bluuebunny/crossref_metadata_2025 huggingface dataset:
Contrasting deterministic and probabilistic ranking of catch quotas and spatially and size-regulated fisheries management
Authors: Apostolaki P , Babcock E A , McAllister M K
Published: August 2006

Large uncertainties over the dynamics of resource systems have increasingly led to the use of probabilistic modeling in the provision of model-based fishery management advice. However, deterministic analysis still remains the easiest and quickest approach to formulate model-based management advice. Here, we contrast deterministic and probabilistic modeling methods in evaluations of the potential consequences of alternative fishery management measures such as spatial and temporal closures and size-specific regulations. We thereby assess how model-based fishery management advice may vary between deterministic and probabilistic analyses of system dynamics. Using data for the sandbar shark (Carcharhinus plumbeus) population off the eastern coast of the USA, it is shown that under a variety of conditions, the use of management measures that provide protection to specific age groups of a population, such as size limits, might be less effective in achieving stock recovery of slow-growing, late-maturing, highly mobile species than catch quotas. It is also shown that management approaches that, according to deterministic calculations, appear to be the most effective are not so when uncertainty in the population dynamics is taken into account.
Distribution of biofilm exopolymeric substances in littoral sediments of Canadian Shield lakes: the effects of light and substrate
Authors: Cyr Hélène , Morton Kathryn E
Published: August 2006

Benthic algal and microbial communities release organic compounds that perform many important functions in food webs and nutrient dynamics. In this study we compared the content and composition of extracellular substances from different types of sediments in the shallow littoral areas of clear and dark Canadian Shield lakes. We report high content of extracellular substances in these littoral sediments, in terms of both carbohydrates and proteins. Total carbohydrate contents increased with increasing sediment chlorophyll content in a relationship very similar to that reported for marine intertidal mudflats. Light availability and sediment type affected the content and composition of exopolymeric substances (EPS) in complex ways. More loosely bound (colloidal) EPS were measured in sandy sediments of dark lakes. Colloidal EPS content did not vary with changes in sediment particle size in clear lakes but may have been positively related to sediment particle size in dark lakes. Tightly bound (capsular) EPS increased with sediment water content with no effect of light availability. These relationships are consistent across the seven lakes. The role of these carbo hydrates and proteins in the productivity and nutrient dynamics of littoral areas in lakes remains to be tested.
Validating species sensitivity distributions using salinity tolerance of riverine macroinvertebrates in the southern Murray–Darling Basin (Victoria, Australia)
Authors: Kefford Ben J , Nugegoda Dayanthi , Metzeling Leon , Fields Elizabeth J
Published: August 2006

Species sensitivity distributions (SSDs) are commonly used in risk assessment and in setting water quality guidelines, yet their predictions have not been validated against loss of species with increasing pollutant concentrations in nature. We used a rapid toxicity testing method to determine the acute salinity tolerance (72 h LC50 values (concentration of salinity lethal to 50% of individuals)) of 110 macroinvertebrate taxa from the southern Murray–Darling Basin in central Victoria, Australia, and construct an SSD. This SSD was compared with loss of riverine macro invertebrates species from increasing salinity in Victoria. Macroinvertebrate species richness per individual sample, when salinity was <9.9 mS·cm–1, was invariant of salinity. However, when species richness was calculated across multiple samples above about 0.3–0.5 mS·cm–1, it declined with increasing salinity. This decline was predicted from the SSD after application of a variable safety factor calculated from an exponential or quadratic equation. Our findings confirm that SSDs can predict the loss of freshwater macroinvertebrate species from increases in salinity. This suggests that SSDs may be useful more generally for other aquatic organisms, other stressors, and toxicants.
Implications of long-term dynamics of fish and zooplankton communities for among-lake comparisons
Authors: Olden Julian D , Jensen Olaf P , Zanden M Jake Vander
Published: August 2006

Understanding the environmental determinants of lake community composition has been a central pursuit in freshwater ecology. Previous studies have defined community composition based on temporally limited surveys, with the implicit assumption that interannual variation is negligible compared with among-lake variability. Using a long-term data set for fish and zooplankton communities in five north temperate lakes (Wisconsin, USA), we found that interannual, within-lake similarity in species composition (a measure of temporal stability in community composition) generally exceeded community similarity among lakes. Despite these differences, however, the strength of community–environment relationships were found to range widely (2%–99% explained variation) depending on the choice of single-year sample used in the analysis, a result of high temporal coherence in limnological and biological characteristics. Perhaps of greatest concern, interannual similarity in species composition showed consistent relationships with habitat variables commonly used to explain community differences among lakes. Decreasing lake area and shoreline perimeter (indicative of lower habitat heterogeneity) and seepage lakes were associated with low interannual similarity in community composition, thus confounding the ability to differentiate among lake communities according to their habitat characteristics. In light of our results, we offer a number of explicit recommendations for the selection and analysis of community data in future cross-lake studies.
Effects of long-distance migration on circulating lipids of sockeye salmon (Oncorhynchus nerka)
Authors: Magnoni Leonardo J , Patterson David A , Farrell Anthony P , Weber Jean-Michel
Published: August 2006

Lipids circulate as nonesterified fatty acids (NEFAs) or as triacylglycerol (TAG) associated with phospholipids (PLs), the two main components of lipoproteins. Changes in plasma lipid levels of migrating salmon were anticipated in response to the combined demands of exercise and osmoregulation. Circulating NEFAs, TAG, and PLs were measured in sockeye salmon (Oncorhynchus nerka) at different stages of their 500 km migration up the Fraser River (British Columbia, Canada). We found that NEFAs represent <7% of total plasma fatty acids (FAs) and show only a minor decrease during migration. In contrast, lipoproteins account for >93% of all the energy of circulating lipids, and concentrations of their main constituents show 27-fold (TAG) and 6-fold (PLs) decreases. The most pronounced change in FA composition of plasma lipids was found in the sample immediately after freshwater transition, with an increase in TAG eicosapentaenoic acid (20:5) and a decrease in TAG palmitic acid (16:0). Lipoproteins are therefore involved in key physiological processes necessary for successful spawning. Previous investigations of lipid metabolism in swimming salmon have focused on plasma NEFAs, but this study shows that shifting attention to lipoproteins should prove more fruitful for future studies of migration energetics.
A diatom-based index for the biological assessment of eastern Canadian rivers: an application of correspondence analysis (CA)
Authors: Lavoie Isabelle , Campeau Stéphane , Grenier Martine , Dillon Peter J
Published: August 2006

We developed a diatom-based index that integrates the effects of multiple stresses on streams and provides information related to the "distance" from the nonimpacted state. The Eastern Canadian Diatom Index (IDEC) was based on a correspondence analysis (CA) to develop a chemistry-free index where the position of the sites along the gradient of maximum variance (first axis) is strictly determined by diatom community structure and is therefore independent of measured environmental variables. The index value indicates the distance of each diatom community from its specific reference community. A high index value represents a non- or less-impacted site, while a low index value represents a more heavily impacted site. Two sub-indices were developed based on two sets of reference communities. The IDEC-circumneutral includes the sites that have reference communities characteristic of slightly acidic or neutral environments. The IDEC-alkaline includes the sites that have reference communities characteristic of environments where pH values are naturally higher than 7.5. The distinction between the two sub-indices is fundamental to make sure that each stream has the potential to reach a high IDEC value following complete restoration of its ecosystem.
Spatial variability in nursery functions along a temperate estuarine gradient: role of detrital versus algal trophic pathways
Authors: Islam Md. Shahidul , Tanaka Masaru
Published: August 2006

We aimed to identify spatial variability in estuarine trophic pathways and to elucidate their role as a nursery for juvenile fishes along Chikugo River estuary, Japan. First, we investigated distribution of larval and juvenile fishes and their diets. Using estuarine-dependent species as a model, we analyzed diets of Japanese sea bass (Lateolabrax japonicus) and conducted copepod distribution and gut fluorescence studies. To evaluate the nursery functions of spatially variable food webs, we used several indices: copepod biomass, feeding intensity, gut content biomass, growth rates, RNA/DNA ratio, condition factor, and starvation status of sea bass larvae and juveniles. We identified four different spatial distribution patterns of fishes: oligohaline, mesohaline, euryhaline, and polyhaline. Copepod assemblages and diets of fishes were completely different among the regions. Gut chlorophyll a and phaeopigment indicated that copepods in the oligohaline region depend on a detrital food web, while in the euryhaline region they depend on an algal food web. The oligohaline region had maximum turbidity, nutrients, chlorophyll pigments, and copepod biomass, and sea bass juveniles had higher feeding intensity, gut content biomass, RNA/DNA ratio, growth rate, and condition factor and lower starvation rates. This suggests that the oligohaline region, supported by a detrital food web, is an important nursery that positively influences fish growth and condition.
Critical appraisal of the cone penetration method of determining soil plasticity
Authors: Prakash K , Sridharan A
Published: August 2006

Plasticity is a characteristic feature that all plastic soils possess. It is shown that the soil plasticity is mainly due to undrained cohesion. Soil plasticity characteristics obtained from laboratory tests are reasonable for use only when the testing procedures adopted to determine them measure the factors responsible for the soil plasticity. It is shown that this is the case with the percussion method of liquid limit determination and the 3 mm thread rolling method of plastic limit determination. Further, it is also shown that the results obtained from the cone penetration method cannot represent the soil plasticity fully, as the mechanisms that come into play during testing relate to undrained strength due to both undrained cohesion and undrained friction. It is stressed that the percussion and 3 mm thread rolling methods must be the only ones used to determine the plasticity of soils. The circumstance under which the cone penetration method can be used is also indicated.Key words: clays, laboratory tests, plasticity, soil classification.
Fragmentation energy in rock avalanches
Authors: Locat Pascal , Couture Réjean , Leroueil Serge , Locat Jacques , Jaboyedoff Michel
Published: August 2006

Fragmentation is one of the mechanisms involved in rock avalanches. Quantifying the associated energy during a rock avalanche can help to assess the influence of fragmentation on post-failure mass movements. In this paper, in situ block size distributions of the intact rock mass and the debris deposits are presented and analyzed for nine rock avalanches, five in the Canadian Rocky Mountains and four in the European Alps. Degrees of fragmentation are estimated from these data. Two methods are examined to assess fragmentation energy, one based on the comminution theory, and one on the blasting energy used in the mining industry. The results show that, for the studied rock avalanches, there is a relationship between the reduction in diameter ratio, Rr = D50/d50 (where D50 and d50 are the mean diameter of the intact rock mass and the mean diameter of the debris, respectively), and the potential energy per unit volume normalized with respect to the point load strength of rock (γHG/σc), where γ is the unit weight of the material, HG is the vertical distance between the centres of gravity of the mass at the start and end positions, and σc is the point load strength). For the cases studied, fragmentation energy calculations average 20% of the potential energy. An empirical relationship between Rr and γHG/σc has been established and is used in the definition of a disintegration index (ID). This index seems to reflect the physics of the disintegration process, since it accounts for the fact that the reduction in diameter ratio is a function of the dissipated energy and the strength of the rock. These factors have long been known to affect fragmentation but have never been presented in a coherent manner for rock avalanches.Key words: rock avalanches, disintegration, fragmentation energy, Canadian Rocky Mountains, European Alps.
Prediction of evaporation from soil slopes
Authors: Weeks B , Wilson G W
Published: August 2006

The calculation of evaporation from soil surfaces is of critical importance in predicting the surface water balance for soil cover systems constructed on waste disposal sites and for geotechnical problems where the prediction of pore-water pressures is important. There are several well-established approaches available for predicting evaporation from horizontal soil surfaces, but the issues that affect evaporation from soil slopes have not been fully investigated for geotechnical applications. The importance of variations in solar radiation with respect to evaporation from soil slopes is examined here, and a method to predict the solar radiation on soil slopes is presented. The method is applied to a fully three-dimensional surface, based on the digital map of a soil cover placed at a mine site, to illustrate variations in potential evaporation over the surface of the site. The implication of radiation variations for actual evaporation on slopes is also illustrated. The results show that north-facing slopes at greater latitudes in the northern hemisphere can receive significantly less net radiation than horizontal or south-facing slopes, resulting in less actual evaporation.Key words: slope, evaporation, solar energy, soil cover, water balance.
AUTOMATIC CIRCUIT TUNING VIA UNSUPERVISED LEARNING PARADIGMS
Authors: EL-GAMAL M. A. , ABDEL-MALEK H. L. , SOROUR M. A.
Published: August 2006

This work describes a novel technique for automating the post-fabrication circuit tuning process. A training set that characterizes the behavior of the circuit under test is first constructed. The data in this set consists of input measurement vectors with no output attributes, and is clustered via unsupervised learning algorithm in order to explore its underlying structure and correlations. The generated clusters are labeled and utilized in circuit tuning by calculating the value(s) of the tuning parameter(s). Three prominent and fundamentally different unsupervised learning algorithms, namely, the self-organizing map, the Gaussian mixture model, and the fuzzy C-means algorithm are employed and their performance is compared. The experimental results demonstrate that the proposed technique provides a robust and efficient circuit tuning approach.
RESIZABLE TRANSLATION STORAGE BUFFERS
Authors: SAGAHYROON ASSIM , MOHAMED AHMED H.
Published: August 2006

A translation lookaside buffer (TLB) is a high-speed associative cache of recently used virtual-to-physical address translations. The operating system can deal with a TLB miss through software trap handling. A possible technique for such software trap handling uses translation storage buffers (TSBs). A TSB is an operating system data structure that caches the most recent address translations. On a TLB miss, the TLB trap handler searches the TSB for the missing address translation. If the search generates a hit, the address mapping is added to the TLB. In current implementations, TSBs are organized in a variety of ways: a global TSB for all CPUs within the system, a per-processor TSB, or a per-process TSB. All of the aforementioned techniques have various limitations that will be addressed in this paper. In this work, we propose a new framework for TSBs generation and allocation. In the proposed approach, a policy of resizing and dynamically allocating TSBs for the different processes is used. This dynamic policy allows the system to adopt to different workloads while achieving a low TSB context invalidation overhead. In addition, with the ability to assign a separate TSB to each process, thrashing is practically eliminated. Implementation and experimental results of the proposed scheme are reported. Comparisons against existing implementations confirmed the expected performance enhancement.
A NOVEL RADIX-3/9 ALGORITHM FOR TYPE-III GENERALIZED DISCRETE HARTLEY TRANSFORM
Authors: YANG XIAOFAN , MEGSON GRAHAM M. , XING YONGKANG , EVANS DAVID J.
Published: August 2006

A novel radix-3/9 algorithm for type-III generalized discrete Hartley transform (GDHT) is proposed, which applies to length-3p sequences. This algorithm is especially efficient in the case that multiplication is much more time-consuming than addition. A comparison analysis shows that the proposed algorithm outperforms a known algorithm when one multiplication is more time-consuming than five additions. When combined with any known radix-2 type-III GDHT algorithm, the new algorithm also applies to length-2q3p sequences.
DOMINO LOGIC SYNTHESIS SYSTEM AND ITS APPLICATIONS
Authors: YOSHIKAWA KO , INUI SHIGETO , HAGIHARA YASUHIKO , NAKAMURA YUICHI , YOSHIMURA TAKESHI
Published: August 2006

We have developed a domino logic synthesis system with a new technology mapping algorithm based on a bin packing algorithm that reduces the levels of the circuits and considers the complexity of domino primitive cells. Domino logic circuits have 20–50% performance advantage over static circuits. By using this system, designing domino logic circuits becomes much easier than manual design. The primary reason is that logic design is completely automated by the system. The second reason is that domino primitive cell layout is simplified by our new technology mapping algorithms that considers the complexity of domino primitive cells.
THREE-STAGE CLOS-NETWORK SWITCH ARCHITECTURE WITH BUFFERED CENTER STAGE FOR MULTI-CLASS TRAFFIC
Authors: KANG MOO-KYUNG , KYUNG CHONG-MIN
Published: August 2006

Memory-space-memory (MSM) arrangement is a popular architecture to implement three-stage Clos-network switches with distributed arbitration. The scalability of this architecture, however, is limited by the round-trip communication delay between the first and the second stages. Moreover, virtual output queue does not completely remove the blocking in the buffered modules under multi-class traffic. In this paper, we propose a competition-free memory–memory–memory (CFM3) switch which is a three-stage Clos-network switch with buffered center stage. The CFM3 deploys buffered modules in all stages to simplify communication between stages. To reduce the blocking, each module is equipped with a set of buffers fully separated according to the destinations, classes of packets and the input ports of the module. Despite the buffered center stage, CFM3 is free from reordering problem due to simple control mechanism. Simulation result shows the delay of the proposed CFM3 switch closely approaches that of the ideal Output Queued switch under multi-class traffic when strict priority policy popularly used for class-based switch is deployed. The CFM3 achieves 100% throughput under uniformly distributed four-class traffic with strict priority policy while traditional MSM switch records about 77% throughput.
INTEGRATED RELIABILITY DEVELOPMENT FOR THE FRONT SUSPENSION SYSTEMS IN LIGHT DUTY DODGE RAM TRUCK
Authors: LING JING
Published: August 2006

Although there is great progress in the research of reliability tools and methods, it has always being a challenge on how to develop the required reliability into products through systematic and synergistic use of reliability tools and methods. In this application paper, we show how we developed the required reliability into the front suspension systems in light duty Dodge Ram truck program. In reliability management, we emphasized the integration of reliability engineering process into product development process. In reliability engineering, we upheld "The Three Principles" we crystallized from our experience in reliability implementation. These principles are "Design-In Reliability", "Test-Out Un-Reliability", and "Integrated Reliability Demonstration". With disciplined management and rigorous engineering, we reduced 36,000 miles warranty cost for the light duty Dodge Ram front suspension system by almost 50%, comparing it to the warranty cost for the same system in the replaced vehicle model.
MONITORING OF BATCH PROCESSES WITH VARYING DURATIONS BASED ON THE HAUSDORFF DISTANCE
Authors: CASTAGLIOLA PHILIPPE , ROSA ARIANE FERREIRA PORTO
Published: August 2006

In some industrial situations, the classical assumption used in the batch process monitoring that all batches have equal durations and are synchronized does not hold. A batch process is carried out in sequential phases and a significant variability generally occurs in the duration of the phases such that events signifying the beginning or the end of a phase are generally misaligned in time within the various batches. The consequence is that the variable trajectories, in the different runs of the same batch process, are unsynchronized. In this case, data analysis from process for performing the multivariate statistical process control can be difficult. In this paper, we propose several innovative methods for the off-line and on-line monitoring of batch processes with varying durations, all based on the Hausdorff distance. These methods have been successfully tested on a simulated example and on an industrial case example. The conclusion is that these methods are able to efficiently discriminate between nominal and non-nominal batches.
Rapamycin at subimmunosuppressive levels inhibits mesangial cell proliferation and extracellular matrix production
Authors: Lock Helen R. , Sacks Steven H. , Robson Michael G.
Published: August 2006

In view of its proven antiproliferative effects, rapamycin offers potential in the treatment of mesangioproliferative disease. Previous data have shown an effect of rapamycin on mesangial cell proliferation at high doses and have not explored the mechanism of action. Therefore, we explored the effects and mechanism of action of low levels of rapamycin on mesangial cell proliferation. Primary cultures of mouse mesangial cells were grown in medium containing serum with differing concentrations of rapamycin. A rapamycin concentration of 0.1 ng/ml caused a decrease in cell number and DNA synthesis with no effect on apoptosis. Type IV collagen protein production was inhibited at 0.01 ng/ml rapamycin, although gene expression was unaffected. P70S6K phosphorylation was inhibited in parallel with the effects on cell number and DNA synthesis in a dose-dependent manner, but no effect was seen at 0.01 ng/ml rapamycin. These data show an effect on mesangial cell proliferation and p70S6 kinase phosphorylation of 0.1 ng/ml rapamycin and an effect on collagen IV production of 0.01 ng/ml rapamycin. We suggest that further in vivo studies should explore the potential for low-dose rapamycin in the treatment of mesangioproliferative glomerulonephritis.
Glibenclamide prevents increased extracellular matrix formation induced by high glucose concentration in mesangial cells
Authors: Giannico Giovanna , Cortes Pedro , Baccora Mohammed H. , Hassett Clare , Taube David W. , Yee Jerry
Published: August 2006

Other than stimulation of cell contractility, little is known about the potential metabolic effects induced by sulfonylureas, independently of insulin action. Previous studies from our laboratory demonstrated complete abrogation of glomerulosclerosis in an experimental model of type 1 diabetes chronically (9 mo) treated with low-dose sulfonylureas (Biederman JI, Vera E, Pankhaniya R, Hassett C, Giannico G, Yee J, Cortes P. Kidney Int 67: 554–565, 2005). Therefore, the effects of glibenclamide (Glib) on net collagen I, collagen IV, and fibronectin medium net secretion and cell layer collagen I deposition were investigated in mesangial cells continuously exposed to 25 mM glucose for 8 wk and treated with predetermined increasing concentrations of Glib for the same period. Clinically relevant concentrations (0.01 μM) of Glib fully suppressed the high glucose-enhanced accumulation of collagen I, collagen IV, and fibronectin in the medium and inhibited collagen I deposition in the cell layer. These effects occurred while transforming growth factor (TGF)-β1 medium concentration remained elevated and glucose uptake was increased to levels above those in 25 mM glucose-incubated cultures. The decreased collagen I accumulation occurred simultaneously with enhanced collagen I mRNA expression in concert with marked suppression of plasminogen inhibitor type-1 (PAI-1) mRNA and protein expression. This strongly suggests an accelerated matrix turnover favoring breakdown. Glib-induced effects demonstrated a biphasic pattern, being absent or reversed in cells treated with higher Glib concentrations (0.1 or 1 μM). Therefore, chronic Glib treatment at low concentrations markedly diminishes the high glucose-induced enhanced accumulation of extracellular matrix components by suppression of steady-state PAI-1 transcriptional activity. These results and those previously reported in vivo suggest that long-term Glib treatment may prevent glomerulosclerosis in insulin-deficient diabetes.
Differences in Cancer Incidence among Indians in Alaska and New Mexico and U.S. Whites, 1993-2002
Authors: Kelly Janet J. , Lanier Anne P. , Alberts Steven , Wiggins Charles L.
Published: August 2006

Cancer incidence for American Indians and Alaska Natives is typically reported as a single rate for all U.S. indigenous populations combined. Previously reported combined rates suggest that American Indians and Alaska Natives have lower cancer incidence rates compared with the U.S. population. Alaska Native people comprise three major ethnic groups: Eskimo, Indian, and Aleut people. We examined cancer incidence from only Alaska Indians and compared incidence rates with an American Indian population living in New Mexico. These data indicate striking differences in cancer patterns between two American Indian populations. Cancer data for the years 1993 to 2002 for American Indians of New Mexico and U.S. Whites are from the National Cancer Institute Surveillance, Epidemiology, and End Results Program Public-use data set. Data for Alaska Indians are from the Alaska Native Tumor Registry, which is also a Surveillance Epidemiology and End Results Program participant. Overall, cancer incidence rates for all sites combined in New Mexico Indian men and women were lower than U.S. White rates, whereas Alaska Indian men and women exceeded U.S. rates. In comparing Alaska and New Mexico Indians, we observed a 2.5-fold higher incidence of cancer among Alaska Indians. The largest differences between the two Indian populations were noted primarily in cancers associated with tobacco use, including cancers of the oral cavity/pharynx, esophagus (only in men), colon and rectum, pancreas, larynx (men), lung, prostate, and urinary bladder (men). Lung cancer rates in Alaska Indian men and women were 7 and 10 times those of New Mexico Indian men and women. (Cancer Epidemiol Biomarkers Prev 2006;15(8):1515–9)
Tobacco Use in Adult Long-term Survivors of Retinoblastoma
Authors: Foster Meredith C. , Kleinerman Ruth A. , Abramson David H. , Seddon Johanna M. , Tarone Robert E. , Tucker Margaret A.
Published: August 2006

A significant risk of lung cancer was identified among hereditary, but not nonhereditary, retinoblastoma (Rb) patients. Tobacco use was investigated to determine whether differences in smoking prevalence might explain the lung cancer excess and to characterize smoking patterns in adult survivors of Rb. Subjects were 441 hereditary and 395 nonhereditary 1-year survivors of Rb, age ≥18 years, who responded to a telephone survey about current health behavior, including tobacco use. Response rates were 76% for hereditary and 73% for nonhereditary survivors. We compared patterns and predictors of current tobacco use among hereditary and nonhereditary survivors with other childhood cancer survivor studies and the U.S. population. Hereditary Rb survivors currently smoke cigarettes significantly less frequently than nonhereditary survivors (16. 8% versus 24.3%), although among current smokers, age at smoking initiation (17 years old) and average cigarettes (1.5 packs) smoked daily are similar. Predictors of current and ever cigarette smoking include nonhereditary Rb, older age, being female, less education, and use of other tobacco products. Rb survivors smoke cigarettes significantly less than the U.S. population (rate ratio, 0.63; 95% confidence interval, 0.5-0.8 for males; rate ratio, 0.75; 95% confidence interval, 0.6-0.9 for females), but Rb survivors have comparable smoking rates with other childhood cancer survivors. Smoking did not account for the increased risk of lung cancer among hereditary Rb patients, and this may point to an enhanced sensitivity to the carcinogenic effects of tobacco. Adult survivors of Rb should be encouraged to stop smoking. (Cancer Epidemiol Biomarkers Prev 2006;15(8):1464–8)
Merkel Cell Carcinoma and Multiple Primary Cancers
Authors: Howard Regan A. , Dores Graça M. , Curtis Rochelle E. , Anderson William F. , Travis Lois B.
Published: August 2006

Merkel cell carcinoma (MCC) is an aggressive neuroendocrine tumor of the skin for which causative factors remain largely unknown. The site-specific risks of multiple primary cancers associated with MCC, which may provide insight into etiologic influences, have not been quantified in large population-based studies. We estimated the long-term risk of subsequent primary tumors after a first primary MCC (1,306 patients) and the risk of second primary MCC following other first primary cancers (2,048,739 patients) within 11 population-based cancer registries which report to the National Cancer Institute's Surveillance, Epidemiology, and End Results Program (1986-2002). Patients with first primary MCC were at significantly increased risk of developing a subsequent cancer [standardized incidence ratio (SIR), 1.22; 95% confidence intervals (95% CI), 1.01-1.45; observed (O = 122)], with significant excesses restricted to the first year after diagnosis (SIR, 1.71; 95% CI, 1.21-2.33; O = 39). Significantly elevated site-specific risks were observed for cancers of salivary gland (SIR, 11.55; 95% CI, 2.32-33.76; O = 3), biliary sites other than liver and gallbladder (SIR, 7.24; 95% CI, 1.46-21.16; O = 3), and non–Hodgkin lymphoma (SIR, 2.56; 95% CI, 1.23-4.71; O = 10). Nonsignificantly increased risks of 2-fold or higher were seen for chronic lymphocytic leukemia, and cancers of the small intestine and brain. A significantly increased 1.36-fold risk (95% CI, 1.19-1.55; O = 221) of MCC as a second primary malignancy was observed among patients with all other first primary cancers taken together. In particular, significant 3- to 7-fold excesses of MCC followed multiple myeloma (SIR, 3.70; 95% CI, 1.01-9.47; O = 4), chronic lymphocytic leukemia (SIR, 6.89; 95% CI, 3.77-11.57; O = 14), non–Hodgkin lymphoma (SIR, 3.37; 95% CI, 1.93-5.47; O = 16), and malignant melanoma (SIR, 3.05; 95% CI, 1.74-4.95; O = 16). Although enhanced medical surveillance may play a role, increased reciprocal risks suggest that MCC may share etiologic influences with other malignancies. Heightened awareness of the associations of lymphohematopoietic malignancies with MCC may facilitate early clinical recognition. (Cancer Epidemiol Biomarkers Prev 2006;15(8):1545–9)
Validity and Reliability of Adult Recall of Past Sun Exposure in a Case-Control Study of Multiple Sclerosis
Authors: van der Mei I.A.F. , Blizzard L. , Ponsonby A-L. , Dwyer T.
Published: August 2006

Background: Measurement of past sun exposure through recall by adults has the potential for measurement error. We aimed to investigate aspects of validity and reliability of self-reported past sun exposure.

Methods: A population-based case-control study was conducted in Tasmania on 136 cases with multiple sclerosis and 272 age- and sex-matched community controls. Repeat interviews on 52 cases and 52 controls were done on average 11 weeks after the initial interview. Sun exposure was assessed by questionnaire and lifetime calendar. Other measurements included serum 25-hydroxyvitamin D, actinic damage, and skin phenotype.

Results: There was an association between recent sun exposure and serum vitamin D (time in the sun: r = 0.22, P < 0.01; activities outside: r = 0.31, P < 0.01 for controls) and between lifetime sun exposure and actinic damage [correlation between 0.34 (P < 0.01) and 0.17 (P = 0.01) for controls]. The test-retest weighted κ statistic of self-reported sun exposure ranged from 0.43 to 0.74. Recall of childhood/adolescent sun exposure by standardized questioning was no less reproducible than recall of recent adult sun exposure and no less reliable when made with the calendar method. Comparing the questionnaire and calendar method, the measures of childhood/adolescent sun exposure had a similar predictive validity for multiple sclerosis.

Conclusions: The results of this study provide further evidence that adults are able to recall past sun exposure with shown validity and reliability and present information about the possible reasons for the good reliability of recalled sun exposure measures. (Cancer Epidemiol Biomarkers Prev 2006;15(8):1538–44)
Vitamin D, Calcium, and Breast Cancer Risk: A Review
Authors: Cui Yan , Rohan Thomas E.
Published: August 2006

Vitamin D and calcium are metabolically interrelated and highly correlated dietary factors. Experimental studies have shown their anticarcinogenic effects due to their participation in regulating cell proliferation, differentiation, and apoptosis in normal and malignant breast cells. Given the emerging interest in their potential roles in the etiology of breast cancer, we review the current epidemiologic literature on dietary and/or supplemental intakes of vitamin D, endogenous circulating levels of vitamin D, and dietary and/or supplemental intakes of calcium in relation to breast cancer risk. To place these studies in context, we also provide a brief review of other supporting epidemiologic evidence. Despite inconsistent results from the epidemiologic studies, several lines of evidence suggest that vitamin D and calcium may be involved in the development of breast cancer. Specifically, (a) there is some epidemiologic evidence for inverse associations between vitamin D and calcium intakes and breast cancer; (b) serum, plasma, and/or blood levels of vitamin D metabolites have been inversely associated with breast cancer risk in some studies; (c) high sunlight exposure, presumably reflecting vitamin D synthesis in the skin, has been associated with a reduced risk of breast cancer; (d) vitamin D and calcium intakes have been inversely related to breast density, an intermediate end point for breast cancer; (e) calcium has been associated with a reduced risk of benign proliferative epithelial disorders of the breast, putative precursors of breast cancer; and (f) certain polymorphisms of the vitamin D receptor might modify breast cancer susceptibility. To further confirm the potential protective effects of calcium and vitamin D on breast cancer, well-designed cohort studies and clinical trials are warranted. (Cancer Epidemiol Biomarkers Prev 2006;15(8):1427-37)
Prenatal Diethylstilbestrol Exposure and Risk of Breast Cancer
Authors: Palmer Julie R. , Wise Lauren A. , Hatch Elizabeth E. , Troisi Rebecca , Titus-Ernstoff Linda , Strohsnitter William , Kaufman Raymond , Herbst Arthur L. , Noller Kenneth L. , Hyer Marianne , Hoover Robert N.
Published: August 2006

It has been hypothesized that breast cancer risk is influenced by prenatal hormone levels. Diethylstilbestrol (DES), a synthetic estrogen, was widely used by pregnant women in the 1950s and 1960s. Women who took the drug have an increased risk of breast cancer, but whether risk is also increased in the daughters who were exposed in utero is less clear. We assessed the relation of prenatal DES exposure to risk of breast cancer in a cohort of DES-exposed and unexposed women followed since the 1970s by mailed questionnaires. Eighty percent of both exposed and unexposed women completed the most recent questionnaire. Self-reports of breast cancer were confirmed by pathology reports. Cox proportional hazards regression was used to compute incidence rate ratios (IRR) for prenatal DES exposure relative to no exposure. During follow-up, 102 incident cases of invasive breast cancer occurred, with 76 among DES-exposed women (98,591 person-years) and 26 among unexposed women (35,046 person-years). The overall age-adjusted IRR was 1.40 [95% confidence interval (95% CI), 0.89-2.22]. For breast cancer occurring at ages ≥40 years, the IRR was 1.91 (95% CI, 1.09-3.33) and for cancers occurring at ages ≥50 years, it was 3.00 (95% CI, 1.01-8.98). Control for calendar year, parity, age at first birth, and other factors did not alter the results. These results, from the first prospective study on the subject, suggest that women with prenatal exposure to DES have an increased risk of breast cancer after age 40 years. The findings support the hypothesis that prenatal hormone levels influence breast cancer risk. (Cancer Epidemiol Biomarkers Prev 2006;15(8):1509–14)
Cancer after Total Joint Arthroplasty: A Meta-analysis
Authors: Onega Tracy , Baron John , MacKenzie Todd
Published: August 2006

Background: Some epidemiologic and laboratory studies have suggested that total joint arthroplasty could increase the risk of cancer. In this meta-analysis, we attempt to clarify the association of joint arthroplasty with subsequent cancer incidence.

Methods: We identified population-based studies reporting standardized incidence ratios (SIR) for cancer following large joint arthroplasty. After summing the observed and expected numbers of cases across all qualifying studies, we calculated SIRs for all cancers, and for those at 28 anatomic sites. Latency analysis involving 175,166 patients characterized short-term and long-term cancer associations.

Results: The analyses included 1,435,356 person-years of follow-up and 20,045 cases of cancer. Overall cancer risk among patients with arthroplasty was equal to that for the general population. The relative risk of lung cancer, reduced in the first 5 years after arthroplasty, increased significantly over time to approach that of the general population. Risks for all sites in the luminal gastrointestinal tract were significantly reduced by 10% to 20%; with relative risks that were generally stable over time. Increased risks were seen for cancer of the prostate (SIR, 1.12; 95% confidence interval, 1.08-1.16); similar relative risks were seen in each time period after the procedure. For melanoma, relative risks increased with follow-up to a SIR of 1.43 (95% confidence interval, 1.13-1.79) for 10 or more years after arthroplasty. There was a similar delayed emergence of increased risks for cancers of the urinary tract and oropharynx. The relative risk for bone cancer decreased with time after the procedure.

Conclusions: There does not seem to be an overall increased risk of cancer following total joint arthroplasty. Although the risks of prostate cancer and melanoma seem to be elevated, there is no obvious mechanism for these associations. Reductions in risk for some malignancies may not be causal. (Cancer Epidemiol Biomarkers Prev 2006;15(8):1532–7)
Associations of Ki-ras Proto-oncogene Mutation and p53 Gene Overexpression in Sporadic Colorectal Adenomas with Demographic and Clinicopathologic Characteristics
Authors: Einspahr Janine G. , Martinez Maria Elena , Jiang Ruiyun , Hsu Chiu-Hsieh , Bhattacharrya Achyut K. , Ahnen Dennis J. , Jacobs Elizabeth T. , Houlihan P. Scott , Webb C. Renee , Alberts David S. , Hamilton Stanley R.
Published: August 2006

In colorectal tumorigenesis, Ki-ras proto-oncogene mutation often occurs early in the adenoma-adenocarcinoma sequence, whereas mutation of the p53 gene is associated with late progression to carcinoma. We evaluated the relationship of demographic and clinicopathologic characteristics to Ki-ras mutation and p53 gene product overexpression in 1,093 baseline sporadic colorectal adenomas from 926 individuals enrolled in a phase III recurrence prevention trial. Ki-ras mutation was found in 14.7% of individuals and p53 overexpression was found in 7.0% of those tested. Multivariate analysis found older age, rectal location, and villous histology to be independently associated with Ki-ras mutation. Individuals with an advanced adenoma (≥1 cm or high-grade dysplasia or villous histology) had a 4-fold higher likelihood of Ki-ras mutation [odds ratios (OR), 3.96; 95% confidence intervals (CI), 2.54-6.18]. Ki-ras mutations in codon 12 and of the G-to-A transition type were more frequent in older individuals, whereas G-to-T transversion was more frequent in rectal adenomas than in the colon. Multivariate analysis showed that previous history of a polyp (P = 0.03) was inversely associated with p53 overexpression. Large adenoma size (≥1 cm), high-grade dysplasia, and villous histology were independently associated with p53 overexpression, with the strongest association for advanced adenomas (OR, 7.20; 95% CI, 3.01-17.22). Individuals with a Ki-ras mutated adenoma were more likely to overexpress p53 (OR, 2.46; 95% CI, 1.36-4.46), and 94.8% of adenomas with both alterations were classified as advanced (P ≤ 0.0001). Our large cross-sectional study supports the role of both Ki-ras and p53 in the progression of adenomas and shows that their molecular pathogenesis differs by anatomic location, age, and mucosal predisposition as evidenced by previous history of a polyp. (Cancer Epidemiol Biomarkers Prev 2006;15(8):1443–50)
Estrogen and α-Fetoprotein Levels in Maternal and Umbilical Cord Blood Samples in Relation to Birth Weight
Authors: Nagata Chisato , Iwasa Shinichi , Shiraki Makoto , Shimizu Hiroyuki
Published: August 2006

Birth weight has been associated with a subsequent risk of breast cancer. The present study examined associations between birth weight and pregnancy estrogens and α-fetoprotein (AFP). The concentrations of estradiol, estriol, and AFP were measured in maternal and umbilical cord blood samples from 194 women during pregnancy and at birth. Birth weight was significantly positively correlated with maternal serum estradiol and estriol levels in the 29th week (estradiol: r = 0.16, P = 0.03; estriol: r = 0.29, P = 0.001) and at delivery (estradiol: r = 0.20, P = 0.01; estriol: r = 0.41, P < 0.0001) after controlling for covariates. The umbilical cord estriol level was moderately but significantly correlated with birth weight (r = 0.15, P = 0.049). There was no significant association between umbilical cord serum estradiol and birth weight. There was no significant association between birth weight and maternal serum AFP in any gestational week. Umbilical cord AFP was significantly inversely correlated with birth weight (r = −0.16, P = 0.04). Umbilical cord AFP was unrelated to cord levels of estradiol and estriol. The data suggested a greater exposure to estriol and a lower exposure to AFP among high birth weight babies. (Cancer Epidemiol Biomarkers Prev 2006;15(8):1469–72)
Diabetes Mellitus and Pancreatic Cancer in a Population-Based Case-Control Study in the San Francisco Bay Area, California
Authors: Wang Furong , Gupta Samir , Holly Elizabeth A.
Published: August 2006

Background: Diabetes has been postulated to be both a risk factor and a consequence of pancreatic cancer, but the degree of risk and associated clinical factors remain unclear.

Methods: We conducted a population-based case-control study of pancreatic cancer in the San Francisco Bay Area between 1995 and 1999. Rapid case ascertainment through the Surveillance, Epidemiology and End Results registry for cases and random selection from the general population for controls were employed to identify study participants with no proxy interviews.

Results: Five hundred thirty-two cases and 1,701 controls were interviewed. Participants with pancreatic cancer were more likely to report a history of diabetes (13%) than were controls [9%; odds ratio (OR), 1.5; 95% confidence interval (95% CI), 1.1-2.1]. Compared with diabetics in the control group, diabetics in the case group had a shorter duration of diabetes (P = 0.0003) and a larger proportion of insulin users (P = 0.002). Risk for pancreatic cancer varied with duration of diabetes (OR, 2.4; 95% CI, 1.4-4.0 for 1-4 years; OR, 2.0; 95% CI, 1.2-3.4 for 5-9 years; and OR, 0.86; 95% CI, 0.52-1.4 for ≥10 years diabetes duration; Ptrend = 0.004). Among diabetics, use of oral diabetes medication or insulin for ≥5 years was not associated with pancreatic cancer, but insulin use of <5 years was associated with a 6.8-fold risk for pancreatic cancer (95% CI, 3.7-12).

Conclusion: Recent-onset diabetes may be a complication or an early marker of pancreatic cancer. Diabetes of short duration with insulin use conferred a substantially elevated risk for pancreatic cancer and may reflect insulin resistance that is elicited by pancreatic cancer. (Cancer Epidemiol Biomarker Prev 2006;15(8):1458–63)
Combined Analysis of r-1,t-2,3,c-4-Tetrahydroxy-1,2,3,4-Tetrahydrophenanthrene and 4-(Methylnitrosamino)-1-(3-Pyridyl)-1-Butanol in Smokers' Plasma
Authors: Carmella Steven G. , Yoder Andrea , Hecht Stephen S.
Published: August 2006

Polycyclic aromatic hydrocarbons (PAH) and tobacco-specific nitrosamines, such as 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), are widely accepted to be two important types of lung carcinogens in cigarette smoke. In this study, we have developed a method to estimate individual uptake of these compounds by quantifying r-1,t-2,3,c-4-tetrahydroxy-1,2,3,4-tetrahydrophenanthrene (PheT) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) in 1 mL of smokers' plasma. PheT and NNAL are biomarkers of PAH and NNK uptake, respectively. [D10]PheT and [pyridine-D4]NNAL were added to plasma as internal standards. The plasma was treated with β-glucuronidase to release any conjugated PheT and NNAL. The analytes were enriched by solid-phase extraction on a mixed mode cation exchange cartridge and the PheT fraction was further purified by high-performance liquid chromatography. The appropriate fractions were analyzed by gas chromatography-negative ion chemical ionization-mass spectrometry for PheT and liquid chromatography-electrospray ionization-mass spectrometry for NNAL. The method was sensitive (limits of quantitation: PheT, 13 fmol/mL; NNAL, 3 fmol/mL), accurate, and precise. Levels of PheT and NNAL in plasma from 16 smokers averaged 95 ± 71 and 36 ± 21 fmol/mL, respectively, which are ∼1% to 2% of the amounts found in urine. This method should be useful in molecular epidemiology studies of carcinogen uptake and lung cancer in smokers. (Cancer Epidemiol Biomarkers Prev 2006;15(8):1490–4)