bluuebunny/crossref_metadata_2025 huggingface dataset:
Conidium ontogeny in hyphomycetes. The sympodulae of Beauveria and Curvularia
Authors: Kendrick W. B. , Cole G. T.
Published: August 2008

The conidium and conidiophore ontogeny of Beauveria globulifera (Speg.) Picard and Curvularia inaequalis (Shear) Boedijn are analyzed by time-lapse photomicrography. Although the conidia of C. inaequalis are porospores (Hughes' group VI), the sympodial extension of its conidiophore axis is shown to be basically similar to that exhibited by the sympodulae of B. globulifera (Hughes' group II).
The effect of water stress on the translocation of recent photosynthate to the roots of young plants of Pinus strobus
Authors: Ursino D. J. , Krotkov G.
Published: August 2008

White pine plants in their third year of growth were maintained for a 4-month period on soil having a moisture content of either 7% or 14%. In September, at the end of this period and at a time when translocation to the root is known to be high, the plants were permitted to photoassimilate 14CO2, and 8 hours later the distribution of 14C among the root, the old shoot, and the new shoot was determined.The plants maintained for the 4-month period on the 7% soil moisture environment had values for new needle length and root and new shoot fresh weights which were approximately 55–60% of the values from those plants grown on the higher soil moisture environment. However, despite such retarded growth, the magnitude of translocation to the root during the 8 hours after 14CO2 assimilation was only slightly lower in those plants grown on the lower soil moisture environment.From the results it is suggested that the decreased amount of translocation to the roots previously observed in pine plants in June and July cannot be attributed to reduced root metabolic activity and growth caused at that time by lowered soil water content.
Intertidal lignicolous fungi from Newfoundland
Authors: Hughes Gilbert C.
Published: August 2008

From a total of 18 species of lignicolous fungi collected, 11 Ascomycetes, 1 Basidiomycete, and 3 Deuteromycetes represent first records from Newfoundland. Digitatispora marina Doguet and Zalerion varium Anastasiou are reported from the western North Atlantic area and the nematode-trapping Hyphomycete Arthrobotrys superba Corda was collected in a marine habitat. The Deuteromycete Monodictys pelagica (Johnson) Jones was the most frequently collected species.
A single-spore analysis of rust pustules produced by mixing isolates of two races of Puccinia coronata var. avenue
Authors: Dinoor A. , Khair J. , Fleischmann G.
Published: August 2008

Urediospores of pairs of isolates of Puccinia coronata var. avenae were simultaneously inoculated side by side on a susceptible oat leaf to produce a common pustule. The infection types of the culture from the single pustule, and from single-spore isolates of the pustule, were determined on key differential varieties distinguishing the component biotypes. The composition of the pustule was found to vary with the component races involved, and among pustules established from the same components.One pair of component races produced pustules which were phenotypically like one or the other of the isolates used in the mixture. Single-spore isolates from these pustules gave the same infection type as the pustule from which they were isolated, indicating that either one isolate alone produced the pustule, or that it predominated in what would then be a compound pustule.Another pair produced infection types unlike those of either parent race, and thus behaved phenotypically as a new race on the differential varieties. However, single-spore isolates from such pustules behaved as one or the other of the components. The masking effect of virulence over avirulence was also demonstrated by single-spore analysis of these compound pustules.
Leaf spot of bananas caused by Mycosphaerella musicola: action of oil on the life cycle of the pathogen
Authors: Stover R. H. , Dickson J. D.
Published: August 2008

Oil spray reduced germination, germ tube growth, and appressoria formation by spores of Mycosphaerella musicola under field conditions for periods varying from 2 days to 2 weeks. Inhibition occurred only when spores were on the same leaf surface to which oil was applied. Appressoria formation and germ tube growth were reduced up to 33% and 25%, respectively. Conidia and ascospore production and dissemination were not adversely affected by oil spray. However, there were fewer sporodochia and perithecia in spots that were slow to develop as a result of oil spray. Oil application up to 2 weeks before or after infection increased the incubation period and the generation time, and reduced the number of spots. Oil is effective in retarding spot development when applied either before streaks appear or at the yellow streak stage of disease development. Oil, when applied during the incubation period or to yellow streaks, causes a variable amount of reduction in spotting and in only a minority of cases is disease development stopped completely. Therefore, leaf spot can build up on oil-sprayed plants when inoculum is abundant and weather favorable. The behavior of the pathogen on oil-sprayed susceptible banana plants is similar to that on partially resistant varieties.
Potential Secondary Production from Herring Spawning in the Strait of Georgia
Authors: Hay D. E. , Fulton J.
Published: August 2008

About 22% of the total herring spawning stock biomass is released annually as milt and eggs. The carbon contribution from herring spawning products to the Strait of Georgia is small in comparison with estimates of annual primary productivity. However, when the carbon contribution is calculated over the ~ 50-d period of spawning, egg incubation and larval emergence for the areas of herring spawning, the estimate of 6.92 g C∙m−2∙d−1 is substantially higher than maximum estimates of primary productivity. Even allowing for considerable dilution and dispersion of spawning products, the estimate of carbon contribution is high relative to primary production. We propose that this material may be a source of energy to promote secondary production, particularly in the form of microzooplankton, such as protozoa, copepod nauplii, or larvae of benthic animals all of which could serve as food for emerging herring larvae.Key words: Clupea harengus pallasi, herring spawning, secondary production, primary production, microzooplankton
Factors Affecting the Relation Between Phosphorus and Chlorophyll a in Midwestern Reservoirs
Authors: Hoyer Mark V. , Jones John R.
Published: August 2008

The mean chlorophyll a (mg/m3) yield per unit of total phosphorus (mg/m3) (P–C relation) in 96 midwest reservoirs and the variance about this yield was similar to relations for natural lakes reported in the literature. The remaining error term for this relation could not be reduced by adding variables for nitrogen, zooplankton abundance, or hydrologic flushing rate. In reservoirs with ratios of total nitrogen to total phosphorus of less than 10, nitrogen accounted for the same amount of variance in chlorophyll a as did phosphorus. Using partial regression path analysis, we found that when the concentration of phosphorus was held constant, increasing the concentration of inorganic suspended solids (mg/L) significantly decreased chlorophyll a. The following multivariate equation was developed to account for the effect of inorganic solids on the P–C relation:[Formula: see text]This equation accounted for 7% more variance than the univariate equation and the 95% predictive confidence interval, at an average phosphorus concentration, was reduced by 10%. This equation should be useful for predicting chlorophyll a in lakes with inorganic turbidities. When Secchi transparency data were regressed on both chlorophyll a and inorganic suspended solids, they accounted for 42% more variance in transparency than did chlorophyll a.Key words: lake trophic state, nitrogen, zooplankton, flushing rate, suspended solids, reservoirs
Behavior and Distribution of Larval and Early Jevenile Homarus americanus
Authors: Cobb J. S. , Gulbransen T. , Phillips B. F. , Wang D. , Syslo M.
Published: August 2008

Field behavioral observations and plankton tows show that American lobster (Homarus americanus) larvae are concentrated in downwellings characteristic of shallow sea fronts. Stage IV lobsters swimming at the surface avoided floating weeds and sticks. Seventy percent of laboratory-reared fourth stage lobsters swam near the surface for more than a minute when released but only 25% of fifth stage lobsters did so. When early fourth stage lobsters encountered bottom, they did not remain long in one place, but late fourth and early fifth stage lobsters began to burrow. Late fourth and early fifth stage lobsters were less likely to return to the surface when they reached the bottom. If the bottom was unsuitable (featureless sand), the lobsters resumed swimming. These behaviors appear to be an appropriate mechanism for substrate selection during settlement.
The English–Wabigoon River System: IV. Interaction between Mercury and Selenium Accumulated from Waterborne and Dietary Sources by Northern Pike (Esox lucius)
Authors: Turner Michael A. , Swick Alison L.
Published: August 2008

Although selenium is a pollutant released by several industries, it is also an essential nutrient that protects mammals against mercury intoxication. When added to aquatic ecosystems, selenium is bioaccumulated readily and can reduce mercury accumulation in some biota. Using a predator–prey experimental model, we investigated both the route of selenium uptake and the mechanism of reduction in mercury accumulation. Young northern pike (Esox lucius) and yellow perch (Perca flavescens) were caged in situ in mercury-contaminated Clay Lake, northwestern Ontario. Pike were held in water containing trace (< 0.2 μg Se/L) or elevated (4.5–6.4 μg Se/L) concentrations of selenium and were able to accumulate 203Hg and 75Se from food (yellow perch) only, water only, or from food and water. Control pike accumulated as much as 20 times more 73Se from food than from water, assimilating ~30% of selenium in food. With increased levels of selenium in water (around 5 μg Se/L), food and water were of similar importance as sources. Waterborne selenium did not alter either the amount of 203Hg accumulated from water or its subsequent partitioning among the pike tissues sampled. When elevated in food, selenium decreased both the body burden of 203Hg in pike and the proportion in muscle. It is inferred that selenium added to aquatic ecosystems, and incorporated subsequently in the food web, would interfere with biomagnification of mercury. Furthermore, future studies of selenium toxicity in fish should emphasize its accumulation from food.
Establishment of a Bedrock Epilithic Community in a Small Stream: Microbial (Algal and Bacterial) Metabolism and Physical Structure
Authors: Stock Marsha S. , Ward Amelia K.
Published: August 2008

Patterns of epilithic algal and bacterial productivity were examined in a developing community on newly exposed stream bedrock for a period of 10 wk and in an undisturbed bedrock community used as a seasonal control. Physical and chemical changes were minimal over the experimental period. Bacterial colonization occurred initially and was rapidly followed by the development of a monolayer of adnate diatoms. Subsequent bacterial development coupled with maximum rates of bacterial productivity may have depended upon the algal cells for physical refugia, mucilage production, and/or other growth-promoting substrates present in algal photosynthate. After the diatom monolayer, filamentous algae developed despite the presence of high densities of snail grazers. By the end of the experiment, community composition on both substrata was generally similar although filamentous blue-green algae were a more important component of the native communities. Communities on newly exposed rock had higher total levels of epilithic productivity than on native rock where bacterial numbers averaged 2.26 × 1011 cells/m2. On native rock epilithic bacterial productivity averaged 72 mg C∙m−2∙d−1, yielding an average turnover time of 0.56 d; algal productivity averaged 224 mg C∙m−2∙d−1. These data suggested that epilithic production was not quantitatively limiting as a food resource for grazing snails in this stream during the summer months.
Larval Fish Age, Growth, and Body Shrinkage: Information Available from Otoliths
Authors: Radtke Richard L.
Published: August 2008

External and internal examination of Atlantic cod (Gadus morhua) otoliths for macrostructure and microstructure, by light and scanning electron microscopy, indicated daily rhythmic patterns. The first daily increment developed the day after hatching. Sagittae changed shape from spherical to oblong at 20 d and to crenulated at 50−60 d old. Cod were reared at three temperatures (6,8 and 10 °C), to provide a range of growth and developmental rates. Distinctive marks formed at yolk-sac absorption, initiation of feeding and settlement. It was possible to determine age and growth rate from otolith analyses. The relationship between otolith length and fish size was independent of growth rate; it followed a quadratic function for the smaller individuals (< 6.5 mm), and it was linear in individuals greater than 25 mm. Larval fish shrank considerably at death. The magnitude of shrinkage was dependent on larval length, and the elapsed time between death and fixation. Immediate fixation in ethanol resulted in minimal shrinkage. The relationship between fish length and otolith diameter may be used to correct for shrinkage associated with collection and death.
Microbiological Characteristics of White Whale (Delphinapterus leucas) From Capture Through Extended Captivity
Authors: Buck John D. , Shepard L. Louise , Bubucis Patricia M. , Spotte Stephen , McClave Kate , Cook Robert A.
Published: August 2008

For proper husbandry, it is important to sample the environment from which marine mammals for captivity are taken and to monitor the animals frequently over an extended period. Samples for microbiological analysis were collected from 20 beluga whales during capture in the Churchill River. Seven animals were retained in three U.S. aquaria with anal and blowhole cultures taken over a 945-d period. Bacteria isolated from whales at capture included many soil and water forms found also in environmental samples. Pasteurella multocida was isolated from three whales at capture and infrequently several times in captivity from two of these which were studied the most intensively. From this latter group maintained at Mystic (CT) Marinelife Aquarium, the most frequently recovered bacteria from both animals were members of the Achromobacter-Acinetobacter-Alcaligenes-CDC IV E-Moraxella-Pasteurella-Pseudomonas group, Escherichia coli, Pseudomonas putrefaciens, Staphylococcus epidermidis, Streptococcus faecalis, and Vibrio fluvialis. Only one of these whales yielded cultures of Klebsiella pneumoniae, Plesiomonas shigelloides, and coagulase positive Staphylococcus aureus. Species of Acinetobacter, Aeromonas, Pseudomonas, and Vibrio were most common in whales maintained at the other aquaria although, as noted for animals at Mystic, several species were isolated from some samples and were absent in others.
Size-Dependent Overwinter Mortality of Young-of-the-Year Yellow Perch (Perca flavescens): Laboratory, In Situ Enclosure, and Field Experiments
Authors: Post John R. , Evans David O.
Published: August 2008

In laboratory experiments, fed and starved young-of-the-year yellow perch (Perca flavescens) lost weight when kept under simulated overwinter temperature and photoperiod regimes, small fish losing a greater proportion of their mass than larger ones. Perch in fed and starved treatments suffered 1 and 46% mortality, respectively, mortality being higher among the smaller individuals. Winter duration was an important determinant of both total mortality and the intensity of size-selective mortality. Size-selective mortality also occurred in yellow perch from the same stock kept overwinter in an in situ lake enclosure with natural food. Fall and spring population estimates for two cohorts of young-of-the-year yellow perch from Lake St. George also indicated the occurence of size-selective overwinter mortality. We present a quantitative technique for identification of size-dependent mortality and size-dependent growth from sequential length frequency distributions. This technique allowed identification of overwinter size-selective mortality for five natural cohorts sampled in the field. Results from a stochastic simulation model, incorporating observed variability in both first year growth and winter duration suggest that overwinter starvation mortality can cause substantial variability in year-class strength that is independent of adult stock size.
Sublethal Copper Effects on Bluegill, Lepomis macrochirus, Foraging Behavior
Authors: Sandheinrich Mark B. , Atchison Gary J.
Published: August 2008

The effects of four copper concentrations (5 [control], 31, 180, 1710 μg L−1) on bluegill (Lepomis macrochirus) foraging behavior were examined with two separate experiments; one experiment assessing copper effects on the reaction distance of bluegill to two sizes of untreated zooplankton and one assessing copper effects on the functional response of bluegill to untreated (five tests) and treated (five tests) invertebrate prey. Prey used in these experiments were: Daphnia pulex, D. magna (Cladocera), Hyalella azteca (Amphipoda), and two sizes of Enallagma sp. (Zygoptera). Copper had no effect on the reaction distance of fish to zooplankton. There was a significant negative dose-response relationship for consumption rates of all untreated prey but not of treated prey groups. Prey handling time for bluegill capturing treated and untreated prey increased significantly with copper concentration and was the most consistently sensitive parameter measured. Capture efficiency by bluegill, although altered by copper for some prey types, was not as consistent a measure of toxicant stress. This study suggests that mechanistic measures are valuable indicators of toxicant effects on fish feeding behavior and that copper concentrations near the U.S. Environmental Protection Agency water quality criteria (18–28 μ L−1) may alter food consumption and reduce growth of fish in the wild.
Bivariate Normal Swimbladder Size Allometry Models and Allometric Exponents for 38 Mesopelagic Swimbladdered Fish Species Commonly Found in the North Sargasso Sea
Authors: Saenger R. Alfred
Published: August 2008

With x and y log-transformed fish standard length/and equivalent swimbladder radius R, respectively, probability density distributions p(x,y) for mesopelagic swimbladdered fish species are assumed to be bivariate normal. From archival measurements, models are developed for 36 nonregressive species, 2 regressive species, and selected species groups found off Bermuda. Statistical tests suggest the hypothesis is valid for many of these species, and that failures are due largely to small sample variability and bias in the available data. Marked differences between regression, major axis, and reduced major axis allometric exponents, which sometimes occur when x,y correlation is low, are explained. A dimensionless allometric law R′* = k* (l′*)m involving structural variables l′* and R′* scaled to lmax is used to compare specific swimbladder growth trends. Major axis estimates of m* and k* for the nonregressive species group are each lognormally distributed with respective means [Formula: see text] and [Formula: see text]. A structural relation model for this group based on the hypothesis that swimbladder wall area grows approximately as the first power of fish volume or mass is verified. Last, detailed buoyancy properties are calculated for 6 nonregressive species with bivariate normal (x,w*)-distributions, where w* is the logarithm of percentage swimbladder volume.
Comparative proteomic analysis reveals differentially expressed proteins regulated by a potential tumor promoter, BRE, in human esophageal carcinoma cells
Authors: Chen Hai Bin , Pan Ke , Tang Mei Kuen , Chui Yiu Loon , Chen Ling , Su Zhong Jing , Shen Zhong Ying , Li En Min , Xie Wei , Lee Kenneth K.H.
Published: August 2008

Esophageal tumorigenesis is a complex and cascading process, involving the interaction of many genes and proteins. In this study, we have used the comparative proteomic approach to identify tumor-associated proteins and explore the carcinogenic mechanisms. Two-dimensional electrophoresis (2-DE) and MALDI-TOF MS analysis of esophageal carcinoma and control cells revealed 10 proteins that were upregulated. A further 10 proteins were downregulated. Among these 20 differentially expressed proteins, brain and reproductive organ-expressed (BRE) protein was identified as a potential tumor promoter. It was high expressed by the esophageal carcinoma cells, as confirmed by RT–PCR and immunoblotting. BRE has been reported to be a stress-responsive protein. To gain further insight into its function, BRE expression was silenced in esophageal carcinoma cells using BRE-specific small interference RNA. It was discovered that silencing BRE expression downregulated prohibitin expression, but upregulated tumor-suppressor p53 expression. Furthermore, cyclin A and CDK2 expressions were suppressed suggesting that BRE inhibited cell proliferation. These results implied that BRE plays a significant role in mediating antiapoptotic and proliferative responses in esophageal carcinoma cells.
A novel testis protein, RSB-66, interacting with INCA1 (inhibitor of Cdk interacting with cyclin A1)
Authors: Chen Xu , Hu Tinghui , Liang Gang , Yang Maojun , Zong Shudong , Miao Shiying , Koide Samuel S. , Wang Linfang
Published: August 2008

rsb-66 is a novel gene from a suppression subtracted hybridization (SSH) library of round spermatid-specific cDNAs against those of primary spermatocytes. It was found to be specifically expressed in round spermatids. To explore the function of RSB-66, a yeast two-hybrid system was used to screen for potential interacting partners in a human testis cDNA library. HSD45, also known as INCA1 (inhibitor of Cdk interacting with cyclin A1), was identified as one of the positive clones. The interaction between RSB-66 and INCA1 was demonstrated to occur by GST pull down and coimmunoprecipitation. Using immunofluorescence, RSB-66 was found to be specifically expressed in round spermatids, mainly in the cytoplasm. When being transfected into HeLa cells, RSB-66 and INCA1 were found to be co-localized principally in the cytoplasm. The α helix in the RSB-66 C terminal and two amino acid residues (tyr117 and his119) appear to be crucial for its function.
The Performance of the Endangered Species Act
Authors: Schwartz Mark W.
Published: August 2008

Arguably the most notable success of the Endangered Species Act (ESA) is that listed species improve in status through time. More species are downlisted than the converse; more species transition from stable to improving status than the converse. Although some listed species have gone extinct, this number is smaller than expected. Given modest recovery funding, the fraction of listed species responding positively is remarkable. Several factors have been linked to improving species status including recovery expenditures, critical habitat listing, and time spent under protection. The inability of government to fully empower the agencies to implement the law has been the most notable failure of the ESA. Listing of species has not matched need, recovery expenditures do not match need or agency-set priorities, and critical habitat determinations have lagged. Alternative protection strategies to listing may be having a positive effect, but are difficult to assess because of sparse data.
Connexin 37 profoundly slows cell cycle progression in rat insulinoma cells
Authors: Burt Janis M. , Nelson Tasha K. , Simon Alexander M. , Fang Jennifer S.
Published: August 2008

In addition to providing a pathway for intercellular communication, the gap junction-forming proteins, connexins, can serve a growth-suppressive function that is both connexin and cell-type specific. To assess its potential growth-suppressive function, we stably introduced connexin 37 (Cx37) into connexin-deficient, tumorigenic rat insulinoma (Rin) cells under the control of an inducible promoter. Proliferation of these iRin37 cells, when induced to express Cx37, was profoundly slowed: cell cycle time increased from 2 to 9 days. Proliferation and cell cycle time of Rin cells expressing Cx40 or Cx43 did not differ from Cx-deficient Rin cells. Cx37 suppressed Rin cell proliferation irrespective of cell density at the time of induced expression and without causing apoptosis. All phases of the cell cycle were prolonged by Cx37 expression, and progression through the G1/S checkpoint was delayed, resulting in accumulation of cells at this point. Serum deprivation augmented the effect of Cx37 to accumulate cells in late G1. Cx43 expression also affected cell cycle progression of Rin cells, but its effects were opposite to Cx37, with decreases in G1 and increases in S-phase cells. These effects of Cx43 were also augmented by serum deprivation. Cx-deficient Rin cells were unaffected by serum deprivation. Our results indicate that Cx37 expression suppresses cell proliferation by significantly increasing cell cycle time by extending all phases of the cell cycle and accumulating cells at the G1/S checkpoint.
Position Perception: Influence of Motion With Displacement Dissociated From the Influence of Motion Alone
Authors: Linares Daniel , Holcombe Alex O.
Published: August 2008

When humans view a moving object, the spatial lag in perception expected from neural delays may be partially corrected by motion mechanisms biasing perceived position. The drifting-Gabor illusion seems to support this view: the perceived location of a static envelope filled with a moving pattern is shifted in the direction of motion. To test whether this shifting mechanism also extrapolates the position of moving displacing objects, we compared the perceptual position shift for drifting versus displacing Gabors when the motion is toward the fovea and when the motion is away from the fovea. For displacing Gabors, the shift was much greater for motion toward the fovea, whereas for drifting Gabors, the shift was greater for motion away from the fovea. This dissociation suggests that the illusions are caused by different mechanisms.
Phlorizin Prevents Glomerular Hyperfiltration but not Hypertrophy in Diabetic Rats
Authors: Malatiali Slava , Francis Issam , Barac-Nieto Mario
Published: August 2008

The relationships of renal and glomerular hypertrophies to development of hyperfiltration and proteinuria early in streptozotocin‐induced diabetes were explored. Control, diabetic, phlorizin‐treated controls, and diabetic male Fischer rats were used. Phlorizin (an Na+‐glucose cotransport inhibitor) was given at a dose sufficient to normalize blood glucose. Inulin clearance (Cinulin) and protein excretion rate (PER) were measured. For morphometry, kidney sections were stained with periodic acid Schiff. At one week, diabetes PER increased 2.8‐folds (P < .001), Cinulin increased 80% (P < .01). Kidney wet and dry weights increased 10%–12% (P < .05), and glomerular tuft area increased 9.3% (P < .001). Phlorizin prevented proteinuria, hyperfiltration, and kidney hypertrophy, but not glomerular hypertrophy. Thus, hyperfiltration, proteinuria, and whole kidney hypertrophy were related to hyperglycemia but not to glomerular growth. Diabetic glomerular hypertrophy constitutes an early event in the progression of glomerular pathology which occurs in the absence of mesangial expansion and persists even after changes in protein excretion and GFR are reversed through glycemic control.
The Impact of the Eastern Mediterranean Teleconnection Pattern on the Mediterranean Climate
Authors: Hatzaki Maria , Flocas Helena A. , Giannakopoulos Christos , Maheras Panagiotis
Published: August 2008

The objective of this study is to investigate the impact of the eastern Mediterranean teleconnection pattern (EMP) on the present and future climate of the eastern Mediterranean during winter. For the present climate, daily precipitation and maximum and minimum surface temperature station data are employed for the period of 1958–2003. For the future climate, datasets of the same parameters are derived from the Hadley Centre Regional Climatic Model (HadRM3P) for the period of 2070–2100, using two Intergovernmental Panel on Climate Change (IPCC) emission scenarios for the evolvement of the future atmospheric concentrations of greenhouse gases. The investigation of the impact was based on the regularized canonical correlation analysis (RCCA), while qualitative estimations were performed for each phase of the pattern. It was found that the pattern indeed affects the mean winter patterns of temperature, precipitation, and their extreme events with inverse impacts between the two phases. More specifically, a positive phase of EMP is associated with a decrease in temperatures and an increase in precipitation, while the opposite occurs during the negative phase of EMP. In the future, the present impact according to each phase persists and intensifies in most of the cases. However, results are quite different between the two scenarios, because of the different estimated future shift of the EMP poles.
Soil Moisture Feedbacks on Convection Triggers: The Role of Soil–Plant Hydrodynamics
Authors: Siqueira Mario , Katul Gabriel , Porporato Amilcare
Published: August 2008

The linkages between soil moisture dynamics and convection triggers, defined here as the first crossing between the boundary layer height (hBL) and lifting condensation level (hLCL), are complicated by a large number of interacting processes occurring over a wide range of space and time scales. To progress on this problem, a soil–plant hydrodynamics model was coupled to a simplified ABL budget to explore the feedback of soil moisture on convection triggers. The soil–plant hydraulics formulation accounted mechanistically for features such as root water uptake, root water redistribution, and midday stomatal closure, all known to affect diurnal cycles of surface fluxes and, consequently, ABL growth. The ABL model considered the convective boundary layer as a slab with a discontinuity at the inversion layer. The model was parameterized using the wealth of data already collected for a maturing Loblolly pine plantation situated in the southeastern United States. A 30-day dry-down simulation was used to investigate the possible feedback mechanisms between soil moisture and convective rainfall triggers. Previous studies, which made use of surface flux measurements to drive an ABL model, have postulated that a negative feedback was possible, which could award the ecosystem with some degree of self-regulation of its water status. According to model simulation results here, this negative feedback is unlikely. However, drastic changes in external water sources to the ABL are needed for triggering convection when soil moisture is depleted. The apparent negative feedback originated from a decoupling between the water vapor sources needed to produce convection triggers and surface water vapor fluxes.
Kinship and Shifting Intra-Family Focalism among the Italo-Brussels Jehovah's Witnesses
Authors: Leman Johan
Published: August 2008

The author reports on the observation of the communities of Italo-Brussels Jehovah's Witnesses over a 30-year period (research in 1976, 1996 and 2005). In the 1970s, “conversion” as the means of entry into a new religious community was dominant as a theme in the Kingdom Halls. Thirty years later, it is recruitment through kin and the “vécu” of kinship relations inside the religious enclaves which has become the main objective of these communities. The author analyses the processes in the composition of the socio-cultural basis and the structure of the intra-family relations in these communities between 1976 and 2005. He also tries to develop further the social network recruitment theories on this issue, not in order to object to the recruitment practices, but in order to show the changes that have taken place, and the appearance of “internal” cultural bias in the system.
Predictive Modeling in Hostage and Barricade Incidents
Authors: Michaud Patrick , St-Yves Michel , Guay Jean-Pierre
Published: August 2008

The study examined 534 hostage and barricade incidents. Its objective was to present an integrated and formalized vision of current conceptualizations of critical incidents to optimize decision making. To this end, logistic regression and recursive partitioning models are presented and compared. In all, 18 distinct static and dynamic individual and situational factors were used to predict various outputs during this type of situation. Results highlight the importance of considering the origin of the emergency call and being barricaded in one's home in the assessment of perpetrator's propensity for violence, the fact that time is not always on the police's side during critical incidents, and the relatively minor importance of hostage taking in the general comprehension of these high-risk events.
The Language of Prognostication in Intensive Care Units
Authors: White Douglas B. , Engelberg Ruth A. , Wenrich Marjorie D. , Lo Bernard , Curtis J. Randall
Published: August 2008

Rationale. Although misunderstandings about prognosis are common in intensive care units (ICUs), little is known about how physicians actually communicate prognostic information. Objectives. The authors sought to 1) develop a framework to describe the language physicians use to disclose prognosis, 2) determine whether physicians frame prognostic statements as estimates for populations or estimates for individual patients, and 3) determine whether physicians use the recommended ‘‘ask-tell-ask’’ approach when discussing prognosis. Methods. The authors conducted a multicenter, cross-sectional study of 51 audiotaped physician-family conferences about life support decisions in ICUs. They identified each prognostic statement and used grounded theory methods to develop a framework to understand the language physicians use to communicate prognosis. Main Results. Physicians prognosticated in 50 of 51 conferences. When discussing prognosis, physicians used qualitative probability statements in 72% (36/50) of conferences, numeric statements in 20% (10/50), absolute statements in 13% (4/32), and nonprobabilistic statements in 40% (20/50). Physicians exclusively used population-based language in 10% (5/50) of conferences, single-event probability statements in 62% (31/50), and both in 28% (14/ 50). In only 2% (1/50) of conferences did physicians ask whether the family wished to hear prognostic information prior to discussing it, and in only 14% of conferences (7/50) did physicians check to verify that families understood the prognostic information. Conclusions. There is considerable variability in the language used by physicians to disclose prognosis, with only 20% of physicians using quantitative terms. Very few physicians checked whether families understood prognostic information. These findings may provide potential targets for interventions to improve communication about prognosis in ICUs.
Data Selection for Hand-eye Calibration: A Vector Quantization Approach
Authors: Schmidt Jochen , Niemann Heinrich
Published: August 2008

This paper presents new vector quantization based methods for selecting well-suited data for hand-eye calibration from a given sequence of hand and eye movements. Data selection can improve the accuracy of classic hand-eye calibration, and make it possible in the first place in situations where the standard approach of manually selecting positions is inconvenient or even impossible, especially when using continuously recorded data. A variety of methods is proposed, which differ from each other in the dimensionality of the vector quantization compared to the degrees of freedom of the rotation representation, and how the rotation angle is incorporated. The performance of the proposed vector quantization based data selection methods is evaluated using data obtained from a manually moved optical tracking system (hand) and an endoscopic camera (eye).
Simple Robots with Minimal Sensing: From Local Visibility to Global Geometry
Authors: Suri Subhash , Vicari Elias , Widmayer Peter
Published: August 2008

We consider problems of geometric exploration and self-deployment for simple robots that can only sense the combinatorial (non-metric) features of their surroundings. Even with such a limited sensing, we show that robots can achieve complex geometric reasoning and perform many non-trivial tasks. Specifically, we show that one robot equipped with a single pebble can decide whether the workspace environment is a simply connected polygon and, if not, it can also count the number of holes in the environment. Highlighting the subtleties of our sensing model, we show that a robot can decide whether the environment is a convex polygon, yet it cannot resolve whether a given vertex is convex. Finally, we show that by using such local and minimal sensing a robot can compute a proper triangulation of a polygon and that the triangulation algorithm can be implemented collaboratively by a group of m such robots, each with Θ(n/m) word memory. As a corollary of the triangulation algorithm, we derive a distributed analog of the well-known Art Gallery Theorem. A group of [n/3] (bounded memory) robots in our minimal sensing model can self-deploy to achieve visibility coverage of an n-vertex art gallery (polygon). This resolves an open question raised recently.
Stable isotope variations in stalagmites from northwestern Sweden document changes in temperature and vegetation during the early Holocene: a reply to Hammarlund and Edwards
Authors: Sundqvist H.S. , Holmgren K. , Lauritzen S.-E.
Published: August 2008

In a comment on the paper by Sundqvist et al. (2007a), Hammarlund and Edwards suggest that the oxygen isotope signal of the speleothem records K1 and L4 from northwestern Sweden as well as for the earlier published stalagmite SG93 from northern Norway should mainly reflect variation in the δ 18O of mean annual precipitation. The main argument used by the authors is that the SG93 δ18O record should show remarkable similarities with the lacustrine carbonate δ18O record from Lake Tibetanus. The similarities between SG93 and Lake Tibetanus are mainly seen for the period between 10 and 9 ka BP, which is a period where both records have higher δ18O values compared with later in the Holocene. If true, this would indicate that temperatures in northern Scandinavia would have reached their Holocene maximum between 10 and 9 ka BP, which is contrary to what has been reported from other archives in the region which place the Holocene climatic optimum somewhere between 8 and 5 ka BP. Several factors affect the δ18O of speleothems and definitely also by annual mean δ18O of the local precipitation. However, for Holocene speleothems from northern Scandinavia as well as from the Alps this signal seems to be overridden by other factors, such as variable mixing of summer and winter precipitation of cave drip water as well as the temperature-dependent fractionation between calcite and water. But the relative importance of the factors can differ between different timescales, caves and even speleothems from the same cave, depending on hydrological pathways. To better understand the factors controlling the stable oxygen isotopes in precipitation and proxy archives back in time there is a need for more highly resolved records as well as for more atmospheric and hydrological modelling.
Palaeodrainage on Marajó Island, northern Brazil, in relation to Holocene relative sea-level dynamics
Authors: Rossetti Dilce F. , Valeriano Márcio M. , Góes Ana M. , Thales Marcelo
Published: August 2008

A large area in northeastern Marajó Island, northern Brazil, has been characterized geomorphologically, applying information acquired from Landsat imagery. This study was combined with detailed sedimentologic analysis of continuous cores, which provided a record of depositional settings developed in this area through the Holocene. The results revealed well-preserved, meandering to anastomosed drainage networks of wide palaeochannels that were superimposed by a narrower palaeochannel system. In both cases, the sedimentary record consists of sands, heterolithic deposits and muds, locally rich in plant debris. The strata are organized into fining upward successions that reach approximately 18 m thick in the wide channels and 4 m thick in the narrow channels. Sedimentary features suggestive of a coastal location for the wider palaeochannels and reworking of sediments by tidal currents include the prevalence of well to moderately sorted, rounded to sub-rounded, fine- to medium-grained sands displaying foreset packages separated by mud couplets, suggestive of tidal cycles. The data presented herein point to a rise in relative sea level reaching the Lake Arari area during the early to late/mid Holocene. This event was followed by a relative sea level drop. Tectonics seem to have contributed to an overall lowering in relative sea level in the study area since the mid-Holocene, which does not follow the same pattern recorded in other areas along the northern Brazilian coast.
Aeolian sand movement and relative sea-level rise in Ho Bugt, western Denmark, during the `Little Ice Age'
Authors: Szkornik Katie , Gehrels W. Roland , Murray Andrew S.
Published: August 2008

This study documents an extensive aeolian sand sheet buried in the salt marshes of the Ho Bugt embayment in western Denmark. The extent of the sand sheet was mapped from c. 60 cores and sections, which were also used to reconstruct late-Holocene changes in relative sea level based on diatom analyses. Chronology was provided by optically stimulated luminescence (OSL) and radiocarbon dating. Our study shows that since 2000 cal. yr BP relative sea level in Ho Bugt has risen by approximately 1.5 m. The overall rise was punctuated by two periods with higher than average rates of sea-level rise, the first between 2000 and 1400 cal. yr BP and the second commencing c. 500 cal. yr BP. Around 700 cal. yr BP the evolution of the Skallingen Spit may have been responsible for a reduction in the local tidal range and the formation of an extensive `black layer' in the western part of the embayment. OSL analyses date the sand sheet to between AD 1460 ± 40 and AD 1550 ± 30 (490 ± 40 and 400 ± 30 cal. yr BP), consistent with a period of increased storminess, coastal dune building, saltmarsh formation and increased relative sea-level rise during the early part of the LIA. Other studies have ascribed formation of coastal dunes along western European coastlines during the `Little Ice Age' (LIA) to a combination of increased storminess and low relative sea level. In contrast, we conclude that during the LIA in western Denmark, storminess, transgressive conditions and relative sea-level rise, rather than a sea-level low stand, were important contributing factors to coastal sand movement and dune formation.
Holocene environmental change at the upper forest line in northern Ecuador
Authors: Bakker Johan , Moscol Olivera Marcela , Hooghiemstra Henry
Published: August 2008

We have reconstructed the altitudinal position of the upper forest line (UFL) during the last 6000 years. This boundary between montane forest and páramo (tropical alpine grasslands) has important ecological and societal relevance. It is suggested that human-induced fires and deforestation during the long occupation history of the Central Valley of Ecuador have caused a downslope shift of the UFL and have given way to a downslope expansion of páramo vegetation. More recently, montane forests and lower páramo have been replaced to a large extent by agricultural land. Pollen analysis of a 90 cm long sediment core G15-II from a small mire at 3400 m elevation, 200 m below the actual UFL in Guandera Biological Reserve (0°36′N, 77°42′E), shows the altitudinal position of the UFL during seven discrete intervals: (1) from 7150 to 6240 cal. yr BP the UFL was at c. 3100—3200 m and climatic conditions were cool; (2) from 6240 to 5320 cal. yr BP the UFL shifted to c. 3600 m and upper montane rainforest (UMRF) surrounded the mire; (3) from 5320 to 2160 cal. yr BP the UFL was at 3600—3650 m elevation and montane forest consisted mainly of Hedyosmum, Weinmannia , Melastomataceae, Ilex, Scrophulariaceae and Symplocos; (4) from 2160 to 910 cal. yr BP the UFL shifted downslope to 3350 m and the mire was located in the lowermost páramo; (5) from 910 to 520 cal. yr BP cooler climatic conditions prevailed and the UFL was at 3250—3300 m; (6) since c. 520 cal. yr BP the UFL has shifted upslope to 3600 m. During this period presence of agricultural weeds ( Rumex) and evidence of draining and disturbance of the mire indicate that agricultural activities expanded and almost reached the reserve area; (7) during the last 150 cal. yr disturbance increased. We conclude that during the last 6000 years the UFL reached a maximum altitude of 3650 to 3700 m, indicating that páramo grasslands above this elevation represent a natural ecosystem. Under the Kyoto Protocol-driven reforestation activities, trees should be planted up to a maximum of 3700 m. Planting trees (exotic species in particular) above 3700 m would contribute to the degradation of the natural ecosystem.
Therapeutic benefit of treatment with anti-thymocyte globulin and latent TGF-β1 in the MRL/lpr lupus mouse model
Authors: Kaplan JM , Woodworth L , Smith K , Coco J , Vitsky A , McPherson JM
Published: August 2008

The pathogenesis of systemic lupus erythematosus is believed to involve defects in regulatory T cell (Treg) activity and abnormal activation of B and T lymphocytes. The purpose of this study was to test the therapeutic potential of rabbit anti-mouse thymocyte globulin (ATG), a lymphocyte-depleting agent, in conjunction with transforming growth factor (TGF)-β1, a factor involved in the induction and expansion of Tregs. MRL/lpr mice with active disease were treated with ATG followed by a 12-day course of latent TGF-β1 during the period of lymphocyte repopulation. Treatment with ATG + latent TGF-β1 synergistically inhibited the progression of proteinuria and albuminuria and provided a significant improvement in long-term survival. This therapeutic benefit correlated histologically with reduced glomerular pathology and protein cast formation. The mechanism of action did not involve suppression of autoantibody formation but may involve the activity of CD4+CD25+FoxP3+ Tregs, which were found to be induced by ATG + TGF-β1 treatment in vitro.
The role of surveillance and data use in the development of public health policies
Authors: Stachenko Sylvie
Published: August 2008

Decision makers consider numerous factors besides surveillance data in establishing public health policies and programmes. In an evidence-informed system, it is important to collect, interpret, and present information that has maximum impact on the broader policy agenda.

Successful policies and programmes are rational, feasible, and practical, with wide public support. Surveillance systems must align and interact with the other parts of the policy infrastructure. There must be continuous links between data providers, collectors, and users. Data must be representative of population variations.

For chronic diseases, the major challenge is multiple risks. Surveillance systems must capture many factors from many sources. Data must be presented in plain language and tailored to the needs of various users — politicians, policy makers, health providers, researchers, and the public. Data must be linked to other policy areas such as taxation. Economic arguments, including modelling, strongly influence decisions. Broad data ownership through alliances also has significant impact. (Promot Educ 2008;15(3): 27-29)