bluuebunny/crossref_metadata_2025_split huggingface dataset:
The coupled estuarine‐shelf response of a river‐dominated system during the transition from low to high discharge
Authors: Dzwonkowski Brian , Park Kyeong , Collini Renee 
Published: August 2015

AbstractOpportunistic observations captured the coupled estuarine‐shelf interactions as the Alabama coastal region transitioned from a period of low to flood river discharge conditions. The period of focus was 18 February to 10 April 2011 during which time a combination of in situ (water level, salinity and velocity) and remote sensing (ocean color) data provided information on the estuarine and shelf environment prior to, during, and post a major river discharge event that captured a relatively rare spatially synoptic view of the structural evolution of a discharge plume in response to changing forcing conditions. The discharge event generated major changes in the hydrographic conditions and forcing responses within the estuary and on the shelf. The resulting surface advected plume was observed for approximately two weeks, during which time the observed differences in shelf circulation were directly linked to the discharge plume and a plume bulge with anticyclonic circulation was identified at times throughout the event. The plume was exposed to a range of wind conditions which modulated the surface structure: downwelling winds elongated the plume structure and upwelling winds reversed and widened the plume. The influence of wind forcing, even during very low wind (<3.75 m s−1) and large outflow (∼7000 m3 s−1) conditions, was apparent, as a result of the shallow and wide characteristics of the plume. Anticyclonic bulge regions have only been identified in a few systems and the occurrence of this feature on the Alabama shelf has significant implications on transport and fate of river discharge in this region.
A comparison of temperature and precipitation responses to different Earth radiation management geoengineering schemes
Authors: Crook J. A. , Jackson L. S. , Osprey S. M. , Forster P. M. 
Published: August 2015

AbstractEarth radiation management has been suggested as a way to rapidly counteract global warming in the face of a lack of mitigation efforts, buying time and avoiding potentially catastrophic warming. We compare six different radiation management schemes that use surface, troposphere, and stratosphere interventions in a single climate model in which we projected future climate from 2020 to 2099 based on RCP4.5. We analyze the surface air temperature responses to determine how effective the schemes are at returning temperature to its 1986–2005 climatology and analyze precipitation responses to compare side effects. We find crop albedo enhancement is largely ineffective at returning temperature to its 1986–2005 climatology. Desert albedo enhancement causes excessive cooling in the deserts and severe shifts in tropical precipitation. Ocean albedo enhancement, sea‐spray geoengineering, cirrus cloud thinning, and stratospheric SO2 injection have the potential to cool more uniformly, but cirrus cloud thinning may not be able to cool by much more than 1 K globally. We find that of the schemes potentially able to return surface air temperature to 1986–2005 climatology under future greenhouse gas warming, none has significantly less severe precipitation side effects than other schemes. Despite different forcing patterns, ocean albedo enhancement, sea‐spray geoengineering, cirrus cloud thinning, and stratospheric SO2 injection all result in large scale tropical precipitation responses caused by Hadley cell changes and land precipitation changes largely driven by thermodynamic changes. Widespread regional scale changes in precipitation over land are significantly different from the 1986–2005 climatology and would likely necessitate significant adaptation despite geoengineering.
Analysis of long‐term aerosol size distribution data from Jungfraujoch with emphasis on free tropospheric conditions, cloud influence, and air mass transport
Authors: Herrmann Erik , Weingartner Ernest , Henne Stephan , Vuilleumier Laurent , Bukowiecki Nicolas , Steinbacher Martin , Conen Franz , Collaud Coen Martine , Hammer Emanuel , Jurányi Zsofia , Baltensperger Urs , Gysel Martin 
Published: August 2015

AbstractSix years of aerosol size distribution measurements between 20 and 600 nm diameters and total aerosol concentration above 10 nm from March 2008 to February 2014 at the high‐alpine site Jungfraujoch are presented. The size distribution was found to be typically bimodal with mode diameters and widths relatively stable throughout the year and the observation period. New particle formation was observed on 14.5% of all days without a seasonal preference. Particles typically grew only into the Aitken mode and did not reach cloud condensation nucleus (CCN) sizes on the time scale of several days. Growth of preexisting particles in the Aitken mode, on average, contributed very few CCN. We concluded that the dominant fraction of CCN at Jungfraujoch originated in the boundary layer. A number of approaches were used to distinguish free tropospheric (FT) conditions and episodes with planetary boundary layer (PBL) influence. In the absence of PBL injections, the concentration of particles larger than 90 nm (N90, roughly corresponding to the CCN concentration) reached a value ~40 cm−3 while PBL influence caused N90 concentrations of several hundred or even 1000 cm−3. Comparing three criteria for free tropospheric conditions, we found FT prevalence for 39% of the time with over 60% during winter and below 20% during summer. It is noteworthy that a simple criterion based on standard trace gas measurements appeared to outperform alternative approaches.
Lightning channel length and flash energy determined from moments of the flash area distribution
Authors: Bruning Eric C. , Thomas Ronald J. 
Published: August 2015

AbstractA widely used approach in observational and modeling studies of NOx produced by lightning is to relate NOx production to the number of flashes, without regard for the distribution of lightning flash sizes. Recent studies have begun to consider channel length and flash size, which is now observable with VHF Lightning Mapping Array data. This study uses a capacitor model for flash energy based on the flash coverage area, which defines a size scale. This flash area is then filled with channel using a fractal method and compared to other methods that estimate length directly from the VHF source locations. In the presence of instrument measurement errors, area‐ and fractal‐based estimates are shown to be more stable estimators of flash length than connect‐the‐dots approaches and therefore are better suited for comparison to NOx production. A geometric interpretation of using vertical profiles of VHF source density to weight the altitude distribution of total channel length is developed. An example of the time series of moments of the lightning flash size distribution is shown for an example case, and some meteorological interpretation is given.
Molecular level characterization of diatom‐associated biopolymers that bind 234Th, 233Pa, 210Pb, and 7Be in seawater: A case study with Phaeodactylum tricornutum
Authors: Chuang Chia‐Ying , Santschi Peter H. , Xu Chen , Jiang Yuelu , Ho Yi‐Fang , Quigg Antonietta , Guo Laodong , Hatcher Patrick G. , Ayranov Marin , Schumann Dorothea 
Published: August 2015

AbstractIn order to investigate the importance of biogenic silica associated biopolymers on the scavenging of radionuclides, the diatom Phaeodactylum tricornutum was incubated together with the radionuclides 234Th, 233Pa, 210Pb, and 7Be during their growth phase. Normalized affinity coefficients were determined for the radionuclides bound with different organic compound classes (i.e., proteins, total carbohydrates, uronic acids) in extracellular (nonattached and attached exopolymeric substances), intracellular (ethylene diamine tetraacetic acid and sodium dodecyl sulfate extractable), and frustule embedded biopolymeric fractions (BF). Results indicated that radionuclides were mostly concentrated in frustule BF. Among three measured organic components, Uronic acids showed the strongest affinities to all tested radionuclides. Confirmed by spectrophotometry and two‐dimensional heteronuclear single quantum coherence‐nuclear magnetic resonance analyses, the frustule BF were mainly composed of carboxyl‐rich, aliphatic‐phosphoproteins, which were likely responsible for the strong binding of many of the radionuclides. Results from this study provide evidence for selective absorption of radionuclides with different kinds of diatom‐associated biopolymers acting in concert rather than as a single compound. This clearly indicates the importance of these diatom‐related biopolymers, especially frustule biopolymers, in the scavenging and fractionation of radionuclides used as particle tracers in the ocean.
Ionosphere plasma electron parameters from radio frequency sweeping impedance probe measurements
Authors: Spencer E. , Patra S. 
Published: August 2015

AbstractIn this work we will describe the technique of using an RF sweeping impedance probe (SIP) to measure the AC impedance of an electrically short monopole immersed in a plasma. We analyze the SIP measurements which are taken from the payload of the Storms sounding rocket, launched from Wallops Island, Virginia, in 2007. The scientific objective of the Storms mission was to concentrate on whether density irregularities observed in midlatitude spread F could arise from ionospheric coupling to terrestrial weather. As such, independent measurements of the electron density profile are crucial. Since the inherent nature of the SIP technique makes it relatively insensitive to errors introduced through spacecraft charging, probe contamination, and other DC effects, it is an ideal instrument to employ under disturbed plasma conditions. The instrument measures both the magnitude and phase of the AC impedance from 100 kHz to 20 MHz in 128 frequency steps, performing 45,776 sweeps over the entire flight. From these measurements we infer both the absolute electron density ne and the electron neutral collision frequencies νen throughout the flight trajectory. The SIP data can be approximately analyzed using a fluid formulation and thin sheath approximation particularly at altitudes below 200 km, which allows us to match the measurements to quasi‐static analytical formulas. At about 265 km on the upleg, the magnitude data transitioned to a highly damped response with increasing altitude. The phase data, on the other hand, continued to indicate increased plasma density and reduced collisionality as expected. For a large portion of the flight, the payload of the Storms mission exhibited an uncontrolled coning motion, making the local magnetic field orientation with respect to the dipole difficult to decipher. Despite these difficulties, we were able to obtain robust estimates of the electron density profile, using the phase information from each sweep. In addition, the electron neutral collision frequency obtained from matching to phase data alone was on the correct order of magnitude with respect to Naval Research Laboratory Mass Spectrometer Incoherent Scatter‐Extended model values in the ionosphere between 100 km and 150 km.
Emerging Coronaviruses: Severe Acute Respiratory Syndrome (
SARS
) and Middle East Respiratory Syndrome (MERS)
Authors: Sisk Jeanne M , Frieman Matthew B 
Published: August 2015

Abstract

The severe acute respiratory syndrome Coronavirus (
SARS‐CoV
) and the Middle East respiratory syndrome Coronavirus (
MERS‐CoV
) are two highly pathogenic viruses that recently emerged from zoonotic sources. In 2002,
SARS‐CoV
was identified as the agent that causes severe acute respiratory syndrome, or
SARS
, in the Guangdong province of China (Drosten
et al
., 2003; Marra
et al
., 2003; Rota
et al
., 2003). Almost 10 years later in 2012,
MERS‐CoV
was identified as the cause of Middle East respiratory syndrome, or
MERS
, in the Kingdom of Saudi Arabia (
KSA
) (Coleman and Frieman, 2014). There have been no new infections of
SARS‐CoV
reported since 2004, but it is possible that this virus could re‐emerge, as it is capable of spreading to humans again from its zoonotic source (Yang
et al
., 2013). In 2015,
MERS‐CoV
continues to spread throughout the Middle East and to other neighboring countries. Here, we review the epidemiology, clinical disease and virology of these disease‐causing viruses.

Key Concepts

Emerging Coronaviruses are serious threat to global public health.

Infection control in outbreak setting is crucial for containing Coronavirus spread.

Coronavirus genome structures are conserved between known and newly identified family members.

Therapeutic development is crucial for front line healthcare worker protection.

Animal model development is essential to understand the underlying pathology of each virus.

Comparisons between SARS‐CoV, MERS‐CoV and other human coronaviruses will give us insights into disease progression and therapeutic direction.
Plasma Cells
Authors: Minges Wols Heather A 
Published: August 2015

Abstract

Plasma cells are terminally differentiated B lymphocytes that provide protective immunity through the continuous secretion of antibodies. Antibody‐secreting cells develop in secondary lymphoid tissue following antigen stimulation and may enter a short‐lived plasma cell population that resides primarily in the nonlymphoid area of the spleen or lymph nodes. Alternatively, antibody‐secreting cells can migrate to the bone marrow where the majority enter a long‐lived, nonproliferative population of plasma cells. Within the marrow, plasma cells situate themselves within niches where longevity is supported by factors such as
APRIL
,
IL
‐6, and
CXCL2
, provided by support cells that include
CXCL12
‐abundant reticular (
CAR
) cells, eosinophils, megakaryocytes and dendritic cells, among others.

Key Concepts

Plasma cells are terminally differentiated cells of the B lymphocyte lineage. They are committed to secreting antibody that provides an organism with protective immunity.

Plasma cells may be short‐lived, surviving only 3–5 days. Generally, these secrete lower affinity antibody. Alternatively, plasma cells may be long‐lived, surviving decades or the lifetime of an animal, secreting high‐affinity antibody resulting from somatic hypermutation within a germinal centre reaction.

Long‐lived plasma cells are primarily found in the bone marrow, where specialized niches provide contact and growth factors necessary for survival.

Multiple cell types in the niches can contribute to the extended lifespan of bone marrow plasma cells. However, plasma cells are not completely eliminated when any one cell type is depleted, suggesting that all of the supporting cells are critical and contributing components.

As B cells differentiate into plasma cells, they undergo molecular and morphological changes that better suit a highly secretory cell. They are easily identifiable via microscopy by their voluminous cytoplasm full of immunoglobulin and rough endoplasmic reticulum (RER).

Plasma cells can be identified by high surface expression of Syndecan‐1 (CD138) protein, and little to no expression of BCR, B220 or MHC class II.
Channelrhodopsin: Potential Applications in Vision Restoration
Authors: Tomita Hiroshi 
Published: August 2015

Abstract

Channelrhodopsins, the directly light‐gated ion channels from green algae, provide a powerful tool for basic research in neuroscience as well as potential applications for treating neurological diseases and disorders. One of the promising clinical applications is to cure blindness caused by the death of rod and cone photoreceptors. Retinitis pigmentosa (
RP
) is one of diseases that causes blindness. Although photoreceptor cells are degenerated in the retina of
RP
patients, other retinal neurons such as retinal ganglion cells and on bipolar cells still survive. Owing to the inherent characteristics of chlamydomonas‐derived channelrhodopsin‐2 (
ChR2
), photosensitive neurons can be produced in the retina by the transfer of the
ChR2
gene into survived retinal neurons. A single injection of a virus vector into the eye can achieve the vision restoration in rodent model that will be a useful treatment for the patients with blindness. Herein, we introduce the molecular properties of
ChR2
and a potential as a new strategy for restoring vision in humans.

Key Concepts

Channelrhodopsins, microbial retinal binding proteins, transiently induce photo currents by light stimuli.

Photocycle of channelrhodopsins remains preserved when they are heterologously expressed in animal and human cells.

Channelrhodoposins functions as a directly light‐gated cation channels with million second activation and deactivation kinetics.

Artificial photoreceptor cells can be produced in various types of animal neurons by transducing a single gene.

Converting surviving inner retinal neurons into directly photosensitive cells is a new strategy to treating blindness after the death of rod and cone photoreceptors.

Using delivery by adeno‐associated viral vectors, long‐term expression of channelrhodopsin‐2 can be achieved in rodent inner retinal neurons
in vivo
.

ChR2 can be expressed without immunologically harmful reactions
in vivo
.
Expanding Substrate Specificity of ω‐Transaminase by Rational Remodeling of a Large Substrate‐Binding Pocket
Authors: Han Sang‐Woo , Park Eul‐Soo , Dong Joo‐Young , Shin Jong‐Shik 
Published: August 2015

AbstractProduction of structurally diverse chiral amines via biocatalytic transamination is challenged by severe steric interference in a small active site pocket of ω‐transaminase (ω‐TA). Herein, we demonstrated that structure‐guided remodeling of a large pocket by a single point mutation, instead of excavating the small pocket, afforded desirable alleviation of the steric constraint without deteriorating parental activities toward native substrates. Molecular modeling suggested that the L57 residue of the ω‐TA from Ochrobactrum anthropi acted as a latch that forced bulky substrates to undergo steric interference with the small pocket. Removal of the latch by a L57A substitution allowed relocation of the small pocket and dramatically improved activities toward various arylalkylamines and alkylamines (e.g., 1100‐fold increase in kcat/KM for α‐propylbenzylamine). This approach may provide a facile strategy to broaden the substrate specificity of ω‐TAs.magnified image
Cobalt‐Catalyzed Electrophilic Cyanation of Arylzinc Halides with N‐Cyano‐N‐phenyl‐p‐methylbenzenesulfonamide (NCTS)
Authors: Cai Yingxiao , Qian Xin , Rérat Alice , Auffrant Audrey , Gosmini Corinne 
Published: August 2015

AbstractThe cobalt‐catalyzed cross‐coupling of organozinc bromides with N‐cyano‐N‐phenyl‐p‐methylbenzenesulfonamide (NCTS) is described. The same cobalt catalyst, cobalt(II) bromide, was used for both the synthesis of the organozinc species and the cross‐coupling reaction. However in this case, a catalytic amount of zinc dust is necessary in the second step to release the low‐valent cobalt. Under these mild conditions, moderate to excellent yields of different benzonitriles were obtained.magnified image
Catalyst‐Free Domino Reaction of 1‐Acryloyl‐1‐N‐arylcarbamylcyclopropanes with Amines: One‐Pot Approach to 2,3,6,7‐Tetrahydro‐1H‐pyrrolo[3,2‐c]pyridin‐4(5H)‐ones
Authors: Zhang Zhiguo , Zhang Feisong , Wang Huanhuan , Wu Hao , Duan Xinyu , Liu Qingfeng , Liu Tongxin , Zhang Guisheng 
Published: August 2015

AbstractA facile one‐pot, catalyst‐free reaction has been developed for the synthesis of 2,3,6,7‐tetrahydro‐1H‐pyrrolo[3,2‐c]pyridin‐4(5H)‐ones from readily available 1‐acryloyl‐1‐N‐arylcarbamylcyclopropanes and amines using a domino ring‐opening/cyclization/aza‐addition sequence. magnified image
Impact of cigarette smoking on the middle meatus microbiome in health and chronic rhinosinusitis
Authors: Ramakrishnan Vijay R. , Frank Daniel N. 
Published: August 2015

BackgroundAlthough cigarette smoking aggravates chronic rhinosinusitis (CRS), a detailed examination of the sinus microbiota in CRS and its clinical subtypes has yet to be performed in relation to history of smoking. Consequently, we examined associations between smoking history and sinonasal microbiome alterations in both CRS and non‐CRS populations.MethodsMiddle meatus swabs collected during endoscopic sinus surgery were analyzed by analysis of 16S ribosomal RNA (rRNA) sequences. Multiple analysis of variance tests were performed to determine whether microbiome composition varied with smoking history and other clinical/demographic covariates associated with CRS subtypes.ResultsA total 70 CRS patients and 31 control subjects were analyzed. In a univariate analysis, smoking (p = 0.04), preoperative antibiotics (p = 0.03), and purulence (p = 0.0002) were significantly associated with the genus‐level composition of the middle meatus microbiota. When included in a multivariable model, smoking was found to have significant interactions with CRS (p = 0.02), polyposis (p = 0.03), purulence (p = 0.0004), and use of saline rinses (p = 0.05). Diverse bacterial taxa differed significantly in abundance between never‐smokers and current/former smokers, as well as between different CRS subtypes.ConclusionSubstantial changes in sinus bacterial colonization were observed in smokers and nonsmokers. Although the microbiota of both CRS and non‐CRS subjects were altered with smoking history, different bacterial taxa were affected by smoking in the 2 patient groups. Thus, the effects of smoking on the sinus microbiota are likely to be modified by physiological and immunological functions of the underlying sinus mucosa.
Identification of Intermediates in the Biosynthesis of PR Toxin by Penicillium roqueforti
Authors: Riclea Ramona , Dickschat Jeroen S. 
Published: August 2015

AbstractThe sesquiterpenoid 7‐epi‐neopetasone was synthesized via the Wieland–Miescher ketone. The compound was identical to a previously tentatively identified headspace constituent of Penicillium roqueforti. Feeding experiments with 13C‐labeled mevalonolactone isotopomers demonstrated that oxidation at C12 and an isomerization of the C11C12 to a C7C11 double bond must occur independently and not via a C7‐C11‐C12 allyl radical in one step. Feeding with (11,12,13‐13C3)‐7‐epi‐neopetasone resulted in labelling of the PR toxin, thus establishing this compound as a newly identified pathway intermediate.
Emulsifier‐free cationic latexes based on vinylbenzyl chloride and 2‐(dimethylamino)ethyl methacrylate with adjusted hydrophilic–hydrophobic properties
Authors: Türk Hayrettin , Karabacak R. Bengü , Erdem Murat 
Published: August 2015

ABSTRACTFunctional emulsifier‐free cationic latexes based on styrenic monomer vinylbenzyl chloride (VBC) and acrylic monomer 2‐(dimethylamino)ethyl methacrylate (DMA) were successfully prepared with dual quaternary ammonium ions (36–63 mol %) on both monomer moieties in two‐stages. First, [2‐(methacryloyloxy)ethyl]dimethylhexadecylammonium bromide monomer (DMA(C16)), prepared via quaternization of DMA with 1‐bromohexadecane, was utilized as a comonomer (5–20%) as well as a surfactant in the emulsion polymerization of VBC. Next, the quaternization of chloromethyl groups in the VBC moiety in latex particles with trimethylamine and N,N‐dimethylhexadecylamine created a second type of quaternized sites on the latex particles. The percentages of the quaternary ammonium ions of the first‐stage latexes (P[VBC‐DMA(C16‐x)]) and the second‐stage latexes (P[VBC(R)‐DMA(C16‐x)]) were determined using bromide and chloride ion‐selective electrodes. The particles were characterized with a scanning electron microscope, Zetasizer, measuring water contact angles of their pellets. The polymer structure and the alkyl group length in their quaternary ammonium ions played an important role on the sizes, zeta potentials and hydrophilic–hydrophobic balances of the latexes. The water contact angles of the pellets of the latex particles varied from 50.3 to 109.6° depending on both the polymer structure and the alkyl group length. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42775.