bluuebunny/crossref_metadata_2025 huggingface dataset:
The social rationale of the gift relationship
Authors: Voo Teck Chuan
Published: May 2011

This paper argues that, for Richard Titmuss, the rationale of the gift relationship (TGR) as a national blood policy is to reconcile liberty with social justice in the provision of an essential health resource. Underpinned by a needs-based distributive principle, TGR provides a social space for a plurality of values in which to engage with and motivate people to voluntarily give blood and other body materials as a common good. This understanding of TGR as a value pluralistic framework and its implications will be used to discuss the issue of using economic mechanisms to increase the supply of body materials or goods, including organs for transplantation. It is argued that, while TGR excludes a policy in which body goods are treated as private commodities and distributed primarily on the basis of achieving market efficiency, it is not in principle opposed to the use of material rewards, including financial ones, to motivate people to donate.
Retractions in the medical literature: how many patients are put at risk by flawed research?
Authors: Steen R Grant
Published: May 2011

Background

Clinical papers so flawed that they are eventually retracted may put patients at risk. Patient risk could arise in a retracted primary study or in any secondary study that draws ideas or inspiration from a primary study.

Methods

To determine how many patients were put at risk, we evaluated 788 retracted English-language papers published from 2000 to 2010, describing new research with humans or freshly derived human material. These primary papers—together with all secondary studies citing them—were evaluated using ISI Web of Knowledge. Excluded from study were 468 basic science papers not studying fresh human material; 88 reviews presenting older data; 22 case reports; 7 papers retracted for journal error and 23 papers unavailable on Web of Knowledge. Overall, 180 retracted primary papers (22.8%) met the inclusion criteria. Subjects enrolled and patients treated in 180 primary studies and 851 secondary studies were combined.

Results

Retracted papers were cited over 5000 times, with 93% of citations being research related, suggesting that ideas promulgated in retracted papers can influence subsequent research. Over 28 000 subjects were enrolled—and 9189 patients were treated—in 180 retracted primary studies. Over 400 000 subjects were enrolled—and 70 501 patients were treated—in 851 secondary studies which cited a retracted paper. Papers retracted for fraud (n=70) treated more patients per study (p<0.01) than papers retracted for error (n=110).

Conclusions

Many patients are put at risk by retracted studies. These are conservative estimates, as only patients enrolled in published clinical studies were tallied.
Sing, Muse: songs in Homer and in hospital
Authors: Marshall Robert , Bleakley Alan
Published: May 2011

This paper progresses the original argument of Richard Ratzan that formal presentation of the medical case history follows a Homeric oral-formulaic tradition. The everyday work routines of doctors involve a ritual poetics, where the language of recounting the patient's ‘history’ offers an explicitly aesthetic enactment or performance that can be appreciated and given meaning within the historical tradition of Homeric oral poetry and the modernist aesthetic of Minimalism. This ritual poetics shows a reliance on traditional word usages that crucially act as tools for memorisation and performance and can be linked to forms of clinical reasoning; both contain a tension between the oral and the written record, questioning the priority of the latter; and the performance of both helps to create the Janus-faced identity of the doctor as a ‘performance artist’ or ‘medical bard’ in identifying with medical culture and maintaining a positive difference from the patient as audience, offering a valid form of patient-centredness.
Literature and disability: the medical interface in Borges and Beckett
Authors: Novillo-Corvalán Patricia
Published: May 2011

Samuel Beckett and Jorge Luis Borges have presented 20th century literature with a distinctive gallery of solitary figures who suffer from a series of physiological ailments: invalidism, decrepitude, infirmity and blindness, as well as neurological conditions such as amnesia and autism spectrum disorders. Beckett and Borges were concerned with the dynamics between illness and creativity, the literary representation of physical and mental disabilities, the processes of remembering and forgetting, and the inevitability of death. This article explores the depiction of physically and mentally disabled characters in Borges'Funes the Memorious(1942)—a story about an Uruguayan gaucho who has been left paralysed after a fall from a horse which simultaneously endowed him with an infallible memory and perception—and Beckett'sTrilogy: Molloy(1951),Malone Dies(1951) andThe Unnamable(1953). It examines the prodigious memory of Funes and the forgetful minds of Molloy and Malone with reference to influential neuropsychological studies such as Alexander Luria's twofold exploration of memory and forgetfulness inThe Mind of a Mnemonist(1968) andThe Man with a Shattered World(1972). The article demonstrates that in contrast to Beckett's amnesiacs and Luria's brain-damaged patient, who are able to transcend their circumstances through cathartic writing, Borges' and Luria's mnemonic prodigies fail to achieve anything significant with their unlimited memories and remain imprisoned within their cognitive disabilities. It reveals that medical discourses can provide invaluable insights and lead to a deeper understanding of the minds and bodily afflictions of literary characters.
Physical and psychosocial ergonomic risk factors for low back pain in automobile manufacturing workers
Authors: Vandergrift Jonathan L , Gold Judith E , Hanlon Alexandra , Punnett Laura
Published: May 2011

Objectives

To examine the association between ergonomic physical and psychosocial exposures and the risk of prevalent and incident low back pain (LBP) in a longitudinal cohort of automobile manufacturing workers.

Methods

Ergonomic exposure intensity and LBP presence were determined through questionnaires at baseline (n=1181) and to workers in the same job 1 year later (n=505). Models were constructed using log-binomial regression with special attention to interactions between ergonomic exposures.

Results

Awkward back posture (prevalence ratio (PR) 1.12, 95% CI 1.07 to 1.17), hand force (PR 1.06, 95% CI 1.02 to 1.10), physical effort (PR 1.10, 95% CI 1.04 to 1.16) and whole body vibration (PR 1.04, 95% CI 1.01 to 1.08) were each associated cross-sectionally with LBP. Awkward back posture (RR 1.13, 95% CI 0.98 to 1.31) and hand force (RR 1.07, 95% CI 0.93 to 1.22) also predicted incident LBP, although estimates were statistically less precise. Neither job control, psychological demands, nor job strain was independently related to risk of incident LBP. Among participants reporting high physical ergonomic exposures and moderate to high job control, increasing job demands was associated with a reduced LBP risk (RR 0.72, 95% CI 0.52 to 1.00). Among participants reporting high physical exposures and low job control, psychological demands was associated with an increased LBP risk (RR 1.30, 95% CI 1.02 to 1.66).

Conclusions

Psychosocial workplace interventions for LBP should prioritise jobs in which there are high physical ergonomic exposures. Future studies of LBP should examine the interactions between physical ergonomic risk factors.
ON SECOND COHOMOLOGY OF DUALS OF COMPACT GROUPS
Authors: NESHVEYEV SERGEY , TUSET LARS
Published: May 2011

We show that for any compact connected group G the second cohomology group defined by unitary invariant two-cocycles on Ĝ is canonically isomorphic to [Formula: see text]. This implies that the group of autoequivalences of the C*-tensor category Rep G is isomorphic to [Formula: see text]. We also show that a compact connected group G is completely determined by Rep G. More generally, extending a result of Etingof–Gelaki and Izumi–Kosaki we describe all pairs of compact separable monoidally equivalent groups. The proofs rely on the theory of ergodic actions of compact groups developed by Landstad and Wassermann and on its algebraic counterpart developed by Etingof and Gelaki for the classification of triangular semisimple Hopf algebras. We give a self-contained account of amenability of tensor categories, fusion rings and discrete quantum groups, and prove an analog of Radford's theorem on minimal Hopf subalgebras of quasitriangular Hopf algebras for compact quantum groups.
FIBERS OF PENCILS OF CURVES ON SMOOTH SURFACES
Authors: MONSERRAT FRANCISCO
Published: May 2011

Let X be a smooth projective surface such that linear and numerical equivalence of divisors on X coincide and let σ ⊆ |D| be a linear pencil on X with integral general fibers. A fiber of σ will be called special if either it is not integral or it has nongeneric multiplicity at some of the base points (including the infinitely near ones) of the pencil. In this paper, we provide a procedure to compute the integral components of the special fibers of σ.
A NOTE ON THE CONFORMAL INVARIANCE OF G-GENERALIZED GRADIENTS
Authors: PILCA MIHAELA
Published: May 2011

We consider generalized gradients in the general context of G-structures. They are natural first-order differential operators acting on sections of vector bundles associated to irreducible G-representations. We study their geometric properties and show in particular their conformal invariance.
FINE GRADINGS ON EXCEPTIONAL SIMPLE LIE SUPERALGEBRAS
Authors: DRAPER CRISTINA , ELDUQUE ALBERTO , MARTÍN GONZÁLEZ CÁNDIDO
Published: May 2011

The fine abelian group gradings on the simple exceptional classical Lie superalgebras over algebraically closed fields of characteristic 0 are determined up to equivalence.
Effects of Auricular Acupressure on Weight Reduction and Abdominal Obesity in Asian Young Adults: A Randomized Controlled Trial
Authors: Hsieh Ching Hsiu , Su Tsann-Jnn , Fang Yu-Wen , Chou Pei-Hsuan
Published: May 2011

The current study was designed to test the efficacy of auricular acupressure on weight reduction and changes of waist circumference and waist-to-hip ratio. This study used a randomized design with one control group and one experimental group consisting of Asian young adults with a waist circumference ≥80 cm in the females and ≥90cm in the males. At completion of eight weeks of auricular therapy, the total sample size was 55 young adults who ranged in age from 18 to 20 years old.

Each participant was treated weekly for ear acupressure in ten-minute sessions. Sessions continued for eight weeks wherein the control group received acupressure only while the experimental group received acupressure with the Japanese Magnetic Pearl on the ear acupoints.

While both the control and treatment groups showed significant reduction (p ≤ 0.05) to body weight and waist circumference after eight weeks of treatment, only the group treated with Japanese Magnetic Pearls showed decreased waist to hip ratio. Thus, auricular acupressure may be a beneficial addition to weight loss programs for young adults.

Auricular acupressure is thus a reasonable option in the treatment of overweight and obesity in young adults.
Cordyceps SoboliferaExtract Ameliorates Lipopolysaccharide-Induced Renal Dysfunction in the Rat
Authors: Wu Ming-Feng , Li Ping-Chia , Chen Chin-Chiu , Ye Su-Shin , Chien Chiang-Ting , Yu Chia-Cherng
Published: May 2011

Cordyceps Sobolifera (CS), an economic traditional Chinese herb, may ameliorate nephrotoxicity-induced renal dysfunction in the rat via antioxidant, anti-apoptosis, and anti-autophagy mechanisms. We investigated the water extract of fermented whole broth of CS on lipopolysaccharide (LPS)-induced renal cell injury in vitro and in vivo. CS effect on LPS-induced epithelial Lilly pork kidney (PK1) and Madin-Darby canine kidney epithelial (MDCK) cell death was detected with MTT assay. Two-month treatment of CS effects on renal blood flow (RBF), glomerular filtration rate (GFR), plasma blood urea nitrogen, creatinine level and leukocytes (WBC) count were determined in the LPS-treated rats. We further examined the effects of CS supplement on renal tubular oxidative stress, endoplasmic reticulum stress, apoptosis and autophagy by Western blot analysis. LPS dose-dependently induced PK1 and MDCK cell death, which can be ameliorated by CS treatment. LPS significantly decreased RBF and GFR and increased blood leukocyte counts, plasma blood urea nitrogen and creatinine level in the rat after 24 hours of injury. LPS enhanced renal tubular ER stress, autophagy and apoptosis via by increase protein expressions of GRP78, caspase 12, Beclin-1 and Bax/Bcl-2 ratio. These findings are associated with the significant staining in renal proximal and distal tubular ED-1, GRP78, Beclin-1 autophagy, and TUNEL apoptosis in the LPS-treated kidneys. Two months of CS supplement significantly improved RBF, GFR and WBC values and reduced ED-1, GRP78, Beclin-1 autophagy and TUNEL apoptosis in the LPS-treated kidneys. Long-term CS treatment reduced LPS-induced stress responses and tissue damage possibly via blocking LPS-triggered signaling pathways.
Corydalis yanhusuo W.T. Wang Extract Inhibits MCF-7 Cell Proliferation by Inducing Cell Cycle G2/M Arrest
Authors: Xu Zengtao , Chen Xiuping , Zhang Qingwen , Chen Lidian , Wang Yitao
Published: May 2011

Corydalis yanhusuo W.T. Wang (YHS) is a traditional Chinese herb widely prescribed for promoting blood circulation, reinforcing vital energy and alleviating pain. Our previous studies showed that an ethanol extract of YHS inhibits metastasis of breast cancer cells in vitro. In the present study, the anti-proliferative effect of the extract was determined by MTT assay and the LDH release was measured with a commercial kit. Intracellular reactive oxygen species (ROS) production and mitochondrial membrane potential (ΔΨm) were monitored by CM- H2DCF-DA and JC-1 staining, respectively. Cell cycle was analyzed with propidium iodide (PI) staining by flow cytometry and protein expressions were measured by Western blotting. The YHS extract significantly inhibited MCF-7 cell proliferation in a dose-dependent manner. Significant increase of ROS formation and decrease of ΔΨm were observed. Furthermore, it induced MCF-7 cell cycle arrest at the G2/M phases. In addition, the p-cdc-2/cdc-2 protein expression ratio was increased while Rb and p21 protein expressions were decreased.

The YHS extract inhibited MCF-7 proliferation by inducing G2/M cell cycle arrest, which might be mediated by inducing ROS formation, decreasing ΔΨm and regulating cell cycle related protein expressions.
PARTICLE SIMULATIONS OF MORPHOGENESIS
Authors: KOUMOUTSAKOS PETROS , BAYATI BASIL , MILDE FLORIAN , TAURIELLO GERARDO
Published: May 2011

The simulation of the creation and evolution of biological forms requires the development of computational methods that are capable of resolving their hierarchical, spatial and temporal complexity. Computations based on interacting particles, provide a unique computational tool for discrete and continuous descriptions of morphogenesis of systems ranging from the molecular to the organismal level. The capabilities of particle methods hinge on the simplicity of their formulation which enables the formulation of a unifying computational framework encompassing deterministic and stochastic models. In this paper, we discuss recent advances in particle methods for the simulation of biological systems at the mesoscopic and the macroscale level. We present results from applications of particle methods including reaction–diffusion on deforming surfaces, deterministic and stochastic descriptions of tumor growth and angiogenesis and discuss successes and challenges of this approach.
PARTICLES WITH NEGATIVE ENERGIES IN BLACK HOLES
Authors: GRIB A. A. , PAVLOV Y. V.
Published: May 2011

The problem of the existence of particles with negative energies inside and outside of Schwarzschild, charged and rotating black holes is investigated. Different definitions of the energy of the particle inside the Schwarzschild black hole are analyzed and it is shown in which cases this energy can be negative. A comparison is made for the cases of rotating black holes between those described by the Kerr metric when the energy of the particle can be negative in the ergosphere and the Reissner–Nordstrøm metric.
COSMOLOGICAL HISTORY OF THE VACUUM
Authors: GUNZIG EDGARD
Published: May 2011

In this contribution, the author wishes to express his profound friendship and intellectual admiration towards Mario Castagnino. The playful tone of this contribution serves to underline some key elements of the longstanding scientific collaboration between the author and MC. These are used to construct a bootstrap-like cosmological history. The Universe appears to be its own cause, resulting from a prior stage which is nothing but itself. This leads to a self-consistent multiverse devoid of past or future singularities.
CENTER OF MASS AND SPIN FOR AXIALLY SYMMETRIC SPACETIMES
Authors: KOZAMEH CARLOS , ORTEGA RAUL , ROJAS TERESITA
Published: May 2011

We give equations of motion for the center of mass and intrinsic angular momentum of axially symmetric sources that emit gravitational radiation. This symmetry is used to uniquely define the notion of total angular momentum. The center of mass then singles out the intrinsic angular momentum of the system.
Lp-SOLUTIONS FOR REFLECTED BACKWARD STOCHASTIC DIFFERENTIAL EQUATIONS
Authors: HAMADÈNE SAÏD , POPIER ALEXANDRE
Published: May 2011

This paper deals with the problem of existence and uniqueness of a solution for a backward stochastic differential equation (BSDE for short) with one reflecting barrier in the case when the terminal value, the generator and the obstacle process are Lp-integrable with p ∈ ]1, 2[. To construct the solution we use two methods: penalization and Snell envelope. As an application we broaden the class of functions for which the related obstacle partial differential equation problem has a unique viscosity solution.
JUMP SYSTEMS WITH THE MEAN-REVERTING γ-PROCESS AND CONVERGENCE OF THE NUMERICAL APPROXIMATION
Authors: JIANG FENG , SHEN YI , WU FUKE
Published: May 2011

In this paper, a class of jump systems with the mean-reverting γ-process are considered in finance. The analytical properties including the positivity, boundedness and pathwise estimations of the solution are discussed. Moreover, the authors show that the Euler–Maruyama approximate solutions converge to the true solutions in probability. Finally, the authors apply the convergence to examine a bond and a path-dependent option price in the financial pricing.
WIENER–POISSON TYPE MULTIVALUED STOCHASTIC EVOLUTION EQUATIONS IN BANACH SPACES
Authors: WU JING
Published: May 2011

We prove the existence and uniqueness of solutions to Wiener–Poisson type multivalued stochastic evolution equations in abstract spaces. We also prove that the solution has the Markov property. Moreover, applications to stochastic ordinary differential equations and stochastic partial differential equations are presented.
Calculation and prediction of rate and equilibrium constants for aggregation of porphyrin by molecular dynamics, Docking and QSPR methods
Authors: Ghadamgahi Maryam , Ajloo Davood
Published: May 2011

The aggregation of 85 porphyrin derivatives and a report on a kinetic and thermodynamic study of such aggregation behavior on varying the derivatives of porphyrin was carried out using molecular dynamics simulation and Docking. Distance diagrams of simulated compounds were obtained and decrease of curves is a clear evidence of the aggregation. Aggregation rates were studied by origin software. In order to calculate interaction energies of derivatives, compounds were docked and the equilibrium constant of porphyrin-porphyrin interaction were obtained. Quantitative Structure-Property Relationship (QSPR) studies were performed for the sets of 85 Porphyrin derivatives. Multiple Linear Regression method (MLR) and Principal Component Analysis (PCA) were used and resulted in useful models with good prediction ability. This models were able to predict the kinetic and equilibrium constant for all sets of our compounds. The correlation coefficients for prediction of rate and logarithm of equilibrium constants were 0.67 and 0.97 by MLR method respectively and 0.90 for prediction of equilibrium constant by PCA analyses. In order to have a better prediction, compounds were divided into two groups, oxygenated and non-oxygenated group and correlation coefficient for prediction of rate constants of them were obtained 0.89 and 0.94 by MLR model respectively. Results of structure-property relationship showed that, larger, more hydrophobe and more planner derivatives have higher aggregation rate.
Supramolecular hetero-porphyrin SWNT complexes
Authors: Brewer Ashley , Lacey Matthew , Owen John R. , Nandhakumar Iris , Stulz Eugen
Published: May 2011

The complexation of single walled carbon nanotubes (SWNTs) with neutral, anionic and cationic porphyrins has been investigated under identical complex forming conditions. The determination of the porphyrin loading reveals large differences depending on the nature of the porphyrin used. Combinations of different porphyrins to form mixed hetero-porphyrin complexes shows that the mixture of a cationic and anionic porphyrin results in loading which is an order of magnitude larger than in all other complexes. This complex also exhibits high adsorption and emission intensities and can be regarded as an extended co-operative binary ionic (CBI) solid. The complexes were further studied using Raman spectroscopy, elemental analysis, AFM and cyclic voltammetry.
DAMAGE-CONTROLLABLE STRUCTURE SYSTEMS USING FRP COMPOSITES
Authors: WU Z. S. , FAHMY MOHAMED F. M. , WU GANG
Published: May 2011

Today, key infrastructures are required to have usability and repairability after earthquakes. Based on the requirements of the new codes, a mechanical model of damage-controllable structure using fiber reinforced polymers (FRPs) is proposed. Hence, the aim of the study is to examine the required recoverability for existing and new structures. First, an intensive study on the inelastic performance of FRP-retrofitted bridge columns was conducted. The study showed that recoverability of such columns is probable. Subsequently, an advanced FRP-strengthening design guideline that considers and evaluates structural recoverability is proposed. Second, innovative reinforcing rebars (steel fiber composite bars (SFCBs)) were developed to enhance the post-earthquake recoverability of new reinforced concrete (RC) bridges. The performance of RC bridge columns reinforced with two types of the innovative rebars, i.e. steel basalt-fiber composite bar (SBFCB) and steel carbon-fiber composite bar (SCFCB), were experimentally studied. Furthermore, numerical studies were conducted to investigate the performance of bond-controlled structures reinforced with the innovative rebars. Experimental results showed that SFCBs, as longitudinal reinforcement, guarantee the gradual increase of column strength in the inelastic stage and substantially mitigate column residual deformations. In the light of the analytical results, concrete-to-SFCB bond would be a reasonable tool to control the required recoverability, where both column post-yield stiffness and residual deformations could be controlled.
A PERSONAL REFLECTION ON MY PH.D. ADVISOR DR. BRITTON CHANCE
Authors: CHEN YU
Published: May 2011

This article briefly reflects some of my interactions with Dr. Britton Chance (BC), from a perspective of his graduate student.
Rethinking weathering and pedogenesis in alpine periglacial regions: some Scandinavian evidence
Authors: Thorn C. E. , Darmody R. G. , Dixon J. C.
Published: May 2011

Research in the Arctic and alpine regions of NW Sweden and south-central Norway reveals an active chemical-weathering regime: in Kärkevagge, Swedish Lapland, pyrite weathers to produce an acidic environment with vigorous chemical weathering and active pedogenesis as indicated by locally well-developed Spodosols; in the Jotunheimen Mountains of Norway, soil horizons form slowly but cobbles develop weathering rinds within
c
. 250 years. Such results indicate that chemical weathering and pedogenesis may be quite advanced in alpine periglacial regions and is just one illustration that such regions may be profitably scrutinized using geomorphological and pedological conceptual frameworks other than the traditional periglacial framework.
Role of lichens in granite weathering in cold and arid environments of continental Antarctica
Authors: Guglielmin Mauro , Favero-Longo Sergio E. , Cannone Nicoletta , Piervittori Rosanna , Strini Andrea
Published: May 2011

The mechanical and chemical effects of lichens on the outer and inner surfaces of tafoni features were investigated through a multidisciplinary approach at two locations (Oasi 74°42′S, 164°07′E, 40–250 m a.s.l.; Mount Keinath, 74°32′S; 163°58′E; 850 m a.s.l.) close to the Italian Antarctic station (Mario Zucchelli). Outer tafoni roof surfaces show low values of effective porosity coupled with pervasive hyphal penetration and an extensive reddish-brown weathering rind. Inner tafoni surfaces show higher values of effective porosity, which correspond with an almost absent weathering rind and low hyphal penetration. Our observations indicate that: (a) iron oxy-hydroxides, particularly concentrated where hyphal patches and bundles contact biotite, consist of hematite; (b) the microcosms of lichen hyphae and their precipitates fill voids to form case hardening on outer surfaces; and (c) on inner surfaces biological action is less active, most likely because of more intense thermal stress and salt action.
Periglacial sediments: do they exist?
Authors: Vandenberghe Jef
Published: May 2011

‘Periglacial deposits’ have often been reported in the Quaternary geological literature. Sometimes their identity has been confused with the periglacial processes, landforms and environments with which these deposits are linked. However, the question arises: what are the diagnostic characteristics of such ‘periglacial’ deposits? A number of examples illustrate that ‘periglacial deposition’ follows the general geomorphological and sedimentological laws, although it may be influenced by specific conditions of vegetation and sediment availability. These may be completely or partly dependent on periglacial climatic conditions. Some marginal conditions are specific to cold environments, for instance the scarcity of vegetation that has a clear effect on transport and deposition of aeolian sediments. In addition, the intensity of some processes is governed by climate-derived conditions, for instance in the case of fluvial and slope processes. In this sense, the answer to the question in the title is negative. ‘Periglacial deposits’ do not correspond to any particular sedimentary process. This conclusion is, however, only valid when post-depositional weathering and deformations at micro- and macro-scale are excluded.
Holocene slope dynamics in Sierra Nevada (south Spain). Sedimentological analysis of solifluction landforms and lake deposits
Authors: Oliva M. , Ortiz A. Gómez
Published: May 2011

The activity of geomorphic processes in the current periglacial belt of Sierra Nevada during the Holocene has been strongly controlled by climate variability. We examined two sedimentary records showing several cycles with varying intensity of slope processes in the massif. Chronostratigraphic studies of solifluction landforms have revealed seven cycles of enhanced slope activity in Sierra Nevada during the last 7 ka. Lake sediments show eight periods with increased slope activity over the last 6 ka. Depending on temperature and moisture regime, erosion or conditions of slope stability prevailed. Cold and wet periods triggered slope processes and favoured deposition of coarse-grained sediments into the lakes, whereas warm phases were prone to soil development and fine-grained sedimentation in the lakes. The lake sediments also show evidence for an increasing aridity trend since the Holocene Optimum Warm Period in Sierra Nevada, which induced a shift of solifluction processes to higher elevations accompanying late-lying snow patches.
Aeolian processes and features in cool climates
Authors: Brookfield Michael E.
Published: May 2011

This review concentrates on the characteristics of wind processes and products in cold lowland deserts. Its main aims are: to show how difficult it can be to separate wind-generated from water-generated processes and features without detailed study of lamination types; to suggest cold aeolian interpretations for some ancient pre-Quaternary rocks; and to encourage students to revisit many ancient deposits with such interpretations in mind. Although upper Quaternary and Recent cold-climate aeolian deposits have been studied for many years there are very few older examples described. Martian features are included since Mars is now one of the most exciting areas of study for geologists.
Palaeoshorelines of glacial Lake Kuray–Chuja, south-central Siberia: form, sediments and process
Authors: Carling P. A. , Knaapen M. , Borodavko P. , Herget J. , Koptev I. , Huggenberger P. , Parnachev S.
Published: May 2011

Glacial lake Kuray–Chuja which occupied the Kuray and Chuja Basins during the Quaternary Period (Marine Isotope Stages 2 and 3) left distinct shoreline features around the basin margins. At the greatest extent the lake had a surface area of 2951 km
2
with wind fetches up to 70 km. Wind waves constructed erosional, erosional-accumulative and accumulative strandlines, the latter including spits, tombolos, barrier beaches and offshore bars. Strandlines range in altitude between
c
. 1600 and 2100 m, the range in altitudes demonstrating lake level variations through time. The shoreline forms and stratigraphy are detailed. Particular attention is given to the presence of pocket beaches on rock-coasts, the alluvial strandlines of which have distinctive alongshore gradients. Although reasonably ascribed to regional differential tectonic uplift, the possibility that the local alongshore gradients are augmented as a process response to alongshore drift of sediment in a sediment-starved system of closed coastal cells is explored using a simple numerical model.
Inhibition of suicidal erythrocyte death by blebbistatin
Authors: Lang Elisabeth , Qadri Syed M. , Zelenak Christine , Gu Shuchen , Rotte Anand , Draeger Annette , Lang Florian
Published: May 2011

Blebbistatin, a myosin II inhibitor, interferes with myosin-actin interaction and microtubule assembly. By influencing cytoskeletal dynamics blebbistatin counteracts apoptosis of several types of nucleated cells. Even though lacking nuclei and mitochondria, erythrocytes may undergo suicidal cell death or eryptosis, which is characterized by cell shrinkage and cell membrane scrambling with phosphatidylserine exposure at the cell surface. Triggers of eryptosis include energy depletion and osmotic shock, which enhance cytosolic Ca2+ activity with subsequent Ca2+-sensitive cell shrinkage and cell membrane scrambling. The present study explored the effect of blebbistatin on eryptosis. Cell membrane scrambling was estimated from binding of annexin V to phosphatidylserine at the erythrocyte surface, cell volume from forward scatter in fluorescence-activated cell sorting analysis and cytosolic Ca2+ concentration from Fluo3 fluorescence. Exposure to blebbistatin on its own (1–50 μM) did not significantly modify cytosolic Ca2+ concentration, forward scatter, or annexin V binding. Glucose depletion (48 h) was followed by a significant increase of Fluo3 fluorescence and annexin V binding, effects significantly blunted by blebbistatin (Fluo3 fluorescence ≥ 25 μM, annexin V binding ≥ 10 μM). Osmotic shock (addition of 550 mM sucrose) again significantly increased Fluo3 fluorescence and annexin binding, effects again significantly blunted by blebbistatin (Fluo3 fluorescence ≥ 25 μM, annexin V binding ≥ 25 μM). The present observations disclose a novel effect of blebbistatin, i.e., an influence on Ca2+ entry and suicidal erythrocyte death following energy depletion and osmotic shock.
Role of nonselective cation channels in spontaneous and protein kinase A-stimulated calcium signaling in pituitary cells
Authors: Tomić Melanija , Kucka Marek , Kretschmannova Karla , Li Shuo , Nesterova Maria , Stratakis Constantine A. , Stojilkovic Stanko S.
Published: May 2011

Several receptors linked to the adenylyl cyclase signaling pathway stimulate electrical activity and calcium influx in endocrine pituitary cells, and a role for an unidentified sodium-conducting channel in this process has been proposed. Here we show that forskolin dose-dependently increases cAMP production and facilitates calcium influx in about 30% of rat and mouse pituitary cells at its maximal concentration. The stimulatory effect of forskolin on calcium influx was lost in cells with inhibited PKA (cAMP-dependent protein kinase) and in cells that were haploinsufficient for the main PKA regulatory subunit but was preserved in cells that were also haploinsufficient for the main PKA catalytic subunit. Spontaneous and forskolin-stimulated calcium influx was present in cells with inhibited voltage-gated sodium and hyperpolarization-activated cation channels but not in cells bathed in medium, in which sodium was replaced with organic cations. Consistent with the role of sodium-conducting nonselective cation channels in PKA-stimulated Ca2+ influx, cAMP induced a slowly developing current with a reversal potential of about 0 mV. Two TRP (transient receptor potential) channel blockers, SKF96365 and 2-APB, as well as flufenamic acid, an inhibitor of nonselective cation channels, also inhibited spontaneous and forskolin-stimulated electrical activity and calcium influx. Quantitative RT-PCR analysis indicated the expression of mRNA transcripts for TRPC1 >> TRPC6 > TRPC4 > TRPC5 > TRPC3 in rat pituitary cells. These experiments suggest that in pituitary cells constitutively active cation channels are stimulated further by PKA and contribute to calcium signaling indirectly by controlling the pacemaking depolarization in a sodium-dependent manner and directly by conducting calcium.
Metabolomic linkage reveals functional interaction between glucose-dependent insulinotropic polypeptide and ghrelin in humans
Authors: Rudovich Natalia N. , Nikiforova Victoria J. , Otto Baerbel , Pivovarova Olga , Gögebakan Özlem , Erban Alexander , Möhlig Matthias , Weickert Martin O. , Spranger Joachim , Tschöp Matthias H. , Willmitzer Lothar , Nauck Michael , Pfeiffer Andreas F. H.
Published: May 2011

The gastric peptide ghrelin promotes energy storage, appetite, and food intake. Nutrient intake strongly suppresses circulating ghrelin via molecular mechanisms possibly involving insulin and gastrointestinal hormones. On the basis of the growing evidence that glucose-dependent insulinotropic polypeptide (GIP) is involved in the control of fuel metabolism, we hypothesized that GIP and/or insulin, directly or via changes in plasma metabolites, might affect circulating ghrelin. Fourteen obese subjects were infused with GIP (2.0 pmol·kg−1·min−1) or placebo in the fasting state during either euglycemic hyperinsulinemic (EC) or hyperglycemic hyperinsulinemic clamps (HC). Apart from analysis of plasma ghrelin and insulin levels, GC-TOF/MS analysis was applied to create a hormone-metabolite network for each experiment. The GIP and insulin effects on circulating ghrelin were analyzed within the framework of those networks. In the HC, ghrelin levels decreased in the absence (19.2% vs. baseline, P = 0.028) as well as in the presence of GIP (33.8%, P = 0.018). Ghrelin levels were significantly lower during HC with GIP than with placebo, despite insulin levels not differing significantly. In the GIP network combining data on GIP-infusion, EC+GIP and HC+GIP experiments, ghrelin was integrated into hormone-metabolite networks through a connection to a group of long-chain fatty acids. In contrast, ghrelin was excluded from the network of experiments without GIP. GIP decreased circulating ghrelin and might have affected the ghrelin system via modification of long-chain fatty acid pools. These observations were independent of insulin and offer potential mechanistic underpinnings for the involvement of GIP in systemic control of energy metabolism.
Dietary fat impacts fetal growth and metabolism: uptake of chylomicron remnant core lipids by the placenta
Authors: Rebholz Sandra L. , Burke Katie T. , Yang Qing , Tso Patrick , Woollett Laura A.
Published: May 2011

The fetus requires significant energy for growth and development. Although glucose is a major source of energy for the fetus, other maternal nutrients also appear to promote growth. Thus, the goal of these studies was to determine whether triglyceride-rich remnants are taken up by the placenta and whether maternal dietary lipids, independently of adiposity, can impact fetal growth. To accomplish our first goal, chylomicron particles were duallly labeled with cholesteryl ester and triglycerides. The placenta took up remnant particles/core lipids at rates greater than adipose tissue and skeletal muscle but less than the liver. Although the placenta expresses apoE receptors, uptake of chylomicron remnants and/or core lipids can occur independently of apoE. To determine the impact of dietary lipid on fetal growth, independent of maternal adiposity, females were fed high-fat diets (HFD) for 1 mo; there was no change in adiposity or leptin levels prior to or during pregnancy of dams fed HFD. Fetal masses were greater in dams fed HFD, and mRNA levels of proteins involved in fatty acid oxidation (CPT I, PPARα), but not glucose oxidation (pyruvate kinase) or other regulatory processes (HNF-4α, LXR), were increased with maternal dietary fat. There was also no change in mRNA levels of proteins involved in placental glucose and fatty acid transport, and GLUT1 protein levels in microvillous membranes were similar in placentas of dams fed either diet. Thus, the ability of the placenta to take up chylomicron remnant core lipids likely contributes to accelerated fetal growth in females fed high fat diets.
Dynamic alteration of adiponectin/adiponectin receptor expression and its impact on myocardial ischemia/reperfusion in type 1 diabetic mice
Authors: Ma Yanzhuo , Liu Yi , Liu Shaowei , Qu Yan , Wang Rutao , Xia Chenhai , Pei Haifeng , Lian Kun , Yin Tao , Lu Xiaoyan , Sun Lu , Yang Lu , Cao Yanjie , Lau Wayne Bond , Gao Erhe , Wang Haichang , Tao Ling
Published: May 2011

The present study determined the dynamic change of adiponectin (APN, a cardioprotective adipokine), its receptor expression, and their impact upon myocardial ischemia/reperfusion (MI/R) injury during type 1 diabetes mellitus (T1DM) progression, and involved underlying mechanisms. Diabetic state was induced in mice via multiple intraperitoneal injections of low-dose streptozotocin. The dynamic change of plasma APN concentration and cardiac APN receptor-1 and -2 (AdipoR1/2) expression were assessed immediately after diabetes onset (0 wk) and 1, 3, 5, and 7 wk thereafter. Indicators of MI/R injury (infarct size, apoptosis, and LDH release) were determined at 0, 1, and 7 wk of DM duration. The effect of APN on MI/R injury was determined in mice subjected to different diabetic durations. Plasma APN levels (total and HMW form) increased, whereas cardiac AdipoR1 expression decreased early after T1DM onset. With T1DM progression, APN levels were reduced and cardiac AdipoR1 expression increased. MI/R injury was exacerbated with T1DM progression in a time-dependent manner. Administration of globular APN (gAD) failed to attenuate MI/R injury in 1-wk T1DM mice, while an AMP-activated protein kinase (AMPK) activator (AICAR) reduced MI/R injury. However, administration of gAD (and AICAR) reduced infarct size and cardiomyocyte apoptosis in 7-wk T1DM mice. In conclusion, our results demonstrate a dynamic dysfunction of APN/AdipoR1 during T1DM progression. Reduced cardiac AdipoR1 expression and APN concentration may be responsible for increased I/R injury susceptibility at early and late T1DM stages, respectively. Interventions bolstering AdipoR1 expression during early T1DM stages and APN supplementation during advanced T1DM stages may potentially reduce the myocardial ischemic injury in diabetic patients.
Hypoxia augments muscle sympathetic neural response to leg cycling
Authors: Katayama Keisho , Ishida Koji , Iwamoto Erika , Iemitsu Motoyuki , Koike Teruhiko , Saito Mitsuru
Published: May 2011

It was demonstrated that acute hypoxia increased muscle sympathetic nerve activity (MSNA) by using a microneurographic method at rest, but its effects on dynamic leg exercise are unclear. The purpose of this study was to clarify changes in MSNA during dynamic leg exercise in hypoxia. To estimate peak oxygen uptake (V̇o2 peak), two maximal exercise tests were conducted using a cycle ergometer in a semirecumbent position in normoxia [inspired oxygen fraction (FiO2) = 0.209] and hypoxia (FiO2 = 0.127). The subjects performed four submaximal exercise tests; two were MSNA trials in normoxia and hypoxia, and two were hematological trials under each condition. In the submaximal exercise test, the subjects completed two 15-min exercises at 40% and 60% of their individual V̇o2 peak in normoxia and hypoxia. During the MSNA trials, MSNA was recorded via microneurography of the right median nerve at the elbow. During the hematological trials, the subjects performed the same exercise protocol as during the MSNA trials, but venous blood samples were obtained from the antecubital vein to assess plasma norepinephrine (NE) concentrations. MSNA increased at 40% V̇o2 peak exercise in hypoxia, but not in normoxia. Plasma NE concentrations did not increase at 40% V̇o2 peak exercise in hypoxia. MSNA at 40% and 60% V̇o2 peak exercise were higher in hypoxia than in normoxia. These results suggest that acute hypoxia augments muscle sympathetic neural activation during dynamic leg exercise at mild and moderate intensities. They also suggest that the MSNA response during dynamic exercise in hypoxia could be different from the change in plasma NE concentrations.
Evidence for a hyporesponsive limbic-hypothalamic-pituitary-adrenal axis following early-life repetitive hypoglycemia in adult male rats
Authors: Lehmann Ashton E. , Ennis Kathleen , Georgieff Michael K. , Rao Raghavendra , Tran Phu V.
Published: May 2011

The developing limbic-hypothalamic-pituitary-adrenal (LHPA) axis is highly vulnerable to programming by early-life environmental factors, including exposure to synthetic glucocorticoids and nutrient deficiencies. Early-life repetitive hypoglycemia (RHG) is a common complication of insulin therapy for type-1 diabetes that may have long-term consequences in adulthood. Recent observations in a rat model of early RHG suggest persistent changes in LHPA axis function, including changes in relevant hormones and affective behaviors, which support a hyperresponsive LHPA axis. Thus, we hypothesized that early RHG would alter the expression of key genes regulating LHPA axis function in adulthood. The present study employed a rat model of insulin-induced RHG spanning postnatal days (P)24–28, a neurodevelopmental equivalent of early childhood in humans, to assess the long-term effects on mRNA levels for proteins relevant to the LHPA function and the corticosterone responses to ACTH stimulation of dispersed adrenocortical cells in vitro and restraint stress in vivo at adulthood. This early RHG model resulted in a hyporesponsive LHPA axis characterized by impaired corticosterone response, increased hippocampal glucocorticoid and mineralocorticoid receptor (GR and MR), decreased hypothalamic corticotropin-releasing hormone, increased adrenal steroidogenic-acute-regulatory protein and GR, and decreased adrenal MR, melanocortin-type-2 receptor and low-density lipoprotein receptor expression. Our findings highlight a complex environmental-gene interaction between RHG and LHPA axis during development that influences regulation of this axis in adulthood. The findings are consistent with the developmental origins of disease and underscore the influences of early-life events on the programming of a major regulatory system.
Generation and analyses of R8L barttin knockin mouse
Authors: Nomura Naohiro , Tajima Masato , Sugawara Noriko , Morimoto Tetsuji , Kondo Yoshiaki , Ohno Mayuko , Uchida Keiko , Mutig Kerim , Bachmann Sebastian , Soleimani Manoocher , Ohta Eriko , Ohta Akihito , Sohara Eisei , Okado Tomokazu , Rai Tatemitsu , Jentsch Thomas J. , Sasaki Sei , Uchida Shinichi
Published: May 2011

Barttin, a gene product of BSND, is one of four genes responsible for Bartter syndrome. Coexpression of barttin with ClC-K chloride channels dramatically induces the expression of ClC-K current via insertion of ClC-K-barttin complexes into plasma membranes. We previously showed that stably expressed R8L barttin, a disease-causing missense mutant, is retained in the endoplasmic reticulum (ER) of Madin-Darby canine kidney (MDCK) cells, with the barttin β-subunit remaining bound to ClC-K α-subunits (Hayama A, Rai T, Sasaki S, Uchida S. Histochem Cell Biol 119: 485–493, 2003). However, transient expression of R8L barttin in MDCK cells was reported to impair ClC-K channel function without affecting its subcellular localization. To investigate the pathogenesis in vivo, we generated a knockin mouse model of Bartter syndrome that carries the R8L mutation. These mice display disease-like phenotypes (hypokalemia, metabolic alkalosis, and decreased NaCl reabsorption in distal tubules) under a low-salt diet. Immunofluorescence and immunoelectron microscopy revealed that the plasma membrane localization of both R8L barttin and the ClC-K channel was impaired in these mice, and transepithelial chloride transport in the thin ascending limb of Henle's loop (tAL) as well as thiazide-sensitive chloride clearance were significantly reduced. This reduction in transepithelial chloride transport in tAL, which is totally dependent on ClC-K1/barttin, correlated well with the reduction in the amount of R8L barttin localized to plasma membranes. These results suggest that the major cause of Bartter syndrome type IV caused by R8L barttin mutation is its aberrant intracellular localization.
Mechanisms mediating the diuretic and natriuretic actions of the incretin hormone glucagon-like peptide-1
Authors: Crajoinas Renato O. , Oricchio Felipe T. , Pessoa Thaissa D. , Pacheco Bruna P. M. , Lessa Lucília M. A. , Malnic Gerhard , Girardi Adriana C. C.
Published: May 2011

Glucagon-like peptide-1 (GLP-1) is a gut incretin hormone considered a promising therapeutic agent for type 2 diabetes because it stimulates beta cell proliferation and insulin secretion in a glucose-dependent manner. Cumulative evidence supports a role for GLP-1 in modulating renal function; however, the mechanisms by which GLP-1 induces diuresis and natriuresis have not been completely established. This study aimed to define the cellular and molecular mechanisms mediating the renal effects of GLP-1. GLP-1 (1 μg·kg−1·min−1) was intravenously administered in rats for the period of 60 min. GLP-1-infused rats displayed increased urine flow, fractional excretion of sodium, potassium, and bicarbonate compared with those rats that received vehicle (1% BSA/saline). GLP-1-induced diuresis and natriuresis were also accompanied by increases in renal plasma flow and glomerular filtration rate. Real-time RT-PCR in microdissected rat nephron segments revealed that GLP-1 receptor-mRNA expression was restricted to glomerulus and proximal convoluted tubule. In rat renal proximal tubule, GLP-1 significantly reduced Na+/H+ exchanger isoform 3 (NHE3)-mediated bicarbonate reabsorption via a protein kinase A (PKA)-dependent mechanism. Reduced proximal tubular bicarbonate flux rate was associated with a significant increase of NHE3 phosphorylation at the PKA consensus sites in microvillus membrane vesicles. Taken together, these data suggest that GLP-1 has diuretic and natriuretic effects that are mediated by changes in renal hemodynamics and by downregulation of NHE3 activity in the renal proximal tubule. Moreover, our findings support the view that GLP-1-based agents may have a potential therapeutic use not only as antidiabetic drugs but also in hypertension and other disorders of sodium retention.