bluuebunny/crossref_metadata_2025 huggingface dataset:
Preparing for climate change: an evaluative framework for prioritizing adaptation measures in Nepal
Authors: Shrestha Asheshwor Man
Published: March 2011

Severe potential climate threats for Nepal are expected to impact water resource, agriculture, biodiversity and livelihood. While adaptation and mitigation are both valid policy options to tackle climate change, it is advantageous for developing countries to opt for adaptation. It is also desirable that the most feasible adaptation actions be applied to protect development investment from climate risks and to ensure maximum preparedness. Adaptation strategies consist of a set of measures that are highly effective, affordable, technically and socially feasible and contribute towards disaster risk reduction. An evaluative framework using scoring matrix is utilized to prioritize adaptation options. Adaptation options for threat areas identified for Nepal are analyzed based on literature in the context of Nepal as well as for Asia and for least developed countries (LDCs). The measures are evaluated across multiple categories like public/private costs, effectiveness, social/cultural feasibility, speed, support for mitigation and aid in disaster preparedness. Based on the scoring matrix evaluation, following measures appear most feasible: (1) water conservation and management; (2) investment in smaller hydro-power plants; (3) research/planting of climate resistant crops; (4) diversification of agriculture; (5) development of early warning system for disasters; and (6) flood control measures downstream. Due to financial and technical constraints, it is advantageous to opt for ‘no-regrets’ strategies which benefit even without climate change. These set of measures can be carried out at low costs to reap sure benefits and should be prioritized for execution through environmental policies especially climate policies. Key-words: Adaptation; climate change; climate policy; disaster risk reduction; Nepal. DOI: 10.3126/botor.v7i0.4371Botanica Orientalis – Journal of Plant Science (2010) 7: 35-42
Distribution Patterns of Begonia species in the Nepal Himalaya
Authors: Rajbhandary Sangeeta , Hughes Mark , Shrestha Krishna K
Published: March 2011

The 29 Nepalese species of the pantropical genus Begonia largely belong to 2 sections, Begonia sect. Diploclinium and Begonia sect. Platycentrum. The former comprises tuberous species which occur along the Himalayan range. They die back during the dry season and their flowering time is strongly constrained by the onset of the monsoon. The latter comprises evergreen rhizomatous species some of which extend their distribution into more aseasonal areas such as Indo-China. They have a more extended flowering period which is not strictly constrained by the monsoon. There is a gradient of Begonia species richness increasing from west to east across Nepal, in relation to the increased intensity of the monsoon in the east. Key words: Distribution modelling; geophytes; monsoon; phenology; species richness.DOI: 10.3126/botor.v7i0.4386Botanica Orientalis - Journal of Plant Science (2010) 7: 73-78
Weed species composition and growth in wheat field of mountain ecosystem Khokana, Lalitpur, Nepal
Authors: Sapkota N , Dongol BR , Bhuju DR
Published: March 2011

A study was carried out to determine the composition and predominance of weed species in wheat field in Khokana of Kathmandu valley as a representative sample of mountain ecosystem in Nepal. A total of 44 weed species representing 18 families were recorded. The most abundant species were Chenopodium album, Polygonum plebeium and Spergula arvensis. With the improved temperature after February, the weeds flourished in the late winter which had deterrent effect on the growth of wheat. Weeding practice was not much followed, while the fallowing gave more chances to weed species to germinate and grow. Periodic surveys on weeds help catalogue the existing weeds and extent of harm caused by them. Key-words: Rice-wheat cropping practice; weed ecology; weed management. DOI: 10.3126/botor.v7i0.4388Botanica Orientalis - Journal of Plant Science (2010) 7: 85-91
TVPD: The Generational Diegetics of the Police Procedural on American Television
Authors: Arntfield Michael
Published: March 2011

Abstract:

This paper examines the crime fiction genre known as the police procedural and traces its evolution from televisual inception to the present. The police procedural in the context of American network television is generally divisible into three canonical periods—the Golden Age, the Gilded Age, and the Dark Age—with the series populating these eras serving not only as social dramas that calibrate public sentiments about the police, but more importantly as historical texts that reflect how the police perceive their role as workers in American society: a self-assessment based primarily on their relationship to technology. As policing has undergone tremendous technological change in concert with the popularization of the police procedural, having largely evolved, technologically speaking, into an automated industry, the TV cop has similarly devolved into a composite figure alienated from both work and American society at large.
Simulation of the Effect of Intensive Forest Management on Forest Production in Sweden
Authors: Nilsson Urban , Fahlvik Nils , Johansson Ulf , Lundström Anders , Rosvall Ola
Published: March 2011

The effects of intensifying the management of 15% of the Swedish forest land on potential future forest production over a 100-year period were investigated in a simulation study. The intensive management treatments, which were introduced over a period of 50 years, were: intensive fertilization of Norway spruce (IntFert); bulking-up Norway spruce elite populations using somatic embryogenesis (SE-seedlings); planting of lodgepole pine, hybrid larch, and Sitka spruce (Contorta, Larch, and Sitka); fertilization with wood ash on peatlands (Wood ash); and conventional fertilization in mature forests (ConFert). Potential sites for applying intensive forest management (IFM) to sites with low nature conservation values were determined with a nature conservation score (NCS). Four different scenarios were simulated: “Base scenario”, which aimed at reducing the negative impact on nature conservation values, “Fast implementation”, “No IntFert” (IntFert was not used), and “Large Forest Companies”, where the majority of plots were selected on company land. Total yields during the 100-year simulation period were about 85–92% higher for the intensive forest management scenarios than for the reference scenario (business as usual). In the “No IntFert” scenario total production was 1.8% lower and in the “Large Forest Companies” scenario total production was 4.8% lower than in the “Base scenario”. “Fast implementation” of IFM increased yield by 15% compared to the “Base scenario”. Norway spruce SE-seedlings and IntFert gave the highest yields, measured as total production during the 100-year simulation period, but relative to the yields in the reference scenario, the highest increases in yield were for Contorta. The “Base scenario” and “No IntFert” gave the highest yields for plots with the lowest NCS, but plots with higher NCS had to be used in the “Fast implementation” and “Large Forest Companies” scenarios. More than half of the effect on future growth of IFM methods was because of increased intensity in the regenerations. It took a relatively long time (40–60 years) for the simulated IFM treatments to result in a significant increase in stem volume production.
The Role of the Leukemia Inhibitory Factor (LIF) — Pathway in Derivation and Maintenance of Murine Pluripotent Stem Cells
Authors: Graf Urs , Casanova Elisa A. , Cinelli Paolo
Published: March 2011

Developmental biology, regenerative medicine and cancer biology are more and more interested in understanding the molecular mechanisms controlling pluripotency and self-renewal in stem cells. Pluripotency is maintained by a synergistic interplay between extrinsic stimuli and intrinsic circuitries, which allow sustainment of the undifferentiated and self-renewing state. Nevertheless, even though a lot of efforts have been made in the past years, the precise mechanisms regulating these processes remain unclear. One of the key extrinsic factors is leukemia inhibitory factor (LIF) that is largely used for the cultivation and derivation of mouse embryonic and induced pluripotent stem cells. LIF acts through the LIFR/gp130 receptor and activates STAT3, an important regulator of mouse embryonic stem cell self-renewal. STAT3 is known to inhibit differentiation into both mesoderm and endoderm lineages by preventing the activation of lineage-specific differentiation programs. However, LIF activates also parallel circuitries like the PI3K-pathway and the MEK/ERK-pathway, but its mechanisms of action remain to be better elucidated. This review article aims at summarizing the actual knowledge on the importance of LIF in the maintenance of pluripotency and self-renewal in embryonic and induced pluripotent stem cells.
Combined 3D-QSAR, Molecular Docking and Molecular Dynamics Study on Derivatives of Peptide Epoxyketone and Tyropeptin-Boronic Acid as Inhibitors Against the β5 Subunit of Human 20S Proteasome
Authors: Liu Jianling , Zhang Hong , Xiao Zhengtao , Wang Fangfang , Wang Xia , Wang Yonghua
Published: March 2011

An abnormal ubiquitin-proteasome is found in many human diseases, especially in cancer, and has received extensive attention as a promising therapeutic target in recent years. In this work, several in silico models have been built with two classes of proteasome inhibitors (PIs) by using 3D-QSAR, homology modeling, molecular docking and molecular dynamics (MD) simulations. The study resulted in two types of satisfactory 3D-QSAR models, i.e., the CoMFA model (Q2 = 0.462, R2pred = 0.820) for epoxyketone inhibitors (EPK) and the CoMSIA model (Q2 = 0.622, R2pred = 0.821) for tyropeptin-boronic acid derivatives (TBA). From the contour maps, some key structural factors responsible for the activity of these two series of PIs are revealed. For EPK inhibitors, the N-cap part should have higher electropositivity; a large substituent such as a benzene ring is favored at the C6-position. In terms of TBA inhibitors, hydrophobic substituents with a larger size anisole group are preferential at the C8-position; higher electropositive substituents like a naphthalene group at the C3-position can enhance the activity of the drug by providing hydrogen bond interaction with the protein target. Molecular docking disclosed that residues Thr60, Thr80, Gly106 and Ser189 play a pivotal role in maintaining the drug-target interactions, which are consistent with the contour maps. MD simulations further indicated that the binding modes of each conformation derived from docking is stable and in accord with the corresponding structure extracted from MD simulation overall. These results can offer useful theoretical references for designing more potent PIs.
A Low-Power Hardware-Friendly Binary Decision Tree Classifier for Gas Identification
Authors: Li Qingzheng , Bermak Amine
Published: March 2011

In this paper, we present a hardware friendly binary decision tree (DT) classifier for gas identification. The DT classifier is based on an axis-parallel decision tree implemented as threshold networks—one layer of threshold logic units (TLUs) followed by a programmable binary tree implemented using combinational logic circuits. The proposed DT classifier circuit removes the need for multiplication operation enabling up to 80% savings in terms of silicon area and power compared to oblique based-DT while achieving 91.36% classification accuracy without throughput degradation. The circuit was designed in 0.18 μm Charter CMOS process and tested using a data set acquired with in-house fabricated tin-oxide gas sensors.
Antimicrobial Properties of Some Bis(Iminoacenaphthene (BIAN)-Supported N-Heterocyclic Carbene Complexes of Silver and Gold
Authors: Butorac Rachel R. , Al-Deyab Salem S. , Cowley Alan H.
Published: March 2011

The AgCl, AgOAc, AuCl, and AuOAc complexes of the new bis(imino)acenaphthene(BIAN)-supported N-heterocyclic carbene ligand and the precursor imidazolium salt have been investigated with respect to their antimicrobial activities against Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Psudomonas aeruginosa. The most active antimicrobial is the precursor imidazolium salt, which has a minimum inhibitory concentration (MIC) value of
Synthesis and Antimicrobial Evaluation of Some Heterocyclic Chalcone Derivatives
Authors: Hamada Nagwa Mohamed Mahrous , Sharshira Essam Mohamed
Published: March 2011

Some new heterocyclic compounds containing isoxazole, pyrazole and oxadiazole ring systems were prepared from various chalcones. The synthesized compounds have been characterized by elemental analysis and spectral methods. These compounds were screened for their antimicrobial activities.
The Dynactin Complex Enhances the Speed of Microtubule-Dependent Motions of Adenovirus Both Towards and Away from the Nucleus
Authors: Engelke Martin F. , Burckhardt Christoph J. , Morf Matthias K. , Greber Urs F.
Published: March 2011

Unlike transport vesicles or organelles, human adenovirus (HAdV) directly binds to the microtubule minus end-directed motor dynein for transport to the nucleus. The dynein cofactor dynactin enhances nuclear transport of HAdV and boosts infection. To determine if dynactin has a specific role in cytoplasmic trafficking of incoming HAdV on microtubules, we used live cell spinning disc confocal microscopy at 25 Hz acquisition frequency and automated tracking of single virus particles at 20–50 nm spatial resolution. Computational dissection by machine-learning algorithms extracted specific motion patterns of viral trajectories. We found that unperturbed cells supported two kinds of microtubule-dependent motions, directed motions (DM) and fast drifts (FD). DM had speeds of 0.2 to 2 µm/s and run lengths of 0.4 up to 7 µm, while FD were slower and less extensive at 0.02 to 0.4 µm/s and 0.05 to 2.5 µm. Dynactin interference by overexpression of p50/dynamitin or a coiled-coil domain of p150/Glued reduced the speeds and amounts of both center- and periphery-directed DM but not FD, and inhibited infection. These results indicate that dynactin enhances adenovirus infection by increasing the speed and efficiency of dynein-mediated virus motion to the nucleus, and, surprisingly, also supports a hereto unknown motor activity for virus transport to the cell periphery.
A New Role for the HTLV-1 p8 Protein: Increasing Intercellular Conduits and Viral Cell-to-Cell Transmission
Authors: Malbec Marine , Roesch Ferdinand , Schwartz Olivier
Published: March 2011

Retroviruses like HIV-1 and HTLV-1 can be transmitted efficiently by direct contact between infected and target cells. For HIV-1, various modes of cell-to-cell transfer have been reported, including virological synapses, polysynapses, filopodial bridges, and nanotube-like structures. So far, only synapses and biofilms have been described for HTLV-1 transmission. Recently, Van Prooyen et al. [1] identified an additional mode of HTLV-1 transmission through cellular conduits induced by the viral accessory protein p8.
Assessing the role of the RND efflux pump in metronidazole resistance of Helicobacter pylori by RT-PCR assay
Authors: Mehrabadi Jalil Fallah , Sirous Mehrandokht , Daryani Naser Ebrahimi , Eshraghi Saeed , Akbari Bahram , Shirazi Mohammad Hasan
Published: March 2011

Introduction: Metronidazole is a significant antibiotic used for eradication of Helicobactor pylori infections and it is of notice that metronidazole-resistant clinical isolates have been found in high rates worldwide. While the RND family of efflux pumps plays a central role in drug resistance among Gram-negative bacteria, this is questionable for H. pylori. Methodology: To understand whether TolC homologues of RND pumps contribute to metronidazole resistance in H. pylori isolates, expression of four TolC homologous genes of five resistant clinical isolates exposed to varying concentrations of metronidazole were evaluated by RT-PCR and transcriptional analysis. Results: The results indicate that excess amounts of metronidazole are able to increase the expression level of these genes at the transcriptional stage. Conclusions: Therefore, it may be hypothesized that use of metronidazole in H. pyori infection can induce metronidazole resistance. Furthermore, the RND family of efflux pumps may contribute to metronidazole resistance in clinical isolates of H. pylori.
A nine-year clinico-epidemiological study of Histoid Hansen in India
Authors: Mendiratta Vibhu , Jain Arpita , Chander Ram , Khan Anamita , Barara Meenu
Published: March 2011

Introduction: Histoid Hansen is rare but a well-defined entity with specific clinical, histopathological, and bacteriological features. The incidence has been reported to vary from 1-2% amongst total leprosy patients. Methodology:  We performed a retrospective analysis of the records of patients identified as histoid Hansen on the basis of clinico-histopathological criteria, who attended the Hansen clinic from 2000-2009. Results: A total of 962 leprosy patients attended the Hansen clinic from 2000-2009, and of these, 11 (1.14%) were diagnosed as histoid Hansen. The youngest patient on record was 14 years of age. Nearly 70% of the patients were untreated and the rest were on multidrug therapy (MDT) before development of histoid lesions. Three patients showed Erythema nodusum leposum (ENL) reaction. Conclusion: India has achieved elimination of leprosy, but new cases of histoid are still recorded with the same incidence rate. Reactions are not uncommon in such forms, and may be a transition phase to manifest lepromatous leprosy. A thorough knowledge and early detection is needed for this uncommon variant of leprosy which can pose a threat to our elimination drive.
Serotypes and antibiotic susceptibility of Streptococcus pneumoniae isolates causative of invasive diseases in Mexican children
Authors: Arredondo-García José Luis , Calderón Ernesto , Echániz-Aviles Gabriela , Soto-Noguerón Araceli , Arzate Patricia , Amabile-Cuevas Carlos F
Published: March 2011

Introduction: Streptococcus pneumoniae is a worldwide leading cause of morbidity and mortality, while susceptibility towards penicillin and macrolides can be less than 50% in many regions. Methodology: A total of 150 isolates of S. pneumoniae causative of invasive diseases in children were characterized, of which 24.6% had a fatal outcome. Results: The most prevalent serotypes were 19F, 6B, 23F and 14. Resistance to penicillin, erythromycin (mostly of macrolide-lincosamide-streptogramin resistance phenotype) or trimethoprim-sulfamethoxazole was found in more than 40% of the isolates, but no resistance phenotype appeared linked to lethality. Serotype 3 isolates, which were seldom resistant, had a twofold lethality rate compared to the total sample. Conclusion: Serotyping could provide a better outcome-predicting tool than susceptibility testing. The seven-valent vaccine does not include the most prevalent serotypes found in Mexico.
Scénariser le « social » pour le filmer.
Authors: Mariette Audrey
Published: March 2011

Résumé En partant de la catégorie floue et mal définie de « cinéma social », nous abordons la question des liens entre art et politique à l'aune de la mise en scène cinématographique des classes populaires en France dans les années 1990-2000. En alliant analyse interne et externe des films, il s'agit ici d'étudier l'« engagement par les  uvres ». Cet article prend plus particulièrement pour objet les scénarios de ces films et les manières dont ils ont été écrits. L'écriture n'est, au cinéma, que la première étape de la réalisation d'un film : la mise en récit précède et anticipe la mise en images et en sons (le tournage). Elle ne concerne pas seulement le sujet du film : elle est déterminante pour l'esthétique cinématographique adoptée. L'étude des scénarios d'un corpus de films étiquetés « sociaux » permet d'observer qu'ils participent à une vision globalement pessimiste du « populaire ». Cette vision, celle d'un monde en déclin, s'explique par le fait que les « auteurs » de scénarios ont pour point commun de faire appel non à des membres des classes populaires mais à des personnes qui ont pour caractéristique d'être dans une position d'« encadrant » de ces dernières. Pour autant, ces scénarios et les manières dont ils ont été écrits sont loin d'être homogènes ­ en cela, le « cinéma social » ne constitue pas un genre cinématographique. Deux modes d'écriture ­ qui correspondent à deux pôles schématiques ­ sont alors analysés : le recours à la fable (à partir du cas des films de Robert Guédiguian) et le recours à un fort « effet de réel » (à partir du cas du premier long métrage de Laurent Cantet). Différentes, ces formes de politisation des  uvres se comprennent au regard des trajectoires et des ressources dont disposent les réalisateurs pour écrire leurs scénarios, ainsi qu'au regard des « règles de l'art ».
La mue des « gaspilleurs de pellicule ».
Authors: Lecler Romain
Published: March 2011

Résumé Le cinéma militant a rejeté en Mai 68 la notion d'auteur élaborée par la génération de la Nouvelle Vague. Ils l'ont assimilée à la notion d'autorité. Novices, les cinéastes militants ont repris les techniques du cinéma direct des années 1960. Jeunes, ils se sont ainsi initiés au cinéma. Militants, ils ont couvert les mouvements sociaux des années 1970. Ce rejet de l'auteur a néanmoins été ambivalent. Que ce soit les critiques, les auteurs tentés par le cinéma militant comme Chris. Marker ou Godard, ou peu à peu les cinéastes militants, tous ont participé de la réhabilitation de l'auteur. Celle-ci a été rendue possible grâce à un détour par la mise-en-scène et la fiction, et a permis la mise en place du genre documentaire dans les années 1980. Seuls les plus dotés des cinéastes militants ont alors réussi à se reconvertir dans le documentaire, les autres demeurant invisibles.
Cinéma et politique colombiens : l'évanescence de la mort
Authors: Launay Stephen
Published: March 2011

Résumé Le cinéma colombien est longtemps resté en friche, en particulier dans son rapport au politique. Obnubilé par la violence, il s'est concentré sur le trépas sans prendre à bras-le-corps la mise en scène de la mort, sauf exceptions. Celles-ci ont pu réussir non seulement en s'appuyant sur un certain sentiment esthétique, mais aussi sur la tradition civiliste colombienne.
Cinématographie du rapport à la Loi dans The Trial d'Orson Welles
Authors: Smadja David
Published: March 2011

Résumé Dans le prolongement de l'article de Michael Löwy publié dans ce volume de Raisons politiques, et afin de montrer la spécificité du cinématographe comme écriture du politique comme images-mouvement, cet article vise à expliquer comment, par ses ressources spécifiques, le filmage d'Orson Welles dans The Trial parvient à restituer la critique kafkaïenne de l'État et de l'administration. Il s'inspire en cela d'une perspective construite par André Bazin qui privilégie « les partis pris formels » pour saisir la signification des films. Ainsi, l'article met en évidence trois modalités du rapport à la Loi : l'hésitation, le franchissement et la panique, auxquels correspondent, entre autre, les moyens cinématographiques propres au cadrage et aux mouvements de caméra.
Les justifications de la règle de majorité en démocratie moderne
Authors: Mineur Didier
Published: March 2011

Résumé Cet article porte sur les fondements de la légitimité de la règle majoritaire en démocratie. Les différents principes de la légitimité formulés par les philosophies des Lumières se conjuguent avec l'unanimité plutôt qu'avec la majorité : l'idéal selon lequel la raison est créatrice de ses normes plutôt qu'elle ne les découvre dans l'ordre des choses, l'idéal de l'autonomie de chacun et l'idéal du peuple souverain. On dégage donc de l'histoire des idées politiques modernes trois types de légitimations du principe majoritaire, chacune d'entre elles faisant du principe majoritaire une approximation de la raison, de l'autonomie et de l'unité. On fait par ailleurs l'hypothèse que ces justifications sous-tendent la pratique du vote en démocratie, ce que l'on tente de montrer en évoquant les débats tenus lors de deux référendums contemporains, exceptionnels en ce qu'ils ont été l'occasion d'une mise en  uvre explicite de ces justifications ordinairement implicites, le référendum national de ratification du TCE du 29 mai 2005, et le référendum interne au Parti socialiste de décembre 2004.
Marketing and Branding the Agronomy Major at Iowa State University
Authors: Miller Bradley A.
Published: March 2011

The decline of enrollments in agronomy programs across the United States has been a concern for more than a decade. In an effort to reverse this trend, the Agronomy Department at Iowa State University (ISU) launched the I'm An Agronomist marketing campaign in 2006. This article reports on these efforts and the change in the undergraduate agronomy student population at Iowa State University since the campaign's inception. In the spring of 2010, 106 more students were studying agronomy than in 2005. This was an increase of 91%. Prior to implementing marketing strategies, agronomy enrollment at ISU had been on a 6‐year decline. The campaign has also had the additional benefits of generating a sense of pride and excitement among department staff, students, and alumni. The execution of the marketing campaign has been accomplished through close collaboration between staff within our department including graphic artists, communication specialists, and those passionate about the topic. In designing our marketing strategies, we observed and learned from marketing approaches in widespread use. The most important elements in the development of our marketing campaign were a simple message, artistic style, branding, and advertising in smart locations. While direct connections between marketing efforts and enrollment increases are difficult to prove, the I'm An Agronomist campaign has coincided with a time of extraordinary growth in student numbers. The campaign has halso appeared to have had additional benefits with regard to internal morale and external relations.
Combined retrievals of boreal forest fire aerosol properties with a polarimeter and lidar
Authors: Knobelspiesse K. , Cairns B. , Ottaviani M. , Ferrare R. , Hair J. , Hostetler C. , Obland M. , Rogers R. , Redemann J. , Shinozuka Y. , Clarke A. , Freitag S. , Howell S. , Kapustin V. , McNaughton C.
Published: March 2011

Abstract. Absorbing aerosols play an important, but uncertain, role in the global climate. Much of this uncertainty is due to a lack of adequate aerosol measurements. The Aerosol Polarimetery Sensor (APS), which is on the NASA Glory satellite scheduled for launch in the spring of 2011, is designed to help resolve this issue by making accurate, multi-spectral, multi-angle polarized observations. Field observations with the Research Scanning Polarimeter (RSP, the APS airborne prototype), however, have established that simultaneous retrievals of aerosol absorption and vertical distribution over bright land surfaces are quite uncertain. We test a merger of RSP and High Spectral Resolution Lidar (HSRL) data with observations of boreal forest fire smoke, collected during the Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS). During ARCTAS, the RSP and HSRL instruments were mounted on the same aircraft, and validation data were provided by instruments on an aircraft flying a coordinated flight pattern. We found that the lidar data did indeed improve aerosol retrievals using an optimal estimation method, although not primarily because of the contraints imposed on the aerosol vertical distribution. The more useful piece of information from the HSRL was the total column aerosol optical depth, which was used to select the initial value (optimization starting point) of the aerosol number concentration. When ground based sun photometer network climatologies of number concentration were used as an initial value, we found that roughly half of the retrievals had unrealistic sizes and imaginary indices, even though the retrieved spectral optical depths agreed within uncertainties to independent observations. The convergence to an unrealistic local minimum by the optimal estimator is related to the relatively low sensitivity to particles smaller than 0.1 µm at large optical thicknesses. Thus, optimization algorithms used for operational APS retrievals of the fine mode size distribution, when the total optical depth is large, will require initial values generated from table look-ups that exclude unrealistic size/complex index mixtures. External constraints from lidar on initial values used in the optimal estimation methods will also be valuable in reducing the likelihood of obtaining spurious retrievals.
Investigations of primary and secondary particulate matter of different wood combustion appliances with a high-resolution time-of-flight aerosol mass spectrometer
Authors: Heringa M. F. , DeCarlo P. F. , Chirico R. , Tritscher T. , Dommen J. , Weingartner E. , Richter R. , Wehrle G. , Prevot A. S. H. , Baltensperger U.
Published: March 2011

Abstract. A series of photo-oxidation smog chamber experiments were performed to investigate the primary emissions and secondary aerosol formation from two different log wood burners and a residential pellet burner under different burning conditions: starting and flaming phase. Emissions were sampled from the chimney and injected into the smog chamber leading to primary organic aerosol (POA) concentrations comparable to ambient levels. The composition of the aerosol was measured by an Aerodyne high resolution time-of-flight aerosol mass spectrometer (HR-TOF-AMS) and black carbon (BC) instrumentation. The primary emissions were then exposed to xenon light to initiate photo-chemistry and subsequent secondary organic aerosol (SOA) production. After correcting for wall losses, the average increase in organic matter (OM) concentrations by SOA formation for the starting and flaming phase experiments with the two logwood burners was found to be a factor of 4.1 ± 1.4 after five hours of aging. No SOA formation was observed for the stable burning phase of the pellet burner. The startup emissions of the pellet burner showed an increase in OM concentration by a factor of 3.3. Average emission factors of BC + POA + SOA, calculated from CO2 emission, were found to be in the range of 0.04 to 3.9 g kg−1 wood for the stable burning pellet burner and an old log wood burner during startup respectively. SOA contributed significantly to the ion C2H4O2+ at mass to charge ratio m/z 60, a commonly used marker for primary emissions of wood burning. The primary organic emissions from the three different burners showed a wide range in O/C atomic ratio (0.19–0.60) for the starting and flaming conditions, which also increased during aging. Primary wood burning emissions have a rather low relative contribution at m/z 43 (f43) to the total organic mass spectrum. The non-oxidized fragment C3H7+ has a considerable contribution at m/z 43 for the fresh OA with an increasing contribution of the oxygenated ion C2H3O+ during aging. After five hours of aging, the OA has a rather low C2H3O+ signal for a given CO2+ fraction, possibly indicating a higher ratio of acid to non-acid oxygenated compounds in wood burning OA compared to other OOA.
Investigation of nucleation events vertical extent: a long term study at two different altitude sites
Authors: Boulon J. , Sellegri K. , Hervo M. , Picard D. , Pichon J.-M. , Freville P. , Laj P.
Published: March 2011

Abstract. In this work we present an analysis of the occurrence of nucleation events during more than three years of measurements at two different rural altitude sites, the puy de Dôme research station (1465 m a.s.l.) and the Opme station (660 m a.s.l.), central France. The collected database is a unique combination of a Scanning Mobility Particle Sizer (SMPS, 10–400 nm) measurements, an air ion spectrometers (AIS, 0.5 to 45 nm) and neutral clusters and air ion spectrometers (NAIS, 0.5 to 45 nm) measurements at two different altitudes nearly located research stations, from February 2007 to June 2010. During the measurement period, neither the particle formation rates (J2 = 1.382 ± 0.195 s−1) nor the growth rates (GR1.3–20 nm = 6.20 ± 0.12 nm h−1) differ from one site to the other on average. Hovewer, we found that, on 437 sampling days in common to the two sites, the nucleation frequency was higher at the puy de Dôme station (35.9%, 157 days) than at the low elevation station of Opme (20.8%, 91 days). The role of sulfuric acid in the nucleation process was investigated at the altitude station and no correlation was found between nucleation events and the estimated sulfuric acid concentrations. Nevertheless, the contribution of ion-induced nucleation was found to be relatively high (12.49 ± 2.03% of the total nucleation rate). LIDAR measurements and the evolution of the potential equivalent temperature revealed that the nucleation could be triggered either (i) within the whole low tropospheric column at the same time from the planetary boundary layer to the top of the injection layer (29.2%, 47 events), (ii) above the planetary boundary layer upper limit (43.5%, 70 events), and (iii) at low altitude and then transported, conserving dynamic and properties, at high altitude (24.8%, 40 events). This is the first time that the vertical extent of nucleation can be studied over a long observational period, allowing for a rigorous statistical analysis of the occurrence of nucleation over the whole lower troposphere. This work highlights the fact that nucleation can have occur over a large vertical extent, at least the whole low tropospheric column, and also the fact that it occurs twice as frequently as actually detected in the planetary boundary layer.
Coupled forest growth-hydrology modelling as an instrument for the assessment of effects of forest management on hydrology in forested catchments
Authors: Sutmöller J. , Hentschel S. , Hansen J. , Meesenburg H.
Published: March 2011

Abstract. The type and intensity of forest management directly influences regional catchment hydrology. Future forest management must optimise the effects of its practices to achieve sustainable management. With scenario analysis of forestry practices, the effects of different forest utilisation strategies on the hydrology of forested catchments can be temporally and spatially quantified. The approach adopted in this study necessitated the development of an interactive system for the spatially distributed modelling of hydrology in relation to forest stand development. Consequently, a forest growth model was used to simulate stand development assuming various forest management activities. Selected simulated forest growth parameters were entered into the hydrological model to simulate water fluxes under different conditions of forest structure. The approach enables the spatially differentiated quantification of changes in the water regime (e.g. increased evapotranspiration). The results of hydrological simulations in the study area, the Oker catchment (northern Harz Mountains), show that forests contribute to the protection of water systems because they have a balancing effect on the hydrological regime. As scenario simulations also suggest, however, forestry practices can also lead to substantial changes in water budgets of forested catchments. The preservation of the hydrological services of forests requires a sustainable and long-term forest conversion on the basis of current management directives for near natural silviculture. Management strategies on basis of moderate harvesting regimes are preferred because of their limited impact on the water budget.
Influence of the calibration on experimental UV index at a midlatitude site, Granada (Spain)
Authors: Antón M. , Gil J. E. , Cazorla A. , Fernández-Gálvez J. , Vilaplana J. M. , Olmo F. J. , Alados-Arboledas L.
Published: March 2011

Abstract. The ultraviolet index (UVI) is the most commonly used variable to inform about the level and potential harmful effect of ultraviolet (UV) radiation reaching the Earth's surface. This variable is derived from the output signal of UV radiometers applying conversion factors from calibration methods. This paper focused on the influence of the use of two of these methods (called one-step and two-steps methods) on the experimental UVI measured by a YES UVB-1 radiometer located in a midlatitude station, Granada (Spain) for the period 2006–2009. In addition, it also analyzes the deviation from the UVI values obtained when the manufacturer's calibration factors are applied. For this goal, a detailed characterization of the UVB-1 radiometer from the first Spanish calibration campaign of broadband UV radiometers at the "El Arenosillo" INTA station in 2007 was used. In addition, modeled UVI data derived from the LibRadtran/UVSPEC radiative transfer code are compared with the experimental values recorded at Granada for cloud-free conditions. Absolute mean differences between measured and modeled UVI data at Granada were around 5% using the one-step and two-steps calibration methods, indicating an excellent performance of these two techniques for obtaining UVI data from the UVB-1 radiometer. Conversely, the application of the manufacture's calibration factor produced a large overestimation (~14%) of the UVI values, generating unreliable alarming high UVI data in summer. Thus, the number of days with an extreme erythemal risk (UVI higher than 10) increased up to 46% between May and September at Granada. This percentage reduced to a more reliable value of 3% when the conversion factors obtained with the two-steps calibration method are used. These results evidence the need for a sound calibration of the broadband UV instruments in order to obtain reliable measurements.
The complementary power of pH and lake water organic carbon reconstructions for discerning the influences on surface waters across decadal to millennial time scales
Authors: Rosén P. , Bindler R. , Korsman T. , Mighall T. , Bishop K.
Published: March 2011

Abstract. Lake Lysevatten has experienced both acidification and recent changes in the amount of lake water organic carbon (TOC) over which is causing concern across Europe and North America. A range of paleolimnological tools – diatom inferred pH, inferred lake water TOC from visible-near-infrared spectroscopy (VNIRS), multi-element geochemistry and pollen analysis, combined with geochemical modeling were used to reconstruct the lake's chemistry and surroundings back to the most recent deglaciation 12 500 years ago. The results reveal that the recent anthropogenic impacts are similar in magnitude to the long-term variation driven by natural catchment changes and early agricultural land use occurring over centuries and millennia. The combined reconstruction of both lake water TOC and lithogenic element delivery can explain the major changes in lake-water pH and modeled acid neutralizing capacity during the past 12 500 years. The results raise important questions regarding what precisely comprises ''reference'' conditions (i.e., free from human impacts) as encapsulated in the European Water Framework Directive.
Initiation of a Marinoan Snowball Earth in a state-of-the-art atmosphere-ocean general circulation model
Authors: Voigt A. , Abbot D. S. , Pierrehumbert R. T. , Marotzke J.
Published: March 2011

Abstract. We study the initiation of a Marinoan Snowball Earth (~635 million years before present) with the state-of-the-art atmosphere-ocean general circulation model ECHAM5/MPI-OM. This is the most sophisticated model ever applied to Snowball initiation. A comparison with a pre-industrial control climate shows that the change of surface boundary conditions from present-day to Marinoan, including a shift of continents to low latitudes, induces a global-mean cooling of 4.6 K. Two thirds of this cooling can be attributed to increased planetary albedo, the remaining one third to a weaker greenhouse effect. The Marinoan Snowball Earth bifurcation point for pre-industrial atmospheric carbon dioxide is between 95.5 and 96% of the present-day total solar irradiance (TSI), whereas a previous study with the same model found that it was between 91 and 94% for present-day surface boundary conditions. A Snowball Earth for TSI set to its Marinoan value (94% of the present-day TSI) is prevented by doubling carbon dioxide with respect to its pre-industrial level. A zero-dimensional energy balance model is used to predict the Snowball Earth bifurcation point from only the equilibrium global-mean ocean potential temperature for present-day TSI. We do not find stable states with sea-ice cover above 55%, and land conditions are such that glaciers could not grow with sea-ice cover of 55%. Therefore, none of our simulations qualifies as a "slushball" solution. While uncertainties in important processes and parameters such as clouds and sea-ice albedo suggest that the Snowball Earth bifurcation point differs between climate models, our results contradict previous findings that Snowball Earth initiation would require much stronger forcings.
Examination of homogeneity of selected Irish pooling groups
Authors: Das S. , Cunnane C.
Published: March 2011

Abstract. Flood frequency analysis is a necessary and important part of flood risk assessment and management studies. Regional flood frequency methods, in which flood data from groups of catchments are pooled together in order to enhance the precision of flood estimates at project locations, is an accepted part of such studies. This enhancement of precision is based on the assumption that catchments so pooled together are homogeneous in their flood producing properties. If homogeneity is assured then a homogeneous pooling group of sites lead to a reduction in the error of quantile estimates, relative to estimators based on single at-site data series alone. Homogeneous pooling groups are selected by using a previously nominated rule and this paper examines how effective one such rule is in selecting homogeneous groups. In this paper a study, based on annual maximum series obtained from 85 Irish gauging stations, examines how successful a common method of identifying pooling group membership is in selecting groups that actually are homogeneous. Each station has its own unique pooling group selected by use of a Euclidean distance measure in catchment descriptor space, commonly denoted dij and with a minimum of 500 station years of data in the pooling group. It was found that dij could be effectively defined in terms of catchment area, mean rainfall and baseflow index. The study then investigated how effective this selected method is in selecting groups of catchments that are actually homogenous as indicated by their L-Cv values. The sampling distribution of L-CV (t2) in each pooling group and the 95% confidence limits about the pooled estimate of t2 are obtained by simulation. The t2 values of the selected group members are compared with these confidence limits both graphically and numerically. Of the 85 stations, only 1 station's pooling group members have all their t2 values within the confidence limits, while 7, 33 and 44 of them have 1, 2 or 3 or more, t2 values outside the confidence limits. The outcomes are also compared with the heterogeneity measures H1 and H2. The H1 values show an upward trend with the ranges of t2 values in the pooling group whereas the H2 values do not show any such dependency. A selection of 27 pooling groups, found to be heterogeneous, were further examined with the help of box-plots of catchment descriptor values and one particular case is considered in detail. Overall the results show that even with a carefully considered selection procedure, it is not certain that perfectly homogeneous pooling groups are identified.
GPS-controlled tide gauges in Indonesia – a German contribution to Indonesia's Tsunami Early Warning System
Authors: Schöne T. , Illigner J. , Manurung P. , Subarya C. ,   Khafid, Zech C. , Galas R.
Published: March 2011

Abstract. Coastal tide gauges do not only play a central role in the study of climate-related sea level changes but also in tsunami warning systems. Over the past five years, ten GPS-controlled tide gauge systems have been installed by the German Research Centre for Geosciences (GFZ) in Indonesia to assist the development of the Indonesian Tsunami Early Warning System (InaTEWS). These stations are mainly installed at the Indonesian coastline facing the Indian Ocean. The tide gauge systems deliver information about the instantaneous sea level, vertical control information through GPS, and meteorological observations. A tidal analysis at the station's computer allows the detection of rapid changes in the local sea level ("sea level events"/SLE), thus indicating, for example, the arrival time of tsunamis. The technical implementation, communication issues, the operation and the sea level event detection algorithm, and some results from recent earthquakes and tsunamis are described in this paper.
GPS water level measurements for Indonesia's Tsunami Early Warning System
Authors: Schöne T. , Pandoe W. , Mudita I. , Roemer S. , Illigner J. , Zech C. , Galas R.
Published: March 2011

Abstract. On Boxing Day 2004, a severe tsunami was generated by a strong earthquake in Northern Sumatra causing a large number of casualties. At this time, neither an offshore buoy network was in place to measure tsunami waves, nor a system to disseminate tsunami warnings to local governmental entities. Since then, buoys have been developed by Indonesia and Germany, complemented by NOAA's Deep-ocean Assessment and Reporting of Tsunamis (DART) buoys, and have been moored offshore Sumatra and Java. The suite of sensors for offshore tsunami detection in Indonesia has been advanced by adding GPS technology for water level measurements. The usage of GPS buoys in tsunami warning systems is a relatively new approach. The concept of the German Indonesian Tsunami Early Warning System (GITEWS) (Rudloff et al., 2009) combines GPS technology and ocean bottom pressure (OBP) measurements. Especially for near-field installations where the seismic noise may deteriorate the OBP data, GPS-derived sea level heights provide additional information. The GPS buoy technology is precise enough to detect medium to large tsunamis of amplitudes larger than 10 cm. The analysis presented here suggests that for about 68% of the time, tsunamis larger than 5 cm may be detectable.