bluuebunny/crossref_metadata_2025 huggingface dataset:
The Usage of Opportunity Cost to Maximize Performance in Revenue Management*
Authors: Deng Honghui , Wang Qiwen , Leong G. Keong , Sun Sherry X.
Published: December 2008

To meet customer requirements efficiently, a manager needs to supply adequate quantities of products, capacity, or services at the right time with the right prices. Revenue management (RM) techniques can help firms use differential pricing strategies and capacity allocation tactics to maximize revenue. In this article, we propose a marginal revenue‐based capacity management (MRBCM) model to manage stochastic demand in order to create improved revenue opportunities. The new heuristic employs opportunity cost estimation logic that is unique and is the reason for the increased performance. The MRBCM model generates order acceptance policies that allocate available capacity to higher revenue generating market segments in both service and manufacturing environments. To evaluate these models, we design and conduct simulation experiments for 64 scenarios using a wide range of operating conditions. The experimental results show that the MRBCM model generates significantly higher revenues over the first come, first served rule when capacity is tight. In addition, we also show that the MRBCM model generally performs better than a recent RM model published in the literature.
ORIGINAL ARTICLE: The Association of Apoprotien E Polymorphisms with Recurrent Pregnancy Loss
Authors: Goodman Chelsi , Goodman Cyle S. , Hur Jee , Jeyendran R. S. , Coulam Carolyn
Published: December 2008

Problem  We have previously reported the role of polymorphisms of thrombogenic genes involved in coagulation and fibrinolysis as risk factors for recurrent pregnancy loss. Thrombophilia has been viewed as a multigenic disorder rather than a monogenetic clinical phenotype and Apo E has been shown to play an important role in lipid metabolism in pregnancy. As individuals carrying the E4 allele of the ApoE gene have the highest risk for thrombosis, we evaluated the frequency of the Apo E4 genotype among women suffering from recurrent pregnancy loss.

Method of study  Buccal swabs were obtained from 69 women with a history of two or more consecutive spontaneous abortions and 37 women with at least two live births and not more than one miscarriage. DNA was extracted from the buccal swabs and PCR amplification of Apo E2, E3, and E4 was performed.

Results  Women experiencing recurrent pregnancy loss had a significantly higher prevalence of Apo E3/4, E4/4 genotypes (21.7%) compared with control women (5.4%) (P = 0.036).

Conclusion  Apo E4 polymorphism may contribute to the thrombophilic risk factors contributing to recurrent pregnancy loss.
Cognitive and non‐cognitive behaviors in an APPswe/PS1 bigenic model of Alzheimer’s disease
Authors: Filali M. , Lalonde R. , Rivest S.
Published: December 2008

Neuropsychiatric signs are critical in primary caregiving of Alzheimer patients and yet have been relatively ignored in murine models. In the present study, APPswe/PS1 bigenic mice had higher levels of irritability than non‐transgenic controls as measured in the touch escape test. Moreover, APPswe/PS1 mice showed poorer nest building than controls and a higher duration of immobility in the forced swimming assay. These results are concordant with the hypothesis of increased apathy and depression‐like behavior in an Alzheimer’s disease model. In addition, APPswe/PS1 bigenic mice were deficient in retention of passive avoidance learning and left–right discrimination learning, concordant with previous findings in other Alzheimer‐like models.
Child eating patterns and weight regulation: a developmental behaviour genetics framework
Authors: Kral Tanja V E , Faith Myles S
Published: December 2008

There is relatively limited knowledge about the development of child eating patterns and how they may contribute to excess weight gain in early life. Particularly scarce are genetically informative studies that addressed environmental and genetic influences which can be challenging to disentangle. A review of this literature can help identify ongoing themes in the field and may stimulate new ideas for future research. The purpose of this paper is to provide an overview about how select environmental factors (e.g. the portion size of foods) and parental feeding practices (e.g. dietary restriction) can affect children's eating behaviour and weight status. The second part of the review explains in more detail the types of studies that can be employed to assess genetic influences (e.g. heritability estimates) on child food intake and body weight and composition. The review closes with suggestions for future research emphasizing the importance of collaborations among investigators from different disciplines to further elucidate gene–environment interactions in the domains of child eating behaviour and obesity.
Effects of Foliar Endophytic Fungi on the Preference and Performance of the Leaf BeetleChelymorpha alternansin Panama
Authors: Van Bael Sunshine A. , Valencia Mariana C. , Rojas Enith I. , Gómez Nélida , Windsor Donald M. , Herre Edward A.
Published: December 2008

Foliar endophytic fungi live inside healthy plant leaves, and in some cases they confer herbivore resistance to the host. All previous studies of endophyte–herbivore interactions have occurred in temperate areas, and many use correlations rather than experiments. In Panama,Glomerella cingulatais a common endophyte species found in healthy leaves, andChelymorpha alternansis a common herbivore onMerremia umbellata, a tropical vine. We manipulated the abundance ofG. cingulatain the leaves ofM. umbellata. We then assessed the effects of high and low endophyte densities on the food choice, development, and reproductive success of the leaf beetle,C. alternans. In ‘choice’ experiments, adult females with a history of feeding on wild plants showed no preference when offered food plants with high and low endophyte densities. Further, in ‘no‐choice’ experiments,C. alternanslarvae that were fed high‐ or low‐density endophyte leaves did not differ in development or survivorship. However, when larvae fed on leaves with low endophyte densities became adults, they produced 80 percent more offspring. This suggests high endophyte levels in hosts can have a negative effect on herbivore fecundity. Further experiments are necessary to understand whether the reproductive effects are due to feeding on low‐density endophytes in the larval or adult stages, and whether changes in reproductive success are motivated by the adult's perception of food quality or by physiological constraint due to food quality.
Vertebrate Fruit Removal and Ant Seed Dispersal in the Neotropical Ginger Renealmia alpinia (Zingiberaceae)*
Authors: García‐Robledo Carlos , Kuprewicz Erin K.
Published: December 2008

Plants frequently display fruit characteristics that support multiple seed‐dispersal syndromes. These ambiguous characteristics may reflect the fact that seed dispersal is usually a complex process involving multiple dispersers. This is the case for the Neotropical ginger Renealmia alpinia (Zingiberaceae). It was originally suggested that the aromatic fruits of R. alpinia located at the base of the plant are adapted for terrestrial mammal seed dispersal. However, the dark‐purple coloration of the fruits and bright orange aril surrounding the seeds suggest that birds may play a role in R. alpinia seed dispersal. At La Selva Biological Station, Costa Rica, we used camera traps to record vertebrate visits to infructescences of R. alpinia. Most visitors were toucans and aracaris (Ramphastidae). However fruits were also removed by terrestrial mammals (coatis and armadillos). In addition to vertebrate fruit removal, some of the fruits dehisce and the seeds that fall on the ground are dispersed by ants. Fruitfall traps showed that 77 percent of fruits are removed by vertebrates. However, 15 percent of fruits fall to the base of parent plants to be potentially dispersed by ants. Experiments using a laboratory ant colony showed that ants are effective seed dispersers of R. alpinia. Ant seed manipulation increased germination success and reduced time to germination. In conclusion, primary seed dispersal in the Neotropical ginger R. alpinia is mostly performed by birds, additionally ants are effective dispersers at short distances. Seed dispersal in R. alpinia is a complex process involving a diverse array of dispersal agents.
Runoff Simulation of the Headwaters of the Yellow River Using The SWAT Model With Three Snowmelt Algorithms1
Authors: Zhang Xuesong , Srinivasan Raghavan , Debele Bekele , Hao Fanghua
Published: December 2008

Abstract:  The Soil and Water Assessment Tool (SWAT) model combined with different snowmelt algorithms was evaluated for runoff simulation of an 114,345 km2 mountainous river basin (the headwaters of the Yellow River), where snowmelt is a significant process. The three snowmelt algorithms incorporated into SWAT were as follows: (1) the temperature‐index, (2) the temperature‐index plus elevation band, and (3) the energy budget based SNOW17. The SNOW17 is more complex than the temperature‐based snowmelt algorithms, and requires more detailed meteorological and topographical inputs. In order to apply the SNOW17 in the SWAT framework, SWAT was modified to operate at the pixel scale rather than the normal Hydrologic Response Unit scale. The three snowmelt algorithms were evaluated under two parameter scenarios, the default and the calibrated parameters scenarios. Under the default parameters scenario, the parameter values were determined based on a review of the current literature. The purpose of this type of evaluation was to assess the applicability of SWAT in ungauged basins, where there is little observed data available for calibration. Under the calibrated parameters scenario, the parameters were calibrated using an automatic calibration program, the Shuffled Complex Evolution (SCE‐UA). The purpose of this type of evaluation was to assess the applicability of SWAT in gauged basins. Two time periods (1975‐1985 and 1986‐1990) of monthly runoff data were used in this study to evaluate the performance of SWAT with different snowmelt algorithms. Under the default parameters scenario, the SWAT model with complex energy budget based SNOW17 performed the best for both time periods. Under the calibrated parameters scenario, the parameters were calibrated using monthly runoff from 1975‐1985 and validated using monthly runoff from 1986‐1990. After parameter calibration, the performance of SWAT with the three snowmelt algorithms was improved from the default parameters scenario. Further, the SWAT model with temperature‐index plus elevation band performed as well as the SWAT model with SNOW17. The SWAT model with temperature‐index algorithm performed the poorest for both time periods under both scenarios. Therefore, it is suggested that the SNOW17 model be used for modeling ungauged basins; however, for gauged basins, the SNOW17 and simple temperature‐index plus elevation band models could provide almost equally good runoff simulation results.
Impacts of Climate Variability and Land Use Alterations on Frequency Distributions of Terrestrial Runoff Loading to Coastal Waters in Southern California1
Authors: Beighley R. Edward , Dunne Thomas , Melack John M.
Published: December 2008

Abstract:  The transport of water, sediment, dissolved and particulate chemicals, and bacteria from coastal watersheds affects the nearshore marine and estuarine waters. In southern California, coastal watersheds deliver water and associated constituents to the nearshore system in discrete pulses. To better understand the pulsed nature of these watersheds, frequency distributions of simulated runoff events are presented for: (1) three land use conditions (1929, 1998, 2050); (2) three time periods (all water years 1989‐2002), only El Nino years (1992, 1993, 1995, 1998); and only non‐El Nino years; and (3) three regions (watershed, uplands, and lowlands). At the watershed scale, there was a significant increase (>200%) in mean event runoff from 1929 to 2050 (0.4‐1.3 cm) due to localized urbanization, which shifted the dominant sources of runoff from the mountains in 1929 (78% of watershed runoff) to the coastal plane for 2050 conditions (51% of watershed runoff). Inter‐annual climate variability was strong in the rainfall and runoff frequency distributions, with mean event rainfall and runoff 66 and 60% larger in El Nino relative to non‐El Nino years. Combining urbanization and climate variability, 2050 land conditions resulted in El Nino years being five times more likely to produce large (>3.0 cm) runoff events relative to non‐El Nino years. Combining frequency distributions of event runoff with regional nutrient export relationships, we show that in El Nino years, one in five events produced runoff ≥2.5 cm and temporary nearshore nitrate and phosphate concentrations of 12 and 1.4 μM, respectively, or approximately 5‐10 times above ambient conditions.
Combination of CCNU and DTIC Chemotherapy for Treatment of Resistant Lymphoma in Dogs
Authors: Flory A.B. , Rassnick K.M. , Al‐Sarraf R. , Bailey D.B. , Balkman C.E. , Kiselow M.A. , Autio K.
Published: December 2008

Background:Pleotropic‐glycoprotein (P‐gp)–mediated resistance is the usual cause of relapse in dogs with lymphoma. 1‐(2‐chloroethyl)3‐cyclohexyl‐1‐nitrosurea (CCNU) and 5‐(3,3‐dimethyl‐1‐triazeno)‐imidazole‐4‐carboxamide (DTIC) are alkylating agents that are not affected by P‐gp and lack cross‐resistance to each other. A combination protocol offers the advantage of improved summation dose and synergistic activity.

Hypothesis:A combination of CCNU and DTIC that is well tolerated can be used to treat dogs with lymphoma that developed resistance or failed to respond to previously administered chemotherapy.

Animals:Fifty‐seven dogs with lymphoma that were resistant to treatment with standard chemotherapy (l‐CHOP;l‐asparaginase, cyclophosphamide, doxorubicin, vincristine, prednisone).

Methods:Prospective phase I and II trials were performed. CCNU was given PO immediately before a 5‐h IV infusion of DTIC. Concurrent antiemetics and prophylactic antibiotics were used. Treatments were administered every 4 weeks.

Results:Based on the results of 8 dogs in the phase I study, CCNU at 40 mg/m2PO combined with DTIC at 600 mg/m2IV was used to treat 57 dogs with resistant lymphoma. Thirteen (23%) dogs had a complete response (CR) for a median of 83 days and 7 (12%) had a partial response for a median of 25 days. The medianl‐CHOP CR duration of the dogs that did not respond to CCNU‐DTIC was significantly longer than that of the dogs that did achieve remission with CCNU‐DTIC (225 days versus 92 days,P= .02). The principal toxic event was neutropenia; the median neutrophil count 7 days after treatment was 1,275 cells/μL. Increases in alanine transaminase activity, possibly associated with hepatotoxicity, were detected in 7 dogs.

Conclusions and Clinical Importance:A combination of CCNU and DTIC can be an effective option to rescue dogs with resistant lymphoma.
Polyneuropathy Associated with Forage Sources in Norwegian Horses
Authors: Hanche‐Olsen S. , Teige J. , Skaar I. , Ihler C.F.
Published: December 2008

Background: Cases of hindlimb digital extensor weakness of unknown etiology have been observed in Norway since 1995.

Hypothesis: We hypothesized that the observed bilateral extensor weakness was attributable to neuropathy of the distal nerves and that this was related to environmental factors, possibly dietary.

Animals: Seventy‐five horses with digital extensor weakness occurring from 1995 to 2004 are described.

Methods: Eleven horses were examined at The Norwegian School of Veterinary Science, and the medical records of 64 horses seen in ambulatory practice were reviewed.

Results: There was no apparent sex, age, or breed predilection, but the majority were horses kept for pleasure or breeding purposes. Clinical signs varied from intermittent knuckling of the hindlimbs to paraplegia. Some horses showed no or only slow progression of signs, whereas others developed severe signs within hours. No other neurologic deficits were detected in any of the horses. Epidemiologic data and laboratory results were not supportive of an infectious etiology. The only common factor for all affected horses seemed to be feeding big bale silage or, occasionally, hay of poor microbiologic quality. Forty of the 75 horses were euthanized. Histopathologic examination of peripheral nervous tissue was performed in 22 horses, all of which had neuronal fiber degeneration. The majority of horses with mild signs recovered after 5–6 months of rest.

Conclusions and Clinical Importance: Clinical signs correlated with polyneuropathy involving sciatic nerves.
Experimentally Induced Systemic Hyperchloremic Acidosis in Calves
Authors: Gentile A. , Lorenz I. , Sconza S. , Klee W.
Published: December 2008

Background:Among the various metabolic disturbances occurring in calves affected by neonatal diarrhea or ruminal acidosis, acidemia constitutes an important condition requiring specific therapy. Although various attempts have been made to estimate the degree of metabolic acidosis on the basis of clinical signs alone, some doubts have been raised regarding the accuracy and predictive value of the clinical variables suggested.

Hypothesis:The induction of metabolic acidosis in healthy calves via the infusion of hydrochloric acid (HCl) will lead to a clinical picture similar to that seen in neonatal calves with diarrhea or ruminal acidosis.

Animals:The study was carried out on 15 Holstein male calves between 5 and 19 days of age.

Methods:Hyperchloremic metabolic acidosis was induced over a period of 80 minutes by an IV infusion of 4,000 mL of 0.9% NaCl solution containing 400 mM HCl.

Results:Acidemia occurred rapidly and increased constantly up to a maximum value, which was reached in all calves by the end of the administration and amounted to a 22.4 mM/L mean base deficit (range from 17.0 to 33.1 mM/L). Despite the relatively severe acute acid‐base imbalance during the entire observation period, no calves showed any clinical signs or depressed appetite.

Conclusions and Clinical Importance:Factors other than a disturbance of the acid‐base balance should be considered to be primarily responsible for the clinical picture in calves affected by diarrhea or ruminal acidosis.
The Bone Biologic Effects of Zoledronate in Healthy Dogs and Dogs with Malignant Osteolysis
Authors: Fan T.M. , De Lorimier L.P. , Garrett L.D. , Lacoste H.I.
Published: December 2008

Background: Malignant osteolysis is a process whereby cancer cells in concert with osteoclasts erode bone matrix. Aminobisphosphonates (NBPs) such as zoledronate induce osteoclast apoptosis and thereby decrease malignant skeletal destruction, severity of bone pain, and frequency of pathologic fracture.

Hypothesis: IV‐administered zoledronate will reduce homeostatic bone turnover in healthy dogs and pathologic bone resorption in dogs diagnosed with primary and secondary bone tumors.

Animals: Six healthy dogs and 20 dogs with naturally occurring primary or metastatic bone tumors were administered zoledronate IV.

Methods: Prospective study: In all dogs, healthy (n = 6) and with malignant osteolysis (n = 20), the bone biologic effects of zoledronate were evaluated by quantifying changes in serum C‐telopeptide (CTx) or urine N‐telopeptide (NTx) concentrations or both. In dogs with osteosarcoma (OSA) (n = 10), serial changes in tumor relative bone mineral density (rBMD) assessed by dual‐energy x‐ray absorptiometry were used to characterize zoledronate's antiresorptive effects within the immediate tumor microenvironment. Additionally, the biochemical tolerability of zoledronate was assessed in 9 dogs receiving multiple (≥2) consecutive treatments.

Results: All dogs had significant reductions in serum CTx or urine NTx concentrations or both after zoledronate administration. In a subset of dogs with appendicular OSA, reduced urine NTx concentrations and increased primary tumor rBMD coincided with improved limb usage as reported by pet owners in dogs treated with zoledronate and concurrent oral analgesics. Multiple zoledronate infusions were not associated with biochemical evidence of toxicosis.

Conclusions and Clinical Importance: In dogs with skeletal neoplasms, IV‐administered zoledronate exerts bone biologic effects, appears safe, and can provide pain relief.
Role of the amiloride‐sensitive epithelial Na+ channel in the pathogenesis and as a therapeutic target for cystic fibrosis lung disease
Authors: Mall Marcus A.
Published: December 2008

Increased airway Na+ absorption mediated by the amiloride‐sensitive epithelial Na+ channel (ENaC) is a basic defect in cystic fibrosis (CF) lung disease. Cystic fibrosis is one of the most common lethal hereditary diseases and is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. The CFTR acts as a cAMP‐dependent Cl− channel and regulator of ENaC, and CFTR dysfunction causes impaired Cl− secretion and increased Na+ absorption in the airways of CF patients. Evidence from in vitro studies suggested that increased Na+ absorption produces airway surface liquid (ASL) volume depletion and led to the generation of transgenic mice with airway‐specific overexpression of ENaC to elucidate the role of this mechanism in the in vivo pathogenesis of lung disease. Studies of the pulmonary phenotype of βENaC‐overexpressing mice demonstrated that increased airway Na+ absorption caused ASL depletion and reduced mucus transport, producing a CF‐like lung disease with airway mucus plugging, chronic airway inflammation and pulmonary mortality. Further, recent pharmacological studies demonstrated that preventive, but not late, inhibition of increased airway Na+ absorption with the ENaC blocker amiloride reduced morbidity and mortality in this murine model of CF lung disease. These results support a critical role of ENaC in the in vivo pathogenesis of CF lung disease and suggest that amiloride may be an effective preventive therapy for CF patients.
Intermittent hypoxia and respiratory plasticity in humans and other animals: does exposure to intermittent hypoxia promote or mitigate sleep apnoea?
Authors: Mateika Jason H. , Narwani Gunjan
Published: December 2008

This review focuses on two phenomena that are initiated during and after exposure to intermittent hypoxia. The two phenomena are referred to as long‐term facilitation and progressive augmentation of respiratory motor output. Both phenomena are forms of respiratory plasticity. Long‐term facilitation is characterized by a sustained elevation in respiratory activity after exposure to intermittent hypoxia. Progressive augmentation is characterized by a gradual increase in respiratory activity from the initial to the final hypoxic exposure. There is much speculation that long‐term facilitation may have a significant role in individuals with sleep apnoea because this disorder is characterized by periods of upper airway collapse accompanied by intermittent hypoxia, one stimulus known to induce long‐term facilitation. It has been suggested that activation of long‐term facilitation may serve to mitigate apnoea by facilitating ventilation and, more importantly, upper airway muscle activity. We examine the less discussed but equally plausible situation that exposure to intermittent hypoxia might ultimately lead to the promotion of apnoea. There are at least two scenarios in which apnoea might be promoted following exposure to intermittent hypoxia. In both scenarios, long‐term facilitation of upper airway muscle activity is initiated but ultimately rendered ineffective because of other physiological conditions. Thus, one of the primary goals of this review is to discuss, with support from basic and clinical studies, whether various forms of respiratory motor neuronal plasticity have a beneficial and/or a detrimental impact on breathing stability in individuals with sleep apnoea.
The kinin B1 receptor contributes to the cardioprotective effect of angiotensin‐converting enzyme inhibitors and angiotensin receptor blockers in mice
Authors: Xu Jiang , Carretero Oscar A. , Shesely Edward G. , Rhaleb Nour‐Eddine , Yang James J. , Bader Michael , Yang Xiao‐Ping
Published: December 2008

Recent studies have shown that inhibition of angiotensin‐converting enzyme (ACE) or angiotensin II receptors causes upregulation of the B1 receptor (B1R). Here we tested the hypothesis that activation of the B1R partly contributes to the cardiac beneficial effect of ACE inhibitor (ACEi) and angiotensin II receptor blockers (ARB). B1R knockout mice (B1R−/−) and C57Bl/6J (wild‐type control animals, WT) were subjected to myocardial infarction (MI) by ligating the left anterior descending coronary artery. Three weeks after MI, each strain of mice was treated with vehicle, ACEi (ramipril, 2.5 mg kg−1 day−1 in drinking water) or ARB (valsartan, 40 mg kg−1 day−1 in drinking water) for 5 weeks. We found that: (1) compared with WT mice, B1R−/− mice that underwent sham surgery had slightly but significantly increased left ventricular (LV) diastolic dimension, LV mass and myocyte size, whereas systolic blood pressure, cardiac function and collagen deposition did not differ between strains; (2) MI leads to LV hypertrophy, chamber dilatation and dysfunction similarly in both WT and B1R−/− mice; and (3) ACEi and ARB improved cardiac function and remodelling in both strains; however, these benefits were significantly diminished in B1R−/− mice. Our data suggest that kinins, acting via the B1R, participate in the cardioprotective effects of ACEi and ARB.
Ovalbumin‐induced sensitization affects non‐quantal acetylcholine release from motor nerve terminals and alters contractility of skeletal muscles in mice
Authors: Teplov Alexander Y. , Grishin Sergey N. , Mukhamedyarov Marat A. , Ziganshin Airat U. , Zefirov Andrey L. , Palotás András
Published: December 2008

Skeletal muscles play key roles in the development of various pathologies, including bronchial asthma and several types of auto‐immune disorders, e.g. polymyositis. Since most of these maladies have an immunological/allergic element, this paper is devoted to assessing the impact of immunobiological reorganization on the functional properties of isolated skeletal muscles in mice. A combination of two methods (myography and electrophysiology) was used to evaluate extensor digitorum longus (EDL) and diaphragmatic muscle (DM) in this regard. Conventional myographic technique showed that ovalbumin‐induced sensitization (OS) produced different changes in the contractile properties of EDL and DM. The amplitudes of carbachol (CCh)‐induced contractions increased in DM but decreased in EDL. Those changes were inversely related to OS‐mediated changes of non‐quantal acetylcholine (ACh) release intensity within the muscle endplate, as shown by the electrophysiologically measured H‐effect. These results clearly show that OS‐mediated changes of non‐quantal ACh release alter the functional properties of postjunctional ACh receptors and therefore contribute to the disturbance of CCh‐induced contractility of skeletal muscles. Other mechanisms of OS‐mediated changes of skeletal muscle contractility are also proposed and discussed.
Secondary Metabolites Produced by the Marine Bacterium
Halobacillus salinus
That Inhibit Quorum Sensing-Controlled Phenotypes in Gram-Negative Bacteria
Authors: Teasdale Margaret E. , Liu Jiayuan , Wallace Joselynn , Akhlaghi Fatemeh , Rowley David C.
Published: December 2008

Certain bacteria use cell-to-cell chemical communication to coordinate community-wide phenotypic expression, including swarming motility, antibiotic biosynthesis, and biofilm production. Here we present a marine gram-positive bacterium that secretes secondary metabolites capable of quenching quorum sensing-controlled behaviors in several gram-negative reporter strains. Isolate C42, a
Halobacillus salinus
strain obtained from a sea grass sample, inhibits bioluminescence production by
Vibrio harveyi
in cocultivation experiments. With the use of bioassay-guided fractionation, two phenethylamide metabolites were identified as the active agents. The compounds additionally inhibit quorum sensing-regulated violacein biosynthesis by
Chromobacterium violaceum
CV026 and green fluorescent protein production by
Escherichia coli
JB525. Bacterial growth was unaffected at concentrations below 200 μg/ml. Evidence is presented that these nontoxic metabolites may act as antagonists of bacterial quorum sensing by competing with
N
-acyl homoserine lactones for receptor binding.
Production of Glucaric Acid from a Synthetic Pathway in Recombinant
Escherichia coli
Authors: Moon Tae Seok , Yoon Sang-Hwal , Lanza Amanda M. , Roy-Mayhew Joseph D. , Prather Kristala L. Jones
Published: December 2008

A synthetic pathway has been constructed for the production of glucuronic and glucaric acids from glucose in
Escherichia coli
. Coexpression of the genes encoding
myo
-inositol-1-phosphate synthase (Ino1) from
Saccharomyces cerevisiae
and
myo
-inositol oxygenase (MIOX) from mice led to production of glucuronic acid through the intermediate
myo
-inositol. Glucuronic acid concentrations up to 0.3 g/liter were measured in the culture broth. The activity of MIOX was rate limiting, resulting in the accumulation of both
myo
-inositol and glucuronic acid as final products, in approximately equal concentrations. Inclusion of a third enzyme, uronate dehydrogenase (Udh) from
Pseudomonas syringae
, facilitated the conversion of glucuronic acid to glucaric acid. The activity of this recombinant enzyme was more than 2 orders of magnitude higher than that of Ino1 and MIOX and increased overall flux through the pathway such that glucaric acid concentrations in excess of 1 g/liter were observed. This represents a novel microbial system for the biological production of glucaric acid, a “top value-added chemical” from biomass.
Shiga Toxins, and the Genes Encoding Them, in Fecal Samples from Native Idaho Ungulates
Authors: Gilbreath Jeremy J. , Shields Malcolm S. , Smith Rebekah L. , Farrell Larry D. , Sheridan Peter P. , Spiegel Kathleen M.
Published: December 2008

Cattle are a known reservoir of Shiga toxin-producingEscherichia coli. The prevalence and stability of Shiga toxin and/or Shiga toxin genes among native wild ungulates in Idaho were investigated. The frequency of both Shiga genes and toxin was similar to that reported for Idaho cattle (∼19%).
Overexpression of Wild-Type Aspartokinase Increases
l
-Lysine Production in the Thermotolerant Methylotrophic Bacterium
Bacillus methanolicus
Authors: Jakobsen Øyvind M. , Brautaset Trygve , Degnes Kristin F. , Heggeset Tonje M. B. , Balzer Simone , Flickinger Michael C. , Valla Svein , Ellingsen Trond E.
Published: December 2008

Aspartokinase (AK) controls the carbon flow into the aspartate pathway for the biosynthesis of the amino acids
l
-methionine,
l
-threonine,
l
-isoleucine, and
l
-lysine. We report here the cloning of four genes (
asd
, encoding aspartate semialdehyde dehydrogenase;
dapA
, encoding dihydrodipicolinate synthase;
dapG
, encoding AKI; and
yclM
, encoding AKIII) of the aspartate pathway in
Bacillus methanolicus
MGA3. Together with the known AKII gene
lysC
,
dapG
and
yclM
form a set of three AK genes in this organism. Overexpression of
dapG
,
lysC
, and
yclM
increased
l
-lysine production in wild-type
B. methanolicus
strain MGA3 2-, 10-, and 60-fold (corresponding to 11 g/liter), respectively, without negatively affecting the specific growth rate. The production levels of
l
-methionine (less than 0.5 g/liter) and
l
-threonine (less than 0.1 g/liter) were low in all recombinant strains. The AK proteins were purified, and biochemical analyses demonstrated that they have similar
V
max
values (between 47 and 58 μmol/min/mg protein) and

K
m

values for
l
-aspartate (between 1.9 and 5.0 mM). AKI and AKII were allosterically inhibited by
meso
-diaminopimelate (50% inhibitory concentration [IC
50
], 0.1 mM) and by
l
-lysine (IC
50
, 0.3 mM), respectively. AKIII was inhibited by
l
-threonine (IC
50
, 4 mM) and by
l
-lysine (IC
50
, 5 mM), and this enzyme was synergistically inhibited in the presence of both of these amino acids at low concentrations. The correlation between the impact on
l
-lysine production in vivo and the biochemical properties in vitro of the individual AK proteins is discussed. This is the first example of improving
l
-lysine production by metabolic engineering of
B. methanolicus
and also the first documentation of considerably increasing
l
-lysine production by overexpression of a wild-type AK.
Inactivation of
Ascaris
Eggs in Source-Separated Urine and Feces by Ammonia at Ambient Temperatures
Authors: Nordin Annika , Nyberg Karin , Vinnerås Björn
Published: December 2008

Sustainable management of toilet waste must prevent disease transmission but allow reuse of plant nutrients. Inactivation of uterus-derived
Ascaris suum
eggs was studied in relation to ammonia in source-separated urine without additives and in human feces to which urea had been added, in order to evaluate ammonia-based sanitation for production of safe fertilizers from human excreta. Urine was used concentrated or diluted 1:1 and 1:3 with tap water at 4, 14, 24, and 34°C. Fecal material, with and without ash, was treated with 1% or 2% (wt/wt) urea at 24 and 34°C. At 34°C eggs were inactivated in less than 10 days in urine and in amended feces. At 24°C only feces with 2% (wt/wt) urea or 1% (wt/wt) urea at high pH (10) inactivated all eggs within 1 month, and no inactivation was observed after 75 days in urine diluted 1:3 (18 ± 11 mM NH
3
). At temperatures of ≥24°C, NH
3
proved to be an efficient sanitizing agent in urine and feces at concentrations of ≥60 mM. Treating fecal material at 34°C can give a 6-log
10
egg inactivation within 1 month, whereas at 24°C 6 months of treatment is necessary for the same level of egg inactivation. At temperatures of 14°C and below, inactivation rates were low, with viable eggs after 6 months even in concentrated urine.
A 1.1-Kilobase Region Downstream of the
bin
Operon in
Bacillus sphaericus
Strain 2362 Decreases Bin Yield and Crystal Size in Strain 2297
Authors: Park Hyun-Woo , Tang Mujin , Sakano Yuko , Federici Brian A.
Published: December 2008

The 2297 strain of
Bacillus sphaericus
produces a crystal of the Bin (binary) toxin that is approximately fourfold larger than that of strain 2362, the strain currently used in VectoLex, a commercial mosquito larvicide. Comparison of the regions downstream from the
bin
operon in these two strains showed that strain 2362 contained a 1.6-kb region with four
orf
genes not found in strain 2297. Insertion of a 1.1-kb portion of this region from strain 2362 by homologous recombination downstream from the
bin
operon in strain 2297 reduced Bin toxin production by 50 to 70% and toxicity to fourth-instar larvae of
Culex quinquefasciatus
by 68%. These results suggest that the 1.6-kb region downstream from the
bin
operon in
B. sphaericus
2362 is responsible for the lower Bin yield and smaller crystal size characteristic of this strain.
Isolation and Characterization of Intestinal
Escherichia coli
Clones from Wild Boars in Germany
Authors: Schierack Peter , Römer Antje , Jores Jörg , Kaspar Heike , Guenther Sebastian , Filter Matthias , Eichberg Jürgen , Wieler Lothar H.
Published: December 2008

Our understanding of the composition of
Escherichia coli
populations in wild boars is very limited. In order to obtain insight into the
E. coli
microflora of wild boars, we studied
E. coli
isolates from the jejunums, ileums, and colons of 21 wild boars hunted in five geographic locations in Germany. Ten isolates per section were subjected to clonal determination using pulsed-field gel electrophoresis. One representative isolate per clone was further investigated for virulence traits, phylogenetic affiliation, and antimicrobial susceptibility. Macrorestriction analysis of 620 isolates revealed a range of clone diversity among the sections and animals, with up to 9 and 16 different clones per section and animal, respectively. Most of the clones for a given animal were shared between two adjacent intestinal sections. The overall highest clonal diversity was observed within the colon. While the
astA
gene was present in a large number of clones, other virulence genes and hemolytic ability were detected only sporadically. Clones of all four ECOR groups dominated the intestinal sections. Phylogenetic analysis and the occurrence of virulence genes correlated with the isolation frequencies for clones. All
E. coli
clones from wild boars were susceptible to all antimicrobial agents tested. In conclusion, though several parameters (including an animal-specific and highly diverse
E. coli
clone composition, the simultaneous occurrence of single clones in two adjacent intestinal sections of a given animal, and a higher
E. coli
diversity in the large intestine than in the small intestine) of
E. coli
populations of wild boars were similar to those of previously described
E. coli
populations of conventionally reared domestic pigs, our data also indicate possible differences, as seen for the
E. coli
diversity in the large intestine, the occurrence of certain virulence genes and phylogenetic groups, and antimicrobial susceptibilities.
Differential Role of Passerine Birds in Distribution of
Borrelia
Spirochetes, Based on Data from Ticks Collected from Birds during the Postbreeding Migration Period in Central Europe
Authors: Dubska Lenka , Literak Ivan , Kocianova Elena , Taragelova Veronika , Sychra Oldrich
Published: December 2008

Borrelia
spirochetes in bird-feeding ticks were studied in the Czech Republic. During the postbreeding period (July to September 2005), 1,080 passerine birds infested by 2,240
Ixodes ricinus
subadult ticks were examined.
Borrelia garinii
was detected in 22.2% of the ticks,
Borrelia valaisiana
was detected in 12.8% of the ticks,
Borrelia afzelii
was detected in 1.6% of the ticks, and
Borrelia burgdorferi
sensu stricto was detected in 0.3% of the ticks. After analysis of infections in which the blood meal volume and the stage of the ticks were considered, we concluded that Eurasian blackbirds (
Turdus merula
), song thrushes (
Turdus philomelos
), and great tits (
Parus major
) are capable of transmitting
B. garinii
; that juvenile blackbirds and song thrushes are prominent reservoirs for
B. garinii
spirochetes; that some other passerine birds investigated play minor roles in transmitting
B. garinii
; and that the presence
B. afzelii
in ticks results from infection in a former stage. Thus, while
B. garinii
transmission is associated with only a few passerine bird species, these birds have the potential to distribute millions of Lyme disease spirochetes between urban areas.
Construction and Enhancement of a Minimal Genetic AND Logic Gate
Authors: Sayut Daniel J. , Niu Yan , Sun Lianhong
Published: December 2008

The ability of genetic networks to integrate multiple inputs in the generation of cellular responses is critical for the adaptation of cellular phenotype to distinct environments and of great interest in the construction of complex artificial circuits. To develop artificial genetic circuits that can integrate intercellular signaling molecules and commonly used inducing agents, we have constructed an artificial genetic AND gate based on the P

luxI

quorum-sensing promoter and the
lac
repressor. The hybrid promoter exhibited reduced basal and induced expression levels but increased expression capacity, generating clear logical responses that could be described using a simple mathematical model. The model also predicted that the AND gate's logic could be improved by altering the properties of the LuxR transcriptional activator and, in particular, by increasing its rate of transcriptional activation. Following these predictions, we were able to improve the AND gate's logic by ∼1.5-fold using a LuxR mutant library generated by directed evolution, providing the first example of the use of mutant transcriptional activators to improve the logic of a complex regulatory circuit. In addition, detailed characterizations of the AND gate's responses shed light on how LuxR, LacI, and RNA polymerase interact to activate gene expression.
Enhanced Secretion of Biologically Active Murine Interleukin-12 by
Lactococcus lactis
Authors: Fernandez Antonio , Horn Nikki , Wegmann Udo , Nicoletti Claudio , Gasson Michael J. , Narbad Arjan
Published: December 2008

The novel signal peptide SLPmod was used for the secretion of murine interleukin-12 (mIL-12) by
Lactococcus lactis
. A >4-fold increase in secretion was observed when SLPmod was used instead of the Usp45-derived secretion signal. Oral delivery of this cytokine using the autoinducible host
L. lactis
FI5876 utilizing SLPmod resulted in a significant increase in mIL-12 plasma levels in mice.
Molecular Detection, Penetrance, and Transmission of an Inherited Virus Responsible for Behavioral Manipulation of an Insect Parasitoid
Authors: Patot Sabine , Lepetit David , Charif Delphine , Varaldi Julien , Fleury Frédéric
Published: December 2008

For insects, the prevalence of numerous vertically transmitted viruses can be high in their host populations. These viruses often have few, if any, pathological effects on their hosts, and consequently, many of them can remain unnoticed for long periods, despite their potential role in the evolution of the host phenotype. Some females of
Leptopilina boulardi
, a solitary parasitoid of
Drosophila
larvae, are infected by an inherited virus (LbFV) that manipulates the behavior of the wasp by increasing its tendency to lay eggs in a host that is already parasitized (superparasitism). This behavioral alteration allows horizontal transmission of the virus within superparasitized
Drosophila
larvae. Using suppressive subtractive hybridization with infected and uninfected lines, we identified one putative viral sequence. Based on this sequence, we developed a simple PCR test. We tested the correlation between the superparasitism phenotype and PCR amplification of the putative viral marker using several experimental conditions (including horizontal transfers) and several parasitoid genotypes. All of the results revealed that there was a perfect match between the superparasitism phenotype and the amplification profile, which validated use of the molecular marker as a tool to track the presence of the virus and provided the first genomic data for this fascinating virus. The results also show that there was very efficient horizontal and vertical transmission of LbFV, which probably explains its high prevalence in the French populations that we sampled (67 and 70% of infected females). This manipulative virus is likely to play a major role in the ecology and evolution of its parasitoid host.
Genome Analysis of the Meat Starter Culture BacteriumStaphylococcus carnosusTM300
Authors: Rosenstein Ralf , Nerz Christiane , Biswas Lalitha , Resch Alexandra , Raddatz Guenter , Schuster Stephan C. , Götz Friedrich
Published: December 2008

TheStaphylococcus carnosusgenome has the highest GC content of all sequenced staphylococcal genomes, with 34.6%, and therefore represents a species that is set apart fromS. aureus,S. epidermidis,S. saprophyticus, andS. haemolyticus. With only 2.56 Mbp, the genome belongs to a family of smaller staphylococcal genomes, and theoriandterregions are asymmetrically arranged with the replichores I (1.05 Mbp) and II (1.5 Mbp). The events leading up to this asymmetry probably occurred not that long ago in evolution, as there was not enough time to approach the natural tendency of a physical balance. Unlike the genomes of pathogenic species, the TM300 genome does not contain mobile elements such as plasmids, insertion sequences, transposons, or STAR elements; also, the number of repeat sequences is markedly decreased, suggesting a comparatively high stability of the genome. While mostS. aureusgenomes contain several prophages and genomic islands, the TM300 genome contains only one prophage, ΦTM300, and one genomic island, νSCA1, which is characterized by a mosaic structure mainly composed of species-specific genes. Most of the metabolic core pathways are present in the genome. Some open reading frames are truncated, which reflects the nutrient-rich environment of the meat starter culture, making some functions dispensable. The genome is well equipped with all functions necessary for the starter culture, such as nitrate/nitrite reduction, various sugar degradation pathways, two catalases, and nine osmoprotection systems. The genome lacks most of the toxins typical ofS. aureusas well as genes involved in biofilm formation, underscoring the nonpathogenic status.
Surface Properties of
Toxoplasma gondii
Oocysts and Surrogate Microspheres
Authors: Shapiro Karen , Largier John , Mazet Jonna A. K. , Bernt William , Ell John R. , Melli Ann C. , Conrad Patricia A.
Published: December 2008

The physical properties that govern the waterborne transmission of
Toxoplasma gondii
oocysts from land to sea were evaluated and compared to the properties of carboxylated microspheres, which could serve as surrogates for
T. gondii
oocysts in transport and water treatment studies. The electrophoretic mobilities of
T. gondii
oocysts, lightly carboxylated Dragon Green microspheres, and heavily carboxylated Glacial Blue microspheres were determined in ultrapure water, artificial freshwater with and without dissolved organic carbon, artificial estuarine water, and artificial seawater. The surface wettabilities of oocysts and microspheres were determined using a water contact angle approach.
Toxoplasma gondii
oocysts and microspheres were negatively charged in freshwater solutions, but their charges were neutralized in estuarine water and seawater. Oocysts, Glacial Blue microspheres, and unwashed Dragon Green microspheres had low contact angles, indicating that they were hydrophilic; however, once washed, Dragon Green microspheres became markedly hydrophobic. The hydrophilic nature and negative charge of
T. gondii
oocysts in freshwater could facilitate widespread contamination of waterways. The loss of charge observed in saline waters may lead to flocculation and subsequent accumulation of
T. gondii
oocysts in locations where freshwater and marine water mix, indicating a high risk of exposure for humans and wildlife in estuarine habitats with this zoonotic pathogen. While microspheres did not have surface properties identical to those of
T. gondii
, similar properties shared between each microsphere type and oocysts suggest that their joint application in transport and fate studies could provide a range of transport potentials in which oocysts are likely to behave.
b
-Type Dihydroorotate Dehydrogenase Is Purified as a H
2
O
2
-Forming NADH Oxidase from
Bifidobacterium bifidum
Authors: Kawasaki Shinji , Satoh Takumi , Todoroki Mitsunori , Niimura Youichi
Published: December 2008

Our previous report showed the existence of microaerophilic
Bifidobacterium
species that can grow well under aerobic conditions rather than anoxic conditions in a liquid shaking culture. The difference in the aerobic growth properties between the O
2
-sensitive and microaerophilic species is due to the existence of a system to produce H
2
O
2
in the growth medium. In this study, we purified and characterized the NADH oxidase that is considered to be a key enzyme in the production of H
2
O
2
.
Bifidobacterium bifidum
, an O
2
-sensitive bacterium and the type species of the genus
Bifidobacterium
, possessed one dominant active fraction of NADH oxidase and a minor active fraction of NAD(P)H oxidase activity detected in the first step of column chromatography for purification of the enzyme. The dominant active fraction was further purified and determined from its N-terminal sequence to be a homologue of
b
-type dihydroorotate dehydrogenase (DHOD), composed of PyrK (31 kDa) and PyrDb (34 kDa) subunits. The genes that encode PyrK and PryDb are tandemly located within an operon structure. The purified enzyme was found to be a heterotetramer showing the typical spectrum of a flavoprotein, and flavin mononucleotide and flavin adenine dinucleotide were identified as cofactors. The purified enzyme was characterized as the enzyme that catalyzes the DHOD reaction and also catalyzes a H
2
O
2
-forming NADH oxidase reaction in the presence of O
2
. The kinetic parameters suggested that the enzyme could be involved in H
2
O
2
production in highly aerated environments.