bluuebunny/crossref_metadata_2025 huggingface dataset:
Extracellular Arginine Rapidly Dilates In Vivo Intestinal Arteries and Arterioles Through a Nitric Oxide Mechanism
Authors: Pezzuto Laura , Bohlen H. Glenn
Published: February 2008

Objective: Arginine used for nitric oxide formation can be from intracellular stores or transported into cells. The study evaluated the rapidity, and primary site of NO and vascular resistance responses to arginine at near physiological concentrations (100–400 μ M). Methods: Arginine was applied to a single arteriole through a micropipette to determine the fastest possible responses. For vascular blood flow and [NO] responses, arginine was added to the bathing media. Results: Dilation of single arterioles to arginine began in 10–15 seconds and application over the entire vasculature increased [NO] in ∼ 60–90 seconds, and flow increased within 120–300 seconds. Resting periarteriolar [NO] for arterioles was 493.6 ± 30.5 nM and increased to 696.1 ± 68.2 and 820.1 ± 110.5 nM at 200 and 400 μ M L‐arginine. The blood flow increased 50% at 400–1200 μ M L‐arginine. The reduced arterial resistance during topical arginine was significantly greater than microvascular resistance at 100 and 200 μ M arginine. All responses were blocked by L‐NAME. Conclusions: This study demonstrated arterial resistance responses are as or more responsive to arginine induced NO formation as arterioles at near physiological concentrations of arginine. The vascular NO and resistance responses occurred rapidly at L‐arginine concentrations at and below 400 μ M, which predict arginine transport processes were involved.
Afferent Arteriolar Dilation to 11, 12‐EET Analogs Involves PP2A Activity and Ca2+‐Activated K+ Channels
Authors: Imig John D. , Dimitropoulou Christiana , Reddy D. Sudarshan , White Richard E. , Falck John R.
Published: February 2008

The epoxygenase metabolite, 11, 12‐epoxyeicosatrienoic acid (11, 12‐EET), has renal vascular actions. 11, 12‐EET analogs have been developed to determine the structure activity relationship for 11, 12‐EET and as a tool to investigate signaling mechanisms responsible for afferent arteriolar dilation. We hypothesized that 11, 12‐EET mediated afferent arteriolar dilation involves increased phosphoprotein phosphatase 2A (PP2A) and large‐conductance calcium activated K+ (KCa) channels. We evaluated the chemically and/or metabolically table 11, 12‐EET analogs: 11, 12‐EET‐N‐methylsulfonimide (11, 12‐EET‐SI), 11‐nonyloxy‐undec‐8(Z)‐enoic acid (11, 12‐ether‐EET‐8‐ZE), and 11, 12‐trans‐oxidoeicosa‐8(Z)‐eonoic acid (11, 12‐tetra‐EET‐8‐ZE). Afferent arteriolar responses were assessed. Activation of KCa channels by 11, 12‐EET analogs were established by single cell channel recordings in renal myocytes. Assessment of renal vascular responses revealed that 11, 12‐EET analogs increased afferent arteriolar diameter. Vasodilator responses to 11, 12‐EET analogs were abolished by K+ channel or PP2A inhibition. 11, 12‐EET analogs activated renal myocyte large‐conductance KCa channels. 11, 12‐EET analogs increased cAMP by 2‐fold and PP2A activity increased 3–8 fold in renal myocytes. PP2A inhibition did not significantly affect the 11, 12‐EET analog mediated increase in cAMP and PP2A increased renal myocyte KCa channel activity to a much greater extent than PKA. These data support the concept that 11, 12‐EET utilizes PP2A dependent pathways to activate large‐conductance KCa channels and dilate the afferent arteriole.
Automated Method for Tracking Vast Numbers of FITC‐Labeled RBCs in Microvessels of Rat Brain In Vivo Using a High‐Speed Confocal Microscope System
Authors: Tomita Minoru , Osada Takashi , Schiszler Istvan , Tomita Yutaka , Unekawa Miyuki , Toriumi Haruki , Tanahashi Norio , Suzuki Norihiro
Published: February 2008

High‐speed camera investigation of rapidly moving red blood cells (RBCs) in the microvasculature has been limited by an inability to handle the vast volume of data. We have developed a novel method to analyze large numbers of RBC images captured by a high‐resolution, high‐speed camera fitted on a confocal fluorescence microscope, to determine the velocities of individual RBCs in capillaries in vivo. Fluorescein isothiocyanate (FITC)‐labeled RBCs flowing in the microvasculature of the cerebral cortex of urethane‐anesthetized Wistar rats were recorded through the skull window on video clips during specified periods at high frame rates (500 fps). Sequential frames of moving RBCs in the video clips for a specified period were analyzed offline with in‐house software (KEIO‐IS2). Images of RBCs acquired were numbered automatically in order of appearance and displayed in a two‐dimensional (2‐D) RBC tracking map. The velocities of individual RBCs were automatically computed based on the RBC displacement per frame multiplied by the frame rate (fps), and the results were displayed in a 2‐D velocity map and a 2‐D RBC number map. Single capillaries were identified by staining with FITC‐dextran. The mean capillary velocity of RBCs was evaluated as 2.05 ± 1.59 mm/second in video clips obtained at 500 fps. This method is considered to have wide potential applicability.
Taking the Measure of Congress: Reply to Chiou and Rothenberg
Authors: Binder Sarah A.
Published: February 2008

Chiou and Rothenberg raise important questions about how to measure key concepts in the study of legislative stalemate in the U.S. Congress. In challenging my choice of measures to capture bicameral differences, Chiou and Rothenberg argue that my findings are the artifact of measurement error. In this reply, I review the hurdles involved in measuring policy views over time and across institutions and suggest that the preferred measure of Chiou and Rothenberg falls short for measuring bicameral differences. Second, I assess the extent to which measurement choices affect the robustness of my findings about the determinants of gridlock. Drawing on new measures and model specifications, I show that my results are robust to alternative specifications. I conclude with an assessment of the broader challenges posed by how we measure critical concepts in the study of congressional performance.
Identification of a PTEN-regulated STAT3 brain tumor suppressor pathway
Authors: de la Iglesia Núria , Konopka Genevieve , Puram Sidharth V. , Chan Jennifer A. , Bachoo Robert M. , You Mingjian J. , Levy David E. , DePinho Ronald A. , Bonni Azad
Published: February 2008

Activation of the transcription factor STAT3 is thought to potently promote oncogenesis in a variety of tissues, leading to intense efforts to develop STAT3 inhibitors for many tumors, including the highly malignant brain tumor glioblastoma. However, the function of STAT3 in glioblastoma pathogenesis has remained unknown. Here, we report that STAT3 plays a pro-oncogenic or tumor-suppressive role depending on the mutational profile of the tumor. Deficiency of the tumor suppressor PTEN triggers a cascade that inhibits STAT3 signaling in murine astrocytes and human glioblastoma tumors. Specifically, we forge a direct link between the PTEN–Akt–FOXO axis and the leukemia inhibitory factor receptor β (LIFRβ)–STAT3 signaling pathway. Accordingly, PTEN knockdown induces efficient malignant transformation of astrocytes upon knockout of the STAT3 gene. Remarkably, in contrast to the tumor-suppressive function of STAT3 in the PTEN pathway, STAT3 forms a complex with the oncoprotein epidermal growth factor receptor type III variant (EGFRvIII) in the nucleus and thereby mediates EGFRvIII-induced glial transformation. These findings indicate that STAT3 plays opposing roles in glial transformation depending on the genetic background of the tumor, providing the rationale for tailored therapeutic intervention in glioblastoma.
Rb intrinsically promotes erythropoiesis by coupling cell cycle exit with mitochondrial biogenesis
Authors: Sankaran Vijay G. , Orkin, Stuart H. , Walkley Carl R.
Published: February 2008

Regulation of the cell cycle is intimately linked to erythroid differentiation, yet how these processes are coupled is not well understood. To gain insight into this coordinate regulation, we examined the role that the retinoblastoma protein (Rb), a central regulator of the cell cycle, plays in erythropoiesis. We found that Rb serves a cell-intrinsic role and its absence causes ineffective erythropoiesis, with a differentiation block at the transition from early to late erythroblasts. Unexpectedly, in addition to a failure to properly exit the cell cycle, mitochondrial biogenesis fails to be up-regulated concomitantly, contributing to this differentiation block. The link between erythropoiesis and mitochondrial function was validated by inhibition of mitochondrial biogenesis. Erythropoiesis in the absence of Rb resembles the human myelodysplastic syndromes, where defects in cell cycle regulation and mitochondrial function frequently occur. Our work demonstrates how these seemingly disparate pathways play a role in coordinately regulating cellular differentiation.
Systematic evaluation of variability in ChIP-chip experiments using predefined DNA targets
Authors: Johnson David S. , Li Wei , Gordon D. Benjamin , Bhattacharjee Arindam , Curry Bo , Ghosh Jayati , Brizuela Leonardo , Carroll Jason S. , Brown Myles , Flicek Paul , Koch Christoph M. , Dunham Ian , Bieda Mark , Xu Xiaoqin , Farnham Peggy J. , Kapranov Philipp , Nix David A. , Gingeras Thomas R. , Zhang Xinmin , Holster Heather , Jiang Nan , Green Roland D. , Song Jun S. , McCuine Scott A. , Anton Elizabeth , Nguyen Loan , Trinklein Nathan D. , Ye Zhen , Ching Keith , Hawkins David , Ren Bing , Scacheri Peter C. , Rozowsky Joel , Karpikov Alexander , Euskirchen Ghia , Weissman Sherman , Gerstein Mark , Snyder Michael , Yang Annie , Moqtaderi Zarmik , Hirsch Heather , Shulha Hennady P. , Fu Yutao , Weng Zhiping , Struhl Kevin , Myers Richard M. , Lieb Jason D. , Liu X. Shirley
Published: February 2008

The most widely used method for detecting genome-wide protein–DNA interactions is chromatin immunoprecipitation on tiling microarrays, commonly known as ChIP-chip. Here, we conducted the first objective analysis of tiling array platforms, amplification procedures, and signal detection algorithms in a simulated ChIP-chip experiment. Mixtures of human genomic DNA and “spike-ins” comprised of nearly 100 human sequences at various concentrations were hybridized to four tiling array platforms by eight independent groups. Blind to the number of spike-ins, their locations, and the range of concentrations, each group made predictions of the spike-in locations. We found that microarray platform choice is not the primary determinant of overall performance. In fact, variation in performance between labs, protocols, and algorithms within the same array platform was greater than the variation in performance between array platforms. However, each array platform had unique performance characteristics that varied with tiling resolution and the number of replicates, which have implications for cost versus detection power. Long oligonucleotide arrays were slightly more sensitive at detecting very low enrichment. On all platforms, simple sequence repeats and genome redundancy tended to result in false positives. LM-PCR and WGA, the most popular sample amplification techniques, reproduced relative enrichment levels with high fidelity. Performance among signal detection algorithms was heavily dependent on array platform. The spike-in DNA samples and the data presented here provide a stable benchmark against which future ChIP platforms, protocol improvements, and analysis methods can be evaluated.
Redirection of Flavonoid Biosynthesis through the Down-Regulation of an Anthocyanidin Glucosyltransferase in Ripening Strawberry Fruit
Authors: Griesser Markus , Hoffmann Thomas , Bellido Mari Luz , Rosati Carlo , Fink Barbara , Kurtzer Robert , Aharoni Asaph , Muñoz-Blanco Juan , Schwab Wilfried
Published: February 2008

Strawberry (Fragaria × ananassa) fruit contains several anthocyanins that give the ripe fruits their attractive red color. The enzyme that catalyzes the formation of the first stable intermediate in the anthocyanin pathway is anthocyanidin-3-O-glucosyltransferase. A putative glycosyltransferase sequence (FaGT1) was cloned from a strawberry fruit cDNA library and the recombinant FaGT1 transferred UDP-glucose to anthocyanidins and, to a lesser extent, flavonols, generating the respective 3-O-glucosides. Quantitative polymerase chain reaction revealed that transcripts of FaGT1 were almost undetectable in green fruits, but gene expression increased dramatically in both turning and ripe red fruit, corresponding closely to the accumulation of anthocyanins during fruit ripening. The expression of FaGT1 is fruit associated and negatively regulated by auxin. To elucidate the in planta function of FaGT1, Agrobacterium tumefaciens cells harboring an intron-hairpin construct of a partial FaGT1 sequence were injected into midsized ripening fruits. In about one-third of the injected fruits, this led to significant down-regulation of FaGT1 transcript levels that corresponded to reduced concentrations of anthocyanin pigments in ripe strawberry fruits. In contrast, significant levels of epiafzelechin—formed by anthocyanidin reductase (ANR) from pelargonidin—were identified in FaGT1-silenced fruits, indicating competition of FaGT1 and FaANR for the common anthocyanidin substrate. Thus, FaGT1 represents an important branching-point enzyme because it is channeling the flavonoid pathway to anthocyanins. These results demonstrate a method to redirect the anthocyanin biosynthesis into flavan-3-ol production to increase the levels of bioactive natural products or modify pigments in plant tissues.
Identification of Negative cis-Acting Elements in Response to Copper in the Chloroplastic Iron Superoxide Dismutase Gene of the Moss Barbula unguiculata
Authors: Nagae Miwa , Nakata Masaru , Takahashi Yohsuke
Published: February 2008

Superoxide dismutases (SODs) are ubiquitous metalloenzymes that catalyze the dismutation of superoxide radicals. Chloroplasts have two isozymes, copper/zinc SOD (Cu/ZnSOD) and iron SOD (FeSOD), encoded by nuclear genes. Because bryophytes are considered as the earliest land plants, they are one of the most interesting plant models for adaptation against oxidative stress. In a previous study, we found that the FeSOD gene was expressed under Cu-deficient conditions and repressed under high-Cu-supply conditions; on the other hand, the Cu/ZnSOD gene was induced by Cu in a moss, Barbula unguiculata. The expression of Cu/ZnSOD and FeSOD is coordinately regulated at the transcriptional level depending on metal bioavailability. Here, using transgenic moss plants, we determined that the GTACT motif is a negative cis-acting element of the moss FeSOD gene in response to Cu. Furthermore, we found that a plant-specific transcription factor, PpSBP2 (for SQUAMOSA promoter-binding protein), and its related proteins bound to the GTACT motif repressed the expression of the FeSOD gene. The moss FeSOD gene was negatively regulated by Cu in transgenic Nicotiana tabacum plants, and the Arabidopsis thaliana FeSOD gene promoter containing the GTACT motif was repressed by Cu. Our results suggested that molecular mechanisms of GTACT motif-dependent transcriptional suppression by Cu are conserved in land plants.
Single nucleotide polymorphisms refine QTL intervals for hip joint laxity in dogs
Authors: Zhu L. , Zhang Z. , Feng F. , Schweitzer P. , Phavaphutanon J. , Vernier‐Singer M. , Corey E. , Friedenberg S. , Mateescu R. , Williams A. , Lust G. , Acland G. , Todhunter R.
Published: February 2008

Hip laxity is one characteristic of canine hip dysplasia (CHD), an inheritable disease that leads to hip osteoarthritis. Using a genome‐wide screen with 250 microsatellites in a crossbreed pedigree of 159 dysplastic Labrador retrievers and unaffected greyhounds, we previously identified putative (P < 0.01) QTL on canine chromosomes 11 and 29 (CFA11 and CFA29). To refine these QTL locations, we have genotyped 257 dogs including 105 Labrador retrievers, seven greyhounds, four generations of their crossbreed offspring and three German shepherds for 111 and 171 SNPs on CFA11 and CFA29 respectively. The distraction index (DI, a measure of maximum hip laxity) was used as an intermediate phenotype that predicts whether a hip joint will or will not develop osteoarthritis. Using a multipoint linkage analysis, significant evidence (95% posterior probability) was found for QTL contributing to hip laxity in the 16.2–21 cM region on CFA11 that explained 15–18% of the total variance in DI. Evidence for an independent QTL on CFA29 was weaker than that on CFA11. Identification of the causative mutation(s) will lead to better understanding of biochemical pathways in both dogs and humans with hip laxity and dysplasia.
SNP‐finding in pig mitochondrial ESTs
Authors: Scheibye‐Alsing K. , Cirera S. , Gilchrist M. J. , Fredholm M. , Gorodkin J.
Published: February 2008

The Sino‐Danish pig genome project produced 685 851 ESTs (Gorodkin et al. 2007), of which 41 499 originated from the mitochondrial genome. In this study, the mitochondrial ESTs were assembled, and 374 putative SNPs were found. Chromatograms for the ESTs containing SNPs were manually inspected, and 112 total (52 non‐synonymous) SNPs were found to be of high confidence (five of them are close to disease‐causing SNPs in humans). Nine of the high‐confidence SNPs were tested experimentally, and eight were confirmed. The SNPs can be accessed online at http://pigest.ku.dk/more/mito.
Genetic divergence and ecological specialisation of seed weevils (Exapion spp.) on gorses (Ulex spp.)
Authors: BARAT MYRIAM , TARAYRE MICHÈLE , ATLAN ANNE
Published: February 2008

Abstract 1. Reproductive isolation of sympatric populations may result from divergent selection of populations in different environments, and lead to ecological specialisation. In Brittany (France), the gorse Ulex europaeus (Fabaceae, Genisteae), may be encountered in sympatry with one of the two other gorse species present: U. gallii and U. minor. A recent study based on morphological identification of seed predators of gorse has shown that two weevil species (Curculionoidea, Apionidae) infest gorse pods at different seasons and have different host ranges: Exapion ulicis infests U. europaeus in spring, whereas E. lemovicinum infests U. gallii and U. minor in autumn. Weevil populations may thus have diverged in sympatry.

2. As morphological identification of weevils is often difficult and some of the characters used may exhibit individual or environmental variation, mitochondrial and nuclear sequences of weevils collected within pods of the three gorse species in 10 populations of Brittany were used to reconstruct their phylogeny.

3. The results reveal that species differentiation based on morphological characters is confirmed by the two molecular data sets, showing that E. ulicis and E. lemovicinum are distinct species, and suggesting the absence of host races. Finally, E. ulicis was able to use U. gallii and U. minor pods in spring in some years in some populations, which appeared to depend on the availability of pods present during its reproductive period.

4. Divergence between E. ulicis and E. lemovicinum may have resulted from temporal isolation of reproductive periods of weevil populations followed by specialisation of insects to host phenology.
Strategic ejaculation in the egg parasitoid Trichogramma turkestanica (Hymenoptera: Trichogrammatidae)
Authors: MARTEL VÉRONIQUE , DAMIENS DAVID , BOIVIN GUY
Published: February 2008

Abstract 1. Several parameters influence sperm allocation by males, including their size and sperm stock, intra‐specific variability, quality of females’, as well as the risk and intensity of sperm competition.

2. Models predict that males should invest the maximum ejaculate size when sperm competition intensity is low. As sperm competition intensity increases, males should decrease the number of sperm transferred during mating.

3. This decrease in sperm transfer to females occurs because the benefits gained by males with each extra unit of expenditure on sperm decrease. When sperm supply is not unlimited, males could expect a better return by keeping some or all sperm for mating under lower competition intensity.

4. In this study, the ejaculate size of males that were kept in groups of one, five or 10 males prior to mating, has been investigated in the haplodiploid egg parasitoid Trichogramma turkestanica Meyer (Hymenoptera: Trichogrammatidae).

5. As predicted by theory, the number of sperm transferred decreased significantly with an increase in the number of rivals.

6. This is the first study showing strategic sperm allocation depending on sperm competition intensity in a parasitoid.
Neither the devil nor the deep blue sea: larval mortality factors fail to explain the abundance and distribution ofTischeria ekebladella
Authors: GRIPENBERG SOFIA , ROSLIN TOMAS
Published: February 2008

Abstract1. The distribution, abundance and population dynamics of herbivorous insects may be affected by trophic interactions, by abiotic influences, or by intra‐specific processes. Relatively little is known about how trophic influences vary across space. Here, we investigate spatial variation in mortality in the oak‐feeding leaf minerTischeria ekebladellaas attributable to individual causal agents.

2. Leaf miners were experimentally introduced on 67 trees on an island 5 km2in area in south‐western Finland. On each tree, some larvae were protected by a muslin bag, others by a glue barrier around the branch and some left exposed.

3. In the bagged transplants, 78.4% of larvae survived, compared with only 9.6% in the other two treatments. Most of the mortality was because of airborne agents: mortality on branches sheltered by a glue barrier was as high as on fully exposed branch tips.

4. We consider mortality caused by parasitoid wasps to be the main source of larval death and the primary factor driving general patterns of survival. The effects of bird predation and premature leaf abscission were negligible.

5. We detected spatial aggregation in larval survival and parasitism rates at the level of individual trees, but not across the landscape.

6. Spatial variation in overall leaf miner survival, parasitism and leaf abscission does not suffice to explain patterns of incidence and abundance of wildT. ekebladellaon experimental trees. Rather, we identify metapopulation dynamics as a likely determinant of the spatial distribution ofT. ekebladellain the landscape.
Improving light‐based geolocation by including sea surface temperature
Authors: NIELSEN ANDERS , BIGELOW KEITH A. , MUSYL MICHAEL K. , SIBERT JOHN R.
Published: February 2008

An approach to integrate sea surface temperature (SST) measurements into estimates of geolocations calculated by changes in ambient light level from data downloaded from pop‐up satellite archival tags (PSAT) is presented. The model is an extension of an approach based on Kalman filter estimation in a state‐space model. The approach uses longitude and latitude estimated from light, and SST. The extra information on SST is included in a consistent manner within the milieu of the Kalman filter. The technique was evaluated by attaching PSATs directly on thermistor‐equipped global positioning system drifter buoys. SSTs measured in the PSATs and drifter buoy were statistically compared with SSTs determined from satellites. The method is applied to two tracks derived from PSAT‐tagged blue sharks (Prionace glauca) in the central Pacific Ocean. The inclusion of SST in the model produced substantially more probable tracks with lower prediction variance than those estimated from light‐level data alone.
Evidence of density‐dependent effects on population variation of Japanese sardine (Sardinops melanosticta) off Korea
Authors: KIM JIN YEONG , KIM SUAM , CHOI YOUNG MIN , LEE JAE BONG
Published: February 2008

Interannual variation of some biological parameters for the Japanese sardine, Sardinops melanosticta, population in Korean waters was investigated using scientific surveys and fisheries information since the late 1970s. The abundance and geographical coverage of sardine eggs were high (peak in 1986) and broad when spawning biomasses were high in the mid 1980s, and vice versa in the late 1970s and the early 1990s. Also, feeding and spawning areas based on fisheries information exhibited the same pattern of expansion/contraction as seen in ichthyoplankton surveys. Annual Gonadal Somatic Index (GSI) in spawning season (February to April) and the size at age 1 of sardine were reduced during the high abundance period. It is suggested that density‐dependent effects on the reproduction and growth of the sardine population in Korean waters existed.
Special regulatory T‐cell review: T‐cell dependent suppression revisited
Authors: Basten Antony , Fazekas de St Groth Barbara
Published: February 2008

The concept of T‐cell dependent regulation of immune responses has been a central tenet of immunological thinking since the delineation of the two cell system in the 1960s. Indeed T‐cell dependent suppression was discovered before MHC restriction. When reviewing the data from the original wave of suppression, it is intriguing to reflect not just on the decline and fall of suppressor T cells in the 1980s, but on their equally dramatic return to respectability over the past decade. Hopefully their resurgence will be supported by solid mechanistic data that will underpin their central place in our current and future understanding of the immune system.

Cannon to right of them,

Cannon to left of them,

Cannon in front of them

Volley’d and thunder’d

Storm’d at with shot and shell,

Boldly they rode and well,

Into the jaws of Death,

Into the mouth of Hell,

Rode the six hundred (suppressionists).

(Adapted from The Charge of the Light Brigade, Alfred, Lord Tennyson)
Special regulatory T‐cell review: regulation of immune responses – examining the role of T cells
Authors: Simpson Elizabeth
Published: February 2008

The history of regulatory T cells goes back to the realisation that T cells could provide ‘help’ for antibody responses: the obverse of this is their ability to hold them in check. This brief personal overview follows the initial designation of T cells as ‘suppressor’ and the various hypotheses, some now disproved, put forward for their mechanism of action. We now cautiously label them T regulatory cells, but realise they do not control not all immune regulation. They probably operate through several mechanisms, and some of these are discussed.
Giant Holocene Freshwater Microbialites, Laguna Bacalar, Quintana Roo, Mexico
Authors: GISCHLER EBERHARD , GIBSON MICHAEL A. , OSCHMANN WOLFGANG
Published: February 2008

With more than 10 km of total length, Holocene microbialites in Laguna Bacalar, Mexico, belong to the largest freshwater microbialite occurrences. Microbialites include domes, ledges and oncolites. Domal forms can grow to diameters and heights of 3 m. Microbialites are composed of low magnesium calcite which is, to a large extent, precipitated due to the metabolic activity of the cyanobacteria Homeothrix and Leptolyngbya, and associated diatoms. Photosynthesis removes carbon dioxide and triggers carbonate precipitation. Also, an elevated carbonate concentration in lagoon waters, derived from dissolution of Cenozoic limestone in a karst system, supports carbonate precipitation. Trapping and binding of detrital grains is also observed, but is not as common as precipitation. Bacalar microbialites are largely thrombolitic, however, stromatolitic sections occur as well. The bulk of Bacalar microbialites probably formed in the Late Holocene (ca 1 kyr BP until present). According to 14C dating, microbialites accreted 9 to 8 cal kyr BP; however, these ages may be too old as a result of a strong hard water effect. This effect is seen in 14C ages of living bivalve and gastropod mollusc shells from Bacalar Lagoon, which are 8 to 7 cal kyr BP. The modern associated fauna of microbialites is characterized by low diversity and high abundance of the bivalve mollusc Dreissena sp. and the gastropod Pomacea sp. The abundant grazing gastropods presumably hamper modern microbialite formation. A comparison of Bacalar microbialites with other modern microbialite occurrences worldwide shows only a few patterns: sizes, shapes, microbial taxa, mineralogy, type of accretion and settings including water properties of microbialite occurrences exhibit high variability. A trend may be seen in the grazing metazoa, which are rare to absent in the marine and brackish examples, but apparently present in all the freshwater occurrences of microbialites. Also, freshwater examples are usually characterized by elevated concentrations of carbonate and/or calcium ions in the surrounding waters.
Interplay between JA, SA and ABA signalling during basal and induced resistance against Pseudomonas syringae and Alternaria brassicicola
Authors: Flors Victor , Ton Jurriaan , Van Doorn Ronald , Jakab Gabor , García‐Agustín Pilar , Mauch‐Mani Brigitte
Published: February 2008

We have examined the role of the callose synthase PMR4 in basal resistance and β‐aminobutyric acid‐induced resistance (BABA‐IR) of Arabidopsis thaliana against the hemi‐biotrophic pathogen Pseudomonas syringae and the necrotrophic pathogen Alternaria brassicicola. Compared to wild‐type plants, the pmr4‐1 mutant displayed enhanced basal resistance against P. syringae, which correlated with constitutive expression of the PR‐1 gene. Treating the pmr4‐1 mutant with BABA boosted the already elevated levels of PR‐1 gene expression, and further increased the level of resistance. Hence, BABA‐IR against P. syringae does not require PMR4‐derived callose. Conversely, pmr4‐1 plants showed enhanced susceptibility to A. brassicicola, and failed to show BABA‐IR. Wild‐type plants showing BABA‐IR against A. brassicicola produced increased levels of JA. The pmr4‐1 mutant produced less JA upon A. brassicicola infection than the wild‐type. Blocking SA accumulation in pmr4‐1 restored basal resistance, but not BABA‐IR against A. brassicicola. This suggests that the mutant’s enhanced susceptibility to A. brassicicola is caused by SA‐mediated suppression of JA, whereas the lack of BABA‐IR is caused by its inability to produce callose. A. brassicicola infection suppressed ABA accumulation. Pre‐treatment with BABA antagonized this ABA accumulation, and concurrently potentiated expression of the ABA‐responsive ABI1 gene. Hence, BABA prevents pathogen‐induced suppression of ABA accumulation, and sensitizes the tissue to ABA, causing augmented deposition of PMR4‐derived callose.
Chromosomal rearrangements and genetic structure at different evolutionary levels of theSorex araneusgroup
Authors: BASSET P. , YANNIC G. , HAUSSER J.
Published: February 2008

Robertsonian (Rb) fusions received large theoretical support for their role in speciation, but empirical evidence is often lacking. Here, we address the role of Rb rearrangements on the genetic differentiation of the karyotypically diversified group of shrews,Sorex araneus. We compared genetic structure between ‘rearranged’ and ‘common’ chromosomes in pairwise comparisons of five karyotypic taxa of the group. Considering all possible comparisons, we found a significantly greater differentiation at rearranged chromosomes, supporting the role of chromosomal rearrangements in the general genetic diversification of this group. Intertaxa structure and distance were larger across rearranged chromosomes for most of the comparisons, although these differences were not significant. This last result could be explained by the large variance observed among microsatellite‐based estimates. The differences observed among the pairs of taxa analysed support the role of both the hybrid karyotypic complexity and the level of evolutionary divergence.
The State as Parent: The Reluctant Parent? The Problems of Parents of Last Resort
Authors: Masson Judith
Published: February 2008

This paper will explore the idea of the local authority as a reluctant parent. It will consider the extent to which this reluctance is produced by the care proceedings system and its consequences for children. Local authorities are both expected to refrain from intervening (care proceedings are a measure of last resort) and to be fully prepared for intervention (whilst leaving children with their parents). Amongst the themes which will be developed here are the impact of the juridification of social work and the emphasis on the courts for holding local authorities to account; the balance between voluntary accommodation and compulsory care; and the problems of resourcing care services. Its main focus will be on children who enter care because of abuse or neglect. Its thesis is that the conflicting expectations on local authorities, resource constraints, and considerations of legal process make them reluctant parents.
Perspectives on Parenting Responsibility: Contextualizing Values and Practices
Authors: Gillies Val
Published: February 2008

This paper critically explores the classed assumptions underpinning contemporary family policy, situating them within the context of broader political and theoretical debates about parenting responsibility. Analysis of policy documents over the past few years suggests that the family is being prioritized as a mechanism for tackling wider social ills such as crime and poverty. Families are portrayed as the ‘building blocks for safe and sustainable communities’, with good parents fostering and transmitting crucial values to their children which protect and reproduce the common good. Although the current government has pledged to support all parents, policy initiatives point to a class‐specific focus on disadvantaged or 'socially excluded’ families. Poor parents are viewed as reproducing a cycle of deprivation and anti‐social behaviour and are therefore targeted for behaviour modification. Drawing on research from a qualitative study of parenting resources, this paper will challenge the notion that social inclusion can be promoted at the level of the family, and will argue instead that parenting practices and values are grounded in social and economic realities.
Youth Crime: Whose Responsibility?
Authors: Newbury Alex
Published: February 2008

Responsibility is an increasingly important concept within both political and academic debates about youth justice. As an alternative approach to youth crime, restorative justice ideology has contributed to this debate. Restorative justice emphasizes the importance of repairing harm by encouraging offenders to address past behaviour and to become responsible for future actions. This article reflects on empirical findings from the author's research with 41 young offenders who were the subjects of Referral Orders, a purportedly restorative disposal. It considers how successfully the English youth justice system has adopted this approach, arguing that there is a significant difference between the theory of restorative justice and its use in practice. To some extent, New Labour's emphasis on the criminal justice system has missed the point behind the ideology of restorative justice and the wider opportunities it offers for a proactively restorative society.
The ‘Change for Children’ Programme in England: Towards the ‘Preventive‐Surveillance State’
Authors: Parton Nigel
Published: February 2008

Following the Children Act 2004 and the launch of the ‘Every Child Matters: Change for Children’ programme, England has embarked on the most ambitious changes in children's services for over a generation. While the government presented the changes as a response to the Laming Report into the death of Victoria Climbié, they are much more than this. They build on a number of ideas and policies that had been developed over a number of years, which emphasize the importance of intervening in children's lives at an early stage in order to prevent problems in later life. This paper provides a critical analysis of the assumptions that underpin the changes and argues that the relationships between parents, children, professionals, and the state, and their respective responsibilities, are being reconfigured as a result, and that the priority given to the accumulation, monitoring, and exchange of electronic information has taken on a central significance. What we are witnessing is the emergence of the ‘preventive‐surveillance’ state, where the role of the state is becoming broader, more interventive, and regulatory at the same time.
Collaborative emergency management: better community organising, better public preparedness and response
Authors: Kapucu Naim
Published: February 2008

Community coordination requires communication and planning of precautions to take when faced with a severe threat of disaster. The unique case of the four Florida hurricanes of 2004—Charley, Frances, Ivan, and Jeanne—is used here to assess community responses to repeated threats of hurricanes. The paper examines how effectiveness in coordinating community disaster response efforts affects future public preparedness. The findings suggest that pre‐season planning, open communication between emergency managers and elected officials, and the use of technology all had a significant impact on community responses. The repeated threat scenario indicates that emergency managers must work vigilantly to keep residents informed of the seriousness of a situation. The study describes how emergency managers in Florida countered public complacency during four hurricanes in six weeks. The strategies identified as useful by public managers in the context of hurricanes are applicable to other natural and man‐made disasters.
A Comparative Case Study of Care Systems for Frail Elderly People: Germany, Spain, France, Italy, United Kingdom and Sweden
Authors: Bihan Blanche Le , Martin Claude
Published: February 2008

Comparative studies of European social policies towards frail elderly people typically focus on the systems and their implementation. The study presented in this article, conducted in 2001 in six European countries (Germany, Spain, Italy, France, the United Kingdom and Sweden) aims at comparing the rights of the individuals within the different care systems. The methodology used is a case study approach, which draws on a series of situations of dependent elderly people. Therefore, the analysis focuses on the public authorities’ responses – the care packages, which determine the type of care required and the financial contribution of the user – in each of the six countries, in relation to the concrete situations of frail elderly people. As local variations are important, in all the countries studied, local authorities have been chosen in each of the countries. This approach gives us interesting concrete elements on the services and financial help which can be given to frail elderly people, but it also enables us to understand precisely the national care systems organized in the different countries and the main difficulties encountered by public authorities in facing this problem of frail elderly people.
The Politics of Welfare State Retrenchment: A Literature Review
Authors: Starke Peter
Published: February 2008

Welfare state retrenchment is widely seen as a highly unpopular endeavour and, therefore, as politically difficult to pursue. This assumption has underpinned most of the political science research on this issue, notably Paul Pierson's seminal contributions about the ‘new politics of the welfare state’. Yet, the question remains why and under what circumstances cutbacks take place in highly developed welfare states despite these formidable political obstacles. This article reviews the literature on the politics of retrenchment, namely on the impact of socio‐economic problem pressure, political parties, political institutions, welfare state structures and ideas. Most authors agree that socio‐economic problems – particularly domestic problems – contribute to an atmosphere of ‘permanent austerity’ which inspires cutbacks. Moreover, according to most scholars, the extent of retrenchment possible depends on the specific institutional configuration of a political system and the path dependence of existing welfare state structures. The debate on the relevance of political parties and ideas, by contrast, is still far from settled. Further unresolved issues include the nature of the dependent variable in retrenchment studies. Also, the exact motives for cutbacks are theoretically still little understood, as are the political mechanisms through which they are realized. I argue that, because of the nature of these persisting issues, the pluralistic dialogue between different methods and approaches – as well as their combination – remains the most promising way forward in the study of welfare state politics.
Relational Thinking: A Critique of Co-Deterministic Theories of Structure and Agency
Authors: Dépelteau François
Published: February 2008

This article presents a relational criticism of the “morphogenetic theory” of M. Archer. This theory is founded and representative of the most influential mode of perception of the social universe of the last few decades: co-determinism (structure ↔ agency). Co-determinism's influence can be explained by its integration of modern general presuppositions like freedom, individualism, and the quest for a new social order. By identifying five basic principles of relational sociology, we see that Archer's co-deterministic theory offers a complicated solution to avoid voluntarism and co-determinism, limits the potential of sociological imagination, cannot adequately see the fluidity of social processes, produces a certain reification of social structures and agency, and is based on an inconsistent use of egocentric and relational perspectives. These problems can be avoided if we use a relational approach (actor ↔ actor ⇒ structures) based on the study of complex and empirical trans-actions.
A behaviour‐genetic analysis of orthographic learning, spelling and decoding
Authors: Byrne Brian , Coventry William L. , Olson Richard K. , Hulslander Jacqueline , Wadsworth Sally , DeFries John C. , Corley Robin , Willcutt Erik G. , Samuelsson Stefan
Published: February 2008

As part of a longitudinal twin study of literacy and language, we conducted a behaviour‐genetic analysis of orthographic learning, spelling and decoding in Grade 2 children (225 identical and 214 fraternal twin pairs) in the United States and Australia. Each variable showed significant genetic and unique environment influences. Multivariate analyses revealed very high genetic correlations among the variables, indicating that the same genes are involved in their aetiology. These genes are partly independent of those contributing to intelligence. A further analysis indicated that the covariation between decoding and orthographic learning is mediated by shared genes rather than by a direct causal path. The authors argue that a learning parameter, most directly assessed by orthographic learning in this study, underlies all three literacy variables. The results are also discussed in relation to Share's self‐teaching hypothesis, which may require modification.
Spelling as a self‐teaching mechanism in orthographic learning
Authors: Shahar‐Yames Daphna , Share David L.
Published: February 2008

The present study examined the possibility that spelling fulfils a self‐teaching function in the acquisition of orthographic knowledge because, like decoding, it requires close attention to letter order and identity as well as to word‐specific spelling–sound mapping. We hypothesised that: (i) spelling would lead to significant (i.e. above‐chance) levels of orthographic learning; (ii) spelling would actually result in superior learning relative to reading owing to the additional processing demands invoked when spelling; (iii) there would be stronger outcomes for post‐test spelling production compared with spelling recognition; and (iv) relative to reading, spelling would produce superior orthographic learning in the case of later‐occurring orthographic detail compared with information appearing earlier in the letter string. In a fully within‐subjects design, third grade Hebrew readers were exposed to novel letter strings presented in three conditions: spelling, reading and an unseen control condition. With the exception of the position by condition interaction (our fourth hypothesis), which, although in the expected direction, failed to attain significance, all hypotheses were supported. These data highlight yet another dimension of reading–writing reciprocity by suggesting that spelling offers a powerful self‐teaching tool in the compilation of word‐specific orthographic representations.
Effects of repeated reading on the length effect in word and pseudoword reading
Authors: Martens Vanessa E. G. , De Jong Peter F.
Published: February 2008

In this study the effect of repeated reading on the acquisition of orthographic knowledge was examined. Acquisition of orthographic knowledge was assessed by the effect of word length on reading speed. We predicted that the effect of length in a set of words and pseudowords would decrease after the repeated reading of these (pseudo)words. The study involved fourth and fifth grade dyslexic children, in addition to normal readers in second and fourth grade. Words and pseudowords ranged from four to six letters and were read 16 times. A length effect was found in the dyslexic and younger normal readers, but not in the older normal readers. The length effect did not change from pre‐test to post‐test, although a large overall improvement in reading speed was found in all groups. These results suggest that repeated reading did not alter the predominantly sub‐lexical reading procedure of the dyslexic and younger normal readers. Implications for the interpretation of the length effect and the notion of word‐specific orthographic knowledge are discussed.
Orthographic processing and visual sequential memory in unexpectedly poor spellers
Authors: Holmes Virginia M. , Malone Aisling M. , Redenbach Holly
Published: February 2008

Does unexpectedly poor spelling in adults result from inferior visual sequential memory? In one experiment, unexpectedly poor spellers performed significantly worse than better spellers in the immediate reproduction of sequences of visual symbols, but in a second experiment, the effect was not replicated. Poor spellers were also no worse at the immediate recognition of symbol sequences. Overall, the results indicate that inferior visual memory is not characteristic of unexpectedly poor spellers. However, they do have less efficient orthographic processing skill: they were significantly slower and more error prone than better spellers at classifying both regularly and strangely spelt words, as well as at detecting letter transpositions in long words. They can thus be considered as subtly worse word readers than better spellers. While the findings question the notion of unexpectedly poor spelling in relation to normal adults, they provide confirmation of the intimate relationship between reading and spelling processes.
Patterns of generalisation after treating sub‐lexical spelling deficits in a child with mixed dysgraphia
Authors: Kohnen Saskia , Nickels Lyndsey , Brunsdon Ruth , Coltheart Max
Published: February 2008

This paper presents a treatment study with a developmental dysgraphic girl, KM, and addresses the mechanisms by which orthographic learning of spelling rules might occur. Before treatment, KM's spelling of words and nonwords was impaired. Analyses of spelling errors indicated poor knowledge of sound‐to‐letter correspondences. Treatment focused on two spelling rules and was successful: spelling improved for both regular words and nonwords. Untrained words that included the training rules also improved, but later than nonwords and trained words. This delayed generalisation was explained through feedback mechanisms between orthographic lexicon and graphemic buffer.