Optimal conditions for the fluorometric determination of DNA

The Kissane and Robbins method of estimating DNA by the fluorescence of the product of its reaction with 3,5-diaminobenzoic acid dihydrochloride has been examined to determine the conditions which maximize the contribution of the reaction product to the observed fluorescence and minimize the level of the fluorescence in the assay blanks.     

Specific measurement of DNA in nuclei and nucleic acids using diaminobenzoic acid

The diaminobenzoic acid (DABA) reaction with DNA, first described by Kissane and Robbins (J. M. Kissane and E. Robbins, 1958, J. Biol. Chem.233, 184–188) and variously modified, was reinvestigated and applied to the measurement of submicrogram quantities of DNA in nuclear fractions and nucleic acid preparations. The reaction conditions were optimized using a small volume of DABA. This method measures 0.1 μg of DNA with a fluorescence twice that of background and is linear to 10 μg of DNA. DABA yeilds a 1000-fold higher fluorescence with DNA compared with RNA, protein, and polysaccharides, and 0.1 μg of DNA is detectable in the presence of 200 μg of RNA or protein. The method is useful for detecting contaminating DNA in RNA preparations prior to hybridization. A simple procedure using ethanol precipitation was developed for removal of common interfering reagents such as sucrose, glycerol, salts, and Triton X-100. Nuclei isolated using detergents and assayed by this method are also free of measurable interfering lipids.     

Use of the modified robbins device and fluorescent staining to screen plant extracts for the inhibition of S. mutans biofilm formation

Streptococcus mutans plays an important role in the formation of dental plaque. To study biofilm growth on hydroxyapatite (HA) in vitro, a flow system based on a Modified Robbins Device (MRD) and a method for the quantification of the biomass using fluorescent staining with SYTO(R) 9 were developed. The combined approach was used to assess the inhibitory effect of plant extracts on biofilm formation in concentrations below their minimal inhibitory concentrations.     

Stepwise and Canonical Discriminant Analysis of Longidorus Species (Nematoda: Longidoridae) from Arkansas

During a 1998-to-2001 survey from Arkansas, nine distinct species of Longidorus were found including five new species. Morphometrics of these nine species were used in a stepwise and canonical discrimination to select a subset of characteristics that best identified each species. Student''s t test was applied to compare Longidorus breviannulatus Norton &Hoffman, 1975; L. crassus Thorne, 1974; L. diadecturus Eveleigh &Allen, 1982; L. fragilis Thorne, 1974; L. biformis Ye &Robbins, 2004; L. glycines Ye &Robbins, 2004; L. grandis Ye &Robbins, 2003; L. paralongicaudatus Ye &Robbins, 2003; and L. paravineacola Ye &Robbins, 2003 to examine interspecies variation and test for the most useful morphometric characters in species discrimination. Most of the morphometric characters were useful to differentiate species, but species identification could not be based on a single character because the morphometric character ranges often overlap. Stepwise discriminant analysis indicated that the guide ring position, head width, tail length, body length, odontostyle length, and anal body width were the most important variables. These were used to generate canonical variables in discriminating the species. The first three canonical variables accounted for 95% of the total variance. The scatterplots by the first three canonical variables grouped and separated the Longidorus species from Arkansas. Stepwise and canonical discriminant analyses were useful for examining the groupings and morphometric relationships of the nine Longidorus species.     

Reproductive compatibility between mite populations previously identified as Euseius concordis (Acari: Phytoseiidae)

The objective of the present research is to study the reproductive compatibility between populations of predatory mites previously identified as Euseius concordis (Chant) based on morphological characteristics. Colonies of these mite populations were established in the lab with specimens collected from different localities and host plants. Reproductive compatibility was evaluated through crosses and backcrosses within and between populations and the subsequent observation of females' oviposition, over a period of 10 days. The levels of oviposition obtained in the crosses between individuals from the same population were higher than those obtained in the crosses between individuals from different populations. Results indicate the occurrence of post-mating reproductive incompatibility between the mite population from Petrolina and the other populations studied. Crosses and backcrosses between populations involving female mites from Petrolina did not produce offspring, although endospermatophores were present inside the spermathecas of those females. Oviposition was reduced, and only sons were obtained, in crosses between populations with males from Petrolina. Crosses of females from Pontes e Lacerda and males from Jaguariúna and vice versa produced only male progeny. Our results established that the populations originating from Arroio do Meio, Pontes e Lacerda, Jaguariúna and Viçosa, are reproductively compatible. However, the latter populations and the population from Petrolina are genetically isolated. Based on these results we suggest that more cytological and genetic studies are needed to establish if this reproductive isolation represents a species barrier.     

In situ colonization of polyvinyl chloride, brass, and copper by Legionella pneumophila.

A sampling device (Robbins device) was used to expose brass, copper, and polyvinyl chloride plugs to potable water contaminated by Legionella pneumophila serogroup 1. Plugs were removed at approximately 1-week intervals and cultured. The colonization rates were polyvinyl chloride, 70; copper, 31; and brass, 25%. Quantitative cultures revealed that polyvinyl chloride was most heavily colonized, whereas brass was least colonized. We conclude that materials used in plumbing systems are readily colonized by Legionella and that the Robbins device provides a means for testing such materials in an in situ setting.     

Within a Range of Possibilities: Morality and Ethics in Social Life

Despite its now common currency the anthropological concept of morality remains underdeveloped. One anthropologist who has made several important attempts to work out a more precise theoretical concept of morality is Joel Robbins. In his most recent contribution to this endeavor Robbins addresses the tension in anthropology between what he calls the morality of reproduction and the morality of freedom. In this article, I suggest an alternative solution to the problem of conceiving the distinction between a nonconsciously enacted morality and the conscious awareness of ethical dilemmas and moral questioning. I will support this distinction with ethnographic and life-historical material from my research on the moral lives of some Muscovites.     

Biofilm formation in laminar flow usingPseudomonas fluorescens EX101

The relationship between biofilm formation and Reynolds number in laminar flow has been investigated usingPseudomonas fluorescens EX101. It was shown using a Modified Robbins Device that in laminar flow, numbers of viable cells in a developed biofilm increased with Reynolds number (Re 2, 17 and 51.5), as would be expected in a system where molecular transport to the wall is limited by diffusion. By monitoring fluorescent beads in a flowcell with a scanning confocal laser microscope at similar low Reynolds numbers, the velocity profile close to the solid surface was determined. It was shown that the presence of a thin bacterial film (up to 12 m) displaced the flow profile away from the wall by a distance equivalent to the film thickness. Total cell counts from the Modified Robbins Device samples were not significantly different at the different flow rates but were higher than viable counts. Interruption of the flow had no significant effect on colonisation by the bacteria through the Modified Robbins Device in the first few hours. However, viable numbers were reduced when the flow was stopped at 7 h after initial colonisation.     

Kinetics of endosome acidification in mutant and wild-type Chinese hamster ovary cells

Acidification of endocytic compartments is necessary for the proper sorting and processing of many ligands and their receptors. Robbins and co-workers have obtained Chinese hamster ovary (CHO) cell mutants that are pleiotropically defective in endocytosis and deficient in ATP- dependent acidification of endosomes isolated by density centrifugation (Robbins, A. R., S. S. Peng, and J. L. Marshall. 1983. J. Cell Biol. 96:1064-1071; Robbins, A. R., C. Oliver, J. L. Bateman, S. S. Krag, C. J. Galloway, and I. Mellman. 1984. J. Cell Biol. 99:1296-1308). In this and the following paper (Yamashiro, D. J., and F. R. Maxfield. 1987. J. Cell Biol. 105:2723-2733) we describe detailed studies of endosome acidification in the mutant and wild-type CHO cells. Here we describe a new microspectrofluorometry method based on changes in fluorescein fluorescence when all cellular compartments are equilibrated to the same pH value. Using this method we measured the pH of endocytic compartments during the first minutes of endocytosis. We found in wild- type CHO cells that after 3 min, fluorescein-labeled dextran (F-Dex) was in endosomes having an average pH of 6.3. By 10 min, both F-Dex and fluorescein-labeled alpha 2-macroglobulin (F-alpha 2M) had reached acidic endosomes having an average pH of 6.0 or below. In contrast, endosome acidification in the CHO mutants DTG 1-5-4 and DTF 1-5-1 was markedly slowed. The average endosomal pH after 5 min was 6.7 in both mutant cell lines. At least 15 min was required for F-Dex and F-alpha 2M to reach an average pH of 6.0 in DTG 1-5-4. Acidification of early endocytic compartments is defective in the CHO mutants DTG 1-5-4 and DTF 1-5-1, but pH regulation of later compartments on both the recycling pathway and lysosomal pathway is nearly normal. The properties of the mutant cells suggest that proper functioning of pH regulatory mechanisms in early endocytic compartments is critical for many pH-mediated processes of endocytosis.     

Simultaneous confidence intervals from randomization tests with application in testing bioequivalence with multiple endpoints

We propose a method to construct simultaneous confidence intervals for a parameter vector from inverting a series of randomization tests (RT). The randomization tests are facilitated by an efficient multivariate Robbins–Monro procedure that takes the correlation information of all components into account. The estimation method does not require any distributional assumption of the population other than the existence of the second moments. The resulting simultaneous confidence intervals are not necessarily symmetric about the point estimate of the parameter vector but possess the property of equal tails in all dimensions. In particular, we present the constructing the mean vector of one population and the difference between two mean vectors of two populations. Extensive simulation is conducted to show numerical comparison with four methods. We illustrate the application of the proposed method to test bioequivalence with multiple endpoints on some real data.     

Converts,Christians and anthropologists: A critique of Mark Mosko’s partible penitent thesis

First advanced in a major essay published in 2010, Mark Mosko's ‘partible penitent’ thesis asserts that Melanesian and Christian cultures are based upon analogous conceptions of dividual personhood. Consequently, conversion in the region has been characterised by continuity rather than rupture, as argued most prominently by Joel Robbins. This essay offers an assessment of Mosko's thesis in terms of his critique of the theoretical and ethnographic literature and his recent application of the model to religious change in the Trobriand Islands. Robbins’ work proves more convincing and provocative on both theoretical and methodological grounds. Yet both approaches, which frame their analysis of Christianity in terms of conversion, appear increasingly out of sync with the experience of the vast majority of Melanesians who are more accurately considered active participants in a diverse global religious tradition rather than recipients of it.     

Global Problems and the Culture of Capitalism

Global Problems and the Culture of Capitalism. Richard H. Robbins. Needham Heights, MA: Allyn and Bacon, 1999. 421 pp.     

Optimization of a valine:isoleucine methyl ester pheromone blend and comparison of Robbins and Trécé traps for capture of Phyllophaga anxia (Coleoptera: Scarabaeidae) in Rhode Island

Eight ratios of L-valine:L-isoleucine methyl esters were tested in Robbins traps for capture of Phyllophaga anxia (LeConte) adult males. The 90:10, 80:20, and 60:40 ratios of valine:isoleucine were the most effective blends for capture of beetles in Rhode Island. Females were captured in small numbers in some traps but not consistently to any particular blend. Other male Phyllophaga species captured included Phyllophaga fusca (Fr?lich), Phyllophaga forsteri (Burmeister), P. hirsuta (Knoch), and P. marginalis (LeConte). The number of these species collected was low, and it was not possible to determine whether they were attracted to any particular pheromone blend. Peak captures of P. anxia males occurred 31 May in 1999 and 2002 in Kingston, RI. The standard Japanese beetle trap manufactured by Trécé (Adair, OK) captured significantly more beetles than the Robbins trap. Because the Trécé trap is already marketed for Japanese beetles, a lure and trapping system can be adopted for P. anxia.     

Money and Modernity: State and Local Currencies in Melanesia

Money and Modernity: State and Local Currencies in Melanesia. David Akin and Joel Robbins. eds. ASAO Monograph Series, 17. Pittsburgh: University of Pittsburgh Press, 1999. 284 pp.     

Binary culture biofilm formation by Stenotrophomonas maltophilia and Fusarium oxysporum

Binary culture biofilm formation by Stenotrophomonas maltophilia and Fusarium oxysporum was investigated using the recirculating modified Robbins device batch culture system. Sequential attachment studies were carried out in the Robbins device on PVC and glass surfaces, with each species as either the first or the second colonizer. Different surfaces had no significant effect on total numbers of S. maltophilia and F. oxysporum in the binary population biofilm. The attachment of the second colonizer was not influenced significantly by the previous attachment of the first colonizer. These results were confirmed using scanning electron micrographs. Journal of Industrial Microbiology & Biotechnology (2001) 26, 178–183. Received 06 July 1999/ Accepted in revised form 02 November 2000     

Review of the species level taxonomy of the neotropical butterfly genus Oenomaus (Lycaenidae,?Theclinae,?Eumaeini)

Seven new species of the Neotropical hairstreak genus Oenomaus are described: Oenomaus mancha Busby & Faynel, sp. n. (type locality Ecuador); Oenomaus gwenish Robbins & Faynel, sp. n. (type locality Panama); Oenomaus lea Faynel & Robbins, sp. n. (type locality Ecuador); Oenomaus myrteana Busby, Robbins & Faynel, sp. n. (type locality Ecuador); Oenomaus mentirosa Faynel & Robbins, sp. n. (type locality Peru); Oenomaus andi Busby & Faynel, sp. n. (type locality Ecuador) and Oenomaus moseri Robbins & Faynel, sp. n. (type locality Brazil, Santa Catarina). For each new Oenomaus species, we present diagnostic characters and notes on its habitat and biology. We illustrate adults, genitalia, and distribution. New distributional and biological data are presented for 21 previously described Oenomaus species. Oenomaus melleus guyanensis Faynel, 2008 is treated as a new synonym of Oenomaus melleus melleus (Druce, 1907). Females are described and associated with males for ten species using a variety of factors, including mitochondrial COI DNA “barcode” sequences. We summarize the reasons why the number of recognized Oenomaus species has grown in the past decade from one species to 28 species. Finally, we overview the habitats that Oenomaus species occupy and note that the agricultural pest on Annonaceae, Oenomaus ortygnus, is the only Oenomaus species that regularly occurs in greatly disturbed habitats.     

Recombination of 4p16 DNA markers in an unusual family with Huntington disease

The Huntington disease (HD) mutation has been localized to human chromosome 4p16, in a 6-Mb region between the D4S10 locus and the 4p telomere. In a report by Robbins et al., a family was identified in which an affected individual failed to inherit three alleles within the 6-Mb region originating from the parental HD chromosome. To explain these results, it was suggested that the HD locus (HD) lies close to the telomere and that a recombination event took place between HD and the most telomeric marker examined, D4S90. As a test of this telomere hypothesis, we examined six members of this family, five of whom are affected with HD, for the segregation of 12 polymorphic markers from 4p16, including D4S169, which lies within 80 kb of the 4p telomere. We separated, in somatic cell hybrids, the chromosomes 4 from each family member, to determine the phase of marker alleles on each chromosome. We excluded nonpaternity by performing DNA fingerprint analyses on all six family members, and we found no evidence for chromosomal rearrangements when we used high-resolution karyotype analysis. We found that two affected siblings, including one of the patients originally described by Robbins et al., inherited alleles from the non-HD chromosome 4 of their affected parents, throughout the 6-Mb region. We found that a third affected sibling, also studied by Robbins et al., inherited alleles from the HD chromosome 4 of the affected parent, throughout the 6-Mb region. Finally, we found that a fourth sibling, who is likely affected with HD, has both a recombination event within the 6-Mb region and an additional recombination event in a more centromeric region of the short arm of chromosome 4. Our results argue against a telomeric location for HD and suggest that the HD mutation in this family is either associated with DNA predisposed to double recombination and/or gene conversion within the 6-Mb region or is in a gene that is outside this region and that is different from that mutated in most other families with HD.     

Silver as a Residual Disinfectant To Prevent Biofilm Formation in Water Distribution Systems

Biofilms can have deleterious effects on drinking water quality and may harbor pathogens. Experiments were conducted using 100 μg/liter silver to prevent biofilm formation in modified Robbins devices with polyvinyl chloride and stainless steel surfaces. No significant difference was observed on either surface between the silver treatment and the control.     

Statistical evaluation of a newly modified Robbins device using a bioluminescent pseudomonad to quantify adhesion to plastic

A modified Robbins device (MRD) has frequently been used as a model system to study adhesion and biofilm formation. This study investigates the reproducibility of attachment and whether a statistically significant gradient of adhesion exists along the 25 sampling ports of a MRD. A simple, quantitative, non‐destructive, bioluminescence assay was developed in order to measure attachment of bioluminescent P. veronii BL146bio cells to plastic discs of Thermanox? in newly modified Robbins devices (nMRD). No statistically significant difference in mean bioluminescence values occurred between pairs of nMRDs run in parallel, but there was a significant difference in bioluminescence values between different batches of bacteria (p < 0.05). Generalised Linear Modelling showed that the position of the sample disc influenced the numbers attaching. In 50% of devices a significant positive gradient of attachment occurred and bioluminescence values varied from disc 1 to disc 25 by 29.6–58.0%. In the other 50% of nMRDs there was a smaller, non‐significant gradient. A disc sampling regime was devised to take this gradient into account and used to prove a positive correlation between bioluminescence and numbers of viable P. veronii BL146bio cells during a 6h biofilm accumulation period.     

Further studies on the anatomy and ecology of opisthobranch molluscs feeding on the scleractinian coral Pontes

Three further species of opisthobranch molluscs are reported to feed on the scleractinian coral Pontes in Tanzania. Further information on Cuthona poritophages Rudman, 1979, is also included. The anatomy of the aeolid Phestilla lugubris {Bergh, 1870, = P. sibogae Bergh, 1905) and a new species of Phestilla is described, as is the anatomy of the arminacean Pinufius rebus. The new species of Phestilla , and Pinufius , are, for the first time, reported to feed on Porites. Notes on the anatomy of the type-species of Phestilla, P. melanobrachia Bergh, 1874, are included to make possible a definition of the genus Phestilla.
Aspects of the feeding biology, life history, defence mechanisms and habitat specificity of the four Porites-feeding opisthobranchs are described and discussed. The four species are shown to have evolved radular teeth of remarkably similar shape. Each species utilizes a different part of the coral tissue as food. The three aeolids have replaced functional cnidosacs at the tip of their cerata with batteries of large secretory cells.
Phestilla lugubris and Pinufius rebus are also reported for the first time from the Great Barrier Reef, Queensland and the new species of Phestilla is reported from Queensland and Hawaii.