bluuebunny/crossref_metadata_2025 huggingface dataset:
Invariance of molecular charge transport upon changes of extended molecule size and several related issues
Authors: Bâldea Ioan
Published: March 2016

As a sanity test for the theoretical method employed, studies on (steady-state) charge transport through molecular devices usually confine themselves to check whether the method in question satisfies the charge conservation. Another important test of the theory’s correctness is to check that the computed current does not depend on the choice of the central region (also referred to as the “extended molecule”). This work addresses this issue and demonstrates that the relevant transport and transport-related properties are indeed invariant upon changing the size of the extended molecule, when the embedded molecule can be described within a general single-particle picture (namely, a second-quantized Hamiltonian bilinear in the creation and annihilation operators). It is also demonstrates that the invariance of nonequilibrium properties is exhibited by the exact results but not by those computed approximately within ubiquitous wide- and flat-band limits (WBL and FBL, respectively). To exemplify the limitations of the latter, the phenomenon of negative differential resistance (NDR) is considered. It is shown that the exactly computed current may exhibit a substantial NDR, while the NDR effect is absent or drastically suppressed within the WBL and FBL approximations. The analysis done in conjunction with the WBLs and FBLs reveals why general studies on nonequilibrium properties require a more elaborate theoretical than studies on linear response properties (e.g., ohmic conductance and thermopower) at zero temperature. Furthermore, examples are presented that demonstrate that treating parts of electrodes adjacent to the embedded molecule and the remaining semi-infinite electrodes at different levels of theory (which is exactly what most NEGF-DFT approaches do) is a procedure that yields spurious structures in nonlinear ranges of current–voltage curves.
Community organizing , pansement aux politiques néolibérales ou révolution lente ?
Authors: Balazard Hélène , Fisher Robert
Published: March 2016

Au Royaume-Uni, le programme conservateur de la Big Society mis en place par le précédent gouvernement Cameron (2010-2015) et Citizens UK , une community organization suivant le modèle initié par Alinsky, ont en commun une rhétorique de responsabilisation des « communautés » ( communities ). Les citoyens doivent être capables de s’« organiser » pour résoudre les problèmes rencontrés. Cette rhétorique est ambivalente et ces deux démarches peuvent tout autant être interprétées comme un pansement accompagnant les politiques néolibérales que comme un pas vers l’émancipation des classes populaires.
L’importation des notions d’ empowerment et de community organizing en France
Authors: Cottin-Marx Simon , Osganian Patricia
Published: March 2016

Dans cet entretien, Marie-Hélène Bacqué revient sur les notions d’ empowerment et de community organizing . Elle explique leurs ambiguïtés et les tensions qui les traversent, mais aussi leur potentiel et leur réception en France, comment elles sont mobilisées à la fois par les travailleurs sociaux et les militants des quartiers populaires.
Assessment of ochratoxin A stability following gamma irradiation: experimental approaches for feed detoxification perspectives
Authors: Mehrez A. , Maatouk I. , Romero-González R. , Amara A. Ben , Kraiem M. , Frenich A. Garrido , Landoulsi A.
Published: March 2016

The present study evaluated the effect of gamma irradiation on the stability of ochratoxin A (OTA) under various conditions. The effects of the physical state of OTA (solid vs aqueous), initial OTA concentration, irradiation dose and dose rate as well as the presence of model substances simulating food matrix compounds on OTA radiostability were investigated. First, pure OTA with and without food model compounds including α-D-glucose (monosaccharide), Methyl α-D-glucopyranoside (starch) and the amino acid derivatives N-α-acetyl-L-lysine methyl ester and N-α-acetyl-L-cysteine methyl ester (protein models) were irradiated with doses of 2, 4 and 8 kGy applied at 15.117 and 108.24 Gy/min. Secondly, artificially OTA-contaminated wheat with different moisture content (11, 14 and 16%) was irradiated with doses of 2, 4 and 8 kGy applied at 63.39 Gy/min. Residual OTA levels were analysed using ultra-high performance liquid chromatography coupled with tandem mass spectrometry. Solid OTA (50 and 3,200 ng/ml)showed great irradiation stability, even with irradiation doses up to 8 kGy. Under dry conditions, the presence of food model components did not affect OTA radiostability. However, in an aqueous solution, complete reduction was achieved at the initial OTA concentration of 50 ng/ml and irradiation dose of 2 kGy. Applying gamma irradiation to cereal-based food model systems produced a significant OTA reduction (5,000 µg/kg) of 47.2% in moistened wheat kernels (16%) with an absorbed dose of 8 kGy but failed to reduce the OTA content of low moisture content wheat (11%). These model experiments offered a useful tool to assess the main key factors affecting gamma irradiation-induced OTA reduction. Gamma irradiation is promising since the irradiation doses applied could partially reduce OTA contamination. Nevertheless, its efficacy was largely affected by initial moisture content and could be dangerous if toxic by-products are produced or nutritive quality is lost and needs further study.
Total Hip Arthroplasty Complicated by a Gluteal Hematoma Resulting in Acute Foot Drop
Authors: Khattar Nicolas K. , Parry Phillip V. , Agarwal Nitin , George Hope K. , Kretz Eric S. , Larkin Timothy M. , Gruen Gary S. , Abla Adnan A.
Published: March 2016

Total hip arthroplasty is a prevalent orthopedic intervention in the United States. Massive postoperative hematomas are a rare albeit serious complication of the procedure. Sequelae of these hematomas can include lower extremity paralysis from compression of the sciatic nerve. A 66-year-old woman taking aspirin and clopidogrel for coronary stents presented with a complete foot drop, paresthesias, and lower extremity pain 10 days after a total hip arthroplasty. The patient was initially seen by a neurology service at another hospital and thought to have lateral recess stenosis. At the authors' center, magnetic resonance imaging of the lumbar spine failed to show lateral recess stenosis. Urgent pelvic computed tomography showed a large hematoma and raised suspicion of sciatic nerve compression. Hip magnetic resonance imaging showed a right gluteal hematoma compressing the sciatic nerve. The patient was then taken to the operating room for the clot to be evacuated and was later referred for rehabilitation. Massive hematomas after total hip arthroplasty are an important consideration in the differential diagnosis of nontraumatic acute foot drop. Prompt diagnosis may correlate with improved neurological outcome and help reduce overall morbidity. [
Orthopedics.
2016; 39(2):e374–e376.]
Repair of Chronic Tibialis Anterior Tendon Ruptures
Authors: Funk Shawn S. , Gallagher Bethany , Thomson A. Brian
Published: March 2016

This article presents a novel technique for repair of chronic tibialis anterior tendon ruptures. All chronic tibialis anterior tendon ruptures reviewed were treated with this technique. Patients with chronic tibialis anterior tendon ruptures presenting to the authors' institution from 2006 to 2012 had preoperative and postoperative Foot and Ankle Ability Measure scores. The average follow-up time was 2.1 years. The average Foot and Ankle Ability Measure score was 66.1% preoperatively and 87.1% postoperatively (
P=
.002). This technique offers theoretical improved strength and may help avoid the need for tendon graft often required by other techniques. [
Orthopedics.
2016; 39(2):e386–e390.]
Decline of the Endangered Morro Bay Kangaroo Rat in California
Authors: Kofron Christopher P. , Villablanca Francis X.
Published: March 2016

The Morro Bay kangaroo rat Dipodomys heermanni morroensis occurs in the vicinity of Morro Bay (specifically in and near Los Osos) in western San Luis Obispo County in coastal central California. It was listed as endangered pursuant to the U.S. Endangered Species Conservation Act in 1970 and subsequently the U.S. Endangered Species Act in 1973. Field research from the late 1950s to the mid-1980s has documented a rapid population decline. Despite many efforts, researchers have not captured the Morro Bay kangaroo rat since 1986, and the last captive individual died in 1993. We review the biology and conservation status of the Morro Bay kangaroo rat, including taxonomy and genetics, soil type and burrows, history of decline, primary causes of decline, breeding in the wild and in captivity, habitat restoration, and threats. In particular, there are two primary causes of decline. First, development (urban, agricultural, and industrial) has resulted in direct loss of habitat. Second, in the absence of fire, the early seral stages of coastal dune scrub (optimal habitat) have matured to later successional stages of vegetation, which are denser and with substantially fewer annual food plants, and which negatively impact the locomotion of kangaroo rats and change the diversity of the small mammal community with a likely increase in competition. In 2016 only pockets of habitat remain, with optimal habitat comprising an estimated 1% of the historical geographic range. Although researchers have not demonstrated predation by domestic cats, it is likely a major threat and we suspect it has contributed to the decline based upon a review of the literature. In 2011 we observed potential signs of the Morro Bay kangaroo rat at two historical areas, which suggests it may be persisting at extremely low densities in a few isolated colonies. In addition, we could not obtain permission to survey on four private properties with potential habitat. In consideration of the vast loss and fragmentation of its habitat, along with the continuing and pervasive threats, the Morro Bay kangaroo rat is clearly conservation-reliant. We believe that without urgent human intervention, the Morro Bay kangaroo rat will soon become extinct if it is not already.
Visualizing Sequential Educational Datamining Patterns
Authors: Jordão Vilma Rodrigues , Gama Sandra , Gonçalves Daniel
Published: March 2016

The use of educational datamining techniques to elicit patterns in student behavior and learning outcomes can be a useful for the analysis of the effectiveness of teaching strategies and the coordination of study programs. However, results from those techniques are, often, large sets of symbolic patterns, numbering in the thousands, usually presented in text format. This makes them hard to understand which, coupled with the lack of an overall view, hinders a more comprehensive data analysis. The authors propose that information visualization techniques can be used to display relevant information in those patterns in effective ways, allowing decision makers to better insights about the reality at hand. They present a solution built upon two linked views, one based on node-link representations and another a multi-matrix representation. The complementarity of both visualization techniques allows the most important patterns to be immediately apparent, while at the same time permitting their interactive exploration in meaningful ways. The authors performed user tests proving their effectiveness.
An Approach to Data Annotation for Internet of Things
Authors: Atanasov Ivaylo , Nikolov Anastas , Pencheva Evelina , Dimova Rozalina , Ivanov Martin
Published: March 2016

The increasing number of connected devices which use Internet of Things (IoT) technology and variety of associated services is a real challenge to interoperability. There is a need of an abstraction layer which hides the technology heterogeneity. The paper presents an approach to data modeling in the domain of home energy saving which extends existing solutions with context-ware concepts and relationships. Requirements to data annotation are identified by use cases. Problem-solving principle is applied to data annotation which defines the vocabulary related to a certain task or activities. An observation and actuation models which show how data annotation works are proposed and formally verified. As a proof of concept, the server model includes web services that illustrate the usage of the proposed data annotation. The potential of home appliance power control is estimated.
A Decentralized Framework for Semantic Web Services Discovery Using Mobile Agent
Authors: Ben Seghir Nadia , Kazar Okba , Rezeg Khaled
Published: March 2016

Web services discovery provided by the UDDI registries is relatively primitive. It does not take into account the continuous growth in the number of services on the Web. The UDDI standard has been proposed and used for Web service publication and discovery. However, it does not allow users to choose the best provider. It does not offer a mechanism to choose a Web service based on its quality. The standard also lacks of sufficient semantic description in the content of Web services, this lack makes it difficult to find and compose suitable Web services during analysis, search, and matching processes. In addition, a central UDDI suffers from one centralized point problem and the high cost of maintenance. To get around these problems, the authors propose in this paper a novel framework based on mobile agent and metadata catalogue for Web services discovery. Their approach is based on user profile in order to discover appropriate Web services, meeting customer requirements, in less time and taking into account the QoS properties.
Computer Based E-Healthcare Clinical Systems
Authors: Watfa Mohamed K. , Majeed Hina , Salahuddin Tooba
Published: March 2016

Over the years, interactive computer-based systems have provided crucial support to clinics, hospitals and other health-based centers. These systems have continued to influence the manner in which clinical tasks are organized and fulfilled in terms of performing tests, diagnosis procedures, treatment methods, as well as storing, analyzing and accessing patient and staff information. At the present time, the computer-based systems used in healthcare settings of high standards are the result of joint efforts of clinicians, software developers and clinical informaticians hence triggering the outcome of the desired system to outdo that of existing applications. Major concerns arise in designing clinical application including data privacy, minimal bias offered by a system (i.e. in terms of searching and decision-making), a user friendly GUI and an efficient integration of the new system with the existing standard applications at the health based setting being considered. In this paper, we provide a comprehensive survey on the existing research work on computer based E-Healthcare applications for clinicians highlighting both the challenges and benefits of such applications which would be of value to both patients and clinicians.
Portuguese Citizens and Oncologic Institutions in Social Networks
Authors: Martins Nuno , Brandão Daniel
Published: March 2016

This paper aims to unravel the way Portuguese citizens and institutions have been adopting online platforms for social networks within the framework of solidarity and citizenship against cancer. The authors will present an analysis of the communication strategies implemented by institutions and their outcomes, aiming at clarifying the contribution that this type of participatory media have been giving to the oncological cause. In the Portuguese case, this activity occurs essentially among the most disseminated online platforms, namely: Twitter, YouTube, blogs and mostly on Facebook. The study focuses on the activity of renowned oncologic institutions on Facebook, as well as on various other online platforms for social networks. After the analysis and evaluation of the institutions' activity the authors present a set of recommendations that will help them in using social networks to citizenship missions in oncology.
Evaluation of Community Perception towards Tourism Industry
Authors: Mare Yidnekachew , Gebreyohannes Emmanuel , Tesfay Yohannes Yebabe
Published: March 2016

The purpose of this study was to identify and analyze the factors affecting the perception of Hawassa community towards the tourism industry using Factor Analysis, Multiple linear regression and Multivariate Analysis of Variance (MANOVA). Cross-sectional survey was conducted on a sample of 591 from a target population of 24021 of Hawassa City. The Factor analysis estimation result identified five potential factors that affect the community's perception towards the tourism industry. These potential factors are economic, socio-cultural, environmental, community service and community attitude factors, which explained 77.5 percent of the total variation of the community's perception towards the tourism industry. Multiple linear regression analysis indicated that length of residency, number of tourist contacts, number of recreational activities, job creation and tourism policy participation are found significant in explaining the variation in the underlined perceptions of the community towards tourism. Among the demographic characteristics, sub city, sex, educational level, working profession and monthly income of the respondents are found were statistically significant different for the mean scores of the perceptions towards tourism.
Population dynamics and epidemiology of four species ofDendroctonus(Coleoptera: Curculionidae): 100 years since J.M. Swaine
Authors: Aukema Brian H. , McKee Fraser R. , Wytrykush Debra L. , Carroll Allan L.
Published: March 2016

Almost 100 years have passed since J.M. Swaine, the assistant entomologist in charge of Forest Insect Investigations, wrote, “Canadian bark-beetles: a preliminary classification, with an account of the habits and means of control”. The goal was to “put into the hands of practical foresters information of inestimable practical value… to prevent the continued loss of timber now being destroyed” by “the most insidious enemies of the forest”. In this paper, we celebrate Swaine’s pioneering work by summarising the foundational aspects of his early treatise of 1918: the “general habits” of bark beetles, classifications of their behaviour, causes of population increase, and mitigation tactics. In the founding text, Swaine identified all majorDendroctonusErichson (Coleoptera: Curculionidae) bark beetles found in Canada, although details on life histories were scarce. We summarise current knowledge of the life histories and population dynamics of the spruce beetle,D.rufipennisKirby; the Douglas-fir beetle,D. pseudotsugaeHopkins; the eastern larch beetle,D. simplex; and address the current range expansion of mountain pine beetle,D. ponderosaeHopkins. We review how aspects of global change, such as invasive species, have altered the population dynamics of certain bark beetles. Finally, we conclude with lessons from two of the many past contributors to bark beetle ecology in Canada, J.M. Swaine and H.A. Richmond.
Assessment of activities performed by clinical nurse practitioners and implications for staffing and patient care at primary health care level in South Africa
Authors: Igumbor Jude , Davids Alta , Nieuwoudt Catharina , Lee Jessica , Roomaney Rifqah
Published: March 2016

Background: The shortage of nurses in public healthcare facilities in South Africa is well documented; finding creative solutions to this problem remains a priority.Objective: This study sought to establish the amount of time that clinical nurse practitioners (CNPs) in one district of the Western Cape spend on clinical services and the implications for staffing and skills mix in order to deliver quality patient care.Methods: A descriptive cross-sectional study was conducted across 15 purposively selected clinics providing primary health services in 5 sub-districts. The frequency of activities and time CNPs spent on each activity in fixed and mobile clinics were recorded. Time spent on activities and health facility staff profiles were correlated and predictors of the total time spent by CNPs with patients were identified.Results: The time spent on clinical activities was associated with the number of CNPs in the facilities. CNPs in fixed clinics spent a median time of about 13 minutes with each patient whereas CNPs in mobile clinics spent 3 minutes. Fixed-clinic CNPs also spent more time on their non-core functions than their core functions, more time with patients, and saw fewer patients compared to mobile-clinic CNPs.Conclusions: The findings give insight into the time CNPs in rural fixed and mobile clinics spend with their patients, and how patient caseload may affect consultation times. Two promising strategies were identified – task shifting and adjustments in health workerd eployment – as ways to address staffing and skills mix, which skills mix creates the potential for using healthcare workers fully whilst enhancing the long-term health of these rural communities.
A case-based approach to UTI imaging – making sense of the guidelines
Authors: Kilborn Tracy , Moodley Halvani , Brink Anita , Nourse Peter
Published: March 2016

Urinary tract infections (UTIs) are common amongst children and invariably result in imaging tests to look for correctable causes that may predispose the child to infection. The objective of imaging is to identify those children at risk of long-term renal damage. The ideal imaging algorithm is extensively debated in the literature owing to the lack of evidence-based data, evolving theories on the pathophysiology of UTI and vesicoureteric reflux (VUR). The present article provides a case-based approach to the imaging of UTIs and proposes guidelines relevant to the South African setting.
Aplicaciones de la digitalización 3D del patrimonio
Authors: Torres J.C. , Cano P. , Melero J. , España M. , Moreno J.
Published: March 2016

3D digitalization has become a common tool in archaeology. However, the post processing of the data produced by the scanners is still quite complex, and the computer models generated are given very few practical applications.

In this paper, we analyse the key steps involved in the processing of the point clouds. We also review some of the more usual applications for the digital models and propose a conceptual framework for the use of this models in the documentation of cultural heritage.
Pompeya como caso de estudio: La visualización digital aplicada a la arqueología de una ciudad vesubiana
Authors: Apollonio F.I. , Benedetti B. , Diarte Blasco P. , Gaiani M. , Guidazzoli A.
Published: March 2016

The objective of the experience in Pompeii is to set up an Information System that will enable us to conserve, manage and integrate the data, files and documents gathered at different times and in different areas of the archeological dig; a 3D Unified Information System capable of providing us with a uniform framework for scientific visualization and web-based presentation of the set data -characterized by their heterogeneity- of this city and the Vesuvian Area in general. The final objective will be to facilitate the interpretation, exploration and, finally, analysis of a large volume of data with significative geo-spatial, temporal and semantic features.
La Realidad Virtual aplicada a la explotación sostenible del Patrimonio Arqueológico. Un caso éxito: la Cueva de Santimamiñe.
Authors: Barrera Mayo Sergio , Baeza Santamaría Unai
Published: March 2016

Archaeological complex are important heritage elements that require special care because of its fragility and because of the need of spreading its richness to the society along the time. The archaeological heritage used as education, scientific, cultural, economical resource, sometimes does not combine with the duty of its protection and conservation because the unwise exploitation of archaeological sites can generate irreversible damage. Combining the appropriate technologies, a virtual reconstruction can be developed in a high quality level, allowing the massive tourism exploitation in a respectful way. This technology enables the communication and spread to future generations in the best conditions, adding an innovative value.
Restituciones virtuales de la vajilla de mesa romana (Terra Sigillata)
Authors: Delgado Aguilar Salvador
Published: March 2016

The following work takes as a fundamental object the study of the ceramic index Roman recovered in different interventions so much in Onoba's city (Huelva) like in that of Arucci/Turobriga (Aroche, Huelva), both included in the Project: The Roman cities of the from Huelva territory, at the expense of the group of investigation Hum 132 of the University of Huelva. The above mentioned study turns in exclusivity on the china of Roman table, named as Terra Sigillata, of whom it has been recovered diverse forms and types in these deposits. These ceramics of table are stated in cause in poor condition of conservation, nevertheless, we have could across the analysis and study of the same one realize virtual restitutions that help to a better comprehension so much for the scientific community as the society.
Uso de sistemas basados en escáner 3D para digitalización y estudio del patrimonio arqueológico
Authors: González Muñoz Manuel J. , Rueda Ruiz Antonio J. , Segura Sánchez Rafael J. , Ogáyar Anguita Carlos J. , Esteban Hoyas Antonio , Lara Javier
Published: March 2016

3D scanners are becoming useful tools in many fields like civil engineering, heritage restoration or archaeology. Speed, accuracy and security are several key features of these systems. The data generated by a 3D scanner can be used in many ways: since a simple virtual representation to complex studies of multiple kinds. Nowadays companies like Sacyr know the advantages that these systems offer, an example was the use of a 3D scanner to carry out a virtual construction and a study of the restoration project of the Roman Bridge of Cordoba.
SIG y Paisajes Virtuales en 3D. Posibilidades de divulgación de la Prehistoria Reciente de la Sierra de Atapuerca
Authors: Marcos Sáiz Francisco Javier
Published: March 2016

Archaeology has developed several theoretical and methodological perspectives with the application of the Geographical Information Systems (GIS), Digital Terrain Models (DTM), Virtual Reality (VR) and the 3D Modelling. In the spreading a gradual progress has begun for mapping the sites on its environmental context with the virtual generation of the topographic and ecological features. The aim of this paper is the analysis of the possibilities of spreading of the settlement patterns in the Late Prehistory around Sierra de Atapuerca (Burgos), VI to II millennium cal. BC-. The technical process is the modelling and 3D animation for video of Virtual Landscapes with GIS. The conclusion is that the Virtual Flying with GIS is a fundamental tool for the graphical spreading of the prehistoric settlement, especially with archaeological sites of surveys.
Comparison of retrieved Noctilucent cloud particle properties from Odin tomography scans and model simulations
Authors: Megner Linda , Christensen Ole M. , Karlsson Bodil , Benze Susanne , Fomichev Victor I.
Published: March 2016

Abstract. Mesospheric ice particles, known as Noctilucent clouds or Polar Mesospheric Clouds, have long been observed by rocket instruments and satellites, while models have been used to simulate ice particle growth and cloud properties. However, the fact that different measurement techniques are sensitive to different parts of the ice particle distribution makes it difficult to compare retrieved parameters such as ice particle radius or particle number density from different experiments. In this work we investigate the accuracy of satellite retrieval based on scattered light and how this affects derived cloud properties. We run the retrieval algorithm on modelled cloud distributions and compare the results to the properties of the original distributions. We find that ice mass density is accurately retrieved whereas mean radius often is overestimated and high number densities generally are underestimated. The reason is that the retrieval algorithm assumes a Gaussian size distribution, whereas the modelled size distributions often are multimodal. Once we know the limits of the satellite retrieval we proceed to compare the properties retrieved from the modelled cloud distributions to those observed by the Optical, Spectroscopic, and Infrared Remote Imaging System (OSIRIS) instrument on the Odin satellite. We find that a model with a stationary atmosphere, as given by average atmospheric conditions, does not yield cloud properties that are in agreement with the observations, whereas a model with realistic temperature and vertical wind variations does. This indicates that average atmospheric conditions are insufficient to understand the process of Noctilucent cloud growth and that a realistic atmospheric variability is crucial for cloud formation and growth. Further, the agreement between results from the model – when set up with a realistically variable atmosphere – and the observations suggests that our understanding of the growth process itself is reasonable.
Time since death and decay rate constants of Norway spruce and European larch deadwood in subalpine forests determined using dendrochronology and radiocarbon dating
Authors: Petrillo Marta , Cherubini Paolo , Fravolini Giulia , Marchetti Marco , Ascher-Jenull Judith , Schärer Michael , Synal Hans-Arno , Bertoldi Daniela , Camin Federica , Larcher Roberto , Egli Markus
Published: March 2016

Abstract. Due to the large size (e.g. sections of tree trunks) and highly heterogeneous spatial distribution of deadwood, the timescales involved in the coarse woody debris (CWD) decay of Picea abies (L.) Karst. and Larix decidua Mill. in Alpine forests are largely unknown. We investigated the CWD decay dynamics in an Alpine valley in Italy using the chronosequence approach and the five-decay class system that is based on a macromorphological assessment. For the decay classes 1–3, most of the dendrochronological samples were cross-dated to assess the time that had elapsed since tree death, but for decay classes 4 and 5 (poorly preserved tree rings) radiocarbon dating was used. In addition, density, cellulose, and lignin data were measured for the dated CWD. The decay rate constants for spruce and larch were estimated on the basis of the density loss using a single negative exponential model, a regression approach, and the stage-based matrix model. In the decay classes 1–3, the ages of the CWD were similar and varied between 1 and 54 years for spruce and 3 and 40 years for larch, with no significant differences between the classes; classes 1–3 are therefore not indicative of deadwood age. This seems to be due to a time lag between the death of a standing tree and its contact with the soil. We found distinct tree-species-specific differences in decay classes 4 and 5, with larch CWD reaching an average age of 210 years in class 5 and spruce only 77 years. The mean CWD rate constants were estimated to be in the range 0.018 to 0.022 y−1 for spruce and to about 0.012 y−1 for larch. Snapshot sampling (chronosequences) may overestimate the age and mean residence time of CWD. No sampling bias was, however, detectable using the stage-based matrix model. Cellulose and lignin time trends could be derived on the basis of the ages of the CWD. The half-lives for cellulose were 21 years for spruce and 50 years for larch. The half-life of lignin is considerably higher and may be more than 100 years in larch CWD. Consequently, the decay of Picea abies and Larix decidua is very low. Several uncertainties, however, remain: 14C dating of CWD from decay classes 4 and 5 and having a pre-bomb age is often difficult (large age range due to methodological constraints) and fall rates of both European larch and Norway spruce are missing.
Predicting biomass of hyperdiverse and structurally complex central Amazonian forests – a virtual approach using extensive field data
Authors: Magnabosco Marra Daniel , Higuchi Niro , Trumbore Susan E. , Ribeiro Gabriel H. P. M. , dos Santos Joaquim , Carneiro Vilany M. C. , Lima Adriano J. N. , Chambers Jeffrey Q. , Negrón-Juárez Robinson I. , Holzwarth Frederic , Reu Björn , Wirth Christian
Published: March 2016

Abstract. Old-growth forests are subject to substantial changes in structure and species composition due to the intensification of human activities, gradual climate change and extreme weather events. Trees store ca. 90 % of the total aboveground biomass (AGB) in tropical forests and precise tree biomass estimation models are crucial for management and conservation. In the central Amazon, predicting AGB at large spatial scales is a challenging task due to the heterogeneity of successional stages, high tree species diversity and inherent variations in tree allometry and architecture. We parameterized generic AGB estimation models applicable across species and a wide range of structural and compositional variation related to species sorting into height layers as well as frequent natural disturbances. We used 727 trees (diameter at breast height  ≥  5 cm) from 101 genera and at least 135 species harvested in a contiguous forest near Manaus, Brazil. Sampling from this data set we assembled six scenarios designed to span existing gradients in floristic composition and size distribution in order to select models that best predict AGB at the landscape level across successional gradients. We found that good individual tree model fits do not necessarily translate into reliable predictions of AGB at the landscape level. When predicting AGB (dry mass) over scenarios using our different models and an available pantropical model, we observed systematic biases ranging from −31 % (pantropical) to +39 %, with root-mean-square error (RMSE) values of up to 130 Mg ha−1 (pantropical). Our first and second best models had both low mean biases (0.8 and 3.9 %, respectively) and RMSE (9.4 and 18.6 Mg ha−1) when applied over scenarios. Predicting biomass correctly at the landscape level in hyperdiverse and structurally complex tropical forests, especially allowing good performance at the margins of data availability for model construction/calibration, requires the inclusion of predictors that express inherent variations in species architecture. The model of interest should comprise the floristic composition and size-distribution variability of the target forest, implying that even generic global or pantropical biomass estimation models can lead to strong biases. Reliable biomass assessments for the Amazon basin (i.e., secondary forests) still depend on the collection of allometric data at the local/regional scale and forest inventories including species-specific attributes, which are often unavailable or estimated imprecisely in most regions.
Upwelling and isolation in oxygen-depleted anticyclonic modewater eddies and implications for nitrate cycling
Authors: Karstensen Johannes , Schütte Florian , Pietri Alice , Krahmann Gerd , Fiedler Björn , Grundle Damian , Hauss Helena , Körtzinger Arne , Löscher Carolin R. , Testor Pierre , Vieira Nuno , Visbeck Martin
Published: March 2016

Abstract. The physical (temperature, salinity, velocity) and biogeochemical (oxygen, nitrate) structure of an oxygen depleted coherent, baroclinic, anticyclonic mode-water eddy (ACME) is investigated using high-resolution autonomous glider and ship data. A distinct core with a diameter of about 70 km is found in the eddy, extending from about 60 to 200 m depth and. The core is occupied by fresh and cold water with low oxygen and high nitrate concentrations, and bordered by local maxima in buoyancy frequency. Velocity and property gradient sections show vertical layering at the flanks and underneath the eddy characteristic for vertical propagation (to several hundred-meters depth) of near inertial internal waves (NIW) and confirmed by direct current measurements. A narrow region exists at the outer edge of the eddy where NIW can propagate downward. NIW phase speed and mean flow are of similar magnitude and critical layer formation is expected to occur. An asymmetry in the NIW pattern is seen that possible relates to the large-scale Ekman transport interacting with ACME dynamics. NIW/mean flow induced mixing occurs close to the euphotic zone/mixed layer and upward nutrient flux is expected and supported by the observations. Combing high resolution nitrate (NO3−) data with the apparent oxygen utilization (AOU) reveals AOU:NO3− ratios of 16 which are much higher than in the surrounding waters (8.1). A maximum NO3− deficit of 4 to 6 µmol kg−1 is estimated for the low oxygen core. Denitrification would be a possible explanation. This study provides evidence that the recycling of NO3−, extracted from the eddy core and replenished into the core via the particle export, may quantitatively be more important. In this case, the particulate phase is of keys importance in decoupling the nitrogen from the oxygen cycling.
Imprints of climate forcings in global gridded temperature data
Authors: Mikšovský Jiří , Holtanová Eva , Pišoft Petr
Published: March 2016

Abstract. Monthly near-surface temperature anomalies from several gridded data sets (GISTEMP, Berkeley Earth, MLOST, HadCRUT4, 20th Century Reanalysis) were investigated and compared with regard to the presence of components attributable to external climate forcings (associated with anthropogenic greenhouse gases, as well as solar and volcanic activity) and to major internal climate variability modes (El Niño/Southern Oscillation, North Atlantic Oscillation, Atlantic Multidecadal Oscillation, Pacific Decadal Oscillation and variability characterized by the Trans-Polar Index). Multiple linear regression was used to separate components related to individual explanatory variables in local monthly temperatures as well as in their global means, over the 1901–2010 period. Strong correlations of temperature and anthropogenic forcing were confirmed for most of the globe, whereas only weaker and mostly statistically insignificant connections to solar activity were indicated. Imprints of volcanic forcing were found to be largely insignificant in the local temperatures, in contrast to the clear volcanic signature in their global averages. Attention was also paid to the manifestations of short-term time shifts in the responses to the forcings, and to differences in the spatial fingerprints detected from individual temperature data sets. It is shown that although the resemblance of the response patterns is usually strong, some regional contrasts appear. Noteworthy differences from the other data sets were found especially for the 20th Century Reanalysis, particularly for the components attributable to anthropogenic forcing over land, but also in the response to volcanism and in some of the teleconnection patterns related to the internal climate variability modes.
30 years of upper air soundings on board of R/V POLARSTERN
Authors: Driemel Amelie , Loose Bernd , Grobe Hannes , Sieger Rainer , König-Langlo Gert
Published: March 2016

Abstract. The research vessel and supply icebreaker POLARSTERN is the flagship of the Alfred-Wegener-Institut in Bremerhaven (Germany) and one of the infrastructural pillars of German Antarctic research. Since its commissioning in 1982, POLARSTERN has conducted 30 campaigns to Antarctica (157 legs, mostly austral summer), and 29 to the Arctic (94 legs, northern summer). Usually, POLARSTERN is more than 300 days per year in operation and crosses the Atlantic Ocean in a meridional section twice a year. The first radiosonde on POLARSTERN was released on the 29th of December 1982, two days after POLARSTERN started on its maiden voyage to the Antarctic. And these daily soundings have continued up to the present. Due to the fact that POLARSTERN has reliably and regularly been providing upper air observations from data sparse regions (oceans and polar regions), the radiosonde data are of special value for researchers and weather forecast services alike. In the course of 30 years (1982-12-29 to 2012-11-25) a total of 12378 radiosonde balloons were started on POLARSTERN. All radiosonde data can now be found at doi:10.1594/PANGAEA.810000. Each dataset contains the directly measured parameters air temperature, relative humidity and air pressure, and the derived altitude, wind direction and wind speed. 432 datasets additionally contain ozone measurements. Although more sophisticated techniques (meteorological satellites, aircraft observation, remote sensing systems, etc.) have nowadays become increasingly important, the high vertical resolution and quality of radiosonde data remains paramount for weather forecasts and modelling approaches.
Digital photography for assessing vegetation phenology in two contrasting northern ecosystems
Authors: Linkosalmi Maiju , Aurela Mika , Tuovinen Juha-Pekka , Peltoniemi Mikko , Tanis Cemal M. , Arslan Ali N. , Kolari Pasi , Aalto Tuula , Rainne Juuso , Laurila Tuomas
Published: March 2016

Abstract. Digital repeat photography has become a widely used tool for assessing the annual course of vegetation phenology of different ecosystems. A greenness measure derived from digital images potentially provides an inexpensive and powerful means to analyze the annual cycle of ecosystem phenology. By using the Green Chromatic Coordinate (GCC), we examined the feasibility of digital repeat photography for assessing the vegetation phenology in two contrasting high-latitude ecosystems. While the seasonal changes in GCC are more obvious for the ecosystem that is dominated by annual plants (open wetland), clear seasonal patterns were also observed for the evergreen ecosystem (coniferous forest). Limited solar radiation restricts the use of images during the night and in wintertime, for which time windows were determined based on images of a grey reference plate. The variability in cloudiness had only a minor effect on GCC, and GCC did not depend on the sun angle and direction either. The GCC of wetland developed in tandem with the daily photosynthetic capacity estimated from the atmosphere-ecosystem flux measurements. At the forest site, the seasonal GCC cycle correlated well with the flux data in 2015 but there were some temporary deviations in 2014. The year-to-year differences were most likely generated by meteorological conditions, especially the differences in temperature. In addition to depicting the seasonal course of ecosystem functioning, GCC was shown to respond to physiological changes on a daily time scale. It seems that our northern sites, with a short and pronounced growing season, suit especially well for the monitoring of phenological variations with digital images.
Access to Credit and Constraint Analysis: The Case of Smallholder Rice Farmers in Ghana
Authors: Denkyirah Elisha Kwaku , Aziz Ahmed Abdul , Denkyirah Elijah Kofi , Nketiah Ofori Obeng , Okoffo Elvis Dartey
Published: March 2016

The study assessed rice farmers’ access to credit and constraints in rice production in the Tolon District of Ghana. A total of 140 rice farmers were sampled for the study using multi-stage sampling technique. The probit model was used to estimate the factors that affected rice farmers’ access to credit. The Kendall’s coefficient of concordance was used to assess the constraints in rice production. The results of the study revealed that majority of the rice farmers accessed credit from family and friends and invested the credit into non-agricultural activities. The probit result revealed that age, marital status, member of farmer based organization, extension visit, record keeping and farm income were the significant variables that influenced rice farmers’ access to credit. The results also revealed that high cost of inputs and pest were the most pressing institutional and technical constraints in rice production, respectively. The study recommends that credit should be converted to physical inputs and other services and delivered to farmers to help minimize credit diversion from the farm sector. Rice farmers should be encouraged to form farmer groups and keep records of farming activities considering the fact that it positively influenced farmers’ access to credit. Subsidies should be provided on farm inputs. Effective ways of eliminating pest on rice fields should be developed since it was a major challenge facing the rice farmers in their production.
Metanephric Adenoma of the Kidney: Study of Eight Patients and Review of the Literature
Authors: Saraceni Giacomo , Mengoni Francesco , Brunocilla Eugenio , Corti Barbara , Severini Giuseppe , Martorana Giuseppe
Published: March 2016

Background

Metanephric adenoma is a rare benign tumor of the kidney polycythemia is associated and it might be possible to suspect the diagnosis of this neoplasia.

Methods

From the beginning of 2000 till the end 2011, we identified eight male patients with methanephric adenoma in our hospital, only two of these were selected to surgery for this tumor; in the other six the finding occasionally at pathological anatomy other pathology of the kidney.

Results

All patients are in good clinical condition except two died for other diseases. The mean (range) dimension was about 2 cm.

Conclusion

The adenoma is a benign condition; suspect this adenomais recommended nephron sparing surgery.
About Surgical Correction of Urethral Stenosis: Urethroplasty
Authors: Pace Gianna , Micheli Emanuele , Valenti Sergio , Borgonovo Giulio , Vismara Alberto , Tocco Antonella , Lembo Antonino
Published: March 2016

Objective

The aim of our study has been to evaluate our results in the treatment of urethral stenosis through several surgical approaches of urethroplasty: the one-stage procedure by direct end-to-end anastomosis, the free dorsal onlay graft urethroplasty using buccal mucosa, and the two-stage urethroplasty.

Methods

Between February 2009 and January 2012, 53 patients were enrolled and analyzed for different types of urethral reconstruction.

Results

The procedures included direct end-to-end anastomosis in 26 patients (49%), 18 (34%) underwent a two-stage urethroplasty (Johansen's), in 9 a free dorsal onlay buccal mucosa urethroplasty was performed. At a mean follow-up of 17 months, we had an overall success rate of 95%. When stratified on the basis of the procedure performed, in the direct end-to-end anastomosis 98% of patients had no evidence of recurrent stricture, 96% of success rate was reached in the onlay buccal mucosa urethroplasty, and 91% in the two-stage procedure.

Conclusions

In patients with urethral strictures, urethroplasty has to be preferred with respect to urethrotomy, which is the cause of a high percentage of recurrence, and holds the risk of compromising the success of further surgical procedures of urethroplasty. Differently, several techniques of urethroplasty offer a high percentage of success rate until 95%, as showed by our results.
Ruminal pH and N-NH3 behavior: a Bayesian approach
Authors: Souza Osvaldo Martins , Martins Elias Nunes , Rossi Robson Marcelo , Oliveira Carlos Antonio Lopes de , Aguiar Sílvia Cristina de , Paula Edson Júnior Heitor de , Geron Luiz Juliano Valério , Stivanin Tádia Emanuele , Ferreira Eric Batista
Published: March 2016

In this work, we present the Bayesian approach as an alternative to frequentist analysis regarding correlated data of pH and N-NH3 in the Holstein cow rumen. It was observed that for pH and N-NH3 data, a posteriori estimates of coefficients of the regression models were significant, which was not observed for least-squares estimates. Thus, the Bayesian approach allowed inferences that were directly linked to the sampling of parameters of interest and statistical comparisons of non-linear functions of the estimated parameters.