Showing papers by "Stony Brook University published in 2001"
TL;DR: In this article, it was shown that the likelihood ratio statistic based on the Kullback-Leibler information criterion of the null hypothesis that a random sample is drawn from a k 0 -component normal mixture distribution against the alternative hypothesis that the sample was drawn from an k 1 -component normalized mixture distribution is asymptotically distributed as a weighted sum of independent chi-squared random variables with one degree of freedom, under general regularity conditions.
Abstract: We demonstrate that, under a theorem proposed by Vuong, the likelihood ratio statistic based on the Kullback-Leibler information criterion of the null hypothesis that a random sample is drawn from a k 0 -component normal mixture distribution against the alternative hypothesis that the sample is drawn from a k 1 -component normal mixture distribution is asymptotically distributed as a weighted sum of independent chi-squared random variables with one degree of freedom, under general regularity conditions. We report simulation studies of two cases where we are testing a single normal versus a two-component normal mixture and a two-component normal mixture versus a three-component normal mixture. An empirical adjustment to the likelihood ratio statistic is proposed that appears to improve the rate of convergence to the limiting distribution.
3,531 citations
TL;DR: Meta-analysis is used to synthesize data on the response of soil respiration, net N mineralization, and aboveground plant productivity to experimental ecosystem warming at 32 research sites representing four broadly defined biomes, including high (latitude or altitude) tundra, low tundara, grassland, and forest.
Abstract: Climate change due to greenhouse gas emissions is predicted to raise the mean global temperature by 1.0–3.5°C in the next 50–100 years. The direct and indirect effects of this potential increase in temperature on terrestrial ecosystems and ecosystem processes are likely to be complex and highly varied in time and space. The Global Change and Terrestrial Ecosystems core project of the International Geosphere-Biosphere Programme has recently launched a Network of Ecosystem Warming Studies, the goals of which are to integrate and foster research on ecosystem-level effects of rising temperature. In this paper, we use meta-analysis to synthesize data on the response of soil respiration, net N mineralization, and aboveground plant productivity to experimental ecosystem warming at 32 research sites representing four broadly defined biomes, including high (latitude or altitude) tundra, low tundra, grassland, and forest. Warming methods included electrical heat-resistance ground cables, greenhouses, vented and unvented field chambers, overhead infrared lamps, and passive night-time warming. Although results from individual sites showed considerable variation in response to warming, results from the meta-analysis showed that, across all sites and years, 2–9 years of experimental warming in the range 0.3–6.0°C significantly increased soil respiration rates by 20% (with a 95% confidence interval of 18–22%), net N mineralization rates by 46% (with a 95% confidence interval of 30–64%), and plant productivity by 19% (with a 95% confidence interval of 15–23%). The response of soil respiration to warming was generally larger in forested ecosystems compared to low tundra and grassland ecosystems, and the response of plant productivity was generally larger in low tundra ecosystems than in forest and grassland ecosystems. With the exception of aboveground plant productivity, which showed a greater positive response to warming in colder ecosystems, the magnitude of the response of these three processes to experimental warming was not generally significantly related to the geographic, climatic, or environmental variables evaluated in this analysis. This underscores the need to understand the relative importance of specific factors (such as temperature, moisture, site quality, vegetation type, successional status, land-use history, etc.) at different spatial and temporal scales, and suggests that we should be cautious in "scaling up" responses from the plot and site level to the landscape and biome level. Overall, ecosystem-warming experiments are shown to provide valuable insights on the response of terrestrial ecosystems to elevated temperature.
1,988 citations
TL;DR: In this paper, the upper crustal abundances of several trace elements, including rare earth elements (REEs), were compared to the upper continental crust of the United States, and the results showed that no revisions are needed for these elements.
Abstract: [1] Estimates of the average composition of various Precambrian shields and a variety of estimates of the average composition of upper continental crust show considerable disagreement for a number of trace elements, including Ti, Nb, Ta, Cs, Cr, Ni, V, and Co. For these elements and others that are carried predominantly in terrigenous sediment, rather than in solution (and ultimately into chemical sediment), during the erosion of continents the La/element ratio is relatively uniform in clastic sediments. Since the average rare earth element (REE) pattern of terrigenous sediment is widely accepted to reflect the upper continental crust, such correlations provide robust estimates of upper crustal abundances for these trace elements directly from the sedimentary data. Suggested revisions to the upper crustal abundances of Taylor and McLennan [1985] are as follows (all in parts per million): Sc = 13.6, Ti = 4100, V = 107, Cr = 83, Co = 17, Ni = 44, Nb = 12, Cs = 4.6, Ta = 1.0, and Pb = 17. The upper crustal abundances of Rb, Zr, Ba, Hf, and Th were also directly reevaluated and K, U, and Rb indirectly evaluated (by assuming Th/U, K/U, and K/Rb ratios), and no revisions are warranted for these elements. In the models of crustal composition proposed by Taylor and McLennan [1985] the lower continental crust (75% of the entire crust) is determined by subtraction of the upper crust (25%) from a model composition for the bulk crust, and accordingly, these changes also necessitate revisions to lower crustal abundances for these elements.
1,643 citations
TL;DR: In this article, Buchdahl and Tolman showed that the moment of inertia and the binding energy of a neutron star are nearly universal functions of the star's compactness, which can be understood by considering two analytic, yet realistic, solutions of Einstein's equations.
Abstract: The structure of neutron stars is considered from theoretical and observational perspectives We demonstrate an important aspect of neutron star structure: the neutron star radius is primarily determined by the behavior of the pressure of matter in the vicinity of nuclear matter equilibrium density In the event that extreme softening does not occur at these densities, the radius is virtually independent of the mass and is determined by the magnitude of the pressure For equations of state with extreme softening or those that are self-bound, the radius is more sensitive to the mass Our results show that in the absence of extreme softening, a measurement of the radius of a neutron star more accurate than about 1 km will usefully constrain the equation of state We also show that the pressure near nuclear matter density is primarily a function of the density dependence of the nuclear symmetry energy, while the nuclear incompressibility and skewness parameters play secondary roles In addition, we show that the moment of inertia and the binding energy of neutron stars, for a large class of equations of state, are nearly universal functions of the star's compactness These features can be understood by considering two analytic, yet realistic, solutions of Einstein's equations, by, respectively, Buchdahl and Tolman We deduce useful approximations for the fraction of the moment of inertia residing in the crust, which is a function of the stellar compactness and, in addition, the pressure at the core-crust interface
1,354 citations
TL;DR: A reflection on the results indicates that HA coatings can promote earlier and stronger fixation but exhibit a durability that can be related to the coating quality.
Abstract: The clinical use of plasma-sprayed hydroxyapatite (HA) coatings on metal implants has aroused as many controversies as interests over the last decade. Although faster and stronger fixation and more bone growth have been revealed, the performance of HA-coated implants has been doubted. This article will initially address the fundamentals of the material selection, design, and processing of the HA coating and show how the coating microstructure and properties can be a good predictor of the expected behavior in the body. Further discussion will clarify the major concerns with the clinical use of HA coatings and introduce a comprehensive review concerning the outcomes experienced with respect to clinical practice over the past 5 years. A reflection on the results indicates that HA coatings can promote earlier and stronger fixation but exhibit a durability that can be related to the coating quality. Specific relationships between coating quality and clinical performance are being established as characterization methods disclose more information about the coating.
985 citations
TL;DR: In this paper, four key issues that hinder the successful application of social identity theory to political phenomena are the existence of identity choice, the subjective meaning of identities, gradations in identity strength, and the considerable stability of many social and political identities.
Abstract: Interest in the concept of identity has grown exponentially within both the humanities and social sciences, but the discussion of identity has had less impact than might be expected on the quantitative study of political behavior in general and on political psychology more specifically. One of the approaches that holds the most promise for political psychologists is social identity theory, as reflected in the thinking of Henri Tajfel, John Turner, and colleagues. Although the theory addresses the kinds of problems of interest to political psychologists, it has had limited impact on political psychology because of social identity theorists' disinclination to examine the sources of social identity in a real world complicated by history and culture. In this review, four key issues are examined that hinder the successful application of social identity theory to political phenomena. These key issues are the existence of identity choice, the subjective meaning of identities, gradations in identity strength, and the considerable stability of many social and political identities.
926 citations
TL;DR: Evidence is provided that methamphetamine at dose levels taken by human abusers of the drug leads to dopamine transporter reduction that is associated with motor and cognitive impairment and the urgency of alerting clinicians and the public of the long-term changes that methamphetamine can induce in the human brain.
Abstract: OBJECTIVE: Methamphetamine is a popular and highly addictive drug of abuse that has raised concerns because it has been shown in laboratory animals to be neurotoxic to dopamine terminals. The authors evaluated if similar changes occur in humans and assessed if they were functionally significant. METHOD: Positron emission tomography scans following administration of [11C]d-threo-methylphenidate (a dopamine transporter ligand) measured dopamine transporter levels (a marker of dopamine cell terminals) in the brains of 15 detoxified methamphetamine abusers and 18 comparison subjects. Neuropsychological tests were also performed to assess motor and cognitive function. RESULTS: Methamphetamine abusers showed significant dopamine transporter reduction in the striatum (mean differences of 27.8% in the caudate and 21.1% in the putamen) relative to the comparison subjects; this reduction was evident even in abusers who had been detoxified for at least 11 months. Dopamine transporter reduction was associated with mo...
900 citations
University of Tokyo1, Boston University2, Massachusetts Institute of Technology3, Brookhaven National Laboratory4, University of California, Irvine5, California State University, Dominguez Hills6, George Mason University7, Gifu University8, Kobe University9, Kyoto University10, Louisiana State University11, University of Maryland, College Park12, University of Minnesota13, Stony Brook University14, University of Utah15, Niigata University16, Osaka University17, Seoul National University18, Shizuoka University19, Tohoku University20, Tokai University21, Tokyo Institute of Technology22, University of Warsaw23, University of Washington24
TL;DR: Solar neutrino measurements from 1258 days of data from the Super-Kamiokande detector are presented and the recoil electron energy spectrum is consistent with no spectral distortion.
Abstract: Solar neutrino measurements from 1258days of data from the Super-Kamiokande detector are presented. The measurements are based on recoil electrons in the energy range 5.0{endash}20.0MeV. The measured solar neutrino flux is 2.32{+-}0.03(stat){sup +0.08}{sub {minus}0.07}(syst){times}10{sup 6} cm{sup {minus}2}s{sup {minus}1} , which is 45.1{+-}0.5(stat ){sup +1.6}{sub {minus}1.4}(syst) % of that predicted by the BP2000 SSM. The day vs night flux asymmetry ({Phi}{sub n}{minus}{Phi}{sub d})/ {Phi}{sub average} is 0.033{+-}0.022(stat){sup +0.013}{sub {minus}0.012}(syst) . The recoil electron energy spectrum is consistent with no spectral distortion. For the hep neutrino flux, we set a 90% C.L.upper limit of 40{times}10{sup 3} cm{sup {minus}2}s{sup {minus}1} , which is 4.3times the BP2000 SSM prediction.
878 citations
TL;DR: In this paper, the authors measured the transverse momentum spectra for charged hadrons and neutral pions in the range 1 Gev/c < P-T < 5 GeV/c.
Abstract: Transverse momentum spectra for charged hadrons and for neutral pions in the range 1 Gev/c < P-T < 5 GeV/c have been measured by the PHENIX experiment at RHIC in Au + Au collisions at rootS(NN) = 130 GeV. At high p(T) the spectra from peripheral nuclear collisions are consistent with scaling the spectra from p + p collisions by the average number of binary nucleon-nucleon collisions. The spectra from central collisions are significantly suppressed when compared to the binary-scaled p + p expectation, and also when compared to similarly binary-scaled peripheral collisions, indicating a novel nuclear-medium effect in central nuclear collisions at RHIC energies.
803 citations
TL;DR: With the EOS fixed from SPS data, predictions at RHIC are quantified where the quark-gluon plasma (QGP) pressure is expected to drive additional radial and elliptic flows and the strong elliptic flow observed in the first RHIC measurements does not conclusively signal this nascent QGP pressure.
Abstract: Radial and elliptic flow in noncentral heavy-ion collisions can constrain the effective equation of state (EOS) of the excited nuclear matter. To this end, a model combining relativistic hydrodynamics and a hadronic transport code [Sorge, Phys. Rev. C 52, 3291 (1995)] is developed. For an EOS with a first-order phase transition, the model reproduces both the radial and elliptic flow data at the SPS. With the EOS fixed from SPS data, we quantify predictions at RHIC where the quark-gluon plasma (QGP) pressure is expected to drive additional radial and elliptic flows. Currently, the strong elliptic flow observed in the first RHIC measurements does not conclusively signal this nascent QGP pressure.
686 citations
TL;DR: It is suggested that protracted abstinence may reverse some of methamphetamine-induced alterations in brain DA terminals, and neuropsychological tests did not improve to the same extent as during short abstinence, which suggests that the increase of the DA transporters was not sufficient for complete function recovery.
Abstract: Methamphetamine is a popular drug of abuse that is neurotoxic to dopamine (DA) terminals when administered to laboratory animals. Studies in methamphetamine abusers have also documented significant loss of DA transporters (used as markers of the DA terminal) that are associated with slower motor function and decreased memory. The extent to which the loss of DA transporters predisposes methamphetamine abusers to neurodegenerative disorders such as Parkinsonism is unclear and may depend in part on the degree of recovery. Here we assessed the effects of protracted abstinence on the loss of DA transporters in striatum, in methamphetamine abusers using positron emission tomography and [(11)C]d-threo-methylphenidate (DA transporter radioligand). Brain DA transporters in five methamphetamine abusers evaluated during short abstinence (<6 months) and then retested during protracted abstinence (12-17 months) showed significant increases with protracted abstinence (caudate, +19%; putamen, +16%). Although performance in some of the tests for which we observed an association with DA transporters showed some improvement, this effect was not significant. The DA transporter increases with abstinence could indicate that methamphetamine-induced DA transporter loss reflects temporary adaptive changes (i.e., downregulation), that the loss reflects DA terminal damage but that terminals can recover, or that remaining viable terminals increase synaptic arborization. Because neuropsychological tests did not improve to the same extent, this suggests that the increase of the DA transporters was not sufficient for complete function recovery. These findings have treatment implications because they suggest that protracted abstinence may reverse some of methamphetamine-induced alterations in brain DA terminals.
TL;DR: Adult oligodendrocyte precursor cells make up around 5-8% of the glial cell population in the CNS, and their function in the undamaged CNS is largely unknown, but their processes are in contact with nodes of Ranvier and synapses, suggesting a regulatory role at these structures.
TL;DR: There is around an 85 per cent chance that the world's population will stop growing before the end of the century, and for different regions, the date and size of the peak population will vary considerably.
Abstract: There has been enormous concern about the consequences of human population growth for the environment and for social and economic development. But this growth is likely to come to an end in the foreseeable future. Improving on earlier methods of probabilistic forecasting, here we show that there is around an 85 per cent chance that the world's population will stop growing before the end of the century. There is a 60 per cent probability that the world's population will not exceed 10 billion people before 2100, and around a 15 per cent probability that the world's population at the end of the century will be lower than it is today. For different regions, the date and size of the peak population will vary considerably....
Brown University1, University of Pittsburgh2, University of California, Los Angeles3, New York University4, Dalhousie University5, University of Pennsylvania6, Stony Brook University7, Kaiser Permanente8, University of Texas at Austin9, Washington University in St. Louis10, University of Toronto11, Oregon Health & Science University12, Columbia University13, GlaxoSmithKline14
TL;DR: Paroxetine demonstrated significantly greater improvement compared with placebo in Hamilton Rating Scale for Depression total score < or = 8, HAM-D depressed mood item, K-SADS-L depressed Mood item, and CGI score of 1 or 2.
Abstract: Objective To compare paroxetine with placebo and imipramine with placebo for the treatment of adolescent depression. Method After a 7- to 14-day screening period, 275 adolescents with major depression began 8 weeks of double-blind paroxetine (20–40 mg), imipramine (gradual upward titration to 200–300 mg), or placebo. The two primary outcome measures were endpoint response (Hamilton Rating Scale for Depression [HAM-D] score ≤8 or ≥50% reduction in baseline HAM-D) and change from baseline HAM-D score. Other depression-related variables were (1) HAM-D depressed mood item; (2) depression item of the Schedule for Affective Disorders and Schizophrenia for Adolescents-Lifetime version (K-SADS-L); (3) Clinical Global Impression (CGI) improvement scores of 1 or 2; (4) nine-item depression subscale of K-SADS-L; and (5) mean CGI improvement scores. Results Paroxetine demonstrated significantly greater improvement compared with placebo in HAM-D total score ≤8, HAM-D depressed mood item, K-SADS-L depressed mood item, and CGI score of 1 or 2. The response to imipramine was not significantly different from placebo for any measure. Neither paroxetine nor imipramine differed significantly from placebo on parent-or self-rating measures. Withdrawal rates for adverse effects were 9.7% and 6.9% for paroxetine and placebo, respectively. Of 31.5% of subjects stopping imipramine therapy because of adverse effects, nearly one third did so because of adverse cardiovascular effects. Conclusions Paroxetine is generally well tolerated and effective for major depression in adolescents.
TL;DR: The results link L-domain function in HIV to the Ub machinery and a specific component of the cellular trafficking apparatus, indicating that features that distinguish Tsg101 from active E2 enzymes were important for binding the viral protein.
Abstract: Ubiquitination appears to be involved in virus particle release from infected cells. Free ubiquitin (Ub), as well as Ub covalently bound to a small fraction of p6 Gag, is detected in mature HIV particles. Here we report that the p6 region in the Pr55Gag structural precursor polyprotein binds to Tsg101, a putative Ub regulator that is involved in trafficking of plasma membrane-associated proteins. Tsg101 was found to interact with Gag in (i) a yeast two-hybrid assay, (ii) in vitro coimmunoprecipitation by using purified Pr55Gag and rabbit reticulocyte lysate-synthesized Tsg101, and (iii) in vivo in the cytoplasm of COS cells transfected with gag. The PTAPP motif [or late (L) domain] within p6, which is required for release of mature virus from the plasma membrane, was the determinant for binding Pr55Gag. The N-terminal region in Tsg101, which is homologous to the Ubc4 class of Ub-conjugating (E2) enzymes, was the determinant of interaction with p6. Mutation of Tyr-110 in Tsg101, present in place of the active-site Cys that binds Ub in E2 enzymes, and other residues unique to Tsg101, impaired p6 interaction, indicating that features that distinguish Tsg101 from active E2 enzymes were important for binding the viral protein. The results link L-domain function in HIV to the Ub machinery and a specific component of the cellular trafficking apparatus.
TL;DR: It is shown that uncentered correlations and regressions through the origin using the PIC method are identical to those obtained using PGLS with an intercept included in the model, and the PA method is shown to have several problems that limit its usefulness in comparative studies.
Abstract: This study is concerned with statistical methods used for the analysis of comparative data (in which observations are not expected to be independent because they are sampled across phylogenetically related species). The phylogenetically independent contrasts (PIC), phylogenetic generalized least-squares (PGLS), and phylogenetic autocorrelation (PA) methods are compared. Although the independent contrasts are not orthogonal, they are independent if the data conform to the Brownian motion model of evolution on which they are based. It is shown that uncentered correlations and regressions through the origin using the PIC method are identical to those obtained using PGLS with an intercept included in the model. The PIC method is a special case of PGLS. Corrected standard errors are given for estimates of the ancestral states based on the PGLS approach. The treatment of trees with hard polytomies is discussed and is shown to be an algorithmic rather than a statistical problem. Some of the relationships among the methods are shown graphically using the multivariate space in which variables are represented as vectors with respect to OTUs used as coordinate axes. The maximum-likelihood estimate of the autoregressive parameter, p, has not been computed correctly in previous studies (an appendix with MATLAB code provides a corrected algorithm). The importance of the eigenvalues and eigenvectors of the connection matrix, W, for the distribution of p is discussed. The PA method is shown to have several problems that limit its usefulness in comparative studies. Although the PA method is a generalized least-squares procedure, it cannot be made equivalent to the PGLS method using a phylogenetic model.
TL;DR: It is shown that rapid progestin-induced activation of Src and downstream MAP kinase in mammalian cells is dependent on PR-SH3 domain interaction, but not on the transcriptional activity of PR.
TL;DR: These studies identify CED-12/ELMO as an upstream regulator of Rac1 that affects engulfment and cell migration from C. elegans to mammals.
TL;DR: The convergence between geography and philosophy has become increasingly manifest in the past two decades as mentioned in this paper, as if Strabo's celebrated opening claim in his Geographia had finally become true two millennia later: "The science of Geography, which I now propose to investigate, is, I think, quite as much as any other science, a concern of the philosopher" (Strabo I, 3).
Abstract: remarkable convergence between geography and philosophy has become increasingly manifest in the past two decades. It is as if Strabo’s celebrated opening claim in his Geographia had finally become true two millennia later: “The science of Geography, which I now propose to investigate, is, I think, quite as much as any other science, a concern of the philosopher” (Strabo I, 3). What is new (and not in Strabo) is the growing conviction that philosophy is the concern of the geographer as well, or more exactly that philosophy and geography now need each other—and profit from this mutual need. Collaboration between the two fields has been evident ever since concerted attention to place began to emerge just over twenty years ago in, e.g., Edward Relph’s Place and Placelessness (1976) and Yi-Fu Tuan’s Space and Place (1976). Because of their emphasis on the experiential features of place—its “subjective” or “lived” aspects— such works were natural allies of phenomenology, a form of philosophy that attempts to give a direct description of first-person experience. Both geography and phenomenology have come to focus on place as experienced by human beings, in contrast to space, whose abstractness discourages experiential explorations. In the case of geography, a primary task has been to do justice to the indispensability of place in geographic theory and practice. So much is this the case that Robert David Sack (1997, 34, 30), a more recent proponent of the importance of place, can claim unhesitatingly that “[in geography] the truly important factor is place and its relationship to space.” 1
TL;DR: It was found that a small amount of ceramide significantly stabilized domain/raft formation and the molecular basis for, and the implications of, the effects of different sterols and sphingolipids on the behavior and biological function of rafts are discussed.
McMaster University1, University of Iowa2, Tel Aviv University3, Pontifical Catholic University of Chile4, Northwestern University5, Johannesburg Hospital6, Universitaire Ziekenhuizen Leuven7, Stony Brook University8, University of São Paulo9, University of California, San Francisco10, Merck & Co.11
TL;DR: Alendronate is an effective, well-tolerated therapy for the prevention and treatment of glucocorticoid-induced osteoporosis, with sustained treatment advantages for up to 2 years.
Abstract: OBJECTIVE: To evaluate the continued efficacy and safety of alendronate (ALN) for up to 2 years in patients receiving glucocorticoids. METHODS: This is a 12-month extension of a previously completed 1-year trial of daily ALN, performed to evaluate the effects of ALN over a total of 2 years in 66 men and 142 women continuing to receive at least 7.5 mg of prednisone or equivalent daily. All patients received supplemental calcium and vitamin D. The primary end point was the mean percentage change in lumbar spine bone mineral density (BMD) from baseline to 24 months. Other outcomes included changes in hip and total body BMD, biochemical markers of bone turnover, radiographic joint damage of the hands, and vertebral fracture incidence. RESULTS: The mean (+/-SEM) lumbar spine BMD increased by 2.8 +/- 0.6%, 3.9 +/- 0.7%, and 3.7 +/- 0.6%, respectively, in the groups that received 5 mg, 10 mg, and 2.5/10 mg of ALN daily (P < or = 0.001) and decreased by -0.8 +/- 0.6% in the placebo group (P not significant) over 24 months. In patients receiving any dose of ALN, BMD was increased at the trochanter (P < or = 0.05) and maintained at the femoral neck. Total body BMD was increased in patients receiving 5 or 10 mg ALN (P < or = 0.01). These 2 dose levels of ALN were more effective than placebo at all sites (P < or = 0.05). Bone turnover markers (N-telopeptides of type I collagen and bone-specific alkaline phosphatase) decreased 60% and 25%, respectively, during treatment with ALN (P < or = 0.05). There were fewer patients with new vertebral fractures in the ALN group versus the placebo group (0.7% versus 6.8%; P = 0.026). The safety profile was similar between treatment groups. CONCLUSION: Alendronate is an effective, well-tolerated therapy for the prevention and treatment of glucocorticoid-induced osteoporosis, with sustained treatment advantages for up to 2 years.
University of Tokyo1, Boston University2, Massachusetts Institute of Technology3, Brookhaven National Laboratory4, University of California, Irvine5, California State University, Dominguez Hills6, George Mason University7, Gifu University8, Kobe University9, Kyoto University10, Los Alamos National Laboratory11, University of Maryland, College Park12, Louisiana State University13, Korea Research Institute of Standards and Science14, University of Minnesota15, Stony Brook University16, University of Utah17, Niigata University18, Osaka University19, Seoul National University20, Shizuoka University21, Tohoku University22, Tokai University23, Tokyo Institute of Technology24, University of Warsaw25, University of Washington26
TL;DR: The absence of significant zenith angle variation and spectrum distortion places strong constraints on neutrino mixing and mass difference in a flux-independent way, and two allowed regions at large mixing are found.
Abstract: We report the result of a search for neutrino oscillations using precise measurements of the recoil electron energy spectrum and zenith angle variations of the solar neutrino flux from 1258 days of neutrino-electron scattering data in Super-Kamiokande The absence of significant zenith angle variation and spectrum distortion places strong constraints on neutrino mixing and mass difference in a flux-independent way Using the Super-Kamiokande flux measurement in addition, two allowed regions at large mixing are found
TL;DR: Overall, disfluency rates were higher both when speakers acted as directors and when they discussed abstract figures, confirming that disfluencies are associated with an increase in planning difficulty.
Abstract: After reviewing situational and demographic factors that have been argued to affect speakers' disfluency rates, we examined disfluency rates in a corpus of task-oriented conversations ( Schober & Carstensen, 2001) with variables that might affect fluency rates. These factors included: speakers' ages (young, middle-aged, and older), task roles (director vs. matcher in a referential communication task), difficulty of topic domain (abstract geometric figures vs. photographs of children), relationships between speakers (married vs. strangers), and gender(each pair consisted of a man and a woman). Older speakers produced only slightly $higher disfluency rates than young and middle-aged speakers. Overall, disfluency rates were higher both when speakers acted as directors and when they discussed abstract figures, confirming that disfluencies are associated with an increase in planning difficulty. However, fillers (such as uh) were distributed somewhat differently than repeats or restarts, supporting the idea tha...
TL;DR: Serotonin is known to play a role in brain development prior to the time it assumes its role as a neurotransmitter in the mature brain, and disruption of serotonergic development can leave permanent alterations in brain function and behavior.
TL;DR: The Later and Middle Stone Age (MSA) levels at Blombos Cave (BBC) were excavated over four field seasons between 1992 and 1999, and the results from the MSA levels were reported in this article.
TL;DR: The data show that sodium channel isoforms are differentially targeted to distinct domains of the same axon in a process associated with formation of compact myelin.
TL;DR: It is proposed that ubiquitylation regulates TAD function by serving as a dual signal for activation and activator destruction, demonstrating that activator ubiquitylated is essential for transcriptional activation.
Abstract: The ability of transcriptional activation domains (TADs) to signal ubiquitin-mediated proteolysis suggests an involvement of the ubiquitin-proteasome pathway in transcription. To probe this involvement, we asked how ubiquitylation regulates the activity of a transcription factor containing the VP16 TAD. We show that the VP16 TAD signals ubiquitylation through the Met30 ubiquitin-ligase and that Met30 is also required for the VP16 TAD to activate transcription. The requirement for Met30 in transcription is circumvented by fusion of ubiquitin to the VP16 activator, demonstrating that activator ubiquitylation is essential for transcriptional activation. We propose that ubiquitylation regulates TAD function by serving as a dual signal for activation and activator destruction.
TL;DR: In this article, the Lick and Keck observatories revealed two planets orbiting GJ 876 (M4V), and the inner companion was not recognized previously owing to the 2:1 ratio of periods, which allowed its signature to masquerade as added orbital eccentricity of the outer planet.
Abstract: Precise Doppler measurements during 6 yr from the Lick and Keck observatories reveal two planets orbiting GJ 876 (M4V). The orbital Ðt yields companion masses of M sin i \ 0.56 and 1.89 orbital M J , periods of P \ 30.1 and 61.0 days, semimajor axes of a \ 0.13 and 0.21 AU, and eccentricities of e \ 0.28 and 0.10, respectively. The orbital periods are nearly in the ratio of 2:1, unprecedented among major planets but common among moons and asteroids. Moreover, the axes of the elliptical orbits appear to be nearly aligned. The inner companion was not recognized previously owing to the 2:1 ratio of periods, which allowed its signature to masquerade as added orbital eccentricity of the outer planet. Dynamical simulations show that the system is stable within a subset of the observed orbital parameters. The stability may be provided by a mean-motion resonance and the apparent alignment of the major axes. These planets pose unsolved questions about their formation and dynamical evolution, which brought them within 0.08 AU of each other and locked them in resonance. Subject headings : planetary systems E stars : individual (GJ 876)
TL;DR: Test the hypothesis that the lateralization of encoding processes in the MTL and frontal regions is dependent on the verbalizability of the material and demonstrate differing verbalizabilities of three classes of non-verbal stimuli using a dual-task verbal interference behavioural paradigm.
Abstract: Numerous observations in patients with unilateral lesions of the medial temporal lobe (MTL) and the prefrontal cortex indicate that memory processes are lateralized according to content. Left-sided lesions interfere with verbal memory processes, whereas right-sided lesions interfere with visuospatial (non-verbal) memory processes. However, functional imaging studies have resulted in contradictory data, some studies showing lateralization in the prefrontal cortex determined by stage of processing (encoding versus retrieval) and others suggesting that lateralization is dependent on the type of material. Few studies have examined this issue in the MTL. In order to test the hypothesis that the lateralization of encoding processes in the MTL and frontal regions is dependent on the verbalizability of the material, we performed behavioural and functional imaging studies. We demonstrated differing verbalizabilities of three classes of non-verbal stimuli (scenes > faces > abstract patterns) using a dual-task verbal interference behavioural paradigm. A functional neuroimaging study of encoding was carried out using these three types of stimuli, plus words. During whole-brain functional MRI at 1.5 T, eight normal right-handed adults were presented with alternating blocks of novel and repeated stimuli under intentional memory encoding conditions. Verbal encoding resulted in left-lateralized activation of the inferior prefrontal cortex and the MTL. Pattern encoding activated the right inferior prefrontal cortex and the right MTL. Scenes and faces resulted in approximately symmetrical activation in both regions. The data indicate that the lateralization of encoding processes is determined by the verbalizability of stimuli.
TL;DR: The case is made that nature's process of fracture-healing, while elegant, can be accelerated with respect to achieving the ability to support clinically relevant loads.
Abstract: Double-blind, prospective, placebo-controlled clinical trials demonstrate that healing times of fresh fractures of the radius and tibia are reduced by up to 40% with the use of low-intensity ultrasound.
Animal studies indicate that low-intensity ultrasound exposure results in stronger and stiffer callus formation and in acceleration of the endochondral ossification process.
Extensive clinical evidence demonstrates that ultrasound represents a safe, noninvasive method of accelerating the healing of fresh fractures of the tibia, the distal aspect of the radius, the scaphoid, and the metatarsals.
Clinical studies indicate that ultrasound reduces the confounding effect of smoking and patient age on the fracture-healing process.
Ultrasound requires a brief, twenty-minute, daily at-home treatment regimen and has no known contraindications.
The effectiveness of low-intensity ultrasound has also been demonstrated in the clinical treatment of delayed unions and nonunions.
Fracture-healing is a complex biological process that involves the spatial and temporal orchestration of numerous cell types, hundreds if not thousands of genes, and the intricate organization of an extracellular matrix, all working toward restoring the bone's mechanical strength and rapid return to full function. It has often been argued that nature has optimized this process and thus it would be difficult to interventionally accelerate or augment fracture-healing. How can science conceivably improve upon 600 million years of vertebrate evolution? Nevertheless, it is just this goal that has inspired an intense effort among basic-science and clinical investigators from a vast array of biotechnology and bioengineering disciplines at academic as well as industrial laboratories, to seek a means of accelerating the healing of fractured bones. In this article, the basic-science and clinical evaluation of the use of low-intensity ultrasound is reviewed and the case is made that nature's process of fracture-healing, while elegant, can be accelerated with respect to achieving the ability to support clinically relevant loads.
The …