bluuebunny/crossref_metadata_2025 huggingface dataset:
Triacylglycerol structure and interesterification of palmitic and stearic acid-rich fats: an overview and implications for cardiovascular disease
Authors: Berry Sarah E. E.
Published: May 2009

The position of fatty acids in the TAG molecule (sn-1,sn-2 andsn-3) determines the physical properties of the fat, which affects its absorption, metabolism and distribution into tissues, which may have implications for the risk of CHD. The TAG structure of fats can be manipulated by the process of interesterification, which is of increasing commercial importance, as it can be used to change the physical characteristics of a fat without the generation oftrans-fatty acids. Interesterified fats rich in long-chain SFA are commercially important, but few studies have investigated their health effects. Evidence from animal and human infant studies suggests that TAG structure and interesterification affect digestibility, atherogenicity and fasting lipid levels, with fats containing palmitic and stearic acid in thesn-2 position being better digested and considered to be more atherogenic. However, chronic studies in human adults suggest that TAG structure has no effect on digestibility or fasting lipids. The postprandial effects of fats with differing TAG structure are better characterised but the evidence is inconclusive; it is probable that differences in the physical characteristics of fats resulting from interesterification and changes in TAG structure are key determinants of the level of postprandial lipaemia, rather than the position of fatty acids in the TAG. The present review gives an overview of TAG structure and interesterified palmitic and stearic acid-rich fats, their physical properties and their acute and chronic effects in human adults in relation to CHD.
Review Editor's Introduction
Authors: Isaac Jeffrey C.
Published: May 2009

As I write this introduction, barely eight weeks have elapsed since the inauguration of President Barack Obama, and if there were a honeymoon period, it has most definitely passed. In Pakistan, a weak and divided regime is tottering. To its west, the U.S.-installed regime in Afghanistan is in retreat before the Taliban. In a globalized world, no country has been spared the stresses caused by the financial crisis. And here in the U.S., the severity of the downturn has reignited rancorous partisan debate. The topic of Robert Bates's When Things Fell Apart—the focus of our featured symposium—is the breakdown of political order in parts of Africa. But, apropos earlier discussions about area studies and its limits in which Bates was an important participant, the problem of ensuring effective and legitimate governance is hardly the provenance of the “less developed” world.
The moral quality of work in international economic institutions: resisting complacency
Authors: Del Mar Maksymilian , Onazi Oche
Published: May 2009

This paper offers a theory through which, we argue, we can more appropriately evaluate and potentially improve the moral quality of work. There are three components to such a theory. The first two components, which we argue need to be integrated, are normative resources that appeal to two different behavioural capacities: first, the articulation of rules, appealing to the capacity of agents to deliberate about what they ought to do; second, the introduction of forms of institutional design, appealing to the capacity of agents to acquire habits and dispositions in certain social environments. The third and most important component is that of the infinity of suffering and vulnerability. This component has both a negative and a positive aspect. On the negative side, the component is designed to assist us in recognising the inevitable limitations of either normative resource or indeed any one integrated totality of normative resources (i.e., both rules and forms of institutional design). Those limitations consist in the narrowing of the domain of objects of value towards which workers are guided or oriented by either or both normative resources. On the positive side, the component encourages us to construct alternative normative resources on the basis of alternative forms of representation of suffering and vulnerability. In that respect, the specific policy proposal of this paper is that of the establishment of Community Forums, which are designed to offer a framework thanks to which some of the particularities of suffering and vulnerability within a specific community can be recognised and communicated in a multiplicity of ways, thereafter forming a resource for the development of policy with respect to the challenges facing that specific community. The second part of the paper applies this theory to consider the value and limitations of second-generation reforms in international economic institutions. The third part of the paper further considers the values and limitations of reforms for access to public goods and services in Nigeria.
Role of permeability and storage in the initiation and propagation of natural hydraulic fractures
Authors: Boutt David F. , Goodwin Laurel , McPherson Brian J. O. L.
Published: May 2009

Joint sets within sedimentary basins are commonly interpreted to have formed by tensile failure in conditions where pore fluid pressure was elevated. Such tensile fractures are inferred to be a part of the process that relieves high fluid pressure by locally increasing rock permeability. In spite of the importance of this feedback mechanism, the detailed mechanics of hydraulic fracture genesis remain poorly understood. We describe the results of both experimental and numerical studies of hydraulic fracture genesis on the basis of an experimental protocol that combines rock extension with elevated pore fluid pressure such that the hydraulic fracture criterion is met in the sample interior. This is achieved by simultaneously dropping both minimum stress and external pore fluid pressure, inducing a large fluid pressure drop between the sample interior and its ends. Poroelastic modeling suggests that the pore fluid pressure is highest close to, but not at, the sample ends and is locally maintained at levels that meet the hydraulic fracture criterion for up to 50 s. Application of this experimental protocol to an impure sample of sandstone resulted in the generation of several hydraulic fractures subparallel to the maximum principal stress. Fracturing did not occur in a drained test on the same sample, demonstrating that the elevated pore fluid pressure was critical to fracture formation. To better understand the experimental results, we explore the role of rock permeability and storage on fracture processes using a numerical model that directly couples a lattice‐Boltzmann model for fluid mechanics with a discrete element model for solid mechanics. Like the experiment, the numerical simulations produced opening mode fractures when operated to replicate the conditions of the experiment. Fractures preferentially occur in portions of the model inferred to be mechanically weak. Local fluid pressure gradients strongly influence the state of stress in the solids and thereby fracture growth. Increasing the model permeability increases fracture propagation rate, decreases sample deformation, and increases fracture spacing. Sample deformation increases, and fracture spacing decreases, with increasing overpressure. It appears that bulk forcing of the solid via fluid seepage forces is important in fracture genesis, explaining the key roles of permeability and diffusivity in the hydrofracture process.
Natural magnetic disturbance fields, not precursors, preceding the Loma Prieta earthquake
Authors: Campbell Wallace H.
Published: May 2009

Available records of the magnetic indices Dst and ap together with standard observatory recordings of 1‐min field levels were examined for the period preceding the earthquake of October 1989, centered near Loma Prieta, California. The magnetic records showed that the Fraser‐Smith et al. (1990) report claiming the existence of a 100‐s (ultralow frequency) geomagnetic field precursor signal at Corralitos, California, foretelling a nearby earthquake is not valid. My study shows that the Stanford ULF signal was not local but rather widespread throughout the western United States and, therefore, expected to be due to a coincidental geomagnetic solar‐terrestrial disturbance field.
Interaction of anion exchanger 1 and glycophorin A in human erythroleukaemic K562 cells
Authors: Pang Allison J. , Reithmeier Reinhart A. F.
Published: May 2009

AE1 [anion exchanger 1, also known as SLC4A1 (solute carrier family 4, anion exchanger, member 1) and band 3 (erythrocyte membrane protein band 3)] is a major membrane glycoprotein expressed in human erythrocytes where it mediates the exchange of chloride and bicarbonate across the plasma membrane. Glycophorin A (GPA) is a sialoglycoprotein that associates with AE1 in erythrocytes forming the Wrb (Wright b) blood group antigen. These two integral proteins may also form a complex during biosynthesis, with GPA facilitating the cell surface expression of AE1. This study investigates the interaction of GPA with AE1 in K562 cells, a human erythroleukaemic cell line that expresses GPA, and the role of GPA in the cell surface expression of AE1. In K562 cells, GPA was dimeric and N- and O-glycosylated similar to erythroid GPA. GPA was localized at the cell surface, but also localized to the Golgi. AE1 expressed in K562 cells contained both complex and high-mannose oligosaccharides, and co-localized with GPA at the cell surface and in the endoplasmic reticulum (ER). The Wrb antigen was detected at the cell surface of AE1-transfected K562 cells, indicating the existence of an AE1–GPA complex. Immunofluorescence and co-immunoprecipitation studies using AE1 and an ER-localized hereditary spherocytosis mutant (R760Q AE1) showed that GPA and AE1 could interact in the ER. GPA knockdown by shRNAs (small-hairpin RNAs), however, had no effect on the level of cell surface expression of AE1. The results indicate that AE1 and GPA form a complex in the ER of human K562 cells, but that both proteins can also traffic to the cell surface independently of each other.
Mutational analysis of the PTEN gene in women with premature ovarian failure
Authors: SHIMIZU YOSHIHIKO , KIMURA FUMINORI , TAKEBAYASHI KOICHI , FUJIWARA MUTSUKO , TAKAKURA KENJI , TAKAHASHI KENTARO
Published: May 2009

Recent studies in mammals have suggested that the phosphatase and tensin homolog deleted on chromosome 10 (PTEN) – phosphatidylinositol‐3, 4, 5‐trisphosphate pathway in oocytes might be related to the pathogenesis of premature ovarian failure (POF). The aim of this study was to investigate whether mutations of the PTEN gene are present in women with POF. We analyzed the coding region of the PTEN gene in 20 women with idiopathic POF and 20 normal controls. The PTEN gene was amplified by the polymerase chain reaction using genomic DNA isolated from blood samples. Amplified DNA was analyzed by denaturing gradient gel electrophoresis and direct sequencing. No causative mutation was detected in the coding regions of this gene. Although we found a point variation in exon 7 of one POF patient, this was a single nucleotide polymorphism that has already been reported.
Exploiting Knowledge of R/Avr Genes to Rapidly Clone a New LZ-NBS-LRR Family of Late Blight Resistance Genes from Potato Linkage Group IV
Authors: Lokossou Anoma A. , Park Tae-ho , van Arkel Gert , Arens Marjon , Ruyter-Spira Carolien , Morales Juan , Whisson Steve C. , Birch Paul R. J. , Visser Richard G. F. , Jacobsen Evert , van der Vossen Edwin A. G.
Published: May 2009

In addition to the resistance to Phytophthora infestans (Rpi) genes Rpi-blb1 and Rpi-blb2, Solanum bulbocastanum appears to harbor Rpi-blb3 located at a major late blight resistance locus on LG IV, which also harbors Rpi-abpt, R2, R2-like, and Rpi-mcd1 in other Solanum spp. Here, we report the cloning and functional analyses of four Rpi genes, using a map-based cloning approach, allele-mining strategy, Gateway technology, and transient complementation assays in Nicotiana benthamiana. Rpi-blb3, Rpi-abpt, R2, and R2-like contain all signature sequences characteristic of leucine zipper nucleotide binding site leucine-rich repeat (LZ-NBS-LRR) proteins, and share amino-acid sequences 34.9% similar to RPP13 from Arabidopsis thaliana. The LRR domains of all four Rpi proteins are highly homologous whereas LZ and NBS domains are more polymorphic, those of R2 being the most divergent. Clear blocks of sequence affiliation between the four functional resistance proteins and those encoded by additional Rpi-blb3 gene homologs suggest exchange of LZ, NBS, and LRR domains, underlining the modular nature of these proteins. All four Rpi genes recognize the recently identified RXLR effector PiAVR2.
Missing the rarest: is the positive interspecific abundance–distribution relationship a truly general macroecological pattern?
Authors: Komonen Atte , Päivinen Jussi , Kotiaho Janne S.
Published: May 2009

Lepidopterists have long acknowledged that many uncommon butterfly species can be extremely abundant in suitable locations. If this is generally true, it contradicts the general macroecological pattern of the positive interspecific relationship between abundance and distribution, i.e. locally abundant species are often geographically more widespread than locally rare species. Indeed, a negative abundance–distribution relationship has been documented for butterflies in Finland. Here we show, using the Finnish butterflies as an example, that a positive abundance–distribution relationship results if the geographically restricted species are missed, as may be the case in studies based on random or restricted sampling protocols, or in studies that are conducted over small spatial scales. In our case, the abundance–distribution relationship becomes negative when approximately 70 per cent of the species are included. This observation suggests that the abundance–distribution relationship may in fact not be linear over the entire range of distributions. This intriguing possibility combined with some taxonomic biases in the literature may undermine the generalization that for a given taxonomic assemblage there is a positive interspecific relationship between local abundance and regional distribution.
Walter Eric Spear. 20 January 1921 — 21 February 2008
Authors: Adams Alfred
Published: May 2009

Walter Spear was a multi-talented individual who decided to make a career in science in the UK. After his studies in London he joined the academic staff of the Physics Department in Leicester in 1953. In 1968 he was appointed to the Harris Chair of Physics at the University of Dundee in Scotland, where he stayed until retirement. Although his work was primarily driven by a desire to understand the basic physics of electrical conduction in solids, his discoveries had considerable impact on the electronics industry. For example, he will be well remembered for his research on amorphous semiconductors, which resulted in a variety of applications within the optoelectronics industry, including solar cells and the liquid crystal displays (LCDs) used in televisions, computer monitors and a wide range of hand-held devices. His work was characterized throughout by high experimental skill, felicitous choice of materials and full theoretical understanding. Walter won many international prizes during his career, including the Royal Society Rumford Medal in 1990.
Detailed analyses of self‐poisoning episodes presenting to a large regional teaching hospital in the UK
Authors: Prescott Katherine , Stratton Richard , Freyer Anette , Hall Ian , Le Jeune Ivan
Published: May 2009

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

• Deliberate self‐poisoning accounts for 170 000 presentations to UK hospitals each year with a profound impact on the health of individual patients. We have basic demographic information on self‐poisoning but there is a relative paucity of contemporary, detailed information on the patterns of presentation, drugs taken in overdose and the current impact on services.

WHAT THIS STUDY ADDS

• This study provides detailed analyses of demographics, timing of presentation, patterns of overdose, drugs taken with special emphasis on paracetamol, the patient pathway through hospital and an estimation of the financial impact to the hospital of this patient group. This information is essential in planning the necessary service developments in emergency departments and medical admissions units that are required to optimize management of this patient group.

AIMS

The primary aim of this paper is to provide comprehensive contemporaneous data on the demographics, patterns of presentation and management of all episodes of deliberate self‐poisoning presenting to a large regional teaching hospital over a 12 month period.

METHODS

We undertook detailed, retrospective analyses using information from electronic patient records and local patient‐tracking, pathology and administrative databases. Statistical analyses were performed using Chi‐squared tests, anova and two‐tailed t‐tests (Graphpad Prism).

RESULTS

One thousand five hundred and ninety‐eight episodes of deliberate self‐poisoning presented over the year. Demographic data and information on the month, day and time of admission are provided. 70.7% presented to the emergency department (ED) within 4 h of ingestion. 76.3% of patients had only one episode in an extended 29 month follow‐up period. A mean of 1.72 drugs were taken per episode with just over half of all episodes involving a single drug only. Paracetamol and ibuprofen were the two most commonly ingested drugs involved in 42.5% and 17.3% of all overdoses respectively. 56.3% of patients taking paracetamol reported ingesting over 8 g (one over the counter packet). Detailed mapping of the patients' pathway through the hospital allowed an estimation of the hospital cost of caring for this patient group at £1.6 million pounds per year.

CONCLUSIONS

We present comprehensive and contemporary data on presentations to hospital resulting from deliberate self‐poisoning. We include demographic information, presentation patterns, drugs used, a detailed analysis of episodes involving paracetamol and an estimate of the financial burden to hospitals of overdose presentations.
Exaggerated inflammatory response of primary human myeloid dendritic cells to lipopolysaccharide in patients with inflammatory bowel disease
Authors: Baumgart D C , Thomas S , Przesdzing I , Metzke D , Bielecki C , Lehmann S M , Lehnardt S , Dörffel Y , Sturm A , Scheffold A , Schmitz J , Radbruch A
Published: May 2009

Inflammatory bowel disease (IBD) results from a breakdown of tolerance towards the indigenous flora in genetically susceptible hosts. Failure of dendritic cells (DC) to interpret molecular microbial patterns appropriately when directing innate and adaptive immune responses is conceivable. Primary (conventional, non-monocyte generated) CD1c+CD11c+CD14-CD16-CD19- myeloid blood or mucosal dendritic cells (mDC) from 76 patients with Crohn’s disease (CD) or ulcerative colitis (UC) in remission, during flare-ups (FU) and 76 healthy or non-IBD controls were analysed by fluorescence activated cell sorter (FACS) flow cytometry and real-time polymerase chain reaction. Cytokine secretion of freshly isolated, cultured and lipopolysaccharide (LPS)-stimulated highly purified mDC (purity >95%) was assessed using cytometric bead arrays (CBA). More cultured and stimulated circulating mDC express CD40 in IBD patients. Stimulated circulating mDC from IBD patients secrete significantly more tumour necrosis factor (TNF)-α and interleukin (IL)-8. Toll-like receptor (TLR)-4 expression by mDC was higher in remission and increased significantly in flaring UC and CD patients compared with remission (P < 0·05) and controls (P < 0·001). Fluorochrome-labelled LPS uptake by mDC was evaluated at different time-points over 24 h by measuring mean fluorescence intensity (MFI). Circulating mDC from IBD patients take up more LPS and the uptake begins earlier compared with controls (P < 0·05 in CD-FU and UC-FU at 24 h). The frequency of mucosal mDC (P < 0·05) and the number of CD40 expressing mucosal mDC is significantly greater in UC and CD compared with non-IBD controls (P < 0·001 versus P < 0·01, respectively). Our data suggest an aberrant LPS response of mDC in IBD patients, resulting in an inflammatory phenotype and possibly intestinal homing in acute flares.
Vaccinia virus decreases major histocompatibility complex (MHC) class II antigen presentation, T‐cell priming, and peptide association with MHC class II
Authors: Rehm Kristina E. , Connor Ramsey F. , Jones Gwendolyn J. B. , Yimbu Kenneth , Mannie Mark D. , Roper Rachel L.
Published: May 2009

Vaccinia virus (VACV) is the current live virus vaccine used to protect humans against smallpox and monkeypox, but its use is contraindicated in several populations because of its virulence. It is therefore important to elucidate the immune evasion mechanisms of VACV. We found that VACV infection of antigen‐presenting cells (APCs) significantly decreased major histocompatibility complex (MHC) II antigen presentation and decreased synthesis of 13 chemokines and cytokines, suggesting a potent viral mechanism for immune evasion. In these model systems, responding T cells were not directly affected by virus, indicating that VACV directly affects the APC. VACV significantly decreased nitric oxide production by peritoneal exudate cells and the RAW macrophage cell line in response to lipopolysaccharide (LPS) and interferon (IFN)‐γ, decreased class II MHC expression on APCs, and induced apoptosis in macrophages and dendritic cells. However, VACV decreased antigen presentation by 1153 B cells without apparent apoptosis induction, indicating that VACV differentially affects B lymphocytes and other APCs. We show that the key mechanism of VACV inhibition of antigen presentation may be its reduction of antigenic peptide loaded into the cleft of MHC class II molecules. These data indicate that VACV evades the host immune response by impairing critical functions of the APC.
Immunological dysfunction in HIV‐1‐infected individuals caused by impairment of adenosine deaminase‐induced costimulation of T‐cell activation
Authors: Martinez‐Navio José M. , Climent Núria , Pacheco Rodrigo , Garcia Felipe , Plana Montserrat , Nomdedeu Meritxell , Oliva Harold , Rovira Cristina , Miralles Laia , Gatell José M. , Gallart Teresa , Mallol Josefa , Lluis Carme , Franco Rafael
Published: May 2009

The cell surface association between CD26 and adenosine deaminase (ADA) has a costimulatory function during T‐cell activation. Several studies have revealed correlations among CD4+ CD26+ T‐cell depletion, increased serum levels of ADA, and the evolution of human immunodeficiency virus (HIV) infection, implicating CD26 and ADA in HIV disease progression. In this context, we aimed to determine whether ADA costimulation could be altered during HIV infection. ADA costimulation was investigated in cells from HIV‐infected patients (n = 36) in terms of proliferation and cytokine secretion. An effect of ADA on T‐cell proliferation was found in HIV‐1‐infected patients and correlated positively with the CD4+ percentage and the nadir CD4 count and negatively with viral load, demonstrating that the response depends on the immunological status of the patient. The robust ADA‐induced increase in cytokine production [interferon (IFN)‐γ, interleukin (IL)‐6 and IL‐10] was markedly reduced in T cells from HIV‐1‐infected subjects. To eliminate some of the variables associated with immunological defects in HIV‐1‐infected patients, anti‐CD3 plus ADA assays with T cells from healthy volunteers were performed in the presence of recombinant glycoprotein 120 (gp120). It was found that gp120 was responsible for the impairment of the ADA–CD26 interaction and consequently of the ADA‐induced effect on both costimulation and cytokine production. The gp120‐mediated disruption of the CD26–ADA interaction is a novel mechanism that might explain, at least in part, the altered immunological features observed in HIV‐1‐infected patients and may have significant relevance in AIDS pathogenesis.
Characterization of CD4+ T‐cell–dendritic cell interactions during secondary antigen exposure in tolerance and priming
Authors: Rush Catherine M. , Millington Owain R. , Hutchison Sharon , Bryson Karen , Brewer James M. , Garside Paul
Published: May 2009

Despite the recent advances in our understanding of the dynamics of the cellular interactions associated with the induction of immune responses, comparatively little is known about the in vivo behaviour of antigen‐experienced T cells upon secondary antigen exposure in either priming or tolerance. Such information would provide an insight into the functional mechanisms employed by memory T cells of distinct phenotypes and provide invaluable knowledge of how a specific tolerogenic or immunogenic state is maintained. Using real‐time imaging to follow the in vivo motility of naïve, primed and tolerized CD4+ T cells and their interactions with dendritic cells (DCs), we demonstrate that each of these distinct functional phenotypes is associated with specific patterns of behaviour. We show that antigen‐experienced CD4+ T cells, whether primed or tolerized, display inherently slower migration, making many short contacts with DCs in the absence of antigen. Following secondary exposure to antigen, primed T cells increase their intensity or area of interaction with DCs whereas contacts between DCs and tolerized T cells are reduced. Importantly, this was not associated with alterations in the contact time between DCs and T cells, suggesting that T cells that have previously encountered antigen are more effective at surveying DCs. Thus, our studies are the first to demonstrate that naïve, primed and tolerized T cells show distinct behaviours before and after secondary antigen‐encounter, providing a novel mechanism for the increased immune surveillance associated with memory T cells. These findings have important consequences for many immunotherapeutics, which aim to manipulate secondary immune responses.
Unexpected panmixia in a long‐lived, deep‐sea fish with well‐defined spawning habitat and relatively low fecundity
Authors: WHITE THOMAS A. , STEFANNI SERGIO , STAMFORD JOANNE , HOELZEL A. RUS
Published: May 2009

The marine environment presents particular challenges for our understanding of the factors that determine gene flow and consequent population structure. For marine fish, various aspects of life history have been considered important in an environment with few physical barriers, but dominated by current patterns, often varying with depth. These factors include the abundance and longevity of larval stages, typically more susceptible to movement along current paths. It also includes adult body size, fecundity and longevity with ‘r‐selected’ species typically thought capable of greater gene flow and consequent panmixia. Here we investigate the population genetics of the orange roughy (Hoplostethus atlanticus), a clearly ‘K‐selected’ species with habitat dependence on sea mounts for spawning, relatively large body size, a brief larval stage and relatively low fecundity. We used 14 polymorphic microsatellite loci to test the hypothesis that these characteristics will result in philopatry and genetic structure in the Atlantic Ocean. We discuss possible evolutionary mechanisms that could explain the results, which show the opposite pattern, with effective panmixia across thousands of kilometres in the North Atlantic.
Phylogeography of the North American red fox: vicariance in Pleistocene forest refugia
Authors: AUBRY KEITH B. , STATHAM MARK J. , SACKS BENJAMIN N. , PERRINE JOHN D. , WISELY SAMANTHA M.
Published: May 2009

Fossil, archaeological, and morphometric data suggest that indigenous red foxes in North America were derived from vicariance in two disjunct refugia during the last glaciation: one in Beringia and one in the contiguous USA. To test this hypothesis, we conducted a phylogeographical analysis of the North American red fox within its presettlement range. We sequenced portions of the mitochondrial cytochrome b (354 bp) gene and D‐loop (342 bp) from 220 historical red fox specimens. Phylogenetic analysis of the cytochrome b gene produced two clades that diverged c. 400 000 years before present (bp): a Holarctic and a Nearctic clade. D‐loop analyses of the Nearctic clade indicated three distinct subclades (≥ 99% Bayesian posterior probability); two that were more recently derived (rho estimate c. 20 000 bp) and were restricted to the southwestern mountains and the eastern portion of North America, and one that was older (rho estimate c. 45 000 bp) and more widespread in North America. Populations that migrated north from the southern refugium following deglaciation were derived from the colonization of North America during or prior to the Illinoian glaciation (300 000–130 000 bp), whereas populations that migrated south from the northern refugium represent a more recent colonization event during the Wisconsin glaciation (100 000–10 000 bp). Our findings indicate that Nearctic clade red foxes are phylogenetically distinct from their Holarctic counterparts, and reflect long‐term isolation in two disjunct forest refugia during the Pleistocene. The montane lineage, which includes endangered populations, may be ecologically and evolutionarily distinct.
Post inflammatory damage to the enteric nervous system in diverticular disease and its relationship to symptoms
Authors: Simpson J. , Sundler F. , Humes D. J. , Jenkins D. , Scholefield J. H. , Spiller R. C.
Published: May 2009

Abstract:  Some patients with colonic diverticula suffer recurrent abdominal pain and exhibit visceral hypersensitivity, though the mechanism is unclear. Prior diverticulitis increases the risk of being symptomatic while experimental colitis in animals increases expression of neuropeptides within the enteric nervous system (ENS) which may mediate visceral hypersensitivity. Our aim was to determine the expression of neuropeptides within the ENS in diverticulitis (study 1) and in patients with symptomatic disease (study 2). Study 1 – Nerves in colonic resection specimens with either acute diverticulitis (AD, n = 16) or chronic diverticulitis (CD, n = 16) were assessed for neuropeptide expression recording % area staining with protein gene product (PGP9.5), substance P (SP), neuropeptide K (NPK), pituitary adenylate cyclase activating polypeptide (PACAP), vasoactive intestinal polypeptide (VIP) and galanin. Study 2 – Seventeen symptomatic and 15 asymptomatic patients with colonic diverticula underwent flexible sigmoidoscopy and multiple peridiverticular mucosal biopsies. Study 1– Neural tissue, as assessed by PGP staining was increased to a similar degree in circular muscle in both AD and CD. The CD specimens showed significant increases in the immunoreactivity of SP, NPK and galanin in both mucosal and circular muscle layer compared with controls. Study 2 – Mucosal histology was normal and PGP9.5 staining was similar between groups however patients with symptomatic diverticular disease demonstrated significantly higher levels of SP, NPK, VIP, PACAP and galanin within the mucosal plexus. Patients with symptomatic diverticular disease exhibit increased neuropeptides in mucosal biopsies which may reflect resolved prior inflammation, as it parallels the changes seen in acute and chronic diverticulitis.
Spatio‐temporal analysis reveals aberrant linkage among sequential propagating pressure wave sequences in patients with symptomatically defined obstructed defecation
Authors: Dinning P. G. , Szczesniak M. M. , Cook I. J.
Published: May 2009

Abstract  Available evidence implicates abnormal colonic contractility in patients suffering from constipation. Traditional analysis of colonic manometry focuses on the frequency, extent and amplitude of propagating sequences (PS). We tested the hypotheses that the spatio‐temporal linkage among sequential PSs exists throughout the healthy human colon and is disrupted during constipation. In eight patients with severe constipation and eight healthy volunteers, we recorded colonic pressures from 16 regions (caecum–rectum) for 24 h. Sequential PSs were regionally linked if the two PSs originated from different colonic regions but the segments of colon traversed by each PS overlapped. In order to determine whether this linkage occurred by chance, a computer program was used to randomly rearrange all PSs in time. Data were re‐analysed to compare regional linkage between randomly re‐ordered PSs (expected) and the natural distribution of PSs (observed). In controls the observed regional linkage (82.5 ± 9.0%) was significantly greater than the expected value (60.5 ± 4.3%; P = 0.0001). In patients the observed and expected regional linkage did not differ. The (observed − expected) delta value of regional linkage in controls was significantly greater than in patients (21.7 ± 8.5%vs−2.3 ± 7.0%; P = 0.01). Regional linkage among sequential PSs in the healthy colon appears to be a real phenomenon and this linkage is lost in patients with constipation. Regional linkage may be important for normal colonic transit and loss of linkage might have pathophysiological relevance to and provide a useful biomarker of severe constipation.
Toxoplasma and schizophrenia
Authors: YOLKEN R. H. , DICKERSON F. B , FULLER TORREY E.
Published: May 2009

Research on infectious agents as a possible cause of schizophrenia has become prominent in the past decade. Toxoplasma gondii has emerged as a prime candidate for a variety of reasons; (i) many studies have reported that individuals with schizophrenia, compared to controls, have a higher prevalence of antibodies to T. gondii, (ii) some individuals with adult toxoplasmosis develop psychotic symptoms similar to those of schizophrenia, (iii) epidemiologically, there are many similarities between toxoplasmosis and schizophrenia, (iv) antipsychotic drugs known to be effective in schizophrenia also inhibit some parasites, including T. gondii, (v) Toxoplasma has been shown to induce elevated levels of dopamine in experimentally infected animals (elevated dopamine is commonly seen in individuals with schizophrenia) and (vi) studies have shown that individuals with schizophrenia, compared to controls, have had greater exposure to cats in childhood. A number of questions remain concerning a role for Toxoplasma in the aetiology of schizophrenia, including the roles of strain variation, the timing and source of infection, and the role of host genes in determining disease susceptibility. The establishment of a firm association between Toxoplasma and the aetiology of schizophrenia and related disorders would represent a major breakthrough in the understanding of these disorders and would lead to novel methods for their treatment and prevention.
Effect of water availability on leaf water isotopic enrichment in beech seedlings shows limitations of current fractionation models
Authors: FERRIO JUAN PEDRO , CUNTZ MATTHIAS , OFFERMANN CHRISTINE , SIEGWOLF ROLF , SAURER MATTHIAS , GESSLER ARTHUR
Published: May 2009

Current models of leaf water enrichment predict that the differences between isotopic enrichment of water at the site of evaporation (Δe) and mean lamina leaf water enrichment (ΔL) depend on transpiration rates (E), modulated by the scaled effective length (L) of water isotope movement in the leaf. However, variations in leaf parameters in response to changing environmental conditions might cause changes in the water path and thus L. We measured the diel course of ΔL for 18O and 2H in beech seedlings under well‐watered and water‐limited conditions. We applied evaporative enrichment models of increasing complexity to predict Δe and ΔL, and estimated L from model fits. Water‐limited plants showed moderate drought stress, with lower stomatal conductance, E and stem water potential than the control. Despite having double E, the divergence between Δe and ΔL was lower in well‐watered than in water‐limited plants, and thus, L should have changed to counteract differences in E. Indeed, L was about threefold higher in water‐limited plants, regardless of the models used. We conclude that L changes with plant water status far beyond the variations explained by water content and other measured variables, thus limiting the use of current evaporative models under changing environmental conditions.
Phytochromes differentially regulate seed germination responses to light quality and temperature cues during seed maturation
Authors: DECHAINE JENNIFER M. , GARDNER GARY , WEINIG CYNTHIA
Published: May 2009

The ratio of red to far‐red light (R : FR) experienced by seeds during maturation affects germination, but the genetic regulation of this effect is poorly understood. In Arabidopsis thaliana, responses to R : FR are governed by five phytochrome photoreceptors, PHYA–PHYE. PHYA, PHYB and PHYE mediate germination, but their roles in germination response to the seed maturation environment are largely unknown. Seeds of A. thaliana phytochrome mutants and natural accessions were matured in a factorial combination of cold (16 °C) and warm (24 °C) temperatures and high (R : FR = 1) and low (R : FR = 0.6) R : FR environments, resembling sunlight and foliar shade, respectively. Germination was observed in resulting seeds. All five phytochromes mediated germination responses to seed maturation temperature and/or R : FR environment. PHYA suppressed germination in seeds matured under cold temperature, and PHYB promoted germination under the same conditions. PHYD and PHYE promoted germination of seeds matured under warm temperature, but this effect diminished when seeds matured under reduced R : FR. The A. thaliana natural accessions exhibited interesting variation in germination responses to the experimental conditions. Our results suggest that the role of individual PHY loci in regulating plant responses to R : FR varies depending on temperature and provide novel insights into the genetic basis of maternal effects.
Does the 13C of foliage‐respired CO2 and biochemical pools reflect the 13C of recently assimilated carbon?
Authors: MORTAZAVI BEHZAD , CONTE MAUREEN H. , CHANTON JEFFREY P. , SMITH MATTHEW C. , WEBER J. C. , CRUMSEY JASMINE , GHASHGHAIE JALEH
Published: May 2009

Isotopic labelling experiments were conducted to assess relationships among 13C of recently assimilated carbon (δCA), foliage respiration (δCF), soluble carbohydrate (δCSC), leaf waxes (δCLW) and bulk organic matter (δCOM). Slash pine, sweetgum and maize were grown under 13C depleted CO2 to label biomass and then placed under ambient conditions to monitor the loss of label. In pine and sweetgum, δCF of labelled plants (∼−44 and −35‰, respectively) rapidly approached control values but remained depleted by ∼4–6‰ after 3–4 months. For these tree species, no or minimal label was lost from δCSC, δCLW and δCOM during the observation periods. δCF and δCSC of labelled maize plants rapidly changed and were indistinguishable from controls after 1 month, while δCLW and δCOM more slowly approached control values and remained depleted by 2–6‰. Changes in δCF in slash pine and sweetgum fit a two‐pool exponential model, with the fast turnover metabolic pool (∼3–4 d half‐life) constituting only 1–2% of the total. In maize, change in δCF fits a single pool model with a half‐life of 6.4 d. The 13C of foliage respiration and biochemical pools reflect temporally integrated values of δCA, with change in isotopic composition dampened by the size of metabolic carbon reserves and turnover rates.
Xylem function of arid‐land shrubs from California, USA: an ecological and evolutionary analysis
Authors: HACKE U. G. , JACOBSEN A. L. , PRATT R. B.
Published: May 2009

Xylem traits were examined among 22 arid‐land shrub species, including measures of vessel dimensions and pit area. These structural measures were compared with the xylem functional traits of transport efficiency and safety from cavitation. The influence of evolution on trait relationships was examined using phylogenetic independent contrasts (PICs). A trade‐off between xylem safety and efficiency was supported by a negative correlation between vessel dimensions and cavitation resistance. Pit area was correlated with cavitation resistance when cross species data were examined, but PICs suggest that these traits have evolved independently of one another. Differences in cavitation resistance that are not explained by pit area may be related to differences in pit membrane properties or the prevalence of tracheids, the latter of which may alter pit area through the addition of vessel‐to‐tracheid pits or through changes in xylem conduit connectivity. Some trait relationships were robust regardless of species ecology or evolutionary history. These trait relationships are likely to be the most valuable in predictive models that seek to examine anatomical and functional trait relationships among extant and fossil woods and include the relationship among hydraulic conductivity and vessel diameter, between vessel diameter and vessel length, and between hydraulic conductivity and wood density.
Lysine requirement studies in modern genotype barrows dependent on age, protein deposition and dietary lysine efficiency
Authors: Wecke C. , Liebert F.
Published: May 2009

N balance experiments were conducted to derive age‐dependent model parameters for modelling of lysine (Lys) requirements in growing pigs. Modern genotype barrows from 16 litters were utilized (four piglets/litter) at 15, 30, 50, 70, 90 and 110 kg body weight respectively. Six diets provided graded dietary protein supply (40 to 320 g/kg) by a constant mixture of barley, wheat, potato protein, wheat gluten, soybean protein concentrate and crystalline amino acids. Lys was set as the first limiting dietary amino acid. Each age period provided 24 N balance data (n = 4) to derive N maintenance requirement (NMR) and theoretical maximum for daily N retention (NRmaxT) by non‐linear regression analysis. At high dietary Lys efficiency, 17–18 g daily Lys intake was required for 170 g daily protein deposition. To achieve similar daily protein deposition, pigs need 21–23 g Lys if the Lys efficiency is 20% lower. For higher daily protein deposition (195–200 g) and varying dietary Lys efficiency, between 22 and 29 g Lys was required. The Lys requirement data yielded by modelling were in line with current recommendations. Further developments of the approach are discussed to improve age‐independent applications.
Successful treatment with rituximab in an elderly patient with acquired factor VIII inhibitor
Authors: Cretel Elodie , Jean Rodolphe , Chiche Laurent , Durand Jean Marc
Published: May 2009

We report here on an elderly patient, aged 88 years, who developed acquired hemophilia, with a high titer of factor VIII inhibitors and severe hemorrhage, in the absence of a detectable cause. Marked and prolonged efficacy was observed after rituximab.
Peer Effects on Children’s Language Achievement During Pre‐Kindergarten
Authors: Mashburn Andrew J. , Justice Laura M. , Downer Jason T. , Pianta Robert C.
Published: May 2009

This study examined associations between peers’ expressive language abilities and children’s development of receptive and expressive language among 1,812 four‐year olds enrolled in 453 classrooms in 11 states that provide large‐scale public pre‐kindergarten (pre‐k) programs. Higher peer expressive language abilities were positively associated with children’s development of receptive and expressive language during pre‐k. The positive association between peers’ expressive language abilities and children’s receptive language development was stronger for children who began pre‐k with higher receptive language skills and within classrooms characterized by better classroom management. Implications of these findings for understanding ecological inputs to children’s language development and for designing effective pre‐k programs are discussed.
American and Chinese Early Adolescents’ Inclusion of Their Relationships With Their Parents in Their Self‐Construals
Authors: Pomerantz Eva M. , Qin Lili , Wang Qian , Chen Huichang
Published: May 2009

This research examined children’s interdependent self‐construals as manifest in their seeing their relationships with their parents as self‐defining. Four times over early adolescence, 825 children (mean age = 12.73 years) in the United States and China reported on their inclusion of their relationships with their parents in their self‐construals as well as other dimensions of their psychological functioning. Although there was continuity in children’s inclusion of their relationships with their parents in their self‐construals, American, but not Chinese, children decreased their inclusion over time. In both the United States and China, the more children defined themselves in terms of their relationships with their parents, the more their perceptions of the quality of these relationships mattered for their subsequent emotional functioning.
A Longitudinal Study of Forms and Functions of Aggressive Behavior in Early Childhood
Authors: Murray‐Close Dianna , Ostrov Jamie M.
Published: May 2009

The purpose of this study was to investigate the distinct forms (i.e., physical and relational) and functions (i.e., proactive and reactive) of aggressive behavior during early childhood (n = 101; M age = 45.09 months). Forms, but not functions, of aggressive behavior were stable over time. A number of contributors to aggression were associated with distinct subtypes of aggressive behavior. Females and socially dominant children were more relationally aggressive and older children were less physically aggressive than their peers. Longitudinal analyses indicated that social dominance predicted decreases in physical aggression and peer exclusion predicted increases in relational aggression. Overall, the results provide support for the distinction between subtypes of aggression in early childhood.
Maternal Sleep‐Related Cognitions and Infant Sleep: A Longitudinal Study From Pregnancy Through the 1st Year
Authors: Tikotzky Liat , Sadeh Avi
Published: May 2009

Infant sleep is a major source of concern for many parents. The aims of this longitudinal study were to assess: (a) the development of sleep patterns among infants, (b) the development of maternal cognitions regarding infant sleep, and (c) the relations between these domains during the 1st year of life. Eighty‐five mothers were recruited during pregnancy and completed a questionnaire aimed at assessing maternal sleep‐related cognitions. After delivery (at 1, 6, and 12 months) sleep was assessed using actigraphy and sleep logs, and maternal cognitions were reassessed. The findings demonstrated significant predictive and concomitant links between maternal cognitions and infant sleep. Maternal soothing behaviors mediated the relations between these domains.
Perceived Support for Promotion-Focused and Prevention-Focused Goals
Authors: Molden Daniel C. , Lucas Gale M. , Finkel Eli J. , Kumashiro Madoka , Rusbult Caryl
Published: May 2009

Perceived emotional support from close relationship partners in times of stress is a major predictor of well-being. However, recent research has suggested that, beyond emotional support, perceived support for achieving personal goals is also important for well-being. The present study extends such research by demonstrating that associations of perceived goal support with well-being differ depending on how people represent their goals and the general motivational context in which they pursue these goals. Among unmarried romantic partners, for whom the context of the relationship presumably is largely attainment oriented, perceived support for attainment-relevant (or promotion-focused) goals independently predicted relationship and personal well-being, whereas perceived support for maintenance-relevant (or prevention-focused) goals did not. In contrast, among married partners, for whom the context of the relationship presumably is both attainment and maintenance oriented, perceived support for both promotion-focused and prevention-focused goals independently predicted well-being. We discuss the implications for forecasting and improving well-being among married couples.