bluuebunny/crossref_metadata_2025 huggingface dataset:
Capturing perceptions: Prisoners assess their health services ‐ Australia, 2001 and 2004
Authors: Barling Jacob , Halpin Rhonda , Levy Michael
Published: March 2006

There is little literature on patient satisfaction related to prisoner health services; the little that does exist refers to specific services, or to sub‐groups of prisoner‐patients. We describe a general assessment of prisoner health services conducted on two separate occasions each with a collective sample of 210 participants, three years apart, using the same instrument. We utilised the World Health Organization Rapid Cluster Sample Survey on both occasions. We conclude that prisoners are interested informants for the health services provided to them. They have valid concerns about the confidentiality of their medical records. Programs and work routines have major impacts on accessibility of prison‐based health services. Given the lack of choice in service‐providers for prisoners, greater flexibility is required by health and custodial agencies to accommodate these two competing areas of activity. We demonstrated that a health service targeting an ‘at risk’ population can respond to inadequacies in service provision.
Finally, we confirmed that the World Health Organization Rapid Cluster Sample Survey methodology is an efficient and effective means of assessing health services to discrete populations.
Women and healthcare in prison: An overview of the experiences of imprisoned women in Italy
Authors: Zoia Donatella
Published: March 2006

The article will discuss the particular needs of women prisoners, many of which are replicated in prisons throughout Europe, and are also often undetected and underestimated. The focus will be on the situation for women in Italian prisons, considering the specific health and social care needs they present, how some needs differ to those of male prisoners, and to what extent the organisation of prison health attempts to meet these needs. The key issue identified is that the organisation of prison health deals predominantly with emergency cases and is not able to provide a preventative healthcare service to women in prison. Also, women prisoners suffer a greater impact on their physical and mental well‐being as a result of poor implementation of healthcare services, as well as from the regime of prison itself.
Prisons as regional drivers of HIV/AIDS and tuberculosis in some Central Asian countries: A matter of ‘least eligibility’?
Authors: Walcher Gesa
Published: March 2006

The Central Asian republics are among the countries which currently experience the world’s fastest growing HIV/AIDS epidemic. At the same time, they are threatened by the re‐emergence of tuberculosis (TB), with the highest rates of new TB cases among the Former Soviet Republics. One of the groups that is at highest risk from TB and HIV/AIDS and that is, at the same time, the major regional drivers of the epidemics is the prison population. Up to an estimated third of HIV/AIDS infected persons in Central Asia are within the penitentiary system. At the same time, prisons are known to be the ‘epidemiological pump’ for TB in the region, fuelled by overcrowding, poor ventilation and inadequate nutrition. Both AIDS and TB incidence and death rates among prisoners are much higher than in the civilian population, with an alarming rising trend. Prison health is a key
issue of public interest, especially in the context of an epidemiological crisis as in Central Asia. This paper looks at the spread of HIV/AIDS and TB in the region and analyses the role prisons play as one of the main multipliers.
Childhood abuse, limited intervention and homelessness: Pathways to the mental health and justice systems
Authors: Liddell Max
Published: March 2006

This paper explores a major pathway that lead people into the ranks of the homeless, the mental health and the justice systems ‐ abuse as a child followed by time in the care of the state. The focus is on Australia with particular emphasis on the Australian state of Victoria as a case example and on the child welfare systems which produce these outcomes. The author argues that child welfare analyses are usually too narrow in their focus. The paper examines the history of the development of child welfare systems in Australia since white settlement in the various colonies in the late eighteenth and early nineteenth centuries. The author demonstrates some of the wide variety of factors that produce the many negative child welfare outcomes. The original focus of child welfare systems in Australia were largely on social control of the street behaviours of children and the perceived immoral behaviour of their parents, especially their mothers. The developing systems further featured parsimonious service provision, limited visions for the future of the children, and exploitation of their labour. Swings to and from institutional and foster care as the key program responses were usually based on inadequacies of previous systems, the perceived need to control costs, and the perceived inadequacies of the non‐government service providers, rather than careful analysis of and response to the needs of children. Service redevelopment and especially
reliance on family support in the late twentieth century has occurred while the traditional issues and problems, including abuse of children in care, remain current and unresolved. The development of managerialist public service practices in recent decades has added to the traditional isolation and lack of integration of the various child welfare components and actively hindered the development of an integrated system. An emphasis on minimal intervention, together with the other factors, has produced a situation in which children are frequently left at risk by the very systems supposed to protect them. The author concludes that not only do the lessons and mistakes of history need to be heeded, but that the principles, programs and management practices of child welfare need to be seen in combination as the factors which set child welfare clients on the road to homelessness or mental health and justice facilities.
Incarcerated women: Consequences and contributions of victimization and intervention
Authors: Severson Margaret , Postmus Judy L. , Berry Marianne
Published: March 2006

The increasing rate of imprisonment of women in the United States and the over‐representation of women victims of violence in the corrections system confirms that there are long‐term, often substantially debilitating consequences to women victims of intimate partner violence, sexual violence
and youth maltreatment and injury, including incarceration. As part of a study funded by the National Institute of Justice, the authors pursued an exploration of the personal risks, resiliencies and life opportunities that make a difference in the lives of women who have ended up incarcerated. The findings of this study about the prevalence and consequences of youth maltreatment and adult victimization and the mitigating factors, which may have had an impact on the life trajectories of adult incarcerated women will be reviewed. Recommendations will be given for preventive and interventive policy and practice measures that stand to reduce the negative consequences of victimization, particularly those that can prevent incarceration.
Novel role of neuronal Ca2+ sensor-1 as a survival factor up-regulated in injured neurons
Authors: Nakamura Tomoe Y. , Jeromin Andreas , Smith George , Kurushima Hideaki , Koga Hitoshi , Nakabeppu Yusaku , Wakabayashi Shigeo , Nabekura Junichi
Published: March 2006

A molecular basis of survival from neuronal injury is essential for the development of therapeutic strategy to remedy neurodegenerative disorders. In this study, we demonstrate that an EF-hand Ca2+-binding protein neuronal Ca2+ sensor-1 (NCS-1), one of the key proteins for various neuronal functions, also acts as an important survival factor. Overexpression of NCS-1 rendered cultured neurons more tolerant to cell death caused by several kinds of stressors, whereas the dominant-negative mutant (E120Q) accelerated it. In addition, NCS-1 proteins increased upon treatment with glial cell line–derived neurotrophic factor (GDNF) and mediated GDNF survival signal in an Akt (but not MAPK)-dependent manner. Furthermore, NCS-1 is significantly up-regulated in response to axotomy-induced injury in the dorsal motor nucleus of the vagus neurons of adult rats in vivo, and adenoviral overexpression of E120Q resulted in a significant loss of surviving neurons, suggesting that NCS-1 is involved in an antiapoptotic mechanism in adult motor neurons. We propose that NCS-1 is a novel survival-promoting factor up-regulated in injured neurons that mediates the GDNF survival signal via the phosphatidylinositol 3-kinase–Akt pathway.
Molecular functions of nuclear actin in transcription
Authors: Percipalle Piergiorgio , Visa Neus
Published: March 2006

Actin is not only a major cytoskeletal component in all eukaryotic cells but also a nuclear protein that plays a role in gene transcription. We put together data from in vitro and in vivo experiments that begin to provide insights into the molecular mechanisms by which actin functions in transcription. Recent studies performed in vitro have suggested that actin, in direct contact with the transcription apparatus, is required in an early step of transcription that is common to all three eukaryotic RNA polymerases. In addition, there is evidence from in vivo studies that actin is involved in the transcription elongation of class II genes. In this case, actin is bound to a specific subset of premessenger RNA binding proteins, and the actin–messenger RNP complex may constitute a molecular platform for recruitment of histone-modifying enzymes. We discuss a general model for actin in RNA polymerase II transcription whereby actin works as a conformational switch in conjunction with specific adaptors to facilitate the remodeling of large macromolecular assemblies at the promoter and along the active gene.
Checkpoint silencing during the DNA damage response in Caenorhabditis elegans embryos
Authors: Holway Antonia H. , Kim Seung-Hwan , La Volpe Adriana , Michael W. Matthew
Published: March 2006

In most cells, the DNA damage checkpoint delays cell division when replication is stalled by DNA damage. In early Caenorhabditis elegans embryos, however, the checkpoint responds to developmental signals that control the timing of cell division, and checkpoint activation by nondevelopmental inputs disrupts cell cycle timing and causes embryonic lethality. Given this sensitivity to inappropriate checkpoint activation, we were interested in how embryos respond to DNA damage. We demonstrate that the checkpoint response to DNA damage is actively silenced in embryos but not in the germ line. Silencing requires rad-2, gei-17, and the polh-1 translesion DNA polymerase, which suppress replication fork stalling and thereby eliminate the checkpoint-activating signal. These results explain how checkpoint activation is restricted to developmental signals during embryogenesis and insulated from DNA damage. They also show that checkpoint activation is not an obligatory response to DNA damage and that pathways exist to bypass the checkpoint when survival depends on uninterrupted progression through the cell cycle.
CD4 memory T cells survive and proliferate but fail to differentiate in the absence of CD40
Authors: MacLeod Megan , Kwakkenbos Mark J. , Crawford Alison , Brown Sheila , Stockinger Brigitta , Schepers Koen , Schumacher Ton , Gray David
Published: March 2006

Secondary T cell responses are enhanced because of an expansion in numbers of antigen-specific (memory) cells. Using major histocompatibility complex class II tetramers we have tracked peptide-specific endogenous (non–T cell receptor transgenic) CD4 memory T cells in normal and in costimulation-deficient mice. CD4 memory T cells were detectable after immunization for more than 200 days, although decay was apparent. Memory cells generated in CD40 knockout mice by immunization with peptide-pulsed wild-type dendritic cells survived in the absence of CD40 and proliferated when boosted with peptide (plus adjuvant) in a CD40-independent fashion. However, differentiation of the memory cells into cytokine-producing effector cells did not occur in the absence of CD40. The data indicate that memory cells can be generated without passing through the effector cell stage.
Control of Epstein-Barr virus infection in vitro by T helper cells specific for virion glycoproteins
Authors: Adhikary Dinesh , Behrends Uta , Moosmann Andreas , Witter Klaus , Bornkamm Georg W. , Mautner Josef
Published: March 2006

Epstein-Barr virus (EBV) establishes lifelong persistent infections in humans by latently infecting B cells, with occasional cycles of reactivation, virus production, and reinfection. Protective immunity against EBV is mediated by T cells, but the role of EBV-specific T helper (Th) cells is still poorly defined. Here, we study the Th response to the EBV lytic cycle proteins BLLF1 (gp350/220), BALF4 (gp110), and BZLF1 and show that glycoprotein-specific Th cells recognize EBV-positive cells directly; surprisingly, a much higher percentage of target cells than those expressing lytic cycle proteins were recognized. Antigen is efficiently transferred to bystander B cells by receptor-mediated uptake of released virions, resulting in recognition of target cells incubated with <1 virion/cell. T cell recognition does not require productive infection and occurs early after virus entry before latency is established. Glycoprotein-specific Th cells are cytolytic and inhibit proliferation of lymphoblastoid cell lines (LCL) and the outgrowth of LCL after infection of primary B cells with EBV. These results establish a novel role for glycoprotein-specific Th cells in the control of EBV infection and identify virion proteins as important immune targets. These findings have implications for the treatment of diseases associated with EBV and potentially other coated viruses infecting MHC class II–positive cells.
Virus-specific CD4+ T cells: ready for direct attack
Authors: Heller Kevin N. , Gurer Cagan , Münz Christian
Published: March 2006

CD4+ T cells are classically thought to orchestrate adaptive immune responses. But recent studies demonstrate that they can also kill infected cells directly. A new paper shows that highly efficient processing of Epstein Barr virus (EBV) glycoproteins for presentation on MHC class II makes virus-transformed B cells susceptible to lysis by CD4+ T cells. Thus, antiviral vaccines should aim to stimulate both helper and cytolytic CD4+ T cells.
A novel method for the preparation of biodegradable microspheres for protein drug delivery
Authors: Pareta R , Edirisinghe M.J
Published: March 2006

Microspheres are potential candidates for the protein drug delivery. In this work, we prepared polymer-coated starch/bovine serum albumin (BSA) microspheres using co-axial electrohydrodynamic atomization (CEHDA). First, starch solution in dimethyl sulphoxide (DMSO) was prepared and then an aqueous solution of BSA was added to it to make a starch–BSA solution. Subsequently, this solution was made to flow through the inner capillary, while the polymer, polydimethylsiloxane (PDMS), flowed through the outer capillary. On collection, filtration and subsequent drying, near-monodisperse microspheres of 5–6 μm in size were obtained. The microspheres were characterized by Fourier-transform infrared (FT-IR) spectroscopy and scanning electron microscopy. Cumulative BSA release was investigated by UV spectroscopy. BSA structure and activity was preserved in the microspheres and its release in 0.01 M phosphate buffered saline (PBS) was studied over a period of 8 days. There was an initial burst with 32 wt% of total BSA released in 2 h. Overall 75 wt% of BSA was released over a 7 day period.
Assembling spatially explicit landscape models of pollen and spore dispersal by wind for risk assessment
Authors: Shaw M.W , Harwood T.D , Wilkinson M.J , Elliott L
Published: March 2006

Models of windblown pollen or spore movement are required to predict gene flow from genetically modified (GM) crops and the spread of fungal diseases. We suggest a simple form for a function describing the distance moved by a pollen grain or fungal spore, for use in generic models of dispersal. The function has power-law behaviour over sub-continental distances. We show that air-borne dispersal of rapeseed pollen in two experiments was inconsistent with an exponential model, but was fitted by power-law models, implying a large contribution from distant fields to the catches observed. After allowance for this ‘background’ by applying Fourier transforms to deconvolve the mixture of distant and local sources, the data were best fit by power-laws with exponents between 1.5 and 2. We also demonstrate that for a simple model of area sources, the median dispersal distance is a function of field radius and that measurement from the source edge can be misleading. Using an inverse-square dispersal distribution deduced from the experimental data and the distribution of rapeseed fields deduced by remote sensing, we successfully predict observed rapeseed pollen density in the city centres of Derby and Leicester (UK).
The systematic position of Meruidae (Coleoptera, Adephaga) and the phylogeny of the smaller aquatic adephagan beetle families
Authors: Beutel Rolf G. , Balke Michael , Steiner Warren E.
Published: March 2006

A phylogenetic analysis of Adephaga is presented. It is based on 148 morphological characters of adults and larvae and focussed on a placement of the recently described Meruidae, and the genus‐level phylogeny of the smaller aquatic families Gyrinidae, Haliplidae and Noteridae. We found a sister group relationship between Gyrinidae and the remaining adephagan families, as was found in previous studies using morphology. Haliplidae are either the sister group of Dytiscoidea or the sister group of a clade comprising Geadephaga and the dytiscoid families. Trachypachidae was placed as the sister group of the rhysodid‐carabid clade or of Dytiscoidea. The monophyly of Dytiscoidea includingMeruis well supported. Autapomorphies are the extensive metathoracic intercoxal septum, the origin of the metafurca from this structure, the loss of Mm. furcacoxalis anterior and posterior, and possibly the presence of an elongated subcubital setal binding patch. Meruidae was placed as sister group of the Noteridae. Synapomorphies are the absence of the transverse ridge of the metaventrite, the fusion of abdominal segments III and IV, the shape of the strongly asymmetric parameres, and the enlargement of antennomeres 5, 7 and 9. TheMeru‐noterid clade is the sister group of the remaining Dytiscoidea. The exact position ofAspidyteswithin this clade remains ambiguous: it is either the sister group of Amphizoidae or the sister group of a clade comprising this family and Hygrobiidae + Dytiscidae. The sister group relationship between Spanglerogyrinae and Gyrininae was strongly supported. The two included genera of Gyrinini form a clade, and Enhydrini are the sister group of a monophylum comprising the remaining Enhydrini and Orectochilini. A branching pattern (Peltodytes+ (Brychius+Haliplus)) within Haliplidae was confirmed.Algophilus,Apteraliplusand theHaliplus‐subgenusLiaphlusform a clade. The generic status of the two former taxa is unjustified. The Phreatodytinae are the sister group of Noterinae, andNotomicrus(+Speonoterus),Hydrocoptus, andPronoterusbranch off successively within this subfamily. The search for the larvae ofMeruand a combined analysis of morphological and molecular data should have high priority.

© The Willi Hennig Society 2006.
Performance of the DNA‐Citoliq liquid‐based cytology system compared with conventional smears
Authors: Alves V. A. F. , Castelo A. , Filho A. L. , Vianna M. R. , Taromaru E. , Namiyama G. , Lorincz A. , Dores G. B. D. ,   DNA‐Citoliq Working Group, São Paulo, Brazil
Published: March 2006

Objective: To evaluate the performance of a new, manual, simplified liquid‐based system, DNA‐Citoliq (Digene Brasil), employed under routine conditions as compared to conventional smears collected from six collaborating private laboratories.

Methods: A panel of cytopathologists, who served as the gold standard diagnosis, adjudicated discordant opinions.

Results:  Of 3206 pairs of slides considered valid for comparison, there were 3008 in full agreement (93.8%), 112 (3.5%) with one diagnostic category discrepancies, and 86 (2.7%) discordant cases. Among the 288 borderline+ by either method, DNA‐Citoliq detected abnormalities in 243 (84.4%), and conventional smears (CS) detected abnormalities in 178 (61.8%) (McNemar test, P < 0.000), a 36.5% increased detection of borderline+ cases.

Conclusions:  For mild dyskaryosis, DNA‐Citoliq detected 176 cases and CS 125 cases (McNemar test, P < 0.000); and for moderate+severe dyskaryosis 66 versus 32 cases respectively (McNemar test, P < 0.000).
Liquid‐based cytology improves productivity in cervical cytology screening
Authors: Doyle B. , O'Farrell C. , Mahoney E. , Turner L. , Magee D. , Gibbons D.
Published: March 2006

Objectives:  The ThinPrep® test was introduced into our institution on a phased basis over 3 years between January 2002 and December 2004. This study set out to assess its effect on productivity (as measured by output of cases per medical scientist per day) during the changeover period. Numbers of high and low‐grade lesions and of unsatisfactory slides were also monitored.

Methods:  The percentage conversion from conventional preparation to liquid‐based cytology (LBC) and output of cases per medical scientist per day were calculated from our database at 6‐month intervals. The average backlog, average number of cases received per month and percentage of unsatisfactory and abnormal cases were calculated similarly.

Results:  Over the study period 92 084 cases were received. The percentage of cases using ThinPrep® increased: from 9% in January 2002 to 73% in December 2004. During the study there was an increase in output from 17.0 to 22.3 cases per medical scientist per day, representing a 31% improvement at 73% conversion. Numbers of unsatisfactory cases decreased substantially and the numbers of low and high‐grade diagnoses were relatively constant.

Conclusions:  The change to ThinPrep® has improved productivity and decreased the number of unsatisfactory cases. There was no adverse effect on quality during the changeover.
Thermal ecology of Interior Alaska dragonflies (Odonata: Anisoptera)
Authors: SFORMO T. , DOAK P.
Published: March 2006

We examined the thermal ecology of Interior Alaska dragonflies (Odonata: Anisoptera). The relationships between mass and passive cooling rate, wing loading, minimum flight temperature (MFT) and thermoregulating ability were examined. These properties were also compared between the behavioural classes: perchers and fliers. All factors with the addition of seasonal and daily flight activity were related to generalized thermal strategies.

Passive cooling rate decreased while wing loading and MFT increased with mass.

While all species were able to elevate thoracic temperature, larger species were better able to maintain a constant temperature.

Both the smallest and largest species of dragonflies were capable of activity at ambient temperatures of approximately 14 °C by employing different thermal strategies: low MFT and physiological heat production, respectively.

For small species active in cool conditions low MFT may be favoured even if accompanied by poor thermoregulating ability. By contrast, thermoregulation and specialization for high‐temperature performance may be favoured in both small and large species during the warmer summer flight season.

The smallest and largest dragonflies in Interior Alaska have the shortest and longest daily activity periods, respectively. However this pattern does not hold for the intermediate‐sized dragonflies. Thermal strategy displays no clear relationship to daily activity pattern.
Factors influencing the prediction of metabolic rate in a reptile
Authors: CLARK T. D. , BUTLER P. J. , FRAPPELL P. B.
Published: March 2006

Measurements of the rate of oxygen consumption (V̇o2) in the field are usually impractical, so several studies of endotherms have utilized heart rate (fH) as a correlate of V̇o2 because of the tight relationship that often exists between the two variables. There have been several reports, however, where the relationship between fH and V̇o2 changes or disassociates under different physiological or psychological circumstances. This may be further confounded in ectothermic vertebrates, which experience relatively large fluctuations in body temperature (Tb).

The aim of the present study was to characterize in Rosenberg's Goanna (Varanus rosenbergi) the relationship that exists between Tb, fH and V̇o2 at rest and at different levels of exercise, during periods of heating and cooling, and following ingestion of a meal.

The combinations of Tb and fH were accurate at predicting V̇o2 of animals at different levels of exercise and recovery, and during the postprandial period.

Predictions of V̇o2 became less reliable during periods of relatively rapid heating when fH and blood flow increase for thermoregulatory purposes with no associated increase in V̇o2. To counter this, fH was excluded from the prediction equation when the rate of heating exceeded 20% of the predicted mass‐dependent maximum attainable rate, and V̇o2 was predicted using Tb alone.

The resultant V̇o2 prediction equation was used to estimate V̇o2 of seven animals that were allowed to thermoregulate behaviourally, and the mean predicted V̇o2 (V̇o2pred) was not significantly different from the mean measured V̇o2 (V̇o2meas) for fasting or postprandial lizards.
Individual variation in thermogenic capacity affects above‐ground activity of high‐altitude Deer Mice
Authors: SEARS M. W. , HAYES J. P. , O'CONNOR C. S. , GELUSO K. , SEDINGER J. S.
Published: March 2006

Understanding an animal's ecology requires knowledge of how individual variation in behaviour and physiology interact with each other and with the environment that an animal experiences.

Environmental variation affects behaviour, but whether individual variation in physiological performance also affects behaviour is poorly known.

We studied a high‐altitude population of Deer Mice (Peromyscus maniculatus) inhabiting an environment cold enough that above‐ground activity (behaviour) may be limited by the thermogenic capacity (maximal rate of oxygen consumption [Vo2max] during cold exposure) of mice.

We measured thermogenic capacity and operative environmental temperature (an integrated measure of the thermal environment), and then used robust‐design capture–mark–recapture (CMR) models to test whether the thermal environmental and individual variation in thermogenic capacity affected capture probabilities (a likely indicator of above‐ground activity).

Models including environmental covariates and thermogenic capacity were strongly favoured over models that did not include them.

Our results demonstrate that individual variation in physiological performance may constrain behaviour in nature.

Besides contributing to our understanding of interactions in the multivariate phenotype, our results suggest that it may be possible to elucidate the mechanistic factors influencing capture probabilities. Such information could be valuable to ecologists, life historians and wildlife managers.
Do standard measures of immunocompetence reflect parasite resistance? The case of Greenfinch coccidiosis
Authors: SAKS L. , KARU U. , OTS I. , HÕRAK P.
Published: March 2006

Much research in evolutionary animal ecology is currently focused on issues related to parasite‐mediated selection. Because of difficulties in estimation of actual parasite resistance, researchers often rely on surrogate measures of immunocompetence, such as the magnitude of immune responses to artificial antigens, assuming that these measures correlate with individuals’ ability to resist disease.

This assumption was tested in the Greenfinch (Carduelis chlorisL.) coccidiosis model by measuring the association between parasite resistance and two standard assays of immune function – a swelling response to phytohaemagglutinin (PHA) and antibody production against sheep red blood cells (SRBC).

Before performing immune challenge assays, host resistance to the intestinal parasiteIsospora lacazei(Labbe) was assessed on the basis of individual infection intensities and responses to challenge infection with alien parasite strains.

Increases in infection intensities after inoculation of birds with novel parasite strains correlated positively with magnitude of swelling response to PHA injection. Thus, intense parasite multiplication in the host's digestive tract resulted in the enhancement of the host's cell‐mediated immune function.

Among birds that were vulnerable to novel infections, no correlations emerged between infection intensities, SRBC antibody titres and condition indices.

Among non‐vulnerable hosts (whose infection intensities did not increase after experimental reinfection), SRBC antibody titres correlated negatively with infection intensities and positively with indices of nutritional condition. Hence, high SRBC antibody titres reflected good nutritional status and superior resistance to an important parasite species in a subsample of studied Greenfinches.

Altogether, our results exemplify the diversity of outcomes when the host's immune system is simultaneously challenged by natural enemies and artificial antigens, and call for the cautious interpretation of the results of standard immune tests in the context of parasite resistance.
Does speed help you survive? A test with Collared Lizards of different ages
Authors: HUSAK J. F.
Published: March 2006

While it is generally accepted that the evolution of morphological traits is mediated by selection on whole‐animal performance, few studies have examined how variation in performance explains variation in fitness. Most studies to date have studied how performance predicts survival, and these typically examine only a single age class.

Maximal sprint speed was measured for hatchling and adult Collared Lizards (Crotaphytus collaris), in addition to morphological measurements, in order to determine how well annual survival could be predicted by performance and whether the relationship between performance and survival differed between age classes.

Logistic regression revealed that no morphological trait or sprint speed performance predicted survival in adults. However, sprint speed predicted survival in hatchlings. Further, hindlimb length differed between survivors and non‐survivors and correlated with sprint speed, suggesting that the evolution of hindlimb length in hatchlings may be driven by selection on sprint speed performance.

Selection on sprint speed may be mediated directly by predators where hatchlings cannot attain speeds sufficient to escape predators or indirectly where slower individuals use a greater proportion of their maximal capacity than faster individuals while escaping predators, perhaps causing elevated stress levels or a higher expenditure of energy stores.
Asynchronous hatching in Nicrophorus vespilloides, an insect in which parents provide food for their offspring
Authors: SMISETH P. T. , WARD R. J. S. , MOORE A. J.
Published: March 2006

Asynchronous hatching has been studied extensively in altricial birds that feed their offspring, but this phenomenon is also known to occur in insects where parents provide food for their offspring.

We examined the proximate mechanisms underlying asynchronous hatching in the burying beetle Nicrophorus vespilloides, an insect species in which parents feed their offspring.

Mean hatching spread was 30 h. As expected if egg‐laying was the major proximate mechanism underlying variation in hatching patterns, the duration of the egg‐laying period had a highly significant and positive effect on hatching spread. The duration of the egg‐laying period was unrelated to clutch size.

Hatching spread was slightly but significantly reduced compared with the duration of the egg‐laying period, and the last eggs laid by females developed slightly but significantly faster than the first eggs. There was no significant difference in the size of the larvae that hatched from the first and last eggs laid by females.

We discuss the value of N. vespilloides and other insects where parents provide food for their offspring as alternative models to birds for the evolution of asynchronous hatching.
Eye size, foraging methods and the timing of foraging in shorebirds
Authors: THOMAS R. J. , SZÉKELY T. , POWELL R. F. , CUTHILL I. C.
Published: March 2006

Birds with large eyes can achieve a greater pupil diameter and/or focal length, and hence, all other things being equal, greater visual sensitivity and resolution than birds with small eyes. Thus eye size is predicted to reflect adaptations to ecology.

We tested three predictions about the relationships between eye size, foraging method (from wholly visual to tactile techniques) and the daily pattern of foraging activity (diurnal/nocturnal) in shorebirds, using phylogenetic comparative methods.

We found that shorebirds that forage at night were more likely to have large eyes, but species using vision to detect their prey did not have larger eyes than species that detect their prey by touch. We also found no evidence that nocturnal foragers are more likely than diurnal foragers to use tactile rather than visual cues to detect their prey.

These results indicate that evolutionary changes toward nocturnal habits are associated with increases in eye size, and thus with increases in aspects of visual capacity, but that foraging mode may not be the prime selective force in this taxon.
Sphagnum modifies climate‐change impacts on subarctic vascular bog plants
Authors: DORREPAAL E. , AERTS R. , CORNELISSEN J. H. C. , VAN LOGTESTIJN R. S. P. , CALLAGHAN T. V.
Published: March 2006

Vascular plant growth forms in northern peatlands differ in their strategies to cope with the harsh climate, low nutrient availability and progressively increasing height of the Sphagnum carpet in which they grow. Climate change may therefore affect growth forms differentially, both directly and through changes in the length growth of Sphagnum mosses. However, the role of mosses as modifiers of climate‐change effects on vascular plants has been largely overlooked so far. We investigated the direct and Sphagnum‐mediated effects of experimental changes in summer, winter and spring climate on four species of contrasting growth forms (evergreen and deciduous shrubs, graminoid, forb) in a subarctic bog, by studying their biomass and nitrogen losses through leaf litter, and the length growth of the two shrubs.

Direct and indirect effects of summer warming differed among the growth forms. Enhanced Sphagnum overgrowth of leaves due to summer warming initially stimulated leaf litter losses of the evergreen shrub Empetrum nigrum. However, changes in its shoot morphology, related to an apparent small increase in its length growth, prevented further effects. A stronger increase in stem growth of the deciduous shrub Betula nana in response to summer warming directly reduced its leaf litter mass, N concentration and N losses. The changed allocation prevented indirect, Sphagnum‐mediated effects on its leaf and N dynamics through overgrowth of buds. In contrast, leaf litter mass, N concentrations or N losses of the forb Rubus chamaemorus and the graminoid Calamagrostis lapponica were not affected by summer warming or enhanced Sphagnum growth.

Increases in winter snow cover, with or without spring warming, did not affect shrub growth, nor the total shoot leaf litter mass or N dynamics of any of the growth forms.

Altogether, summer warming is likely to enhance Sphagnum overgrowth of small shrubs with a limited growth response such as Empetrum. Moreover, increased vertical growth may allow Sphagnum to keep pace with inclined growing, responsive shrubs such as Betula. This might prevent net longer‐term positive effects of summer warming on the vascular plant canopy height. However, leaf litter and N losses are more likely to be affected by direct warming effects on shoot morphology and allocation than by Sphagnum growth. The different responses of the growth forms to summer warming suggest that both direct and Sphagnum‐mediated climate effects have the potential to change the vascular plant community and N dynamics in peatlands.
Dietary routing of nutrients from prey to offspring in a generalist predator: effects of prey quality
Authors: RICKERS S. , LANGEL R. , SCHEU S.
Published: March 2006

Reproduction of female wolf spiders (Pardosa lugubris; Lycosidae) fed with prey of different quality was investigated. Spiders were fed either a single diet of Drosophila melanogaster (Diptera, high quality), Heteromurus nitidus (Collembola, high quality) or Folsomia candida (Collembola, toxic), or a mixed diet of D. melanogaster and H. nitidus, and of D. melanogaster and F. candida.

Nutrient flow from prey into females and from females into offspring during egg production was investigated tracing carbon and nitrogen stable isotopes with prey being enriched in 13C and/or 15N.

There was no benefit of mixing different high‐quality prey on female biomass and performance, contrasting with earlier results obtained with juvenile spiders.

Folsomia candida was toxic for P. lugubris: females, even if fed a mixed diet also containing high‐quality prey, did not reproduce and finally died; spiders did not acquire aversion against F. candida.

Tracing stable isotopes documented the incorporation of C and N from prey into females and their offspring; dietary nutrients were routed almost exclusively into egg production.

Stable isotope analysis strongly supported the assumption that F. candida causes post‐ingestive physiological effects in spiders by inhibiting the incorporation of nutrients from other prey.
Co‐variations in litter decomposition, leaf traits and plant growth in species from a Mediterranean old‐field succession
Authors: KAZAKOU E. , VILE D. , SHIPLEY B. , GALLET C. , GARNIER E.
Published: March 2006

A growing consensus is developing that the impact of species on ecosystem properties is mediated, at least partially, by the traits of their component species. A previous study demonstrated that the field decomposition of complex litters produced by different communities of a Mediterranean successional sere was related to the average trait value of these communities. Here we scale down to the species level, to test whether similar relationships are found for selected species from these communities. We also test whether litter decomposability can be considered as part of the suite of traits characterizing the fast–slow growth continuum in plants.

We chose 12 of the most abundant herbaceous species characteristics of three stages of the old‐field succession mentioned above. We investigated trait variation and covariation for the eight following traits: specific leaf area (SLA), leaf phosphorus (LPC), nitrogen (LNC) and carbon (LCC) concentrations, leaf dry matter content (LDMC) and leaf total phenols (TPh), all on material collected in the field; and litter decomposability (Kpot) and maximum relative growth rate (RGRmax), obtained under standardized conditions in the laboratory.

Five of these traits were significantly lower in species from the advanced successional stage. These trends were similar when comparisons were conducted either with the 12 species, or on a subset incorporating taxonomic information. LDMC was the single trait best correlated with species RGRmax and Kpot; the two latter traits were also significantly correlated with one another.

These results provide clear evidence of functional links between plant growth, leaf traits and litter decomposability. LDMC appears as a pivotal trait of living leaves related to their structural properties. It influences the quality of the litter produced, and hence species’ potential ‘after‐life effects’ on ecosystem properties.
Regulation of mitotic function of Chk1 through phosphorylation at novel sites by cyclin‐dependent kinase 1 (Cdk1)
Authors: Shiromizu Takashi , Goto Hidemasa , Tomono Yasuko , Bartek Jiri , Totsukawa Go , Inoko Akihito , Nakanishi Makoto , Matsumura Fumio , Inagaki Masaki
Published: March 2006

Chk1 is phosphorylated at Ser317 and Ser345 by ATR in response to stalled replication and genotoxic stresses. This Chk1 activation is thought to play critical roles in the prevention of premature mitosis. However, the behavior of Chk1 in mitosis remains largely unknown. Here we reported that Chk1 was phosphorylated in mitosis. The reduction of this phosphorylation was observed at the metaphase‐anaphase transition. Two‐dimensional phosphopeptide mapping revealed that Chk1 phosphorylation sites in vivo were completely overlapped with the in vitro sites by cyclin‐dependent protein kinase (Cdk) 1 or by p38 MAP kinase. Ser286 and Ser301 were identified as novel phosphorylation sites on Chk1. Treatment with Cdk inhibitor butyrolactone I induced the reduction of Chk1‐S301 phosphorylation, although treatment with p38‐specific inhibitor SB203580 or siRNA did not. In addition, ionizing radiation (IR) or ultraviolet (UV) light did not induce Chk1 phosphorylation at Ser317 and Ser345 in nocodazole‐arrested mitotic cells. These observations imply the regulation of mitotic Chk1 function through Chk1 phosphorylation at novel sites by Cdk1.
Atomic force microscopy studies of conditioner thickness distribution and binding interactions on the hair surface
Authors: CHEN N. , BHUSHAN B.
Published: March 2006

The way in which common hair care products, such as conditioner, deposit onto and change hair properties is of interest in beauty care science, as these properties are closely tied to product performance. The binding interaction between conditioner and the hair surface is one of the important factors in determining the conditioner thickness distribution and consequently the proper functions of conditioner. In this study, atomic force microscopy was used to obtain the local conditioner thickness distribution, adhesive forces and effective Young's modulus mapping of various hair surfaces. The conditioner thickness was extracted by measuring the forces on the atomic force microscopy tip as it approached, contacted and pushed through the conditioner layer. The effective Young's moduli of various hair surfaces were calculated from the force distance curves using Hertz analysis. The intrinsic binding interactions between different silicones and the hair surface on the microscopic scale, as well as their effect on the effective Young's modulus of the hair, are also discussed. It was found that the effective Young's modulus of the hair is strongly affected by the binding of conditioner molecules on the hair surface.
Transient analysis of gaseous electron‐ion recombination in the environmental scanning electron microscope
Authors: MORGAN S. W. , PHILLIPS M. R.
Published: March 2006

Most of the work carried out in relation to contrast mechanisms and signal formation in an environmental scanning electron microscope has yet to consider the time dependent aspects of image generation at a quantitative level. This paper quantitatively describes gaseous electron‐ion recombination (also known as ‘signal scavenging’) in an environmental scanning electron microscope at a transient level by utilizing the dark shadows/streaks seen in gaseous secondary electron detector images of alumina (Al2O3) immediately after a region of enhanced secondary electron emission is encountered by a scanning electron beam. The investigation firstly derives a theoretical model of gaseous electron‐ion recombination that takes into consideration transients caused by the time constant of the gaseous secondary electron detector electronics and external circuitry used to generate images. Experimental data of pixel intensity versus time of the streaks are then simulated using the model enabling the relative magnitudes of (i) ionization and recombination rates, (ii) recombination coefficients and (iii) electron drift velocities, as well as absolute values of the total time constant of the gaseous secondary electron detection system and external circuitry, to be determined as a function of microscope operating parameters such as gaseous secondary electron detector bias, sample‐electrode separation, imaging gas pressure, and scan speed. The results revealed, for the first time, the exact dependence that the effects of secondary electron‐ion recombination on signal formation has on reduced electric field and time in an environmental scanning electron microscope. Furthermore, the model implicitly demonstrated that signal loss as a consequence of field retardation due to ion space charges, although obviously present, is not the foremost phenomenon causing streaking in images, as previously thought.
Aclar discs: a versatile substrate for routine high‐pressure freezing of mammalian cell monolayers
Authors: JIMÉNEZ N. , HUMBEL B. M. , VAN DONSELAAR E. , VERKLEIJ A. J. , BURGER K. N. J.
Published: March 2006

High‐pressure freezing avoids the artefacts induced by conventional chemical fixation, and, in combination with freeze‐substitution and plastic embedding, is a reliable method for the ultrastructural analysis of mammalian cell monolayers. In order to high‐pressure freeze mammalian cell monolayers, cells have to be seeded on a suitable substrate. Unfortunately, electron microscopy analysis is often hampered by poor cell growth, changes in cell morphology induced by the cell substrate or cell loss during processing. We report a method to culture, high‐pressure freeze, freeze‐substitute and plastic embed mammalian cell monolayers. The method is based on the use of Aclar, a copolymer film with properties very similar to those of tissue culture plastic. We show that Aclar discs support the normal growth and morphology of a wide variety of mammalian cell types, and form an ideal starting point for high‐pressure freezing, freeze‐substitution and plastic embedding. We present a complete protocol, which, because of its simplicity and reproducibility, provides a method suitable for the routine analysis of mammalian cell monolayers by electron microscopy and tomography.
Chromosome morphology after long‐term storage investigated by scanning near‐field optical microscopy
Authors: BAYLIS R. M. , DOAK S. H. , PARRY J. M. , DUNSTAN P. R.
Published: March 2006

Fluorescence in situ hybridization coupled with far‐field fluorescence microscopy is a commonly used technique to visualize chromosomal aberrations in diseased cells. To obtain the best possible results, chromatin integrity must be preserved to ensure optimal hybridization of fluorescence in situ hybridization probes. However, biological samples are known to degrade and storage conditions can be critical. This study concentrates its investigation on chromatin stability as a function of time following fluorescence in situ hybridization type denaturing protocols. This issue is extremely important because chromatin integrity affects the fluorescence response of the chromosome. To investigate this, metaphase chromosome spreads of human lymphocytes were stored at both −20 and −80 °C, and were then imaged using scanning near‐field optical microscopy over a nine month period. Using the scanning near‐field optical microscope's topography mode, chromosome morphology was analysed before and after the application of fluorescence in situ hybridization type protocols, and then as a function of storage time. The findings revealed that human chromosome samples can be stored at −20 °C for short periods of time (∼ several weeks), but storage over 3 months compromises chromatin stability. Topography measurements clearly show the collapse of the stored chromatin, with variations as large as 60 nm across a chromosome. However, storage at −80 °C considerably preserved the integrity with variations in topography significantly reduced. We report studies of the fluorescent response of stored chromosomes using scanning near‐field optical microscopy and their importance for gaining further understanding of chromosomal aberrations.