Primary and Secondary Metabolite Profiles of Lodgepole Pine Trees Change with Elevation, but Not with Latitude.

Climate change has a large influence on plant functional and phenotypic traits including plant primary and secondary metabolites. One well-established approach to investigating the variation in plant metabolites involves studying plant populations along elevation and latitude gradients. We considered how two space-for-time climate change gradients (elevation and latitude) influence carbohydrate reserves (soluble sugars, starches) and secondary metabolites (monoterpenes, diterpene resin acids) of lodgepole pine trees in western Canada. We were particularly interested in the relationship of terpenes and carbohydrates with a wide range of tree, site, and climatic factors. We found that only elevation had a strong influence on the expression of both terpenes and carbohydrates of trees. Specifically, as elevation increased, concentrations of monoterpenes and diterpenes generally increased and soluble sugars (glucose, sucrose, total sugars) decreased. In contrast, latitude had no impact on either of terpenes or carbohydrates. Furthermore, we found a positive relationship between concentrations of starch and total terpenes and diterpenes in the elevation study; whereas neither starches nor sugars were correlated to terpenes in the latitude study. Similarly, both terpenes and carbohydrates had a much greater number of significant correlations to site characteristics such as slope, basal area index, and sand basal area, in the elevational than in the latitude study. Overall, these results support the conclusion that both biotic and abiotic factors likely drive the patterns of primary and secondary metabolite profiles of lodgepole pine along geographical gradients. Also, presence of a positive relationship between terpenes and starches suggests an interaction between primary ad secondary metabolites of lodgepole pine trees.

Aggregation and a strong Allee effect in a cooperative outbreak insect.

Most species that are negatively impacted when their densities are low aggregate to minimize this effect. Aggregation has the potential to change how Allee effects are expressed at the population level. We studied the interplay between aggregation and Allee effects in the mountain pine beetle (Dendroctonus ponderosae Hopkins), an irruptive bark beetle that aggregates to overcome tree defenses. By cooperating to surpass a critical number of attacks per tree, the mountain pine beetle is able to breach host defenses, oviposit, and reproduce. Mountain pine beetles and Hymenopteran parasitoids share some biological features, the most notable of which is obligatory host death as a consequence of parasitoid attack and development. We developed spatiotemporal models of mountain pine beetle dynamics that were based on the Nicholson-Bailey framework but which featured beetle aggregation and a tree-level attack threshold. By fitting our models to data from a local mountain pine beetle outbreak, we demonstrate that due to aggregation, attack thresholds at the tree level can be overcome by a surprisingly low ratio of beetles per susceptible tree at the stand level. This results confirms the importance of considering aggregation in models of organisms that are subject to strong Allee effects.

Resource Allocation to Flight in an Outbreaking Forest Defoliator Malacosoma disstria.

Allocation of larval nutrients affects adult life history traits in insects. This study assessed the effect of moth age and wing loading on flight capacity in an outbreaking forest lepidopteran, Malacosoma disstria Hübner . Insects were collected from high and low density populations after larval feeding, and flight capacity was tested directly with flight mills and indirectly through the allometric relationship between wing area and body size. Insects from these same populations collected as eggs and fed with a synthetic diet in the laboratory were tested in a separate experiment. Male moth propensity to fly increased with wing loading only when moths were collected as pupae after feeding in the field at high population densities. Moth age and wing loading did not affect the distance flown by male moths in any of the population density-nutrient regime combinations tested. Energy use increased with flight distance in both experiments. The slope of the allometric relationship between wing area and body mass did not differ from isometry when moths were collected as pupae after feeding at low and high population densities in the field. The slope of this relationship was steeper for males collected from high than low population densities. There was no allometric relationship between wing area and body mass of moths collected from these same populations as eggs and fed ad libitum in the laboratory as larvae. The results suggest that male M. disstria can allocate resources to different life history traits in response to differences in population density.

Factors influencing flight capacity of the mountain pine beetle (Coleoptera: Curculionidae: Scolytinae).

The mountain pine beetle, Dendroctonus ponderosae Hopkins (Coleoptera: Curculionidae: Scolytinae) is the most damaging pest of mature pine (Pinaceae) in western North America. Although mountain pine beetles have an obligate dispersal phase during which adults must locate a new host for brood production, dispersal is a poorly understood aspect of its ecology. This flight mill study was designed to test the effects of beetle size, sex, and age on flight capacity. Energy use during flight was assessed through measurements of weight before and after flight and fat content of flown versus control beetles. The mean flight distance achieved by mountain pine beetles varied between 2.12 and 5.95 km over the 23-h bioassay, but the longest total flight of an individual beetle was >24 km. Beetle preflight weight influenced flight initiation, flight distance, and duration. Bigger beetles are more likely to fly and once in flight fly longer and farther than smaller beetles. There was no direct effect of beetle sex on flight capacity. Flight capacity of beetles declined with age postemergence. Although individual flight capacity was variable, flight velocity was relatively constant between 1.55 and 1.93 km/h. Lipids are used to power flight in mountain pine beetles, as lipid content was lower in beetles flown on the flight mills compared with beetles that did not fly. Flight distance was negatively correlated with beetle postflight lipid content. The baseline flight capacity data revealed in this study have implications for understanding the population dynamics of this eruptive forest pest.

Comparative phenotypic characterization of Vibrio cholerae isolates collected from aquatic environments of Georgia.

Vibrio cholerae is ubiquitous in aquatic environment inhabiting marine, fresh and brackish waters. V. cholerae serotypes O1 and O139 cause the devastating diarrheal disease cholera, which is often fatal without proper treatment. Little is known regarding the abundance and diversity of clinically important nonhalophilic vibrios in the South Caucasus region, particularly in Georgia. Here we provide the data on the Georgian environmental strains of V. cholerae isolated in 2006-2009 years from the coastal waters of the Black Sea and inland water reservoirs near Tbilisi. In total, 846 V. cholerae strains were collected from the water samples, most of them (705 strains) obtained from fresh water lakes. Isolation pattern of V. cholerae showed obvious seasonality with the highest isolation rates in late summer - early autumn. Twenty-nine isolates of V. cholerae were attributed to the O1 serotype based on serological studies and PCR identification and were further grouped by biochemical properties into classical and El Tor biotypes as well as hybrids. The study of antibiotic susceptibility profiles for V. cholerae isolates showed that 95% were sensitive to tetracycline, 91% to doxycycline, and 91% to ciprofloxacin. Interestingly, the freshwater isolates appeared to be more resistant to antibiotics than the Black Sea isolates. Among Black Sea isolates of V. cholerae toxigenic strains of O1 serotype revealed higher antibiotic resistance compared to non- O1/non-O139 isolates. In addition, V. cholerae O1 and non- O1/non-O139 isolates differed by phage susceptibility profiles, with higher diversity within the population of environmental non-O1/non-O139 V. cholerae isolates.

Identification and characterization of Francisella species from natural warm springs in Utah, USA.

AIMS: To characterize Francisella isolated from two natural warm springs in Utah and compare them to a strain isolated from a patient with probable exposure to one of the springs in 2001. METHODS AND RESULTS: A total of 39 presumptive Francisella isolates were obtained from two springs, Wasatch Hot Spring and Hobo Warm Spring, just north of Salt Lake City, Utah. All isolates were characterized by a combination of biochemical and molecular analyses, including novel PCR/electrospray ionization-mass spectrometry (ESI-MS) typing assays. Thirty-one were identified as F. philomiragia, while the remaining eight were identified as F. tularensis ssp. novicida. Phylogenetic analysis of the 16S rRNA sequences revealed 27 isolates, which clustered with F. philomiragia, albeit into two distinct clades. The remaining isolates clustered along with other F. tularensis strains including the Utah clinical isolate. Testing with the PCR/ESI-MS assays confirmed the identities of the isolates, but both yielded DNA signatures distinct from that of the clinical isolate. CONCLUSION: We were successful in isolating several Francisella strains from natural warm springs; however, none appeared to genetically match the original 2001 clinical isolate. SIGNIFICANCE AND IMPACT OF THE STUDY: This work highlights the presence of viable, potentially pathogenic Franscisella species living in the unique environmental niche of natural warm springs.

Microbial water quality of the Georgian coastal zone of the Black Sea.

From 2006 to 2008, microbial water quality was monitored along the Georgian coast of the Black Sea. Temperature, pH, salinity, and dissolved oxygen were measured, along with a variety of aquatic microbial parameters, including heterotrophic plate count (HPC), total culturable bacterial count (TCBC), and chlorophyll a (Chl-a) concentration. Total and fecal coliforms and total enterococci counts were recorded as indicators of fecal pollution. Vibrio bacteria, and Escherichia coli- and Vibrio-specific bacteriophages were isolated and enumerated to determine their relationships to standard marine pollution indicators. Persistent microbial pollution was observed, particularly in the summer months, with a higher rate of contamination in estuaries. Microbial indicators generally showed seasonal dependence, suggesting that temperature may influence bacterial dynamics in this environment. No correlation was apparent between fecal pollution indicators and physical-chemical and aquatic microbial parameters, although there were significant relationships amongst the indicators themselves, as well as with the prevalence of Vibrio bacteria and phage.

Review of retrospective dosimetry techniques for external ionising radiation exposures.

The current focus on networking and mutual assistance in the management of radiation accidents or incidents has demonstrated the importance of a joined-up approach in physical and biological dosimetry. To this end, the European Radiation Dosimetry Working Group 10 on 'Retrospective Dosimetry' has been set up by individuals from a wide range of disciplines across Europe. Here, established and emerging dosimetry methods are reviewed, which can be used immediately and retrospectively following external ionising radiation exposure. Endpoints and assays include dicentrics, translocations, premature chromosome condensation, micronuclei, somatic mutations, gene expression, electron paramagnetic resonance, thermoluminescence, optically stimulated luminescence, neutron activation, haematology, protein biomarkers and analytical dose reconstruction. Individual characteristics of these techniques, their limitations and potential for further development are reviewed, and their usefulness in specific exposure scenarios is discussed. Whilst no single technique fulfils the criteria of an ideal dosemeter, an integrated approach using multiple techniques tailored to the exposure scenario can cover most requirements.

Outbreak of gastroenteritis caused by Yersinia pestis in Afghanistan.

Plague, which is most often caused by the bite of Yersinia pestis-infected fleas, is a rapidly progressing, serious disease that can be fatal without prompt antibiotic treatment. In late December 2007, an outbreak of acute gastroenteritis occurred in Nimroz Province of southern Afghanistan. Of the 83 probable cases of illness, 17 died (case fatality 20·5%). Being a case was associated with consumption or handling of camel meat (adjusted odds ratio 4·4, 95% confidence interval 2·2-8·8, P<0·001). Molecular testing of patient clinical samples and of tissue from the camel using PCR/electrospray ionization-mass spectrometry revealed DNA signatures consistent with Yersinia pestis. Confirmatory testing using real-time PCR and immunological seroconversion of one of the patients confirmed that the outbreak was caused by plague, with a rare gastrointestinal presentation. The study highlights the challenges of identifying infectious agents in low-resource settings; it is the first reported occurrence of plague in Afghanistan.

Identification of bacterial plant pathogens using multilocus polymerase chain reaction/electrospray ionization-mass spectrometry.

Polymerase chain reaction/electrospray ionization-mass spectrometry (PCR/ESI-MS, previously known as "TIGER") utilizes PCR with broad-range primers to amplify products from a wide array of organisms within a taxonomic group, followed by analysis of PCR amplicons using mass spectrometry. Computer analysis of precise masses allows for calculations of base compositions for the broad-range PCR products, which can then be compared to a database for identification. PCR/ESI-MS has the benefits of PCR in sensitivity and high-throughput capacity, but also has the distinct advantage of being able to detect and identify organisms with no prior characterization or sequence data. Existing broad range PCR primers, designed with an emphasis on human pathogens, were tested for their ability to amplify DNA of well characterized phytobacterial strains, as well as to populate the existing PCR/ESI-MS bacterial database with base counts. In a blinded panel study, PCR/ESI-MS successfully identified 93% of unknown bacterial DNAs to the genus level and 73% to the species/subspecies level. Additionally, PCR/ESI-MS was capable of detecting and identifying multiple bacteria within the same sample. The sensitivity of PCR/ESI-MS was consistent with other PCR based assays, and the specificity varied depending on the bacterial species. Preliminary tests with real life samples demonstrate a high potential for using PCR/ESI-MS systems for agricultural diagnostic applications.

Multisystemic abscesses in African green monkeys (Chlorocebus aethiops) with invasive Klebsiella pneumoniae--identification of the hypermucoviscosity phenotype.

Invasive Klebsiella pneumoniae is an emerging disease of humans characterized by abscesses in the liver or other sites involving bacteria with the unique hypermucoviscosity phenotype. Over several months, 7 African green monkeys in our research colony developed abscess formation in multiple locations and succumbed to disease. K. pneumoniae was identified by bacterial culture in 6 monkeys and immunohistochemistry in 1 additional monkey. All monkeys had been housed in, or had contact with monkeys housed in, 1 animal room in our facility. All affected monkeys had 1 or more abscesses, most notably in the abdomen, but also affecting the lungs, cerebellum, and skin. Abdominal abscesses and associated adhesions entrapped loops of bowel, forming palpable masses. Abdominal masses were located at the root of the mesentery, the ileocecocolic junction, or the pelvic inlet. In 1 case, culture, serotyping, and polymerase chain reaction (PCR) analysis of the bacterial isolate identified K. pneumoniae expressing the hypermucoviscosity phenotype and capsular serotype K2 and determined that the K. pneumonia was genetically rmpA(+)/magA(-).

The natural history of Niemann-Pick disease type C in the UK.

Niemann-Pick disease type C (NPC) is an autosomal recessive, neurovisceral lipid storage disorder. Mutations in two genes (NPC1 and NPC2) produce indistinguishable clinical phenotypes by biochemical mechanisms that have not yet been entirely clarified. The wide spectrum of clinical presentations of NPC includes hepatic and pulmonary disease as well as a range of neuropsychiatric disorders. Late-onset disease has been increasingly recognized as the biochemical diagnosis of NPC has been more widely applied in adult neurology clinics. The clinical presentation and follow-up of 94 patients with NPC is described, 58 of whom were still alive at the time this report was prepared. The age at diagnosis ranged from the prenatal period (with hydrops fetalis) up to 51 years. This review of NPC patients in the UK confirms the phenotypic variability of this inherited lipid storage disorder reported elsewhere. Although a non-neuronopathic variant has been described, most patients in this series who survived childhood inevitably suffered neurological and in some cases neuropsychiatric deterioration. While symptomatic treatment, such as anticholinergic and antiepileptic drugs, can alleviate some aspects of the disease, there is a clear need to develop a specific treatment for this progressively debilitating neurodegenerative disorder.

G(2) chromosomal radiosensitivity in Danish survivors of childhood and adolescent cancer and their offspring.

In order to investigate the relationship between chromosomal radiosensitivity and early-onset cancer, the G(2) chromosomal radiosensitivity assay was undertaken on a group of 23 Danish survivors of childhood and adolescent cancer, a control group comprising their partners and a group of 38 of their offspring. In addition, the previously reported in-house control group from Westlakes Research Institute (WRI) was extended to 27 individuals. When using the 90th percentile cutoff for the WRI control group, the proportion of individuals with elevated radiosensitivity was 11, 35, 52 and 53% for the WRI control, partner control, cancer survivor and the offspring groups, respectively, with significant differences between the WRI control group and the cancer survivor group (P=0.002) and the offspring group (P<0.001). However, while the comparisons with the WRI control group support an association of chromosomal radiosensitivity with cancer predisposition, when the partner control group was used to define the radiosensitivity cutoff point, no significant differences in radiosensitivity profiles were found between the partner control group and either the cancer survivor group or the offspring group. The failure to distinguish between the G(2) aberration profiles of the apparently normal group of partners and the cancer survivor group suggests that any association with cancer should be viewed with caution, but also raises questions as to the suitability of the partners of cancer survivors to act as an appropriate control group. Heritability of the radiosensitive phenotype was examined by segregation analysis of the Danish families and suggested that 67.3% of the phenotypic variance of G(2) chromosomal radiosensitivity is attributable to a putative major gene locus with dominant effect.

Translocation yields in peripheral blood lymphocytes from control populations.

PURPOSE: To record the latest information on control levels of translocations in cultured human lymphocytes. MATERIALS AND METHODS: Control-level data from seven European laboratories that are using fluorescence in situ hybridization (FISH) techniques for retrospective biological dosimetry have been combined in a meta-analysis. After correction for the differing probe combinations used, tests of consistency are performed. The combined data have been used to test for individual variation, systematic variation with age, gender and smoking habits. RESULTS: There is a strong variation of translocation yield with age but no variation was detectable with gender or smoking habits. After correction for age, homogeneity tests showed that about 10% of individuals were outside the 95% confidence limits as opposed to 5% expected. From a total of 385, there is an excess of about 20 individuals most of whom have an unexpectedly high yield of translocations. CONCLUSIONS: For retrospective biological dosimetry purposes a generic age-dependent control level can be assumed. No other lifestyle factors such as smoking appear to have a significant effect on translocation yield.

Review of translocations detected by FISH for retrospective biological dosimetry applications.

Several European laboratories have combined their research efforts to arrive at a consensus view on using fluorescence in situ hybridisation (FISH) for retrospective dosimetry. The aim of this review is to report these views and to highlight some areas where further work is needed. Translocations in the stable cells should be measured only in the cells that contain the full complement of the painted material. Two-way and one-way translocations should be combined with equal weight. The control level of translocations has a strong dependence on age, which has now been measured and the system has been calibrated. In conclusion, the technique works and a lifetime dose to the bone marrow from low-linear energy transfer radiation of 0.5 Gy above normal background levels can be measured for any individual. The main application is considered to provide an independent verification of lifetime doses to individuals who might form a part of an epidemiological study.

Cytogenetic biodosimetry of an accidental exposure of a radiological worker using multiple assays.

A technician involved in the maintenance of X-ray equipment visited the occupational medicine service with complaints of skin lesions, apparently caused by an accidental exposure three months earlier. To estimate the dose received by the technician in the accident, biodosimetry was performed 6 and 18 months post-exposure with the dicentric and micronucleus assays. Part of the latest blood sample was also used for retrospective dosimetry by fluorescence in situ hybridisation (FISH) analysis for translocations. The data obtained 6 and 18 months post-exposure indicate that both dicentrics and micronuclei disappear with a half-time of 1 y. After correction for delayed blood sampling, dose values of 0.75 Gy (95% confidence limits 0.56-1.05 Gy) from dicentrics and 0.96 Gy (95% confidence limits 0.79-1.18 Gy) from micronuclei were obtained. FISH analysis of translocations resulted in a dose estimate of 0.79 Gy (95% confidence limits 0.61-0.99 Gy). The satisfactory agreement between the three cytogenetic endpoints supports the use of the micronucleus assay for triage purposes in the case of large scale radiological accidents and provides further evidence for the valid use of FISH for translocations as a reliable retrospective biological dosimeter.

Interaction of gramicidin derivatives with phospholipid monolayers.

A study of the interaction of gramicidin A (gA), tert-butyloxycarbonyl-gramicidin (g-BOC), and desformyl gramicidin (g-des) with dioleoyl phosphatidylcholine (DOPC) and DOPC/phosphatidylserine (PS) mixed monolayers on a mercury electrode is reported in this paper. Experiments were carried out in electrolytes KCl (0.1 mol dm(-3)) and Mg(NO3)2 (0.05 mol dm(-3)). The channel-forming properties of the gramicidins were studied by following the reduction of Tl(I) to Tl(Hg). The frequency dependence of the complex impedance of coated electrode surfaces in the presence and absence of the gramicidins was estimated between 65,000 and 0.1 Hz at potentials of -0.4 V versus Ag/AgCl with 3.5 mol dm(-3) KCl. Epifluorescence microscopy was used to qualitatively correlate the interaction of the gramicidin peptides with dipalmitoyl phosphatidylcholine (DPPC) and dipalmitoyl phosphatidylglycerol (DPPG) at the air-water interface. gA was shown to form Tl+ conducting channels in a DOPC monolayer, while g-BOC and g-des did not. In DOPC-30% PS (DOPC-0.3PS) layers, there is a marked increase in channel activity of all three gramicidin derivatives. None of the peptides facilitate the permeability of the DOPC-0.3PS layer to Cd2+. All three peptides interact with the layer as shown by capacitance-potential curves and impedance spectroscopy indicated by penetration of the peptide into the dielectric, an increase in surface "roughness", and an increased significance of low-frequency relaxations. The order of interaction is gA > g-des > g-BOC. The epifluorescence study of DPPC and DPPG layers at the air-water interface shows a selective action of the different gramicidins.

Occupational exposure to ionizing radiation has no effect on T- and B-cell total counts or percentages of helper, cytotoxic and activated T-cell subsets in the peripheral circulation of male radiation workers.

PURPOSE: To investigate changes in immune cell subsets in the peripheral circulation of a male population occupationally exposed to ionizing radiation. MATERIALS AND METHODS: Peripheral blood samples were taken from 194 male workers with cumulative exposures of >200 mSv (mean exposure 331.5 mSv, mean age 51 years) and from a reference population of 131 male workers with cumulative exposures of <27.5 mSv (mean exposure 13.9 mSv, mean age 47 years). Samples were analysed by flow cytometry for T- and B-cell total counts and for the T-cell subset percentages of CD4+ (helper T-cells), CD8+ (cytotoxic T-cells) and CD3+/HLA-DR+ (activated T-cells). RESULTS: Comparison of the >200 and <27.5 mSv exposure groups using linear regression analysis showed no statistically significant differences between the two groups for T-cell total count, B-cell total count or for percentages of the T-cell subsets CD4+, CD8+ or CD3+/HLA-DR+ and CD4+:CD8+. However, statistically significant increases in both T- and B-cell total counts were observed within the two exposure groups and data pooled from both groups when non-smokers (never and ex-smokers) were compared with current smokers. For pooled data T-cell total count increased in smokers by 35% (p=0.0001) and B-cell total count increased by 37% (p=0.0004). CONCLUSIONS: No significant immunological effects were observed in male radiation workers with cumulative exposures of >200 mSv when compared with a reference population with cumulative exposures of <27.5 mSv, although highly significant increases in both T- and B-cell total counts were observed in smokers compared with non-smokers.

The lanceolate hair rat phenotype results from a missense mutation in a calcium coordinating site of the desmoglein 4 gene.

Desmosomal cadherins are essential cell adhesion molecules present throughout the epidermis and other organs, whose major function is to provide mechanical integrity and stability to epithelial cells in a wide variety of tissues. We recently identified a novel desmoglein family member, Desmoglein 4 (Dsg4), using a positional cloning approach in two families with localized autosomal recessive hypotrichosis (LAH) and in the lanceolate hair (lah) mouse. In this study, we report cloning and identification of the rat Dsg4 gene, in which we discovered a missense mutation in a naturally occurring lanceolate hair (lah) rat mutant. Phenotypic analysis of lah/lah mutant rats revealed a striking hair shaft defect with the appearance of a lance head within defective hair shafts. The mutation disrupts a critical calcium binding site bridging the second and third extracellular domains of Dsg4, likely disrupting extracellular interactions of the protein.