bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of Two Methods for Estimating Absolute Risk of Prostate Cancer Based on Single Nucleotide Polymorphisms and Family History
Authors: Hsu Fang-Chi , Sun Jielin , Zhu Yi , Kim Seong-Tae , Jin Tao , Zhang Zheng , Wiklund Fredrik , Kader A. Karim , Zheng S. Lilly , Isaacs William , Grönberg Henrik , Xu Jianfeng
Published: April 2010

Disease risk–associated single nucleotide polymorphisms (SNP) identified from genome-wide association studies have the potential to be used for disease risk prediction. An important feature of these risk-associated SNPs is their weak individual effect but stronger cumulative effect on disease risk. Several approaches are commonly used to model the combined effect in risk prediction, but their performance is unclear. We compared two methods to model the combined effect of 14 prostate cancer risk–associated SNPs and family history for the estimation of absolute risk for prostate cancer in a population-based case-control study in Sweden (2,899 cases and 1,722 controls). Method 1 weighs each risk allele equally using a simple method of counting the number of risk alleles, whereas method 2 weighs each risk SNP differently based on its odds ratio. We found considerable differences between the two methods. Absolute risk estimates from method 1 were generally higher than those of method 2, especially among men at higher risk. The difference in the overall discriminative performance, measured by area under the curve of the receiver operating characteristic, was small between method 1 (0.614) and method 2 (0.618), P = 0.20. However, the performance of these two methods in identifying high-risk individuals (2- or 3-fold higher than average risk), measured by positive predictive values, was higher for method 2 than for method 1. These results suggest that method 2 is superior to method 1 in estimating absolute risk if the purpose of risk prediction is to identify high-risk individuals. Cancer Epidemiol Biomarkers Prev; 19(4); 1083–8. ©2010 AACR.
Standards Affecting the Consistency of Gene Expression Arrays in Clinical Applications
Authors: Enkemann Steven A.
Published: April 2010

The use of microarray technology to measure gene expression has created optimism for the feasibility of using molecular assessments of tumors routinely in the clinical management of cancer. Gene expression arrays have been pioneers in the development of standards; both for research use and now for clinical application. Some of the existing standards have been driven by the early perception that microarray technology was inconsistent and perhaps unreliable. More recent experimentation has shown that reproducible data can be achieved and clinical standards are beginning to emerge. For the transcriptional assessment of tumors, this means a system that correctly samples a tumor, isolates RNA and processes this for microarray analysis, evaluates the data, and communicates findings in a consistent and timely fashion. The most important standard is to show that a clinically important assessment can be made with microarray data. The standards emerging from work on various parts of the entire process could guide the development of a workable system. However, the final standard for each component of the process depends on the accuracy required when the assay becomes part of the clinical routine: a routine that now includes the molecular evaluation of tumors. Cancer Epidemiol Biomarkers Prev; 19(4); 1000–3. ©2010 AACR.
Intra-Person Variation of Urinary Biomarkers of Oxidative Stress and Inflammation
Authors: Wu Xiaoyan , Cai Hui , Xiang Yong-Bing , Cai Qiuyin , Yang Gong , Liu Dake , Sanchez Stephanie , Zheng Wei , Milne Ginger , Shu Xiao-Ou
Published: April 2010

Background: Oxidative stress and inflammation have been linked to many chronic diseases including cancer and cardiovascular diseases. Urinary levels of F2-isoprostanes (F2-IsoPs), 2,3-dinor-5,6-dihydro-15-F2t-IsoP (15-F2t-IsoP-M), a major metabolite of F2-IsoPs, prostaglandin E2 metabolite (PGE-M), and leukotriene E4 (LTE4) have been proposed as biomarkers for oxidative stress and inflammation. However, little information is available regarding the intra-person variation of these biomarkers, hindering their application in epidemiologic studies.

Methods: We evaluated the intra-person variation of these four urinary biomarkers among 48 randomly chosen participants of a validation study of a population-based cohort, the Shanghai Men's Health Study. Four spot urine samples, collected during each season over a 1-year period, were measured for these biomarkers.

Results: The intraclass correlation coefficients for F2-IsoPs, 15-F2t-IsoP-M, PGE-M, and LTE4 were 0.69, 0.76, 0.67, and 0.64, respectively. The Spearman correlation coefficients, derived by using bootstrap analysis of single spot measurements and the average of the other three seasonal measurements, were 0.47, 0.60, 0.61, and 0.57 for F2-IsoPs, 15-F2t-IsoP-M, PGE-M, and LTE4. Except for high correlations between F2-IsoPs and 15-F2t-IsoP-M (r = 0.65), the other biomarkers were moderately correlated (r = 0.21-0.44).

Conclusions: Our study results suggest that these four urinary biomarkers have relatively low intra-person variation over a 1-year period.

Impact: Spot measurements of F2-IsoPs, 15-F2t-IsoP-M, PGE-M, and LTE4 could be useful as biomarkers of oxidative stress and inflammation status for epidemiologic studies. Cancer Epidemiol Biomarkers Prev; 19(4); 947–52. ©2010 AACR.
Molecular Pathology in Epidemiologic Studies: A Primer on Key Considerations
Authors: Sherman Mark E. , Howatt Will , Blows Fiona M. , Pharoah Paul , Hewitt Stephen M. , Garcia-Closas Montserrat
Published: April 2010

The development of molecular pathologic components in epidemiologic studies offers opportunities to relate etiologic factors to specific tumor types, which in turn may allow the development of better overall risk prediction and provide clues about mechanisms that mediate risk factors. In addition, this research may help identify or validate tissue biomarkers related to prognosis and prediction of treatment responses. In this mini review, we highlight specific considerations related to the incorporation of pathology in epidemiologic studies, using breast cancer research as a model. Issues related to ensuring the representativeness of cases for which research tissue is available and understanding limitations resulting from variable procedures for tissue collection, fixation, and processing are discussed. The growing importance of molecular pathology in clinical medicine has led to increased emphasis on optimized tissue preparation, which should enhance this type of research. In addition, the availability of new technologies including tissue microarrays, image scanning, and automated analysis to achieve high-throughput standardized assessment of immunohistochemical markers, and potentially other assays, is enabling consistent scoring of a growing list of markers in large studies. Concurrently, methodologic research to extend the range of assays that can be done on fixed tissues is expanding possibilities for molecular pathologic studies in epidemiologic research. Cancer Epidemiol Biomarkers Prev; 19(4); 966–72. ©2010 AACR.
International Efforts to Develop Biospecimen Best Practices
Authors: Vaught Jimmie B. , Caboux Elodie , Hainaut Pierre
Published: April 2010

Variables introduced during the processes involved in biospecimen collection, processing, storage, and analysis are among the potential sources of bias in biomarker research. International efforts are under way to develop best practices to standardize biospecimen handling protocols. In general, documents on best practices address three major recurring themes: technical best practices on infrastructure and specimen handling, recommendations on informatics and data management, and recommendations on ethical, legal, and social issues. There are many areas of agreement among various international efforts, but no single set of practices has emerged as a unifying document. The ethical, legal, and social issues are particularly difficult to harmonize due to the many country-specific issues that are governed by a variety of local and federal rules and regulations. Given the increasingly international nature of research involving biomarkers and biospecimens, it will be necessary to continue to cooperate in the development of harmonized evidence-based best practices. Several international organizations including the International Cancer Genome Consortium are engaged in such efforts. Cancer Epidemiol Biomarkers Prev; 19(4); 912–5. ©2010 AACR.
The Organization of European Cancer Institute Pathobiology Working Group and its Support of European Biobanking Infrastructures for Translational Cancer Research
Authors: Riegman Peter H.J. , de Jong Bas W.D. , Llombart-Bosch Antonio
Published: April 2010

Background: Today's translational cancer research increasingly depends on international multi-center studies. Biobanking infrastructure or comprehensive sample exchange platforms to enable networking of clinical cancer biobanks are instrumental to facilitate communication, uniform sample quality, and rules for exchange.

Methods: The Organization of European Cancer Institutes (OECI) Pathobiology Working Group supports European biobanking infrastructure by maintaining the OECI-TuBaFrost exchange platform and organizing regular meetings. This platform originated from a European Commission project and is updated with knowledge from ongoing and new biobanking projects. This overview describes how European biobanking projects that have a large impact on clinical biobanking, including EuroBoNeT, SPIDIA, and BBMRI, contribute to the update of the OECI-TuBaFrost exchange platform.

Results: Combining the results of these European projects enabled the creation of an open (upon valid registration only) catalogue view of cancer biobanks and their available samples to initiate research projects. In addition, closed environments supporting active projects could be developed together with the latest views on quality, access rules, ethics, and law.

Conclusions: With these contributions, the OECI Pathobiology Working Group contributes to and stimulates a professional attitude within biobanks at the European comprehensive cancer centers.

Impact: Improving the fundamentals of cancer sample exchange in Europe stimulates the performance of large multi-center studies, resulting in experiments with the desired statistical significance outcome. With this approach, future innovation in cancer patient care can be realized faster and more reliably. Cancer Epidemiol Biomarkers Prev; 19(4); 923–6. ©2010 AACR.
Establishment and Operation of a Biorepository for Molecular Epidemiologic Studies in Costa Rica
Authors: Cortés Bernal , Schiffman Mark , Herrero Rolando , Hildesheim Allan , Jiménez Silvia , Shea Katheryn , González Paula , Porras Carolina , Fallas Greivin , Rodríguez Ana Cecilia
Published: April 2010

Background: The Proyecto Epidemiológico Guanacaste (PEG) has conducted several large studies related to human papillomavirus (HPV) and cervical cancer in Guanacaste, Costa Rica in a long-standing collaboration with the U.S. National Cancer Institute. To improve molecular epidemiology efforts and save costs, we have gradually transferred technology to Costa Rica, culminating in state-of-the-art laboratories and a biorepository to support a phase III clinical trial investigating the efficacy of HPV 16/18 vaccine.

Objective: Here, we describe the rationale and lessons learned in transferring molecular epidemiologic and biorepository technology to a developing country.

Results: At the outset of the PEG in the early 1990s, we shipped all specimens to repositories and laboratories in the United States, which created multiple problems. Since then, by intensive personal interactions between experts from the United States and Costa Rica, we have successfully transferred liquid-based cytology, HPV DNA testing and serology, chlamydia and gonorrhea testing, PCR-safe tissue processing, and viable cryopreservation. To accommodate the vaccine trial, a state-of-the-art repository opened in mid-2004. Approximately 15,000 to 50,000 samples are housed in the repository on any given day, and >500,000 specimens have been shipped, many using a custom-made dry shipper that permits exporting >20,000 specimens at a time. Quality control of shipments received by the NCI biorepository has revealed an error rate of <0.2%. Recently, the PEG repository has incorporated other activities; for example, large-scale aliquotting and long-term, cost-efficient storage of frozen specimens returned from the United States. Using Internet-based specimen tracking software has proven to be efficient even across borders.

Conclusion: For long-standing collaborations, it makes sense to transfer the molecular epidemiology expertise toward the source of specimens. The successes of the PEG molecular epidemiology laboratories and biorepository prove that the physical and informatics infrastructures of a modern biorepository can be transferred to a resource-limited and weather-challenged region. Technology transfer is an important and feasible goal of international collaborations. Cancer Epidemiol Biomarkers Prev; 19(4); 916–22. ©2010 AACR.
Urine Collection and Processing for Protein Biomarker Discovery and Quantification
Authors: Thomas C. Eric , Sexton Wade , Benson Kaaron , Sutphen Rebecca , Koomen John
Published: April 2010

Background: Urine is a useful source of protein for biomarker discovery and assessment because it is readily available, can be obtained by noninvasive collection methods, and enables monitoring of a wide range of physiologic processes and diseases. Urine aliquots provide enough protein for multiple analyses, combining current protocols with new techniques.

Conclusions: Standardized collection and processing protocols are now being established and new methods for protein detection and quantification are emerging to complement traditional immunoassays. The current state of urine collection, specimen processing, and storage is reviewed with regard to discovery and quantification of protein biomarkers for cancer. Cancer Epidemiol Biomarkers Prev; 19(4); 953–9. ©2010 AACR.
A Genome-Wide Association Study of Prognosis in Breast Cancer
Authors: Azzato Elizabeth M. , Pharoah Paul D.P. , Harrington Patricia , Easton Douglas F. , Greenberg David , Caporaso Neil E. , Chanock Stephen J. , Hoover Robert N. , Thomas Gilles , Hunter David J. , Kraft Peter
Published: April 2010

Background: Traditional clinicopathologic features of breast cancer do not account for all the variation in survival. Germline genetic variation may provide additional prognostic information.

Materials and Methods: We conducted a genome-wide association study of survival after a diagnosis of breast cancer by obtaining follow-up data and genotyping information on 528,252 single-nucleotide polymorphisms for 1,145 postmenopausal women with invasive breast cancer (7,711 person-years at risk) from the Nurses' Health Study scanned in the Cancer Genetic Markers of Susceptibility initiative. We genotyped the 10 most statistically significant loci (most significant single-nucleotide polymorphism located in ARHGAP10; P = 2.28 × 10−7) in 4,335 women diagnosed with invasive breast cancer (38,148 years at risk) in the SEARCH (Studies of Epidemiology and Risk factors in Cancer Heredity) breast cancer study.

Results: None of the loci replicated in the SEARCH study (all P > 0.10). Assuming a minimum of 10 associated loci, the power to detect at least one with a minor allele frequency of 0.2 conferring a relative hazard of 2.0 at genome-wide significance (P = 5 × 10−8) was 99%.

Conclusion: We did not identify any common germline variants associated with breast cancer survival overall.

Impact: Our data suggest that it is unlikely that there are common germline variants with large effect sizes for breast cancer survival overall (hazard ratio >2). Instead, it is plausible that common variants associated with survival could be specific to tumor subtypes or treatment approaches. New studies, sufficiently powered, are needed to discover new regions associated with survival overall or by subtype or treatment subgroups. Cancer Epidemiol Biomarkers Prev; 19(4); 1140–3. ©2010 AACR.
Simultaneous Recovery of DNA and RNA from Formalin-Fixed Paraffin-Embedded Tissue and Application in Epidemiologic Studies
Authors: Huang Wen-Yi , Sheehy Timothy M. , Moore Lee E. , Hsing Ann W. , Purdue Mark P.
Published: April 2010

Analysis of DNA, RNA, and protein extracted from tissue specimens in epidemiologic studies is useful for assessing etiologic heterogeneity, mechanisms of carcinogenesis, and biomarkers for prognosis and prediction of treatment responses. Fresh-frozen tissue samples may provide optimal quality nucleic acids, but pose multiple logistical considerations, including rapid access to tissues before histopathologic examination and specialized equipment for freezing, transport, and storage; in addition, morphology is often compromised. In contrast, formalin-fixed paraffin-embedded (FFPE) tissue samples, including enormous archives of existing specimens, represent a valuable source of retrospective biological material for epidemiologic research, although presenting different limitations compared with frozen samples. Recent efforts have made progress toward enhancing the utility of FFPE specimens for molecular analyses, including DNA studies, and increasingly for RNA and other macromolecules. Here, we report the method that we used to simultaneously recover DNA and RNA from FFPE tissue specimens with appreciable quantity and quality and discuss briefly the application of tumor markers in epidemiologic studies. Cancer Epidemiol Biomarkers Prev; 19(4); 973–7. ©2010 AACR.
Factors Affecting Survival of Patients with Neurodegenerative Disease
Authors: Steenland Kyle , MacNeil Jessica , Seals Ryan , Levey Allan
Published: April 2010

Background: Survival varies widely among different neurodegenerative diseases. Data on the role of the Mini Mental State Examination (MMSE) and apolipoprotein E (APOE) in survival are sparse except for Alzheimer’s disease (AD). Methods: We studied mortality of 3,581 patients in an academic clinic from 1993 to 2004. Average follow-up was 4.1 years. We studied patients with amyotrophic lateral sclerosis (ALS) (n = 174), possible AD (n = 206), probable AD (n = 1,175), Parkinson’s disease (PD) (n = 661), mild cognitive impairment (MCI) (n = 357), frontotemporal dementia (FTD) (n = 94), Lewy body disease (LBD) (n = 64), and controls (n = 850). We compared patients’ mortality to the US population and to controls. Results: Mortality ranged from 7% for controls to 58% for ALS patients. The median survival times from initial visit for PD, FTD, probable AD, possible AD, LBD, and ALS were 8.9, 7.0, 5.9, 5.6, 5.3, and 2.7 years, respectively. Mortality rate ratios comparing each disease to controls were 39.43, 7.25, 3.70, 3.51, 2.47, 2.73, and 1.61 for ALS, FTD, LBD, PD, probable AD, possible AD, and MCI, respectively. A lower initial MMSE score was associated with higher mortality for probable AD, PD, and MCI, while APOE4 predicted mortality for PD and LBD. Non-whites had 20% lower mortality rates than whites for all dementias combined, adjusting for education. Conclusions: All neurologic diseases, including MCI, had increased mortality versus controls. A lower MMSE score and APOE4 presence predicted higher mortality for some patient groups.
Relationship of Possible Stress-Related Biochemical Markers to Oxidative/Antioxidative Status in Obsessive-Compulsive Disorder
Authors: Behl A. , Swami G. , Sircar S.S. , Bhatia M.S. , Banerjee B.D.
Published: April 2010

Free radicals have been found to play an important role in obsessive-compulsive disorder (OCD). So, we measured the oxidative/antioxidative status of OCD patients, and assessed its use as a biological marker. The study was carried out on 20 healthy and 20 OCD subjects, aged between 20 and 40 years. Biochemical parameters of all subjects were assessed and compared. A significant difference in superoxide dismutase (SOD) levels was observed between the OCD and control groups (p < 0.05); malondialdehyde (MDA) levels were also significantly higher in OCD subjects (p < 0.05). Our study found an overall oxidative imbalance in OCD, leaning towards the antioxidant side in sufferers (specifically towards SOD). SOD has a protective role in overcoming oxidative stress; therefore, oxidative stress could have a pathophysiological role in OCD. Therapy specifically targeting MDA production will have a beneficial effect in overcoming the oxidative stress, anxiety and affective disorder which may be associated with OCD.
Epidemiological Study of Chronic Tinnitus in Assiut, Egypt
Authors: Khedr Eman M. , Ahmed Mohamed A. , Shawky Ola Ahmed , Mohamed Enass Sayed , El Attar Ghada S. , Mohammad Khaled A.
Published: April 2010

Background and Aim: Few comprehensive epidemiological studies of the prevalence of tinnitus have been undertaken, and none has been carried out in Egypt. A community-based survey was conducted in the Assiut Governorate to estimate the prevalence of tinnitus, its associations with psychiatric disorders and its effect on the quality of life. Material and Methods: The study involved 8,484 subjects, 5,783 (68.2%) from the rural community and 2,701 (31.8%) from the urban community. Patients were identified from a door-to-door survey and evaluated using a semistructured questionnaire, the Tinnitus Handicap Inventory and the Hamilton Anxiety and Depression Scales. Results: Four hundred and thirty-nine patients with tinnitus were found, giving a prevalence of 5.17 tinnitus cases/100 inhabitants. Males and females were equally affected. The highest age-specific prevalence rate was recorded among subjects above 60 years (17.66%) and was significantly higher among urban than rural inhabitants (6.3 vs. 4.6%) and among illiterate than among educated persons (10.15 vs. 3.07%). A majority of patients (53.3%) had some hearing loss; otitis media was common. Only 15.2% of cases were classified as having severe to catastrophic tinnitus. Nearly two thirds had a degree of depression. There were significant correlations between the severity of tinnitus and the degree of hearing loss, temporomandibular joint pain and the Hamilton depression score. Sleep disturbance was reported by 39.4% of subjects. Life enjoyment was severely affected in 15% of tinnitus patients. Conclusion: Tinnitus is a common problem in our locality, especially in older adults, and is associated with some modifiable risk factors.
Cerebral Perfusion Affects the Risk of Ischemia during Carotid Artery Stenting
Authors: Jongen Lisa M. , Hendrikse Jeroen , Moll Frans L. , Mali Willem P.T.M. , van der Worp H. Bart
Published: April 2010

Background: Patients with impaired perfusion in the hemisphere ipsilateral to a stenotic internal carotid artery may have a higher risk of cerebral ischemic complications than those with normal perfusion. We therefore studied whether the occurrence of new ischemic lesions after carotid artery stenting is related to cerebral perfusion. Methods: In 45 patients with symptomatic carotid artery stenosis, CT perfusion and magnetic resonance diffusion-weighted imaging (DWI) were performed before carotid artery stenting; DWI was repeated within 2 days thereafter. Cerebral blood volume (CBV), mean transit time (MTT), and cerebral blood flow (CBF) were measured with CT perfusion in the cortical flow territory of the middle cerebral artery. Hyperintense lesions on postprocedural DWI not visible on baseline DWI were considered new cerebral ischemic lesions. The relation between CBF, CBV, and MTT and new ipsilateral ischemic lesions was tested with logistic regression. Results: In 11 of the 45 (24%) patients, new ischemic lesions were found in the ipsilateral hemisphere. The occurrence of these lesions was related to a lower CBF [adjusted odds ratio (aOR), 0.96; 95% confidence interval (CI), 0.92–1.00] and a longer MTT (aOR, 1.65; 95% CI, 1.02–2.66) compared with ipsilateral hemispheres without new lesions. Conclusions: Patients with impaired cerebral perfusion are more prone to develop ischemic lesions during carotid artery stenting. This suggests that in ischemic stroke during or after carotid artery stenting, embolic and hemodynamic mechanisms act in concert.
Incidence and Clinical Correlation of Intracranial Hemorrhages Observed by 3-Tesla Gradient Echo T2*-Weighted Images following Intravenous Thrombolysis with Recombinant Tissue Plasminogen Activator
Authors: Harada Masafumi , Morita Naomi , Uno Masaaki , Satomi Junichiro , Izumi Yuishin , Asanuma Kotaro , Nishitani Hiromu , Kaji Ryuuji , Nagahiro Shinji
Published: April 2010

Background: The purpose of this study was to determine the incidence and clinical correlation of intracranial hemorrhages (ICHs) detected by 3-tesla gradient echo T2*-weighted images after intravenous recombinant tissue plasminogen activator (rt-PA) administration. Methods: We included 43 consecutive patients with anterior-circulation ischemia who underwent MRI studies before and after thrombolysis. Each hemorrhage was classified as a hemorrhagic infarction (HI) or parenchymal hemorrhage (PH) according to the European Cooperative Acute Stroke Study definition. The clinical outcome was defined as an improvement (≧4-point reduction) or deterioration (≧4-point increase) based on a comparison between the initial and the 30-day NIHSS scores. Results: The incidence of ICHs was 58%, and the HI rate was 52%; both were higher than the rates reported in the literature. Most of the patients with HI improved clinically, and these patients had second MRAs that showed recanalization. None of the patients with PH demonstrated improvement. Conclusions: Three-tesla MRI may reveal a higher frequency of HI type hemorrhages than lower-field MRIs, and HI may be a predictor of good recovery by reflecting the presence of recanalization. The rate of PH in our study was low compared to other studies, probably due to the lower dosage of rt-PA.
Spatial and temporal segregation allows coexistence in a hybrid zone among two Mediterranean vipers (Vipera aspis and V. latastei)
Authors: Martínez-Freiría Fernando , Lizana Miguel , Amaral José Pedro do , Brito José C.
Published: April 2010

Mediterranean vipers are ecologically very similar. When in contact, they
constitute an exceptional model to study the effects of competitive
interactions and niche segregation mechanisms. In High Ebro, distinct
methodologies (random visual encounter, road sampling and radio-tracking
surveys, captive maintenance, standardized transects and ad hoc field
observations) were used to compare ecological traits (diet, micro-habitat,
activity, reproductive and demographic) of V. aspis, V. latastei and hybrids
among both species and determine competitive advantages of each form. Diet
preferences were similar but few differences were found in feeding frequency
and annual variation in diet consumption. Males of the three forms compete
for areas with similar characteristics but differences were found mainly
during summer. Significant differences in average movement rates and home
range size were found among males. Fecundity and new-borns fitness were
lower in V. aspis than in V. latastei, whereas hybrids had intermediate
values. Male and female adult hybrids were more abundant than parental
forms, whereas female and juvenile V. latastei and juvenile hybrids had high
road-mortality. The three forms seem to be competing intensely for resources
but the segregation on the spatial and temporal axes of their niches could
be reducing interspecific competition and allowing coexistence. The use of
different resources probably confers reproductive and demographic advantages
for V. latastei and hybrids, respectively. Moreover, reproductive fitness of
hybrids suggests the occurrence of endogenous selection. Comparative thermal
and genetic studies are needed to clarify the limiting factors of vipers and
to establish a model of the hybrid zone.
Ecology of juvenile Northern watersnakes (Nerodia sipedon) inhabiting low-order streams
Authors: Cecala Kristen , Dorcas Michael , Price Steven
Published: April 2010

The juvenile stage for many reptiles is considered “the lost years” because of low capture probabilities, however understanding factors impacting juvenile survivorship and recruitment is critical for conservation of populations. We studied the ecology of juvenile Northern watersnakes, Nerodia sipedon, by intensively sampling a first-order stream and determined the occupancy of juveniles in 30 low-order streams in the Piedmont of North Carolina. Juveniles were relatively abundant within a single stream (n = 62 ± 9), and their capture probabilities were positively related to increasing stream-water temperatures. We also found that juveniles had high survivorship (ϕ = 0.87 ± 0.017). Occupancy of juvenile N. sipedon in low-order, Piedmont streams may be greater at streams that have confluences with high order streams or lakes, which potentially support adult N. sipedon populations. This study provides important information regarding the natural history of juvenile reptiles and indicates the importance of low order streams as habitat for N. sipedon populations.
Anuran life history plasticity: Variable practice in determining the end-point of larval development
Authors: Walsh Patrick Thomas
Published: April 2010

Plasticity in the timing of life history events and their impact on individual fitness, particularly the timing of and size at metamorphosis in animals with complex life cycles such as anuran amphibians, has long been of interest to ecologists. For different studies on life history plasticity to be comparable, there must be clearly defined and commonly agreed transition points, but it is unclear how consistently this is being performed in studies using anuran amphibians. In a review of 157 published studies, I found considerable variation in defining the end point of the larval phase. While a slight majority used the emergence of the forelimbs as the conclusion of the larval phase, some used a period within the developmental phase of metamorphic climax and others used the resorption of the tail. Studies included in this review, that assessed the same life history variable at two different developmental stages, reported some differences in results depending on which developmental stage was used. Recent evidence also shows that metamorphic climax is itself a period which can vary with environmental conditions, but, even in studies that included part or all of metamorphic climax in the larval phase, the treatment of individuals during metamorphic climax was not reported. Therefore, I argue that life history studies on anuran amphibians should distinguish the following phases: larval, metamorphic climax, juvenile, adult; that the end of the larval phase is best defined in ecological studies by forelimb emergence and that conditions under which individuals undergo metamorphic climax should be fully described.
Image analysis of the ventral colour pattern discriminates between Spectacled salamanders, Salamandrina perspicillata and S. terdigitata (Amphibia, Salamandridae)
Authors: Angelini Claudio , Utzeri Carlo , Costa Corrado , Menesatti Paolo , Raimondi Stefano
Published: April 2010

In the present study, we applied statistical methods to quantitative image analysis of the persistent and individual ventral colour pattern of Salamandrina salamanders, in order to discriminate between individuals of the two species belonging to this genus. Pictures of 238 individuals from three populations of S. perspicillata and pictures of 95 S. terdigitata from two populations were analysed. Partial least squares discriminant analysis (PLSDA) classified 98.78% of individuals into the correct species. PLSDA reaches lower percentages of correct classification when applied to discriminate individuals from different populations of the same species (74.14% for S. perspicillata, 78.26% for S. terdigitata). An ANOVA analysis of colour abundances in different body sectors reveals significant differences between species. The results show that colour pattern has a specific basis, the most discriminant areas being the head and the pectoral girdle. We discuss these results in the light of the proposed evolutionary scenarios of the species, and suggest that ventral colour patterns were driven by founder effect.
An isolated population of Podarcis vaucheri (Sauria: Lacertidae) in south-eastern Spain: genetic data suggest human-mediated range expansion
Authors: Beddek Menad , Renoult Julien , Geniez Philippe , Crochet Pierre-André
Published: April 2010

In this study, we investigate the identity and origin of a population of Iberian Wall Lizards (Podarcis hispanicus complex) that we recently discovered inside the distribution range of the nominotypical form P. hispanicus. In the field, these animals were clearly identified as different from this species but their identity remained problematic. Using morphological and mitochondrial DNA analyses, we here identify this population as P. vaucheri, which constitutes a significant range extension for this species. Molecular results suggest a North African origin to this population. However, according to morphological results, these individuals are closer to the Spanish morphotype than to the North African morphotypes of P. vaucheri. Taken together, these results suggest a human-mediated introduction as the origin of this population, with local adaptation or phenotypic plasticity responsible of phenotypic convergence.
Advertisement call of Peltophryne florentinoi (Anura: Bufonidae), an endemic toad from Zapata Swamp, Cuba
Authors: Alonso Roberto , Hernández Maike , Rodríguez Ariel
Published: April 2010

The advertisement call of Peltophryne florentinoi, an endemic toad from Zapata Swamp, Matanzas, Cuba, is described in terms of temporal properties and dominant frequency. A comparison with the advertisement calls produced by the other three species of large toads in Cuba (P. peltocephala, P. fustiger and P. taladai) is also provided. Like other large toads from Cuba, P. florentinoi produces advertisement calls with long duration (> 10 s), low dominant frequency (< 1 kHz), and a series of complex pulses that are composed of two to five sub-pulses. All temporal features of the P. florentinoi call are significantly different from P. fustiger calls: number of pulses, pulse duration, and pulse rate separates it from P. peltocephala. P. florentinoi differs from P. taladai in call duration, number of pulses, and pulse rate. The occurrence of different types of complex pulses differed in all species studied. Typically, P. florentinoi pulses contain three sub-pulses, P. taladai four, and P. fustiger and P. peltocephala contain two sub-pulses. The dominant frequency of the advertisement call of P. florentinoi did not differ from the other species' calls. Call duration and pulse rate are the most useful acoustic properties to distinguish P. florentinoi advertisement calls from those of the other three large Cuban toads.
Foraging behaviour and territoriality of the strawberry poison frog (Oophaga pumilio) in dependence of the presence of ants
Authors: Pröhl Heike , Mebs Dietrich , Ospina Santiago Meneses , Staudt Konrad
Published: April 2010

The present study investigates foraging and territorial behaviour of the strawberry poison frog (Oophaga pumilio) in dependence of the presence of formicine and myrmicine ants, which constitute the main food source of the frogs. Species of the formicine ant genera Brachymyrmex and Paratrechina contain highly toxic alkaloids (pumiliotoxins), which the frogs incorporate and accumulate in their skin what may serve for predator deterrence. Twelve male frogs of two populations (primary and secondary forest) in Hitoy Cerere, Costa Rica, were observed each for a full day. Calling time, feeding attempts and time spent inside and outside the core area of their territories were recorded. Furthermore, twelve males of both populations were observed during the main foraging time to determine, whether the frogs search for prey in specific patches of their territories. The ants inside the core areas of twenty four frog territories were collected and classified to genus. Ants of the genera Brachymyrmex and Paratrechina were classified to species or morphospecies, respectively. The presence of formicine and myrmicine ants in territorial areas was compared to non-territorial sites. We found that formicine ants (Brachymyrmex and Paratrechina) were more present inside the territorial core areas than outside. The higher presence of these ants in the core areas was associated with longer foraging times. We verified that toxic alkaloids of the pumiliotoxin group are present in the dendrobatid frogs of Hitoy Cerere. The results of this study suggest that toxic diet may be linked to territoriality in this frog species.
Age structure, size and growth rate of water frogs from central European natural Pelophylax ridibundus-Pelophylax esculentus mixed populations estimated by skeletochronology
Authors: Socha Małgorzata , Ogielska Maria
Published: April 2010

Central European water frog Pelophylax esculentus (formerly known as Rana esculenta) is a natural hybrid between P. lessonae and P. ridibundus. The hybrids reproduce by hybridogenesis and usually share populations with one of the parental species. Natural ridibundus-esculentus (R-E) mixed populations are rare. The population described herein is composed of 80% P. ridibundus and 20% P. esculentus represented by both sexes. We analyzed 159 adults and 228 juveniles. Age of adults collected from breeding sites ranged from 2 to 6 years in males and from 3 to 7 years in females of both taxa. The percentage of individuals older than 5 years was low. Average age of P. ridibundus was higher than that of P. esculentus. In P. ridibundus the average age of females was higher than that of males. In P. esculentus the difference between ages of females and males was not significant. Measurements of yearly radial growth of long bones revealed that the frogs grew intensively before reaching sexual maturity (3 years for females and 2 years for males). In the group of juveniles before I hibernation, P. esculentus were significantly bigger than P. ridibundus, however, there was no difference in body size between both taxa after I hibernation i.e., before the start of a new growth season. Mean LAG-1 diameters were significantly greater in adults P. ridibundus than in juveniles after I hibernation, but not in P. esculentus.
A comparison of external and internal attachments of radio transmitters on adult crested newts Triturus cristatus
Authors: Berg Ole , Arnemo Jon , Skei Jon , Kraabøl Morten , Dervo Børre , Dolmen Dag
Published: April 2010

Telemetry studies of newt species demand small transmitters. Two types of external attachments (sutured to epidermis and backpack) and traditional implanting in the peritoneal cavity were tested between groups of 5 adult individuals of the crested newt Triturus cristatus (mass 6-15 g) held in terrariums under controlled environmental conditions. The newts were anaesthetized with 1.5 g l–1 MS222, delivered in water and buffered to pH 6.9 by Na2CO2. Surgical plane of anaesthesia was achieved after 5-12 minutes and lasted for 30-60 minutes. External tagging proved unsuitable because transmitters became entangled in vegetation, and all animals shed their transmitters shortly after tagging, except for one that died. Transmitters that were surgically implanted in the peritoneal cavity were more successful. By the fourth day following surgery, the animals that had undergone surgery behaved similarly to control animals with respect to the use of cover. Two of the newts died, however, without showing any signs of illness in advance, and the cause of death could not be established. Based on the present experiments and published studies, implantable transmitters appear to be the best method for radiotagging small and medium sized urodele species such as T. cristatus, to gain crucial information on spatio-temporal terrestrial activity patterns, habitat utilization and hibernation sites. Additional research is needed to evaluate both short and long term effects on activity, behaviour and survival.
Temperature differentials between the bodies and tails of ribbon snakes (Thamnophis sauritus): ecological and physiological implications
Authors: Amiel Joshua , Wassersug Richard
Published: April 2010

We present evidence that eastern ribbon snakes (Thamnophis sauritus) at low environmental temperatures can maintain significant temperature differentials between their bodies and tails. We used a high resolution infrared camera to record thermal data from ribbon snakes in the spring and summer. An independent two sample t-test confirmed that ribbon snakes at low spring environmental temperatures maintain significantly warmer bodies than tails relative to ribbon snakes at high summer environmental temperatures (t = 5.495, P < 0.001). Given our results that ribbon snakes at low environmental temperatures are able to maintain body temperatures higher than tail temperatures, we speculate on possible mechanisms that could account for these temperature differentials and their ecological significance.
La identidad social y el locus de control interno en habitantes pobres del sur de Nuevo León, México
Authors: García Cirilo H. , Corral-Verdugo Víctor
Published: April 2010

Se investigaron, mediante un modelo de ecuaciones estructurales, los efectos de la identidad social, la edad y los ingresos sobre el locus de control interno en habitantes del sur de Nuevo León, México. Como los ingresos no tuvieron ningún efecto estadísticamente significativo (β =.089, p>.05), se re-especificó el modelo, dejando sólo la identidad social y la edad. Estas sí tuvieron efectos estadísticamente significativos (β=.79, p <.05 y (β= -.19, p <.05, respectivamente), alcanzando a explicar un 60,00% de la varianza del locus de control interno gracias al modelo bifactorial. Se interpretaron los resultados en términos de la carencia de poder, para entender la relación negativa de la edad sobre el locus de control interno, y se acudió a las características de permeabilidad e impermeabilidad de la teoría de la identidad social para interpretar el efecto positivo de la identidad social de un grupo de bajo estatus sobre el locus de control interno, variable entendida en muchas ocasiones como característica de personalidad. De los índices de bondad de ajuste, el modelo sólo cumplió con el criterio de la RMSEA (p <.05), el cual es uno de los indicadores específicos más efectivos.
Identidad social y discriminación intergrupal. ¿Una relación inevitable? El caso de las identidades regionales en Chile
Authors: Zúñiga Claudia , Asún Rodrigo
Published: April 2010

La teoría de la categorización del yo reconoce explícitamente la posibilidad de que distintas identidades tengan relaciones “anidadas” entre sí, de manera que no hay ni incompatibilidad ni conflicto entre ellas, pues se ubicarían a diferentes niveles de abstracción para los sujetos. Nuestro objetivo fue poner a prueba esta afirmación a través del estudio de un caso idiosincrásico: la identificación con las regiones chilenas, creadas hace 30 años por el gobierno central, y con pocas raíces socio-históricas. Se encuestó a 504 estudiantes universitarios en dos regiones distintas (seleccionados aleatoriamente), y los resultados indican que estas regiones se han constituido en referentes para el autoconcepto de las personas. Los participantes mostraron altos niveles de identidad regional, la cual aparece como complementaria y compatible con altos niveles de identificación con el país y se encuentra asociada a valores de benevolencia y universalismo (medidos con la escala de valores de Schwartz), así como a actitudes positivas hacia otros grupos regionales. Todo ello indica que estas emergentes identidades regionales serían compatibles con la tradicional identidad chilena al anidarse con ella.
Emoción y meta-cognición: implicaciones para el cambio de actitud
Authors: Briñol Pablo , Gandarillas Beatriz , Horcajo Javier , Becerra Alberto
Published: April 2010

En el presente trabajo se describen los principales procesos psicológicos a través de los cuales las emociones influyen sobre el cambio de actitudes. La primera parte de la presente revisión se ocupa de la relación entre emoción y cognición, en ella se describen cómo las emociones influyen sobre la forma en que se procesa la información persuasiva (e.g., afectando a la cantidad y dirección de pensamientos generados ante una propuesta). A continuación, se examina cómo las emociones pueden cambiar no sólo los pensamientos que vienen a la mente, sino también lo que pensamos sobre dichos pensamientos (meta-cognición). La investigación meta-cognitiva revisada demuestra que las emociones pueden hacer que las personas confíen o desconfíen tanto de lo que piensan como de lo que sienten. En concreto, varios paradigmas experimentales sugieren que las emociones pueden validar o invalidar a otras emociones (e.g., sentirse triste de sentir alegría) y pensamientos (e.g., sentir ira de pensar algo). Por otra parte, no sólo las emociones, sino también los pensamientos pueden validar o invalidar lo que se piensa y lo que se siente (e.g., en función de la facilidad con la que los pensamientos y emociones vienen a la mente).
Introducción: Teoría de la identidad social y algunas aplicaciones actuales
Authors: Lisbona Ana
Published: April 2010

Esta introducción se inicia con un breve recorrido histórico por los orígenes de la teoría de la identidad social, junto con la descripción del contexto en que surge y se desarrolla. Tras una sucinta explicación del concepto se da paso a la presentación de los artículos que componen este monográfico, cuyo objetivo principal es mostrar algunos de los trabajos que se están desarrollando en la actualidad bajo el marco teórico de la Identidad Social, aplicados a diversos ámbitos de la psicología social como, por ejemplo, el organizational o el político.
Percepción de continuidad e identificación grupal: implicaciones para el bienestar social
Authors: Herrera Marina , Sani Fabio , Bowe Mhairi
Published: April 2010

La investigación sobre los grupos en general y sobre la percepción grupal en particular ha tendido a analizar los grupos como entidades a-temporales, sin tener en cuenta su continuidad. En este trabajo se presentan tres estudios en los que se demuestra la relevancia de un nuevo constructor la ‘percepción de continuidad colectiva’ (PCC), y su relación con la identificación grupal y el bienestar social. El primer estudio muestra que la PCC correlaciona positivamente con la percepción de entitatividad grupal y con diversas medidas relacionadas con la identidad social, como la autoestima colectiva y la identificación grupal. El segundo estudio revela que la percepción de continuidad colectiva favorece el bienestar y la integración social, y que esta relación está mediada por la autoestima colectiva y la entitatividad percibida. En el tercer estudio se demuestra que la inducción de la saliencia de la propia mortalidad conduce a aumentar la percepción de duración temporal de los grupos y que, a su vez, dicha percepción aumenta la identificación grupal. En conjunto, los tres estudios confirman que la PCC es un constructo teórico relevante que tiene importantes implicaciones para el bienestar social.