bluuebunny/crossref_metadata_2025 huggingface dataset:
Understanding Transnational Entrepreneurship Through a Network Lens: Theoretical and Methodological Considerations
Authors: Chen Wenhong , Tan Justin
Published: September 2009

Although networks have been considered crucial to transnational entrepreneurship (TE), there has been a lack of theoretical and methodological engagement with social network analysis in the existing TE research. We approach TE through a lens of glocalized networks—networks with both local and global connection. We develop a framework that articulates the relation of glocalized networks and TE and discuss how to capture the structure and impacts of glocalized networks in the process of TE.
Transnational Entrepreneurs‘ Venture Internationalization Strategies: A Practice Theory Approach
Authors: Terjesen Siri , Elam Amanda
Published: September 2009

How do entrepreneurs working across multiple countries leverage individual experiences and institutional environments to pursue international markets? This research utilizes Bourdieu's theory of practice as a sensitizing framework to explore transnational entrepreneurs‘ internationalization strategies. Four case studies reveal the ways in which transnational entrepreneurs rely on diverse sets of resources—economic, social, cultural, and symbolic capital—to navigate multiple institutional environments—cultural repertoires, social networks, legal and regulatory regimes, and power relations—when making strategic decisions about internationalization. Transnational entrepreneurs are uniquely positioned to internationalize directly and, in many cases, as an intermediary for local firms. As such, transnational entrepreneurs pursue a modern middleman role that transcends the multiple institutional environments in which they are embedded.
Oral health inequalities between young Aboriginal and non‐Aboriginal children living in Ontario, Canada
Authors: Lawrence Herenia P. , Binguis Darlene , Douglas Jan , McKeown Lynda , Switzer Bonita , Figueiredo Rafael , Reade Margaret
Published: September 2009

Abstract –  Objectives:  To investigate (i) oral health inequalities between off‐reserve Aboriginal and non‐Aboriginal children entering junior kindergarten (JK) in the Thunder Bay District, Northwest Ontario, Canada, (ii) oral health inequalities between kindergarten‐aged (4 years old) Aboriginal children living on reserves in the Sioux Lookout Zone (SLZ), Northwest Ontario and those living off‐reserve in the Thunder Bay District and (iii) early childhood caries (ECC) trends among SLZ children between 2001 and 2005.

Methods:  Cross‐sectional oral health data (dmft/s Indices) for 416 (2003/2004), 687 (2004/2005) and 544 (2005/2006) 3‐ to 5‐year olds attending JK in the Thunder Bay District were collected by calibrated dental hygienists with the District’s Health Unit. Secondary analysis of oral health status data from two studies conducted in the SLZ between 2001 and 2005 provided the dmft of random samples of children younger than 6 years of age living in 16–20 First Nations communities.

Results:  When compared with non‐Aboriginal children aged 3–5 years attending the same schools in the Thunder Bay District between 2003 and 2006, off‐reserve Aboriginal children had 1.9 to 2.3 times the risk of having ECC (dmft > 0), 2.9 to 3.5 times the risk of a dmft > 3 and 1.8 to 2.5 times the risk of untreated decayed teeth after adjusting the prevalence ratios for child’s age and sex, school’s risk level and clustered‐correlated data. The mean dmft of on‐reserve Aboriginal 4‐year olds in 2005 was 11.2 and 5.9 for their off‐reserve Aboriginal counterparts. In 2001, the mean dmft scores (95% confidence interval) of 2‐, 3‐ and 4‐year‐old Aboriginal children in the SLZ were: 9.1 (8.3–9.9), 12.4 (11.8–13.1), 13.1 (12.1–14.2). In 2005, similarly aged SLZ children had a mean dmft of: 6.2 (5.2–7.1), 8.9 (8.2–9.6), 11.2 (10.5–11.9), representing significant reductions in caries severity (32%, 28% and 14.5%, respectively).

Conclusions:  Significant disparities in caries experience exist between off‐reserve Aboriginal and non‐Aboriginal children living in the same locales and between Aboriginal children living on‐ and off‐reserve in northwestern Ontario. The study showed decreased trends in the severity of ECC for children in the SLZ occurring over the 5‐year period. Despite this progress, the oral health of young Aboriginal children in Ontario continues to lag far behind that of non‐Aboriginal children, demanding further programs and policies to tackle the social determinants of oral health and resolve these inequalities.
The role of keratinocyte growth factor in melanogenesis: a possible mechanism for the initiation of solar lentigines
Authors: Chen Nannan , Hu Yaping , Li Wen‐Hwa , Eisinger Magdalena , Seiberg Miri , Lin Connie B.
Published: September 2009

Please cite this paper as: The role of keratinocyte growth factor in melanogenesis: a possible mechanism for the initiation of solar lentigines. Experimental Dermatology 2010; 19: 865–872.

Abstract:  Solar lentigines (SLs) are hyperpigmentary lesions presented on sun‐exposed areas of the skin and associated with ageing. The molecular mechanism of SL initiation is not completely understood. Ultraviolet B (UVB) stimulates keratinocytes to produce interlukin‐1 alpha (IL‐1α), which then induces keratinocyte growth factor (KGF) secretion; therefore, we examined their possible roles in the induction of SLs. We found that KGF increases pigment production in both pigmented epidermal equivalents and human skin explants. In addition, UVB exposure increases KGF expression, and KGF treatment induces tyrosinase (TYR) expression in primary melanocytes. The KGF‐induced pigmentary changes were confirmed using pigmented Yucatan swine, and human skins grafted onto immuno‐deficient mice. In both model systems, the topical treatment with KGF, alone or in combination with IL‐1α, resulted in the in vivo formation of hyperpigmentary lesions with increased pigment deposition and elongated rete ridges, which resemble the histological features of human SLs. Preliminary immunohistochemical analysis of human skins showed a moderate increase in KGF, and a strong induction in KGF receptor (KGFR) in SL lesions. In summary, KGF increases pigment production and deposition in vitro and in vivo. Moreover, we show for the first time the in vivo generation of hyperpigmentary lesions with histological resemblance to human SLs and indicate the involvement of KGF/KGFR in the molecular pathology of human SLs.
Effects of N-acetylcysteine on substance use in bipolar disorder: a randomised placebo-controlled clinical trial
Authors: Bernardo Michelle , Dodd Seetal , Gama Clarissa S. , Copolov David L , Dean Olivia , Kohlmann Kristy , Jeavons Susan , Schapkaitz Ian , Anderson-Hunt Murray , Bush Ashley I , Berk Michael
Published: September 2009

Objective:

To evaluate the effect of N-acetylcysteine (NAC) on substance use in a double-blind, placebo-controlled trial of NAC in bipolar disorder. It is hypothesised that NAC will be superior to placebo for reducing scores on the Clinical Global Impressions scale for Substance Use (CGI-SU).

Methods:

Participants were randomised to 6-months of treatment with 2 g/day NAC (n = 38) or placebo (n = 37). Substance use was assessed at baseline using the Habits instrument. Change in substance use was assessed at regular study visits using the CGI-SU.

Results:

Amongst the 75 participants 78.7% drank alcohol (any frequency), 45.3% smoked tobacco and 92% consumer caffeine. Other substances were used by fewer than six participants. Caffeine use was significantly lower for NAC-treated participants compared with placebo at week 2 of treatment but not at other study visits.

Conclusion:

NAC appeared to have little effect on substance use in this population. A larger study on a substance using population will be necessary to determine if NAC may be a useful treatment for substance use.
ALKALINE NOODLES AND FLOUR/GEL PROPERTIES OF HARD RED AND WHITE WINTER WHEAT
Authors: RAYAS‐DUARTE P. , FRANCISCO C. , PAYTON M.E. , BELLMER D.D. , CARVER B.F. , HUANG W.N.
Published: September 2009

Alkaline noodle characteristics and flour gel properties made with one white and one red hard winter wheat cultivar were studied. The wheat was grown in four Oklahoma agricultural districts, with two to seven locations on each district. Both cultivars had similar flour protein content and overall raw dough sheet color stability (ΔL* andΔb*) in three out of four agricultural districts. Cimarron and Oro Blanco showed differences inΔa*,Δb* and adhesiveness in the North Central agricultural district. Resilience values of cooked noodles from Oro Blanco were small, but significantly higher in the Central district. Higher flour peak viscosity was observed for Oro Blanco, plus a trend to lower polyphenol oxidase activity and higher elastic modulus than Cimarron.

PRACTICAL APPLICATIONS

Hard red winter wheat from the U.S.A. is used in the manufacturing of alkaline noodles in Asia. Color and texture characteristics are among the most important attributes that determine the quality of this type of noodles. Two types of winter wheat cultivars, red and white, were compared and their key properties (including gel properties) of importance in the international trade and noodle manufacturing are reported.
BAKING AND SENSORY CHARACTERISTICS OF MUFFINS INCORPORATED WITH APPLE SKIN POWDER
Authors: VASANTHA RUPASINGHE H.P. , WANG LAIXIN , PITTS NANCY L. , ASTATKIE T.
Published: September 2009

Apple fruit skin, a rich source of dietary fiber and phenolics, is a by‐product of apple processing. The feasibility of incorporating dried apple skin powder (ASP) as a value‐added food ingredient in bakery food products using a model system of muffins was investigated. The blanched, dehydrated and ground ASP was incorporated into muffins at 0, 4, 8, 16, 24 or 32% (w/w) levels with replacement of equivalent amount of wheat flour of a standard muffin mixture. The highest level of replacement (32% w/w) had a significant adverse effect on the baking characteristics. A taste panel of 66 panelists showed that the replacement of wheat flour with 8, 16 or 24% ASP in the muffin mixture did not affect the overall acceptability.

PRACTICAL APPLICATIONS

Identification of ways to incorporate apple skins, one of the by‐products of apple pie and sauce manufacturing, as a health food ingredient in human diet could provide many health benefits. Furthermore, better use of the by‐product will also provide benefits to the apple industry as well as solutions for environment concerns associated with disposal. The results of the present study indicate that blanched and dehydrated apple skin powder (ASP) could be considered as an alternative dietary fiber source or specialty food ingredient for muffins. Therefore, the potential for the industrial exploitation of ASP as a health food ingredient for the bakery industry and selected functional foods is promising.
MATURITY AND SOURCE‐ROCK POTENTIAL OF MESOZOIC AND PALAEOZOIC SEDIMENTS, JIFARAH BASIN, NW LIBYA
Authors: Abohajar A. , Krooss B.M. , Harouda M. , Littke R.
Published: September 2009

The Jifarah Basin, NW Libya, has a sedimentary fill which includes marine shales of Triassic, Permian, Silurian and Ordovician ages together with Jurassic evaporites and Cambro‐Ordovician aeolian sandstones. Major risk in exploration of the basin is associated with the presence of source rocks. The present study investigates potential source rocks in the basin and assesses their thermal maturity, petroleum generation potential, organic richness and distribution. Cuttings and core samples from nine wells were analyzed using a Rock‐Eval 6 instrument and by standard petrographic microscopy. Kerogen type and amount were recorded.

Triassic and Ordovician formations were only drilled in parts of the basin and have minor petroleum generation potential. Permian and Devonian samples also had low generation potential, as did samples from the upper part of the Silurian. The Devonian succession is of limited extent as a result of Hercynian uplift and erosion.

Major petroleum generation potential is associated with the lower part of the Silurian Tanezzuft Formation in which high TOC values and moderate to high HI values were recorded. The formation is characterized by abundant fluorescing alginite. Most samples studied were early mature to mid‐mature but there was some regional variability.
Changes in Cancer Incidence Patterns Among a Northeastern American Indian Population: 1955‐1969 Versus 1990‐2004
Authors: Mahoney Martin C. , Va Puthiery , Stevens Adrian , Kahn Amy R. , Michalek Arthur M.
Published: September 2009

ABSTRACT: 
Purpose:

This manuscript examines shifts in patterns of cancer incidence among the Seneca Nation of Indians (SNI) for the interval 1955‐1969 compared to 1990‐2004. Methods: A retrospective cohort design was used to examine cancer incidence among the SNI during 2 time intervals: 1955‐1969 and 1990‐2004. Person‐years at risk were multiplied by cancer incidence rates for New York State, exclusive of New York City, over 5‐year intervals. A computer‐aided match with the New York State Cancer Registry was used to identify incident cancers. Overall and site‐specific standardized incidence ratios (SIRs = observed/expected × 100), and 95% confidence intervals (CIs), were calculated for both time periods. Results: During the earlier interval, deficits in overall cancer incidence were noted among males (SIR = 56, CI 36‐82) and females (SIR = 71, CI 50‐98), and for female breast cancers (SIR = 21, CI 4‐62). During the more recent intervals, deficits in overall cancer incidence persisted among both genders (males SIR = 63, CI 52‐77; females SIR = 67, CI 55‐80). Deficits were also noted among males for cancers of the lung (SIR = 60, CI 33‐98), prostate (SIR = 51, CI = 33‐76) and bladder (SIR = 17, CI = 2–61) and among females for breast (SIR = 33, CI = 20‐53) and uterus (SIR = 36, CI = 10‐92). No cancer sites demonstrated increased incidence. Persons ages 60‐69 years, 70‐79 years, and ages 80+ years tended to exhibit deficits in overall incidence. Conclusions: Despite marked changes over time, deficits in overall cancer incidence have persisted between the time intervals studied. Tribal‐specific cancer data are important for the development and implementation of comprehensive cancer control plans which align with local needs.
Adaptation of Consultation Planning for Native American and Latina Women With Breast Cancer
Authors: Belkora Jeffrey , Franklin Lauren , O’Donnell Sara , Ohnemus Julie , Stacey Dawn
Published: September 2009

ABSTRACT: 
Context:

Resource centers in rural, underserved areas are implementing Consultation Planning (CP) to help women with breast cancer create a question list before a doctor visit. Purpose: To identify changes needed for acceptable delivery of CP to rural Native Americans and Latinas. Methods: We interviewed and surveyed 27 Native American and Latino key informants. We coded interviews thematically, and calculated summary statistics for the survey data. Findings: Native American and Latino respondents endorsed CP as culturally acceptable to their communities, while suggesting changes. Respondents also raised the topic of how to further support patients once they have successfully prepared a question list using CP. Conclusions: The resource centers implemented the requested changes.
Designated Medical Directors for Emergency Medical Services: Recruitment and Roles
Authors: Slifkin Rebecca T. , Freeman Victoria A. , Patterson P. Daniel
Published: September 2009

ABSTRACT: 
Context:

Emergency medical services (EMS) agencies rely on medical oversight to support Emergency Medical Technicians (EMTs) in the provision of prehospital care. Most states require EMS agencies to have a designated medical director (DMD), who typically is responsible for the many activities of medical oversight. Purpose: To assess rural‐urban differences in obtaining a DMD and in their responsibilities. Methods: A national survey of 1,425 local EMS directors, conducted in 2007. Findings: Rural EMS directors were more likely than urban ones to report DMD recruitment problems, but recruitment barriers were similar, with the most commonly reported barrier being an unwillingness of local physicians to serve. Rural EMS directors reported that their DMDs were less likely to be trained in Emergency Medicine, and were less likely to provide educational support functions such as continuing education. Rural agencies were more likely to get on‐line medical direction from their DMD, but were less likely to always get the on‐line support they needed. Common barriers to on‐line support were typical of rural communication barriers. Conclusions: Existing recommendations for DMD qualifications may be difficult to attain in rural communities. To develop programs that will support medical direction for rural EMS agencies, it is important to learn what physicians identify as the barriers to serving as DMDs, and whether there are alternative and innovative ways to provide an optimal level of medical oversight. Solutions will likely be multi‐faceted, as EMS activities and organizational structures are diverse and the responsibilities of the DMD are broad.
Double Whammy? Rural Youth With Serious Emotional Disturbance and the Transition to Adulthood
Authors: Heflinger Craig Anne , Hoffman Cheri
Published: September 2009

ABSTRACT: 
Context:

All youth, especially those with serious emotional disturbances (SED), face challenges as they transition to adulthood. Little is known about rural youth at risk for transition problems. Purpose: To examine transition‐age youth who use publicly funded services in rural and urban/suburban locations in Tennessee in order to describe youth at risk for transition difficulties who need policy and service planning. Methods: Using Medicaid enrollment and claims/encounter data, youth at high risk for transition difficulties were identified in the following groups: SED, at risk of or in foster care/state custody, intensive or frequent mental health services users, or diagnosed with major mental disorders, behavior disorders, mental retardation, or substance use. Membership in these groups was compared between youth living in rural and urban/suburban counties. Multivariate regression was used to examine factors related to multiple group membership. Findings: Rural youth were more likely to be in groups at high risk for problems transitioning to adulthood, and enrolled in Medicaid as uninsured/uninsurable, compared to their urban counterparts. The strongest factors associated with multiple risk group membership were being in state custody/foster care and receiving Supplemental Security Income (SSI). Conclusions: Services are needed to support the transition to adulthood for youth at high risk of behavioral and adjustment problems. Systems to support coordinated planning and accountability are needed, including data on populations and services, and research on transition‐age youth.
Horse‐Related Injuries Among Agricultural Household Members: Regional Rural Injury Study II (RRIS‐II)
Authors: Erkal Sibel , Gerberich Susan G. , Ryan Andrew D. , Alexander Bruce H. , Renier Colleen M.
Published: September 2009

ABSTRACT: 
Purpose:

To determine the incidence, associated consequences, and potential risk factors for horse‐related injuries among youth and adults residing in Midwestern agricultural households. Methods: Demographic, injury, and exposure data were collected for 1999 and 2001 among randomly selected agricultural households within a 5‐state region. A causal model facilitated survey design, data analysis, and interpretation of results; directed acyclic graphs guided multivariate modeling. Findings: From 7,420 households (84% response of eligible), involving 32,601 persons, 5,045 total injury events were reported; 1,016 were animal‐related injuries, of which 215 (21%) were horse‐related (rate, 6.7 events per 1,000 persons per year). Seventy‐seven percent (77%) required health care; comparing those under age 20 and those 20 and older, 49% and 54%, respectively, lost work time on their operation (28% and 26%, one week or more), as a result of injuries largely associated with horse riding activities (70% and 56%). Multivariate analysis for youths under age 20 indicated: increased risks in North and South Dakota, for >0 hours worked, and for having a history of prior agriculture‐related injury; and decreased risks for males. For those 20 and older, increased risks were identified for a prior injury history and less than high school education. Conclusions: Horse‐related injuries, primarily associated with riding activities, are a significant problem among agricultural communities, and greatly impact their operations.
‘Everybody's talking at me’: the dynamics of information disclosure and consultation in high‐skill workplaces in the UK
Authors: Danford Andy , Durbin Sue , Richardson Mike , Tailby Stephanie , Stewart Paul
Published: September 2009

This article examines the dynamics of direct and indirect consultation processes in three high‐skill work establishments in the UK. Drawing on a mix of case study survey and interview data, it analyses the experiences and attitudes of predominantly well‐qualified professional employees. Adopting the concept of ‘embeddedness’ of employee consultation at the workplace level, we find that despite considerable breadth and depth of practice, many employees remain dissatisfied with the extent of their individual and collective influence over management decision‐making processes. Four underlying contributory factors are presented: extant hierarchical and bureaucratic management styles, the negative impact of work overload, the individualisation of consultation through computerisation, and the weakness of cooperative forms of union engagement.
The Self‐Conscious Emotions: How are they Experienced, Expressed, and Assessed?
Authors: Robins Richard W. , Schriber Roberta A.
Published: September 2009

The self‐conscious emotions (e.g., embarrassment, guilt, pride, shame) are a special class of emotions that critically involve the self, including the capacity to form stable self‐representations and to evaluate oneself relative to internal and external standards. In this article, we summarize five areas of recent research on self‐conscious emotions: (a) the cognitive elicitors, or causal appraisals, that generate them; (b) their non‐verbal expressions; (c) the underlying neural processes; (d) the degree to which their experience and expression varies across cultures; and (e) the measures that have been developed to assess them. In each section, we provide recommendations for future research directions.
Lay Theories of Personality: Cornerstones of Meaning in Social Cognition
Authors: Plaks Jason E. , Levy Sheri R. , Dweck Carol S.
Published: September 2009

Lay theories (or ‘implicit theories’) are cornerstones for social cognition: people use lay theories to help them make sense of complex and ambiguous behavior. In this study, we describe recent research on the entity and incremental theories (the belief that personality is fixed or malleable). In so doing, we demonstrate that each theory does not act alone. Instead, each is associated with a set of allied beliefs, the sum total of which cohere into two distinct meaning systems. We present evidence that these meaning systems produce systematic differences in a range of fundamental social cognition processes, with important implications for the field’s understanding of trait/situation attribution, moral judgment, person memory, and stereotyping. We further argue that because meaning systems serve a central meaning‐making function, people are motivated to believe that the meaning system they are using is effective and accurate. Accordingly, we present evidence that people exhibit processing distortions and compensatory mechanisms to minimize the impact of information that violates their meaning system. We discuss the implications of these findings for the field’s understanding of basic social cognition.
Relational Self‐Construal: Past and Future
Authors: Cross Susan E.
Published: September 2009

Relational self‐construal is characterized as the extent to which a person defines the self in terms of close relationships. In this article, I distinguish relational self‐construal from collective‐interdependent self‐construal and from other similar‐sounding constructs. I review the history of the concept of relational self‐construal and how it is most frequently measured or manipulated. The remainder of the article focuses on research that examines the role of relational self‐construal in cognition, affect, motivation, and close interpersonal relationships.
Beneficial effects of preoperative intravitreal bevacizumab on trabeculectomy outcomes in neovascular glaucoma
Authors: Saito Yoshiaki , Higashide Tomomi , Takeda Hisashi , Ohkubo Shinji , Sugiyama Kazuhisa
Published: September 2009

Purpose:  This study aimed to investigate the effects of preoperative intravitreal bevacizumab (IVB) on outcomes in trabeculectomy for neovascular glaucoma (NVG).

Methods:  Charts for 52 NVG eyes of 52 consecutive patients who received primary trabeculectomy with mitomycin C (MMC) were reviewed. Postoperative follow‐up periods for all patients were ≥ 4 months. Thirty‐two consecutive eyes were treated without IVB (control group) and 20 consecutive eyes received IVB (1.25 mg) 10 ± 11 days before trabeculectomy (IVB group). The main outcome measures were postoperative intraocular pressure (IOP) and incidence of postoperative complications. Surgical success was defined as IOP< 21 mmHg with or without medication (qualified or complete success, respectively). Failure was defined as IOP exceeding these criteria, phthisis bulbi, loss of light perception or additional glaucoma surgeries. Kaplan–Meier survival analysis with the log‐rank test was performed to compare surgical success rates between the two groups.

Results:  Complete and qualified success rates at 6 months were 95% versus 50% and 95% versus 75% in the IVB and control groups, respectively. The IVB group achieved significantly better surgical success rates than the control group (complete success, p < 0.001; qualified success, p = 0.026). Postoperative hyphaema on day 1 or hyphaema with a duration of > 1 week occurred significantly less frequently in the IVB group than in the control group (p = 0.009, p = 0.014, respectively). The incidence of serious complications such as endophthalmitis, phthisis bulbi and a marked decrease in visual acuity did not increase in the IVB group.

Conclusions:  This retrospective study showed that preoperative IVB decreased postoperative hyphaema and increased surgical success rates, and thus may be an effective adjunct to trabeculectomy in NVG.
Association between genetic variants inVEGF,ERCC3and occupational benzene haematotoxicity
Authors: Hosgood H D , Zhang L , Shen M , Berndt S I , Vermeulen R , Li G , Yin S , Yeager M , Yuenger J , Rothman N , Chanock S , Smith M , Lan Q
Published: September 2009

Introduction:

Benzene is an established human haematotoxin, with substantial interindividual variation in benzene-induced toxicity.

Methods:

To further examine if genetic variation contributes to benzene haematotoxicity, we analysed 1023 tagSNPs in 121 gene regions important for benzene metabolism, haematopoiesis, leukaemia and lymphoma among 250 workers exposed to benzene and 140 unexposed controls in a cross-sectional study carried out in China. Linear regression was used to analyse the relationship between genetic polymorphisms and total white blood cell (WBC) count and its subtypes, adjusting for potential confounders and occupational exposure to benzene and toluene among exposed workers. The minp test assessed the association on the gene region level. The false discovery rate method was used to control for multiple comparisons.

Results:

VEGF(minp = 0.0030) andERCC3(minp = 0.0042) were the most significantly associated gene regions with altered WBC counts among benzene-exposed workers, after accounting for multiple comparisons. Highly significant changes were also found for WBC subtype counts, including granulocytes, CD4+ T cells and lymphocytes forVEGFand granulocytes and NK cells forERCC3. Further, in workers exposed to <1 ppm, a SNP inVEGFwas associated with changes in WBC and granulocyte counts, and SNPs inERCC3were associated with changes in WBC, NK cell and granulocyte counts.

Discussion:

Our findings suggest that genetic variation inVEGF, which plays an important role in blood vessel growth, andERCC3, which is a member of the DNA repair pathway and is responsible for repairing bulky DNA adducts formed by chemicals, may contribute to individual susceptibility to benzene-induced haematotoxicity at relatively low levels of benzene exposure.
Prolonged time to pregnancy in residents exposed to ionising radiation in cobalt-60-contaminated buildings
Authors: Lin C-M , Chang W P , Doyle P , Wang J-D , Lee L-T , Lee C L , Chen P-C
Published: September 2009

Objectives

Radiation-induced cytogenetic damage in somatic cells has raised concern that low-dose ionising radiation can also damage germ cells and influence gamete production and/or function, resulting in decreased fertility. Time to pregnancy (TTP) was used to investigate whether exposure to γ-radiation affected fertility among the residents of cobalt-60-contaminated buildings in Taiwan.

Methods

This was a retrospective pregnancy-based study of 357 pregnancies born to 124 exposed couples. Both the cumulative dose and the dose rate for each pregnancy was estimated based on a physical dose reconstruction programme. The comparison population consisted of 612 pregnancies born to 225 couples randomly sampled from the Taiwan general population. Information on TTP was collected by personal interviews. Fecundability ratios (FRs) were calculated with a discrete proportional hazards model.

Results

For exposed mothers, fertility decreased significantly when unprotected intercourse began during the period of living in the radiation-contaminated buildings (FR 0.75, 95% CI 0.61 to 0.92). The effect was borderline significant for fathers (FR 0.83, 95% CI 0.68 to 1.02). There was evidence that prolonged TTP was associated with the rate of exposure for both mothers and fathers (tests for trend: female, p=0.0006; male, p=0.03), especially evident for dose rates ≥10 mSv/year (female, FR 0.60, 95% CI 0.43 to 0.84; male, FR 0.68, 95% CI 0.49 to 0.96).

Conclusions

Our findings suggest that exposure to low-dose ionising radiation of cobalt-60-contaminated buildings may decrease fertility, especially in females. Fertility declined with increasing concurrent dose but not with cumulative dose.
Cross-validation and refinement of the Stoffenmanager as a first tier exposure assessment tool for REACH
Authors: Schinkel Jody , Fransman Wouter , Heussen Henri , Kromhout Hans , Marquart Hans , Tielemans Erik
Published: September 2009

Objectives

For regulatory risk assessment under REACH a tiered approach is proposed in which the first tier models should provide a conservative exposure estimate that can discriminate between scenarios which are of concern and those which are not. The Stoffenmanager is mentioned as a first tier approach in the REACH guidance. In an attempt to investigate the validity of the Stoffenmanager algorithms, a cross-validation study was performed.

Methods

Exposure estimates using the Stoffenmanager algorithms were compared with exposure measurement results (n=254). Correlations between observed and predicted exposures, bias and precision were calculated. Stratified analyses were performed for the scenarios “handling of powders and granules” (n=82), “handling solids resulting in comminuting” (n=60), “handling of low-volatile liquids” (n=40) and “handling of volatile liquids” (n=72).

Results

The relative bias of the four algorithms ranged between −9% and −77% with a precision of approximately 1.7. The 90th percentile estimate of one out of four algorithms was not conservative enough. Based on these statistics and analyses of residual plots the underlying algorithm was adapted. Subsequently, the calibration and the cross-validation dataset were merged into one dataset (n=952) used for calibrating the adapted Stoffenmanager algorithms. This new calibration resulted in new exposure algorithms for the four scenarios.

Conclusions

The Stoffenmanager is capable of discriminating among exposure levels mainly between scenarios in different companies. The 90th percentile estimates of the Stoffenmanager are verified to be sufficiently conservative. Therefore, the Stoffenmanager could be a useful tier 1 exposure assessment tool for REACH.
Long-term exposure to traffic-related air pollution and mortality in Shizuoka, Japan
Authors: Yorifuji Takashi , Kashima Saori , Tsuda Toshihide , Takao Soshi , Suzuki Etsuji , Doi Hiroyuki , Sugiyama Masumi , Ishikawa-Takata Kazuko , Ohta Toshiki
Published: September 2009

Objectives

The number of studies investigating the health effects of long-term exposure to air pollution is increasing, however, most studies have been conducted in Western countries. The health status of Asian populations may be different to that of Western populations and may, therefore, respond differently to air pollution exposure. Therefore, we evaluated the health effects of long-term exposure to traffic-related air pollution in Shizuoka, Japan.

Methods

Individual data were extracted from participants of an ongoing cohort study. A total of 14 001 older residents, who were randomly chosen from all 74 municipalities of Shizuoka, completed questionnaires and were followed from December 1999 to March 2006. Individual nitrogen dioxide exposure data, as an index for traffic-related exposure, were modelled using a land use regression model. We assigned participants an estimated concentration of nitrogen dioxide exposure during 2000–2006. We then estimated the adjusted HR and their CI for a 10 μg/m3increase in exposure to nitrogen dioxide for all-cause or cause-specific mortality.

Results

The adjusted HR for all-cause mortality was 1.02 (95% CI 0.96 to 1.08). Regarding cause-specific mortality, the adjusted HR for cardiopulmonary mortality was 1.16 (95% CI 1.06 to 1.26); in particular the adjusted HR for ischaemic heart disease mortality was 1.27 (95% CI 1.02 to 1.58) and for pulmonary disease mortality it was 1.19 (95% CI 1.02 to 1.38). Furthermore, among non-smokers, a 10 μg/m3increase in nitrogen dioxide was associated with a higher risk for lung cancer mortality (HR 1.30, 95% CI 0.85 to 1.93).

Conclusion

Long-term exposure to traffic-related air pollution, indexed by nitrogen dioxide concentration, increases the risk of cardiopulmonary mortality, even in a population with a relatively low body mass index and increases the risk of lung cancer mortality in non-smokers.
Manipulation of Reproductive Function in Atlantic Salmon (Salmo salar) Kelts with Controlled Photoperiod and Temperature
Authors: Johnston C. E. , Hambrook M. J. , Gray R. W. , Davidson K. G.
Published: September 2009

Atlantic salmon (Salmo salar) kelts exposed to a regime of two 6-mo seasonally accelerated light increases and decreases (2CP) in 1989 spawned in the spring of 1990 when water temperatures were above 7 °C during the winter months. Kelts exposed to water temperatures below 4 °C during the same period failed to spawn in the spring. Exposure of the nonspawning 2CP kelts to warmer water temperatures in the summer of 1990 stimulated egg development and ovulation by 17 October 1990. Kelts exposed to a simulated natural 12-mo photoperiod regime also spawned at this time. Eggs and sperm from kelts spawned in the spring were viable. Spring-spawned eggs fertilized with fresh sperm had lower survival levels to the eyed-egg stage or to hatch than did eggs from wild fall-spawned stocks. Kelts entrained to spawn in the spring with 2CP photocycles were manipulated to spawn again in the spring of the next year following exposure to a time-shifted photoperiod and elevated winter/spring water temperature.
Chronic Toxicity and Metabolism of Cd and Zn in Juvenile Minnows (Phoxinus phoxinus) Exposed to a Cd and Zn Mixture
Authors: Glynn Anders Wicklund , Haux Carl , Hogstrand Christer
Published: September 2009

Minnows (Phoxinus phoxinus) were exposed in the laboratory to 3 nM Cd (Cd group), 2000 nM Zn (Zn group), or to both metals (CdZn group) in soft water for 142 d. A fourth group was kept with no metals added to the water (Low group). After 80 d, the Cd and Zn groups were statically exposed to 109Cd and 65Zn, respectively, for 24 h. The CdZn group was exposed to both tracers. Fish were sampled for 61 d after the tracer exposure. At the end of the experiment, an increased metallothionein level was detected in the kidney of fish exposed to the metal mixture (Low group: 0.14 nmol/g fish; CdZn group: 0.54 nmol/g fish). However, the fish did not acquire tolerance to the metals because mortality continued at a constant rate during the whole experiment. Metabolism of Cd and Zn was altered in fish exposed to the metal mixture compared with fish exposed to Cd or Zn alone. The main effect was a Zn-induced increase in Cd turnover rate in the fish. Nevertheless, the toxic action of metals was additive, since mortality at the end of the experiment was 24, 32, and 54% in the Zn, Cd, and CdZn groups, respectively.
Bioaccumulation of PCBs from Sediments by Oligochaetes and Fishes: Comparison of Laboratory and Field Studies
Authors: Ankley Gerald T. , Cook Philip M. , Carlson Anthony R. , Call Daniel J. , Swenson Julie A. , Corcoran Henry F. , Hoke Robert A.
Published: September 2009

Fathead minnows (Pimephales promelas) and oligochaetes (Lumbriculus variegatus) were exposed in the laboratory to sediment samples from the lower Fox River/Green Bay, and their bioaccumulation of PCBs was compared with PCB concentrations in synoptic collections of fish (black bullhead, Ameiurus melas) and oligochaetes (primarily Limnodrilus sp.) from the field. Total PCBs and PCB homologues (expressed as lipid-normalized tissue concentrations/organic carbon-normalized sediment concentrations) were qualitatively and quantitatively similar in the laboratory-exposed and field-collected oligochaetes. PCB concentrations in A. melas generally were greater than in any of the other test species, due possibly to differences in exposure (e.g. biomagnification) compared with the other organisms. PCB concentrations in P. promelas were consistently smaller than in any of the other species investigated. These results indicate that, under the exposure regime used in this study, laboratory tests with L. variegatus can provide a reasonable quantitative estimate of the bioaccumulation of PCBs in field populations of oligochaetes. However, the use of P. promelas in laboratory sediment tests may result in significant underprediction of the exposure of indigenous benthic invertebrates and fishes to bioaccumulable contaminants.
Size Selectivity of Diamond and Square Mesh Codends in Pelagic Herring Trawls: Only Small Herring Will Notice the Difference
Authors: Suuronen Petri , Millar Russell B.
Published: September 2009

A twin codend trawl was fished in the northern Baltic to study the size selectivity of square mesh and diamond mesh codends of 36-mm nominal mesh size. For each codend, 15 hauls were completed with a small mesh (20 mm) codend deployed on the other side of the trawl. The relative size of the catches in the two sides of the trawl varied considerably from haul to haul (the separator section was not operating properly) and selection curves were estimated from each individual haul using a method that incorporated the differences in catching efficiency of the two sides. The length of 50% retention decreased with increased catch for both the diamond and square mesh codends, although in neither case was this relationship statistically significant. Selection curves fitted to the combined haul data were asymmetric. The square mesh codend retained significantly less small herring than the diamond mesh codend, and for larger herring the two codends had similar selectivity. In both codends, most escapes occurred at the front of the catch bulge, from the upper side of the codend. At high catch rates, mesh blockage was observed for several metres ahead of the catch bulge during the later part of the tow.
Temporal and Spatial Dynamics in Riverbed Chemistry: The Influence of Flow and Sediment Composition
Authors: Chambers P. A. , Prepas E. E. , Gibson K.
Published: September 2009

To characterize the nutrient pool in the riverbed of an unregulated river in western Canada and identify factors controlling spatial and temporal variability, nitrogen and phosphorus concentrations in open water, porewater, and sediment-exchangeable pools were monitored in the Pembina River, Alberta, at three sites that differed in sediment composition (cobble, sand, and fine sediments). Comparison of porewater chemistry for three years showed that interannual variation was related to discharge rate (22, 87, and 68 m3/s for May–November 1988, 1989, and 1990, respectively) and changes in the size composition of the bottom sediments. However, within-year variations in riverbed chemistry were not correlated with either flow or current velocity. These results suggest that large-scale interannual changes in flow act as a set-point mechanism, defining the particle size composition and chemistry of the riverbed; flow changes of short duration had no predictable effect on riverbed chemistry. Our finding on the highly dynamic nature of riverbed chemistry has important implications for benthic productivity and elemental fluxes between surface waters and the riverbed because dramatic changes in riverbed chemistry can occur in the span of a year even without a flushing scour.
Community Response to Cumulative Toxic Impact: Effects of Acclimation on Zinc Tolerance of Aufwuchs
Authors: Niederlehner B. R. , Cairns Jr. John
Published: September 2009

Aufwuchs communities were developed on artificial substrates in a local pond. Second-generation communities were developed on identical substrates in laboratory systems receiving three levels of zinc (Zn): background, 73, and 172 μg∙L−1. After 21 d, second-generation communities were exposed to five concentrations of Zn ranging from background to 10 078 μg∙L−1 for 48 h. Protozoan communities developed under Zn stress were initially less rich taxonomically but subsequently lost fewer species in response to acute Zn exposures. Richness remaining after exposure to high Zn levels [Formula: see text] was similar for all groups. Taxonomic composition changed less in acclimated communities than in the control in response to secondary stress. Gross primary productivity was less impaired by secondary stress in communities acclimated to Zn. Community respiration, algal biomass, total biomass, respiration to biomass ratios, and ratios of soluble to total reactive phosphates did not differ in response to secondary stress. In general, communities developed under Zn stress were initially impaired but changed less in response to additional stress relative to their initial state.
Patterns of Life-History Diversification in North American Fishes: implications for Population Regulation
Authors: Winemiller Kirk O. , Rose Kenneth A.
Published: September 2009

Interspecific patterns of fish life histories were evaluated in relation to several theoretical models of life-history evolution. Data were gathered for 216 North American fish species (57 families) to explore relationships among variables and to ordinate species. Multivariate tests, performed on freshwater, marine, and combined data matrices, repeatedly identified a gradient associating later-maturing fishes with higher fecundity, small eggs, and few bouts of reproduction during a short spawning season and the opposite suite of traits with small fishes. A second strong gradient indicated positive associations between parental care, egg size, and extended breeding seasons. Phylogeny affected each variable, and some higher taxonomic groupings were associated with particular life-history strategies. High-fecundity characteristics tended to be associated with large species ranges in the marine environment. Age at maturation, adult growth rate, life span, and egg size positively correlated with anadromy. Parental care was inversely correlated with median latitude. A trilateral continuum based on essential trade-offs among three demographic variables predicts many of the correlations among life-history traits. This framework has implications for predicting population responses to diverse natural and anthropogenic disturbances and provides a basis for comparing responses of different species to the same disturbance.
AN INTRODUCTION TO QUANTITATIVE POINCARÉ RECURRENCE IN DYNAMICAL SYSTEMS
Authors: SAUSSOL BENOIT
Published: September 2009

We present some recurrence results in the context of ergodic theory and dynamical systems. The main focus will be on smooth dynamical systems, in particular, those with some chaotic/hyperbolic behavior. The aim is to compute recurrence rates, limiting distributions of return times, and short returns. We choose to give the full proofs of the results directly related to recurrence, avoiding as much as possible to hide the ideas behind technical details. This drove us to consider as our basic dynamical system a one-dimensional expanding map of the interval. We note, however, that most of the arguments still apply to higher dimensional or less uniform situations, so that most of the statements continue to hold. Some basic notions from the thermodynamic formalism and the dimension theory of dynamical systems will be recalled.
ANOMALOUS BEHAVIOR OF IDEAL FERMI GAS BELOW 2D: THE "IDEAL QUANTUM DOT" AND THE PAUL EXCLUSION PRINCIPLE
Authors: GRETHER M. , DE LLANO M. , LEE M. HOWARD
Published: September 2009

A physical interpretation is given to a curious "hump" that develops in the chemical potential as a function of absolute temperature in an ideal Fermi gas for any spatial dimensionality d < 2, integer or not, in contrast with the more familiar monotonic decrease for all d ≥ 2. The hump height increases without limit as d decreases to zero. The divergence at d = 0 is shown to be a clear manifestation of the Pauli Exclusion Principle whereby two spinless fermions cannot sit on top of each other in configuration space. The hump itself is thus an obvious precursor of this manifestation, otherwise well understood in momentum space. It also constitutes an "ideal quantum dot" when d = 0.
ON THE QUANTUM HALL EFFECT IN GRAPHENE
Authors: FUJITA SHIGEJI , KIM JEONG-HYUK , ITO KEI , DE LLANO MANUEL
Published: September 2009

The unusual quantum Hall effect (QHE) in graphene is often discussed in terms of Dirac fermions moving with a linear dispersion. A new theory describing the same phenomena is presented in terms of the more traditional composite bosons. The "electron" (wave packet) is shown to move easier in the direction [110] ≡ [110 c- axis ] of the honeycomb lattice than perpendicular to it, while the "hole" moves easier in [001]. Since "electrons" and "holes" move in different channels, the number densities can be very high especially when the Fermi surface has "necks". The strong QHE at filling factor ν = 2 arises from the "neck" Fermi surfaces.
MODELLING CHARGE TRANSPORT IN DNA USING TRANSFER MATRICES WITH DIAGONAL TERMS
Authors: WELLS STEPHEN A. , SHIH CHI-TIN , RÖMER RUDOLF A.
Published: September 2009

There is increasing evidence that DNA can support a considerable degree of charge transport along the strand by hopping of holes from one base to another, and that this charge transport may be relevant to DNA regulation, damage detection and repair. A surprisingly useful amount of insight can be gained from the construction of simple tight-binding models of charge transport, which can be investigated using the transfer-matrix method. The data thus obtained indicate a correlation between DNA charge-transport properties and the locations of cancerous mutation. We review models for DNA charge transport and their extension to include more physically realistic diagonal-hopping terms.