bluuebunny/crossref_metadata_2025 huggingface dataset:
Physical fitness assessment of older adults in the primary care setting
Authors: Purath Janet , Buchholz Susan W. , Kark Deborah L.
Published: February 2009

Purpose:  To explore the relationships between the physical fitness and the demographic characteristics, general health and well‐being, social support, and physical activity in a group of community‐dwelling older adults. This study also assessed the feasibility of obtaining physical fitness measures in the primary care setting.

Data sources:  Thirty‐four persons older than 60 years completed self‐report measures and the Senior Fitness Test (SFT), a battery of fitness measures normed for older adults. Self‐report measures included demographics, general health and well‐being (SF‐36), social support (Social Support for Physical Activity Scale), and physical activity levels (Physical Activity Scale for the Elderly).

Conclusions:  Physically active older adults had significantly better upper and lower body strength, aerobic endurance, and dynamic balance. Older adults who reported better general health and had fewer chronic conditions scored better on the physical fitness tests. The SFT took 10‐15 min to complete in the primary care setting.

Implications for practice:  Physical fitness measures give primary care providers objective information to develop a physical activity program for their patients. A physical activity program that includes recommendations for aerobic endurance, strength, flexibility, and/or balance that is based on objective findings may be a useful tool to promote better health and physical fitness in older adults.
Challenges in achieving 100% voluntary blood donation
Authors: Gabra G.
Published: February 2009

The call for voluntary non‐remunerated blood donation has been echoing around the globe for many years. Progress has been very slow particularly in countries with limited resources. The long‐term approach to build a sustainable supply of safe blood and blood products is often sacrificed when health facilities abdicate this responsibility to the patients and their relatives. The management of this community interface requires continued efforts, substantial resources as well as special studies and research in order to establish the appropriate approach to reach potential donors in these societies.

The organisational role, plans and strategy for community education, recruitment, donor care and actual blood collection, are all important in establishing a committed well informed donor base, if not more, than the altruism and motives of individual donors.
Blood‐derived biomaterials: fibrin sealant, platelet gel and platelet fibrin glue
Authors: Burnouf T. , Su C.‐Y. , Radosevich M. , Goubran H. , El‐Ekiaby M.
Published: February 2009

Blood‐derived biomaterials include fibrin sealant (FS) (also called fibrin glue), platelet gel (PG), and platelet fibrin glue. They are used in many surgical fields because of their functional properties and unique physical advantages compared to synthetic products. FS can be made industrially by the fractionation of large plasma pools, or from single plasma donations. Thanks to a high content in fibrinogen, FS exhibits, after activation by thrombin and formation of a strong fibrin clot, tissue sealing and haemostatic properties. PG and platelet fibrin glue are made from single blood donations (platelet concentrates combined or not with cryoprecipitate). Owing to their richness in platelet, PG and PFG can release, upon thrombin activation, a myriad of growth factors that can stimulate cell growth and differentiation, generating much interest for hard and soft tissues regeneration and healing, as well as, increasingly, cell therapy protocols to replace fetal bovine serum. Blood‐derived biomaterials have the advantages, over synthetic glues and other biomaterials, of being physiologically compatible with human tissues, and of not inducing tissue necrosis or other tissue reactions. They can be readily colonized by cells and are totally biodegradable in a matter of days to weeks. These blood‐derived biomaterials are used increasingly as tissue engineering tools, allowing surgeons to influence and improve thein vitroorin vivocellular environment to enhance the success of tissue grafting. We review here the three main types of biomaterials that can be made from human blood and describe their biochemical and physiological properties as well as their clinical applications.
Pathogen‐reduction methods: advantages and limits
Authors: Klein H. G. , Bryant B. J.
Published: February 2009

Pathogen‐reduction (inactivation) provides a proactive approach to reducing transfusion‐transmitted infection. Pathogen‐reduction technologies have been successfully implemented by plasma fractionators resulting in no transmission of human immunodeficiency, hepatitis C, or hepatitis B viruses by US‐licensed plasma derivatives since 1987. Fractionation technologies cannot be used to treat cellular blood components. Although blood donor screening, deferral and disease testing have drastically reduced the incidence of transfusion‐transmitted diseases, the threat of new or re‐emerging pathogens remains. Of particular concern is the silent emergence of a new agent with a prolonged latent period in which asymptomatic infected carriers would donate and spread infection. The ultimate goal of pathogen‐inactivation is to reduce transmission of potential pathogens without significantly compromising the therapeutic efficacy of the cellular and protein constituents of blood. The acceptable technology must not introduce toxicities into the blood supply nor result in neoantigen formation and subsequent antibody production. Several promising pathogen‐inactivation technologies are being developed and tested, and others are currently in use, but all of them have limits. Pathogen‐reduction promises an additional ‘layer of protection’ from infectious agents and has the potential to impact the safety of blood transfusions worldwide.
Alloimmunization to the platelet antigen human platelet antigen‐1a and characterization of the helper T‐cell responses in fetomaternal alloimmune thrombocytopenia
Authors: Urbaniak S. J.
Published: February 2009

The major cause of severe FMAIT in Caucasians is fetal‐maternal incompatibility for the human platelet antigen HPA‐1a, which leads to the production of maternal anti‐HPA‐1a alloantibodies that cross the placenta and cause thrombocytopenia. The estimated incidence of severe FMAIT is approximately 1 in 1100 neonates, and the clinical manifestations range from mild purpura to intracranial hemorrhage and death. At present, there are no preventative measures or antenatal routine screening procedures in place to identify women at risk of HPA‐1a alloimmunization, nor reliable predictors of severe fetal disease, although maternal responsiveness is associated with DR52a (DRB3*0101). Anti‐HPA‐1a production depends on antigen specific T helper lymphocytes that recognize HPA‐a peptides bound to MHC molecules on antigen‐presenting cells (APC). The core epitope on HPA‐1a responsible for the alloimmune response has been identified by a combination of functional studies with immune lymphocytes and helper T cell clones, peptide binding and antigen processing studies. This dominant epitope has the potential to prevent or reverse the anti‐HPA‐1a response in women if used to induce tolerance.
Hydrometeorological modelling for flash flood areas: the case of the 2002 Gard event in France
Authors: Anquetin S. , Ducrocq V. , Braud I. , Creutin J.‐D.
Published: February 2009

In the context of flash flood forecasting, this paper proposes a few advances in our understanding of the hydrometeorological processes and their associated modelling requirements that may be useful to introduce within an operational forecasting chain. The study is focused on the September 2002 storm that produced more than 600 mm of rainfall in <24 h and triggered a series of flash floods in the South of France. This catastrophic event took 23 human lives in 16 distinct subcatchments. This paper proposes a combined detailed analysis of the meteorological event and hydrological simulations of the response of four small‐ungauged catchments. The meteorological analyses are based on observations and results of simulation of rain fields obtained with the MesoNH model. These analyses explained the steadiness of the storms that led to a locally intense precipitation: the role of the orography and favourable synoptic conditions. The hydrological model is set up without any calibration and the soil parameter specification is based on an existing soil database. Radar rainfall estimations are used. Simulated specific peak discharges are found to be in agreement with estimations from a postevent in situ investigation. Based on the model results, a cartography of the dominant process is proposed for the four selected catchments.
Cannabidiol: A Promising Drug for Neurodegenerative Disorders?
Authors: Iuvone Teresa , Esposito Giuseppe , De Filippis Daniele , Scuderi Caterina , Steardo Luca
Published: February 2009

Neurodegenerative diseases represent, nowadays, one of the main causes of death in the industrialized country. They are characterized by a loss of neurons in particular regions of the nervous system. It is believed that this nerve cell loss underlies the subsequent decline in cognitive and motor function that patients experience in these diseases. A range of mutant genes and environmental toxins have been implicated in the cause of neurodegenerative disorders but the mechanism remains largely unknown. At present, inflammation, a common denominator among the diverse list of neurodegenerative diseases, has been implicated as a critical mechanism that is responsible for the progressive nature of neurodegeneration. Since, at present, there are few therapies for the wide range of neurodegenerative diseases, scientists are still in search of new therapeutic approaches to the problem. An early contribution of neuroprotective and antiinflammatory strategies for these disorders seems particularly desirable because isolated treatments cannot be effective. In this contest, marijuana derivatives have attracted special interest, although these compounds have always raised several practical and ethical problems for their potential abuse. Nevertheless, amongCannabiscompounds, cannabidiol (CBD), which lacks any unwanted psychotropic effect, may represent a very promising agent with the highest prospect for therapeutic use.
Pharmacology of Ramelteon, a Selective MT1/MT2Receptor Agonist: A Novel Therapeutic Drug for Sleep Disorders
Authors: Miyamoto Masaomi
Published: February 2009

An estimated one‐third of the general population is affected by insomnia, and this number is increasing due to more stressful working conditions and the progressive aging of society. However, current treatment of insomnia with hypnotics, gamma‐aminobutyric acid A (GABAA) receptor modulators, induces various side effects, including cognitive impairment, motor disturbance, dependence, tolerance, hangover, and rebound insomnia. Ramelteon (Rozerem; Takeda Pharmaceutical Company Limited, Osaka, Japan) is an orally active, highly selective melatonin MT1/MT2receptor agonist. Unlike the sedative hypnotics that target GABAAreceptor complexes, ramelteon is a chronohypnotic that acts on the melatonin MT1and MT2receptors, which are primarily located in the suprachiasmatic nucleus, the body's “master clock.” As such, ramelteon possesses the first new therapeutic mechanism of action for a prescription insomnia medication in over three decades. Ramelteon has demonstrated sleep‐promoting effects in clinical trials, and coupled with its favorable safety profile and lack of abuse potential or dependence, this chronohypnotic provides an important treatment option for insomnia.
The Use of a Synthetic Cannabinoid in the Management of Treatment‐Resistant Nightmares in Posttraumatic Stress Disorder (PTSD)
Authors: Fraser George A.
Published: February 2009

This is the report of an open label clinical trial to evaluate the effects of nabilone, an endocannabinoid receptor agonist, on treatment‐resistant nightmares in patients diagnosed with posttraumatic stress disorder (PTSD). Methods: Charts of 47 patients diagnosed with PTSD and having continuing nightmares in spite of conventional antidepressants and hypnotics were reviewed after adjunctive treatment with nabilone was initiated. These patients had been referred to a psychiatric specialist outpatient clinic between 2004 and 2006. The majority of patients (72%) receiving nabilone experienced either cessation of nightmares or a significant reduction in nightmare intensity. Subjective improvement in sleep time, the quality of sleep, and the reduction of daytime flashbacks and nightsweats were also noted by some patients. The results of this study indicate the potential benefits of nabilone, a synthetic cannabinoid, in patients with PTSD experiencing poor control of nightmares with standard pharmacotherapy. This is the first report of the use of nabilone (Cesamet; Valeant Canada, Ltd., Montreal, Canada) for the management of treatment‐resistant nightmares in PTSD.
Comparative Neuroprotective Properties of Stilbene and Catechin Analogs: Action Via a Plasma Membrane Receptor Site?
Authors: Bastianetto Stéphane , Dumont Yvan , Han Yingshan , Quirion Rémi
Published: February 2009

Various studies have reported on the neuroprotective effects of polyphenols, widely present in food, beverages, and natural products. For example, we have shown that resveratrol, a polyphenol enriched in red wine and other foods such as peanuts, protects hippocampal cells against β‐amyloid (Aβ)‐induced toxicity, a key protein involved in the neuropathology of Alzheimer disease. This effect involves, at least in part, the capacity of resveratrol to activate the phosphorylation of delta isoform of protein kinase C (PKC‐δ). The neuroprotective action of resveratrol is shared by piceatannol, a stilbene derivative, as well as by tea‐derived catechin gallate esters. The thioflavin T assay indicated that all these polyphenols inhibited the formation of Aβ fibrils, suggesting that this action likely also contributes to their neuroprotective effects. Binding and autoradiographic studies revealed that the effects of polyphenols might involve specific binding sites that are particularly enriched in the choroid plexus in the rat brain. Interestingly, the choroid plexus secretes transthyretin, a protein that has been shown to modulate Aβ aggregation and that may be critical to the maintenance of normal learning capacities in aging. Taken together, these data suggest that polyphenols target multiple enzymes/proteins, leading to their neuroprotective actions, possibly through action via specific plasma membrane binding sites.
Chronic Intestinal Inflammation and Intestinal Disease in Dogs
Authors: German A.J. , Hall E.J. , Day M.J.
Published: February 2009

Normal individuals maintain tolerance to the endogenous bacterial flora residing within their alimentary tract, a phenomenon mediated by the gastrointestinal lymphoid tissue. Loss of this tolerance is a key factor in the development of chronic intestinal inflammation. Manifestations of such uncontrolled inflammation in humans include inflammatory bowel disease and celiac disease. Dogs may similarly be affected, and although the etiopathogenesis is likely similar, the lesions differ. This review includes discussion of the factors involved in breakdown of mucosal tolerance, the immunologic basis of canine enteropathies, and the use of novel immunotherapies for these diseases.
Increased Mean Arterial Pressure and Aldosterone‐to‐Renin Ratio in Persian Cats with Polycystic Kidney Disease
Authors: Pedersen Karen M. , Pedersen Henrik D. , Haggstrom Jens , Koch Jørgen , Ersbøll Annette K.
Published: February 2009

Polycystic kidney disease (PKD) in Persian cats has been increasingly reported and compared to human autosomal dominant polycystic kidney disease (ADPKD) in the last decade. In cats, however, few studies have dealt with the occurrence and hormonal determinants of hypertension, one of the most common extrarenal manifestations of ADPKD in humans. The purpose of this study was to compare Persian cats >4 years old with PKD to unaffected control cats with regard to blood pressure (BP), plasma renin activity (PRA), serum aldosterone concentration, plasma atrial natriuretic peptide (ANP) concentration, and aldosterone‐to‐renin ratio (ARR). Three gender‐ and age‐matched groups were studied, each consisting of 7 cats: (1) a control group without cysts, (2) a group with mild PKD, and (3) a group with severe PKD (multiple cysts and renal enlargement). Mild renal insufficiency was found in only 1 of 14 cats with PKD. Cats with PKD had a higher mean arterial pressure(P= .04) and more often had a high ARR(P= .047) than did control cats. Tendencies toward higher diastolic and systolic arterial pressures (DAPs and SAPs, respectively) and lower PRAs were observed in cats with PKD compared to controls (.05 <P≥ .1). No significant differences were found between the groups in serum aldosterone and plasma ANP concentrations. None of the cats had echocardiographic evidence of cardiac hypertrophy. In conclusion, cats with PKD had a minor increase in mean arterial pressure compared to control cats, and half of the cats had a high ARR.
A Comparison of Dobutamine Infusion to Exercise as a Cardiac Stress Test in Healthy Horses
Authors: Frye M.A. , Bright J.M. , Dargatz D.A. , Fettman M.J. , Frisbie D.D. , Baker D.C. , Traub‐Dargatz J.L.
Published: February 2009

This study was done to determine whether administration of dobutamine would produce echocardiographic and electrocardiographic alterations comparable to those induced by treadmill exercise in healthy horses. Fourteen horses received maximal treadmill exercise and, separately, intravenous dobutamine infusion up to a maximum rate of 50 |xg/kg/min. Ten of the 14 horses were euthanized, and the myocardial tissues were examined grossly and histopathologically. No significant differences were found in the chronotropic effects of dobutamine and exercise(P=.905). Dobutamine induced greater interventricular septal thickening during systole (dobutamine=4.78 cm, exercise=4.03 cm;P=.004), and greater left ventricular diameters during diastole (dobutamine=9.73 cm, exercise=9.26 cm;P=.037), than did exercise treatment. Horses exhibited transient signs of sweating and restlessness during infusion of moderate to maximum doses of dobutamine. Ventricular ectopy seen in 11 of 14 horses was attributed to the arrhythmogenic properties of dobutamine, as well as to increased vagal tone present at low dobutamine doses. Myocardial lesions characteristic of catecholamine myotoxicity were present in 2 of the 10 horses examined. Although dobutamine induces chronotropic and inotropic changes similar to those induced by exercise, the use of high‐dose dobutamine as a cardiac stressor in horses cannot be advocated because of potential development of arrhythmias or myotoxicity.
Comparative Diagnostic Test Characteristics of Oscillometric and Doppler Ultrasonographic Methods in the Detection of Systolic Hypertension in Dogs
Authors: Stepien Rebecca L. , Rapoport Gregg S. , Henik Rosemary A. , Wenholz Lisa , Thomas Chester B.
Published: February 2009

Comparison of test characteristics allows a clinician to choose the optimal diagnostic test method for an individual patient. This study assessed the comparative test characteristics of noninvasive (NI) blood pressure measurement methods (oscillometric and Doppler) and used this information to develop optimal cutoff values for diagnosis of systolic hypertension in dogs by these NI methods. Simultaneous NI (oscillometric or Doppler methods) and invasive (arterial puncture [AP]) systolic blood pressure (SBP) measurements were obtained prospectively from normal dogs and dogs suspected of having systemic hypertension based on clinical signs. Oscillometric SBP readings were obtained from the distal hind limb (Osc‐L, n=54) or the proximal tail (T, n=27). Doppler BP measurements were obtained using a forelimb cuff (n = 57). AP‐SBP was categorized as hypertensive if a 160 mmHg, and sensitivity (Se), specificity (Sp), and likelihood ratios (LR) were calculated for diagnostic cutoff values ranging from 130 to 220 mmHg. Receiver operator characteristic (ROC) curves were analyzed to determine optimal cutoff values for diagnosis of AP‐SBP a 160 mmHg. Optimal NI SBP cutoff values considered to reflect AP values a 160 mmHg were: Osc‐L = 160 mmHg (Se: 65%, Sp: 85%, LR = 4.33:1), Osc‐T = 150 mmHg (Se: 84%, Sp: 75%, LR = 3.36:1), and Doppler = 160 mmHg (Se: 71%, Sp: 86%, LR: 5:1).
Treatment of Dogs with Oral Melanoma by Hypofractionated Radiation Therapy and Platinum‐Based Chemotherapy (1987–1997)
Authors: Freeman Kim P. , Hahn Kevin A. , Harris F. Dee , King Glen K.
Published: February 2009

This retrospective study in 39 dogs with incompletely resected oral melanoma examined the efficacy of hypofractionated radiation therapy and platinum‐containing chemotherapy. All dogs were completely staged, with the majority of dogs classified as stage I. Dogs received 6 weekly fractions of 6‐gray (Gy) megavoltage irradiation with a cobalt‐60 unit or a 4‐MeV (megaelectron volts) linear accelerator. Dogs received cisplatin (10–30 mg/m2IV) or carboplatin (90 mg/m2IV) chemotherapy 60 minutes before radiation delivery. Durations of local control, metastasis‐free survival time, and overall survival time were recorded. By the Kaplan‐Meier method, 15% of the dogs had local recurrence within a median time of 139 days. Fifty‐one percent of the dogs developed metastatic disease within a median time of 311 days (range, 24–2,163 days). Median survival time for all 39 dogs was 363 days. The combined use of chemotherapy and radiation therapy in this protocol provided local control consistent with previous studies. Low‐dose chemotherapy was used with the intent of enhancing radiation therapy for the local control of an incompletely excised tumor. Survival times were longer than previously reported for dogs with oral malignant melanoma. Additional studies are required to determine whether these results were due to the effects of chemotherapy on microscopic disease or the enhanced local control provided by chemoradiation therapy.
How fast could Usain Bolt have run? A dynamical study
Authors: Eriksen H. K. , Kristiansen J. R. , Langangen Ø. , Wehus I. K.
Published: February 2009

Since that memorable day at the Beijing 2008 Olympics, a big question has been, “What would the 100m dash world record have been had Usain Bolt not celebrated at the end of his race?” Bolt’s coach suggested that the time could have been 9.52s or better. We consider this question by measuring Bolt’s position as a function of time using footage of the run, and then extrapolate the last 2s with two different assumptions. First, we conservatively assume that Bolt could have maintained the runner-up’s acceleration during the end of the race. Second, based on the race development prior to the celebration, we assume that Bolt could have kept an acceleration of 0.5m∕s2 greater than the runner-up. We find that the new world record in these two cases would have been 9.61±0.04 and 9.55±0.04s, respectively, where the uncertainties denote 95% statistical errors.
Simulating a toy model of electrodynamics in (1+1) dimensions
Authors: Boozer A. D.
Published: February 2009

We show how to simulate a toy model of electrodynamics in (1+1) dimensions and describe several numerical experiments. The toy model is much simpler than ordinary electrodynamics, but shares many of the same physical features. For example, there are analogs to the electric and magnetic fields, and these fields generate forces between charged particles and support freely propagating radiation. Unlike electrodynamics, however, the toy model is not Lorentz invariant, gives an attractive force between charges of the same sign, and yields a radiation reaction force that depends on the particle velocity.
Laboratory exercises on oscillation modes of pipes
Authors: Haeberli Willy
Published: February 2009

This paper describes an improved lab setup to study the vibrations of air columns in pipes. Features of the setup include transparent pipes which reveal the position of a movable microphone inside the pipe; excitation of pipe modes with a miniature microphone placed to allow access to the microphone stem for open, closed, or conical pipes; and sound insulation to avoid interference between different setups in a student lab. The suggested experiments on the modes of open, closed, and conical pipes, the transient response of a pipe, and the effect of pipe diameter are suitable for introductory physics laboratories, including laboratories for nonscience majors and music students, and for more advanced undergraduate laboratories. For honors students or for advanced laboratory exercises, the quantitative relation between the resonance width and damping time constant is of interest.
A demonstration of rotating sound waves in free space and the transfer of their angular momentum to matter
Authors: Santillán Arturo O. , Volke-Sepúlveda Karen
Published: February 2009

We describe an apparatus for generating rotating sound waves in free space by superimposing two orthogonal standing modes with a quarter wave phase lag. The creation of a standing wave from the superposition of two counter-rotating waves is also possible with the same apparatus. The experiment permits direct measurement of both the amplitude and phase structure of the sound waves. A demonstration of angular momentum transfer from rotating acoustic waves to matter in free field is also described.
When Your Gain Is My Pain and Your Pain Is My Gain: Neural Correlates of Envy and Schadenfreude
Authors: Takahashi Hidehiko , Kato Motoichiro , Matsuura Masato , Mobbs Dean , Suhara Tetsuya , Okubo Yoshiro
Published: February 2009

We often evaluate the self and others from social comparisons. We feel envy when the target person has superior and self-relevant characteristics. Schadenfreude occurs when envied persons fall from grace. To elucidate the neurocognitive mechanisms of envy and schadenfreude, we conducted two functional magnetic resonance imaging studies. In study one, the participants read information concerning target persons characterized by levels of possession and self-relevance of comparison domains. When the target person's possession was superior and self-relevant, stronger envy and stronger anterior cingulate cortex (ACC) activation were induced. In study two, stronger schadenfreude and stronger striatum activation were induced when misfortunes happened to envied persons. ACC activation in study one predicted ventral striatum activation in study two. Our findings document mechanisms of painful emotion, envy, and a rewarding reaction, schadenfreude.
The Hallucinogen
N,N
-Dimethyltryptamine (DMT) Is an Endogenous Sigma-1 Receptor Regulator
Authors: Fontanilla Dominique , Johannessen Molly , Hajipour Abdol R. , Cozzi Nicholas V. , Jackson Meyer B. , Ruoho Arnold E.
Published: February 2009

The sigma-1 receptor is widely distributed in the central nervous system and periphery. Originally mischaracterized as an opioid receptor, the sigma-1 receptor binds a vast number of synthetic compounds but does not bind opioid peptides; it is currently considered an orphan receptor. The sigma-1 receptor pharmacophore includes an alkylamine core, also found in the endogenous compound
N,N
-dimethyltryptamine (DMT). DMT acts as a hallucinogen, but its receptor target has been unclear. DMT bound to sigma-1 receptors and inhibited voltage-gated sodium ion (Na
+
) channels in both native cardiac myocytes and heterologous cells that express sigma-1 receptors. DMT induced hypermobility in wild-type mice but not in sigma-1 receptor knockout mice. These biochemical, physiological, and behavioral experiments indicate that DMT is an endogenous agonist for the sigma-1 receptor.
Comment on "Dynamic Shifts of Limited Working Memory Resources in Human Vision"
Authors: Cowan Nelson , Rouder Jeffrey N.
Published: February 2009

Bays and Husain (Reports, 8 August 2008, p. 851) reported that human working memory, the limited information currently in mind, reflects resources distributed across all items in an array. In an alternative interpretation, memory is limited to several well-represented items. We argue that this item-limit model fits the extant data better than the distributed-resources model and is more interpretable theoretically.
Tracking Long-Distance Songbird Migration by Using Geolocators
Authors: Stutchbury Bridget J. M. , Tarof Scott A. , Done Tyler , Gow Elizabeth , Kramer Patrick M. , Tautin John , Fox James W. , Afanasyev Vsevolod
Published: February 2009

We mapped migration routes of migratory songbirds to the Neotropics by using light-level geolocators mounted on breeding purple martins (Progne subis) and wood thrushes (Hylocichla mustelina). Wood thrushes from the same breeding population occupied winter territories within a narrow east-west band in Central America, suggesting high connectivity of breeding and wintering populations. Pace of spring migration was rapid (233 to 577 kilometers/day) except for one individual (159 kilometers/day) who took an overland route instead of crossing the Gulf of Mexico. Identifying songbird wintering areas and migration routes is critical for predicting demographic consequences of habitat loss and climate change in tropical regions.
Skyrmion Lattice in a Chiral Magnet
Authors: Mühlbauer S. , Binz B. , Jonietz F. , Pfleiderer C. , Rosch A. , Neubauer A. , Georgii R. , Böni P.
Published: February 2009

Skyrmions represent topologically stable field configurations with particle-like properties. We used neutron scattering to observe the spontaneous formation of a two-dimensional lattice of skyrmion lines, a type of magnetic vortex, in the chiral itinerant-electron magnet MnSi. The skyrmion lattice stabilizes at the border between paramagnetism and long-range helimagnetic order perpendicular to a small applied magnetic field regardless of the direction of the magnetic field relative to the atomic lattice. Our study experimentally establishes magnetic materials lacking inversion symmetry as an arena for new forms of crystalline order composed of topologically stable spin states.
Differences in Early Gesture Explain SES Disparities in Child Vocabulary Size at School Entry
Authors: Rowe Meredith L. , Goldin-Meadow Susan
Published: February 2009

Children from low–socioeconomic status (SES) families, on average, arrive at school with smaller vocabularies than children from high-SES families. In an effort to identify precursors to, and possible remedies for, this inequality, we videotaped 50 children from families with a range of different SES interacting with parents at 14 months and assessed their vocabulary skills at 54 months. We found that children from high-SES families frequently used gesture to communicate at 14 months, a relation that was explained by parent gesture use (with speech controlled). In turn, the fact that children from high-SES families have large vocabularies at 54 months was explained by children's gesture use at 14 months. Thus, differences in early gesture help to explain the disparities in vocabulary that children bring with them to school.
Bounties from Biomarkers
Authors: Freeman Katherine H.
Published: February 2009

Echoes of Life
. What Fossil Molecules Reveal About Earth History.
By Susan M. Gaines, Geoffrey Eglinton, and Jürgen Rullkötter
. Oxford University Press, New York, 2009. 375 pp. $35, £18.99. ISBN 9780195176193.

Writing for the interested nonspecialist, the authors interweave an account of the development of biomarker research and sketches of what these fossil organic molecules tell us about the histories of Earth and life.
Omnidirectional Printing of Flexible, Stretchable, and Spanning Silver Microelectrodes
Authors: Ahn Bok Y. , Duoss Eric B. , Motala Michael J. , Guo Xiaoying , Park Sang-Il , Xiong Yujie , Yoon Jongseung , Nuzzo Ralph G. , Rogers John A. , Lewis Jennifer A.
Published: February 2009

Flexible, stretchable, and spanning microelectrodes that carry signals from one circuit element to another are needed for many emerging forms of electronic and optoelectronic devices. We have patterned silver microelectrodes by omnidirectional printing of concentrated nanoparticle inks in both uniform and high–aspect ratio motifs with minimum widths of approximately 2 micrometers onto semiconductor, plastic, and glass substrates. The patterned microelectrodes can withstand repeated bending and stretching to large levels of strain with minimal degradation of their electrical properties. With this approach, wire bonding to fragile three-dimensional devices and spanning interconnects for solar cell and light-emitting diode arrays are demonstrated.
Bonding between the cesium cation and substituted benzoic acids or benzoate anions in the gas phase: A density functional theory and mass spectrometric study
Authors: Mayeux Charly , Massi Lionel , Gal Jean-François , Maria Pierre-Charles , Tammiku-Taul Jaana , Lohu Ene-Liis , Burk Peeter
Published: February 2009

Substituent effects on the formation of cesium cation complexes with a series of 17 benzoic acids (AH), benzoates (A–), and the ion pairs (Cs+A–) are studied by density functional theory (DFT) and mass spectrometry. This study is positioned in the context of the fate of cesium in the environment, with emphasis of the influence of natural organic matter and humic substances. The bond length Cs+-(carboxylic O) in the various adduct geometries are discussed as regards the interaction strength, but quantitative relationships are limited by secondary effects arising mostly from long-distance interactions in systems bearing polar groups in meta-position. Relative cesium cation affinities of [Cs+A–] were experimentally determined by the kinetic method, i.e. by dissociating the required cesium cluster formed by electrospray ionization in a quadrupole ion-trap. Experiments and calculations are in agreement, except for the adducts derived from 3- and 4-hydroxybenzoic acids. A change in the localization of the negative charge is proposed as a possible explanation for the divergence.
A hybrid method applied to a 2.5D scalar wave equation
Authors: Daley P. F. , Krebes E. S. , Lines L. R.
Published: February 2009

The 3D acoustic wave equation for a heterogeneous medium is used for the seismic modeling of compressional (P-) wave propagation in complex subsurface structures. A combination of finite difference and finite integral transform methods is employed to obtain a “2.5D” solution to the 3D equation. Such 2.5D approaches are attractive because they result in computational run times that are substantially smaller than those for the 3D finite difference method. The acoustic parameters of the medium are assumed to be constant in one of the three Cartesian spatial dimensions. This assumption is made to reduce the complexity of the problem, but still retain the salient features of the approach. Simple models are used to address the computational issues that arise in the modeling. The conclusions drawn can also be applied to the more general fully inhomogeneous problem. Although similar studies have been carried out by others, the work presented here is new in the sense that (i) it applies to subsurface models that are both vertically and laterally heterogeneous, and (ii) the computational issues that need to be addressed for efficient computations, which are not trivial, are examined in detail, unlike previous works. We find that it is feasible to generate true-amplitude synthetic seismograms using the 2.5D approach, with computational run times, storage requirements, and other factors, being at reduced and acceptable levels.
The impact of double-crested cormorant (Phalacrocorax auritus) predation on anadromous alewife (Alosa pseudoharengus) in south-central Connecticut, USA
Authors: Dalton Christopher M. , Ellis David , Post David M.
Published: February 2009

The decline of anadromous alewife ( Alosa pseudoharengus ) threatens an important recreational and commercial fishery. While the cause of this decline is uncertain, predators could be trapping alewives at low abundance by preying on them during spawning migrations. Here we investigate the impact of predation by double-crested cormorants ( Phalacrocorax auritus ) on spawning adult alewives in south-central Connecticut, USA. We use a bioenergetic model together with estimates of cormorant diets and cormorant and alewife population sizes to estimate the consumption of alewives by cormorants both in Bride Lake, Connecticut, and regionally. We find that cormorants are important predators of spawning adult alewives at Bride Lake but do not have a notable impact on alewife mortality or population size. We also find that cormorants have little effect on alewife populations across south-central Connecticut because few alewives are consumed away from Bride Lake. We conclude that cormorants are important predators for anadromous alewives, but do not pose an immediate threat to the recovery of regional alewife stocks.
Nutrient limitation of phytoplankton growth in Arctic lakes of the lower Mackenzie River Basin, northern Canada
Authors: Ogbebo Fortune E. , Evans Marlene S. , Waiser Marley J. , Tumber Vijay P. , Keating Jonathan J.
Published: February 2009

Water chemistry and the nutrients limiting phytoplankton growth were examined in lakes located in the Northwest Territories, Canada, along a transect from the Mackenzie River Delta south to Travaillant Lake. This 230 km stretch spans gradients in vegetation types (tundra to boreal forest) and elevation (flooded by the Mackenzie River versus higher elevation lakes). Total phosphorus concentrations generally were typical of oligotrophic lakes (<10 µg·L–1), while nitrate and orthophosphate concentrations were below detection limits. Although some growth was noted in bioassays receiving single additions of nitrogen (N) or phosphorus (P), the greatest growth occurred in those bioassays in which nitrogen and phosphorus were added. This suggests that phytoplankton in the majority of study lakes were strongly co-limited by N and P irrespective of watershed type and Mackenzie River influence. Furthermore, it suggests that algal communities will be highly responsive to anthropogenic disturbances, which result in increased N and P loading to these lakes. Experimental results from March bioassays suggest that anthropogenic eutrophication would be exacerbated by increased temperatures (e.g., those associated with global warming).
Impacts of road access on lake trout (Salvelinus namaycush) populations: regional scale effects of overexploitation and the introduction of smallmouth bass (Micropterus dolomieu)
Authors: Kaufman Scott D. , Snucins Ed , Gunn John M. , Selinger Wayne
Published: February 2009

In lake trout ( Salvelinus namaycush ) lakes of northeastern Ontario, Canada, aerial surveys of fishing activity on individual lakes (N = 589) and quantitative gillnet surveys (N = 65) were used to assess the effects of road access on angling effort and the presence of introduced smallmouth bass ( Micropterus dolomieu ). Angling effort, particularly during the open-water season, was highest and often exceeded estimated sustainable levels on lakes with good road access. Approximately 25% of the remote lakes also received excessive pressure during the winter season. Angler numerical responses to lake trout abundance were detected in remote lakes, but not in road-accessible lakes. Smallmouth bass were more prevalent in lakes with road access and human settlement (either cottages or lodges), supporting the theory that they were introduced into these lakes. Lake trout populations were depleted throughout much of the study range. Even without road access or smallmouth bass, lake trout abundance was still 47% lower than in unexploited reference lakes. When bass and (or) road access were present, lake trout abundance decreased by 77%. Remote lake trout populations in this area are clearly vulnerable to the negative impacts of improved access, a vector for both overexploitation and species introductions.
Effect of flow rules and elastic strains on pressuremeter test results in dense sand
Authors: Silvestri Vincenzo , Abou-Samra Ghassan , Bravo-Jonard Christian
Published: February 2009

Simple numerical methods that allow to obtain stress and strain paths in sand during self-boring pressuremeter tests are presented in this paper. The material is considered to undergo deformation in drained and plane-strain conditions. The flow rules of Rowe, Cambridge-type (Cam clay and Nova) model, and the sawtooth model are used in the analysis. Elastic strains are also considered in relation with the flow rule of Rowe. The proposed approach has been evaluated using a reference pressuremeter test performed on Ticino sand in a calibration chamber. The results indicate that the stress–strain–volume change responses of the sand predicted by the various models are quite similar, with and without consideration of the elastic strain components.
Three-dimensional numerical analysis of centrifuge experiments on a model jack-up drilling rig on sand
Authors: Bienen B. , Cassidy M. J.
Published: February 2009

Jack-up drilling rigs are usually founded on three shallow footings. Under wind, wave, and current loading offshore, the footings of these tall multi-footing systems transfer large moment loads in addition to self-weight, horizontal load, and even torsion to the underlying soil. To be able to deploy a jack-up safely at a particular offshore site, the unit’s capacity to withstand a 50 year return period storm is required to be checked in accordance with current guidelines (Site specific assessment of mobile jack-up units, The Society of Naval Architects & Marine Engineers). As the overall system behaviour is influenced significantly by the footing restraint, models that account for the complex nonlinear foundation–soil interaction behaviour are required to be integrated with the structural and loading models. Displacement-hardening plasticity theory has been suggested as an appropriate framework to formulate force-resultant models to predict shallow foundation behaviour. Recent research has extended such a model to account for six degree-of-freedom loading of circular footings on sand, allowing integrated structure–soil analysis in three dimensions. This paper discusses “class A” numerical predictions of experiments on a model jack-up in a geotechnical centrifuge, using the integrated modelling approach, and critically evaluates the predictive performance. The numerical simulations are shown to represent a significant improvement compared with the method outlined in the current guidelines.
Swelling characteristics of bentonites in artificial seawater
Authors: Komine Hideo , Yasuhara Kazuya , Murakami Satoshi
Published: February 2009

Bentonite is currently designated for use as a buffer material for the repository of high-level radioactive waste because such a material requires swelling characteristics to seal the waste. A high-level radioactive waste disposal facility may be built in a coastal area of Japan because transportation of this waste by ships is feasible. Therefore, it is important to investigate the effects of seawater on a bentonite-based buffer. This study is intended to investigate the influence of seawater on the swelling pressure and swelling deformation characteristics of five common types of bentonite. The experiments described herein clarify the relations between the influence of seawater grade and compaction density, type of exchangeable cation, montmorillonite content of the bentonite, and vertical pressure condition. Based on experimental results, suitable specifications have been defined for a bentonite-based buffer that can withstand the effects of seawater.
Thaw–Consolidation of Some Layered Systems
Authors: Nixon John F.
Published: February 2009

In order to assess the stability and deformation qualities of thawing arctic soils, a theory of thaw–consolidation must be established to predict the dissipation of excess pore fluids. The predictive power of current mathematical models is considerably enhanced by consideration of some common departures from homogeneity. In the first instance a permafrost profile of two different soil types is analyzed numerically, each layer having different thermal and geotechnical properties. The presence of a surficial layer, although minor in extent, may influence for a considerable time the behavior of the underlying layer. Secondly, the excess pore pressures in a fine-grained soil overlying an ice layer are treated theoretically, and the results suggest that foundation conditions over a thawing ice layer may not be as critical as sometimes is supposed.
Volume Displacement Effects on Pile Capacity in Loose Sand
Authors: Robinsky Eli I. , Cragg Christopher B. H.
Published: February 2009

Preliminary tests in the new large-scale testing facility at the University of Toronto reveal that bearing capacity on a pile volume basis is more efficiently developed by a long slender pile or a group of short slender piles than by a pile of larger diameter. The authors attribute this to increased arching in the soil around the pile of greater volume displacement, believing arching buffers the pile from the effects of lateral soil pressure.
True Shear Parameters of Saturated Clays
Authors: Sridharan A. , Rao S. Narasimha
Published: February 2009

Ever since Hvorslev proposed a failure criterion incorporating intrinsic parameters, several test procedures have come into practice to determine these ‘true’ strength parameters. Several consolidated undrained triaxial compression tests with pore water pressure measurement were conducted on both montmorillonite and kaolinite clays and the results were analyzed using different existing methods. All the methods through which the data were analyzed fail to assign any unique true strength parameters. Even a particular method yields different values depending upon the initial conditions (stress history, water content) of the sample and stress level during testing. It has been reasoned that these variations are due to the probable differences in fabric between the samples which are involved in various methods. There seems to be a unique linear relationship between tan [Formula: see text] and Cc/pe irrespective of the sample state, stress level, and stress history in both undisturbed and remolded conditions for all the procedures adopted.
A DFT study of thymine and its tautomers
Authors: Jiao Dongsheng , Wang Hongyan , Zhang Yanlan , Tang Yu
Published: February 2009

The structures and the relative energies of six possible tautomers of the thymine base have been studied by density functional theory (DFT) using the B3LYP and BP86 functionals. The keto-thymine (T1) is predicted to be the most stable thymine tautomer, which is consistent with the other theoretical results and experimental data. The corresponding thymine cations and anions are studied using the same level of theory with double-ζ plus polarization and diffuse functions (DZP++) basis sets. The ionization potentials (IPs), the electron affinities (EAs), and proton affinities (PAs) for different protonation sites in thymine base are obtained. T1 has the largest ionization potential and the lowest proton affinity among all the considered thymine tautomers.
Chemical constituents from the bark of Anisopus mannii
Authors: Tsopmo Apollinaire , Kamnaing Pierre , Watchueng Jean , Gao Jin-Ming , Konishi Yasuo , Sterner Olov
Published: February 2009

A minor novel 1,7-naphthyridine alkaloid with an unprecedented skeleton, named anisopusine (1), was isolated from the CH2Cl2 soluble materials of an acetone extract of the bark of Anisopus mannii (Asclepiadaceae) together with four known compounds 5α-hydroxy-lup-20(29)-en-3β-yl eicosanoate (2), [6]-gingerdione (3), [6]-dehydrogingerdione (4), and ferulic acid (5). Their structures were determined on the basis of spectroscopic data, including 1D and 2D NMR, HR-EI-MS. Compounds (2–5) were characterized for the first time from this genus.