bluuebunny/crossref_metadata_2025 huggingface dataset:
Structural remodeling of GPI anchors during biosynthesis and after attachment to proteins
Authors: Fujita Morihisa , Kinoshita Taroh
Published: November 2009

Glycosylphosphatidylinositol (GPI) anchoring of proteins is a conserved post‐translational modification in eukaryotes. In mammalian cells, approximately 150 proteins on the plasma membrane are attached to the cell surface by GPI anchors, which confer specific properties on proteins, such as association with membrane microdomains. The structures of lipid and glycan moieties on GPI anchors are remodeled during biosynthesis and after attachment to proteins. The remodeling processes are critical for transport and microdomain‐association of GPI‐anchored proteins. Here, we describe the structural remodeling of GPI anchors and genes required for the processes in mammals, yeast, and trypanosomes.
Depletion of mammalian target of rapamycin (mTOR) via siRNA mediated knockdown leads to stabilization of β‐catenin and elicits distinct features of cardiomyocyte hypertrophy
Authors: Hagenmueller Marco , Malekar Pratima , Fieger Christiane , Weiss Celine S. , Buss Sebastian J. , Wolf David , Katus Hugo A. , Hardt Stefan E.
Published: November 2009

Cardiac myocyte growth is under differential control of mammalian target of rapamycin (mTOR) and glycogen‐synthase‐kinase‐3β (GSK3β). Whereas active GSK3β negatively regulates growth and down‐regulates cellular protein synthesis, activation of the mTOR pathway promotes protein expression and cell growth. Here we report that depletion of mTOR via siRNA mediated knockdown causes marked down‐regulation of GSK3β protein in cardiac myocytes. As a result, GSK3β target protein β‐catenin becomes stabilized and translocates into the nucleus. Moreover, mTOR knockdown leads to increase in cardiac myocyte surface area and produces an up‐regulation of the fetal gene program. Our findings suggest a new type of convergence of mTOR and GSK3β activities, indicating that GSK3β‐dependent stabilization of β‐catenin in cardiac myocytes is influenced by mTOR.
RETRACTED: Theaflavins retard human breast cancer cell migration by inhibiting NF‐κB via p53‐ROS cross‐talk
Authors: Adhikary Arghya , Mohanty Suchismita , Lahiry Lakshmishri , Hossain Dewan Md. Sakib , Chakraborty Samik , Das Tanya
Published: November 2009

MINT‐7295816: p53 (uniprotkb:P04637) physically interacts (MI:0915) with IKK beta (uniprotkb:O14920) by anti bait coimmunoprecipitation (MI:0006)
Changing Practice Models in Otolaryngology–Head and Neck Surgery: The Role for Collaborative Practice
Authors: Reger Christine , Kennedy David W.
Published: November 2009

The increased complexity of medicine, the imperative of reducing health care costs, and the goals of improving quality and patient satisfaction require that we rethink current models of practice. Such reevaluation will receive additional impetus from workforce changes within medicine and the specialty. Furthermore, as chronic disorder care becomes more complex, it may increasingly be provided within a specialty setting. Our goal is to stimulate discussion regarding the potential for alternative health care delivery models within the specialty in the face of predicted workforce shortages and the impetus toward health care reform. A collaborative practice model utilizing midlevel health care providers increases productivity and patient satisfaction and provides the potential to deliver an exceptionally high level of care for chronic disorders when such care is sufficiently complex to require specialty management.
The Relationship Between the Air‐Bone Gap and the Size of Superior Semicircular Canal Dehiscence
Authors: Yuen Heng‐Wai , Boeddinghaus Rudolf , Eikelboom Robert H. , Atlas Marcus D.
Published: November 2009

OBJECTIVE

To examine the relationship between the air‐bone gap (ABG) and the size of the superior semicircular canal dehiscence (SSCD) as measured on a computed tomography (CT) scan. STUDY DESIGN: Case series with chart review.

SETTING

Tertiary referral center.

PATIENTS

Twenty‐three patients (28 ears) diagnosed with SSCD.

MAIN OUTCOME MEASURES

The size of the dehiscence on CT scans and the ABG on pure‐tone audiometry were recorded.

RESULTS

The size of the dehiscence ranged from 1.0 to 6.0 mm (mean, 3.5 ± 1.6 mm). Six ears with a dehiscence measuring less than 3.0 mm did not have an ABG (0 dB). The remaining 18 ears showed an average ABG at 500, 1000, and 2000 Hz (AvABG500–2000) ranging from 3.3 to 27.0 dB (mean, 11.6 ± 5.7 dB). The analysis of the relationship between the dehiscence size and AvABG500–2000 revealed a correlation of R 2 = 0.828 (P < 0.001, quadratic fit) and R 2 = 0.780 (P < 0.001, linear fit). Therefore, the larger the dehiscence, the larger the ABG at lower frequencies on pure‐tone audiometry.

CONCLUSIONS

In SSCD patients, an ABG is consistently shown at the low frequency when the dehiscence is larger than 3 mm. The size of the average ABG correlates with the size of the dehiscence. These findings highlight the effect of the dehiscence size on conductive hearing loss in SSCD and contribute to a better understanding of the symptomatology of patients with SSCD.
Preservation of the External Jugular Venous Drainage System in Neck Dissection
Authors: Chung Man Ki , Choi Jeesun , Lee Jae‐Kwon , Jeong Jong In , Lee Won Yong , Jeong Han‐Sin
Published: November 2009

OBJECTIVE

To investigate whether preserving the external jugular vein (EJV) in neck dissection reduces postoperative edema of the face and neck.

STUDY DESIGN

A prospective, randomized controlled trial.

SETTING

A tertiary hospital.

SUBJECTS AND METHODS

Thirty‐eight subjects were randomly assigned to two groups: EJV preservation versus sacrifice during neck dissection after stratification according to the neck dissection extent and type, the previous treatment, the primary site, and the reconstruction type. The relative soft‐tissue thickness was evaluated by follow‐up computed tomography (CT) scans at one week and four to five weeks postoperatively and compared with preoperative findings. The preserved EJV patency was also determined by contrast enhancement of EJV on follow‐up CT scans. In addition, the scores for pain/discomfort on the upper neck/face and laryngeal edema were recorded at each time point.

RESULTS

Relative soft‐tissue thickness reached up to 160 percent of preoperative status at the hyoid and cricoid levels at one week postoperatively but resolved at four to five weeks. EJV preservation reduced the soft‐tissue thickness significantly compared with EJV sacrifice (P < 0.05) at one week postoperatively, particularly at the mandible and hyoid level. All preserved EJVs remained patent at one week, and 18 of 19 remained patent at four to five weeks. In addition, EJV preservation diminished the discomfort/pain of the upper neck/face compared with EJV sacrifice at one week (P = 0.036). The extent of laryngeal edema did not differ between the two groups.

CONCLUSION

EJV preservation may reduce immediate postoperative neck edema and pain/discomfort related to neck dissection.
Technik und Gesundheit – Einsatzbereiche von Technik zum Nutzen in der Gesundheitsversorgung
Authors: Kraft Marc
Published: November 2009

Einleitung

Die demografische Entwicklung, eine Veränderung des Krankheitsspektrums hin zu chronischen und chronisch-degenerativen Erkrankungen, der medizinische und technologische Fortschritt und die damit verbundenen Veränderungen in der Erwartungshaltung der Patienten stellen das Gesundheitswesen vor erhebliche neue Herausforderungen. Gleichzeitig stoßen die aktuellen Finanzierungs- und Vergütungssysteme an ihre Grenzen. Somit unterliegt das Gesundheitssystem insgesamt einem außerordentlich hohen Innovationsdruck. Dabei hat die Gesundheitstechnologie das Potenzial, die gesundheitliche Versorgung unserer Gesellschaft durch einen fortschreitenden Innovationsprozess dauerhaft zu verändern.
Aktionsplan Medizintechnik: Übersicht zur Forschungs- und Innovationspolitik
Authors: Quennet-Thielen Cornelia
Published: November 2009

Einleitung

Im Gesundheitsbereich liegen große Potenziale, Wohlbefinden und Leistungsfähigkeit der Menschen bis ins hohe Alter zu befördern und zugleich zu neuem, nachhaltigem Wachstum beizutragen. Der Medizintechnik kommt hierbei eine Schlüsselrolle zu, denn sie ermöglicht durch rasante Fortschritte eine immer bessere und schnellere Diagnostik von Krankheiten, krankheitsvorbeugende Therapien und ein selbständiges, würdevolles Leben für eine älter werdende Bevölkerung in Deutschland.
Internal wave beam propagation in non-uniform stratifications
Authors: MATHUR MANIKANDAN , PEACOCK THOMAS
Published: November 2009

In addition to being observable in laboratory experiments, internal wave beams are reported in geophysical settings, which are characterized by non-uniform density stratifications. Here, we perform a combined theoretical and experimental study of the propagation of internal wave beams in non-uniform density stratifications. Transmission and reflection coefficients, which can differ greatly for different physical quantities, are determined for sharp density-gradient interfaces and finite-width transition regions, accounting for viscous dissipation. Thereafter, we consider even more complex stratifications to model geophysical scenarios. We show that wave beam ducting can occur under conditions that do not necessitate evanescent layers, obtaining close agreement between theory and quantitative laboratory experiments. The results are also used to explain recent field observations of a vanishing wave beam at the Keana Ridge, Hawaii.
On the Genus Cumanotus
Authors: Eliot Charles
Published: November 2009

(See Eliot on Coryphella beaumonti in Notes on some British Nudibranchs, Journ. Mar. Biol. Assoc., vol. vii., No. 3, June, 1906, pp. 361–3; and Nils Odhner on Cumanotus laticeps in Northern and Arctic Invertebrates, iii. Opisthobranchia. Kngl. Svenska Vetenskapsakademiens Handlingar. Band 41, No. 4, 1907, pp. 29, 80, and 101–2).

In describing (l.c.) Coryphella beaumonti as a new species, I pointed out that in many important characters it differs markedly from the other known Coryphellœ, and might be made the type of a new genus. But I did not create a new genus, thinking it might be well to examine further specimens, both of this animal and of allied forms, before deciding on its place in the classification. In the next year Odhner created (I.c.) the genus Cumanotus to which Coryphella beavmonti is certainly referable, and which is shown by his researches to be well characterized. It is allied to Coryphella inasmuch as it has unperfoliate rhinophores, tentacular angles to the foot, a triseriate radula and denticulate jaws; but it also possesses the following special characters: (1) The oral tentacles are very small and connected by a cutaneous fold which runs across the head; (2) there are several (at least, as many as three) rows of cerata in front of the rhinophores; (3) the verge is deeply grooved, and there is a bursa copulatrix, the entrance to which bears on its upper and lower margin a circular pad, armed on the periphery with twelve small cones terminating in hooks.
Note on a Conger with Abnormal Gonad
Authors: Hefford A. E.
Published: November 2009

Among a sample of seven small Conger, from 58 to 77 cm. in length, obtained from the Plymouth Fish Quay on 31st March, one was found with unsymmetrical reproductive organs. The other six were immature females with the normal pair of ovaries. The abnormal specimen has a right gonad quite similar to the ovaries of females at the same stage of maturity. It is bandlike in form, extending along the whole length of the abdominal cavity. The inner or left side is covered with smooth peritoneal epithelium (mesoarium). The greater part of the surface of the right (outer) side is raised into transverse lamellæ containing the as yet little-developed ova embedded in fat-tissue. For about one to two millimetres from its free edge, the organ consists of a strip of fat-tissue quite free from germinal cells, and there is a similarly constituted longitudinal fold—here and there divided into a subsidiary one—extending parallel to and about 2 mm. from the free edge and bordering the lamellated germinal area. The ovary is 17.5 cm. long, its greatest width 12 mm., and the widest part of the lamellated area is about 7 mm.
The Mollusca collected by the “Huxley” from the North Side of the Bay of Biscay, in August, 1906
Authors: Reynell Alexander
Published: November 2009

THIS paper deals with the Mollusca collected on the cruise of the s.s.Huxleyto the north side of the Bay of Biscay in August, 1906, with the exception of the Cephalopoda, which are being worked out by Dr. W. E. Hoyle. The collection, though small, taking into account the area over which dredgings were taken, contains a fair number of interesting species. Though there is nothing new, there are several species represented which one would not expect to find in such high latitudes, and their discovery adds somewhat to our, as yet, slight knowledge of the fauna of the deeper seas and its distribution.
The Brachiopoda collected by the “Huxley” from the North Side of the Bay of Biscay, in August, 1906
Authors: Reynell Alexander
Published: November 2009

Of the three species of Brachiopoda found, two,Magellania craniumandM. septigera, are found in the British list. The third species,Mühlfeldtia truncata, has not, as far as I can discover, previously been recorded from so high a latitude, Turton's Torbay locality being very doubtful.
Combable functions, quasimorphisms, and the central limit theorem
Authors: CALEGARI DANNY , FUJIWARA KOJI
Published: November 2009

A function on a discrete group is weakly combable if its discrete derivative with respect to a combing can be calculated by a finite-state automaton. A weakly combable function is bicombable if it is Lipschitz in both the left- and right-invariant word metrics. Examples of bicombable functions on word-hyperbolic groups include:

(1)

homomorphisms to ℤ;

(2)

word length with respect to a finite generating set;

(3)

most known explicit constructions of quasimorphisms (e.g. the Epstein–Fujiwara counting quasimorphisms).

We show that bicombable functions on word-hyperbolic groups satisfy acentral limit theorem: if$\overline {\phi }_n$is the value of ϕ on a random element of word lengthn(in a certain sense), there areEandσfor which there is convergence in the sense of distribution$n^{-1/2}(\overline {\phi }_n - nE) \to N(0,\sigma )$, whereN(0,σ) denotes the normal distribution with standard deviationσ. As a corollary, we show that ifS1andS2are any two finite generating sets forG, there is an algebraic numberλ1,2depending onS1andS2such that almost every word of lengthnin theS1metric has word lengthn⋅λ1,2in theS2metric, with error of size$O(\sqrt {n})$.
Epsilon-hypercyclic operators
Authors: BADEA CATALIN , GRIVAUX SOPHIE , MÜLLER VLADIMIR
Published: November 2009

Let X be a separable infinite-dimensional Banach space, and T a bounded linear operator on X; T is hypercyclic if there is a vector x in X with dense orbit under the action of T. For a fixed ε∈(0,1), we say that T is ε-hypercyclic if there exists a vector x in X such that for every non-zero vector y∈X there exists an integer n with $\|T^nx-y\|\leq \varepsilon \|y\|$. The main result of this paper is a construction of a bounded linear operator T on the Banach space ℓ1 which is ε-hypercyclic without being hypercyclic. This answers a question from V. Müller [Three problems, Mini-Workshop: Hypercyclicity and linear chaos, organized by T. Bermudez, G. Godefroy, K.-G. Grosse-Erdmann and A. Peris. Oberwolfach Rep.3 (2006), 2227–2276].
Analytic integrability of quadratic–linear polynomial differential systems
Authors: LLIBRE JAUME , VALLS CLÀUDIA
Published: November 2009

For the quadratic–linear polynomial differential systems with a finite singular point, we classify the ones which have a global analytic first integral, and provide the explicit expression of their first integrals.
PANEL UNIT ROOT TESTS WITH CROSS-SECTION DEPENDENCE: A FURTHER INVESTIGATION
Authors: Bai Jushan , Ng Serena
Published: November 2009

An effective way to control for cross-section correlation when conducting a panel unit root test is to remove the common factors from the data. However, there remain many ways to use the defactored residuals to construct a test. In this paper, we use the panel analysis of nonstationarity in idiosyncratic and common components (PANIC) residuals to form two new tests. One estimates the pooled autoregressive coefficient, and one simply uses a sample moment. We establish their large-sample properties using a joint limit theory. We find that when the pooled autoregressive root is estimated using data detrended by least squares, the tests have no power. This result holds regardless of how the data are defactored. All PANIC-based pooled tests have nontrivial power because of the way the linear trend is removed.
CHARACTERISTIC FUNCTION–BASED TESTING FOR MULTIFACTOR CONTINUOUS-TIME MARKOV MODELS VIA NONPARAMETRIC REGRESSION
Authors: Chen Bin , Hong Yongmiao
Published: November 2009

We develop a nonparametric regression-based goodness-of-fit test for multifactor continuous-time Markov models using the conditional characteristic function, which often has a convenient closed form or can be approximated accurately for many popular continuous-time Markov models in economics and finance. An omnibus test fully utilizes the information in the joint conditional distribution of the underlying processes and hence has power against a vast class of continuous-time alternatives in the multifactor framework. A class of easy-to-interpret diagnostic procedures is also proposed to gauge possible sources of model misspecification. All the proposed test statistics have a convenient asymptoticN(0, 1) distribution under correct model specification, and all asymptotic results allow for some data-dependent bandwidth. Simulations show that in finite samples, our tests have reasonable size, thanks to the dimension reduction in nonparametric regression, and good power against a variety of alternatives, including misspecifications in the joint dynamics, but the dynamics of each individual component is correctly specified. This feature is not attainable by some existing tests. A parametric bootstrap improves the finite-sample performance of proposed tests but with a higher computational cost.
Maternal predictors of neonatal bone size and geometry: the Southampton Women’s Survey
Authors: Harvey N. C. , Javaid M. K. , Arden N. K. , Poole J. R. , Crozier S. R. , Robinson S. M. , Inskip H. M. , Godfrey K. M. , Dennison E. M. , Cooper C. ,   the SWS Study Team
Published: November 2009

Early growth is associated with later risk of osteoporosis and fractures. In this study, we aimed to evaluate the relationships between maternal lifestyle and body composition and neonatal bone size, geometry and density in the offspring. Participants were recruited from the Southampton Women’s Survey, a unique prospective cohort of 12,500 initially non-pregnant women aged 20–34 years, resident in Southampton, UK. These women were studied in detail before and during pregnancy, and the offspring underwent anthropometric and bone mineral assessment (using dual energy-X-ray absorptiometry) at birth. A total of 841 mother–baby pairs were studied (443 boys and 398 girls). The independent predictors of greater neonatal whole body bone area (BA) and bone mineral content included greater maternal birthweight, height, parity, triceps skinfold thickness and lower walking speed in late pregnancy. Maternal smoking was independently associated with lower neonatal bone mass. Neonatal BA adjusted for birth length (a measure of bone width) was predicted positively by maternal parity and late pregnancy triceps skinfold thickness and negatively by late pregnancy walking speed. These findings were similar in both genders. We have confirmed, in a large cohort, previous findings that maternal lifestyle and body build predict neonatal bone mineral; additionally, maternal parity and fat stores and walking speed in late pregnancy were associated with neonatal bone geometry. These findings may suggest novel public health strategies to reduce the burden of osteoporotic fracture in future generations.
Korrektur der Hyponatriämie – Ein schwieriges Unterfangen?
Authors: Stober Christina Nicole , Huynh-Do Uyen
Published: November 2009

Die chronische Hyponatriämie und deren Therapie ist ein häufiges und oft auch unterschätztes Problem bei der Hospitalisation von Patienten, da meistens ein anderes Leiden im Vordergrund steht. Eine zu rasche Korrektur kann schwerwiegende neurologische Defizite durch eine Myelinolyse verursachen. Welche Pathomechanismen zur Myelinolyse führen und wie schnell, wie viel und mit welchen Mitteln die Korrektur erfolgen darf, ist im folgenden Artikel zusammengefasst.
The Relationship Between Frontal Brain Asymmetry and Exercise Addiction
Authors: Gapin Jennifer , Etnier Jennifer L. , Tucker Denise
Published: November 2009

Previous research on the causes of exercise addiction has focused primarily on the relationships among personality traits, social influences, and disordered eating ( Bamber, Cockerill, & Carroll, 2000 ; Beals, 2004 ). Few studies, however, have examined the psychophysiological nature of exercise addiction. In a related area of research in which brain activity has been related to affect and mood, results show that frontal asymmetry, as measured by electroencephalogram (EEG), is associated with negative emotions. More specifically, greater activity at right frontal electrode sites is found among individuals suffering from negative affect and depression. Because a defining feature of exercise addiction is the use of exercise to control negative mood states, it is expected that those with exercise addiction exhibit different frontal activity. This study explores the hypothesized relationship between exercise addiction and the level of baseline frontal activity asymmetry, as measured by EEG. Regularly active women (n = 28, M age = 32.43, SD = 10.89) were recruited to participate in the study. Exercise addiction status was determined by the Exercise Addiction Inventory (EAI) ( Terry, Szabo, & Griffiths, 2004 ). After completing the EAI, each participant took part in an EEG session consisting of eight 1-min resting trials, four with eyes open, and four with eyes closed, presented in counterbalanced order. Electrodes were applied to the left and right frontal sites (F3 and F4). A regression analysis, predicting exercise addiction from frontal asymmetry, was significant, F(1, 27) = 6.4, p < .05, and indicated that greater relative left frontal activity with higher exercise addiction scores. There may be a link between frontal asymmetry, as an indicator of negative emotions, and exercise addiction in women.
The Relationship Between Spectral Changes in Heart Rate Variability and Fatigue
Authors: Tran Yvonne , Wijesuriya Nirupama , Tarvainen Mika , Karjalainen Pasi , Craig Ashley
Published: November 2009

Fatigue is a prevalent problem in the workplace and a common symptom of many diseases. However, its relationship with the autonomic nervous system, specifically with sympathetic arousal, needs clarification. The objective of this study was to determine the association between fatigue and heart rate variability (HRV). HRV is regarded as an indicator of the autonomic regulation activity of heart rate, specifically sympathetic and parasympathetic activity. Spectral changes in low-frequency (LF; 0.04–0.15 Hz) and high-frequency (HF; 0.15–0.4 Hz) components of HRV have been reported to be associated with distressing conditions such as hemorrhagic shock, acute myocardial infarction, elevated anxiety, and depressed mood. While HRV changes have been found in persons with chronic fatigue syndrome, its association with fatigue in healthy individuals still needs clarification. HRV was assessed in a total of 50 participants who were asked to perform a task until becoming fatigued. Low-frequency HRV activity increased, while indices of parasympathetic modulation such as RMSSD and pNN50 remained stable as participants experienced fatigue, suggesting that fatigue in healthy individuals may be associated with increased sympathetic arousal. In addition, employing multiple regression analyses, we could positively associate the change in LF/HF HRV ratio from baseline to fatigue with factors such as emotional stability, warmth and tension and negatively associate it with social boldness and self-reported levels of vigor.
Constraints on the stress state of the San Andreas Fault with analysis based on core and cuttings from San Andreas Fault Observatory at Depth (SAFOD) drilling phases 1 and 2
Authors: Tembe Sheryl , Lockner David , Wong Teng‐fong
Published: November 2009

Analysis of field data has led different investigators to conclude that the San Andreas Fault (SAF) has either anomalously low frictional sliding strength (μ < 0.2) or strength consistent with standard laboratory tests (μ > 0.6). Arguments for the apparent weakness of the SAF generally hinge on conceptual models involving intrinsically weak gouge or elevated pore pressure within the fault zone. Some models assert that weak gouge and/or high pore pressure exist under static conditions while others consider strength loss or fluid pressure increase due to rapid coseismic fault slip. The present paper is composed of three parts. First, we develop generalized equations, based on and consistent with the Rice (1992) fault zone model to relate stress orientation and magnitude to depth‐dependent coefficient of friction and pore pressure. Second, we present temperature‐ and pressure‐dependent friction measurements from wet illite‐rich fault gouge extracted from San Andreas Fault Observatory at Depth (SAFOD) phase 1 core samples and from weak minerals associated with the San Andreas Fault. Third, we reevaluate the state of stress on the San Andreas Fault in light of new constraints imposed by SAFOD borehole data. Pure talc (μ≈0.1) had the lowest strength considered and was sufficiently weak to satisfy weak fault heat flow and stress orientation constraints with hydrostatic pore pressure. Other fault gouges showed a systematic increase in strength with increasing temperature and pressure. In this case, heat flow and stress orientation constraints would require elevated pore pressure and, in some cases, fault zone pore pressure in excess of vertical stress.
Ocean acidification and biologically induced seasonality of carbonate mineral saturation states in the western Arctic Ocean
Authors: Bates Nicholas R. , Mathis Jeremy T. , Cooper Lee W.
Published: November 2009

Calcium carbonate (CaCO3) mineral saturation states for aragonite (Ωaragonite) and calcite (Ωcalcite) are calculated for waters of the Chukchi Sea shelf and Canada Basin of the western Arctic Ocean during the Shelf‐Basin Interactions project from 2002 to 2004. On the Chukchi Sea shelf, a strong seasonality and vertical differentiation of aragonite and calcite saturation states was observed. During the summertime sea ice retreat period, high rates of phytoplankton primary production and net community production act to increase the Ωaragonite and Ωcalcite of surface waters, while subsurface waters become undersaturated with respect to aragonite due primarily to remineralization of organic matter to CO2. This seasonal “phytoplankton‐carbonate saturation state” interaction induces strong undersaturation of aragonite (Ωaragonite = <0.7–1) at ∼40–150 m depth in the northern Chukchi Sea and in the Canada Basin within upper halocline waters at ∼100–200 m depth. Patches of aragonite undersaturated surface water were also found in the Canada Basin resulting from significant sea ice melt contributions (>10%). The seasonal aragonite undersaturation of waters observed on the Chukchi Sea shelf is likely a recent phenomenon that results from the uptake of anthropogenic CO2 and subsequent ocean acidification, with seasonality of saturation states superimposed by biological processes. These undersaturated waters are potentially highly corrosive to calcifying benthic fauna (e.g., bivalves and echinoderms) found on the shelf, with implications for the food sources of large benthic feeding mammals (e.g., walrus, gray whales, and bearded seals). The benthic ecosystem of the Chukchi Sea (and other Arctic Ocean shelves) is thus potentially vulnerable to future ocean acidification and suppression of CaCO3 saturation states.
Global distribution of the decay timescale of mixed layer inertial motions observed by satellite‐tracked drifters
Authors: Park Jong Jin , Kim Kuh , Schmitt Raymond W.
Published: November 2009

The decay timescale of mixed layer inertial amplitudes has been estimated from satellite tracked drifter trajectories from 1990 to 2004 as the e‐folding timescale of the temporal correlation functions. The decay timescales increase with latitude in all basins except the North Atlantic. A beta dispersion model shows that dephasing leads to meridional variations of the decay timescale in the North Pacific and the Southern Ocean, but meridional variations of the buoyancy structure in the North Atlantic act to compensate the beta effect, leading to a lack of meridional variation of the decay timescale in that ocean.
A preferential flow leaching index
Authors: McGrath Gavan Sean , Hinz Christoph , Sivapalan Murugesu
Published: November 2009

The experimental evidence suggests that for many chemicals surface runoff and rapid preferential flow through the shallow unsaturated zone are significant pathways for transport to streams and groundwater. The signature of this is the episodic and pulsed leaching of these chemicals. The driver for this transport is the timing and magnitude of rainfall events which trigger rapid flow and the release of solute from a source zone, located near the soil surface. Based on these considerations we develop a conceptual model capable of reproducing many of the signatures of this rapid transport. This driver‐source‐trigger‐signature framework forms the basis of the development of a new leaching index which describes the potential for rapid solute transport by preferential flow or surface runoff. This preferential flow (PF) index is based upon soil and chemical parameters as well as the timing and magnitude of rainfall and preferential flow events. The PF index suggests that a chemical's potential to experience rapid transport increases as sorption strength increases, however, when an approximation to account for sorption kinetics is considered the PF index peaks at moderate sorption values. The model is sensitive to the timing and magnitude of rapid flow events, which may require existing data or infiltration models for their estimation.
Controls on Northern Hemisphere snow albedo feedback quantified using satellite Earth observations
Authors: Fernandes Richard , Zhao Hongxu , Wang Xuanji , Key Jeff , Qu Xin , Hall Alex
Published: November 2009

Observation based estimates of controls on snow albedo feedback (SAF) are needed to constrain the snow and albedo parameterizations in general circulation model (GCM) projections of air temperature over the Northern Hemisphere (NH) landmass. The total April‐May NH SAF, corresponding to the sum of the effect of temperature on surface albedo over snow covered surfaces (‘metamorphism’) and over surfaces transitioning from snow covered to snow free conditions (‘snow cover’), is derived with daily NH snow cover and surface albedo products using Advanced Very High Resolution Radiometer Polar Pathfinder satellite data and surface air temperature from ERA40 reanalysis data between 1982–1999. Without using snow cover information, the estimated total SAF, for land surfaces north of 30°N, of −0.93 ± 0.06%K−1 was not significantly different (95% confidence) from estimates based on International Satellite Cloud Climatology Project surface albedo data. The SAF, constrained to only snow covered areas, grew to −1.06 ± 0.08%K−1 with similar magnitudes for the ‘snow cover’ and ‘metamorphosis’ components. The SAF pattern was significantly correlated with the ‘snow cover’ component pattern over both North America and Eurasia but only over Eurasia for the ‘metamorphosis’ component. However, in contrast to GCM model based diagnoses of SAF, the control on the ‘snow cover’ component related to the albedo contrast of snow covered and snow free surfaces was not strongly correlated to the total SAF.
Impact of anthropogenic aerosols on Indian summer monsoon
Authors: Wang Chien , Kim Dongchul , Ekman Annica M. L. , Barth Mary C. , Rasch Phillip J.
Published: November 2009

Using an interactive aerosol‐climate model we find that absorbing anthropogenic aerosols, whether coexisting with scattering aerosols or not, can significantly affect the Indian summer monsoon system. We also show that the influence is reflected in a perturbation to the moist static energy in the sub‐cloud layer, initiated as a heating by absorbing aerosols to the planetary boundary layer. The perturbation appears mostly over land, extending from just north of the Arabian Sea to northern India along the southern slope of the Tibetan Plateau. As a result, during the summer monsoon season, modeled convective precipitation experiences a clear northward shift, coincidently in general agreement with observed monsoon precipitation changes in recent decades particularly during the onset season. We demonstrate that the sub‐cloud layer moist static energy is a useful quantity for determining the impact of aerosols on the northward extent and to a certain degree the strength of monsoon convection.
Future changes in the Mediterranean water budget projected by an ensemble of regional climate models
Authors: Sanchez‐Gomez E. , Somot S. , Mariotti A.
Published: November 2009

The Mediterranean basin is a region characterized by its vulnerability to changes in the water cycle. Hence, the impact of global warming on the water resources in the Mediterranean zone is one of the major concerns for the scientific community. The future climate projections used to elaborate the IPCC report of 2007 show great alterations in the evaporation and precipitation over the Mediterranean Sea at the end of 21st century. In this work we investigate the changes in the Mediterranean Sea water budget by using SRES‐A1B scenario experiments performed with high resolution (25 km) regional climate models (RCMs). The RCMs provide good estimates of the water budget components, in particular with a significant improvement of the runoff and Black Sea discharge terms compared to the coarser resolution general circulation models (GCMs) used in the last Intergovernmental Panel of Climate Change (IPCC) report. As for the case of GCMs, the RCMs show that the Mediterranean water budget is likely to be significantly altered at the end of 21st century. The response of the hydrological variables to global warming starts to be statistically significant from 2050, though some alterations are already observed before 2050. The RCMs predict an increase of evaporation, and a decrease of precipitation, and river and Black Sea discharge, yielding to a large increase of the Mediterranean fresh water deficit. The freshwater deficit for the period 2070–2099 related to 1950–1999 presents a mean increase of +40% for both RCMs and GCMs.
Possible orographic and solar controls of Late Holocene centennial‐scale moisture oscillations in the northeastern Tibetan Plateau
Authors: Zhao Cheng , Yu Zicheng , Zhao Yan , Ito Emi
Published: November 2009

We present a record of lake‐level changes from Hurleg Lake, a freshwater lake in the arid Qaidam Basin on the NE Tibetan Plateau, an area with few high‐resolution paleoclimate records. The carbonate percentage and ostracode abundance show a consistent pattern with ∼200‐year moisture oscillations during the last 1000 years. The moisture pattern in the Qaidam Basin is in opposite relation to tree‐ring‐based monsoon precipitations in the surrounding mountains, suggesting that topography may be important in controlling regional moisture patterns as mediated by rising and subsiding air masses in this topographically‐complex region. Cross‐spectral analysis between our moisture proxies and solar activity proxy shows high coherence at the ∼200‐year periodicity which is similar to Chinese monsoon intensity records, implying the possible solar forcing of moisture oscillations in the NE Tibetan Plateau.
Propagation of Biot slow waves in heterogeneous pipe networks: Effect of the pipe radius distribution on the effective wave velocity and attenuation
Authors: Bernabé Y.
Published: November 2009

This paper extends a previous study of the harmonic (or AC) flow of a compressible fluid through a single, elastic, thick‐wall pipe. The model previously developed is used to investigate propagation of pore‐scale Biot slow waves through heterogeneous one‐, two‐ and three‐dimensional networks of pipes. A novel method is applied to the results of the network simulations to numerically determine the dispersion equation of the upscaled Biot slow waves and investigate its dependence on pore‐scale heterogeneity. As a function of frequency, the phase velocity of the macroscale Biot slow waves displays an S‐shaped curve, increasing from zero at low frequencies (i.e., nonpropagative regime) to C at high frequencies (i.e., propagative regime with C lower than the sound velocity in the fluid). The transition between these two regimes is marked by the inflection point at the frequency ωB (where ωB is inversely proportional to the length scale Λ characteristic of fluid flow and permeability). The high‐frequency phase velocity C depends on the dimensionality of the network considered and decreases with increasing heterogeneity. The wave attenuation (as measured by the inverse quality factor) also presents an S‐shaped curve, decreasing from 2 (i.e., critical damping) to zero, with the same inflection point at ωB. This behavior is approximately independent on the pore radius distribution, provided that ωB (or the corresponding fluid flow length scale Λ) is held constant. A mechanism based on wave scattering and interferences of forward and backward traveling (pore‐scale) Biot slow waves is proposed to explain the observations.
Changes in Glucose Uptake Rather than Lactate Shuttle Take Center Stage in Subserving Neuroenergetics: Evidence from Mathematical Modeling
Authors: DiNuzzo Mauro , Mangia Silvia , Maraviglia Bruno , Giove Federico
Published: November 2009

In this paper, we combined several mathematical models of cerebral metabolism and nutrient transport to investigate the energetic significance of metabolite trafficking within the brain parenchyma during a 360-secs activation. Glycolytic and oxidative cellular metabolism were homogeneously modeled between neurons and astrocytes, and the stimulation-induced neuronal versus astrocytic Na+ inflow was set to 3:1. These assumptions resemble physiologic conditions and are supported by current literature. Simulations showed that glucose diffusion to the interstitium through basal lamina dominates the provision of the sugar to both neurons and astrocytes, whereas astrocytic endfeet transfer less than 4% of the total glucose supplied to the tissue. Neuronal access to paracellularly diffused glucose prevails even after halving (doubling) the ratio of neuronal versus astrocytic glycolytic (oxidative) metabolism, as well as after reducing the neuronal versus astrocytic Na+ inflow to a nonphysiologic value of 1:1. Noticeably, displaced glucose equivalents as intercellularly shuttled lactate account for ∼6% to 7% of total brain glucose uptake, an amount comparable with the concomitant drainage of the monocarboxylate by the bloodstream. Overall, our results suggest that the control of carbon recruitment for neurons and astrocytes is exerted at the level of glucose uptake rather than that of lactate shuttle.
Polyamine homoeostasis
Authors: Persson Lo
Published: November 2009

The polyamines are essential for a variety of functions in the mammalian cell. Although their specific effects have not been fully elucidated, it is clear that the cellular polyamines have to be kept within certain levels for normal cell function. Polyamine homoeostasis in mammalian cells is achieved by a complex network of regulatory mechanisms affecting synthesis and degradation, as well as membrane transport of polyamines. The two key enzymes in the polyamine biosynthetic pathway, ODC (ornithine decarboxylase) and AdoMetDC (S-adenosylmethionine decarboxylase), are strongly regulated by feedback mechanisms at several levels, including transcriptional, translational and post-translational. Some of these mechanisms have been shown to be truly unique and include upstream reading frames and ribosomal frameshifting, as well as ubiquitin-independent proteasomal degradation. SSAT (spermidine/spermine N1-acetyltransferase), which is a crucial enzyme for degradation and efflux of polyamines, is also highly regulated by polyamines. A cellular excess of polyamines rapidly induces SSAT, resulting in increased degradation/efflux of the polyamines. The polyamines appear to induce both transcription and translation of the SSAT mRNA. However, the major part of the polyamine-induced increase in SSAT is caused by a marked stabilization of the enzyme against degradation by the 26S proteasome. In addition, active transport of extracellular polyamines into the cell contributes to cellular polyamine homoeostasis. Depletion of cellular polyamines rapidly induces an increased uptake of exogenous polyamines, whereas an excess of polyamines down-regulates the polyamine transporter(s). However, the protein(s) involved in polyamine transport and the exact mechanisms by which the polyamines regulate the transporter(s) are not yet known.
Cells and polyamines do it cyclically
Authors: Alm Kersti , Oredsson Stina
Published: November 2009

Cell-cycle progression is a one-way journey where the cell grows in size to be able to divide into two equally sized daughter cells. The cell cycle is divided into distinct consecutive phases defined as G1 (first gap), S (synthesis), G2 (second gap) and M (mitosis). A non-proliferating cell, which has retained the ability to enter the cell cycle when it receives appropriate signals, is in G0 phase, and cycling cells that do not receive proper signals leave the cell cycle from G1 into G0. One of the major events of the cell cycle is the duplication of DNA during S-phase. A group of molecules that are important for proper cell-cycle progression is the polyamines. Polyamine biosynthesis occurs cyclically during the cell cycle with peaks in activity in conjunction with the G1/S transition and at the end of S-phase and during G2-phase. The negative regulator of polyamine biosynthesis, antizyme, shows an inverse activity compared with the polyamine biosynthetic activity. The levels of the polyamines, putrescine, spermidine and spermine, double during the cell cycle and show a certain degree of cyclic variation in accordance with the biosynthetic activity. When cells in G0/G1-phase are seeded in the presence of compounds that prevent the cell-cycle-related increases in the polyamine pools, the S-phase of the first cell cycle is prolonged, whereas the other phases are initially unaffected. The results point to an important role for polyamines with regard to the ability of the cell to attain optimal rates of DNA replication.
Ultrastructural analysis of interneuronal syncytial perforations
Authors: Sotnikov Oleg S. , Paramonova Nataly M. , Archakova Ludmila I.
Published: November 2009

The structural regularities of the organization of interneuronal syncytial cytoplasmic connections between neuronal bodies in gyrus dentatus and CA1 and CA2 (CA is cornu ammonis) of hippocampus, as well as between cell neurites of the caudal mesenteric ganglion were studied by transmission electron microscopy. The syncytial perforations are located only on the base of tight junctions. The perforations have rounded edges corresponding to the fusion edges of perforated membranes of adjacent neurons – or where their edges have a form of thinned plate – a remnant of the tight junction. In the lumen of the perforations, remnants of contact membranes – residual bodies – are revealed. On living neurons in tissue culture, the syncytial connection of two contacting processes of different neurons is found during the death of the body of one of them, but with preservation of viability of its processes that contact with other neurons.
The Use of Narratives to Identify Characteristics Leading to a Productive Life Following Acquired Brain Injury
Authors: Fraas Michael R. , Calvert Margaret
Published: November 2009

Purpose

To determine the factors leading to successful recovery and productive lifestyles after acquired brain injury (ABI).

Method

Qualitative investigation examined semistructured interviews of 31 survivors of ABI. Thematic analysis followed a phenomenological approach and revealed 4 major themes and 28 subthemes in the interviews. Four participants stood out as exemplars of the themes embodied by all the participants in this investigation. Quotes from each are used to highlight the prevailing themes.

Results

The following 4 major themes emerged from the interviews: development of social support networks, grief and coping strategies, acceptance of the injury and redefinition of self, and empowerment.

Conclusions

The issues raised in these interviews may serve to inspire other survivors and provide them with hope and motivation as they progress through the recovery process. Suggestions on how clinicians can help to facilitate this process are discussed.
Does Race/Ethnicity Really Matter in Adult Neurogenics?
Authors: Ellis Charles
Published: November 2009

Purpose

Recent evidence suggests that race/ethnicity is a variable that is critical to outcomes in neurological disorders. The purpose of this article was to examine the proportion of studies published in the
American Journal of Speech-Language Pathology
(
AJSLP
) and the
Journal of Speech, Language, and Hearing Research
(
JSLHR
) that were designed to examine neurologically based disorders of communication in adults and that reported the race/ethnicity of the participants.

Method

A review of articles in
AJSLP
and
JSLHR
from 1997 through 2007 was completed to determine what proportion of articles in the area of adult neurogenic communication disorders reported the race/ethnicity of the participants.

Results

Between 1997 and 2007, less than 15% of the 116 articles published in the 2 journals reported the race/ethnicity of the participants. The review of studies indicates that the reporting of the race/ethnicity of participants in studies of adult neurogenic communication disorders remains inconsistent.

Conclusions

Because few studies report race/ethnicity or consider how race/ethnicity has the potential to confound the results and conclusions drawn, the generalization of the reported findings may be limited. Reporting race/ethnicity is likely critical to the external validity of studies in adult neurogenic communication disorders and when available can enhance the relevance of the findings reported.
Validation of an Inventory of Best Practices in the Provision of Augmentative and Alternative Communication Services to Students With Severe Disabilities in General Education Classrooms
Authors: Calculator Stephen N. , Black Tibbany
Published: November 2009

Purpose

To compile and then validate a set of evidence-based best practices related to augmentative and alternative communication (AAC) and its role in fostering the inclusion of students with severe disabilities in general education classrooms and other inclusive settings.

Method

A comprehensive review of the literature pertaining to AAC and inclusive education for students with severe disabilities in inclusive classrooms resulted in an inventory of possible best practices. Reliability testing was conducted to verify levels of evidence assigned to each source and corresponding practice. Practices were reviewed and validated by a panel of 8 experts. Statistical analysis revealed a high level of internal consistency across items composing the inventory.

Results

An inventory of 91 practices, each assigned to 1 of 8 predetermined categories, was uncovered. Themes arising in experts' comments related to items in the inventory are discussed.

Conclusions

Possible uses of the inventory are discussed along with suggestions for future research.