Good‐for‐nothing haya names: Powers of recollection in northwest Tanzania

This article explores names and naming practices in Haya communities of Northwest Tanzania. Certain Haya names evoke past experiences and circumstances that surround the birth of a child, as well as the social reputation of the child's parents, I argue that this act of recollection embedded in such names can best be understood as an effort to displace past reputations, and overcome the disparaging views of one's consociates. From this perspective, Haya names can be understood as modes of remembering designed to both recall and undermine past memories; as well as forms of social agency through which people actively attempt to engage in and transform their social conditions.     

Crystal Structure and Conformation of 5‐Fluorouridine: Conformational Preferences for 5‐Fluorinated Pyranosides

Crystals of 5‐fluorouridine (5FUrd) have unit cell dimensions a = 7.716(1), b = 5.861(2), c = 13.041(1)Å, α = γ = 90°, β = 96.70° (1), space group P2₁, Z = 2, ρ_obs = 1.56 gm/c.c and ρ_calc = 1574 gm/c.c The crystal structure was determined with diffractometric data and refined to a final reliability index of 0.042 for the observed 2205 reflections (I ≥ 3σ). The nucleoside has the anti conformation [χ = 53.1(4)°] with the furanose ring in the favorite C2′–endo conformation. The conformation across the sugar exocyclic bond is g⁺, with values of 49.1(4) and ? 69.3(4)° for Φ_θc and Φ_∞ respectively. The pseudorotational amplitude τ_m is 34.5 (2) with a phase angle of 171.6(4)°. The crystal structure is stabilized by a network of N–H…O and O–H…O involving the N3 of the uracil base and the sugar O3′ and O2′ as donors and the O2 and O4 of the uracil base and O3′ oxygen as acceptors respectively. Fluorine is neither involved in the hydrogen bonding nor in the stacking interactions. Our studies of several 5‐fluorinated nucleosides show the following preferred conformational features: 1) the most favored anti conformation for the nucleoside [χ varies from ? 20 to + 60°] 2) an inverse correlation between the glycosyl bond distance and the χ angle 3) a wide variation of conformations of the sugar ranging froni C2′–endo through C3′–endo to C4′–exo 4) the preferred g⁺ across the exocyclic C4′–C5′ bond and 5) no role for the fluorine atom in the hydrogen bonding or base stacking interactions.     

Immucillins as Antibiotics for T‐Cell Proliferation and Malaria

The genetic deficiency of human PNP causes a specific immunodeficiency by inducing apoptosis in dividing T‐cells. Powerful inhibitors of PNP have been designed from the experimental determination of the transition state structure of PNPs. The Immucillins are transition state analogue inhibitors with K _d values as low as 7 pM. In the presence of deoxyguanosine the Immucillins kill activated human T‐cells but not other cell types. The Immucillins are orally available and of low toxicity to mice. Immucillins also inhibit PNP from Plasmodium falciparum. Parasites cultured in human erythrocytes are killed by purine starvation in the presence of Immucillins and can be rescued by hypoxanthine.     

Costs and benefits of pre‐feeding for possum control

Abstract

Four control operations, each with paired pre‐feed and no‐pre‐feed treatments, and comprising two baited with carrot and two with cereal, provided strong support for the hypothesis that pre‐feeding produces higher possum kills than no pre‐feeding. In these replicates, even where high kills were achieved, the modelled two‐ to three‐fold extension of the period of population depression given by pre‐feeding was sufficient to warrant the expense of the additional bait sown. The benefits of pre‐feeding were clear‐cut, and were greatest where poorest kills were achieved, irrespective of bait type. Pre‐feeding is thus likely to reduce the probability of failure and should be considered a form of operational insurance.     

Multi‐taxon and forest structure sampling for identification of indicators and monitoring of old‐growth forest

Abstract

The most commonly used old‐growth forest indicators are structural attributes; nevertheless, they do not necessarily represent the biodiversity value of old‐growth forests. The aim of this study is to analyse the relationships between species richness data of different taxa and structural indicators of old‐growth and to identify taxonomic/functional groups, species and structural attributes that may be used as indicators of old‐growth. To achieve this goal we sampled forest structure, vascular plants, lichens, bryophytes, fungi, saproxylic beetles and birds in mature and old‐growth stands in southern Italy. We calculated Spearman’s correlation coefficients between species richness data and structural attributes. Analyses of indicator species, co‐occurrences and two‐way clusters were performed on the multi‐taxonomic list. The group of vascular plants most significantly correlated with other groups in terms of species richness; furthermore, it displays the highest proportion of between‐group co‐occurrences. The resulting multi‐taxonomic list of potential indicators may serve as an effective means of detecting and monitoring forest ecosystems; however, for this goal, structure‐based indicators, such as forest structural attributes and vascular plant species composition, are of primary importance.     

Dose assessment considerations for remedial action on plutonium‐contaminated soil

This article describes some of the dose assessment issues that should be considered when planning and executing a soil remedial activity. What is the proper dose scenario/ model? What are the appropriate cleanup criteria? How is the data gathered and analyzed (both before and after) cleanup?

By describing the features and aspects of how these issues and others were considered or not considered in planning for the remedial action underway at Maralinga, Australia (former site of the Nuclear Weapons Testing Program of the United Kingdom) when compared with historical international experience of this type, the author attempts to illustrate that it is almost nonsensical to preselect a single soil value for Pu in soil (for national or international use), particulariy when expressed as a soil concentration (pCi/g or bq/g). This is especially so when the problem is Pu on the surface or near the surface of the soil. This is the situation common at nuclear test sites where “one point safe tests” were conducted. At these locations aspects of resuspension (i.e., area size, particle size, wind speed, etc.) become the dominant drivers for the development of cleanup criteria, sampling regimes, data gathering, and analysis regimes, etc. These particular elements and others are discussed and illustrated.     

Arctic waters: Needs and options for CANADIAN‐AMERICAN cooperation

Abstract

Four major factors bid the United States and Canada to move toward more formalized arrangements for cooperative ocean management in the Arctic. Ocean currents in the Beaufort Sea region have the potential of transporting marine pollutants from one country to the other. Living resources, such as bowhead and beluga whales, undertake extensive transboundary migrations. Alaskan and Canadian Inuit depend heavily on renewable marine resources and raise the need for ocean management on an ecological basis. Cost savings could occur by coordinating development of offshore cold‐water technologies and shipping safety systems. This paper suggests six options for moving toward a more regionalized approach to the management of Arctic waters: a Beaufort Sea Boundary Agreement, a Beaufort Marine Cooperation Agreement, a Northwest Passage Agreement, an Equal Access Agreement, a Marine Mammal Cooperation Agreement, and an Arctic Regional Action Plan.     

An adaptable multithreaded prefetching technique for client‐server object bases

Given the existence of powerful multiprocessor client workstations in many client-server object database applications, the performance bottleneck is the delay in transferring pages from the server to the client. We present a prefetching technique that can avoid this delay, especially where the client application requests pages from several database servers. This technique has been added to the EXODUS storage manager. Part of the novelty of this approach lies in the way that multithreading on the client workstation is exploited, in particular for activities such as prefetching and flushing dirty pages to the server. Using our own complex object benchmark, we analyze the performance of the prefetching technique with multiple clients and multiple servers. The technique is also tested under a variety of client host workload levels. This revised version was published online in July 2006 with corrections to the Cover Date.     

Estimation of effective cleanup radius for soil‐vapor extraction systems

Soil‐vapor extraction (SVE) is a standard and effective in situ treatment for the removal of volatile contaminants from vadose‐zone soil. The duration of SVE operation required to reach site closure is quite variable, however, ranging up to several years or more. An understanding of the contaminant recovery rate as a function of distance from each vapor‐extraction well allows SVE systems to be designed so that cleanup goals can be achieved within a specified time frame.

A simple one‐dimensional model has been developed that provides a rough estimate of the effective cleanup radius (defined as “the maximum distance from a vapor extraction point through which sufficient air is drawn to remove the required fraction of contamination in the desired time") for SVE systems. Because the model uses analytical rather than numerical methods, it has advantages over more sophisticated, multidimensional models, including simplicity, speed, versatility, and robustness.

The contaminant removal rate at a given distance from the vapor‐extraction point is assumed to be a function of the local rate of soil‐gas flow, the contaminant soil concentration, and the contaminant volatility. Soil‐gas flow rate as a function of distance from the vapor‐extraction point is estimated from pilot test data by assuming that the infiltration of atmospheric air through the soil surface is related to the vacuum in the soil. Although widely applicable, the model should be used with some caution when the vadose zone is highly stratified or when venting contaminated soil greater than 30 ft below grade. Since 1992, Groundwater Technology, Inc. has been using this model routinely as a design tool for SVE systems.     

Microbial diagnostic microarray for food‐ and water‐borne pathogens

A microbial diagnostic microarray for the detection of the most relevant bacterial food- and water-borne pathogens and indicator organisms was developed and thoroughly validated. The microarray platform based on sequence-specific end labelling of oligonucleotides and the pyhylogenetically robust gyrB marker gene allowed a highly specific (resolution on genus/species level) and sensitive (0.1% relative and 10⁴ cfu absolute detection sensitivity) detection of the target pathogens. Validation was performed using a set of reference strains and a set of spiked environmental samples. Reliability of the obtained data was additionally verified by independent analysis of the samples via fluorescence in situ hybridization (FISH) and conventional microbiological reference methods. The applicability of this diagnostic system for food analysis was demonstrated through extensive validation using artificially and naturally contaminated spiked food samples. The microarray-based pathogen detection was compared with the corresponding microbiological reference methods (performed according to the ISO norm). Microarray results revealed high consistency with the reference microbiological data.     

Different Structural Requirements for Melanin‐Concentrating Hormone (MCH) Interacting with Rat MCH‐R1 (SLC‐1) and Mouse B16 Cell MCH‐R

Abstract

Melanin‐concentrating hormone (MCH) is a neuropeptide occurring in all vertebrates and some invertebrates and is now known to stimulate pigment aggregation in teleost melanophores and food‐intake in mammals. Whereas the two MCH receptor subtypes hitherto cloned, MCH‐R₁ and MCH‐R₂, are thought to mediate mainly the central effects of MCH, the MCH‐R on pigment cells has not yet been identified, although in some studies MCH‐R₁ was reported to be expressed by human melanocytes and melanoma cells. Here we present data of a structure‐activity study in which 12 MCH peptides were tested on rat MCH‐R₁ and mouse B16 melanoma cell MCH‐R, by comparing receptor binding affinities and biological activities. For receptor binding analysis with HEK‐293 cells expressing rat MCH‐R₁ (SLC‐1), the radioligand was [¹²⁵I]–[Tyr¹³]‐MCH with the natural sequence. For B16 cells (F1 and G4F sublines) expressing B16 MCH‐R, the analog [¹²⁵I]–[D‐Phe¹³, Tyr¹⁹]‐MCH served as radioligand. The bioassay used for MCH‐R₁ was intracellular Ca²⁺ mobilization quantified with the FLIPR instrument, whereas for B16 MCH‐R the signal determined was MAP kinase activation. Our data show that some of the peptides displayed a similar relative increase or decrase of potency in both cell types tested. For example, linear MCH with Ser residues at positions 7 and 16 was almost inactive whereas a slight increase in side‐chain hydrophilicity at residues 4 and 8, or truncation of MCH at the N‐terminus by two residues hardly changed binding affinity or bioactivity. On the other hand, salmonic MCH which also lacks the first two residues of the mammalian sequence but in addition has different residues at positions 4, 5, 9, and 18 exhibited a 5‐ to 10‐fold lower binding activity than MCH in both cell systems. A striking difference in ligand recognition between MCH‐R₁ and B16 MCH‐R was however observed with modifications at position 13 of MCH: whereas L‐Phe¹³ in [Phe¹³, Tyr¹⁹]‐MCH was well tolerated by both MCH‐R₁ and B16 MCH‐R, change of configuration to D‐Phe¹³ in [D‐Phe¹³, Tyr¹⁹]‐MCH or [D‐Phe¹³]‐MCH led to a complete loss of biological activity and to a 5‐ to 10‐fold lower binding activity with MCH‐R₁. By contrast, the D‐Phe¹³ residue increased the affinity of [D‐Phe¹³, Tyr¹⁹]‐MCH to B16 MCH‐R about 10‐fold and elicited MAP kinase activation as observed with [Phe¹³, Tyr¹⁹]‐MCH or MCH. These data demonstrate that ligand recognition by B16 MCH‐R differs from that of MCH‐R₁ in several respects, indicating that the B16 MCH‐R represents an MCH‐R subtype different from MCH‐R₁.     

Acyclonucleoside Iron Chelators of 1‐(2‐Hydroxyethoxy)methyl‐2‐alkyl‐3‐hydroxy‐4‐pyridinones: Potential Oral Iron Chelation Therapeutics

The method of synthesizing acyclonucleoside iron chelators is both convenient and cost effective compared to that of synthesizing ribonucleoside iron chelators. The X‐ray crystal structural analysis shows that the 2‐hydroxyethoxymethyl group does not affect the geometry of the iron chelating sites. Therefore, the iron binding and removal properties of the acyclonucleoside iron chelators should remain similar to the ribonucleoside iron chelators, which is confirmed by the titration and competition reaction of the acyclonucleoside chelators with iron and ferritin, respectively. The acyclonucleoside iron chelators are more lipophilic with measured n‐octanol and Tris buffer distribution coefficients than ribonucleoside iron chelators.     

Validity of the Morningness‐Eveningness Scale for Children among Spanish Adolescents

Adolescents tend to be much later chronotypes than other age groups. This circadian phase delay is attributed as much to biological as psychosocial factors. Because the consequences of this change on performance and health have been documented, questionnaires to identify morning and evening‐type adolescents are necessary. The aim of the present study was to validate a Spanish version of the Morningness‐Eveningness Scale for Children (MESC) by means of several relevant psychological variables as external criteria. A sample of 623 urban high school students completed the MESC and self‐reported measures of sleep behaviors, subjective alertness, physical performance, and mood. On the whole, results indicate a good validity of MESC. Significant differences in the self‐reported ratings between morning and evening types were obtained by time‐of‐day. These results provide preliminary support for the Spanish version of MESC.     

Estimating and comparing food availability for tree‐seed predators in typical pulsed‐resource systems: Alpine conifer forests

Abstract

Alpine conifers produce pulsed resources for the community of tree‐seed consumers. Here, we describe field and statistical methods to estimate spatio‐temporal variation in seed‐crops in forests with different species composition. Annual and between‐site variation in seed production was high and characterised by occurrence of mast‐crops followed by seed‐crop failure the following year. Seed‐crops of different species did not fluctuate in parallel.

Abbreviations: DLSM, differences of least square means; CED, Cedrasco; OGA, Oga; VAL, Valfurva; BOR, Bormio; RHE, Rhemes; COG, Cogne     

Sterol carrier protein‐2:Not just for cholesterol any more

Although sterol carrier protein-2 (SCP-2) mediates cholesterol esterification in L-cell fibroblasts and stimulates an accumulation of cholesterol in these cells, a potential role for SCP-2 in fatty acid uptake and trafficking has not been appreciated. Certainly, recent experiments have shown that SCP-2 binds fatty acids in vitro with an affinity similar to that observed for fatty acid binding proteins. Because of the ubiquitous tissue distribution of SCP-2, as opposed to the specific distribution of fatty acid binding proteins, as well as the need for fatty acid trafficking in all cells, I have recently proposed that SCP-2 is the universal fatty acid trafficking protein. This supposition is based on a number of observations made with L-cell fibroblasts expressing either the 13.2 kDa SCP-2 or the 15 kDa proSCP-2. In L-cells expressing the 13.2 kDa SCP-2, fluorescent fatty acid uptake was increased by 10–30% depending upon the probe used. In 15 kDa proSCP-2 expressing cells, fluorescent fatty acid uptake was increased 20–40% depending upon the probe used. However, only expression of the 15 kDa pro-SCP-2 increased the cytoplasmic diffusion of the fluorescent fatty acid. Expression of either protein increased the uptake of [³H]-oleic acid 1.9-fold compared to control, with targeting of [³H]-oleic acid for esterification into cholesteryl esters. The 13.2 kDa SCP-2 did target a significant amount of [³H]-oleic acid for esterification into the triacylglycerol pool. Expression of either protein markedly reduced total cellular phospholipid levels, however both proteins increased cholesteryl ester levels. Interestingly, expression of the 15 kDa proSCP-2 decreased ethanolamine plasmalogen levels with a concomitant increase in choline plasmalogen. Expression of both proteins increased PUFA content of the phospholipids, although this effect was greater in 15 kDa proSCP-2 expressing cells. Hence, expression of SCP-2 increased fatty acid uptake and targeted fatty acid to unique lipid pools, suggesting that SCP-2 may effectively serve as universal fatty acid binding and trafficking protein.     

A decision framework for selecting remediation technologies at hydrocarbon‐contaminated sites

A variety of remediation technologies are available to address hydrocarbon contamination, including free product recovery, soil venting, air sparging, groundwater recovery and treatment, and in situ bioremediation. These technologies address hydrocarbon contamination distributed between free, adsorbed, and dissolved phases in both the vadose and saturated zones. Selection of appropriate technologies is dependent on a number of factors, including contaminants, site‐specific characteristics, clean‐up goals, technology feasibility, cost, and regulatory and time requirements. This article describes a decision framework for selecting appropriate remediation technologies at hydrocarbon‐contaminated sites in a structured and tiered manner. Decision modules include (1) site characterization and product recovery; (2) vadosezone treatment: soil venting, bioremediation, and excavation; (3) saturated zone treatment: sparging, bioremediation, groundwater recovery, and excavation; and (4) groundwater treatment: carbon, air stripping, advanced oxidation, and bioreactors. Selection criteria for treatment technologies that address vadose‐ and saturated‐zone soils, as well as recovered groundwater, are described. The decision framework provides a systematic process to formulate solutions to complex problems and documents the rationale for selecting remediation systems designed to achieve closure at hydrocarbon‐contaminated sites.     

Simplified methods for monitoring petroleum‐contaminated ground water and soil vapor

Portable meters and simplified gas Chromatographic (GC) techniques were investigated for monitoring volatile hydrocarbon (HC), CO₂, and O₂, concentrations in groundwater, exhaust gases, and soil vapor during in situ remediation using soil vapor extraction (SVE) and air sparging (AS). Results of groundwater samples analyzed in‐house using a headspace technique compared well to split samples analyzed by a certified analytical laboratory (r² = 0.94). SVE exhaust gas HC and CO₂ concentrations measured using a GT201 portable HC/O₂ meter and a RA‐411A meter (GasTech), respectively, were highly correlated with in‐house laboratory GC analyses (r² = 0.91). O₂ concentrations fell in a small range and meter analyses were not well correlated with laboratory analyses. Results of soil gas monitoring were not as well correlated as those for exhaust gases for HC, CO₂, or O₂, perhaps due to environmental conditions such as changes in relative humidity or the wider range of soil gas values. Overall, the meters were good indicators of vapor contamination, they greatly simplified estimates of total HC mass removal, and they allowed estimates of the biological contribution to contaminant removal during the remediation process.