bluuebunny/crossref_metadata_2025_split huggingface dataset:
The role of food, weather and climate in limiting the abundance of animals
Authors: White T. C. R. 
Published: June 2008

AbstractMore and more studies are demonstrating that populations of animals ‐ from herbivores to top predators, vertebrates and invertebrates ‐ are limited by their food, and that the availability of this food is dictated by the weather. Satellite monitoring is revealing how cyclic and quasi‐cyclic climatic patterns, like the El Niño Southern Oscillation and the North Atlantic Oscillation, are driving and synchronising these weather‐driven changes in the supplies of food. Changes in the amount of food available operate to limit the abundance of populations largely through their influence on the survival of the very young: the Achilles heel of all populations.Any individual organism struggles to use whatever resources it can get from a mostly inhospitable environment to maximise the proliferation of its genes. Each level of a food chain is thus dependent upon, and pressing hard against the limits set by the one below. The resulting intra‐ and inter‐specific interactions produce a multitude of complex outcomes, that significantly influence the dynamics of populations, but do not determine their ultimate size. There is no density‐dependent regulation of abundance. Intra‐specific competition does not determine the size of populations, it only decides which few individuals gain access to the limited food. Nor do predators regulate their prey. They, too, are limited by their food, and the abundance and quality of food is dictated by the weather.
Origin and evolution of the protein‐repairing enzymes methionine sulphoxide reductases
Authors: Zhang Xing‐Hai , Weissbach Herbert 
Published: June 2008

AbstractThe majority of extant life forms thrive in an O2‐rich environment, which unavoidably induces the production of reactive oxygen species (ROS) during cellular activities. ROS readily oxidize methionine (Met) residues in proteins/peptides to form methionine sulphoxide [Met(O)] that can lead to impaired protein function. Two methionine sulphoxide reductases, MsrA and MsrB, catalyse the reduction of the S and R epimers, respectively, of Met(O) in proteins to Met. The Msr system has two known functions in protecting cells against oxidative damage. The first is to repair proteins that have lost activity due to Met oxidation and the second is to function as part of a scavenger system to remove ROS through the reversible oxidation/reduction of Met residues in proteins. Bacterial, plant and animal cells lacking MsrA are known to be more sensitive to oxidative stress. The Msr system is considered an important cellular defence mechanism to protect against oxidative stress and may be involved in ageing/senescence. MsrA is present in all known eukaryotes and eubacteria and a majority of archaea, reflecting its essential role in cellular life. MsrB is found in all eukaryotes and the majority of eubacteria and archaea but is absent in some eubacteria and archaea, which may imply a less important role of MsrB compared to MsrA. MsrA and MsrB share no sequence or structure homology, and therefore probably emerged as a result of independent evolutionary events. The fact that some archaea lack msr genes raises the question of how these archaea cope with oxidative damage to proteins and consequently of the significance of msr evolution in oxic eukaryotes dealing with oxidative stress. Our best hypothesis is that the presence of ROS‐destroying enzymes such as peroxiredoxins and a lower dissolved O2 concentration in those msr‐lacking organisms grown at high temperatures might account for the successful survival of these organisms under oxidative stress.
Osteology of Icadyptes salasi, a giant penguin from the Eocene of Peru
Authors: Ksepka Daniel T. , Clarke Julia A. , DeVries Thomas J. , Urbina Mario 
Published: June 2008

AbstractWe present the first detailed description of the giant Eocene penguin Icadyptes salasi. The species is characterized by a narrow skull with a hyper‐elongate spear‐like beak, a robust cervical column and a powerful flipper. The bony beak tip of Icadyptes is formed by fusion of several elements and is unique among penguins, differing markedly from previously described giant penguin beaks. Vascular canal patterning similar to that of boobies, frigatebirds and albatrosses suggests I. salasi may have had a thin, sheet‐like rhamphotheca unlike the thick rugose rhamphotheca of modern penguins. Together, these features suggest a novel ecology for I. salasi, most likely involving the capture of larger prey items via spearing. As the first described giant penguin specimen to preserve a complete wing skeleton, the I. salasi holotype yields significant insight into the shape, proportions and orientation of the wing in giant penguins. In articulation, the forelimb of I. salasi is straighter, permitting less manus and antibrachium flexion, than previous depictions of giant penguin wings. Cross‐sections of the humerus and ulna reveal a level of osteosclerosis equalling or surpassing that of extant penguins. Based on ontogenetic data from extant penguins and the morphology of the carpometacarpus of I. salasi, we infer the retention of a free alular phalanx in basal penguins. Previously, the status of this element in penguins was disputed. Differences in the proportions of the manual phalanges contribute to a more abruptly tapering wingtip in I. salasi compared with crown penguins. Fossils from Peru, including the I. salasi holotype specimen, document that penguins expanded to nearly the whole of their extant latitudinal range early in their evolutionary history and during one of the warmest intervals in the Cenozoic.
Preschoolers’ sleep behaviour: associations with parental hardiness, sleep‐related cognitions and bedtime interactions
Authors: Johnson Nikki , McMahon Catherine 
Published: June 2008

Background:  Childhood sleep problems which are prevalent in Western societies are associated with a wide range of emotional, cognitive and behavioural disturbances. Growing evidence suggests that parents play a pivotal role in children's sleep behaviour and that a parenting style which promotes self‐regulation is beneficial. This study tested a unique model that included parental hardiness, sleep‐related cognitions, bedtime interactions and child sleep behaviour.Methods:  Parents (N = 110) with a child attending preschool (mean age = 3.81 years, SD = .84) responded to a survey assessing their level of hardiness, sleep‐related cognitions, bedtime interactions and their child's sleep behaviour and temperament. Secondary caregivers completed a survey assessing child sleep and temperament, and teachers/childcare workers also reported on child temperament.Results:  In line with previous research, 37% of children in this community sample met criteria for a sleep problem. Regression analyses and structural equation modelling confirmed that low parental hardiness, problematic sleep‐related cognitions and a greater number of parental interactions at bedtime significantly predicted child sleep problems, after considering child temperament.Conclusions:  This study's theoretically driven model not only offers an explanation for what contributes to and maintains sleep problems in childhood but also suggests new areas for research. Importantly, the model can also be readily translated into clinical interventions to develop and enhance effective authoritative parenting.
Feasibility and behavioral effects of an at‐home multi‐night sleep restriction protocol for adolescents
Authors: Beebe Dean W. , Fallone Gahan , Godiwala Neha , Flanigan Matt , Martin David , Schaffner Laura , Amin Raouf 
Published: June 2008

Background:  Sleep deprivation is common among adolescents and has been associated with adverse behavioral and educational outcomes. However, it is difficult to draw strong causal conclusions because of a dearth of experimental sleep research. In part, this appears related to methodological challenges when working with this population. This study tested the feasibility and behavioral effects of a multi‐night, at‐home experimental sleep restriction protocol in a sample of adolescents.Methods:  Twenty healthy adolescents aged 13.9–16.9 years were enrolled in a three‐week sleep manipulation protocol using a counterbalanced cross‐over experimental design. The protocol included a baseline week, followed in random order by a short sleep week (Monday–Friday nights limited to 6.5 hours time in bed) and an extended sleep week (10 hours lights‐out time in bed Monday–Friday nights). Sleep was monitored via self‐report and objective actigraphy. These were reviewed with participants and parents on the Saturdays at the end of each week, when parents and participants also completed behavior rating questionnaires.Results:  One participant dropped out of the study, but each of the remaining 19 displayed markedly less sleep in the short sleep condition than the extended sleep condition (average nightly gap ∼2.5 hours). Data also reflected indirect effects of sleep deprivation that are consistent with an increase in homeostatic sleep drive. Compared to the extended sleep week, parents during the short sleep week reported that the participants displayed significantly greater problems with sleepiness, attention, oppositionality/irritability, behavior regulation, and metacognition. Participant self‐report results were similar, though less robust.Conclusions:  A multi‐night, at‐home sleep manipulation protocol for use with adolescents is indeed feasible. This study also provided the first experimental evidence that chronic sleep restriction during adolescence is causally related to a wide range of behavioral deficits.
Poor utility of the age of onset criterion for DSM‐IV attention deficit/hyperactivity disorder: recommendations for DSM‐V and ICD‐11
Authors: Todd Richard D. , Huang Hongyan , Henderson Cynthia A. 
Published: June 2008

Background:  To test whether the retrospective reporting of the age of onset impairment criterion for attention deficit/hyperactivity disorder (ADHD) required in the Diagnostic and Statistical Manual of Mental Disorders – IV (DSM‐IV) complicates identification of new and known child and adolescent cases later in life.Methods:  A birth‐records‐based cohort of twins assessed at ages 7 to 19 years were blindly reassessed five years later using the MAGIC interview. Study outcome measures were differences in reported ages of onset for attention deficit/hyperactivity disorder (ADHD), oppositional defiant disorder (ODD), conduct disorder (CD) and major depressive disorder (MDD).Results:  For all age groups and respondents (parent on youth or youth self‐report), later ages of ADHD onset were reported five years later. The same phenomenon was also present for the other diagnostic groups. Of the initial ADHD individuals who continued to meet all other ADHD criteria at follow‐up, 46% failed the age of onset criterion five years later. When ignoring the age of onset criterion, late onsets of ages 7–16 years accounted for about 10% of all ADHD.Conclusions:  Use of the DSM‐IV age of onset criterion for attention deficit/hyperactivity disorder in the assessment of adolescents and young adults results in under‐identification of affected individuals. Consideration should be given to revising the current nomenclatures to reflect the reality of retrospective reporting errors in age of onset as well as the presence of late onset cases.
The developmental course of illicit substance use from age 12 to 22: links with depressive, anxiety, and behavior disorders at age 18
Authors: Lansford Jennifer E. , Erath Stephen , Yu Tianyi , Pettit Gregory S. , Dodge Kenneth A. , Bates John E. 
Published: June 2008

Background:  Previous theory and research suggest links between substance use and externalizing behavior problems, but links between substance use and internalizing problems are less clear. The present study sought to understand concurrent links among diagnoses of substance use disorders, internalizing disorders, and behavior disorders at age 18 as well as developmental trajectories of illicit substance use prior to and after this point.Methods:  Using data from 585 participants in the Child Development Project, this study examined comorbidity among substance use, behavior, and internalizing disorders at age 18 and trajectories of growth in illicit substance use from age 12 to age 22.Results:  In this community sample, meeting diagnostic criteria for comorbid internalizing disorders, a behavioral disorder (conduct disorder or oppositional defiant disorder) alone, or both internalizing and behavioral disorders predicted higher concurrent substance use disorders (abuse, dependence, or withdrawal). Meeting diagnostic criteria for an anxiety disorder alone or depression alone did not predict higher concurrent substance use diagnoses. Over time, youths with behavioral disorders at age 18 showed a pattern of increasing substance use across early adolescence and higher levels of substance use than those with no diagnosis at age 18. Substance use declines from late adolescence to early adulthood were observed for all groups.Conclusions:  Substance use disorders were more highly comorbid with behavior disorders than with internalizing disorders at age 18, and behavior disorder and comorbid behavior‐internalizing disorders at age 18 were related to trajectories characterized by steep increases in illicit substance use during adolescence and high rates of illicit substance use over time.
What’s in a game: the effect of social motivation on interference control in boys with ADHD and autism spectrum disorders
Authors: Geurts Hilde M. , Luman Mariolein , Van Meel Catharina S. 
Published: June 2008

Background:  Children with attention deficit hyperactivity disorder (ADHD) and with autism spectrum disorders (ASD) are known to have cognitive control deficits. Some studies suggest that such deficits may be reduced when motivation is increased through tangible reinforcers. Whether these deficits can also be modulated by non‐tangible reinforcers has hardly been studied.Methods:  Therefore, the effect of social motivation on the ability to suppress irrelevant information (i.e., interference control) was investigated in 22 ADHD boys, 22 ASD boys, and 33 typically developing (TD) boys. An adapted Eriksen Flanker task was administered under a motivational condition in which the boys were told that they were competing with peers, and under a neutral condition in which standard instructions were given.Results:  In comparison with TD boys, boys with ADHD were impaired even when no interference was present, while this was not the case for the ASD boys. All groups benefited from the motivation manipulation, i.e., their performance increased when they thought they were competing with peers. Although the boys with ADHD were still slower than TD boys when motivated, they performed as accurately as TD boys. Children with ASD also improved slightly in accuracy and response speed, but this did not reach significance.Conclusion:  Children with ADHD are able to exert sufficient cognitive control when they are motivated, which is in line with the current models of ADHD. However, motivation seems to have a general effect on performance and is not solely related to cognitive control abilities. In contrast, this effect was not obtained in children with ASD.
Fetal origins of child non‐right‐handedness and mental health
Authors: Rodriguez Alina , Waldenström Ulla 
Published: June 2008

Background:  Environmental risk during fetal development for non‐right‐handedness, an index of brain asymmetry, and its relevance for child mental health is not fully understood.Methods:  A Swedish population‐based prospective pregnancy–offspring cohort was followed‐up when children were five years old (N = 1714). Prenatal environmental risk exposures were the number of ultrasound examinations and maternal distress during pregnancy. Child mental health, including symptoms of attention deficit hyperactivity disorder (ADHD), language difficulties, and care‐seeking for child behavior problems, was assessed via maternal and/or kindergarten teacher’s ratings.Results:  Prenatal exposure to maternal depressive symptoms and critical life events were associated with increased risk of child non‐right‐handedness and mixed handedness, after adjustment for parity, maternal age, birth outcomes, infant sex, and parental handedness. No association was found between handedness and number of ultrasound examinations. Non‐right and mixed‐handedness, rather than left‐handedness, were associated with increased risk of language difficulties and particularly with ADHD symptoms, after adjustment for current parental ADHD symptoms, current maternal depressive symptoms, birth outcomes, smoking during pregnancy, depressive symptoms and critical life events. Problems were significant enough to prompt mothers to seek care for children’s behavioral problems, and parents were more likely to have received advice from the children’s kindergarten teachers to seek care.Conclusions:  This study suggests that mixed‐handedness, i.e., reflecting atypical brain laterality, can be a marker of both severity of prenatal exposure to maternal distress and of increased risk of ADHD symptoms in childhood. Our results support the idea that the fetal environment plays a role in subsequent child mental health.
Emotion regulation and internalizing symptoms in a longitudinal study of sexual minority and heterosexual adolescents
Authors: Hatzenbuehler Mark L. , McLaughlin Katie A. , Nolen‐Hoeksema Susan 
Published: June 2008

Background:  Sexual minority adolescents appear to be at increased risk for internalizing disorders relative to their heterosexual peers, but there is a paucity of research explaining this elevated risk. Emotion regulation deficits are increasingly understood as important predictors of internalizing psychopathology among general samples of adolescents. The present study sought to examine whether deficits in emotion regulation could account for disparities in internalizing symptoms between sexual minority and heterosexual adolescents.Methods:  The present study utilized longitudinal data from a racially/ethnically diverse (68% non‐Hispanic Black and Hispanic/Latino) community sample of 1,071 middle school students (ages 11–14).Results:  Adolescents who endorsed same‐sex attraction evidenced higher rates of internalizing symptoms at both time points. Structural equation modeling indicated that sexual minority adolescents exhibited greater deficits in emotion regulation (rumination and poor emotional awareness) than their heterosexual peers. Emotion regulation deficits in turn mediated the relationship between sexual minority status and symptoms of depression and anxiety.Conclusions:  The results demonstrate the importance of considering normative psychological processes in the development of internalizing symptomatology among sexual minority adolescents, and suggest emotion regulation deficits as specific targets of prevention and intervention efforts with this population. Future studies are needed to determine whether stigma‐related stressors are responsible for emotion regulation deficits among sexual minority youth.
Consumer empowerment: global context, UK strategies and vulnerable consumers
Authors: Brennan Carol , Coppack Martin 
Published: June 2008

AbstractGlobalization has created new consumer needs and wants, and resulted in consumer confusion regarding the increasing complexity of products and services. This has stimulated global interest in educating and empowering consumers. The UK government has made a very ambitious commitment to ensure that the framework for consumer empowerment and support is at the level of the best in the world by 2008. The government, many consumer organizations and regulators believe that empowered consumers are key to the success of competitive markets. Two national strategies to co‐ordinate activities in the UK have been developed by the Office of Fair Trading (OFT) and the Financial Services Authority (FSA). The OFT consumer education strategy aims to deliver targeted, effective consumer education by increasing co‐ordination and making the best use of available resources. The FSA is leading a financial capability strategy designed to deliver change to improve the UK's financial capability. Both strategies share a vision of educated and confident consumers making informed choices about the products and services they buy, and both aim to empower vulnerable consumers. Given the global interest and the development of national strategies, it is useful to consider what is meant by the term consumer empowerment. Is there a shared view of consumer empowerment internationally? Does the education of consumers result in empowered consumers? To what extent do the national strategies address the empowerment of vulnerable, disadvantaged, excluded or susceptible consumers? These questions will be addressed in this article which reviews the global context for the consumer education and empowerment agenda and considers key UK developments, with particular reference to the needs of vulnerable consumers. The study found that the language of consumer empowerment is gaining prominence in policy and strategy documents at the highest levels internationally in the Organisation of Economic Cooperation and Development and the European Community, and nationally in the UK.
Customer loyalty to food retailers in Northern Ireland: ‘devoted loyals’ or ‘promiscuous switchers’?
Authors: Doherty Susan , Nelson Roy 
Published: June 2008

AbstractStore loyalty is a major challenge for food retailers, and the food retail market in Northern Ireland has been subject to considerable change in the past decade. Although shoppers will often patronize many stores, they typically have a primary affiliation to a ‘main’ food store that captures the majority of their food purchases. This study uses a unique approach to segmenting customers into groups based on loyalty in terms of both the type of data used to generate a loyalty score and the data collection techniques used. Innovative projective techniques have been used alongside traditional questioning techniques to reveal ‘behavioural’ and ‘emotional’ loyalty indicators, and in doing so create a holistic measure of customer loyalty to a main food store, allowing customers to be segmented into groups based on loyalty. A paper‐based questionnaire was administered to 152 food shoppers from throughout Northern Ireland. Responses to traditional questioning formats and projective techniques (cartoon friends and mini case studies) were analysed and used to generate a loyalty score for each respondent. The first group of customers nearly always visit the same store, are willing to recommend the store to others and are less likely to switch to a competitor, even when offered an incentive to do so. They also rate the ‘hard’ attributes of this store highly. As a result of these characteristics, customers in this segment were termed ‘devoted loyals’. The second group of customers may occasionally use a different supermarket for food shopping, some would consider switching to a competitor if offered an incentive, and they rate ‘hard’ store attributes at a slightly lower level than the ‘devoted loyals’. Based on their group profile, these customers were assigned the title of ‘susceptibles’. The third group of customers are less willing to actively encourage friends and family to shop at a specific store. Many in this group did not consider their current store as their number one choice in the next few years. An incentive to switch to a competitor store is more likely to trigger a transfer of loyalty by this group. These customers were termed ‘promiscuous switchers’.