bluuebunny/crossref_metadata_2025 huggingface dataset:
Geology, Petrography and Geochemistry of Rhyolite-Hosted Uranium Mineralization at Mohar, Shivpuri District, Madhya Pradesh
Authors: Kumar Shailendra , Roy Madhupurna , Pandey Pradeep , Bhairam C. L. , Parihar P. S.
Published: April 2013

In the westernmost part of the Bundelkhand Granitoid Complex (BGC), a mesa structure represents a unique outlier, surrounded by brecciated granite and filled with Vindhyan sedimentary rocks locally known as the Dhala Formation near Mohar village of Shivpuri district, Madhya Pradesh. Uranium mineralisation located in the area is mostly associated with rhyolite of peralkaline to peraluminous in nature, that has a high average uranium concentration (30 ppm). The mineralization is in or adjacent to caldera and is hydrothermal vein-type. Radioactivity is mainly due to coffinite with limited radioactivity due to U-Ti complex, uranium adsorbed in clay and labile uranium along fracture. Coffinite occurs in association with pyrite and chalcopyrite or chlorite with presence of fluorite. Features such as chloritisation, clay formation and sulfide mineralisation manifest hydrothermal alteration. Chemical analysis indicates the aluminous nature of the rock and their high K2O / Na2O (3.81-12.84) ratios are suggestive of predominance of potash feldspar over sodic. The alteration index varies from 49.88-92.40, which, reflects high intensity of hydrothermal alteration. Chlorite-carbonate-pyrite index (CCPI), a measure of the intensity of replacement of sodic feldspars and glass by sericite, chlorite, carbonate, and pyrite associated with hydrothermal alteration proximal to the ore bodies varies from 3.84-49.66. On the basis of core study, geochemistry and mineralogy, it is envisaged that epigenetic hydrothermal solutions were responsible for concentration of uranium as coffinite, radioactive carbonaceous matter and adsorbed uranium phases in rhyolite with sulfide confined to weak planes.
Interpretation of Voids or Buried Pipes using Ground Penetrating Radar Modeling
Authors: Singh K. K. K. , Kumar Indresh , Singh Upendra K.
Published: April 2013

In coal mines abandoned works or voids at shallow depth, might be a potential hazard and therefore, such areas are considered for redevelopment. As voids and fractures accumulate groundwater which may be hazardous for the mines work. Subsidence, fire, flooding and some other kinds of environmental hazards related to shallow coal works, necessitate for better understanding of voids and their interpretation for Ground Penetrating Radar (GPR) data. Whereas, in civil engineering, GPR is used for detection of the buried pipe, however, it becomes difficult to differentiate betweem the pipes used for water supply and for electrical cable. In order to better interpretation of voids and buried pipes we present a finite-difference time-domain (FDTD) solution based on Maxwell’s equations that allows accounting for the frequency dependence of the dielectric permittivity and electrical conductivity of many near-surface materials. The algorithm and the results presented here, however, offer the perspective to improve some of these inherent problems and thus help to make 2-D structure a more reliable and effective tool for probing the shallow subsurface. Also it is found that the different dispersion mechanisms cause significant amplitude and phase differences, which may be relevant to amplitude variation with offset (AVO) and stratigraphic investigations using Ground Penetrating Radar.
Petroleum Potential of the Chalbi Basin, NW Kenya
Authors: Rop Bernard K.
Published: April 2013

This paper deals with the study of subsurface stratigraphy of the Chalbi rift basin, northwest Kenya. The basin is known to have evolved through extension tectonics that brought out continental rifting as a part of the major Gondwanaland breakup in the Late Paleozoic and continued in the Mesozoic and Tertiary. This work has been based on gravity, seismic and gamma ray data, as well as the drill core logs available. The geophysical data used was collected by AMOCO as part of the hydrocarbon programme. But the gravity anomaly maps as well as seismic profiles were most useful for the interpretations incorporated in the present paper. They revealed the presence of several horst and graben structural systems. It was also revealed that the basin attracted sedimentary piles ranging up to 5 km thickness, which were deposited on basement rocks of Precambrian age. The basin subsequently got covered by basaltic flows of mainly Miocene age. The drill core lithologs that were available pertain to wells: C1, C2 and C3 in the Chalbi basin (Cretaceous). Comparing the lithologs from these wells with the seismic and gamma ray characteristics have been discussed in order to characterise the strata in which there was oil/gas shows. These characteristics were further seen in the light of the porosities, organic matter and other sedimentological parameters in order to understand the essential features of source rocks, reservoir rocks and the cap rocks. An attempt has been made to extrapolate the knowledge gained for recommending the probable prognostic sites for future drilling in the Chalbi Basin.
Trace Elements in Groundwater of Hindon-Yamuna Interfluve Region, Baghpat District, Western Uttar Pradesh
Authors: Alam Fakhre , Umar Rashid
Published: April 2013

The present study was carried out in parts of Hindon-Yamuna interfluve region to evaluate the concentration of trace elements (Al, Cr, Mn, Fe, Ni, Co, Cu, Zn, As, Se, Cd, B and Pb) in groundwater. Pre-monsoon groundwater samples were collected in 2007 from 22 locations distributed throughout the study area, and were analyzed using Inductive Coupled Plasma Mass-Spectrophotometer (ICPMS).

Trace element analyses show high concentration levels for Al and Cr in almost all groundwater samples. Relatively high values are also reported for Pb, Se, Fe and Mn (as per B.I.S (1991) standard for drinking water) in few samples. These high concentrations of metal ions in groundwater were probably due to discharge of untreated effluents from Textile , dyeing and other industries. As far as Al is concerned, its source is rather enigmatic.
Research skills for undergraduates: a must!
Authors: Lemon Thomas I. , Lampard Rhianon , Stone Benjamin A.
Published: April 2013

None
Energy Politics and Geopolitical Competition in the Caspian Basin
Authors: Kubicek Paul
Published: April 2013

This article explores geopolitical rivalry in the Caspian Basin, driven in large measure by the desire to control and exploit energy resources. It focuses in particular on actions by Russia, China, and the United States. While outside actors play an important role in the region, local states have demonstrated that they are not merely passive players. They have managed, in many cases, to use the ‘geopolitical pluralism’ of great power competition to gain room to maneuver. The result is a complicated picture of geopolitical balance. Looking ahead, however, China may be in the best position to assume the pre-eminent role in the region.
Problems of corruption and distrust in political and administrative institutions in Slovenia
Authors: Hacek Miro , Kukovic Simona , Brezovsek Marjan
Published: April 2013

Corruption is perceived in all societies as a social pathology that causes great material and moral damage and is a threat to the society’s continual development. Especially in countries with a freshly consolidated democracy, as Slovenia, the phenomena of corruption must be treated with all due attention. This article emphasises that corruption in Slovenia is publicly perceived as one of the most important and even increasing problems in society. We are also analysing one of the crucial side effects of the corruption, resulting itself in ever deeper public distrust to most significant political and administrative institutions.
THE EFFECTS OF RECOGNIZED FOREIGN JUDGMENTS IN CIVIL AND COMMERCIAL MATTERS
Authors: Harder Sirko
Published: April 2013

This article investigates what effects a recognized foreign judgment in civil and commercial matters has in English proceedings. Does the judgment have the effects that it has in the foreign country (extension of effects) or the effects that a comparable English judgment would have (equalization of effects), or a combination of these? After a review of the current law, it will be discussed what approach is preferable on principle. The suggested approach will then be illustrated by considering whether a foreign decision on one legal basis of a certain claim ought to preclude English proceedings involving another legal basis of the same claim. Finally, it will be discussed whether and how the effects of a recognized foreign judgment in England are affected by interests of a third country.
OUTER CONTINENTAL SHELF BOUNDARY AGREEMENTS
Authors: Magnússon Bjarni Már
Published: April 2013

The article analyses the trends in continental shelf boundary agreements that extend beyond 200 nautical miles. The focus is on three issues: first, the delimitation method; second, whether States have acted on the basis that they have to delineate the limits between the continental shelf beyond 200 nautical miles and the international seabed area before they engage in a boundary delimitation with neighbouring states; and third, how the end point of the boundary line has been defined. The goal of the analysis is to find out whether any rule of customary law has emerged which seems not to be the case.
Justice, Happiness, and the Sensible Knave: Hume's Incomplete Defense of the Just Life
Authors: Culp Jonathan
Published: April 2013

In his response to the fictitious “sensible knave” in theEnquiry Concerning the Principles of Morals, Hume argues that the practice of justice is always in our own interest. This article provides the first comprehensive interpretation of Hume's response, incorporating his discussion of virtue and happiness in his essay “The Sceptic.” It will be seen that this argument is a hedonistic one, resting on the superior pleasure and security of a life of modest wealth and intellectual cultivation. Hume's argument ultimately fails, and he knows it. He offers it nonetheless because it is generally true and socially beneficial.
Recent Work at the Lower Palaeolithic Site of Corfe Mullen, Dorset, England
Authors: McNabb John , Hosfield Robert , Dearling Kevin , Barker Dominic , Strutt Kristian , Cole James , Bates Martin , Toms Phillip
Published: April 2013

Changes in the geological interpretation of the history of the ancient Solent river basin have focused attention on the handaxes discovered in the Corfe Mullen area during quarrying before the Second World War. Recent geological research suggests that the fluvial terrace the handaxes are associated with may pre-date the Anglian glaciation. This is important because it contributes to the question of just when the Solent basin was first occupied by hominins, and how this relates to other areas of possible contemporary pre-Anglian occupation such as the Boxgrove Marine embayment. However, the artefacts were believed to come from the bluff of the river terrace and were thus not in situ. This paper explores that question and re-examines the context from which the handaxes at Corfe Mullen were discovered.
IMITATION FICTION: PIRATE CITINGS IN ROBERT LOUIS STEVENSON'STREASURE ISLAND
Authors: Cohen Monica F.
Published: April 2013

When Charles Dickens triedto lobby for American support of an international copyright agreement during his wildly popular 1842 tour of the United States, the English author was famously shocked to find himself lambasted as an elitist who dared expect payment for what Americans believed they had the right to read for free (McGill 109–40; Claybaugh 71; Pettitt 152). Dickens encountered in the practice of literary piracy, or what was called in the United States, the culture of reprinting, a deep fissure in capitalist democratic culture between individual ownership and public access, an ideological divide that forms the backdrop for the creation and circulation of nineteenth-century print. If the legal privatization of intellectual property hovered in the imagination of so many Victorian writers, it formed the happy ending of a long nineteenth-century struggle over literary piracy, a contention of goods that shaped the Victorian stage as we well as the transatlantic literary marketplace.
ORDER BOUNDED WEIGHTED COMPOSITION OPERATORS
Authors: WOLF ELKE
Published: April 2013

Let$\phi $and$\psi $be analytic maps on the open unit disk$D$such that$\phi (D) \subset D$. Such maps induce a weighted composition operator$C_{\phi ,\psi }$acting on weighted Banach spaces of type$H^{\infty }$or on weighted Bergman spaces, respectively. We study when such operators are order bounded.
Ideal amplification of broadband signals
Authors: McCallister Ron
Published: April 2013

This paper describes a digital signal processing (DSP) method for achieving “ideal” amplification, maximizing both the average output signal power and power-added-efficiency for any signal waveform and any power amplifier (PA) transfer characteristic. Detailed algorithms are described for optimally accomplishing peak reduction (PR), predistortion (PD) linearization, and integration of these DSP techniques with envelope tracking PAs. Hardware characterization results validate the theories of PD and PR operation.
Molecular mechanisms for the subversion of MyD88 signaling by TcpC from virulent uropathogenicEscherichia coli
Authors: Snyder Greg A. , Cirl Christine , Jiang Jiansheng , Chen Kang , Waldhuber Anna , Smith Patrick , Römmler Franziska , Snyder Nathaniel , Fresquez Theresa , Dürr Susanne , Tjandra Nico , Miethke Thomas , Xiao Tsan Sam
Published: April 2013

The Toll/IL-1 receptor (TIR) domains are crucial signaling modules during innate immune responses involving the Toll-like receptors (TLRs) and IL-1 receptor (IL-1R). Myeloid differential factor 88 (MyD88) is a central TIR domain-containing adapter molecule responsible for nearly all TLR-mediated signaling and is targeted by a TIR domain-containing protein C (TcpC) from virulent uropathogenicEscherichia coli, a common human pathogen. The mechanism of such molecular antagonism has remained elusive. We present the crystal structure of the MyD88 TIR domain with distinct loop conformations that underscore the functional specialization of the adapter, receptor, and microbial TIR domains. Our structural analyses shed light on the genetic mutations at these loops as well as the Poc site. We demonstrate that TcpC directly associates with MyD88 and TLR4 through its predicted DD and BB loops to impair the TLR-induced cytokine induction. Furthermore, NMR titration experiments identify the unique CD, DE, and EE loops from MyD88 at the TcpC-interacting surface, suggesting that TcpC specifically engages these MyD88 structural elements for immune suppression. These findings thus provide a molecular basis for the subversion of TLR signaling by the uropathogenicE. colivirulence factor TcpC and furnish a framework for the design of novel therapeutic agents that modulate immune activation.
Range expansion promotes cooperation in an experimental microbial metapopulation
Authors: Datta Manoshi Sen , Korolev Kirill S. , Cvijovic Ivana , Dudley Carmel , Gore Jeff
Published: April 2013

Natural populations throughout the tree of life undergo range expansions in response to changes in the environment. Recent theoretical work suggests that range expansions can have a strong effect on evolution, even leading to the fixation of deleterious alleles that would normally be outcompeted in the absence of migration. However, little is known about how range expansions might influence alleles under frequency- or density-dependent selection. Moreover, there is very little experimental evidence to complement existing theory, since expanding populations are difficult to study in the natural environment. In this study, we have used a yeast experimental system to explore the effect of range expansions on the maintenance of cooperative behaviors, which commonly display frequency- and density-dependent selection and are widespread in nature. We found that range expansions favor the maintenance of cooperation in two ways: (i) through the enrichment of cooperators at the front of the expanding population and (ii) by allowing cooperators to “outrun” an invading wave of defectors. In this system, cooperation is enhanced through the coupling of population ecology and evolutionary dynamics in expanding populations, thus providing experimental evidence for a unique mechanism through which cooperative behaviors could be maintained in nature.
Rational design of a ligand-controlled protein conformational switch
Authors: Dagliyan Onur , Shirvanyants David , Karginov Andrei V. , Ding Feng , Fee Lanette , Chandrasekaran Srinivas N. , Freisinger Christina M. , Smolen Gromoslaw A. , Huttenlocher Anna , Hahn Klaus M. , Dokholyan Nikolay V.
Published: April 2013

Design of a regulatable multistate protein is a challenge for protein engineering. Here we design a protein with a unique topology, called uniRapR, whose conformation is controlled by the binding of a small molecule. We confirm switching and control ability of uniRapRin silico, in vitro, and in vivo. As a proof of concept, uniRapR is used as an artificial regulatory domain to control activity of kinases. By activating Src kinase using uniRapR in single cells and whole organism, we observe two unique phenotypes consistent with its role in metastasis. Activation of Src kinase leads to rapid induction of protrusion with polarized spreading in HeLa cells, and morphological changes with loss of cell–cell contacts in the epidermal tissue of zebrafish. The rational creation of uniRapR exemplifies the strength of computational protein design, and offers a powerful means for targeted activation of many pathways to study signaling in living organisms.
Single-molecule colocalization FRET evidence that spliceosome activation precedes stable approach of 5′ splice site and branch site
Authors: Crawford Daniel J. , Hoskins Aaron A. , Friedman Larry J. , Gelles Jeff , Moore Melissa J.
Published: April 2013

Removal of introns from the precursors to messenger RNA (pre-mRNAs) requires close apposition of intron ends by the spliceosome, but when and how apposition occurs is unclear. We investigated the process by which intron ends are brought together using single-molecule fluorescence resonance energy transfer together with colocalization single-molecule spectroscopy, a combination of methods that can directly reveal how conformational transitions in macromolecular machines are coupled to specific assembly and disassembly events. The FRET measurements suggest that the 5′ splice site and branch site remain physically separated throughout spliceosome assembly, and only approach one another after the spliceosome is activated for catalysis, at which time the pre-mRNA becomes highly dynamic. Separation of the sites of chemistry until very late in the splicing pathway may be crucial for preventing splicing at incorrect sites.
Newly characterized Golgi-localized family of proteins is involved in calcium and pH homeostasis in yeast and human cells
Authors: Demaegd Didier , Foulquier François , Colinet Anne-Sophie , Gremillon Louis , Legrand Dominique , Mariot Pascal , Peiter Edgar , Van Schaftingen Emile , Matthijs Gert , Morsomme Pierre
Published: April 2013

Defects in the human protein TMEM165 are known to cause a subtype of Congenital Disorders of Glycosylation. Transmembrane protein 165 (TMEM165) belongs to an uncharacterized family of membrane proteins called Uncharacterized Protein Family 0016, which are well conserved throughout evolution and share characteristics reminiscent of the cation/Ca
2+
exchanger superfamily. Gcr1 dependent translation factor 1 (Gdt1p), the budding yeast member of this family, contributes to Ca
2+
homeostasis via an uncharacterized Ca
2+
transport pathway localized in the Golgi apparatus. The
gdt1Δ
mutant was found to be sensitive to high concentrations of Ca
2+
, and interestingly, this sensitivity was suppressed by expression of TMEM165, the human ortholog of Gdt1p, indicating conservation of function among the members of this family. Patch-clamp analyses on human cells indicated that TMEM165 expression is linked to Ca
2+
ion transport. Furthermore, defects in TMEM165 affected both Ca
2+
and pH homeostasis. Based on these results, we propose that Gdt1p and TMEM165 could be members of a unique family of Golgi-localized Ca
2+
/H
+
antiporters and that modification of the Golgi Ca
2+
and pH balance could explain the glycosylation defects observed in TMEM165-deficient patients.
Intestinal alkaline phosphatase prevents metabolic syndrome in mice
Authors: Kaliannan Kanakaraju , Hamarneh Sulaiman R. , Economopoulos Konstantinos P. , Nasrin Alam Sayeda , Moaven Omeed , Patel Palak , Malo Nondita S. , Ray Madhury , Abtahi Seyed M. , Muhammad Nur , Raychowdhury Atri , Teshager Abeba , Mohamed Mussa M. Rafat , Moss Angela K. , Ahmed Rizwan , Hakimian Shahrad , Narisawa Sonoko , Millán José Luis , Hohmann Elizabeth , Warren H. Shaw , Bhan Atul K. , Malo Madhu S. , Hodin Richard A.
Published: April 2013

Metabolic syndrome comprises a cluster of related disorders that includes obesity, glucose intolerance, insulin resistance, dyslipidemia, and fatty liver. Recently, gut-derived chronic endotoxemia has been identified as a primary mediator for triggering the low-grade inflammation responsible for the development of metabolic syndrome. In the present study we examined the role of the small intestinal brush-border enzyme, intestinal alkaline phosphatase (IAP), in preventing a high-fat-diet–induced metabolic syndrome in mice. We found that both endogenous and orally supplemented IAP inhibits absorption of endotoxin (lipopolysaccharides) that occurs with dietary fat, and oral IAP supplementation prevents as well as reverses metabolic syndrome. Furthermore, IAP supplementation improves the lipid profile in mice fed a standard, low-fat chow diet. These results point to a potentially unique therapy against metabolic syndrome in at-risk humans.
Choreography of importin-α/CAS complex assembly and disassembly at nuclear pores
Authors: Sun Changxia , Fu Guo , Ciziene Danguole , Stewart Murray , Musser Siegfried M.
Published: April 2013

Significance

Nucleocytoplasmic transport requires the orchestrated assembly and disassembly of cargo–carrier complexes. Visualizing the dynamics of these interactions during nuclear import and export with millisecond time resolution using single-molecule FRET provides new insight into the mechanism of the transport cycle. We show that although key interactions between components are reversible and multiple outcomes are often possible, effective transport is generated through precise spatiotemporal control of cargo–carrier complex assembly and disassembly. The novel transient intermediates identified and the kinetic models developed emphasize that the distinct environments at the nuclear and cytoplasmic faces of nuclear pores are necessary for productive transport.
Developmental timing of mutations revealed by whole-genome sequencing of twins with acute lymphoblastic leukemia
Authors: Ma Yussanne , Dobbins Sara E. , Sherborne Amy L. , Chubb Daniel , Galbiati Marta , Cazzaniga Giovanni , Micalizzi Concetta , Tearle Rick , Lloyd Amy L. , Hain Richard , Greaves Mel , Houlston Richard S.
Published: April 2013

Acute lymphoblastic leukemia (ALL) is the major pediatric cancer. At diagnosis, the developmental timing of mutations contributing critically to clonal diversification and selection can be buried in the leukemia's covert natural history. Concordance of ALL in monozygotic, monochorionic twins is a consequence of intraplacental spread of an initiated preleukemic clone. Studying monozygotic twins with ALL provides a unique means of uncovering the timeline of mutations contributing to clonal evolution, pre- and postnatally. We sequenced the whole genomes of leukemic cells from two twin pairs with ALL to comprehensively characterize acquired somatic mutations in ALL, elucidating the developmental timing of all genetic lesions. Shared, prenatal, coding-region single-nucleotide variants were limited to the putative initiating lesions. All other nonsynonymous single-nucleotide variants were distinct between tumors and, therefore, secondary and postnatal. These changes occurred in a background of noncoding mutational changes that were almost entirely discordant in twin pairs and likely passenger mutations acquired during leukemic cell proliferation.
Plasmodium falciparum
-like parasites infecting wild apes in southern Cameroon do not represent a recurrent source of human malaria
Authors: Sundararaman Sesh A. , Liu Weimin , Keele Brandon F. , Learn Gerald H. , Bittinger Kyle , Mouacha Fatima , Ahuka-Mundeke Steve , Manske Magnus , Sherrill-Mix Scott , Li Yingying , Malenke Jordan A. , Delaporte Eric , Laurent Christian , Mpoudi Ngole Eitel , Kwiatkowski Dominic P. , Shaw George M. , Rayner Julian C. , Peeters Martine , Sharp Paul M. , Bushman Frederic D. , Hahn Beatrice H.
Published: April 2013

Wild-living chimpanzees and gorillas harbor a multitude of
Plasmodium
species, including six of the subgenus
Laverania
, one of which served as the progenitor of
Plasmodium falciparum
. Despite the magnitude of this reservoir, it is unknown whether apes represent a source of human infections. Here, we used
Plasmodium
species-specific PCR, single-genome amplification, and 454 sequencing to screen humans from remote areas of southern Cameroon for ape
Laverania
infections. Among 1,402 blood samples, we found 1,000 to be
Plasmodium
mitochondrial DNA (mtDNA) positive, all of which contained human parasites as determined by sequencing and/or restriction enzyme digestion. To exclude low-abundance infections, we subjected 514 of these samples to 454 sequencing, targeting a region of the mtDNA genome that distinguishes ape from human
Laverania
species. Using algorithms specifically developed to differentiate rare
Plasmodium
variants from 454-sequencing error, we identified single and mixed-species infections with
P. falciparum
,
Plasmodium malariae
, and/or
Plasmodium ovale
. However, none of the human samples contained ape
Laverania
parasites, including the gorilla precursor of
P. falciparum
. To characterize further the diversity of
P. falciparum
in Cameroon, we used single-genome amplification to amplify 3.4-kb mtDNA fragments from 229 infected humans. Phylogenetic analysis identified 62 new variants, all of which clustered with extant
P. falciparum
, providing further evidence that
P. falciparum
emerged following a single gorilla-to-human transmission. Thus, unlike
Plasmodium knowlesi
-infected macaques in southeast Asia, African apes harboring
Laverania
parasites do not seem to serve as a recurrent source of human malaria, a finding of import to ongoing control and eradication measures.
A Population Model to Assess Influences on the Viability of the Shortnose Sturgeon Population in the Ogeechee River, Georgia
Authors: Jager Henriette I. , Peterson Douglas L. , Farrae Daniel , Bevelhimer Mark S.
Published: April 2013

Southern populations of the federally endangered Shortnose Sturgeon Acipenser brevirostrum are considered to be at greater risk of extirpation than northern populations. Our study focused on the Ogeechee River, Georgia, a small, undeveloped, coastal river that supports a population with fewer than 300 Shortnose Sturgeon. We designed a population viability analysis (PVA) model to represent and quantify the demographic influences of three factors (poor water quality, intrusion of saline water via rice canals, and incidental harvest) on the viability of this population. As an isolated population, only 75% of simulated populations persisted beyond a 20‐year time horizon with all factors simulated. However, immigration from the Altamaha River may help to support the population. We quantified population persistence with and without simulating each factor and found that (1) incidental harvest had no effect on simulated persistence, (2) poor water quality decreased simulated persistence by 29%, primarily due to low oxygen conditions in summer, and (3) roughly one‐third of this effect was attributed to rice canals (premature exposure of juveniles to high salinities). Simulated recruitment to age 1 was limited by a habitat squeeze between density‐dependent starvation upstream near the spawning grounds and premature exposure to salinity downstream. These results highlight a need for research on availability of summer refuge and freshwater rearing habitat. As these results derived from a PVA model, which required many assumptions, they should be considered preliminary. Further field research is needed to confirm those results where it is possible to test intermediate predictions. We conclude by suggesting that efforts to maintain or increase the number of viable populations of Shortnose Sturgeon in southern U.S. rivers will probably require an understanding of (1) source‐sink dynamics between populations in rivers with access to adequate freshwater rearing habitat and those without, and (2) the effects of climate change.
Xenopus oocyte meiosis lacks spindle assembly checkpoint control
Authors: Shao Hua , Li Ruizhen , Ma Chunqi , Chen Eric , Liu X. Johné
Published: April 2013

The spindle assembly checkpoint (SAC) functions as a surveillance mechanism to detect chromosome misalignment and to delay anaphase until the errors are corrected. The SAC is thought to control mitosis and meiosis, including meiosis in mammalian eggs. However, it remains unknown if meiosis in the eggs of nonmammalian vertebrate species is also regulated by SAC. Using a novel karyotyping technique, we demonstrate that complete disruption of spindle microtubules in Xenopus laevis oocytes did not affect the bivalent-to-dyad transition at the time oocytes are undergoing anaphase I. These oocytes also acquired the ability to respond to parthenogenetic activation, which indicates proper metaphase II arrest. Similarly, oocytes exhibiting monopolar spindles, via inhibition of aurora B or Eg5 kinesin, underwent monopolar anaphase on time and without additional intervention. Therefore, the metaphase-to-anaphase transition in frog oocytes is not regulated by SAC.
Similar antigen cross-presentation capacity and phagocytic functions in all freshly isolated human lymphoid organ–resident dendritic cells
Authors: Segura Elodie , Durand Mélanie , Amigorena Sebastian
Published: April 2013

Dendritic cells (DCs) represent a heterogeneous population of antigen-presenting cells that initiate and orient immune responses in secondary lymphoid organs. In mice, lymphoid organ–resident CD8+ DCs are specialized at cross-presentation and have developed specific adaptations of their endocytic pathway (high pH, low degradation, and high export to the cytosol). In humans, blood BDCA3+ DCs were recently shown to be the homologues of mouse CD8+ DCs. They were also proposed to cross-present antigens more efficiently than other blood DC subsets after in vitro activation, suggesting that in humans cross-presentation is restricted to certain DC subsets. The DCs that cross-present antigen physiologically, however, are the ones present in lymphoid organs. Here, we show that freshly isolated tonsil-resident BDCA1+ DCs, BDCA3+ DCs, and pDCs all cross-present soluble antigen efficiently, as compared to macrophages, in the absence of activation. In addition, BDCA1+ and BDCA3+ DCs display similar phagosomal pH and similar production of reactive oxygen species in their phagosomes. All three DC subsets, in contrast to macrophages, also efficiently export internalized proteins to the cytosol. We conclude that all freshly isolated lymphoid organ–resident human DCs, but not macrophages, display high intrinsic cross-presentation capacity.
Beyond the Hawthorne Effect: Reduction of Clostridium difficile Environmental Contamination through Active Intervention to Improve Cleaning Practices
Authors: Guerrero Dubert M. , Carling Philip C. , Jury Lucy A. , Ponnada Suresh , Nerandzic Michelle M. , Donskey Curtis J.
Published: April 2013

Education and passive observation resulted in a significant improvement in housekeeper disinfection of nontoxigenic Clostridium difficile spores artificially inoculated onto surfaces in C. difficile infection rooms. A further significant reduction occurred with direct supervision and real-time feedback, suggesting that optimal disinfection is achieved by working closely with housekeepers.
Is Environmental Contamination Associated with Staphylococcus aureus Clinical Infection in Maximum Security Prisons?
Authors: Miko Benjamin A. , Herzig Carolyn T. A. , Mukherjee Dhritiman V. , Befus Montina , Apa Zoltan L. , Bai Ruo Yu , Lee Caroline J. , Uhlemann Anne-Catrin , Larson Elaine L. , Lowy Franklin D.
Published: April 2013

Over the past decade, large outbreaks of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) infections have occurred in correctional facilities across the country. Although many have been managed with aggressive interventions, response to standard infection control procedures has been variable, highlighting our incomplete understanding of staphylococcal transmission in this setting. Environmental contamination has recently emerged as a possible target for novel prevention and control strategies. This study sought to characterize the relationship between environmental contamination and clinical infection in this vulnerable population.

We conducted a case-control study of S. aureus environmental contamination at 2 New York State (NYS) maximum security prisons: Sing Sing (men) and Bedford Hills (women).
Single-Incision Thoracoscopic Right Upper Lobectomy with Chest Wall Resection by Posterior Approach
Authors: Gonzalez-Rivas Diego , Fernandez Ricardo , Fieira Eva , Mendez Lucia
Published: April 2013

Lobectomy requiring chest wall resection is usually performed by thoracotomy, but thanks to the advances in the field of thoracoscopic surgery, this procedure can be performed by video-assisted thoracoscopic surgery (VATS). Recent improvements in surgical devices and previous VATS experience have allowed this complex surgery for advanced stages to be undertaken safely. Most of the thoracoscopic lobectomies with rib resection are performed using three to four incisions. We report a different minimally invasive technique for chest wall resection (minimally invasive posterior approach) and VATS right upper lobectomy (single-incision anterior approach).
One-Stage Triple Hybrid Arch Debranching
Authors: Lee Jeffrey D. , Williams James B. , Winkler Janet L.
Published: April 2013

Traditionally, repair of complex arch and descending aortic disease has required a two-stage surgical approach. We describe a novel one-stage repair that combines primary revascularization of the subclavian with stent coverage of diffuse aortic disease. A 31-year-old woman with Marfan syndrome presented with a growing arch aneurysm. At age 16 years, she had undergone the Ross procedure followed by a redo sternotomy and valve conduit. On follow-up, a distal arch aneurysm measuring 6 cm with an aneurismal upper thoracic aorta and a localized distal thoracic aortic dissection was identified. In one stage, triple hybrid off-pump arch debranching with endovascular stent grafting was performed using two GORE Hybrid Vascular Grafts to perform the distal left carotid and subclavian anastomoses, which provided complete primary arch debranching without requiring a carotid-subclavian shunt. The patient had no complications, was discharged home on postoperative day 3, and continues to do well 3 months post-operatively. We conclude that one-stage repair of complex aortic arch disease with primary revascularization of the subclavian is feasible.
Mechanical Properties and Biological Interaction of Aortic Clamps: Are These All Minimally Invasive?
Authors: Bianchi Giacomo , Pucci Angela , Matteucci Marco , Varone Egidio , Romano Simone Lorenzo , Lionetti Vincenzo , Glauber Mattia
Published: April 2013

Objective

Although specifically designed aortic clamps are mainstay of minimally invasive cardiac surgery, so far, no comparative reports about their mechanical properties and interaction with the aortic wall have been reported. In this study, the generated force in the clamps’ jaws and the biological response of the aorta after clamping are evaluated.

Methods

The jaw force of five commercially available clamps [Geister, Cygnet, Cardiovision (CV) 195.10, CV 195.40, and CV 195.83] was assessed by clamping a 2.2-mm compression load cell with a dedicated computer universal serial bus interface at the proximal, the middle, and the distal site from the fulcrum. Biological response of the aortic wall was assessed in five minipigs (weight, 38–40 kg) that underwent thoracic aorta clamping and leakage point test. Immunohistochemistry and morphometric analysis were carried out for each aortic segment tested.

Results

Force generation pattern is peculiar of each clamp, being higher in the proximal and the middle portion and lower in the distal part. One clamp (Cygnet) exhibited homogeneous maximal force generation at all three sites. All clamps exhibited peculiar crushing artifacts. A variable degree of endothelial layer disruption occurred in all clamping tests; three clamps (CV 195.10, Cygnet, and Geister) had the lower amount of intact endothelium. The clamping force was not associated with the degree of endothelial disruption (P value was not significant).

Conclusions

The choice of a clamp that is not only minimally invasive in design but also least traumatic will help avoid complications of aortic manipulation.
Novel Sternum Lifting Technique for Robotic Internal Thoracic Artery Graft Harvesting
Authors: Watanabe Go , Matsumoto Isao , Kiuchi Ryuta
Published: April 2013

Internal thoracic artery (ITA) harvesting using the robotic system usually requires artificially induced capnothorax to provide visualization and working space, but this procedure has the disadvantage of deteriorating the hemodynamics. We developed an electrical sternum lifting system (ESLS) for robotic ITA harvesting, which is robust and can be finely adjusted, capable of lifting the sternum for a maximum of 5 to 10 cm. Using a mechanical sternum lifting device significantly (P < 0.01) shortened the time of ITA harvesting from a mean ± SD of 55.5 ± 24.1 minutes to 33.0 ± 15.7 minutes. No patient using the ESLS required induced capnothorax. Our novel ESLS provides a good operative field of view and allows ITA harvesting without inducing capnothorax.
Advanced Esophageal Cancer in Patients who Underwent Radiofrequency Ablation for Barrett Esophagus with High-Grade Dysplasia
Authors: Kim Min P. , Brown Kendra N. , Schwartz Mary R. , Blackmon Shanda H.
Published: April 2013

Objective

We sought to evaluate clinicopathologic features of patients who underwent esophageal surgery after radiofrequency ablation (RFA) treatment using the HALO system for Barrett esophagus (BE) with high-grade dysplasia (HGD).

Methods

We evaluated patients from our hospital database who underwent esophagectomy from August 2006 to January 2012 after previously receiving RFA for BE. Information on demographics, time between RFA and surgery, indications for surgery, and final esophageal pathology was collected.

Results

In our study, we selected 102 patients who underwent esophagectomy. Five patients had a history of RFA for BE with HGD. Three patients were referred because of persistent HGD despite RFA, and all three patients had HGD in the esophagectomy specimen. Two patients presented with a benign diagnosis (esophageal perforation and leiomyoma), and both of these patients had pathologic stage T3N2M0 adenocarcinoma of the esophagus in the resected specimen. One of these patients had normal mucosa overlying carcinoma in the muscularis propria and adventitia. The patients with stage T3N2M0 cancer did not have pre-RFA endoscopic ultrasound, first treatment of RFA with HALO360, or surveillance endoscopic biopsy every 3 months.

Conclusions

Radiofrequency ablation for BE with HGD may mask underlying esophageal cancer. Patients who are counseled to undergo RFA for HGD should be aware that RFA could lead to delayed diagnosis and delayed treatment of invasive esophageal cancer without careful patient selection, appropriate RFA use, and close surveillance.
Outcome of the Impella Device for Acute Mechanical Circulatory Support
Authors: Lemaire Anthony , Anderson Mark B. , Prendergast Thomas , Stockmaster Neil , Goodman Andrew , Lozane Ann Marie , Batsides George
Published: April 2013

Objective

The contribution of cardiogenic shock to in-hospital mortality has not decreased significantly despite prompt revascularization, advances in medical therapy, and mechanical circulatory support. For patients in cardiogenic shock, mechanical circulatory support has been provided by a variety of devices. We report the outcome of the Impella device for acute mechanical circulatory support in cardiogenic shock in a setting of a large-volume single institution. The primary end points include survival to 30 days and recovery of native heart function and survival to 90 days and 1 year. The secondary end points include device complications.

Methods

We performed a retrospective chart review of 36 consecutive patients who underwent placement of the Impella device from February 6, 2006, to December 31, 2010. The charts were evaluated for data relative to the patients’ demographics, hemodynamics, operative details, 30-day outcome including the patients’ native heart function recovery, and 90-day and 1-year survival.

Results

Thirty-six consecutive patients were included in our study. The mean ± SD age was 60.3 ± 13 years, and 69% were men. The indication for placement of the Impella device included postcardiotomy cardiogenic shock in 23 patients (64%), acute myocardial infarction complicated with cardiogenic shock in 10 patients (28%), acute decompensated ischemic cardiomyopathy in 2 patients (6%), and myocarditis with cardiogenic shock in 1 patient (3%). The mean ± SD duration of the Impella support was 4.5 ± 3.9 days (range, 1–18). The 30-day survival rate was 72% (26/36), and, of those, 96% (25/26) recovered their native heart function and one (4%) was bridged to long-term left ventricular assist device (HeartMate II; Thoratec, Inc, Pleasanton, CA USA). The 90-day and 1-year survival was 64% and 61%, respectively.

Conclusions

The Impella devices yielded a very favorable outcome in patients with cardiogenic shock.
Genome evolution during progression to breast cancer
Authors: Newburger Daniel E. , Kashef-Haghighi Dorna , Weng Ziming , Salari Raheleh , Sweeney Robert T. , Brunner Alayne L. , Zhu Shirley X. , Guo Xiangqian , Varma Sushama , Troxell Megan L. , West Robert B. , Batzoglou Serafim , Sidow Arend
Published: April 2013

Cancer evolution involves cycles of genomic damage, epigenetic deregulation, and increased cellular proliferation that eventually culminate in the carcinoma phenotype. Early neoplasias, which are often found concurrently with carcinomas and are histologically distinguishable from normal breast tissue, are less advanced in phenotype than carcinomas and are thought to represent precursor stages. To elucidate their role in cancer evolution we performed comparative whole-genome sequencing of early neoplasias, matched normal tissue, and carcinomas from six patients, for a total of 31 samples. By using somatic mutations as lineage markers we built trees that relate the tissue samples within each patient. On the basis of these lineage trees we inferred the order, timing, and rates of genomic events. In four out of six cases, an early neoplasia and the carcinoma share a mutated common ancestor with recurring aneuploidies, and in all six cases evolution accelerated in the carcinoma lineage. Transition spectra of somatic mutations are stable and consistent across cases, suggesting that accumulation of somatic mutations is a result of increased ancestral cell division rather than specific mutational mechanisms. In contrast to highly advanced tumors that are the focus of much of the current cancer genome sequencing, neither the early neoplasia genomes nor the carcinomas are enriched with potentially functional somatic point mutations. Aneuploidies that occur in common ancestors of neoplastic and tumor cells are the earliest events that affect a large number of genes and may predispose breast tissue to eventual development of invasive carcinoma.
Administration of metoclopramide by infusion or bolus does not affect the incidence of drug‐induced akathisia
Authors: Egerton‐Warburton Diana , Povey Kirsty
Published: April 2013

Objective

The study aims to determine if slow intravenous infusion of metoclopramide reduces the incidence of acute drug‐induced akathisia (DIA) compared with intravenous bolus.

Methods

A prospective, double‐blind, double dummy trial of adult patients requiring intravenous metoclopramide in the ED. Participants were randomised to receive either: metoclopramide 20 mg as a bolus and normal saline infusion over 15 min, or normal saline bolus and metoclopramide 20 mg infused over 15 min. Patients were assessed for DIA using the Prince Henry Akathisia Rating Scale before treatment was commenced and at 20, 40 and 60 min post. Nausea was assessed with a visual analog scale.

Results

Of 210 participants assessed for eligibility, 206 were randomised and 205 were included in the final analysis. Participant characteristics and indication for metoclopramide were well matched between the treatment groups. Overall, incidence of DIA was 26 out of 205 participants (12.68%, 95% confidence interval [CI] 8.09–17.3). DIA occurred in 11 out of 103 (10.68%, 95% CI 4.61–16.74%) in the bolus group, and in 15 out of 102 (14.71%, 95% CI 7.71–21.70%) in the infusion group (P = 0.67). Severe DIA occurred in six patients in each group. The mean age of patients experiencing DIA was 34 years (interquartile range 29–40) and 42 years (interquartile range 40–45) in those without akathisia (P = 0.04). Nausea reduction was equivalent in both groups.

Conclusion

The incidence of DIA and reduction in nausea is unaffected by the rate of administration of intravenous metoclopramide 20 mg.
Benign acute childhood myositis following human parainfluenza virus type‐1 infection
Authors: Tippett Emma , Clark Ronald
Published: April 2013

Benign acute childhood myositis (BACM) is a post‐respiratory tract infection condition of school‐age children. Presentation is typically with acute onset calf pain and tenderness and refusal to walk or altered gait during the convalescent period of an influenza A or B infection. We describe a unique cluster of children with BACM following infection with human parainfluenza 1 virus, with no evidence of influenza A or B infection. BACM is a commonly missed diagnosis of altered gait in children presenting to the emergency department. This is the first report to describe a cluster of human parainfluenza virus type‐1 associated BACM. We discuss the presentation, clinical examination and investigation results of the children identified. Furthermore, we review the current research surrounding BACM, overview the clinical presentation to healthcare professionals, and present an interesting case of a child presenting for the second time with BACM.