bluuebunny/crossref_metadata_2025 huggingface dataset:
Source References and the Scientist's Mind-Map: Harvard vs. Vancouver Style
Authors: Clauss Marcus , Müller Dennis W. H. , Codron Daryl
Published: March 2013

As a scientist develops, a referencing system (linking results/hypotheses to sources) evolves in the mind. This mind-map is an essential working tool that uses indexing features—such as author names—as reference points. The Harvard style (HS), in which citations in the text are made of names and years of publication and the references are listed in alphabetical order, actively helps to establish this mind-map. In our view, the Vancouver style (VS), in which citations in the text are numbers and the references are listed in order of appearance within the text, does not enhance the formation of a mind-map in a similar way and makes detections of incongruity between the reader's mind-map and the text more difficult. In an ideal academic world, HS would be used because of these two effects: constant education of and easy quality control by the scientific reader. Although VS reduces printing space and allows easier reading for less academically trained readers, scientific readers may find this style difficult when trying to check and verify sources. For reviewers, who cannot opt not to make such checks, VS is even more tedious. We advocate that journals using VS in print should use HS for the reviewing process; further, in the final printed version, the references should be numbered and listed alphabetically rather than according to the order in which they are cited. Especially for maturing scientists, reading texts with HS referencing is essential.
Ice-sheet model sensitivities to environmental forcing and their use in projecting future sea level (the SeaRISE project)
Authors: Bindschadler Robert A. , Nowicki Sophie , Abe-Ouchi Ayako , Aschwanden Andy , Choi Hyeungu , Fastook Jim , Granzow Glen , Greve Ralf , Gutowski Gail , Herzfeld Ute , Jackson Charles , Johnson Jesse , Khroulev Constantine , Levermann Anders , Lipscomb William H. , Martin Maria A. , Morlighem Mathieu , Parizek Byron R. , Pollard David , Price Stephen F. , Ren Diandong , Saito Fuyuki , Sato Tatsuru , Seddik Hakime , Seroussi Helene , Takahashi Kunio , Walker Ryan , Wang Wei Li
Published: March 2013

Ten ice-sheet models are used to study sensitivity of the Greenland and Antarctic ice sheets to prescribed changes of surface mass balance, sub-ice-shelf melting and basal sliding. Results exhibit a large range in projected contributions to sea-level change. In most cases, the ice volume above flotation lost is linearly dependent on the strength of the forcing. Combinations of forcings can be closely approximated by linearly summing the contributions from single forcing experiments, suggesting that nonlinear feedbacks are modest. Our models indicate that Greenland is more sensitive than Antarctica to likely atmospheric changes in temperature and precipitation, while Antarctica is more sensitive to increased ice-shelf basal melting. An experiment approximating the Intergovernmental Panel on Climate Change’s RCP8.5 scenario produces additional first-century contributions to sea level of 22.3 and 8.1 cm from Greenland and Antarctica, respectively, with a range among models of 62 and 14 cm, respectively. By 200 years, projections increase to 53.2 and 26.7 cm, respectively, with ranges of 79 and 43 cm. Linear interpolation of the sensitivity results closely approximates these projections, revealing the relative contributions of the individual forcings on the combined volume change and suggesting that total ice-sheet response to complicated forcings over 200 years can be linearized.
Prevalence of Dermatoses in Rural Paediatric Population
Authors: Hadiuzzaman Md , Rahman Muhammad Hasibur , Islam Nahida , Islam Md Shahidul , Mumu Sabrina Alam , Bhuyan Mohammod Kamruj Jaman
Published: March 2013

The spectra of the prevalence of skin diseases vary worldwide and from country to country. Therefore the information about the local prevalence of diseases is very important in helping the development of appropriate health improvement policies for promotion of better management. To document the types of skin disorders prevalent among rural children attending the Community Based Medical College Hospital out patient department, Mymensigh, a defined population based study was undertaken. The medical register from the Hospital was used to obtain information on pattern and outcome of skin diseases seen from January 2010 to December 2011. The frequency of pediatric dermatoses and their distribution patterns were studied. The results revealed that out of the 9279 Patients attending Dermatology out patient department of Community Based Medical College Hospital, 1753 (18.89%) Children were identified with involvement of skin diseases. Age range related to disease was found between one day old to 14 years. The most frequent skin condition was exposure to fungal diseases which was 25.67% followed by scabies 24.10% and eczema 20.25%. Infectious skin diseases represent considerably a high percentage of skin disorders encountered in pediatric population. DOI: http://dx.doi.org/10.3329/cbmj.v2i1.14175 Community Based Medical Journal Vol.2(1) 2013 9-14
Post-Glacial Spatial Dynamics in a Rainforest Biodiversity Hot Spot
Authors: Mellick Rohan , Wilson Peter , Rossetto Maurizio
Published: March 2013

Here we investigate the interaction between ecology and climate concerning the distribution of rainforest species differentially distributed along altitudinal gradients of eastern Australia. The potential distributions of the two species closely associated with different rainforest types were modelled to infer the potential contribution of post-glacial warming on spatial distribution and altitudinal range shift. Nothofagus moorei is an integral element of cool temperate rainforest, including cloud forests at high elevation. This distinct climatic envelope is at increased risk with future global warming. Elaeocarpus grandis on the other hand is a lowland species and typical element of subtropical rainforest occupying a climatic envelope that may shift upwards into areas currently occupied by N. moorei. Climate envelope models were used to infer range shift differences between the two species in the past (21 thousand years ago), current and future (2050) scenarios, and to provide a framework to explain observed genetic diversity/structure of both species. The models suggest continuing contraction of the highland cool temperate climatic envelope and expansion of the lowland warm subtropical envelope, with both showing a core average increase in elevation in response to post-glacial warming. Spatial and altitudinal overlap between the species climatic envelopes was at a maximum during the last glacial maximum and is predicted to be a minimum at 2050.
The Imposition of the Death Penalty on Mexican Nationals in the United States and the Cultural, Legal and Political Context
Authors: Olivero James
Published: March 2013

This paper reviews death penalty perspectives from the United States, Mexico and international law. The United States practices the death penalty on not only its citizens, but those of other nations who commit capital crimes. Mexico is a death penalty abolitionist state that takes significant issue with the United States over executing Mexican nationals. The paper analyzes the cultural, legal and political conflict between the two countries surrounding the application of the death penalty on Mexican nationals.
Evaluation of Macroalgae Sulfated Polysaccharides on the Leishmania (L.) amazonensis Promastigote
Authors: Lehnhardt Pires Camila , Rodrigues Selma , Bristot Daniel , Gaeta Henrique , De Oliveira Toyama Daniela , Lobo Farias Wladimir , Toyama Marcos
Published: March 2013

The sulfated polysaccharides from Solieria filiformis (Sf), Botryocladia occidentalis (Bo), Caulerpa racemosa (Cr) and Gracilaria caudata (Gc) were extracted and extensively purified. These compounds were then subjected to in vitro assays to evaluate the inhibition of these polysaccharides on the growth of Leishmania (L.) amazonensis promastigotes. Under the same assay conditions, only three of the four sulfated polysaccharides were active against L. amazonensis, and the polysaccharide purified from Cr was the most potent (EC50 value: 34.5 μg/mL). The polysaccharides derived from Bo and Sf demonstrated moderate anti-leishmanial activity (EC50 values of 63.7 μg/mL and 137.4 μg/mL). In addition, we also performed in vitro cytotoxic assays toward peritoneal macrophages and J774 macrophages. For the in vitro cytotoxicity assay employing J774 cells, all of the sulfated polysaccharides decreased cell survival, with CC50 values of 27.3 μg/mL, 49.3 μg/mL, 73.2 μg/mL, and 99.8 μg/mL for Bo, Cr, Gc, and Sf, respectively. However, none of the sulfated polysaccharides reduced the cell growth rate of the peritoneal macrophages. These results suggest that macroalgae contain compounds with various chemical properties that can control specific pathogens. According to our results, the assayed sulfated polysaccharides were able to modulate the growth rate and cell survival of Leishmania (L.) amazonensis promastigotes in in vitro assays, and these effects involved the interaction of the sulfated polysaccharides on the cell membrane of the parasites.
Rank Awareness in Group-Sparse Recovery of Multi-Echo MR Images
Authors: Majumdar Angshul , Ward Rabab
Published: March 2013

This work addresses the problem of recovering multi-echo T1 or T2 weighted images from their partial K-space scans. Recent studies have shown that the best results are obtained when all the multi-echo images are reconstructed by simultaneously exploiting their intra-image spatial redundancy and inter-echo correlation. The aforesaid studies either stack the vectorised images (formed by row or columns concatenation) as columns of a Multiple Measurement Vector (MMV) matrix or concatenate them as a long vector. Owing to the inter-image correlation, the thus formed MMV matrix or the long concatenated vector is row-sparse or group-sparse respectively in a transform domain (wavelets). Consequently the reconstruction problem was formulated as a row-sparse MMV recovery or a group-sparse vector recovery. In this work we show that when the multi-echo images are arranged in the MMV form, the thus formed matrix is low-rank. We show that better reconstruction accuracy can be obtained when the information about rank-deficiency is incorporated into the row/group sparse recovery problem. Mathematically, this leads to a constrained optimization problem where the objective function promotes the signal’s groups-sparsity as well as its rank-deficiency; the objective function is minimized subject to data fidelity constraints. The experiments were carried out on ex vivo and in vivo T2 weighted images of a rat's spinal cord. Results show that this method yields considerably superior results than state-of-the-art reconstruction techniques.
Plant Species Restoration: Effects of Different Founding Patterns on Sustaining Future Population Size and Genetic Diversity
Authors: Rogstad Steven , Pelikan Stephan
Published: March 2013

Efforts to sustain the earth’s biodiversity will include the establishment and manipulation of isolated rescue populations, derived either via in situ fragmentation, or under ex situ circumstances. For target species, especially those with limited propagation resources, major goals of such projects include both the optimization of population size and the preservation of genetic diversity. Such rescue populations will be founded in a variety of ways, but little is known about how the geometric patterning of founders can affect population growth and genetic diversity retention. We have developed a computer program, NEWGARDEN, to investigate this issue for plant species that vary in life history characteristics. To use NEWGARDEN, input files are created that specify the size and structure of the preserve, the positioning and genetic diversity of the founders, and life history characteristics of the species (e.g., age-specific reproduction and mortality; gene dispersal distances; rates of selfing, etc.). The program conducts matings with consequent offspring establishment such that the virtual population develops through generations as constrained by the input. Output statistics allow comparisons of population development for populations that differ in one or more input conditions. Here, with NEWGARDEN analyses modeling a triennial species, we show that rescue population project managers will often have to carefully consider the geometric placement of founders to minimize effort expended while maximizing population growth and conservation of genetic diversity, such considerations being heavily dependent on the life history characteristics of particular species.
Witwer, K.W.; et al. Correction: miRNA Profiles of Monocyte-Lineage Cells Are Consistent with Complicated Roles in HIV-1 Restriction. Viruses 2012, 4, 1844-1864.
Authors: Sisk Jeanne , Clements Janice , Witwer Kenneth
Published: March 2013

A funding designation in our 2012 Viruses publication, doi: 10.3390/v4101844 (Viruses 2012, 4, 1844-1864), contained an incorrect digit. On page 1860, (Acknowledgments), U19 support was incorrectly listed as AI076113. The correct designation is AI096113. [...]
A survey of the fern gametophyte flora of Japan: Frequent independent occurrences of noncordiform gametophytes
Authors: Ebihara Atsushi , Yamaoka Asami , Mizukami Naoko , Sakoda Aki , Nitta Joel H. , Imaichi Ryoko
Published: March 2013

• Premise of the study: Ferns and lycophytes are the only extant land plants with two free‐living generations (sporophytes and gametophytes); hence, a single species may have two different distributions. The distribution of the gametophytes of most fern species, which are much smaller in size than sporophytes, are almost unknown due to the difficulty of identifying gametophytes using morphological characters.

• Methods: Twelve quadrats (1 m2 or 0.25 m2), each subdivided into a grid of 100 (10 × 10) or 25 (5 × 5) squares, were used to survey gametophytes in the Japanese Archipelago, where distribution data of sporophytes and “DNA barcodes” for identification of gametophytes have fully been established in previous studies. Collected gametophytes were identified using the plastid rbcL‐a region.

• Key results: In total, gametophytes of 38 species in two broad morphological categories (28 cordiform and 10 noncordiform species) were identified among 407 collections. The cordiform gametophytes discovered are without exception accompanied by their conspecific sporophytes at the periphery of the quadrats. On the other hand, the sporophytic counterparts of the noncordiform gametophytes are often not found or are rare around the sites.

• Conclusions: This study demonstrates with a regional flora that fern gametophytes do not always co‐occur with sporophytes of the same species. In particular, noncordiform gametophytes tended to occur independently of conspecific sporophytes. This pattern may be due to the capability for indeterminate growth and vegetative reproduction by gemmae in noncordiform gametophytes.
Influence of Pars Plana Vitrectomy on Macular Sensitivity and Morphology in Patients with Branch Retinal Vein Occlusion and Serous Retinal Detachment
Authors: Noma Hidetaka , Funatsu Hideharu , Shimada Katsunori , Mimura Tatsuya
Published: March 2013

BACKGROUND AND OBJECTIVE:

To evaluate the influence of serous retinal detachment (SRD) on the outcome of pars plana vitrectomy (PPV) for macular edema in patients with branch retinal vein occlusion (BRVO).

PATIENTS AND METHODS:

In an interventional case series, 20 patients (20 eyes) with BRVO and macular edema underwent PPV, including 12 patients with SRD and eight with cystoid macular edema (CME). Microperimetry of the macular region and optical coherence tomography were performed before and 6 months after PPV.

RESULTS:

In both the CME and SRD groups, the mean macular thickness and macular volume decreased significantly from baseline to 3 and 6 months after PPV (all
P
< .01), while visual acuity improved significantly in both groups (both
P
< .01). However, mean macular sensitivity only increased significantly in the SRD group (
P
< .05).

CONCLUSION:

PPV achieves greater improvement of macular sensitivity in BRVO patients with SRD than in those with CME.

[
Ophthalmic Surg Lasers Imaging Retina.
2013;44:160–167]
Tratamiento del acero con escorias sintéticas de calcio y aluminio con óxido de titanio añadido
Authors: Putan A. , Putan V. , Heput T. , Socalici A.
Published: March 2013

En el trabajo se presentan los resultados del experimento que se refiere a la desulfuración y desoxidación de las escorias sintéticas con escorias del sistema ternario CaO-Al2O3-TiO2.. Los experimentos se hicieron en un horno con inducción de 10 kg de capacidad. Para formar las escorias reductoras se ha utilizado una mezcla compuesta de cal, alúmina y óxido de titanio en porcentaje de 2 % del peso de la carga de acero más escoria sintética. Para los experimentos se usaron mezclas mecánicas producidas por varias recetas y de cada experimento se tomaron muestras de escorias para determinar la composición química y muestras de acero para determinar el contenido de azúfre y oxígeno. Los datos obtenidos fueron procesados en el programa de cálculo EXCEL, obteniéndose ecuaciones de correlación entre la eficiencia de la desulfuración y desoxidación y la composición química de la escoria sintética.
Determinación de la tensión de laminación en caliente a partir de ensayos de tracción
Authors: Monsalve A. , Artigas A. , Celentano D. , Guzmán A. , Colás R. , Houbaert Y.
Published: March 2013

La predicción del comportamiento mecánico de aceros laminados en caliente es un aspecto importante durante el procesamiento industrial. En el presente trabajo, las tensiones necesarias para el proceso de laminado, fueron estimadas usando tres métodos, el primero de los cuales se basa en la aplicación del modelo de Sellars, que toma en cuenta el coeficiente de fricción y el límite elástico. El segundo método, estima la tensión de laminado a partir de la tensión promedio obtenida durante los ensayos de tracción. El tercer método, estima la tensión de laminado a partir de los datos de potencia consumida por el equipo de laminación. Esta metodología fue aplicada en este estudio a un acero al carbono. La conclusión de este trabajo es que los resultados obtenidos por los métodos basados en el modelo de Sellars y de la potencia consumida, son coincidentes, en tanto que el método basado en la tensión de tracción, presenta valores ligeramente menores a los predichos por los otros modelos.
Willingness and professional motivations of medical students to work in rural areas: a study in Alexandria, Egypt
Authors: Mohamed Aida M.
Published: March 2013

Retaining health workers in rural areas is challenging for a number of reasons, e.g. personal preferences, difficult work conditions and low remuneration. Our aim was to determine the effect of motivational factors on willingness to accept postings to rural underserved areas in Alexandria, Egypt and to identify perceived attributes of rural service.,A cross-sectional survey involving 302 4th-year medical students was conducted in March-July 2012. Logistic regression analysis was used to assess the association between students’ willingness to accept rural postings and their professional motivations, rural exposure and family parental professional and educational status (PPES). Perceived attributes to rural service were also assessed. Over 85% students were born in urban areas and 41.4% came from affluent backgrounds. More than half students reported strong intrinsic motivation to study medicine. After controlling for demographic characteristics and rural exposure, motivational factors significantly influenced willingness to practice in rural areas. High-family PPES was consistently associated with lower willingness to work in rural areas. A sizable portion of medical students are motivated to study and practice medicine in rural areas. Efforts should be made to build on motivation during medical training and designing rural postings, as well as favor lower PPES students for admission and improving organizational and contextual issues of rural service.
Two sampling techniques for game meat
Authors: Van der Merwe Maretha , Jooste Piet J. , Hoffman Louw C. , Calitz Frikkie J.
Published: March 2013

A study was conducted to compare the excision sampling technique used by the export market and the sampling technique preferred by European countries, namely the biotrace cattle and swine test. The measuring unit for the excision sampling was grams (g) and square centimetres (cm2) for the swabbing technique. The two techniques were compared after a pilot test was conducted on spiked approved beef carcasses (n = 12) that statistically proved the two measuring units correlated. The two sampling techniques were conducted on the same game carcasses (n = 13) and analyses performed for aerobic plate count (APC), Escherichia coli and Staphylococcus aureus, for both techniques. A more representative result was obtained by swabbing and no damage was caused to the carcass. Conversely, the excision technique yielded fewer organisms and caused minor damage to the carcass. The recovery ratio from the sampling technique improved 5.4 times for APC, 108.0 times for E. coli and 3.4 times for S. aureus over the results obtained from the excision technique. It was concluded that the sampling methods of excision and swabbing can be used to obtain bacterial profiles from both export and local carcasses and could be used to indicate whether game carcasses intended for the local market are possibly on par with game carcasses intended for the export market and therefore safe for human consumption.
Geothermal Dynamics in Vochysia Divergens Forest in a Brazilian Wetland
Authors: Novais Jonathan Willian Zangeski , Rodrigues Thiago Rangel , Curado Leone Francisco Amorim , Oliveira Allan Gonçalves , de Paulo Sérgio Roberto , de Souza Nogueira José , de Oliveira Renan Gonçalves
Published: March 2013

Research involving the thermal soil dynamics of wetland areas has not yet been explored in a way that promotes a deeper understanding of the dynamics of this region. This makes it necessary for further studies to contribute to the understanding of this biome. In the present work, we studied the thermal dynamics of the soil contrasting seasonal conditions in the Vochysia Divergens Forest. The Fourier equation was used to analyze the influence of the thermal conductivity and thermal gradient on the soil heat flux. We determined how variable water content causes the system to behave differently in the four seasons, observing seasonality in soil when completely dry and when completely flooded.
Safety and Efficacy of Fidaxomicin in Patients with Clostridium Difficile Infection
Authors: Donnelley Monica A. , Duby Jeremiah J. , Cocanour Christine S.
Published: March 2013

Fidaxomicin is a bactericidal macrolide that is indicated for the treatment of Clostridium difficile infection (CDI) in adults. Fidaxomicin is not effective for the treatment of systemic infections due to minimal systemic absorption. Until recently, oral vancomycin was the only medication with United States Food and Drug Administration (FDA) approval for the treatment of CDI. In clinical studies, fidaxomicin demonstrated noninferiority to vancomycin for the treatment of CDI. Lower recurrence rates of CDI with fidaxomicin than with oral vancomycin were observed. The lower recurrence rates were not observed with highly virulent strains of C. difficile. Lower recurrence rates of CDI with fidaxomicin are believed to be associated with its narrow spectrum of activity. Fidaxomicin was approved for use after publication of the most recent guideline from the Society for Healthcare Epidemiology of America (SHEA) and Infectious Diseases Society of America (IDSA). However, its current place in clinical practice is unknown. The cost of fidaxomicin should be considered when prescribing this medication.
Magnetic Resonance in the Detection of Breast Cancers of Different Histological Types
Authors: Mayrhofer Rebecca M. , Ng Hsiao Piau , Putti Thomas C. , Kuchel Philip W.
Published: March 2013

Breast cancer incidence is increasing worldwide. Early detection is critical for long-term patient survival, as is monitoring responses to chemotherapy for management of the disease. Magnetic resonance imaging and spectroscopy (MRI/MRS) has gained in importance in the last decade for the diagnosis and monitoring of breast cancer therapy. The sensitivity of MRI/MRS for anatomical delineation is very high and the consensus is that MRI is more sensitive in detection than x-ray mammography. Advantages of MRS include delivery of biochemical information about tumor metabolism, which can potentially assist in the staging of cancers and monitoring responses to treatment. The roles of MRS and MRI in screening and monitoring responses to treatment of breast cancer are reviewed here. We rationalize how it is that different histological types of breast cancer are differentially detected and characterized by MR methods.
A sharp Strichartz estimate for the wave equation with data in the energy space
Authors: Bez Neal , Rogers Keith M.
Published: March 2013

We prove a sharp bilinear estimate for the wave equation from which we obtain the sharp constant in the Strichartz estimate which controls the

L^{4}_{t,x}(\mathbb R^{5+1})

norm of the solution in terms of the energy. We also characterise the maximisers.
Host model uncertainties in aerosol radiative forcing estimates: results from the AeroCom Prescribed intercomparison study
Authors: Stier P. , Schutgens N. A. J. , Bellouin N. , Bian H. , Boucher O. , Chin M. , Ghan S. , Huneeus N. , Kinne S. , Lin G. , Ma X. , Myhre G. , Penner J. E. , Randles C. A. , Samset B. , Schulz M. , Takemura T. , Yu F. , Yu H. , Zhou C.
Published: March 2013

Abstract. Simulated multi-model "diversity" in aerosol direct radiative forcing estimates is often perceived as a measure of aerosol uncertainty. However, current models used for aerosol radiative forcing calculations vary considerably in model components relevant for forcing calculations and the associated "host-model uncertainties" are generally convoluted with the actual aerosol uncertainty. In this AeroCom Prescribed intercomparison study we systematically isolate and quantify host model uncertainties on aerosol forcing experiments through prescription of identical aerosol radiative properties in twelve participating models. Even with prescribed aerosol radiative properties, simulated clear-sky and all-sky aerosol radiative forcings show significant diversity. For a purely scattering case with globally constant optical depth of 0.2, the global-mean all-sky top-of-atmosphere radiative forcing is −4.47 Wm−2 and the inter-model standard deviation is 0.55 Wm−2, corresponding to a relative standard deviation of 12%. For a case with partially absorbing aerosol with an aerosol optical depth of 0.2 and single scattering albedo of 0.8, the forcing changes to 1.04 Wm−2, and the standard deviation increases to 1.01 W−2, corresponding to a significant relative standard deviation of 97%. However, the top-of-atmosphere forcing variability owing to absorption (subtracting the scattering case from the case with scattering and absorption) is low, with absolute (relative) standard deviations of 0.45 Wm−2 (8%) clear-sky and 0.62 Wm−2 (11%) all-sky. Scaling the forcing standard deviation for a purely scattering case to match the sulfate radiative forcing in the AeroCom Direct Effect experiment demonstrates that host model uncertainties could explain about 36% of the overall sulfate forcing diversity of 0.11 Wm−2 in the AeroCom Direct Radiative Effect experiment. Host model errors in aerosol radiative forcing are largest in regions of uncertain host model components, such as stratocumulus cloud decks or areas with poorly constrained surface albedos, such as sea ice. Our results demonstrate that host model uncertainties are an important component of aerosol forcing uncertainty that require further attention.
The role of vegetation in the CO2 flux from a tropical urban neighbourhood
Authors: Velasco E. , Roth M. , Tan S. H. , Quak M. , Nabarro S. D. A. , Norford L.
Published: March 2013

Abstract. Urban surfaces are usually net sources of CO2. Vegetation can potentially have an important role in reducing the CO2 emitted by anthropogenic activities in cities, particularly when vegetation is extensive and/or evergreen. Negative daytime CO2 fluxes, for example have been observed during the growing season at suburban sites characterized by abundant vegetation and low population density. A direct and accurate estimation of carbon uptake by urban vegetation is difficult due to the particular characteristics of the urban ecosystem and high variability in tree distribution and species. Here, we investigate the role of urban vegetation in the CO2 flux from a residential neighbourhood in Singapore using two different approaches. CO2 fluxes measured directly by eddy covariance are compared with emissions estimated from emissions factors and activity data. The latter includes contributions from vehicular traffic, household combustion, soil respiration and human breathing. The difference between estimated emissions and measured fluxes should approximate the biogenic flux. In addition, a tree survey was conducted to estimate the annual CO2 sequestration using allometric equations and an alternative model of the metabolic theory of ecology for tropical forests. Palm trees, banana plants and turfgrass were also included in the survey with their annual CO2 uptake obtained from published growth rates. Both approaches agree within 2% and suggest that vegetation captures 8% of the total emitted CO2 in the residential neighbourhood studied. A net uptake of 1.4 ton km−2 day−1 (510 ton km−2 yr−1 ) was estimated from the difference between the daily CO2 uptake by photosynthesis (3.95 ton km−2 ) and release by respiration (2.55 ton km−2). The study shows the importance of urban vegetation at the local scale for climate change mitigation in the tropics.
Climate response due to carbonaceous aerosols and aerosol-induced SST effects in NCAR community atmospheric model CAM3.5
Authors: Hsieh W.-C. , Collins W. D. , Liu Y. , Chiang J. C. H. , Shie C.-L. , Caldeira K. , Cao L.
Published: March 2013

Abstract. This study used Community Atmospheric Model 3.5 (CAM3.5) to investigate the effects of carbonaceous aerosols on climate. The simulations include control runs with carbonaceous aerosols and no carbon runs in which carbonaceous aerosols were removed. The Slab Ocean Model (SOM) and the fixed Sea Surface Temperature (SST) were used to examine effects of ocean boundary conditions. Throughout this study, climate response induced by aerosol forcing was mainly analyzed in the following three terms: (1) aerosol radiative effects under fixed SST, (2) effects of aerosol-induced SST feedbacks , and (3) total effects including effects of aerosol forcing and SST feedbacks. The change of SST induced by aerosols has large impacts on distribution of climate response, the magnitudes in response patterns such as temperature, precipitation, zonal winds, mean meridional circulation, radiative fluxes and cloud coverage are different between the SOM and fixed SST runs. Moreover, different spatial responses between the SOM and fixed SST runs can also be seen in some local areas. This implies the importance of SST feedbacks on simulated climate response. The aerosol dimming effects cause a cooling predicted at low layers near the surface in most of carbonaceous aerosol source regions. The temperature response shows a warming (cooling) predicted in the north (south) high latitudes, suggesting that aerosol forcing can cause climate change in regions far away from its origins. Our simulation results show that warming of the troposphere due to black carbon decreases rainfall in the tropics. This implies that black carbon has possibly strong influence on weakening of the tropical circulation. Most of these changes in precipitation are negatively correlated with changes of radiative fluxes at the top of model. The changes in radiative fluxes at top of model are physically consistent with the response patterns in cloud fields. On global average, low-level cloud coverage increases, mid- and high-level cloud coverage decreases in response to changes in radiative energy induced by aerosol forcing. An approximated moisture budget equation was analyzed in order to understand physical mechanism of precipitation changes induced by carbonaceous aerosols. Our results show that changes in tropical precipitation are mainly dominated by dynamic effect, i.e. vertical moisture transport carried by the perturbed flow.
Quantification of waves in lidar observations of noctilucent clouds at scales from seconds to minutes
Authors: Kaifler N. , Baumgarten G. , Fiedler J. , Lübken F.-J.
Published: March 2013

Abstract. We present small-scale structures and waves observed in noctilucent clouds by lidar at an unprecedented temporal resolution of 30 s and less. The measurements were taken with the Rayleigh-/Mie-/Raman-lidar at the ALOMAR observatory in northern Norway (69° N) in the years 2008–2011. We find multiple layer NLC in 7.9% of the time for a brightness threshold of δ β = 12×10−10 m−1 sr−1. In comparison to 10 min averaged data, the 30 s data set shows considerably more structure. For limited periods, quasi-monochromatic waves in NLC altitude variations are common, in accord with ground-based NLC imagery. For the combined dataset on the other hand, we do not find preferred periods but significant periods at all time scales observed (1 min to 1 h). Typical wave amplitudes in the layer vertical displacements are 0.2 km with maximum amplitudes up to 2.3 km. Average spectral slopes of temporal altitude and brightness variations are −1.84 ± 0.31 for centroid altitude, −1.28 ± 0.29 for peak brightness and −1.62 ± 0.28 for integrated brightness. Evaluating a new single-pulse detection system, we observe altitude variations of 70 s period and spectral slopes down to a scale of 10 s. We evaluate the suitability of NLC parameters as tracers for gravity waves.
A study of the impact of land-use change in Borneo on atmospheric composition using a global model
Authors: Warwick N. J. , Archibald A. T. , Ashworth K. , Dorsey J. , Edwards P. M. , Heard D. E. , Langford B. , Lee J. , Misztal P. K. , Whalley J. L. K. , Pyle J. A.
Published: March 2013

Abstract. In this study, we use a high resolution version of the Cambridge p-TOMCAT model, along with data collected during the 2008 NERC-funded Oxidant and Particle Photochemical Processes (OP3) project, to examine the potential impact of the expansion of oil palm in Borneo on air quality and atmospheric composition. Several model emission scenarios are run for the OP3 measurement period, incorporating emissions from both global datasets and local flux measurements. Isoprene fluxes observed at a forest site during OP3 were considerably less than fluxes calculated using the MEGAN model. Incorporating the observed isoprene fluxes into p-TOMCAT substantially improved the comparison between modelled and observed isoprene surface mixing ratios and OH concentrations relative to using the MEGAN emissions. If both observed isoprene fluxes and HOx recycling chemistry were included, the ability of the model to capture diurnal variations in isoprene and OH was further improved. However, a similar improvement was also achieved using a~standard chemical mechanism without HOx recycling, by fixing boundary layer isoprene concentrations over Borneo to follow the OP3 observations. Further model simulations, considering an extreme scenario with all of Borneo converted to oil palm plantation, were run to determine the maximum atmospheric impact of land use change in Borneo. In these simulations, the level of nitrogen oxides was found to be critical. If only isoprene emissions from oil palm are considered, then large scale conversion to oil palm produced a decrease in monthly mean surface ozone of up to ~20%. However, if related changes in NOx emissions from fertilisation, industrial processing and transport are also included then ozone increases of up to ~70% were calculated. Although the largest changes occurred locally, the model also calculated significant regional changes of O3, OH and other species downwind of Borneo and in the free troposphere.
Seasonal changes in Fe species and soluble Fe concentration in the atmosphere in the Northwest Pacific region based on the analysis of aerosols collected in Tsukuba, Japan
Authors: Takahashi Y. , Furukawa T. , Kanai Y. , Uematsu M. , Zheng G. , Marcus M. A.
Published: March 2013

Abstract. Atmospheric iron (Fe) can be a significant source of nutrition for phytoplankton inhabiting remote oceans, which in turn has a large influence on the Earth's climate. The bioavailability of Fe in aerosols depends mainly on the fraction of soluble Fe (= [FeSol]/[FeTotal], where [FeSol] and [FeTotal] are the atmospheric concentrations of soluble and total Fe, respectively). However, the numerous factors affecting the soluble Fe fraction have not been fully understood. In this study, the Fe species, chemical composition, and soluble Fe concentrations in aerosols collected in Tsukuba, Japan were investigated over a year (nine samples from December 2002 to October 2003) to identify the factors affecting the amount of soluble Fe supplied into the ocean. The soluble Fe concentration in aerosols is correlated with those of sulfate and oxalate originated from anthropogenic sources, suggesting that soluble Fe is mainly derived from anthropogenic sources. Moreover, the soluble Fe concentration is also correlated with the enrichment factors of vanadium and nickel emitted by fossil fuel combustion. These results suggest that the degree of Fe dissolution is influenced by the magnitude of anthropogenic activity, such as fossil fuel combustion. X-ray absorption fine structure (XAFS) spectroscopy was performed in this study to identify the Fe species in aerosols. The fitting of XAFS spectra coupled with micro X-ray fluorescence analysis (XRF) determined the main Fe species in aerosols in Tsukuba to be illite, ferrihydrite, hornblende, and Fe(III) sulfate. Moreover, the soluble Fe fraction in each sample measured by leaching experiments is closely correlated with the Fe(III) sulfate fraction determined by the XAFS spectrum fitting, suggesting that Fe(III) sulfate is the main soluble Fe in the ocean. Another possible factor that can control the amount of soluble Fe supplied into the ocean is the total Fe(III) concentration in the atmosphere, which was high in spring due to the high mineral dust concentrations during spring in East Asia. However, this factor does not contribute to the amount of soluble Fe to a larger degree than the effect of Fe speciation, or more strictly speaking the presence of Fe(III) sulfate. Therefore, based on these results, the most significant factor influencing the amount of soluble Fe in the North Pacific region is the concentration of anthropogenic Fe species such as Fe(III) sulfate that can be emitted from megacities in Eastern Asia.
Simulations of the transport and deposition of 137Cs over Europe after the Chernobyl NPP accident: influence of varying emission-altitude and model horizontal and vertical resolution
Authors: Evangeliou N. , Balkanski Y. , Cozic A. , Møller A. P.
Published: March 2013

Abstract. The coupled model LMDzORINCA has been used to simulate the transport, wet and dry deposition of the radioactive tracer 137Cs after accidental releases. For that reason, two horizontal resolutions were deployed and used in the model, a regular grid of 2.5°×1.25°, and the same grid stretched over Europe to reach a resolution of 0.45°×0.51°. The vertical dimension is represented with two different resolutions, 19 and 39 levels, respectively, extending up to mesopause. Four different simulations are presented in this work; the first uses the regular grid over 19 vertical levels assuming that the emissions took place at the surface (RG19L(S)), the second also uses the regular grid over 19 vertical levels but realistic source injection heights (RG19L); in the third resolution the grid is regular and the vertical resolution 39 vertical levels (RG39L) and finally, it is extended to the stretched grid with 19 vertical levels (Z19L). The best choice for the model validation was the Chernobyl accident which occurred in Ukraine (ex-USSR) on 26 May 1986. This accident has been widely studied since 1986, and a large database has been created containing measurements of atmospheric activity concentration and total cumulative deposition for 137Cs from most of the European countries. According to the results, the performance of the model to predict the transport and deposition of the radioactive tracer was efficient and accurate presenting low biases in activity concentrations and deposition inventories, despite the large uncertainties on the intensity of the source released. However, the best agreement with observations was obtained using the highest horizontal resolution of the model (Z19L run). The model managed to predict the radioactive contamination in most of the European regions (similar to Atlas), and also the arrival times of the radioactive fallout. As regards to the vertical resolution, the largest biases were obtained for the 39 layers run due to the increase of the levels in conjunction with the uncertainty of the source term. Moreover, the ecological half-life of 137Cs in the atmosphere after the accident ranged between 6 and 9 days, which is in good accordance to what previously reported and in the same range with the recent accident in Japan. The high response of LMDzORINCA model for 137Cs reinforces the importance of atmospheric modeling in emergency cases to gather information for protecting the population from the adverse effects of radiation.
A robust threshold-based cloud mask for the HRV channel of MSG SEVIRI
Authors: Bley S. , Deneke H.
Published: March 2013

Abstract. A robust threshold-based cloud mask for the high-resolution visible (HRV) channel (1 × 1 km2) of the METEOSAT SEVIRI instrument is introduced and evaluated. It is based on operational EUMETSAT cloud mask for the low resolution channels of SEVIRI (3 × 3 km2), which is used for the selection of suitable thresholds to ensure consistency with its results. The aim of using the HRV channel is to resolve small-scale cloud structures which cannot be detected by the low resolution channels. We find that it is of advantage to apply thresholds relative to clear-sky reflectance composites, and to adapt the threshold regionally. Furthermore, the accuracy of the different spectral channels for thresholding and the suitability of the HRV channel are investigated for cloud detection. The case studies show different situations to demonstrate the behaviour for various surface and cloud conditions. Overall, between 4 and 24% of cloudy low-resolution SEVIRI pixels are found to contain broken clouds in our test dataset depending on considered region. Most of these broken pixels are classified as cloudy by EUMETSAT's cloud mask, which will likely result in an overestimate if the mask is used as estimate of cloud fraction.
A survey of carbon monoxide and non-methane hydrocarbons in the Arctic Ocean during summer 2010
Authors: Tran S. , Bonsang B. , Gros V. , Peeken I. , Sarda-Esteve R. , Bernhardt A. , Belviso S.
Published: March 2013

Abstract. During the ARK XXV 1 + 2 expedition in the Arctic Ocean carried out in June–July 2010 aboard the R/V Polarstern, we measured carbon monoxide (CO), non-methane hydrocarbons (NMHC) and phytoplankton pigments at the sea surface and down to a depth of 100 m. The CO and NMHC sea-surface concentrations were highly variable; CO, propene and isoprene levels ranged from 0.6 to 17.5 nmol L−1, 1 to 322 pmol L−1 and 1 to 541 pmol L−1, respectively. The CO and alkene concentrations as well as their sea–air fluxes were enhanced in polar waters off of Greenland, which were more stratified because of ice melting and richer in chromophoric dissolved organic matter (CDOM) than typical North Atlantic waters. The spatial distribution of the surface concentrations of CO was consistent with our current understanding of CO-induced UV photoproduction in the sea. The vertical distributions of the CO and alkenes were comparable and followed the trend of light penetration, with the concentrations displaying a relatively regular exponential decrease down to non-measurable values below 50 m. However, no diurnal variations of CO or alkene concentrations were observed in the stratified and irradiated surface layers. On several occasions, we observed the existence of subsurface CO maxima at the level of the deep chlorophyll maximum. This finding suggests the existence of a non-photochemical CO production pathway, most likely of phytoplanktonic origin. The corresponding production rates normalized to the chlorophyll content were in the range of those estimated from laboratory experiments. In general, the vertical distributions of isoprene followed that of the phytoplankton biomass. These data support the existence of a dominant photochemical source of CO and light alkenes enhanced in polar waters of the Arctic Ocean, with a minor contribution of a biological source of CO. The biological source of isoprene is observed in the different water masses but significantly increases in the warmer Atlantic waters.
Technical Note: The determination of enclosed water volume in large flexible-wall mesocosms "KOSMOS"
Authors: Czerny J. , Schulz K. G. , Krug S. A. , Ludwig A. , Riebesell U.
Published: March 2013

Abstract. The volume of water enclosed inside flexible-wall mesocosm bags is hard to estimate using geometrical calculations and can be strongly variable among bags of the same dimensions. Here we present a method for precise water volume determination in mesocosms using salinity as a tracer. Knowledge of the precise volume of water enclosed allows establishment of exactly planned treatment concentrations and calculation of elemental budgets.
Ground-motion scenarios consistent with PSH deaggregation for Tehran, capital city of Iran
Authors: Abdi F. , Mirzaei N. , Shabani E.
Published: March 2013

Abstract. This study presents the results of probabilistic seismic hazard (PSH) deaggregation for 5%-damped 0.2 and 1.0 s spectral accelerations, corresponding to mean return periods (MRPs) of 50, and 475 yr for Tehran city. The aim of this paper is to quantify the dominant events that have the most contribution on ground-motion exceedance from the above mentioned hazard levels. The scenario earthquakes are characterized by bins of magnitude (M), source-to-site distance (R), and epsilon (ε). The results reveal that for Tehran city, the hazard is mainly controlled by local seismicity. Generally, as the spectral acceleration period increase, the contribution of larger and more distant scenario earthquakes to the overall seismic hazard increase.
Site investigation of masonry buildings damaged during the 23 October and 9 November 2011 Van Earthquakes in Turkey
Authors: Piroglu F. , Ozakgul K.
Published: March 2013

Abstract. The purpose of this study is to scrutinize and interpret the damages to masonry buildings after a series of earthquakes that occurred in Van, which is an eastern city of Turkey, within 17 days in 2011, i.e., the first earthquake hit on 23 October having the magnitude 7.1, and the second on 9 November with the magnitude 5.6 on the Richter scale. These consecutive earthquakes and their aftershocks caused extensive damage and the collapse of buildings in the city of Van and its villages and especially its near town, namely Ercis. For the investigation of masonry buildings, Hacibekir district, which is one of the regions comprising the highest density of masonry buildings in the city of Van, was selected and the seismic performance of these buildings was observed, tested in the field, and interpreted according to the Turkish earthquake-resistant design codes. In this region, masonry buildings were classified as adobe, unreinforced and confined masonry buildings. As a result of this field study, it was observed that whereas the confined masonry buildings had usually shown good performance during the earthquakes, the adobe and the unreinforced masonry buildings were seriously damaged and some of them were partially collapsed.