bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessment of Noise and Associated Health Impacts at Selected Secondary Schools in Ibadan, Nigeria
Authors: Ana Godson R. E. E. , Shendell Derek G. , Brown G. E. , Sridhar M. K. C.
Published: October 2009

Background. Most schools in Ibadan, Nigeria, are located near major roads (mobile line sources). We conducted an initial assessment of noise levels and adverse noise-related health and learning effects.Methods. For this descriptive, cross-sectional study, four schools were selected randomly from eight participating in overall project. We administered 200 questionnaires, 50 per school, assessing health and learning-related outcomes. Noise levels (A-weighted decibels, dBA) were measured with calibrated sound level meters. Traffic density was assessed for school with the highest measured dBA. Observational checklists assessed noise control parameters and building physical attributes.Results. Short-term, cross-sectional school-day noise levels ranged 68.3–84.7 dBA. Over 60% of respondents reported that vehicular traffic was major source of noise, and over 70% complained being disturbed by noise. Three schools reported tiredness, and one school lack of concentration, as the most prevalent noise-related health problems.Conclusion. Secondary school occupants in Ibadan, Nigeria were potentially affected by exposure to noise from mobile line sources.
Chaotic Image Encryption Design Using Tompkins‐Paige Algorithm
Authors: Etemadi Borujeni Shahram , Eshghi Mohammad
Published: October 2009

In this paper, we have presented a new permutation‐substitution image encryption architecture using chaotic maps and Tompkins‐Paige algorithm. The proposed encryption system includes two major parts, chaotic pixels permutation and chaotic pixels substitution. A logistic map is used to generate a bit sequence, which is used to generate pseudorandom numbers in Tompkins‐Paige algorithm, in 2D permutation phase. Pixel substitution phase includes two process, the tent pseudorandom image (TPRI) generator and modulo addition operation. All parts of the proposed chaotic encryption system are simulated. Uniformity of the histogram of the proposed encrypted image is justified using the chi‐square test, which is less thanχ2(255, 0.05). The vertical, horizontal, and diagonal correlation coefficients, as well as their average and RMS values for the proposed encrypted image are calculated that is about 13% less than previous researches. To quantify the difference between the encrypted image and the corresponding plain‐image, three measures are used. These are MAE, NPCR, and UACI, which are improved in our proposed system considerably. NPCR of our proposed system is exactly the ideal value of this criterion. The key space of our proposed method is large enough to protect the system against any Brute‐force and statistical attacks.
Region‐Based PDEs for Cells Counting and Segmentation in 3D+Time Images of Vertebrate Early Embryogenesis
Authors: Rizzi Barbara , Sarti Alessandro
Published: October 2009

This paper is devoted to the segmentation of cell nuclei from time lapse confocal microscopy images, taken throughout early Zebrafish embryogenesis. The segmentation allows to identify and quantify the number of cells in the animal model. This kind of information is relevant to estimate important biological parameters such as the cell proliferation rate in time and space. Our approach is based on the active contour model without edges. We compare two different formulations of the model equation and evaluate their performances in segmenting nuclei of different shapes and sizes. Qualitative and quantitative comparisons are performed on both synthetic and real data, by means of suitable gold standard. The best approach is then applied on a number of time lapses for the segmentation and counting of cells during the development of a zebrafish embryo between the sphere and the shield stage.
Aberrant Methylation of RASSF1A in Plasma DNA Before Breast Cancer Diagnosis in the Breast Cancer Family Registry
Authors: Yazici Hulya , Terry Mary Beth , Cho Yoon Hee , Senie Ruby T. , Liao Yuyan , Andrulis Irene , Santella Regina M.
Published: October 2009

In addition to classic genetic mechanisms such as deletions and mutations, growth regulatory genes can be inactivated via methylation of cytosine-residues in their promoter regions. Hypermethylation of promoter CpG islands is now recognized as an important and early event in carcinogenesis. Detection of methylated DNA in serum or plasma has been suggested to be a marker for early cancer development. We examined methylation changes in RASSF1A, a growth regulatory gene in plasma DNA from blood collected before diagnosis from women with breast cancer and from controls. Samples were from two sets of subjects, 28 women with breast cancer and 10 of their unaffected siblings, and 33 women with breast cancer and 29 age- and ethnicity-matched population-based controls. Using methylation specific PCR, we found 11 of 61 (18%) cases were positive for methylation of RASSF1A in their plasma DNA collected before diagnosis. Two of 10 healthy high-risk sibling controls (20%) had plasma DNA positive for RASSF1A methylation in their plasma DNA compared with 0 of 29 (0%) population-based controls. Tumor tissue was available for 12 cases and all were positive for RASSF1A methylation. These results, if replicated, suggest that aberrant promoter hypermethylation in serum/plasma DNA may be common among high-risk women and may be present years before cancer diagnosis. (Cancer Epidemiol Biomarkers Prev 2009;18(10):2723–5)
Association of Area Socioeconomic Status and Breast, Cervical, and Colorectal Cancer Screening: A Systematic Review
Authors: Pruitt Sandi L. , Shim Matthew J. , Mullen Patricia Dolan , Vernon Sally W. , Amick Benjamin C.
Published: October 2009

Background: Although numerous studies have examined the association of area socioeconomic status (SES) and cancer screening after controlling for individual SES, findings have been inconsistent. A systematic review of existing studies is timely to identify conceptual and methodologic limitations and to provide a basis for future research directions and policy.

Objective: The objectives were to (a) describe the study designs, constructs, methods, and measures; (b) describe the independent association of area SES and cancer screening; and (c) identify neglected areas of research.

Methods: We searched six electronic databases and manually searched cited and citing articles. Eligible studies were published before 2008 in peer-reviewed journals in English, represented primary data on individuals ages ≥18 years from developed countries, and measured the association of area and individual SES with breast, cervical, or colorectal cancer screening.

Results: Of 19 eligible studies, most measured breast cancer screening. Studies varied widely in research design, definitions, and measures of SES, cancer screening behaviors, and covariates. Eight employed multilevel logistic regression, whereas the remainder analyzed data with standard single-level logistic regression. The majority measured one or two indicators of area and individual SES; common indicators at both levels were poverty, income, and education. There was no consistent pattern in the association between area SES and cancer screening.

Discussion: The gaps and conceptual and methodologic heterogeneity in the literature to date limit definitive conclusions about an underlying association between area SES and cancer screening. We identify five areas of research deserving greater attention in the literature. (Cancer Epidemiol Biomarkers Prev 2009;18(10):2579–99)
Cost-Effectiveness of Prophylactic Surgery for Duodenal Cancer in Familial Adenomatous Polyposis
Authors: Greenblatt Wesley H. , Hur Chin , Knudsen Amy B. , Evans John A. , Chung Daniel C. , Gazelle G. Scott
Published: October 2009

Background: Duodenal cancer is the leading cause of cancer death in familial adenomatous polyposis after colorectal cancer. The lifetime risk for developing duodenal cancer is 4% to 10%. Current treatment guidelines recommend endoscopic surveillance with a prophylactic pancreaticoduodenectomy in advanced duodenal polyposis, defined using the Spigelman staging system. Because no clinical trials have assessed this recommendation, a modeling approach was used to evaluate the cost-effectiveness of various treatment strategies.

Methods: A Markov model was constructed to estimate the life expectancy and cost of three different strategies: pancreaticoduodenectomy at Spigelman stage III, pancreaticoduodenectomy at Spigelman stage IV, and pancreaticoduodenectomy at cancer diagnosis. A cohort of 30-year-old familial adenomatous polyposis patients with total colectomies was simulated until age 80. The analysis was from a societal perspective. Extensive sensitivity analysis was performed to assess the impact of model uncertainty on results.

Results: At all stages of polyposis and all ages <80 years, prophylactic surgery at Spigelman stage IV resulted in the greatest life expectancy. Surgery at stage IV was more effective and more expensive than surgery at cancer diagnosis, with an incremental cost of $3,200 per quality-adjusted life year gained. Surgery at stage III was not a viable option. The results were robust to wide variation in model parameters but were sensitive to the post-pancreaticoduodenectomy quality of life score.

Conclusions: Prophylactic pancreaticoduodenectomy at stage IV duodenal polyposis in familial adenomatous polyposis is a cost-effective approach that results in greater life expectancy than surgery at either stage III or cancer diagnosis. (Cancer Epidemiol Biomarkers Prev 2009;18(10):2677–84)
Nicotinic Acetylcholine Receptor β2 Subunit (CHRNB2) Gene and Short-Term Ability to Quit Smoking in Response to Nicotine Patch
Authors: Perkins Kenneth A. , Lerman Caryn , Mercincavage Melissa , Fonte Carolyn A. , Briski Jessica L.
Published: October 2009

Genes coding for nicotinic acetylcholine receptors may influence response to nicotine replacement therapy for smoking cessation. We examined the association of a 3′ untranslated region polymorphism (rs2072661) in the nicotinic acetylcholine receptor β2 subunit (CHRNB2) gene with quitting success in response to nicotine versus placebo patch during a short-term test of patch effects. In a within-subjects cross-over design, smokers of European descent (n = 156) received 21 mg nicotine and placebo patch in counter-balanced order, during two separate 5-day simulated quit attempts, each preceded by a week of ad libitum smoking. Abstinence was assessed daily by CO < 5 ppm. Smokers with the CHRNB2 GG genotype had more days of abstinence during the nicotine versus placebo patch week compared with those with the AG or AA genotypes (P < 0.01). Moreover, nicotine patch increased the probability of quitting on the target quit day, quitting anytime during the patch week, and avoiding relapse among those with the GG genotype but not the AA/AG genotypes, although the nicotine × genotype interaction was significant only for quitting on the target quit day (P < 0.05). Regardless of patch condition, quitting on the target quit day was more likely in those with the GG genotype versus AA/AG genotypes (P < 0.05). Genetic associations were not observed for craving or withdrawal responses to nicotine versus placebo patch. These findings are consistent with previous evidence of association of this variant with smoking cessation and suggest that polymorphisms in the nicotinic acetylcholine receptor β2 subunit gene may influence therapeutic responsiveness to cessation medications. (Cancer Epidemiol Biomarkers Prev 2009;18(10):2608–12)
An Experimental Test of the Effect of Incentives on Recruitment of Ethnically Diverse Colorectal Cancer Cases and Their First-Degree Relatives into a Research Study
Authors: Maxwell Annette E. , Bastani Roshan , Glenn Beth A. , Mojica Cynthia M. , Chang L. Cindy
Published: October 2009

Background: Optimizing participant response rates is important for obtaining representative samples and the timely completion of studies. It is a common practice to use participant incentives to boost response rates, but few studies have systematically examined their effectiveness, particularly among minority groups.

Methods: We experimentally tested three incentive strategies for their effectiveness in improving response rates among colorectal cancer cases (n = 3,816) and their relatives (n = 2,353). A 2 × 2 × 2 factorial design compared (a) registered versus first class mail, (b) $5 cash with the initial mailing (yes/no), and (c) $20 promise (yes/no) upon completion of the information form (for cases) or $10 promise (yes/no) upon completion of the baseline survey (for relatives). Outcome measures were provision of contact information on first-degree relatives for cases and completion of the baseline survey for relatives.

Results: The response rate among cases was low in all ethnic groups (28-37%) and incentive strategies did not have an effect. Among relatives, the overall baseline survey response rate was 71%, ranging from 66% among Asians to 76% among Whites. Modest absolute increases were observed for payment schedules that included a $5 cash enclosure with the initial mailing in the total sample [odds ratio (OR), 1.65 and 1.47] and among Latinos (OR, 1.94 and 1.74) but not among Asians (OR, 1.61 and 1.55) or African Americans (OR, 1.19 and 1.02). Response rates were not influenced by registered versus first-class mailing.

Conclusion: The effects of incentives in this study were modest with some suggestion of differences by ethnic group and type of incentive. (Cancer Epidemiol Biomarkers Prev 2009;18(10):2620–5)
Medical Advances and Racial/Ethnic Disparities in Cancer Survival
Authors: Tehranifar Parisa , Neugut Alfred I. , Phelan Jo C. , Link Bruce G. , Liao Yuyan , Desai Manisha , Terry Mary Beth
Published: October 2009

Background: Although advances in early detection and treatment of cancer improve overall population survival, these advances may not benefit all population groups equally and may heighten racial/ethnic differences in survival.

Methods: We identified cancer cases in the Surveillance, Epidemiology and End Results program, who were ages ≥20 years and diagnosed with one invasive cancer in 1995 to 1999 (n = 580,225). We used 5-year relative survival rates to measure the degree to which mortality from each cancer is amenable to medical interventions (amenability index). We used Kaplan-Meier methods and Cox proportional hazards regression to estimate survival differences between each racial/ethnic minority group relative to Whites, by the overall amenability index, and three levels of amenability (nonamenable, partly amenable, and mostly amenable cancers, corresponding to cancers with 5-year relative survival rate <40%, 40-69%, and ≥70%, respectively), adjusting for gender, age, disease stage, and county-level poverty concentration.

Results: As amenability increased, racial/ethnic differences in cancer survival increased for African Americans, American Indians/Native Alaskans, and Hispanics relative to Whites. For example, the hazard ratios (95% confidence intervals) for African Americans versus Whites from nonamenable, partly amenable, and mostly amenable cancers were 1.05 (1.03-1.07), 1.38 (1.34-1.41), and 1.41 (1.37-1.46), respectively. Asians/Pacific Islanders had similar or longer survival relative to Whites across amenability levels; however, several subgroups experienced increasingly poorer survival with increasing amenability.

Conclusions: Cancer survival disparities for most racial/ethnic minority populations widen as cancers become more amenable to medical interventions. Efforts in developing cancer control measures must be coupled with specific strategies for reducing the expected disparities. (Cancer Epidemiol Biomarkers Prev 2009;18(10):2701–8)
The Association between Skin Characteristics and Skin Cancer Prevention Behaviors
Authors: Wheless Lee , Ruczinski Ingo , Alani Rhoda M. , Clipp Sandra , Hoffman-Bolton Judith , Jorgensen Timothy J. , Liégeois Nanette J. , Strickland Paul T. , Alberg Anthony J.
Published: October 2009

Background: Behaviors such as sunscreen use and wearing sun-protective clothing are thought to prevent certain types of skin cancer and precancerous lesions, but few studies have examined differences in these prevention behaviors by skin type.

Methods: We carried out a cross-sectional study (n = 6,858) nested within a community-based prospective cohort in Washington County, Maryland. We measured the associations between skin type, complexion, freckling, and eye color, and sunscreen and sun-protective clothing use.

Results: The prevalence of regular sunscreen use was 23% and regular sun-protective clothing use was 21%. There were consistent trends indicating those with the most sun-sensitive skin type were most likely to engage in prevention behaviors. For example, compared with those who tan without burning, those who develop blistering sunburns were more likely to use sunscreen [odds ratio (OR), 6.04; 95% confidence interval (95% CI), 2.82-12.95 men; OR, 4.89; 95% CI, 3.34-7.16 women] and sun-protective clothing (OR, 2.87; 95% CI, 1.71-4.80 men; OR, 4.44; 95% CI, 2.88-6.85 women). Health-related characteristics such as body mass index and cigarette smoking were also significantly inversely associated with prevention behaviors.

Conclusion: The overall prevalence of prevention behaviors was low. Those with phenotypic risk factors for skin cancer were most likely to use sunscreen and sun-protective clothing. Those with high-risk skin cancer phenotypes may also be those who are most receptive to skin cancer prevention educational interventions. (Cancer Epidemiol Biomarkers Prev 2009;18(10):2613–9)
Role of Inflammation Gene Polymorphisms on Pain Severity in Lung Cancer Patients
Authors: Reyes-Gibby Cielito C. , Spitz Margaret R. , Yennurajalingam Sriram , Swartz Michael , Gu Jian , Wu Xifeng , Bruera Eduardo , Shete Sanjay
Published: October 2009

Many of the same inflammatory factors that promote tumor growth are also hypothesized to function as pain modulators. There is substantial interindividual variation in pain severity in cancer patients. Therefore, we evaluated 59 single nucleotide polymorphisms in 37 inflammation genes in newly diagnosed non-Hispanic Caucasian lung cancer patients (n = 667) and assessed their association with pain severity. Patients rated their pain “during the past week” on an 11-point numeric scale (0 = “no pain” and 10 = “pain as bad as you can imagine”) at presentation before initiating cancer therapy. Reported analgesic use was abstracted from charts and converted to morphine equivalent daily dose. Results showed that 16% of the patients reported severe pain (score ≥7). Advanced stage of disease [odds ratio (OR), 2.34; 95% confidence interval (95% CI), 1.50-3.65; P = 0.001], age ≤50 years (OR, 2.10; 95% CI, 1.32-3.30; P = 0.002), reports of depressed mood (OR, 3.68; 95% CI, 1.96-6.93; P = 0.001), fatigue (OR, 3.72; 95% CI, 2.36-5.87; P = 0.001), and morphine equivalent daily dose (OR, 1.02; 95% CI, 1.01-1.03) were significantly correlated with severe pain. Controlling for these nongenetic covariates, we found that patients with CC genotypes for PTGS2 exon10+837T>C (rs5275) were at lower risk for severe pain (OR, 0.33; 95% CI, 0.11-0.97) and an additive model for TNFα −308GA (rs1800629; OR, 1.67; 95% CI, 1.08-2.58) and NFKBIA Ex6+50C>T (rs8904) was predictive of severe pain (OR, 0.64; 95% CI, 0.43-0.93). In a multigene analysis, we found a gene-dose effect, with each protective genotype reducing the risk for severe pain by as much as 38%. This study suggests the importance of inflammation gene polymorphisms in modulating pain severity. Additional studies are needed to validate our findings. (Cancer Epidemiol Biomarkers Prev 2009;18(10):2636–42)
Folate Status and Aberrant DNA Methylation Are Associated With HPV Infection and Cervical Pathogenesis
Authors: Flatley Janet E. , McNeir Kristelle , Balasubramani Latha , Tidy John , Stuart Emma L. , Young Tracey A. , Powers Hilary J.
Published: October 2009

Aberrant DNA methylation is a recognized feature of human cancers, and folate is directly involved in DNA methylation via one-carbon metabolism. Previous reports also suggest that folate status is associated with the natural history of human papillomavirus (HPV) infection. A cross-sectional study was conducted to test the hypothesis that folate status and aberrant DNA methylation show a progressive change across stages of cervical pathology from normal cells to cervical cancer. Additionally, we postulated that a gene-specific hypermethylation profile might be used as a predictive biomarker of cervical cancer risk. DNA hypermethylation of seven tumor suppressor genes, global DNA hypomethylation, systemic folate status, and HPV status were measured in 308 women with a diagnosis of normal cervix (n = 58), low-grade cervical intraepithelial neoplasia (CIN1; n = 68), high-grade cervical intraepithelial neoplasia (CIN2, n = 56; and CIN3, n = 76), or invasive cervical cancer (ICC; n = 50). Lower folate status was associated with high-risk HPV infection (P = 0.031) and with a diagnosis of cervical intraepithelial neoplasia or invasive cervical cancer (P < 0.05). Global DNA hypomethylation was greater in women with invasive cervical cancer than all other groups (P < 0.05). A cluster of three tumor suppressor genes, CDH1, DAPK, and HIC1, displayed a significantly increased frequency of promoter methylation with progressively more severe cervical neoplasia (P < 0.05). These findings are compatible with a role for folate in modulating the risk of cervical cancer, possibly through an influence over high-risk HPV infection. DAPK, CDH1, and HIC1 genes are potential biomarkers of cervical cancer risk. (Cancer Epidemiol Biomarkers Prev 2009;18(10):2782–9)
Evaluation of 11 Breast Cancer Susceptibility Loci in African-American Women
Authors: Zheng Wei , Cai Qiuyin , Signorello Lisa B. , Long Jirong , Hargreaves Margaret K. , Deming Sandra L. , Li Guoliang , Li Chun , Cui Yong , Blot William J.
Published: October 2009

Recent genome-wide association studies (GWAS) have identified multiple common genetic risk variants for breast cancer among women of Asian and European ancestry. Investigating these genetic susceptibility loci in other populations would be helpful to evaluate the generalizability of the findings and identify the causal variants for breast cancer. We evaluated 11 GWAS-identified genetic susceptibility loci for breast cancer in a study including 2,594 African-American women (810 cases and 1,784 controls). Two single-nucleotide polymorphisms, rs13387042 (2q35) and rs1219648 (FGFR2 gene), were found to be associated with breast cancer risk. Risk increased nearly linearly with the number of affected risk alleles, with a 2-fold elevated risk for women homozygous for the risk alleles in both single-nucleotide polymorphisms. No additional significant associations, however, were identified for the other nine loci evaluated in the study. The results from this study extend some of the recent GWAS findings to African-Americans and may guide future efforts to identify the causal variants for breast cancer. (Cancer Epidemiol Biomarkers Prev 2009;18(10):2761–4)
No Risk of Maternal EBV Infection for Childhood Leukemia
Authors: Tedeschi Rosamaria , Luostarinen Tapio , Marus Alessia , Bzhalava Davit , Ögmundsdottir Helga M. , Dillner Joakim , De Paoli Paolo , Surcel Heljä-Marja , Pukkala Eero , Lehtinen Matti , Lehtinen Tuula
Published: October 2009

We performed a large nested case-control study within the Finnish and Icelandic maternity cohorts to verify/falsify the association of maternal EBV infection with an increased risk of acute lymphoblastic leukemia (ALL) in the offspring found in previous studies. All hematologic malignancies diagnosed among children born during 1983 to 2006 in Finland and 1997 to 2005 in Iceland were identified through national cancer registries. For each index mother of a leukemia case, three matched control mothers with cancer-free offspring were identified. First trimester sera from 561 ALL and 144 non-ALL index mothers and from 2,105 control mothers were analyzed for antibodies to EBV viral capsid antigen (IgG and IgM), early antigen (IgG) and ZEBRA protein (IgG). Conditional logistic regression-based estimates of odds ratios and 95% confidence intervals adjusted for birth order and sib-ship size were calculated. Overall, there was no evidence of increased risk of ALL associated to EBV viral capsid antigen IgM (odds ratio, 0.9; 95% confidence interval, 0.5-1.8). The early antigen and ZEBRA antibodies (EBV reactivation markers) were also not associated with risk. The data argue against a role of EBV in ALL. (Cancer Epidemiol Biomarkers Prev 2009;18(10):2790–2)
Human Studies of Angiogenic Gene Therapy
Authors: Gupta Rajesh , Tongers Jörn , Losordo Douglas W.
Published: October 2009

Abstract
:

Despite significant advances in medical, interventional, and surgical therapy for coronary and peripheral arterial disease, the burden of these illnesses remains high. To address this unmet need, the science of therapeutic angiogenesis has been evolving for almost two decades. Early preclinical studies and phase I clinical trials achieved promising results with growth factors administered as recombinant proteins or as single-agent gene therapies, and data accumulated through 10 years of clinical trials indicate that gene therapy has an acceptable safety profile. However, more rigorous phase II and phase III clinical trials have failed to unequivocally demonstrate that angiogenic agents are beneficial under the conditions and in the patients studied to date. Investigators have worked to understand the biology of the vascular system and to incorporate their findings into new treatments for patients with ischemic disease. Recent gene- and cell-therapy trials have demonstrated the bioactivity of several new agents and treatment strategies. Collectively, these observations have renewed interest in the mechanisms of angiogenesis and deepened our understanding of the complexity of vascular regeneration. Gene therapy that incorporates multiple growth factors, approaches that combine cell and gene therapy, and the administration of “master switch” agents that activate numerous downstream pathways are among the credible and plausible steps forward. In this review, we examine the clinical development of angiogenic gene therapy, summarize several of the lessons learned during the conduct of these trials, and suggest how this prior experience may guide the conduct of future preclinical investigations and clinical trials.
Male salamanders remember individuals based on chemical or visual cues
Authors: Kohn Nancy , Jaeger Robert
Published: October 2009

The use of multiple cues can enhance the detection, recognition, discrimination, and memorability of individuals by receivers. We conducted two experiments, using only males, to test whether territorial red-backed salamanders, Plethodon cinereus, could use only chemical or only visual cues to remember familiar conspecifics. In both experiments, focal males spent significantly more time threatening unfamiliar than familiar male intruders. They also chemoinvestigated the filter paper containing chemical cues of unfamiliar intruders more often than that of familiar intruders. These results suggest that red-backed salamanders can use both chemical and visual cues to recognize familiar individuals, allowing them to distinguish between less threatening neighbours and more threatening intruders in the heterogeneous forest floor habitat, where visual cues alone would not always be available.
The reproductive status of both sexes affects the frequency of mating and the reproductive success of males in the ball roller beetle Canthon cyanellus cyanellus (Coleoptera: Scarabaeidae)
Authors: Favila Mario , Chamorro-Florescano Ivette
Published: October 2009

Several studies have shown that males assess female reproductive status and use different mechanisms to increase their reproductive success. However, a male's reproductive status can also affect its own reproductive success. In Canthon cyanellus cyanellus, a male–female pair makes several brood balls during nesting and both care for the brood balls. However, in females that are transported to the nest by males, the spermatheca is often already filled with viable sperm from other males, such that sperm competition is strong. We analyze the effect of the reproductive status of males and females on the frequency of mating during brood ball construction, as well as the reproductive success of males that nest with previously mated females. Virgin and previously mated males copulated with the same frequency before the construction of each brood ball when they nested with virgin females. However, when both types of males nested with previously mated females, the frequency of mating increased before the construction of the first brood ball. The paternity of previously mated males was significantly higher (82%) than that of virgin males (62%). Therefore, the reproductive status of both sexes of C. c. cyanellus affects the frequency of mating and the reproductive success of males.
Using a behaviour discovery curve to predict optimal observation time
Authors: Lea Stephen , Leaver Lisa , Jule Kristen
Published: October 2009

Behavioural observations are vital to furthering our knowledge of species' ecology. Determining a method for formalising the length of behavioural observation time (coined Behaviour Discovery Curve) is practical for both reducing disturbance to the animals observed and limiting costs to the researcher. This paper suggests a method of calculating behaviour discovery curves, which allows researchers to estimate the optimal amount of data to collect when establishing an ethogram. The curve is fitted to a logarithmic model that predicts the rate of new behaviours that will be observed in any given length of observation time. To illustrate the methods, 31 captive red pandas (Ailurus fulgens fulgens) were observed for 30 h each and a behaviour discovery curve was estimated for each animal based on the rate at which new behaviours were observed. We demonstrate how to use the curve in the evaluation of an ethogram, whilst also providing an indication of how many more behaviours would be observed in a specified longer observation period. This is an important consideration in the creation of any ethogram, since there are currently no standard methodologies for establishing ethograms, and no guidelines on how much data is 'sufficient' for determining a species' behavioural repertoire. The curve does not allow an estimate of the total size of the behavioural repertoire, but does allow a systematic analysis of the likely costs and benefits of further observation. We also suggest a method for quantifying the degree of idiosyncrasy of a population.
Innovation in groups: does the proximity of others facilitate or inhibit performance?
Authors: Morand-Ferron Julie , Overington Sarah , Cauchard Laure , Lefebvre Louis
Published: October 2009

Foraging innovation, in which an individual eats a novel food or uses a novel foraging technique, has been observed in a wide range of species. If other individuals are nearby, they may adopt the innovation, thus spreading it through the population. Much research has focused on this social transmission of behaviour, but the effect of social context on the emergence of novel behaviour is unclear. Here, we examine the effect of social context on innovative feeding behaviour in the Carib grackle (Quiscalus lugubris), an opportunistic, gregarious bird. We test the effect of the proximity of conspecifics, while eliminating the direct effects of interference, scrounging, or aggression. Using a repeated-measures design, we found that birds took significantly longer to contact novel foraging tasks when in the presence of others vs. alone, and during playbacks of alarm calls vs. a control sound. Further, performance of a food-processing behaviour decreased when birds were with others, and individuals adjusted their behaviour depending on their distance from conspecifics. Our results suggest that feeding in groups may slow down or inhibit innovative foraging behaviour in this species. We discuss the implications of a trade-off between feeding in groups and taking advantage of new feeding opportunities.
Behavioural responses to alarm cues by free-ranging rainbow darters (Etheostoma caeruleum)
Authors: Woods  , Mathis  , Crane
Published: October 2009

Responses of fishes to chemical alarm cues have been well-documented in the laboratory, but relatively few taxa have been tested under free-ranging conditions in natural habitats. While snorkeling in a stream, we exposed rainbow darters (Etheostoma caeruleum) to skin extracts from conspecifics (alarm cue), skin extracts from heterospecifics (no alarm cue) and a blank control. Darters showed a significantly longer latency to move ('freezing') in the presence of the alarm cue relative to the other two stimuli. These results indicate that rainbow darters can detect chemical alarm cues under natural conditions and respond with appropriate antipredator behaviour.
An Assessment of the Surface Longwave Direct Radiative Effect of Airborne Saharan Dust during the NAMMA Field Campaign
Authors: Hansell R. A. , Tsay S. C. , Ji Q. , Hsu N. C. , Jeong M. J. , Wang S. H. , Reid J. S. , Liou K. N. , Ou S. C.
Published: October 2009

In September 2006, NASA Goddard’s mobile ground-based laboratories were deployed to Sal Island in Cape Verde (16.73°N, 22.93°W) to support the NASA African Monsoon Multidisciplinary Analysis (NAMMA) field study. The Atmospheric Emitted Radiance Interferometer (AERI), a key instrument for spectrally characterizing the thermal IR, was used to retrieve the dust IR aerosol optical depths (AOTs) in order to examine the diurnal variability of airborne dust with emphasis on three separate dust events. AERI retrievals of dust AOT are compared with those from the coincident/collocated multifilter rotating shadowband radiometer (MFRSR), micropulse lidar (MPL), and NASA Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) sensors. The retrieved AOTs are then inputted into the Fu–Liou 1D radiative transfer model to evaluate local instantaneous direct longwave radiative effects (DRELW) of dust at the surface in cloud-free atmospheres and its sensitivity to dust microphysical parameters. The top-of-atmosphere DRELW and longwave heating rate profiles are also evaluated. Instantaneous surface DRELW ranges from 2 to 10 W m−2 and exhibits a strong linear dependence with dust AOT yielding a DRELW of 16 W m−2 per unit dust AOT. The DRELW is estimated to be ∼42% of the diurnally averaged direct shortwave radiative effect at the surface but of opposite sign, partly compensating for the shortwave losses. Certainly nonnegligible, the authors conclude that DRELW can significantly impact the atmospheric energetics, representing an important component in the study of regional climate variation.
Regional Aspects of Prolonged Meteorological Droughts over Mexico and Central America
Authors: Méndez Matías , Magaña Víctor
Published: October 2009

Major prolonged droughts in Mexico during the twentieth century are mainly related to anomalous dry summers, such as those observed in the 1930s, the 1950s, or the 1990s. Droughts in northern Mexico frequently coincide with anomalously wet conditions over Mesoamerica (i.e., southern Mexico and Central America), and vice versa, displaying a dominant “seesaw” structure in persistent precipitation anomalies, mostly in relation to tropical sea surface temperature (SST) anomalies. A warmer North Atlantic Ocean, expressed as a positive phase of Atlantic multidecadal oscillation (AMO), is related to the occurrence of major droughts in North America associated with weaker-than-normal moisture flux into northern Mexico. Drought over northern Mexico may also be related to changes in transient activity in the Caribbean Sea. During the negative phase of the Pacific decadal oscillation (PDO), the Caribbean low-level jet (CLLJ) weakens and easterly wave (EW) activity increases, leading to more tropical convection over Mesoamerica and less moisture flux into northern Mexico. On the other hand, when EW activity is weak over the intra-Americas seas (IAS) (i.e., the Gulf of Mexico and the Caribbean Sea) because of a stronger-than-normal CLLJ, precipitation increases over northern Mexico. Therefore, the interaction between easterly waves and the trade winds over the IAS appears to be crucial to explain the spatial patterns of droughts that have affected Mexico. In addition, low-frequency modulators, such as AMO or PDO, may serve to explain the spatial patterns of severe prolonged droughts in Mexico during the nineteenth century.
Influence of the Icelandic Low on the Variability of Surface Air Temperature in the Gulf of Lion: Implications for Intermediate Water Formation
Authors: Jordi Antoni , Hameed Sultan
Published: October 2009

The authors investigate the interannual variability of surface air temperature in the Gulf of Lion (northwestern Mediterranean Sea) during the winter season, which has been proposed as the dominant factor for the Mediterranean Intermediate Water (WIW) formation. Recent studies suggest that the variability of WIW formation in the Gulf of Lion can be partially explained by the North Atlantic Oscillation. To examine this process in more detail, the authors separate the North Atlantic Oscillation into two centers of action, the Azores high and the Icelandic low. This approach reveals that the pressure of the Icelandic low controls the surface air temperature in the Gulf of Lion, and the influence of the Azores high is insignificant. It is found that the winds over Europe are predominately northerly during winters with high pressure values of the Icelandic low. These conditions also correspond to colder air temperatures in the Gulf of Lion, which have been proposed previously to be correlated with ocean convection to intermediate depths.
Diagnosis of Extended Cold-Season Temperature Anomalies in Alaska
Authors: Shulski Martha , Walsh John , Stevens Eric , Thoman Richard
Published: October 2009

During the early winter of 2002 and late winter of 2007, the Alaskan sector of the North Pacific Ocean region experienced record-breaking temperature anomalies. The duration of these episodes was unusually long, with each lasting more than 1 month: 55 days for the warm anomaly of October–December 2002 and 37 days for the cold anomaly of February–March 2007. Temperature departures over each respective period were the largest for the continental climate of interior Alaska (>10°C) and the smallest for the maritime regions of Alaska (<4°C). Mean temperatures over the event periods in 2002 and 2007 easily ranked as the record warmest and coldest, respectively, for many surface observing stations. In addition, heating degree-day anomalies were on the order of 700 units for these periods. Atmospheric circulation patterns at the surface and upper levels for the circum-Arctic proved to be the driver for these persistent events. The 2002 warm anomaly was driven by enhanced southerly advection associated with an unusually strong Aleutian low and a positive Pacific decadal oscillation index, which resulted in a large area of anomalous temperatures in Alaska and northern Canada. The 2007 cold anomaly was driven by a weakening of the circulation pattern in the subpolar Pacific sector and a strengthening of the Siberian high, with the strongest temperature anomalies in Alaska and northwestern Canada.
Learning Teaching in, from, and for Practice: What Do We Mean?
Authors: Lampert Magdalene
Published: October 2009

In talk about teacher preparation and professional development, we often hear the word practice associated with what, how, or when the learning of teaching is supposed to happen. In this article, four different conceptions of practice are investigated, and their implications for how learning teaching might be organized are explored. Rather than a comprehensive review of the literature, what is presented here is a set of ideas that draw on both past and present efforts at reform. The purpose of this essay is to provoke clarification of what we mean when we talk about practice in relation to learning teaching. The author draws on her own research on the work of teaching from the perspective of practice to represent the nature of the work and to speculate from various perspectives on how that work might be learned.
What Does Teacher Education Have to Do With Teaching? Implications for Diversity Studies
Authors: Milner H. Richard
Published: October 2009

Several concepts that are important for inclusion in any teacher education curriculum regarding diversity studies are elucidated in this article. The framing question of the discussion is: What are some relevant conceptions regarding issues of diversity that every teacher education program should consider including in its curriculum? The author outlines important concepts that contribute to what he calls teachers’ conceptual repertoires of diversity. The concepts are: color-blindness, cultural conflict, meritocracy, deficit conceptions, and expectations. The idea is that when teachers enter teacher education, their conceptions—their mindset, thinking, belief systems, attitudes, and overall understanding of the teaching and learning exchange—need to be addressed because these conceptions shape their curricula and instructional practices with P-12 students. The author is not suggesting that the five conceptual repertoires of diversity presented in this article are exhaustive; based on research, the list represents some areas that seem important for teachers’ building repertoires to teach culturally diverse students successfully. The author concludes with a call to action for teacher educators and teacher education.
Lifting Off the Ground to Return Anew: Mediated Praxis, Transformative Learning, and Social Design Experiments
Authors: Gutiérrez Kris D. , Vossoughi Shirin
Published: October 2009

This article examines a praxis model of teacher education and advances a new method for engaging novice teachers in reflective practice and robust teacher learning. Social design experiments—cultural historical formations designed to promote transformative learning for adults and children—are organized around expansive notions of learning and mediated praxis and provide new tools and practices for envisioning new pedagogical arrangements, especially for students from nondominant communities. The authors examine one long-standing social design experiment, the UCLA UC Links/ Las Redes partnership and the work of one exemplary novice teacher to illustrate the importance of mediated, reflective practices in helping apprentice teachers develop a coherent and orienting framework for teaching and learning that has both heuristic and explanatory power. The authors illustrate how cultural historical concepts of learning and development and situated practice become the means for university students to gain distance and reflect on the beliefs and practices that have informed their understandings of teaching and to “rise to the concrete” practices of learning jointly and resonantly.
Lost in Transition: A Critical Analysis of Power Transition Theory
Authors: Lebow Richard Ned , Valentino Benjamin
Published: October 2009

In this paper we identify and critique the key propositions of power transition theory. We find little support for any of power transition theory’s main empirical implications. Contrary to most versions of the theory, we fin d that the European and international systems almost never have been characterized by hegemony. No state has achieved a position that allowed it for any extended period to order the international system to suit its interests at the expense of the other major powers. Power transitions are remarkably rare, they seldom occur as the result of differential rates of economic growth, and have most often occurred peacefully. Power transitions are more often the results of wars, rather than the causes of them. Wars between rising and dominant powers are infrequent and are not waged by either side primarily in the effort to defend or revise the international order in their favor. Finally, we find that war rarely resolves the fundamental conflicts of interest caused by power transitions.
Waltz, Realism and Democracy
Authors: Williams Michael C.
Published: October 2009

Waltz is generally seen as one the most important advocates of a systemic theory of international politics that stresses the importance of international anarchy and marginalizes domestic politics. Locating Waltz’s thinking against debates within realism in the 1950s, and drawing especially on his neglected Foreign Policy and Democratic Politics, this article argues that Waltz’s thinking actually contains powerful domestic political dimensions that centre on a defence of democratic foreign policymaking. Rather than marginalizing domestic politics, Waltz’s theory — and his critique of classical realism — is in part actually a subtle intervention in domestic politics.
Hegemony, Equilibrium and Counterpower: A Synthetic Approach
Authors: Beyer Cornelia
Published: October 2009

This article claims that realist and constructivist ideas are compatible. Structural realism is needed to understand the constraining and stabilizing role of material factors. Furthermore, it detects process in a law-like tendency towards international power equilibrium which is achieved via balancing. Constructivism, in turn, highlights the importance of ideas and norms as engines for change and the creative role of agency. The article therefore combines a materialist and an idealist perspective. It both detects elements of stability and argues for necessary improvements in current international relations (IR) by looking at the issues of United States hegemony, the rise of new challengers and the threat of sub-state international terrorism. This article, therefore, takes up important claims made by Kenneth Waltz on realism, hegemony and terrorism, and interprets them in the light of IR theory today. It is argued that structural realism and Waltz’s ideas are still important and viable, but that we need to combine them with additional perspectives, notably constructivism.
Transformational Leadership in Distributed Work Groups: The Moderating Role of Follower Regulatory Focus and Goal Orientation
Authors: Whitford Tarli , Moss Simon A.
Published: October 2009

This study addressed the question of whether the benefits of transformational leadership extend to virtual environments. Furthermore, whether regulatory focus or goal orientation moderate the extent to which these benefits apply to virtual environments was also explored. A total of 165 employees completed a survey that assessed the leadership style of their supervisors as well their own regulatory focus, goal orientation, work engagement, and job satisfaction. When followers and leaders worked at different locations, visionary leadership was positively related to work attitudes, provided that promotion focus was sufficiently high or prevention focus was sufficiently low. Furthermore, when followers and leaders worked in the same location, personal recognition was positively associated with work engagement, especially if prevention focus or performance goal orientation was high. These findings align with the proposition, derived from construal level theory, that leadership advice and support in which only the essence needs to be extracted apply to virtual environments.