    Frantz Fanon, a pioneer of post-colonial theory, attempted to seek some unbeknown possibilities through a Sartrean existentialism thought toward ethnic liberation and the fighting against imperialism. This article tries to enter Fanon's short life that was full of humanism and existentialist thought and to explore the hidden theoretical context…

  6. Reliving Colonial Days in Your Classroom. Curriculum Boosters. Social Studies.

    ERIC Educational Resources Information Center

    Hennessey, Gail Skroback

    1994-01-01

    The article presents hands-on classroom projects to teach elementary students about colonial American history. Students make their own natural dyes, cook blueberry slump, and play cup-and-ball the way the colonists did. The activities integrate science, math, history, art, and language arts. (SM)

  7. Mass Spectral Molecular Networking of Living Microbial Colonies

    SciTech Connect

    Watrous, Jeramie D.; Roach, Patrick J.; Alexandrov, Theodore; Heath, Brandi S.; Yang, Jane Y.; Kersten, Roland; vander Voort, Menno; Pogliano, Kit; Gross, Harald; Raaijmakers, Jos M.; Moore, Bradley S.; Laskin, Julia; Bandeira, Nuno; Dorrestein, Pieter C.

    2012-06-26

    Integrating the governing chemistry with the genomics and phenotypes of microbial colonies has been a "holy grail" in microbiology. This work describes a highly sensitive, broadly applicable, and costeffective approach that allows metabolic profiling of live microbial colonies directly from a Petri dish without any sample preparation. Nanospray desorption electrospray ionization mass spectrometry (MS), combined with alignment of MS data and molecular networking, enabled monitoring of metabolite production from live microbial colonies from diverse bacterial genera, including Bacillus subtilis, Streptomyces coelicolor, Mycobacterium smegmatis, and Pseudomonas aeruginosa. This work demonstrates that, by using these tools to visualize small molecular changes within bacterial interactions, insights can be gained into bacterial developmental processes as a result of the improved organization of MS/MS data. To validate this experimental platform, metabolic profiling was performed on Pseudomonas sp. SH-C52, which protects sugar beet plants from infections by specific soil-borne fungi [R. Mendes et al. (2011) Science 332:1097–1100]. The antifungal effect of strain SHC52 was attributed to thanamycin, a predicted lipopeptide encoded by a nonribosomal peptide synthetase gene cluster. Our technology, in combination with our recently developed peptidogenomics strategy, enabled the detection and partial characterization of thanamycin and showed that it is amonochlorinated lipopeptide that belongs to the syringomycin family of antifungal agents. In conclusion, the platform presented here provides a significant advancement in our ability to understand the spatiotemporal dynamics of metabolite production in live microbial colonies and communities.

  8. Colonial Broadsides: A Student-Created Play. [Lesson Plan].

    ERIC Educational Resources Information Center

    2002

    "Broadsides" are notices written on disposable, single sheets of paper printed on one side only, intended to have an immediate impact on readers. Broadsides had an impact in colonial America--they delivered the latest news and much more: government proclamations, public service announcements, opinion papers, advertisements, and entertainment…

  9. Isolation of a murine osteoclast colony-stimulating factor

    SciTech Connect

    Lee, M.Y.; Eyre, D.R.; Osborne, W.R.A. )

    1991-10-01

    Cultures of a cell line derived from a murine mammary carcinoma that induces hypercalcemia were examined for soluble products that could induce osteoclasts to differentiate from murine bone marrow cells. The serum-free culture supernatant of this cell line stimulated growth of colonies from bone marrow cells that exhibited tartrate-resistant acid phosphatase (TRAPase) activity. These TRAPase-positive cells demonstrated essential features of osteoclasts when cocultured with mineralized bone or dentin. The culture period required for colony development and the frequency of colony-forming cells indicated that relatively primitive marrow progenitors were stimulated by a tumor-derived factor(s) to form immature osteoclasts. Other colony-stimulating factors (CSFs), including granulocyte CSF, macrophage CSF, granulocyte-macrophase CSF and interleukin 3, were ruled out as the source of the activity produced by the tumor cells. The biological activity was successfully purified by gel filtration chromatography and reverse-phase HPLC. By SDS/PAGE, the activity was traced to a protein of {approx}17 kDa. Functional and biochemical studies of the purified factor suggest that it is distinct from any known CSF of myeloid cells. This protein appears to be a CSF for the osteoclast lineage, osteoclast CSF (O-CSF).

  10. Generating thermotolerant colonies by pairing Beauveria bassiana isolates.

    PubMed

    Kim, Jae Su; Skinner, Margaret; Gouli, Svetlana; Parker, Bruce L

    2011-11-01

    Low thermotolerance in entomopathogenic fungi is the main impediment to their industrialization. This research, for the first time, describes the generation of a thermotolerant colony by pairing and subculturing (cycling) two Beauveria bassiana isolates without sexual reproduction. A mixture of B. bassiana ERL1578 and ERL1576 was inoculated on quarter-strength Sabouraud dextrose agar with yeast extract (¼SDAY). The paired culture (ERL1578 + 1576) was cycled three times to increase the frequency of possible hyphal fusion at the first cycle (c. 5/5 × 10(5) conidia), followed by a heat treatment as a selection pressure. Two non-paired isolates served as controls. Two morphologically different colonies (BbHet1 and BbHet2) were isolated from the pairing. BbHet1 colony had the highest conidial yield. BbHet2 had the most rapid mycelial growth and produced sponge-like mycelial masses (the others were flat), and its conidia were darker than the non-paired colonies under a microscope (400×). BbHet2 conidia had 60.7% germination after exposure to 45 °C for 60 min (the others had < 15%) without significant loss of virulence against Western flower thrips, Frankliniella occidentalis; however, there was a slight decrease in conidial yield. The new phenotypes formed suggested that a genetic variation happened as a result of heterokaryosis and/or recombination, more than environmental adaptation, when mixing different conidia. This methodology seems to be very useful for enhancing thermotolerance in fungi. PMID:22092818

  11. Interrelationships between Colonies, Biofilms, and Planktonic Cells of Pseudomonas aeruginosa? †

    PubMed Central

    Mikkelsen, H.; Duck, Z.; Lilley, K. S.; Welch, M.

    2007-01-01

    Pseudomonas aeruginosa is a gram-negative bacterium and an opportunistic human pathogen that causes chronic infections in immunocompromised individuals. These infections are hard to treat, partly due to the high intrinsic resistance of the bacterium to clinically used antibiotics and partly due to the formation of antibiotic-tolerant biofilms. The three most common ways of growing bacteria in vitro are as planktonic cultures, colonies on agar plates, and biofilms in continuous-flow systems. Biofilms are known to express genes different from those of planktonic cells, and biofilm cells are generally believed to closely resemble planktonic cells in stationary phase. However, few, if any, studies have examined global gene expression in colonies. We used a proteomic approach to investigate the interrelationships between planktonic cells, colonies, and biofilms under comparable conditions. Our results show that protein profiles in colonies resemble those of planktonic cells. Furthermore, contrary to what has been reported previously, the protein profiles of biofilms were found to more closely resemble those of exponentially growing planktonic cells than those of planktonic cells in the stationary phase. These findings raise some intriguing questions about the true nature of biofilms. PMID:17220232

  12. Honeybee Colony Vibrational Measurements to Highlight the Brood Cycle

    PubMed Central

    Bencsik, Martin; Le Conte, Yves; Reyes, Maritza; Pioz, Maryline; Whittaker, David; Crauser, Didier; Simon Delso, Noa; Newton, Michael I.

    2015-01-01

    Insect pollination is of great importance to crop production worldwide and honey bees are amongst its chief facilitators. Because of the decline of managed colonies, the use of sensor technology is growing in popularity and it is of interest to develop new methods which can more accurately and less invasively assess honey bee colony status. Our approach is to use accelerometers to measure vibrations in order to provide information on colony activity and development. The accelerometers provide amplitude and frequency information which is recorded every three minutes and analysed for night time only. Vibrational data were validated by comparison to visual inspection data, particularly the brood development. We show a strong correlation between vibrational amplitude data and the brood cycle in the vicinity of the sensor. We have further explored the minimum data that is required, when frequency information is also included, to accurately predict the current point in the brood cycle. Such a technique should enable beekeepers to reduce the frequency with which visual inspections are required, reducing the stress this places on the colony and saving the beekeeper time. PMID:26580393

  13. View looking southeast (generally) to causeway leading from the Colonial ...

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

    View looking southeast (generally) to causeway leading from the Colonial House to the Practice House; note causeway enters to the east of the portico and curved parapet pictured belongs to the power plant - National Park Seminary, Chateau Causeways, Between Linden Lane & Beach Drive, Silver Spring, Montgomery County, MD

  14. Across the Colonial Divide: Conversations about Evaluation in Indigenous Contexts

    ERIC Educational Resources Information Center

    Cavino, Hayley Marama

    2013-01-01

    This essay engages questions of evaluator role and indigenous peoples participation in evaluation within colonial and decolonization contexts. Specifically, I critique the Western emphasis on cultural competence and contrast the utility of "mainstream" evaluation approaches alongside three indigenous inquiry models (Te Kotahitanga,…

  15. Host specificity and colony impacts of Solenopsis invicta virus 3

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A thorough understanding of host specificity is essential before pathogens can be used as biopesticides or self-sustaining biocontrol agents. In order to define the host range of the recently discovered Solenopsis invicta virus 3 (SINV-3), we exposed colonies of 19 species of ants in 14 different g...

  16. Sudden deaths and colony population decline in Greek honey bee colonies.

    PubMed

    Bacandritsos, N; Granato, A; Budge, G; Papanastasiou, I; Roinioti, E; Caldon, M; Falcaro, C; Gallina, A; Mutinelli, F

    2010-11-01

    During June and July of 2009, sudden deaths, tremulous movements and population declines of adult honey bees were reported by the beekeepers in the region of Peloponnesus (Mt. Mainalo), Greece. A preliminary study was carried out to investigate these unexplained phenomena in this region. In total, 37 bee samples, two brood frames containing honey bee brood of various ages, eight sugar samples and four sugar patties were collected from the affected colonies. The samples were tested for a range of pests, pathogens and pesticides. Symptomatic adult honey bees tested positive for Varroa destructor, Nosema ceranae, Chronic bee paralysis virus (CBPV), Acute paralysis virus (ABPV), Deformed wing virus (DWV), Sacbrood virus (SBV) and Black queen cell virus (BQCV), but negative for Acarapis woodi. American Foulbrood was absent from the brood samples. Chemical analysis revealed that amitraz, thiametoxan, clothianidin and acetamiprid were all absent from symptomatic adult bees, sugar and sugar patty samples. However, some bee samples, were contaminated with imidacloprid in concentrations between 14 ng/g and 39 ng/g tissue. We present: the infection of Greek honey bees by multiple viruses; the presence of N. ceranae in Greek honey bees and the first record of imidacloprid (neonicotonoid) residues in Greek honey bee tissues. The presence of multiple pathogens and pesticides made it difficult to associate a single specific cause to the depopulation phenomena observed in Greece, although we believe that viruses and N. ceranae synergistically played the most important role. A follow-up in-depth survey across all Greek regions is required to provide context to these preliminary findings. PMID:20804765

  17. FluG affects secretion in colonies of Aspergillus niger.

    PubMed

    Wang, Fengfeng; Krijgsheld, Pauline; Hulsman, Marc; de Bekker, Charissa; Müller, Wally H; Reinders, Marcel; de Vries, Ronald P; Wösten, Han A B

    2015-01-01

    Colonies of Aspergillus niger are characterized by zonal heterogeneity in growth, sporulation, gene expression and secretion. For instance, the glucoamylase gene glaA is more highly expressed at the periphery of colonies when compared to the center. As a consequence, its encoded protein GlaA is mainly secreted at the outer part of the colony. Here, multiple copies of amyR were introduced in A. niger. Most transformants over-expressing this regulatory gene of amylolytic genes still displayed heterogeneous glaA expression and GlaA secretion. However, heterogeneity was abolished in transformant UU-A001.13 by expressing glaA and secreting GlaA throughout the mycelium. Sequencing the genome of UU-A001.13 revealed that transformation had been accompanied by deletion of part of the fluG gene and disrupting its 3' end by integration of a transformation vector. Inactivation of fluG in the wild-type background of A. niger also resulted in breakdown of starch under the whole colony. Asexual development of the ?fluG strain was not affected, unlike what was previously shown in Aspergillus nidulans. Genes encoding proteins with a signal sequence for secretion, including part of the amylolytic genes, were more often downregulated in the central zone of maltose-grown ?fluG colonies and upregulated in the intermediate part and periphery when compared to the wild-type. Together, these data indicate that FluG of A. niger is a repressor of secretion. PMID:25370014

  18. The global distribution of ammonia emissions from seabird colonies

    NASA Astrophysics Data System (ADS)

    Riddick, S. N.; Dragosits, U.; Blackall, T. D.; Daunt, F.; Wanless, S.; Sutton, M. A.

    2012-08-01

    Seabird colonies represent a significant source of atmospheric ammonia (NH3) in remote maritime systems, producing a source of nitrogen that may encourage plant growth, alter terrestrial plant community composition and affect the surrounding marine ecosystem. To investigate seabird NH3 emissions on a global scale, we developed a contemporary seabird database including a total seabird population of 261 million breeding pairs. We used this in conjunction with a bioenergetics model to estimate the mass of nitrogen excreted by all seabirds at each breeding colony. The results combined with the findings of mid-latitude field studies of volatilization rates estimate the global distribution of NH3 emissions from seabird colonies on an annual basis. The largest uncertainty in our emission estimate concerns the potential temperature dependence of NH3 emission. To investigate this we calculated and compared temperature independent emission estimates with a maximum feasible temperature dependent emission, based on the thermodynamic dissociation and solubility equilibria. Using the temperature independent approach, we estimate global NH3 emissions from seabird colonies at 404 Gg NH3 per year. By comparison, since most seabirds are located in relatively cold circumpolar locations, the thermodynamically dependent estimate is 136 Gg NH3 per year. Actual global emissions are expected to be within these bounds, as other factors, such as non-linear interactions with water availability and surface infiltration, moderate the theoretical temperature response. Combining sources of error from temperature (±49%), seabird population estimates (±36%), variation in diet composition (±23%) and non-breeder attendance (±13%), gives a mid estimate with an overall uncertainty range of NH3 emission from seabird colonies of 270 [97-442] Gg NH3 per year. These emissions are environmentally relevant as they primarily occur as "hot-spots" in otherwise pristine environments with low anthropogenic emissions.

  19. Ant Larval Demand Reduces Aphid Colony Growth Rates in an Ant-Aphid Interactio

    PubMed Central

    Oliver, Tom H.; Leather, Simon R.; Cook, James M.

    2012-01-01

    Ants often form mutualistic interactions with aphids, soliciting honeydew in return for protective services. Under certain circumstances, however, ants will prey upon aphids. In addition, in the presence of ants aphids may increase the quantity or quality of honeydew produced, which is costly. Through these mechanisms, ant attendance can reduce aphid colony growth rates. However, it is unknown whether demand from within the ant colony can affect the ant-aphid interaction. In a factorial experiment, we tested whether the presence of larvae in Lasius niger ant colonies affected the growth rate of Aphis fabae colonies. Other explanatory variables tested were the origin of ant colonies (two separate colonies were used) and previous diet (sugar only or sugar and protein). We found that the presence of larvae in the ant colony significantly reduced the growth rate of aphid colonies. Previous diet and colony origin did not affect aphid colony growth rates. Our results suggest that ant colonies balance the flow of two separate resources from aphid colonies- renewable sugars or a protein-rich meal, depending on demand from ant larvae within the nest. Aphid payoffs from the ant-aphid interaction may change on a seasonal basis, as the demand from larvae within the ant colony waxes and wanes. PMID:26467951

  20. Ant Larval Demand Reduces Aphid Colony Growth Rates in an Ant-Aphid Interaction.

    PubMed

    Oliver, Tom H; Leather, Simon R; Cook, James M

    2012-01-01

    Ants often form mutualistic interactions with aphids, soliciting honeydew in return for protective services. Under certain circumstances, however, ants will prey upon aphids. In addition, in the presence of ants aphids may increase the quantity or quality of honeydew produced, which is costly. Through these mechanisms, ant attendance can reduce aphid colony growth rates. However, it is unknown whether demand from within the ant colony can affect the ant-aphid interaction. In a factorial experiment, we tested whether the presence of larvae in Lasius niger ant colonies affected the growth rate of Aphis fabae colonies. Other explanatory variables tested were the origin of ant colonies (two separate colonies were used) and previous diet (sugar only or sugar and protein). We found that the presence of larvae in the ant colony significantly reduced the growth rate of aphid colonies. Previous diet and colony origin did not affect aphid colony growth rates. Our results suggest that ant colonies balance the flow of two separate resources from aphid colonies- renewable sugars or a protein-rich meal, depending on demand from ant larvae within the nest. Aphid payoffs from the ant-aphid interaction may change on a seasonal basis, as the demand from larvae within the ant colony waxes and wanes. PMID:26467951

  1. Derivation of guidelines for uranium residual radioactive material in soil at the Colonie Site, Colonie, New York

    SciTech Connect

    Dunning, D.

    1996-05-01

    Residual radioactive material guidelines for uranium in soil were derived for the Colonie site located in Colonie, New York. This site has been designated for remedial action under the Formerly Utilized Sites Remedial Action Program (FUSRAP) of the U.S. Department of Energy (DOE). The site became contaminated with radioactive material as a result of operations conducted by National Lead (NL) Industries from 1958 to 1984; these activities included brass foundry operations, electroplating of metal products, machining of various components using depleted uranium, and limited work with small amounts of enriched uranium and thorium. The Colonie site comprises the former NL Industries property, now designated the Colonie Interim Storage Site (CISS), and 56 vicinity properties contaminated by fallout from airborne emissions; 53 of the vicinity properties were previously remediated between 1984 and 1988. In 1984, DOE accepted ownership of the CISS property from NL Industries. Residual radioactive material guidelines for individual radionuclides and total uranium were derived on the basis of the requirement that the 50-year committed effective dose equivalent to a hypothetical individual who lives or works in the immediate vicinity of the site should not exceed a dose of 30 mrem/yr following remedial action for the current use and likely future use scenarios or a dose of 100 mrem/yr for less likely future use scenarios. The DOE residual radioactive material guideline computer code, RESRAD, was used in this evaluation; RESRAD implements the methodology described in the DOE manual for establishing residual radioactive material guidelines.

  2. Colony-forming progenitor cells in the postnatal mouse liver and pancreas give rise to morphologically distinct insulin-expressing colonies in 3D cultures.

    PubMed

    Jin, Liang; Feng, Tao; Chai, Jing; Ghazalli, Nadiah; Gao, Dan; Zerda, Ricardo; Li, Zhuo; Hsu, Jasper; Mahdavi, Alborz; Tirrell, David A; Riggs, Arthur D; Ku, Hsun Teresa

    2014-01-01

    In our previous studies, colony-forming progenitor cells isolated from murine embryonic stem cell-derived cultures were differentiated into morphologically distinct insulin-expressing colonies. These colonies were small and not light-reflective when observed by phase-contrast microscopy (therefore termed "Dark" colonies). A single progenitor cell capable of giving rise to a Dark colony was termed a Dark colony-forming unit (CFU-Dark). The goal of the current study was to test whether endogenous pancreas, and its developmentally related liver, harbored CFU-Dark. Here we show that dissociated single cells from liver and pancreas of one-week-old mice give rise to Dark colonies in methylcellulose-based semisolid culture media containing either Matrigel or laminin hydrogel (an artificial extracellular matrix protein). CFU-Dark comprise approximately 0.1% and 0.03% of the postnatal hepatic and pancreatic cells, respectively. Adult liver also contains CFU-Dark, but at a much lower frequency (~0.003%). Microfluidic qRT-PCR, immunostaining, and electron microscopy analyses of individually handpicked colonies reveal the expression of insulin in many, but not all, Dark colonies. Most pancreatic insulin-positive Dark colonies also express glucagon, whereas liver colonies do not. Liver CFU-Dark require Matrigel, but not laminin hydrogel, to become insulin-positive. In contrast, laminin hydrogel is sufficient to support the development of pancreatic Dark colonies that express insulin. Postnatal liver CFU-Dark display a cell surface marker CD133?CD49f(low)CD107b(low) phenotype, while pancreatic CFU-Dark are CD133?. Together, these results demonstrate that specific progenitor cells in the postnatal liver and pancreas are capable of developing into insulin-expressing colonies, but they differ in frequency, marker expression, and matrix protein requirements for growth. PMID:25148366

  3. Effect of formic acid formulations on honey bee (Hymenoptera: Apidae) colonies and influence of colony and ambient conditions on formic acid concentration in the hive.

    PubMed

    Ostermann, David J; Currie, Robert W

    2004-10-01

    The interaction between the effects of varroa, Varroa destructor Anderson & Trueman, and formic acid treatments on colonies of honey bees, Apis mellifera L., were examined in two field experiments. In experiment 1, colonies with low varroa levels were exposed to two different slow-release formulations and compared with untreated colonies. In experiment 2, colonies inoculated with varroa and uninoculated colonies were exposed to a slow-release formulation, a pour-on formulation, or were left untreated. The effects of treatments, hive temperature, and hive relative humidity on formic acid concentration in hive air also were examined. Slow-release formic acid application improved colony development in colonies that had been inoculated with varroa. However, in uninoculated colonies where the mean abundance of varroa was low, slow-release formic acid application suppressed colony development. The pour-on application did not have a negative impact on worker population growth in uninoculated colonies, but also it was not as effective as the slow-release treatment in improving population growth in varroa-inoculated colonies. Equivalent volumes of acid applied in pour-on and slow-release formulations provided the same cumulative dose in hive air but differed in the daily pattern of formic acid release. Colonies that were not inoculated with varroa had higher concentrations of formic acid in hive air than colonies that were inoculated with varroa on three of the five pour-on application dates. The data suggest that reductions in worker population and/or activity caused by varroa can interact with ambient conditions to affect the volatilization or sorption of formic acid in the hive. PMID:15568335

  4. Patients with methicillin-resistant Staphylococcus aureus infection: twenty-first century lepers.

    PubMed

    Mozzillo, K L; Ortiz, N; Miller, L G

    2010-06-01

    In the recent past, there has been a rapid increase in the incidence of methicillin-resistant Staphylococcus aureus (MRSA) infections, especially community-associated (CA)-MRSA. Many media descriptions of MRSA are sensational and focus on its potential for severe disease and contagiousness. Our objective is to describe psychological and social morbidity associated with MRSA infection via a case series of five patients with CA-MRSA infection. We also analyse the resulting stigmatization associated with being diagnosed with MRSA infection. We learned that patients describe a variety of stigmatization related to their diagnosis of MRSA, including being shunned at home and in the workplace. Patients describe being asked by family, colleagues, and clients to take extraordinary measures to prevent MRSA transmission. Consequences of MRSA diagnoses have included erosion or termination of key personal and business relationships. In conclusion, stigmatization resulting from the diagnosis of MRSA can have profound personal and social morbidity. Media and public health awareness of MRSA infection needs to be balanced with information about how MRSA transmission is usually preventable with simple hygienic measures. PMID:20236730

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  6. A child of the empire: British sociology and colonialism, 1940s-1960s.

    PubMed

    Steinmetz, George

    2013-01-01

    British sociology was established as an academic discipline between 1945 and 1965, just as the British Empire was gearing up for a new phase of developmental colonialism backed by the social and other sciences. Many parts of the emerging sociological discipline became entangled with colonialism. Key themes and methods in sociology and the staff of sociology departments emerged from this colonial context. Historians have tended to place postwar British sociology in the context of expanding higher education and the welfare state, and have overlooked this colonial constellation. The article reconstructs this forgotten moment of disciplinary founding and explores three of the factors that promoted colonial sociology: the Colonial Social Science Research Council, the so-called Asquith universities, and the social research institutes in the colonies; and the involvement of sociologists from the London School of Economics in training colonial officials. PMID:24037899

  7. Breeding colonies of least terns (Sternula antillarum) in northern Sonora, Mexico, 2006-2008

    USGS Publications Warehouse

    Rosemartin, Alyssa; van Riper, Charles, III

    2012-01-01

    We document distribution of breeding least terns (Sternula antillarum) in northern Sonora, Mexico, 2006-2008. We report breeding activity at six sites with active colonies, including three previously undocumented colonies.

  8. Soft agarose colony formation assay for human renal cell carcinoma: comparison of optical colony counting versus tritiated thymidine incorporation

    SciTech Connect

    Hosaka, Y.; Tsukamoto, T.; Lieber, M.M.

    1986-11-01

    Use of the Hamburger-Salmon soft agar assay method for in vitro chemotherapy sensitivity testing of samples of renal cell carcinoma has been somewhat limited by a relatively low proliferation/evaluability rate for this tumor type (approximately 50%). The tritiated thymidine ((/sup 3/H)-TdR) incorporation assay method of Tanigawa et al. (Cancer Res., 42: 2159, 1982) was compared to a standard optical colony counting assay technique. Fifty-seven different primary and five metastatic fresh samples of human renal cell carcinoma were studied. Evaluability rate by the (/sup 3/H)-TdR assay was 90% (greater than or equal to 300 cpm control). In comparison, evaluability rate by optical colony counting was 43% for this group of tumors. (/sup 3/H)-TdR incorporation increased with increasing tumor grade and increasing stage. Spindle cell tumors showed significantly higher cpm than other cell types. Twenty-three primary tumors were evaluable by both (/sup 3/H)-TdR and colony counting methods. The correlation coefficient (r) for regression lines for drug sensitivity data points (optical counting vs. (/sup 3/H)-TdR) of these individual experiments ranged from 0.50 to 0.99 with a mean r +/- S.D. of 0.76 +/- 0.15. For all 260 paired drug response observations of 23 tumors exposed to different drugs, the correlation was very good with r = 0.71. Since the (/sup 3/H)-TdR assay has an evaluability rate of approximately 90% for renal cell carcinoma, gives drug sensitivity information which correlates well with the colony counting endpoint and yields chemotherapy sensitivity information four days after sample accession, the (/sup 3/H)-TdR assay may be a more useful method for study of human renal cell carcinoma in vitro chemotherapy sensitivity testing than standard colony counting techniques.

  9. Geographic structure of adelie penguin populations: overlap in colony-specific foraging areas

    USGS Publications Warehouse

    Ainley, D.G.; Ribic, C.A.; Ballard, G.; Heath, S.; Gaffney, I.; Karl, B.J.; Barton, K.J.; Wilson, P.R.; Webb, S.

    2004-01-01

    In an investigation of the factors leading to geographic structuring among Ade??lie Penguin (Pygoscelis adeliae) populations, we studied the size and overlap of colony-specific foraging areas within an isolated cluster of colonies. The study area, in the southwestern Ross Sea, included one large and three smaller colonies, ranging in size from 3900 to 135000 nesting pairs, clustered on Ross and Beaufort Islands. We used triangulation of radio signals from transmitters attached to breeding penguins to determine foraging locations and to define colony-specific foraging areas during the chick-provisioning period of four breeding seasons, 1997-2000. Colony populations (nesting pairs) were determined using aerial photography just after egg-laying; reproductive success was estimated by comparing ground counts of chicks fledged to the number of breeding pairs apparent in aerial photos. Foraging-trip duration, meal size, and adult body mass were estimated using RFID (radio frequency identification) tags and an automated reader and weighbridge. Chick growth was assessed by weekly weighing. We related the following variables to colony size: foraging distance, area, and duration; reproductive success; chick meal size and growth rate; and seasonal variation in adult body mass. We found that penguins foraged closest to their respective colonies, particularly at the smaller colonies. However, as the season progressed, foraging distance, duration, and area increased noticeably, especially at the largest colony. The foraging areas of the smaller colonies overlapped broadly, but very little foraging area overlap existed between the large colony and the smaller colonies, even though the foraging area of the large colony was well within range of the smaller colonies. Instead, the foraging areas of the smaller colonies shifted as that of the large colony grew. Colony size was not related to chick meal size, chick growth, or parental body mass. This differed from the year previous to the study, when foraging trips of the large colony were very long, parents lost mass, and chick meals were smaller. In light of existing data on prey abundance in neritic waters in Antarctica suggesting that krill are relatively evenly distributed and in high abundance in the Southern Ross Sea, we conclude that penguins depleted or changed the availability of their prey, that the degree of alteration was a function of colony size, and that the large colony affected the location (and perhaps ultimately the size) of foraging areas for the smaller colonies. It appears, therefore, that foraging dynamics play a role in the geographic structuring of colonies in this species. ?? 2004 by the Ecological Society of America.

  10. Qur'anic and "Ajami" Literacies in Pre-Colonial West Africa

    ERIC Educational Resources Information Center

    Diallo, Ibrahima

    2012-01-01

    Traditional African literacy practices have often been ignored in the wake of European colonialism and the educational policies of colonial governments. Nonetheless, literacy had been established in parts of Africa following the introduction of Islam. This paper will examine the developments of literacy in pre-colonial West Africa. In this region,…

  11. Intracolonial genetic diversity in honey bee (Apis mellifera) colonies increases pollen foraging efficiency

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Multiple mating by honey bee queens results in colonies of genotypically diverse workers. Recent studies have demonstrated that increased genetic diversity within a honey bee colony increases the variation in the frequency of tasks performed by workers. We show that genotypically diverse colonies, ...

  12. Creating Germans Abroad: White Education and the Colonial Condition in German Southwest Africa, 1894-1914

    ERIC Educational Resources Information Center

    Walther, Daniel Joseph

    2013-01-01

    From the perspective of German colonial supporters and authorities, appropriate white education in the settler colony of Southwest Africa (SWA) was essential for maintaining German hegemony in the territory. In order to reach this objective, the German colonial administration in SWA, with assistance from pedagogues and institutions in Germany,…

  13. The Politics of Writing Tribal Identities in the Sudan: The Case of the Colonial Nuba Policy

    ERIC Educational Resources Information Center

    Abdelhay, Ashraf Kamal

    2010-01-01

    Linguistics is implicated in the colonial project of the invention of "self-contained" "racial" and "tribal units" in the Sudan. This paper has two objectives. First, to historicise the notions of "language" in the postcolonial discourse of language planning in the Sudan by reviewing one of the significant colonial policies: the colonial Nuba…

  14. Investigation of growth processes in bacterial colonies by the LASCA technique

    NASA Astrophysics Data System (ADS)

    Ulianova, O. V.; Rebeza, O. S.; Ulyanov, S. S.

    2016-01-01

    The method of analysis of the temporal and spatial contrasts of speckle fields formed during the coherent scattering of radiation in bacterial colonies has been adapted to monitor the growth and structure of bacterial colonies by the example of E. coli. A noticeable change in the spatial structures of colonies during their growth has been demonstrated.

  15. 75 FR 28685 - Colonial Bankshares, MHC, Vineland, NJ; Approval of Conversion Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-21

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF THE TREASURY Office of Thrift Supervision Colonial Bankshares, MHC, Vineland, NJ; Approval of Conversion Application... Colonial Bankshares, MHC, and Colonial Bank, Vineland, New Jersey, to convert to the stock form...

  16. Parasites and Pathogens of the Honeybee (Apis mellifera) and Their Influence on Inter-Colonial Transmission

    PubMed Central

    Frey, Eva; Rosenkranz, Peter; Paxton, Robert J.; Moritz, Robin F. A.

    2015-01-01

    Pathogens and parasites may facilitate their transmission by manipulating host behavior. Honeybee pathogens and pests need to be transferred from one colony to another if they are to maintain themselves in a host population. Inter-colony transmission occurs typically through honeybee workers not returning to their home colony but entering a foreign colony (“drifting”). Pathogens might enhance drifting to enhance transmission to new colonies. We here report on the effects infection by ten honeybee viruses and Nosema spp., and Varroa mite infestation on honeybee drifting. Genotyping of workers collected from colonies allowed us to identify genuine drifted workers as well as source colonies sending out drifters in addition to sink colonies accepting them. We then used network analysis to determine patterns of drifting. Distance between colonies in the apiary was the major factor explaining 79% of drifting. None of the tested viruses or Nosema spp. were associated with the frequency of drifting. Only colony infestation with Varroa was associated with significantly enhanced drifting. More specifically, colonies with high Varroa infestation had a significantly enhanced acceptance of drifters, although they did not send out more drifting workers. Since Varroa-infested colonies show an enhanced attraction of drifting workers, and not only those infected with Varroa and its associated pathogens, infestation by Varroa may also facilitate the uptake of other pests and parasites. PMID:26451849

  17. Response of mountain plovers to plague-driven dynamics of black-tailed prairie dog colonies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sylvatic plague is a major factor influencing prairie dog colony dynamics in the western Great Plains. We studied the nesting response of the mountain plover (Charadrius montanus), a grassland bird that nests on prairie dog colonies, to plague-driven dynamics of prairie dog colonies at three sites i...

  18. Population dynamics of Varroa destructor (Acari: Varroidae) in commercial honey bee colonies and implications for control

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Treatment schedules to maintain low levels of Varroa mites in honey bee colonies were tested in hives started from either package bees or splits of larger colonies. The schedules were developed based on predictions of Varroa population growth generated from a mathematical model of honey bee colony ...

  19. Heavy metal residues in prefledgling black-crowned night-herons from three Atlantic coast colonies

    USGS Publications Warehouse

    Custer, T.W.; Mulhern, B.L.

    1983-01-01

    Aquatic birds may serve as indicators of regional metal contamination. Because the food of prefledgling herons (Nycticorax nycticorax ) comes only from areas near the colony, their tissues should reflect local metal contamination. The authors' hypothesis was that prefledgling herons from the Rhode Island colony should have higher concentrations of metals than do those from either the North Carolina or Massachusetts colonies.

  20. Distribution species abundance and nesting site use of Atlantic coast colonies of herons and their allies

    USGS Publications Warehouse

    Custer, T.W.; Osborn, R.G.; Stout, W.F.

    1980-01-01

    In 1975 and 1976, 8 teams of investigators located 262 colonies of nesting herons and their allies along the Atlantic coast from Florida to Maine [USA]. Fourteen species [Ajaia ajaja, Plegadis falcinellus, Nycticorax nycticorax, Ardea herodias, Eudocimus albus, Egretta thula, Hydranassa tricolor, Bubulcus ibis, Casmerodius albus, Butorides striatus, Florida caerulea, Dichromanassa rufescens, Nyctanassa violacea and Mycteria americana] were found in Florida, numbers decreasing to 7 in Maine. Colonies censused in the extreme south and north of the study area were lower in number of species and number of adults than those in the intermediate area. More than 90% of the colony sites surveyed in 1975 were active in 1976. The total number of nesting adults per colony, number of species per colony and number of nesting adults of each species per colony in 1976 were significantly correlated with their respective values for 1975. Abandoned and new colonies may be satellites of nearby reused colonies; they had fewer individuals and species than reused colonies and were closer to reused colonies than reused colonies were to each other. [This study was part of an attempt to examine colonially nesting herons as biological indicators of environmental quality.

  1. Qur'anic and "Ajami" Literacies in Pre-Colonial West Africa

    ERIC Educational Resources Information Center

    Diallo, Ibrahima

    2012-01-01

    Traditional African literacy practices have often been ignored in the wake of European colonialism and the educational policies of colonial governments. Nonetheless, literacy had been established in parts of Africa following the introduction of Islam. This paper will examine the developments of literacy in pre-colonial West Africa. In this region,…

  2. Parasites and Pathogens of the Honeybee (Apis mellifera) and Their Influence on Inter-Colonial Transmission.

    PubMed

    Forfert, Nadège; Natsopoulou, Myrsini E; Frey, Eva; Rosenkranz, Peter; Paxton, Robert J; Moritz, Robin F A

    2015-01-01

    Pathogens and parasites may facilitate their transmission by manipulating host behavior. Honeybee pathogens and pests need to be transferred from one colony to another if they are to maintain themselves in a host population. Inter-colony transmission occurs typically through honeybee workers not returning to their home colony but entering a foreign colony ("drifting"). Pathogens might enhance drifting to enhance transmission to new colonies. We here report on the effects infection by ten honeybee viruses and Nosema spp., and Varroa mite infestation on honeybee drifting. Genotyping of workers collected from colonies allowed us to identify genuine drifted workers as well as source colonies sending out drifters in addition to sink colonies accepting them. We then used network analysis to determine patterns of drifting. Distance between colonies in the apiary was the major factor explaining 79% of drifting. None of the tested viruses or Nosema spp. were associated with the frequency of drifting. Only colony infestation with Varroa was associated with significantly enhanced drifting. More specifically, colonies with high Varroa infestation had a significantly enhanced acceptance of drifters, although they did not send out more drifting workers. Since Varroa-infested colonies show an enhanced attraction of drifting workers, and not only those infected with Varroa and its associated pathogens, infestation by Varroa may also facilitate the uptake of other pests and parasites. PMID:26451849

  3. Effect of time on colony odour stability in the ant Formica exsecta

    NASA Astrophysics Data System (ADS)

    Martin, S. J.; Shemilt, S.; Drijfhout, F. P.

    2012-04-01

    Among social insects, maintaining a distinct colony profile allows individuals to distinguish easily between nest mates and non-nest mates. In ants, colony-specific profiles can be encoded within their cuticular hydrocarbons, and these are influenced by both environmental and genetic factors. Using nine monogynous Formica exsecta ant colonies, we studied the stability of their colony-specific profiles at eight time points over a 4-year period. We found no significant directional change in any colony profile, suggesting that genetic factors are maintaining this stability. However, there were significant short-term effects of season that affected all colony profiles in the same direction. Despite these temporal changes, no significant change in the profile variation within colonies was detected: each colony's profile responded in similar manner between seasons, with nest mates maintaining closely similar profiles, distinct from other colonies. These findings imply that genetic factors may help maintain the long-term stability of colony profile, but environmental factors can influence the profiles over shorter time periods. However, environmental factors do not contribute significantly to the maintenance of diversity among colonies, since all colonies were affected in a similar way.

  4. COLONY INSULARITY THROUGH QUEEN CONTROL ON WORKER SOCIAL MOTIVATION IN ANTS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We investigated the relative contribution of the queen and workers to colony nestmate recognition cues and on colony territoriality in the ant Camponotus fellah. Workers were either individually isolated, preventing contact with both queen and workers (Colony Deprived, CD), kept in queenless groups,...

  5. Flight activity of 4-lb Australian package bee colonies used for almond pollination.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Increasing acreage of almonds in California has increased the demand for honey bee colonies for pollination. Since 2005, domestic U.S. colonies have been supplemented with colonies started from package bees imported from Australia. The need for almond pollination in late winter in California fits we...

  6. The Formulation of British Colonial Education Policy, 1929-1961. Final Report.

    ERIC Educational Resources Information Center

    Clatworthy, F. James

    The study investigates the formulation of British colonial education policy and attempts to evaluate the hypothesis that the policies formulated by the Advisory Committee on Education in the Colonies reflected a consistent attempt to orient education policy in the colonies to the local needs for human resource development. The use of historical…

  7. Feeding flights of nesting wading birds at a Virginia colony

    USGS Publications Warehouse

    Erwin, R.M.

    1984-01-01

    Feeding flights of Snowy Egrets (Egretta thula), Tricolored Herons (E. tricolor), Little Blue Herons (E. caerulea), and Cattle Egrets (Bubulcus ibis) were monitored at a small nesting colony near Chincoteague, Virginia during late May and June 1979. All four species varied their flight directions over a series of days. Cattle Egrets oriented in a different direction (toward uplands) from the other three wetland-feeding species, which oriented toward Spartina marsh areas. None of the species showed a tendency to form groups while departing from or arriving at the colony. Tide level had little influence on flight directions used. Comparisons are made between these results and those from a similar study in coastal North Carolina.

  8. Transatlantic abundance of the N2-fixing colonial cyanobacterium Trichodesmium.

    PubMed

    Davis, Cabell S; McGillicuddy, Dennis J

    2006-06-01

    Colonial diazotrophic cyanobacteria of the genus Trichodesmium are thought to play a significant role in the input of new nitrogen to upper layers of the tropical and subtropical oceanic ecosystems that cover nearly half of Earth's surface. Here we describe results of a transatlantic survey in which a noninvasive underwater digital microscope (the video plankton recorder), was towed across the North Atlantic at 6 meters per second while undulating between the surface and 130 meters. Colony abundance had a basin-scale trend, a clear association with anticyclonic eddies, and was not affected by hurricane-forced mixing. Subsurface abundance was higher than previously reported, which has important implications for the global ocean nitrogen cycle. PMID:16763148

  9. Random mitotic activities across human embryonic stem cell colonies.

    SciTech Connect

    Jin, Q.; Duggan, R.; Dasa, S.; Li, F.; Chen, L.

    2010-08-01

    A systemic and quantitative study was performed to examine whether different levels of mitotic activities, assessed by the percentage of S-phase cells at any given time point, existed at different physical regions of human embryonic stem (hES) cell colonies at 2, 4, 6 days after cell passaging. Mitotically active cells were identified by the positive incorporation of 5-bromo-2-deoxyuridine (BrdU) within their newly synthesized DNA. Our data indicated that mitotically active cells were often distributed as clusters randomly across the colonies within the examined growth period, presumably resulting from local deposition of newly divided cells. This latter notion was further demonstrated by the confined growth of enhanced green florescence protein (EGFP) expressing cells amongst non-GFP expressing cells. Furthermore, the overall percentage of mitotically active cells remained constantly at about 50% throughout the 6-day culture period, indicating mitotic activities of hES cell cultures were time-independent under current growth conditions.

  10. A Hybrid Ant Colony Algorithm for Loading Pattern Optimization

    NASA Astrophysics Data System (ADS)

    Hoareau, F.

    2014-06-01

    Electricité de France (EDF) operates 58 nuclear power plant (NPP), of the Pressurized Water Reactor (PWR) type. The loading pattern (LP) optimization of these NPP is currently done by EDF expert engineers. Within this framework, EDF R&D has developed automatic optimization tools that assist the experts. The latter can resort, for instance, to a loading pattern optimization software based on ant colony algorithm. This paper presents an analysis of the search space of a few realistic loading pattern optimization problems. This analysis leads us to introduce a hybrid algorithm based on ant colony and a local search method. We then show that this new algorithm is able to generate loading patterns of good quality.

  11. Ant Colony Optimization With Combining Gaussian Eliminations for Matrix Multiplication.

    PubMed

    Zhou, Yuren; Lai, Xinsheng; Li, Yuanxiang; Dong, Wenyong

    2013-02-01

    One of the main unsolved problems in computer algebra is to determine the minimal number of multiplications which is necessary to compute the product of two matrices. For practical value, the small format is of special interest. This leads to a combinatorial optimization problem which is unlikely solved in polynomial time. In this paper, we present a method called combining Gaussian eliminations to reduce the number of variables in this optimization problem and use heuristic ant colony algorithm to solve the problem. The results of experiments on 2 × 2 case show that our algorithm achieves significant performance gains. Extending this algorithm from 2 × 2 case to 3 × 3 case is also discussed. Index Terms—Ant colony optimization (ACO), evolutionary algorithms, Gaussian eliminations, matrix multiplication, multiplicative complexity, Strassen's algorithm. PMID:22835561

  12. Improved Clonal Selection Algorithm Combined with Ant Colony Optimization

    NASA Astrophysics Data System (ADS)

    Gao, Shangce; Wang, Wei; Dai, Hongwei; Li, Fangjia; Tang, Zheng

    Both the clonal selection algorithm (CSA) and the ant colony optimization (ACO) are inspired by natural phenomena and are effective tools for solving complex problems. CSA can exploit and explore the solution space parallely and effectively. However, it can not use enough environment feedback information and thus has to do a large redundancy repeat during search. On the other hand, ACO is based on the concept of indirect cooperative foraging process via secreting pheromones. Its positive feedback ability is nice but its convergence speed is slow because of the little initial pheromones. In this paper, we propose a pheromone-linker to combine these two algorithms. The proposed hybrid clonal selection and ant colony optimization (CSA-ACO) reasonably utilizes the superiorities of both algorithms and also overcomes their inherent disadvantages. Simulation results based on the traveling salesman problems have demonstrated the merit of the proposed algorithm over some traditional techniques.

  13. Water extraction on Mars for an expanding human colony.

    PubMed

    Ralphs, M; Franz, B; Baker, T; Howe, S

    2015-11-01

    In-situ water extraction is necessary for an extended human presence on Mars. This study looks at the water requirements of an expanding human colony on Mars and the general systems needed to supply that water from the martian atmosphere and regolith. The proposed combination of systems in order to supply the necessary water includes a system similar to Honeybee Robotics' Mobile In-Situ Water Extractor (MISWE) that uses convection, a system similar to MISWE but that directs microwave energy down a borehole, a greenhouse or hothouse type system, and a system similar to the Mars Atmospheric Resource Recovery System (MARRS). It is demonstrated that a large water extraction system that can take advantage of large deposits of water ice at site specific locations is necessary to keep up with the demands of a growing colony. PMID:26553638

  14. The Piano, the animus, and the colonial experience.

    PubMed

    Izod, J

    1996-01-01

    Focused principally on an analysis of Ada, the mute heroine of Jane Campion's The Piano, this article shows how post-Jungian animus theory illuminates that character's mysterious personality. In particular, Ann Ulanov's thoughts about animus development are connected with Demaris Wehr's observations concerning the internalization of social oppression in an argument that shows how, notwithstanding she is a woman, Ada is a product of colonial oppression. Her mythological antecedents are also considered, and are particularly marked in that she resembles the handless maiden in Marie-Louise von Franz's analysis of that fairy tale. In this context Ada's ultimate renunciation of her husband is symbolically reinforced by the developing personality of her daughter Flora. The changes in both characters can be seen as implying not only the rebirth of Ada's psyche but also the emergence of a new psychological readiness to throw off the colonial mantle. PMID:8851259

  15. Response Ant Colony Optimization of End Milling Surface Roughness

    PubMed Central

    Kadirgama, K.; Noor, M. M.; Abd Alla, Ahmed N.

    2010-01-01

    Metal cutting processes are important due to increased consumer demands for quality metal cutting related products (more precise tolerances and better product surface roughness) that has driven the metal cutting industry to continuously improve quality control of metal cutting processes. This paper presents optimum surface roughness by using milling mould aluminium alloys (AA6061-T6) with Response Ant Colony Optimization (RACO). The approach is based on Response Surface Method (RSM) and Ant Colony Optimization (ACO). The main objectives to find the optimized parameters and the most dominant variables (cutting speed, feedrate, axial depth and radial depth). The first order model indicates that the feedrate is the most significant factor affecting surface roughness. PMID:22294914

  16. [Effect of solid substrates of microbial colony development].

    PubMed

    Bomar, M T

    1984-03-01

    Bacteria have been found to grow differently at contact sites to both organic and anorganic solids as on pure agar media. Of 16 ad hoc selected bacterial strains, the following species (arranged in decreasing order) responded with stronger colony formation: Bacillus subtilis, B. cereus, Streptococcus sanguis, S. saprophyticus, S. faecalis, Escherichia coli, Micrococcus flavus, Actinomyces viscosus, Veillonella sp., Enterobacter liquefaciens, Yersinia enterocolitica. Lactobacillus casei behaved neutral. Proteus vulgaris, Y. enterocolitica and Chromobacterium violaceum grow on certain media only in the presence of solid particles. The yeasts Endomyces lactis, Saccharomyces cerevisiae, Rhodotorula mucilaginosa and Cryptococcus nigricans did not respond to solid particles during colony formation. The kind of protein-animal (meat) or vegetable (soy beans)-did not influence the behaviour of the microorganisms in these experiments. PMID:6326398

  17. Quantifying Spatiotemporal Patterns in the Expansion of Twitching Bacterial Colonies

    NASA Astrophysics Data System (ADS)

    Shelton, Erin; Giuliani, Maximiliano; Burrows, Lori; Dutcher, John

    2015-03-01

    Type IV pili (T4P) are very thin (5-8 nm in diameter) protein filaments that can be extended and retracted by certain classes of Gram-negative bacteria including P. aeruginosa. These bacteria use T4P to move across viscous interfaces, referred to twitching motility. Twitching can occur for isolated cells or in a collective manner. We have developed experimental and data analysis techniques to quantify the expansion of P. aeruginosa PAO1 bacterial colonies at the glass-agar interface under well-controlled environmental conditions. By using particle image velocimetry (PIV) and Fourier analysis techniques, we have characterized the evolution of the advancing front of expanding colonies for a range of agar concentrations. This has allowed us to observe a transition in the collective motion of the bacterial cells as the agar concentration is increased.

  18. [The National Museum of Chilean Medicine: I. The Colonial period].

    PubMed

    Cruz-Coke, R

    1989-09-01

    The first museum of Chilean Medicines was founded by Dr Enrique Laval in 1955. The new museum is a fusion of this one and patrimony of the School of Medicine and the ancient San Vicente Hospital. It was created in 1987 by the present Dean, Aleksandar Goic. The present article describes one of the halls, the Colony. Pictures of Governors and Conquerors who founded the first hospitals are in display. The period of Religious Medicine (1616-1823) is represented by pictures and religious objects, as well as hospital utensils. The times of the University of San Felipe and the "Protomedicato" (1756-1839) includes pictures and documentation from the first colonial physicians. Chilean medicine at that time stayed at a medieval level, lacking the influence of the Renaissance, the Barroque and other movements enlighting european medicine. PMID:2519478

  19. Generation of a Specific-Pathogen–Free Baboon Colony

    PubMed Central

    Wolf, Roman F; Eberle, Richard; White, Gary L

    2010-01-01

    We undertook establishing an SPF baboon colony in response to requests from researchers. To enable the widest possible future use of SPF baboons, our aim was to develop an SPF colony of baboons (Papio hamadryas anubis) free of 12 target viruses: 5 herpesviruses, 4 retroviruses, simian virus 40, measles, and monkeypox. Infant baboons were removed from their mothers within 24 h of birth and nursery-reared. Groups of 3 to 8 age-matched conspecifics were isolated in separate rooms for 1 y while undergoing repeated testing for target viruses. During the initial 7 y of the SPF program, 171 infants were enrolled, of which 76 (44.4%) subsequently were removed from the program. Of those removed, 54 (71.0%) were culled due to breaks in virus-free status, 12 (15.8%) died of various causes, 4 (5.3%) developed seizures, and 6 (7.9%) were removed for other reasons. The most problematic viruses were baboon cytomegalovirus (25.9% of culls), Herpesvirus papio 1 (51.9%), and simian foamy virus (7.4%). Using conspecific groups of 3 to 4 infants reduced first-year program losses as compared with groups of 6 to 8. There have been 17 births in the SPF colony, and all these infants have been free of all target viruses since birth. On the basis of these results, early removal of infants from their dams, housing in small peer groups, frequent virus testing, and aggressive culling of virus-positive animals is an effective approach for development of a baboon colony free of multiple viruses. PMID:21205446

  20. Protein structure optimization with a "Lamarckian" ant colony algorithm.

    PubMed

    Oakley, Mark T; Richardson, E Grace; Carr, Harriet; Johnston, Roy L

    2013-01-01

    We describe the LamarckiAnt algorithm: a search algorithm that combines the features of a "Lamarckian" genetic algorithm and ant colony optimization. We have implemented this algorithm for the optimization of BLN model proteins, which have frustrated energy landscapes and represent a challenge for global optimization algorithms. We demonstrate that LamarckiAnt performs competitively with other state-of-the-art optimization algorithms. PMID:24407312

  1. Granulocyte colony stimulating factor treatment for alloimmune neonatal neutropenia.

    PubMed

    Rodwell, R L; Gray, P H; Taylor, K M; Minchinton, R

    1996-07-01

    Granulocyte colony stimulating factor (G-CSF) treatment was successfully used in three preterm infants with alloimmune neonatal neutropenia (AINN). Two infants had persistent neutropenia despite treatment with intravenous immunoglobulin and random donor granulocyte transfusions for presumed sepsis. Neutrophil counts returned to normal with G-CSF treatment; the response was least convincing in one infant with fulminant necrotising enterocolits. It is suggested that treatment with G-CSF be considered early for the treatment of infants with AINN. PMID:8795359

  2. Space Colony from a Commercial Asteroid Mining Company Town

    NASA Astrophysics Data System (ADS)

    Taylor, Thomas C.; Grandl, Werner; Pinni, Martina; Benaroya, Haym

    2008-01-01

    Commercial mining towns on Earth become cities. Company towns need commerce to drive the growth and economy of early space colonies. Water is an early resource for camp consumables plus propellant export sales from asteroid mining operations at proposed burned out comets with water methane ice cores for sustainable growth over 50 years, financed from profits and capable with affordable logistics to support resource recovery. One co-author's perspective includes remote resource recovery sites on Earth. Other co-authors' experiences include architecture, lunar habitation, and architectural space colony concepts. This paper combines these experiences to propose commercial opportunities possible as mankind moves beyond one planet. Alaska's North Slope commercial history indicates that different multiple logistics transportation systems are required to reduce the risk to humans and families moved in before the oil flowed. Commercial enterprises have risked $20 billion and spent hundreds of billions in private money after profits were created. The lessons learned are applied to a burned out comet designated Wilson-Harrington (1979) and explores the architecture for early living within the burned out comet disk created from ice recovery and later sealed with an expected methane ice interior. Considered is the recovery of the resources, the transport of water back to Earth orbit or L-1, plus later the development of more comfortable space colony living. Commercial markets produce cities on Earth and the same can happen on Space Colonies. The key is an ``in place'' affordable commercial logistics system that can service, stimulate and sustain a 50-year commercial propellant market.

  3. Disease control during the colonial period in Australia.

    PubMed

    Turner, A J

    2011-07-01

    The first permanent European settlers of Australia arrived in 1788 to establish a penal colony at Sydney, New South Wales (NSW). As the colony grew and wool production increased, more free settlers and emancipists developed farming in inland Australia. During the 1840s veterinarians commenced arriving in small numbers but they were not closely associated with the development and execution of disease control programs, which was left to lay inspectors of stock. The arrival of William Tyson Kendall and coordinated action with Graham Mitchell led to the establishment of a private veterinary college following the passage of veterinary surgeons legislation in Victoria. From this time, veterinarians came to be appointed to positions formerly occupied by lay inspectors and the veterinary profession was able to take up the role of planning and executing government-led disease control programs. From a colony relying on wool for export to the UK, technical advancements in meat freezing and pasture improvement widened the range and increased the quantity of exported products. Before the advent of veterinary advances, sheep scab was eradicated, a vaccine was developed for anthrax and glanders infection of horses was prevented entry to Australia. Graduates from the Melbourne Veterinary College spread across Australia and in this period a conservative quarantine policy was developed following inaction to control an outbreak of contagious bovine pleuropneumonia (CBPP) and the escape of rabbits to form a plague across the continent. Coordinated control of CBPP had to await the next century and advancement of technology increased our understanding of bacteriology and immunity of infectious diseases. Veterinary services were provided to the militia sent by the colonies to the Boer Wars in South Africa 1987-1901 and the veterinarians from Victoria were led by an Australian trained veterinarian. PMID:21696369

  4. Enterococcus faecium small colony variant endocarditis in an immunocompetent patient

    PubMed Central

    Egido, S. Hernández; Ruiz, M. Siller; Inés Revuelta, S.; García, I. García; Bellido, J.L. Muñoz

    2015-01-01

    Small colony variants (SCV) are slow-growing subpopulations of bacteria usually associated with auxotrophism, causing persistent or recurrent infections. Enterococcus faecalis SCV have been seldom described, and only one case of Enterococcus faecium SCV has been reported, associated with sepsis in a leukaemia patient. Here we report the first case described of bacteraemia and endocarditis by SCV E. faecium in an immunocompetent patient. PMID:26862434

  5. The importance of small colonies in sustaining Microcystis population exposed to mixing conditions: an exploration through colony size, genotypic composition and toxic potential.

    PubMed

    Sabart, Marion; Misson, Benjamin; Descroix, Aurélie; Duffaud, Emilie; Combourieu, Bruno; Salençon, Marie-José; Latour, Delphine

    2013-10-01

    Microcystis is a toxic colony-forming cyanobacterium, which can bloom in a wide range of freshwater ecosystems. Despite the ecological advantage of the colonial form, few studies have paid attention to the size of Microcystis colonies in the field. With the aim of evaluating the impact of a fluctuating physical environment on the colony size, the genotypic composition and the toxic potential of a Microcystis population, we investigated five different colony size classes of a Microcystis bloom in the Grangent reservoir (France). By sequencing the internal transcribed spacer of the ribosomal operon, we evidenced changes in the genetic structure among size classes in response to environmental change. While similar genotypes were seen in every size class in stable conditions, new dominant genotypes appeared in the smallest colonies (< 160 ?m) concomitantly with mixing conditions, strongly suggesting the importance of these colonies in response to disturbances. Moreover, these small colonies played a major role in microcystin production during this bloom, since very high microcystin contents (> 1 pg.cell.(-1)) were found in their cells. These findings indicate that the colony size distribution of a Microcystis population in response to disturbance could be an adaptive strategy that may explain its ecological success in freshwater ecosystems. PMID:24115626

  6. The Role of Non-Foraging Nests in Polydomous Wood Ant Colonies

    PubMed Central

    Ellis, Samuel; Robinson, Elva J. H.

    2015-01-01

    A colony of red wood ants can inhabit more than one spatially separated nest, in a strategy called polydomy. Some nests within these polydomous colonies have no foraging trails to aphid colonies in the canopy. In this study we identify and investigate the possible roles of non-foraging nests in polydomous colonies of the wood ant Formica lugubris. To investigate the role of non-foraging nests we: (i) monitored colonies for three years; (ii) observed the resources being transported between non-foraging nests and the rest of the colony; (iii) measured the amount of extra-nest activity around non-foraging and foraging nests. We used these datasets to investigate the extent to which non-foraging nests within polydomous colonies are acting as: part of the colony expansion process; hunting and scavenging specialists; brood-development specialists; seasonal foragers; or a selfish strategy exploiting the foraging effort of the rest of the colony. We found that, rather than having a specialised role, non-foraging nests are part of the process of colony expansion. Polydomous colonies expand by founding new nests in the area surrounding the existing nests. Nests founded near food begin foraging and become part of the colony; other nests are not founded near food sources and do not initially forage. Some of these non-foraging nests eventually begin foraging; others do not and are abandoned. This is a method of colony growth not available to colonies inhabiting a single nest, and may be an important advantage of the polydomous nesting strategy, allowing the colony to expand into profitable areas. PMID:26465750

  7. Multiplexed automated DNA sequencing directly from single bacterial colonies.

    PubMed

    Zhang, Y; Tan, H; Yeung, E S

    1999-11-15

    Sample preparation has been one of the major bottlenecks for large-scale DNA sequencing projects in terms of time and cost. To improve sample throughput and to integrate the front-end tasks to capillary-array DNA sequencers, protocols for directly sequencing the plasmids from a single bacterial colony in fused-silica capillaries were developed. After the colony is picked, lysis is accomplished in situ in the plastic sample tube using either a thermocycler or a heating block. Upon heating, the plasmids are released while chromosomal DNA and membrane proteins are denatured and precipitate to the bottom of the tube. After adding enzyme and Sanger reagents, the resulting solution was aspirated into the reaction capillaries by a syringe pump, and cycle sequencing was initiated. No deleterious effect upon the reaction efficiency, the on-line purification system, or the capillary electrophoresis separation was observed, even though the crude lysate was used as the template. Multiplexed online DNA sequencing data from 8 parallel channels allowed base calling up to 620 bp with an accuracy of 98%. The entire system can be automatically regenerated for repeated operation. By the marriage of colony sequencing with the capillary array sequencer, both the front end and the back end of DNA sequencing are combined in a miniaturized format. This protocol will ultimately reduce the cost of sequencing to well below current levels. PMID:10575960

  8. Improved Aerobic Colony Count Technique for Hydrophobic Grid Membrane Filters

    PubMed Central

    Parrington, Lorna J.; Sharpe, Anthony N.; Peterkin, Pearl I.

    1993-01-01

    The AOAC International official action procedure for performing aerobic colony counts on hydrophobic grid membrane filters (HGMFs) uses Trypticase soy-fast green FCF agar (FGA) incubated for 48 h. Microbial growths are various shades of green on a pale green background, which can cause problems for automated as well as manual counting. HGMFs which had been incubated 24 or 48 h at 35°C on Trypticase soy agar were flooded underneath with 1 to 2 ml of 0.1% triphenyltetrazolium chloride (TTC) solution by simply lifting one corner of the filter while it was still on the agar and adding the reagent. Microbial growths on HGMFs were counted after color had been allowed to develop for 15 min at room temperature. With representative foods, virtually all colonies stained pink to red. Automated electronic counts made by using the MI-100 HGMF Interpreter were easier and more reliable than control HGMF counts made by the AOAC International official action procedure. Manual counting was easier as well because of increased visibility of the microbial growths. Except in the case of dairy products, 24-h TTC counts did not differ significantly from 48-h FGA counts, whereas the FGA counts at 24 h were always significantly lower, indicating that for many food products the HGMF TTC flooding method permits aerobic colony counts to be made after 24 h. PMID:16349033

  9. Colony disassociation following diet partitioning in a unicolonial ant

    NASA Astrophysics Data System (ADS)

    Silverman, J.; Liang, D.

    2001-01-01

    Discriminating nestmates from alien conspecifics via chemical cues is recognized as a critical element in maintaining the integrity of insect societies. We determined, in laboratory experiments, that nestmate recognition in an introduced population of the Argentine ant, Linepithema humile, is modified by hydrocarbons acquired from insect prey, and that workers from spatially isolated colony fragments, each provided with prey that possessed distinct cuticular hydrocarbons, displayed aggressive behavior towards their former nestmates. Isolation for 28 days or more between colony fragments fed different prey was sufficient to prevent re-establishment of inter-nest communication for at least an additional 28 days through the introduction of a bridge between the nests. Ants possessed intrinsic cuticular hydrocarbons plus only those hydrocarbons from the prey they received during the isolation period. Colony fragments which were isolated for less than 28 days reunited with workers possessing both prey hydrocarbons. Therefore, L. humile nestmate recognition may be dynamic, being in part dependent on the spatio-temporal distribution of prey, along with physical factors permitting or restricting access of subcolony units to those prey.

  10. Radial and Spiral Stream Formation in Proteus mirabilis Colonies

    PubMed Central

    Xue, Chuan; Budrene, Elena O.; Othmer, Hans G.

    2011-01-01

    The enteric bacterium Proteus mirabilis, which is a pathogen that forms biofilms in vivo, can swarm over hard surfaces and form a variety of spatial patterns in colonies. Colony formation involves two distinct cell types: swarmer cells that dominate near the surface and the leading edge, and swimmer cells that prefer a less viscous medium, but the mechanisms underlying pattern formation are not understood. New experimental investigations reported here show that swimmer cells in the center of the colony stream inward toward the inoculation site and in the process form many complex patterns, including radial and spiral streams, in addition to previously-reported concentric rings. These new observations suggest that swimmers are motile and that indirect interactions between them are essential in the pattern formation. To explain these observations we develop a hybrid model comprising cell-based and continuum components that incorporates a chemotactic response of swimmers to a chemical they produce. The model predicts that formation of radial streams can be explained as the modulation of the local attractant concentration by the cells, and that the chirality of the spiral streams results from a swimming bias of the cells near the surface of the substrate. The spatial patterns generated from the model are in qualitative agreement with the experimental observations. PMID:22219724

  11. Towards a colony counting system using hyperspectral imaging

    NASA Astrophysics Data System (ADS)

    Masschelein, B.; Robles-Kelly, A.; Blanch, C.; Tack, N.; Simpson-Young, B.; Lambrechts, A.

    2012-03-01

    Colony counting is a procedure used in microbiology laboratories for food quality monitoring, environmental management, etc. Its purpose is to detect the level of contamination due to the presence and growth of bacteria, yeasts and molds in a given product. Current automated counters require a tedious training and setup procedure per product and bacteria type and do not cope well with diversity. This contrasts with the setting at microbiology laboratories, where a wide variety of food and bacteria types have to be screened on a daily basis. To overcome the limitations of current systems, we propose the use of hyperspectral imaging technology and examine the spectral variations induced by factors such as illumination, bacteria type, food source and age and type of the agar. To this end, we perform experiments making use of two alternative hyperspectral processing pipelines and compare our classification results to those yielded by color imagery. Our results show that colony counting may be automated through the automatic recovery of the illuminant power spectrum and reflectance. This is consistent with the notion that the recovery of the illuminant should minimize the variations in the spectra due to reflections, shadows and other photometric artifacts. We also illustrate how, with the reflectance at hand, the colonies can be counted making use of classical segmentation and classification algorithms.

  12. Automated counting of bacterial colonies by image analysis.

    PubMed

    Chiang, Pei-Ju; Tseng, Min-Jen; He, Zong-Sian; Li, Chia-Hsun

    2015-01-01

    Research on microorganisms often involves culturing as a means to determine the survival and proliferation of bacteria. The number of colonies in a culture is counted to calculate the concentration of bacteria in the original broth; however, manual counting can be time-consuming and imprecise. To save time and prevent inconsistencies, this study proposes a fully automated counting system using image processing methods. To accurately estimate the number of viable bacteria in a known volume of suspension, colonies distributing over the whole surface area of a plate, including the central and rim areas of a Petri dish are taken into account. The performance of the proposed system is compared with verified manual counts, as well as with two freely available counting software programs. Comparisons show that the proposed system is an effective method with excellent accuracy with mean value of absolute percentage error of 3.37%. A user-friendly graphical user interface is also developed and freely available for download, providing researchers in biomedicine with a more convenient instrument for the enumeration of bacterial colonies. PMID:25451456

  13. A Burkholderia pseudomallei Colony Variant Necessary for Gastric Colonization

    PubMed Central

    Austin, C. R.; Goodyear, A. W.; Bartek, I. L.; Stewart, A.; Sutherland, M. D.; Silva, E. B.; Zweifel, A.; Vitko, N. P.; Tuanyok, A.; Highnam, G.; Mittelman, D.; Keim, P.; Schweizer, H. P.; Vázquez-Torres, A.; Dow, S. W. C.

    2015-01-01

    ABSTRACT  Diverse colony morphologies are a hallmark of Burkholderia pseudomallei recovered from infected patients. We observed that stresses that inhibit aerobic respiration shifted populations of B. pseudomallei from the canonical white colony morphotype toward two distinct, reversible, yet relatively stable yellow colony variants (YA and YB). As accumulating evidence supports the importance of B. pseudomallei enteric infection and gastric colonization, we tested the response of yellow variants to hypoxia, acidity, and stomach colonization. Yellow variants exhibited a competitive advantage under hypoxic and acidic conditions and alkalized culture media. The YB variant, although highly attenuated in acute virulence, was the only form capable of colonization and persistence in the murine stomach. The accumulation of extracellular DNA (eDNA) was a characteristic of YB as observed by 4′,6-diamidino-2-phenylindole (DAPI) staining of gastric tissues, as well as in an in vitro stomach model where large amounts of eDNA were produced without cell lysis. Transposon mutagenesis identified a transcriptional regulator (BPSL1887, designated YelR) that when overexpressed produced the yellow phenotype. Deletion of yelR blocked a shift from white to the yellow forms. These data demonstrate that YB is a unique B. pseudomallei pathovariant controlled by YelR that is specifically adapted to the harsh gastric environment and necessary for persistent stomach colonization. PMID:25650400

  14. Organochlorine residues in two Norwegian puffin (Fratercula arctica) colonies.

    PubMed

    Ingebrigtsen, K; Skaare, J U; Teigen, S W

    1984-01-01

    Residue levels of the chlorinated hydrocarbons hexachlorobenzene (HCB), polychlorinated biphenyls (PCBs), alpha-, beta-, and gamma-hexachlorocyclohexane (HCH), oxychlordane, trans-nonachlor, aldrin, and dieldrin in adult puffins (Fratercula arctica) from two colonies in Norway (Røst 67 degrees 30'N and Hornøy 70 degrees 20'N) showing differences in breeding performance were compared in 1982. Furthermore, residue levels in puffin chicks from Røst in 1982, when breeding failed totally, were compared with the corresponding levels in 1983, when breeding was successful. Residue levels of chlorinated hydrocarbons were also measured in eggs from Røst 1982. An autoradiographic study of the distribution of [14C]HCB in adult puffins and chicks from Røst 1982 was included. In general, organochlorine contamination was low, and the results are interpreted to eliminate the organochlorines as a serious factor for impaired reproduction in the Røst colony. Significant differences between the two colonies are discussed in relation to geographical and nutritional aspects. The finding of significantly higher levels of organochlorines in organ tissue from puffin chicks from Røst in 1982 compared to the corresponding levels in 1983 may reflect the dramatic difference in nutritional status between the two years. PMID:6084067

  15. Simulation Studies on Harnessing of Artificial Ecosystems in Space Colonies

    NASA Astrophysics Data System (ADS)

    Miyajima, Hiroyuki

    Space Colonies are an artificial habitation built in space, an idea first proposed by Gerard K. O'Neill in 1969. He suggested they be placed at Lagrange points which are points in space that balance out the gravitational attraction of the Earth and Moon. There are three types of space colonies proposed: Bernard, Cylinder, and Stanford Torus. The cylinder type, designed by Gerard K. O'Neill, is the most popular in concept at 6 km diameter and 30 km length, corresponding to about 845 cubic km, ten thousand people would potentially be able to reside these. The habitation area would be rotated to generate a quasi-gravitation by centrifugal force. It would be rotated at 0.55 rpm to generate a gravitation equivalent to that of the earth. In the space colony, there would be six areas axially, consisting of flooring and windows alternately. Mobile mirrors would be located outside the windows to reflect sun light toward the habitation areas and generate day, night, and seasons within the space colony. Thus an artificial ecosystem would be created allowing people live in much the same way as they do on the earth. According to my former research on micro ecosystems, it is very difficult to keep the environment balanced at all points due to the large volume of the habitation area and the thermal input of the mobile mirrors. It is predicted that there will be differences in the environment at each point of the cylinder due to the mirror angle. Although controlling the whole artificial ecosystem balance is important, local environment control at each point is also important for people to live and work comfortably. Therefore, it is needed to develop simulation models which can study the whole ecosystem as well as local environments at each point at the same time. This model has to be able to simulate dynamics of the whole system as well as the local environments. In this study, I have developed a new model to simulate the whole and local dynamics in a space colony by using a cell automaton consisting of structure, thermal, air, water, and vegetation models.

  16. Adaptive self-organization during growth of bacterial colonies

    NASA Astrophysics Data System (ADS)

    Ben-Jacob, Eshel; Shmueli, Haim; Shochet, Ofer; Tenenbaum, Adam

    1992-09-01

    We present a study of interfacial pattern formation during diffusion-limited growth of Bacillus subtilis. It is demonstrated that bacterial colonies can develop patterns similar to morphologies observed during diffusion-limited growth in non-living (azoic) systems such as solidification and electro-chemical deposition. The various growth morphologies, that is the global structure of the colony, are observed as we vary the growth conditions. These include fractal growth, dense-branching growth, compact growth, dendritic growth and chiral growth. The results demonstrate the action of a singular interplay between the micro-level (individual bacterium) and macro-level (the colony) in selecting the observed morphologies as is understood for non-living systems. Furthermore, the observed morphologies can be organized within a morphology diagram indicating the existence of a morphology selection principle similar to the one proposed for azoic systems. We propose a phase-field-like model (the phase being the bacterial concentration and the field being the nutrient concentration) to describe the growth. The bacteria-bacteria interaction is manifested as a phase dependent diffusion constant. Growth of a bacterial colony presents an inherent additional level of complexity compared to azoic systems, since the building blocks themselves are living systems. Thus, our studies also focus on the transition between morphologies. We have observed extended morphology transitions due to phenotypic changes of the bacteria, as well as bursts of new morphologies resulting from genotypic changes. In addition, we have observed extended and heritable transitions (mainly between dense branching growth and chiral growth) as well as phenotypic transitions that turn genotypic over time. We discuss the implications of our results in the context of the evolving picture of genome cybernetics. Diffusion limited growth of bacterial colonies combined with new understanding of pattern formation in azoic systems provide new tools for the study of adaptive self-organization and mutation in the presence of selective pressures. We include brief reviews of both the recent developments in the study of interfacial pattern formation in non-living systems and the current trends in the view of mutation dynamics.

  17. Visualization of Biosurfactant Film Flow in a Bacillus subtilis Swarm Colony on an Agar Plate

    PubMed Central

    Kim, Kyunghoon; Kim, Jung Kyung

    2015-01-01

    Collective bacterial dynamics plays a crucial role in colony development. Although many research groups have studied the behavior of fluidic swarm colonies, the detailed mechanics of its motion remains elusive. Here, we developed a visualization method using submicron fluorescent beads for investigating the flow field in a thin layer of fluid that covers a Bacillus subtilis swarm colony growing on an agar plate. The beads were initially embedded in the agar plate and subsequently distributed spontaneously at the upper surface of the expanding colony. We conducted long-term live cell imaging of the B. subtilis colony using the fluorescent tracers, and obtained high-resolution velocity maps of microscale vortices in the swarm colony using particle image velocimetry. A distinct periodic fluctuation in the average speed and vorticity of flow in swarm colony was observed at the inner region of the colony, and correlated with the switch between bacterial swarming and growth phases. At the advancing edge of the colony, both the magnitudes of velocity and vorticity of flow in swarm colony were inversely correlated with the spreading speed of the swarm edge. The advanced imaging tool developed in this study would facilitate further understanding of the effect of micro vortices in swarm colony on the collective dynamics of bacteria. PMID:26343634

  18. Ontogeny of worker body size distribution in bumble bee (Bombus impatiens) colonies

    PubMed Central

    Couvillon, Margaret J.; Jandt, Jennifer M.; Duong, Nhi; Dornhaus, Anna

    2015-01-01

    Bumble bees exhibit worker size polymorphisms; highly related workers within a colony may vary up to 10-fold in body mass. As size variation is an important life history feature in bumble bees, the distribution of body sizes within the colony and how it fluctuates over the colony cycle were analysed.Ten commercially purchased colonies of Bombus impatiens (Cresson) were reared in ad libitum conditions. The size of all workers present and newly emerging workers (callows) was recorded each week.The average size of bumble bee workers did not change with colony age, but variation in body size tended to decrease over time. The average size of callows did not change with population size, but did tend to decrease with colony age. In all measures, there was considerable variation among colonies.Colonies of B. impatiens usually produced workers with normally distributed body sizes throughout the colony life cycle. Unlike most polymorphic ants, there was no increase in worker body size with colony age or colony size. This provides the first, quantitative data on the ontogeny of bumble bee worker size distribution. The potential adaptive significance of this size variation is discussed. PMID:26023250

  19. A critical number of workers in a honeybee colony triggers investment in reproduction

    NASA Astrophysics Data System (ADS)

    Smith, Michael L.; Ostwald, Madeleine M.; Loftus, J. Carter; Seeley, Thomas D.

    2014-10-01

    Social insect colonies, like individual organisms, must decide as they develop how to allocate optimally their resources among survival, growth, and reproduction. Only when colonies reach a certain state do they switch from investing purely in survival and growth to investing also in reproduction. But how do worker bees within a colony detect that their colony has reached the state where it is adaptive to begin investing in reproduction? Previous work has shown that larger honeybee colonies invest more in reproduction (i.e., the production of drones and queens), however, the term `larger' encompasses multiple colony parameters including number of adult workers, size of the nest, amount of brood, and size of the honey stores. These colony parameters were independently increased in this study to test which one(s) would increase a colony's investment in reproduction via males. This was assayed by measuring the construction of drone comb, the special type of comb in which drones are reared. Only an increase in the number of workers stimulated construction of drone comb. Colonies with over 4,000 workers began building drone comb, independent of the other colony parameters. These results show that attaining a critical number of workers is the key parameter for honeybee colonies to start to shift resources towards reproduction. These findings are relevant to other social systems in which a group's members must adjust their behavior as a function of the group's size.

  20. A critical number of workers in a honeybee colony triggers investment in reproduction.

    PubMed

    Smith, Michael L; Ostwald, Madeleine M; Loftus, J Carter; Seeley, Thomas D

    2014-10-01

    Social insect colonies, like individual organisms, must decide as they develop how to allocate optimally their resources among survival, growth, and reproduction. Only when colonies reach a certain state do they switch from investing purely in survival and growth to investing also in reproduction. But how do worker bees within a colony detect that their colony has reached the state where it is adaptive to begin investing in reproduction? Previous work has shown that larger honeybee colonies invest more in reproduction (i.e., the production of drones and queens), however, the term 'larger' encompasses multiple colony parameters including number of adult workers, size of the nest, amount of brood, and size of the honey stores. These colony parameters were independently increased in this study to test which one(s) would increase a colony's investment in reproduction via males. This was assayed by measuring the construction of drone comb, the special type of comb in which drones are reared. Only an increase in the number of workers stimulated construction of drone comb. Colonies with over 4,000 workers began building drone comb, independent of the other colony parameters. These results show that attaining a critical number of workers is the key parameter for honeybee colonies to start to shift resources towards reproduction. These findings are relevant to other social systems in which a group's members must adjust their behavior as a function of the group's size. PMID:25142633

  1. Colony mapping: A new technique for monitoring crevice-nesting seabirds

    USGS Publications Warehouse

    Renner, H.M.; Renner, M.; Reynolds, J.H.; Harping, A.M.A.; Jones, I.L.; Irons, D.B.; Byrd, G.V.

    2006-01-01

    Monitoring populations of auklets and other crevice-nesting seabirds remains problematic, although numerous methods have been attempted since the mid-1960s. Anecdotal evidence suggests several large auklet colonies have recently decreased in both abundance and extent, concurrently with vegetation encroachment and succession. Quantifying changes in the geographical extent of auklet colonies may be a useful alternative to monitoring population size directly. We propose a standardized method for colony mapping using a randomized systematic grid survey with two components: a simple presence/absence survey and an auklet evidence density survey. A quantitative auklet evidence density index was derived from the frequency of droppings and feathers. This new method was used to map the colony on St. George Island in the southeastern Bering Sea and results were compared to previous colony mapping efforts. Auklet presence was detected in 62 of 201 grid cells (each grid cell = 2500 m2) by sampling a randomly placed 16 m2 plot in each cell; estimated colony area = 155 000 m2. The auklet evidence density index varied by two orders of magnitude across the colony and was strongly correlated with means of replicated counts of birds socializing on the colony surface. Quantitatively mapping all large auklet colonies is logistically feasible using this method and would provide an important baseline for monitoring colony status. Regularly monitoring select colonies using this method may be the best means of detecting changes in distribution and population size of crevice-nesting seabirds. ?? The Cooper Ornithological Society 2006.

  2. Colony variation in the collective regulation of foraging by harvester ants

    PubMed Central

    Guetz, Adam; Greene, Michael J.; Holmes, Susan

    2011-01-01

    This study investigates variation in collective behavior in a natural population of colonies of the harvester ant, Pogonomyrmex barbatus. Harvester ant colonies regulate foraging activity to adjust to current food availability; the rate at which inactive foragers leave the nest on the next trip depends on the rate at which successful foragers return with food. This study investigates differences among colonies in foraging activity and how these differences are associated with variation among colonies in the regulation of foraging. Colonies differ in the baseline rate at which patrollers leave the nest, without stimulation from returning ants. This baseline rate predicts a colony's foraging activity, suggesting there is a colony-specific activity level that influences how quickly any ant leaves the nest. When a colony's foraging activity is high, the colony is more likely to regulate foraging. Moreover, colonies differ in the propensity to adjust the rate of outgoing foragers to the rate of forager return. Naturally occurring variation in the regulation of foraging may lead to variation in colony survival and reproductive success. PMID:22479133

  3. Genetic diversity within honeybee colonies increases signal production by waggle-dancing foragers

    PubMed Central

    Mattila, Heather R; Burke, Kelly M; Seeley, Thomas D

    2008-01-01

    Recent work has demonstrated considerable benefits of intracolonial genetic diversity for the productivity of honeybee colonies: single-patriline colonies have depressed foraging rates, smaller food stores and slower weight gain relative to multiple-patriline colonies. We explored whether differences in the use of foraging-related communication behaviour (waggle dances and shaking signals) underlie differences in foraging effort of genetically diverse and genetically uniform colonies. We created three pairs of colonies; each pair had one colony headed by a multiply mated queen (inseminated by 15 drones) and one colony headed by a singly mated queen. For each pair, we monitored the production of foraging-related signals over the course of 3 days. Foragers in genetically diverse colonies had substantially more information available to them about food resources than foragers in uniform colonies. On average, in genetically diverse colonies compared with genetically uniform colonies, 36% more waggle dances were identified daily, dancers performed 62% more waggle runs per dance, foragers reported food discoveries that were farther from the nest and 91% more shaking signals were exchanged among workers each morning prior to foraging. Extreme polyandry by honeybee queens enhances the production of worker–worker communication signals that facilitate the swift discovery and exploitation of food resources. PMID:18198143

  4. Trade-offs limiting the evolution of coloniality: ecological displacement rates used to measure small costs

    PubMed Central

    Yokota, Kiyoko; Sterner, Robert W.

    2011-01-01

    Multicellular organisms that benefit from division of labour are presumably descended from colonial species that initially derived benefits from larger colony size, before the evolution of specialization. Life in a colony can have costs as well as benefits, but these can be hard to measure. We measured physiological costs to life in a colony using a novel method based on population dynamics, comparing growth rates of unicells and kairomone-induced colonies of a green alga Desmodesmus subspicatus against a reference co-occurring species. Coloniality negatively affected growth during the initial log growth phase, while no adverse effect was detected under nutrient-limited competitive conditions. The results point to costs associated with traits involved in rapid growth rather than those associated with efficient growth under resource scarcity. Some benefits of coloniality (e.g. defence from herbivory) may be different from when this trait evolved, but our approach shows how costs would have depended on conditions. PMID:20739317

  5. Comparative studies on growth and physiological responses of unicellular and colonial Microcystis aeruginosa to Acorus calamus.

    PubMed

    Zhang, S-H; Chang, J-J; Cao, J-Y; Yang, C-L

    2015-02-01

    In order to explore the growth inhibition and physiological responses of unicellular and colonial Microcystis aeruginosa during coexistence with Acorus calamus, algal densities, chlorophyll a contents, exopolysaccharide (EPS) concentrations, malondialdehyde (MDA) contents, catalase (CAT) activities, and peroxidase (POD) activities of the two algae strains were analyzed. Although the unicellular and colonial strains of M. aeruginosa were both inhibited by A. calamus, unicellular algae were more sensitive than the colonial algae. The measurement results for EPS, MDA, CAT, and POD showed that unicellular M. aeruginosa had higher levels of stress related damage than colonial strains when they were exposed to the same density of A. calamus, and the cellular defense system of colonial M. aeruginosa was stronger than that of unicellular M. aeruginosa. Natural blooms of Microcystis are typically composed of colonial forms of M. aeruginosa, therefore future efforts to control such blooms, possibly through the development of new algicides, should focus on the unique characteristics of colonial M. aeruginosa strains. PMID:25416545

  6. Work plan for the remedial investigation/feasibility study-environmental assessment for the Colonie site, Colonie, New York

    SciTech Connect

    Not Available

    1990-06-01

    This work plan has been prepared to document the scoping and planning process performed by the US Department of Energy (DOE) to support remedial action activities at the Colonie site. The site is located in eastern New York State in the town of Colonie near the city of Albany. Remedial action of the Colonie site is being planned as part of DOE's Formerly Utilized Sites Remedial Action Program. The DOE is responsible for controlling the release of all radioactive and chemical contaminants from the site. Under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), a remedial investigation/feasibility study (RI/FS) must be prepared to support the decision-making process for evaluating remedial action alternatives. This work plan contains a summary of information known about the site as of January 1988, presents a conceptual site model that identifies potential routes of human exposure to site containments, identifies data gaps, and summarizes the process and proposed studies that will be used to fill the data gaps. In addition, DOE activities must be conducted in compliance with the National Environmental Policy Act (NEPA), which requires consideration of the environmental consequences of a proposed action as part of its decision-making process. This work also describes the approach that will be used to evaluate potential remedial action alternatives and includes a description of the organization, project controls, and task schedules that will be employed to fulfill the requirements of both CERCLA and NEPA. 48 refs., 18 figs., 25 tabs.

  7. Internal skeletal analysis of the colonial azooxanthellate scleractinian Dendrophyllia cribrosa using microfocus X-ray CT images: underlying basis for its rigid and highly adaptive colony structure.

    PubMed

    Sentoku, Asuka; Morisaki, Hitomi; Masumoto, Shinji; Ohno, Rie; Tomiyama, Takayuki; Ezaki, Yoichi

    2015-01-01

    Dendrophyllid Scleractinia exhibit a variety of colonial morphologies, formed under the strict constraints on (1) budding sites, (2) orientations of the directive septa of offsets, (3) inclination of budding direction, and (4) those constraints in every generation. Dendrophyllia cribrosa exhibits a sympodial dendroid form, characteristically large coralla, and occasional fusions of adjacent branches within the same colony. Adjacent corallites are bound and supported by coenosteum skeleton. This study examined the inner skeletal structures at the junctions of fused branches using a non-destructive microfocus X-ray computed tomography (CT) imaging approach, and considered the reasons for the large colonial sizes and their adaptive significance. Three-dimensional reconstructions of two-dimensional X-ray CT images reveal that individual corallites are not directly connected in fused parts. Additionally, no completely buried individuals were found within fused skeleton. When adjacent branches approach one another, constituent corallites change their growth directions to avoid collisions between the branches. The adjacent branches fuse without a reduction in the number of constituent corallites, leading to the establishment of reticular and rigid colonial structures. In addition, a nearly even distribution of individuals on the colony surface facilitates efficient intake of nutrients. Thus, the growth of large D. cribrosa colonies involves avoidance of collision between constituent individuals, the reinforcement of colonial structure, and efficient uptake of nutrients. These observations provide insights on the dynamics of interrelationships between colony-making mechanisms and the adaptive strategies required under habitat conditions such as specific current activities. PMID:25463019

  8. Sexual Reproductive Biology of a Colonial Rotifer Sinantherina socialis (Rotifera: Monogononta): Do mating strategies vary between colonial and solitary rotifer species?

    PubMed

    Rico-Martínez, Roberto; Walsh, Elizabeth J

    2013-12-01

    In many aquatic invertebrates including monogonont rotifers, sex provides genetic variation and dormant stages that allows dispersal in time and space. While the reproductive biology of some solitary monogonont rotifer species is known, little is known concerning mating behaviors in colonial rotifers. Coloniality poses unique challenges to the typical mating behavior of solitary rotifers. For instance, most species engage in circling behavior, where the male swims in close proximity to the female. In colonial forms, access to a particular female may be hindered by nearby colony mates. Here we provide descriptions of (1) male morphology, (2) mating behavior, and (3) types of eggs of the widespread colonial rotifer Sinantherina socialis, and discuss modifications in mating strategies as a consequence of coloniality. Two important differences from mating patterns documented in solitary rotifers were found in S. socialis. First, duration of circling phase of mating is protracted for males encountering small colonies of females as compared to solitary females. Males encountering single females removed from their colonies behave similarly to those of solitary species. Second, duration of copulation in S. socialis is the shortest reported for any rotifer species. Endogamy might occur in this species as sons copulate with their sisters and mothers, at least under laboratory conditions. Examples of behaviour in linked video clips. PMID:24932095

  9. Sexual Reproductive Biology of a Colonial Rotifer Sinantherina socialis (Rotifera: Monogononta): Do mating strategies vary between colonial and solitary rotifer species?

    PubMed Central

    Rico-Martínez, Roberto; Walsh, Elizabeth J.

    2014-01-01

    In many aquatic invertebrates including monogonont rotifers, sex provides genetic variation and dormant stages that allows dispersal in time and space. While the reproductive biology of some solitary monogonont rotifer species is known, little is known concerning mating behaviors in colonial rotifers. Coloniality poses unique challenges to the typical mating behavior of solitary rotifers. For instance, most species engage in circling behavior, where the male swims in close proximity to the female. In colonial forms, access to a particular female may be hindered by nearby colony mates. Here we provide descriptions of (1) male morphology, (2) mating behavior, and (3) types of eggs of the widespread colonial rotifer Sinantherina socialis, and discuss modifications in mating strategies as a consequence of coloniality. Two important differences from mating patterns documented in solitary rotifers were found in S. socialis. First, duration of circling phase of mating is protracted for males encountering small colonies of females as compared to solitary females. Males encountering single females removed from their colonies behave similarly to those of solitary species. Second, duration of copulation in S. socialis is the shortest reported for any rotifer species. Endogamy might occur in this species as sons copulate with their sisters and mothers, at least under laboratory conditions. Examples of behaviour in linked video clips. PMID:24932095

  10. Assimilation and Segregation of Imperial Subjects: "Educating" the Colonised during the 1910-1945 Japanese Colonial Rule of Korea

    ERIC Educational Resources Information Center

    Pak, Soon-Yong; Hwang, Keumjoong

    2011-01-01

    This study looks at how education policies in colonial Korea changed over time in order to accommodate the needs of the colonial authorities during the period of Japanese colonial rule in Korea (1910-1945). The colonial experience can be divided into four different periods according to the four Educational Ordinances issued in 1911, 1922, 1938,…

  11. Habitat-related microgeographic variation of worker size and colony size in the ant Cataglyphis cursor.

    PubMed

    Clémencet, Johanna; Doums, Claudie

    2007-05-01

    In social insects, colony size is a crucial life-history trait thought to have major implications for the evolution of social complexity, especially in relation to worker size polymorphism. Yet, little is known about how ecological factors can affect and constrain colony. Here, we explored the pattern of colony-size and worker-size variation in the Mediterranean ant Cataglyphis cursor, in relation to the type of habitats colonized (seaside vs. vineyard). The high level of the water table in the seaside habitat could constrain the depth of C. cursor underground nests and directly constrain its colony size. If worker size increases with colony size, as observed in other ant species, larger colony size and larger workers should be found in the vineyard populations. By comparing worker size among 16 populations, we verified that workers were significantly larger in the vineyard populations. We further determined that the morphological similarities detected among populations from the same habitat type were not due to geographic or genetic proximity. In two populations from each habitat type, the depth of nests was positively correlated with colony size and colony size with worker size. Using a type II regression approach, we further showed that the difference between the two populations in the depth of nest was sufficient to explain the difference in colony size, and similarly, variation in colony size was sufficient to explain variation in worker size. Our results suggest that a single proximate ecological factor could lead to significant variation in major life-history parameters. PMID:17245588

  12. Disturbance Driven Colony Fragmentation as a Driver of a Coral Disease Outbreak

    PubMed Central

    Brandt, Marilyn E.; Smith, Tyler B.; Correa, Adrienne M. S.; Vega-Thurber, Rebecca

    2013-01-01

    In September of 2010, Brewer's Bay reef, located in St. Thomas (U.S. Virgin Islands), was simultaneously affected by abnormally high temperatures and the passage of a hurricane that resulted in the mass bleaching and fragmentation of its coral community. An outbreak of a rapid tissue loss disease among coral colonies was associated with these two disturbances. Gross lesion signs and lesion progression rates indicated that the disease was most similar to the Caribbean coral disease white plague type 1. Experiments indicated that the disease was transmissible through direct contact between colonies, and five-meter radial transects showed a clustered spatial distribution of disease, with diseased colonies being concentrated within the first meter of other diseased colonies. Disease prevalence and the extent to which colonies were bleached were both significantly higher on unattached colony fragments than on attached colonies, and disease occurred primarily on fragments found in direct contact with sediment. In contrast to other recent studies, disease presence was not related to the extent of bleaching on colonies. The results of this study suggest that colony fragmentation and contact with sediment played primary roles in the initial appearance of disease, but that the disease was capable of spreading among colonies, which suggests secondary transmission is possible through some other, unidentified mechanism. PMID:23437335

  13. Inducible morphology, heterochrony, and size hierarchies in a colonial invertebrate monoculture.

    PubMed Central

    Harvell, C D; Padilla, D K

    1990-01-01

    Conditional or inducible strategies are a powerful tool for analyzing the evolution of aggressive behavior. Structures such as stolons and nematocyst-laden tentacles, induced to deter encroachment by competitors, are proportionately better represented in clonal and colonial marine invertebrates than in aclonal animals. Stolons can be produced by colonies of Membranipora membranacea (Bryozoa) within 48 hr after contact with conspecifics. Absolute size and relative size of interacting colonies determine whether stolons will be produced. Although individual stolons are eventually overgrown by conspecifics, they reduce the size of affected zooids by 27%. Since stolon production is primarily a strategy of large colonies, we suggest that stolons function to limit space occupied by small colonies and may also trigger early and localized reproduction. Thus large colonies can surround multiple small mates and, because they reproduce only locally where induced by contact with small colonies, still maintain high growth rates on free colony perimeters. Stolons appear to be juvenilized zooids and to originate through a process of heterochrony. These induced facultative polymorphisms may be one pathway by which fixed polymorphisms arise in colonial invertebrates. We attribute the unique production of inducible structures against competitors by clonal and colonial invertebrates to both unusually high levels of development plasticity and an energetically favorable architecture for perimeter defense. Images PMID:11607055

  14. Effects of juvenile hormone analogs on new reproductives and colony growth of Pharaoh ant (Hymenoptera: Formicidae).

    PubMed

    Lim, S P; Lee, C Y

    2005-12-01

    Two juvenile hormone analogs (JHAs), pyriproxyfen and S-methoprene, were impregnated into dried tuna fish and fed to colonies of Monomorium pharaonis (L.) at very low concentrations (1.0, 2.0, 3.0, 4.0, and 5.0 microg/ml). Its effects on the production of sexuals and colonial growth were observed. Colonies treated with pyriproxyfen yielded sexuals with physical abnormalities. Both female and male sexuals developed bulbous wings, decreased melanization, and died shortly after emergence. Sexuals emerged from colonies treated with S-methoprene did not possess anomalous characteristics. Both pyriproxyfen and S-methoprene did not have significant effects on colonial growth because of the low concentrations of the baits. A commercial bait containing 0.3% S-methoprene (Bioprene-BM) also was evaluated for its efficacy on Pharaoh's ant colonies. Results showed that Pharaoh's ant colonies succumbed to the lethal effects of S-methoprene. Colony members were reduced significantly. Production of queens also decreased significantly in treated colonies and treated queens were unable to lay eggs. JHAs are slow acting and eliminate ant colonies at a relatively slow rate. At low concentrations, pyriproxyfen recorded baffling results, i.e., bulbous wings and demelanized exoskeleton, and it is vital that further studies are initiated to solidify these findings. PMID:16539147

  15. 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. PMID:24725944

  16. Disturbance driven colony fragmentation as a driver of a coral disease outbreak.

    PubMed

    Brandt, Marilyn E; Smith, Tyler B; Correa, Adrienne M S; Vega-Thurber, Rebecca

    2013-01-01

    In September of 2010, Brewer's Bay reef, located in St. Thomas (U.S. Virgin Islands), was simultaneously affected by abnormally high temperatures and the passage of a hurricane that resulted in the mass bleaching and fragmentation of its coral community. An outbreak of a rapid tissue loss disease among coral colonies was associated with these two disturbances. Gross lesion signs and lesion progression rates indicated that the disease was most similar to the Caribbean coral disease white plague type 1. Experiments indicated that the disease was transmissible through direct contact between colonies, and five-meter radial transects showed a clustered spatial distribution of disease, with diseased colonies being concentrated within the first meter of other diseased colonies. Disease prevalence and the extent to which colonies were bleached were both significantly higher on unattached colony fragments than on attached colonies, and disease occurred primarily on fragments found in direct contact with sediment. In contrast to other recent studies, disease presence was not related to the extent of bleaching on colonies. The results of this study suggest that colony fragmentation and contact with sediment played primary roles in the initial appearance of disease, but that the disease was capable of spreading among colonies, which suggests secondary transmission is possible through some other, unidentified mechanism. PMID:23437335

  17. Space colonies and energy supply to the earth

    NASA Technical Reports Server (NTRS)

    Oneill, G. K.

    1975-01-01

    It is pointed out that a space manufacturing facility may be economically more effective than alternative industries on the earth for the construction of products which are to be used in geosynchronous or higher orbits. The suggestion is made to construct solar power stations at a space colony and relocate them in geosynchronous orbit to supply energy to the earth. Attention is given to energy problems and approaches for solving them, taking into account environmental effects and economic factors. Economic aspects of space manufacturing are discussed in some detail.

  18. Design of broadband omnidirectional antireflection coatings using ant colony algorithm.

    PubMed

    Guo, X; Zhou, H Y; Guo, S; Luan, X X; Cui, W K; Ma, Y F; Shi, L

    2014-06-30

    Optimization method which is based on the ant colony algorithm (ACA) is described to optimize antireflection (AR) coating system with broadband omnidirectional characteristics for silicon solar cells incorporated with the solar spectrum (AM1.5 radiation). It's the first time to use ACA method for optimizing the AR coating system. In this paper, for the wavelength range from 400 nm to 1100 nm, the optimized three-layer AR coating system could provide an average reflectance of 2.98% for incident angles from Raveθ+ to 80° and 6.56% for incident angles from 0° to 90°. PMID:24978076

  19. The Colonie FUSRAP Site: CY2002 Situation Report

    SciTech Connect

    Sheeran, A. R.; Dufek, K.; Moore, J.

    2003-02-26

    This paper presents a summary of accomplishments at the Colonie FUSRAP Site in Fiscal Year 2002. During this period several significant milestones were achieved and have set the stage for the project to be completed in a more comprehensive manner, ahead of schedule and at a lower cost than the original Remedial Plan inherited from the Dept of Energy in 1997. Discussion of the DOE and subsequent USACE remedial plans is included along with summary level discussions of the key site infrastructure and remedial elements.

  20. Multi-Megawatt Gas Turbine Power Systems for Lunar Colonies

    NASA Astrophysics Data System (ADS)

    Juhasz, Albert J.

    2006-12-01

    A concept for development of second generation 10 MWe prototype lunar power plant utilizing a gas cooled fission reactor supplying heated helium working fluid to two parallel 5 MWe closed cycle gas turbines is presented. Such a power system is expected to supply the energy needs for an initial lunar colony with a crew of up to 50 persons engaged in mining and manufacturing activities. System performance and mass details were generated by an author developed code (BRMAPS). The proposed pilot power plant can be a model for future plants of the same capacity that could be tied to an evolutionary lunar power grid.

  1. Multi-Megawatt Gas Turbine Power Systems for Lunar Colonies

    NASA Technical Reports Server (NTRS)

    Juhasz, Albert J.

    2006-01-01

    A concept for development of second generation 10 MWe prototype lunar power plant utilizing a gas cooled fission reactor supplying heated helium working fluid to two parallel 5 MWe closed cycle gas turbines is presented. Such a power system is expected to supply the energy needs for an initial lunar colony with a crew of up to 50 persons engaged in mining and manufacturing activities. System performance and mass details were generated by an author developed code (BRMAPS). The proposed pilot power plant can be a model for future plants of the same capacity that could be tied to an evolutionary lunar power grid.

  2. Improved Robustness through Population Variance in Ant Colony Optimization

    NASA Astrophysics Data System (ADS)

    Matthews, David C.; Sutton, Andrew M.; Hains, Doug; Whitley, L. Darrell

    Ant Colony Optimization algorithms are population-based Stochastic Local Search algorithms that mimic the behavior of ants, simulating pheromone trails to search for solutions to combinatorial optimization problems. This paper introduces Population Variance, a novel approach to ACO algorithms that allows parameters to vary across the population over time, leading to solution construction differences that are not strictly stochastic. The increased exploration appears to help the search escape from local optima, significantly improving the robustness of the algorithm with respect to suboptimal parameter settings.

  3. Clinical disorders observed in a beagle breeding colony.

    PubMed

    Fukuda, S; Iida, H; Oghiso, Y; Matsuoka, O

    1985-01-01

    Disorders in a beagle breeding colony were discussed, based on 472 clinical charts made in 1974-1983. In 201 neonates less than a week old, hypothermia associated with pneumonia was mostly seen. In 31 puppies from one week to two months old and in 46 young dogs from two months to a year old, pneumonia, canine parvovirus infection, dermal abscess and dermatosis were mostly found. In 91 dogs aged from one to five, trauma, intervertebral disc protrusion, dermal abscess, dystocia, claudication and otohematoma were frequently noted. In 103 animals over five years old, intervertebral disc protrusion, tumors, abscess, trauma and otohematoma were observed most often. PMID:3987822

  4. Artificial bee colony algorithm for constrained possibilistic portfolio optimization problem

    NASA Astrophysics Data System (ADS)

    Chen, Wei

    2015-07-01

    In this paper, we discuss the portfolio optimization problem with real-world constraints under the assumption that the returns of risky assets are fuzzy numbers. A new possibilistic mean-semiabsolute deviation model is proposed, in which transaction costs, cardinality and quantity constraints are considered. Due to such constraints the proposed model becomes a mixed integer nonlinear programming problem and traditional optimization methods fail to find the optimal solution efficiently. Thus, a modified artificial bee colony (MABC) algorithm is developed to solve the corresponding optimization problem. Finally, a numerical example is given to illustrate the effectiveness of the proposed model and the corresponding algorithm.

  5. Aerial estimation of the size of gull breeding colonies

    USGS Publications Warehouse

    Kadlec, J.A.; Drury, W.H.

    1968-01-01

    Counts on photographs and visual estimates of the numbers of territorial gulls are usually reliable indicators of the number of gull nests, but single visual estimates are not adequate to measure the number of nests in individual colonies. To properly interpret gull counts requires that several islands with known numbers of nests be photographed to establish the ratio of gulls to nests applicable for a given local census. Visual estimates are adequate to determine total breeding gull numbers by regions. Neither visual estimates nor photography will reliably detect annual changes of less than about 2.5 percent.

  6. Parent–offspring resemblance in colony-specific adult survival of cliff swallows

    USGS Publications Warehouse

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

    2015-01-01

    Survival is a key component of fitness. Species that occupy discrete breeding colonies with different characteristics are often exposed to varying costs and benefits associated with group size or environmental conditions, and survival is an integrative net measure of these effects. We investigated the extent to which survival probability of adult (?1-year old) cliff swallows (Petrochelidon pyrrhonota) occupying different colonies resembled that of their parental cohort and thus whether the natal colony had long-term effects on individuals. Individuals were cross-fostered between colonies soon after hatching and their presence as breeders monitored at colonies in the western Nebraska study area for the subsequent decade. Colony-specific adult survival probabilities of offspring born and reared in the same colony, and those cross-fostered away from their natal colony soon after birth, were positively and significantly related to subsequent adult survival of the parental cohort from the natal colony. This result held when controlling for the effect of natal colony size and the age composition of the parental cohort. In contrast, colony-specific adult survival of offspring cross-fostered to a site was unrelated to that of their foster parent cohort or to the cohort of non-fostered offspring with whom they were reared. Adult survival at a colony varied inversely with fecundity, as measured by mean brood size, providing evidence for a survival–fecundity trade-off in this species. The results suggest some heritable variation in adult survival, likely maintained by negative correlations between fitness components. The study provides additional evidence that colonies represent non-random collections of individuals.

  7. Population regulation in Magellanic penguins: what determines changes in colony size?

    PubMed

    Pozzi, Luciana M; García Borboroglu, Pablo; Boersma, P Dee; Pascual, Miguel A

    2015-01-01

    Seabirds are often studied at individual colonies, but the confounding effects of emigration and mortality processes in open populations may lead to inappropriate conclusions on the mechanisms underlying population changes. Magellanic penguin (Spheniscus magellanicus) colonies of variable population sizes are distributed along the Argentine coastline. In recent decades, several population and distributional changes have occurred, with some colonies declining and others newly established or increasing. We integrated data of eight colonies scattered along ?600 km in Northern Patagonia (from 41°26´S, 65°01´W to 45°11´S, 66°30´W, Rio Negro and Chubut provinces) and conducted analysis in terms of their growth rates, production of young and of the dependence of those vital rates on colony age, size, and location. We contrasted population trends estimated from abundance data with those derived from population modeling to understand if observed growth rates were attainable under closed population scenarios. Population trends were inversely related to colony size, suggesting a density dependent growth pattern. All colonies located in the north--which were established during the last decades--increased at high rates, with the smallest, recently established colonies growing at the fastest rate. In central-southern Chubut, where colonies are the oldest, the largest breeding aggregations declined, but smaller colonies remained relatively stable. Results provided strong evidence that dispersal played a major role in driving local trends. Breeding success was higher in northern colonies, likely mediated by favorable oceanographic conditions. However, mean foraging distance and body condition of chicks at fledging were influenced by colony size. Recruitment of penguins in the northern area may have been triggered by a combination of density dependence, likely exacerbated by less favorable oceanographic conditions in the southern sector. Our results reaffirm the idea that individual colony trends do not provide confident indicators of population health, highlighting the need to redefine the scale for the study of population changes. PMID:25786254

  8. Honeybee colony disorder in crop areas: the role of pesticides and viruses.

    PubMed

    Simon-Delso, Noa; San Martin, Gilles; Bruneau, Etienne; Minsart, Laure-Anne; Mouret, Coralie; Hautier, Louis

    2014-01-01

    As in many other locations in the world, honeybee colony losses and disorders have increased in Belgium. Some of the symptoms observed rest unspecific and their causes remain unknown. The present study aims to determine the role of both pesticide exposure and virus load on the appraisal of unexplained honeybee colony disorders in field conditions. From July 2011 to May 2012, 330 colonies were monitored. Honeybees, wax, beebread and honey samples were collected. Morbidity and mortality information provided by beekeepers, colony clinical visits and availability of analytical matrix were used to form 2 groups: healthy colonies and colonies with disorders (n?=?29, n?=?25, respectively). Disorders included: (1) dead colonies or colonies in which part of the colony appeared dead, or had disappeared; (2) weak colonies; (3) queen loss; (4) problems linked to brood and not related to any known disease. Five common viruses and 99 pesticides (41 fungicides, 39 insecticides and synergist, 14 herbicides, 5 acaricides and metabolites) were quantified in the samples.The main symptoms observed in the group with disorders are linked to brood and queens. The viruses most frequently found are Black Queen Cell Virus, Sac Brood Virus, Deformed Wing Virus. No significant difference in virus load was observed between the two groups. Three acaricides, 5 insecticides and 13 fungicides were detected in the analysed samples. A significant correlation was found between the presence of fungicide residues and honeybee colony disorders. A significant positive link could also be established between the observation of disorder and the abundance of crop surface around the beehive. According to our results, the role of fungicides as a potential stressor for honeybee colonies should be further studied, either by their direct and/or indirect impacts on bees and bee colonies. PMID:25048715

  9. Honeybee Colony Disorder in Crop Areas: The Role of Pesticides and Viruses

    PubMed Central

    Simon-Delso, Noa; San Martin, Gilles; Bruneau, Etienne; Minsart, Laure-Anne; Mouret, Coralie; Hautier, Louis

    2014-01-01

    As in many other locations in the world, honeybee colony losses and disorders have increased in Belgium. Some of the symptoms observed rest unspecific and their causes remain unknown. The present study aims to determine the role of both pesticide exposure and virus load on the appraisal of unexplained honeybee colony disorders in field conditions. From July 2011 to May 2012, 330 colonies were monitored. Honeybees, wax, beebread and honey samples were collected. Morbidity and mortality information provided by beekeepers, colony clinical visits and availability of analytical matrix were used to form 2 groups: healthy colonies and colonies with disorders (n = 29, n = 25, respectively). Disorders included: (1) dead colonies or colonies in which part of the colony appeared dead, or had disappeared; (2) weak colonies; (3) queen loss; (4) problems linked to brood and not related to any known disease. Five common viruses and 99 pesticides (41 fungicides, 39 insecticides and synergist, 14 herbicides, 5 acaricides and metabolites) were quantified in the samples.The main symptoms observed in the group with disorders are linked to brood and queens. The viruses most frequently found are Black Queen Cell Virus, Sac Brood Virus, Deformed Wing Virus. No significant difference in virus load was observed between the two groups. Three acaricides, 5 insecticides and 13 fungicides were detected in the analysed samples. A significant correlation was found between the presence of fungicide residues and honeybee colony disorders. A significant positive link could also be established between the observation of disorder and the abundance of crop surface around the beehive. According to our results, the role of fungicides as a potential stressor for honeybee colonies should be further studied, either by their direct and/or indirect impacts on bees and bee colonies. PMID:25048715

  10. Population Regulation in Magellanic Penguins: What Determines Changes in Colony Size?

    PubMed Central

    Pozzi, Luciana M.; Borboroglu, Pablo García; Boersma, P. Dee; Pascual, Miguel A.

    2015-01-01

    Seabirds are often studied at individual colonies, but the confounding effects of emigration and mortality processes in open populations may lead to inappropriate conclusions on the mechanisms underlying population changes. Magellanic penguin (Spheniscus magellanicus) colonies of variable population sizes are distributed along the Argentine coastline. In recent decades, several population and distributional changes have occurred, with some colonies declining and others newly established or increasing. We integrated data of eight colonies scattered along ∼ 600 km in Northern Patagonia (from 41°26´S, 65°01´W to 45°11´S, 66°30´W, Rio Negro and Chubut provinces) and conducted analysis in terms of their growth rates, production of young and of the dependence of those vital rates on colony age, size, and location. We contrasted population trends estimated from abundance data with those derived from population modeling to understand if observed growth rates were attainable under closed population scenarios. Population trends were inversely related to colony size, suggesting a density dependent growth pattern. All colonies located in the north—which were established during the last decades—increased at high rates, with the smallest, recently established colonies growing at the fastest rate. In central-southern Chubut, where colonies are the oldest, the largest breeding aggregations declined, but smaller colonies remained relatively stable. Results provided strong evidence that dispersal played a major role in driving local trends. Breeding success was higher in northern colonies, likely mediated by favorable oceanographic conditions. However, mean foraging distance and body condition of chicks at fledging were influenced by colony size. Recruitment of penguins in the northern area may have been triggered by a combination of density dependence, likely exacerbated by less favorable oceanographic conditions in the southern sector. Our results reaffirm the idea that individual colony trends do not provide confident indicators of population health, highlighting the need to redefine the scale for the study of population changes. PMID:25786254

  11. Genetic homogeneity among colonies of the white-nest swiftlet (Aerodramus fuciphagus) in Thailand.

    PubMed

    Aowphol, Anchalee; Voris, Harold Knight; Feldheim, Kevin Andrew; Harnyuttanakorn, Pongchai; Thirakhupt, Kumthorn

    2008-04-01

    The white-nest swiftlet, Aerodramus fuciphagus, originally lived in large colonies in natural caves, but now it also occurs in man-made buildings. We investigated the patterns of genetic differentiation in two mitochondrial DNA genes (cyt-b and ND2) and eight microsatellite loci among and within colonies of A. fuciphagus from across recently established man-made colonies in Thailand. Ten white-nest swiftlet colonies were sampled along the coast of the Gulf of Thailand and the Andaman Sea in Thailand during 2003-2006. The genetic diversity of mtDNA was very low, and few significant PhiST values were found between pairs of colonies. Analyses of haplotype relationships did not show genetic structure across the sampled distribution. The level of genetic diversity for microsatellite loci was high, but FST values were not significant. However, due to small sample sizes for some colonies that could limit conclusions on genetic differentiation from PhiST and FST, we also analyzed the microsatellite data using STRUCTURE and found that number of subpopulations of white-nest swiftlets in sampled colonies was one. The lack of genetic differentiation among swiftlet house colonies could be a result of high gene flow between colonies and large population sizes. Our results suggest that A. fuciphagus living in recently established man-made colonies in Thailand should be considered members of a single panmictic population. Future work will be necessary to determine whether this panmixia is stable or a temporary result of the recent explosive expansion of the number of colonies, and comparisons to natural colonies may provide an understanding of mechanisms producing the lack of genetic structure in swiftlet house colonies. PMID:18459819

  12. Distribution, species abundance, and nesting-site use of Atlantic coast colonies of herons and their allies

    USGS Publications Warehouse

    Custer, T.W.; Osborn, R.G.; Stout, W.F.

    1980-01-01

    In 1975 and 1976, eight teams of investigators located 262 colonies of nesting herons and their allies along the Atlantic coast from Florida to Maine. Fourteen species were found in Florida, numbers decreasing to seven in Maine. Colonies censused in the extreme south and north of the study area were lower in number of species and number of adults than those in the intermediate area. More than 90% of the colony sites surveyed in 1975 were active in 1976. The total number of nesting adults per colony, number of species per colony, and number of nestinga dults of each speciesp er colonyi n 1976 were significantlyc orrelatedw ith their respective values for 1975. Abandoned and new colonies appeared to be satellites of nearby reused colonies; they had fewer individuals and species than reused colonies and were closer to reused colonies than reused colonies were to each other.

  13. Mechanically-driven phase separation in a growing bacterial colony

    PubMed Central

    Ghosh, Pushpita; Mondal, Jagannath; Ben-Jacob, Eshel; Levine, Herbert

    2015-01-01

    Secretion of extracellular polymeric substances (EPSs) by growing bacteria is an integral part of forming biofilm-like structures. In such dense systems, mechanical interactions among the structural components can be expected to significantly contribute to morphological properties. Here, we use a particle-based modeling approach to study the self-organization of nonmotile rod-shaped bacterial cells growing on a solid substrate in the presence of self-produced EPSs. In our simulation, all of the components interact mechanically via repulsive forces, occurring as the bacterial cells grow and divide (via consuming diffusing nutrient) and produce EPSs. Based on our simulation, we show that mechanical interactions control the collective behavior of the system. In particular, we find that the presence of nonadsorbing EPSs can lead to spontaneous aggregation of bacterial cells by a depletion attraction and thereby generates phase separated patterns in the nonequilibrium growing colony. Both repulsive interactions between cell and EPSs and the overall concentration of EPSs are important factors in the self-organization in a nonequilibrium growing colony. Furthermore, we investigate the interplay of mechanics with the nutrient diffusion and consumption by bacterial cells and observe that suppression of branch formation occurs due to EPSs compared with the case where no EPS is produced. PMID:25870260

  14. Colony-level impacts of parasitoid flies on fire ants.

    PubMed Central

    Mehdiabadi, Natasha J; Gilbert, Lawrence E

    2002-01-01

    The red imported fire ant is becoming a global ecological problem, having invaded the United States, Puerto Rico, New Zealand and, most recently, Australia. In its established areas, this pest is devastating natural biodiversity. Early attempts to halt fire ant expansion with pesticides actually enhanced its spread. Phorid fly parasitoids from South America have now been introduced into the United States as potential biological control agents of the red imported fire ant, but the impact of these flies on fire ant populations is currently unknown. In the laboratory, we show that an average phorid density of as little as one attacking fly per 200 foraging ants decreased colony protein consumption nearly twofold and significantly reduced numbers of large-sized workers 50 days later. The high impact of a single phorid occurred mainly because ants decreased foraging rates in the presence of the flies. Our experiments, the first (to our knowledge) to link indirect and direct effects of phorids on fire ants, demonstrate that colonies can be stressed with surprisingly low parasitoid densities. We interpret our findings with regard to the more complex fire ant-phorid interactions in the field. PMID:12204130

  15. Collective chemotaxis and segregation of active bacterial colonies

    PubMed Central

    Amar, M. Ben

    2016-01-01

    Still recently, bacterial fluid suspensions have motivated a lot of works, both experimental and theoretical, with the objective to understand their collective dynamics from universal and simple rules. Since some species are active, most of these works concern the strong interactions that these bacteria exert on a forced flow leading to instabilities, chaos and turbulence. Here, we investigate the self-organization of expanding bacterial colonies under chemotaxis, proliferation and eventually active-reaction. We propose a simple model to understand and quantify the physical properties of these living organisms which either give cohesion or on the contrary dispersion to the colony. Taking into account the diffusion and capture of morphogens complicates the model since it induces a bacterial density gradient coupled to bacterial density fluctuations and dynamics. Nevertheless under some specific conditions, it is possible to investigate the pattern formation as a usual viscous fingering instability. This explains the similarity and differences of patterns according to the physical bacterial suspension properties and explain the factors which favor compactness or branching. PMID:26888040

  16. Collective chemotaxis and segregation of active bacterial colonies.

    PubMed

    Amar, M Ben

    2016-01-01

    Still recently, bacterial fluid suspensions have motivated a lot of works, both experimental and theoretical, with the objective to understand their collective dynamics from universal and simple rules. Since some species are active, most of these works concern the strong interactions that these bacteria exert on a forced flow leading to instabilities, chaos and turbulence. Here, we investigate the self-organization of expanding bacterial colonies under chemotaxis, proliferation and eventually active-reaction. We propose a simple model to understand and quantify the physical properties of these living organisms which either give cohesion or on the contrary dispersion to the colony. Taking into account the diffusion and capture of morphogens complicates the model since it induces a bacterial density gradient coupled to bacterial density fluctuations and dynamics. Nevertheless under some specific conditions, it is possible to investigate the pattern formation as a usual viscous fingering instability. This explains the similarity and differences of patterns according to the physical bacterial suspension properties and explain the factors which favor compactness or branching. PMID:26888040

  17. Whole Cell Modeling: From Single Cells to Colonies

    PubMed Central

    Cole, John A.

    2015-01-01

    A great deal of research over the last several years has focused on how the inherent randomness in movements and reactivity of biomolecules can give rise to unexpected large-scale differences in the behavior of otherwise identical cells. Our own research has approached this problem from two vantage points – a microscopic kinetic view of the individual molecules (nucleic acids, proteins, etc.) diffusing and interacting in a crowded cellular environment; and a broader systems-level view of how enzyme variability can give rise to well-defined metabolic phenotypes. The former led to the development of the Lattice Microbes software – a GPU-accelerated stochastic simulator for reaction-diffusion processes in models of whole cells; the latter to the development of a method we call population flux balance analysis (FBA). The first part of this article reviews the Lattice Microbes methodology, and two recent technical advances that extend the capabilities of Lattice Microbes to enable simulations of larger organisms and colonies. The second part of this article focuses on our recent population FBA study of Escherichia coli, which predicted variability in the usage of different metabolic pathways resulting from heterogeneity in protein expression. Finally, we discuss exciting early work using a new hybrid methodology that integrates FBA with spatially resolved kinetic simulations to study how cells compete and cooperate within dense colonies and consortia. PMID:26989262

  18. Mechanically-driven phase separation in a growing bacterial colony.

    PubMed

    Ghosh, Pushpita; Mondal, Jagannath; Ben-Jacob, Eshel; Levine, Herbert

    2015-04-28

    Secretion of extracellular polymeric substances (EPSs) by growing bacteria is an integral part of forming biofilm-like structures. In such dense systems, mechanical interactions among the structural components can be expected to significantly contribute to morphological properties. Here, we use a particle-based modeling approach to study the self-organization of nonmotile rod-shaped bacterial cells growing on a solid substrate in the presence of self-produced EPSs. In our simulation, all of the components interact mechanically via repulsive forces, occurring as the bacterial cells grow and divide (via consuming diffusing nutrient) and produce EPSs. Based on our simulation, we show that mechanical interactions control the collective behavior of the system. In particular, we find that the presence of nonadsorbing EPSs can lead to spontaneous aggregation of bacterial cells by a depletion attraction and thereby generates phase separated patterns in the nonequilibrium growing colony. Both repulsive interactions between cell and EPSs and the overall concentration of EPSs are important factors in the self-organization in a nonequilibrium growing colony. Furthermore, we investigate the interplay of mechanics with the nutrient diffusion and consumption by bacterial cells and observe that suppression of branch formation occurs due to EPSs compared with the case where no EPS is produced. PMID:25870260

  19. Hidden peasant women in colonial Awadh: some hypotheses.

    PubMed

    Jassal, S T

    1998-01-01

    This article proposes that it is necessary to understand the conditions governing the access of Indian women to productive resources as well as the nature of their involvement in production in order to analyze historical agrarian relationships as well as increasing differentiation between social classes in the colonial era. After an introduction, the article describes 1) how residential location allowed differentiation among peasant groups who cultivated their own village lands from those who cultivated lands of neighboring villages and 2) the crucial role of peasant women as agricultural laborers on the family holdings. The next section looks at caste differentiation among the peasants and points out that high-caste peasants paid a lower rent, perhaps in recognition of the fact that their position barred them and their women from certain agricultural chores and forced them to hire laborers. The article continues by describing the changes that occurred as a consequence of Colonial rule when peasants with land rights found themselves recast as tenants-at-will and, sometimes, evicted from land they had controlled for generations. This had an impact on caste relationships and led to a growth in "begar," the obligation of a peasant to work for the landlord. Women, especially, suffered harsh consequences when they refused to provide begar. In conclusion, it is hypothesized that increased differentiation among classes was based on the use of women's productivity, which also distinguished rank and status, but that women had no access to or control over resources. PMID:12321578

  20. Visual Navigation during Colony Emigration by the Ant Temnothorax rugatulus

    PubMed Central

    Bowens, Sean R.; Glatt, Daniel P.; Pratt, Stephen C.

    2013-01-01

    Many ants rely on both visual cues and self-generated chemical signals for navigation, but their relative importance varies across species and context. We evaluated the roles of both modalities during colony emigration by Temnothorax rugatulus. Colonies were induced to move from an old nest in the center of an arena to a new nest at the arena edge. In the midst of the emigration the arena floor was rotated 60°around the old nest entrance, thus displacing any substrate-bound odor cues while leaving visual cues unchanged. This manipulation had no effect on orientation, suggesting little influence of substrate cues on navigation. When this rotation was accompanied by the blocking of most visual cues, the ants became highly disoriented, suggesting that they did not fall back on substrate cues even when deprived of visual information. Finally, when the substrate was left in place but the visual surround was rotated, the ants' subsequent headings were strongly rotated in the same direction, showing a clear role for visual navigation. Combined with earlier studies, these results suggest that chemical signals deposited by Temnothorax ants serve more for marking of familiar territory than for orientation. The ants instead navigate visually, showing the importance of this modality even for species with small eyes and coarse visual acuity. PMID:23671713

  1. Opinions from the Front Lines of Cat Colony Management Conflict

    PubMed Central

    Peterson, M. Nils; Hartis, Brett; Rodriguez, Shari; Green, Matthew; Lepczyk, Christopher A.

    2012-01-01

    Outdoor cats represent a global threat to terrestrial vertebrate conservation, but management has been rife with conflict due to differences in views of the problem and appropriate responses to it. To evaluate these differences we conducted a survey of opinions about outdoor cats and their management with two contrasting stakeholder groups, cat colony caretakers (CCCs) and bird conservation professionals (BCPs) across the United States. Group opinions were polarized, for both normative statements (CCCs supported treating feral cats as protected wildlife and using trap neuter and release [TNR] and BCPs supported treating feral cats as pests and using euthanasia) and empirical statements. Opinions also were related to gender, age, and education, with females and older respondents being less likely than their counterparts to support treating feral cats as pests, and females being less likely than males to support euthanasia. Most CCCs held false beliefs about the impacts of feral cats on wildlife and the impacts of TNR (e.g., 9% believed feral cats harmed bird populations, 70% believed TNR eliminates cat colonies, and 18% disagreed with the statement that feral cats filled the role of native predators). Only 6% of CCCs believed feral cats carried diseases. To the extent the beliefs held by CCCs are rooted in lack of knowledge and mistrust, rather than denial of directly observable phenomenon, the conservation community can manage these conflicts more productively by bringing CCCs into the process of defining data collection methods, defining study/management locations, and identifying common goals related to caring for animals. PMID:22970269

  2. ABCluster: the artificial bee colony algorithm for cluster global optimization.

    PubMed

    Zhang, Jun; Dolg, Michael

    2015-10-01

    Global optimization of cluster geometries is of fundamental importance in chemistry and an interesting problem in applied mathematics. In this work, we introduce a relatively new swarm intelligence algorithm, i.e. the artificial bee colony (ABC) algorithm proposed in 2005, to this field. It is inspired by the foraging behavior of a bee colony, and only three parameters are needed to control it. We applied it to several potential functions of quite different nature, i.e., the Coulomb-Born-Mayer, Lennard-Jones, Morse, Z and Gupta potentials. The benchmarks reveal that for long-ranged potentials the ABC algorithm is very efficient in locating the global minimum, while for short-ranged ones it is sometimes trapped into a local minimum funnel on a potential energy surface of large clusters. We have released an efficient, user-friendly, and free program "ABCluster" to realize the ABC algorithm. It is a black-box program for non-experts as well as experts and might become a useful tool for chemists to study clusters. PMID:26327507

  3. Vanishing point detection based on an artificial bee colony algorithm

    NASA Astrophysics Data System (ADS)

    Han, Lei; Fan, Tanghuai; Zheng, Shengnan; Huang, Chenrong

    2015-05-01

    Vanishing points (VPs) are crucial for inferring the three-dimensional structure of a scene and can be exploited in various computer vision applications. Previous VP detection algorithms have been proven effective but generally cannot guarantee a strong performance in both accuracy and computational time. We propose an artificial bee colony algorithm called dynamic clustering artificial bee colony (DCABC) that accurately and efficiently detects VPs in the image plane. The task is regarded as a dynamic line-clustering problem, and the line clusters are initialized by their orientation information. Inspired by the foraging behavior of bees, DCABC selects the clustering center and reclassifies the line segments based on a distance criterion until the terminating condition is met. The optimal line clusters determine the estimated VP. The dissimilarity among solutions is measured by the Hamming distance between two binary vectors, which simplifies the new solution construction. The performances of the proposed and existing algorithms are evaluated on the York Urban database. The results verify the efficiency and accuracy of our proposed algorithm.

  4. Modeling the role of water in Bacillus subtilis colonies.

    PubMed

    Mezanges, X; Regeard, C; Gerin, C; Deroulers, C; Grammaticos, B; Badoual, M

    2012-04-01

    We propose a simple cellular automaton model for the description of the evolution of a colony of Bacillus subtilis. The originality of our model lies in the fact that the bacteria can move in a pool of liquid. We assume that each migrating bacterium is surrounded by an individual pool, and the overlap of the latter gives rise to a collective pool with a higher water level. The bacteria migrate collectively when the level of water is high enough. When the bacteria are far enough from each other, the level of water becomes locally too low to allow migration, and the bacteria switch to a proliferating state. The proliferation-to-migration switch is triggered by high levels of a substance produced by proliferating bacteria. We show that it is possible to reproduce in a fairly satisfactory way the various forms that make up the experimentally observed morphological diagram of B. subtilis. We propose a phenomenological relation between the size of the water pool used in our model and the agar concentration of the substrate on which the bacteria migrate. We also compare experimental results from cutting the central part of the colony with the results of our simulations. PMID:22680504

  5. Granulocyte colony-stimulating factor and reproductive medicine: A review

    PubMed Central

    Cavalcante, Marcelo Borges; Costa, Fabrício DA Silva; Barini, Ricardo; Araujo Júnior, Edward

    2015-01-01

    Background: Recently, the use of granulocyte colony-stimulating factor (G-CSF) has been proposed to improve pregnancy outcomes in reproductive medicine. Objective: A systematic review of the current use of G-CSF in patients who have difficulty conceiving and maintaining pregnancy was performed. Materials and Methods: Two electronic databases (PubMed/ Medline and Scopus) were searched. Study selection, data extraction and quality assessment were performed in duplicate. The subject codes used were granulocyte colony-stimulating factor, G-CSF, recurrent miscarriage, IVF failure, and endometrium. Results: The search of electronic databases resulted in 215 citations (PubMed/ Medline: 139 and Scopus: 76), of which 38 were present in both databases. Of the remaining 177 publications, seven studies were included in the present review. Conclusion: Treatment with G-CSF is a novel proposal for immune therapy in patients with recurrent miscarriage and implantation failure following cycles of IVF. However, a larger number of well-designed studies are required for this treatment to be established. PMID:26131007

  6. Modeling the role of water in Bacillus subtilis colonies

    NASA Astrophysics Data System (ADS)

    Mezanges, X.; Regeard, C.; Gerin, C.; Deroulers, C.; Grammaticos, B.; Badoual, M.

    2012-04-01

    We propose a simple cellular automaton model for the description of the evolution of a colony of Bacillus subtilis. The originality of our model lies in the fact that the bacteria can move in a pool of liquid. We assume that each migrating bacterium is surrounded by an individual pool, and the overlap of the latter gives rise to a collective pool with a higher water level. The bacteria migrate collectively when the level of water is high enough. When the bacteria are far enough from each other, the level of water becomes locally too low to allow migration, and the bacteria switch to a proliferating state. The proliferation-to-migration switch is triggered by high levels of a substance produced by proliferating bacteria. We show that it is possible to reproduce in a fairly satisfactory way the various forms that make up the experimentally observed morphological diagram of B. subtilis. We propose a phenomenological relation between the size of the water pool used in our model and the agar concentration of the substrate on which the bacteria migrate. We also compare experimental results from cutting the central part of the colony with the results of our simulations.

  7. Age and breeding success related to nest position in a White stork Ciconia ciconia colony

    NASA Astrophysics Data System (ADS)

    Vergara, Pablo; Aguirre, José I.

    2006-11-01

    Coloniality is a breeding system that may produce benefits in terms of breeding success, although these advantages could vary according to factors such as colony size or nest position. We studied breeder's age in relation to nest position (peripheral or central) within the colony. In addition, we studied the relationship between breeding success and nest position, controlling for breeder's age, a highly correlated factor, in a White Stork Ciconia ciconia colony over a 7-year period. Our results show that central nests are mainly occupied by adult birds and had lower failure rates. However, controlling for breeder's age, nest position per se did not explain breeding success. The scarce predation and the lack of human disturbance in the study colony could explain the absence of differences in breeding success between different nest positions within the colony.

  8. Lower disease infections in honeybee (Apis mellifera) colonies headed by polyandrous vs monandrous queens

    NASA Astrophysics Data System (ADS)

    Tarpy, David R.; Seeley, Thomas D.

    2006-04-01

    We studied the relationship between genetic diversity and disease susceptibility in honeybee colonies living under natural conditions. To do so, we created colonies in which each queen was artificially inseminated with sperm from either one or ten drones. Of the 20 colonies studied, 80% showed at least one brood disease. We found strong differences between the two types of colonies in the infection intensity of chalkbrood and in the total intensity of all brood diseases (chalkbrood, sacbrood, American foulbrood, and European foulbrood) with both variables lower for the colonies with higher genetic diversity. Our findings demonstrate that disease can be an important factor in the ecology of honeybee colonies and they provide strong support for the disease hypothesis for the evolution of polyandry by social insect queens.

  9. Quantifying Two-Dimensional Filamentous and Invasive Growth Spatial Patterns in Yeast Colonies

    PubMed Central

    Binder, Benjamin J.; Sundstrom, Joanna F.; Gardner, Jennifer M.; Jiranek, Vladimir; Oliver, Stephen G.

    2015-01-01

    The top-view, two-dimensional spatial patterning of non-uniform growth in a Saccharomyces cerevisiae yeast colony is considered. Experimental images are processed to obtain data sets that provide spatial information on the cell-area that is occupied by the colony. A method is developed that allows for the analysis of the spatial distribution with three metrics. The growth of the colony is quantified in both the radial direction from the centre of the colony and in the angular direction in a prescribed outer region of the colony. It is shown that during the period of 100–200 hours from the start of the growth of the colony there is an increasing amount of non-uniform growth. The statistical framework outlined in this work provides a platform for comparative quantitative assays of strain-specific mechanisms, with potential implementation in inferencing algorithms used for parameter-rate estimation. PMID:25719406

  10. Predation of artificial ground nests on white-tailed prairie dog colonies

    USGS Publications Warehouse

    Baker, B.W.; Stanley, T.R.; Sedgwick, J.A.

    1999-01-01

    Prairie dog (Cynomys spp.) colonies are unique to prairie and shrub-steppe landscapes. However, widespread eradication, habitat loss, and sylvatic plague (Yersinia pestis) have reduced their numbers by 98% since historical times. Birds associated with prairie dogs also are declining. Potential nest predators, such as coyotes (Canis latrans), swift foxes (Vulpes velox), and badgers (Taxidea taxus), may be attracted to colonies where a high concentration of prairie dogs serve as available prey. Increased abundance of small mammals, including prairie dogs, also may increase the risk of predation for birds nesting on colonies. Finally, because grazing by prairie dogs may decrease vegetation height and canopy cover, bird nests may be easier for predators to locate. In this study, we placed 1,444 artificial ground nests on and off 74 white-tailed prairie dog (C. leucurus) colonies to test the hypothesis that nest predation rates are higher on colonies than at nearby off sites (i.e., uncolonized habitat). We sampled colonies from 27 May to 16 July 1997 at the following 3 complexes: Coyote Basin, Utah and Colorado; Moxa Arch, Wyoming; and Shirley Basin, Wyoming. Differences in daily predation rates between colonies and paired off sites averaged 1.0% (P = 0.060). When converted to a typical 14-day incubation period, predation rates averaged 14% higher on colonies (57.7 ?? 2.7%; ?? ?? SE) than at off sites (50.4 ?? 3.1%). Comparisons of habitat variables on colonies to off sites showed percent canopy cover of vegetation was similar (P = 0.114), percent bare ground was higher on colonies (P 0.288). Although we found the risk of nest predation was higher on white-tailed prairie dog colonies than at off sites, fitness of birds nesting on colonies might depend on other factors that influence foraging success, reproductive success, or nestling survival.

  11. Gi-Coupled GPCR Signaling Controls the Formation and Organization of Human Pluripotent Colonies

    PubMed Central

    Nakamura, Kenta; Salomonis, Nathan; Tomoda, Kiichiro; Yamanaka, Shinya; Conklin, Bruce R.

    2009-01-01

    Background Reprogramming adult human somatic cells to create human induced pluripotent stem (hiPS) cell colonies involves a dramatic morphological and organizational transition. These colonies are morphologically indistinguishable from those of pluripotent human embryonic stem (hES) cells. G protein-coupled receptors (GPCRs) are required in diverse developmental processes, but their role in pluripotent colony morphology and organization is unknown. We tested the hypothesis that Gi-coupled GPCR signaling contributes to the characteristic morphology and organization of human pluripotent colonies. Methodology/Principal Findings Specific and irreversible inhibition of Gi-coupled GPCR signaling by pertussis toxin markedly altered pluripotent colony morphology. Wild-type hES and hiPS cells formed monolayer colonies, but colonies treated with pertussis toxin retracted inward, adopting a dense, multi-layered conformation. The treated colonies were unable to reform after a scratch wound insult, whereas control colonies healed completely within 48 h. In contrast, activation of an alternative GPCR pathway, Gs-coupled signaling, with cholera toxin did not affect colony morphology or the healing response. Pertussis toxin did not alter the proliferation, apoptosis or pluripotency of pluripotent stem cells. Conclusions/Significance Experiments with pertussis toxin suggest that Gi signaling plays a critical role in the morphology and organization of pluripotent colonies. These results may be explained by a Gi-mediated density-sensing mechanism that propels the cells radially outward. GPCRs are a promising target for modulating the formation and organization of hiPS and hES cell colonies and may be important for understanding somatic cell reprogramming and for engineering pluripotent stem cells for therapeutic applications. PMID:19936228

  12. Impact of Chronic Neonicotinoid Exposure on Honeybee Colony Performance and Queen Supersedure

    PubMed Central

    Sandrock, Christoph; Tanadini, Matteo; Tanadini, Lorenzo G.; Fauser-Misslin, Aline; Potts, Simon G.; Neumann, Peter

    2014-01-01

    Background Honeybees provide economically and ecologically vital pollination services to crops and wild plants. During the last decade elevated colony losses have been documented in Europe and North America. Despite growing consensus on the involvement of multiple causal factors, the underlying interactions impacting on honeybee health and colony failure are not fully resolved. Parasites and pathogens are among the main candidates, but sublethal exposure to widespread agricultural pesticides may also affect bees. Methodology/Principal Findings To investigate effects of sublethal dietary neonicotinoid exposure on honeybee colony performance, a fully crossed experimental design was implemented using 24 colonies, including sister-queens from two different strains, and experimental in-hive pollen feeding with or without environmentally relevant concentrations of thiamethoxam and clothianidin. Honeybee colonies chronically exposed to both neonicotinoids over two brood cycles exhibited decreased performance in the short-term resulting in declining numbers of adult bees (−28%) and brood (−13%), as well as a reduction in honey production (−29%) and pollen collections (−19%), but colonies recovered in the medium-term and overwintered successfully. However, significantly decelerated growth of neonicotinoid-exposed colonies during the following spring was associated with queen failure, revealing previously undocumented long-term impacts of neonicotinoids: queen supersedure was observed for 60% of the neonicotinoid-exposed colonies within a one year period, but not for control colonies. Linked to this, neonicotinoid exposure was significantly associated with a reduced propensity to swarm during the next spring. Both short-term and long-term effects of neonicotinoids on colony performance were significantly influenced by the honeybees’ genetic background. Conclusions/Significance Sublethal neonicotinoid exposure did not provoke increased winter losses. Yet, significant detrimental short and long-term impacts on colony performance and queen fate suggest that neonicotinoids may contribute to colony weakening in a complex manner. Further, we highlight the importance of the genetic basis of neonicotinoid susceptibility in honeybees which can vary substantially. PMID:25084279

  13. 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

    2004-01-01

    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. PMID:14705009

  14. Censusing wading bird colonies: An update on the 'flight-line' count method

    USGS Publications Warehouse

    Erwin, R.M.

    1981-01-01

    1. Thirteen mixed-species heronries (10 in Florida, two in Virginia, one in North Carolina) were studied in 1980 as part of a project begun in 1979 aimed at evaluating the 'flight-line' census method..2. Standardized counts of Snowy and Cattle Egrets, Louisiana and Little Blue Herons flying to and from the nesting colony were made for three hr periods, followed by a nest count of the colony. 3.Significant differences were found in the flight rates (number of birds per nest x hour) of the four species at the Chincoteague colony. However, when Cattle Egrets and Louisiana Herons were compared at all 13 colonies, their respective flight rates were in opposite rank to those at Chincoteague. Colony differences, then, may mask species differences. 4. A linear regression model showed a strong fit (R2=0.92) between the hourly flight number (3 hr means) and the nest number, but point estimates (single colony) had very large confidence limits. A given colony might be over-or underestimated by a factor of 2, using the regression equation as a predictive model. 5. A more appropriate application of the method would be to determine regionwide (e.g., state), rather than colony-specific, population estimates. 'Total' estimates for all (n= 13) colonies were within 10% of the actual nest number.

  15. Estimated areal extent of colonies of black-tailed prairie dogs in the northern Great Plains

    USGS Publications Warehouse

    Sidle, John G.; Johnson, D.H.; Euliss, B.R.

    2001-01-01

    During 1997-1998, we undertook an aerial survey, with an aerial line-intercept technique, to estimate the extent of colonies of black-tailed prairie dogs (Cynomys ludovicianus) in the northern Great Plains states of Nebraska, North Dakota, South Dakota, and Wyoming. We stratified the survey based on knowledge of colony locations, computed 2 types of estimates for each stratum, and combined ratio estimates for high-density strata with average density estimates for low-density strata. Estimates of colony areas for black-tailed prairie dogs were derived from the average percentages of lines intercepting prairie dog colonies and ratio estimators. We selected the best estimator based on the correlation between length of transect line and length of intercepted colonies. Active colonies of black-tailed prairie dogs occupied 2,377.8 km2 i?? 186.4 SE, whereas inactive colonies occupied 560.4 i?? 89.2 km2. These data represent the 1st quantitative assessment of prairie-dog colonies in the northern Great Plains. The survey dispels popular notions that millions of square kilometers of colonies of black-tailed prairie dogs exist in the northern Great Plains and can form the basis for future survey efforts

  16. The rewards of restraint in the collective regulation of foraging by harvester ant colonies.

    PubMed

    Gordon, Deborah M

    2013-06-01

    Collective behaviour, arising from local interactions, allows groups to respond to changing conditions. Long-term studies have shown that the traits of individual mammals and birds are associated with their reproductive success, but little is known about the evolutionary ecology of collective behaviour in natural populations. An ant colony operates without central control, regulating its activity through a network of local interactions. This work shows that variation among harvester ant (Pogonomyrmex barbatus) colonies in collective response to changing conditions is related to variation in colony lifetime reproductive success in the production of offspring colonies. Desiccation costs are high for harvester ants foraging in the desert. More successful colonies tend to forage less when conditions are dry, and show relatively stable foraging activity when conditions are more humid. Restraint from foraging does not compromise a colony's long-term survival; colonies that fail to forage at all on many days survive as long, over the colony's 20-30-year lifespan, as those that forage more regularly. Sensitivity to conditions in which to reduce foraging activity may be transmissible from parent to offspring colony. These results indicate that natural selection is shaping the collective behaviour that regulates foraging activity, and that the selection pressure, related to climate, may grow stronger if the current drought in their habitat persists. PMID:23676676

  17. Growth and differentiation of spermatogenetic colonies in the mouse testis after irradiation with fission neutrons

    SciTech Connect

    van den Aardweg, G.J.M.J.; de Ruiter-Bootsma, A.L.; Kramer, M.F.; Davids, J.A.G.

    1983-06-01

    The longitudinal outgrowth of spermatogenetic colonies arising from stem cells that survived neutron doses of 150, 300, and 350 rad was studied up to 30 weeks in histological sections of CBA mouse testes. Two methods were used: (1) the repopulation index (RI) as a measure of the length of total colonies per testis and (2) measurement of the individual length of all colonies in serially sectioned testes 4 and 15 weeks after 300 rad and 15 weeks after 350 rad. The mean initial growth of the colonies is linear up to 8, 15, and 20 weeks after 150, 300, and 350 rad, respectively. Counting of colonies after 300 rad showed that all surviving stem cells had started to form a colony within 4 weeks after irradiation. The development of spermatogenetic cells to mature spermatozoa was studied after 100, 150, 300, and 350 rad in sections of repopulating tubules used for RI determination as well as in serial sections of individual colonies. Although after 300 and 350 rad spermatogenetic cell types beyond the stage of young spermatocytes reappeared 1 week late, we found no great disturbances in the regular reappearance of the successive spermatogenetic cell types after irradiation. Our data suggest that this retardation in the reappearance of further developed cells is caused by a delay in the production of developed cells in spermatogonia in an increasing fraction of the colonies after higher neutron doses. Even in fully developed colonies the production of differentiating spermatogenetic cell types was subnormal after 300 and 350 rad.

  18. Changes in Learning and Foraging Behaviour within Developing Bumble Bee (Bombus terrestris) Colonies

    PubMed Central

    Evans, Lisa J.; Raine, Nigel E.

    2014-01-01

    Organisation in eusocial insect colonies emerges from the decisions and actions of its individual members. In turn, these decisions and actions are influenced by the individual's behaviour (or temperament). Although there is variation in the behaviour of individuals within a colony, we know surprisingly little about how (or indeed if) the types of behaviour present in a colony change over time. Here, for the first time, we assessed potential changes in the behavioural type of foragers during colony development. Using an ecologically relevant foraging task, we measured the decision speed and learning ability of bumble bees (Bombus terrestris) at different stages of colony development. We determined whether individuals that forage early in the colony life cycle (the queen and early emerging workers) behaved differently from workers that emerge and forage at the end of colony development. Whilst we found no overall change in the foraging behaviour of workers with colony development, there were strong differences in foraging behaviour between queens and their workers. Queens appeared to forage more cautiously than their workers and were also quicker to learn. These behaviours could allow queens to maximise their nectar collecting efficiency whilst avoiding predation. Because the foundress queen is crucial to the survival and success of a bumble bee colony, more efficient foraging behaviour in queens may have strong adaptive value. PMID:24599144

  19. Changes in learning and foraging behaviour within developing bumble bee (Bombus terrestris) colonies.

    PubMed

    Evans, Lisa J; Raine, Nigel E

    2014-01-01

    Organisation in eusocial insect colonies emerges from the decisions and actions of its individual members. In turn, these decisions and actions are influenced by the individual's behaviour (or temperament). Although there is variation in the behaviour of individuals within a colony, we know surprisingly little about how (or indeed if) the types of behaviour present in a colony change over time. Here, for the first time, we assessed potential changes in the behavioural type of foragers during colony development. Using an ecologically relevant foraging task, we measured the decision speed and learning ability of bumble bees (Bombus terrestris) at different stages of colony development. We determined whether individuals that forage early in the colony life cycle (the queen and early emerging workers) behaved differently from workers that emerge and forage at the end of colony development. Whilst we found no overall change in the foraging behaviour of workers with colony development, there were strong differences in foraging behaviour between queens and their workers. Queens appeared to forage more cautiously than their workers and were also quicker to learn. These behaviours could allow queens to maximise their nectar collecting efficiency whilst avoiding predation. Because the foundress queen is crucial to the survival and success of a bumble bee colony, more efficient foraging behaviour in queens may have strong adaptive value. PMID:24599144

  20. Impact of Varroa destructor on honeybee (Apis mellifera scutellata) colony development in South Africa.

    PubMed

    Strauss, Ursula; Pirk, Christian W W; Crewe, Robin M; Human, Hannelie; Dietemann, Vincent

    2015-01-01

    The devastating effects of Varroa destructor Anderson & Trueman on European honeybee colonies (Apis mellifera L.) have been well documented. Not only do these mites cause physical damage to parasitised individuals when they feed on them, they also transmit viruses and other pathogens, weaken colonies and can ultimately cause their death. Nevertheless, not all honeybee colonies are doomed once Varroa mites become established. Some populations, such as the savannah honeybee, A. m. scutellata, have become tolerant after the introduction of the parasite and are able to withstand the presence of these mites without the need for acaricides. In this study, we measured daily Varroa mite fall, Varroa infestation rates of adult honeybees and worker brood, and total Varroa population size in acaricide treated and untreated honeybee colonies. In addition, honeybee colony development was compared between these groups in order to measure the cost incurred by Varroa mites to their hosts. Daily Varroa mite fall decreased over the experimental period with different dynamics in treated and untreated colonies. Varroa infestation rates in treated adult honeybees and brood were lower than in untreated colonies, but not significantly so. Thus, indicating a minimal benefit of treatment thereby suggesting that A. m. scutellata have the ability to maintain mite populations at low levels. We obtained baseline data on Varroa population dynamics in a tolerant honeybee over the winter period. Varroa mites appeared to have a low impact on this honeybee population, given that colony development was similar in the treated and untreated colonies. PMID:25037745

  1. A metagenomic survey of microbes in honey bee colony collapse disorder.

    PubMed

    Cox-Foster, Diana L; Conlan, Sean; Holmes, Edward C; Palacios, Gustavo; Evans, Jay D; Moran, Nancy A; Quan, Phenix-Lan; Briese, Thomas; Hornig, Mady; Geiser, David M; Martinson, Vince; vanEngelsdorp, Dennis; Kalkstein, Abby L; Drysdale, Andrew; Hui, Jeffrey; Zhai, Junhui; Cui, Liwang; Hutchison, Stephen K; Simons, Jan Fredrik; Egholm, Michael; Pettis, Jeffery S; Lipkin, W Ian

    2007-10-12

    In colony collapse disorder (CCD), honey bee colonies inexplicably lose their workers. CCD has resulted in a loss of 50 to 90% of colonies in beekeeping operations across the United States. The observation that irradiated combs from affected colonies can be repopulated with naive bees suggests that infection may contribute to CCD. We used an unbiased metagenomic approach to survey microflora in CCD hives, normal hives, and imported royal jelly. Candidate pathogens were screened for significance of association with CCD by the examination of samples collected from several sites over a period of 3 years. One organism, Israeli acute paralysis virus of bees, was strongly correlated with CCD. PMID:17823314

  2. Modeling light propagation through bacterial colonies and its correlation with forward scattering patterns

    NASA Astrophysics Data System (ADS)

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

    2010-07-01

    Bacterial colonies play an important role in the isolation and identification of bacterial species, and plating on a petri dish is still regarded as the gold standard for confirming the cause of an outbreak situation. A bacterial colony consists of millions of densely packed individual bacteria along with matrices such as extracellular materials. When a laser is directed through a colony, complicated structures encode their characteristic signatures, which results in unique forward scattering patterns. We investigate the connection between the morphological parameters of a bacterial colony and corresponding forward scattering patterns to understand bacterial growth morphology. A colony elevation is modeled with a Gaussian profile, which is defined with two critical parameters: center thickness and diameter. Then, applying the scalar diffraction theory, we compute an amplitude modulation via light attenuation from multiple layers of bacteria while a phase modulation is computed from the colony profile. Computational results indicate that center thickness plays a critical role in the total number of diffraction rings while the magnitude of the slope of a colony determines the maximum diffraction angle. Experimental validation is performed by capturing the scattering patterns, monitoring colony diameters via phase contrast microscope, and acquiring the colony profiles via confocal displacement meter.

  3. Characterization of a human hematopoietic progenitor cell capable of forming blast cell containing colonies in vitro.

    PubMed Central

    Brandt, J; Baird, N; Lu, L; Srour, E; Hoffman, R

    1988-01-01

    A hematopoietic cell (CFU-B1) capable of producing blast cell containing colonies in vitro was detected using a semisolid culture system. The CFU-B1 has the capacity for self-renewal and commitment to a number of hematopoietic lineages. Monoclonal antibody to the human progenitor cell antigen-1 (HPCA-1) and a monoclonal antibody against the major histocompatibility class II antigen (HLA-DR) were used with fluorescence activated cell sorting to phenotype the CFU-B1. The CFU-B1 was found to express My10 but not HLA-DR antigen; experiments using complement-dependent cytotoxicity to eliminate DR positive cells confirmed this finding. Pretreatment of marrow cells with two chemotherapeutic agents, 5-fluorouracil and 4-hydroperoxycyclophosphamide facilitated detection of CFU-B1 derived colonies, while diminishing or totally inhibiting colony formation by other hematopoietic progenitor cells. CFU-B1-derived colony formation was dependent upon the addition of exogenous hematopoietic growth factors. Media conditioned either by the human bladder carcinoma cell line 5637 or lectin stimulated leukocytes, as well as recombinant granulocyte-macrophage colony stimulating factor, interleukin 3 or interleukin 1 alpha promoted blast cell colony formation. By contrast, neither recombinant erythropoietin, recombinant interleukin 4, purified macrophage colony stimulating factor or recombinant granulocyte colony-stimulating factor alone promoted blast cell colony formation. Images PMID:3047166

  4. Cooperatively Generated Stresslet Flows Supply Fresh Fluid to Multicellular Choanoflagellate Colonies

    NASA Astrophysics Data System (ADS)

    Roper, Marcus; Dayel, Mark J.; Pepper, Rachel E.; Koehl, M. A. R.

    2013-05-01

    The flagellated protozoan Salpingoeca rosetta is one of the closest relatives of multicellular animals. Unicellular S. rosetta can be induced to form multicellular colonies, but colonies swim more slowly than individual cells so the advantages conferred by colony formation are uncertain. Here we use theoretical models to show that hydrodynamic cooperation between cells can increase the fluid supply to the colony, an important predictor of feeding rate. Our results suggest that hydrodynamic benefits may have been an important selective factor in the evolution of early multicellular animals.

  5. The relevance of the Mediterranean Region to colonial waterbird conservation

    USGS Publications Warehouse

    Erwin, R.M.

    1996-01-01

    The Mediterranean Sea is the largest partially enclosed sea in the world and provides habitat to more than 100 species of waterbirds from the Palearctic-North African-Middle Eastern regions. Even though the Mediterranean suffers from pollution, has little tidal influence, and is oligotrophic, more than half of the western Palearctic populations of numerous waterfowl species winter in the region. Thirty-three species of colonial waterbirds breed along the 46,000 km Mediterranean coastline with nine species considered threatened or endangered, mostly because of wetland loss and degradation. The long history of human activity and scientific investigations in the region has taught some valuable lessons. In the area of colonial waterbird biology and conservation, we have learned important lessons about the value of long-term monitoring and research on selected populations. From marking studies of Greater Flamingos (Phoenicopterus ruber roseus) and Little Egrets (Egretta garzetta) results have been used to derive useful information about metapopulation dynamics. Involvement of both African and European biologists allowed year-round Studies of these species that yielded valuable spin-offs for training in avian and wetland conservation. We have also learned the value of man-made wetlands as feeding and nesting sites for some colonial waterbirds. Careful evaluations of the habitat quality of different types of wetlands are required, as in contaminant levels such as lead shot and pesticides. Wetland conservationists have also learned from some instructive mistakes. Dam construction and agricultural incentive programs sponsored by the European Community, the World Bank, and others from the past have largely ignored impacts on wetlands and wildlife. In some areas, economic ventures such as aquaculture operations and salt mining have not involved waterbird habitat needs in their planning. Research and conservation needs include: (1) establishing regional monitoring programs and data banks for seabirds, wading birds, ducks, and geese; (2) implementing a wetland inventory for many Countries with little quantitative data on wetlands; (3) improving habitat quality assessments; (4) improving relationships with industry, the private citizenry, and government officials to further an appreciation for the value of wetlands and waterbirds; (5) enhancing training efforts, especially in underdeveloped Countries; (6) evaluating the effects of hunting and other disturbances to nesting and feeding waterbirds in different regions; (7) setting up 'sister-reserve' (twinned) sites in Europe and Africa to foster international linkages and training; and (8) fostering local-regional conservation programs to preserve reed beds, wet woodlots, and other key habitats.

  6. Different Strategies for Aggregation in Social Amoeba Colonies

    NASA Astrophysics Data System (ADS)

    Franck, Carl; Monaghan, Ryan; Bae, Albert; Loh, Duane; Bodenschatz, Eberhard

    2007-03-01

    When confronted by starvation, collections of the amoeba Dictyostelium discoideum seek to aggregate in order to form genome-preserving stalk and spore structures. We have been interested in the means by which individual cells unite for this purpose. It has long been recognized that communication by means of diffusion of small molecules affords one such strategy: periodic chemical wave signaling can direct individual cells to an aggregation site. By employing thin layer substrates that presumably alter the propagation characteristics of such waves, we have shifted the colonial aggregation strategies to modes that rely on adhesive interactions for initial stages of multicellular assembly. Besides relentless aggregation of individual cells into large scale streams, these substrates reveal remarkable structures composed of only a few cells which we call ``squads'' that search for each other in order to achieve sufficient aggregation mass in sparse populations.

  7. An Artificial Bee Colony Algorithm for Uncertain Portfolio Selection

    PubMed Central

    Chen, Wei

    2014-01-01

    Portfolio selection is an important issue for researchers and practitioners. In this paper, under the assumption that security returns are given by experts' evaluations rather than historical data, we discuss the portfolio adjusting problem which takes transaction costs and diversification degree of portfolio into consideration. Uncertain variables are employed to describe the security returns. In the proposed mean-variance-entropy model, the uncertain mean value of the return is used to measure investment return, the uncertain variance of the return is used to measure investment risk, and the entropy is used to measure diversification degree of portfolio. In order to solve the proposed model, a modified artificial bee colony (ABC) algorithm is designed. Finally, a numerical example is given to illustrate the modelling idea and the effectiveness of the proposed algorithm. PMID:25089292

  8. Wavelet phase estimation using ant colony optimization algorithm

    NASA Astrophysics Data System (ADS)

    Wang, Shangxu; Yuan, Sanyi; Ma, Ming; Zhang, Rui; Luo, Chunmei

    2015-11-01

    Eliminating seismic wavelet is important in seismic high-resolution processing. However, artifacts may arise in seismic interpretation when the wavelet phase is inaccurately estimated. Therefore, we propose a frequency-dependent wavelet phase estimation method based on the ant colony optimization (ACO) algorithm with global optimization capacity. The wavelet phase can be optimized with the ACO algorithm by fitting nearby-well seismic traces with well-log data. Our proposed method can rapidly produce a frequency-dependent wavelet phase and optimize the seismic-to-well tie, particularly for weak signals. Synthetic examples demonstrate the effectiveness of the proposed ACO-based wavelet phase estimation method, even in the presence of a colored noise. Real data example illustrates that seismic deconvolution using an optimum mixed-phase wavelet can provide more information than that using an optimum constant-phase wavelet.

  9. A Multistrategy Optimization Improved Artificial Bee Colony Algorithm

    PubMed Central

    Liu, Wen

    2014-01-01

    Being prone to the shortcomings of premature and slow convergence rate of artificial bee colony algorithm, an improved algorithm was proposed. Chaotic reverse learning strategies were used to initialize swarm in order to improve the global search ability of the algorithm and keep the diversity of the algorithm; the similarity degree of individuals of the population was used to characterize the diversity of population; population diversity measure was set as an indicator to dynamically and adaptively adjust the nectar position; the premature and local convergence were avoided effectively; dual population search mechanism was introduced to the search stage of algorithm; the parallel search of dual population considerably improved the convergence rate. Through simulation experiments of 10 standard testing functions and compared with other algorithms, the results showed that the improved algorithm had faster convergence rate and the capacity of jumping out of local optimum faster. PMID:24982924

  10. Ant Colony Optimization for Markowitz Mean-Variance Portfolio Model

    NASA Astrophysics Data System (ADS)

    Deng, Guang-Feng; Lin, Woo-Tsong

    This work presents Ant Colony Optimization (ACO), which was initially developed to be a meta-heuristic for combinatorial optimization, for solving the cardinality constraints Markowitz mean-variance portfolio model (nonlinear mixed quadratic programming problem). To our knowledge, an efficient algorithmic solution for this problem has not been proposed until now. Using heuristic algorithms in this case is imperative. Numerical solutions are obtained for five analyses of weekly price data for the following indices for the period March, 1992 to September, 1997: Hang Seng 31 in Hong Kong, DAX 100 in Germany, FTSE 100 in UK, S&P 100 in USA and Nikkei 225 in Japan. The test results indicate that the ACO is much more robust and effective than Particle swarm optimization (PSO), especially for low-risk investment portfolios.

  11. Artificial bee colony algorithm for solving optimal power flow problem.

    PubMed

    Le Dinh, Luong; Vo Ngoc, Dieu; Vasant, Pandian

    2013-01-01

    This paper proposes an artificial bee colony (ABC) algorithm for solving optimal power flow (OPF) problem. The objective of the OPF problem is to minimize total cost of thermal units while satisfying the unit and system constraints such as generator capacity limits, power balance, line flow limits, bus voltages limits, and transformer tap settings limits. The ABC algorithm is an optimization method inspired from the foraging behavior of honey bees. The proposed algorithm has been tested on the IEEE 30-bus, 57-bus, and 118-bus systems. The numerical results have indicated that the proposed algorithm can find high quality solution for the problem in a fast manner via the result comparisons with other methods in the literature. Therefore, the proposed ABC algorithm can be a favorable method for solving the OPF problem. PMID:24470790

  12. Termites: a Retinex implementation based on a colony of agents

    NASA Astrophysics Data System (ADS)

    Simone, Gabriele; Audino, Giuseppe; Farup, Ivar; Rizzi, Alessandro

    2012-01-01

    This paper describes a novel implementation of the Retinex algorithm with the exploration of the image done by an ant swarm. In this case the purpose of the ant colony is not the optimization of some constraints but is an alternative way to explore the image content as diffused as possible, with the possibility of tuning the exploration parameters to the image content trying to better approach the Human Visual System behavior. For this reason, we used "termites", instead of ants, to underline the idea of the eager exploration of the image. The paper presents the spatial characteristics of locality and discusses differences in path exploration with other Retinex implementations. Furthermore a psychophysical experiment has been carried out on eight images with 20 observers and results indicate that a termite swarm should investigate a particular region of an image to find the local reference white.

  13. Population growth in colonial America: A study of Ipswich, Massachusetts.

    PubMed

    Norton, S L

    1971-11-01

    Abstract During the colonial period, the settlements that subsequently became the United States of America experienced a tremendous growth of population. Although part of this increase was due to emigration from England and other European countries, most of the growth must be laid to the natural increase of the immigrants and their descendants. We are only beginning to probe the mechanisms ofthis increase. By numerous local studies, using the methods of historical demography that have largely been developed with work in French and English sources, we should eventually be able to describe the demographic nature of New World communities, and to understand how their populations were responding to a new physical, social and economic environment. PMID:22070145

  14. Improved artificial bee colony algorithm based gravity matching navigation method.

    PubMed

    Gao, Wei; Zhao, Bo; Zhou, Guang Tao; Wang, Qiu Ying; Yu, Chun Yang

    2014-01-01

    Gravity matching navigation algorithm is one of the key technologies for gravity aided inertial navigation systems. With the development of intelligent algorithms, the powerful search ability of the Artificial Bee Colony (ABC) algorithm makes it possible to be applied to the gravity matching navigation field. However, existing search mechanisms of basic ABC algorithms cannot meet the need for high accuracy in gravity aided navigation. Firstly, proper modifications are proposed to improve the performance of the basic ABC algorithm. Secondly, a new search mechanism is presented in this paper which is based on an improved ABC algorithm using external speed information. At last, modified Hausdorff distance is introduced to screen the possible matching results. Both simulations and ocean experiments verify the feasibility of the method, and results show that the matching rate of the method is high enough to obtain a precise matching position. PMID:25046019

  15. Mate choice and genetic monogamy in a biparental, colonial fish

    PubMed Central

    van Dongen, Wouter F.D.; Wagner, Richard H.

    2015-01-01

    In socially monogamous species, in which both sexes provide essential parental care, males as well as females are expected to be choosy. Whereas hundreds of studies have examined monogamy in biparental birds, only several such studies exist in fish. We examined mate choice in the biparental, colonial cichlid fish Neolamprologus caudopunctatus in Lake Tanganyika, Zambia. We genotyped more than 350 individuals at 11 microsatellite loci to investigate their mating system. We found no extrapair paternity, identifying this biparental fish as genetically monogamous. Breeders paired randomly according to their genetic similarity, suggesting a lack of selection against inbreeding avoidance. We further found that breeders paired assortatively by body size, a criterion of quality in fish, suggesting mutual mate choice. In a subsequent mate preference test in an aquarium setup, females showed a strong preference for male size by laying eggs near the larger of 2 males in 13 of 14 trials. PMID:26023276

  16. A colonial mentality model of depression for Filipino Americans.

    PubMed

    David, E J R

    2008-04-01

    Many cultural and ethnic minorities have extensive experiences of being oppressed, which they may eventually internalize. However, psychology has yet to actively incorporate various forms of internalized oppression (e.g., colonial mentality [CM]) into the etiological conceptualizations of psychopathology. Using a sample of 248 Filipino Americans, the author tested a more complete and sociopolitically informed cultural model of depression symptoms. Results with structural equation modeling showed that a conceptual model that includes CM better explained depression symptoms among Filipino Americans than the model without CM and revealed that CM had a significant direct effect on Filipino Americans' experiences of depression symptoms. It is argued, through this illustrative case of depression symptoms among Filipino Americans, that incorporating the psychological effects of oppressive historical and contemporary conditions into our conceptualizations of ethnic minority mental health may lead to a more culturally accurate etiological understanding of psychopathology among historically oppressed groups. PMID:18426284

  17. Multiple ant colony algorithm method for selecting tag SNPs.

    PubMed

    Liao, Bo; Li, Xiong; Zhu, Wen; Li, Renfa; Wang, Shulin

    2012-10-01

    The search for the association between complex disease and single nucleotide polymorphisms (SNPs) or haplotypes has recently received great attention. Finding a set of tag SNPs for haplotyping in a great number of samples is an important step to reduce cost for association study. Therefore, it is essential to select tag SNPs with more efficient algorithms. In this paper, we model problem of selection tag SNPs by MINIMUM TEST SET and use multiple ant colony algorithm (MACA) to search a smaller set of tag SNPs for haplotyping. The various experimental results on various datasets show that the running time of our method is less than GTagger and MLR. And MACA can find the most representative SNPs for haplotyping, so that MACA is more stable and the number of tag SNPs is also smaller than other evolutionary methods (like GTagger and NSGA-II). Our software is available upon request to the corresponding author. PMID:22480582

  18. Transport of lunar material to the sites of the colonies

    NASA Technical Reports Server (NTRS)

    Heppenheimer, T. A.

    1977-01-01

    An 'existence proof' is attempted for the feasibility of transport of lunar material to colonies in space. Masses of lunar material are accelerated to lunar escape by a tracked magnetically levitated mass driver; aim precision is to 1 km miss distance at L5 per mm/sec velocity error at the lunar surface. Mass driver design and linear synchronous motor drive design are discussed; laser-sensed checkpoints aid in velocity and directional precision. Moon-L5 trajectories are calculated. The design of the L5 construction station, or 'catcher vehicle,' is described; loads are received by chambers operating in a 'Venus flytrap' mode. Further research studies needed to round out the concept are listed explicitly.

  19. Extracting a cancer model by enhanced ant colony optimisation algorithm.

    PubMed

    Shamsaee, Reza; Fathy, Mahmood; Masoudi-Nejad, Ali

    2014-01-01

    Although Ant-Miner has been used with relative ease for datasets with categorical data and small-sized feature vectors, microarray datasets, which contain a few samples with large amount of genes, are a totally different story. The Ant-Miner is an ant colony optimisation algorithm that extracts predictive rules from datasets and intrinsically works on discrete values. This study has developed a new algorithm, "Enhanced Ant-Miner" (EAM), based on previous works. EAM deals with continuous attributes as well as categorical ones and presents its captured models in the form of predictive rules. EAM has been tested versus SVM, CN2, K-means and hierarchical clustering and the results show that EAM is the best in the context of predictive accuracy. Additionally, its agent-based nature gives it a much more charming ability to speed up the whole process when compared to other trivial miners. PMID:25757256

  20. Artificial Bee Colony Algorithm Based on Information Learning.

    PubMed

    Gao, Wei-Feng; Huang, Ling-Ling; Liu, San-Yang; Dai, Cai

    2015-12-01

    Inspired by the fact that the division of labor and cooperation play extremely important roles in the human history development, this paper develops a novel artificial bee colony algorithm based on information learning (ILABC, for short). In ILABC, at each generation, the whole population is divided into several subpopulations by the clustering partition and the size of subpopulation is dynamically adjusted based on the last search experience, which results in a clear division of labor. Furthermore, the two search mechanisms are designed to facilitate the exchange of information in each subpopulation and between different subpopulations, respectively, which acts as the cooperation. Finally, the comparison results on a number of benchmark functions demonstrate that the proposed method performs competitively and effectively when compared to the selected state-of-the-art algorithms. PMID:25594992

  1. A spectral image clustering algorithm based on ant colony optimization

    NASA Astrophysics Data System (ADS)

    Ashok, Luca; Messinger, David W.

    2012-06-01

    Ant Colony Optimization (ACO) is a computational method used for optimization problems. The ACO algorithm uses virtual ants to create candidate solutions that are represented by paths on a mathematical graph. We develop an algorithm using ACO that takes a multispectral image as input and outputs a cluster map denoting a cluster label for each pixel. The algorithm does this through identication of a series of one dimensional manifolds on the spectral data cloud via the ACO approach, and then associates pixels to these paths based on their spectral similarity to the paths. We apply the algorithm to multispectral imagery to divide the pixels into clusters based on their representation by a low dimensional manifold estimated by the best t ant path" through the data cloud. We present results from application of the algorithm to a multispectral Worldview-2 image and show that it produces useful cluster maps.

  2. An artificial bee colony algorithm for uncertain portfolio selection.

    PubMed

    Chen, Wei

    2014-01-01

    Portfolio selection is an important issue for researchers and practitioners. In this paper, under the assumption that security returns are given by experts' evaluations rather than historical data, we discuss the portfolio adjusting problem which takes transaction costs and diversification degree of portfolio into consideration. Uncertain variables are employed to describe the security returns. In the proposed mean-variance-entropy model, the uncertain mean value of the return is used to measure investment return, the uncertain variance of the return is used to measure investment risk, and the entropy is used to measure diversification degree of portfolio. In order to solve the proposed model, a modified artificial bee colony (ABC) algorithm is designed. Finally, a numerical example is given to illustrate the modelling idea and the effectiveness of the proposed algorithm. PMID:25089292

  3. Canine parvovirus infections in a colony of dogs.

    PubMed

    Parrish, C R; Oliver, R E; McNiven, R

    1982-09-01

    A serological study of canine parvovirus (CPV) infections in a colony of dogs was conducted over a period of 8 months. Twenty-two of 24 adults samples initially had significant antibody titres to CPV. Nine litters of puppies were bled at fortnightly intervals and the sera tested for antibodies to CPV. Twenty-nine of 35 naturally PV infections observed were subclinical. A puppy in one litter developed vomiting and diarrhoea during the same period as seroconversion to CPV. Four puppies from a further litter developed histologically confirmed myocarditis. Serological testing of this latter litter indicated that the virus infections occurred between 2 weeks prior to and 1 week post whelping, and that clinical disease developed 20-40 days after viral infection. The mean half life of the decline of passively derived immunity to CPV was 8.3 days. PMID:7179717

  4. Modified artificial bee colony algorithm for reactive power optimization

    NASA Astrophysics Data System (ADS)

    Sulaiman, Noorazliza; Mohamad-Saleh, Junita; Abro, Abdul Ghani

    2015-05-01

    Bio-inspired algorithms (BIAs) implemented to solve various optimization problems have shown promising results which are very important in this severely complex real-world. Artificial Bee Colony (ABC) algorithm, a kind of BIAs has demonstrated tremendous results as compared to other optimization algorithms. This paper presents a new modified ABC algorithm referred to as JA-ABC3 with the aim to enhance convergence speed and avoid premature convergence. The proposed algorithm has been simulated on ten commonly used benchmarks functions. Its performance has also been compared with other existing ABC variants. To justify its robust applicability, the proposed algorithm has been tested to solve Reactive Power Optimization problem. The results have shown that the proposed algorithm has superior performance to other existing ABC variants e.g. GABC, BABC1, BABC2, BsfABC dan IABC in terms of convergence speed. Furthermore, the proposed algorithm has also demonstrated excellence performance in solving Reactive Power Optimization problem.

  5. Improved Artificial Bee Colony Algorithm Based Gravity Matching Navigation Method

    PubMed Central

    Gao, Wei; Zhao, Bo; Zhou, Guang Tao; Wang, Qiu Ying; Yu, Chun Yang

    2014-01-01

    Gravity matching navigation algorithm is one of the key technologies for gravity aided inertial navigation systems. With the development of intelligent algorithms, the powerful search ability of the Artificial Bee Colony (ABC) algorithm makes it possible to be applied to the gravity matching navigation field. However, existing search mechanisms of basic ABC algorithms cannot meet the need for high accuracy in gravity aided navigation. Firstly, proper modifications are proposed to improve the performance of the basic ABC algorithm. Secondly, a new search mechanism is presented in this paper which is based on an improved ABC algorithm using external speed information. At last, modified Hausdorff distance is introduced to screen the possible matching results. Both simulations and ocean experiments verify the feasibility of the method, and results show that the matching rate of the method is high enough to obtain a precise matching position. PMID:25046019

  6. A closed life-support system for space colonies

    NASA Technical Reports Server (NTRS)

    Johnson, R. D.; Jebens, H. J.; Sweet, H. C.

    1977-01-01

    In 1975, a system design study was performed to examine a completely self-contained system for a permanent colony of 10,000 inhabitants in space. Fundamental to this design was the life support system. Since resupply from earth is prohibitive in transportation costs, it was decided to use a closed system with the initial supply of oxygen coming from processing of lunar ores, and the supply of carbon, nitrogen and hydrogen from earth. The problem of life support was treated starting with the nutritional and metabolic requirements for the human population, creating a food and water chain sufficient to supply these demands, adding the additional requirements for the animal and plant sources in the food chain, feeding back useful waste products, supplying water as required from different sources, and closing the loop by processing organic wastes into CO2. This concept places the burden of the system upon plants for O2 generation and waste processing the CO2 generation.

  7. Artificial Bee Colony Algorithm for Solving Optimal Power Flow Problem

    PubMed Central

    Le Dinh, Luong; Vo Ngoc, Dieu

    2013-01-01

    This paper proposes an artificial bee colony (ABC) algorithm for solving optimal power flow (OPF) problem. The objective of the OPF problem is to minimize total cost of thermal units while satisfying the unit and system constraints such as generator capacity limits, power balance, line flow limits, bus voltages limits, and transformer tap settings limits. The ABC algorithm is an optimization method inspired from the foraging behavior of honey bees. The proposed algorithm has been tested on the IEEE 30-bus, 57-bus, and 118-bus systems. The numerical results have indicated that the proposed algorithm can find high quality solution for the problem in a fast manner via the result comparisons with other methods in the literature. Therefore, the proposed ABC algorithm can be a favorable method for solving the OPF problem. PMID:24470790

  8. Assessment of Chronic Sublethal Effects of Imidacloprid on Honey Bee Colony Health

    PubMed Central

    Dively, Galen P.; Embrey, Michael S.; Kamel, Alaa; Hawthorne, David J.; Pettis, Jeffery S.

    2015-01-01

    Here we present results of a three-year study to determine the fate of imidacloprid residues in hive matrices and to assess chronic sublethal effects on whole honey bee colonies fed supplemental pollen diet containing imidacloprid at 5, 20 and 100 μg/kg over multiple brood cycles. Various endpoints of colony performance and foraging behavior were measured during and after exposure, including winter survival. Imidacloprid residues became diluted or non-detectable within colonies due to the processing of beebread and honey and the rapid metabolism of the chemical. Imidacloprid exposure doses up to 100 μg/kg had no significant effects on foraging activity or other colony performance indicators during and shortly after exposure. Diseases and pest species did not affect colony health but infestations of Varroa mites were significantly higher in exposed colonies. Honey stores indicated that exposed colonies may have avoided the contaminated food. Imidacloprid dose effects was delayed later in the summer, when colonies exposed to 20 and 100 μg/kg experienced higher rates of queen failure and broodless periods, which led to weaker colonies going into the winter. Pooled over two years, winter survival of colonies averaged 85.7, 72.4, 61.2 and 59.2% in the control, 5, 20 and 100 μg/kg treatment groups, respectively. Analysis of colony survival data showed a significant dose effect, and all contrast tests comparing survival between control and treatment groups were significant, except for colonies exposed to 5 μg/kg. Given the weight of evidence, chronic exposure to imidacloprid at the higher range of field doses (20 to 100 μg/kg) in pollen of certain treated crops could cause negative impacts on honey bee colony health and reduced overwintering success, but the most likely encountered high range of field doses relevant for seed-treated crops (5 μg/kg) had negligible effects on colony health and are unlikely a sole cause of colony declines. PMID:25786127

  9. Assessment of chronic sublethal effects of imidacloprid on honey bee colony health.

    PubMed

    Dively, Galen P; Embrey, Michael S; Kamel, Alaa; Hawthorne, David J; Pettis, Jeffery S

    2015-01-01

    Here we present results of a three-year study to determine the fate of imidacloprid residues in hive matrices and to assess chronic sublethal effects on whole honey bee colonies fed supplemental pollen diet containing imidacloprid at 5, 20 and 100 μg/kg over multiple brood cycles. Various endpoints of colony performance and foraging behavior were measured during and after exposure, including winter survival. Imidacloprid residues became diluted or non-detectable within colonies due to the processing of beebread and honey and the rapid metabolism of the chemical. Imidacloprid exposure doses up to 100 μg/kg had no significant effects on foraging activity or other colony performance indicators during and shortly after exposure. Diseases and pest species did not affect colony health but infestations of Varroa mites were significantly higher in exposed colonies. Honey stores indicated that exposed colonies may have avoided the contaminated food. Imidacloprid dose effects was delayed later in the summer, when colonies exposed to 20 and 100 μg/kg experienced higher rates of queen failure and broodless periods, which led to weaker colonies going into the winter. Pooled over two years, winter survival of colonies averaged 85.7, 72.4, 61.2 and 59.2% in the control, 5, 20 and 100 μg/kg treatment groups, respectively. Analysis of colony survival data showed a significant dose effect, and all contrast tests comparing survival between control and treatment groups were significant, except for colonies exposed to 5 μg/kg. Given the weight of evidence, chronic exposure to imidacloprid at the higher range of field doses (20 to 100 μg/kg) in pollen of certain treated crops could cause negative impacts on honey bee colony health and reduced overwintering success, but the most likely encountered high range of field doses relevant for seed-treated crops (5 μg/kg) had negligible effects on colony health and are unlikely a sole cause of colony declines. PMID:25786127

  10. Influence of fire on black-tailed prairie dog colony expansion in shortgrass steppe

    USGS Publications Warehouse

    Augustine, D.J.; Cully, J.F., Jr.; Johnson, T.L.

    2007-01-01

    Factors influencing the distribution and abundance of black-tailed prairie dog (Cynomys ludovicianus) colonies are of interest to rangeland managers because of the significant influence prairie dogs can exert on both livestock and biodiversity. We examined the influence of 4 prescribed burns and one wildfire on the rate and direction of prairie dog colony expansion in shortgrass steppe of southeastern Colorado. Our study was conducted during 2 years with below-average precipitation, when prairie dog colonies were expanding throughout the study area. Under these dry conditions, the rate of black-tailed prairie dog colony expansion into burned grassland (X?? = 2.6 ha??100-m perimeter-1??y-1; range = 0.8-5.9 ha??100-m perimeter-1??y-1; N = 5 colonies) was marginally greater than the expansion rate into unburned grassland (X?? =1.3 ha??100-m perimeter-1??y-1; range = 0.2-4.9 ha??100-m perimeter-1??y-1; N = 23 colonies; P = 0.066). For 3 colonies that were burned on only a portion of their perimeter, we documented consistently high rates of expansion into the adjacent burned grassland (38%-42% of available burned habitat colonized) but variable expansion rates into the adjacent unburned grassland (2%-39% of available unburned habitat colonized). While our results provide evidence that burning can increase colony expansion rate even under conditions of low vegetative structure, this effect was minor at the scale of the overall colony complex because some unburned colonies were also able to expand at high rates. This result highlights the need to evaluate effects of fire on colony expansion during above-average rainfall years, when expansion into unburned grassland may be considerably lower.

  11. Trade-offs in the evolution of bumblebee colony and body size: a comparative analysis.

    PubMed

    Cueva Del Castillo, Raúl; Sanabria-Urbán, Salomón; Serrano-Meneses, Martín Alejandro

    2015-09-01

    Trade-offs between life-history traits - such as fecundity and survival - have been demonstrated in several studies. In eusocial insects, the number of organisms and their body sizes can affect the fitness of the colony. Large-than-average body sizes as well as more individuals can improve a colony's thermoregulation, foraging efficiency, and fecundity. However, in bumblebees, large colonies and large body sizes depend largely on high temperatures and a large amount of food resources. Bumblebee taxa can be found in temperate and tropical regions of the world and differ markedly in their colony sizes and body sizes. Variation in colony size and body size may be explained by the costs and benefits associated with the evolutionary history of each species in a particular environment. In this study, we explored the effect of temperature and precipitation (the latter was used as an indirect indicator of food availability) on the colony and body size of twenty-one bumblebee taxa. A comparative analysis controlling for phylogenetic effects as well as for the body size of queens, workers, and males in bumblebee taxa from temperate and tropical regions indicated that both temperature and precipitation affect colony and body size. We found a negative association between colony size and the rainiest trimester, and a positive association between the colony size and the warmest month of the year. In addition, male bumblebees tend to evolve larger body sizes in places where the rain occurs mostly in the summer and the overall temperature is warmer. Moreover, we found a negative relationship between colony size and body sizes of queens, workers, and males, suggesting potential trade-offs in the evolution of bumblebee colony and body size. PMID:26445652

  12. From the agricultural colony to the hospital-colony: configurations for psychiatric care in Brazil in the first half of the twentieth century.

    PubMed

    Venancio, Ana Teresa A

    2011-12-01

    The meanings given to the institutional model of the colonies in psychiatric care in Brazil are assessed, duly considering their different configurations in the context of public health policies in the first half of the twentieth century. The central thread of this analysis is the case of the Colônia Juliano Moreira, an institution founded in 1924 in Rio de Janeiro. It seeks to show the meaning attributed to the concept of agricultural colony and its importance in shaping the Colônia Juliano Moreira, in order to understand how the ideological precept of agricultural colony was translated into the concept of hospital-colony from the 1940s onwards, when this institution experienced a steady process of marked expansion of its physical structure and its therapeutic resources. PMID:22240946

  13. Microtable Arrays for Culture and Isolation of Cell Colonies

    PubMed Central

    Pai, Jeng-Hao; Xu, Wei; Sims, Christopher E.; Allbritton, Nancy L.

    2010-01-01

    Cell microarrays with culture sites composed of individually removable microstructures or micropallets have proven benefits for isolation of cells from a mixed population. The laser energy required to selectively remove these micropallets with attached cells from the array depends on the microstructure surface area in contact with the substrate. Laser energies sufficient to release micropallets greater than 100 ?m resulted in loss of cell viability. A new 3-dimensional culture site similar in appearance to a table was designed and fabricated using a simple process that relied on a differential sensitivity of two photoresists to UV-mediated photopolymerization. With this design, the larger culture area rests on four small supports to minimize the surface area in contact with the substrate. Microtables up to 250 × 250 ?m were consistently released with single 10 ?J pulses to each of the 4 support structures. In contrast, microstructures with a 150 × 150 ?m surface area in contact with the substrate could not be reliably released at pulse energies up to 212 ?J. Cassie-Baxter wetting is required to provide a barrier of air to localize and sequester cells to the culture sites. A second asset of the design was an increased retention of this air barrier under conditions of decreased surface tension and after prolonged culture of cells. The improved air retention was due to the hydrophobic cavity created beneath the table and above the substrate which entrapped air when an aqueous solution was added to the array. The microtables proved an efficient method for isolating colonies from the array with 100% of selected colonies competent to expand following release from the array. PMID:20644916

  14. Melanoma Cell Colony Expansion Parameters Revealed by Approximate Bayesian Computation

    PubMed Central

    Vo, Brenda N.; Drovandi, Christopher C.; Pettitt, Anthony N.; Pettet, Graeme J.

    2015-01-01

    In vitro studies and mathematical models are now being widely used to study the underlying mechanisms driving the expansion of cell colonies. This can improve our understanding of cancer formation and progression. Although much progress has been made in terms of developing and analysing mathematical models, far less progress has been made in terms of understanding how to estimate model parameters using experimental in vitro image-based data. To address this issue, a new approximate Bayesian computation (ABC) algorithm is proposed to estimate key parameters governing the expansion of melanoma cell (MM127) colonies, including cell diffusivity, D, cell proliferation rate, λ, and cell-to-cell adhesion, q, in two experimental scenarios, namely with and without a chemical treatment to suppress cell proliferation. Even when little prior biological knowledge about the parameters is assumed, all parameters are precisely inferred with a small posterior coefficient of variation, approximately 2–12%. The ABC analyses reveal that the posterior distributions of D and q depend on the experimental elapsed time, whereas the posterior distribution of λ does not. The posterior mean values of D and q are in the ranges 226–268 µm2h−1, 311–351 µm2h−1 and 0.23–0.39, 0.32–0.61 for the experimental periods of 0–24 h and 24–48 h, respectively. Furthermore, we found that the posterior distribution of q also depends on the initial cell density, whereas the posterior distributions of D and λ do not. The ABC approach also enables information from the two experiments to be combined, resulting in greater precision for all estimates of D and λ. PMID:26642072

  15. Accumulation of neutral mutations in growing cell colonies with competition

    PubMed Central

    Sorace, Ron; Komarova, Natalia L.

    2012-01-01

    Neutral mutations play an important role in many biological processes including cancer initiation and progression, the generation of drug resistance in bacterial and viral diseases as well as cancers, and the development of organs in multicellular organisms. In this paper we study how neutral mutants are accumulated in nonlinearly-growing colonies of cells subject to growth constraints such as crowding or lack of resources. We investigate different types of growth control which range from “division-controlled” to “death-controlled” growth (and various mixtures of both). In division-controlled growth, the burden of handling overcrowding lies with the process of cell-divisions, the divisions slow down as the carrying capacity is approached. In death-controlled growth, it is death rate that increases to slow down expansion. We show that division-controlled growth minimizes the number of accumulated mutations, and death-controlled growth corresponds to the maximum number of mutants. We check that these results hold in both deterministic and stochastic settings. We further develop a general (deterministic) theory of neutral mutations and achieve an analytical understanding of the mutant accumulation in colonies of a given size in the absence of back-mutations. The long-term dynamics of mutants in the presence of back-mutations is also addressed. In particular, with equal forward-and back-mutation rates, if division-controlled and a death-controlled types are competing for space and nutrients, cells obeying division-controlled growth will dominate the population. PMID:22940236

  16. New approach for determination of an optimum honeybee colony’s carrying capacity based on productivity and nectar secretion potential of bee forage species

    PubMed Central

    Al-Ghamdi, Ahmed; Adgaba, Nuru; Getachew, Awraris; Tadesse, Yilma

    2014-01-01

    The present study was carried out to determine an optimum honeybee colony’s carrying capacity of selected valleys dominated by Ziziphus spina-christi and Acacia tortilis in the Al-Baha region, Kingdom of Saudi Arabia. The study was conducted based on the assessment of the number of colonies kept, their productivities and the existing productive bee forage resources in the target valleys with its economic implication. In the existing beekeeping practice, the average number of managed honeybee colonies introduced per square kilometer was 530 and 317 during the flowering period of Z. spina-christi and A. tortilis, respectively. Furthermore, the overall ratios of productive bee forage plants to the number of honeybee colonies introduced were 0.55 and 11.12 to Ziziphus trees and A. tortilis shrubs respectively. In the existing situation the average honey production potential of 5.21 and 0.34 kg was recorded per Ziziphus and A. tortilis plants per flowering season, respectively. The present study, revealed that the number of honeybee colonies introduced in relation to the existing bee forage potential was extremely overcrowding which is beyond the carrying capacity of bee forage resources in selected valleys and it has been observed to affect the productivities and subsequent profitability of beekeeping. The study infers that, by keeping the optimum honeybee colony’s carrying capacity of valleys (88 traditional hives/km2 or 54 Langstroth hives/km2 in Ziziphus field and 72 traditional hives/km2 or 44 Langstroth hives/km2 in A. tortilis field), profitability of beekeeping can be boosted up to 130.39% and 207.98% during Z. spina-christi and A. tortilis, flowering seasons, respectively. PMID:26858544

  17. Stability of pathogenic colony types of Neisseria gonorrhoeae in liquid culture by using the parameters of colonial morphology and deoxyribonucleic acid transformation.

    PubMed Central

    La Scolea, L J; Dul, M J; Young, F E

    1975-01-01

    This investigation describes the surveillance of the colonial stability of the pathogenic type 1 from the gonococcal strain F62 to the nonvirulent types 3 and 4 in different liquid media. The maintenance of the colony types was monitored by the parameters of colonial morphology and deoxyribonucleic acid-mediated transformation. During growth in a complex medium, Mueller-Hinton broth, only 46.7% of the gonococcal population remained as type 1 after 12 h. The greatest change in the type 1 colony-forming units correlated with the decline in viable count. The conversion process could not be prevented by the continual maintenance of the gonococcus in logarithmic growth. The frequency of transformation from PRO(minus) (proline) to PRO(plus) was proportional to this decrease in type 1 colony-forming units. In contrast to Mueller-Hinton medium, the chemically defined minimal medium Gonococcal Genetic Medium (GGM) was capable of maintaining approximately 90% of the gonococcal population in the type 1 colonial form after 16 h of growth, despite a decrease in the viable count. Although the percentage of type 1 appeared to remain constant in GGM, the apparent transformation frequency increased approximately 24-fold from 0 to 12 h of growth. GGM appears to stimulate or maintain competence, as evidenced by an eightfold increase in transformation when cells are exposed to deoxyribonucleic acid in GGM as compared to Mueller-Hinton. PMID:809469

  18. Weight Watching and the Effect of Landscape on Honeybee Colony Productivity: Investigating the Value of Colony Weight Monitoring for the Beekeeping Industry

    PubMed Central

    Lecocq, Antoine; Kryger, Per; Vejsnæs, Flemming; Bruun Jensen, Annette

    2015-01-01

    Over the last few decades, a gradual departure away from traditional agricultural practices has resulted in alterations to the composition of the countryside and landscapes across Europe. In the face of such changes, monitoring the development and productivity of honey bee colonies from different sites can give valuable insight on the influence of landscape on their productivity and might point towards future directions for modernized beekeeping practices. Using data on honeybee colony weights provided by electronic scales spread across Denmark, we investigated the effect of the immediate landscape on colony productivity. In order to extract meaningful information, data manipulation was necessary prior to analysis as a result of different management regimes or scales malfunction. Once this was carried out, we were able to show that colonies situated in landscapes composed of more than 50% urban areas were significantly more productive than colonies situated in those with more than 50% agricultural areas or those in mixed areas. As well as exploring some of the potential reasons for the observed differences, we discuss the value of weight monitoring of colonies on a large scale. PMID:26147392

  19. Weight Watching and the Effect of Landscape on Honeybee Colony Productivity: Investigating the Value of Colony Weight Monitoring for the Beekeeping Industry.

    PubMed

    Lecocq, Antoine; Kryger, Per; Vejsnæs, Flemming; Bruun Jensen, Annette

    2015-01-01

    Over the last few decades, a gradual departure away from traditional agricultural practices has resulted in alterations to the composition of the countryside and landscapes across Europe. In the face of such changes, monitoring the development and productivity of honey bee colonies from different sites can give valuable insight on the influence of landscape on their productivity and might point towards future directions for modernized beekeeping practices. Using data on honeybee colony weights provided by electronic scales spread across Denmark, we investigated the effect of the immediate landscape on colony productivity. In order to extract meaningful information, data manipulation was necessary prior to analysis as a result of different management regimes or scales malfunction. Once this was carried out, we were able to show that colonies situated in landscapes composed of more than 50% urban areas were significantly more productive than colonies situated in those with more than 50% agricultural areas or those in mixed areas. As well as exploring some of the potential reasons for the observed differences, we discuss the value of weight monitoring of colonies on a large scale. PMID:26147392

  20. Current status and future prospects of using advanced computer-based methods to study bacterial colonial morphology.

    PubMed

    Bae, Euiwon; Kim, Huisung; Rajwa, Bartek; Thomas, John G; Robinson, J Paul

    2016-02-01

    Despite the advancement of recent molecular technologies, culturing is still considered the gold standard for microbial sample analysis. Here we review three different bacterial colony-based screening modalities that provide significant information beyond the simple shape and color of the colony. The plate imaging technique provides numeration and quantitative spectral reflectance information for each colony, while Raman spectroscopic analysis of bacteria colonies relates the Raman-shifted peaks to specific chemical bonding. Finally, the elastic-light-scatter technique provides a volumetric interaction of the whole colony through laser-bacteria interactions, instantly capturing the morphological traits of the colony and allowing quantitative classifications. PMID:26582139

  1. COLONY INVASION OF SMALL HIVE BEETLES: THE EFFECTS OF HONEY BEE TYPE AND ENTRANCE REDUCERS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Frake, A. M. & L. I. de Guzman COLONY INVASION OF SMALL HIVE BEETLES: THE EFFECTS OF HONEY BEE TYPE AND ENTRANCE REDUCERS - First detected in Florida in 1998, small hive beetles (SHB) are now found in at least 30 states. Although SHB can kill colonies (Elzen et al., 1999, Apidologie 30: 361-366...

  2. Engaging Diversity in Teaching Religion and Theology: An Intercultural, De-Colonial Epistemic Perspective

    ERIC Educational Resources Information Center

    Andraos, Michel Elias

    2012-01-01

    This essay explores new ways of engaging diversity in the production of knowledge in the classroom using coloniality as an analytical lens. After briefly engaging some of the recent literature on coloniality, focusing on the epistemic dimension, the author uses the example of teaching a course on religion, culture, and theology, where he employs…

  3. Colonial Hangovers: Social Studies Curriculum Dilemmas for Zimbabwe--Implications for Indiana Social Studies Teachers.

    ERIC Educational Resources Information Center

    Nziramasanga, Caiphas T.

    This paper briefly examines the historical background to political independence in African nations, highlighting the control of the colonial masters on those nations. The "hangovers" describes how early colonial control has had serious influence on the development of social studies curriculum in Zimbabwe. The paper concludes by narrating the…

  4. Corrected species identification of the predator Orius pumilio (Heteroptera: Anthocoridae) in a research colony

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Our laboratories have reported on the predatory minute pirate bugs (Family Anthocoridae) in a research colony that was obtained in December 2002. The species was originally thought to be Orius insidiosus (Say) However, specimens from the colony were identified as O. pumilio (Champion) by T. Lewis (...

  5. Musical Acculturation through Primary School Activities during Japanese Colonial Rule of Korea (1910-1945)

    ERIC Educational Resources Information Center

    Kim, Jeong Ha

    2014-01-01

    Global colonialism and continuing post-colonial influences caused widespread cultural change at the interface of different cultures. Musical acculturation can be observed in most colonised countries. Some pro-colonialists apologetically allege that through colonisation the colonised territories would receive developmental aid and economical…

  6. Ligia Grischa: A Successful Swiss Colony on the Dakota Territory Frontier

    ERIC Educational Resources Information Center

    Quinn, Todd; Benedict, Karl; Dickey, Jeff

    2012-01-01

    In 1877 a small group of Swiss immigrants from the Graubunden canton formed a cooperative with another Swiss group in Stillwater, Minnesota, to begin a colony in eastern South Dakota. These settlers founded the Badus Swiss colony on the open prairie in Lake County, Dakota Territory (later South Dakota), based on cooperative rules written in…

  7. Colony Size of Phaeocystis Antarctica (Prymnesiophyceae) as Influenced by Zooplankton Grazers

    EPA Science Inventory

    The haptophyte Phaeocystis antarctica is a dominant phytoplankton species in the Ross Sea, Antarctica, and exists as solitary cells and mucilaginous colonies that differ by several orders of magnitude in size. Recent studies with P. globosa suggested that colony formation and enl...

  8. The Spatial-Temporal Evolution of the Interface Between Growing E. coli Colonies

    NASA Astrophysics Data System (ADS)

    Pen, Ue-Yu; Sigal, Dan; Ryu, William

    2014-03-01

    An Escherichia coli colony is a popular model used to study the physical interactions of a multicellular system. However, the development of the interface between two interacting colonies has not been well studied. In this work, we tracked the development and interaction of two cellular colonies formed from single founder cells. We observed that the colony-colony interface exhibited a range of roughening, sometimes producing a linear interface (zero roughening) and other times producing a highly sinuous interface (increased roughening). Using time-lapse microscopy, we captured images of a number of interacting colonies and quantified the evolution of their interface and show that it is highly correlated with a number of factors such as colony distance, growth rate, and age. To connect the microscopic details of the spatial orientation of cells to the macroscopic roughening, we simulated growing colonies and found that the orientation of the cells at the interface plays an important role in the roughening of the interface. Initially cells are highly aligned along the interface, but as time progresses, the cell alignment becomes more anisotropic, and it is the level of anisotropy that is highly correlated with the interface roughening. NSERC

  9. Phelps-Stokes in Congo: Transferring Educational Policy Discourse to Govern Metropole and Colony

    ERIC Educational Resources Information Center

    Seghers, Maud

    2004-01-01

    This article combines a historical with a social/political anthropological framework to examine the role played by the transfer of educational discourse between the United States-based Phelps-Stokes Fund and the Belgian Ministry of Colonies in the formulation of the colonial education policy of "adapted education" in the 1920s. The author argues…

  10. The Influence of Colonial Ideology on Schoolbooks in the Belgian Congo.

    ERIC Educational Resources Information Center

    Mbandaka, Honore Vinck

    1995-01-01

    An analysis of 50 textbooks used in the elementary schools of the former Belgian Congo reveals an overt attempt to propagate colonial ideology. Fundamental themes included the legitimacy of the colonization, denigration of the indigenous culture, and establishment of colonial authority. Three books, however, resisted this indoctrination and one…

  11. Language Legislation in the Belgian Colonial Charter of 1908: A Textual-Historical Analysis

    ERIC Educational Resources Information Center

    Meeuwis, Michael

    2015-01-01

    When in 1908 the Belgian government took over the Congo from King Leopold II, a charter was drafted that would serve as a constitution-like statutory code for the new colony. Article 3 in this "Colonial Charter" dealt with language and linguistic rights. It epitomized the duality of language questions with which Belgium remained faced…

  12. Benjamin Franklin's Pictorial Representations of the British Colonies in America: A Study in Rhetorical Iconology.

    ERIC Educational Resources Information Center

    Olson, Lester C.

    1987-01-01

    Investigates the underlying reasons for the fundamental shift in Benjamin Franklin's portrayals of the British colonies in America. Explores the hypothesis that "Magna Britannia" was both a deliberative work directed toward the British Parliament and an apologetic work directed toward conservatives in the colonial public. Also discusses Franklin's…

  13. Effects of Colony Creation Method and Beekeeper Education on Honeybee ("Apis mellifera") Mortality

    ERIC Educational Resources Information Center

    Findlay, J. Reed; Eborn, Benjamin; Jones, Wayne

    2015-01-01

    The two-part study reported here analyzed the effects of beekeeper education and colony creation methods on colony mortality. The first study examined the difference in hive mortality between hives managed by beekeepers who had received formal training in beekeeping with beekeepers who had not. The second study examined the effect on hive…

  14. Silencing the Subaltern: Nation-State/Colonial Governmentality and Bilingual Education in the United States

    ERIC Educational Resources Information Center

    Flores, Nelson

    2013-01-01

    This article introduces the concept of "nation-state/colonial governmentality" as a framework for analyzing the ways current language ideologies marginalize the language practices of subaltern populations. Specifically, the article focuses on the innate limitations of re-appropriating nation-state/colonial governmentality in an attempt…

  15. OUTBREAK OF CRYPTOSPORIDIUM FELIS AND GIARDIA DUODENALIS ASSEMBLAGE F IN A CAT COLONY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Eighteen cats, 3 to 6 mo of age, bred and housed in a closed colony, were transferred from that colony and placed in separate stainless steel cages in a building designed for housing animals. At daily intervals, feces were collected from the litter pans in each cage, cages were cleaned, and fresh fo...

  16. Inadvertent Propagation of Factor VII Deficiency in a Canine Mucopolysaccharidosis Type I Research Breeding Colony

    PubMed Central

    Carlstrom, Lucas P; Jens, Jackie K; Dobyns, Marley E; Passage, Merry; Dickson, Patricia I; Ellinwood, N Matthew

    2009-01-01

    Issues of cost and genetics can result in inbreeding of canine genetic disease colonies. Beagles often are used to maintain such colonies, providing stock for outcrosses. Factor VII (FVII) deficiency is a hemostatic disorder found at increased frequency in beagles and has been characterized at the DNA level. Deficiency of FVII presents obstacles in colonies founded with beagles. An initial finding of a FVII-deficient pup from a longstanding colony prompted us to evaluate FVII deficiency fully in this colony. Current and archival records and tissues were used to reconstruct the colony pedigree, assess the contribution from beagles, and test samples to document the source and frequency of the mutant FVII allele. As part of this study we developed a PCR-based diagnostic assay that was simpler than what was previously available. Pedigree analysis revealed a founder effect implicating beagles that led to high frequency (55%) of the mutant allele. In addition, affected animals were identified. The complete picture of the clinical effect within the colony remains unclear, but unusual neonatal presentations, including hemoabdomen, have occurred in pups affected with FVII deficiency. Use of a PCR-based diagnostic assay to screen all potential beagle breeding stock will prevent similar occurrences of FVII deficiency in future canine research colonies. PMID:19712579

  17. Colony social structure in native and invasive populations of the social wasp Vespula pensylvanica

    USGS Publications Warehouse

    Hanna, Cause; Cook, Erin D.; Thompson, Ariel R.; Dare, Lyndzey E.; Palaski, Amanda L.; Foote, David; Goodisman, Michael A. D.

    2014-01-01

    Social insects rank among the most invasive of terrestrial species. The success of invasive social insects stems, in part, from the flexibility derived from their social behaviors. We used genetic markers to investigate if the social system of the invasive wasp, Vespula pensylvanica, differed in its introduced and native habitats in order to better understand variation in social phenotype in invasive social species. We found that (1) nestmate workers showed lower levels of relatedness in introduced populations than native populations, (2) introduced colonies contained workers produced by multiple queens whereas native colonies contained workers produced by only a single queen, (3) queen mate number did not differ significantly between introduced and native colonies, and (4) workers from introduced colonies were frequently produced by queens that originated from foreign nests. Thus, overall, native and introduced colonies differed substantially in social phenotype because introduced colonies more frequently contained workers produced by multiple, foreign queens. In addition, the similarity in levels of genetic variation in introduced and native habitats, as well as observed variation in colony social phenotype in native populations, suggest that colony structure in invasive populations may be partially associated with social plasticity. Overall, the differences in social structure observed in invasive V. pensylvanica parallel those in other, distantly related invasive social insects, suggesting that insect societies often develop similar social phenotypes upon introduction into new habitats.

  18. Responses to human intruders by birds nesting in colonies: Experimental results and management guidelines

    USGS Publications Warehouse

    Erwin, R.M.

    1989-01-01

    Colonies of nesting wading birds and seabirds were studied at coastal sites in Virginia and North Carolina to determine distances at which birds flushed in response to human intrusion. There were few statistically significant relationships between flushing distances and colony size. Similarly, there were few differences between responses during incubation compared to post-hatching periods.

  19. Effects of selfing on offspring survival and reproduction in a colonial simultaneous hermaphrodite (Bugula stolonifera, Bryozoa).

    PubMed

    Johnson, Collin H

    2010-08-01

    Understanding the consequences of selfing in simultaneous hermaphrodites requires investigating potential deleterious effects on fitness at all stages of life. In this study, I examined the effects of selfing throughout the life cycle of the marine bryozoan Bugula stolonifera, a colonial simultaneous hermaphrodite. In 2008, larvae from field-collected colonies were cultured through metamorphosis to reproductively mature colonies either in the presence of one other colony, the paired treatment, or alone, the solitary treatment. Results demonstrated that selfing in this species is possible, in that colonies in the solitary treatment produced viable larvae that successfully completed metamorphosis. On average, however, these colonies released significantly fewer larvae, which experienced reduced rates of metamorphic initiation and completion compared to the paired treatment. These experiments were extended in 2009, when metamorphs from colonies reared in the solitary (n = 58) and paired (n = 61) treatments were transferred to the field for growth to reproductive maturity and then brought back to the laboratory for larval collection. Results revealed additional deleterious effects associated with selfing, as no viable larvae were recovered from colonies deriving from the solitary treatment. In contrast, offspring from the paired treatment released 1030 larvae and 99% initiated metamorphosis, 97% of which completed metamorphosis. Overall, selfed larvae not only had significantly decreased chances of survival, but those that did survive did not successfully reproduce. PMID:20813987

  20. Effects of a Fipronil Spot-Treatment on field colonies of Coptotermes formosanus (Isoptera: Rhinotermitidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This field study investigated the colony effect of a Fipronil spot-treatment applied to active infestations of Formosan subterranean termite, Coptotermes formosanus Shiraki. Spot-treatments were applied to a single active independent monitor from each of four colonies in which multiple independent m...