bluuebunny/crossref_metadata_2025 huggingface dataset:
Expert Panel on Weight Loss Surgery: Executive Report Update
Authors: Blackburn George L. , Hutter Matthew M. , Harvey Alan M. , Apovian Caroline M. , Boulton Hannah R.W. , Cummings Susan , Fallon John A. , Greenberg Isaac , Jiser Michael E. , Jones Daniel B. , Jones Stephanie B. , Kaplan Lee M. , Kelly John J. , Kruger Rayford S. , Lautz David B. , Lenders Carine M. , LoNigro Robert , Luce Helen , McNamara Anne , Mulligan Ann T. , Paasche‐Orlow Michael K. , Perna Frank M. , Pratt Janey S.A. , Riley Stancel M. , Robinson Malcolm K. , Romanelli John R. , Saltzman Edward , Schumann Roman , Shikora Scott A. , Snow Roger L. , Sogg Stephanie , Sullivan Mary A. , Tarnoff Michael , Thompson Christopher C. , Wee Christina C. , Ridley Nancy , Auerbach John , Hu Frank B. , Kirle Leslie , Buckley Rita B. , Annas Catherine L.
Published: February 2009

Rapid shifts in the demographics and techniques of weight loss surgery (WLS) have led to new issues, new data, new concerns, and new challenges. In 2004, this journal published comprehensive evidence‐based guidelines on WLS. In this issue, we've updated those guidelines to assure patient safety in this fast‐changing field. WLS involves a uniquely vulnerable population in need of specialized resources and ongoing multidisciplinary care. Timely best‐practice updates are required to identify new risks, develop strategies to address them, and optimize treatment. Findings in these reports are based on a comprehensive review of the most current literature on WLS; they directly link patient safety to methods for setting evidence‐based guidelines developed from peer‐reviewed scientific publications. Among other outcomes, these reports show that WLS reduces chronic disease risk factors, improves health, and confers a survival benefit on those who undergo it. The literature also shows that laparoscopy has displaced open surgery as the predominant approach; that government agencies and insurers only reimburse procedures performed at accredited WLS centers; that best practice care requires close collaboration between members of a multidisciplinary team; and that new and existing facilities require wide‐ranging changes to accommodate growing numbers of severely obese patients. More than 100 specialists from across the state of Massachusetts and across the many disciplines involved in WLS came together to develop these new standards. We expect them to have far‐reaching effects of the development of health care policy and the practice of WLS.
Sustained NPY Overexpression in the PVN Results in Obesity via Temporarily Increasing Food Intake
Authors: Tiesjema Birgitte , la Fleur Susanne E. , Luijendijk Mieneke C.M. , Adan Roger A.H.
Published: February 2009

Increasing neuropeptide Y (NPY) signaling in the paraventricular nucleus (PVN) by recombinant adeno‐associated virus (rAAV)‐mediated overexpression of NPY in rats, results in hyperphagia and obesity in rats. To determine the importance of hyperphagia in the observed obesity phenotype, we pair‐fed a group of AAV‐NPY‐injected rats to AAV‐control‐injected rats and compared parameters of energy balance to ad libitum fed AAV‐NPY‐injected rats. For 3 weeks, AAV‐NPY‐injected rats, received the same amount of food as ad libitum‐fed rats injected with control rAAV They did not gain more body weight than these controls. When allowed access to food ad libitum, these AAV‐NPY‐injected rats increased food intake, which subsequently decreased when rats reached the same body weight as AAV‐NPY‐injected rats that were fed ad libitum for the entire study. These data indicate that overexpression of NPY in the PVN results in obesity by increasing food intake until a certain body weight is achieved.
Childhood Overweight Prevalence in the United States: The Impact of Parent‐reported Height and Weight
Authors: Akinbami Lara J. , Ogden Cynthia L.
Published: February 2009

Parent‐reported height and weight are often used to estimate BMI and overweight status among children. The quality of parent‐reported data has not been compared to measured data on a national scale for all race/ethnic groups in the United States. Parent‐reported height and weight for 2–17‐year‐old children in two national health interview surveys—the 1999–2004 National Health Interview Survey (NHIS) and the 2003–2004 National Survey of Children's Health (NSCH)—were compared to measured values from a national examination survey—the 1999–2004 National Health and Nutrition Examination Survey (NHANES). Compared to measured data, parent‐reported data overestimated childhood overweight in both interview surveys. For example, overweight prevalence among 2–17‐year‐olds was 25% (s.e. 0.2) using parent‐reported NHIS data vs. 16% (s.e. 0.6) using measured NHANES data. Parent‐reported data overestimated overweight among younger children, but underestimated overweight among older children. The discrepancy between reported and measured estimates arose mainly from reported height among very young children. For children aged 2–11 years, the mean reported height from NHIS was 3–6 cm less than mean measured height from NHANES (P < 0.001) vs. no difference among children aged 16–17 years. Measured data remains the gold standard for surveillance of childhood overweight. Although this analysis compared mean values from survey populations rather than parent‐reported and measured data for individuals, the results from nationally representative data reinforce previous recommendations based on small samples that parent‐reported data should not be used to estimate overweight prevalence among preschool and elementary school–aged children.
Body Composition Measured by Dual‐energy X‐ray Absorptiometry Half‐body Scans in Obese Adults
Authors: Rothney Megan P. , Brychta Robert J. , Schaefer Emily V. , Chen Kong Y. , Skarulis Monica C.
Published: February 2009

Dual‐energy X‐ray absorptiometry (DXA) has become a common measurement of human body composition. However, obese subjects have been understudied largely due to weight and scan area restrictions. Newer DXA instruments allow for heavier subjects to be supported by the DXA scanner, but the imaging area is still smaller than the body size of some obese subjects. In this study, we determined the validity of an automated half‐scan methodology by comparing to the standard whole‐body scans in a cohort of obese volunteers. Fifty‐two subjects whose BMI >30 kg/m2 completed whole‐body iDXA (GE Lunar) scans. The resulting scans were analyzed in three ways: the standard whole‐body scan, total body estimated from the left side, and from the right side. Fat mass, nonbone lean mass, bone mineral content (BMC), and percent fat derived from each half scan were compared to the whole‐body scans. Total fat mass, nonbone lean mass, or percent fat was comparable for the whole‐body scans, left, and right side scans (>97% within individuals and >99.9% for the group). The BMC estimate using the right side scan was slightly but statistically higher than the whole‐body BMC (∼30 g or 1%, P < 0.001), while the left side scan BMC estimate was lower than the whole‐body BMC by the same magnitude. No significant magnitude bias was found for any of the composition variables. We conclude that the new iDXA half‐body analysis in obese subjects appears to be closely comparable to whole‐body analysis for fat mass, nonbone lean mass, and percent fat.
Two‐year Follow‐up in 21,784 Overweight Children and Adolescents With Lifestyle Intervention
Authors: Reinehr Thomas , Widhalm Kurt , l'Allemand Dagmar , Wiegand Susanna , Wabitsch Martin , Holl Reinhard W. ,   The APV‐Wiss Study Group and German Competence Net Obesity
Published: February 2009

Although randomized controlled trials demonstrated the long‐term efficacy of lifestyle interventions in overweight children, the effects of these interventions in clinical practice under real‐life conditions are largely unknown. One hundred twenty‐nine centers specialized in outpatient pediatric obesity care participated in this quality assessment. All patients presenting before the year 2006 for lifestyle intervention of at least 6 months duration in these institutions were analyzed in a 2‐year follow‐up. A total of 21,784 (45% male) overweight children and adolescents aged 2–20 years (mean BMI 30.4 kg/m2, mean SDS‐BMI 2.51, mean age 12.6 years) were included in the analysis. Based on an intention‐to‐treat analysis with variables set back to baseline in lost of follow‐up, 22% of the children reduced their SDS‐BMI after 6 months, 15% after 12 months, and 7% after 24 months, but only in 24, 17, and 8% of children, respectively, complete data were available. In the five treatment centers with the best outcome (518 patients), 83% of the children reduced their overweight after 6 months, 67% after 12 months, and 51% after 24 months. Under real‐life conditions, most treatment centers cannot prove the long‐term efficacy of their interventions due to high drop‐out rate or lack of documentation. Conversely, some institutions achieved a reduction of overweight in nearly the half of their patients 24 months after baseline demonstrating the great heterogeneity in outcome. To improve the effectiveness of lifestyle interventions in real‐life studying, the process and structure quality as well as their long‐term results is urgently needed.
Exercise Improves Body Fat, Lean Mass, and Bone Mass in Breast Cancer Survivors
Authors: Irwin Melinda L. , Alvarez‐Reeves Marty , Cadmus Lisa , Mierzejewski Eileen , Mayne Susan T. , Yu Herbert , Chung Gina G. , Jones Beth , Knobf M. Tish , DiPietro Loretta
Published: February 2009

Given the negative effects of a breast cancer diagnosis and its treatments on body weight and bone mass, we investigated the effects of a 6‐month randomized controlled aerobic exercise intervention vs. usual care on body composition in breast cancer survivors. Secondary aims were to examine the effects stratified by important prognostic and physiologic variables. Seventy‐five physically inactive postmenopausal breast cancer survivors were recruited through the Yale–New Haven Hospital Tumor Registry and randomly assigned to an exercise (n = 37) or usual care (n = 38) group. The exercise group participated in 150 min/week of supervised gym‐ and home‐based moderate‐intensity aerobic exercise. The usual care group was instructed to maintain their current physical activity level. Body composition was assessed at baseline and 6‐months through dual‐energy X‐ray absorptiometry (DXA) by one radiologist blinded to the intervention group of the participants. On an average, exercisers increased moderate‐intensity aerobic exercise by 129 min/week over and above baseline levels compared with 45 min/week among usual care participants (P < 0.001). Exercisers experienced decreases in percent body fat (P = 0.0022) and increases in lean mass (P = 0.047) compared with increases in body fat and decreases in lean mass in usual care participants. Bone mineral density (BMD) was also maintained among exercisers compared with a loss among usual care participants (P = 0.043). In summary, moderate‐intensity aerobic exercise, such as brisk walking, produces favorable changes in body composition that may improve breast cancer prognosis.
Overweight, Medical Comorbidity and Health‐related Quality of Life in a Community Sample of Women and Men
Authors: Mond Jonathan M. , Baune Bernhard T.
Published: February 2009

Associations among gender, overweight and obesity, medical comorbidity, and health‐related quality of life (HRQoL) were examined in a general population sample of 4,181 women and men aged 18–65 years. Anthropometric measurements and medical comorbidity were assessed as part of a computer‐assisted physician interview. HRQoL was assessed with the Physical and Mental Component Summary scales of the Medical Outcomes Study Short Form (SF‐36 PCS, MCS). General linear models were used to examine the associations among gender, weight status, medical comorbidity, and HRQoL. Controlling for age, social status, the occurrence of specific medical conditions, and the total number of medical conditions, mild obesity was associated with impairment in physical health functioning, as measured by the PCS, among women, whereas impairment in men's physical health was apparent only for moderate obesity. There was no association between weight status and psycho‐social functioning, as measured by the MCS, in women, whereas overweight was associated with better perceived psycho‐social functioning in men. The findings are consistent with the hypothesis that women suffer a disproportionately large share of the disease burden of overweight and obesity that is not due solely to differences in medical comorbidity. The possibility that aspects of emotional well‐being may mediate the association between obesity and physical health functioning warrants further attention in this regard. The findings also indicate the need to stratify data by gender and to include more sensitive measures of psycho‐social functioning in future studies.
Youth BMI Trajectories: Evidence From the NLSY97
Authors: Nonnemaker James M. , Morgan‐Lopez Antonio A. , Pais Joanne M. , Finkelstein Eric A.
Published: February 2009

We examined heterogeneity in BMI trajectory classes among youth and variables that may be associated with trajectory class membership. We used data from seven rounds (1997–2003) of the 1997 National Longitudinal Survey of Youth (NLSY97), a nationally representative, longitudinal survey of people born between 1980 and 1984 who were living in the United States in 1997. The analyses were based on an accelerated longitudinal design. General growth mixture modeling implemented in Mplus (version 4.1) was used to identify subtypes of youth BMI growth trajectories over time. Four distinct youth BMI trajectories were identified. Class 1 includes youth at high risk for becoming obese by young adulthood (at age 12 and 23, ∼67 and 90%, respectively, are classified as obese, and almost 72% will have had a BMI ≥ 40 at some time during this developmental period). Class 2 includes youth at moderate‐to‐high risk (at age 12 and 23, ∼55 and 68%, respectively, are classified as obese). Class 3 includes youth at low‐to‐moderate risk (i.e., at age 12 and 23, ∼8 and 27%, respectively, are classified as obese). Class 4 includes youth at low risk (few of these youth are obese at any age during this developmental period). These results highlight the importance of considering heterogeneity in BMI growth among youth and early interventions among those most at risk of the adverse health consequences of excess weight.
Plant mechanisms to optimise access to soil phosphorus
Authors: Richardson Alan E. , Hocking Peter J. , Simpson Richard J. , George Timothy S.
Published: February 2009

Phosphorus (P) is an important nutrient required for plant growth and its management in soil is critical to ensure sustainable and profitable agriculture that has minimal impact on the environment. Although soils may contain a large amount of total P, only a small proportion is immediately available to plants. Australian soils often have low availability of P for plant growth and P-based fertilisers are, therefore, commonly used to correct P deficiency and to maintain productivity. For many soils, the sustained use of P fertiliser has resulted in an accumulation of total P, a proportion of which is in forms that are poorly available to most plants. The efficiency with which different P fertilisers are used in agricultural systems depends on their capacity to supply P in a soluble form that is available for plant uptake (i.e. as orthophosphate anions). In addition to fertiliser source, the availability of P in soil is influenced to a large extent by physico-chemical and biological properties of the soil. Plant access to soil P is further affected by root characteristics (e.g. rate of growth, specific root length, and density and length of root hairs) and biochemical processes that occur at the soil–root interface. The ability of roots to effectively explore soil, the release of exudates (e.g. organic anions and phosphatases) from roots that influence soil P availability, and the association of roots with soil microorganisms such as mycorrhizal fungi are particularly important. These processes occur as a natural response of plants to P deficiency and, through better understanding, may provide opportunities for improving plant access to soil and fertiliser P in conventional and organic agricultural systems.
Phosphorus management on extensive organic and low-input farms
Authors: Cornish P. S.
Published: February 2009

A synthesis of the Australian literature reporting soil and plant phosphorus (P) status under organic methods of broadacre farming provides clear evidence that available soil P is lower in organic systems, although there have been no reports of farm P balances that might help to explain the lower P concentrations. There is also evidence, which is largely circumstantial, to suggest that P deficiency significantly reduces productivity of broadacre organic farms, but few experiments prove this conclusively because of other confounding factors. An overview of international literature suggests similar findings for mixed farms. Nine case studies further examined the constraints imposed by P on broadacre organic and low-input farms in Australia. Two farms on fertile soils had negative P balances but maintained productivity without fertilisers by ‘mining available’ P reserves. Five extensive organic farms on inherently less fertile soils had positive P balances because P fertiliser was used. Four of these farmers reported low productivity, which was supported by comparisons of wheat yields with estimated water-limited potential yields. Low productivity appeared to be related to P deficiency despite the use of allowable mineral fertilisers, mostly reactive phosphate rock (RPR), on these farms. The apparent ineffectiveness of RPR is most likely due to the modest rainfall at these farms (380–580 mm/year). The highest research priority is to develop effective, allowable fertilisers. Until this has been achieved, or ways of using less labile P have been developed, there is a case for derogation in the Certification Standards to allow the use of soluble forms of P fertiliser on soils with low soil solution P and high soil P-sorption. Two low-input farms practicing pasture-cropping had approximately balanced P budgets and from this perspective were the most sustainable of the farms studied.
Agronomic management options for phosphorus in Australian dryland organic and low-input cropping systems
Authors: McNeill A. M. , Penfold C. M.
Published: February 2009

Maintenance of available phosphorus (P) is a problem faced by both conventional and organic systems but it is exacerbated in the latter given that manufactured inorganic sources of P fertiliser are not permitted under the International Federation of Organic Agriculture Movements certification guidelines. The focus of this paper is a discussion of potential agronomic strategies to assist in sustainable management of the soil P resource in organic and low-input broadacre farming systems within the Australian rain-fed cereal–livestock belt. The paper considers three broad strategies for agronomic management of P in this context and draws on reported research from overseas and within Australia. An analysis of the current knowledge suggests that the option most likely to ensure that soluble P is not a limitation in the system is the importation of allowable inputs that contain P from off-farm, although for much of the Australian cereal–livestock belt the immediate issue may be access to economically viable sources. Research targeted at quantifying the economic and biological benefits to the whole-farm system associated with the adoption of these practices is required. Improving the P-use efficiency of the system by incorporating species into rotation or intercropping systems that are able to use P from less soluble sources has been a successful strategy in parts of the world with climate similar to much of the Australian cereal–sheep belt, and deserves further research effort in Australia. Agronomic management to maximise quantity and quality of pasture and crop plant residues undoubtedly builds labile soil organic matter and facilitates P cycling, but the strategy may be of limited benefit in low-rainfall areas that do not have the capacity to produce large biomass inputs. Evidence that organic or low-input systems naturally increase the numbers and diversity of soil organisms is sparse and published studies from Australian systems suggest that P nutrition is not enhanced. However, seed and soil microbial inoculants to facilitate improved P uptake have been developed and are currently being field tested in Australia. Progress in selection and breeding for cereal genotypes that are more P efficient and other plant genotypes that can use less labile P sources, is gaining momentum but still remains a long-term prospect, and may involve genetic modification which will not be acceptable for organic systems.
Potential to improve root access to phosphorus: the role of non-symbiotic microbial inoculants in the rhizosphere
Authors: Harvey P. R. , Warren R. A. , Wakelin S.
Published: February 2009

Phosphate anions in soil solution are extremely reactive and may be rapidly immobilised in the soil through precipitation and adsorption reactions, resulting in sparingly soluble forms of phosphorus (P) that are essentially unavailable to plants. This low P-fertiliser efficiency is often offset through high application rates, which are economically and environmentally unsustainable and not an available option for organic producers. Microorganisms play a fundamental role in the biogeochemical cycling of inorganic and organic P in the rhizosphere and detritusphere. Free-living rhizosphere microbes can directly increase the availability of phosphate to plant roots via mechanisms associated with solubilisation and mineralisation of P from inorganic and organic forms of total soil P. These include releasing organic anions, H+ ions, phosphatases, and cation chelating compounds into the rhizosphere. Many soil-borne microbes also increase P availability indirectly by producing phytohormones that increase root density and function. There is increasing interest worldwide in the use of rhizosphere microorganisms as inoculants to increase P availability for agricultural production. Recent research has focussed on developing actively sporulating Penicillium fungi known to express mechanisms to enhance P mobilisation and therefore, considered to be a key component of the mycoflora involved in P cycling in soils. Penicillium species do not exhibit specific plant or soil associations and have a broad agro-ecological range, indicating their potential to be developed as inoculants for a range of plant production systems. Successful adoption of microbial inoculants requires a thorough understanding of their rhizosphere ecology, genetic stability, and the mechanisms associated with enhancing P availability in soils and plant-growth promotion. This will provide a better understanding of which inoculants to use under particular agro-ecological conditions for increased efficacy and consistent performance.
Phosphorus uptake in faba bean, field pea, and corn cultivars from different sources: preliminary studies of two options for organic farmers
Authors: Nachimuthu Gunasekhar , Lockwood Peter , Guppy Chris , Kristiansen Paul
Published: February 2009

Low soil phosphorus (P) availability commonly limits yield in Australian broadacre organic production systems where superphosphate fertiliser is not permitted, and alternative P nutrition strategies are sought. Glasshouse experiments were conducted to investigate the potential of faba beans (Vicia faba L.) (FB), or field peas (Pisum sativum L.) (FP), grown in acidic sandy loam or alkaline clay, to accumulate P, which could then be supplied to a subsequent crop as part of a green manure rotation or after harvest. Another experiment investigated differences in growth and P acquisition between corn (Zea mays L.) cultivars: Hycorn 424 (a modern hybrid), and four traditional cultivars used in organic production. The experiments were carried out under conditions of P stress and had rock phosphate (RP), poultry manure (PM), or single superphosphate (SP) applied at 50 kg P/ha. For FP, maximum P input to the soil from incorporation would occur at or after pod initiation. However, P uptake by both legumes in both soils from sparingly soluble RP was low, with fertiliser P-use efficiencies of 0–1.3% compared with 1.8–12.7% for PM and 6.1–9.9% for SP. In the corn experiment, P fertiliser source had much larger effects than cultivar on plant biomass and P uptake, with responses generally ranked SP > PM > > RP > Control. Hycorn 424 generally produced higher dry matter and P uptake than the traditional cultivars under all P treatments. The implications of these preliminary investigations for Australian broadacre organic agriculture are discussed.
Surface features of a
Mononegavirales
matrix protein indicate sites of membrane interaction
Authors: Money Victoria A. , McPhee Helen K. , Mosely Jackie A. , Sanderson John M. , Yeo Robert P.
Published: February 2009

The matrix protein (M) of respiratory syncytial virus (RSV), the prototype viral member of the
Pneumovirinae
(family
Paramyxoviridae
, order
Mononegavirales
), has been crystallized and the structure determined to a resolution of 1.6 Å. The structure comprises 2 compact β-rich domains connected by a relatively unstructured linker region. Due to the high degree of side-chain order in the structure, an extensive contiguous area of positive surface charge covering ≈600 Å
2
can be resolved. This unusually large patch of positive surface potential spans both domains and the linker, and provides a mechanism for driving the interaction of the protein with a negatively-charged membrane surface or other virion components such as the nucleocapsid. This patch is complemented by regions of high hydrophobicity and a striking planar arrangement of tyrosine residues encircling the C-terminal domain. Comparison of the RSV M sequence with other members of the
Pneumovirinae
shows that regions of divergence correspond to surface exposed loops in the M structure, with the majority of viral species-specific differences occurring in the N-terminal domain.
Weak, strong, and coherent regimes of Fröhlich condensation and their applications to terahertz medicine and quantum consciousness
Authors: Reimers Jeffrey R. , McKemmish Laura K. , McKenzie Ross H. , Mark Alan E. , Hush Noel S.
Published: February 2009

In 1968, Fröhlich showed that a driven set of oscillators can condense with nearly all of the supplied energy activating the vibrational mode of lowest frequency. This is a remarkable property usually compared with Bose–Einstein condensation, superconductivity, lasing, and other unique phenomena involving macroscopic quantum coherence. However, despite intense research, no unambiguous example has been documented. We determine the most likely experimental signatures of Fröhlich condensation and show that they are significant features
remote
from the extraordinary properties normally envisaged. Fröhlich condensates are classified into 3 types: weak condensates in which profound effects on chemical kinetics are possible, strong condensates in which an extremely large amount of energy is channeled into 1 vibrational mode, and coherent condensates in which this energy is placed in a single quantum state. Coherent condensates are shown to involve extremely large energies, to
not
be produced by the Wu–Austin dynamical Hamiltonian that provides the simplest depiction of Fröhlich condensates formed using mechanically supplied energy, and to be extremely fragile. They are inaccessible in a biological environment. Hence the Penrose–Hameroff orchestrated objective-reduction model and related theories for cognitive function that embody coherent Fröhlich condensation as an essential element are untenable. Weak condensates, however, may have profound effects on chemical and enzyme kinetics, and may be produced from biochemical energy or from radio frequency, microwave, or terahertz radiation. Pokorný's observed 8.085-MHz microtubulin resonance is identified as a possible candidate, with microwave reactors (green chemistry) and terahertz medicine appearing as other feasible sources.
A Bayesian approach for evaluating the impact of historical events on rates of diversification
Authors: Moore Brian R. , Donoghue Michael J.
Published: February 2009

Evolutionary biologists often wish to explore the impact of a particular historical event (e.g., the origin of a novel morphological trait, an episode of biogeographic dispersal, or the onset of an ecological association) on rates of diversification (speciation minus extinction). We describe a Bayesian approach for evaluating the correlation between such events and differential rates of diversification that relies on cross-validation predictive densities. This approach exploits estimates of the marginal posterior probability for the rate of diversification (in the unaffected part of the tree) and the marginal probability for the timing of the event to generate a predictive distribution of species diversity that would be expected had the event not occurred. The realized species diversity can then be compared to this predictive diversity distribution to assess whether rates of diversification associated with the event are significantly higher or lower than expected. Although simple, this Bayesian approach provides a robust inference framework that accommodates various sources of uncertainty, including error associated with estimates of divergence times, diversification-rate parameters, and event history. Furthermore, the proposed approach is relatively flexible, allowing exploration of various types of events (including changes in discrete morphological traits, episodes of biogeographic movement, etc.) under both hypothesis-testing and data-exploration inference scenarios. Importantly, the cross-validation predictive densities approach facilitates evaluation of both replicated and unique historical events. We demonstrate this approach with empirical examples concerning the impact of morphological and biogeographic events on rates of diversification in Adoxaceae and
Lupinus
, respectively.
Neuronal cell depolarization induces intragenic chromatin modifications affecting NCAM alternative splicing
Authors: Schor Ignacio E. , Rascovan Nicolás , Pelisch Federico , Alló Mariano , Kornblihtt Alberto R.
Published: February 2009

In search for physiological pathways affecting alternative splicing through its kinetic coupling with transcription, we found that membrane depolarization of neuronal cells triggers the skipping of exon 18 from the neural cell adhesion molecule (NCAM) mRNA, independently of the calcium/calmodulin protein kinase IV pathway. We show that this exon responds to RNA polymerase II elongation, because its inclusion is increased by a slow polymerase II mutant. Depolarization affects the chromatin template in a specific way, by causing H3K9 hyper-acetylation restricted to an internal region of the NCAM gene surrounding the alternative exon. This intragenic histone hyper-acetylation is not paralleled by acetylation at the promoter, is associated with chromatin relaxation, and is linked to H3K36 tri-methylation. The effects on acetylation and splicing fully revert when the depolarizing conditions are withdrawn and can be both duplicated and potentiated by the histone deacetylase inhibitor trichostatin A. Our results are consistent with a mechanism involving the kinetic coupling of splicing and transcription in response to depolarization through intragenic epigenetic changes on a gene that is relevant for the differentiation and function of neuronal cells.
Assessing dangerous climate change through an update of the Intergovernmental Panel on Climate Change (IPCC) “reasons for concern”
Authors: Smith Joel B. , Schneider Stephen H. , Oppenheimer Michael , Yohe Gary W. , Hare William , Mastrandrea Michael D. , Patwardhan Anand , Burton Ian , Corfee-Morlot Jan , Magadza Chris H. D. , Füssel Hans-Martin , Pittock A. Barrie , Rahman Atiq , Suarez Avelino , van Ypersele Jean-Pascal
Published: February 2009

Article 2 of the United Nations Framework Convention on Climate Change [United Nations (1992)
http://unfccc.int/resource/docs/convkp/conveng.pdf
. Accessed February 9, 2009] commits signatory nations to stabilizing greenhouse gas concentrations in the atmosphere at a level that “would prevent dangerous anthropogenic interference (DAI) with the climate system.” In an effort to provide some insight into impacts of climate change that might be considered DAI, authors of the Third Assessment Report (TAR) of the Intergovernmental Panel on Climate Change (IPCC) identified 5 “reasons for concern” (RFCs). Relationships between various impacts reflected in each RFC and increases in global mean temperature (GMT) were portrayed in what has come to be called the “burning embers diagram.” In presenting the “embers” in the TAR, IPCC authors did not assess whether any single RFC was more important than any other; nor did they conclude what level of impacts or what atmospheric concentrations of greenhouse gases would constitute DAI, a value judgment that would be policy prescriptive. Here, we describe revisions of the sensitivities of the RFCs to increases in GMT and a more thorough understanding of the concept of vulnerability that has evolved over the past 8 years. This is based on our expert judgment about new findings in the growing literature since the publication of the TAR in 2001, including literature that was assessed in the IPCC Fourth Assessment Report (AR4), as well as additional research published since AR4. Compared with results reported in the TAR, smaller increases in GMT are now estimated to lead to significant or substantial consequences in the framework of the 5 “reasons for concern.”
Antigen-specific B-1a antibodies induced byFrancisella tularensisLPS provide long-term protection againstF. tularensisLVS challenge
Authors: Cole Leah E. , Yang Yang , Elkins Karen L. , Fernandez Ellen T. , Qureshi Nilofer , Shlomchik Mark J. , Herzenberg Leonard A. , Herzenberg Leonore A. , Vogel Stefanie N.
Published: February 2009

Francisella tularensis(Ft), a Gram-negative intracellular bacterium, is the etiologic agent of tularemia. Infection of mice with <10FtLive Vaccine Strain (FtLVS) organisms i.p. causes a lethal infection that resembles human tularemia. Here, we show that immunization with as little as 0.1 ngFtLVS lipopolysaccharide (Ft-LPS), but notFtlipid A, generates a rapid antibody response that protects wild-type (WT) mice against lethalFtLVS challenge. Protection is not induced inFt-LPS-immunized B cell-deficient mice (μMT or JhD), malexidmice, or Ig transgenic mice that produce a single IgH (not reactive withFt-LPS). Focusing on the cellular mechanisms that underlie this protective response, we show thatFt-LPS specifically stimulates proliferation of B-1a lymphocytes that bind fluorochrome-labeledFt-LPS and the differentiation of these cells to plasma cells that secrete antibodies specific forFt-LPS. This exclusively B-1a antibody response is equivalent in WT, T-deficient (TCRαβ−/−, TCRγδ−/−), and Toll-like receptor 4 (TLR4)-deficient (TLR4−/−) mice and thus is not dependent on T cells or typical inflammatory processes. Serum antibody levels peak ≈5 days afterFt-LPS immunization and persist at low levels for months. Thus, immunization withFt-LPS activates a rare population of antigen-specific B-1a cells to produce a persistent T-independent antibody response that provides long-term protection against lethalFtLVS infection. These data support the possibility of creating effective, minimally invasive vaccines that can provide effective protection against pathogen invasion.
The estimated risk of miscarriage should be corrected for induced abortion rates
Authors: ESKILD ANNE , VATTEN LARS J. , NESHEIM BRITT‐INGJERD , VANGEN SIRI
Published: February 2009

Objective. We wanted to study to what extent induced abortion rates influence the age‐dependent estimates of miscarriage risk. Design. Register‐based study. Setting. Linkage between hospital records and the Norwegian Population Registry. Population. Included were all women 15–49 years of age in Oslo, Norway, who were pregnant during the three‐year study period, 27,932 women. Methods. We estimated proportions with miscarriage according to maternal age with and without inclusion of women with induced abortion in the denominator. Main outcome measure. Proportions with miscarriage in each age group and odds ratios of miscarriage, with age group 25–29 years as the reference. Results. When only women with pregnancies intended to term were included in the denominator, 9.4% of the women were estimated to have miscarriage as the only reproductive event during the three‐year period and 6.8% had both miscarriage and delivery. The corresponding figures when also women with induced abortions were included in the denominator, were 7.0 and 5.0%. When taking induced abortion into account, the reduction in estimated proportion with miscarriage during the study period was greatest in the age groups with the highest induced abortion rates, women 15–19 years old (from 22.8 to 6.4%) and women 45–49 years old (from 57.9 to 41.0%). Conclusions. Estimates of age‐dependent risk of miscarriage may be strongly influenced by induced abortion rates.
Spondylolisthesis and posterior instability
Authors: Niggemann P. , Simons P. , Kuchta J. , Beyer H. K. , Frey H. , Grosskurth D.
Published: February 2009

We present the case of a patient with a spondylolisthesis of L5 on S1 due to spondylolysis at the level L5/S1. The vertebral slip was fixed and no anterior instability was found. Using functional magnetic resonance imaging (MRI) in an upright MRI scanner, posterior instability at the level of the spondylolytic defect of L5 was demonstrated. A structure, probably the hypertrophic ligament flava, arising from the spondylolytic defect was displaced toward the L5 nerve root, and a bilateral contact of the displaced structure with the L5 nerve root was shown in extension of the spine. To our knowledge, this is the first case described of posterior instability in patients with spondylolisthesis. The clinical implications of posterior instability are unknown; however, it is thought that this disorder is common and that it can only be diagnosed using upright MRI.
Plasma–surface interaction issues of an all-metal ITER
Authors: Brooks J.N. , Allain J.P. , Doerner R.P. , Hassanein A. , Nygren R. , Rognlien T.D. , Whyte D.G.
Published: February 2009

We assess key plasma–surface interaction issues of an all-metal plasma facing component (PFC) system for ITER, in particular a tungsten divertor, and a beryllium or tungsten first wall. Such a system eliminates problems with carbon divertor erosion and T/C codeposition, and for an all-tungsten system would better extrapolate to post-ITER devices. The issues studied are sputtering, transport and formation of mixed surface layers, tritium codeposition, plasma contamination, edge-localized mode (ELM) response and He-on-W irradiation effects. Code package OMEGA computes PFC sputtering erosion/redeposition in an ITER full power D–T plasma with convective edge transport. The HEIGHTS package analyses plasma transient response. PISCES and other data are used with code results to assess PFC performance. Predicted outer-wall sputter erosion rates are acceptable for Be (0.3 nm s−1) or bare (stainless steel/Fe) wall (0.05 nm s−1) for the low duty factor ITER, and are very low (0.002 nm s−1) for W. T/Be codeposition in redeposited wall material could be significant (∼2 gT/400 s-ITER pulse). Core plasma contamination from wall sputtering appears acceptable for Be (∼2%) and negligible for W (or Fe). A W divertor has negligible sputter erosion, plasma contamination and T/W codeposition. Be can grow at/near the strike point region of a W divertor, but for the predicted maximum surface temperature of ∼800 °C, deleterious Be/W alloy formation as well as major He/W surface degradation will probably be avoided. ELMs are a serious challenge to the divertor, but this is true for all materials. We identify acceptable ELM parameters for W. We conclude that an all-metal PFC system is likely a much better choice for ITER D–T operation than a system using C. We discuss critical R&D needs, testing requirements, and suggest employing a 350–400 °C baking capability for T/Be reduction and using a deposited tungsten first wall test section.
Certain optimal correspondences between plane curves, I: Manifolds of shapes and bimorphisms
Authors: Groisser David
Published: February 2009

In previous joint work, a theory introduced earlier by Tagare was developed for establishing certain kinds of correspondences, termed bimorphisms, between simple closed regular plane curves of differentiability class at least

C
2

C^2

. A class of objective functionals was introduced on the space of bimorphisms between two fixed curves

C
1

C_1

and

C
2

C_2

, and it was proposed that one define a “best non-rigid match” between

C
1

C_1

and

C
2

C_2

by minimizing such a functional. In this paper we prove several theorems concerning the nature of the shape-space of plane curves and of spaces of bimorphisms as infinite-dimensional manifolds. In particular, for

2
≤
j
>
∞

2\leq j>\infty

, the space of parametrized bimorphisms is a differentiable Banach manifold, but the space of unparametrized bimorphisms is not. Only for

C
∞

C^\infty

curves is the space of bimorphisms an infinite-dimensional manifold, and then only a Fréchet manifold, not a Banach manifold. This paper lays the groundwork for a companion paper in which we use the Nash Inverse Function Theorem and our results on

C
∞

C^\infty

curves and bimorphisms to show that if

Γ
\Gamma

is strongly convex, if

C
1

C_1

and

C
2

C_2

are

C
∞

C^\infty

curves whose shapes are not too dissimilar (

C
j

C^j

-close for a certain finite

j
j

) and if neither curve is a perfect circle, then the minimum of a regularized objective functional exists and is locally unique.
Certain optimal correspondences between plane curves, II: Existence, local uniqueness, regularity, and other properties
Authors: Groisser David
Published: February 2009

This paper is a companion to the author’s paper (this volume), in which several theorems were proven concerning the nature, as infinite-dimensional manifolds, of the shape-space of plane curves and of spaces of certain curve-correspondences called bimorphisms. In Tagare, O’Shea, Groisser, 2002, a class of objective functionals, depending on a choice of cost-function

Γ
\Gamma

, was introduced on the space of bimorphisms between two fixed curves

C
1

C_1

and

C
2

C_2

, and it was proposed that one define a “best non-rigid match” between

C
1

C_1

and

C
2

C_2

by minimizing such a functional. In this paper we use the Nash Inverse Function Theorem to show that for strongly convex functions

Γ
\Gamma

, if

C
1

C_1

and

C
2

C_2

are

C
∞

C^\infty

curves whose shapes are not too dissimilar (specifically, are

C
j

C^j

-close for a certain finite

j
j

), and neither is a perfect circle, then the minimum of a certain regularized objective functional exists and is locally unique. We also study certain properties of the Euler-Lagrange equation for the objective functional, and obtain regularity results for “exact matches” (bimorphisms for which the objective functional achieves its absolute minimum value of 0) that satisfy a genericity condition.
Polynomials, meanders, and paths in the lattice of noncrossing partitions
Authors: Savitt David
Published: February 2009

For every polynomial

f
f

of degree

n
n

with no double roots, there is an associated family

C

(
f
)

\mathcal {C}(f)

of harmonic algebraic curves, fibred over the circle, with at most

n
−
1

n-1

singular fibres. We study the combinatorial topology of 

C

(
f
)

\mathcal {C}(f)

in the generic case when there are exactly

n
−
1

n-1

singular fibres. In this case, the topology of 

C

(
f
)

\mathcal {C}(f)

is determined by the data of an

n
n

-tuple of noncrossing matchings on the set

{
0
,
1
,
…
,
2
n
−
1
}

\{0,1,\ldots ,2n-1\}

with certain extra properties. We prove that there are

2
(
2
n

)

n
−
2

2(2n)^{n-2}

such

n
n

-tuples, and that all of them arise from the topology of

C

(
f
)

\mathcal {C}(f)

for some polynomial

f
f

.
Sturmian and spectral theory for discrete symplectic systems
Authors: Bohner Martin , Došlý Ondřej , Kratz Werner
Published: February 2009

We consider

2
n
×
2
n

2n\times 2n

symplectic difference systems together with associated discrete quadratic functionals and eigenvalue problems. We establish Sturmian type comparison theorems for the numbers of focal points of conjoined bases of a pair of symplectic systems. Then, using this comparison result, we show that the numbers of focal points of two conjoined bases of one symplectic system differ by at most

n
n

. In the last part of the paper we prove the Rayleigh principle for symplectic eigenvalue problems and we show that finite eigenvectors of such eigenvalue problems form a complete orthogonal basis in the space of admissible sequences.
A trace on fractal graphs and the Ihara zeta function
Authors: Guido Daniele , Isola Tommaso , Lapidus Michel
Published: February 2009

Starting with Ihara’s work in 1968, there has been a growing interest in the study of zeta functions of finite graphs, by Sunada, Hashimoto, Bass, Stark and Terras, Mizuno and Sato, to name just a few authors. Then, Clair and Mokhtari-Sharghi studied zeta functions for infinite graphs acted upon by a discrete group of automorphisms. The main formula in all these treatments establishes a connection between the zeta function, originally defined as an infinite product, and the Laplacian of the graph. In this article, we consider a different class of infinite graphs. They are fractal graphs, i.e. they enjoy a self-similarity property. We define a zeta function for these graphs and, using the machinery of operator algebras, we prove a determinant formula, which relates the zeta function with the Laplacian of the graph. We also prove functional equations, and a formula which allows approximation of the zeta function by the zeta functions of finite subgraphs.
Bi-invariant metrics on the group of symplectomorphisms
Authors: Han Zhigang
Published: February 2009

This paper studies the extension of the Hofer metric and general Finsler metrics on the Hamiltonian symplectomorphism group

Ham

(
M
,
ω
)

\textrm {Ham}(M,\omega )

to the identity component

Symp

0

(
M
,
ω
)

\textrm {Symp}_0(M,\omega )

of the symplectomorphism group. In particular, we prove that the Hofer metric on

Ham

(
M
,
ω
)

\textrm {Ham}(M,\omega )

does not extend to a bi-invariant metric on

Symp

0

(
M
,
ω
)

\textrm {Symp}_0(M,\omega )

for many symplectic manifolds. We also show that for the torus

T

2
n

\mathbb T^{2n}

with the standard symplectic form

ω
\omega

, no Finsler metric on

Ham

(

T

2
n

,
ω
)

\textrm {Ham}(\mathbb T^{2n},\omega )

that satisfies a strong form of the invariance condition can extend to a bi-invariant metric on

Symp

0

(

T

2
n

,
ω
)

\textrm {Symp}_0(\mathbb T^{2n},\omega )

. Another interesting result is that there exists no

C
1

C^1

-continuous bi-invariant metric on

Symp

0

(

T

2
n

,
ω
)

\textrm {Symp}_0(\mathbb T^{2n},\omega )

.
Topological entropies of equivalent smooth flows
Authors: Sun Wenxiang , Young Todd , Zhou Yunhua
Published: February 2009

We construct two equivalent smooth flows, one of which has positive topological entropy and the other has zero topological entropy. This provides a negative answer to a problem posed by Ohno.
Representations of Lie groups and random matrices
Authors: Collins Benoît , Śniady Piotr
Published: February 2009

We study the asymptotics of representations of a fixed compact Lie group. We prove that the limit behavior of a sequence of such representations can be described in terms of certain random matrices; in particular operations on representations (for example: tensor product, restriction to a subgroup) correspond to some natural operations on random matrices (respectively: sum of independent random matrices, taking the corners of a random matrix). Our method of proof is to treat the canonical block matrix associated to a representation as a random matrix with non-commutative entries.