bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental evaluation of a radiant heated floor coupled to an air-to-water heat pump for the cooling of greenhouses
Authors: Valiño V. , Perdigones A. , García J.L. , Luna L.
Published: November 2013

This paper describes the experimental cooling of a greenhouse in Madrid (Spain) using a radiant heated floor (RHF) coupled to an air-water heat pump (HP). Two cooling scenarios were studied over the summers of 2005 and 2006: natural ventilation + a shading screen (control system), and natural ventilation + a shading screen + an RHF (concrete) coupled to an air-water heat pump (i.e., in cooling mode; nominal power, 34.1 W m–2). Using the difference between the outside and inside air temperatures, it was concluded that at 0.5 m above the floor the RHF system reduced the temperature by 1.1°C in 2005 and 0.8°C in 2006. Both cooling scenarios were compared with other cooling technologies: the use of the natural ventilation + shading + RHF gave a smaller air temperature difference than fogging at a height equal to or lower than 0.5 m. A model based on the heat pump performance curves was constructed to predict its power consumption and good predictions of the variation over the day were obtained. The power consumption of the heat pump was 104.8 Wh m–2 d–1 (from 13:00 to 18:00 h) under our test conditions in Madrid. The RHF-HP system may only be appropriate for cooling greenhouses under certain circumstances, e.g., when growing high value crops or when cost is not a limiting factor, as its initial investment cost is about € 38 m–2.
Evaluation of production performance and carcass quality characteristics of boars immunised against gonadotropin-releasing hormone (GnRH) compared with physically castrated male, entire male and female pigs
Authors: Morales J. , Gispert M. , Hortos M. , Pérez J. , Suárez P. , Piñeiro C.
Published: November 2013

The objectives of this study were to assess the performance and carcass quality characteristics of boars immunised against gonadotropin-releasing hormone GnRH (IM) compared with physically castrated males (PM), entire males (EM) and entire female pigs (EF). For the study 288 crossbred (Large White × Landrace) pigs were used comprising four equal groups of 72 IM, 72 PM, 72 EM and 72 EF. The study period was from 74 days of age (31.2 ± 5.57 kg body weight; mean ± std. dev.) to slaughter at 172 days of age (107.7 ± 14.82 kg body weight). PM were physically castrated at 5 days of age and IM pigs were vaccinated with the GnRH vaccine Improvac® (Pfizer Animal Health) at 74 and 145 days of age (89.1 ± 15.93 kg body weight). Across the duration of the study period, growth rate was numerically highest in IM group and significantly higher than EF (P < 0.01). This was also reflected in respective slaughter weights. EM had the lowest feed:gain ratio (P < 0.001) followed by IM which had a lower ratio than both PM and EF. At slaughter, testes weights were reduced in IM by approximately 55% (P < 0.001) compared with EM. Fat content (backfat thickness and intramuscular fat) was higher and lean percentage of carcass lower in PM compared to all other groups (P < 0.05), with no differences between EF, EM and IM. Boar taint compounds, skatole and androstenone, were lower in IM pigs compared with EM (P < 0.05), and not differing from the concentrations measured in PM and EF. Immunisation of entire male pigs against GnRH allows improved feed efficiency compared with physical castrates with no detriment to carcass or meat quality.
Prediction of weight and yield of main lean cuts related to carcass weight in heavy pigs intended for Spanish high quality dry-cured ham
Authors: Daza A. , Latorre M. A. , López-Bote C. J.
Published: November 2013

The aim of this study was to evaluate the possibility of predicting the weight and yield (as % of carcass) of the main lean cuts related to carcass weight (CW) in pigs intended for Spanish dry-cured ham. A total of 98 Duroc × (Large White × Landrace) pigs were used. Simple regression equations were carried out to find the relations between CW (independent variable) and ham (H), foreleg (F), loin (L) and H+F+L weights and yields (dependent variables). Also, multiple regression equations were carried out to estimate the relations between these dependent variables and other size carcass characteristics (backfat thickness, carcass length, and ham length and perimeter). The best simple relationship between independent and dependent variables was obtained by means of linear functions. The CW explained 84%, 75%, 60% and 89% of the variability of H, F, L and H+F+L weights, respectively, whereas 10%, 10%, 0.15% and 14% of the variability of H, F, L and H+F+L percentages, respectively. The addition of the size carcass characteristics, as independent variables, to the prediction equations of H, F, L and H+F+L weights and yields improved the predictions. The simple and multiple regression equations calculated underestimated the dependent variables, but the mean prediction error and relative prediction error values were low, suggesting that the independent variables considered are good predictors of the dependent variables. It is concluded that CW is an easy and available measurement for industry to predict carcass lean cuts weights in pigs from genetic lines intended for Spanish dry-cured ham.
Short communication. The detection of Israeli Acute Paralysis virus (IAPV), fipronil and imidacloprid in professional apiaries are not related with massive honey bee colony loss in Spain
Authors: Garrido-Bailón E. , Martín-Hernández R. , Bernal J. , Bernal J .L. , Martínez-Salvador A. , Barrios L. , Meana J. A. , Higes M.
Published: November 2013

This study is presented in order to determine the presence and impact of some factors related with honeybee colony losses such as Israeli Acute Paralysis virus (IAPV) and certain pesticides. Samples (house worker bees and stored pollen from brood chamber) were selected from one hundred apiaries, half of them with a clear underpopulation, in accordance with region and time of the year. Total prevalence of IAPV either in spring or in autumn was 18% (CI95% = 9.9-26.0; p < 0.0001), no relationship between IAPV and depopulated colonies was established. Fipronil was only detected in two samples of stored pollen from asymptomatic colonies and imidacloprid was not detected in any sample. Like IAPV, neither fipronil nor imidacloprid appeared to be directly related with the generalized problem of colony death and honey bee losses in professional Spanish apiaries.
Variation of five major glucosinolate genes in Brassica rapa in relation to Brassica oleracea and Arabidopsis thaliana
Authors: Yang B. , Qiu D. , Quiros C. F.
Published: November 2013

Glucosinolates and their derivatives isothiocyanates are important secondary metabolites in the Brassicacea that has biological activity, such as cancer protecting and biofumigant properties. The putative orthologs of five major genes in the glucosinolate biosynthetic pathway, Bra.GSELONG.a, Bra.GSALK.a, Bra.CYP83B1, Bra.SUR1.a and Bra.ST5.a, were cloned from both cDNA and genomic DNA from different subspecies of Brassica rapa. Interspecies comparative analysis disclosed high conservation of exon number and size for GS-Elong, GS-Alk, GS-CYP83B1 and GS-ST5a among B. rapa, B. oleracea and A. thaliana. Splice site mutations caused the differences observed for exon numbers and sizes in GS-SUR1 among the three species. However, the exonic sequences were highly conserved for this gene. There were not major differences of intronic sizes among the three species for these genes, except for intron 1 for GS-Elong in two subspecies of B. rapa. The cloning of the putative orthologs of all these major genes involved in the glucosinolate biosynthesis pathway of B. rapa and sequence analysis provide a useful base for their genetic manipulation and functional analysis.
Computer aided selection in breeding programs using genetic algorithm in MATLAB program
Authors: Azimzadeh M. , Amiri R. , Davoodi-Bojd E. , Soltanian-Zadeh H. , Vahedi S. , Hoori M.
Published: November 2013

In plant and animal breeding, the best individuals are selected for the next breeding cycle based on the selection index computed from observed phenotypic values of several traits. However, in calculating the selection index, large amounts of data must be analyzed which is still performed by a calculator. This can cause imperfections in the breeding procedures. In this paper an automatic method for simulating a population under natural selection is proposed based on the selection operator of the genetic algorithms. The fitness function of the algorithm is a linear combination of the individual traits imported by the user. The algorithm generates both general and detailed scores of each trait for each labeled individual. The individuals are sorted with respect to their general scores and it is possible to extract individuals whose general scores are greater than a threshold defined by the user. The outlier individuals can also be eliminated. Moreover, for improved illustration and comparison, the individuals are displayed in a graph based on their index values. The proposed algorithm was applied to two distinct dataset and shown that results of the two methods coincide. The proposed method is automatic, fast, and free of human mistakes. Therefore, it is expected to improve the breeding procedures, especially when the numbers of individuals and traits are huge.
Defoliation frequency effects on winter forage production and nutritive value of different entries of Agropyron cristatum (L.) Gaertn
Authors: Abraham E. M. , Kyriazopoulos A. , Parissi Z. M. , Sklavou P. , Tsiouvaras C. N.
Published: November 2013

The objective of this study was to evaluate the effect of different defoliation frequencies on winter forage production and nutritive value of improved population of Agropyron cristatum (L.) Gaertn. Four entries, a) base population, b) selected plants from mass honeycomb selection (MHS), c) selected plants from pedigree honeycomb selection (PHS) and d) selected plants from pedigree honeycomb selection using the combined criterion CC = x¯2 (1 – CV) / CV [PHS (CC)] were tested under four defoliation frequencies: 1) frequent, 2) moderate, 3) infrequent and 4) control. Dry matter production under moderate defoliation treatment was 9% and 107% respectively higher than frequent and infrequent the first harvest year, while the second harvest year the corresponding percentages were 26% and 44%. The selected populations of A. cristatum consistently exceeded in herbage production the base population under all defoliation treatments during winter. Among the selected entries, [PHS (CC)] had consistently higher DM production compared to MHS and PHS for the two experimental years. The CP content was significantly higher, while NDF, ADF and ADL contents were lower in the increased defoliation frequency compared to the control in both harvest years. There were no significant differences of the nutritive value among the entries (P > 0.05). Generally, herbage production of the moderate defoliation frequency was more stable through the years with relatively high nutritive value.
Short communication. Phytophthora nicotianae, the causal agent of root and crown rot (Tristeza disease) of red pepper in La Vera region (Cáceres, Spain)
Authors: Rodríguez-Molina M. C. , Morales-Rodríguez M. C. , Palo Osorio C. , Palo Núñez E. , Verdejo Alonso E. , Duarte Maya M. S. , Picón-Toro J.
Published: November 2013

Root and crown rot (Tristeza disease) is an increasing problem for red pepper crop in La Vera region (Cáceres, western Spain). Field surveys were carried on in 2006 and 2007 to identify the causal agents of this disease. A Phytophthora species was isolated from diseased plants in most of the surveyed fields (27 of 36 in 2006 and 15 of 16 in 2007), while Verticillium spp. were not detected. Fifteen Phytophthora isolates were examined and identified as P. nicotianae, all of them were heterothalic isolates of mating type A2. Pathogenicity tests conducted on 'Jaranda' red pepper plants developed symptoms of wilt and root and crown rot, although disease severity differed significantly (P < 0.001) among isolates. Results indicate that P. nicotianae is the principal causal agent of the Tristeza disease of red pepper plants in La Vera region and this has several implications for the development of future disease management strategies. The host range of isolates from red pepper plants should be studied in order to establish suitable crop rotation in this region.
Short communication. Efficacy of phosphine as a fumigant against Rhynchophorus ferrugineus (Coleoptera: Curculionidae) in palms
Authors: Llácer E. , Jacas J. A.
Published: November 2013

The red palm weevil, Rhynchophorus ferrugineus (Olivier) (Coleoptera, Curculionidae), the major pest of palms in the Mediterranean, has mainly spread through movement of infested plants. The aim of this work was to determine the possibility of using aluminium phosphide in palms as a safe quarantine treatment against this pest. Laboratory tests were carried out on eggs, young and old larvae, pupae and adults of R. ferrugineus with different doses of Eurofume® and mortality was assessed. Fumigations of infested canary palms were carried out in a hermetic container and subsequently palms were carefully dissected and all R. ferrugineus specimens found, either dead or alive, were counted. Results suggest that a dose of 1.14 g aluminium phosphide m–3 for 3 days is enough to kill all stages of R. ferrugineus in an infested palm tree. Provided that applied dose of aluminium phosphide is not phytotoxic for palms, this treatment could significantly reduce at low cost the enormous risks that palm imports suppose worldwide.
Use of multinodal explants for micropropagation of Leucadendron ‘Safari Sunset’
Authors: Suárez E. , Pérez-Francés J. F. , Rodríguez-Pérez J. A.
Published: November 2013

Leucadendron 'Safari Sunset' is one of the most valuable Proteaceae cultivar, due to its economic importance as cutflower. In vitro tissue culture of this cultivar and others may offer a massive cloned plant production that permit to satisfy the market demand. Multinodal explants of Leucadendron 'Safari Sunset' were established in vitro on a half strength Murashige and Skoog medium supplemented with 2.2 µM benzylaminopurine (BAP). Various antioxidant treatments were used to reduce the presence of phenolic compounds in culture. No important differences in growth and multiplication between these treatments were detected during in vitro establishment and multiplication, but explants cultured on a medium with 1 g L–1 of polyvinylpyrrolidone (PVP) developed a higher number of buds in the establishment phase. Proliferation of axillary shoots was achieved with 0.88 µM BAP, being slightly higher on a medium with 2.2 µM BAP although the buds were deformed, showing abnormal leaves. The use of phytagel in this phase increased proliferation rate and shoot growth. Low percentages rooting were obtained when microcuttings were cultured on the same basal medium supplemented with several indole-3-butyric acid (IBA) concentrations. The best rooting percentage (37.5%) was obtained with 44.1 µM IBA. This work shows that micropropagation of L. 'Safari Sunset' is possible with multinodal explants, although is necessary to optimize the protocol for commercial applications.
Petrografia de zonas de alteração hidrotermal mesoproterozóicas do tipo Kuroko no Grupo Serra do Itaberaba (SP) e seu uso na exploração mineral
Authors: Pérez-Aguilar Annabel , Juliani Caetano , Monteiro Lena V.S
Published: November 2013

Na seqüência vulcano-sedimentar do Grupo Serra do Itaberaba, localizado na porção central da Faixa Ribeira, paleo-sistemas hidrotermais mesoproterozóicos se desenvolveram ao redor de pequenos corpos de andesitos/riodacitos. Estes sistemas foram responsáveis pela alteração hidrotermal de rochas ígneas e vulcanoclásticas básicas e intermediárias. Apesar da sobreposição de dois eventos metamórficos de grau médio e um de grau baixo podem ser reconhecidas diferentes zonas de alteração hidrotermal. Uma primeira e extensa zona de alteração clorítica (ZC1) foi sobreposta por zonas cloríticas restritas (ZC2), similares àquelas associadas a depósitos de metais de base do tipo Kuroko. Os produtos metamórficos da ZC1 são rochas que apresentam anfibólio(s) magnesiano(s) em diferentes proporções (rochas com cummingtonita/antofilita) e os da ZC2, clorita magnesiana (meta-clorititos). Estes produtos metamórficos são constituídos por associações minerais exóticas e podem ser usadas como rochas-guia para a exploração de depósitos de metais de base do tipo Kuroko em seqüências vulcano-sedimentares metamorfisadas.
Remoção de metais pesados em solução por zeólitas naturais: revisão crítica
Authors: Shinzato Mirian Chieko
Published: November 2013

Nesta síntese são discutidos os resultados de trabalhos publicados nos últimos anos referentes à aplicação das zeólitas naturais na remoção de metais pesados em solução. A seqüência de seletividade iônica, bem como os parâmetros associados à eficiência de adsorção e capacidade de troca catiônica (CTC), estão inteiramente relacionados à estrutura cristalina das zeólitas e às características químicas dos íons encontrados em solução. Cabe ressaltar que, algumas variáveis externas como temperatura, pH e concentração iônica inicial podem interferir no processo de remoção de metais, assim como na seqüência de seletividade iônica. De forma geral, íons com menor energia de hidratação possuem maior preferência pelos sítios de troca disponíveis nas estruturas das zeólitas. A eficiência de remoção de íons de maior energia de hidratação, por sua vez, pode ser controlada pela sua concentração na solução: quanto menor, melhor. Verifica-se, portanto, que as zeólitas naturais possuem grande potencial de aplicação em tratamentos de efluentes contaminados com metais pesados.
Unidades quaternárias e vegetação nativa de planície costeira e baixa encosta da Serra do mar no litoral norte de São Paulo
Authors: SOUZA Celia Regina de Gouveia , LUNA Graciele da Costa
Published: November 2013

Na zona costeira do Estado de São Paulo, apesar das fortes pressões sócioeconômicas para a utilização de seus recursos e espaços naturais, ainda podem ser encontrados importantes remanescentes de Mata Atlântica e ecossistemas associados, principalmente no Litoral Norte. Estes ecossistemas incluem os manguezais e todas as demais vegetações presentes nas planícies costeiras e baixas encostas da Serra do Mar (vegetação de restinga), as quais são caracterizadas pela estreita relação que guardam com o substrato sedimentar que recobrem. Este trabalho apresenta os resultados de mapeamentos realizados no Litoral Norte de São Paulo e tem os seguintes objetivos: atualizar os mapas do Quaternário costeiro realizados na década de 1970, realizar o mapeamento pioneiro das fitofisionomias de restinga descritas na Resolução Conama nº 07/1996, estabelecer as associações entre as Unidades Geológico-Geomorfológicas Quaternárias e essas fitofisionomias e calcular as porcentagens de supressão da vegetação nativa em relação à paisagem original na área de estudo.
Ocorrência do orvalho na cidade de São Paulo
Authors: ARMANI Gustavo , FUNARI Frederico Luiz , SALUM Sergio Torre
Published: November 2013

O presente trabalho analisa a ocorrência de dias com orvalho na cidade de São Paulo e a relaciona com as temperaturas do ar e do ponto de orvalho, bem como com as umidades relativa e absoluta do ar. Foram utilizados dados diários da Estação Meteorológica do Instituto de Astronomia, Geofísica e Ciências Atmosféricas (IAG) - USP, localizada no Parque Estadual Fontes do Ipiranga (PEFI), no período de 1958 a 2007. A partir de análises estatísticas de regressão linear e análise de variância (ANOVA), verificou-se, nestes 50 anos, aumento da frequência dos dias com orvalho, principalmente no outono, acompanhado de aumento da temperatura do ar e umidade absoluta e diminuição da umidade relativa.
Aqüíferos fraturados: uma revisão dos condicionantes geológicos e dos métodos de investigação
Authors: Fernandes Amélia João
Published: November 2013

A investigação detalhada dos condicionantes geológicos que regem a circulação de água em aqüíferos fraturados permite a elaboração de modelos conceituais os quais são imprescindíveis para um desenho adequado de testes hidráulicos e amostragens, cujos resultados, por sua vez, refinam os modelos conceituais. Este procedimento leva à previsão dos caminhos preferenciais de fluxo e assim à economia tanto de tempo como de recursos financeiros. No país ainda há pouca experiência no estudo de aqüíferos fraturados. Boa parte das investigações tem sido voltada à indicação de critérios para locação de poços e baseia-se na confrontação entre a capacidade específica ou vazão de poços e uma série de fatores (tais como lineamentos, litologias, compartimento topográfico, etc.) que, tradicionalmente, são considerados como sendo influentes sobre as produções. Recomenda-se aqui que os dados utilizados para a confrontação sejam apresentados na forma de distribuições acumuladas, pois a utilização de somente médias ou medianas, feita na maioria dos trabalhos, não é suficiente para separar populações de dados com comportamentos distintos, limitando a avaliação do alcance de resultados. Este tipo de estudo deveria constituir a análise preliminar do comportamento dos aqüíferos fraturados já que sugere as suas linhas gerais em escala de semi-detalhe ou regional. Mais recentemente e principalmente fora do país, têm sido desenvolvidos estudos que relacionam neotectônica e/ou campos de esforços atuais com a orientação de zonas de fraturas mais transmissivas, ou seja, com os caminhos preferenciais de fluxo. Estes têm concluído que tais fatores preponderam no controle sobre a circulação de água subterrânea. No entanto, a origem dos esforços que determinam a atitude das fraturas mais transmissivas ainda é assunto de debate e pode ter influências locais. Este trabalho apresenta uma síntese de fundamentos teóricos com relação a: fluxo de água subterrânea em meios fraturados, deformação rúptil e geração de fraturas extensionais, características geométricas das fraturas em função da litologia e da escala, e métodos diretos e indiretos de levantamento de fraturas. Além disso também apresenta uma análise de dados de poços com relação aos fatores que controlam o fluxo e indica métodos voltados à identificação dos caminhos preferenciais de circulação de água em meios fraturados.
Paternalism and Urban Reform
Authors: Olson Sherry
Published: November 2013

The papers introduced deal with changes in the condition of women in Canadian cities. These changes were closely associated with movements of charity and urban reform and they might better be regarded as "counter-reforms" that imposed a new social discipline. In age-sex structures presented for Montreal families and institutional "families" ht 1861, women can be identified as subjects and instruments of the new social "order."
Mortality Patterns and Public Health in Hamilton, Canada, 1900–14
Authors: Gagan Rosemary R.
Published: November 2013

In recent years a wide-ranging debate has focused on the origins and extent of the decline in mortality rates in Britain in the 18th century and in North America during the closing decades of the 19th century. Some historians suggest that the decrease was tied to a general improvement in living standards and in particular to better nutrition while others point to municipal public health measures carried out by vigilant medical health officers. This paper examines the experience of Hamilton, Ont., during a period of extreme urban and industrial expansion, 1900-14. The evidence, both qualitative and quantitative, suggests that these years were not a ''golden age" of public health: the health of Hamiltonions did not improve, and, in fact, mortality rates increased. Moreover, infants and children of the working class were the most obvious casualties of an inhospitable environment that hurt those least able to exert any degree of control over their circumstances. Public health was not a popular cause in the city, and as a consequence, much of the minimal progress that did occur was either fortuitous or the result of the exertions of one man, Dr James Roberts, the crusading medical health officer.
Post-War Trends in Canadian Housing Policy
Authors: Carroll Barbara Wake
Published: November 2013

Introduction Housing is an important urban policy area because it is an essential good, and because its visibility and durability mean that the quality and appearance of the housing stock shape our current and our future urban environments. This article analyzes the evolution of post-war Canadian housing policy, identifying three distinct but interrelated policy phases. The analysis suggests that the solutions, adopted by governments to meet the problems deemed to be central during one phase, have often created problems requiring different solutions in the subsequent period. The article concludes by identifying some of the, as yet, unresolved problems facing those who make housing policy in the current phase.
Landscapes of Victorian Hamilton
Authors: Peace Walter G.
Published: November 2013

"The City is often called the Birmingham of Canada, and though comparison with the world's great work-shop in the English midlands is presumptuous, it is not altogether unwarranted."
A Review on Ultrasound-Based Thyroid Cancer Tissue Characterization and Automated Classification
Authors: Acharya U. Rajendra , Swapna G. , Sree S. Vinitha , Molinari Filippo , Gupta Savita , Bardales Ricardo H. , Witkowska Agnieszka , Suri Jasjit S.
Published: November 2013

In this paper, we review the different studies that developed Computer Aided Diagnostic (CAD) for automated classification of thyroid cancer into benign and malignant types. Specifically, we discuss the different types of features that are used to study and analyze the differences between benign and malignant thyroid nodules. These features can be broadly categorized into (a) the sonographic features from the ultrasound images, and (b) the non-clinical features extracted from the ultrasound images using statistical and data mining techniques. We also present a brief description of the commonly used classifiers in ultrasound based CAD systems. We then review the studies that used features based on the ultrasound images for thyroid nodule classification and highlight the limitations of such studies. We also discuss and review the techniques used in studies that used the non-clinical features for thyroid nodule classification and report the classification accuracies obtained in these studies.
The role of mineral aerosols in shaping the regional climate of West Africa
Authors: Marcella Marc P. , Eltahir Elfatih A. B.
Published: November 2013

This article examines the role of mineral aerosols in the regional climate of West Africa. Analysis is completed by comparing two 30 year simulations using a regional climate model (RegCM3‐IBIS). The two simulations are identical in structure except one includes the representation of mineral aerosols via a fully coupled radiatively interactive dust emissions and aerosol tracer model; the other simulation does not. To discern the impact of dust on West Africa's climate, comparisons are made between the two simulations' surface climatology as well as atmospheric dynamics. It is found that RegCM3‐IBIS and its dust model perform well in simulating the temporal and spatial distributions of mineral aerosols over the Sahel and Sahara. Consistent with previous studies over the region, RegCM3‐IBIS simulates high‐dust loading over the region (aerosol optical depth of 0.5–1.1), which results in significant incident shortwave radiation attenuation (25–50 W/m2) and temperature cooling (0.5°C–1.25°C). Depending on the underlying surface brightness, the top of atmosphere net radiative forcing may be positive (bright desert surfaces) or negative (dark, vegetated surface) with important implications on surface temperature cooling. Here it is proposed that the effects of dust on West African rainfall are distinctly different across the ocean‐land border and the desert border region of the Sahel/Sahara. Nevertheless, in both regions, the change in rainfall is less than 10% of the total annual values. Therefore, this work concludes that the current, observed, dust loading over West Africa does not significantly affect rainfall via changes in the radiation budget. However, it is important to note that this work does not include mineral aerosol effects on sea surface temperatures, which may be significant in influencing the results.
Environmental controls over methane emissions from bromeliad phytotelmata: The role of phosphorus and nitrogen availability, temperature, and water content
Authors: Kotowska Martyna M. , Werner Florian A.
Published: November 2013

Tank bromeliads are common epiphytic plants throughout neotropical forests that store significant amounts of water in phytotelmata (tanks) formed by highly modified leafs. Methanogenic archaea in these tanks have recently been identified as a significant source of atmospheric methane. We address the effects of environmental drivers (temperature, tank water content, sodium phosphate [P], and urea [N] addition) on methane production in anaerobically incubated bromeliad slurry and emissions from intact bromeliad tanks in montane Ecuador. N addition ≥ 1 mg g−1 had a significantly positive effect on headspace methane concentrations in incubation jars while P addition did not affect methane production at any dosage (≤ 1 mg g−1). Tank bromeliads (Tillandsia complanata) cultivated in situ showed significantly increased effluxes of methane in response to the addition of 26 mg N addition per tank but not to lower dosage of N or any dosage of P (≤ 5.2 mg plant−1). There was no significant interaction between N and P addition. The brevity of the stimulatory effect of N addition on plant methane effluxes (1–2 days) points at N competition by other microorganisms or bromeliads. Methane efflux from plants closely followed within‐day temperature fluctuations over 24 h cycles, yet the dependency of temperature was not exponential as typical for terrestrial wetlands but instead linear. In simulated drought, methane emission from bromeliad tanks was maintained with minimum amounts of water and regained after a short lag phase of approximately 24 h. Our results suggest that methanogens in bromeliads are primarily limited by N and that direct effects of global change (increasing temperature and seasonality, remote fertilization) on bromeliad methane emissions are of moderate scale.
Redistribution of forest carbon caused by patch blowdowns in subalpine forests of the Southern Rocky Mountains, USA
Authors: Wohl Ellen
Published: November 2013

Patch blowdowns varying in size from 0.1 to 33 ha affected several areas in Rocky Mountain National Park, Colorado, USA, during the winter of 2011–2012. These blowdowns resulted in substantial redistribution of forest carbon by snapping and uprooting trees, thereby increasing instream wood recruitment, recruitment of dead wood to the forest floor, and exposure of organic soil on uprooted tree plates. Estimates of carbon redistribution at five sites in Rocky Mountain National Park range as high as 308 Mg C/ha in high‐severity patches to 106 Mg C/ha in low‐severity patches, of which typically 10–30% is soil C and the remainder is downed wood. Masses of carbon redistributed from living to dead biomass at high‐severity sites represent a substantial portion of average total biomass in old‐growth subalpine forests in the region. Consequently, the potential for increasing frequency and/or severity of blowdowns under a warming climate represents a significant potential source of terrestrial carbon to the atmosphere. The majority of this carbon is in the form of downed wood that becomes a carbon source to the atmosphere, although interactions between downed wood and river processes can locally increase carbon storage in floodplain soil. Predictions of changes in precipitation and wind patterns, and associated changes in wildfire and insect infestation, suggest that blowdowns may become more common in future in the Southern Rockies, but the consequences for carbon dynamics depend on site‐specific interactions between blowdowns and other processes such as floodplain storage of organic matter.
Ionospheric redistribution during geomagnetic storms
Authors: Immel T. J. , Mannucci A. J.
Published: November 2013

The abundance of plasma in the daytime ionosphere is often seen to grow greatly during geomagnetic storms. Recent reports suggest that the magnitude of the plasma density enhancement depends on the UT of storm onset. This possibility is investigated over a 7year period using global maps of ionospheric total electron content (TEC) produced at the Jet Propulsion Laboratory. The analysis confirms that the American sector exhibits, on average, larger storm time enhancement in ionospheric plasma content, up to 50% in the afternoon middle‐latitude region and 30% in the vicinity of the high‐latitude auroral cusp, with largest effect in the Southern Hemisphere. We investigate whether this effect is related to the magnitude of the causative magnetic storms. Using the same advanced Dst index employed to sort the TEC maps into quiet and active (Dst<−100 nT) sets, we find variation in storm strength that corresponds closely to the TEC variation but follows it by 3–6h. For this and other reasons detailed in this report, we conclude that the UT‐dependent peak in storm time TEC is likely not related to the magnitude of external storm time forcing but more likely attributable to phenomena such as the low magnetic field in the South American region. The large Dst variation suggests a possible system‐level effect of the observed variation in ionospheric storm response on the measured strength of the terrestrial ring current, possibly connected through UT‐dependent modulation of ion outflow.
Core electron temperature and density in the innermost Saturn's magnetosphere from HF power spectra analysis on Cassini
Authors: Schippers P. , Moncuquet M. , Meyer‐Vernet N. , Lecacheux A.
Published: November 2013

We analyze the large‐scale structures of electrons in Saturn's inner magnetosphere equatorial plane, from 2.8 to about 10 Saturnian radii (RS). The electron total density and core temperature are obtained using the quasi‐thermal noise spectroscopy method, based on the HF power spectra measurements acquired with the Cassini/Radio and Plasma Wave Science instrument around the local plasma frequency from July 2004 to May 2012. The results reveal the existence of two regions. An inner region around Enceladus orbit (3–5 RS) is characterized by a high variability of the electron density, an increasing core temperature profile (∝ R2.7), and a strong correlation of the density and temperature. An outer region, beyond 5 RS, is characterized by a decrease of the density (∝ R−4.19) and a slight decrease of the core temperature with distance from the planet (∝ R−0.3). The electron temperature profile is consistent with heating by thermalization of the electrons with the ions in the inner region and with thermalization balanced by cooling due to outward radial transport in the outer region. In the outer region, we identify a local time asymmetry of both the density and the temperature: higher core temperatures are observed in the nightside while higher densities are observed in the dayside. We finally estimate the plasma scale height from a few orbits at quasi‐constant altitude. We find that it varies as R1.53 inside Dione's orbit and displays a bell‐shaped profile between 7 and 9 RS, consistent with the maximum in the corotation lag previously observed.
Inferring fault rheology from low‐frequency earthquakes on the San Andreas
Authors: Beeler N. M. , Thomas Amanda , Bürgmann Roland , Shelly David
Published: November 2013

Families of recurring low‐frequency earthquakes (LFEs) within nonvolcanic tremor (NVT) on the San Andreas fault in central California show strong sensitivity to shear stress induced by the daily tidal cycle. LFEs occur at all levels of the tidal shear stress and are in phase with the very small, ~400 Pa, stress amplitude. To quantitatively explain the correlation, we use a model from the existing literature that assumes the LFE sources are small, persistent regions that repeatedly fail during shear of a much larger scale, otherwise aseismically creeping fault zone. The LFE source patches see tectonic loading, creep of the surrounding fault which may be modulated by the tidal stress, and direct tidal loading. If the patches are small relative to the surrounding creeping fault then the stressing is dominated by fault creep, and if patch failure occurs at a threshold stress, then the resulting seismicity rate is proportional to the fault creep rate or fault zone strain rate. Using the seismicity rate as a proxy for strain rate and the tidal shear stress, we fit the data with possible fault rheologies that produce creep in laboratory experiments at temperatures of 400 to 600°C appropriate for the LFE source depth. The rheological properties of rock‐forming minerals for dislocation creep and dislocation glide are not consistent with the observed fault creep because strong correlation between small stress perturbations and strain rate requires perturbation on the order of the ambient stress. The observed tidal modulation restricts ambient stress to be at most a few kilopascal, much lower than rock strength. A purely rate dependent friction is consistent with the observations only if the product of the friction rate dependence and effective normal stress is ~ 0.5 kPa. Extrapolating the friction rate strengthening dependence of phyllosilicates (talc) to depth would require the effective normal stress to be ~50 kPa, implying pore pressure is lithostatic. If the LFE source is on the order of tens of meters, as required by the model, rate‐weakening friction rate dependence (e.g., olivine) at 400 to 600°C requires that the minimum effective pressure at the LFE source is ~ 2.5 MPa.
Spectral calibration and validation of the Cross‐track Infrared Sounder on the Suomi NPP satellite
Authors: Strow L. Larrabee , Motteler Howard , Tobin David , Revercomb Henry , Hannon Scott , Buijs Henry , Predina Joe , Suwinski Lawrence , Glumb Ronald
Published: November 2013

The Cross‐track Infrared Sounder (CrIS) radiometric accuracy depends upon accurate frequency calibration. Here we present both the prelaunch calibration of the sensor and the minor modifications needed to this calibration post launch. Particular emphasis is given to ensuring that all nine detectors on each of the three CrIS focal planes are on a common frequency scale with accurate off‐axis apodization corrections. Radiances from the current operational algorithm have a frequency calibration that is stable to 2 ppm, although this work suggests that the CrIS instrument is capable of a frequency calibration stability of better than 1 ppm.
Neutron background environment measured by the Mars Science Laboratory's Dynamic Albedo of Neutrons instrument during the first 100 sols
Authors: Jun I. , Mitrofanov I. , Litvak M. L. , Sanin A. B. , Kim W. , Behar A. , Boynton W. V. , DeFlores L. , Fedosov F. , Golovin D. , Hardgrove C. , Harshman K. , Kozyrev A. S. , Kuzmin R. O. , Malakhov A. , Mischna M. , Moersch J. , Mokrousov M. , Nikiforov S. , Shvetsov V. N. , Tate C. , Tret'yakov V. I. , Vostrukhin A.
Published: November 2013

The Dynamic Albedo of Neutrons (DAN) instrument on board Mars Science Laboratory has been operating successfully since the landing and has been making measurements regularly along Curiosity's traverse at the surface. DAN measures thermal (E < 0.4 eV) and epithermal neutrons (0.4 eV < E < ~1 keV) while operating in two different modes: active and passive. The active mode uses a pulsed neutron generator (PNG) to study the geological characteristics of the subsurface. In the passive mode, DAN measures the background neutron environment. This paper presents results of measurements in the passive mode from landing through to sol 100 and provides an interpretation of the data based on extensive Monte Carlo simulations. The main observations are summarized as follows: (1) the thermal neutron counts vary strongly along the rover traverse while the epithermal counts do not show much variation; (2) the neutrons from the Multi‐Mission Radioisotope Thermoelectric Generator (MMRTG) are a larger contributor to the DAN passive data than the Galactic Cosmic Ray (GCR)‐induced neutrons; (3) for the MMRTG neutrons, both the thermal and the epithermal counts increase as a function of the subsurface water content; (4) on the other hand, for the GCR‐induced neutrons, the thermal counts increase but the epithermal counts decrease as a function of the subsurface water content; and (5) relative contributions by the MMRTG and GCR to the DAN thermal neutron counts at the Rocknest site, where the rover was stationed from sol 59 to sol 100, are estimated to be ~60% and ~40%, respectively.
Regulation of bacterial metabolic activity by dissolved organic carbon and viruses
Authors: Xu Jie , Jing Hongmei , Sun Mingming , Harrison Paul J. , Liu Hongbin
Published: November 2013

The regulation of bacterial metabolic activity by viruses and dissolved organic carbon (DOC) was examined using natural microbial communities in three treatments (active viruses, inactive viruses, and virus free) at two contrasting coastal sites (pristine vs. eutrophic) with substantial differences in environmental conditions during the wet and dry seasons. Our results showed that net growth rates and production of bacterioplankton were reduced primarily by viruses via repressing metabolically active bacteria with high nucleic acid (HNA) content which had a high capacity for incorporating carbon, while bacterial respiration was primarily regulated by DOC lability. The quality of organic matter played a more important role in regulating bacterial growth efficiency (BGE) than the supply of organic matter in eutrophic coastal waters. The lack of HMW‐DOC and high carbon demand in the virus‐free treatment resulted in a significant increase in cell‐specific bacterial respiration, which was responsible for the lowest bacterial growth efficiency among the three treatments. The presence of viruses did not necessarily lower bacterial growth efficiency since virus‐induced mortality alleviated bacterial carbon demand and enhanced carbon cycling. Virus‐induced mortality was greater in relatively pristine waters than eutrophic waters, likely since the high supply of substrates alleviated the pressure of viral infection, through extracellular proteases produced by bacteria, which might result in the hydrolytic destruction or modification of viral capsids. An important implication of our results was that the input of riverine DOC and nutrients improved bacterial metabolic activity by alleviating virus‐induced mortality of bacteria in estuarine and coastal waters.
The influence of climate change on recent peat accumulation patterns of Distichia muscoides cushion bogs in the high‐elevation tropical Andes of Colombia
Authors: Benavides Juan C. , Vitt Dale H. , Wieder R. Kelman
Published: November 2013

Extensive cushions of Distichia muscoides found at high elevations in the Andes form deep deposits of peat and function as peatland. The location of Distichia peatlands at the highest elevations makes them susceptible to the effects of global change including global warming. Accumulation rates of organic matter are the key function of peatland ecosystems and are highly susceptible to changes in climate. This study used 210Pb chronologies to infer the recent dynamics of three Distichia muscoides peatlands located above 4000 m in elevation. Chronological markers from dated volcanic eruptions were correlated to the 210Pb chronologies of Distichia peat and validated the 210Pb chronologies. Changes in 210Pb activity with depth indicated rapid accumulation in recent times. Organic matter had a mean accumulation rate of 1400 g m−2 yr−1 during the past 10 years, with values well above the observed regional accumulation rate of 300–400 g m−2 yr−1. The same pattern was observed in peat accretion rates, with growth rates of 1–2 cm per year during the last 10 years. Cushion plants engineer their own environment, allowing the system to be less susceptible to direct changes in climate. However, the high rates of peat accretion in recent times may be originated from increasing temperatures and excess water from nearby glacier melt. However, glaciers are predicted to disappear during the next 20 years in the northern Andes, reducing water inputs in tropical high‐elevation ecosystems.
Transparent Ultrathin Oxygen‐Doped Silver Electrodes for Flexible Organic Solar Cells
Authors: Wang Wei , Song Myungkwan , Bae Tae‐Sung , Park Yeon Hyun , Kang Yong‐Cheol , Lee Sang‐Geul , Kim Sei‐Yong , Kim Dong Ho , Lee Sunghun , Min Guanghui , Lee Gun‐Hwan , Kang Jae‐Wook , Yun Jungheum
Published: November 2013

An effective method for depositing highly transparent and conductive ultrathin silver (Ag) electrodes using minimal oxidation is reported. The minimal oxidation of Ag layers significantly improves the intrinsic optical and structural properties of Ag without any degradation of its electrical conductivity. Oxygen‐doped Ag (AgOx) layers of thicknesses as low as 6 nm exhibit completely 2D and continuous morphologies on ZnO films, smaller optical reflections and absorbances, and smaller sheet resistances compared with those of discontinuous and granular‐type Ag layers of the same thickness. A ZnO/AgOx/ZnO (ZAOZ) electrode using an AgOx (O/Ag = 3.4 at%) layer deposited on polyethylene terephthalate substrates at room temperature shows an average transmittance of 91%, with a maximum transmittance of 95%, over spectral range 400−1000 nm and a sheet resistance of 20 Ω sq−1. The average transmittance value is increased by about 18% on replacing a conventional ZnO/Ag/ZnO (ZAZ) electrode with the ZAOZ electrode. The ZAOZ electrode is a promising bottom transparent conducting electrode for highly flexible inverted organic solar cells (IOSCs), and it achieves a power conversion efficiency (PCE) of 6.34%, whereas an IOSC using the ZAZ electrode exhibits a much lower PCE of 5.65%.
The Effect of Polymer Chain Alignment and Relaxation on Force‐Induced Chemical Reactions in an Elastomer
Authors: Beiermann Brett A. , Kramer Sharlotte L. B. , May Preston A. , Moore Jeffrey S. , White Scott R. , Sottos Nancy R.
Published: November 2013

Simultaneous measurements of mechanical response, optical birefringence, and fluorescence signal are acquired in situ during tensile testing of a mechanophore‐linked elastomeric polymer. Mechanical stress, deformation, and polymer chain alignment are correlated with force‐induced chemical reaction of the mechanophore. The mechanochemically responsive polymer under investigation is spiropyran‐ (SP‐) linked poly(methyl acrylate) (PMA). Force‐driven conversion (activation) of SP to its merocyanine (MC) form is indicated by the emergence of a fluorescence signal with 532 nm light incident on the sample. Increasing rate of tensile deformation leads to an increase in both stress and SP‐to‐MC conversion, indicating a positive correlation between macroscopic stress and activation. Simultaneously collected birefringence measurements reveal that rapid mechanophore activation occurs when maximum polymer chain alignment is reached. It is found that SP‐to‐MC conversion in PMA requires both a sufficient level of stress and adequate orientation of the polymer chains in the direction of applied force.