bluuebunny/crossref_metadata_2025 huggingface dataset:
Surficial geology, Snowdrift, Northwest Territories, NTS 75-L
Authors: Kerr D E , Knight R D , Sharpe D R , Cummings D I , Kjarsgaard B A
Published: February 2014

The Snowdrift map area is characterized by predominantly glaciated, scoured and washed bedrock terrain. The more elevated areas north and south of the East Arm have isolated deposits of till veneer and blanket. Within the East Arm, some low lying depressions
between bedrock ridges are infilled by glaciolacustrine sediments, with various colluvial deposits covering the steepest slopes. Glaciofluvial complexes consisting of eskers, ice-contact sediments and outwash, trend southwestward in the north and westward in the southern map areas. The Snowdrift
River valley and its tributaries are predominantly infilled by terraced and floodplain alluvial sediments, and ridged and outwash glaciofluvial sediments, some with active dunes. The last ice flow recorded by glacial striae, fluted bedrock and crag-and-tails, was generally southwestward to westward,
in the extreme southeast region of the map area. At various elevations, evidence of glacial Lake McConnell is found: isolated glaciolacustrine deltas at 350 m, 335 m, 320 m, 275 m, 260 m; washing limits at 335 m and 320 m; and raised beaches and wave-cut terraces at 335 m, 320 m, 305 m, 285 m, 228
m, 213 m, 200 m, 183 m and 168 m a.s.l.
Micromorphological descriptions of till from pit K-62, Pine Point mining district, Northwest Territories
Authors: Rice J M , Paulen R
C , Menzies J , McClenaghan M
B
Published: February 2014

A better understanding of glacial transport and depositional environments has resulted from micromorphological studies of glacial sediments over the last several decades. The past-producing Pb-Zn mine at Pine Point, Northwest Territories, has >20 m of
continuous diamicton overlying low-relief Paleozoic bedrock, which provides a unique opportunity to further the investigation of micromorphology in the study of glacial sediments, in particular the sustained depositional record versus the erosional records of various ice-flow trajectories and how
that information can help document indicator mineral dispersal. Pit-K62 at Pine Point has a ~23 m section of diamicton from which 19 samples were collected and thin sections prepared. This report describes sample collection, thin section production and analysis, and microstructure
identification of each of these 19 samples. These results will be combined with glacial stratigraphy and indicator-mineral work previously completed for the area to refine exploration techniques for Mississippi Valley-type Pb-Zn deposits utilizing the transportation history of their indicator
minerals.
Noncommutative determinants, Cauchy–Binet formulae, and Capelli-type identities II. Grassmann and quantum oscillator algebra representation
Authors: Caracciolo Sergio , Sportiello Andrea
Published: February 2014

We prove that, for

X

,

Y

,

A

and

B

matrices with entries in a non-commutative ring such that

\hbox{$[X_{ij},Y_{k\ell}]=-A_{i\ell} B_{kj}$},

satisfying suitable commutation relations (in particular,

X

is a Manin matrix), row-pseudo-commutative matrix (a Manin matrix), the following identity holds:

\mathrm {col-det } \ X \ \mathrm { col-det } \ Y \ = \langle 0\mid \mathrm { col-det } \ (aA + X (I-a^{\dagger} B)^{-1} Y)\mid 0\rangle

Furthermore, if also

Y

is a Manin matrix,

[Y_{ij},Y_{kl}]=0

for

i\neq k

,

j\neq l

\mathrm {col-det } \ X \ \mathrm { col-det } \ Y =\int \mathcal{D}(\psi, \bar{\psi}) \exp \big(\sum_{k \geq 0}\frac{(\bar{\psi} A \psi)^{k}}{k+1}(\bar{\psi} X B^k Y \psi)\big)

Here

\langle 0 \mid

and

\mid 0\rangle

, are respectively the bra and the ket of the ground state,

a^{\dagger}

and

a

the creation and annihilation operators of a quantum harmonic oscillator, while

\bar{\psi}_i

and

\psi_i

are Grassmann variables in a Berezin integral. These results should be seen as a generalization of the classical Cauchy–Binet formula, in which

A

and

B

are null matrices, and of the non-commutative generalization, the Capelli identity, in which

A

and

B

are identity matrices and

[X_{ij},X_{k\ell}]=[Y_{ij},Y_{k\ell}]=0

.
The Potts model and chromatic functions of graphs
Authors: Klazar Martin , Loebl Martin , Moffatt Iain
Published: February 2014

The

U

-polynomial of Noble and Welsh is known to have intimate connections with the Potts model as well as with several important graph polynomials. For each graph

G

,

U(G)

is equivalent to the Stanley's symmetric bad colouring polynomial

XB(G)

. Moreover Sarmiento established the equivalence between

U

and the polychromate of Brylawski. All these functions have countable number of variables, even though the restrictions to an arbitrary graph are honest polynomials. Loebl defined the

q

-dichromate

B_q(G,x,y)

as a function of graph

G

and three independent variables

q,x,y

, proved that it is equal to the partition function of the Potts model with variable number of states and with certain magnetic field contribution, and conjectured that

q

-dichromate is equivalent to the

U

-polynomial. He also proposed a stronger conjecture on integer partitions. The aim of this paper is two-fold. We present a construction disproving the Loebl's integer partitions conjecture, and we introduce a new function

B_{r,q}(G,x,k)

which is also equal to the partition function of the Potts model with variable number of states and with a (different) external field contribution, and we show that

B_{r,q}(G,x,k)

is equivalent to

U

-polynomial. This gives a Potts model-type formulation for the

U

-polynomial.
Counting tensor model observables and branched covers of the 2-sphere
Authors: Ben Geloun Joseph , Ramgoolam Sanjaye
Published: February 2014

Lattice gauge theories of permutation groups with a simple topological action (henceforth permutation-TFTs) have recently found several applications in the combinatorics of quantum field theories (QFTs). They have been used to solve counting problems of Feynman graphs in QFTs and ribbon graphs of large

N

, often revealing inter-relations between different counting problems. In another recent development, tensor theories generalizing matrix theories have been actively developed as models of random geometry in three or more dimensions. Here, we apply permutation-TFT methods to count gauge invariants for tensor models, colored as well as non-colored. For the colored case, we exhibit a relationship with the counting of branched covers of the 2-sphere, where the rank

d

of the tensor gets related to a number of branch points. We give explicit generating functions for the relevant countings and describe algorithms for the enumeration of the invariants. While the counting of colored tensor invariants is related to the classic counting of Hurwitz equivalence classes of branched covers with fixed branch points, collecting these under a further equivalence of permuting the branch points is relevant to the color-symmetrized tensor invariant counting. We also apply the permutation-TFT methods to obtain some formulae for correlators of the tensor model invariants.
Integrated School-Based Surveillance for Soil-Transmitted Helminth Infections and Lymphatic Filariasis in Gampaha District, Sri Lanka
Authors: Gunawardena Sharmini , Gunawardena Nipul K. , Kahathuduwa Ganga , Karunaweera Nadira D. , de Silva Nilanthi R. , Ranasinghe Udaya B. , Samarasekara Sandhya D. , Nagodavithana Kumara C. , Rao Ramakrishna U. , Rebollo Maria P. , Weil Gary J.
Published: February 2014

We explored the practicality of integrating surveillance for soil-transmitted helminthiasis (STH, assessed by Kato-Katz) with transmission assessment surveys for lymphatic filariasis (LF) in two evaluation units (EUs) in Gampaha district, Sri Lanka (population 2.3 million). The surveys were performed 6 years after five annual rounds of mass drug administration with diethylcarbamazine and albendazole. Each transmission assessment survey tested children (N = 1,462 inland EU; 1,642 coastal EU) sampled from 30 primary schools. Low filarial antigenemia rates (0% and 0.1% for the inland and coastal EUs) suggest that LF transmission is very low in this district. The STH rates and stool sample participation rates were 0.8% and 61% (inland) and 2.8% and 58% (coastal). Most STH detected were low or moderate intensity Trichuris trichiura infections. The added cost of including STH testing was ∼$5,000 per EU. These results suggest that it is feasible to integrate school-based surveillance for STH and LF.
Oxidative Stress Markers Correlate with Renal Dysfunction and Thrombocytopenia in Severe Leptospirosis
Authors: Araújo Alan M. , Reis Eliana A. G. , Athanazio Daniel A. , Ribeiro Guilherme S. , Hagan José E. , Araujo Guilherme C. , Damião Alcineia O. , Couto Nicolli S. , Ko Albert I. , Noronha-Dutra Alberto , Reis Mitermayer G.
Published: February 2014

Leptospirosis is a zoonotic disease that causes severe manifestations such as Weil's disease and pulmonary hemorrhage syndrome. The aim of this study was to evaluate whether reactive oxygen species (ROS) production and antioxidant reduced glutathione (GSH) levels are related to complications in patients hospitalized with leptospirosis. The ROS production and GSH levels were measured in blood samples of 12 patients and nine healthy controls using chemiluminescence and absorbance assays. We found that ROS production was higher and GSH levels were lower in leptospirosis patients compared with healthy individuals. Among patients, GSH depletion was correlated with thrombocytopenia and elevated serum creatinine, whereas a strong positive correlation was observed between ROS production and elevated serum potassium. Additional investigation of the biological significance of ROS production and GSH levels is warranted as they may guide the development of novel adjuvant therapies for leptospirosis targeting oxidative stress.
Nasal Carriage of Multi-Drug Resistant Panton-Valentine Leucocidin-Positive Methicillin-Resistant Staphylococcus aureus in Children in Tripoli-Libya
Authors: Al-haddad Omaima H. , Zorgani Abdulaziz , Ghenghesh Khalifa Sifaw
Published: February 2014

Methicillin-resistant Staphylococcus aureus (MRSA) colonized children are at an increased risk of developing infections than methicillin-sensitive S. aureus colonized children. Nasal specimens from inpatient children, mothers of inpatient children, healthcare workers, and outpatient children at Tripoli Children Hospital (TCH) were examined for MRSA by chromogenic MRSA ID medium. Susceptibility of MRSA isolates to antibiotics was determined by the disc diffusion method. The nasal carriage rate of MRSA among inpatient children (8.3%, 24 of 289), their mothers (11%, 22 of 200), and healthcare workers (12.4%, 22 of 178) was significantly higher than among outpatient children (2.2%, 2 of 91) (P < 0.05, P < 0.02, and P < 0.006, respectively). Of the examined MRSA isolates (N = 35) 10 (28.6%) were positive for Panton-Valentine leucocidin genes by polymerase chain reaction. Multidrug resistance was found in 24.3% (17 of 70) of MRSA isolates. Nasal carriage of multidrug-resistant Panton-Valentine leucocidin-positive MRSA is not uncommon among inpatient children and their mothers in Tripoli.
Estimating greenhouse gas fluxes from an agriculture-dominated landscape using multiple planetary boundary layer methods
Authors: Zhang X. , Lee X. , Griffis T. J. , Baker J. M. , Xiao W.
Published: February 2014

Abstract. Quantification of regional greenhouse gas (GHG) fluxes is essential for establishing mitigation strategies and evaluating their effectiveness. Here, we used multiple top-down approaches and multiple trace gas observations at a tall tower to estimate GHG regional fluxes and evaluate the GHG fluxes derived from bottom-up approaches. We first applied the eddy covariance, equilibrium, inverse modeling (CarbonTracker), and flux aggregation methods using three years of carbon dioxide (CO2) measurements on a 244 m tall tower in the Upper Midwest, USA. We then applied the equilibrium method for estimating methane (CH4) and nitrous oxide (N2O) fluxes with one-month high-frequency CH4 and N2O gradient measurements on the tall tower and one-year concentration measurements on a nearby tall tower, and evaluated the uncertainties of this application. The results indicate that: (1) the flux aggregation, eddy covariance, the equilibrium method, and the CarbonTracker product all gave similar seasonal patterns of the regional CO2 flux (105–106 km2), but that the equilibrium method underestimated the July CO2 flux by 52–69%. (2) The annual budget varied among these methods from 74 to −131 g C-CO2 m−2 yr−1, indicating a large uncertainty in the annual CO2 flux estimation. (3) The regional CH4 and N2O emissions according to a top-down method were at least six and two times higher than the emissions from a bottom-up inventory (Emission Database for Global Atmospheric Research), respectively. (4) The global warming potentials of the CH4 and N2O emissions were equal in magnitude to the cooling benefit of the regional CO2 uptake. The regional GHG budget, including both biological and anthropogenic origins, is estimated at 7 ± 160 g CO2 eq m−2 yr−1.
Heterogeneity of impacts of high CO2 on the North Western European Shelf
Authors: Artioli Y. , Blackford J. C. , Nondal G. , Bellerby R. G. J. , Wakelin S. L. , Holt J. T. , Butenschön M. , Allen J. I.
Published: February 2014

Abstract. The increase in atmospheric CO2 is a dual threat to the marine environment: from one side it drives climate change, leading to modifications in water temperature, circulation patterns and stratification intensity; on the other side it causes a decrease in marine pH (ocean acidification, or OA) due to the increase in dissolved CO2. Assessing the combined impact of climate change and OA on marine ecosystems is a challenging task. The response of the ecosystem to a single driver can be highly variable and remains still uncertain; additionally the interaction between these can be either synergistic or antagonistic. In this work we use the coupled oceanographic–ecosystem model POLCOMS-ERSEM driven by climate forcing to study the interaction between climate change and OA. We focus in particular on carbonate chemistry, primary and secondary production. The model has been run in three different configurations in order to assess separately the impacts of climate change on net primary production and of OA on the carbonate chemistry, which have been strongly supported by scientific literature, from the impact of biological feedbacks of OA on the ecosystem, whose uncertainty still has to be well constrained. The global mean of the projected decrease of pH at the end of the century is about 0.27 pH units, but the model shows significant interaction among the drivers and high variability in the temporal and spatial response. As a result of this high variability, critical tipping point can be locally and/or temporally reached: e.g. undersaturation with respect to aragonite is projected to occur in the deeper part of the central North Sea during summer. Impacts of climate change and of OA on primary and secondary production may have similar magnitude, compensating in some area and exacerbating in others.
Technical Note: Disturbance of soil structure can lead to release of entrapped methane in glacier forefield soils
Authors: Nauer P. A. , Chiri E. , Zeyer J. , Schroth M. H.
Published: February 2014

Abstract. Investigations of sources and sinks of atmospheric CH4 are needed to understand the global CH4 cycle and climate-change mitigation options. Glaciated environments might play a critical role due to potential feedbacks with global glacial meltdown. In an emerging glacier forefield, an ecological shift occurs from an anoxic, potentially methanogenic subglacial sediment to an oxic proglacial soil, in which soil-microbial consumption of atmospheric CH4 is initiated. The development of this change in CH4 turnover can be quantified by soil-gas profile analysis. We found evidence for CH4 entrapped in glacier forefield soils when comparing two methods for the collection of soil-gas samples: a modified steel rod (SR) designed for one-time sampling and rapid screening (samples collected ∼1 min after hammering the SR into the soil), and a novel multilevel sampler (MLS) for repetitive sampling through a previously installed access tube (samples collected weeks after access-tube installation). In glacier forefields on siliceous bedrock, sub-atmospheric CH4 concentrations were observed with both methods. Conversely, elevated soil-CH4 concentrations were observed in calcareous glacier forefields, but only in samples collected with the SR, while MLS samples all showed sub-atmospheric CH4 concentrations. Time-series of SR soil-gas sampling (additional samples collected 2, 3, 5, and 7 min after hammering) confirmed the transient nature of the elevated soil-CH4 concentrations, which were decreasing from ∼100 μL L−1 towards background levels within minutes. This hints towards the existence of entrapped CH4 in calcareous glacier forefield soil that can be released when sampling soil-gas with the SR. Laboratory experiments with miniature soil cores collected from two glacier forefields confirmed CH4 entrapment in these soils. Treatment by sonication and acidification resulted in a massive release of CH4 from calcareous cores (on average 0.3–1.8 μg CH4 (g d.w.)−1) (d.w. – dry weight); release from siliceous cores was 1–2 orders of magnitude lower (0.02–0.03 μg CH4 (g d.w.)−1). Clearly, some form of CH4 entrapment exists in calcareous glacier forefield soils, and to a much lesser extent in siliceous glacier forefield soils. Its nature and origin remain unclear and will be subject of future investigations.
How well can we predict soil respiration with climate indicators, now and in the future?
Authors: Berridge C. T. , Hadju L. H. , Dolman A. J.
Published: February 2014

Abstract. Soils contain the largest terrestrial store of carbon; three times greater than present atmospheric concentrations, whilst the annual soil-atmosphere exchange of carbon is an order of magnitude larger than all anthropogenic effluxes. Quantifying future pool sizes and fluxes is therefore sensitive to small methodological errors, yet unfortunately remains the second largest area of uncertainty in Intergovernmental Panel on Climate Change projections. The flux of carbon from heterotrophic decomposition of soil organic matter is parameterized as a rate constant. This parameter is calculated from observed total soil carbon efflux and contemporaneously observed temperature and soil moisture. This metric is then used to simulate future rates of heterotrophic respiration, as driven by the projections of future climate- temperature and precipitation. We examine two underlying assumptions: how well current climate (mean temperature and precipitation) can account for contemporary soil respiration, and whether an observational parameter derived from this data will be valid in the future. We find mean climate values to be of some use in capturing total soil respiration to the 95% confidence interval, but note an inability to distinguish between subtropical and Mediterranean fluxes, or wetland-grassland and wetland-forest fluxes. Regarding the future, we present a collection of CO2 enrichment studies demonstrating a strong agreement in soil respiration response (a 25% increase) independent of changes in temperature and moisture, however these data are spatially limited to the northern mid-latitudes. In order to "future-proof" simple statistical parameters used to calculate the output from heterotrophic soil respiration, we propose a correction factor derived from empirical observations, but note the spatial and temporal limitations. In conclusion, there seems to be no sound basis to assume that models with the best fit to contemporary data will produce the best estimates of future fluxes, given the methods, future dynamics and the nature of the observational constraints. Only through long-term field observations and appropriate, perhaps novel, data collection can we improve statistical respiration modelling, without adding mechanistic details at a computational cost.
Seasonality of the hydrological cycle in major South and Southeast Asian river basins as simulated by PCMDI/CMIP3 experiments
Authors: Hasson S. , Lucarini V. , Pascale S. , Böhner J.
Published: February 2014

Abstract. In this study, we investigate how PCMDI/CMIP3 general circulation models (GCMs) represent the seasonal properties of the hydrological cycle in four major South and Southeast Asian river basins (Indus, Ganges, Brahmaputra and Mekong). First, we examine the skill of the GCMs by analysing their performance in simulating the 20th century climate (1961–2000 period) using historical forcing (20c3m experiment), and then we analyse the projected changes for the corresponding 21st and 22nd century climates under the SRESA1B scenario. The CMIP3 GCMs show a varying degree of skill in simulating the basic characteristics of the monsoonal precipitation regimes of the Ganges, Brahmaputra and Mekong basins, while the representation of the hydrological cycle over the Indus Basin is poor in most cases, with a few GCMs not capturing the monsoonal signal at all. While the model outputs feature a remarkable spread for the monsoonal precipitation, a satisfactory representation of the western mid-latitude precipitation regime is instead observed. Similarly, most of the models exhibit a satisfactory agreement for the basin-integrated runoff in winter and spring, while their spread is large for the runoff during the monsoon season. For the future climate scenarios, most models foresee a decrease in the winter P − E over all four basins, while agreement is found on the decrease of the spring P − E over the Indus and Ganges basins only. Such decreases in P − E are mainly due to the decrease in precipitation associated with the western mid-latitude disturbances. Consequently, for the Indus and Ganges basins, the runoff drops during the spring season while it rises during the winter season. Such changes indicate a shift from rather glacial and nival to more pluvial runoff regimes, particularly for the Indus Basin. Furthermore, the rise in the projected runoff, along with the increase in precipitation during summer and autumn, indicates an intensification of the summer monsoon regime for all study basins.
A quality assessment framework for natural hazard event documentation: application to trans-basin flood reports in Germany
Authors: Uhlemann S. , Thieken A. H. , Merz B.
Published: February 2014

Abstract. Written sources that aim at documenting and analysing a particular natural hazard event in the recent past are published at vast majority as grey literature (e.g. as technical reports) and therefore outside of the scholarly publication routes. In consequence, the application of event-specific documentation in natural hazard research has been constrained by barriers in accessibility, concerns of credibility towards these sources and by limited awareness of their content and its usefulness for research questions. In this study we address the concerns of credibility for the first time and present a quality assessment framework for written sources from a user's perspective, i.e. we assess the documents' fitness for use to enhance the understanding of trans-basin floods in Germany in the period 1952–2002. The framework is designed to be generally applicable for any natural hazard event documentation and assesses the quality of a document, addressing accessibility as well as representational, contextual, and intrinsic dimensions of quality. We introduce an ordinal scaling scheme to grade the quality in the individual quality dimensions and the Pedigree score which serves as a measure for the overall document quality. We present results of an application of the framework to a set of 133 cases of event-specific documentation relevant for understanding trans-basin floods in Germany. Our results show that the majority of flood event-specific reports are of good quality, i.e. they are well enough drafted, largely accurate and objective, and contain a substantial amount of information on the sources, pathways and receptors/consequences of the floods. The validation of our results against assessments of two independent peers confirms the objectivity and transparency of the quality assessment framework. Using an example flood event that occurred in October/November 1998 we demonstrate how the information from multiple reports can be synthesised.
Barriers to transport in aperiodically time-dependent two-dimensional velocity fields: Nekhoroshev's theorem and "Nearly Invariant" tori
Authors: Wiggins S. , Mancho A. M.
Published: February 2014

Abstract. In this paper we consider fluid transport in two-dimensional flows from the dynamical systems point of view, with the focus on elliptic behaviour and aperiodic and finite time dependence. We give an overview of previous work on general nonautonomous and finite time vector fields with the purpose of bringing to the attention of those working on fluid transport from the dynamical systems point of view a body of work that is extremely relevant, but appears not to be so well known. We then focus on the Kolmogorov–Arnold–Moser (KAM) theorem and the Nekhoroshev theorem. While there is no finite time or aperiodically time-dependent version of the KAM theorem, the Nekhoroshev theorem, by its very nature, is a finite time result, but for a "very long" (i.e. exponentially long with respect to the size of the perturbation) time interval and provides a rigorous quantification of "nearly invariant tori" over this very long timescale. We discuss an aperiodically time-dependent version of the Nekhoroshev theorem due to Giorgilli and Zehnder (1992) (recently refined by Bounemoura, 2013 and Fortunati and Wiggins, 2013) which is directly relevant to fluid transport problems. We give a detailed discussion of issues associated with the applicability of the KAM and Nekhoroshev theorems in specific flows. Finally, we consider a specific example of an aperiodically time-dependent flow where we show that the results of the Nekhoroshev theorem hold.
C ≈ 0.85 scaling and the universal clustering structure of earthquake networks
Authors: Abe S. , Suzuki N.
Published: February 2014

Abstract. Earthquake network describes the complexity of seismicity both qualitatively and quantitatively. The procedure of constructing an earthquake network contains as a single parameter the size of the cells, into which a geographical region under consideration is divided. Then, the characteristics of the network depend on the cell size, in general. Here, the dependency of the clustering coefficient, C, of network on the cell size is studied. Remarkably, C of the earthquake networks constructed from the seismic data taken from California, Japan, and Iran well coincide for each value of the scaled dimensionless cell size. It is found that the networks in California and Japan are three-dimensional, whereas the one in Iran is rather two-dimensional. In addition, the values of C of all these three networks monotonically converge to C ≈ 0.85 as the scaled dimensionless cell size increases, highlighting a universal aspect of the concept of earthquake network.
Screened Conversations
Authors: Talbert Bonnie ,   Philosophy Documentation Center
Published: February 2014

Social scientists have documented some recent, dramatic changes in the nature of our social lives. Many scholars have thought that our reliance on technology to communicate with others is in large part responsible for that loss. However, there is also data to support the opposite conclusion—it might be the case that social networking technologies have helped, rather than hindered our social interactions. What I would like to propose is a philosophical argument, which I hope will offer a different sort of answer to the questions about whether we know people in the same ways, or perhaps more or less well, than we once did, in the days before Facebook, email, and such. Whether or not technology has enhanced our social lives, it is worth considering whether coming to know another person is a different sort of exercise than it used to be, when face-to-face interactions with others were the preferred way to find out what was going on in someone else’s life. What is different in sharing my thoughts, beliefs, feelings, desires, and such with another over the Internet versus in person? Is there any kind of knowledge that is available only in a face-to-face context? If so, what is the nature of that knowledge? In philosophical terms, what I want to examine is how our knowledge of others’ minds changes with various technologies that we use to communicate the contents of our mental states.
Preliminary Study of Autologous Bone Marrow Nucleated Cells Transplantation in Children With Spinal Cord Injury
Authors: Jarocha Danuta , Milczarek Olga , Kawecki Zdzislaw , Wendrychowicz Anna , Kwiatkowski Stanislaw , Majka Marcin
Published: February 2014

The objective of this study was to assess the safety and efficacy of transplanting bone marrow nucleated cells (BMNCs) to treat children with complete interruption of spinal cord (SC) continuity. The present study was conducted from 2005 to 2011. The inclusion criteria were a magnetic resonance imaging-confirmed complete interruption of SC continuity and no improvement in neurological status within 6 months after standard therapy. Bone marrow was isolated from the iliac ala and submitted to BMNC isolation. Subsequently, the cell suspension was administered into the SC cavity and intravenously. In total, 18 of 19 intraspinal and intravenous BMNC transplantation procedures performed caused no adverse events. One case was connected with transient bradycardia. The experimental therapy showed no late complications in the 1- to 6-year follow-up evaluation period. Neurological improvement was observed in two patients who received multiple implantations. One patient demonstrated improved superficial sensation from Th3 to Th12/L1 and a restored bladder-filling sensation. In the other case, superficial sensation was improved from C2 to C5, and the respiratory drive, the swallowing reflex, and tongue movements were restored. Spasticity and quality of life were improved in three of five patients. In addition, skin pressure ulcers healed and did not recur. Our preliminary results demonstrate the safety and feasibility of BMNC transplantation in children with complete SC injury. The results indicate that a certain degree of neurological and quality-of-life improvement can be attained by children with chronic complete SC injury who receive multiple BMNC implantations.
Chemically Induced Specification of Retinal Ganglion Cells From Human Embryonic and Induced Pluripotent Stem Cells
Authors: Riazifar Hamidreza , Jia Yousheng , Chen Jing , Lynch Gary , Huang Taosheng
Published: February 2014

The loss of retinal ganglion cells (RGCs) is the primary pathological change for many retinal degenerative diseases. Although there is currently no effective treatment for this group of diseases, cell transplantation to replace lost RGCs holds great potential. However, for the development of cell replacement therapy, better understanding of the molecular details involved in differentiating stem cells into RGCs is essential. In this study, a novel, stepwise chemical protocol is described for the differentiation of human embryonic stem cells and induced pluripotent stem cells into functional RGCs. Briefly, stem cells were differentiated into neural rosettes, which were then cultured with the Notch inhibitor N-[N-(3,5-difluorophenacetyl)-l-alanyl]-S-phenylglycine t-butyl ester (DAPT). The expression of neural and RGC markers (BRN3A, BRN3B, ATOH7/Math5, γ-synuclein, Islet-1, and THY-1) was examined. Approximately 30% of the cell population obtained expressed the neuronal marker TUJ1 as well the RGC markers. Moreover, the differentiated RGCs generated action potentials and exhibited both spontaneous and evoked excitatory postsynaptic currents, indicating that functional and mature RGCs were generated. In combination, these data demonstrate that a single chemical (DAPT) can induce PAX6/RX-positive stem cells to undergo differentiation into functional RGCs.
The Phillips Curve in the United States and Canada: A GARCHDCC Analysis
Authors: Yang Lu , Hamori Shigeyuki
Published: February 2014

By applying the GARCH-DCC model, we reexamine the Phillips curve based on a time-varying correlation analysis for Canada and the United States from January 1985 to December 2012. The empirical results show that the sign of the correlation between the inflation rate and the unemployment rate is negative during recession periods but positive during boom periods.
Monopoly by Contract: The Practice of Franchised Fee and Royalty Rate
Authors: Ramjerdi Maria Hamideh
Published: February 2014

This paper uses a theoretical framework and a by use of a franchising model will examine the practice of charging a franchise fee for the use of the trademark and will show how this practice by controlling the number of franchised operations enables franchisor to extract monopoly profit. Paper will further examine the conditions which the joint practice of franchise fee and royalty rate allows extraction of monopoly rent.
Delayed‐type hypersensitivity (DTH) test anergy does not impact CD4 reconstitution or normalization of DTH responses during antiretroviral therapy
Authors: Minidis Natascha M , Mesner Octavio , Agan Brian K , Okulicz Jason F
Published: February 2014

Introduction

Delayed‐type hypersensitivity (DTH) testing is an in vivo assessment of cell‐mediated immunity. Although highly active antiretroviral therapy (HAART) improves immunologic parameters, the relationship between DTH responsiveness and CD4 gains on HAART is not completely understood. We investigated CD4 reconstitution and the change in DTH responses from treatment baseline through 24 months of viral load (VL)‐suppressive HAART in the U.S. Military HIV Natural History Study.

Methods

Treatment‐naïve subjects with VL <400 copies/mL after ≥24 months on HAART were included (n=302). DTH testing consisted of ≥3 recall antigens, and responses were classified by the number of positive skin tests: anergic (0–1) or non‐anergic (≥2). Pre‐HAART DTH results were compared for the outcome of CD4 reconstitution at 24 months of HAART. Improvement in DTH responses was also analyzed for those anergic before HAART initiation.

Results

Non‐anergic responses were observed in 216 (72%) participants, while 86 (28%) individuals were anergic prior to HAART initiation. Demographically there were similar distributions of age at HIV diagnosis and HAART initiation, as well as gender and race or ethnicity. There were no significant differences between non‐anergic and anergic participants in pre‐HAART CD4 count (409 cells/μL, interquartile range (IQR) 315–517 vs. 373 cells/μL, IQR 228–487; p=0.104) and VL (4.3 log10 copies/mL, IQR 3.4–4.9 vs. 4.4 log10 copies/mL, IQR 3.6–5.0; p=0.292). Median CD4 gains 24 months after HAART initiation were similar between the non‐anergic (220 cells/μL, IQR 115–358) and anergic groups (246 cells/μL, IQR 136–358; p=0.498). For individuals anergic before HAART initiation, DTH normalization occurred at 24 months post‐HAART in the majority of participants (51 of 86, 59%). Normalization of DTH responses was not associated with CD4 count at HAART initiation (OR 0.73, 95% CI 0.47, 1.09 per 100 cells; p=0.129) nor with AIDS diagnoses prior to HAART (OR 0.34, 95% CI 0.04, 2.51; p=0.283).

Conclusions

DTH responsiveness has been shown to predict HIV disease progression independent of CD4 count in untreated individuals. In the setting of HAART, pre‐HAART anergy does not appear to impact CD4 gains or the ability to normalize DTH responses after 24 months of VL‐suppressive HAART.
Shugoshin biases chromosomes for biorientation through condensin recruitment to the pericentromere
Authors: Verzijlbergen Kitty F , Nerusheva Olga O , Kelly David , Kerr Alastair , Clift Dean , de Lima Alves Flavia , Rappsilber Juri , Marston Adele L
Published: February 2014

To protect against aneuploidy, chromosomes must attach to microtubules from opposite poles (‘biorientation’) prior to their segregation during mitosis. Biorientation relies on the correction of erroneous attachments by the aurora B kinase, which destabilizes kinetochore-microtubule attachments that lack tension. Incorrect attachments are also avoided because sister kinetochores are intrinsically biased towards capture by microtubules from opposite poles. Here, we show that shugoshin acts as a pericentromeric adaptor that plays dual roles in biorientation in budding yeast. Shugoshin maintains the aurora B kinase at kinetochores that lack tension, thereby engaging the error correction machinery. Shugoshin also recruits the chromosome-organizing complex, condensin, to the pericentromere. Pericentromeric condensin biases sister kinetochores towards capture by microtubules from opposite poles. Our findings uncover the molecular basis of the bias to sister kinetochore capture and expose shugoshin as a pericentromeric hub controlling chromosome biorientation.
An allosteric Sec61 inhibitor traps nascent transmembrane helices at the lateral gate
Authors: MacKinnon Andrew L , Paavilainen Ville O , Sharma Ajay , Hegde Ramanujan S , Taunton Jack
Published: February 2014

Membrane protein biogenesis requires the coordinated movement of hydrophobic transmembrane domains (TMD) from the cytosolic vestibule of the Sec61 channel into the lipid bilayer. Molecular insight into TMD integration has been hampered by the difficulty of characterizing intermediates during this intrinsically dynamic process. In this study, we show that cotransin, a substrate-selective Sec61 inhibitor, traps nascent TMDs in the cytosolic vestibule, permitting detailed interrogation of an early pre-integration intermediate. Site-specific crosslinking revealed the pre-integrated TMD docked to Sec61 near the cytosolic tip of the lateral gate. Escape from cotransin-arrest depends not only on cotransin concentration, but also on the biophysical properties of the TMD. Genetic selection of cotransin-resistant cancer cells uncovered multiple mutations clustered near the lumenal plug of Sec61α, thus revealing cotransin’s likely site of action. Our results suggest that TMD/lateral gate interactions facilitate TMD transfer into the membrane, a process that is allosterically modulated by cotransin binding to the plug.
Arf1/COPI machinery acts directly on lipid droplets and enables their connection to the ER for protein targeting
Authors: Wilfling Florian , Thiam Abdou Rachid , Olarte Maria-Jesus , Wang Jing , Beck Rainer , Gould Travis J , Allgeyer Edward S , Pincet Frederic , Bewersdorf Jörg , Farese Robert V , Walther Tobias C
Published: February 2014

Lipid droplets (LDs) are ubiquitous organelles that store neutral lipids, such as triacylglycerol (TG), as reservoirs of metabolic energy and membrane precursors. The Arf1/COPI protein machinery, known for its role in vesicle trafficking, regulates LD morphology, targeting of specific proteins to LDs and lipolysis through unclear mechanisms. Recent evidence shows that Arf1/COPI can bud nano-LDs (∼60 nm diameter) from phospholipid-covered oil/water interfaces in vitro. We show that Arf1/COPI proteins localize to cellular LDs, are sufficient to bud nano-LDs from cellular LDs, and are required for targeting specific TG-synthesis enzymes to LD surfaces. Cells lacking Arf1/COPI function have increased amounts of phospholipids on LDs, resulting in decreased LD surface tension and impairment to form bridges to the ER. Our findings uncover a function for Arf1/COPI proteins at LDs and suggest a model in which Arf1/COPI machinery acts to control ER-LD connections for localization of key enzymes of TG storage and catabolism.
Integrating influenza antigenic dynamics with molecular evolution
Authors: Bedford Trevor , Suchard Marc A , Lemey Philippe , Dudas Gytis , Gregory Victoria , Hay Alan J , McCauley John W , Russell Colin A , Smith Derek J , Rambaut Andrew
Published: February 2014

Influenza viruses undergo continual antigenic evolution allowing mutant viruses to evade host immunity acquired to previous virus strains. Antigenic phenotype is often assessed through pairwise measurement of cross-reactivity between influenza strains using the hemagglutination inhibition (HI) assay. Here, we extend previous approaches to antigenic cartography, and simultaneously characterize antigenic and genetic evolution by modeling the diffusion of antigenic phenotype over a shared virus phylogeny. Using HI data from influenza lineages A/H3N2, A/H1N1, B/Victoria and B/Yamagata, we determine patterns of antigenic drift across viral lineages, showing that A/H3N2 evolves faster and in a more punctuated fashion than other influenza lineages. We also show that year-to-year antigenic drift appears to drive incidence patterns within each influenza lineage. This work makes possible substantial future advances in investigating the dynamics of influenza and other antigenically-variable pathogens by providing a model that intimately combines molecular and antigenic evolution.
Local electroporation of a single cell using a scanning ion conductance microscope
Authors: Iwata Futoshi , Yamazaki Koji , Ishizaki Kimihiro , Ushiki Tatuo
Published: February 2014

We developed a novel electroporation technique for molecular delivery into a single cell. A nanopipette, a thermally pulled glass capillary, is prepared as to act as a pair of tiny electrodes for single-cell electroporation. An Ag/AgCl wire is inserted into the nanopipette, and the outside edge of the nanopipette is coated by Ag sputtering. Electric pulses are applied between the outside and inside electrodes to form a local electric field at the edge of the nanopipette. To position the pipette edge in the vicinity of the cell membrane, we control the probe–surface distance using a scanning ion conductance microscope (SICM). The SICM technique achieves non-contact approach of the nanopipette edge on the cell membrane, which allows low-invasive electroporation of a single cell. As a demonstration of this technique, a fluorescent molecule of propidium iodide was successfully delivered into a single HeLa cell.
The Ex-PRESS Glaucoma Drainage Device: Current Perspective
Authors: Angmo Dewang , Temkar Shreyas , Saini Manu , Aggarwal Rohit , Dada Tanuj
Published: February 2014

The ExPRESS glaucoma implant is a miniature stainless steel device that offers a simple and safe alternative to the classic trabeculectomy. It is a minimally penetrating glaucoma surgery (MPGS), with proposed advantages of standardizing filtration surgery with reduced risk of early postoperative complications and a short learning curve. However, the device is associated with unique intraoperative and postoperative problems in addition to a high cost which merits a serious review of its role in current glaucoma practice despite tremendous market pressures. We put forth this review for a balanced perspective on the merits, pitfalls and cautions on the use of this device, giving the implant details, indications, current surgical procedure for implantation, and a literature review comparing ExPRESS to trabeculectomy.
Prevalence and Pattern of Corneal Morbidity Based on a New Nomogram and Graticule
Authors: Bhardwaj Richa , Chaudhary KP , Sharma RL , Gupta Vinay
Published: February 2014

Purpose:

To study the pattern of corneal diseases using a new nomogram and graticule.

Materials and Methods:

256 eyes of 200 patients attending the cornea services of the institute from July 2011 to June 2012 were included in the study. The visual status of the patients was assessed using the WHO definition for visual impairment. Patient evaluation was done using Haag-Striet photo slit lamp and images were recorded. A new nomogram was created for topographical mapping of corneal lesions by dividing the cornea into four concentric zones i.e. central optical (4mm), paracentral (4-8mm), peripheral (8-11mm) and limbal (11-12mm) taking the optical centre of the cornea (O) as the reference. Each zone was further divided into four quadrants (UN, UT, LN and LT) by a horizontal and vertical axis passing through O. Visual axis (VA) passed through V, represented 5°nasal to O. The graticule (magnification 6X) was superimposed on the photograph for mapping the lesions.

Results:

The most common disease entities affecting the cornea were infective causes (27%), corneal opacities (25%) and PBK (13%). Central zone (Z I) was involved most frequently and VA involvement was seen in (79%) cases. The corneal lesions were described as per the methodology and correlated well with the visual morbidity pattern.

Conclusions:

This new nomogram may provide a precise methodology for mapping of corneal lesions along with the assessment of visual morbidity and VA involvement.
Ocular Torsional Changes in Anterior Plagiocephaly
Authors: Jethani Jitendra , Jethani Monika
Published: February 2014

Introduction:

Anterior plagiocephaly has been associated with a mechanical disadvantage to superior oblique secondary to the retrusion of trochlea. This posterior placement should theoretically strengthen the superior oblique in its torsion action both in primary and secondary position (abduction).

Materials and Methods:

We did an observation study to document the ocular torsional changes by measuring disc foveal angle (DFA) in fundus photograph in five patients with anterior plagiocephaly and unilateral inferior oblique overaction. All patients had right sided anterior plagiocephaly and 2 patients had an associated posterior plagiocephaly.

Results:

Mean DFA in right eye (affected eye) was 15.8 +/-1.9 (13 -18 degrees) and the unaffected eye was 7.6 +/- 2 (range 6-10 degrees). All the patients showed inferior oblique overaction and a V pattern. We found that the affected eye shows excyclotorsion instead of an expected incyclotorsion. This cannot be explained on the basis of retrusion of trochlea and a mechanical disadvantage to the posterior fibres (responsible for depression in adduction) of the superior oblique.

Conclusions:

The affected eye in anterior plagiocephaly shows excyclotorsion.
Orbital Granulocytic Sarcoma (Chloroma) as Initial Manifestation Of Acute Myeloid Leukaemia
Authors: Bagri PK , V Beniwal , Beniwal SK , Jakhar SL , Sharma N , Kumar HS , Sharma A
Published: February 2014

Chloroma is an extramedullary manifestation of acute myeloid leukemia (AML). Chloroma may be found in a variety of locations throughout the body. The most common areas of involvement are the skin and the gums. Other tissues which can be involved include lymph nodes, small intestine, mediastinum, lung, epidural sites, uterus, ovaries and the orbit of the eye. A Chloroma is a solid tumor composed of immature white blood cells called myeloblasts. Children are affected more often than adults. There is a slight male predominance in these cases. The diagnosis is made by clinical examination, computed tomography and confirmed by haematological investigations. It may present at any time in the course of the disease. Diagnosis is particularly challenging in this situation. We report the case of a 11 year old male child who presented with bilateral exophthalmos (more in left eye) with computerized tomography (CT) evidence of a retro-orbital mass revealing acute myeloid leukemia. The patient was put on BFM-93 chemotherapy protocol. The patient has completed treatment of 1.5 years without relapse