bluuebunny/crossref_metadata_2025 huggingface dataset:
From QTL to QTN identification in livestock – winning by points rather than knock‐out: a review
Authors: Ron M. , Weller J. I.
Published: August 2007

Many quantitative trait loci (QTL) affecting economic traits in livestock have now been identified. However, the confidence interval (CI) of individual QTL as determined by linkage analysis often spans tens of map units, containing hundreds of genes. Linkage disequilibrium (LD) mapping can reduce the CI to individual map units, but this reduced interval will still contain tens of genes. Methods suitable for model animals to find and validate specific quantitative trait nucleotides (QTN) underlying the QTL cannot be easily applied to livestock species because of their long generation intervals, the cost of maintaining each animal and the difficulty of producing transgenics or ‘knock‐outs’. Considering these limitations, we review successful approaches for identifying QTN in livestock and outline a schematic strategy for QTN determination and verification. In addition to linkage and LD mapping, the methods include positional cloning, selection of candidate genes, DNA sequencing and statistical analyses. Concordance determination and functional assays are the critical tests for validation of a QTN; we provide a generalized formula for the probability of concordance by chance. Three genes that meet the burden of proof for QTN identification –DGAT1 in cattle, IGF2 in swine and GDF8 in sheep – are discussed in detail. The genetic and economic ramifications of identified QTN and the horizon for selection and introgression are also considered.
The impact of elevated CO2, increased nitrogen availability and biodiversity on plant tissue quality and decomposition
Authors: KNOPS JOHANNES M. H. , NAEEM SHAHID , REICH P. B.
Published: August 2007

Elevated CO2, increased nitrogen (N) deposition and increasing species richness can increase net primary productivity (NPP). However, unless there are comparable changes in decomposition, increases in productivity will most likely be unsustainable. Without comparable increases in decomposition nutrients would accumulate in dead organic matter leading to nutrient limitations that could eventually prohibit additional increases in productivity. To address this issue, we measured aboveground plant and litter quality and belowground root quality, as well as decomposition of aboveground litter for one and 2‐year periods usingin situlitterbags in response to a three‐way factorial manipulation of CO2(ambient vs. 560 ppm), N deposition (ambient vs. the addition of 4 g N m−2 yr−1) and plant species richness (one, four, nine and 16 species) in experimental grassland plots.

Litter chemistry responded to the CO2, N and plant diversity treatments, but decomposition was much less responsive. Elevated CO2induced decreases in % N and % lignin in plant tissues. N addition led to increases in % N and decreases in % lignin. Increasing plant diversity led to decreases in % N and % lignin and an increase in % cellulose. In contrast to the litter chemistry changes, elevated CO2had a much lower impact on decomposition and resulted in only a 2.5% decrease in carbon (C) loss. Detectable responses were not observed either to N addition or to species richness.

These results suggest that global change factors such as biodiversity loss, elevated CO2and N deposition lead to significant changes in tissue quality; however, the response of decomposition is modest. Thus, the observed increases in productivity at higher diversity levels and with elevated CO2and N fertilization are not matched by an increase in decomposition rates. This lack of coupled responses between production and decomposition is likely to result in an accumulation of nutrients in the litter pool which will dampen the response of NPP to these factors over time.
Dentine removal in the coronal portion of root canals following two preparation techniques
Authors: Plotino G. , Grande N. M. , Falanga A. , Di Giuseppe I. L. , Lamorgese V. , Somma F.
Published: August 2007

Aim  To measure the root canal area and the reduction of the mesial and buccal/lingual wall thickness at the level of the coronal interference in mesial roots of mandibular molars after instrumentation with a crown‐down or a simultaneous root canal preparation technique.

Methodology  Twenty mesial roots of first mandibular molars with a moderate root canal curvature were embedded in resin and sectioned horizontally at the level of the coronal interference, using a modification of the Bramante technique. After scanning and processing, the sections were reassembled. One root canal of each root was prepared using ProTaper instruments, while Mtwo instruments were used in the other root canal of the same mesial root. After scanning and processing, the data obtained were analysed for two parameters: changes in root canal area after instrumentation (ΔA) and reduction of the mesial and buccal/lingual wall thickness (ΔT). The data were subjected to Student's t‐tests for statistical analysis at a significance level of P < 0.05.

Results  No statistically significant differences were found between the two groups with respect to the changes in the areas (ΔA) at the level considered (P = 0.410). No statistically significant differences were noticed between the two groups for dentine thickness (ΔT) of both the mesial wall (P = 0.077) and the buccal or lingual wall (P = 0.171).

Conclusions  There was no difference between the ProTaper and Mtwo groups for the amount of dentine removed.
Assessment and treatment units for people with intellectual disabilities and challenging behaviour in England: an exploratory survey
Authors: Mackenzie‐Davies N. , Mansell J.
Published: August 2007

Background  Evaluative studies have shown that special units for people with intellectual disabilities (ID) who have challenging behaviour have advantages and disadvantages. There has been no survey of their number or characteristics for nearly 20 years.

Methods  A questionnaire was sent to all National Health Service trusts that had ID inpatient beds, and all private or voluntary healthcare establishments providing services for people with mental health problems or ID. This asked for information about the unit, its residents and the views of the unit manager.

Results  Forty‐four agencies confirmed that they provided assessment and treatment units, of which 38 returned questionnaires. These units served 333 people, of whom 75% had mild or moderate ID. A quarter had been there for more than 2 years. Forty per cent of residents had a discharge plan, and 20% had this and the type of placement considered ideal for them in their home area. The main strengths of the units were identified as the knowledge and experience of the staff and having sufficient staff; the main problems as inappropriate admissions, bed‐blocking and the relationship with other services; difficulties with recruiting and retaining staff; the location and environment of the unit; and the mix of residents.

Conclusions  There has been an increasing rate of provision of special units, which now predominantly serve people with moderate or mild ID. This model of service provision is becoming more widespread, but the potential problems identified 20 years ago are still present. Areas are identified for further research.
Evolutionary biology and practical conservation: bridging a widening gap
Authors: MACE GEORGINA M. , PURVIS ANDY
Published: August 2007

At the ecosystem, species and population level, available measures suggest that average rates of loss of populations and habitats are now around 1% per year and seem likely to increase in the future. Habitat conversion continues in most parts of the world, especially in areas of high species richness, and novel threats, especially climate change, will pose new challenges. With this pressure, maintaining evolutionary processes in natural populations will be critical to longer term persistence, and will often require specific planning relevant to the context. However, in many areas of policy and practice, urgent actions tend to focus on pattern‐based analyses and considerations of evolutionary and ecological processes are neglected. At a variety of levels, from setting goals to implementing conservation management at the site or species level, there are simple adjustments that can be made. Improved methods for integrating the work of scientists and policymakers is recommended, from the beginning to end of the planning process.
Fetal growth and neonatal mortality in Korea
Authors: Hong Jae S. , Yi Sang‐Wook , Han Young J. , Park Yong W. , Nam Chung M. , Kang Hee C. , Ohrr Heechoul
Published: August 2007

The fetal growth curve and neonatal mortality rate, based on gestational age and birthweight, are important for identifying groups of high‐risk neonates and developing appropriate medical services and health‐care programmes. The purpose of this study was to develop a national fetal growth curve for neonates in Korea, and examine the Korean national references for fetal growth and death according to their characteristics. Data of Korean vital statistics linked National Infant Mortality Survey conducted on births in 1999 were used in this study. The total livebirths were 621 764 in 1999, which were grouped into singletons (n = 609 643) and twins (n = 9805) for analysis. Birthweight/gestational age‐specific fetal growth curves and neonatal mortality rates were based on 250 g of birthweight and weekly gestational age intervals for each characteristic of the birth.

The features of high‐risk neonates such as small‐for‐gestational‐age and the limit of viability in Korea were different from those of Western countries. Difference in fetal growth and death was also detected in other characteristics of the fetus (gender and plurality of birth) besides race. The fetal growth curve of males was higher than that of females, and was higher in singleton than in twins. The neonatal mortality rate was higher in males (singleton, 2.6; twin, 23.5) than females (singleton, 2.1; twin, 15.9), and higher in twins (19.8/1000) than in singletons (2.4/1000). However, in neonates with gestational age >29 weeks and birthweight >1000 g, the neonatal mortality rate was lower in twins than in singletons. The limit of viability was gestational age 27 weeks and birthweight 1000 g, which was similar in singletons and twins regardless of gender.

To improve the health of neonates in a country, it is imperative to investigate the characteristics of fetal growth and death under the particular circumstances of the country. When risk is defined for neonates account must be taken of differences in race, gender and plurality of birth, as the neonatal mortality rate varies depending on those factors.
Distribution of Mating Types and Genetic Diversity of Ascochyta rabiei Populations in Tunisia Revealed by Mating‐type‐specific PCR and Random Amplified Polymorphic DNA Markers
Authors: Rhaiem A. , Cherif M. , Dyer P. S. , Peever T. L.
Published: August 2007

The distribution of mating types of Ascochyta rabiei (teleomorph: Didymella rabiei) was determined in Tunisia using a MAT‐specific PCR assay. Among 123 isolates tested, 80% were MAT1‐1 and 20%MAT1‐2. Only MAT1‐1 isolates were present in the Beja and Bizerte regions of Tunisia, whereas both mating types were present in Nabeul, Kef and Jendouba. In the latter three regions, the hypothesis of random mating could not be rejected based on chi‐squared tests of mating‐type ratios (P > 0.05). The lower frequency of the MAT1‐2 coupled with the restricted distribution of this mating type in Tunisia may indicate a recent introduction of MAT1‐2 in Tunisia. This speculation is consistent with the recent (2001) observation of D. rabiei pseudothecia on chickpea debris in Tunisia. Forty isolates representative of the five regions were genetically analysed using 10 random amplified polymorphic DNA (RAPD) primers to provide a preliminary estimate of genetic diversity of the pathogen in Tunisia. Among 129 putative RAPD loci amplified, 81% were polymorphic and 32 unique RAPD fingerprints were detected. A high level of genetic differentiation was detected among subpopulations (GST = 0.33). Cluster analyses revealed that isolates from Bizerte, Beja and Jendouba were genetically similar and distinct from isolates sampled in Nabeul and Kef. MAT1‐1 isolates were clustered separately from MAT1‐2 isolates in Jendouba and Nabeul suggesting that recombination may not yet be occurring in these regions despite the occurrence of both mating types in equal frequency in these regions. This lack of recombination between MAT1‐1 and MAT1‐2 also supports the hypothesis of a recent introduction of MAT1‐2 into Tunisia.
Genetic Diversity of Cryphonectria hypovirus 1 in China, Japan and Italy
Authors: Liu F.‐X. , Ding P. , Xu C.‐X. , Wang K.‐R.
Published: August 2007

The aim of this study was to examine the origin of Cryphonectria hypovirus 1 (CHV1) which infects chestnut blight fungus, Cryphonectria parasitica. The genetic diversity of 39 CHV1 isolates from China, Japan and Italy was assessed by combining sequencing and restriction fragment length polymorphic (RFLP) experiments. Based on their partial sequences, 26 CHV1 isolates within 26 haplotypes were grouped into three subtypes. The 17 viruses from China were distributed between subtypes I and III, while all four of the isolates from Japan were subtype II. Of the five isolates from Italy, four were subtype I, and one (IT 192) was subtype III. Our analysis of the geographic distribution of the isolates indicated that all but one of the Chinese subtype III CHV1s are present in northern China; meanwhile all but three of the Chinese subtype I CHV1s are present in South China. Unlike in Europe where there is one predominant CHV1 subtype, our distribution analysis indicates that there has been gene flow between the populations in Asia. Cluster analysis based on the RFLP banding patterns showed that the viral isolates could be separated into four clusters. Most of the viral isolates (29 of 39, 74.4%) were grouped into one large cluster. Greater genetic diversity was observed among the CHV1s from China than among those from Japan and Italy. The Italian isolates were genetically more similar to the Japanese and South Chinese isolates than to the North Chinese isolates, indicating that CHV1 in Italy may have originated from Japan and/or South China.
Plasma Levels of Cortisol, Progesterone, Oestradiol‐17β and Prostaglandin F2α Metabolite After ACTH (Synacthen Depot®) Administration in Ovariectomized Gilts
Authors: Mwanza A. M. , Madej A. , Kindahl H. , Lundeheim N. , Einarsson S.
Published: August 2007

In order to elucidate the effect of stress on reproductive hormones, the present study was designed to investigate the effect of adrenocorticotropic hormone (ACTH) on the plasma levels of cortisol, progesterone, oestradiol‐17 β and prostaglandin F2α metabolite in ovariectomized gilts. Ovariectomy and cannulation of the jugular vein were performed within 1 week of oestrous detection, under general anaesthesia. Approximately 1 week after surgery, two gilts were each administered ACTH (Synacthen Depot®) intravenously, at a dose of 0.01 mg/kg body weight, and one gilt was given saline solution (5 ml). The reverse was performed on the following day. The administration of ACTH was followed by a concomitant elevation of cortisol, progesterone and prostaglandin F2α metabolite but not of oestradiol‐17β. Peak cortisol, progesterone and prostaglandin F2α metabolite levels were reached at 80 ± 10.0, 80 ± 10.0 and 46.6 ± 13.3 min after ACTH administration and the durations of the peaks were 181.8 ± 19.8, 308.1 ± 49.7 and 181.8 ± 7.9 min, respectively. The total area under the curve for cortisol, progesterone and prostaglandin F2α metabolite was significantly higher in the ACTH than in the control group. The present results indicate that during stress, cortisol, progesterone and prostaglandin F2α levels are elevated while the level of oestradiol‐17β is less affected. It can be concluded that the administration of ACTH to ovariectomized gilts, results in the elevation of cortisol, progesterone and prostaglandin F2α metabolite but not of oestradiol‐17β.
Effect of N‐acetylcysteine on renal function in patients with chronic kidney disease
Authors: MAINRA RAHUL , GALLO KERRI , MOIST LOUISE
Published: August 2007

Background:  N‐acetylcysteine (NAC) is commonly administered to high‐risk individuals to attenuate the risk of contrast‐induced nephropathy in spite of the debate regarding its efficacy. In several studies serum creatinine decreased after exposure to NAC and contrast dye. The mechanism by which NAC attenuates the decline in renal function is not known. Studies in subjects with normal renal function suggest NAC may have an effect on tubular secretion.

Aim:  The aim of this study was to determine the effect of NAC on renal function, measured by serum creatinine and Cystatin C, in patients with stage 3 chronic kidney disease.

Method:  Serum creatinine and Cystatin C were measured prior to, 4, 24 and 48 h after the administration of 600 mg oral NAC in 30 patients. The protocol was repeated with the addition of 1200 mg oral cimetidine administered 3 h before NAC.

Results:  Serum creatinine was not significantly different from baseline (186 ± 65 μmol/L) to 4 h (185 ± 62 μmol/L), 24 h (187 ± 64 μmol/L) or 48 h (184 ± 61 μmol/L) post NAC, nor were Cystatin C levels. Co‐administration of cimetidine resulted in a significant rise in serum creatinine with no change in Cystatin C levels.

Conclusion:  This study failed to detect a change in serum creatinine or Cystatin C after a single dose of NAC in participants with stage 3 chronic kidney disease. Further randomized trials of multiple doses and longer follow up are needed to confirm these results.
Renal‐related deaths in Indigenous people in Queensland, Australia
Authors: ANDREASYAN KAREN , HOY WENDY E
Published: August 2007

Aim:  Indigenous Australians have much higher mortality than non‐Indigenous Australians. We aimed to quantify the excess of deaths with a renal causal assignment among Indigenous people aged 25 years and over in Queensland, Australia, 1997–2000 and their distribution by remoteness.

Methods:  Both underlying and associated causes defined by ICD, 10th edition, were examined. Mortality rates were standardized to the concurrent non‐Indigenous population.

Results:  In Indigenous people, standardized mortality ratios with a renal assignment of death by remoteness of residence were 194% (Major City and Inner Regional), 439% (Outer Regional and Remote) and 782% (Very Remote). Of all these deaths with a renal assignment, only 18% had a renal assignment as the underlying cause. Diabetes and cardiovascular disease were frequent concomitant causes in deaths with a renal assignment.

Conclusion:  The Indigenous population in Queensland has elevated rates of renal deaths compared with the non‐Indigenous population. This disparity increases markedly with increasing remoteness of residence. Reliance on underlying causes of death alone greatly underestimates the association of renal disease with deaths in this population.
The maximum entropy formalism and the idiosyncratic theory of biodiversity
Authors: Pueyo Salvador , He Fangliang , Zillio Tommaso
Published: August 2007

Why does the neutral theory, which is based on unrealistic assumptions, predict diversity patterns so accurately? Answering questions like this requires a radical change in the way we tackle them. The large number of degrees of freedom of ecosystems pose a fundamental obstacle to mechanistic modelling. However, there are tools of statistical physics, such as the maximum entropy formalism (MaxEnt), that allow transcending particular models to simultaneously work with immense families of models with different rules and parameters, sharing only well‐established features. We applied MaxEnt allowing species to be ecologically idiosyncratic, instead of constraining them to be equivalent as the neutral theory does. The answer we found is that neutral models are just a subset of the majority of plausible models that lead to the same patterns. Small variations in these patterns naturally lead to the main classical species abundance distributions, which are thus unified in a single framework.
MONETARY POLICY AND BEHAVIOURAL FINANCE
Authors: Cuthbertson K. , Nitzsche D. , Hyde S.
Published: August 2007

Abstract There have been major advances in both theory and econometric techniques in mainstream macro‐models and parallel advances in knowledge of the monetary transmission mechanism acting via asset prices. At the same time, behavioural finance has provided evidence that not all actors in the economy are ‘fully rational’ and this has influenced models of asset pricing on which part of the monetary policy transmission mechanism depends. Such uncertainty about the behaviour of asset prices has in part stimulated a move towards ‘robustness’, as an important criterion for guiding monetary policy. We argue that although we have discovered much, including ‘what not to do’, nevertheless our knowledge of the transmission mechanism is very incomplete. This is because, in spite of all the theoretical advances that have been made, there is still considerable uncertainty over the behaviour of agents, which has been reinforced by insights from behavioural finance.
NON‐STATIONARY DEMAND IN A DURABLE GOODS MONOPOLY*
Authors: USATEGUI JOSÉ M.
Published: August 2007

In a context where demand for the services of a durable good changes over time, and this change may be uncertain, we show in this paper that social welfare may be higher when the monopolist seller can commit to any future price level he wishes than when he cannot. Moreover, the equilibrium under a monopolist with commitment power may Pareto‐dominate the equilibrium under a monopolist without commitment ability. These results affect the desired regulation of a durable goods monopolist in this context.
A Critique of the Similarity Space Theory of Concepts
Authors: GAUKER CHRISTOPHER
Published: August 2007

Abstract:  A similarity space is a hyperspace in which the dimensions represent various dimensions on which objects may differ. The similarity space theory of concepts is the thesis that concepts are regions of similarity spaces that are somehow realized in the brain. Proponents of such a theory of concepts include Paul Churchland and Peter Gärdenfors. This paper argues that the similarity space theory of concepts is mistaken because regions of similarity spaces cannot serve as the components of judgments. It emerges that although similarity spaces cannot model concepts, they may model a kind of nonconceptual representation.
The Legacy of Methodological Dualism
Authors: JOHNSON KENT
Published: August 2007

Abstract: Methodological dualism in linguistics occurs when its theories are subjected to standards that are inappropriate for them qua scientific theories. Despite much opposition, methodological dualism abounds in contemporary thinking. In this paper, I treat linguistics as a scientific activity and explore some instances of dualism. By extracting some ubiquitous aspects of scientific methodology from its typically quantitative expression, I show that two recent instances of methodologically dualistic critiques of linguistics are ill‐founded. I then show that there are nonetheless some divergences between linguistic and other ordinary scientific methods, reflecting yet a third instance of methodological dualism.
TheBut NotAll: A Partitive Account of Plural Definite Descriptions
Authors: BROGAARD BERIT
Published: August 2007

Abstract: A number of authors in favor of a unitary account of singular descriptions have alleged that the unitary account can be extrapolated to account for plural definite descriptions. In this paper I take a closer look at this suggestion. I argue that while the unitary account is clearly onto something right, it is in the end empirically inadequate. At the end of the paper I offer a new partitive account of plural definite descriptions that avoids the problems with both the unitary account and standard Russellian analyses.
Peaks and Valleys: Predicting interests in leadership and managerial positions from personality profiles
Authors: Dilchert Stephan
Published: August 2007

This study investigates the relationship between personality and leadership and managerial interests at different levels of the vocational interest taxonomy. Personality scale scores from four different inventories were used to predict vocational interests of 574 adults. Influencing/enterprising interests, leadership and supervisory interests, and job‐specific managerial interests (e.g., CEO, Media Executive, Human Resources Director) served as criterion measures. A multiple regression‐based pattern recognition procedure recently devised by Davison and Davenport was applied to identify configurations of personality scores relating to these interest criteria. The personality profile pattern predictive of influencing and leadership interests was stable across different managerial domains. Results indicate that personality profile patterns drive the predictive power of personality scores, and that they explain a larger proportion of the variance in influencing and leadership interests compared with individuals' absolute trait levels.
Managing breeding forest songbirds with conspecific song playbacks
Authors: Hahn B. A. , Silverman E. D.
Published: August 2007

Recent studies confirm that several territorial songbird species use conspecific cues, including song, when selecting habitat. We conducted a controlled experiment with a population of black‐throated blue warblersDendroica caerulescens, a species of concern in boreal hardwood transition forests, to determine whether song playbacks influence settlement patterns. We tested whether conspecific song broadcast during spring arrival attracts black‐throated blue warblers during territory establishment, and whether song playbacks shift territories from the previous year's breeding distributions. The results of our experiment demonstrate that song playbacks significantly increased territorial occupancy and shifted territories closer to the speakers. Loss of breeding habitat is implicated in population declines of many songbirds, and our results suggest that song playbacks should be further investigated as a tool for mitigating the effects of disruptive management actions. Additional work should consider the spatial arrangement of playback speakers to avoid attracting birds from safe areas. The demographic consequences of conspecific attraction must also be explored before this technique is widely implemented.
Resistance to chytridiomycosis varies among amphibian species and is correlated with skin peptide defenses
Authors: Woodhams D. C. , Ardipradja K. , Alford R. A. , Marantelli G. , Reinert L. K. , Rollins‐Smith L. A.
Published: August 2007

Innate immune mechanisms of defense are especially important to ectothermic vertebrates in which adaptive immune responses may be slow to develop. One innate defense in amphibian skin is the release of abundant quantities of antimicrobial peptides. Chytridiomycosis is an emerging infectious disease of amphibians caused by the skin fungus, Batrachochytrium dendrobatidis. Susceptibility to chytridiomycosis varies among species, and mechanisms of disease resistance are not well understood. Previously, we have shown that Australian and Panamanian amphibian species that possess skin peptides that effectively inhibit the growth of B. dendrobatidis in vitro tend to survive better in the wild or are predicted to survive the first encounter with this lethal pathogen. For most species, it has been difficult to experimentally infect individuals with B. dendrobatidis and directly evaluate both survival and antimicrobial peptide defenses. Here, we demonstrate differences in susceptibility to chytridiomycosis among four Australian species (Litoria caerulea, Litoria chloris, Mixophyes fasciolatus and Limnodynastes tasmaniensis) after experimental infection with B. dendrobatidis, and show that the survival rate increases with the in vitro effectiveness of the skin peptides. We also observed that circulating granulocyte, but not lymphocyte, counts differed between infected and uninfected Lit. chloris. This suggests that innate granulocyte defenses may be activated by pathogen exposure. Taken together, our data suggest that multiple innate defense mechanisms are involved in resistance to chytridiomycosis, and the efficacy of these defenses varies by amphibian species.
The role of nucleotides in the neuron–glia communication responsible for the brain functions
Authors: Inoue Kazuhide , Koizumi Schuichi , Tsuda Makoto
Published: August 2007

Accumulating findings indicate that nucleotides play an important role in cell‐to‐cell communication through P2 purinoceptors, even though ATP is recognized primarily to be a source of free energy and nucleotides are key molecules in cells. P2 purinoceptors are divided into two families, ionotropic receptors (P2X) and metabotropic receptors (P2Y). P2X receptors (7 types; P2X1–P2X7) contain intrinsic pores that open by binding with ATP. P2Y (8 types; P2Y1, 2, 4, 6, 11, 12, 13, and 14) are activated by nucleotides and couple to intracellular second‐messenger systems through heteromeric G‐proteins. Nucleotides are released or leaked from non‐excitable cells as well as neurons in physiological and pathophysiological conditions. One of the most exciting cells in non‐excitable cells is the glia cells, which are classified into astrocytes, oligodendrocytes, and microglia. Astrocytes express many types of P2 purinoceptors and release the ‘gliotransmitter’ ATP to communicate with neurons, microglia and the vascular walls of capillaries. Microglia also express many types of P2 purinoceptors and are known as resident macrophages in the CNS. ATP and other nucleotides work as ‘warning molecules’ especially through activating microglia in pathophysiological conditions. Microglia play a key role in neuropathic pain and show phagocytosis through nucleotide‐evoked activation of P2X4 and P2Y6 receptors, respectively. Such strong molecular, cellular and system‐level evidence for extracellular nucleotide signaling places nucleotides in the central stage of cell communications in glia/CNS.
TECHNICAL ADVANCES: A maximum‐likelihood relatedness estimator allowing for negative relatedness values
Authors: KONOVALOV DMITRY A. , HEG DIK
Published: August 2007

Previously reported maximum‐likelihood pairwise relatedness (r) estimator of Thompson and Milligan (M) was extended to allow for negative r estimates under the regression interpretation of r. This was achieved by establishing the equivalency of the likelihoods used in the kinship program and the likelihoods of Thompson. The new maximum‐likelihood (ML) estimator was evaluated by Monte Carlo simulations. It was found that the new ML estimator became unbiased significantly faster compared to the original M estimator when the amount of genotype information was increased. The effects of allele frequency estimation errors on the new and existing relatedness estimators were also considered.
The Botanist Effect Revisited: Plant Species Richness, County Area, and Human Population Size in the United States
Authors: PAUTASSO MARCO , McKINNEY MICHAEL L.
Published: August 2007

Abstract: The “botanist effect” is thought to be the reason for higher plant species richness in areas where botanists are disproportionately present as an artefactual consequence of a more thorough sampling. We examined whether this was the case for U.S. counties. We collated the number of species of vascular plants, human population size, and the area of U.S. counties. Controlling for spatial autocorrelation and county area, plant species richness increased with human population size and density in counties with and without universities and/or botanical gardens, with no significant differences in the relation between the two subsets. This is consistent with previous findings and further evidence of a broad‐scale positive correlation between species richness and human population presence, which has important consequences for the experience of nature by inhabitants of densely populated regions. Combined with the many reports of a negative correlation between the two variables at a local scale, the positive relation between plant species richness in U.S. counties and human population presence stresses the need for the conservation of seminatural areas in urbanized ecosystems and for the containment of urban and suburban sprawl.
Effectiveness of Corridors Relative to Enlargement of Habitat Patches
Authors: FALCY MATTHEW R. , ESTADES CRISTIÁN F.
Published: August 2007

Abstract:  The establishment of biological corridors between two otherwise isolated habitat patches is a common yet contentious strategy for conserving populations in fragmented landscapes. We compared the effectiveness of corridors with the effectiveness of an alternate conservation strategy, the enlargement of existing habitat patches. We used a spatially explicit population model that simulated population size in two kinds of patches. One patch had a corridor that connected it to a larger “source” patch and the other patch was unconnected and enlarged at the periphery by an area the same size as the corridor. Patch isolation, corridor width, patch size, and the probability that individuals would cross the border from habitat to matrix were varied independently. In general, population size was greater in enlarged patches than in connected patches when patches were relatively large and isolated. Corridor width and the probability of crossing the border from habitat to matrix did not affect the relative benefit of corridors versus patch enlargement. Although biological corridors may mitigate potential effects of inbreeding depression at long time scales, our results suggest that they are not always the best method of conserving fragmented populations.
Verbal and Physical Abuse and Neglect as Manifestations of HIV/AIDS Stigma in Five African Countries
Authors: Dlamini Priscilla S. , Kohi Thecla W. , Uys Leana R. , Phetlhu René Deliwe , Chirwa Maureen L. , Naidoo Joanne R. , Holzemer William L. , Greeff Minrie , Makoae Lucy N.
Published: August 2007

ABSTRACT
Objective: To explore the experience of HIV/AIDS‐related stigma for people living with HIV/AIDS (PLWA) in Lesotho, Malawi, South Africa, Swaziland, and Tanzania.

Design and sample: Descriptive study using 43 focus groups (n=251 participants), which included male and female PLWA from both rural and urban areas and nurses working with PLWA.

Methods: Participants were asked to relate incidents of HIV/AIDS‐related stigma that they had experienced or observed. Focus group discussions were taped, and data were content analyzed to identify examples of abuse (verbal and physical abuse and neglect) related to HIV/AIDS stigma. Data analysis also explored targets of abuse, abusers, and consequences of abuse.

Results: Participant reports documented extensive verbal and physical abuse and neglect or negating (disallowing of access to services and opportunities) experienced by PLWA and observed by nurses caring for them, and identified negative consequences experienced by PLWA whose HIV‐positive status was disclosed to family, friends, or community members.

Conclusions: Health care workers who encourage PLWA to disclose their HIV status must carefully consider the implications of encouraging disclosure in an environment with high levels of stigma, and must recognize the real possibility that PLWA may experience serious verbal and physical abuse as a consequence of disclosure.
Concerns in Workforce Development: Linking Certification and Credentialing to Outcomes
Authors: Ogolla Christopher , Cioffi Joan P.
Published: August 2007

ABSTRACT
Investments in public health workforce development are based on the assumption that capacity and competencies are linked with the effectiveness and efficiency of providing essential public health services. However, evidence of the effects of workforce quantity or quality on the performance of core public health functions is limited. A review of public health, health care, and teacher education literature was conducted to determine the state of research in the field and to identify promising approaches and study designs for application to public health workforce training. A total of 861 articles and abstracts were reviewed from the health literature and 470 from teacher education literature. Sixty‐five reports in the public health or health care literature and 68 in the education literature met the inclusion criteria. Eleven studies in public health or health literature reported positive correlations and 3 determined no substantial correlation to credentials. In the education literature, 10 studies reported a positive link, whereas 9 studies reported mixed or nonsignificant results. We conclude that a paucity of quality research or compelling evidence exists linking certification or credentialing to any related outcome. Until further research is conducted, discussions on the need for public health workforce certification and credentialing will be based on good‐faith expectations for improving individual and organizational performance.
Physical Activity and Leg Strength Predict Decline in Mobility Performance in Older Persons
Authors: Buchman Aron S. , Wilson Robert S. , Boyle Patricia A. , Tang Yuxiao , Fleischman Debra A. , Bennett David A.
Published: August 2007

OBJECTIVES: To assess the extent to which physical activity and leg strength are associated with change in mobility in older persons.

DESIGN: Prospective, observational cohort study.

SETTING: Retirement communities across the Chicago metropolitan area participating in the Rush Memory and Aging Project.

PARTICIPANTS: Eight hundred eighty‐six ambulatory older persons without dementia.

MEASUREMENT: Rate of change in mobility.

RESULTS: In a linear mixed‐effects model that controlled for age, sex, education, and a term for baseline physical activity, a higher level of physical activity was associated with a slower rate of mobility decline (estimate=0.006, standard error (SE)=0.003, P=.03); each additional hour of physical activity at baseline was associated with an approximately 3% decrease in the rate of mobility decline. In a similar model, a higher level of baseline leg strength was associated with a slower rate of mobility decline (estimate=0.031, SE=0.132, P=.02); each additional unit of leg strength at baseline was associated with an approximately 20% decrease in the rate of mobility decline. In a final model, which included terms for physical activity and leg strength together, both were associated with decline in mobility. Furthermore, both remained associated with mobility even after controlling for body composition, balance, pulmonary function, cognition, history of joint pain, cardiovascular diseases and risk factors, and medications.

CONCLUSION: Physical activity and leg strength are relatively independent predictors of mobility decline in older persons. Although physical activity may improve strength, the beneficial effect of physical activity on mobility is likely to involve other pathways.
Rational Inattention and Portfolio Selection
Authors: HUANG LIXIN , LIU HONG
Published: August 2007

Costly information acquisition makes it rational for investors to obtain important economic news with only limited frequency or limited accuracy. We show that this rational inattention to important news may make investors over‐ or underinvest. In addition, the optimal trading strategy is “myopic” with respect to future news frequency and accuracy. We find that the optimal news frequency is nonmonotonic in news accuracy and investment horizon. Furthermore, when both news frequency and news accuracy are endogenized, an investor with a higher risk aversion or a longer investment horizon chooses less frequent but more accurate periodic news updates.
Gene expression in lung and basal forebrain during influenza infection in mice
Authors: Ding M. , Lu L. , Toth L. A.
Published: August 2007

Inbred mice develop strain‐dependent changes in sleep during the first few days after inoculation with influenza virus. To identify genes with the potential to differentially modulate sleep under this condition, we performed complementary DNA microarray analysis of both lung and basal forebrain (BF) of infected (I) and uninfected BALB/cByJ (C) and C57BL/6J (B6) mice. This analysis showed significant variation in the expression pattern of 667 and 1217 of the surveyed genes in BF and lung, respectively (P < 0.01). Applying the additional criterion of an effect size ≥2, 495 genes differed in expression in lung compared with 204 in BF. In BF, more genes were differentially expressed as a function of mouse strain, whereas in lung, more genes were differentially expressed as a function of health status. Significant alterations in expression after infection were more numerous and robust in BALB/cByJ vs. C57BL/6J mice. Some genes showed significant variation in both tissues as a function of strain or condition, but the changes in general were not parallel. Genes that showed significant and robust variation as a function of strain, health status or tissue included those related to immune function, metabolism, signal transduction, cell cycle regulation, apoptosis and other miscellaneous categories. Different patterns of gene expression in BF of uninfected mice suggest the possibility of fundamental mechanistic differences in pathways that modulate vigilance in these strains, whereas differences in expression of lung of infected mice suggests different peripherally generated sleep‐modulatory stimuli in the two strains.
Brain gene expression correlates with changes in behavior in the R6/1 mouse model of Huntington’s disease
Authors: Hodges A. , Hughes G. , Brooks S. , Elliston L. , Holmans P. , Dunnett S. B. , Jones L.
Published: August 2007

Huntington’s disease (HD) is an inherited neurodegeneration that causes a severe progressive illness and early death. Several animal models of the disease have been generated carrying the causative mutation and these have shown that one of the earliest molecular signs of the disease process is a substantial transcriptional deficit. We examined the alterations in brain gene expression in the R6/1 mouse line over the course of the development of phenotypic signs from 18 to 27 weeks. Changes in R6/1 mice were similar to those previously reported in R6/2 mice, and gene ontology analysis shows that pathways related to intracellular and electrical signaling are altered among downregulated genes and lipid biosynthesis and RNA processes among upregulated genes. The R6/1 mice showed deficits in rotarod performance, locomotor activity and exploratory behavior over the time–course. We have correlated the alterations in gene expression with changes in behavior seen in the mice and find that few alterations in gene expression correlate with all behavioral changes but rather that different subsets of the changes are uniquely correlated with one behavior only. This indicates that multiple behavioral tasks assessing different behavioral domains are likely to be necessary in therapeutic trials in mouse models of HD.
Structural adaptation to low temperatures − analysis of the subunit interface of oligomeric psychrophilic enzymes
Authors: Tronelli Daniele , Maugini Elisa , Bossa Francesco , Pascarella Stefano
Published: August 2007

Enzymes from psychrophiles show higher catalytic efficiency in the 0–20 °C temperature range and often lower thermostability in comparison with meso/thermophilic homologs. Physical and chemical characterization of these enzymes is currently underway in order to understand the molecular basis of cold adaptation. Psychrophilic enzymes are often characterized by higher flexibility, which allows for better interaction with substrates, and by a lower activation energy requirement in comparison with meso/thermophilic counterparts. In their tertiary structure, psychrophilic enzymes present fewer stabilizing interactions, longer and more hydrophilic loops, higher glycine content, and lower proline and arginine content. In this study, a comparative analysis of the structural characteristics of the interfaces between oligomeric psychrophilic enzyme subunits was carried out. Crystallographic structures of oligomeric psychrophilic enzymes, and their meso/thermophilic homologs belonging to five different protein families, were retrieved from the Protein Data Bank. The following structural parameters were calculated: overall and core interface area, characterization of polar/apolar contributions to the interface, hydrophobic contact area, quantity of ion pairs and hydrogen bonds between monomers, internal area and total volume of non‐solvent‐exposed cavities at the interface, and average packing of interface residues. These properties were compared to those of meso/thermophilic enzymes. The results were analyzed using Student's t‐test. The most significant differences between psychrophilic and mesophilic proteins were found in the number of ion pairs and hydrogen bonds, and in the apolarity of their subunit interface. Interestingly, the number of ion pairs at the interface shows an opposite adaptation to those occurring at the monomer core and surface.
Mitochondrial targeting of intact CYP2B1 and CYP2E1 and N‐terminal truncated CYP1A1 proteins in Saccharomyces cerevisiae − role of protein kinase A in the mitochondrial targeting of CYP2E1
Authors: Sepuri Naresh B. V. , Yadav Sanjay , Anandatheerthavarada Hindupur K. , Avadhani Narayan G.
Published: August 2007

Previously we showed that intact rat cytochrome P450 2E1, cytochrome P450 2B1 and truncated cytochrome P450 1A1 are targeted to mitochondria in rat tissues and COS cells. However, some reports suggest that truncated cytochrome P450 2E1 is targeted to mitochondria. In this study, we used a heterologous yeast system to ascertain the conservation of targeting mechanisms and the nature of mitochondria‐targeted proteins. Mitochondrial integrity and purity were established using electron microscopy, and treatment with digitonin and protease. Full‐length cytochrome P450 2E1 and cytochrome P450 2B1 were targeted both to microsomes and mitochondria, whereas truncated cytochrome P450 1A1 (+ 5 and + 33/cytochrome P450 1A1) were targeted to mitochondria. Inability to target intact cytochrome P450 1A1 was probably due to lack of cytosolic endoprotease activity in yeast cells. Mitochondrial targeting of cytochrome P450 2E1 was severely impaired in protein kinase A‐deficient cells. Similarly, a phosphorylation site mutant cytochrome P450 2E1 (Ser129A) was poorly targeted to the mitochondria, thus confirming the importance of protein kinase A‐mediated protein phosphorylation in mitochondrial targeting. Mitochondria‐targeted proteins were localized in the matrix compartment peripherally associated with the inner membrane and their ethoxyresorufin O‐dealkylation, erythromycin N‐demethylase, benzoxyresorufin O‐dealkylation and nitrosodimethylamine N‐demethylase activities were fully supported by yeast mitochondrial ferredoxin and ferredoxin reductase.
Cross‐Disciplinarity in Australian Geography Presidential Address to the Institute of Australian Geographers’ Conference, Melbourne, July 20071
Authors: KIRKPATRICK J.B.
Published: August 2007

The disciplinary space that geographers conceive to be theirs has all been previously possessed, or latterly colonised, by other disciplines. Geographers defend their existence on the basis of their oft‐asserted, but never tested, cross‐disciplinarity. The journals in which refereed papers were published by members of the Institute of Australian Geographers (IAG) and the papers in Australian Geographical Studies were analysed for the period 1998–2002 to test the hypothesis of cross‐disciplinarity in both subject and method. IAG members do strongly tend to publish in more than one disciplinary area, and a large proportion of papers in Australian Geographical Studies are integrative across subdisciplines in geography, with many using more than one methodological approach. However, transgression of the physical geography/human geography divide was sufficiently uncommon to create a statistical break between sets of subdisciplines. Based on the data used in the present paper, Australian geographers can make a case for being members of a vital, integrative discipline, likely to make substantial advances in the hybrid spaces.