Showing papers by "Cornell University published in 2007"
TL;DR: In this article, statistical methods in the Atmospheric Sciences are used to estimate the probability of a given event to be a hurricane or tropical cyclone, and the probability is determined by statistical methods.
Abstract: (2007). Statistical Methods in the Atmospheric Sciences. Journal of the American Statistical Association: Vol. 102, No. 477, pp. 380-380.
7,052 citations
25 Jun 2007
TL;DR: An open-source toolkit for statistical machine translation whose novel contributions are support for linguistically motivated factors, confusion network decoding, and efficient data formats for translation models and language models.
Abstract: We describe an open-source toolkit for statistical machine translation whose novel contributions are (a) support for linguistically motivated factors, (b) confusion network decoding, and (c) efficient data formats for translation models and language models. In addition to the SMT decoder, the toolkit also includes a wide variety of tools for training, tuning and applying the system to many translation tasks.
6,008 citations
Ewan Birney, John A. Stamatoyannopoulos1, Anindya Dutta2, Roderic Guigó3 +317 more•Institutions (44)
TL;DR: Functional data from multiple, diverse experiments performed on a targeted 1% of the human genome as part of the pilot phase of the ENCODE Project are reported, providing convincing evidence that the genome is pervasively transcribed, such that the majority of its bases can be found in primary transcripts.
Abstract: We report the generation and analysis of functional data from multiple, diverse experiments performed on a targeted 1% of the human genome as part of the pilot phase of the ENCODE Project. These data have been further integrated and augmented by a number of evolutionary and computational analyses. Together, our results advance the collective knowledge about human genome function in several major areas. First, our studies provide convincing evidence that the genome is pervasively transcribed, such that the majority of its bases can be found in primary transcripts, including non-protein-coding transcripts, and those that extensively overlap one another. Second, systematic examination of transcriptional regulation has yielded new understanding about transcription start sites, including their relationship to specific regulatory sequences and features of chromatin accessibility and histone modification. Third, a more sophisticated view of chromatin structure has emerged, including its inter-relationship with DNA replication and transcriptional regulation. Finally, integration of these new sources of information, in particular with respect to mammalian evolution based on inter- and intra-species sequence comparisons, has yielded new mechanistic and evolutionary insights concerning the functional landscape of the human genome. Together, these studies are defining a path for pursuit of a more comprehensive characterization of human genome function.
5,091 citations
TL;DR: Experiments on large coauthorship networks suggest that information about future interactions can be extracted from network topology alone, and that fairly subtle measures for detecting node proximity can outperform more direct measures.
Abstract: Given a snapshot of a social network, can we infer which new interactions among its members are likely to occur in the near future? We formalize this question as the link-prediction problem, and we develop approaches to link prediction based on measures for analyzing the “proximity” of nodes in a network. Experiments on large coauthorship networks suggest that information about future interactions can be extracted from network topology alone, and that fairly subtle measures for detecting node proximity can outperform more direct measures. © 2007 Wiley Periodicals, Inc.
4,181 citations
TL;DR: Here, the natural resistance of plant cell walls to microbial and enzymatic deconstruction is considered, collectively known as “biomass recalcitrance,” which is largely responsible for the high cost of lignocellulose conversion.
Abstract: Lignocellulosic biomass has long been recognized as a potential sustainable source of mixed sugars for fermentation to biofuels and other biomaterials. Several technologies have been developed during the past 80 years that allow this conversion process to occur, and the clear objective now is to make this process cost-competitive in today's markets. Here, we consider the natural resistance of plant cell walls to microbial and enzymatic deconstruction, collectively known as "biomass recalcitrance." It is this property of plants that is largely responsible for the high cost of lignocellulose conversion. To achieve sustainable energy production, it will be necessary to overcome the chemical and structural properties that have evolved in biomass to prevent its disassembly.
4,035 citations
01 Jun 2007
TL;DR: This chapter presents the ecological model of human development that has been introduced in a prior edition of this Handbook, and defines the defining properties of the model, which involves four principal components, and the dynamic, interactive relationships among them.
Abstract: In this chapter, we undertake to present the ecological model of human development that has been introduced in a prior edition of this Handbook. The bioecological model is an evolving theoretical system for the scientific study of human development over time. The model presented in this chapter represents major theoretical innovations from the 1983 chapter in both form and content. The new model is not a paradigm shift, but rather represents a transition from a focus on the environment to a focus on proximal processes as engines of development. We begin with the defining properties of the model, which involves four principal components (process, person, context, and time), and the dynamic, interactive relationships among them. We then turn to the research designs required for testing the model. In doing so, we not only present the next stage in the evolution of an ecological theory of human development, but we also document the requirements for conducting developmental research in the discovery mode. We conclude with a look to the future—and what the bioecological model means for the future development of our species.
Keywords:
bioecological;
context;
macrosystem;
microsystem;
person;
proximal processes;
time
3,978 citations
TL;DR: This paper shows with two simple attacks that a \kappa-anonymized dataset has some subtle, but severe privacy problems, and proposes a novel and powerful privacy definition called \ell-diversity, which is practical and can be implemented efficiently.
Abstract: Publishing data about individuals without revealing sensitive information about them is an important problem. In recent years, a new definition of privacy called k-anonymity has gained popularity. In a k-anonymized dataset, each record is indistinguishable from at least k − 1 other records with respect to certain identifying attributes.In this article, we show using two simple attacks that a k-anonymized dataset has some subtle but severe privacy problems. First, an attacker can discover the values of sensitive attributes when there is little diversity in those sensitive attributes. This is a known problem. Second, attackers often have background knowledge, and we show that k-anonymity does not guarantee privacy against attackers using background knowledge. We give a detailed analysis of these two attacks, and we propose a novel and powerful privacy criterion called e-diversity that can defend against such attacks. In addition to building a formal foundation for e-diversity, we show in an experimental evaluation that e-diversity is practical and can be implemented efficiently.
3,780 citations
Rockefeller University1, University of Basel2, Memorial Sloan Kettering Cancer Center3, Swiss Institute of Bioinformatics4, Sapienza University of Rome5, German Cancer Research Center6, Ludwig Maximilian University of Munich7, University of Freiburg8, Miltenyi Biotec9, J. Craig Venter Institute10, Columbia University11, University of Naples Federico II12, University of Düsseldorf13, University of Bonn14, Semmelweis University15, Yeshiva University16, National Institutes of Health17, Cornell University18
TL;DR: A relatively small set of miRNAs, many of which are ubiquitously expressed, account for most of the differences in miRNA profiles between cell lineages and tissues.
3,687 citations
TL;DR: Two factors with available worldwide data—the prevalence of early childhood stunting and the number of people living in absolute poverty—are identified as indicators of poor development and show that both indicators are closely associated with poor cognitive and educational performance in children.
2,942 citations
TL;DR: Synthesis of six case studies from around the world shows that couplings between human and natural systems vary across space, time, and organizational units and have legacy effects on present conditions and future possibilities.
Abstract: Integrated studies of coupled human and natural systems reveal new and complex patterns and processes not evident when studied by social or natural scientists separately. Synthesis of six case studies from around the world shows that couplings between human and natural systems vary across space, time, and organizational units. They also exhibit nonlinear dynamics with thresholds, reciprocal feedback loops, time lags, resilience, heterogeneity, and surprises. Furthermore, past couplings have legacy effects on present conditions and future possibilities.
2,890 citations
TL;DR: The thinnest resonator consists of a single suspended layer of atoms and represents the ultimate limit of two-dimensional nanoelectromechanical systems and is demonstrated down to 8 × 10–4 electrons per root hertz.
Abstract: Nanoelectromechanical systems were fabricated from single- and multilayer graphene sheets by mechanically exfoliating thin sheets from graphite over trenches in silicon oxide. Vibrations with fundamental resonant frequencies in the megahertz range are actuated either optically or electrically and detected optically by interferometry. We demonstrate room-temperature charge sensitivities down to 8 × 10 –4 electrons per root hertz. The thinnest resonator consists of a single suspended layer of atoms and represents the ultimate limit of two-dimensional nanoelectromechanical systems.
TL;DR: In this paper, a new graph generator based on a forest fire spreading process was proposed, which has a simple, intuitive justification, requires very few parameters (like the flammability of nodes), and produces graphs exhibiting the full range of properties observed both in prior work and in the present study.
Abstract: How do real graphs evolve over timeq What are normal growth patterns in social, technological, and information networksq Many studies have discovered patterns in static graphs, identifying properties in a single snapshot of a large network or in a very small number of snapshots; these include heavy tails for in- and out-degree distributions, communities, small-world phenomena, and others. However, given the lack of information about network evolution over long periods, it has been hard to convert these findings into statements about trends over time.Here we study a wide range of real graphs, and we observe some surprising phenomena. First, most of these graphs densify over time with the number of edges growing superlinearly in the number of nodes. Second, the average distance between nodes often shrinks over time in contrast to the conventional wisdom that such distance parameters should increase slowly as a function of the number of nodes (like O(log n) or O(log(log n)).Existing graph generation models do not exhibit these types of behavior even at a qualitative level. We provide a new graph generator, based on a forest fire spreading process that has a simple, intuitive justification, requires very few parameters (like the flammability of nodes), and produces graphs exhibiting the full range of properties observed both in prior work and in the present study.We also notice that the forest fire model exhibits a sharp transition between sparse graphs and graphs that are densifying. Graphs with decreasing distance between the nodes are generated around this transition point.Last, we analyze the connection between the temporal evolution of the degree distribution and densification of a graph. We find that the two are fundamentally related. We also observe that real networks exhibit this type of relation between densification and the degree distribution.
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TL;DR: On the climate change mitigation front, the incorporation of ‘biochar’ into the soil is one idea gaining support, and Johannes Lehmann argues that trapping biomass carbon in this way is more effective than storing it in plants and trees that will one day decompose.
Abstract: Locking carbon up in soil makes more sense than storing it in plants and trees that eventually decompose, argues Johannes Lehmann. Can this idea work on a large scale? With the rash of IPCC reports in climate much in the news, geoengineering — the deliberate large-scale modification of the environment — is now being taken seriously in scientific and political circles that would previously have scoffed at the notion. Oliver Morton reports on the state of play in the field [News Feature p. 132] On the climate change mitigation front, the incorporation of ‘biochar’ into the soil is one idea gaining support. Johannes Lehmann argues that trapping biomass carbon in this way is more effective than storing it in plants and trees that will one day decompose. The latest IPCC report — round 3 — is covered in the News pages this week.
Clark University1, National Institutes of Health2, Louisiana State University3, CABI4, Umeå University5, Field Museum of Natural History6, Duke University7, University of Minnesota8, University of Alabama9, Oregon State University10, Centraalbureau voor Schimmelcultures11, United States Department of Agriculture12, University of Tübingen13, Max Planck Society14, University of Florida15, Pennsylvania State University16, Aberystwyth University17, Complutense University of Madrid18, University of Oslo19, University of Hong Kong20, University of Tartu21, University of Gothenburg22, University of Kansas23, University of Maine24, University of Illinois at Urbana–Champaign25, Royal Ontario Museum26, Georgia State University27, Estonian University of Life Sciences28, Washington State University29, Nova Southeastern University30, Ludwig Maximilian University of Munich31, University of Western Ontario32, Uppsala University33, Brandon University34, Royal Botanic Garden Edinburgh35, State University of New York at Purchase36, Boise State University37, Cornell University38
TL;DR: A comprehensive phylogenetic classification of the kingdom Fungi is proposed, with reference to recent molecular phylogenetic analyses, and with input from diverse members of the fungal taxonomic community.
TL;DR: These genome sequences augment the formidable genetic tools that have made Drosophila melanogaster a pre-eminent model for animal genetics, and will further catalyse fundamental research on mechanisms of development, cell biology, genetics, disease, neurobiology, behaviour, physiology and evolution.
Abstract: Comparative analysis of multiple genomes in a phylogenetic framework dramatically improves the precision and sensitivity of evolutionary inference, producing more robust results than single-genome analyses can provide. The genomes of 12 Drosophila species, ten of which are presented here for the first time (sechellia, simulans, yakuba, erecta, ananassae, persimilis, willistoni, mojavensis, virilis and grimshawi), illustrate how rates and patterns of sequence divergence across taxa can illuminate evolutionary processes on a genomic scale. These genome sequences augment the formidable genetic tools that have made Drosophila melanogaster a pre-eminent model for animal genetics, and will further catalyse fundamental research on mechanisms of development, cell biology, genetics, disease, neurobiology, behaviour, physiology and evolution. Despite remarkable similarities among these Drosophila species, we identified many putatively non-neutral changes in protein-coding genes, non-coding RNA genes, and cis-regulatory regions. These may prove to underlie differences in the ecology and behaviour of these diverse species.
04 Jun 2007
TL;DR: This work presents PUF designs that exploit inherent delay characteristics of wires and transistors that differ from chip to chip, and describes how PUFs can enable low-cost authentication of individual ICs and generate volatile secret keys for cryptographic operations.
Abstract: Physical Unclonable Functions (PUFs) are innovative circuit primitives that extract secrets from physical characteristics of integrated circuits (ICs). We present PUF designs that exploit inherent delay characteristics of wires and transistors that differ from chip to chip, and describe how PUFs can enable low-cost authentication of individual ICs and generate volatile secret keys for cryptographic operations.
Princeton University1, Goddard Space Flight Center2, University of Texas at Austin3, University of Toronto4, Johns Hopkins University5, Cornell University6, University of British Columbia7, University of Chicago8, Brown University9, University of Pennsylvania10, University of California, Los Angeles11
TL;DR: In this article, the authors presented a model of polarized foreground emission that captures the large angular scale characteristics of the microwave sky and analyzed the 3-year full-sky maps of the polarization and cosmological implications.
Abstract: The Wilkinson Microwave Anisotropy Probe (WMAP) has mapped the entire sky in five frequency bands between 23 and 94 GHz with polarization-sensitive radiometers. We present 3 year full-sky maps of the polarization and analyze them for foreground emission and cosmological implications. These observations open up a new window for understanding how the universe began and help set a foundation for future observations. WMAP observes significant levels of polarized foreground emission due to both Galactic synchrotron radiation and thermal dust emission. Synchrotron radiation is the dominant signal at l < 50 and ν 40 GHz, while thermal dust emission is evident at 94 GHz. The least contaminated channel is at 61 GHz. We present a model of polarized foreground emission that captures the large angular scale characteristics of the microwave sky. After applying a Galactic mask that cuts 25.7% of the sky, we show that the high Galactic latitude rms polarized foreground emission, averaged over l = 4-6, ranges from ≈5 μK at 22 GHz to 0.6 μK at 61 GHz. By comparison, the levels of intrinsic CMB polarization for a ΛCDM model with an optical depth of τ = 0.09 and assumed tensor-to-scalar ratio r = 0.3 are ≈0.3 μK for E-mode polarization and ≈0.1 μK for B-mode polarization. To analyze the maps for CMB polarization at l < 16, we subtract a model of the foreground emission that is based primarily on a scaling WMAP's 23 GHz map. In the foreground-corrected maps, we detect l(l + 1)C/2π = 0.086 ± 0.029 (μK)2. This is interpreted as the result of rescattering of the CMB by free electrons released during reionization at zr = 10.9 for a model with instantaneous reionization. By computing the likelihood of just the EE data as a function of τ we find τ = 0.10 ± 0.03. When the same EE data are used in the full six-parameter fit to all WMAP data (TT, TE, EE), we find τ = 0.09 ± 0.03. Marginalization over the foreground subtraction affects this value by δτ < 0.01. We see no evidence for B modes, limiting them to l(l + 1)C/2π = -0.04 ± 0.03 (μK)2. We perform a template fit to the E-mode and B-mode data with an approximate model for the tensor scalar ratio. We find that the limit from the polarization signals alone is r < 2.2 (95% CL), where r is evaluated at k = 0.002 Mpc-1. This corresponds to a limit on the cosmic density of gravitational waves of ΩGWh2 < 5 × 10-12. From the full WMAP analysis, we find r < 0.55 (95% CL) corresponding to a limit of ΩGWh2 < 1 × 10-12 (95% CL). The limit on r is approaching the upper bound of predictions for some of the simplest models of inflation, r ~ 0.3.
TL;DR: It is shown that molecular recapitulations of three prototypical adaptations associated with the unsusceptible phenotype are each sufficient to promote resistant behavior and validate a multidisciplinary approach to examine the neurobiological mechanisms of variations in stress resistance.
TL;DR: In this article, the authors examine the conceptualization and measurement of ethnic identity as a multidimensional, dynamic construct that develops over time through a process of exploration and commitment, and discuss the theoretical and empirical basis for understand- ing ethnic identity in a developmental process.
Abstract: In this article, the authors examine the conceptualization and measurement of ethnic identity as a multidimensional, dynamic construct that develops over time through a process of exploration and commitment. The authors discuss the components of ethnic identity that have been studied and the theoretical background for a developmental model of ethnic identity. The authors review research on the measurement of ethnic identity using the Multigroup Ethnic Identity Measure (J. Phinney, 1992) and present a revised version of the measure. The authors conclude with a consideration of the measurement issues raised by J. E. Helms (2007) and K. Cokley (2007) and suggestions for future research on ethnic identity. Ethnic identity is many faceted. This is made clear in the special issue of which this article is a part. But recognizing that ethnic identity has many facets is merely a start to understanding it. Ethnic identity derives from a sense of peoplehood within a group, a culture, and a particular setting. Yet ethnic identity is not merely knowledge and understanding of one's ingroup affiliations, even as such insights and comprehension are part of it. The achievement of a secure ethnic identity derives from experience, but experience is not sufficient to produce it. Because one's ethnic identity is con- structed over time, the actions and choices of individuals are essential to the process. Ethnic identity is distinct in some ways from other group identities, such as racial identity, but it also shares aspects of both personal and group identities. Our purpose in this article was to examine the conceptualization and measurement of ethnic identity from social psychological and developmental perspectives. We first review the various dimen- sions of ethnic identity that have been proposed in the literature. We then discuss the theoretical and empirical basis for understand- ing ethnic identity as a developmental process. We review research on the measurement of ethnic identity based on the widely used Multigroup Ethnic Identity Measure (MEIM, Phinney, 1992; Rob- erts et al., 1999), discuss recent measurement research that has led to a revision of the MEIM, and present a revised version of the MEIM. We conclude with a discussion of issues that might be profitably considered in future ethnic identity research, with a consideration of the ideas and recommendations offered by Helms (2007) and Cokley (2007). In keeping with the focus of the special issue, we discuss ethnic identity with reference to ethnic minorities in the United States.
TL;DR: This article found that mothers were penalized on a host of measures, including perceived competence and recommended starting salary, while men were not penalized for, and sometimes benefited from, being a parent.
Abstract: Survey research finds that mothers suffer a substantial wage penalty, although the causal mechanism producing it remains elusive. The authors employed a laboratory experiment to evaluate the hypothesis that status-based discrimination plays an important role and an audit study of actual employers to assess its real-world implications. In both studies, participants evaluated application materials for a pair of same-gender equally qualified job candidates who differed on parental status. The laboratory experiment found that mothers were penalized on a host of measures, including perceived competence and recommended starting salary. Men were not penalized for, and sometimes benefited from, being a parent. The audit study showed that actual employers discriminate against mothers, but not against fathers.
TL;DR: An analytical framework for opportunistic spectrum access based on the theory of partially observable Markov decision process (POMDP) is developed and cognitive MAC protocols that optimize the performance of secondary users while limiting the interference perceived by primary users are proposed.
Abstract: We propose decentralized cognitive MAC protocols that allow secondary users to independently search for spectrum opportunities without a central coordinator or a dedicated communication channel. Recognizing hardware and energy constraints, we assume that a secondary user may not be able to perform full-spectrum sensing or may not be willing to monitor the spectrum when it has no data to transmit. We develop an analytical framework for opportunistic spectrum access based on the theory of partially observable Markov decision process (POMDP). This decision-theoretic approach integrates the design of spectrum access protocols at the MAC layer with spectrum sensing at the physical layer and traffic statistics determined by the application layer of the primary network. It also allows easy incorporation of spectrum sensing error and constraint on the probability of colliding with the primary users. Under this POMDP framework, we propose cognitive MAC protocols that optimize the performance of secondary users while limiting the interference perceived by primary users. A suboptimal strategy with reduced complexity yet comparable performance is developed. Without additional control message exchange between the secondary transmitter and receiver, the proposed decentralized protocols ensure synchronous hopping in the spectrum between the transmitter and the receiver in the presence of collisions and spectrum sensing errors
Boston Children's Hospital1, University of Colorado Denver2, Emory University3, Harvard University4, University of Texas at Austin5, University of Texas Southwestern Medical Center6, Cornell University7, Tulane University8, Primary Children's Hospital9, University of Pennsylvania10, University of New Mexico11, Children's Hospital Oakland Research Institute12, University of Hawaii at Manoa13, Children's Hospital of Orange County14, Oregon Health & Science University15, Children's Memorial Hospital16, Palmetto Health Richland17, Centers for Disease Control and Prevention18
TL;DR: Prophylaxis with recombinant factor VIII can prevent joint damage and decrease the frequency of joint and other hemorrhages in young boys with severe hemophilia A.
Abstract: Sixty-five boys younger than 30 months of age were randomly assigned to prophylaxis (32 boys) or enhanced episodic therapy (33 boys). When the boys reached 6 years of age, 93% of those in the prophylaxis group and 55% of those in the episodic-therapy group were considered to have normal index-joint structure on MRI (P = 0.006). The relative risk of MRI-detected joint damage with episodic therapy as compared with prophylaxis was 6.1 (95% confidence interval, 1.5 to 24.4). The mean annual numbers of joint and total hemorrhages were higher at study exit in the episodic-therapy group than in the prophylaxis group (P<0.001 for both comparisons). High titers of inhibitors of factor VIII developed in two boys who received prophylaxis; three boys in the episodic-therapy group had a life-threatening hemorrhage. Hospitalizations and infections associated with central-catheter placement did not differ significantly between the two groups. Conclusions Prophylaxis with recombinant factor VIII can prevent joint damage and decrease the frequency of joint and other hemorrhages in young boys with severe hemophilia A. (ClinicalTrials.gov number, NCT00207597.)
TL;DR: The precise half-life of biochar is still disputed, and this will have important implications for the value of the technology, particularly in carbon trading as mentioned in this paper, and it is not clear under what conditions, and over what period of time, biochar develops its adsorbing properties.
Abstract: At best, common renewable energy strategies can only offset fossil fuel emissions of CO2 – they cannot reverse climate change. One promising approach to lowering CO2 in the atmosphere while producing energy is biochar bio-energy, based on low-temperature pyrolysis. This technology relies on capturing the off-gases from thermal decomposition of wood or grasses to produce heat, electricity, or biofuels. Biochar is a major by-product of this pyrolysis, and has remarkable environmental properties. In soil, biochar was shown to persist longer and to retain cations better than other forms of soil organic matter. The precise half-life of biochar is still disputed, however, and this will have important implications for the value of the technology, particularly in carbon trading. Furthermore, the cation retention of fresh biochar is relatively low compared to aged biochar in soil, and it is not clear under what conditions, and over what period of time, biochar develops its adsorbing properties. Research is still n...
TL;DR: Analysis of tumor samples from multiple independent patient cohorts and array-based comparative genomic hybridization suggest that MET amplification occurs independently of EGFRT790M mutations and that MET may be a clinically relevant therapeutic target for some patients with acquired resistance to gefitinib or erlotinib.
Abstract: In human lung adenocarcinomas harboring EGFR mutations, a second-site point mutation that substitutes methionine for threonine at position 790 (T790M) is associated with approximately half of cases of acquired resistance to the EGFR kinase inhibitors, gefitinib and erlotinib. To identify other potential mechanisms that contribute to disease progression, we used array-based comparative genomic hybridization (aCGH) to compare genomic profiles of EGFR mutant tumors from untreated patients with those from patients with acquired resistance. Among three loci demonstrating recurrent copy number alterations (CNAs) specific to the acquired resistance set, one contained the MET proto-oncogene. Collectively, analysis of tumor samples from multiple independent patient cohorts revealed that MET was amplified in tumors from 9 of 43 (21%) patients with acquired resistance but in only two tumors from 62 untreated patients (3%) (P = 0.007, Fisher's Exact test). Among 10 resistant tumors from the nine patients with MET amplification, 4 also harbored the EGFRT790M mutation. We also found that an existing EGFR mutant lung adenocarcinoma cell line, NCI-H820, harbors MET amplification in addition to a drug-sensitive EGFR mutation and the T790M change. Growth inhibition studies demonstrate that these cells are resistant to both erlotinib and an irreversible EGFR inhibitor (CL-387,785) but sensitive to a multikinase inhibitor (XL880) with potent activity against MET. Taken together, these data suggest that MET amplification occurs independently of EGFRT790M mutations and that MET may be a clinically relevant therapeutic target for some patients with acquired resistance to gefitinib or erlotinib.
TL;DR: This article investigated the relationship between two types of change-oriented leadership (transformational leadership and managerial openness) and subordinate improvement-oriented voice in a two-phase study and found that openness is more consistently related to voice, given controls for numerous individual differences in subordinates' personality, satisfaction, and job demography.
Abstract: We investigate the relationships between two types of change-oriented leadership (transformational leadership and managerial openness) and subordinate improvement-oriented voice in a two-phase study. Findings from 3,149 employees and 223 managers in a restaurant chain indicate that openness is more consistently related to voice, given controls for numerous individual differences in subordinates’ personality, satisfaction, and job demography. This relationship is shown to be mediated by subordinate perceptions of psychological safety, illustrating the importance of leaders in subordinate assessments of the risks of speaking up. Also, leadership behaviors have the strongest impact on the voice behavior of the best-performing employees.
TL;DR: In patients undergoing chemotherapy for acute myelogenous leukemia or the myelodysplastic syndrome, posaconazoles prevented invasive fungal infections more effectively than did either fluconazole or itraconazole and improved overall survival.
Abstract: Background Patients with neutropenia resulting from chemotherapy for acute myelogenous leukemia or the myelodysplastic syndrome are at high risk for difficult-to-treat and often fatal invasive fungal infections. Methods In this randomized, multicenter study involving evaluators who were unaware of treatment assignments, we compared the efficacy and safety of posaconazole with those of fluconazole or itraconazole as prophylaxis for patients with prolonged neutropenia. Patients received prophylaxis with each cycle of chemotherapy until recovery from neutropenia and complete remission, until occurrence of an invasive fungal infection, or for up to 12 weeks, whichever came first. We compared the incidence of proven or probable invasive fungal infections during treatment (the primary end point) between the posaconazole and fluconazole or itraconazole groups; death from any cause and time to death were secondary end points. Results A total of 304 patients were randomly assigned to receive posaconazole, and 298 ...
TL;DR: The HiRISE camera as mentioned in this paper provides detailed images (0.25 to 1.3 m/pixel) covering ∼1% of the Martian surface during the 2-year Primary Science Phase (PSP) beginning November 2006.
Abstract: [1] The HiRISE camera features a 0.5 m diameter primary mirror, 12 m effective focal length, and a focal plane system that can acquire images containing up to 28 Gb (gigabits) of data in as little as 6 seconds. HiRISE will provide detailed images (0.25 to 1.3 m/pixel) covering ∼1% of the Martian surface during the 2-year Primary Science Phase (PSP) beginning November 2006. Most images will include color data covering 20% of the potential field of view. A top priority is to acquire ∼1000 stereo pairs and apply precision geometric corrections to enable topographic measurements to better than 25 cm vertical precision. We expect to return more than 12 Tb of HiRISE data during the 2-year PSP, and use pixel binning, conversion from 14 to 8 bit values, and a lossless compression system to increase coverage. HiRISE images are acquired via 14 CCD detectors, each with 2 output channels, and with multiple choices for pixel binning and number of Time Delay and Integration lines. HiRISE will support Mars exploration by locating and characterizing past, present, and future landing sites, unsuccessful landing sites, and past and potentially future rover traverses. We will investigate cratering, volcanism, tectonism, hydrology, sedimentary processes, stratigraphy, aeolian processes, mass wasting, landscape evolution, seasonal processes, climate change, spectrophotometry, glacial and periglacial processes, polar geology, and regolith properties. An Internet Web site (HiWeb) will enable anyone in the world to suggest HiRISE targets on Mars and to easily locate, view, and download HiRISE data products.
Michigan State University1, University of California, Davis2, University of California, Santa Barbara3, Grinnell College4, Florida Institute of Technology5, University of California, San Diego6, Smithsonian Institution7, Cornell University8, Academy of Natural Sciences of Drexel University9, Dartmouth College10, Yale University11, University of Chicago12, University of Missouri13, University of Georgia14, University of British Columbia15
TL;DR: Two major hypotheses for the origin of the latitudinal diversity gradient are reviewed, including the time and area hypothesis and the diversification rate hypothesis, which hold that tropical regions diversify faster due to higher rates of speciation, or due to lower extinction rates.
Abstract: A latitudinal gradient in biodiversity has existed since before the time of the dinosaurs, yet how and why this gradient arose remains unresolved. Here we review two major hypotheses for the origin of the latitudinal diversity gradient. The time and area hypothesis holds that tropical climates are older and historically larger, allowing more opportunity for diversification. This hypothesis is supported by observations that temperate taxa are often younger than, and nested within, tropical taxa, and that diversity is positively correlated with the age and area of geographical regions. The diversification rate hypothesis holds that tropical regions diversify faster due to higher rates of speciation (caused by increased opportunities for the evolution of reproductive isolation, or faster molecular evolution, or the increased importance of biotic interactions), or due to lower extinction rates. There is phylogenetic evidence for higher rates of diversification in tropical clades, and palaeontological data demonstrate higher rates of origination for tropical taxa, but mixed evidence for latitudinal differences in extinction rates. Studies of latitudinal variation in incipient speciation also suggest faster speciation in the tropics. Distinguishing the roles of history, speciation and extinction in the origin of the latitudinal gradient represents a major challenge to future research.
TL;DR: In this issue of the JCI, Gallagher and colleagues demonstrate that in diabetic mice, hyperoxia enhances the mobilization of circulating endothelial progenitor cells (EPCs) from the bone marrow to the peripheral circulation, resulting in accelerated wound healing.
Abstract: Diabetic foot ulcers (DFUs), a leading cause of amputations, affect 15% of people with diabetes. A series of multiple mechanisms, including decreased cell and growth factor response, lead to diminished peripheral blood flow and decreased local angiogenesis, all of which can contribute to lack of healing in persons with DFUs. In this issue of the JCI, Gallagher and colleagues demonstrate that in diabetic mice, hyperoxia enhances the mobilization of circulating endothelial progenitor cells (EPCs) from the bone marrow to the peripheral circulation (see the related article beginning on page 1249). Local injection of the chemokine stromal cell–derived factor–1α then recruits these EPCs to the cutaneous wound site, resulting in accelerated wound healing. Thus, Gallagher et al. have identified novel potential targets for therapeutic intervention in diabetic wound healing.
TL;DR: The HDL cholesterol levels in patients receiving statins was predictive of major cardiovascular events across the TNT study cohort, both when HDL cholesterol was considered as a continuous variable and when subjects were stratified according to quintiles of HDL cholesterol level.
Abstract: METHODS A post hoc analysis of the recently completed Treating to New Targets (TNT) study assessed the predictive value of HDL cholesterol levels in 9770 patients. The primary outcome measure was the time to a first major cardiovascular event, defined as death from coronary heart disease, nonfatal non–procedure-related myocardial infarction, resuscitation after cardiac arrest, or fatal or nonfatal stroke. The predictive relationship between HDL cholesterol levels at the third month of treatment with statins and the time to the first major cardiovascular event was assessed in univariate and multivariate analyses and was also assessed for specific LDL cholesterol strata, including subjects with LDL cholesterol levels below 70 mg per deciliter (1.8 mmol per liter). RESULTS The HDL cholesterol level in patients receiving statins was predictive of major cardiovascular events across the TNT study cohort, both when HDL cholesterol was considered as a continuous variable and when subjects were stratified according to quintiles of HDL cholesterol level. When the analysis was stratified according to LDL cholesterol level in patients receiving statins, the relationship between HDL cholesterol level and major cardiovascular events was of borderline significance (P = 0.05). Even among study subjects with LDL cholesterol levels below 70 mg per deciliter, those in the highest quintile of HDL cholesterol level were at less risk for major cardiovascular events than those in the lowest quintile (P = 0.03). CONCLUSIONS In this post hoc analysis, HDL cholesterol levels were predictive of major cardiovascular events in patients treated with statins. This relationship was also observed among patients with LDL cholesterol levels below 70 mg per deciliter. (ClinicalTrials.gov number, NCT00327691.)