bluuebunny/crossref_metadata_2025 huggingface dataset:
DECAY SPECTRUM OF K+ → e+νeγ
Authors: CHEN C. H. , GENG C. Q. , LIH C. C.
Published: September 2008

The form factors of the K+ → γ transition are studied in the light-front quark model and chiral perturbation theory of O(p6). The decay spectrum of K+ → e+νeγ, dominated by the structure dependent contribution, is illustrated in both models.
SOME MASS RELATIONS IN CHARMONIUM
Authors: KONG YANMEI , SHAN HONGYUN , ZHANG AILIN
Published: September 2008

Regge trajectories and hyperfine splitting relations among spin-singlets and spin-triplets in charmonium spectrum were studied. Some interesting conclusions were obtained from the combination of these relations. Especially, the newly observed X(3872) and the old ψ(3836) were analyzed.
RECENT RESULTS ON B DECAYS AT BELLE
Authors: CHEON BYUNGGU
Published: September 2008

We present the recent B decay results from BELLE experiment operated at the asymmetric e+e− KEKB collider in the energy of ϒ(4S) resonance. In this report, we mainly mention the B decays including multineutrinos sensitive on beyond Standard Model, and new charged charmonium-like state from B hadronic decays, which should be explained in the future.
CHARMLESS 3-BODY B DECAYS: RESONANT AND NONRESONANT CONTRIBUTIONS
Authors: CHENG HAI-YANG
Published: September 2008

Charmless 3-body decays of B mesons are studied using a simple model based on the framework of the factorization approach. We have identified a large source of the nonresonant signal in the matrix elements of scalar densities, e.g. [Formula: see text]. This explains the dominance of the nonresonant background in B → KKK decays, the sizable nonresonant fraction of order (35 ~ 40)% in K−π+π− and [Formula: see text] modes and the smallness of nonresonant rates in B → πππ decays. We have computed the resonant and nonresonant contributions to charmless 3-body decays and determined the rates for the quasi-two-body decays B → VP and B → SP. Time-dependent CP asymmetries sin 2β eff and ACP in K+K−KS, KSKSKS, KSπ+π− and KSπ0π0 modes are estimated.
SEMILEPTONIC B(Bs, Bc) DECAYS IN THE LIGHT-CONE QCD SUM RULES
Authors: HUANG TAO , LI ZUO-HONG , WU XING-GANG , ZUO FEN
Published: September 2008

Semileptonic B(Bs, Bc) decays are investigated systematically in the light-cone QCD sum rules. Special emphasis is put on the LCSR calculation on weak form factors with an adequate chiral current correlator, which turns out to be particularly effective to control the pollution by higher twist components of spectator mesons. The result for each channel depends on the distribution amplitude of the the producing meson. The leading twist distribution amplitudes of the related heavy mesons and charmonium are worked out by a model approach in the reasonable way. A practical scenario is suggested to understand the behavior of weak form factors in the whole kinematically accessible ranges. The decay widths and branching ratios are estimated for several B(Bc) decay modes of current interest.
pQCD STUDY FOR SOME B → J/ψP DECAYS
Authors: XIAO ZHEN-JUN , LIU XIN
Published: September 2008

We here report our recent calculations for the branching ratios of B → J/ψP decays. The pQCD factorization approach are used to calculate both the factorizable and spectator Feynman diagrams.
CHARMLESS HADRONIC B AND Bs DECAYS IN PERTURBATIVE QCD APPROACH
Authors: LÜ CAI-DIAN
Published: September 2008

We review the perturbative QCD approach study of hadronic B decays. Utilizing the constrained parameters in these well measured decay channels, we study most of the possible charmless Bs → PP, PV and VV decay channels in the perturbative QCD approach. In addition to the branching ratios and CP asymmetries, we also give predictions to the polarization fractions of the vector meson final states. The size of SU (3) breaking effect is also discussed. These predictions can be tested by the future LHCb experiment.
RADIATIVE M1-TRANSITIONS OF HEAVY MESONS IN LIGHT-FRONT QUARK MODEL
Authors: CHOI HO-MEOYNG
Published: September 2008

We present the magnetic dipole(M1) transitions V → Pγ of various heavy-flavored mesons such as [Formula: see text] and [Formula: see text] using the light-front quark model constrained by the variational principle for the QCD-motivated effective Hamiltonian. Our numerical results for the radiative decay widths are in good agreement with the available experimental data as well as other theoretical model calculations.
CP VIOLATION AT BABAR
Authors:   for the BaBar Collaboration, YÈCHE CHRISTOPHE
Published: September 2008

We report recent measurements of the three CKM angles of the Unitarity Triangle using about 383 millions [Formula: see text] pairs collected with the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC.
EXTRACTING THE CKM PHASE ANGLE γ(≡ φ3) FROM ISOSPIN ANALYSIS IN B → Kπ DECAY
Authors: KIM C. S. , OH SECHUL , YOON YEO WOONG
Published: September 2008

We propose a new method to extract the CKM phase angle γ(≡ φ3) from the isospin analysis in B → Kπ decays only. Unlike previously proposed methods, we do not employ flavor SU (3) symmetry, so that this method is free from the hadronic uncertainty coming from the SU (3) breaking effect. Neither we adopt any Dalitz-plot analysis, which may involve multiple strong phases and large final state interactions. Since no theoretical assumption, except the isospin relations, is imposed on B → Kπ decays, this method will work well, regardless of possible new physics effects unless the isospin relations do not hold. Since the mixing induced CP asymmetry SKSπ0 plays a crucial role in this method, more precise measurement on SKSπ0 in future experiments will be greatly helpful to extract γ accurately. Using current experimental data for B → Kπ including SKSπ0, we extract γ within [Formula: see text] or [Formula: see text].
RECENT RESULTS IN b QUARK PHYSICS AT CDF
Authors: FARRINGTON SINÉAD M.
Published: September 2008

The summer 2007 results in b quark physics in 0.7 to 2.2 fb −1 of CDFII data are summarised. Results in b production, mixing, new observations and branching ratio measurements are discussed.
THE THEORETICAL STATUS OF $\bar{B} - B$-MIXING AND LIFETIMES OF HEAVY HADRONS
Authors: LENZ ALEXANDER
Published: September 2008

In this talk we review the theoretical status of the lifetime ratios of heavy hadrons and of the B-mixing quantities ΔMs, ΔΓs and φs. While ΔMs and ΔΓs suffer from large uncertainties due to the badly known decay constants, the ratio ΔΓs/ΔMs can be determined with almost no non-perturbative uncertainties, therefore it can be used to look for possible new physics effects.
THE PHYSICS PROSPECTS AND STATUS OF THE LHCb EXPERIMENT
Authors:   for the LHCb Collaboration, HARNEW NEVILLE
Published: September 2008

This paper summarises the B-physics prospects of the LHCb experiment. The focus is on the uniqueness of LHCb over and above the B-factories and the Tevatron experiments: the measurement of the unitarity angle γ using a number of complementary methods, the measurement of the [Formula: see text] mixing phase φs in tree and penguin decay modes, and the expected observation of the rare decay mode [Formula: see text] below Standard Model predictions.
$D - \bar{D}$ MIXING FROM NEUTRINO MIXING IN SUSY FLIPPED SU(5) MODEL
Authors: LIAO WEI
Published: September 2008

We point out that in SUSY flipped SU(5) model the bilarge neutrino mixing which can be accommodated in the lepton Yukawa couplings can induce interesting flavor mixings for the left-handed charged slepton and right-handed up-type squark. FCNC processes such as τ → μ + γ, [Formula: see text] mixing and t → u, c + h0 are predicted.
UNPARTICLE PHYSICS AND NEUTRAL MESON MIXING
Authors: WEI ZHENG-TAO
Published: September 2008

The concept of exact and broken scale invariance is discussed. We give a brief introduction to unparticle physics. The neutral meson mixing can be caused by exchange of unparticle at the tree level. The constraints on interaction between unparticle and SM quarks are discussed.
ELECTROWEAK SYMMETRY BREAKING AND COLD DARK MATTER FROM HIDDEN SECTOR TECHNICOLORS
Authors: KO PYUNGWON
Published: September 2008

We consider models with a vectorlike confining gauge theory in the hidden sector, and demonstrate that the origin of the electroweak symmetry breaking (EWSB) is due to the dimensional transmutation in the hidden sector gauge theory, and the lightest mesons in the hidden sector could be a good cold dark matter (CDM) candidate. There would be more than one neutral Higgs-like scalar bosons, and they could decay mainly into the CDM pair, if that decay channel is kinemtically allowed.
RECENT RESULTS FROM THE SUPER-KAMIOKANDE EXPERIMENT
Authors: CHEN SHAOMIN
Published: September 2008

This talk presents the current status of the Super-Kamiokande experiment, including the recent results on atmospheric, solar and supernova neutrino physics. Also presented are the searches on ΔB ≠ 0 transition processes and the future prospects.
GENERALIZED FRIEDBERG-LEE MODEL FOR NEUTRINO MASSES AND LEPTONIC CP VIOLATION FROM μ-τ SYMMETRY BREAKING
Authors: XING ZHI-ZHONG , ZHANG HE , ZHOU SHUN
Published: September 2008

Assuming the Majorana nature of massive neutrinos, we generalize the Friedberg-Lee neutrino mass model to include CP violation in the neutrino mass matrix Mν. The most general case with all the free parameters of Mν being complex is discussed. We show that a favorable neutrino mixing pattern (with θ12 ≈ 35.3°, θ23 = 45°, θ13 ≠ 0° and δ = 90°) can naturally be derived from Mν, if it has an approximate or softly-broken μ-τ symmetry. We also point out a different way to obtain the nearly tri-bimaximal neutrino mixing pattern with δ = 0° and non-vanishing Majorana phases.
LONG BASELINE NEUTRINO EXPERIMENTS WITH TWO-DETECTOR SETUP
Authors: MINAKATA HISAKAZU
Published: September 2008

I discuss why and how powerful is the two-detector setting in neutrino oscillation experiments. I cover three concrete examples: (1) reactor θ13 experiments, (2) T2KK, Tokai-to-Kamioka-Korea two-detector complex for measuring CP violation, determining the neutrino mass hierarchy, and resolving the eight-fold parameter degeneracy, (3) two-detector setting in a neutrino factory at baselines 3000 km and 7000 km for detecting effects of non-standard interactions (NSI) of neutrinos.
CUORE EXPERIMENT: THE SEARCH FOR NEUTRINOLESS DOUBLE BETA DECAY
Authors: PEDRETTI MARISA , BARUCCI M. , RISEGARI L. , VENTURA G. , DI DOMIZIO S. , OTTONELLO P. , PALLAVICINI M. , BALATA M. , BUCCI C. , GIACHERO A. , GORLA P. , NISI S. , TATANANNI E. L. , TOMEI C. , ZARRA C. , ANDREOTTI E. , FOGGETTA L. , GIULIANI A. , SALVIONI C. , KEPPEL G. , MENEGATTI P. , PALMIERI V. , RAMPAZZO V. , ALESSANDRIA F. , ARNABOLDI C. , BROFFERIO C. , CAPELLI S. , CARBONE L. , CARRETTONI M. , CLEMENZA M. , CREMONESI O. , FIORINI E. , GIRONI L. , KRAFT S. , NONES C. , NUCCIOTTI A. , PAVAN M. , PESSINA G. , PIRRO S. , PREVITALI E. , SCHAEFFER D. , SISTI M. , ZANOTTI L. , ARDITO R. , MAIERN G. , BELLINI F. , COSMELLI C. , DAFINEI I. , FACCINI R. , FERRONI F. , GARGIULO C. , LONGO E. , MORGANTI S. , OLCESE M. , VIGNATI M. , MARTINEZ M. , BEEMAN J. , BRYANT A. , DECOWSKI M. P. , FREEDMAN S. J. , GUARDINCERRI E. , HALLER E. E. , KADEL R. , KOGLER L. , KOLOMENSKY YU. G. , SMITH A. R. , XU N. , DOLINSKI M. J. , KAZKAZ K. , NORMAN E. B. , SCIELZO N. D. , HUANG H. Z. , TRENTALANGE S. , WHITTEN C. , GUTIERREZ T. D. , AVIGNONE F. T. , BANDAC I. , CRESWICK R. J. , FARACH H. A. , MARTINEZ C. , MIZOUNI L. , ROSENFELD C. , EJZAK L. , HEEGER K. M. , MARUYAMA R. H. , SANGIORGIO S.
Published: September 2008

The main purpose of the Cryogenic Underground Observatory for Rare Events (CUORE) experiment is the search for the Neutrinoless Double Beta Decay (0νDBD) of 130 Te reaching a sensitivity on Majorana mass better than 50 meV. Cuoricino represents not only the first stage of CUORE, but also the most massive 0νDBD experiment presently running. Present results and future planning of these experiments will be described in the paper.
QUINTESSENTIAL KINATION AND LEPTOGENESIS
Authors: CHUN EUNG JIN , SCOPEL STEFANO
Published: September 2008

We analyze leptogenesis in the background of a quintessential kination scenario1 in which the wash-out parameter K, defined as the ratio between the right handed neutrino (RHN) decay rate and the Hubble parameter, can be as low as K ≃ 10−7 even with the effective neutrino mass [Formula: see text]. Successful leptogenesis places a limit on the temperature Tr below which kination stops to dominate and radiation takes over; [Formula: see text] where M is the RHN mass.
CPT CONSERVING COSMOLOGICAL BIREFRINGENCE
Authors: GENG C. Q. , HO S. H. , NG J. N.
Published: September 2008

We demonstrate that the cosmological birefringence can arise from CPT conserving effect, originated from the CPT-even dimension-six Chern-Simons-like term. We show that a sizable rotation polarization angle in the data of the cosmic microwave background radiation polarization can be induced.
TeV-SCALE TYPE-II SEESAW MODELS AND POSSIBLE COLLIDER SIGNATURES
Authors: CHAO WEI , LUO SHU , XING ZHI-ZHONG , ZHOU SHUN
Published: September 2008

A natural extension of the standard model to accommodate massive neutrinos is to introduce one Higgs triplet and three right-handed Majorana neutrinos, leading to a 6×6 neutrino mass matrix. We show that three light Majorana neutrinos (i.e., the mass eigenstates of νe, νμ and ντ) are exactly massless, if and only if [Formula: see text] exactly holds in this seesaw model. We propose three simple Type-II seesaw scenarios with broken A4 × U(1)x flavor symmetry to interpret the observed neutrino mass spectrum and neutrino mixing pattern. Such a TeV-scale neutrino model can be tested in two complementary ways: (1) searching for possible collider signatures of lepton number violation induced by the right-handed Majorana neutrinos and doubly-charged Higgs particles; and (2) searching for possible consequences of unitarity violation of the 3 × 3 neutrino mixing matrix in the future long-baseline neutrino oscillation experiments.
What Drives the Cash Dividend Policy of the Poorly Performing Firms in Hong Kong?
Authors: Cheng Louis T. W. , Fung Hung-Gay , Leung T. Y.
Published: September 2008

We use financial data on poorly performing firms in Hong Kong to examine the motives behind paying out cash dividends when they suffer an earnings decline. We test three hypotheses behind the cash dividend policy: the maturity hypothesis, the free cash flow hypothesis, and the self-interest hypothesis of directors (i.e., the cash channeling hypothesis of directors). The findings are largely consistent with the maturity hypothesis and the free cash flow hypothesis but do not support the cash channeling hypothesis, confirming good market transparency and governance of the Hong Kong market.
The α-subunit of AMPK is essential for submaximal contraction-mediated glucose transport in skeletal muscle in vitro
Authors: Lefort Natalie , St.-Amand Emmanuelle , Morasse Sébastien , Côté Claude H. , Marette André
Published: September 2008

AMP-activated protein kinase (AMPK) is a key signaling protein in the regulation of skeletal muscle glucose uptake, but its role in mediating contraction-induced glucose transport is still debated. The effect of contraction on glucose transport is impaired in EDL muscle of transgenic mice expressing a kinase-dead, dominant negative form of the AMPKα2subunit (KD-AMPKα2mice). However, maximal force production is reduced in this muscle, raising the possibility that the defect in glucose transport was due to a secondary decrease in force production and not impaired AMPKα2activity. Generation of force-frequency curves revealed that muscle force production is matched between wild-type (WT) and KD-AMPKα2mice at frequencies ≤50 Hz. Moreover, AMPK activation is already maximal at 50 Hz in muscles of WT mice. When EDL muscles from WT mice were stimulated at a frequency of 50 Hz for 2 min (200-ms train, 1/s, 30 volts), contraction caused an ∼3.5-fold activation of AMPKα2activity and an ∼2-fold stimulation of glucose uptake. Conversely, whereas force production was similar in EDL of KD-AMPKα2animals, no effect of contraction was observed on AMPKα2activity, and glucose uptake stimulation was reduced by 50% ( P < 0.01) As expected, 5-aminoimidazole-4-carboxamide-1-β-d-ribofuranosyl 5′-monophosphate (AICAR) caused a 2.3-fold stimulation of AMPKα2activity and a 1.7-fold increase in glucose uptake in EDL from WT mice, whereas no effect was detected in muscle from KD-AMPKα2mice. These data demonstrate that AMPK activation is essential for both AICAR and submaximal contraction-induced glucose transport in skeletal muscle but that AMPK-independent mechanisms are also involved.
The ubiquitin-proteasome and the mitochondria-associated apoptotic pathways are sequentially downregulated during recovery after immobilization-induced muscle atrophy
Authors: Vazeille Emilie , Codran Audrey , Claustre Agnès , Averous Julien , Listrat Anne , Béchet Daniel , Taillandier Daniel , Dardevet Dominique , Attaix Didier , Combaret Lydie
Published: September 2008

Immobilization produces morphological, physiological, and biochemical alterations in skeletal muscle leading to muscle atrophy and long periods of recovery. Muscle atrophy during disuse results from an imbalance between protein synthesis and proteolysis but also between apoptosis and regeneration processes. This work aimed to characterize the mechanisms underlying muscle atrophy and recovery following immobilization by studying the regulation of the mitochondria-associated apoptotic and the ubiquitin-proteasome-dependent proteolytic pathways. Animals were subjected to hindlimb immobilization for 4–8 days (I4 to I8) and allowed to recover after cast removal for 10–40 days (R10 to R40). Soleus and gastrocnemius muscles atrophied from I4 to I8 to a greater extent than extensor digitorum longus and tibialis anterior muscles. Gastrocnemius muscle atrophy was first stabilized at R10 before being progressively reduced until R40. Polyubiquitinated proteins accumulated from I4, whereas the increased ubiquitination rates and chymotrypsin-like activity of the proteasome were detectable from I6 to I8. Apoptosome and caspase-3 or -9 activities increased at I6 and I8, respectively. The ubiquitin-proteasome-dependent pathway was normalized early when muscle stops to atrophy (R10). By contrast, the mitochondria-associated apoptotic pathway was first downregulated below basal levels when muscle started to recover at R15 and completely normalized at R20. Myf 5 protein levels decreased from I4 to I8 and were normalized at R10. Altogether, our results suggest a two-stage process in which the ubiquitin-proteasome pathway is rapidly up- and downregulated when muscle atrophies and recovers, respectively, whereas apoptotic processes may be involved in the late stages of atrophy and recovery.
Central blockade of oxytocin receptors during mid-late gestation reduces amplitude of slow afterhyperpolarization in supraoptic oxytocin neurons
Authors: Teruyama R. , Lipschitz D. L. , Wang L. , Ramoz G. R. , Crowley W. R. , Bealer S. L. , Armstrong W. E.
Published: September 2008

The neurohypophysial hormone oxytocin (OT), synthesized in magnocellular paraventricular (PVN) and supraoptic (SON) nuclei, is well known for its effects in lactation. Our previous studies showed that central OT receptor (OTR) binding is increased during gestation and that blockade of central OTRs, specifically during mid-late gestation, causes a delay in OT release during suckling and reduces weight gain in pups, suggesting decreased milk delivery. In the present study, we tested whether central OTR blockade during late gestation disrupts the gestation-related plasticity in intrinsic membrane properties. Whole cell current-clamp recordings were performed in OT neurons from pregnant rats (19–22 days in gestation) that were infused with an OTR antagonist (OTA) or artificial cerebrospinal fluid (aCSF) and from virgin rats infused with aCSF into the third ventricle via an osmotic minipump beginning on days 12–14 of gestation. The amplitudes of both Ca2+-dependent afterhyperpolarizations (AHPs), an apamin-sensitive medium AHP (mAHP) and an apamin-insensitive slow AHP (sAHP), were significantly increased during late gestation in control pregnant animals. However, the amplitude of the sAHP from pregnant rats treated with the OTA was significantly smaller than that of pregnant control rats and similar to that of virgins. These results indicate that the diminished efficiency in lactation due to OTR blockade may be partly a result of an altered sAHP that would shape OT bursting. These findings suggest that central actions of OT during late gestation are necessary for programming the plasticity of at least some of the intrinsic membrane properties in OT neurons during lactation.
Telemetric signal-driven servocontrol of renal perfusion pressure in acute and chronic rat experiments
Authors: Xia Min , Li Pin-Lan , Li Ningjun
Published: September 2008

The present study was designed to take advantage of telemetry data acquisition and develop an easy and reliable system to servocontrol renal perfusion pressure (RPP). Digitized pressure signals from lower abdominal aorta in rats, reflecting RPP, was obtained by a telemetry device and dynamically exported into an Excel worksheet. A computer program (LabVIEW) compared the RPP data with a preselected pressure range and drove a bidirectional syringe pump to control the inflation of a vascular occluder around the aorta above renal arteries. When RPP was higher than the preselected range, the syringe pump inflated the occluder and decreased RPP, and vice versa. If RPP was within range, there was no action. In this way, RPP was servocontrolled within the desired range. In experiments with norepinephrine- or ANG II-induced acute increases in systemic arterial pressure (120–145 mmHg), the system controlled RPP at a constant range of 100–105 mmHg within 30–50 s and differentiated the pressure-dependent and -independent effects on renal functions. In Dahl S rats with high-salt-induced hypertension, this system maintained RPP at 100–120 mmHg over 10 days, while systemic arterial pressures were 150 ± 5.9 mmHg in uncontrolled animals. This system also has the ability of simultaneity and multiplexing to control multiple animals. Our results suggest that this is an effective and reliable system to servocontrol RPP, which can be easily established with general computer knowledge. This system provides a powerful tool and may greatly facilitate the studies in pressure-dependent/-independent effects of a variety of cardiovascular factors.
A Cerebellar Deficit in Sensorimotor Prediction Explains Movement Timing Variability
Authors: Bo Jin , Block Hannah J. , Clark Jane E. , Bastian Amy J.
Published: September 2008

A popular theory is that the cerebellum functions as a timer for clocking motor events (e.g., initiation, termination). Consistent with this idea, cerebellar patients have been reported to show greater deficits during hand movements that repeatedly start and stop (i.e., discontinuous movements) compared with continuous hand movements. Yet, this finding could potentially be explained by an alternate theory in which the cerebellum acts as an internal model of limb mechanics. We tested whether a timing or internal model hypothesis best explains results from a circle-drawing task, where individuals trace a circle with the hand at a desired tempo. We first attempted to replicate prior results showing greater impairment for discontinuous versus continuous circling movements, and then asked whether we could improve patient performance by reducing demands in each domain. First, we slowed the movement down to reduce the need to predict and compensate for limb dynamics. Second, we supplied external timing information to reduce the need for an internal event timer. Results showed that we did not replicate the previous findings—cerebellar patients were impaired in both discontinuous and continuous movements. Slowing the movement improved cerebellar performance to near control values. The addition of an external visual timing signal paradoxically worsened timing deficits rather than mitigating them. One interpretation of these combined results is that the cerebellum is indeed functioning as an internal model and is needed to make appropriate predictions for movement initiation and termination.
Control of Predictive Error Correction During a Saccadic Double-Step Task
Authors: Sharika K. M. , Ramakrishnan Arjun , Murthy Aditya
Published: September 2008

We explored the nature of control during error correction using a modified saccadic double-step task in which subjects cancelled the initial saccade to the first target and redirected gaze to a second target. Failure to inhibit was associated with a quick corrective saccade, suggesting that errors and corrections may be planned concurrently. However, because saccade programming constitutes a visual and a motor stage of preparation, the extent to which parallel processing occurs in anticipation of the error is not known. To estimate the time course of error correction, a triple-step condition was introduced that displaced the second target during the error. In these trials, corrective saccades directed at the location of the target prior to the third step suggest motor preparation of the corrective saccade in parallel with the error. To estimate the time course of motor preparation of the corrective saccade, further, we used an accumulator model (LATER) to fit the reaction times to the triple-step stimuli; the best-fit data revealed that the onset of correction could occur even before the start of the error. The estimated start of motor correction was also observed to be delayed as target step delay decreased, suggesting a form of interference between concurrent motor programs. Taken together we interpret these results to indicate that predictive error correction may occur concurrently while the oculomotor system is trying to inhibit an unwanted movement and suggest how inhibitory control and error correction may interact to enable goal-directed behaviors.
High-Resolution Three-Dimensional Microelectrode Brain Mapping Using Stereo Microfocal X-ray Imaging
Authors: Cox David D. , Papanastassiou Alexander M. , Oreper Daniel , Andken Benjamin B. , DiCarlo James J.
Published: September 2008

Much of our knowledge of brain function has been gleaned from studies using microelectrodes to characterize the response properties of individual neurons in vivo. However, because it is difficult to accurately determine the location of a microelectrode tip within the brain, it is impossible to systematically map the fine three-dimensional spatial organization of many brain areas, especially in deep structures. Here, we present a practical method based on digital stereo microfocal X-ray imaging that makes it possible to estimate the three-dimensional position of each and every microelectrode recording site in “real time” during experimental sessions. We determined the system's ex vivo localization accuracy to be better than 50 μm, and we show how we have used this method to coregister hundreds of deep-brain microelectrode recordings in monkeys to a common frame of reference with median error of <150 μm. We further show how we can coregister those sites with magnetic resonance images (MRIs), allowing for comparison with anatomy, and laying the groundwork for more detailed electrophysiology/functional MRI comparison. Minimally, this method allows one to marry the single-cell specificity of microelectrode recording with the spatial mapping abilities of imaging techniques; furthermore, it has the potential of yielding fundamentally new kinds of high-resolution maps of brain function.
Transcriptomic analysis of PPARα-dependent alterations during cardiac hypertrophy
Authors: Smeets Pascal J. H. , de Vogel-van den Bosch Heleen M. , Willemsen Peter H. M. , Stassen Alphons P. , Ayoubi Torik , van der Vusse Ger J. , van Bilsen Marc
Published: September 2008

Peroxisome proliferator-activated receptor (PPAR)α regulates lipid metabolism at the transcriptional level and modulates the expression of genes involved in inflammation, cell proliferation, and differentiation. Although PPARα has been shown to mitigate cardiac hypertrophy, knowledge about underlying mechanisms and the nature of signaling pathways involved is fragmentary and incomplete. The aim of this study was to identify the processes and signaling pathways regulated by PPARα in hearts challenged by a chronic pressure overload by means of whole genome transcriptomic analysis. PPARα−/− and wild-type mice were subjected to transverse aortic constriction (TAC) for 28 days, and left ventricular gene expression profile was determined with Affymetrix GeneChip Mouse Genome 430 2.0 arrays containing >45,000 probe sets. In unchallenged hearts, the mere lack of PPARα resulted in 821 differentially expressed genes, many of which are related to lipid metabolism and immune response. TAC resulted in a more pronounced cardiac hypertrophy and more extensive changes in gene expression (1,910 and 312 differentially expressed genes, respectively) in PPARα−/− mice than in wild-type mice. Many of the hypertrophy-related genes were related to development, signal transduction, actin filament organization, and collagen synthesis. Compared with wild-type hypertrophied hearts, PPARα−/− hypertrophied hearts revealed enrichment of gene clusters related to extracellular matrix remodeling, immune response, oxidative stress, and inflammatory signaling pathways. The present study therefore demonstrates that, in addition to lipid metabolism, PPARα is an important modulator of immune and inflammatory response in cardiac muscle.
Definition and Classification of Acute Kidney Injury
Authors: Kellum John A. , Bellomo Rinaldo , Ronco Claudio
Published: September 2008

Changes in urine output and glomerular filtration rate are neither necessary nor sufficient for the diagnosis of renal pathology. Yet no simple alternative for the diagnosis currently exists. Until recently, there has been no consensus as to diagnostic criteria or clinical definition of acute renal failure. Depending on the definition used, acute renal failure has been reported to affect from 1 to 25% of ICU patients and has led to mortality rates from 15 to 60%. The RIFLE criteria were developed to standardize the diagnosis of acute renal failure and in the process the term acute kidney injury (AKI) has been proposed to encompass the entire spectrum of the syndrome from minor changes in renal function to requirement for renal replacement therapy. Thus, AKI is not acute renal failure but a more general description. Small changes in kidney function in hospitalized patients are important and are associated with significant changes in short and possibly long-term outcomes. The RIFLE criteria provide a uniform definition of AKI and have now been validated in numerous studies.
The Epidemiology of Severe Acute Kidney Injury: from BEST to PICARD, in Acute Kidney Injury: New Concepts
Authors: Pisoni Roberto , Wille Keith M. , Tolwani Ashita J.
Published: September 2008

Various definitions of acute kidney injury (AKI) exist, making comparisons among studies difficult. Despite this, significant changes have occurred in the epidemiology of AKI during the last decade. Recent studies, including PICARD and BEST, have examined the epidemiology of ICU-related AKI in the USA and worldwide, respectively, and found that AKI remains a major cause of morbidity and mortality. The incidence of AKI has increased, most likely due to a trend toward older, more severely and chronically ill patients admitted to the hospital. Sepsis and multi-organ system failure continue to be strongly associated with AKI, as well as pre-morbid chronic kidney disease. The proportion of patients with AKI requiring dialysis is high. The mortality of ICU-related AKI, although still very elevated, may be decreasing. Understanding these changes, in the context of standardized definitions, will be essential for the design of successful interventional studies.
Biomarkers for the Diagnosis of Acute Kidney Injury
Authors: Waikar Sushrut S. , Bonventre Joseph V.
Published: September 2008

The identification of acute kidney injury relies on tests like blood urea nitrogen and serum creatinine that were identified and incorporated into clinical practice several decades ago. This review summarizes clinical studies of newer biomarkers that may permit earlier and more accurate identification of acute kidney injury. The urine may contain sensitive and specific markers of kidney injury that are present due to either impaired tubular reabsorption and catabolism of filtered molecules or release of tubular cell proteins in response to ischemic or nephrotoxic injury. Many potential markers have been studied. Promising injury markers in the urine include N-acetyl-β-D-glucosaminidase, neutrophil gelatinase-associated lipocalin, kidney injury molecule-1, and interleukin-18. New biomarkers of kidney injury hold the promise of substantially improving the diagnostic approach to acute kidney injury. Adequately powered clinical studies of multiple biomarkers are needed to qualify the biomarkers before they can be fully adopted in clinical practice. Once adopted, more sensitive biomarkers of acute kidney injury hold the potential to transform the care of patients with renal disease.
Phenotype Characterization and DSPP Mutational Analysis of Three Brazilian Dentinogenesis Imperfecta Type II Families
Authors: Acevedo A.C. , Santos L.J.S. , Paula L.M. , Dong J. , MacDougall M.
Published: September 2008

The aim of this study was to perform phenotype analysis and dentin sialophosphoprotein (DSPP) mutational analysis on 3 Brazilian families diagnosed with dentinogenesis imperfecta type II (DGI-II) attending the Dental Anomalies Clinic in Brasilia, Brazil. Physical and oral examinations, as well as radiographic and histopathological analyses, were performed on 28 affected and unaffected individuals. Clinical, radiographic and histopathological analyses confirmed the diagnosis of DGI-II in 19 individuals. Pulp stones were observed in ground sections of several teeth in 2 families, suggesting that obliteration of pulp chambers and root canals results from the growth of these nodular structures. Mutational DSPP gene analysis of representative affected family members revealed 7 various non-disease-causing alterations in exons 1–4 within the dentin sialoprotein domain. Further longitudinal studies are necessary to elucidate the progression of pulpal obliteration in the DGI-II patients studied as well as the molecular basis of their disease.
Baseline Staging of Melanoma with Unknown Primary Site: The Value of Serum S100 Protein and Positron Emission Tomography
Authors: Oberholzer Patrick A. , Urosevic Mirjana , Steinert Hans C. , Dummer Reinhard
Published: September 2008

Background: Baseline staging is important in all melanoma types, including melanoma with unknown primary site (MUP). Staging includes different examination strategies, each with different accuracy. Objective: To determine the value of serum S100 protein levels and positron emission tomography (PET) in the baseline staging of MUP. Methods: Twenty patients with MUP were evaluable for the analysis between 1996 and 2007 with both S100 assessment and PET performed for baseline staging. Results: Serum S100 was elevated in 7 patients (35%). The PET scan detected the metastases in 6 of 7 patients with elevated serum S100 protein showing a strong correlation (p = 0.005). Patients with metastases had significantly higher serum S100 levels (p = 0.01) than the ones without. Serum S100 protein was shown to be discriminative between patients with and without metastases (receiver-operating characteristic, p = 0.012) with 75% sensitivity and 92% specificity. Conclusion: Serum S100 protein appears to be a sensitive as well as specific marker to detect metastases. We therefore might recommend serum S100 assessment to be included in the baseline staging of MUP.
Cell Therapy for Age-Related Disorders: Myocardial Infarction and Stroke – A Mini-Review
Authors: Williams Brent A. , Keating Armand
Published: September 2008

Background: The leading causes of death and disability in the elderly are from cardiovascular and cerebrovascular diseases. The biological role of stem cells in the hematopoietic system has been well characterized and has led to the development of hematopoietic stem and progenitor cell (HSPC) transplantation for the treatment of numerous malignant and nonmalignant diseases. More recently, stem cells have been found in many other tissues of the body including the heart and brain. As the field of stem cell biology has progressed, cell therapies for the treatment of myocardial infarction and stroke have been tested in early stage clinical trials using a variety of cellular agents. Objective: To review the clinical evidence supporting the role of cell therapies for myocardial infarction and stroke. Methods: A systematic review of the literature was conducted to identify clinical trials using cell therapies for myocardial infarction and stroke. Results: Clinical trials of granulocyte colony-stimulating factor to mobilize HSPC after percutaneous coronary intervention for acute myocardial infarction have not shown clinical benefit. Direct delivery of HSPC to coronary arteries supplying the infarcted region using percutaneous coronary intervention does improve hemodynamic endpoints such as left ventricular ejection fraction in many studies. One randomized trial demonstrated improvement in clinically meaningful endpoints such as death, recurrence of myocardial infarction and re-hospitalization for heart failure. Several small trials of cell therapy for stroke have been reported, including cytokine-mobilized HSPC, mesenchymal stromal cells and cell lines transplanted stereotactically into the region affected by stroke. Conclusions: In some prospective randomized trials, cell therapy for myocardial infarction leads to improvement in hemodynamic parameters. Cell therapy for stroke is a relatively new area of translational and clinical research with preliminary studies showing safety and some measurable benefit in small numbers of subjects.
Changes in Neuropsychological Functioning during Alcohol Detoxification
Authors: Manning V. , Wanigaratne S. , Best D. , Hill R.G. , Reed L.J. , Ball D. , Marshall J. , Gossop M. , Strang J.
Published: September 2008

This study investigates changes in neuropsychological functioning during early abstinence from alcohol. 30 alcohol-dependent inpatients were tested at intake (day 4 of admission) and post detoxification (day 26), using a test-retest design. The neuropsychological battery included measures of pre-morbid IQ, full-scale IQ, verbal and non-verbal measures of memory and executive function. IQ was within the normal range at intake and comparable with age-adjusted normative values and there were some impairments in memory and executive function. There were significant increases in performance scores post detoxification in working memory, verbal fluency and verbal inhibition but not in non-verbal executive function tasks (mental flexibility and planning ability). Despite increased scores on tests of verbal and memory skills after 3 weeks of abstinence, complex executive abilities showed little change. These may have a negative impact on engagement and response to treatment and compromise clinical outcomes, heightening the risk of relapse.
Ecology of Female Social Relationships: Hanuman Langurs (Presbytis entellus) and the van Schaik Model
Authors: Borries Carola
Published: September 2008

The ecological model of Carel van Schaik provides clear predictions for female-female relationships in relation to scramble or contest within-group competition and contest between-group competition. These predictions were applied to data from a 12-year field study on Hanuman langurs (Presbytis entellus) that ranged freely around Jodhpur (India). It appears that hierarchical relationships between females (unstable, inconsistent, individualistic, with low rates of agonistic coalitions) reflect scramble within-group competition. Such competition, however, results in individual evolutionary advantages (differential feeding time; differential reproductive success) so that dominance effects mirror contest within-group competition. Between-group contest competition at Jodhpur is strong (low predator pressure, high population density, good food defensibility, essential role of females during intergroup encounters, loud vocalization of males). The results are discussed in the light of langur feeding habits.
Effects of Tourists on Barbary Macaques at Gibraltar
Authors: O’Leary Helen , Fa John E.
Published: September 2008

Interactions between tourists and Barbary macaques (Macaca sylvanus) at Queen’s Gate, Gibraltar, are described. Interaction rates are high, with 99.6 interactions/h at peak times. Macaques spend 13.2% of their day interacting with tourists and 41.9% inactive. An overall ratio of 3.2:1 between human-initiated and macaque-initiated interactions was found. Of interactions involving humans, 85% concerned tourists. Diurnal activity patterns of the macaques were adapted to tourist visitation patterns. Old animals initiated more food-related interactions than younger ones. Infants/juveniles were the commonest class in contacts with humans and vehicles. Interactions involving more than one macaque were rare. High interaction rates were recorded for mothers and babies.
Annual Birth Patterns of Savanna Baboons (Papio cynocephalus anubis) over a Ten-Year Period at Gilgil, Kenya
Authors: Bercovitch Fred B. , Harding Robert S O.
Published: September 2008

Most cercopithecines reproduce on a seasonal basis, but the proximate mechanisms influencing birth periodicity are often unclear. We analyze 10 years of data from the Gilgil Baboon Project (Kenya) in order to examine the relationship between annual birth patterns and rainfall. Savanna baboons at Gilgil copulated in all months of the year, and births did not occur on a seasonal basis. Annual rainfall patterns showed no association with annual birth patterns, but the chances of conception were significantly greater following the end of the long rainy season than at other times of the year. Nonseasonal reproduction is a general characteristic of savanna baboons (Pαpio cynocephalus subsp.) throughout Africa. The extreme dietary diversity of baboons enables them to utilize a wide variety of resources and facultatively manipulate the timing of different stages in the reproductive cycle in accordance with resource availability. We predict that nonseasonality of reproduction will be more likely to occur among species with a large dietary diversity than among species with a more restricted diet.
Social Organization in a Wild Population of Callithrix jacchus
Authors: Digby Leslie J. , Barreto Claudio E.
Published: September 2008

Data are presented on group dynamics in a wild population of the common marmoset, Callithrix jacchus, in northeastern Brazil. Three marked and habituated groups were observed, and composition noted, for at least 5 days a month over 12–18 consecutive months. Group sizes ranged from 5 to 15 individuals, and changes in group composition were the result of births, emigrations, and disappearances. No immigrations into the main study groups were observed throughout the study period. None of the three known emigrants was known to join an established or incipient group for up to 10 weeks after their departure. One group contained only breeding individuals and their offspring. Observations of recruitment and loss in the other two groups suggest that they, too, were extended family groups. The group dynamics described in studies of other populations of Callithrix suggest that extended family groups, or at least groups consisting of breeding individuals and their close relatives, may be characteristic of those populations.
The Giant Aye-Aye Daubentonia robusta
Authors: Simons E.L.
Published: September 2008

Subfossils of a giant form of aye-aye are found at scattered sites in the south and southwest of the island of Madagascar, outside the known distribution of the living, or common, aye-aye. The subfossil aye-aye, named Daubentonia robusta, has massive, robust limb bones implying a species with a body weight 2.5-5 times as great as that of the living species. A mystery exists regarding how a species this large with the same specializations of teeth and manus as the living species could have existed in a xeric environment.
Evidence for Nonseasonal Reproduction in Wild Aye-Ayes (Daubentonia madagascariensis)
Authors: Sterling Eleanor J.
Published: September 2008

The lemurs of Madagascar typically exhibit a strictly seasonal pattern of breeding, with a limited number of successive estrous cycles occurring at a particular time of the year, which varies from species to species. Previous reports indicated that aye-ayes also exhibit such a strictly seasonal polyestrous pattern. Data from the author’s 2-year field study of aye-ayes on the island of Nosy Mangabe, combined with information from recently initiated captive breeding programs, now indicate that this species in fact shows an extended breeding season or even year-round breeding. Actual mating or signs of estrus were observed in the field throughout a 5-month period (October–February). Further, data from captured pregnant females and young offspring indicate that births take place during the period from February to September. Apart from aye-ayes, extended breeding periods have been reported for wild Eulemur coronatus and for captive Eulemur fulvus and Mirza coquereli. Analysis of information on seasonal variation in food availability for aye-ayes and other lemurs provides no clear evidence that the degree of seasonality of breeding is directly dependent on ecological factors.
Maintenance and Breeding of Aye-Ayes (Daubentonia madagascariensis) in Captivity: A Review
Authors: Carroll J. Bryan , Haring David M.
Published: September 2008

The husbandry practices of the 3 institutions currently holding captive aye-ayes outside Madagascar (Jersey Wildlife Preservation Trust, Duke University Primate Center and Paris Zoo) are reviewed. Information on housing, diet, oestrous cycles and infant rearing is included. Aye-ayes are active, nocturnal animals that are mainly solitary in the wild. They need large cages that are well furnished with arboreal substrates. Captive diet consists of fruit, nuts, insects and a pellet- or cereal-based gruel. Breeding of aye-ayes occurs either within stable pairs of animals or in pairs that are mixed only during the peri-ovulatory period.
Preliminary Study of the Sexual Behaviour of Three Aye-Ayes (Daubentonia madagascariensis) in Captivity
Authors: Winn Renée M.
Published: September 2008

This paper deals with the process of mating among captive aye-ayes (Daubentonia madagascariensis). Data on sexual behaviour of 3 wild-caught aye-ayes were collected over a period of 3 years (1986-1989). The group of 2 adult females and a young male was housed at the Vincennes Zoo, Paris. The seasonal poly-oestrous sexual cycle was found to be marked by four clear phases of the females’ vulval tumescence and coincided with sexual interest shown by both sexes. The external genitalia of the females are described, as are marking behaviour and sexual behaviour patterns before, during and after copulation. The behaviour and sexual cycles of these 2 females were compared with records from other lemurs.