bluuebunny/crossref_metadata_2025 huggingface dataset:
From Tula Chico to Chichén Itzá: Implications of the Epiclassic Sculpture of Tula for the Nature and Timing of Tula-Chichén Contact
Authors: Jordan Keith
Published: December 2016

In the last four decades, a number of archaeologists and art historians have posited that “Toltec” Chichén Itzá (Yucatán, Mexico) flourished during the ninth and tenth centuries A.D. They argued that because the “Toltec” style in Yucatán predated the Tollan phase at Tula (Hidalgo, Mexico), most of the style features shared between the cities originated with the Maya. Here, I examine the relevance of the Epiclassic relief sculpture of Tula Chico for the timing and nature of contact between Tula and Chichén Itzá. The presence of reliefs of reclining figures in clear “Toltec” style at Tula Chico in contexts predating their occurrence at Chichén Itzá suggests that claims for a predominantly Maya origin for that style stand in need of revision. Such a rethinking is supported by other fragmentary images from Tula Chico (eagles and Venus symbols), as well as by new studies of ceramic materials and chronology at Chichén Itzá. It is clear that Tula was an active participant in whatever interactions led to similar visual arts at Chichén Itzá, and at least some of the shared iconography has temporal priority at Tula.
A First Report of Variscite Tairona Artifacts (A.D. 1100-1600) from the Sierra Nevada de Santa Marta, Colombia, and Its Implications for Precolumbian exchange Networks in the Region
Authors: Acevedo Natalia , Weber Marion , García-Casco Antonio , Proenza Joaquín Antonio , Sáenz Juanita , Cardona Agustín
Published: December 2016

Archaeometric analyses (Raman Spectroscopy Analysis, X-Ray Diffraction, and Electron Microprobe Analysis) of greenstone beads of the precolumbian Tairona culture (A.D. 1100–1600) of the Sierra Nevada de Santa Marta, Colombia, have revealed that they are made of variscite-group minerals. These beads were curated at the Museo del Oro, Bogotá, and the Archaeology Laboratory of the Universidad del Norte, Barranquilla. Variscite minerals of the variscite-strengite series are rare in nature, and therefore provenance data of source material are useful for the development of intercultural influence models. The abundance of this rare material in prehistoric Colombian collections strongly indicates not only that this material had important symbolic and prestige value for ancient Tairona societies (Nahuange and Tairona periods) but also that these societies participated in ancient trade routes, including, at least, the Andes of present-day Colombia and Venezuela, and the southern Caribbean coast.
Vidas Heterotópicas, Vidas Infames, Vidas Outras: um percurso antropológico no pensamento de Foucault
Authors: Naidin Julia
Published: December 2016

Proclamada em As Palavras e as Coisas, a tese foucaultiana de que o sujeito não é evidente recebe diferentes tratamentos nos movimentos do pensamento do filósofo. “O sujeito” sempre foi tratado como um problema e como um lugar de problematização, de diagnóstico da genealogia das forças, em constantes agenciamentos. Foucault pensa a antropologia a partir da crise epistêmica da modernidade para reposicionar os limites e as possibilidades do sujeito moderno em sua relação com seu mundo. Apresenta-se, através de breves existências que emergem e ousam contra o poder, a importância de uma nova imaginação para criar outras formas de vida. O que Foucault nos diz através de vidas intempestivas as extrapola e nos mostra a explicitação de experiências radicais em outros modos de ser. Outros corpos, outros desejos, novas audácias, outros modos de ser e de lutar, via corpo, arte, loucura, pensamento crítico, ação política. Em todas essas formas tão diferentes, identificamos um lugar de ruptura em comum. “Estranhos poemas” é como Foucault se refere a experiências de vidas irredutíveis, sobre as quais pretendemos apontar um olhar. Defendemos a ideia de que o tema do trabalho sobre si, entendido como uma demanda pela criação de gestos ativos e transgressores direcionados a dar nova forma e sentido ao próprio modo de ser — a questão da subjetividade na obra de Foucault.
Ler, traduzir, ensinar
Authors: Tannus Muchail Salma
Published: December 2016

A experiência de traduzir textos filosóficos (no caso, especificamente textos de Michel Foucault) permite o levantamento de reflexões sobre analogias possíveis entre o trabalho de tradução, por um lado e, por outro, a leitura e o ensino filosóficos. Também conduz à hipótese de um parentesco possível entre a tradução e a redação de apresentações e prefácios.
Foucault e a arqueologia do impensado: paragens fenomenológicas
Authors: De Freitas da Silva Claudinei Aparecido
Published: December 2016

Foucault inscreve a fenomenologia num movimento de desconstrução da racionalidade. Esse registro será arqueologicamente operado em As Palavras e as Coisas como signo de uma subversão radical vinda a lume pela “modernidade” em franca oposição à “idade clássica” da cultura no Ocidente, tendo como pano de fundo algo que se revela aquém do cogito: o “impensado”. O que emerge, aqui, é a dimensão mais profunda da razão e da epistémê, ou seja, a camada subterrânea pela qual o acontecimento e a historicidade operam sob a superfície do saber. É essa nova figura que entra em cena, por exemplo, via diferentes discursos como a “alienação” (marxismo), o “inconsciente” (psicanálise) ou o “irrefletido” (fenomenologia). No tocante à tradição fenomenológica, a admissão da Lebenswelt (Husserl), do Dasein (Heidegger), do cogito pré-reflexivo (Sartre) ou da Carne (Merleau-Ponty), o “impensado” transfigura a região privilegiada pela qual o pensamento sempre retorna. Ora, se é patente que Foucault circunscreve essa operação como uma posição de princípio a ser superada, não deixa, contudo, de ser plausível o quanto ele parece selar uma espécie de “aliança à distância” com o espírito fenomenológico. O “retorno às coisas mesmas”, em termos foucaultianos, investe-se de outro estatuto, liberando a história de todo pressuposto teleológico, num regresso ao coração do presente. É esse agenciamento que permite, sob certos aspectos, situar a obra de Foucault próxima a de Merleau-Ponty, à maneira de uma reflexão marginal, “transgressora”, abrindo, pois, uma zona de sombra, “impensada”, em sua infraestrutura última. Tal é a “paragem” interpretativa a ser, aqui, perseguida.
Michel Foucault e a analítica da finitude
Authors: Barbosa Lopes Rodrigo
Published: December 2016

Em Les mots et les choses, Foucault (1996) procedeu, por meio da pesquisa arqueológica, a uma investigação acerca da constituição histórica dos saberes sobre o homem. Isso significa dizer que, na verdade, não se tratava de uma história das Ciências Humanas, mas de uma investigação na qual elas fossem tomadas como instituições, enquanto práticas ou discursos que definem o homem como objeto de um saber possível, a partir principalmente das ciências empíricas — biologia, economia política e filologia — que o analisam nas relações fundamentais com a vida, o trabalho e a linguagem; e, por outro lado, a reflexão filosófica que o admite como sujeito e fundamento de todas essas positividades. Com o objetivo de elaborar uma arqueologia das Ciências Humanas, caracterização a mais geral de Les mots et les choses, Foucault ponderou que o objetivo pretendido por essa análise não poderia decorrer simplesmente de uma história das ideias ou das ciências. Na verdade, o nível arqueológico de análise permitiu descobrir e avaliar os sistemas de saber subjacentes às três grandes fases do pensamento ocidental, convencionalmente chamadas pelo filósofo de Renascença, a Época Clássica e a Modernidade. No caso da Modernidade, Foucault a definiu como a Idade do Homem e procurou demonstrar de que modo nesta épistémè o homem é, ao mesmo tempo, sujeito e objeto total de seu próprio saber. Este é o problema ao qual se volta a crítica de Foucault à estrutura antropológico-humanista do pensamento moderno, que passamos a analisar neste artigo admitindo, para tanto, a indicação de um estudo dos modos de problematização e a centralidade que a analítica da finitude ocupa nesta tarefa filosófica de diagnosticar a atualidade.
THE CONCENTRATION ANALYSIS OF AGRICULTURAL SECTOR IN TURKEY: ARE THERE ANY CHANGES IN THE PERIOD 2010 - 2015?
Authors: GENCLER Funda , TURKEKUL Berna
Published: December 2016

Despite the regional policies taken into agenda in all development plans inTurkey, inter-regional imbalances could not be resolved. Dynamics of the regionmust be examined in detail to resolve the inter-regional imbalance problems andin the light of these data differing policies should be developed in each specificregion. Thus, detailed studies are needed on basis of regions and provinces. It iscritically important to establish the priorities in agro-food production for utilizingthe resources effectively and for competing against others like in Turkey whoseagro-food sector is relatively dominant both in terms of population andemployment. Therefore, it is aimed to determine the sectorial priorities inagriculture for using geographic concentration coefficient analysis in agriculturalsub-sectors in Turkey.Inthiscontext, considering the Nomenclature of TerritorialUnits for Statistics (NUTS) - Level 2 (26 regions), the weight of employmentstructure of rural areas in Turkey will be analyzed for each region. Locationcoefficients will be calculated for each sector by comparing the population that isliving in rural areas and working in agricultural, industrial and service sectors,withsector values of Turkey’s rural areas. Later,agricultural sector will be analyzed onthe basis of sub-sector for Level 2 regions. These analyses will be done for both2010 and 2015 to compare the differences during this period. The reason of thesediversities between mentioned time periods will be clarified by utilizing theagricultural policy applications in Turkey.
THE USE OF UREASE INHIBITOR FERTILIZERS (AGROTAIN) AND THEIR EFFECT ON CEREAL CROPS AND COTTON YIELD
Authors: GIANNOULIS Kyriakos D. , BARTZIALIS Dimitrios , SKOUFOGIANNI Elpiniki , DANALATOS Nicholaos G.
Published: December 2016

Many commercial compounds exist that promise the increasing efficiency of ureafertilizers by inhibiting urease activity in soils. Such a compound gaining incommercial importance in the last decades is N-(n-butyl) thiophosphoric triamide,broadly known with its registered trade name of “Agrotain”. In this paper, theeffect of nitrogen fertilizer dressings using Agrotain versus conventional (urea)fertilizers was studied under field conditions. In particular, the effect of threedifferent nitrogen dressings using conventional N-fertilizers and Agrotain wasinvestigated on the growth and final yield of (rainfed) durum wheat, and (irrigated)maize and cotton, grown on a fertile clay loamy soil in Velestino (Thessaly plain)area in central Greece in the year 2015. It was demonstrated that all three cropsfertilized Agrotain obtained greater chlorophyll contents and reached significantlyhigher biomass and grain yields comparing to the crops receiving traditionalnitrogen fertilization, obviously due to the more effective nitrogen release anduptake by the crops.Therefore, application of urease inhibitor fertilizers, such asAgrotain, might reduce nitrogen application dressings, reduce N-losses andnitrification, and their introduction to existing crop rotations is highly advisable.
WAYS TO PRESERVE SOIL FERTILITY BASED ON AGROLANDSCAPE
Authors: LINKINA Anna , NEDICOVA Elena
Published: December 2016

As it is known, fertility is the most important property of soils to meet the needs ofplants in nutrient elements, moisture or air and to provide conditions for theirnormal life. It is clear that yield of crops depends on soil quality. That is why thepreservation of fertility is an important task in the implementation of agriculturalproduction. Agrolandscape systems based on environmental based should beintroduced in agriculture to solve the problem of preventing the degradation ofsoils, reducing water and wind erosion. Principles and methodology of landscapeplanning can be successfully adopted in farming systems that combine highenvironmental and economic indicators. During the years with unfavorableconditions such as drought or excessive moisture in farms with adaptive farmingthe yield is 30 % higher than in agricultural enterprises with the traditional farmingsystem. The article discussed that the minimum value of the environmentstabilizingfarm land agrolandscapes should not exceed 40% of the total land. Theconducted experiments proved that the humus content in the households underconsideration was increased by 0.24%. Average crop yields in the years withunfavorable weather conditions in the test farm (Kantemirovsky District, Voronezhregion) are the following: grains 29 dt/ ha, sunflower 24 dt/ha, and forKantemirovsky District, on average, 19.4 dt/ha and 17 dt/ha respectively. Stabilityof agrolandscapes depends on correlation between sustainable and destruct lands.Percentage ratio of agricultural lands for the sustainable agrolandscapes isdetermined.
APPLICATION OF MYCORRHIZAL FUNGI IN LANDSCAPE TURFGRASS ESTABLISHMENT UNDER ARID AND SEMIARID ENVIRONMENTS
Authors: AL-KARAKI Ghazi N.
Published: December 2016

Turf grasses are considered an integral part of landscape ecological systemsworldwide which provide functional, recreational and aesthetic benefits to societyand the environment. In arid and semiarid regions (e.g., Mediterranean region),turf grass is usually grown under harsh and unfavorable growing conditions withlow rainfall and high rates of evapotranspiration as well as in soils with nutrientdeficiencies. Hence, growing turf grass in these regions becomes dependent onapplication of high levels of fertilizers as well as on excessive use of irrigationwater, resulting in an environmental pollution. Therefore, it is important that turfgrass plantations are managed in a sustainable way to reduce the impact of turfgrass cultivation on ecosystems while maintaining healthy and productive turfthrough using such practices as mycorrhizal fungi technology. The application ofmycorrhizal fungi technology is an option that can benefit both agronomic planthealth and ecosystems. Mycorrhizae confer numerous benefits to host plantsincluding improved plant growth, mineral nutrition, water uptake, tolerance todiseases and stresses such as drought and salinity. The aims of this paper were toreview how mycorrhizal fungi might play a role in enhancing landscape turfestablishment and productivity in arid and semiarid regions and to evaluate theeffectiveness of application of commercial mycorrhizal inoculum to enhance plantgrowth and survival under field conditions. Field experiment was conducted tostudy the effects of arbuscular mycorrhiza (AM) fungi inoculation on water useefficiency and establishment of a landscape turf. The results showed that turf grassinoculated with AM fungi used water more efficiently, established lawn morequickly and had more biomass than uninoculated turf grass. The conclusions of thispaper indicated the potential of mycorrhiza inoculation in improving the fastestablishment of turf landscape plants under arid and semiarid environments.
SPECTROSCOPIC CHARACTERIZATION OF HUMIC SUBSTANCES OF ANTHROPOGENIC SOILS DERIVED FROM TERRA ROSSA
Authors: BENSA Aleksandra , MILOŠ Boško , JURKOVIĆ BALOG Nikolina , TORIĆ Ivana
Published: December 2016

The aim of the study was spectroscopic characterization of humic substances andevaluation of humus quality of anthropogenic soils derived from Terra Rossa. Thestudy was conducted on 15 soil samples collected from top-soil horizon of olivegroves in Middle Dalmatia (Croatia). Total organic carbon was determinedaccording to Walkley-Black method (1934) and humic substances isolationfollowing procedure given by Schnitzer (1982). Spectroscopic characterization ofisolated humic substances was carried out by measuring absorbance in VIS spectralrange 400-700 nm and optical indices (Q4/6, E4/6) were calculated. SOC content intop-soil samples varied from 1.45% to 4.21% with mean value of 2.98%. Theabsorption spectrum showed monotonous decrease of absorbance from 400 to 700nm for all samples. The optical indices E4/6 and Q4/6 varied from 3.58 to 5.05 andfrom 3.91 to 5.04, respectively and indicated differences of humus quality. Theoptical index below 4, which implies a high quality of humus, was determined insix samples. The low humus quality (optical index above 4) was determined inother nine samples. The SOC content has significant positive correlation withoptical indices Q4/6 and E4/6. Soils with higher organic carbon content have lowerhumus quality.
POPULATION DYNAMICS OF DAGGER NEMATODE ATTACKING ALEPPO PINE TREE IN JORDAN
Authors: IRSHAID Leena , ALBANNA Luma , SADDER Monther
Published: December 2016

The temporal distribution of an isolate of the dagger nematode attacking Aleppopine, Pinus halepensis grown in AL-Jubiha area in Jordan was investigated. A totalof eighteen samples were collected from rhizosphere about 30 cm deep in soil and50 cm away from the trunk of a Pine tree showing decline and brown needles asone sample per month starting in November 2014 until April 2016. Cobb sievingand gravity methods were used for the nematode isolation from rhizosoil. The soiltype is clay with 51 % porosity. The monthly air temperature, precipitation, andrelative humidity were monitored and tabulated. The results showed that thenumber of recovered nematodes ranged from 2 individuals /100 cm3 to 88individuals /100cm3 of rhizosoil. The lowest number was recovered on Octoberwhereas the highest numbers were recovered in December. The reason of declinein numbers may be due to a raise in temperature. The highest number may be dueto favorable temperature and soil moisture. The difference of nematode in samemonth in two different years may be due to the temperature and precipitations.
MILK PRICES IN THE EUROPEAN UNION BY 2025 AND PROJECTION OF THE PROFITABILITY OF MILK PRODUCTION IN POLAND IN 2020
Authors: SKARŻYNSKA Aldona , JABŁOŃSKI Konrad
Published: December 2016

In Europe, more than 70% of milk production falls on the European Unioncountries. Among the largest milk producers in the EU, Poland ranks fourth. Theabolition of quotas for milk production and increase in supply to the marketcontributed to the decline in milk prices. The aim of the study is to determine theimpact of the rate of change in prices of agricultural inputs and changes in milkyield of cows and milk prices on the profitability of milk production in Polandprojected for 2020. The sample consisted of 169 farms which in 2014-2015 kept anaverage of 27 cows. In 2015, the index of the profitability of milk productionamounted to 130.7%, and in comparison to 2014 it decreased by 18.4 percentagepoint. The results projection for 2020 show an improvement in milk yield of cows(by 12.4%) and milk prices (by 15.4%). Stronger growth in the revenues (by29.1%) than the cost of keeping cows (by 15.5%) will stimulate the improvementof economic results. The index of the profitability of milk production will increaseby 15.4 percentage points, and income per cow by 73.3%. This means that it willbe at a level similar to 2014. Research shows that fluctuations in selling prices ofmilk are possible (+/-8.7%). Despite this, the milk production will continue to beprofitable. Results of this study are consistent with the projection of the EuropeanCommission, which provides for an increase in milk prices and milk production inthe EU.
OPTIMIZATION MODEL OF VEGETABLE PRODUCTION STRUCTURE IN SERBIA
Authors: PAUNOVIĆ Tamara , NOVKOVIĆ Nebojša , CERANIĆ Slobodan
Published: December 2016

Indoor vegetable production, or production in greenhouses enables year-roundproduction, the combined off-season production, greater control of diseases andpests, but also significantly greater production value compared to open field cropproduction. The aim of this paper is to determine such a structure of vegetableproduction in greenhouses that will realize the maximum financial resultconsidering various biotechnological, production, technological and marketconstraints. In this context, model for optimization of vegetable productionstructure in greenhouses was formulated, and at the same time, model analysis andmodel solving was made using the method of linear programming and the softwarepackage "LINDO". Model was analyzed in three variants, depending on theselected optimality criterion: maximization of net income (variant I), maximizationof economics of production (variant II), minimum deviation from the extremevalues (variant III). The results show the optimal sowing - planting structure for allthree variants of defined model; the participation of certain groups of crops in theoverall sowing - planting structure; the required number of working hours in theobserved months of working peaks; that variant I achieves the highest net incomefor defined limiting conditions (4.216.867 din); that variant II achieves the highesteconomics of production (2,25), while variant I and variant III generate the sameeconomics of production (2,20).Moreover, variant I realized the greatest valueofproduction (7.080.300 din), but also the highest variable (2.863.433 din) and totalcosts (3.263.433 din). Published data of various experimental paperworks wereused for this analysis, as well as data from the accounting records of the farms anddata of Statistical Office of the Republic of Serbia.
IMPACT OF LAND SIZE ON PRODUCTIVITY, INCOME AND PROFITS FROM PEPPER CULTIVATION IN SRI LANKA
Authors: SIVARAJAH Ponniah , WICKRAMASINGHE Randima
Published: December 2016

Pepper is an important spice crop grown in Matale District of Sri Lanka, forexports and domestic consumption. Varieties of pepper grown are Sri Lankan localvariety and ‘Panniyur’. Pepper production had shown variations over the years dueto poor management and low productivity. This study analyzed and compared theproduction levels and costs, income and profitability of pepper cultivation amongsmall and large scale pepper farmers. A stratified random sample of 120 farmers,consisting of 76 small famers (<5 acre farms) and 44 large farmers (>5 acre farms)were selected for study. A pre-tested questionnaire was used for data collection.Descriptive statistics and mean comparisons were performed. The average extentof land under pepper cultivation was significantly different (P<0.01) with 3.49acres for small farms and 8.85 acres for large farms, and 66% of lands were underlocal pepper varieties. Fertilizer was the only input applied by both group offarmers. The mean yield of pepper was 636 kgs and 560 kgs per acre for small andlarge farms respectively and did not differ significantly. Mean comparison showedthat there was a significant difference (P<0.01) in cost of production, income frompepper sales and profits from pepper between small and large farmers. There wereno significant differences in farm gate prices received for raw and processedpepper by small and large scale farmers. It can be concluded that there issignificant differences between small and large scale pepper farmers in the extentcultivated, incomes received, cost of production and profits earned, while there isno differences in the prices received for raw and processed pepper.
SENSITIVITY ANALYSIS OF AQUACROP EVAPOTRANSPIRATION TO WEATHER STATION DISTANCE
Authors: SIMONIS Claire , TYCHON Bernard , GELLENSMEULENBERGHS Françoise
Published: December 2016

Water balance calculation is essential for reliable agricultural management, and theactual evapotranspiration (ET) is the most complicated balance term to estimate. Inagriculture, the most common method used is based on Penman-Monteith referenceevaporation is determined from weather conditions for an unstressed grass cover,further multiplied by crop specific and soil water availability coefficients to obtainthe actual evapotranspiration. This approach is also used in the AquaCrop model.This model has proven to be accurate when all weather data are locally available.However, in many cases, weather data can’t be collected on the site due to thelimited number of stations and the vast region covered by each of them. Instead,data are often collected at many kilometers from the study site. The question wewant to study is: how does evapotranspiration accuracy evolves with respect toweather station distance? A winter wheat plot in Lonzée (Belgium) was studiedduring the 2014-2015 agricultural seasons. Actual evapotranspiration wassimulated with AquaCrop thanks to the weather data collected at 3 differentdistances from the study site: on the site (data collected by a fluxnet station), 20km, 50 km and 70km from the site. The non-on-site weather data were derivedfrom spatially interpolated 10 km grid data. These results were then compared tothe fluxnet station evapotranspiration measurements to assess the impact of theweather station distance. Substantial differences, which were found between thefour cases, evoking the importance of assimilating satellite derived ET products(e.g. MSG) into AquaCrop.
“Since both of us are using antiretrovirals, we have been supportive to each other”: facilitators and barriers of pre‐exposure prophylaxis use in heterosexual HIV serodiscordant couples in Kisumu, Kenya
Authors: Patel Rena C , Stanford‐Moore Gaelen , Odoyo Josephine , Pyra Maria , Wakhungu Imeldah , Anand Keerthana , Bukusi Elizabeth A , Baeten Jared M , Brown Joelle M
Published: December 2016

Introduction

Since 2015, the World Health Organization recommends pre‐exposure prophylaxis (PrEP) for all persons at substantial risk for HIV, including HIV‐uninfected partners in serodiscordant relationships in resource‐limited settings. As PrEP moves from clinical trials to real‐world use, understanding facilitators of and barriers to PrEP initiation and adherence is critical to successful PrEP implementation and rollout.

Methods

We conducted 44 in‐depth individual or couple interviews with 63 participants (30 without HIV and 33 with HIV) enrolled in the Partners Demonstration Project in Kisumu, Kenya, between August and September 2014. The semi‐structured interviews discussed the following: 1) perceived advantages and disadvantages of antiretroviral therapy (ART)/PrEP; 2) reasons for accepting or declining ART/PrEP and 3) influence of prevention of transmission to partner or infant on ART/PrEP use. Transcripts from the interviews were iteratively analyzed using inductive content analysis.

Results

Our study identified three key factors that may facilitate initiation of PrEP in this population. First, participants using PrEP felt reduced stress and increased trust in their HIV serodiscordant relationships. Second, greater community‐wide knowledge of PrEP was thought to likely increase PrEP acceptance. Third, greater education and counselling by providers on PrEP use was also considered to likely increase the adoption of PrEP. We also identified three key barriers to initiation of and adherence to PrEP. First, most participants who declined PrEP expressed doubts about the relative additional effectiveness of PrEP in combination with other prevention tools. Second, perceived stigma related to PrEP use was an important barrier to PrEP initiation. Third, many struggled with overcoming perceived side effects or logistical challenges of taking daily PrEP, particularly when they themselves were not ill.

Conclusions

Leveraging the facilitators and overcoming barriers to PrEP uptake may enhance the successful rollout of PrEP among HIV serodiscordant couples in Kenya and other areas in sub‐Saharan Africa, thereby reducing sexual transmission of HIV. Further research focused on how best to provide counselling on combination HIV prevention tools in the context of PrEP use is a crucial next step to delivering PrEP.
Cellular encoding of Cy dyes for single-molecule imaging
Authors: Leisle Lilia , Chadda Rahul , Lueck John D , Infield Daniel T , Galpin Jason D , Krishnamani Venkatramanan , Robertson Janice L , Ahern Christopher A
Published: December 2016

A general method is described for the site-specific genetic encoding of cyanine dyes as non-canonical amino acids (Cy-ncAAs) into proteins. The approach relies on an improved technique for nonsense suppression with in vitro misacylated orthogonal tRNA. The data show that Cy-ncAAs (based on Cy3 and Cy5) are tolerated by the eukaryotic ribosome in cell-free and whole-cell environments and can be incorporated into soluble and membrane proteins. In the context of the Xenopus laevis oocyte expression system, this technique yields ion channels with encoded Cy-ncAAs that are trafficked to the plasma membrane where they display robust function and distinct fluorescent signals as detected by TIRF microscopy. This is the first demonstration of an encoded cyanine dye as a ncAA in a eukaryotic expression system and opens the door for the analysis of proteins with single-molecule resolution in a cellular environment.
Regulation of signaling directionality revealed by 3D snapshots of a kinase:regulator complex in action
Authors: Trajtenberg Felipe , Imelio Juan A , Machado Matías R , Larrieux Nicole , Marti Marcelo A , Obal Gonzalo , Mechaly Ariel E , Buschiazzo Alejandro
Published: December 2016

Two-component systems (TCS) are protein machineries that enable cells to respond to input signals. Histidine kinases (HK) are the sensory component, transferring information toward downstream response regulators (RR). HKs transfer phosphoryl groups to their specific RRs, but also dephosphorylate them, overall ensuring proper signaling. The mechanisms by which HKs discriminate between such disparate directions, are yet unknown. We now disclose crystal structures of the HK:RR complex DesK:DesR from Bacillus subtilis, comprising snapshots of the phosphotransfer and the dephosphorylation reactions. The HK dictates the reactional outcome through conformational rearrangements that include the reactive histidine. The phosphotransfer center is asymmetric, poised for dissociative nucleophilic substitution. The structural bases of HK phosphatase/phosphotransferase control are uncovered, and the unexpected discovery of a dissociative reactional center, sheds light on the evolution of TCS phosphotransfer reversibility. Our findings should be applicable to a broad range of signaling systems and instrumental in synthetic TCS rewiring.
Biogenesis of phased siRNAs on membrane-bound polysomes in Arabidopsis
Authors: Li Shengben , Le Brandon , Ma Xuan , Li Shaofang , You Chenjiang , Yu Yu , Zhang Bailong , Liu Lin , Gao Lei , Shi Ting , Zhao Yonghui , Mo Beixin , Cao Xiaofeng , Chen Xuemei
Published: December 2016

Small RNAs are central players in RNA silencing, yet their cytoplasmic compartmentalization and the effects it may have on their activities have not been studied at the genomic scale. Here we report that Arabidopsis microRNAs (miRNAs) and small interfering RNAs (siRNAs) are distinctly partitioned between the endoplasmic reticulum (ER) and cytosol. All miRNAs are associated with membrane-bound polysomes (MBPs) as opposed to polysomes in general. The MBP association is functionally linked to a deeply conserved and tightly regulated activity of miRNAs – production of phased siRNAs (phasiRNAs) from select target RNAs. The phasiRNA precursor RNAs, thought to be noncoding, are on MBPs and are occupied by ribosomes in a manner that supports miRNA-triggered phasiRNA production, suggesting that ribosomes on the rough ER impact siRNA biogenesis. This study reveals global patterns of cytoplasmic partitioning of small RNAs and expands the known functions of ribosomes and ER.
How ants send signals in saliva
Authors: Knaden Markus
Published: December 2016

Adult ants use saliva to transfer juvenile hormone and other chemical signals to their larvae.
A new Cu(TiBNx) alloy film for boosting the per-watt illuminance of high power LEDs
Authors: Lin Chon-Hsin
Published: December 2016

In this study, a new Cu(TiBN
x
) alloy film has been explored and utilized as a flexible heat dissipation layer for the substrate of high power LEDs to boost their per-watt illuminance by reducing the thermal resistance and increasing the thermal conductivity of the substrate. The new film is a Cu-alloy seed layer fabricated by co-sputtering Cu and TiB in an N2 atmosphere on a Ta/polyimide (Ta/PI) substrate. The film was then annealed at 340 °C for 1 h without noticeable Cu oxide formation around the film-substrate interface. The new film exhibits low resistivity, high thermal conductivity and low thermal resistance, rendering a substantially higher per-watt illuminance for LEDs that utilize the film as their additional heat dissipation layer. The experimental results gained in the study appear to confirm the new Cu(TiBN
x
) film as a good candidate material, at least, for boosting the per-watt illuminance of high power LEDs.
Assessing ionospheric response during some strong storms in solar cycle 24 using various data sources
Authors: Habarulema John Bosco , Katamzi Zama Thobeka , Sibanda Patrick , Matamba Tshimangadzo Merline
Published: December 2016

We present an analysis of a regional ionospheric response during six strong storms (−200 nT ≤Dst≤−100 nT) that occurred in 2012 for the geographic latitudinal coverage of 10°S–40°S within a longitude sector of 10°E–40°E. Although these storms occurred during the same solar activity period and were all coronal mass ejection driven, their impacts and associated features on the ionosphere have been found different due to different contributing factors to their driving mechanisms. With the exception of one case, the rest of the storm periods were characterized by positive storm effects during the main and (or) recovery phases with varying physical mechanisms including low‐latitude electrodynamics, neutral composition changes, and traveling ionospheric disturbances (TIDs). The common result to all the analyzed strong storms was the presence of large‐scale TIDs during the storm main phases. Using total electron content data derived from the Global Navigational Satellite System (GNSS) observations and radio occultation (RO) electron density data on a regional scale, we have attempted to investigate meridional and vertical propagation of TIDs simultaneously during the strong storms. We have showed that it is possible to identify vertical motion of TIDs using RO data in cases when equatorward TIDs, as revealed by GNSS total electron content data, are present. RO results were compared to ionosonde data, and both data sources gave vertical velocities below 100 m/s of the associated TIDs.
Scalings for the Alfvén‐cyclotron instability: Linear dispersion theory and hybrid particle‐in‐cell simulations
Authors: Gary S. Peter , Fu Xiangrong , Cowee Misa M. , Winske Dan , Liu Kaijun
Published: December 2016

The Alfvén‐cyclotron instability is driven by an ion temperature anisotropy such that T⊥/T|| >1 where ⊥ and || denote directions perpendicular and parallel to a uniform background magnetic field Bo, respectively. The computations presented here consider a model of a magnetized, homogeneous, collisionless plasma. Two representations of the proton velocity distribution are considered: a single bi‐Maxwellian and a magnetospheric‐like configuration of two components, a more dense, relatively cool, isotropic component and a less dense, relatively hot, bi‐Maxwellian component which drives the instability. Only wave propagation parallel to Bo is considered. Using numerical solutions of the full kinetic linear dispersion equation, concise analytic expressions for the scaling of the dimensionless maximum instability growth rate and the corresponding dimensionless real frequency are derived as functions of three dimensionless variables: the hot proton temperature anisotropy, the relative hot proton density, and the hot proton β||. Furthermore, using one‐dimensional hybrid particle‐in‐cell simulations of this same instability, a third relation for the scaling of the maximum amplitude of the dimensionless fluctuating magnetic field energy density is derived.
LEOPARD: A grid‐based dispersion relation solver for arbitrary gyrotropic distributions
Authors: Astfalk Patrick , Jenko Frank
Published: December 2016

Particle velocity distributions measured in collisionless space plasmas often show strong deviations from idealized model distributions. Despite this observational evidence, linear wave analysis in space plasma environments such as the solar wind or Earth's magnetosphere is still mainly carried out using dispersion relation solvers based on Maxwellians or other parametric models. To enable a more realistic analysis, we present the new grid‐based kinetic dispersion relation solver LEOPARD (Linear Electromagnetic Oscillations in Plasmas with Arbitrary Rotationally‐symmetric Distributions) which no longer requires prescribed model distributions but allows for arbitrary gyrotropic distribution functions. In this work, we discuss the underlying numerical scheme of the code and we show a few exemplary benchmarks. Furthermore, we demonstrate a first application of LEOPARD to ion distribution data obtained from hybrid simulations. In particular, we show that in the saturation stage of the parallel fire hose instability, the deformation of the initial bi‐Maxwellian distribution invalidates the use of standard dispersion relation solvers. A linear solver based on bi‐Maxwellians predicts further growth even after saturation, while LEOPARD correctly indicates vanishing growth rates. We also discuss how this complies with former studies on the validity of quasilinear theory for the resonant fire hose. In the end, we briefly comment on the role of LEOPARD in directly analyzing spacecraft data, and we refer to an upcoming paper which demonstrates a first application of that kind.
A damped Newton variational inversion method for SAR wind retrieval
Authors: Jiang Zhuhui , Li Yuanxiang , Yu Fangjie , Chen Ge , Yu Wenxian
Published: December 2016

The variational inversion for synthetic aperture radar (SAR) wind retrieval can take all sources' errors into account, but its iterative computation is very time consuming. For the wind vectors, (u, v) components are commonly used for variational inversion, but they are not intuitive for practical applications. In this paper, we modify the decomposition of wind vectors in the cost function into wind speed and wind direction and adopt the damped Newton method (DNVAR) to solve the cost function. Experimental results on simulated data show that DNVAR can effectively reduce background wind vector errors. Additionally, the average number of iterations is reduced drastically compared to prior arts. Furthermore, a detailed comparison between direct SAR wind retrieval (DIRECT) and DNVAR is performed. Simulations reveal that the DNVAR errors are smaller than the background wind vector errors in all considered cases. Thus, DNVAR could be employed to retrieve SAR sea surface wind. For practical applications, when the background wind speed is within moderate and high wind speed range, DNVAR has higher accuracy and is thus preferred. Otherwise, both DNVAR and DIRECT are feasible, considering the unknown actual errors of both background wind vectors and geophysical model function. Experimental results on Envisat/advanced synthetic aperture radar data show that the wind speed accuracy of DIRECT is largely affected by the background wind direction errors, but DNVAR can reduce the wind direction errors with minor effect on the wind speed errors in comparison with the background wind errors.
Dominance of pollutant aerosols over an urban region and its impact on boundary layer temperature profile
Authors: Talukdar Shamitaksha , Jana Soumyajyoti , Maitra Animesh
Published: December 2016

Collocated measurements of aerosol optical depth (AOD) and black carbon at different wavelengths over Kolkata, an urban region in eastern India, have been used to calculate aerosol single‐scattering albedo (SSA). The wavelength dependence of SSA and AOD has been presented to discriminate the aerosol types over this highly populated metropolitan area. The spectral pattern shows that SSA decreases with wavelength for most of the time in a year and corresponding Ångström coefficient is greater than unity. These optical properties indicate the dominance of fine‐mode pollutant particles over the city. The temperature lapse rate profile within the surface boundary layer has been found to be significantly influenced by the heating effect of fine‐mode pollutants, and consequently, the growth of the convective processes in the lower troposphere is notably affected. In addition, a back trajectory analysis has also been presented to indicate that transported air masses can have significant impact on spectral pattern of SSA.
Intrawave sand suspension in the shoaling and surf zone of a field‐scale laboratory beach
Authors: Brinkkemper J. A. , de Bakker A. T. M. , Ruessink B. G.
Published: December 2016

Short‐wave sand transport in morphodynamic models is often based solely on the near‐bed wave‐orbital motion, thereby neglecting the effect of ripple‐induced and surface‐induced turbulence on sand transport processes. Here sand stirring was studied using measurements of the wave‐orbital motion, turbulence, ripple characteristics, and sand concentration collected on a field‐scale laboratory beach under conditions ranging from irregular nonbreaking waves above vortex ripples to plunging waves and bores above subdued bed forms. Turbulence and sand concentration were analyzed as individual events and in a wave phase‐averaged sense. The fraction of turbulence events related to suspension events is relatively high (∼50%), especially beneath plunging waves. Beneath nonbreaking waves with vortex ripples, the sand concentration close to the bed peaks right after the maximum positive wave‐orbital motion and shows a marked phase lag in the vertical, although the peak in concentration at higher elevations does not shift to beyond the positive to negative flow reversal. Under plunging waves, concentration peaks beneath the wavefront without any notable phase lags in the vertical. In the inner‐surf zone (bores), the sand concentration remains phase coupled to positive wave‐orbital motion, but the concentration decreases with distance toward the shoreline. On the whole, our observations demonstrate that the wave‐driven suspended load transport is onshore and largest beneath plunging waves, while it is small and can also be offshore beneath shoaling waves. To accurately predict wave‐driven sand transport in morphodynamic models, the effect of surface‐induced turbulence beneath plunging waves should thus be included.
100 nm Thin‐Film Solid‐Composite Electrolyte for Lithium‐Ion Batteries
Authors: Chen Xubin , Vereecken Philippe M.
Published: December 2016

A thin‐film composite electrolyte (CE) with thickness of only 100 nm is fabricated for the first time. The conductivity of the solid electrolyte is 2 × 10−7 S cm−1 which corresponds to a cell resistance of only 50 Ω cm2 at this thickness. The electrolyte is composed of a nanoporous thin film, a lithium salt, and a polymer, and is fabricated by a two‐step approach. First, a porous SiOxCyHz film is deposited on the electrode substrate, then the porous structure is filled with a polyethylene glycol (PEG)‐LiX mixture by spin‐coating. The filling ratio of the mesoporous SiOxCyHz is as high as 90% with less than 1% remaining porosity, as determined from ellipsometric porosimetry. The effect of the anion, X−, of the LiX salt as well as the molecular weight of the PEG on the Li+ ion conductivity of the CE is investigated. The CE with smaller anion and with lower molecular weight PEG yields the highest conductivity. A functional Li/CE/TiO2 battery is built for demonstration purposes.
Photo‐Cross‐Linked Dual‐Responsive Hollow Capsules Mimicking Cell Membrane for Controllable Cargo Post‐Encapsulation and Release
Authors: Liu Xiaoling , Appelhans Dietmar , Wei Qiang , Voit Brigitte
Published: December 2016

Multifunctional and responsive hollow capsules are ideal candidates to establish highly sophisticated compartments mimicking cell membranes for controllable bio‐inspired functions. For this purpose pH and temperature dual‐responsive and photo‐cross‐linked hollow capsules, based on silica‐templated layer‐by‐layer approach by using poly(N‐isopropyl acrylamide)‐block‐polymethacrylate) and polyallylamine, have been prepared to use them for the subsequent and easily available post‐encapsulation process of protein‐like macromolecules at room temperature and pH 7.4 and their controllable release triggered by stimuli. The uptake and release properties of the hollow capsules for cargos are highly affected by changes in the external stimuli temperature (25, 37, or 45 °C) and internal stimuli pH of the phosphate‐containing buffer solution (5.5 or 7.4), by the degree of photo‐cross‐linking, and the size of cargo. The photo‐cross‐linked and dual stimuli‐responsive hollow capsules with different membrane permeability can be considered as attractive material for mimicking cell functions triggered by controllable uptake and release of different up to 11 nm sized biomolecules.
Analysis of flow and mixing in screw elements of corotating twin‐screw extruders via SPH
Authors: Eitzlmayr Andreas , Matić Josip , Khinast Johannes
Published: December 2016

Due to its meshless nature, the smoothed particle hydrodynamics method (SPH) provides high potential for the simulation of free‐surface flows and mixing in complex geometries. We used SPH to analyze the flow inside five typical screw elements of corotating twin‐screw extruders, two conveying elements, two kneading elements and a mixing element. Our results show conveying capabilities, pressure generation and power input for various operation states, completely and partially filled. We conducted a detailed mixing analysis based on tracer particles, which yielded the time evolution of the intensity of segregation for different tracers. From that, we determined exponential mixing rates, which describe the relative decrease of the intensity of segregation per screw revolution and characterize the mixing performance in different operation states. This provides valuable input information for simplified models of extruders, which are relevant to industrial applications and can significantly contribute to the efficient design, optimization and scale‐up of extruders. © 2017 American Institute of Chemical Engineers AIChE J, 63: 2451–2463, 2017
Metabolomic data suggest regulation of black howler monkey (Alouatta pigra) diet composition at the molecular level
Authors: Amato Katherine R. , Ulanov Alexander , Ju Kou‐San , Garber Paul A.
Published: December 2016

In addition to macronutrients, foods consist of a complex set of chemical compounds that can influence dietary selectivity and consumer physiology. Metabolomics allow us to describe this complexity by quantifying all small molecules, or metabolites, in a food item. In this study we use GC‐MS based metabolomics to describe the metabolite profiles of foods consumed by one population of Mexican black howler monkeys (Alouatta pigra) over a 10‐month period. Our data indicate that each food exhibited a distinct metabolite profile, and the average weekly intake of metabolites such as neochlorogenic acid and serotonin (5‐hydroxytryptamine) was correlated with the consumption of certain plant parts. We speculate that these patterns result in temporal changes in howler monkey physiology such as food retention time. In contrast, variation in the weekly intake of metabolites such as oxalic acid was 70% less than variation in the concentration of the same metabolites across food items, suggesting that howler monkeys regulated the intake of these metabolites, possibly to avoid physiological consequences such as kidney stone formation. Finally, seasonal variation in the consumption of individual nutrient and non‐nutrient metabolites were correlated with changes in the relative abundances of associated gut microbial taxa, implying indirect effects of food item metabolites on howler monkey nutritional ecology that likely drive foraging decisions. While additional research is needed to validate these findings, the patterns we report serve as important baseline data for understanding the effects of plant metabolites on the food choice in primates.