bluuebunny/crossref_metadata_2025 huggingface dataset:
Minimizing the variance of cluster mixture models for clustering uncertain objects
Authors: Gullo Francesco , Ponti Giovanni , Tagarelli Andrea
Published: November 2012

In recent years, there has been a growing interest in clustering uncertain objects. In contrast to traditional, ‘sharp’ data representation models, uncertain objects are modeled as probability distributions defined over uncertainty regions. In this context, a major issue is related to the poor efficiency of existing algorithms, which is mainly due to expensive computation of the distance between uncertain objects. In this work, we extend our earlier work in which a novel formulation to the problem of clustering uncertain objects is defined based on the minimization of the variance of the mixture models that represent the clusters being discovered. Analytical properties about the computation of variance for cluster mixture models are derived and exploited by a partitional clustering algorithm, called MMVar. This algorithm achieves high efficiency since it does not need to employ any distance measure between uncertain objects. Experiments have shown that MMVar is scalable and outperforms state‐of‐the‐art algorithms in terms of efficiency, while achieving better average performance in terms of accuracy. © 2012 Wiley Periodicals, Inc. Statistical Analysis and Data Mining 6: 116–135, 2013
Systems Thinking: Common Ground or Untapped Territory?
Authors: Buckle Henning Pamela , Chen Wan‐Ching
Published: November 2012

At international gatherings of systems scholars, the term ‘systems thinking’ elicits understanding nods and smiles. Such thinking, it would appear, is a way this largely academic community works ‘all together now’, thinking in a systemic way about our varied areas of inquiry. But how common is this understanding among us? Assessing the degree to which we work ‘all together now’ requires recognizing the different assumptions we make about what systems thinking means. So powerful is systems thinking's capacity to holistically address twenty‐first‐century problems that much has been written about it for laypeople. This article presents a content analysis of 14 popular books on systems thinking, revealing that ISSS members’ understanding nods and smiles belie a plurality of meanings assigned to systems thinking and claims about what it means to be a systems thinker. Copyright © 2012 John Wiley & Sons, Ltd.
High Beta-Palmitate Formula and Bone Strength in Term Infants: A Randomized, Double-Blind, Controlled Trial
Authors: Litmanovitz Ita , Davidson Keren , Eliakim Alon , Regev Rivka H. , Dolfin Tzipora , Arnon Shmuel , Bar-Yoseph Fabiana , Goren Amit , Lifshitz Yael , Nemet Dan
Published: November 2012

We aimed to compare the effect of 12-week feeding of commercially available infant formulas with different percentages of palmitic acid at sn-2 (beta-palmitate) on anthropometric measures and bone strength of term infants. It was hypothesized that feeding infants with high beta-palmitate (HBP) formula will enhance their bone speed of sound (SOS). Eighty-three infants appropriate for gestational age participated in the study; of these, 58 were formula-fed and 25 breast-fed infants, serving as a reference group. The formula-fed infants were randomly assigned to receive HBP formula (43 % of the palmitic acid is esterified to the middle position of the glycerol backbone, study group; n = 30) or regular formula with low-beta palmitate (LBP, 14 % of the palmitic acid is esterified to the middle position of the glycerol backbone, n = 28). Sixty-six infants completed the 12-week study. Anthropometric and quantitative ultrasound measurements of bone SOS for assessment of bone strength were performed at randomization and at 6 and 12 weeks postnatal age. At randomization, gestational age, birth weight, and bone SOS were comparable between the three groups. At 12 weeks postnatal age, the mean bone SOS of the HBP group was significantly higher than that of the LBP group (2,896 ± 133 vs. 2,825 ± 79 m/s respectively, P = 0.049) and comparable with that of the breast-fed group (2,875 ± 85 m/s). We concluded that infants consuming HBP formula had changes in bone SOS that were comparable to those of infants consuming breast milk and favorable compared to infants consuming LBP formula.
Orthopedic surgery and mobility goals for children with cerebral palsy GMFCS level IV: What are we setting out to achieve?
Authors: Blumetti Francesco Camara , Wu Jenny Chia Ning , Bau Karen Vanessa , Martin Brian , Hobson Sally Anne , Axt Matthias Wolfgang , Selber Paulo
Published: November 2012

Background

Multilevel orthopedic surgery is considered to be the gold standard treatment for ambulatory children with cerebral palsy (CP), classified at levels I, II, or III according to the Gross Motor Function Classification System (GMFCS). Hip enlocation and stability are the main goals of orthopedic intervention in the GMFCS level IV subgroup and are well researched; however, there is no evidence to date to support or challenge the effectiveness of orthopedic treatment to preserve functional mobility in this patient group. The aim of this study was to evaluate the results of orthopedic surgery to maintain or restore standing transfers and supported walking in children with CP at GMFCS level IV.

Methods

Twenty-two children with CP GMFCS level IV who underwent orthopedic surgery to improve mobility between the years 2004 and 2008 were included in this study. A retrospective chart review was performed and a satisfaction questionnaire sent to all patients. The primary outcome measure was the attainment and maintenance of mobility goals 2 years post-surgery. The secondary outcome measures were family/patient satisfaction, Functional Mobility Scale (FMS), and complications.

Results

The two goals identified by the patients and carers were standing transfers and supported walking. At the 2-year post-surgery assessment, 14 children (63.6 %) did not reach their pre-determined goals. In the questionnaire, 21.4 % of the families reported that surgery was not beneficial. The FMS score remained unchanged in 95.4 % of the patients. Fourteen patients (63.6 %) had at least one complication that prolonged their post-operative rehabilitation (e.g., neuropraxia).

Conclusion

This study suggests that orthopedic surgery in children with CP at GMFCS level IV is unlikely to maintain or restore mobility. Furthermore, it carries a significant risk of complications.

Level of evidence

Case series, Level IV.
Essential therapeutics skills required of junior doctors
Authors: Mathew J. Baldwin Mathew J. , Abouyannis Michael , Butt Tehreem F.
Published: November 2012

Junior doctors are responsible for the majority of in-hospital prescription
errors. Little research has explored their confidence to prescribe, or practical
therapeutics related tasks which they are required to perform in day-to-day practice.
This survey aimed to explore these areas, gather feedback regarding therapeutics
teaching at undergraduate level, and to apply findings to undergraduate training at
University of Birmingham. Questionnaire-based survey of all first-year postgraduate
doctors (PG1) attending teaching hospitals in the Birmingham and Worcester regions
towards the end of the PG1 year. Doctors were asked about difficulties in prescribing,
satisfaction with undergraduate training, and how frequently they undertook particular
tasks pertaining to therapeutics. Qualitative data on suggestions for improving the
curriculum were also collected. Difficulties were commonly encountered with prescribing
warfarin, controlled drugs and syringe-driven drugs. Most (87.4 %) had been required to
administer intravenous medications. Nearly all had prescribed to ‘special groups’ such
as the elderly (100 %) and patients with renal disease (98.3 %). Thirty-seven percent
were not satisfied with their undergraduate therapeutics teaching, and many (56.2 %)
recommended making teaching more relevant to clinical practice. Many PG1s expressed
difficulties in prescribing potentially dangerous medications. Although better than
other UK surveys, significant numbers were not satisfied with undergraduate teaching.
The strong opinion was for teaching to become more practical and more relevant.
Prescriptions which PG1s are commonly asked to write have been described. Findings have
guided improvements to undergraduate teaching and assessment in therapeutics at the
University of Birmingham, and may offer guidance to other medical schools.
Self‐esteem in adolescent aggression perpetrators, victims and perpetrator‐victims, and the moderating effects of depression and family support
Authors: Wang Peng‐Wei , Yang Pin‐Chen , Yeh Yi‐Chun , Lin Huang‐Chi , Ko Chih‐Hung , Liu Tai‐Ling , Yen Cheng‐Fang
Published: November 2012

The aims of this study were (1) to examine differences in the level of self‐esteem among adolescents with different roles in aggression involvement (aggression perpetrators, victims, perpetrator‐victims and neutrals) according to gender and (2) to examine the moderating effects of depression and family support on association between aggression involvement and self‐esteem. A total of 8085 adolescents in Taiwan completed questionnaires. The relationships between self‐esteem and aggression involvement were examined by multiple regression analysis. The moderating effects of depression and family support on the association between aggression involvement and self‐esteem were examined. The results showed that in females, aggression victims had lower self‐esteem than those in the other three groups (t = −2.940 to 2.173, p < 0.05); however, there was no significant difference in self‐esteem among perpetrators, perpetrator‐victims, and neutrals (t = 0.693–0.933, p > 0.05). In males, self‐esteem in victims and perpetrator‐victims was lower than in neutrals and perpetrators (t = −3.339 to −2.704, p < 0.01); however, there was no difference in self‐esteem between victims and perpetrator‐victims (t = −1.115, p > 0.05) or between perpetrators and neutrals (t = −1.396, p > 0.05). Family support had a moderating effect on the association between self‐esteem and victimization in males. Depression had a moderating effect on the association between self‐esteem and perpetration‐victimization and victimization in males. The results indicate that self‐esteem in adolescents with different patterns of involvement in aggression is not the same as in those without involvement. The moderating effects of depression and family support should be considered when developing intervention strategies to raise self‐esteem in adolescents with aggression involvement.
SalmonellaDublin faecal excretion probabilities in cattle with different temporal antibody profiles in 14 endemically infected dairy herds
Authors: NIELSEN L. R.
Published: November 2012

This longitudinal field study investigated the hypothesis that persistently high antibody levels indicate a high risk ofSalmonellaDublin shedding in animals in 14 endemically infected dairy herds. A hierarchical multivariable logistic regression was used to analyse 6614 paired faecal cultures and four types of temporal antibody profiles from cattle aged ≥180 days. Age and repeated measurements on animals nested within herds were taken into account. Overall, the prevalence of faecal shedders was low (0·3% and 2·8% in the lowest and highest risk groups, respectively). An important predictor of faecal shedding was young age. There was a significant, but modest increase in risk in cattle with persistently high or recently increased antibody levels, but no difference between these two groups. Contrary to previous recommendations, the detection of carriers by the use of repeated antibody testing is not likely to be a plausible control option in mostSalmonellaDublin-infected dairy herds.
Effects of vitamin B12 supplementation on cognition, depression, and fatigue in patients with lacunar stroke
Authors: Huijts Marjolein , van Oostenbrugge Robert J. , Rouhl Rob P. W. , Menheere Paul , Duits Annelien
Published: November 2012

We read the review by Moore et al. (2012), recently published in this journal, with great interest and compliment the authors for their thorough review of cognitive impairment and its relation to vitamin B12.
The Colorado Adoption Project
Authors: Rhea Sally-Ann , Bricker Josh B. , Wadsworth Sally J. , Corley Robin P.
Published: November 2012

This paper describes the Colorado Adoption Project (CAP), an ongoing genetically informative longitudinal study of behavioral development. We describe the features of the adoption design used in CAP, and discuss how this type of design uses data from both parent–offspring and related- versus unrelated-sibling comparisons to estimate the importance of genetic and shared environmental influences for resemblance among family members. The paper provides an overview of CAP's history, how subjects were ascertained, recruited, and retained, and the domains of assessment that have been explored since the CAP's initiation in 1975. Findings from some representative papers that make use of data from CAP participants illustrate the study's multifaceted nature as a parent–offspring and sibling behavioral genetic study, a study that parallels a complimentary twin study, a longitudinal study of development, a source of subjects for molecular genetic investigation, and a study of the outcomes of the adoption process itself. As subjects assessed first at age 1 approach age 40, we hope the CAP will establish itself as the first prospective adoption study of lifespan development.
Response of methanogenic archaea to Late Pleistocene and Holocene climate changes in the Siberian Arctic
Authors: Bischoff Juliane , Mangelsdorf Kai , Gattinger Andreas , Schloter Michael , Kurchatova Anna N. , Herzschuh Ulrike , Wagner Dirk
Published: November 2012

In order to investigate the link between the methane dynamics in permafrost deposits and climate changes in the past, we studied the abundance, composition, and methane production of methanogenic communities in Late Pleistocene and Holocene sediments of the Siberian Arctic. We detected intervals of increased methane concentrations in Late Pleistocene and Holocene deposits along a 42 ka old permafrost sequence from Kurungnakh Island in the Lena Delta (northeast Siberia). Increased amounts of archaeal life markers (intact phospholipid ethers) and a high variety in genetic fingerprints detected by 16S ribosomal ribonucleic acid gene analyses of methanogenic archaea suggest presently living and presumably active methanogenic archaea in distinct layers predominantly in Holocene deposits, but also in deep frozen ground at 17 m depth. Potential methanogenic activity was confirmed by incubation experiments. By comparing methane concentrations, microbial incubation experiments, gene analysis of methanogens, and microbial life markers (intact phospholipid esters and ethers) to already partly degraded membrane lipids, such as archaeol and isoprenoid glycerol dialkyl glycerol tetraethers, we demonstrated that archaeol likely represents a signal of past methanogenic archaea. The archaeol signal was used to reconstruct the response of methanogenic communities to past temperature changes in the Siberian Arctic, and the data suggest higher methane emissions occurred during warm periods, particularly during an interval in the Late Pleistocene and during the Holocene. This new data on present and past methanogenic communities in the Siberian terrestrial permafrost imply that these microorganisms will respond to the predicted future temperature rise in the Arctic with increasing methane production, as demonstrated in previous warmer periods.
U.S. temperature and drought: Recent anomalies and trends
Authors: Karl T. R. , Gleason B. E. , Menne M. J. , McMahon J. R. , Heim R. R. , Brewer M. J. , Kunkel K. E. , Arndt D. S. , Privette J. L. , Bates J. J. , Groisman P. Y. , Easterling D. R.
Published: November 2012

The spring and summer (March through August) of 2011–2012 set many new climatological records across the contiguous United States, including the hottest month in the instrumental record: July 2012. Various measures of temperature extremes and drought severity serve to put this period into historical perspective (1895 to present) and to assess to what extent the recent anomalies are consistent with observed trends. During spring and summer, anomalously high temperatures can combine with unusually dry conditions to amplify temperature and drought feedbacks. Observational data from 2011 and 2012 are strongly suggestive of such an amplification and reveal a number of significant trends for various measures of high temperatures in the United States.
Scaling ecology across the continent
Authors: Kampe Thomas , Berukoff Steve
Published: November 2012

Spatial and Temporal Scaling in Continental‐Scale Ecology Workshop; Boulder, Colorado, 11–12 June 2012 Understanding the functional response of ecosystems across multiple spatial and temporal scales is one of the fundamental challenges in ecology. More than 50 researchers attended a June workshop focused on scaling ecological data from local and regional scales to the continental scale hosted by the National Ecological Observatory Network (NEON). The workshop addressed key issues associated with the influence of scale on the interpretation of ecological variation, particularly in the context of continental‐scale terrestrial ecology. These questions are particularly relevant to NEON, the first ecological observation platform designed to assess the natural and human causes and the biological consequences of environmental change at large scales.
Thriving Earth Exchange: AGU's new grand challenge
Authors: McEntee Chris , Williams Billy
Published: November 2012

Imagine a world where scientists are acknowledged and celebrated for their good works. Imagine being able to make a powerful impact, applying your expertise and experience to create real solutions to ensure a sustainable future. Now imagine those two ideas linked: AGU scientists engaged in creating solutions that are recognized and celebrated for their positive impact on our world. The AGU Grand Challenge: Thriving Earth Exchange, a new idea from our member leaders, is about making this dream real.
Seal‐mounted sensors measure seasonal flows under Antarctic ice
Authors: Schultz Colin
Published: November 2012

Researchers have questioned whether flows of warm deep water into Antarctica's Weddell Sea from farther north might vary seasonally, but hostile Antarctic conditions have made observations difficult. Årthun et al. turned to an unusual approach to measure water temperatures: They attached sensors to the heads of seals. The scientists glued conductivity‐temperature‐depth sensors to the heads of 19 Weddell seals and then loosed them in the region. Over an 8‐month period starting in February 2011, the seals' sensors captured 9000 temperature‐salinity profiles of the conditions under the ice. One region, the Filchner Ice Shelf Front, was particularly well sampled, as a single seal swam up and down 451 times throughout the study period. The authors' seal‐enabled observations were supported by an existing 3‐year‐long profile provided by a fixed sensor.
Carbon dioxide and past Antarctic temperature linked
Authors: Balcerak Ernie
Published: November 2012

Antarctic ice core records indicate a strong connection between a rapid rise in temperature and a rapid increase in atmospheric carbon dioxide (CO2) that occurred during the last ice age. Ahn et al. analyzed the carbon dioxide content of air preserved in Antarctic ice cores covering a time period about 37 to 47 thousand years ago, during which Antarctica went through two warming events in the midst of an ice age. The authors show that approximately half of the CO2 increase that occurred during that period happened very quickly, over less than 200 years. Furthermore, this rapid rise in CO2 occurred nearly simultaneously with a rapid rise in Antarctic temperature. Improved knowledge of the past connection between CO2 and climate can help inform understanding of the feedback relationship between CO2 and climate today. (Geophysical Research Letters, doi:10.1029/2012GL053018, 2012)
Global modeling study of potentially bioavailable iron input from shipboard aerosol sources to the ocean
Authors: Ito Akinori
Published: November 2012

Iron (Fe) is an essential element for phytoplankton. The majority of iron is transported from arid and semiarid regions to the open ocean, but it is mainly in an insoluble form. Since most aquatic organisms can take up iron only in the dissolved form, aerosol iron solubility is a key factor that can influence the air‐sea CO2 fluxes and thus climate. Field observations have shown relatively high iron solubility in aerosols influenced by combustion sources, but specific emissions sources and their contributions to deposition fluxes largely remain uncertain. Here a global chemical transport model was used to investigate the effect of aerosol emissions from ship plumes on iron solubility in particles from the combustion and dust sources. The model results reveal that the oil combustion from shipping mainly contributes to high iron solubility (>10%) at low iron loading (1–110 ng m–3) observed over the high‐latitude North Atlantic Ocean, rather than the other combustion sources from continental industrialized regions. Due to continuing growth in global shipping and no regulations regarding particles emissions over the open ocean, the input of potentially bioavailable iron from ship plumes is likely to increase during the next century. The model results suggest that deposition of soluble iron from ships in 2100 contributes 30–60% of the soluble iron deposition over the high‐latitude North Atlantic and North Pacific.
On the role of the ocean in projected atmospheric stability changes in the Atlantic polar low region
Authors: Woollings T. , Harvey B. , Zahn M. , Shaffrey L.
Published: November 2012

The occurrence of destructive mesoscale ‘polar low’ cyclones in the subpolar North Atlantic is projected to decline under anthropogenic change, due to an increase in atmospheric static stability. This letter reports on the role of changes in ocean circulation in shaping the atmospheric stability. In particular, the Atlantic Meridional Overturning Circulation (AMOC) is projected to weaken in response to anthropogenic forcing, leading to a local minimum in warming in this region. The reduced warming is restricted to the lower troposphere, hence contributing to the increase in static stability. Linear correlation analysis of the CMIP3 climate model ensemble suggests that around half of the model uncertainty in the projected stability response arises from the varied response of the AMOC between models.
Hot and cold ion outflow: Observations and implications for numerical models
Authors: Nilsson H. , Barghouthi I. A. , Slapak R. , Eriksson A. I. , André M.
Published: November 2012

Cluster observations of oxygen ion outflow and low‐frequency waves at high altitude above the polar cap and cold ion outflow in the lobes are used to determine ion heating rates and low‐altitude boundary conditions suitable for use in numerical models of ion outflow. Using our results, it is possible to simultaneously reproduce observations of high‐energy O+ ions in the high‐altitude cusp and mantle and cold H+ ions in the magnetotail lobes. To put the Cluster data in a broader context, we first compare the average observed oxygen temperatures and parallel velocities in the high‐altitude polar cap with the idealized cases of auroral (cusp) and polar wind (polar cap) ion outflow obtained from a model based on other data sets. A cyclotron resonance model using average observed electric field spectral densities as input fairly well reproduces the observed velocities and perpendicular temperatures of both hot O+ and cold H+, if we allow the fraction of the observed waves, which is efficient in heating the ions to increase with altitude and decrease toward the nightside. Suitable values for this fraction are discussed based on the results of the cyclotron resonance model. Low‐altitude boundary conditions, ion heating rates, and centrifugal acceleration are presented in a format suitable as input for models aiming to reproduce the observations.
Tidal wind mapping from observations of a meteor radar chain in December 2011
Authors: Yu You , Wan Weixing , Ning Baiqi , Liu Libo , Wang Zhengui , Hu LianHuan , Ren Zhipeng
Published: November 2012

This article proposes a technique to map the tidal winds in the mesosphere and lower thermosphere (MLT) region from the observations of a four‐station meteor radar chain located at middle‐ and low‐latitudes along the 120°E meridian in the Northern Hemisphere. A 1 month dataset of the horizontal winds in the altitude range of 80–100 km is observed during December 2011. We first decompose the tidal winds into mean, diurnal, semidiurnal, and terdiurnal components for each station. It is found that the diurnal/semidiurnal components dominate at the low‐latitude/midlatitude stations. Their amplitudes increase at lower altitudes and then decrease at higher altitudes after reaching a peak in the MLT region. Hough functions of the classical tidal theory are then used to fit the latitudinal distribution of each decomposed component. The diurnal component is found to be dominated by the first symmetric (1, 1) mode. Yet for the semidiurnal and terdiurnal components, the corresponding dominant modes are the second symmetric modes (2, 4) and (3, 5), and considerable contributions are also from the first antisymmetric modes (2, 3), (3, 4) and second antisymmetric modes (2, 5), (3, 6). Based on the decomposed results, we further map the horizontal winds in the domains of latitude, altitude and local time. The mapped horizontal winds successfully reproduce the local time versus altitudinal distributions of the original observations at the four stations. Thus, we conclude that the meteor radar chain is useful to monitor and study the regional characteristics of the tidal winds in the MLT region.
POES satellite observations of EMIC‐wave driven relativistic electron precipitation during 1998–2010
Authors: Carson Bonar R. , Rodger Craig J. , Clilverd Mark A.
Published: November 2012

Using six Polar Orbiting Environmental Satellites (POES) satellites that have carried the Space Environment Module‐2 instrument package, a total of 436,422 individual half‐orbits between 1998 and 2010 were inspected by an automatic detection algorithm searching for electromagnetic ion cyclotron (EMIC) driven relativistic electron precipitation (REP). The algorithm searched for one of the key characteristics of EMIC‐driven REP, identified as the simultaneity between spikes in the P1 (52 keV differential proton flux channel) and P6 (>800 keV electron channel). In all, 2331 proton precipitation associated REP (PPAREP) events were identified. The majority of events were observed at L‐values within the outer radiation belt (3 < L < 7) and were more common in the dusk and night sectors as determined by magnetic local time. The majority of events occurred outside the plasmasphere, at L‐values ~1 Re greater than the plasmapause location determined from two different statistical models. The events make up a subset of EMIC‐driven proton spikes investigated by Sandanger et al. (2009), and potentially reflect different overall characteristics compared with proton spikes, particularly when comparing their location to that of the plasmapause, i.e., EMIC‐driven proton precipitation inside the plasmapause, and potentially EMIC‐driven REP outside the plasmapause. There was no clear relationship between the location of plasmaspheric plumes and the locations of the PPAREP events detected. Analysis of the PPAREP event occurrence indicates that high solar wind speed and high geomagnetic activity levels increase the likelihood of an event being detected. The peak PPAREP event occurrence was during the declining phase of solar cycle 23, consistent with the 2003 maximum in the geomagnetic activity index, Ap.
High‐resolution interseismic velocity data along the San Andreas Fault from GPS and InSAR
Authors: Tong X. , Sandwell D. T. , Smith‐Konter B.
Published: November 2012

We compared four interseismic velocity models of the San Andreas Fault based on GPS observations. The standard deviations of the predicted secular velocity from the four models are larger north of the San Francisco Bay area, near the creeping segment in Central California, and along the San Jacinto Fault and the East California Shear Zone in Southern California. A coherence spectrum analysis of the secular velocity fields indicates relatively high correlation among the four models at longer wavelengths (>15–40 km), with lower correlation at shorter wavelengths. To improve the short‐wavelength accuracy of the interseismic velocity model, we integrated interferometric synthetic aperture radar (InSAR) observations, initially from Advanced Land Observing Satellite (ALOS) ascending data (spanning from the middle of 2006 to the end of 2010, totaling more than 1100 interferograms), with GPS observations using a Sum/Remove/Filter/Restore approach. The final InSAR line of sight data match the point GPS observations with a mean absolute deviation of 1.5 mm/yr. We systematically evaluated the fault creep rates along major faults of the San Andreas Fault and compared them with creepmeters and alignment array data compiled in Uniform California Earthquake Rupture Forecast, Version 2 (UCERF2). Moreover, this InSAR line of sight dataset can constrain rapid velocity gradients near the faults, which are critical for understanding the along‐strike variations in stress accumulation rate and associated earthquake hazard.
Variations in tropical cyclone precipitation in Texas (1950 to 2009)
Authors: Zhu Laiyin , Quiring Steven M.
Published: November 2012

Spatial and temporal variations of tropical cyclone precipitation (TCP) in Texas are examined using 60 years of precipitation data from Cooperative Observing Network gages (1950 to 2009). An automated extraction method is used to identify TCP. Texas receives an average of 123.5 mm of TCP/year, which is ~13% of the state's mean annual precipitation. September is the month with the most TCP with an average of 18.5 mm. As expected, TCP generally deceases as you move inland. Long‐term trends (>50 years) in TCP are evident at some locations, but there are no statistically significant long‐term trends in aggregated annual TCP metrics for Texas. Despite the lack of long‐term trends, TCP metrics show some spectral power at periodicities of ~2‐3 years, ~5‐8 years, and >10 years. Areas within 400 km of the coast have higher risk of extreme daily TCP (>100 mm), but inland Texas can also occasionally experience extreme TCP. In some areas in southeastern Texas the probability of receiving >100 mm of daily TCP in any given year is ~0.30 (i.e., daily TCP exceeds 100 mm, on average, 1 out every 3 years).
Impact of seabird activity on nitrous oxide and methane fluxes from High Arctic tundra in Svalbard, Norway
Authors: Zhu Renbin , Chen Qingqing , Ding Wei , Xu Hua
Published: November 2012

In this study, tundra N2O and CH4 fluxes were measured from one seabird sanctuary (SBT) and two non‐seabird colonies (NST‐I and NST‐II) in Ny‐Ålesund (79°55′N, 11°56′E), Svalbard during the summers of 2008 and 2009. N2O and CH4 fluxes from SBT showed large temporal and spatial variations depending on the intensity of seabird activity. High seabird activity sites showed large N2O and CH4 emissions while low N2O and CH4 emissions, even CH4 uptake occurred at medium and low seabird activity sites. Overall the mean fluxes were 18.3 ± 3.6 μg N2O m−2 h−1 and 53.5 ± 20.3 μg CH4 m−2 h−1 from tundra SBT whereas tundra NST‐I and NST‐II represented a relatively weak N2O source (8.3 ± 13.2 μg N2O m−2 h−1) and strong CH4 sink (−82.8 ± 22.3 μg CH4 m−2 h−1). Seabird activity was the strongest control of N2O and CH4 fluxes compared with soil temperature and moisture, and high N2O and CH4 emissions were created by soil physical and chemical processes (the sufficient supply of nutrients NH4+–N, NO3−–N, total nitrogen, total phosphorus and total carbon from seabird guano, seabird tramp and appropriate water content) related to the seabird activity. Our work suggests that tundra ecosystems impacted by seabird activity are the potential “hotspots” for N2O and CH4 emissions although these sources have been largely neglected at present. Furthermore the combination of seabird activity and warming climate will likely further enhance N2O and CH4 emissions from the High Arctic tundra.
A new mechanism for Dansgaard‐Oeschger cycles
Authors: Petersen S. V. , Schrag D. P. , Clark P. U.
Published: November 2012

We present a new hypothesis to explain the millennial‐scale temperature variability recorded in ice cores known as Dansgaard‐Oeschger (DO) cycles. We propose that an ice shelf acted in concert with sea ice to set the slow and fast timescales of the DO cycle, respectively. The abrupt warming at the onset of a cycle is caused by the rapid retreat of sea ice after the collapse of an ice shelf. The gradual cooling during the subsequent interstadial phase is determined by the timescale of ice‐shelf regrowth. Once the ice shelf reaches a critical size, sea ice expands, driving the climate rapidly back into stadial conditions. The stadial phase ends when warm subsurface waters penetrate beneath the ice shelf and cause it to collapse. This hypothesis explains the full shape of the DO cycle, the duration of the different phases, and the transitions between them and is supported by proxy records in the North Atlantic and Nordic Seas.
Methicillin-Resistant Staphylococcus aureus Vertebral Osteomyelitis Following Epidural Catheterization: A Case Report and Literature Review
Authors: Krishnakumar R. , Renjitkumar J.
Published: November 2012

Indwelling epidural catheters are frequently used to manage postoperative pain. This report describes a patient who developed methicillin-resistant Staphylococcus aureus (MRSA) vertebral osteomyelitis of the lumbar spine following epidural catheterization. To the best of our knowledge, this is the first reported case of MRSA vertebral osteomyelitis secondary to epidural catheter use in the English orthopedic literature. The patient and his family consented to publishing the data.
Local processing enhancements associated with superior observational drawing are due to enhanced perceptual functioning, not weak central coherence
Authors: Chamberlain Rebecca , McManus I.C. , Riley Howard , Rankin Qona , Brunswick Nicola
Published: November 2012

Individuals with drawing talent have previously been shown to exhibit enhanced local visual processing ability. The aim of the current study was to assess whether local processing biases associated with drawing ability result from a reduced ability to cohere local stimuli into global forms, or an increased ability to disregard global aspects of an image. Local and global visual processing ability was assessed in art students and controls using the Group Embedded Figures Task, Navon shape stimuli, the Block Design Task and the Autism Spectrum Quotient, whilst controlling for nonverbal IQ and artistic ability. Local processing biases associated with drawing appear to arise from an enhancement of local processing alongside successful filtering of global information, rather than a reduction in global processing. The relationship between local processing and drawing ability is independent of individual differences in nonverbal IQ and artistic ability. These findings have implications for bottom-up and attentional theories of observational drawing, as well as explanations of special skills in autism.
A Kuhnian Critique of Psychometric Research on Peer Review
Authors: Lee Carole J.
Published: November 2012

Psychometrically oriented researchers construe low interrater reliability measures for expert peer reviewers as damning for the practice of peer review. I argue that this perspective overlooks different forms of normatively appropriate disagreement among reviewers. Of special interest are Kuhnian questions about the extent to which variance in reviewer ratings can be accounted for by normatively appropriate disagreements about how to interpret and apply evaluative criteria within disciplines during times of normal science. Until these empirical-cum-philosophical analyses are done, it will remain unclear the extent to which low interrater reliability measures represent reasonable disagreement rather than arbitrary differences between reviewers.
Case Studies: One Observation or Many? Justification or Discovery?
Authors: Morgan Mary S.
Published: November 2012

Critiques of case studies as an epistemic genre usually focus on the domain of justification and hinge on comparisons with statistics and laboratory experiments. In this domain, case studies can be defended by the notion of “infirming”: they use many different bits of evidence, each of which may independently “infirm” the account. Yet their efficacy may be more powerful in the domain of discovery, in which these same different bits of evidence must be fully integrated to create an explanatory account with internal validity.
Models, Fictions, and Realism: Two Packages
Authors: Levy Arnon
Published: November 2012

Some philosophers of science—myself included—appeal to fiction as an interpretation of the practice of modeling. This raises the specter of an incompatibility with realism, since fiction making is essentially nontruth regulated. I argue that the prima facie conflict can be resolved in two ways, each involving a distinct notion of fiction and a corresponding formulation of realism. The main goal of the essay is to describe these two packages. I comment also on how to choose between them.
Presidential Address: Will This Policy Work for You? Predicting Effectiveness Better: How Philosophy Helps
Authors: Cartwright Nancy
Published: November 2012

There is a takeover movement fast gaining influence in development economics, a movement that demands that predictions about development outcomes be based on randomized controlled trials. The problem it takes up—of using evidence of efficacy from good studies to predict whether a policy will be effective if we implement it—is a general one, and affects us all. My discussion is the result of a long struggle to develop the right concepts to deal with the problem of warranting effectiveness predictions. Whether I have it right or not, these are questions of vast social importance that philosophers of science can, and should, help answer.
Anatomic Sites of Patent Colonization and Environmental Contamination with Klebsiella pneumoniae Carbapenemase—Producing Enterobacteriaceae at Long-Term Acute Care Hospitals
Authors: Thurlow Caroline J. , Prabaker Kavitha , Lin Michael Y. , Lolans Karen , Weinstein Robert A. , Hayden Mary K. ,   Centers for Disease Control and Prevention Epicenters Program
Published: November 2012

Objective.

To determine anatomic sites of colonization in patients and to assess environmental contamination with Klebsiella pneumoniae carbapenemase (KPC)-producing Enterobacteriaceae.

Design, Setting, and Patients.

We conducted a cross-sectional microbiologic survey of 33 patients and their environments at 6 long-term acute care hospitals (LTACHs) in metropolitan Chicago. Swab samples of anatomic sites and inanimate surfaces in patients' rooms and common areas were cultured. blaKPC was verified by polymerase chain reaction. Patient charts were reviewed for covariates known to be associated with colonization and environmental contamination.

Results.

Mean age was 66 years. Median length of stay prior to surveillance was 50 days. Thirty (91%) patients were mechanically ventilated, 32 (97%) were bedbound, and 27 (82%) had fecal incontinence. Of the 24 patients with KPC-producing Enterobacteriaceae recovered from 1 or more anatomic sites, 23 (96%) had KPC-producing Enterobacteriaceae detected at 1 or more skin sites. Skin colonization was more common in patients with positive rectal/stool swab cultures or positive clinical cultures (P <.001). Rectal/stool swab was the single most sensitive specimen for detecting KPC-producing Enterobacteriaceae colonization (sensitivity, 88%; 95% confidence interval [CI], 68%-97%); addition of inguinal skin swab culture resulted in detection of all colonized patients (sensitivity, 100%; 95% CI, 86%-100%). Only 2 (0.5%) of 371 environmental specimens grew KPC-producing Enterobacteriaceae.

Conclusions.

Culture of more than 1 anatomic site was required to detect all KPC-producing Enterobacteriaceae-colonized Patients. Skin colonization was common, but environmental contamination was rare. These results can guide development of multimodal interventions for control of KPC-producing Enterobacteriaceae in LTACHs.
Improving temperature-stable AZO–Ag–AZO multilayer transparent electrodes using thin Al layer modification
Authors: Zhou Lin , Chen Xiaohong , Zhu Feng , Sun XinXing , Sun Zhuo
Published: November 2012

The thermal stability of AZO/Al/Ag/Al/AZO (5A) compared with AZO/Ag/AZO (3A) electrodes was significantly improved by introducing a thin Al layer at the interface between Ag and AZO layers. The rapidly deteriorated sheet resistance of 3A compared with 5A electrodes is roughly consistent with the XRD results of weaker intensity of the (1 1 1) Ag peak of 3A after annealing for 20 h at 300 or 500 °C for 10 min. The improved thermal stability of the 5A electrode is ascribed to the limitation function of Al atoms on Ag diffusion into the AZO layer. The polymer solar cells based on 5A compared with ITO electrodes showed a similar efficiency.
Dual-band spoof surface plasmon polaritons based on composite-periodic gratings
Authors: Gao Xi , Shi Jin Hui , Ma Hui Feng , Jiang Wei Xiang , Cui Tie Jun
Published: November 2012

We propose a composite grating structure constructed by a double-periodic groove array with finite thickness, which supports two tightly bound spoof surface plasmon polaritons (SPPs) at two frequency bands. The two SPP waves correspond to the dominant modes of two single-periodic gratings with different groove depths, and the cutoff frequency of each mode is determined independently by the individual groove depth. We design and fabricate the dual-band SPP waveguide in the microwave frequency, and the measurement results show good performance of SPP propagations. The ability to guide two independent-band SPP waves could be important for developing novel surface wave devices.
Hybrid plasmonic structures based on CdS nanotubes: a novel route to low-threshold lasing on the nanoscale
Authors: Bian Yusheng , Zheng Zheng , Zhao Xin , Su Yalin , Liu Lei , Liu Jiansheng , Zhou Tao , Zhu Jinsong
Published: November 2012

Nanowires and nanotubes could become important building blocks in advanced photonic systems owing to their fascinating optoelectronic properties and high compatibility with versatile chemical synthetic methods. Many intriguing studies have been enabled by applying these nanostructures in the construction of various types of active and passive photonic components. Successful examples are the recent demonstration of semiconductor and plasmonic lasers based on CdS nanowires (Duan et al 2003 Nature
421 241–5, Oulton et al 2009 Nature
461 629–32, Ma et al 2010 Nature Mater.
10 110–13), which generate and deliver intense coherent light down to and even below the diffraction-limited scale. Here in this paper, by carrying out a numerical investigation of a novel hybrid plasmonic structure that consists of a CdS nanotube sitting above a metal substrate separated by a nanometric MgF2 layer, we show theoretically that nanotube-based plasmonic structures can also act as highly efficient lasing sources. Optical properties of such a laser configuration including modal behaviour and the lasing threshold is investigated with regard to the variation of key geometrical parameters. Simulation results reveal that the employment of a CdS nanotube may result in improved optical performance compared with the conventional CdS-nanowire-based plasmon laser. Reduced lasing threshold with mitigated modal loss can be achieved simultaneously under carefully engineered geometries. We also explore the feasibility of combining nanowire- and nanotube-based active and passive components for on-chip integrations. As a simple demonstration, monolithic integration of a CdS nanotube laser with a CdS-nanowire-based passive component is shown numerically on a single chip. We expect that these studies could lay the foundations for nanotube- and nanowire-based hybrid integrated photonic components and circuits.
Synthesis characteristics of Cu particulates in high-pressure magnetron sputtering plasmas studied by in situ laser-light scattering
Authors: Nafarizal N , Sasaki K
Published: November 2012

This paper reports the temporal evolution, the dependence on the discharge conditions and the spatial distribution of Cu particulates synthesized in high-pressure magnetron sputtering plasmas. The spatial distributions of the size and the density of particulates were examined with precision using a two-wavelength laser light scattering technique. We found that more than 50% of Cu particulates in the discharge space had sizes ranging between 100 and 175 nm. The absolute density of Cu particulate was on the order of 107–109 cm−3. Cu particulates had concentrated distributions in the boundary between the bright plasma and the dark region and in the region connecting to the anode of the magnetron sputtering source. The spatial distribution, the size distribution and the density of Cu particulates were sensitively dependent on the discharge power and pressure.
The local dissociation phenomenon in a nitrogen afterglow
Authors: Levaton J , Amorim J , Ricard A
Published: November 2012

We used the optical emission spectroscopy diagnostic to study the nitrogen afterglow of a
pure N2 flowing dc discharge operating under particular experimental conditions to
facilitate the simultaneous occurrence of the pink afterglow (PA) and the Lewis–Rayleigh
afterglow. The PA is a special kind of nitrogen plasma occurring outside the direct influence
of an external electric field. The phenomenon results from the flux of energy, introduced in
the nitrogen molecules by the electrons in the discharge region, from the lower to the higher

vibrational levels due to vibrational–vibrational (V–V) and
vibrational–translational (V–T) exchange reactions. We studied the following set of
experimental conditions: discharge electric current
(I = 15–50 mA), gas pressure
(p = 200–1070 Pa) and gas flow rate
(Q = 400–1000 sccm). The emissions of the first
positive system of the nitrogen molecules were monitored from the end of the discharge down to
the end of the post-discharge tube. A kinetic numerical model developed to investigate the
nitrogen afterglow generated a calibrating factor for the 580.4 nm band in such a way that
the relative density of the N(4S) atoms could be measured along the afterglow. The
experimental results indicated that N(4S) atoms are created locally in the afterglow
producing atomic density profiles that follow the behaviour of the other species studied
experimentally in the PA, such as

, N2(B 3Πg),
N2(C 3Πu),

,

, N+,

,

, N(2D) and N(2P). The numerical model was also used to
fit the N2(B 3Πg),

and the N(4S) experimental density profiles and to evaluate the
participation of several kinetic pathways capable of producing local dissociation in the
N2 afterglow. It was found that the dominant dissociation channel in the PA is the
reaction

. Its rate constant was estimated, being approximately
5 × 10−12 cm3 s−1.