bluuebunny/crossref_metadata_2025 huggingface dataset:
LuxS Promotes Biofilm Maturation and Persistence of Nontypeable
Haemophilus influenzae
In Vivo via Modulation of Lipooligosaccharides on the Bacterial Surface
Authors: Armbruster Chelsie E. , Hong Wenzhou , Pang Bing , Dew Kristin E. , Juneau Richard A. , Byrd Matthew S. , Love Cheraton F. , Kock Nancy D. , Swords W. Edward
Published: June 2009

Nontypeable
Haemophilus influenzae
(NTHI) is an extremely common airway commensal which can cause opportunistic infections that are usually localized to airway mucosal surfaces. During many of these infections, NTHI forms biofilm communities that promote persistence in vivo. For many bacterial species, density-dependent quorum-signaling networks can affect biofilm formation and/or maturation. Mutation of
luxS
, a determinant of the autoinducer 2 (AI-2) quorum signal pathway, increases NTHI virulence in the chinchilla model for otitis media infections. For example, bacterial counts in middle-ear fluids and the severity of the host inflammatory response were increased in
luxS
mutants compared with parental strains. As these phenotypes are consistent with those that we have observed for biofilm-defective NTHI mutants, we hypothesized that
luxS
may affect NTHI biofilms. A
luxS
mutant was generated using the well-characterized NTHI 86-028NP strain and tested to determine the effects of the mutation on biofilm phenotypes in vitro and bacterial persistence and disease severity during experimental otitis media. Quantitation of the biofilm structure by confocal microscopy and COMSTAT analysis revealed significantly reduced biomass for NTHI 86-028NP
luxS
biofilms, which was restored by a soluble mediator in NTHI 86-028NP supernatants. Analysis of lipooligosaccharide moieties using an enzyme-linked immunosorbent assay and immunoblotting showed decreased levels of biofilm-associated glycoforms in the NTHI 86-028NP
luxS
strain. Infection studies showed that NTHI 86-028NP
luxS
had a significant persistence defect in vivo during chronic otitis media infection. Based on these data, we concluded that a
luxS
-dependent soluble mediator modulates the composition of the NTHI lipooligosaccharides, resulting in effects on biofilm maturation and bacterial persistence in vivo.
A Regulator of
Aspergillus fumigatus
Extracellular Proteolytic Activity Is Dispensable for Virulence
Authors: Bergmann Anna , Hartmann Thomas , Cairns Timothy , Bignell Elaine M. , Krappmann Sven
Published: June 2009

Virulence of the fungal pathogen
Aspergillus fumigatus
is in part based on the saprophytic lifestyle that this mold has evolved. A crucial function for saprophytism resides in secreted proteases that allow assimilation of proteinaceous substrates. The impact of extracellular proteolytic activities on the pathogenesis of aspergillosis, however, remains controversial. In order to address this issue, characterization of a conserved regulatory factor, PrtT, that acts on expression of secreted proteases was pursued. Expression of PrtT appears to be regulated posttranscriptionally, and the existence of an mRNA leader sequence implies translational control via eIF2α kinase signaling. Phenotypic classification of a
prtT
Δ deletion mutant revealed that expression of several major extracellular proteases is PrtT dependent, resulting in the inability to utilize protein as a nutritional source. Certain genes encoding secreted proteases are not regulated by PrtT. Most strikingly, the deletant strain is not attenuated in virulence when tested in a leukopenic mouse model, which makes a strong case for reconsidering any impact of secreted proteases in pulmonary aspergillosis.
Role of Dendritic Cells and Alveolar Macrophages in Regulating Early Host Defense against Pulmonary Infection withCryptococcus neoformans
Authors: Osterholzer John J. , Milam Jami E. , Chen Gwo-Hsiao , Toews Galen B. , Huffnagle Gary B. , Olszewski Michal A.
Published: June 2009

Successful pulmonary clearance of the encapsulated yeastCryptococcus neoformansrequires a T1 adaptive immune response. This response takes up to 3 weeks to fully develop. The role of the initial, innate immune response against the organism is uncertain. In this study, an established model of diphtheria toxin-mediated depletion of resident pulmonary dendritic cells (DC) and alveolar macrophages (AM) was used to assess the contribution of these cells to the initial host response against cryptococcal infection. The results demonstrate that depletion of DC and AM one day prior to infection results in rapid clinical deterioration and death of mice within 6 days postinfection; this effect was not observed in infected groups of control mice not depleted of DC and AM. Depletion did not alter the microbial burden or total leukocyte recruitment in the lung. Mortality (in mice depleted of DC and AM) was associated with increased neutrophil and B-cell accumulation accompanied by histopathologic evidence of suppurative neutrophilic bronchopneumonia, cyst formation, and alveolar damage. Collectively, these data define an important role for DC and AM in regulating the initial innate immune response following pulmonary infection withC. neoformans. These findings provide important insight into the cellular mechanisms which coordinate early host defense against an invasive fungal pathogen in the lung.
Infection withAnaplasma phagocytophilumInduces Multilineage Alterations in Hematopoietic Progenitor Cells and Peripheral Blood Cells
Authors: Johns J. L. , MacNamara K. C. , Walker N. J. , Winslow G. M. , Borjesson D. L.
Published: June 2009

Infection withAnaplasma phagocytophilum, a gram-negative, lipopolysaccharide (LPS)-negative, obligate intracellular bacterium, results in multiple peripheral blood cytopenias. We hypothesized that infection with this organism would result in decreased bone marrow (BM) function and shifts in hematopoietic progenitor cells (HPCs) and lineage-committed cells in a well-established murine model of infection. HPCs and lineage-committed progenitors were enumerated in the BM and spleen during acute infection. BM cytokine production and BM CXCL12 expression were determined. Infection resulted in peripheral blood bicytopenia, marked decreases in the number of lineage-committed HPCs in the BM along with concurrent increases in the number of lineage-committed HPCs in the spleen, and a mixed, predominantly myelosuppressive BM cytokine environment. There was significant downregulation of CXCL12 in BM cells that may have been partially responsible for changes in HPC trafficking observed. Changes occurred in the absence of direct pathogen infection of BM cells. Hematopoietic lineage assessment demonstrated that there was loss of erythrocytes and B lymphocytes from the BM along with increased granulopoiesis. These changes were accompanied by splenomegaly due to lymphoid hyperplasia and increased hematopoiesis, most notably erythropoiesis. These changes largely mimic well-described inflammation and endotoxin-mediated effects on the BM and spleen; however, the numbers of peripheral blood neutrophils appear to be independently modulated as granulocytic hyperplasia does not result in neutrophilia. Our findings highlight a well-conserved series of events that we demonstrate can be instigated by an LPS-negative pathogen in the absence of an endotoxin-mediated acute proinflammatory response.
Transmembrane Tumor Necrosis Factor Alpha Is Required for Enteropathy and Is Sufficient To Promote Parasite Expulsion in Gastrointestinal Helminth Infection
Authors: Ierna M. X. , Scales H. E. , Mueller C. , Lawrence C. E.
Published: June 2009

To study the specific role of transmembrane tumor necrosis factor (tmTNF) in protective and pathological responses against the gastrointestinal helminthTrichinella spiralis, we compared the immune responses of TNF-α/lymphotoxin alpha (LTα)−/−mice expressing noncleavable transgenic tmTNF to those of TNF-α/LTα−/−and wild-type mice. The susceptibility of TNF-α/LTα−/−mice toT. spiralisinfection was associated with impaired induction of a protective Th2 response and the lack of mucosal mastocytosis. Although tmTNF-expressing transgenic (tmTNF-tg) mice also had a reduced Th2 response, the mast cell response was greater than that observed in TNF-α/LTα−/−mice and was sufficient to induce the expulsion of the parasite.T. spiralisinfection of tmTNF-tg mice resulted in significant intestinal pathology characterized by villus atrophy and crypt hyperplasia comparable to that induced following the infection of wild-type mice, while pathology in TNF-α/LTα−/−mice was significantly reduced. Our data thus indicate a role for tmTNF in host defense against gastrointestinal helminths and in the accompanying enteropathy. Furthermore, they also demonstrate that TNF-α is required for the induction of Th2 immune responses related to infection with gastrointestinal helminth parasites.
Staphylococcal Alpha-Toxin Is Not Sufficient To Mediate Escape from Phagolysosomes in Upper-Airway Epithelial Cells
Authors: Giese Bernd , Dittmann Silvia , Paprotka Kerstin , Levin Katja , Weltrowski Annett , Biehler Diana , Lâm Thiên-Trí , Sinha Bhanu , Fraunholz Martin J.
Published: June 2009

Intracellular
Staphylococcus aureus
has been implicated in the establishment of chronic infections. It is therefore imperative to understand by what means
S. aureus
is able to survive within cells. Here we use two expression systems with a fluorescent readout to assay alpha-toxin expression and function within phagolysosomes of infected upper-airway epithelial cells: avirulent
Staphylococcus carnosus
TM300 and phenotypically alpha-toxin-negative
S. aureus
laboratory strains. Data from CFU recovery assays suggest that the presence of alpha-toxin is not beneficial for the intracellular survival of recombinant
Staphylococcus
strains. This finding was corroborated by immunofluorescence studies: whereas
S. carnosus
and
S. aureus
are able to deliver
S. aureus
alpha-toxin to lumina of host cell phagolysosomes, the membrane integrity of these organelles was not affected. Alpha-toxin-expressing strains were detected exclusively within lysosome-associated membrane protein 1 (LAMP1)-yellow fluorescent protein (YFP)-positive vesicles. Measurements of intraphagosomal pH illustrated that all infected phagolysosomes acidified regardless of alpha-toxin expression. In contrast,
S. aureus
expressing
Listeria monocytogenes
listeriolysin O leads to the breakdown of the phagolysosomal membrane, as indicated by staphylococci that are not associated with LAMP1-YFP-decorated vesicles and that do not reside within an acidic cellular environment. Thus, our results suggest that staphylococcal alpha-toxin is not sufficient to mediate phagolysosomal escape in upper-airway epithelial cells.
Elevation errors in a LIDAR digital elevation model of West Seattle and their effects on slope-stability calculations
Authors: Haneberg William C.
Published: June 2009

A comparison of 1719 differential global positioning system (GPS) measurements with a 1 m LIDAR (light detection and ranging) digital elevation model (DEM) covering West Seattle shows that DEM elevation errors range from −4.88 m to +3.32 m. The errors are spatially correlated with a semivariogram range of 40 m, an unclustered mean of −0.11 m, and an unclustered standard deviation of ±0.75 m. Although there are statistically significant correlations between elevation error and elevation, slope angle, and topographic roughness, the relationships are weak and have little explanatory power. Monte Carlo simulations of slope angle, static factor of safety, Newmark yield acceleration, and log Newmark displacement show that elevation errors of the magnitude reported here can have significant effects on derivative calculations. The standard deviation of simulated slope angles increases from ~±2° to ±3° as the true slope angle approaches zero. Errors in slope angles calculated from the LIDAR DEM are smaller than those previously reported for a conventional 10 m DEM covering the same area, but the decrease is not proportional to the decrease in DEM grid spacing. The influence of elevation errors on static factor of safety errors is strongly dependent upon the slope angle and decreases significantly as the slope angle increases. Effects on Newmark yield acceleration and log Newmark displacement are not as profound but are still large enough to impart significant uncertainty into calculated results. Therefore, slope angle errors should be considered to be as significant as geotechnical parameter and pore-water pressure uncertainties when performing slope-stability calculations based on high-resolution LIDAR DEMs.
Shallow landslide hazard map of Seattle, Washington
Authors: Harp Edwin L. , Michael John A. , Laprade William T.
Published: June 2009

Landslides, particularly debris flows, have long been a significant cause of damage and destruction to people and property in the Puget Sound region. Following the years of 1996 and 1997, the Federal Emergency Management Agency designated Seattle as a “Project Impact” city with the goal of encouraging the city to become more disaster resistant to landslides and other natural hazards. A major recommendation of the Project Impact council was that the city and the U.S. Geological Survey collaborate to produce a landslide hazard map. An exceptional data set archived by the city containing more than 100 yr of landslide data from severe storm events allowed comparison of actual landslide locations with those predicted by slope-stability modeling. We used an infinite-slope analysis, which models slope segments as rigid friction blocks, to estimate the susceptibility of slopes to debris flows, which are water-laden slurries that can form from shallow failures of soil and weathered bedrock and can travel at high velocities down steep slopes. Data used for the analysis consisted of a digital slope map derived from recent light detection and ranging (LiDAR) imagery of Seattle, recent digital geologic mapping of the city, and shear-strength test data for the geologic units found in the surrounding area. The combination of these data layers within a geographic information system (GIS) platform allowed us to create a shallow landslide hazard map for Seattle.
Assessing deep-seated landslide susceptibility using 3-D groundwater and slope-stability analyses, southwestern Seattle, Washington
Authors: Brien Dianne L. , Reid Mark E.
Published: June 2009

In Seattle, Washington, deep-seated landslides on bluffs along Puget Sound have historically caused extensive damage to land and structures. These large failures are controlled by three-dimensional (3-D) variations in strength and pore-water pressures. We assess the slope stability of part of southwestern Seattle using a 3-D limit-equilibrium analysis coupled with a 3-D groundwater flow model. Our analyses use a high-resolution digital elevation model (DEM) combined with assignment of strength and hydraulic properties based on geologic units. The hydrogeology of the Seattle area consists of a layer of permeable glacial outwash sand that overlies less permeable glacial lacustrine silty clay. Using a 3-D groundwater model, MODFLOW-2000, we simulate a water table above the less permeable units and calibrate the model to observed conditions. The simulated pore-pressure distribution is then used in a 3-D slope-stability analysis, SCOOPS, to quantify the stability of the coastal bluffs. For wet winter conditions, our analyses predict that the least stable areas are steep hillslopes above Puget Sound, where pore pressures are elevated in the outwash sand. Groundwater flow converges in coastal reentrants, resulting in elevated pore pressures and destabilization of slopes. Regions predicted to be least stable include the areas in or adjacent to three mapped historically active deep-seated landslides. The results of our 3-D analyses differ significantly from a slope map or results from one-dimensional (1-D) analyses.
A prototype system for forecasting landslides in the Seattle, Washington, area
Authors: Chleborad Alan F. , Baum Rex L. , Godt Jonathan W. , Powers Phillip S.
Published: June 2009

Empirical rainfall thresholds and related information form the basis of a prototype system for forecasting landslides in the Seattle area. The forecasts are tied to four alert levels, and a decision tree guides the use of thresholds to determine the appropriate level. From analysis of historical landslide data, we developed a formula for a cumulative rainfall threshold (CT), P3  =  88.9 − 0.67P15, defined by rainfall amounts in millimeters during consecutive 3 d (72 h) periods, P3, and the 15 d (360 h) period before P3, P15. The variable CT captures more than 90% of historical events of three or more landslides in 1 d and 3 d periods recorded from 1978 to 2003. However, the low probability of landslide occurrence on a day when the CT is exceeded at one or more rain gauges (8.4%) justifies a low-level of alert for possible landslide occurrence, but it does trigger more vigilant monitoring of rainfall and soil wetness. Exceedance of a rainfall intensity-duration threshold I  =  82.73D−1.13, for intensity, I (mm/hr), and duration, D (hr), corresponds to a higher probability of landslide occurrence (30%) and forms the basis for issuing warnings of impending, widespread occurrence of landslides. Information about the area of exceedance and soil wetness can be used to increase the certainty of landslide forecasts (probabilities as great as 71%). Automated analysis of real-time rainfall and subsurface water data and digital quantitative precipitation forecasts are needed to fully implement a warning system based on the two thresholds.
Metformin: safety in cardiac patients
Authors: Khurana R , Malik I S
Published: June 2009

Metformin is a biguanide, insulin sensitiser that reduces blood sugar levels. There are concerns about the risk of lactic acidosis in patients receiving metformin who have procedures requiring iodinated contrast, and in those with renal impairment or heart failure. The data on which these concerns are based are reviewed, with the conclusion that metformin treatment is rarely to blame for lactic acidosis. A generic policy of stopping metformin 48 h before and 48 h after the procedure in all patients is counterintuitive, lacks any evidence base and does not conform to the principles of best practice. In patients with heart failure, although the underlying condition can predispose to lactic acidosis, existing evidence suggests that metformin use is associated with improved outcome rather than increased risk.
Belgian euthanasia law: a critical analysis
Authors: Cohen-Almagor R
Published: June 2009

Some background information about the context of euthanasia in Belgium is presented, and Belgian law on euthanasia and concerns about the law are discussed. Suggestions as to how to improve the Belgian law and practice of euthanasia are made, and Belgian legislators and medical establishment are urged to reflect and ponder so as to prevent potential abuse.
Reconsidering prenatal screening: an empirical–ethical approach to understand moral dilemmas as a question of personal preferences
Authors: García E , Timmermans D R M , van Leeuwen E
Published: June 2009

In contrast to most Western countries, routine offer of prenatal screening is considered problematic in the Netherlands. The main argument against offering it to every pregnant woman is that women would be brought into a moral dilemma when deciding whether to use screening or not. This paper explores whether the active offer of a prenatal screening test indeed confronts women with a moral dilemma. A qualitative study was developed, based on a randomised controlled trial that aimed to assess the decision-making process of women when confronted with a test offer. A sample of 59 women was interviewed about the different factors balanced in decision-making. Participants felt themselves caught between a need for knowledge and their unwillingness to take on responsibility. Conflict was reported between wishes, preferences and ethical views regarding parenthood; however, women did not seem to be caught in a choice between two or more ethical principles. Participants balanced the interests of the family against that of the fetus in line with their values and their personal circumstances. Therefore, we conclude that they are not so much faced with an ethical dilemma as conflicting interests. We propose that caregivers should provide the opportunity for the woman to discuss her wishes and doubts to facilitate her decision. This approach would help women to assess the meaning of testing within their parental duties towards their unborn child and their current offspring.
Split views among parents regarding children’s right to decide about participation in research: a questionnaire survey
Authors: Swartling U , Helgesson G , Hansson M G , Ludvigsson J
Published: June 2009

Based on extensive questionnaire data, this paper focuses on parents’ views about children’s right to decide about participation in research. The data originates from 4000 families participating in a longitudinal prospective screening as 1997. Although current regulations and recommendations underline that children should have influence over their participation, many parents in this study disagree. Most (66%) were positive providing information to the child about relevant aspects of the study. However, responding parents were split about whether or not children should at some point be allowed decisional authority when participating in research: 41.6% of the parents reported being against or unsure. Those who responded positively believed that children should be allowed to decide about blood-sampling procedures (70%), but to a less extent about participation (48.5%), analyses of samples (19.7%) and biological bank storage (15.4%). That as many as possible should remain in the study, and that children do not have the competence to understand the consequences for research was strongly stressed by respondents who do not think children should have a right to decide. When asked what interests they consider most important in paediatric research, child autonomy and decision-making was ranked lowest. We discuss the implications of these findings.
Bone marrow transplantation in the prevention of intellectual disability due to inherited metabolic disease: ethical issues
Authors: Louhiala P
Published: June 2009

Many inherited metabolic diseases may lead to varying degrees of brain damage and thus also to intellectual disability. Bone marrow transplantation (BMT) has been used for over two decades as a form of secondary prevention to stop or reverse the progress of the disease process in some of these conditions. At the population level the impact of BMT on the prevalence of intellectual disability is minute, but at the individual level its impact on the prognosis of the disease and the well-being of the patient can be substantial. The dark side of BMT use is the burden of side effects, complications and transplantation-related mortality in less successful cases. The ethical issues involved in this therapy are discussed in this review.
The ethics of the placebo in clinical practice revisited
Authors: Louhiala P
Published: June 2009

Three recent empirical studies on the use of placebos and two papers arguing for the deliberate use of placebos in clinical practice are analysed. Empirical studies demonstrate that placebos are commonly used. The concept of the placebo is currently understood in different ways, many of which do not refer to inert substances or treatments. The papers arguing for the use of placebos are shown to fail to make their case.
Work status, work hours and health in women with and without children
Authors: Floderus B , Hagman M , Aronsson G , Marklund S , Wikman A
Published: June 2009

Objectives:

The authors studied self-reported health in women with and without children in relation to their work status (employed, student, job seeker or homemaker), work hours and having an employed partner.

Methods:

The study group comprised of 6515 women born in 1960–1979 who were interviewed in one of the Swedish Surveys of Living Conditions in 1994–2003. Self-rated health, fatigue and symptoms of anxiety were analysed.

Results:

Having children increased the odds of poor self-rated health and fatigue in employed women, female students and job seekers. The presence of a working partner marginally buffered the effects. In dual-earner couples, mothers reported anxiety symptoms less often than women without children. Few women were homemakers (5.8%). The odds of poor self-rated health and fatigue increased with increasing number of children in employed women, and in women working 40 h or more. Poor self-rated health was also associated with the number of children in students. Many mothers wished to reduce their working hours, suggesting time stress was a factor in their impaired health. The associations between having children and health symptoms were not exclusively attributed to having young children.

Conclusions:

Having children may contribute to fatigue and poor self-rated health particularly in women working 40 h or more per week. Student mothers and job seeking mothers were also at increased risk of poor self-rated health. The results should be noted by Swedish policy-makers. Also countries aiming for economic and gender equality should consider factors that may facilitate successful merging of work and family life.
Seasonal dynamics of the bat stomach worm, Longibucca lasiura (Nematoda: Rhabditoidea), in Alberta
Authors: Measures Lena N.
Published: June 2009

One hundred and sixty-nine bats belonging to 6 different species and collected from 4 ecological zones (aspen parkland, boreal forest, grassland, and montane) in Alberta, Canada, during 1988 and 1989 were examined for helminths. Forty bats were infected with the stomach nematode Longibucca lasiura McIntosh and Chitwood, 1934. Sample size, prevalence, and mean intensity (with range in parentheses) of L. lasiura for the 6 species of bat were as follows: Myotis lucifugus, N = 130, 27%, 39 (1–121); Myotis ciliolabrum, N = 10, 10%, 1; Eptesicus fuscus, N = 6, 33%, 12 (2–22); Lasionycteris noctivagans, N = 2, 100%, 22 (5–39). Myotis evotis (N = 9) and Lasiurus cinereus (N = 3) were not infected. Longibucca lasiura was found in bats from all ecological zones except the boreal forest. This parasite was found in bats active during summer (June to August) and in hibernating M. lucifugus collected in September and April.
Segregation by humpback whale (Megaptera novaeangliae) cows with a calf in coastal habitat near the island of Hawaii
Authors: Smultea Mari A.
Published: June 2009

Humpback whales (Megaptera novaeangliae) were tracked from shore to determine habitat-use patterns in an area relatively undisturbed by human activity near the "Big Island" of Hawaii during the winter 1988 and 1989 calving seasons. The temporal and spatial distributions of whales differed with group size and composition. During afternoon hours, groups containing a calf occurred in water significantly shallower and nearer to shore than did groups without a calf. Late in the breeding season, the same segregation pattern occurred throughout the day. Between-groups distances were significantly greater for groups with a calf than distances between all other groups. The number of whales observed per hour peaked during mid-February, although the relative sighting rates for various group sizes and compositions varied across the breeding season. Adults without a calf may use deep water to facilitate breeding behavior, while maternal females may use shallower water to avoid harassment and injury to calves from sexually active males, turbulent offshore or deep sea conditions, or predators. The predominance of cows with a calf in coastal habitat increases their exposure to expanding human-related development and aquatic activities that could injure, disturb, or displace them.
The effect of ivermectin on the hydatid cyst of Echinococcus multilocularis in gerbils (Meriones unguiculatus)
Authors: Ochieng'-Mitula P. J. , Burt M. D. B. , Tanner C. E. , Mackinnon B. M. , Magambo J. K. , Cowan F. B. M. , Aterman K.
Published: June 2009

The effects of the anthelmintic ivermectin on Echinococcus multilocularis hydatid cysts in gerbils, treated either by intraperitoneal systemic injection or by direct injection into the cyst, were studied by means of light and scanning and transmission electron microscopy. Intraperitoneal systemic treatment with ivermectin generally reduced proliferation of the parasite. The drug also affected the morphology of protoscolices, causing contraction and necrotic changes. However, the cyst tissue from treated animals was still infective to naive hosts. Direct injection of the drug into the cyst caused vesiculation of the cyst tissue cells and induced pathological changes in the treated cyst that included necrosis with detachment of the germinal layer from the laminated layer. However, the effects of both treatments were not generalized and some parts of the hydatid tissue remained intact.
The co-occurrence of moose, white-tailed deer, and Parelaphostrongylus tenuis in Ontario
Authors: Whitlaw Heather A. , Lankester Murray W.
Published: June 2009

Moose (Alces alces) populations were studied in parts of Ontario where they cohabit with white-tailed deer (Odocoileus virginianus) infected with Parelaphostrongylus tenuis. Trend data on changes in cervid numbers for the period 1980–1992, current population density estimates, and records of moose sickness were obtained from Ontario Ministry of Natural Resources managers; presence and abundance of P. tenuis were determined by examining winter deer feces for dorsal-spined larvae. Moose and deer coexist in 45 of 83 Ontario Wildlife Management Units (WMUs) surveyed and have persisted there for at least the past 12 years. Cervid populations in most of these WMUs are presently believed to be stable or increasing. Moose density was inversely related to deer density and was greatest where the latter was <4/km2. In addition, moose densities were lowest in areas with the highest mean intensity of P. tenuis larvae in deer feces. Nonetheless, the documented persistence of moose in numerous areas with infected deer, and case studies of recent moose declines, suggest that the effect of this parasite on moose populations is more subtle than was previously believed, and further study is required to separate and measure its importance relative to other mortality factors known to act on moose populations.
Population inhibitors in cultures of Bulinus truncatus rohlfsi
Authors: Leopard Matthew G. , Isseroff Hadar
Published: June 2009

Bulinus truncatus rohlfsi is a snail host of the human blood fluke Schistosoma haematobium. Observations on the dynamics of laboratory cultures of B. t. rohlfsi are presented from a series of experiments that investigated the effects of population density, pH, and oxygen concentration, and the inhibitory effects of old snail culture media. The data suggest that survival and fecundity are density dependent and that the cause of this effect is a fairly thermostable compound with a molecular weight <1000.
Patterns of protein synthesis and phosphorylation during anoxia in the land snail Otala lactea
Authors: Brooks S. P. J. , Storey K. B.
Published: June 2009

Protein labeling patterns with [32P]phosphorous and [35S]methionine plus [35S]cysteine were examined in normoxic and anoxic tissues of Otala lactea. Analysis of protein phosphorylation showed differences between normoxic and anoxic individuals in both the extent of labeling and the pattern of protein phosphorylation. These changes were confined to the hepatopancreas where anoxia caused overall protein phosphorylation to decrease by a factor of 3. Subcellular fractionation of the hepatopancreas showed that this overall decrease in protein phosphorylation was due to a lower level of protein phosphorylation in individual fractions. Thus, the level of protein phosphorylation during anoxia was 45% (plasma membrane fraction), 21% (mitochondrial fraction), 24% (microsomal fraction), and 22% (cytosolic fraction) of that measured in normoxic tissues. Isoelectric focusing and sodium dodecyl sulfate polyacrylamide gel electrophoresis showed several changes in protein phosphorylation patterns. For example, the relative phosphorylation of cytosolic proteins of molecular mass 65, 49, 30, 25, 21, and 18 kDa was increased in normoxic individuals. Cytosol from anoxic snails showed a relative increase in the phosphorylation of proteins of molecular mass 68, 52, 44, 37, 18, and 16 kDa. No differences in the protein labeling patterns of the mitochondrial and microsomal fractions were apparent. In contrast, analysis of proteins labeled with [35S]methionine plus [35S]cysteine showed no differences when anoxic and normoxic snail tissues were compared.
Apparent demographic changes in black-tailed deer associated with wolf control on northern Vancouver Island
Authors: Hatter Ian W. , Janz Doug W.
Published: June 2009

A simple difference equation model was used to provide a perspective on demographic changes in a Columbian black-tailed deer (Odocoileus hemionus columbianus) population prior to and during wolf (Canis lupus) control on northern Vancouver Island. The model reconstructed spring (pre-fawning) deer numbers and adult survival rates from an annual abundance index, the proportion of the population consisting of juveniles 10–11 months of age, and hunter harvest. The actual (λ) and potential (λp, in the absence of hunting) rates of deer population change, adult nonhunting survival (Sn), adult hunting mortality (Mh) and recruitment (R) rates were estimated for three growth periods: (1) predecline (1970–1976), wolf numbers low but increasing, λ = 1.02, λp = 1.13, Sn = 0.90, Mh = 0.09, R = 0.22; (2) decline (1976–1983), wolves abundant, λ = 0.81, λp = 0.85, Sn = 0.76, Mh = 0.05, R = 0.09; and (3) recovery (1983–1990), wolves reduced, λ = 1.17, λp = 1.24, Sn = 0.94, Mh = 0.03, R = 0.23. The recruitment (Rs) required to balance adult mortality (λ = 1.00) was ~16%. Sensitivity analyses using plausible extremes in demographic rates suggested that changes in juvenile survival had the greatest impact on recruitment. Rate of population change appeared to be most sensitive to juvenile survival and adult nonhunting survival.
The pineal gland signals autumn to reindeer (Rangifer tarandus tarandus) exposed to the continuous daylight of the Arctic summer
Authors: Stokkan Karl-Arne , Tyler Nicholas J. C. , Reiter Russel J.
Published: June 2009

Plasma melatonin concentrations were measured in blood samples taken hourly for 24–30 h once each month for 1 year in four male semidomesticated reindeer. The animals, which included two long-term castrates, were exposed to natural light and temperature conditions at 69°46′N throughout the study. Melatonin levels were individually variable but did not differ systematically between the castrated and the intact animals. In months characterized by a marked diel light–dark cycle, the plasma concentration of melatonin varied throughout the day; levels were high during the dark phase and low during the light phase. In summer (May, June, and July), when daylight was continuous, and in December, when there was only a short period of twilight in the middle of the day, the pooled hourly mean levels of melatonin did not change significantly across 24 h. However, though the light was continuous, the intensity varied markedly between day and night in summer and all animals showed a slight increase in the plasma concentration of melatonin around midnight in July. In addition, daily secretion of melatonin increased from an annual minimum of 66–84 pg/24 h in June and July to an annual maximum of 525 pg/24 h in August when day length began to decrease from 24 h. We suggest that exposure to continuous light throughout the polar summer reduces the sensitivity of the reindeer pineal gland to light and that, consequently, the drop in light intensity around midnight stimulates secretion of melatonin, which in turn provides photoperiodic information even during periods of continuous daylight. It appears, likewise, that the melatonin profile is enhanced in August, signalling a longer night than that actually experienced. In these two ways, reindeer may receive sufficient photoperiodic information to trigger short-day responses, such as development of the gonads, while still exposed to long days and thus compensate for the late onset of short days in autumn, which is characteristic of high latitudes.
Demographics of Lestes disjunctus disjunctus (Odonata: Zygoptera) in a riverine wetland
Authors: Duffy Walter G.
Published: June 2009

I investigated the demographics of Lestes disjunctus disjunctus inhabiting a riverine wetland adjacent to the St. Marys River, Michigan. The areal extent of cover types within the 4.03-ha study area was measured and the densities of all life stages of L. d. disjunctus in separate cover types were converted to population estimates. Data were then analyzed using life-table techniques. The 1982 cohort oviposited an estimated 944 300 eggs in the 4.03-ha study area. Mortality in the egg stage was estimated to be 22.6%, of which 6.0% was associated with hatching and 16.6% was attributed to habitat loss. Survival through all larval instars was 5.5%. Mean larval production was 135 mg dry mass∙m−2∙year−1. The mortality rate was greatest in final-instar larvae. Instars F-8 through F-6 dispersed from wracks to Sparganium eurycarpum beds. The female:male ratio of instars F-2 through F was 1.08:1.00 and varied from 1.91:1.00 to 1.01:1.00 in the adult stage. An estimated 20 100 adult females emerged from the 4.03-ha study area, yielding a survival rate from the egg to adult stage of 4.3%. Lower potential fecundity in 1983 (45.2 eggs/female) than in 1982 (73.5 eggs/female), combined with low survival, yielded a net reproductive rate (R0) of 0.97 and a population rate of increase (r) of −0.03.
Growth and age at maturity of North American tortoises in relation to regional climates
Authors: Germano David J.
Published: June 2009

North American tortoises (Gopherus spp.) are long-lived species that occur in a variety of habitats. I described growth of tortoises using Richards' growth model based on measures of scute annuli. Gopherus flavomarginatus is the largest species and grows the fastest, and Gopherus berlandieri is the smallest species with the slowest growth rates. Gopherus polyphemus and Gopherus agassizii are intermediate in size, with intermediate growth rates. All species grow relatively fast for 18–22 years, after which time growth rates decrease greatly. Estimates of mean age at maturity are 13.3 years for G. berlandieri, 13.9 years for G. flavomarginatus, 14.4 years for G. polyphemus, 13.8 years for Sinaloan G. agassizii, 14.4 years for western Mojave G. agassizii, 15.4 years for eastern Mojave G. agassizii, and 15.7 years for Sonoran G. agassizii. Several measures of growth did not correlate with precipitation among species of Gopherus, although mean yearly growth was negatively correlated with mean annual precipitation in populations of G. agassizii. Also, a matrix of growth variables did not correlate with a matrix of environmental variables. Although other environmental variables should be measured within the ranges of Gopherus spp., preliminary analyses suggest that the environment is not the main determinant of growth rates of North American tortoises.
Effects of protein and energy intake, body condition, and season on nutrient partitioning and milk production in caribou and reindeer
Authors: Chan-McLeod Ann C. Allaye , White Robert G. , Holleman Dan F.
Published: June 2009

We used captive caribou (Rangifer tarandus granti) and reindeer (Rangifer tarandus tarandus) to study the effects of energy intake, protein intake, dietary protein:energy ratio, date, and body condition on (i) body fat versus body protein deposition and (ii) maternal tissue deposition versus milk production. Energy intake was the only variable significantly affecting body mass (BM) changes in either breeding or nonbreeding adult females. Lactating and nonlactating females had comparable efficiency coefficients for net energy retention (60 and 65%, respectively), but the daily maintenance requirement for lactating females (457 kJ/BM0.75) was twice that for nonlactating individuals (232 kJ/BM0.75). In both lactating and nonlactating females, the proportion of tissue deposited as fat rather than protein increased between spring and fall but decreased with increasing fatness. Energy intake increased protein deposition in lactating females but increased fat deposition in nonlactating females. Milk water volume increased with maternal energy intake and decreased with calf age. However, production of milk dry matter, milk fat, and milk energy were not affected by maternal energy or protein intake, maternal body condition, or calf age. Production of milk lactose correlated with maternal energy intake, while production of milk protein correlated with the maternal dietary protein:energy ratio.
Scanning electron microscopy of the larval morphological characteristics of two species of Protocalliphora (Diptera: Calliphoridae)
Authors: Warren Yvonne , McManus William R.
Published: June 2009

To supplement written descriptions, larval morphological characteristics of prothoracic fringe, visible pharyngeal sclerites, and stigmatal areas of third larval instar Protocalliphora interrupta and P. braueri were imaged and photographed. All morphological characteristics imaged were in accordance with previous descriptions except for a horizontal mesostigmatal cuticular fold seen in two of five P. interrupta specimens. Samples of both species were fixed in the same manner, then one group was critical-point dried and a second group air-dried prior to sputter coating. Critical point dried specimens showed significant shrinkage with the collapse of mouthparts and stigmatal areas; air-dried samples had minimal shrinkage and both feeding structures and stigmatal areas were seen clearly.
Adrenergic stimulation of glycolysis without change in glycolytic enzyme binding in rainbow trout (Oncorhynchus mykiss) erythrocytes
Authors: Sephton Dawn H. , Driedzic William R.
Published: June 2009

Whole blood from rainbow trout (Oncorhynchus mykiss) was incubated in vitro with pharmacological levels of isoproterenol. The adrenergic stimulation of glycolysis in erythrocytes (RBCs) was assessed by monitoring the rate of 14C incorporation from [6-14C]-glucose into the acid-soluble RBC fraction. During a 3-h in vitro incubation, incorporation of label into the acid-soluble RBC fraction of isoproterenol-treated whole blood (0.25 ± 0.04 μmol glucose∙mL−1 RBC∙h−1) was higher than into untreated blood (0.08 ± 0.01 μmol glucose∙mL−1 RBC∙h−1). The percentage of cell membrane binding for phosphofructokinase, aldolase, and glyceraldehyde-3-phosphate dehydrogenase ranged from 17 to 35% and was not altered by adrenergic stimulation. Adrenergic stimulation activates glycolysis in rainbow trout RBCs but not through the modulation of enzyme binding.
Characteristics of moose lactation and neonatal growth
Authors: Reese Ed O. , Robbins Charles T.
Published: June 2009

Milk composition, neonatal milk intake, and growth of captive, maternally raised, singleton moose calves (Alces alces gigas) were measured during the first 4 months post partum. Milk intake rose to a peak of 4760 ± 1017 g/day at day 23 and then decreased with increasing calf age. Milk fat and crude protein levels declined until the time of peak milk output, and then increased. Ash content remained relatively constant whereas carbohydrate content diminished as lactation progressed. At peak output, milk averaged 20.5 ± 1.5% dry matter, 7.9 ± 1.5% fat, 7.2 ± 0.4% protein, 1.4 ± 0.1% ash, 3.7 ± 0.2% carbohydrate, and 1.29 ± 0.13 kcal/g wet mass (1 kcal = 4.18 kJ). The growth rates of maternally raised calves during the first 30 days (785 ± 115 g/day) were higher than those reported for bottle-raised calves.
Chromosome banding analysis of two shrews of the cinereus group: Sorex haydeni and Sorex cinereus (Insectivora, Soricidae)
Authors: Volobouev Vitaly T. , Jong Constantinus G. van Zyll de
Published: June 2009

The chromosomes of Sorex haydeni are described for the first time and their banding pattern (R- and C-bands) compared with that of Sorex cinereus. The karyotype of S. haydeni differs from that of S. cinereus in its diploid (64 vs. 66) and fundamental numbers (66 vs. 70). These differences are the result of one tandem translocation and one pericentric inversion. The size and form of the Y chromosomes are also quite different in these taxa. The karyotypic differences strongly support the status of independent species, proposed for these taxa earlier on the basis of gross morphological characters.
COUPLING INTEGRABLE COUPLINGS
Authors: MA WEN XIU , GAO LIANG
Published: June 2009

Integrable couplings are presented by coupling given integrable couplings. It is shown that such coupled integrable couplings can possess zero curvature representations and recursion operators, which yield infinitely many commuting symmetries. The presented zero curvature equations are associated with Lie algebras, each of which has two sub-Lie algebras in form of semi-direct sums of Lie algebras.
EFFECT OF ELECTRON CORRELATION AND SOLVENT ON THE CONFORMATIONAL TRANSITION OF DNA
Authors: ZHANG LINGYUN , WANG PENG-YE
Published: June 2009

The conformational transition of DNA is studied by considering electron–electron interaction and coupling to the environment. It is shown that the effect of counterions on DNA can be expressed approximately by the change of elasticity constant of the DNA backbone. We set up the coupled nonlinear equations to describe the interaction between the longitudinal displacement of DNA backbone and the electronic wave function as well as the solvent effect. It is also proved that the longitudinal displacement of DNA statistics the ϕ4 field form. With the help of the ϕ4 statistics properties, it is illustrated that the salt concentration and electron correlation plays an important role in the structural phase transition of DNA.
THE STABILITY OF FCC CRYSTAL Cu UNDER UNIAXIAL LOADING IN [001] DIRECTION
Authors: LIU X. M. , LIU Z. L. , YOU X. C. , NIE J. F. , ZHUANG Z.
Published: June 2009

Uniaxial loading tests of copper with inter-atomic potential finite-element model are carried out to determine the corresponding ideal tension and compression strength using the modified Born stability criteria. The influence of biaxial stresses applied perpendicularly to the [100] loading axis, on the ideal strength is investigated, and tension-compression asymmetry in ideal strength under [100] loading is also studied. The results suggest that asymmetry for yielding strength of [100] nanowires may result from anisotropic character of crystal instability. Moreover, the results also reveal that the critical resolved shear stress in the direction of slip is not an accurate criterion for the ideal strength since it cannot capture the dependence on the loading conditions and hydrostatic stress components for the ideal strength.
EPITAXIAL LATERAL OVERGROWTH OF GaN ON SILICON-ON-INSULATOR
Authors: ZHANG BO , CHEN JING , WANG XI , WU AIMIN , LUO JIEXIN , WANG XI , ZHANG MIAO , WU YUXIN , ZHU JIANJUN , YANG HUI
Published: June 2009

From a single process, GaN layers were laterally overgrown on maskless stripe-patterned (111) silicon-on-insulator (SOI) substrates by metalorganic chemical vapor deposition. The influence of stress on the behavior of dislocations at the coalescence during growth was observed using transmission electron microscopy (TEM). Improvement of the crystalline quality of the GaN layer was demonstrated by TEM and micro-Raman spectroscopy. Furthermore, the benefits of SOI substrates for GaN growth are also discussed.
FURTHER RESULTS ON FUNCTIONAL PROJECTIVE SYNCHRONIZATION OF GENESIO–TESI CHAOTIC SYSTEM
Authors: PARK JU H.
Published: June 2009

This letter considers the functional projective synchronization problem for Genesio–Tesi chaotic systems. Based on our earlier work, a new control scheme, which consists of a linear dynamic controller and a nonlinear static feedback controller, is applied to achieve the synchronization. A numerical simulation is presented to show the usefulness of the proposed control scheme.