Allochronic speciation, secondary contact, and reproductive character displacement in periodical cicadas (Hemiptera: Magicicada spp.): genetic, morphological, and behavioural evidence.

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Cooley, J R; Simon, C; Marshall, D C; Slon, K; Ehrhardt, C

2001-03-01

Periodical cicadas have proven useful in testing a variety of ecological and evolutionary hypotheses because of their unusual life history, extraordinary abundance, and wide geographical range. Periodical cicadas provide the best examples of synchronous periodicity and predator satiation in the animal kingdom, and are excellent illustrations of habitat partitioning (by the three morphologically distinct species groups), incipient species (the year classes or broods), and cryptic species (a newly discovered 13-year species, Magicicada neotredecim). They are particularly useful for exploring questions regarding speciation via temporal isolation, or allochronic speciation. Recently, data were presented that provided strong support for an instance of allochronic speciation by life-cycle switching. This speciation event resulted in the formation of a new 13-year species from a 17-year species and led to secondary contact between two formerly separated lineages, one represented by the new 13-year cicadas (and their 17-year ancestors), and the other represented by the pre-existing 13-year cicadas. Allozyme frequency data, mitochondrial DNA (mtDNA), and abdominal colour were shown to be correlated genetic markers supporting the life-cycle switching/allochronic speciation hypothesis. In addition, a striking pattern of reproductive character displacement in male call pitch and female pitch preference between the two 13-year species was discovered. In this paper we report a strong association between calling song pitch and mtDNA haplotype for 101 individuals from a single locality within the M. tredecim/M. neotredecim contact zone and a strong association between abdomen colour and mtDNA haplotype. We conclude by reviewing proposed mechanisms for allochronic speciation and reproductive character displacement.

Geographic body size variation in the periodical cicadas Magicicada: implications for life cycle divergence and local adaptation.

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Koyama, T; Ito, H; Kakishima, S; Yoshimura, J; Cooley, J R; Simon, C; Sota, T

2015-06-01

Seven species in three species groups (Decim, Cassini and Decula) of periodical cicadas (Magicicada) occupy a wide latitudinal range in the eastern United States. To clarify how adult body size, a key trait affecting fitness, varies geographically with climate conditions and life cycle, we analysed the relationships of population mean head width to geographic variables (latitude, longitude, altitude), habitat annual mean temperature (AMT), life cycle and species differences. Within species, body size was larger in females than males and decreased with increasing latitude (and decreasing habitat AMT), following the converse Bergmann's rule. For the pair of recently diverged 13- and 17-year species in each group, 13-year cicadas were equal in size or slightly smaller on average than their 17-year counterparts despite their shorter developmental time. This fact suggests that, under the same climatic conditions, 17-year cicadas have lowered growth rates compared to their 13-years counterparts, allowing 13-year cicadas with faster growth rates to achieve body sizes equivalent to those of their 17-year counterparts at the same locations. However, in the Decim group, which includes two 13-year species, the more southerly, anciently diverged 13-year species (Magicicada tredecim) was characterized by a larger body size than the other, more northerly 13- and 17-year species, suggesting that local adaptation in warmer habitats may ultimately lead to evolution of larger body sizes. Our results demonstrate how geographic clines in body size may be maintained in sister species possessing different life cycles. © 2015 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2015 European Society For Evolutionary Biology.

A Possible Population-Driven Phase Transition in Cicada Chorus

International Nuclear Information System (INIS)

Gu Siyuan; Jin Yuliang; Zhao Xiaoxue; Huang Jiping

2009-01-01

We investigate the collective synchronization of cicada chirping. Using both experimental and phenomenological numerical techniques, here we show that the onset of a periodic two-state acoustic synchronous behavior in cicada chorus depends on a critical size of population N c = 21, above which a typical chorus state appears periodically with a 30 second-silence state in between, and further clarify its possibility concerning a new class of phase transition, which is unusually driven by population. This work has relevance to acoustic synchronization and to general physics of phase transition. (general)

Urbanization disrupts latitude-size rule in 17-year cicadas.

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Beasley, DeAnna E; Penick, Clint A; Boateng, Nana S; Menninger, Holly L; Dunn, Robert R

2018-03-01

Many ectotherms show a decrease in body size with increasing latitude due to changes in climate, a pattern termed converse Bergmann's rule. Urban conditions-particularly warmer temperatures and fragmented landscapes-may impose stresses on development that could disrupt these body size patterns. To test the impact of urbanization on development and latitudinal trends in body size, we launched a citizen science project to collect periodical cicadas ( Magicicada septendecim ) from across their latitudinal range during the 2013 emergence of Brood II. Periodical cicadas are long-lived insects whose distribution spans a broad latitudinal range covering both urban and rural habitats. We used a geometric morphometric approach to assess body size and developmental stress based on fluctuating asymmetry in wing shape. Body size of rural cicadas followed converse Bergmann's rule, but this pattern was disrupted in urban habitats. In the north, urban cicadas were larger than their rural counterparts, while southern populations showed little variation in body size between habitats. We detected no evidence of differences in developmental stress due to urbanization. To our knowledge, this is the first evidence that urbanization disrupts biogeographical trends in body size, and this pattern highlights how the effects of urbanization may differ over a species' range.

Allee effect in the selection for prime-numbered cycles in periodical cicadas.

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Tanaka, Yumi; Yoshimura, Jin; Simon, Chris; Cooley, John R; Tainaka, Kei-ichi

2009-06-02

Periodical cicadas are well known for their prime-numbered life cycles (17 and 13 years) and their mass periodical emergences. The origination and persistence of prime-numbered cycles are explained by the hybridization hypothesis on the basis of their lower likelihood of hybridization with other cycles. Recently, we showed by using an integer-based numerical model that prime-numbered cycles are indeed selected for among 10- to 20-year cycles. Here, we develop a real-number-based model to investigate the factors affecting the selection of prime-numbered cycles. We include an Allee effect in our model, such that a critical population size is set as an extinction threshold. We compare the real-number models with and without the Allee effect. The results show that in the presence of an Allee effect, prime-numbered life cycles are most likely to persist and to be selected under a wide range of extinction thresholds.

Exploring the Role of Habitat on the Wettability of Cicada Wings.

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Oh, Junho; Dana, Catherine E; Hong, Sungmin; Román, Jessica K; Jo, Kyoo Dong; Hong, Je Won; Nguyen, Jonah; Cropek, Donald M; Alleyne, Marianne; Miljkovic, Nenad

2017-08-16

Evolutionary pressure has pushed many extant species to develop micro/nanostructures that can significantly affect wettability and enable functionalities such as droplet jumping, self-cleaning, antifogging, antimicrobial, and antireflectivity. In particular, significant effort is underway to understand the insect wing surface structure to establish rational design tools for the development of novel engineered materials. Most studies, however, have focused on superhydrophobic wings obtained from a single insect species, in particular, the Psaltoda claripennis cicada. Here, we investigate the relationship between the spatially dependent wing wettability, topology, and droplet jumping behavior of multiple cicada species and their habitat, lifecycle, and interspecies relatedness. We focus on cicada wings of four different species: Neotibicen pruinosus, N. tibicen, Megatibicen dorsatus, and Magicicada septendecim and take a comparative approach. Using spatially resolved microgoniometry, scanning electron microscopy, atomic force microscopy, and high speed optical microscopy, we show that within cicada species, the wettability of wings is spatially homogeneous across wing cells. All four species were shown to have truncated conical pillars with widely varying length scales ranging from 50 to 400 nm in height. Comparison of the wettability revealed three cicada species with wings that are superhydrophobic (>150°) with low contact angle hysteresis (<5°), resulting in stable droplet jumping behavior. The fourth, more distantly related species (Ma. septendecim) showed only moderate hydrophobic behavior, eliminating some of the beneficial surface functional aspects for this cicada. Correlation between cicada habitat and wing wettability yielded little connection as wetter, swampy environments do not necessarily equate to higher measured wing hydrophobicity. The results, however, do point to species relatedness and reproductive strategy as a closer proxy for predicting

Energetics of emergence in the cicadas, Cyclochila australasiae and Abricta curvicosta (Homoptera: Cicadidae).

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Harvey, Prudence M; Thompson, Michael B

2006-09-01

The final moult in cicadas marks a major transition in lifestyle and is a behaviour that makes the cicada vulnerable to predation. Consequently, emergence times are short and, we predict, therefore the rate of energy consumption would be high. Hence, we measured the energetic cost of emergence in Cyclochila australasiae (green grocer) and Abricta curvicosta (floury baker) cicadas during the final moult from nymph to adult cicada. Maximum energy expended whilst emerging was compared between the sexes and species. Even though C. australasiae take longer to emerge than A. curvicosta, the mass-specific cost of emergence is not different between the two species (C. australasiae: 11.34+/-2.55 J g(-1); A. curvicosta: 12.91+/-1.90 J g(-1)). The mass-specific metabolic rates of fully emerged adults of both species are approximately twice those of the nymphs and the maximum metabolic rate during emergence is about 1.5 times higher than the resting metabolic rate of emerged adults. Emergence times, as indicated by rates of oxygen consumption, are longer than expected and probably reflect limitations in the oxygen capacity of the cicadas during moulting.

Near-Optimal Foraging in the Pacific Cicada Killer Sphecius convallis Patton (Hymenoptera: Crabronidae

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Joseph R. Coelho

2012-02-01

Full Text Available This study evaluated foraging effectiveness of Pacific cicada killers (Sphecius convallis by comparing observed prey loads to that predicted by an optimality model. Female S. convallis preyed exclusively on the cicada Tibicen parallelus, resulting in a mean loaded flight muscle ratio (FMR of 0.187 (N = 46. This value lies just above the marginal level, and only seven wasps (15% were below 0.179. The low standard error (0.002 suggests that S. convallis is the most ideal flying predator so far examined in this respect. Preying on a single species may have allowed stabilizing selection to adjust the morphology of females to a nearly ideal size. That the loaded FMR is slightly above the marginal level may provide a small safety factor for wasps that do not have optimal thorax temperatures or that have to contend with attempted prey theft. Operational FMR was directly related to wasp body mass. Smaller wasps were overloaded in spite of provisioning with smaller cicadas, while larger wasps were underloaded despite provisioning with larger cicadas. Small wasps may have abandoned larger cicadas because of difficulty with carriage.

How do "mute" cicadas produce their calling songs?

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Changqing Luo

Full Text Available Insects have evolved a variety of structures and mechanisms to produce sounds, which are used for communication both within and between species. Among acoustic insects, cicada males are particularly known for their loud and diverse sounds which function importantly in communication. The main method of sound production in cicadas is the tymbal mechanism, and a relative small number of cicada species possess both tymbal and stridulatory organs. However, cicadas of the genus Karenia do not have any specialized sound-producing structures, so they are referred to as "mute". This denomination is quite misleading, as they indeed produce sounds. Here, we investigate the sound-producing mechanism and acoustic communication of the "mute" cicada, Karenia caelatata, and discover a new sound-production mechanism for cicadas: i.e., K. caelatata produces impact sounds by banging the forewing costa against the operculum. The temporal, frequency and amplitude characteristics of the impact sounds are described. Morphological studies and reflectance-based analyses reveal that the structures involved in sound production of K. caelatata (i.e., forewing, operculum, cruciform elevation, and wing-holding groove on scutellum are all morphologically modified. Acoustic playback experiments and behavioral observations suggest that the impact sounds of K. caelatata are used in intraspecific communication and function as calling songs. The new sound-production mechanism expands our knowledge on the diversity of acoustic signaling behavior in cicadas and further underscores the need for more bioacoustic studies on cicadas which lack tymbal mechanism.

How do "mute" cicadas produce their calling songs?

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Luo, Changqing; Wei, Cong; Nansen, Christian

2015-01-01

Insects have evolved a variety of structures and mechanisms to produce sounds, which are used for communication both within and between species. Among acoustic insects, cicada males are particularly known for their loud and diverse sounds which function importantly in communication. The main method of sound production in cicadas is the tymbal mechanism, and a relative small number of cicada species possess both tymbal and stridulatory organs. However, cicadas of the genus Karenia do not have any specialized sound-producing structures, so they are referred to as "mute". This denomination is quite misleading, as they indeed produce sounds. Here, we investigate the sound-producing mechanism and acoustic communication of the "mute" cicada, Karenia caelatata, and discover a new sound-production mechanism for cicadas: i.e., K. caelatata produces impact sounds by banging the forewing costa against the operculum. The temporal, frequency and amplitude characteristics of the impact sounds are described. Morphological studies and reflectance-based analyses reveal that the structures involved in sound production of K. caelatata (i.e., forewing, operculum, cruciform elevation, and wing-holding groove on scutellum) are all morphologically modified. Acoustic playback experiments and behavioral observations suggest that the impact sounds of K. caelatata are used in intraspecific communication and function as calling songs. The new sound-production mechanism expands our knowledge on the diversity of acoustic signaling behavior in cicadas and further underscores the need for more bioacoustic studies on cicadas which lack tymbal mechanism.

The emergence densities of annual cicadas (Hemiptera: Cicadidae) increase with sapling density and are greater near edges in a bottomland hardwood forest.

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Chiavacci, Scott J; Bednarz, James C; McKay, Tanja

2014-08-01

The emergence densities of cicadas tend to be patchy at multiple spatial scales. While studies have identified habitat conditions related to these patchy distributions, their interpretation has been based primarily on periodical cicada species; habitat factors associated with densities of nonperiodical (i.e., annual) cicadas have remained under studied. This is despite their widespread distribution, diversity, and role as an important trophic resource for many other organisms, particularly within riparian areas. We studied habitat factors associated with the emergence densities of Tibicen spp. in a bottomland hardwood forest in east-central Arkansas. We found emergence densities were greatest in areas of high sapling densities and increased toward forest edges, although sapling density was a much stronger predictor of emergence density. Emergence densities also differed among sample areas within our study system. The habitat features predicting nymph densities were likely driven by a combination of factors affecting female selection of oviposition sites and the effects of habitat conditions on nymph survival. The differences in nymph densities between areas of our system were likely a result of the differential effects of flooding in these areas. Interestingly, our findings were similar to observations of periodical species, suggesting that both types of cicadas select similar habitat characteristics for ovipositing or are under comparable selective pressures during development. Our findings also imply that changes in habitat characteristics because of anthropogenically altered disturbance regimes (e.g., flooding) have the potential to negatively impact both periodical and annual species, which could have dramatic consequences for organisms at numerous trophic levels.

How Do “Mute” Cicadas Produce Their Calling Songs?

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Luo, Changqing; Wei, Cong; Nansen, Christian

2015-01-01

Insects have evolved a variety of structures and mechanisms to produce sounds, which are used for communication both within and between species. Among acoustic insects, cicada males are particularly known for their loud and diverse sounds which function importantly in communication. The main method of sound production in cicadas is the tymbal mechanism, and a relative small number of cicada species possess both tymbal and stridulatory organs. However, cicadas of the genus Karenia do not have any specialized sound-producing structures, so they are referred to as “mute”. This denomination is quite misleading, as they indeed produce sounds. Here, we investigate the sound-producing mechanism and acoustic communication of the “mute” cicada, Karenia caelatata, and discover a new sound-production mechanism for cicadas: i.e., K. caelatata produces impact sounds by banging the forewing costa against the operculum. The temporal, frequency and amplitude characteristics of the impact sounds are described. Morphological studies and reflectance-based analyses reveal that the structures involved in sound production of K. caelatata (i.e., forewing, operculum, cruciform elevation, and wing-holding groove on scutellum) are all morphologically modified. Acoustic playback experiments and behavioral observations suggest that the impact sounds of K. caelatata are used in intraspecific communication and function as calling songs. The new sound-production mechanism expands our knowledge on the diversity of acoustic signaling behavior in cicadas and further underscores the need for more bioacoustic studies on cicadas which lack tymbal mechanism. PMID:25714608

Genomic divergence and lack of introgressive hybridization between two 13-year periodical cicadas support life cycle switching in the face of climate change.

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Koyama, Takuya; Ito, Hiromu; Fujisawa, Tomochika; Ikeda, Hiroshi; Kakishima, Satoshi; Cooley, John R; Simon, Chris; Yoshimura, Jin; Sota, Teiji

2016-11-01

Life history evolution spurred by post-Pleistocene climatic change is hypothesized to be responsible for the present diversity in periodical cicadas (Magicicada), but the mechanism of life cycle change has been controversial. To understand the divergence process of 13-year and 17-year cicada life cycles, we studied genetic relationships between two synchronously emerging, parapatric 13-year periodical cicada species in the Decim group, Magicicada tredecim and M. neotredecim. The latter was hypothesized to be of hybrid origin or to have switched from a 17-year cycle via developmental plasticity. Phylogenetic analysis using restriction-site-associated DNA sequences for all Decim species and broods revealed that the 13-year M. tredecim lineage is genomically distinct from 17-year Magicicada septendecim but that 13-year M. neotredecim is not. We detected no significant introgression between M. tredecim and M. neotredecim/M. septendecim thus refuting the hypothesis that M. neotredecim are products of hybridization between M. tredecim and M. septendecim. Further, we found that introgressive hybridization is very rare or absent in the contact zone between the two 13-year species evidenced by segregation patterns in single nucleotide polymorphisms, mitochondrial lineage identity and head width and abdominal sternite colour phenotypes. Our study demonstrates that the two 13-year Decim species are of independent origin and nearly completely reproductively isolated. Combining our data with increasing observations of occasional life cycle change in part of a cohort (e.g. 4-year acceleration of emergence in 17-year species), we suggest a pivotal role for developmental plasticity in Magicicada life cycle evolution. © 2016 John Wiley & Sons Ltd.

The presence of cicada family noise in Javanese and Balinese Pranatamangsa calendar calculation an ethnoecological approach

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Suryadarma, I. G. P.; Handziko, Rio Christy

2017-08-01

The presence and distribution of various cicada families as one of Javanese and Balinese ethnic farmers' season changing indicators. Comprehension of season changing is as an effort to optimize crop result as a mean to support basic needs. Society understands the behaviour of animal of cicada family based on season condition. Traditionally season guideline is based on the sun position from the equator, moon position, astronomy called as pranotomongso. Cicada's family is one of indicators of season changing between rain season and dry season. There were two-selected cicadas: garengpung as indicator of dry season and tenggoreknongas indicator of rainy season. This research aimed to discover the presence and growth dynamics of garengpung and tenggoreknong(cicada) as season changing indicator insects. This research is explorative research and data were taken through observation. Field observations on the manifestation and dynamics of two insects were conducted. The research was conducted in Yogyakarta Special Province and Bali Province during period of 2015 up to 2016. Correlation between the presence dynamics and emergence of garengpung and tenggoreknongvoice could be utilized as indicator of rainy and dry season dynamics change. Calculation of rainy and dry season change is relevant with pranotomongso calculation. The presence and dynamics of cicada emergence is still relevant as one of ecological information through ethnoecological approach.

Cicadas impact bird communication in a noisy tropical rainforest

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Hall, Robert; Ray, William; Beck, Angela; Zook, James

2015-01-01

Many animals communicate through acoustic signaling, and “acoustic space” may be viewed as a limited resource that organisms compete for. If acoustic signals overlap, the information in them is masked, so there should be selection toward strategies that reduce signal overlap. The extent to which animals are able to partition acoustic space in acoustically diverse habitats such as tropical forests is poorly known. Here, we demonstrate that a single cicada species plays a major role in the frequency and timing of acoustic communication in a neotropical wet forest bird community. Using an automated acoustic monitor, we found that cicadas vary the timing of their signals throughout the day and that the frequency range and timing of bird vocalizations closely track these signals. Birds significantly avoid temporal overlap with cicadas by reducing and often shutting down vocalizations at the onset of cicada signals that utilize the same frequency range. When birds do vocalize at the same time as cicadas, the vocalizations primarily occur at nonoverlapping frequencies with cicada signals. Our results greatly improve our understanding of the community dynamics of acoustic signaling and reveal how patterns in biotic noise shape the frequency and timing of bird vocalizations in tropical forests. PMID:26023277

Preparation and characterization of α-chitin from cicada sloughs

International Nuclear Information System (INIS)

Sajomsang, Warayuth; Gonil, Pattarapond

2010-01-01

In this study, a new source of insect chitin was proposed. Insect chitin was extracted from cicada sloughs by 1 M HCl and 1 M NaOH treatment for demineralization and deproteinization, respectively. The brown color of this chitin from cicada sloughs was removed using 6% sodium hypochlorite as an oxidizing agent. It was found that the insect chitin extracted from the cicada sloughs has a higher percent recovery than the chitin from rice-field crab shells. The chemical structure and physicochemical properties of α-chitin from cicada sloughs were characterized using elemental analysis (EA), attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), proton nuclear magnetic resonance spectroscopy ( 1 H NMR), solid-state 13 C cross-polarization magic-angle-spinning nuclear magnetic resonance (CP/MAS) NMR spectroscopy, X-ray diffractometry (XRD), and thermogravimetry (TG). The degree of acetylation (DA) was determined by EA, 1 H NMR, and 13 C CP/MAS NMR techniques. The DA values of chitin from cicada sloughs were in the range of 97% to 102% depending on each technique. Furthermore, it was found that the DA increased with an increasing thermal property and crystallinity.

Stridulatory sound-production and its function in females of the cicada Subpsaltria yangi.

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Changqing Luo

Full Text Available Acoustic behavior plays a crucial role in many aspects of cicada biology, such as reproduction and intrasexual competition. Although female sound production has been reported in some cicada species, acoustic behavior of female cicadas has received little attention. In cicada Subpsaltria yangi, the females possess a pair of unusually well-developed stridulatory organs. Here, sound production and its function in females of this remarkable cicada species were investigated. We revealed that the females could produce sounds by stridulatory mechanism during pair formation, and the sounds were able to elicit both acoustic and phonotactic responses from males. In addition, the forewings would strike the body during performing stridulatory sound-producing movements, which generated impact sounds. Acoustic playback experiments indicated that the impact sounds played no role in the behavioral context of pair formation. This study provides the first experimental evidence that females of a cicada species can generate sounds by stridulatory mechanism. We anticipate that our results will promote acoustic studies on females of other cicada species which also possess stridulatory system.

THE CICADA FAUNA AS PHYTOPLASMA VECTORS IN ISTRIAN VINEYARDS

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Đanfranko Pribetić

2009-12-01

Full Text Available The cicada fauna represents a considerable group of insects in vine-growing. Phytoplasma vine vectors insects are significant. They are fed from the phloem tissues of plants like cicadas from the families Cicadelidae, Coccidae, Fulgoridae and Psyilloidaea. Their phytoplasma is transmitted in a persistent way. Researches on cicada fauna, on the floristic structure of weeds and host plants of vine phytoplasma were done in 2005 and 2006 in Istrian vineyards. The research was being done in 10 vineyards on 11 localities. Cicade collecting was done with an entomological net by means of yellow sticky plates using an exhauster and a method of clonting. The collected cicadas were identified by means of binoculars and keys to identify species while the presence of phytoplasmas BN and Fd was defined by means of molecular analysis (PCR, RFLP. Listing and identifying the floristic structure of weeds were being cloned in the explored vineyards by means of keys to identify species. Samples of plant materials were taken for the analysis using PCR method by checking visually the typical symptoms caused by phytoplasma. Cicadas identifying and molecular analyses were being done at the Viticulture Institute for Research in Conegliano – Italy. During the researches, 243 insect samples were collected. Of the above mentioned number cicadas of 40 genus were identified in 207 samples. On the list of the floristic structure of Weeds 105 species of 36 families were identified. Corylus avellana L and Clematis vitalba L species were included in this list. These species showed sigus of phytoplasma disease and they were found near the explored vineyards. These two species were analysed on the presence for FD and BN phytoplasmas. The PCR method used in the molecular research on the presence of Fd and BN phytoplasmas was done on 34 insect samples and 22 plant samples. None of the mentioned sample was positive for FD and BN. The phytoplasma BN was found in the vine leaves of

Cordyceps cicadae extracts ameliorate renal malfunction in a remnant kidney model.

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Zhu, Rong; Chen, Yi-ping; Deng, Yue-yi; Zheng, Rong; Zhong, Yi-fei; Wang, Lin; Du, Lan-ping

2011-12-01

Chronic kidney disease (CKD) is a growing public health problem with an urgent need for new pharmacological agents. Cordyceps cicadae is widely used in traditional Chinese medicine (TCM) and has potential renoprotective benefits. The current study aimed to determine any scientific evidence to support its clinical use. We analyzed the potential of two kinds of C. cicadae extract, total extract (TE) and acetic ether extract (AE), in treating kidney disease simulated by a subtotal nephrectomy (SNx) model. Sprague-Dawley rats were divided randomly into seven groups: sham-operated group, vehicle-treated SNx, Cozaar, 2 g/(kg∙d) TE SNx, 1 g/(kg∙d) TE SNx, 92 mg/(kg∙d) AE SNx, and 46 mg/(kg∙d) AE SNx. Renal injury was monitored using urine and serum analyses, and hematoxylin and eosin (HE) and periodic acid-Schiff (PAS) stainings were used to analyze the level of fibrosis. The expression of type IV collagen (Col IV), fibronectin (FN), transforming growth factor-β1 (TGF-β1), and connective tissue growth factor (CTGF) was detected by immunohistochemistry. Renal injury, reflected in urine and serum analyses, and pathological changes induced by SNx were attenuated by TE and AE intervention. The depositions of Col IV and FN were also decreased by the treatments and were accompanied by reduced expression of TGF-β1 and CTGF. In some respects, 2 g/(kg∙d) of TE produced better effects than Cozaar. For the first time, we have shown that C. cicadae may inhibit renal fibrosis in vivo through the TGF-β1/CTGF pathway. Therefore, we conclude that the use of C. cicadae could provide a rational strategy for combating renal fibrosis.

A two-in-one superhydrophobic and anti-reflective nanodevice in the grey cicada Cicada orni (Hemiptera)

Energy Technology Data Exchange (ETDEWEB)

Dellieu, Louis, E-mail: louis.dellieu@unamur.be; Sarrazin, Michaël, E-mail: michael.sarrazin@unamur.be; Simonis, Priscilla; Deparis, Olivier; Vigneron, Jean Pol [Research Center in Physics of Matter and Radiation (PMR), Department of Physics, University of Namur (FUNDP), 61 rue de Bruxelles, B-5000 Namur (Belgium)

2014-07-14

Two separated levels of functionality are identified in the nanostructure which covers the wings of the grey cicada Cicada orni (Hemiptera). The upper level is responsible for superhydrophobic character of the wing, while the lower level enhances its anti-reflective behavior. Extensive wetting experiments with various chemical species and optical measurements were performed in order to assess the bi-functionality. Scanning electron microscopy imaging was used to identify the nanostructure morphology. Numerical optical simulations and analytical wetting models were used to prove the roles of both levels of the nanostructure. In addition, the complex refractive index of the chitinous material of the wing was determined from measurements.

A two-in-one superhydrophobic and anti-reflective nanodevice in the grey cicada Cicada orni (Hemiptera)

Science.gov (United States)

Dellieu, Louis; Sarrazin, Michaël; Simonis, Priscilla; Deparis, Olivier; Vigneron, Jean Pol

2014-07-01

Two separated levels of functionality are identified in the nanostructure which covers the wings of the grey cicada Cicada orni (Hemiptera). The upper level is responsible for superhydrophobic character of the wing, while the lower level enhances its anti-reflective behavior. Extensive wetting experiments with various chemical species and optical measurements were performed in order to assess the bi-functionality. Scanning electron microscopy imaging was used to identify the nanostructure morphology. Numerical optical simulations and analytical wetting models were used to prove the roles of both levels of the nanostructure. In addition, the complex refractive index of the chitinous material of the wing was determined from measurements.

A two-in-one superhydrophobic and anti-reflective nanodevice in the grey cicada Cicada orni (Hemiptera)

International Nuclear Information System (INIS)

Dellieu, Louis; Sarrazin, Michaël; Simonis, Priscilla; Deparis, Olivier; Vigneron, Jean Pol

2014-01-01

Two separated levels of functionality are identified in the nanostructure which covers the wings of the grey cicada Cicada orni (Hemiptera). The upper level is responsible for superhydrophobic character of the wing, while the lower level enhances its anti-reflective behavior. Extensive wetting experiments with various chemical species and optical measurements were performed in order to assess the bi-functionality. Scanning electron microscopy imaging was used to identify the nanostructure morphology. Numerical optical simulations and analytical wetting models were used to prove the roles of both levels of the nanostructure. In addition, the complex refractive index of the chitinous material of the wing was determined from measurements.

Organochlorines and heavy metals in 17-year cicadas pose no apparent dietary threat to birds

Science.gov (United States)

Clark, D.R.

1992-01-01

Organochlorine and heavy metal concentrations in 17-year cicadas from Prince Georges and Anne Arundel Counties, Maryland, were well below levels known to be harmful to birds. Cicadas contained concentrations of metals similar to or less than other local invertebrates except they contained more copper than did earthworms. Copper and lead concentrations in cicadas from one site may have been elevated by sewage plant effluent deposited during river floodings. Cicadas from the median of a major highway did not contain more lead than cicadas from non-traffic sites.

Cordyceps cicadae extracts ameliorate renal malfunction in a remnant kidney model*

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Zhu, Rong; Chen, Yi-ping; Deng, Yue-yi; Zheng, Rong; Zhong, Yi-fei; Wang, Lin; Du, Lan-ping

2011-01-01

Background and Objectives: Chronic kidney disease (CKD) is a growing public health problem with an urgent need for new pharmacological agents. Cordyceps cicadae is widely used in traditional Chinese medicine (TCM) and has potential renoprotective benefits. The current study aimed to determine any scientific evidence to support its clinical use. Methods: We analyzed the potential of two kinds of C. cicadae extract, total extract (TE) and acetic ether extract (AE), in treating kidney disease simulated by a subtotal nephrectomy (SNx) model. Sprague-Dawley rats were divided randomly into seven groups: sham-operated group, vehicle-treated SNx, Cozaar, 2 g/(kg∙d) TE SNx, 1 g/(kg∙d) TE SNx, 92 mg/(kg∙d) AE SNx, and 46 mg/(kg∙d) AE SNx. Renal injury was monitored using urine and serum analyses, and hematoxylin and eosin (HE) and periodic acid-Schiff (PAS) stainings were used to analyze the level of fibrosis. The expression of type IV collagen (Col IV), fibronectin (FN), transforming growth factor-β1 (TGF-β1), and connective tissue growth factor (CTGF) was detected by immunohistochemistry. Results: Renal injury, reflected in urine and serum analyses, and pathological changes induced by SNx were attenuated by TE and AE intervention. The depositions of Col IV and FN were also decreased by the treatments and were accompanied by reduced expression of TGF-β1 and CTGF. In some respects, 2 g/(kg∙d) of TE produced better effects than Cozaar. Conclusions: For the first time, we have shown that C. cicadae may inhibit renal fibrosis in vivo through the TGF-β1/CTGF pathway. Therefore, we conclude that the use of C. cicadae could provide a rational strategy for combating renal fibrosis. PMID:22135152

Life cycle replacement by gene introduction under an allee effect in periodical cicadas.

Science.gov (United States)

Nariai, Yukiko; Hayashi, Saki; Morita, Satoru; Umemura, Yoshitaka; Tainaka, Kei-ichi; Sota, Teiji; Cooley, John R; Yoshimura, Jin

2011-04-06

Periodical cicadas (Magicicada spp.) in the USA are divided into three species groups (-decim, -cassini, -decula) of similar but distinct morphology and behavior. Each group contains at least one species with a 17-year life cycle and one with a 13-year cycle; each species is most closely related to one with the other cycle. One explanation for the apparent polyphyly of 13- and 17-year life cycles is that populations switch between the two cycles. Using a numerical model, we test the general feasibility of life cycle switching by the introduction of alleles for one cycle into populations of the other cycle. Our results suggest that fitness reductions at low population densities of mating individuals (the Allee effect) could play a role in life cycle switching. In our model, if the 13-year cycle is genetically dominant, a 17-year cycle population will switch to a 13-year cycle given the introduction of a few 13-year cycle alleles under a moderate Allee effect. We also show that under a weak Allee effect, different year-classes ("broods") with 17-year life cycles can be generated. Remarkably, the outcomes of our models depend only on the dominance relationships of the cycle alleles, irrespective of any fitness advantages.

Life cycle replacement by gene introduction under an allee effect in periodical cicadas.

Directory of Open Access Journals (Sweden)

Yukiko Nariai

2011-04-01

Full Text Available Periodical cicadas (Magicicada spp. in the USA are divided into three species groups (-decim, -cassini, -decula of similar but distinct morphology and behavior. Each group contains at least one species with a 17-year life cycle and one with a 13-year cycle; each species is most closely related to one with the other cycle. One explanation for the apparent polyphyly of 13- and 17-year life cycles is that populations switch between the two cycles. Using a numerical model, we test the general feasibility of life cycle switching by the introduction of alleles for one cycle into populations of the other cycle. Our results suggest that fitness reductions at low population densities of mating individuals (the Allee effect could play a role in life cycle switching. In our model, if the 13-year cycle is genetically dominant, a 17-year cycle population will switch to a 13-year cycle given the introduction of a few 13-year cycle alleles under a moderate Allee effect. We also show that under a weak Allee effect, different year-classes ("broods" with 17-year life cycles can be generated. Remarkably, the outcomes of our models depend only on the dominance relationships of the cycle alleles, irrespective of any fitness advantages.

Cicada (Tibicen linnei steers by force vectoring

Directory of Open Access Journals (Sweden)

Samane Zeyghami

2016-03-01

Full Text Available To change flight direction, flying animals modulate aerodynamic force either relative to their bodies to generate torque about the center of mass, or relative to the flight path to produce centripetal force that curves the trajectory. In employing the latter, the direction of aerodynamic force remains fixed in the body frame and rotations of the body redirect the force. While both aforementioned techniques are essential for flight, it is critical to investigate how an animal balances the two to achieve aerial locomotion. Here, we measured wing and body kinematics of cicada (Tibicen linnei in free flight, including flight periods of both little and substantial body reorientations. It is found that cicadas employ a common force vectoring technique to execute all these flights. We show that the direction of the half-stroke averaged aerodynamic force relative to the body is independent of the body orientation, varying in a range of merely 20 deg. Despite directional limitation of the aerodynamic force, pitch and roll torque are generated by altering wing angle of attack and its mean position relative to the center of mass. This results in body rotations which redirect the wing force in the global frame and consequently change the flight trajectory.

Replication of cicada wing's nano-patterns by hot embossing and UV nanoimprinting

International Nuclear Information System (INIS)

Hong, Sung-Hoon; Hwang, Jaeyeon; Lee, Heon

2009-01-01

The hydrophobicity of the cicada wing originates from its naturally occurring, surface nano-structure. The nano-structure of the cicada wing consists of an array of nano-sized pillars, 100 nm in diameter and 300 nm in height. In this study, the nano-structure of the cicada wing was successfully duplicated by using hot embossing lithography and UV nanoimprint lithography (NIL). The diameter and pitch of replication were the same as those of the original cicada wing and the height was a little smaller than that of the original master. The transmittance of the hot embossed PVC film was increased by 2-6% compared with that of the bare PVC film. The hydrophobicity was measured by water contact angle measurements. The water contact angle of the replica, made of UV cured polymer, was 132 0 ± 2 0 , which was slightly lower than that of the original cicada wing (138 0 ± 2 0 ), but much higher than that of the UV cured polymer surface without any nano-sized pillars (86 0 ).

Analysis of Inter-Individual Bacterial Variation in Gut of Cicada Meimuna mongolica (Hemiptera: Cicadidae).

Science.gov (United States)

Zhou, Wenting; Nan, Xiaoning; Zheng, Zhou; Wei, Cong; He, Hong

2015-01-01

Intestinal bacterial community plays a crucial role in the nutrition, development, survival, and reproduction of insects. When compared with other insects with piercing-sucking mouthparts, the habitats of cicada nymphs and adults are totally different. However, little is known about the differences in the gut bacterial communities in the nymphs and adults within any cicada species. The diversity of bacteria in the gut of nymphs and adults of both genders of Meimuna mongolica (Distant) was studied using the denaturing gradient gel electrophoresis (DGGE) method. Few inter-individual variations among gut microbiota were observed, suggesting that M. mongolica typically harbors a limited and consistent suite of bacterial species. Bacteria in the genera Pseudomonas and Enterobacter were the predominant components of the gut microflora of M. mongolica at all life stages. Bacteria of Pantoea, Streptococcus, and Uruburuella were also widespread in the cicada samples but at relatively lower concentrations. The relative stability and similarity of the PCR-DGGE patterns indicate that all individuals of this cicada species harbor a characteristic bacterial community which is independent from developmental stages and genders. Related endosymbionts that could be harbored in bacteromes of cicadas were not detected in any gut samples, which could be related to the cicada species and the distribution of these endosymbionts in the cicada cavity, or due to some of the possible limitations of PCR-DGGE community profiling. It is worthwhile to further address if related cicada endosymbiont clades distribute in the alimentary canals and other internal organs through diagnostic PCR using group-specific primer sets. © The Author 2015. Published by Oxford University Press on behalf of the Entomological Society of America.

Annual Fire, Mowing and Fertilization Effects on Two Cicada Species (Homoptera: Cicadidae) in Tallgrass Prairie

Science.gov (United States)

Mac A. Callaham; Matt R. Whiles; John M. Blair

2002-01-01

In tallgrass prairie, cicadas emerge annually, are abundant and their emergence can be an important flux of energy and nutrients. However, factors influencing the distribution and abundance of these cicadas are virtually unknown. We examined cicada emergence in plots from a long-term (13 y) experimental manipulation involving common tallgrass prairie management...

Cicada emergence in southwestern riparian forest: Influences of wildfire and vegetation composition

Science.gov (United States)

D. Max Smith; Jeffrey Kelly; Deborah M. Finch

2006-01-01

Annually emerging cicadas are a numerically and ecologically dominant species in Southwestern riparian forests. Humans have altered disturbance regimes that structure these forests such that floods are less common and wildfires occur more frequently than was historically the case. Impacts of these changes on primary consumers such as riparian cicadas are unknown....

Acoustic and temporal partitioning of cicada assemblages in city and mountain environments.

Directory of Open Access Journals (Sweden)

Bao-Sen Shieh

Full Text Available Comparing adaptations to noisy city environments with those to natural mountain environments on the community level can provide significant insights that allow an understanding of the impact of anthropogenic noise on invertebrates that employ loud calling songs for mate attraction, especially when each species has its distinct song, as in the case of cicadas. In this study, we investigated the partitioning strategy of cicada assemblages in city and mountain environments by comparing the acoustic features and calling activity patterns of each species, recorded using automated digital recording systems. Our comparison of activity patterns of seasonal and diel calling revealed that there was no significant temporal partitioning of cicada assemblages in either environment. In addition, there was no correlation between the acoustic distance based on spectral features and temporal segregation. Heterospecific spectral overlap was low in both city and mountain environments, although city and mountain cicada assemblages were subject to significantly different levels of anthropogenic or interspecific noise. Furthermore, for the common species found in both environments, the calling activity patterns at both seasonal and diel time scales were significantly consistent across sites and across environments. We suggest that the temporal calling activity is constrained by endogenous factors for each species and is less flexible in response to external factors, such as anthropogenic noise. As a result, cicada assemblages in city environments with low species diversity do not demonstrate a more significant temporal partitioning than those in mountain environments with high species diversity.

Cordyceps cicadae extracts ameliorate renal malfunction in a remnant kidney model*

OpenAIRE

Zhu, Rong; Chen, Yi-ping; Deng, Yue-yi; Zheng, Rong; Zhong, Yi-fei; Wang, Lin; Du, Lan-ping

2011-01-01

Background and Objectives: Chronic kidney disease (CKD) is a growing public health problem with an urgent need for new pharmacological agents. Cordyceps cicadae is widely used in traditional Chinese medicine (TCM) and has potential renoprotective benefits. The current study aimed to determine any scientific evidence to support its clinical use. Methods: We analyzed the potential of two kinds of C. cicadae extract, total extract (TE) and acetic ether extract (AE), in treating kidney disease si...

Multiple origins of interdependent endosymbiotic complexes in a genus of cicadas.

Science.gov (United States)

Łukasik, Piotr; Nazario, Katherine; Van Leuven, James T; Campbell, Matthew A; Meyer, Mariah; Michalik, Anna; Pessacq, Pablo; Simon, Chris; Veloso, Claudio; McCutcheon, John P

2018-01-09

Bacterial endosymbionts that provide nutrients to hosts often have genomes that are extremely stable in structure and gene content. In contrast, the genome of the endosymbiont Hodgkinia cicadicola has fractured into multiple distinct lineages in some species of the cicada genus Tettigades To better understand the frequency, timing, and outcomes of Hodgkinia lineage splitting throughout this cicada genus, we sampled cicadas over three field seasons in Chile and performed genomics and microscopy on representative samples. We found that a single ancestral Hodgkinia lineage has split at least six independent times in Tettigades over the last 4 million years, resulting in complexes of between two and six distinct Hodgkinia lineages per host. Individual genomes in these symbiotic complexes differ dramatically in relative abundance, genome size, organization, and gene content. Each Hodgkinia lineage retains a small set of core genes involved in genetic information processing, but the high level of gene loss experienced by all genomes suggests that extensive sharing of gene products among symbiont cells must occur. In total, Hodgkinia complexes that consist of multiple lineages encode nearly complete sets of genes present on the ancestral single lineage and presumably perform the same functions as symbionts that have not undergone splitting. However, differences in the timing of the splits, along with dissimilar gene loss patterns on the resulting genomes, have led to very different outcomes of lineage splitting in extant cicadas.

Versatile aggressive mimicry of cicadas by an Australian predatory katydid.

Science.gov (United States)

Marshall, David C; Hill, Kathy B R

2009-01-01

In aggressive mimicry, a predator or parasite imitates a signal of another species in order to exploit the recipient of the signal. Some of the most remarkable examples of aggressive mimicry involve exploitation of a complex signal-response system by an unrelated predator species. We have found that predatory Chlorobalius leucoviridis katydids (Orthoptera: Tettigoniidae) can attract male cicadas (Hemiptera: Cicadidae) by imitating the species-specific wing-flick replies of sexually receptive female cicadas. This aggressive mimicry is accomplished both acoustically, with tegminal clicks, and visually, with synchronized body jerks. Remarkably, the katydids respond effectively to a variety of complex, species-specific Cicadettini songs, including songs of many cicada species that the predator has never encountered. We propose that the versatility of aggressive mimicry in C. leucoviridis is accomplished by exploiting general design elements common to the songs of many acoustically signaling insects that use duets in pair-formation. Consideration of the mechanism of versatile mimicry in C. leucoviridis may illuminate processes driving the evolution of insect acoustic signals, which play a central role in reproductive isolation of populations and the formation of species.

CeasIng Cpap At standarD criteriA (CICADA): impact on weight gain, time to full feeds and caffeine use.

Science.gov (United States)

Broom, Margaret; Ying, Lei; Wright, Audrey; Stewart, Alice; Abdel-Latif, Mohamed E; Shadbolt, Bruce; Todd, David A

2014-09-01

In our previous randomised controlled trial (RCT), we have shown in preterm babies (PBs) Cpap At standarD criteriA (CICADA (method 1)) compared with cycling off continuous positive airway pressure (CPAP) gradually (method 2) or cycling off CPAP gradually with low flow air/oxygen during periods off CPAP (method 3) reduces CPAP cessation time in PBs CPAP; the CICADA method, does not adversely affect weight gain, time to reach full feeds and may reduce time to cease caffeine in PBs <30 weeks gestation. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Bacterial diversity of bacteriomes and organs of reproductive, digestive and excretory systems in two cicada species (Hemiptera: Cicadidae).

Science.gov (United States)

Zheng, Zhou; Wang, Dandan; He, Hong; Wei, Cong

2017-01-01

Cicadas form intimate symbioses with bacteria to obtain nutrients that are scarce in the xylem fluid they feed on. The obligate symbionts in cicadas are purportedly confined to specialized bacteriomes, but knowledge of bacterial communities associated with cicadas is limited. Bacterial communities in the bacteriomes and organs of reproductive, digestive and excretory systems of two cicada species (Platypleura kaempferi and Meimuna mongolica) were investigated using different methods, and the bacterial diversity and distribution patterns of dominant bacteria in different tissues were compared. Within each species, the bacterial communities of testes are significantly different from those of bacteriomes and ovaries. The dominant endosymbiont Candidatus Sulcia muelleri is found not only in the bacteriomes and reproductive organs, but also in the "filter chamber + conical segment" of both species. The transmission mode of this endosymbiont in the alimentary canal and its effect on physiological processes merits further study. A novel bacterium of Rhizobiales, showing ~80% similarity to Candidatus Hodgkinia cicadicola, is dominant in the bacteriomes and ovaries of P. kaempferi. Given that the genome of H. cicadicola exhibits rapid sequence evolution, it is possible that this novel bacterium is a related endosymbiont with beneficial trophic functions similar to that of H. cicadicola in some other cicadas. Failure to detect H. cicadicola in M. mongolica suggests that it has been subsequently replaced by another bacterium, a yeast or gut microbiota which compensates for the loss of H. cicadicola. The distribution of this novel Rhizobiales species in other cicadas and its identification require further investigation to help establish the definition of the bacterial genus Candidatus Hodgkinia and to provide more information on sequence divergence of related endosymbionts of cicadas. Our results highlight the complex bacterial communities of cicadas, and are informative for

Bacterial diversity of bacteriomes and organs of reproductive, digestive and excretory systems in two cicada species (Hemiptera: Cicadidae.

Directory of Open Access Journals (Sweden)

Zhou Zheng

Full Text Available Cicadas form intimate symbioses with bacteria to obtain nutrients that are scarce in the xylem fluid they feed on. The obligate symbionts in cicadas are purportedly confined to specialized bacteriomes, but knowledge of bacterial communities associated with cicadas is limited. Bacterial communities in the bacteriomes and organs of reproductive, digestive and excretory systems of two cicada species (Platypleura kaempferi and Meimuna mongolica were investigated using different methods, and the bacterial diversity and distribution patterns of dominant bacteria in different tissues were compared. Within each species, the bacterial communities of testes are significantly different from those of bacteriomes and ovaries. The dominant endosymbiont Candidatus Sulcia muelleri is found not only in the bacteriomes and reproductive organs, but also in the "filter chamber + conical segment" of both species. The transmission mode of this endosymbiont in the alimentary canal and its effect on physiological processes merits further study. A novel bacterium of Rhizobiales, showing ~80% similarity to Candidatus Hodgkinia cicadicola, is dominant in the bacteriomes and ovaries of P. kaempferi. Given that the genome of H. cicadicola exhibits rapid sequence evolution, it is possible that this novel bacterium is a related endosymbiont with beneficial trophic functions similar to that of H. cicadicola in some other cicadas. Failure to detect H. cicadicola in M. mongolica suggests that it has been subsequently replaced by another bacterium, a yeast or gut microbiota which compensates for the loss of H. cicadicola. The distribution of this novel Rhizobiales species in other cicadas and its identification require further investigation to help establish the definition of the bacterial genus Candidatus Hodgkinia and to provide more information on sequence divergence of related endosymbionts of cicadas. Our results highlight the complex bacterial communities of cicadas, and

Versatile aggressive mimicry of cicadas by an Australian predatory katydid.

Directory of Open Access Journals (Sweden)

David C Marshall

Full Text Available BACKGROUND: In aggressive mimicry, a predator or parasite imitates a signal of another species in order to exploit the recipient of the signal. Some of the most remarkable examples of aggressive mimicry involve exploitation of a complex signal-response system by an unrelated predator species. METHODOLOGY/PRINCIPAL FINDINGS: We have found that predatory Chlorobalius leucoviridis katydids (Orthoptera: Tettigoniidae can attract male cicadas (Hemiptera: Cicadidae by imitating the species-specific wing-flick replies of sexually receptive female cicadas. This aggressive mimicry is accomplished both acoustically, with tegminal clicks, and visually, with synchronized body jerks. Remarkably, the katydids respond effectively to a variety of complex, species-specific Cicadettini songs, including songs of many cicada species that the predator has never encountered. CONCLUSIONS/SIGNIFICANCE: We propose that the versatility of aggressive mimicry in C. leucoviridis is accomplished by exploiting general design elements common to the songs of many acoustically signaling insects that use duets in pair-formation. Consideration of the mechanism of versatile mimicry in C. leucoviridis may illuminate processes driving the evolution of insect acoustic signals, which play a central role in reproductive isolation of populations and the formation of species.

Scheduling and control of programs in the CICADA computer system for TFTR

International Nuclear Information System (INIS)

Christianson, G.B.; Sherrick, M.; Stark, W.

1983-01-01

The CICADA computer system is a network of super minicomputers for data acquisition, reduction, display and device control on the TFTR experiment. Human interaction with the CICADA system is accomplished by consoles offering color displays with a high degree of operator interaction with the computer system, and by interactive terminals offering a limited degree of operator interaction. The authors describe the software packages and data bases used to control the consoles and provide communication to an application program attached to a console. The console control program in its turn schedules the execution of control programs that furnish operating system interfaces to applications programs executing at a console or terminal (in response to human activation), or upon activation by scheduling tasks. The control programs handle functions such as applications task activation. They discuss the implementation of the control programs in the multi-computer CICADA environment, and describe the control program data bases. In a TFTR shot cycle, applications programs must be scheduled for activation at operator-defined stages, in order to accomplish the arming of hardware devices, acquisition of summary waveform data, and the acquisition and archiving of raw data. The authors describe the software tasks and data bases of the CICADA event system, which accomplishes this scheduling of applications task activation in conjunction with the control programs. Future enhancements planned for the console control, program control, and event systems are outlined

Sichuan Snub-Nosed Monkeys (Rhinopithecus roxellana) Consume Cicadas in the Qinling Mountains, China.

Science.gov (United States)

Yang, Bin; Zhang, Peng; Garber, Paul A; Hedley, Richard; Li, Baoguo

2016-01-01

There is limited information on insectivory in folivorous primates. Here, we report that wild Sichuan snub-nosed monkeys (Rhinopithecus roxellana) consume cicadas (Karenia caelatata) in the Qinling Mountains of China. Our research suggests that snub-nosed monkeys expand their diet and prey on cicadas during summer and early autumn, possibly in response to increased availability of these insects and their relatively high protein and fat content relative to leaves. © 2016 S. Karger AG, Basel.

Are cicadas (Diceroprocta apache) both a "keystone" and a "critical-link" species in lower Colorado River riparian communities?

Science.gov (United States)

Andersen, Douglas C.

1994-01-01

Apache cicada (Homoptera: Cicadidae: Diceroprocta apache Davis) densities were estimated to be 10 individuals/m2 within a closed-canopy stand of Fremont cottonwood (Populus fremontii) and Goodding willow (Salix gooddingii) in a revegetated site adjacent to the Colorado River near Parker, Arizona. Coupled with data drawn from the literature, I estimate that up to 1.3 cm (13 1/m2) of water may be added to the upper soil layers annually through the feeding activities of cicada nymphs. This is equivalent to 12% of the annual precipitation received in the study area. Apache cicadas may have significant effects on ecosystem functioning via effects on water transport and thus act as a critical-link species in this southwest desert riverine ecosystem. Cicadas emerged later within the cottonwood-willow stand than in relatively open saltcedar-mesquite stands; this difference in temporal dynamics would affect their availability to several insectivorous bird species and may help explain the birds' recent declines. Resource managers in this region should be sensitive to the multiple and strong effects that Apache cicadas may have on ecosystem structure and functioning.

Tokamak Fusion Test Reactor - CICADA, an overview

International Nuclear Information System (INIS)

Sauthoff, N.; Bosco, J.; Daniels, R.

1983-01-01

The Central Instrumentation, Control and Data Acquisition (CICADA) System provides the interface between the human operators and the equipment to be controlled and monitored in support of TFTR operation. The functions can be partitioned into those that are instantaneous and fundamental components of a processed control system (such as displaying the current monitored value of a point or changing the state of a piece of equipment) and those that are more complex, being composite actions executed in sequences either related to the TFTR shot cycle or in the execution of timed procedures for the operation of subsystems. In this paper, the authors present the configuration of the equipment ''from the outside in'' - meaning from the man and equipment external interfaces inward toward the components internal to the CICADA system; they next present an overview of the fundamental operations, including the concept of the CICADA devices, the assignment of values to the elements of the definition of the device, the monitoring procedure for all of the devices on the system, the control process including the assignment of control authorization, the handling of special devices such as diagnostic data acquisition and timing modules, and graphics. Next they proceed to discuss composite actions and timed sequences which support the TFTR cycle; included are the system for activating, suspending, and resuming tasks in response to the occurrence of hardware and software events, and the typical sequence of tasks involved in operation of a subsystem for data acquisition during the shot cycle and the archival of raw and results data; special cases will be the real time control systems for the plasma position and current and the gas injection system, both of which provide closed-loop feedback control of plasma position, current and lineintegrated density throughout the shot. Finally, future directions and initiatives discussed

Thermal adaptation in North American cicadas (Hemiptera: Cicadidae).

Science.gov (United States)

Sanborn, Allen F; Heath, James E; Heath, Maxine S; Phillips, Polly K

2017-10-01

We determine and summarize the thermal responses for 118 species and subspecies of North American cicadas representing more than 50 years of fieldwork and experimentation. We investigate the role that habitat and behavior have on the thermal adaptation of the North American cicadas. There are general patterns of increasing thermal responses in warmer floristic provinces and increasing maximum potential temperature within a habitat. Altitude shows an inverse relationship with thermal responses. Comparison of thermal responses of species emerging early or late in the season within the same habitat show increases in the thermal responses along with the increasing environmental temperatures late in the summer. However, behavior, specifically the use of endothermy as a thermoregulatory strategy, can influence the values determined in a particular habitat. Subspecies generally do not differ in their thermal tolerances and thermal tolerances are consistent within a species over distances of more than 7600km. Copyright © 2017 Elsevier Ltd. All rights reserved.

Calling songs of some South African cicadas (Homoptera: Cicadidae)

African Journals Online (AJOL)

1987-07-13

Jul 13, 1987 ... Figure 11 Posture of male cicadas during calling song, illustrated by a specimen ... parameters of the smaller samples falls within that of the largest conspecific ... under the control of the neuromuscular system (Pringle. 1954b).

TFTR control and monitoring system (CICADA)

International Nuclear Information System (INIS)

Daniels, R.E.

1981-01-01

The TFTR Central Instrumentation, Control and Data Acquisition System (CICADA) is described. This is a computer based system, supporting three types of user interfaces and supporting real time, terminal, and batch operations. Over one hundred graphic display generators will be supported by the system, four array processors will greatly increase the analysis capabilities, and closed circuit television will distribute performance data throughout the facility. Approximately twenty thousand points wll be interfaced to the system

Pengembangan Desain Mainan Anak Sebagai Identitas Dan Sarana Pengenalan Musik Untuk Anak-anak Di Kampung Akustik Cicadas

OpenAIRE

Fajriani, Novi; Larasati, Dwinita

2014-01-01

Bermain dengan bermusik sebagai contohnya merupakan sebuah kebutuhan bagi anak untuk mengeksplorasi kreativitas alami dalam mengembangkan dirinya. Sebagai salah satu kampung kreatif , Kampung Akustik Cicadas belum memiliki identitas khusus sebagai kampung yang berhubungan erat dengan musik, baik identitas fisik maupun nonfisik dengan minimnya ruang publik terbuka dan sarana bermusik untuk anak-anak Cicadas sebagai salah satu permasalahannya. Berdasarkan analisis kondisi lapangan dan tinjauan ...

Ergosterol peroxide from Cordyceps cicadae ameliorates TGF-β1-induced activation of kidney fibroblasts.

Science.gov (United States)

Zhu, Rong; Zheng, Rong; Deng, Yueyi; Chen, Yiping; Zhang, Shuwei

2014-02-15

Chronic kidney disease is a growing public health problem with an urgent need for new pharmacological agents. Ergosterol peroxide (EP) is the major sterol produced by Cordyceps cicadae Shing (C. cicadae), a widely used traditional Chinese medicine. C. cicadae has been used to treat many kinds of diseases and has a potential benefit on renoprotection. This study aimed to investigate the anti-fibrotic effects of EP as well as the underlying mechanisms. A normal rat kidney fibroblast cell line (NRK-49F) was stimulated to undergo fibroblast activation by transforming growth factor-β1 (TGF-β1) and EP treatment was applied to explore its potential anti-fibrotic effects. Cell proliferation was investigated using MTT analysis. Fibrosis-associated protein expression was analyzed using immunohistochemistry and/or Western blotting. EP treatment attenuated TGF-β1-induced renal fibroblast proliferation, expression of cytoskeleton protein and CTGF, as well as ECM production. Additionally, EP blocked TGF-β1-stimulated phosphorylation of ERK1/2, p38 and JNK pathway. Moreover, the TGF-β1-induced expression of fibronectin was attenuated by either inhibition of MAPKs or by EP treatment. In conclusion, our findings demonstrate that EP is able to suppress TGF-β1-induced fibroblasts activation in NRK-49F. This new information provides a line of theoretical evidence supporting the use of C. cicadae in the intervention of kidney disease and suggests that EP has the potential to be developed as a therapeutic agent to prevent renal fibrosis. Copyright © 2013 Elsevier GmbH. All rights reserved.

CeasIng Cpap At standarD criteriA (CICADA): Implementation improves neonatal outcomes.

Science.gov (United States)

Heath Jeffery, Rachael C; Broom, Margaret; Shadbolt, Bruce; Todd, David A

2016-03-01

A previous randomised controlled trial (RCT) in babies born CPAP) with a view to remain off rather than slow weaning) significantly reduced CPAP time. Post-RCT we introduced the CICADA method and evaluated whether the improved outcomes of the CICADA method during the RCT were replicated in clinical practice. The aim of the study is to compare cardio-respiratory outcomes in PBs CPAP days and corrected GA to cease CPAP post implementation (20.5 ± 2.1, 21.1 ± 2.1, 16.5 ± 1.8 (days ± SE); P = 0.006 and 33.3 ± 0.4, 33.5 ± 0.4, 32.6 ± 0.4 (weeks ± SE); P = 0.01). Compared with the pre RCT epoch, there were significant reductions in patent ductus arteriosus (36/78 (46%), 33/87 (37%), 18/103 (17%); P CPAP time, corrected GA to cease CPAP, patent ductus arteriosus and chronic lung disease significantly reduced following the introduction of the CICADA method. Early cessation of CPAP expedites the transition from neonatal intensive care to special care. © 2016 The Author. Journal of Paediatrics and Child Health © 2016 Paediatrics and Child Health Division (Royal Australasian College of Physicians).

New species of Drymopsalta Heath Cicadas (Cicadidae: Cicadettinae: Cicadettini) from Queensland and Northern Territory, Australia, with overview of genus.

Science.gov (United States)

Ewart, A; Popple, L W

2013-01-01

Three new species are described in the genus Drymopsalta Ewart, previously known only from D. crepitum Ewart and D. daemeli Distant. The three new species occur in Southern Queensland and Northern Territory. D. wallumi sp. nov. occurs along coastal S.E. Queensland, whereas D. hobsoni sp. nov. is restricted to the Bringalily State Forest, near Inglewood, southern inland Queensland. D. acrotela sp. nov. is found in the Litchfield National Park and other locations near Jabaluka, Cahills Crossing, E. Alligator River and Nourlangie, all across the northern Northern Territory. D. crepitum occurs on the Cape York Peninsular extending into the southern Gulf, while D. daemeli occurs in two localised regions in central coastal N.S.W. Each of the species inhabits heath vegetation, often spilling-over into adjacent tree foliage. The species of Drymopsalta are small and inconspicuous cicadas (cicadas. Two additional song variants are described, a more unstructured chirping song without intervening single ticks observed in each of the species except D. crepitum, and periodic extended buzzing echemes emitted within the calling songs (excepting the D. wallumi song).

The cicadas of Argentina with new records, a new genus and fifteen new species (Hemiptera: Cicadoidea: Cicadidae).

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Sanborn, Allen F; Heath, Maxine S

2014-10-11

The Argentine cicada fauna is determined. A total of 108 species belonging to 37 genera, eight tribes, and three subfamilies of cicadas are represented in the Argentine cicada fauna. One genus and 15 species are described as new to science: Torresia Sanborn & Heath gen. n., Fidicinoides ferruginosa Sanborn & Heath sp. n., Proarna alalonga Sanborn & Heath sp. n., Proarna parva Sanborn & Heath sp. n., Prasinosoma medialinea Sanborn & Heath sp. n., Dorisiana noriegai Sanborn & Heath sp. n., Guyalna platyrhina Sanborn & Heath sp. n., Herrera humilastrata Sanborn & Heath sp. n., Herrera umbraphila Sanborn & Heath sp. n., Parnisa lineaviridia Sanborn & Heath sp. n., Parnisa viridis Sanborn & Heath sp. n., Alarcta micromacula Sanborn & Heath sp. n., Torresia lariojaensis Sanborn & Heath sp. n., Torresia sanjuanensis Sanborn & Heath sp. n., Chonosia longiopercula Sanborn & Heath sp. n., and Chonosia septentrionala Sanborn & Heath sp. n. Adusella signata Haupt, 1918 rev. stat. is determined to be a valid species, removed as a junior synonym of Tettigades lebruni Distant, 1906 and reassigned to the genus Odopoea Distant to become Odopoea signata comb. n. Fidicina vinula Stål, 1854 rev. stat. is determined to be a valid species, removed as a junior synonym of Fidicinoides pronoe (Walker, 1850) and assigned to the genus Fidicinoides Boulard & Martinelli to become Fidicinoides vinula comb. n. Proarna capistrata Distant, 1885 rev. stat. is determined to be a valid species, removed as a junior synonym of Proarna montividensis Berg, 1882. Chonosia papa (Berg, 1882) rev. stat. is determined to be a valid species and removed as a junior synonym of Chonosia crassipennis (Walker, 1858). Chonosia crassipennis var. metequei nom. nud. Delétang, 1919 syn. n. is considered natural variation in C. crassipennis. Dorisia bonaerensis var. bergi nom. nud. Delétang, 1919 syn. n. and Dorisia bonaerensis var. dominiquei nom. nud. Delétang, 1919 syn. n. are considered to be natural variation

N(6)-(2-Hydroxyethyl)adenosine in the Medicinal Mushroom Cordyceps cicadae Attenuates Lipopolysaccharide-Stimulated Pro-inflammatory Responses by Suppressing TLR4-Mediated NF-κB Signaling Pathways.

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Lu, Meng-Ying; Chen, Chin-Chu; Lee, Li-Ya; Lin, Ting-Wei; Kuo, Chia-Feng

2015-10-23

Natural products play an important role in promoting health with relation to the prevention of chronic inflammation. N(6)-(2-Hydroxyethyl)adenosine (HEA), a physiologically active compound in the medicinal mushroom Cordyceps cicadae, has been identified as a Ca(2+) antagonist and shown to control circulation and possess sedative activity in pharmacological tests. The fruiting body of C. cicadae has been widely applied in Chinese medicine. However, neither the anti-inflammatory activities of HEA nor the fruiting bodies of C. cicadae have been carefully examined. In this study, we first cultured the fruiting bodies of C. cicadae and then investigated the anti-inflammatory activities of water and methanol extracts of wild and artificially cultured C. cicadae fruiting bodies. Next, we determined the amount of three bioactive compounds, adenosine, cordycepin, and HEA, in the extracts and evaluated their synergistic anti-inflammatory effects. Moreover, the possible mechanism involved in anti-inflammatory action of HEA isolated from C. cicadae was investigated. The results indicate that cordycepin is more potent than adenosine and HEA in suppressing the lipopolysaccharide (LPS)-stimulated release of pro-inflammatory cytokines by RAW 264.7 macrophages; however, no synergistic effect was observed with these three compounds. HEA attenuated the LPS-induced pro-inflammatory responses by suppressing the toll-like receptor (TLR)4-mediated nuclear factor-κB (NF-κB) signaling pathway. This result will support the use of HEA as an anti-inflammatory agent and C. cicadae fruiting bodies as an anti-inflammatory mushroom.

Limited, episodic diversification and contrasting phylogeography in a New Zealand cicada radiation

DEFF Research Database (Denmark)

Marshall, David; Hill, Kathy; Marske, Katharine

2012-01-01

The New Zealand (NZ) cicada fauna contains two co-distributed lineages that independently colonized the isolated continental fragment in the Miocene. One extensively studied lineage includes 90% of the extant species (Kikihia + Maoricicada + Rhodopsalta; ca 51 spp.), while the other contains just...

An Architect Cicada in Brazilian Rainforest: Guyalna chlorogena (Walker).

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Béguin, C F

2017-04-01

To study the noteworthy nest building behavior of the nymph of the Brazilian Rainforest cicada Guyalna chlorogena (Walker) during the last year of its underground life, we monitored a large number of edifices, consisting of a vertical well (up to 1 m deep) with a turret (20 to 40 cm tall) on top, and we also performed experiments. We have shown that the buildings are occupied by a single nymph, male or female, which increases the height of its turret each night by about 3 cm, during a short active growing phase. The nymph softens and reshapes the apex by pushing upwards a lump of freshly mixed soaked clay, without any opening present, i. e., without ever exposing itself to the outside. We also established that the nymph is very active once its building is achieved. For example, it restores the height of the turret to its original value when shortening and opens the top of its building in case of variation of environmental parameters. Finally, we have shown how the nymph opens its edifice to reach the outside for molting into an adult stage (imago). With this work, we contributed to a better understanding of the nesting behavior of Amazon cicadas.

Endothermy in African platypleurine cicadas: the influence of body size and habitat (Hemiptera: Cicadidae).

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Sanborn, Allen F; Villet, Martin H; Phillips, Polly K

2004-01-01

The platypleurine cicadas have a wide distribution across Africa and southern Asia. We investigate endothermy as a thermoregulatory strategy in 11 South African species from five genera, with comparisons to the lone ectothermic platypleurine we found, in an attempt to ascertain any influence that habitat and/or body size have on the expression of endothermy in the platypleurine cicadas. Field measurements of body temperature (T(b)) show that these animals regulate T(b) through endogenous heat production. Heat production in the laboratory elevated T(b) to the same range as in animals active in the field. Maximum T(b) measured during calling activity when there was no access to solar radiation ranged from 13.2 degrees to 22.3 degrees C above ambient temperature in the five species measured. The mean T(b) during activity without access to solar radiation did not differ from the mean T(b) during diurnal activity. All platypleurines exhibit a unique behavior for cicadas while warming endogenously, a temperature-dependent telescoping pulsation of the abdomen that probably functions in ventilation. Platypleurines generally call from trunks and branches within the canopy and appear to rely on endothermy even when the sun is available to elevate T(b), in contrast to the facultative endothermy exhibited by New World endothermic species. The two exceptions to this generalization we found within the platypleurines are Platypleura wahlbergi and Albanycada albigera, which were the smallest species studied. The small size of P. wahlbergi appears to have altered their thermoregulatory strategy to one of facultative endothermy, whereby they use the sun when it is available to facilitate increases in T(b). Albanycada albigera is the only ectothermic platypleurine we found. The habitat and host plant association of A. albigera appear to have influenced the choice of ectothermy as a thermoregulatory strategy, as the species possesses the metabolic machinery to elevate to the T

A checklist of the cicadas (Hemiptera: Cicadidae) of Hainan Island, China, with description of a new species.

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Yang, Mingsheng; Wei, Cong

2013-10-29

A total of 54 cacada species, belonging to 28 genera, nine tribes and three subfamilies of the family Cicadidae, are identified to comprise the cicada fauna of Hainan Island, based on the examination of material collected between 2007 and 2011. One species, Semia hainanensis sp. n., is described as new to science. Nine species are recorded as new to Hainan Island, of which two species, Pomponia subtilita Lee, 2009 and Becquartina bleuzeni Boulard, 2005, are reported for the first time from China. In addition, six species formerly recorded from Hainan are removed from the list of Hainan cicadas. Taxonomic remarks and information on geographic distributions are also provided.

Diapause and prolonged development in the embryo and their ecological significance in two cicadas, Cryptotympana facialis and Graptopsaltria nigrofuscata.

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Moriyama, Minoru; Numata, Hideharu

2008-12-01

The seasonal timing mechanism of egg hatching was examined in two cicadas, Cryptotympana facialis and Graptopsaltria nigrofuscata, with different but overlapping geographical distributions. These species lay eggs in summer, and nymphs hatch in the summer of the following year after egg durations of 10-12 months. When eggs were maintained at 25 degrees C from oviposition, both the species entered embryonic diapause within 60 days irrespective of photoperiod, but at different developmental stages between the two species. The optimal temperature for diapause development was approximately 15 degrees C in both the species. The development rate for postdiapause morphogenesis increased linearly with temperature in the range of 20-27.5 degrees C in C. facialis, and of 15-25 degrees C in G. nigrofuscata. The lower development threshold and the sum of effective temperatures were computed as 14.3 degrees C and 715.3 day-degrees in C. facialis and 12.1 degrees C and 566.6 day-degrees in G. nigrofuscata, respectively. The hatching dates predicted by these large thermal constants accorded with the hatching dates observed in the field, i.e., late June and mid-July in G. nigrofuscata and C. facialis, respectively. Therefore, the high thermal requirements for postdiapause development compel the cicadas to hatch in summer.

Periodical cicadas: A minimal automaton model

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de O. Cardozo, Giovano; de A. M. M. Silvestre, Daniel; Colato, Alexandre

2007-08-01

The Magicicada spp. life cycles with its prime periods and highly synchronized emergence have defied reasonable scientific explanation since its discovery. During the last decade several models and explanations for this phenomenon appeared in the literature along with a great deal of discussion. Despite this considerable effort, there is no final conclusion about this long standing biological problem. Here, we construct a minimal automaton model without predation/parasitism which reproduces some of these aspects. Our results point towards competition between different strains with limited dispersal threshold as the main factor leading to the emergence of prime numbered life cycles.

Biogeography of the Cicadas (Hemiptera: Cicadidae of North America, North of Mexico

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Allen F. Sanborn

2013-04-01

Full Text Available We describe and illustrate the biogeography of the cicadas inhabiting continental North America, north of Mexico. Species distributions were determined through our collecting efforts as well as label data from more than 110 institutional collections. The status of subspecies is discussed with respect to their distributions. As we have shown over limited geographic areas, the distribution of individual species is related to the habitat in which they are found. We discuss the biogeography of the genera with respect to their phylogenetic relationships. California is the state with the greatest alpha diversity (89 species, 46.6% of taxa and unique species (35 species, 18.3% of taxa. Texas, Arizona, Colorado and Utah are the states with the next greatest alpha diversity with Texas, Arizona and Utah being next for unique species diversity. Maine, New Hampshire and Rhode Island are the states with the least amount of cicada diversity. Diversity is greatest in states and areas where there is a diversity of plant communities and habitats within these communities. Mountainous terrain also coincides with increases in diversity. Several regions of the focus area require additional collection efforts to fill in the distributions of several species.

A new genus and species of tettigarctid cicada from the early Miocene of New Zealand: Paratettigarcta zealandica (Hemiptera, Auchenorrhyncha, Tettigarctidae)

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Kaulfuss, Uwe; Moulds, Max

2015-01-01

Abstract A new genus and species of primitive cicada (Hemiptera: Tettigarctidae) is described from the early Miocene of southern New Zealand. Paratettigarcta zealandica gen. et sp. n. is the first cicada (Cicadoidea) fossil from New Zealand and exhibits wing venation patterns typical for the subfamily Tettigarctinae. It differs from other fossil taxa and the extant genus Tettigarcta in the early divergence of CuA2 from the nodal line in the forewing, its parallel-sided subcostal cell, the early bifurcation of vein M and long apical cells of the hindwing, and in wing pigmentation patterns. PMID:25829843

The cicada genus Karenia Distant, 1888 (Hemiptera: Cicadidae), with description of a new species.

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Pham, Hong-Thai; Constant, Jerome

2014-08-19

The cicadas of the genus Karenia are reviewed, and Karenia tibetensis sp.nov. (Hemiptera: Cicadidae) is described from Tibet, China. Pictures of the male adult and illustrations of the male genitalia are provided. A key to the species of Karenia is presented and the distribution of the Karenia species is discussed.

Thermal adaptation and diversity in tropical ecosystems: evidence from cicadas (Hemiptera, Cicadidae.

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Allen F Sanborn

Full Text Available The latitudinal gradient in species diversity is a central problem in ecology. Expeditions covering approximately 16°54' of longitude and 21°4' of latitude and eight Argentine phytogeographic regions provided thermal adaptation data for 64 species of cicadas. We test whether species diversity relates to the diversity of thermal environments within a habitat. There are general patterns of the thermal response values decreasing in cooler floristic provinces and decreasing maximum potential temperature within a habitat except in tropical forest ecosystems. Vertical stratification of the plant communities leads to stratification in species using specific layers of the habitat. There is a decrease in thermal tolerances in species from the understory communities in comparison to middle level or canopy fauna. The understory Herrera umbraphila Sanborn & Heath is the first diurnally active cicada identified as a thermoconforming species. The body temperature for activity in H. umbraphila is less than and significantly different from active body temperatures of all other studied species regardless of habitat affiliation. These data suggest that variability in thermal niches within the heterogeneous plant community of the tropical forest environments permits species diversification as species adapt their physiology to function more efficiently at temperatures different from their potential competitors.

Thermal adaptation and diversity in tropical ecosystems: evidence from cicadas (Hemiptera, Cicadidae).

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Sanborn, Allen F; Heath, James E; Phillips, Polly K; Heath, Maxine S; Noriega, Fernando G

2011-01-01

The latitudinal gradient in species diversity is a central problem in ecology. Expeditions covering approximately 16°54' of longitude and 21°4' of latitude and eight Argentine phytogeographic regions provided thermal adaptation data for 64 species of cicadas. We test whether species diversity relates to the diversity of thermal environments within a habitat. There are general patterns of the thermal response values decreasing in cooler floristic provinces and decreasing maximum potential temperature within a habitat except in tropical forest ecosystems. Vertical stratification of the plant communities leads to stratification in species using specific layers of the habitat. There is a decrease in thermal tolerances in species from the understory communities in comparison to middle level or canopy fauna. The understory Herrera umbraphila Sanborn & Heath is the first diurnally active cicada identified as a thermoconforming species. The body temperature for activity in H. umbraphila is less than and significantly different from active body temperatures of all other studied species regardless of habitat affiliation. These data suggest that variability in thermal niches within the heterogeneous plant community of the tropical forest environments permits species diversification as species adapt their physiology to function more efficiently at temperatures different from their potential competitors.

The hypertrehalosemic neuropeptides of cicadas are structural isomers-evidence by ion mobility mass spectrometry.

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König, Simone; Marco, Heather; Gäde, Gerd

2017-11-01

It has been known for more than 20 years that the neurosecretory glands of the cicadas, the corpora cardiaca, synthesize two isobaric peptides with hypertrehalosemic activity. Both decapeptides have exactly the same amino acid sequence (pGlu-Val-Asn-Phe-Ser-Pro-Ser-Trp-Gly-Asn-NH 2 ) and mass but differ in their retention time in reversed-phase liquid chromatography. A synthetic peptide with the same sequence elutes together with the second more hydrophobic peptide peak of the natural cicada extract. It is not clear what modification is causing the described observations. Therefore, in the current study, ion mobility separation in conjunction with high-resolution mass spectrometry was used to investigate this phenomenon as it was sensitive to changes in conformation. It detected different drift times in buffer gas for both the intact peptides and some of their fragment ions. Based on the ion mobility and fragment ion intensity of the corresponding ions, it is concluded that the region Pro 6 -Ser 7 -Trp 8 contains a structural feature differing from the L-amino acids present in the known peptide. Whether the conformer is the result of racemization or other biochemical processes needs to be further investigated.

Thermal biology of Pacific cicada killers, Sphecius convallis Patton, in the Upper Sonoran Desert.

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Coelho, Joseph R; Holliday, Charles W; Hastings, Jon M; Phillips, Christy M

2016-04-01

A comprehensive investigation of the Pacific cicada killer, Sphecius convallis Patton, was undertaken to examine the behavioral and physiological mechanisms by which they are able to complete their life cycle in the thermal extremes of the Upper Sonoran Desert. S. convallis were endothermic, exhibiting elevated and relatively constant thorax temperatures during many activities. Males basked in trees at dawn to warm up, then used a variety of behaviors and perching strategies to maintain thorax temperature during territorial behavior. The thorax temperature of females was highest during provisioning and orientation flights, somewhat lower while investigating burrows, and lowest while digging burrows. The optimal thorax temperature for flight was about 40°C, which was approximated most closely by males resting in the shade during the afternoon. In mating clusters, the mated male was the hottest, the female was coolest and the other males were intermediate. Wasps lost about 5% of body mass during heating treatments, and may use evaporative water loss for cooling. Pacific cicada killers use a complex suite of behavioral and physiological adaptations to regulate body temperature during their nesting season. Copyright © 2016 Elsevier Ltd. All rights reserved.

Sperm morphology in four species of African platypleurine cicadas (Hemiptera: Cicadomorpha: Cicadidae).

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Chawanji, A S; Hodgson, A N; Villet, M H

2005-08-01

Mature spermatozoa from four species of platypleurine cicadas (Albanycada albigera, Azanicada zuluensis, Platypleura capensis and P. hirtipennis) were examined by light and electron microscopy. The filiform sperm have a similar ultrastructure in all species but notable variations were found in sperm dimensions. All species produce more than one discrete length of nucleated, motile sperm, a form of polymorphism termed polymegaly. Polymegaly is expressed in two ways: sperm have bi- or trimodal head and tail lengths. The anterior parts of sperm heads are embedded in an elongate homogenous matrix forming a spermatodesm. The conical acrosome is deeply invaginated posteriorly, and sits on top of the nucleus. The acrosomal contents are differentiated internally with an electron-lucent central medulla and a denser cortex. The homogenously electron-dense nucleus is pointed anteriorly and is generally cylindrical, although posteriorly there is a lateral invagination that extends part-way along the nucleus. This invagination houses fine granular material of the centriolar adjunct. Vesicle-like elements that are associated with both the posterior nucleus and the centriolar adjunct are also found within the invagination. Immediately posterior of and adjoining the centriolar adjunct is a pair of mitochondrial derivatives that are elongated and extend for almost the entire length of the tail. The absence of accessory bodies in cicada sperm suggests that within the Cicadomorpha, the families Cicadidae and Cercopidae are closely affiliated.

Population structure of Cicada barbara Stål (Hemiptera, Cicadoidea) from the Iberian Peninsula and Morocco based on mitochondrial DNA analysis.

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Pinto-Juma, G A; Quartau, J A; Bruford, M W

2008-02-01

We assess the genetic history and population structure of Cicada barbara in Morocco and the Iberian Peninsula, based on analysis of the mitochondrial cytochrome b gene. The divergence between Morocco and the Iberian Peninsula populations was strongly corroborated by the molecular data, suggesting genetically isolated populations with a low level of gene flow. The Ceuta population from Spanish North Africa was more similar to the Iberian populations than the surrounding Moroccan populations, suggesting that the Strait of Gibraltar has not been acting as a strict barrier to dispersal while the Rif Mountains have. The Iberian Peninsula specimens showed a signature of demographic expansion before that which occurred in Morocco, but some of the assumptions related to the demographic parameters should be considered with caution due to the small genetic variation found. The high haplotype diversity found in Morocco implies higher demographic stability than in the Iberian Peninsula populations. These results do not, however, suggest a Moroccan origin for Iberian cicadas; but the most northwest region in Africa, such as Ceuta, might have acted as a southern refuge for Iberian cicadas during the most severe climatic conditions, from where they could expand north when climate improved. The separation of two subspecies within C. barbara (C. barbara lusitanica and C. barbara barbara) finds support with these results.

Evaluation of insecticides in different dosages to control cicadas in parica plantations

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Odineila Martins Monteiro

2014-07-01

Full Text Available This study aimed to determine the more efficient and economically viable dosage of chemical insecticide to control Quesada gigas (Hemiptera: Cicadidae nymphs in parica plantations. Three dosages of three products (carbofuran, imidacloprid and thiamethoxam were tested based on the maximum recommended dosage for the control of cicadas in coffee plants and applied in total area. The dosage of one kilogram of a commercial product based in thiamethoxam per hectare was more efficient economically and environmentally to control nymphs of Q. gigas in parica plantations.

Spatially resolved chemical analysis of cicada wings using laser-ablation electrospray ionization (LAESI) imaging mass spectrometry (IMS).

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Román, Jessica K; Walsh, Callee M; Oh, Junho; Dana, Catherine E; Hong, Sungmin; Jo, Kyoo D; Alleyne, Marianne; Miljkovic, Nenad; Cropek, Donald M

2018-03-01

Laser-ablation electrospray ionization (LAESI) imaging mass spectrometry (IMS) is an emerging bioanalytical tool for direct imaging and analysis of biological tissues. Performing ionization in an ambient environment, this technique requires little sample preparation and no additional matrix, and can be performed on natural, uneven surfaces. When combined with optical microscopy, the investigation of biological samples by LAESI allows for spatially resolved compositional analysis. We demonstrate here the applicability of LAESI-IMS for the chemical analysis of thin, desiccated biological samples, specifically Neotibicen pruinosus cicada wings. Positive-ion LAESI-IMS accurate ion-map data was acquired from several wing cells and superimposed onto optical images allowing for compositional comparisons across areas of the wing. Various putative chemical identifications were made indicating the presence of hydrocarbons, lipids/esters, amines/amides, and sulfonated/phosphorylated compounds. With the spatial resolution capability, surprising chemical distribution patterns were observed across the cicada wing, which may assist in correlating trends in surface properties with chemical distribution. Observed ions were either (1) equally dispersed across the wing, (2) more concentrated closer to the body of the insect (proximal end), or (3) more concentrated toward the tip of the wing (distal end). These findings demonstrate LAESI-IMS as a tool for the acquisition of spatially resolved chemical information from fragile, dried insect wings. This LAESI-IMS technique has important implications for the study of functional biomaterials, where understanding the correlation between chemical composition, physical structure, and biological function is critical. Graphical abstract Positive-ion laser-ablation electrospray ionization mass spectrometry coupled with optical imaging provides a powerful tool for the spatially resolved chemical analysis of cicada wings.

Sperm morphology in five species of cicadettine cicadas (Hemiptera: Cicadomorpha: Cicadidae).

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Chawanji, Abraham S; Hodgson, Alan N; Villet, Martin H

2006-12-01

Mature spermatozoa from five species of cicadas of the subfamily Cicadettinae (Quintilia wealei, Melampsalta leucoptera, Stagira simplex, Xosopsaltria thunbergi and Monomatapa matoposa) were examined by light and electron microscopy. In each species sperm are elongate, aggregated into organized bundles with their heads embedded in a homogenous matrix to form spermatodesmata, and exhibit polymegaly. The head of the sperm consist of an anteriorly positioned conical acrosome that has a tubular substructure and a deep, posterior invagination that forms the subacrosomal space (eccentrically positioned anteriorly). The acrosome is flattened anteriorly; posteriorly it extends along either side of the nucleus as two tubular processes that gradually decrease in diameter. The filiform nucleus tapers anteriorly and intrudes into the subscrosomal space. Posteriorly the nucleus has a lateral invagination that houses material of the so-called centriolar adjunct. Posterior to the centriolar adjuct and the nucleus are two crystalline mitochondrial derivatives and a centriole, respectively, the latter giving rise to the axoneme, which has a 9 + 9 + 2 arrangement of microtubules. In these respects the sperm are similar to those of platypleurine cicadas. However, some features seem unique to cicadettines, including the structural organization of an enlarged centriolar adjunct and the dimensions of the tails. The enlarged centriolar adjunct has a lamella-like substructure and can be considered a synapomorphic character in the Cicadettinae. It is, therefore, potentially useful in the separation of this subfamily from the Cicadinae. In addition, the great length of the sperm nucleus of long-headed sperm in M. matoposa could be a synapomorphy of this genus and related taphurine and cicadettine species.

Description and key to the fifth-instars of some Cicadas (Hemiptera: Cicadidae) associated with coffee plants in Brazil.

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Maccagnan, D H B; Martinelli, N M

2011-01-01

Fifth-instars of the cicada species Dorisiana drewseni (Stål), Dorisiana viridis (Olivier), Fidicina mannifera (Fabricius), Fidicinoides pronoe (Walker) and Carineta fasciculata (Germar) are described and illustrated. Moreover, a key to the nymphs of these species along with Quesada gigas (Olivier) is also provided.

Revision of the cicada genus Dilobopyga (Hemiptera, Cicadidae) from Sulawesi and the Moluccas.

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Duffels, J P

2018-04-13

This revision of the cicadas of the genus Dilobopyga provides a diagnosis of the genus and descriptions, illustrations and distribution maps for 48 species. The following 33 species described here are new to science: D. angulata, angustata, bifida, curvispina, fasciata, hayashii, hollowayi, johani, knighti, langeraki, laterocurvata, latifascia, luwukensis, macrocerata, maleo, mamasa, mediolobata, nebulosa, operculata, palopoensis, pelengensis, platyacantha, quadrimaculata, rantemario, recurvata, rozendaali, sangihensis, sarasinorum, splendida, tambusisi, toraja, vantoli and watuwila. The key presented is designed for the identification of males of Dilobopyga to the species level. The subdivision of the genus in five species groups viz., opercularis group (17 species), nebulosa group (1 species), chlorogaster group (16 species), minahassae group (6 species) and watuwila group (8 species), is sustained by a phylogenetic analysis of morphological characters of all species described.        The cicadas of the genus Dilobopyga are found in Sulawesi, neighbouring islands and southern Moluccas. Of the 48 species of Dilobopyga 43 species are endemic to Sulawesi. Most of these Sulawesi species are restricted to either one peninsula or to a part of Central Sulawesi. The remaining five species are endemic to either the Sangihe Islands, Banggai Islands or the southern Moluccas. A taxon-area cladogram for the species of Dilobopyga provides a basis for a discussion on the historic biogeography of the genus.

Morphology, songs and genetics identify two new cicada species from Morocco: Tettigettalna afroamissa sp. nov. and Berberigetta dimelodica gen. nov. & sp. nov. (Hemiptera: Cicadettini).

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Costa, Gonçalo João; Nunes, Vera L; Marabuto, Eduardo; Mendes, Raquel; Laurentino, Telma G; Quartau, José Alberto; Paulo, Octávio S; Simões, Paula Cristina

2017-03-01

Morocco has been the subject of very few expeditions on the last century with the objective of studying small cicadas. In the summer of 2014 an expedition was carried out to Morocco to update our knowledge with acoustic recordings and genetic data of these poorly known species. We describe here two new small-sized cicadas that could not be directly assigned to any species of North African cicadas: Tettigettalna afroamissa sp. nov. and Berberigetta dimelodica gen. nov. & sp. nov. In respect to T. afroamissa it is the first species of the genus to be found outside Europe and we frame this taxon within the evolutionary history of the genus. Acoustic analysis of this species allows us to confidently separate T. afroamissa from its congeners. With B. dimelodica, a small species showing a remarkable calling song characterized by an abrupt frequency modulation, a new genus had to be erected. Bayesian inference and maximum likelihood phylogenetic analyses with DNA-barcode sequences of Cytochrome C Oxidase 1 support the monophyly of both species, their distinctness and revealed genetic structure within B. dimelodica. Alongside the descriptions we also provide GPS coordinates of collection points, distributions and habitat preferences.

Appearance of cicada fauna (Homoptera: Cicadoidea) by altitudes in Johor National Park, Mount Ledang, Johor

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Tahir, Aliadi Mohd; Sulaiman, Azman

2015-09-01

A total of 31 cicada species in 15 genera under two families (Cicadidae, 27 species in 11 genera; Tibicinidae, four species in three genera) was recorded for Johor National Park, Mount Ledang, Johor. This was based on 666 individuals were obtained through six sampling occasions in November 2012 until October 2013, each time using light trap set in six sampling locations (L1, L2, L3, L4a, L4b, L4c) that were selected based on altitudes. The most common and abundant species in L1 is Pomponia sp1 and recognized as new species that need to be described as new to science. Orientopsaltria saudarapadda Duffles & Zaidi appeared as the most common and abundant species in L2, represented by 21 individuals which covers 34.43 % of the total cicadas specimen in that area. In the location of L3, Dundubia vaginata (Fabricius) appeared as the most abundant species represented by 37 individuals or 26.81% while Abroma maculicollis Guerin appeared as the most common species. Shannon's Species Diversity Index (H') in L3 was the highest (H'=2.28) followed by L4b (H'=2.21), L2 (H'=1.93) L4a (H'=1.92), L4c (H'=1.84) and L1 (H'=1.58), and the evenness index in L1 was the highest (E= 0.88), followed by L4b (E= 0.79), L3 (E= 0.77), L2 (E= 0.75), L4c (E= 0.74) and L4a (E= 0.79). Margalef Species Richness Index in L3 was the highest (R'=3.65), followed by oleh L4b (R'=3.01), L4a (R'=2.97), L2 (R'=2.92), L4c (R'=2.4), and L1 (R'=2.01). Generally shows that L3 at the altitude 350 m appear as the best sampling site for cicadas species in Mount Ledang Johor with the highest value of species diversity and richness index.

Traces and burrowing behaviors of the Cicada nymph Cicadetta calliope: Neoichnology and paleoecological significance of extant soil-dwelling insects

Science.gov (United States)

Smith, J.J.; Hasiotis, S.T.

2008-01-01

This study documents the traces and burrowing behaviors of nymphs of the prairie cicada Cicadetta calliope (Hemiptera: Cicadidae), as observed in neoichnological experiments. Cicada nymphs were collected from the C horizons of sandy Fluvents along the Kansas River east of Lawrence, Kansas. The nymphs appeared to be fifth instars, 13-17 mm long and 6-7 mm wide. Nymphs were placed in plastic enclosures containing layers of colored, moist, very fine-grained sand. They burrowed immediately, excavating air-filled, sediment-enclosed cells between 20 mm and 40 mm long and averaging 9 mm wide. Burrowing was completed in three stages: (1) sediment in the forward portion of the cell was excavated and rolled into a ball with the forelimbs; (2) the nymph turned 180?? using a forward roll, and moved to the back of the cell; and (3) the sediment ball was pushed up against the back wall of the cell and kneaded with the forelimbs into a thin layer. Resulting burrow traces are sinuous and distinctly meniscate and demonstrate that insect larvae construct meniscate, backfilled burrows in well-drained terrestrial settings. Cicadetta calliope nymphs and their traces are excellent analogs for meniscate trace fossils commonly found in late Paleozoic-Cenozoic alluvial deposits and paleosols. Such meniscate trace fossils are useful for interpreting the paleoenvironment and paleohydrogeology of the units in which they are found. In addition, such backfilled burrows can be used to supplement the fossil record of cicada-like hemipterans, currently known only from the latest Permian to the Early Triassic. Copyright ?? 2008, SEPM (Society for Sedimentary Geology).

Cosmopsaltria halmaherae n. sp. endemic to Halmahera, Maluku, Indonesia (Homoptera, Cicadidae). The relationship of cicadas of Maluku Utara and Maluku Selatan

NARCIS (Netherlands)

Duffels, J.P.

1988-01-01

Cosmopsaltria halmaherae n. sp. is described from Halmahera, Maluku and placed in the C. doryca group. The characters of this group are reconsidered and the relationships of its members are discussed. The C. doryca group and two other monophyletic groups of cicadas demonstrate a vicariant

Optimization of the solid-state fermentation and properties of a polysaccharide from Paecilomyces cicadae (Miquel Samson and its antioxidant activities in vitro.

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Xueyong Ren

Full Text Available The culture conditions for the yield of a polysaccharide (PCPS produced by Paecilomyces cicadae (Miquel Samson on solid-state fermentation were investigated using response surface methodology (RSM. Plackett-Burman design (PBD was applied to screen out significant factors, followed by the paths of steepest ascent to move to the nearest region of maximum response. Then Box-Behnken design (BBD was conducted to optimize the final levels of the culture conditions. After analyzing the regression equation and the response surface contour plots, relative humidity 56.07%, inoculum 13.51 mL/100 g and temperature 27.09°C were found to be the optimal key parameters for PCPS production. The maximum predicted yield of PCPS was 10.76 mg/g under the optimized conditions. The resulting PCPS (FPCPS generated at optimal conditions was purified by chromatography column and found to be composed of mannose (43.2%, rhamnose (32.1%, xylose (14.5% and arabinose (10.2%. Based on the size exclusion chromatography combined with multi-angle laser light scattering (SEC-MALLS analysis, FPCPS adopted a Gaussian coil conformation in 0.1 M NaNO3 solution with 3.75 × 10(6 g/mol of the weight-average molar mass (Mw and 41.1 nm of the root-mean square radius (Rg(2z (1/2. Furthermore, both of the polysaccharides were revealed to have strong antioxidant activities by evaluating in DPPH radical, superoxide radicals and hydroxyl radical assay. These data suggest the polysaccharides of Paecilomyces cicadae (Miquel Samson produced by solid-state fermentation could be explored as potential natural antioxidants.

The eye-catching cicada Hamza ciliaris (Linnaeus, 1758) comb. n. in Indonesia and the Pacific: taxonomie status, synonymy, and distribution (Homoptera, Cicadoidea)

NARCIS (Netherlands)

Duffels, J.P.

1991-01-01

The new combination Hamza ciliaris (Linnaeus) is proposed for a cicada species widely distributed in Maluku ( = Moluccas), Timor, Banda, Kei and Banggai Islands, the Philippines, and the Palau group of the Caroline Islands. The synonymy of five species, treated in the literature as junior synonyms

Hubungan Antara Tingkat Pendidikan Orang Tua dengan Prestasi Siswa Sekolah Dasar dalam Mata Pelajaran Matematika di Kecamatan Cicadas Kota Bandung

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Teti Sofia Yanti

2006-06-01

Full Text Available Keberhasilan siswa dalam menempuh pendidikan di sekolah dipengaruhi oleh beberapa faktor diantaranya kepala sekolah, guru, siswa, orang tua dan lingkungan sekolah. Penelitian ini memberikan gambaran bahwa rata-rata nilai matematika siswa SD di Kecamatan Cicadas Bandung sudah relatif baik serta terdapat korelasi yang positif antara prestasi anak dalam pelajaran matematika dengan tingkat pendidikan Ayah maupun Ibu.

The cicadas (Hemiptera: Cicadidae) of India, Bangladesh, Bhutan, Myanmar, Nepal and Sri Lanka: an annotated provisional catalogue, regional checklist and bibliography.

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Price, Benjamin Wills; Allan, Elizabeth Louise; Marathe, Kiran; Sarkar, Vivek; Simon, Chris; Kunte, Krushnamegh

2016-01-01

The cicadas of the Indian subcontinent, like many other insects in the region, have remained understudied since the early part of the 20th Century, and await modern taxonomic, systematic and phylogenetic treatment. This paper presents an updated systematic catalogue of cicadas (Hemiptera: Cicadidae) from India, Bangladesh, Bhutan, Myanmar, Nepal and Sri Lanka, the first in over a century. This paper treats 281 species, including: India and Bangladesh (189 species), Bhutan (19 species), Myanmar (81 species), Nepal (46 species) and Sri Lanka (22 species). For each species all recognized junior synonyms are included with information on the type material and additional specimens where relevant. The global distributional range and notes on the taxonomy of each species are included where appropriate. Two lists are provided: (1) species known to occur in India and Bangladesh (treated as a geographic unit), Bhutan, Myanmar, Nepal and Sri Lanka; and (2) species previously listed from these countries in error. A bibliography of species descriptions is provided, with the papers containing the original descriptions provided where copyright allows.

Two new genera and five new species of Mugadina-like small grass cicadas (Hemiptera: Cicadidae: Cicadettini) from Central and Eastern Australia: comparative morphology, songs, behaviour and distributions.

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Ewart, A

2018-04-20

Moulds (2012) established the genus Mugadina for two small cicadas, M. marshalli (Distant) and M. emma (Goding and Froggatt), both grass inhabiting species known from Queensland and New South Wales. Both species are notable for their relatively simple 'ticking' songs. Moulds further noted that there were at least two superficially similar genera of cicadas, but each with different genitalia. This paper describes two new genera of small (9-15 mm body lengths) and distinctive grass cicadas with genitalia that are very similar to those of Mugadina, but possess clear morphological, colour and calling song differences. The new genera are: Heremusina n. gen. with two known species namely H. udeoecetes n. sp. and H. pipatio n. sp.; the second new genus is Xeropsalta n. gen., containing four known species, X. thomsoni n. sp., X. aridula n. sp., X. rattrayi n. sp., and X. festiva n. comb. Heremusina n. gen. species are described from the Alice Springs area of Northern Territory and the Cloncurry area of northwest Queensland, from arid to semi arid habitats. The Xeropsalta n. gen. species are described from western, southwest and central Queensland, and from the Simpson and Strzelecki Deserts in northeastern South Australia and northwestern New South Wales, respectively, all locations in very arid to arid habitats, but close to seasonal (often irregular) rivers and lakes. X. festiva n. comb. occurs in semi arid habitats in southern and southeastern Australia.        Detailed taxonomic descriptions are provided of the new species, together with distributions, habitats, and the calling songs. The Heremusina species emit songs with short repetitive buzzing echemes, the echeme durations differing between each species. The Xeropsalta songs are notable for their complexity, containing multiple elements with rapid changes of amplitudes and temporal structures, rather atypical of the songs of most small grass dwelling cicadas. Detailed song structures distinguishing each of

New records of Brazilian cicadas including the description of a new species (Hemiptera: Cicadoidea, Cicadidae).

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Sanborn, Allen F

2008-01-01

A new species of Proarna Stål is described from southern Brazil. Proarna gianucai sp. nov. is distinguished by its coloration and genitalia. The species inhabits coastal dune environments and is associated with the perennial grass Panicum racemosum (P. Beauv.) Spreng. Adults are active from December to March. The first records of Carineta durantoni Boulard, Carineta gemella Boulard, Carineta pilifera Walker, Fidicina christinae Boulard & Martinelli, Fidicina torresi Boulard & Martinellli, Fidicinoides determinata (Walker), Fidicinoides distanti (Goding), Fidicinoides glauca (Goding), Majeorona truncata Goding, and Zammara columbia Distant for Brazil are provided. The new species and new records bring the total cicada diversity of Brazil to 146 species.

Conflicting patterns of DNA barcoding and taxonomy in the cicada genus Tettigettalna from Southern Europe (Hemiptera: Cicadidae).

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Nunes, Vera L; Mendes, Raquel; Marabuto, Eduardo; Novais, Bruno M; Hertach, Thomas; Quartau, José A; Seabra, Sofia G; Paulo, Octávio S; Simões, Paula C

2014-01-01

DNA barcodes have great potential to assist in species identification, especially when high taxonomical expertise is required. We investigated the utility of the 5' mitochondrial cytochrome c oxidase I (COI) region to discriminate between 13 European cicada species. These included all nine species currently recognized under the genus Tettigettalna, from which seven are endemic to the southern Iberian Peninsula. These cicadas have species-specific male calling songs but are morphologically very similar. Mean COI divergence between congeners ranged from 0.4% to 10.6%, but this gene was proven insufficient to determine species limits within genus Tettigettalna because a barcoding gap was absent for several of its species, that is, the highest intraspecific distance exceeded the lowest interspecific distance. The genetic data conflicted with current taxonomic classification for T. argentata and T. mariae. Neighbour-joining and Bayesian analyses revealed that T. argentata is geographically structured (clades North and South) and might constitute a species complex together with T. aneabi and T. mariae. The latter diverges very little from the southern clade of T. argentata and shares with it its most common haplotype. T. mariae is often in sympatry with T. argentata but it remains unclear whether introgression or incomplete lineage sorting may be responsible for the sharing of haplotypes. T. helianthemi and T. defauti also show high intraspecific variation that might signal hidden cryptic diversity. These taxonomic conflicts must be re-evaluated with further studies using additional genes and extensive morphological and acoustic analyses. © 2013 John Wiley & Sons Ltd.

Bayesian Age-Period-Cohort Modeling and Prediction - BAMP

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Volker J. Schmid

2007-10-01

Full Text Available The software package BAMP provides a method of analyzing incidence or mortality data on the Lexis diagram, using a Bayesian version of an age-period-cohort model. A hierarchical model is assumed with a binomial model in the first-stage. As smoothing priors for the age, period and cohort parameters random walks of first and second order, with and without an additional unstructured component are available. Unstructured heterogeneity can also be included in the model. In order to evaluate the model fit, posterior deviance, DIC and predictive deviances are computed. By projecting the random walk prior into the future, future death rates can be predicted.

How the Aridification of Australia Structured the Biogeography and Influenced the Diversification of a Large Lineage of Australian Cicadas.

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Owen, Christopher L; Marshall, David C; Hill, Kathy B R; Simon, Chris

2017-07-01

Over the last 30 million years, Australia's landscape has undergone dramatic cooling and drying due to the establishment of the Antarctic Circumpolar Current and change in global CO$_{2}$ levels. Studies have shown that many Australian organisms went extinct during these major cooling events, while others experienced adaptive radiations and increases in diversification rates as a result of exploiting new niches in the arid zone. Despite the many studies on diversification and biogeography in Australia, few have been continent-wide and none have focused on a group of organisms adapted to feeding on plants. We studied 162 species of cicadas in the Australian Pauropsalta complex, a large generic lineage within the tribe Cicadettini. We asked whether there were changes in the diversification rate of Pauropsalta over time and if so: 1) which clades were associated with the rate change? 2) did timing of rate shifts correspond to known periods of dramatic historical climate change, 3) did increases in diversification rate along select lineages correspond to adaptive radiations with movement into the arid zone? To address these questions, we estimated a molecular phylogeny of the Pauropsalta complex using ${\\sim}$5300 bp of nucleotide sequence data distributed among five loci (one mtDNA locus and four nDNA loci). We found that this large group of cicadas did not diversify at a constant rate as they spread through Australia; instead the signature of decreasing diversification rate changed roughly around the time of the expansion of the east Antarctic ice sheets ${\\sim}$16 Ma and the glaciation of the northern hemisphere ${\\sim}$3 Ma. Unlike other Australian taxa, the Pauropsalta complex did not explosively radiate in response to an early invasion of the arid zone. Instead multiple groups invaded the arid zone and experienced rates of diversification similar to mesic-distributed taxa. We found evidence for relictual groups, located in pre-Mesozoic habitat, that have not

Morphology and identification of the final instar nymphs of three cicadas (Hemiptera, Cicadidae) in Guanzhong Plain, China based on comparative morphometrics.

Science.gov (United States)

Hou, Zehai; Li, Qinglong; Wei, Cong

2014-01-01

The present investigation provides comparative morphometrics of the final instar nymphs of three dominant cicada species, i.e., Cryptotympana atrata (Fabricius), Meimuna mongolica (Distant) and Platypleura kaempferi (Fabricius), in Guanzhong Plain, China. Particularly, characters on the antennae, legs, and apex of abdomen of both males and females of these three species were investigated and analyzed. In addition, the numbers of hind tibial spines of the final instar nymphs of 21 representatives of Cicadoidea were compared. The results provide useful characteristics for nymph identification of related species and for further taxonomic and phylogenetic analysis of Cicadoidea.

Revised predictions of long-period ocean tidal effects on Earth's rotation rate

Science.gov (United States)

Dickman, S. R.; Nam, Young S.

1995-01-01

The rotational response of Earth to long-period tidal forces, embodied in a 'zonal response function,' can be expected to vary with frequency because of variable contributions by the oceans, mantle, and core. The zonal response function has been estimated from 9 years of International Radio Interferometric Surveying (IRIS) universal time (UT1) data and compared with theoretical predictions, using a spherical harmonic tide model to compute the oceans' dynamic response, at semiannual, monthly, fortnightly, and 9-day lunisolar tidal frequencies. Different amounts of mantle anelasticity have been considered for both the oceanic and soild earth responses; predictions have been made assuming axial core-mantle coupling which is either complete or absent. Additionally, an extensive recalibration of the ocean model's frictional parameters was performed using constraints derived in part from Space92 polar motion data; zonal response function predictions have also been made employing this recalibrated ocean tide model. Our results indicate that any amount of core coupling can be ruled out at a fortnightly period and probably at a 9-day period, but not at a monthly period. Our results also suggest that the mantle responds purely elastically at a 9-day period but may behave increasingly anelastically at longer periods. A simple dispersive rule is postulated for periods ranging up to the 14-month Chandler wobble period.

Molecular phylogenetics, diversification, and systematics of Tibicen Latreille 1825 and allied cicadas of the tribe Cryptotympanini, with three new genera and emphasis on species from the USA and Canada(Hemiptera: Auchenorrhyncha: Cicadidae).

Science.gov (United States)

Hill, Kathy B R; Marshall, David C; Moulds, Maxwell S; Simon, Chris

2015-07-10

North America has a diverse cicada fauna with multiple genera from all three Cicadidae subfamilies, yet molecular phylogenetic analyses have been completed only for the well-studied periodical cicadas (Magicicada Davis). The genus Tibicen Latreille, a large group of charismatic species, is in need of such work because morphological patterns suggest multiple groups with complicated relationships to other genera in the tribe Cryptotympanini. In this paper we present a molecular phylogenetic analysis, based on mitochondrial and nuclear DNA, of 35 of the 38 extant USA species and subspecies of the genus Tibicen together with their North American tribal allies (Cornuplura Davis, Cacama Davis), selected Tibicen species from Eurasia, and representatives of other Eurasian and Pacific cryptotympanine genera. This tree shows that Tibicen contains several well-supported clades, one predominating in eastern and central North America and related to Cryptotympana Stål and Raiateana Boulard, another in western North America related to Cacama and Cornuplura, and at least two clades in Eurasia. We also present a morphological cladistic analysis of Tibicen and its close allies based on 27 characters. Character states identified in the cladistic analysis define three new genera, two for North American taxa (Hadoa gen. n. and Neotibicen gen. n.) including several Mexican species, and one for Asian species (Subsolanus gen. n.). Using relaxed molecular clocks and literature-derived mtDNA rate estimates, we estimate the timeframe of diversification of Tibicen clades and find that intergeneric divergence has occurred since the late Eocene, with most extant species within the former Tibicen originating after the mid-Miocene. We review patterns of ecology, behavior, and geography among Tibicen clades in light of the phylogenetic results and note that the study of these insects is still in its early stages. Some Mexican species formerly placed in Tibicen are here transferred to Diceroprocta

6-year periodicity and variable synchronicity in a mass-flowering plant.

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Satoshi Kakishima

Full Text Available Periodical organisms, such as bamboos and periodical cicadas, are very famous for their synchronous reproduction. In bamboos and other periodical plants, the synchronicity of mass-flowering and withering has been often reported indicating these species are monocarpic (semelparous species. Therefore, synchronicity and periodicity are often suspected to be fairly tightly coupled traits in these periodical plants. We investigate the periodicity and synchronicity of Strobilanthes flexicaulis, and a closely related species S. tashiroi on Okinawa Island, Japan. The genus Strobilanthes is known for several periodical species. Based on 32-year observational data, we confirmed that S. flexicaulis is 6-year periodical mass-flowering monocarpic plant. All the flowering plants had died after flowering. In contrast, we found that S. tashiroi is a polycarpic perennial with no mass-flowering from three-year individual tracking. We also surveyed six local populations of S. flexicaulis and found variation in the synchronicity from four highly synchronized populations (>98% of plants flowering in the mass year to two less synchronized one with 11-47% of plants flowering before and after the mass year. This result might imply that synchrony may be selected for when periodicity is established in monocarpic species. We found the selective advantages for mass-flowering in pollinator activities and predator satiation. The current results suggest that the periodical S. flexicaulis might have evolved periodicity from a non-periodical close relative. The current report should become a key finding for understanding the evolution of periodical plants.

RAPID COMMUNICATION: Improving prediction accuracy of GPS satellite clocks with periodic variation behaviour

Science.gov (United States)

Heo, Youn Jeong; Cho, Jeongho; Heo, Moon Beom

2010-07-01

The broadcast ephemeris and IGS ultra-rapid predicted (IGU-P) products are primarily available for use in real-time GPS applications. The IGU orbit precision has been remarkably improved since late 2007, but its clock products have not shown acceptably high-quality prediction performance. One reason for this fact is that satellite atomic clocks in space can be easily influenced by various factors such as temperature and environment and this leads to complicated aspects like periodic variations, which are not sufficiently described by conventional models. A more reliable prediction model is thus proposed in this paper in order to be utilized particularly in describing the periodic variation behaviour satisfactorily. The proposed prediction model for satellite clocks adds cyclic terms to overcome the periodic effects and adopts delay coordinate embedding, which offers the possibility of accessing linear or nonlinear coupling characteristics like satellite behaviour. The simulation results have shown that the proposed prediction model outperforms the IGU-P solutions at least on a daily basis.

Inelastic spectra to predict period elongation of structures under earthquake loading

DEFF Research Database (Denmark)

Katsanos, Evangelos; Sextos, A.G.

2015-01-01

Period lengthening, exhibited by structures when subjected to strong ground motions, constitutes an implicit proxy of structural inelasticity and associated damage. However, the reliable prediction of the inelastic period is tedious and a multi-parametric task, which is related to both epistemic ...... for period lengthening as a function of Ry and Tel. These equations may be used in the framework of the earthquake record selection and scaling....

Prediction of the Fundamental Period of Infilled RC Frame Structures Using Artificial Neural Networks

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Panagiotis G. Asteris

2016-01-01

Full Text Available The fundamental period is one of the most critical parameters for the seismic design of structures. There are several literature approaches for its estimation which often conflict with each other, making their use questionable. Furthermore, the majority of these approaches do not take into account the presence of infill walls into the structure despite the fact that infill walls increase the stiffness and mass of structure leading to significant changes in the fundamental period. In the present paper, artificial neural networks (ANNs are used to predict the fundamental period of infilled reinforced concrete (RC structures. For the training and the validation of the ANN, a large data set is used based on a detailed investigation of the parameters that affect the fundamental period of RC structures. The comparison of the predicted values with analytical ones indicates the potential of using ANNs for the prediction of the fundamental period of infilled RC frame structures taking into account the crucial parameters that influence its value.

Predictive monitoring and diagnosis of periodic air pollution in a subway station.

Science.gov (United States)

Kim, YongSu; Kim, MinJung; Lim, JungJin; Kim, Jeong Tai; Yoo, ChangKyoo

2010-11-15

The purpose of this study was to develop a predictive monitoring and diagnosis system for the air pollutants in a subway system using a lifting technique with a multiway principal component analysis (MPCA) which monitors the periodic patterns of the air pollutants and diagnoses the sources of the contamination. The basic purpose of this lifting technique was to capture the multivariate and periodic characteristics of all of the indoor air samples collected during each day. These characteristics could then be used to improve the handling of strong periodic fluctuations in the air quality environment in subway systems and will allow important changes in the indoor air quality to be quickly detected. The predictive monitoring approach was applied to a real indoor air quality dataset collected by telemonitoring systems (TMS) that indicated some periodic variations in the air pollutants and multivariate relationships between the measured variables. Two monitoring models--global and seasonal--were developed to study climate change in Korea. The proposed predictive monitoring method using the lifted model resulted in fewer false alarms and missed faults due to non-stationary behavior than that were experienced with the conventional methods. This method could be used to identify the contributions of various pollution sources. Copyright © 2010 Elsevier B.V. All rights reserved.

Morphology and identification of the final instar nymphs of three cicadas (Hemiptera, Cicadidae in Guanzhong Plain, China based on comparative morphometrics

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Zehai Hou

2014-07-01

Full Text Available The present investigation provides comparative morphometrics of the final instar nymphs of three dominant cicada species, i.e., Cryptotympana atrata (Fabricius, Meimuna mongolica (Distant and Platypleura kaempferi (Fabricius, in Guanzhong Plain, China. Particularly, characters on the antennae, legs, and apex of abdomen of both males and females of these three species were investigated and analyzed. In addition, the numbers of hind tibial spines of the final instar nymphs of 21 representatives of Cicadoidea were compared. The results provide useful characteristics for nymph identification of related species and for further taxonomic and phylogenetic analysis of Cicadoidea.

New Jurassic tettigarctid cicadas from China with a novel example of disruptive coloration

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Jun Chen

2016-12-01

Full Text Available Tettigarctidae is the most primitive family of Cicadoidea, with only two relict species. Although they are relatively well known from Eurasia, Australia, Africa, and South America, their Mesozoic examples are typically preserved only as isolated forewings. Herein, a new genus Sanmai Chen, Zhang, and B. Wang with three new species (Sanmai kongi Chen, Zhang, and B. Wang, S. mengi Chen, Zhang, and B. Wang, and S. xuni Chen, Zhang, and B. Wang are described based on fossil specimens from the Middle–Upper Jurassic of northeastern China, with well-preserved body structures, forewing and hindwing venations, making it the hitherto best known extinct tettigarctid taxon. The new genus, provisionally assigned to the tribe Turutanoviini, provides some new information about the evolution and palaeobiogeography of Mesozoic Tettigarctidae. The genus Paraprosbole is synonymized with Shuraboprosbole. In addition, the coloration pattern of forewing, prominent on some specimens of Sanmai kongi Chen, Zhang, and B. Wang sp. nov. and Sanmai xuni Chen, Zhang, and B. Wang sp. nov., represents a novel example of disruptive coloration in Tettigarctidae, which can effectively break up the body outline as well as surface, and so likely enabled these cicadas to reduce the detectability of potential predators.

Period, epoch, and prediction errors of ephemerides from continuous sets of timing measurements

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Deeg, H. J.

2015-06-01

Space missions such as Kepler and CoRoT have led to large numbers of eclipse or transit measurements in nearly continuous time series. This paper shows how to obtain the period error in such measurements from a basic linear least-squares fit, and how to correctly derive the timing error in the prediction of future transit or eclipse events. Assuming strict periodicity, a formula for the period error of these time series is derived, σP = σT (12 / (N3-N))1 / 2, where σP is the period error, σT the timing error of a single measurement, and N the number of measurements. Compared to the iterative method for period error estimation by Mighell & Plavchan (2013), this much simpler formula leads to smaller period errors, whose correctness has been verified through simulations. For the prediction of times of future periodic events, usual linear ephemeris were epoch errors are quoted for the first time measurement, are prone to an overestimation of the error of that prediction. This may be avoided by a correction for the duration of the time series. An alternative is the derivation of ephemerides whose reference epoch and epoch error are given for the centre of the time series. For long continuous or near-continuous time series whose acquisition is completed, such central epochs should be the preferred way for the quotation of linear ephemerides. While this work was motivated from the analysis of eclipse timing measures in space-based light curves, it should be applicable to any other problem with an uninterrupted sequence of discrete timings for which the determination of a zero point, of a constant period and of the associated errors is needed.

Hybridization, mitochondrial DNA phylogeography, and prediction of the early stages of reproductive isolation: lessons from New Zealand cicadas (genus Kikihia).

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Marshall, David C; Hill, Kathy B R; Cooley, John R; Simon, Chris

2011-07-01

One of the major tenets of the modern synthesis is that genetic differentiation among subpopulations is translated over time into genetic differentiation among species. Phylogeographic exploration is therefore essential to the study of speciation because it can reveal the presence of subpopulations that may go on to become species or that may already represent cryptic species. Acoustic species-specific mating signals provide a significant advantage for the recognition of cryptic or incipient species. Because the majority of species do not have such easily recognized premating signals, data from acoustically signaling species can serve as a valuable heuristic tool. Acoustic signals are also convenient tools for recognizing hybridization events. Here, we demonstrate that evidence of hybridization in the form of intermediate song phenotypes is present in many contact zones between species of the New Zealand grass cicadas of the Kikihia muta species complex and that recurring mitochondrial DNA (mtDNA) introgression has created misleading patterns that make it difficult to identify certain taxa using song or mtDNA alone. In one case, introgression appears to have occurred between allopatric taxa by dispersal of introgressed populations of an intermediary species ("hybridization by proxy"). We also present a comparison of mtDNA-tree- and song-based taxonomies obtained for the K. muta complex. We find that 12 mtDNA candidate species are identified using shifts in phylogenetic branching rate found by a single-threshold mixed Yule-coalescent lineage model, while only 7 candidate species are identified using songs. Results from the Yule-coalescent model are dependent on factors such as the number of modeled thresholds and the inclusion of duplicate haplotypes. Genetic distances within song species reach a maximum at about 0.028 substitutions/site when likely cases of hybridization and introgression are excluded. Large genetic breaks or "gaps" are not observed between some

A new Neotibicen cicada subspecies (Hemiptera: Cicadidae) from the southeastern USA forms hybrid zones with a widespread relative despite a divergent male calling song.

Science.gov (United States)

Marshall, David C; Hill, Kathy B R

2017-05-31

A morphologically cryptic subspecies of Neotibicen similaris (Smith and Grossbeck) is described from forests of the Apalachicola region of the southeastern United States. Although the new form exhibits a highly distinctive male calling song, it hybridizes extensively where it meets populations of the nominate subspecies in parapatry, by which it is nearly surrounded. This is the first reported example of hybridization between North American nonperiodical cicadas. Acoustic and morphological characters are added to the original description of the nominate subspecies, and illustrations of complex hybrid song phenotypes are presented. The biogeography of N. similaris is discussed in light of historical changes in forest composition on the southeastern Coastal Plain.

Environ: E00507 [KEGG MEDICUS

Lifescience Database Archive (English)

Full Text Available E00507 Cicada flammata larva Crude drug ... Cicada flammata [TAX:186872], Cordyceps sobol...ifera [TAX:94213], Cordyceps cicadae [TAX:218633] ... Cicadidae Cicada flammata larva parasitized by Clavicipitaceae Cordyceps sobolifera, Cordyceps cicadae (dried) ...

Identification of Tibicen cicada species by a Principal Components Analysis of their songs

Directory of Open Access Journals (Sweden)

Eiji Ohya

2004-06-01

Full Text Available Specific identification of three Tibicen cicadas, T. japonicus, T. flammatus and T. bihamatus, by their chirping sounds was carried out using Principal Components Analysis (PCA. High quality recordings of each species were used as the standards. The peak and mean frequencies and the pulse rate were used as the variables. Out of 12 samples recorded in the fields one fell in the vicinity of T. japonicus and all other were positioned near T. bihamatus. Then the cluster analysis of the PCA scores clearly separated each species and allocated the samples in the same way.A identificação de três espécies de cigarras do gênero Tibicen, T. japonicus, T. flammatus e T. bihamatus, através de seus sons estridentes foi realizada por meio da Análise de Componentes Principais (PCA. Gravações de alta fidelidade de cada espécie foram usadas como referencias. As variáveis usadas foram as freqüências máxima e média e a taxa de pulsos. Das 12 amostras gravadas no campo, uma foi colocada perto de T. japonicus e as outras perto de T. bihamatus. A análise de conglomerados dos valores da PCA separou claramente cada espécie e posicionou as amostras da mesma maneira.

Gross morphology and ultrastructure of salivary glands of the mute cicada Karenia caelatata Distant (Hemiptera: Cicadoidea).

Science.gov (United States)

Zhong, Hai-ying; Wei, Cong; Zhang, Ya-lin

2013-02-01

Salivary glands of the cicada Karenia caelatata Distant were investigated using light microscopy and transmission electron microscopy. The salivary glands are paired structures and consist of principal glands and accessory glands. The principal gland is subdivided into anterior lobe and posterior lobe; the former contains about 34-39 long digitate lobules, while the latter contains approximately 30-33 long digitate lobules and 13-22 short digitate lobules. These short digitate lobules, about one fifth or sixth as long as the long digitate lobules, locate at the base of the long digitate lobules of posterior lobe. All of these digitate lobules vary in size, disposition, length and shape. The anterior lobe and the posterior lobe are connected by an anterior-posterior duct. Two efferent salivary ducts, which connect with the posterior lobe, fuse to form a common duct. The accessory gland is composed of three parts: a greatly tortuous and folded accessory salivary tube, a circlet of gular gland constituting of several acini of the same size, and a non-collapsible accessory salivary duct. The digitate lobules and gular glands possess secretory cells containing abundant secretory granules vary in size, shape, and electron density, as might indicate different materials are synthesized in different secretory regions. The anterior-posterior duct lines with a player of cuticular lining, and cells beneath the cuticular lining lack of basal infoldings, as suggests the duct serves just to transport secretions. The accessory salivary duct is lined with cuticular lining; cells of the duct have well developed basal infoldings associated with abundant mitochondria, as probably suggests the duct is a reabsorptive region of ions. The cells of the accessory salivary tube possess deep basal infoldings and well developed apical dense microvilli, indicating the cells of the tube are secretory in function. Concentric lamellar structures and a peculiar structure with abundant membrane

Prediction of electric energy consumption in Cuba for the period 2000-2015

International Nuclear Information System (INIS)

Garcia Rodirguez, B

1999-01-01

This paper consists on a prediction of the growth in electric energy consumption in Cuba, for the period 2000-2015 and with respect to 1990, it also considers the specific features of the National Electroenergetic System. Validated Guidelines in accordance with the Delphi method, which incorporates the basis characteristics considered by international programs for these predictions, were used for this purpose. From the analysis of the behaviour in power consumption of the different consumers and of the expected changes in them according to the expected scenarios, a prediction on the growth in the demand of electric energy is made

CT findings suggesting anastomotic leak and predicting the recovery period following gastric surgery

Energy Technology Data Exchange (ETDEWEB)

Kim, Tae Ho; Kim, Jung Hoon; Shin, Cheong-Il; Kim, Se Hyung; Han, Joon Koo; Choi, Byung Ihn [Seoul National University College of Medicine, Department of Radiology, Institute of Radiation Medicine, Jongno-gu, Seoul (Korea, Republic of)

2015-07-15

To assess diagnostic performance of routine CT for detecting anastomotic leak after gastric surgery, and analyse the relationship between recovery period and CT findings. We included 179 patients who underwent immediate CT and fluoroscopy after gastric surgery. Two reviewers retrospectively rated the possibility of leak on CT using a five-point scale focused on predefined CT findings. They also evaluated CT findings. Patients were categorised as: Group I, leak on fluoroscopy; Group II, possible leak on CT but negative on fluoroscopy; Group III, no leak. We analysed the relationship between recovery period and group. Area under the curve for detecting leak on CT was 0.886 in R1 and 0.668 in R2 with moderate agreement (k = 0.482). Statistically common CT findings for leak included discontinuity, large amount of air-fluid and wall thickening at anastomosis site (p < 0.05). Discontinuity at anastomosis site and a large air-fluid collection were independently associated with leak (p < 0.05). The recovery period including hospitalisation and postoperative fasting period was longer in Group I than Group II or III (p < 0.05). Group II showed a longer recovery period than Group III (p < 0.05). Postoperative routine CT was useful for predicting anastomotic leak using specific findings, and for predicting length of recovery period. (orig.)

Prediction of leakage current of non-ceramic insulators in early aging period

Energy Technology Data Exchange (ETDEWEB)

El-Hag, Ayman H. [Electrical Engineering Department, American University of Sharjah, Sharjah (United Arab Emirates); Jahromi, Ali Naderian [Kinectrics Inc., Transmission and Distribution Technologies, Toronto (Canada); Sanaye-Pasand, Majid [Electrical and Computer Engineering Department, University of Tehran (Iran)

2008-10-15

The paper presents a neural network based prediction technique for the leakage current (LC) of non-ceramic insulators during salt-fog test. Nearly 50 distribution class silicone rubber (SIR) insulators with three different voltage classes have been tested in a salt-fog chamber, where the LC has been continuously recorded for at least 100 h. A boundary for early aging period is defined by the rate of change of the LC instead of a fixed threshold value. Consequently, the Gaussian radial basis network has been adopted to predict the level of LC at the early stage of aging of the SIR insulators and is compared with a classical network. The initial values of LC and its rate of change at 10 min intervals for the first 5 h are selected as the input to the network, and the final value of LC of the early aging period is considered as the output of the network. It is found that Gaussian radial basis function network with a random optimizing training method is an appropriate network to predict the LC with a 3.5-5.3% accuracy, if the training data and the testing data are selected from the same type of SIR insulators. (author)

Prediction of periodically correlated processes by wavelet transform and multivariate methods with applications to climatological data

Science.gov (United States)

Ghanbarzadeh, Mitra; Aminghafari, Mina

2015-05-01

This article studies the prediction of periodically correlated process using wavelet transform and multivariate methods with applications to climatological data. Periodically correlated processes can be reformulated as multivariate stationary processes. Considering this fact, two new prediction methods are proposed. In the first method, we use stepwise regression between the principal components of the multivariate stationary process and past wavelet coefficients of the process to get a prediction. In the second method, we propose its multivariate version without principal component analysis a priori. Also, we study a generalization of the prediction methods dealing with a deterministic trend using exponential smoothing. Finally, we illustrate the performance of the proposed methods on simulated and real climatological data (ozone amounts, flows of a river, solar radiation, and sea levels) compared with the multivariate autoregressive model. The proposed methods give good results as we expected.

Effect of length of measurement period on accuracy of predicted annual heating energy consumption of buildings

International Nuclear Information System (INIS)

Cho, Sung-Hwan; Kim, Won-Tae; Tae, Choon-Soeb; Zaheeruddin, M.

2004-01-01

This study examined the temperature dependent regression models of energy consumption as a function of the length of the measurement period. The methodology applied was to construct linear regression models of daily energy consumption from 1 day to 3 months data sets and compare the annual heating energy consumption predicted by these models with actual annual heating energy consumption. A commercial building in Daejon was selected, and the energy consumption was measured over a heating season. The results from the investigation show that the predicted energy consumption based on 1 day of measurements to build the regression model could lead to errors of 100% or more. The prediction error decreased to 30% when 1 week of data was used to build the regression model. Likewise, the regression model based on 3 months of measured data predicted the annual energy consumption within 6% of the measured energy consumption. These analyses show that the length of the measurement period has a significant impact on the accuracy of the predicted annual energy consumption of buildings

Stochastic model stationarization by eliminating the periodic term and its effect on time series prediction

Science.gov (United States)

Moeeni, Hamid; Bonakdari, Hossein; Fatemi, Seyed Ehsan

2017-04-01

Because time series stationarization has a key role in stochastic modeling results, three methods are analyzed in this study. The methods are seasonal differencing, seasonal standardization and spectral analysis to eliminate the periodic effect on time series stationarity. First, six time series including 4 streamflow series and 2 water temperature series are stationarized. The stochastic term for these series obtained with ARIMA is subsequently modeled. For the analysis, 9228 models are introduced. It is observed that seasonal standardization and spectral analysis eliminate the periodic term completely, while seasonal differencing maintains seasonal correlation structures. The obtained results indicate that all three methods present acceptable performance overall. However, model accuracy in monthly streamflow prediction is higher with seasonal differencing than with the other two methods. Another advantage of seasonal differencing over the other methods is that the monthly streamflow is never estimated as negative. Standardization is the best method for predicting monthly water temperature although it is quite similar to seasonal differencing, while spectral analysis performed the weakest in all cases. It is concluded that for each monthly seasonal series, seasonal differencing is the best stationarization method in terms of periodic effect elimination. Moreover, the monthly water temperature is predicted with more accuracy than monthly streamflow. The criteria of the average stochastic term divided by the amplitude of the periodic term obtained for monthly streamflow and monthly water temperature were 0.19 and 0.30, 0.21 and 0.13, and 0.07 and 0.04 respectively. As a result, the periodic term is more dominant than the stochastic term for water temperature in the monthly water temperature series compared to streamflow series.

Predictive factors for latency period in viable pregnancies complicated by preterm premature rupture of the membranes.

Science.gov (United States)

Çetin, Cihan; Büyükkurt, Selim; Cömert, Ercan; Özlü, Ferda; Bahar, Nilgün; Demir, Cansun

2015-03-01

In this study, we aimed to evaluate some laboratory and clinical factors in the prediction of latency period for pregnant patients complicated with preterm premature rupture of the membranes. Sixty-five pregnant patients between 24 and 34 weeks of gestation, who were admitted to University of Çukurova School of Medicine Hospital with the diagnosis of preterm premature rupture of the membranes (PPROM) between January 01, 2013 and December 31, 2013, were included in this study. Serum CRP, procalcitonin, sedimentation rate, leukocyte count and cervical length (measured with transvaginal ultrasound) of patients were analyzed for the correlation with the latency period. None of the parameters were found to be correlated with the latency period. However, patients with cervical length of premature rupture of the membranes is thought to be either an infection-based disease or a disease increasing the risk of infectious complications, major infection markers are not found to be helpful criteria for the prediction of latency period. Patients with a cervical length of <25 mm can be expected to deliver earlier and, therefore, can be referred to a tertiary center earlier.

Effects of the infectious period distribution on predicted transitions in childhood disease dynamics.

Science.gov (United States)

Krylova, Olga; Earn, David J D

2013-07-06

The population dynamics of infectious diseases occasionally undergo rapid qualitative changes, such as transitions from annual to biennial cycles or to irregular dynamics. Previous work, based on the standard seasonally forced 'susceptible-exposed-infectious-removed' (SEIR) model has found that transitions in the dynamics of many childhood diseases result from bifurcations induced by slow changes in birth and vaccination rates. However, the standard SEIR formulation assumes that the stage durations (latent and infectious periods) are exponentially distributed, whereas real distributions are narrower and centred around the mean. Much recent work has indicated that realistically distributed stage durations strongly affect the dynamical structure of seasonally forced epidemic models. We investigate whether inferences drawn from previous analyses of transitions in patterns of measles dynamics are robust to the shapes of the stage duration distributions. As an illustrative example, we analyse measles dynamics in New York City from 1928 to 1972. We find that with a fixed mean infectious period in the susceptible-infectious-removed (SIR) model, the dynamical structure and predicted transitions vary substantially as a function of the shape of the infectious period distribution. By contrast, with fixed mean latent and infectious periods in the SEIR model, the shapes of the stage duration distributions have a less dramatic effect on model dynamical structure and predicted transitions. All these results can be understood more easily by considering the distribution of the disease generation time as opposed to the distributions of individual disease stages. Numerical bifurcation analysis reveals that for a given mean generation time the dynamics of the SIR and SEIR models for measles are nearly equivalent and are insensitive to the shapes of the disease stage distributions.

Spatial correlations of Diceroprocta apache and its host plants: Evidence for a negative impact from Tamarix invasion

Science.gov (United States)

Ellingson, A.R.; Andersen, D.C.

2002-01-01

1. The hypothesis that the habitat-scale spatial distribution of the Apache cicada Diceroprocta apache Davis is unaffected by the presence of the invasive exotic saltcedar Tamarix ramosissima was tested using data from 205 1-m2 quadrats placed within the flood-plain of the Bill Williams River, Arizona, U.S.A. Spatial dependencies within and between cicada density and habitat variables were estimated using Moran's I and its bivariate analogue to discern patterns and associations at spatial scales from 1 to 30 m.2. Apache cicadas were spatially aggregated in high-density clusters averaging 3 m in diameter. A positive association between cicada density, estimated by exuvial density, and the per cent canopy cover of a native tree, Goodding's willow Salix gooddingii, was detected in a non-spatial correlation analysis. No non-spatial association between cicada density and saltcedar canopy cover was detected.3. Tests for spatial cross-correlation using the bivariate IYZ indicated the presence of a broad-scale negative association between cicada density and saltcedar canopy cover. This result suggests that large continuous stands of saltcedar are associated with reduced cicada density. In contrast, positive associations detected at spatial scales larger than individual quadrats suggested a spill-over of high cicada density from areas featuring Goodding's willow canopy into surrounding saltcedar monoculture.4. Taken together and considered in light of the Apache cicada's polyphagous habits, the observed spatial patterns suggest that broad-scale factors such as canopy heterogeneity affect cicada habitat use more than host plant selection. This has implications for management of lower Colorado River riparian woodlands to promote cicada presence and density through maintenance or creation of stands of native trees as well as manipulation of the characteristically dense and homogeneous saltcedar canopies.

Emergence of Prime Numbers as the Result of Evolutionary Strategy

Science.gov (United States)

Campos, Paulo R.; de Oliveira, Viviane M.; Giro, Ronaldo; Galvão, Douglas S.

2004-08-01

We investigate by means of a simple theoretical model the emergence of prime numbers as life cycles, as those seen for some species of cicadas. The cicadas, more precisely the Magicicadas, spend most of their lives below the ground and then emerge and die in a short period of time. The Magicicadas display an uncommon behavior: their emergence is synchronized and these periods are usually prime numbers. In the current work, we develop a spatially extended model at which preys and predators coexist and can change their evolutionary dynamics through the occurrence of mutations. We verified that prime numbers as life cycles emerge as a result of the evolution of the population. Our results seem to be a first step in order to prove that the development of such strategy is selectively advantageous, especially for those organisms that are highly vulnerable to attacks of predators.

[Prediction of the latency period by cervical ultrasonography in premature rupture of the membranes before term].

Science.gov (United States)

Gabriel, R; Morille, C; Drieux, L; Bige, V; Leymarie, F; Quereux, C

2002-11-01

To assess the value of ultrasonographic measurement of cervical length for predicting the duration of the latency period from admission to delivery in women with preterm premature rupture of the membranes (PROM). Prospective study in 88 women with preterm PROM before 34 weeks of amenorrhea. The median gestational age at admission was of 30.1 weeks. The clinical management included: no digital examination of the uterine cervix, antenatal corticosteroids, antibiotics (amoxicillin & clavulanic acid) for 7 days, and hoding back until 34 weeks. Cervical length at admission was determined with transvaginal ultrasonography. The duration of the latency period was studied in relation with cervical length, serum C-reactive protein (CRP) level and white blood cell (WBC) count at admission. The median latency period was longer in women with a cervical length > or = 25 mm (10 vs 5 days; p = 0.04), but this was not associated with a significant increase in birth weight. The median latency period was also longer in women with CRP < 20 mg/l (10 vs 3 days; p < 0.001) and this was associated with a significant increase in birth weight (1716 +/- 549 vs 1201 +/- 485 g; p < 0.01). Moreover, increased CRP levels were more frequent in women with a cervical length < 25 mm, and cervical length was no more predictive of the duration of the latency period in the subgroup of women with CRP < 20 mg/l and WBC < 20,000 cells/mm3. In women with preterm PROM, the latency period from admission to delivery is shorter when cervical length is < 25 mm. However, the clinical value of transvaginal ultrasonography is limited in comparison with serum CRP.

Fast and Accurate Prediction of Stratified Steel Temperature During Holding Period of Ladle

Science.gov (United States)

Deodhar, Anirudh; Singh, Umesh; Shukla, Rishabh; Gautham, B. P.; Singh, Amarendra K.

2017-04-01

Thermal stratification of liquid steel in a ladle during the holding period and the teeming operation has a direct bearing on the superheat available at the caster and hence on the caster set points such as casting speed and cooling rates. The changes in the caster set points are typically carried out based on temperature measurements at the end of tundish outlet. Thermal prediction models provide advance knowledge of the influence of process and design parameters on the steel temperature at various stages. Therefore, they can be used in making accurate decisions about the caster set points in real time. However, this requires both fast and accurate thermal prediction models. In this work, we develop a surrogate model for the prediction of thermal stratification using data extracted from a set of computational fluid dynamics (CFD) simulations, pre-determined using design of experiments technique. Regression method is used for training the predictor. The model predicts the stratified temperature profile instantaneously, for a given set of process parameters such as initial steel temperature, refractory heat content, slag thickness, and holding time. More than 96 pct of the predicted values are within an error range of ±5 K (±5 °C), when compared against corresponding CFD results. Considering its accuracy and computational efficiency, the model can be extended for thermal control of casting operations. This work also sets a benchmark for developing similar thermal models for downstream processes such as tundish and caster.

On complex periodic motions and bifurcations in a periodically forced, damped, hardening Duffing oscillator

International Nuclear Information System (INIS)

Guo, Yu; Luo, Albert C.J.

2015-01-01

In this paper, analytically predicted are complex periodic motions in the periodically forced, damped, hardening Duffing oscillator through discrete implicit maps of the corresponding differential equations. Bifurcation trees of periodic motions to chaos in such a hardening Duffing oscillator are obtained. The stability and bifurcation analysis of periodic motion in the bifurcation trees is carried out by eigenvalue analysis. The solutions of all discrete nodes of periodic motions are computed by the mapping structures of discrete implicit mapping. The frequency-amplitude characteristics of periodic motions are computed that are based on the discrete Fourier series. Thus, the bifurcation trees of periodic motions are also presented through frequency-amplitude curves. Finally, based on the analytical predictions, the initial conditions of periodic motions are selected, and numerical simulations of periodic motions are carried out for comparison of numerical and analytical predictions. The harmonic amplitude spectrums are also given for the approximate analytical expressions of periodic motions, which can also be used for comparison with experimental measurement. This study will give a better understanding of complex periodic motions in the hardening Duffing oscillator.

Is the Predictability of New-Onset Postpartum Depression Better During Pregnancy or in the Early Postpartum Period? A Prospective Study in Croatian Women.

Science.gov (United States)

Nakić Radoš, Sandra; Herman, Radoslav; Tadinac, Meri

2016-01-01

The researchers' aim was to examine whether it was better to predict new-onset postpartum depression (PPD) during pregnancy or immediately after childbirth. A prospective study conducted in Croatia followed women (N = 272) from the third trimester of pregnancy through the early postpartum period (within the first 3 postpartum days), to 6 weeks postpartum. Questionnaires on depression, anxiety, stress, coping, self-esteem, and social support were administered. Through regression analyses we showed that PPD symptoms could be equally predicted by variables from pregnancy (30.3%) and the early postpartum period (34.0%), with a small advantage of PPD prediction in the early postpartum period.

The highly efficient photocatalytic and light harvesting property of Ag-TiO2 with negative nano-holes structure inspired from cicada wings.

Science.gov (United States)

Zada, Imran; Zhang, Wang; Zheng, Wangshu; Zhu, Yuying; Zhang, Zhijian; Zhang, Jianzhong; Imtiaz, Muhammad; Abbas, Waseem; Zhang, Di

2017-12-08

The negative replica of biomorphic TiO 2 with nano-holes structure has been effectively fabricated directly from nano-nipple arrays structure of cicada wings by using a simple, low-cost and highly effective sol-gel ultrasonic method. The nano-holes array structure was well maintained after calcination in air at 500 °C. The Ag nanoparticles (10 nm-25 nm) were homogeneously decorated on the surface and to the side wall of nano-holes structure. It was observed that the biomorphic Ag-TiO 2 showed remarkable photocatalytic activity by degradation of methyl blue (MB) under UV-vis light irradiation. The biomorphic Ag-TiO 2 with nano-holes structure showed superior photocatalytic activity compared to the biomorphic TiO 2 and commercial Degussa P25. This high-performance photocatalytic activity of the biomorphic Ag-TiO 2 may be attributed to the nano-holes structure, localized surface plasmon resonance (LSPR) property of the Ag nanoparticles, and enhanced electron-hole separation. Moreover, the biomorphic Ag-TiO 2 showed more absorption capability in the visible wavelength range. This work provides a new insight to design such a structure which may lead to a range of novel applications.

Ignoring the irrelevant: auditory tolerance of audible but innocuous sounds in the bat-detecting ears of moths

Science.gov (United States)

Fullard, James H.; Ratcliffe, John M.; Jacobs, David S.

2008-03-01

Noctuid moths listen for the echolocation calls of hunting bats and respond to these predator cues with evasive flight. The African bollworm moth, Helicoverpa armigera, feeds at flowers near intensely singing cicadas, Platypleura capensis, yet does not avoid them. We determined that the moth can hear the cicada by observing that both of its auditory receptors (A1 and A2 cells) respond to the cicada’s song. The firing response of the A1 cell rapidly adapts to the song and develops spike periods in less than a second that are in excess of those reported to elicit avoidance flight to bats in earlier studies. The possibility also exists that for at least part of the day, sensory input in the form of olfaction or vision overrides the moth’s auditory responses. While auditory tolerance appears to allow H. armigera to exploit a food resource in close proximity to acoustic interference, it may render their hearing defence ineffective and make them vulnerable to predation by bats during the evening when cicadas continue to sing. Our study describes the first field observation of an eared insect ignoring audible but innocuous sounds.

Adaptive Control of the Packet Transmission Period with Solar Energy Harvesting Prediction in Wireless Sensor Networks

Directory of Open Access Journals (Sweden)

Kideok Kwon

2015-04-01

Full Text Available A number of research works has studied packet scheduling policies in energy scavenging wireless sensor networks, based on the predicted amount of harvested energy. Most of them aim to achieve energy neutrality, which means that an embedded system can operate perpetually while meeting application requirements. Unlike other renewable energy sources, solar energy has the feature of distinct periodicity in the amount of harvested energy over a day. Using this feature, this paper proposes a packet transmission control policy that can enhance the network performance while keeping sensor nodes alive. Furthermore, this paper suggests a novel solar energy prediction method that exploits the relation between cloudiness and solar radiation. The experimental results and analyses show that the proposed packet transmission policy outperforms others in terms of the deadline miss rate and data throughput. Furthermore, the proposed solar energy prediction method can predict more accurately than others by 6.92%.

Adaptive control of the packet transmission period with solar energy harvesting prediction in wireless sensor networks.

Science.gov (United States)

Kwon, Kideok; Yang, Jihoon; Yoo, Younghwan

2015-04-24

A number of research works has studied packet scheduling policies in energy scavenging wireless sensor networks, based on the predicted amount of harvested energy. Most of them aim to achieve energy neutrality, which means that an embedded system can operate perpetually while meeting application requirements. Unlike other renewable energy sources, solar energy has the feature of distinct periodicity in the amount of harvested energy over a day. Using this feature, this paper proposes a packet transmission control policy that can enhance the network performance while keeping sensor nodes alive. Furthermore, this paper suggests a novel solar energy prediction method that exploits the relation between cloudiness and solar radiation. The experimental results and analyses show that the proposed packet transmission policy outperforms others in terms of the deadline miss rate and data throughput. Furthermore, the proposed solar energy prediction method can predict more accurately than others by 6.92%.

Prediction of Vibration Transmission within Periodic Bar Structures

DEFF Research Database (Denmark)

Domadiya, Parthkumar Gandalal; Andersen, Lars Vabbersgaard; Sorokin, Sergey

2012-01-01

The present analysis focuses on vibration transmission within semi-infinite bar structure. The bar is consisting of two different materials in a periodic manner. A periodic bar model is generated using two various methods: The Finite Element method (FEM) and a Floquet theory approach. A parameter...... study is carried out regarding the influence of the number of periods at various frequencies within a semi-infinite bar, stop bands are illustrated at certain periodic intervals within the structure. The computations are carried out in frequency domain in the range below 500 Hz. Results from both...

Prediction of the period of psychotic episode in individual schizophrenics by simulation-data construction approach.

Science.gov (United States)

Huang, Chun-Jung; Wang, Hsiao-Fan; Chiu, Hsien-Jane; Lan, Tsuo-Hung; Hu, Tsung-Ming; Loh, El-Wui

2010-10-01

Although schizophrenia can be treated, most patients still experience inevitable psychotic episodes from time to time. Precautious actions can be taken if the next onset can be predicted. However, sufficient information is always lacking in the clinical scenario. A possible solution is to use the virtual data generated from limited of original data. Data construction method (DCM) has been shown to generate the virtual felt earthquake data effectively and used in the prediction of further events. Here we investigated the performance of DCM in deriving the membership functions and discrete-event simulations (DES) in predicting the period embracing the initiation and termination time-points of the next psychotic episode of 35 individual schizophrenic patients. The results showed that 21 subjects had a success of simulations (RSS) ≥70%. Further analysis demonstrated that the co-morbidity of coronary heart diseases (CHD), risks of CHD, and the frequency of previous psychotic episodes increased the RSS.

Chaos and loss of predictability in the periodically kicked linear oscillator

International Nuclear Information System (INIS)

Luna-Acosta, G.A.; Cantoral, E.

1989-01-01

Chernikov et.al. [2] have discovered new features in the dynamics of a periodically kicked LHO x'' + ω 0 2 x = ( K/ k 0 T 2 ) sin (k 0 x) x Σ n δ (t / T - n). They report that its phase space motion under exact resonance (p ω 0 = (2 π / T) q; p, q integers), and with initial conditions on the separatrix of the average Hamiltonian , accelerates unboundedly along a fractal stochastic web with q-fold symmetry. Here we investigate with numerical experiments the effects of small deviations from exact resonance on the diffusion and symmetry patterns. We show graphically that the stochastic webs are (topologically) unstable and thus the unbounded motion becomes considerably truncated. Moreover, we analyze numerically and analytically a simpler (integrable) version. We give its exact closed-form solution in complex numbers, realize that it accelerates unboundedly only when ω 0 = (2 π/T) q (q = ± 1,2,...), and show that for small uncertainties in these frequencies, total predictability is lost as time evolves. That is, trajectories of a set of systems, initially described by close neighboring points in phase space strongly diverge in a non-linear way. The great loss of predictability in the integrable model is due to the combination of translational and rotational symmetries, inherent in these systems. (Author)

Chaos and loss of predictability in the periodically kicked linear oscillator

Energy Technology Data Exchange (ETDEWEB)

Luna-Acosta, G A [Universidad Autonoma de Puebla (Mexico). Inst. de Ciencias; Cantoral, E [Universidad Autonoma de Puebla (Mexico). Escuela de Fisica

1989-01-01

Chernikov et.al. [2] have discovered new features in the dynamics of a periodically kicked LHO x'' + [omega] [sub 0] [sup 2] x = ( K/ k[sub 0] T [sup 2]) sin (k[sub 0] x) x [Sigma][sub n] [delta] (t / T - n). They report that its phase space motion under exact resonance (p [omega] [sub 0] = (2 [pi] / T) q; p, q integers), and with initial conditions on the separatrix of the average Hamiltonian , accelerates unboundedly along a fractal stochastic web with q-fold symmetry. Here we investigate with numerical experiments the effects of small deviations from exact resonance on the diffusion and symmetry patterns. We show graphically that the stochastic webs are (topologically) unstable and thus the unbounded motion becomes considerably truncated. Moreover, we analyze numerically and analytically a simpler (integrable) version. We give its exact closed-form solution in complex numbers, realize that it accelerates unboundedly only when [omega][sub 0] = (2 [pi]/T) q (q = [+-] 1,2,...), and show that for small uncertainties in these frequencies, total predictability is lost as time evolves. That is, trajectories of a set of systems, initially described by close neighboring points in phase space strongly diverge in a non-linear way. The great loss of predictability in the integrable model is due to the combination of translational and rotational symmetries, inherent in these systems. (Author).

A flexible and stable surface-enhanced Raman scattering (SERS) substrate based on Au nanoparticles/Graphene oxide/Cicada wing array

Science.gov (United States)

Shi, Guochao; Wang, Mingli; Zhu, Yanying; Shen, Lin; Wang, Yuhong; Ma, Wanli; Chen, Yuee; Li, Ruifeng

2018-04-01

In this work, we presented an eco-friendly and low-cost method to fabricate a kind of flexible and stable Au nanoparticles/graphene oxide/cicada wing (AuNPs/GO/CW) substrate. By controlling the ratio of reactants, the optimum SERS substrate with average AuNPs size of 65 nm was obtained. The Raman enhancement factor for rhodamine 6G (R6G) was 1.08 ×106 and the limit of detection (LOD) was as low as 10-8 M. After calibrating the Raman peak intensities of R6G, it could be quantitatively detected. In order to better understand the experimental results, the 3D finite-different time-domain simulation was used to simulate the AuNPs/GO/CW-1 (the diameter of the AuNPs was 65 nm) to further investigate the SERS enhancement effect. More importantly, the AuNPs/GO/CW-1 substrates not only can provide strong enhancement factors but also can be stable and reproducible. This SERS substrates owned a good stability for the SERS intensity which was reduced only by 25% after the aging time of 60 days and the relative standard deviation was lower than 20%, revealing excellent uniformity and reproducibility. Our positive findings can pave a new way to optimize the application of SERS substrate as well as provide more SERS platforms for quantitative detection of organic contaminants vestige, which makes it very promising in the trace detection of biological molecules.

The Periodic Pyramid

Science.gov (United States)

Hennigan, Jennifer N.; Grubbs, W. Tandy

2013-01-01

The chemical elements present in the modern periodic table are arranged in terms of atomic numbers and chemical periodicity. Periodicity arises from quantum mechanical limitations on how many electrons can occupy various shells and subshells of an atom. The shell model of the atom predicts that a maximum of 2, 8, 18, and 32 electrons can occupy…

High parity predicts use of long-acting reversible contraceptives in the extended postpartum period among women in rural Uganda.

Science.gov (United States)

Anguzu, Ronald; Sempeera, Hassard; Sekandi, Juliet N

2018-01-01

The use of implants and Intra-uterine devices (IUD) during the post-partum period is very low in Uganda especially in rural settings. Long-acting reversible contraceptives (LARC) are known to be the most cost-effective for prevention of unintended pregnancy and unsafe abortions. This study aimed at determining the factors associated with long-acting reversible contraceptive use among women in the extended postpartum period in rural Uganda. We conducted a household-based, cross-sectional study among 400 women in two rural communities in Mityana district, central Uganda. Eligible women were aged 15 to 45 years who had childbirth within 12 months of study enrollment in September 2014. The outcome variable was self-reported use of a LARC method, either IUD or implants in the extended postpartum period. The main independent variables were previous childbirths (parity), fertility desire, willingness to use modern contraception, duration of postpartum period and previous pregnancies (gravidity). A logistic regression model was run in STATA v12.0 to compute adjusted odds ratios (AOR) for factors that predicted LARC use statistically significant at p  postpartum period (AOR = 4.07, 95%CI 1.08-15.4). Willingness to use modern contraception, desire for more children and postpartum duration had no significant association with LARC use in the extended postpartum period. This study revealed low use of LARC within twelve months of child birth despite women's willingness to use them. High parity (≥5 childbirths) predicted LARC use. The next logical step is to identify barriers to using LARC in the extended postpartum period and design appropriate interventions to increase access and use especially in multi-parous women.

Dual-component model of respiratory motion based on the periodic autoregressive moving average (periodic ARMA) method

International Nuclear Information System (INIS)

McCall, K C; Jeraj, R

2007-01-01

A new approach to the problem of modelling and predicting respiration motion has been implemented. This is a dual-component model, which describes the respiration motion as a non-periodic time series superimposed onto a periodic waveform. A periodic autoregressive moving average algorithm has been used to define a mathematical model of the periodic and non-periodic components of the respiration motion. The periodic components of the motion were found by projecting multiple inhale-exhale cycles onto a common subspace. The component of the respiration signal that is left after removing this periodicity is a partially autocorrelated time series and was modelled as an autoregressive moving average (ARMA) process. The accuracy of the periodic ARMA model with respect to fluctuation in amplitude and variation in length of cycles has been assessed. A respiration phantom was developed to simulate the inter-cycle variations seen in free-breathing and coached respiration patterns. At ±14% variability in cycle length and maximum amplitude of motion, the prediction errors were 4.8% of the total motion extent for a 0.5 s ahead prediction, and 9.4% at 1.0 s lag. The prediction errors increased to 11.6% at 0.5 s and 21.6% at 1.0 s when the respiration pattern had ±34% variations in both these parameters. Our results have shown that the accuracy of the periodic ARMA model is more strongly dependent on the variations in cycle length than the amplitude of the respiration cycles

Germalna, a new genus for the New Caledonian cicada previously assigned to the genus Melampsalta Kolenati, plus a complement to the description of the genus Rouxalna Boulard, with the description of two new species (Insecta: Hemiptera, Cicadoidea, Cicadidae).

Science.gov (United States)

Delorme, Quentin

2018-01-31

Species previously assigned to Melampsalta Kolenati, in New Caledonia are reviewed. Morphological studies indicate that New Caledonian cicadas currently placed in this genus have been wrongly assigned and should be placed in a new genus. The genus Germalna gen. nov., is therefore erected to accommodate Germalna germaini comb. nov. The genus Germalna gen. nov. was first documented by Michel Boulard, but remained a nomen nudum until now. A redescription of the genus Rouxalna Boulard is provided and the following new species are described: Rouxalna villosa sp. nov., and Rouxalna scabens sp. nov. Male calling songs of Rouxalna rouxi Boulard and Rouxalna scabens sp. nov. are analysed and described from field recordings. A key to the species of Rouxalna is also provided.

Environ: E00642 [KEGG MEDICUS

Lifescience Database Archive (English)

Full Text Available ri larva parasitized by Clavicipitaceae Cordyceps sobolifera, Cordyceps cicadae (dried) ... ... E00642 Platypleura kaempferi larva Crude drug ... Platypleura kaempferi, Platypleura ...[TAX:70903], Cordyceps sobolifera [TAX:94213], Cordyceps cicadae [TAX:218633] ... Cicadidae Platypleura kaempfe

Prediction of Communication Outage Period between Satellite and Earth station Due to Sun Interference

Directory of Open Access Journals (Sweden)

Yongjun Song

2010-03-01

Full Text Available We developed a computer program to predict solar interference period. To calculate Sun‘s position, we used DE406 ephemerides and Earth ellipsoid model. The Sun‘s position error is smaller than 10arcsec. For the verification of the calculation, we used TU media ground station on Seongsu-dong, and MBSAT geostationary communication satellite. We analysis errors, due to satellite perturbation and antenna align. The time error due to antenna align has -35 to +16 seconds at 0.1 degree, and -27 to +41 seconds at 0.25 degree. The time errors derived by satellite perturbation has 30 to 60 seconds.

Prediction of Mesiodistal Width of Unerupted Lateral Incisors, Canines and Premolars in Orthodontic Patients in Early Mixed Dentition Period

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Mohammad Hossein Toodehzaeim

2017-01-01

Full Text Available Objectives: Proper diagnosis and prevention of malocclusion are superior to treatment. Discrepancy between arch length and tooth size in mixed dentition period is a condition requiring timely diagnosis. Estimating the mesiodistal width of unerupted teeth according to the size of erupted ones can lead to earlier diagnosis of malocclusion. On the other hand, the best timing for serial extractions is before the eruption of lateral incisors. The aim of this study was to present prediction formulas for mesiodistal width of unerupted lateral incisors, canines and premolars in an Iranian population based on the width of erupted permanent mandibular central incisors and maxillary first molars.Materials and Methods: A total of 120 dental models (60 males, 60 females of orthodontic patients between 11-25 years were evaluated in Yazd city. The measurements were made by a digital caliper on the widest mesiodistal width of teeth at the interproximal contacts. Data were analyzed to calculate the prediction equation.Results: The prediction equation in the upper jaw was y=0.57x+10.82 for males, y=0.7x+6.37 for females and y=0.64x+8.46 for both sexes. The equation for the lower jaw was y=0.76x+2.86 for males, y=0.74x+3.53 for females and y=0.77x+2.7 for both sexes.Conclusions: The prediction equations suggested in this study can predict the mesiodistal width of unerupted lateral incisors, canines and premolars in an Iranian population in early mixed dentition period without taking radiographs.Keywords: Dentition, Mixed; Dentition, Permanent; Tooth, Unerupted

Operational validation of a multi-period and multi-criteria model conditioning approach for the prediction of rainfall-runoff processes in small forest catchments

Science.gov (United States)

Choi, H.; Kim, S.

2012-12-01

Most of hydrologic models have generally been used to describe and represent the spatio-temporal variability of hydrological processes in the watershed scale. Though it is an obvious fact that hydrological responses have the time varying nature, optimal values of model parameters were normally considered as time invariants or constants in most cases. The recent paper of Choi and Beven (2007) presents a multi-period and multi-criteria model conditioning approach. The approach is based on the equifinality thesis within the Generalised Likelihood Uncertainty Estimation (GLUE) framework. In their application, the behavioural TOPMODEL parameter sets are determined by several performance measures for global (annual) and short (30-days) periods, clustered using a Fuzzy C-means algorithm, into 15 types representing different hydrological conditions. Their study shows a good performance on the calibration of a rainfall-runoff model in a forest catchment, and also gives strong indications that it is uncommon to find model realizations that were behavioural over all multi-periods and all performance measures, and multi-period model conditioning approach may become new effective tool for predictions of hydrological processes in ungauged catchments. This study is a follow-up study on the Choi and Beven's (2007) model conditioning approach to test how the approach is effective for the prediction of rainfall-runoff responses in ungauged catchments. To achieve this purpose, 6 small forest catchments are selected among the several hydrological experimental catchments operated by Korea Forest Research Institute. In each catchment, long-term hydrological time series data varying from 10 to 30 years were available. The areas of the selected catchments range from 13.6 to 37.8 ha, and all areas are covered by coniferous or broad-leaves forests. The selected catchments locate in the southern coastal area to the northern part of South Korea. The bed rocks are Granite gneiss, Granite or

Skin sites to predict deep-body temperature while wearing firefighters' personal protective equipment during periodical changes in air temperature.

Science.gov (United States)

Kim, Siyeon; Lee, Joo-Young

2016-04-01

The aim of this study was to investigate stable and valid measurement sites of skin temperatures as a non-invasive variable to predict deep-body temperature while wearing firefighters' personal protective equipment (PPE) during air temperature changes. Eight male firefighters participated in an experiment which consisted of 60-min exercise and 10-min recovery while wearing PPE without self-contained breathing apparatus (7.75 kg in total PPE mass). Air temperature was periodically fluctuated from 29.5 to 35.5 °C with an amplitude of 6 °C. Rectal temperature was chosen as a deep-body temperature, and 12 skin temperatures were recorded. The results showed that the forehead and chest were identified as the most valid sites to predict rectal temperature (R(2) = 0.826 and 0.824, respectively) in an environment with periodically fluctuated air temperatures. This study suggests that particular skin temperatures are valid as a non-invasive variable when predicting rectal temperature of an individual wearing PPE in changing ambient temperatures. Practitioner Summary: This study should offer assistance for developing a more reliable indirect indicating system of individual heat strain for firefighters in real time, which can be used practically as a precaution of firefighters' heat-related illness and utilised along with physiological monitoring.

Late quaternary environmental changes in the upper Las Vegas valley, Nevada

Science.gov (United States)

Quade, Jay

1986-11-01

Five stratigraphic units and five soils of late Pleistocene to Holocene age crop out in dissected badlands on Corn Creek Flat, 30 km northwest of Las Vegas, Nevada, and at Tule Springs, nearer to Las Vegas. The record is dominantly fluvial but contains evidence of several moister, marsh-forming periods: the oldest (Unit B) dates perhaps to the middle Wisconsin, and the more widespread Unit D falls between 30,000 and 15,000 yr B.P. Unit D therefore correlates with pluvial maximum lacustrine deposits elsewhere in the Great Basin. Standing water was not of sufficient depth or extent during either period to form lake strandlines. Between 14,000 and 7200 yr B.P. (Unit E), standing surface water gradually decreased, a trend also apparent in Great Basin pluvial lake chronologies during the same period. Groundwater carbonate cementation and burrowing by cicadas (Cicadae) accompany the moist-phase units. After 7200 yr B.P., increased wind action, decreased biotic activity, and at least 25 m of water-table lowering accompanied widespread erosion of older fine-grained deposits. Based on pack-rat midden and pollen evidence, this coincides with major vegetation changes in the valley, from sagebrush-dominated steppe to lower Mohave desertscrub.

Deafferentation-Induced Plasticity of Visual Callosal Connections: Predicting Critical Periods and Analyzing Cortical Abnormalities Using Diffusion Tensor Imaging

Directory of Open Access Journals (Sweden)

Jaime F. Olavarria

2012-01-01

Full Text Available Callosal connections form elaborate patterns that bear close association with striate and extrastriate visual areas. Although it is known that retinal input is required for normal callosal development, there is little information regarding the period during which the retina is critically needed and whether this period correlates with the same developmental stage across species. Here we review the timing of this critical period, identified in rodents and ferrets by the effects that timed enucleations have on mature callosal connections, and compare it to other developmental milestones in these species. Subsequently, we compare these events to diffusion tensor imaging (DTI measurements of water diffusion anisotropy within developing cerebral cortex. We observed that the relationship between the timing of the critical period and the DTI-characterized developmental trajectory is strikingly similar in rodents and ferrets, which opens the possibility of using cortical DTI trajectories for predicting the critical period in species, such as humans, in which this period likely occurs prenatally. Last, we discuss the potential of utilizing DTI to distinguish normal from abnormal cerebral cortical development, both within the context of aberrant connectivity induced by early retinal deafferentation, and more generally as a potential tool for detecting abnormalities associated with neurodevelopmental disorders.

The redoubtable ecological periodic table

Science.gov (United States)

Ecological periodic tables are repositories of reliable information on quantitative, predictably recurring (periodic) habitat–community patterns and their uncertainty, scaling and transferability. Their reliability derives from their grounding in sound ecological principle...

RESEARCH ON STOLBUR OF PEPPER (CAPSICUM ANNUUM L. CULTIVATED UNDER THE CONDITIONS OF ORGANIC FARMING

Directory of Open Access Journals (Sweden)

Veselka Vlahova

2015-06-01

Full Text Available In Bulgaria stolbur is a disease of economic significance that affects pepper, eggplant, tomatoes, and potatoes. Stolbur is referred to the transmission diseases, i.e. the agent is being transferred via vector, namely cicada Hyalesthes obsoletus in this specific case. This research aims at following the stolbur disease of pepper of the variety of Sofiiska Kapiya. The experiment took place in 2010 and in 2011 on the experimental fields of the Agroecological Centre at the Agricultural University- Plovdiv. The occurence of Hyalesthes obsoletus was determined via visual observations of flower sticky traps (yellow, blue, and white. Route investigations were carried out for the purpose of tracking the symptoms of the disease. Reinforced migration of cicadas was established during the second ten days of July. It was established that the larger number of cicadas were reported for the yellow sticky traps, which may be recommended for practical application as a successful fight against cicada and limitation of its flight.

A statistical forecast model using the time-scale decomposition technique to predict rainfall during flood period over the middle and lower reaches of the Yangtze River Valley

Science.gov (United States)

Hu, Yijia; Zhong, Zhong; Zhu, Yimin; Ha, Yao

2018-04-01

In this paper, a statistical forecast model using the time-scale decomposition method is established to do the seasonal prediction of the rainfall during flood period (FPR) over the middle and lower reaches of the Yangtze River Valley (MLYRV). This method decomposites the rainfall over the MLYRV into three time-scale components, namely, the interannual component with the period less than 8 years, the interdecadal component with the period from 8 to 30 years, and the interdecadal component with the period larger than 30 years. Then, the predictors are selected for the three time-scale components of FPR through the correlation analysis. At last, a statistical forecast model is established using the multiple linear regression technique to predict the three time-scale components of the FPR, respectively. The results show that this forecast model can capture the interannual and interdecadal variation of FPR. The hindcast of FPR during 14 years from 2001 to 2014 shows that the FPR can be predicted successfully in 11 out of the 14 years. This forecast model performs better than the model using traditional scheme without time-scale decomposition. Therefore, the statistical forecast model using the time-scale decomposition technique has good skills and application value in the operational prediction of FPR over the MLYRV.

Predictive risk factors of postoperative urinary incontinence following holmium laser enucleation of the prostate during the initial learning period

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Shuichiro Kobayashi

Full Text Available ABSTRACT Purpose: To determine the predictive factors for postoperative urinary incontinence (UI following holmium laser enucleation of the prostate (HoLEP during the initial learning period. Patients and Methods: We evaluated 127 patients with benign prostatic hyperplasia who underwent HoLEP between January 2011 and December 2013. We recorded clinical variables, including blood loss, serum prostate-specific antigen levels, and the presence or absence of UI. Blood loss was estimated as a decline in postoperative hemoglobin levels. The predictive factors for postoperative UI were determined using a multivariable logistic regression analysis. Results: Postoperative UI occurred in 31 patients (24.4%, but it cured in 29 patients (93.5% after a mean duration of 12 weeks. Enucleation time >100 min (p=0.043 and blood loss >2.5g/dL (p=0.032 were identified as significant and independent risk factors for postoperative UI. Conclusions: Longer enucleation time and increased blood loss were independent predictors of postoperative UI in patients who underwent HoLEP during the initial learning period. Surgeons in training should take care to perform speedy enucleation maneuver with hemostasis.

The direct field boundary impedance of two-dimensional periodic structures with application to high frequency vibration prediction.

Science.gov (United States)

Langley, Robin S; Cotoni, Vincent

2010-04-01

Large sections of many types of engineering construction can be considered to constitute a two-dimensional periodic structure, with examples ranging from an orthogonally stiffened shell to a honeycomb sandwich panel. In this paper, a method is presented for computing the boundary (or edge) impedance of a semi-infinite two-dimensional periodic structure, a quantity which is referred to as the direct field boundary impedance matrix. This terminology arises from the fact that none of the waves generated at the boundary (the direct field) are reflected back to the boundary in a semi-infinite system. The direct field impedance matrix can be used to calculate elastic wave transmission coefficients, and also to calculate the coupling loss factors (CLFs), which are required by the statistical energy analysis (SEA) approach to predicting high frequency vibration levels in built-up systems. The calculation of the relevant CLFs enables a two-dimensional periodic region of a structure to be modeled very efficiently as a single subsystem within SEA, and also within related methods, such as a recently developed hybrid approach, which couples the finite element method with SEA. The analysis is illustrated by various numerical examples involving stiffened plate structures.

TFTR movable limiter instrumentation and controls

International Nuclear Information System (INIS)

Frankenberg, J.; Collins, D.; Kaufmann, D.; Mamoun, A.

1983-01-01

The TFTR movable limiter is a single poloidal limiter located within one 18 /SUP o/ segment of the vacuum vessel. It consists of three (3) interconnected inconel backing plates covered with titanium carbide coated graphite tiles. The backing plates are positioned by three independent screw drive actuators. Cooling water is fed through the horizontal port cover to tubes brazed onto the backs of the backing plates. Thermocouples monitor the limiter temperature. (1) and more fully described in refs. (1) and (2). The positioning actuators are driven by independently controlled DC servo motors, controlled either locally or from CICADA. Drive motor shaft position is monitored by chain driven encoders and potentiometers. Limiter blade position can be varied to suit any plasma within the operating range. CICADA is programmed to keep the limiter stroke within safe operating limits. A microprocessor duplicates the CICADA protective function allowing limiter operation without CICADA. The potentiometer signal is sent to an analog computer, which safeguards the limiter against failure of the encoders or the micro-processor. Cooling water flows through the limiter in 3 separate paths, one for each blade. The flow rate and temperature rise through each loop are measured accurately to allow CICADA to calculate the heat into each blade. The water system is also interlocked and alarmed to prevent dumping of water into the vacuum vessel

Periodic motions and grazing in a harmonically forced, piecewise, linear oscillator with impacts

International Nuclear Information System (INIS)

Luo, Albert C.J.; Chen Lidi

2005-01-01

In this paper, an idealized, piecewise linear system is presented to model the vibration of gear transmission systems. Periodic motions in a generalized, piecewise linear oscillator with perfectly plastic impacts are predicted analytically. The analytical predictions of periodic motion are based on the mapping structures, and the generic mappings based on the discontinuous boundaries are developed. This method for the analytical prediction of the periodic motions in non-smooth dynamic systems can give all possible periodic motions based on the adequate mapping structures. The stability and bifurcation conditions for specified periodic motions are obtained. The periodic motions and grazing motion are demonstrated. This model is applicable to prediction of periodic motion in nonlinear dynamics of gear transmission systems

Prediction of electric energy consumption in Cuba for the period 2000-2015; Pronostico del consumo de electricidad en Cuba durante el periodo 2000-2015

Energy Technology Data Exchange (ETDEWEB)

Garcia Rodirguez, B [Centro Nacional de Seguridad Nuclear, La Habana (Cuba)

1999-06-01

This paper consists on a prediction of the growth in electric energy consumption in Cuba, for the period 2000-2015 and with respect to 1990, it also considers the specific features of the National Electroenergetic System. Validated Guidelines in accordance with the Delphi method, which incorporates the basis characteristics considered by international programs for these predictions, were used for this purpose. From the analysis of the behaviour in power consumption of the different consumers and of the expected changes in them according to the expected scenarios, a prediction on the growth in the demand of electric energy is made.

Oviposition of Quesada gigas in weed no hostess: implication in pest management

Directory of Open Access Journals (Sweden)

Douglas Henrique Bottura Maccagnan

Full Text Available ABSTRACT: This study recorded the choice of dry plant of Conyza spp as oviposition site by cicada Quesada gigas (Olivier, 1790. We presented issues of natural history of the cicadas that indicate the inability of immatures to complete life cycle in this species of plant. Some implications on cultures where Q. gigas has economic importance are also discussed.

Magnetospheric Truncation, Tidal Inspiral, and the Creation of Short-period and Ultra-short-period Planets

Energy Technology Data Exchange (ETDEWEB)

Lee, Eve J.; Chiang, Eugene, E-mail: evelee@berkeley.edu [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States)

2017-06-10

Sub-Neptunes around FGKM dwarfs are evenly distributed in log orbital period down to ∼10 days, but dwindle in number at shorter periods. Both the break at ∼10 days and the slope of the occurrence rate down to ∼1 day can be attributed to the truncation of protoplanetary disks by their host star magnetospheres at corotation. We demonstrate this by deriving planet occurrence rate profiles from empirical distributions of pre-main-sequence stellar rotation periods. Observed profiles are better reproduced when planets are distributed randomly in disks—as might be expected if planets formed in situ—rather than piled up near disk edges, as would be the case if they migrated in by disk torques. Planets can be brought from disk edges to ultra-short (<1 day) periods by asynchronous equilibrium tides raised on their stars. Tidal migration can account for how ultra-short-period planets are more widely spaced than their longer-period counterparts. Our picture provides a starting point for understanding why the sub-Neptune population drops at ∼10 days regardless of whether the host star is of type FGK or early M. We predict planet occurrence rates around A stars to also break at short periods, but at ∼1 day instead of ∼10 days because A stars rotate faster than stars with lower masses (this prediction presumes that the planetesimal building blocks of planets can drift inside the dust sublimation radius).

Magnetospheric Truncation, Tidal Inspiral, and the Creation of Short-period and Ultra-short-period Planets

International Nuclear Information System (INIS)

Lee, Eve J.; Chiang, Eugene

2017-01-01

Sub-Neptunes around FGKM dwarfs are evenly distributed in log orbital period down to ∼10 days, but dwindle in number at shorter periods. Both the break at ∼10 days and the slope of the occurrence rate down to ∼1 day can be attributed to the truncation of protoplanetary disks by their host star magnetospheres at corotation. We demonstrate this by deriving planet occurrence rate profiles from empirical distributions of pre-main-sequence stellar rotation periods. Observed profiles are better reproduced when planets are distributed randomly in disks—as might be expected if planets formed in situ—rather than piled up near disk edges, as would be the case if they migrated in by disk torques. Planets can be brought from disk edges to ultra-short (<1 day) periods by asynchronous equilibrium tides raised on their stars. Tidal migration can account for how ultra-short-period planets are more widely spaced than their longer-period counterparts. Our picture provides a starting point for understanding why the sub-Neptune population drops at ∼10 days regardless of whether the host star is of type FGK or early M. We predict planet occurrence rates around A stars to also break at short periods, but at ∼1 day instead of ∼10 days because A stars rotate faster than stars with lower masses (this prediction presumes that the planetesimal building blocks of planets can drift inside the dust sublimation radius).

Multi-Period Trading via Convex Optimization

DEFF Research Database (Denmark)

Boyd, Stephen; Busseti, Enzo; Diamond, Steve

2017-01-01

We consider a basic model of multi-period trading, which can be used to evaluate the performance of a trading strategy. We describe a framework for single-period optimization, where the trades in each period are found by solving a convex optimization problem that trades off expected return, risk......, transaction cost and holding cost such as the borrowing cost for shorting assets. We then describe a multi-period version of the trading method, where optimization is used to plan a sequence of trades, with only the first one executed, using estimates of future quantities that are unknown when the trades....... In this paper, we do not address a critical component in a trading algorithm, the predictions or forecasts of future quantities. The methods we describe in this paper can be thought of as good ways to exploit predictions, no matter how they are made. We have also developed a companion open-source software...

Investigation of Surface Enhanced Coherent Raman Scattering on Nano-patterned Insect Wings

Science.gov (United States)

Ujj, Laszlo; Lawhead, Carlos

2015-03-01

Many insect wings (cicadas, butterflies, mosquitos) poses nano-patterned surface structure. Characterization of surface morphology and chemical composition of insect wings is important to understand the extreme mechanical properties and the biophysical functionalities of the wings. We have measured the image of the membrane of a cicada's wing with the help of Scanning Electron Microscopy (SEM). The results confirm the existing periodic structure of the wing measured previously. In order to identify the chemical composition of the wing, we have deposited silver nanoparticles on it and applied Coherent anti-Stokes Raman Spectroscopy to measure the vibrational spectra of the molecules comprising the wing for the first time. The measured spectra are consistent with the original assumption that the wing membrane is composed of protein, wax, and chitin. The results of these studies can be used to measure other nano-patterned surfaces and to make artificial materials in the future. Authors grateful for financial support from the Department of Physics of the College of Sciences Engineering and Health of UWF and the Pall Corporation for SEM imaging.

Prediction of in-service time period of three differently stabilized single base propellants

Energy Technology Data Exchange (ETDEWEB)

Bohn, Manfred A. [Fraunhofer-Institut fuer Chemische Technologie (ICT), Pfinztal-Berghausen (Germany)

2009-06-15

Three nitrocellulose-based propellants for use in micro gas generators equipped with different stabilizing systems have been investigated to assess the stabilization capability with regard to in-service time, whereby strong time-temperature profiles have been applied. The three stabilizing systems have been (i) 0.74 mass-% diphenylamine (DPA) and 0.48 mass-% Akardite II (Ak II); (ii) 1.25 mass-% Ak II; (iii) 2.04 mass-% Ak II. Several profiles were considered. Two simulate the heating at sun exposure in hot areas, others consider environmental temperatures in hot-humid and hot-dry areas. They were evaluated according to the load and finally one was chosen for the assessment. The contents of stabilizers were determined by high performance liquid chromatography after Soxhlet type extraction. To describe stabilizer consumption, the most suitable kinetic model was taken. Therewith a prediction was made using the chosen time-temperature profile named 'Phoenix', designed for temperatures at the steering wheel. The objective was to reach with this profile 15 years until the consumption of primary stabilizer content. This is conservative, because with the stabilizing action of the consecutive products of the stabilizers longer times are possible. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

Prediction of acute renal allograft rejection in early post-transplantation period by soluble CD30.

Science.gov (United States)

Dong, Wang; Shunliang, Yang; Weizhen, Wu; Qinghua, Wang; Zhangxin, Zeng; Jianming, Tan; He, Wang

2006-06-01

To evaluate the feasibility of serum sCD30 for prediction of acute graft rejection, we analyzed clinical data of 231 patients, whose serum levels of sCD30 were detected by ELISA before and after transplantation. They were divided into three groups: acute rejection group (AR, n = 49), uncomplicated course group (UC, n = 171) and delayed graft function group (DGF, n = 11). Preoperative sCD30 levels of three groups were 183 +/- 74, 177 +/- 82 and 168 +/- 53 U/ml, respectively (P = 0.82). Significant decrease of sCD30 was detected in three groups on day 5 and 10 post-transplantation respectively (52 +/- 30 and 9 +/- 5 U/ml respectively, P sCD30 values on day 5 post-transplantation (92 +/- 27 U/ml vs. 41 +/- 20 U/ml and 48 +/- 18 U/ml, P sCD30 levels on day 10 post-transplantation were virtually similar in patients of three groups (P = 0.43). Receiver operating characteristic (ROC) curve demonstrated that sCD30 level on day 5 post-transplantation could differentiate patients who subsequently suffered acute allograft rejection from others (area under ROC curve 0.95). According to ROC curve, 65 U/ml may be the optimal operational cut-off level to predict impending graft rejection (specificity 91.8%, sensitivity 87.1%). Measurement of soluble CD30 on day 5 post-transplantation might offer a noninvasive means to recognize patients at risk of impending acute graft rejection during early post-transplantation period.

Slow-light dynamics in nonlinear periodic waveguides couplers

DEFF Research Database (Denmark)

Sukhorukov, A.A.; Ha, S.; Powell, D.A.

2009-01-01

We predict pulse switching and reshaping through nonlinear mixing of two slow-light states with different phase velocities in the same frequency range, and report on the first experimental observation of slow-light tunneling between coupled periodic waveguides.......We predict pulse switching and reshaping through nonlinear mixing of two slow-light states with different phase velocities in the same frequency range, and report on the first experimental observation of slow-light tunneling between coupled periodic waveguides....

Vlasov dynamics of periodically driven systems

Science.gov (United States)

Banerjee, Soumyadip; Shah, Kushal

2018-04-01

Analytical solutions of the Vlasov equation for periodically driven systems are of importance in several areas of plasma physics and dynamical systems and are usually approximated using ponderomotive theory. In this paper, we derive the plasma distribution function predicted by ponderomotive theory using Hamiltonian averaging theory and compare it with solutions obtained by the method of characteristics. Our results show that though ponderomotive theory is relatively much easier to use, its predictions are very restrictive and are likely to be very different from the actual distribution function of the system. We also analyse all possible initial conditions which lead to periodic solutions of the Vlasov equation for periodically driven systems and conjecture that the irreducible polynomial corresponding to the initial condition must only have squares of the spatial and momentum coordinate. The resulting distribution function for other initial conditions is aperiodic and can lead to complex relaxation processes within the plasma.

Modeling Interdependent and Periodic Real-World Action Sequences

Science.gov (United States)

Kurashima, Takeshi; Althoff, Tim; Leskovec, Jure

2018-01-01

Mobile health applications, including those that track activities such as exercise, sleep, and diet, are becoming widely used. Accurately predicting human actions in the real world is essential for targeted recommendations that could improve our health and for personalization of these applications. However, making such predictions is extremely difficult due to the complexities of human behavior, which consists of a large number of potential actions that vary over time, depend on each other, and are periodic. Previous work has not jointly modeled these dynamics and has largely focused on item consumption patterns instead of broader types of behaviors such as eating, commuting or exercising. In this work, we develop a novel statistical model, called TIPAS, for Time-varying, Interdependent, and Periodic Action Sequences. Our approach is based on personalized, multivariate temporal point processes that model time-varying action propensities through a mixture of Gaussian intensities. Our model captures short-term and long-term periodic interdependencies between actions through Hawkes process-based self-excitations. We evaluate our approach on two activity logging datasets comprising 12 million real-world actions (e.g., eating, sleep, and exercise) taken by 20 thousand users over 17 months. We demonstrate that our approach allows us to make successful predictions of future user actions and their timing. Specifically, TIPAS improves predictions of actions, and their timing, over existing methods across multiple datasets by up to 156%, and up to 37%, respectively. Performance improvements are particularly large for relatively rare and periodic actions such as walking and biking, improving over baselines by up to 256%. This demonstrates that explicit modeling of dependencies and periodicities in real-world behavior enables successful predictions of future actions, with implications for modeling human behavior, app personalization, and targeting of health interventions. PMID

A distributed predictive control approach for periodic flow-based networks: application to drinking water systems

Science.gov (United States)

Grosso, Juan M.; Ocampo-Martinez, Carlos; Puig, Vicenç

2017-10-01

This paper proposes a distributed model predictive control approach designed to work in a cooperative manner for controlling flow-based networks showing periodic behaviours. Under this distributed approach, local controllers cooperate in order to enhance the performance of the whole flow network avoiding the use of a coordination layer. Alternatively, controllers use both the monolithic model of the network and the given global cost function to optimise the control inputs of the local controllers but taking into account the effect of their decisions over the remainder subsystems conforming the entire network. In this sense, a global (all-to-all) communication strategy is considered. Although the Pareto optimality cannot be reached due to the existence of non-sparse coupling constraints, the asymptotic convergence to a Nash equilibrium is guaranteed. The resultant strategy is tested and its effectiveness is shown when applied to a large-scale complex flow-based network: the Barcelona drinking water supply system.

Using Computer Techniques To Predict OPEC Oil Prices For Period 2000 To 2015 By Time-Series Methods

Directory of Open Access Journals (Sweden)

Mohammad Esmail Ahmad

2015-08-01

Full Text Available The instability in the world and OPEC oil process results from many factors through a long time. The problems can be summarized as that the oil exports dont constitute a large share of N.I. only but it also makes up most of the saving of the oil states. The oil prices affect their market through the interaction of supply and demand forces of oil. The research hypothesis states that the movement of oil prices caused shocks crises and economic problems. These shocks happen due to changes in oil prices need to make a prediction within the framework of economic planning in a short run period in order to avoid shocks through using computer techniques by time series models.

Global Scale Periodic Responses in Saturn’s Magnetosphere

Science.gov (United States)

Jia, Xianzhe; Kivelson, Margaret G.

2017-10-01

Despite having an axisymmetric internal magnetic field, Saturn’s magnetosphere exhibits periodic modulations in a variety of properties at periods close to the planetary rotation period. While the source of the periodicity remains unidentified, it is evident from Cassini observations that much of Saturn’s magnetospheric structure and dynamics is dominated by global-scale responses to the driving source of the periodicity. We have developed a global MHD model in which a rotating field-aligned current system is introduced by imposing vortical flows in the high-latitude ionosphere in order to simulate the magnetospheric periodicities. The model has been utilized to quantitatively characterize various periodic responses in the magnetosphere, such as the displacement of the magnetopause and bow shock and flapping of the tail plasma sheet, all of which show quantitative agreement with Cassini observations. One of our model predictions is periodic release of plasmoids in the tail that occurs preferentially in the midnight-to-dawn local time sector during each rotation cycle. Here we present detailed analysis of the periodic responses seen in our simulations focusing on the properties of plasmoids predicted by the model, including their spatial distribution, occurrence frequency, and mass loss rate. We will compare these modeled parameters with published Cassini observations, and discuss their implications for interpreting in-situ measurements.

Agrometeorological parameters for prediction of the maturation period of Arabica coffee cultivars

Science.gov (United States)

Pezzopane, José Ricardo Macedo; Salva, Terezinha de Jesus Garcia; de Lima, Valéria Bittencourt; Fazuoli, Luiz Carlos

2012-09-01

The objective of this study was to determine the harvest period of coffee fruits based on the relationship between agrometeorological parameters and sucrose accumulation in the seeds. Over the crop years 2004/2005 and 2006/2007, from 150 days after flowering (DAF) onwards, samples of 50 fruits of cultivars Mundo Novo IAC 376-4, Obatã IAC 1669-20 and Catuaí Vermelho IAC 144 were collected from coffee trees located in Campinas, Brazil. The endosperm of the fruits was freeze-dried, ground and analyzed for sucrose content by high-performance liquid chromatography. A weather station provided data to calculate the accumulated growing degree-day (GDD) units, and the reference (ETo) and actual (ETr) evapotranspiration rates. The results showed that the highest rates of sucrose accumulation occurred at the transition from the cane-green to the cherry phenological stage. Models for the estimation of sucrose content during maturation based on meteorological variables exhibited similar or better performance than the DAF variable, with better results for the variables GDD and ETo. The Mundo Novo cultivar reached the highest sucrose level in the endosperm after 2,790 GDD, while cultivar Catuaí attained its maximum sucrose concentration after the accumulated evapotranspiration rate has reached a value of 870 mm. As for cultivar Obatã, the maximum sucrose concentration was predicted with the same degree of accuracy using any of the parameters investigated. For the Obatã cultivar, the values of the variables calculated for the maximum sucrose concentration to be reached were 249 DAF, 3,090 GDD, 1,020 ETo and 900 ETr.

Superconductivity theory applied to the periodic table of the elements

Energy Technology Data Exchange (ETDEWEB)

Elifritz, T.L. [Information Corporation, Madison, WI (United States)

1994-12-31

The modern theory of superconductivity, based upon the BCS to Bose-Einstein transition, is applied to the periodic table of the elements, in order to isolate the essential features of high temperature superconductivity and to predict its occurrence within the periodic table. It is predicted that Sodium-Ammonia, Sodium Zinc Phosphide and Bismuth (I) Iodide are promising materials for experimental explorations of high temperature superconductivity.

Superconductivity theory applied to the periodic table of the elements

International Nuclear Information System (INIS)

Elifritz, T.L.

1994-01-01

The modern theory of superconductivity, based upon the BCS to Bose-Einstein transition, is applied to the periodic table of the elements, in order to isolate the essential features of high temperature superconductivity and to predict its occurrence within the periodic table. It is predicted that Sodium-Ammonia, Sodium Zinc Phosphide and Bismuth (I) Iodide are promising materials for experimental explorations of high temperature superconductivity

Superconductivity theory applied to the periodic table of the elements

Science.gov (United States)

Elifritz, Thomas Lee

1995-01-01

The modern theory of superconductivity, based upon the BCS to Bose-Einstein transition is applied to the periodic table of the elements, in order to isolate the essential features of of high temperature superconductivity and to predict its occurrence with the periodic table. It is predicted that Sodium-Ammonia, Sodium Zinc Phosphide and Bismuth (I) Iodide are promising materials for experimental explorations of high temperature superconductivity.

Trophic shifts of a generalist consumer in response to resource pulses.

Directory of Open Access Journals (Sweden)

Pei-Jen L Shaner

2011-03-01

Full Text Available Trophic shifts of generalist consumers can have broad food-web and biodiversity consequences through altered trophic flows and vertical diversity. Previous studies have used trophic shifts as indicators of food-web responses to perturbations, such as species invasion, and spatial or temporal subsidies. Resource pulses, as a form of temporal subsidies, have been found to be quite common among various ecosystems, affecting organisms at multiple trophic levels. Although diet switching of generalist consumers in response to resource pulses is well documented, few studies have examined if the switch involves trophic shifts, and if so, the directions and magnitudes of the shifts. In this study, we used stable carbon and nitrogen isotopes with a Bayesian multi-source mixing model to estimate proportional contributions of three trophic groups (i.e. producer, consumer, and fungus-detritivore to the diets of the White-footed mouse (Peromyscus leucopus receiving an artificial seed pulse or a naturally-occurring cicadas pulse. Our results demonstrated that resource pulses can drive trophic shifts in the mice. Specifically, the producer contribution to the mouse diets was increased by 32% with the seed pulse at both sites examined. The consumer contribution to the mouse diets was also increased by 29% with the cicadas pulse in one of the two grids examined. However, the pattern was reversed in the second grid, with a 13% decrease in the consumer contribution with the cicadas pulse. These findings suggest that generalist consumers may play different functional roles in food webs under perturbations of resource pulses. This study provides one of the few highly quantitative descriptions on dietary and trophic shifts of a key consumer in forest food webs, which may help future studies to form specific predictions on changes in trophic interactions following resource pulses.

A simple model for yield prediction of rice based on vegetation index derived from satellite and AMeDAS data during ripening period

International Nuclear Information System (INIS)

Wakiyama, Y.; Inoue, K.; Nakazono, K.

2003-01-01

The present study was conducted to show a simple model for rice yield predicting by using a vegetation index (NDVI) derived from satellite and meteorological data. In a field experiment, the relationship between the vegetation index and radiation absorbed by the rice canopy was investigated from transplanting to maturity. Their correlation held. This result revealed that the vegetation index could be used as a measure of absorptance of solar radiation by rice canopy. NDVI multiplied by solar radiation (SR) every day was accumulated (Σ(SR·NDVI)) from the field experiment. Σ(SR·NDVI) was plotted against above ground dry matter. It was obvious that they had a strong relationship. Rice yield largely depends on solar radiation and air temperature during the ripening period. Air temperature affects dry matter production. Relationships between Y SR -1 (Y: rice yield, SR: solar radiation) and mean air temperature were investigated from meteorological data and statistical data on rice yield. There was an optimum air temperature, 21.3°C, for ripening. When it was near 21.3°C in the ripening period, the rice yield was higher. We proposed a simple model for yield prediction of rice based on these results. The model is composed with SR·NDVI and the optimum air temperature. Vegetation index was derived from 3 years, LANDSAT TM data in Toyama, Ishikawa, Fukui and Nagano prefectures at heading. The meteorological data was used from AMeDAS data. The model was described as follows: Y = 0.728 SR·NDVI−2.04(T−21.3) 2 + 282 (r 2 = 0.65, n = 43) where Y is rice yield (kg 10a -1 ), SR is solar radiation (MJ m -2 ) during the ripening period (from 10 days before heading to 30 days after heading), T is mean air temperature (°C) during the ripening period. RMSE was 33.7kg 10a -1 . The model revealed good precision. (author)

A new method for prediction of the hospitalization period in ICU using neural networks

Directory of Open Access Journals (Sweden)

Adel Alinezhad Kolaei

2013-07-01

Full Text Available Introduction:APACHE (Acute Physiologic and Chronic Health Evaluation score is a medical tool designed to measure the severity of disease for adult patients admitted to Intensive Care Units (ICU. However, it is designed based on the American patients’ data and is not well suited to be used for Iranian people. In addition, Iranian hospitals are not equipped with High Dependency Units which is required for original APACHE. Method: We aimed to design an intelligent version of APACHE system for recognition of patients’ hospitalization period in ICUs. The new system can be designed based on Iranian local data and updated locally. Intelligence means that the system has the ability to learn from its previous results and doesn’t need manual update. Results: In this study, this new system is introduced and the technical specifications are presented. It is based on neural networks. It can be trained and is capable of auto-learning. The results obtained from final implemented software show better performance than those obtained from non-local version. Conclusion: Using this method, the efficiency of the prediction has increased from 80% to 90%. Such results were compared with the APACHE outputs to show the superiority of the proposed method.

Ecological periodic tables: in principle and practice (in OIKOS)

Science.gov (United States)

“Science is organized knowledge.” Immanuel Kant (1724–1804) Ecological periodic tables are an information organizing system with categorical habitat types as elements and predictably recurring (periodic) properties of a target biotic community, such as its relative species rich...

Staying Power of Churn Prediction Models

NARCIS (Netherlands)

Risselada, Hans; Verhoef, Peter C.; Bijmolt, Tammo H. A.

In this paper, we study the staying power of various churn prediction models. Staying power is defined as the predictive performance of a model in a number of periods after the estimation period. We examine two methods, logit models and classification trees, both with and without applying a bagging

NASA/MSFC prediction techniques

International Nuclear Information System (INIS)

Smith, R.E.

1987-01-01

The NASA/MSFC method of forecasting is more formal than NOAA's. The data are smoothed by the Lagrangian method and linear regression prediction techniques are used. The solar activity period is fixed at 11 years--the mean period of all previous cycles. Interestingly, the present prediction for the time of the next solar minimum is February or March of 1987, which, within the uncertainties of two methods, can be taken to be the same as the NOAA result

Attractors of the periodically forced Rayleigh system

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Petre Bazavan

2011-07-01

Full Text Available The autonomous second order nonlinear ordinary differential equation(ODE introduced in 1883 by Lord Rayleigh, is the equation whichappears to be the closest to the ODE of the harmonic oscillator withdumping.In this paper we present a numerical study of the periodic andchaotic attractors in the dynamical system associated with the generalized Rayleigh equation. Transition between periodic and quasiperiodic motion is also studied. Numerical results describe the system dynamics changes (in particular bifurcations, when the forcing frequency is varied and thus, periodic, quasiperiodic or chaotic behaviour regions are predicted.

Inflation from periodic extra dimensions

Energy Technology Data Exchange (ETDEWEB)

Higaki, Tetsutaro [Department of Physics, Keio University, Kanagawa 223-8522 (Japan); Tatsuta, Yoshiyuki, E-mail: thigaki@rk.phys.keio.ac.jp, E-mail: y_tatsuta@akane.waseda.jp [Department of Physics, Waseda University, Tokyo 169-8555 (Japan)

2017-07-01

We discuss a realization of a small field inflation based on string inspired supergravities. In theories accompanying extra dimensions, compactification of them with small radii is required for realistic situations. Since the extra dimension can have a periodicity, there will appear (quasi-)periodic functions under transformations of moduli of the extra dimensions in low energy scales. Such a periodic property can lead to a UV completion of so-called multi-natural inflation model where inflaton potential consists of a sum of multiple sinusoidal functions with a decay constant smaller than the Planck scale. As an illustration, we construct a SUSY breaking model, and then show that such an inflaton potential can be generated by a sum of world sheet instantons in intersecting brane models on extra dimensions containing orbifold. We show also predictions of cosmic observables by numerical analyzes.

Engineering of spatial solitons in two-period QPM structures

DEFF Research Database (Denmark)

Johansen, Steffen Kjær; Carrasco, Silvia; Torner, Lluis

2002-01-01

We report on a scheme which might make it practically possible to engineer the effective competing nonlinearities that on average govern the light propagation in quasi-phase-matching (QPM) gratings. Modulation of the QPM period with a second longer period, introduces an extra degree of freedom...... relative lengths of the two periods and we consider the effect on solitons and the bandwidth for their generation. We derive an expression for the bandwidth of multicolor soliton generation in two-period QPM samples and we predict and confirm numerically that the bandwidth is broader in the two-period QPM...

Predicting temperature drop rate of mass concrete during an initial cooling period using genetic programming

Science.gov (United States)

Bhattarai, Santosh; Zhou, Yihong; Zhao, Chunju; Zhou, Huawei

2018-02-01

Thermal cracking on concrete dams depends upon the rate at which the concrete is cooled (temperature drop rate per day) within an initial cooling period during the construction phase. Thus, in order to control the thermal cracking of such structure, temperature development due to heat of hydration of cement should be dropped at suitable rate. In this study, an attempt have been made to formulate the relation between cooling rate of mass concrete with passage of time (age of concrete) and water cooling parameters: flow rate and inlet temperature of cooling water. Data measured at summer season (April-August from 2009 to 2012) from recently constructed high concrete dam were used to derive a prediction model with the help of Genetic Programming (GP) software “Eureqa”. Coefficient of Determination (R) and Mean Square Error (MSE) were used to evaluate the performance of the model. The value of R and MSE is 0.8855 and 0.002961 respectively. Sensitivity analysis was performed to evaluate the relative impact on the target parameter due to input parameters. Further, testing the proposed model with an independent dataset those not included during analysis, results obtained from the proposed GP model are close enough to the real field data.

A common periodic table of codons and amino acids.

Science.gov (United States)

Biro, J C; Benyó, B; Sansom, C; Szlávecz, A; Fördös, G; Micsik, T; Benyó, Z

2003-06-27

A periodic table of codons has been designed where the codons are in regular locations. The table has four fields (16 places in each) one with each of the four nucleotides (A, U, G, C) in the central codon position. Thus, AAA (lysine), UUU (phenylalanine), GGG (glycine), and CCC (proline) were placed into the corners of the fields as the main codons (and amino acids) of the fields. They were connected to each other by six axes. The resulting nucleic acid periodic table showed perfect axial symmetry for codons. The corresponding amino acid table also displaced periodicity regarding the biochemical properties (charge and hydropathy) of the 20 amino acids and the position of the stop signals. The table emphasizes the importance of the central nucleotide in the codons and predicts that purines control the charge while pyrimidines determine the polarity of the amino acids. This prediction was experimentally tested.

Beliefs and social behavior in a multi-period ultimatum game

Science.gov (United States)

Azar, Ofer H.; Lahav, Yaron; Voslinsky, Alisa

2015-01-01

We conduct a multi-period ultimatum game in which we elicit players' beliefs. Responders do not predict accurately the amount that will be offered to them, and do not get better in their predictions over time. At the individual level we see some effect of the mistake in expectations in the previous period on the responder's expectation about the offer in the current period, but this effect is relatively small. The proposers' beliefs about the minimum amount that responders will accept is significantly higher than the minimum amount responders believe will be accepted by other responders. The proposer's belief about the minimal acceptable offer does not change following a rejection. Nevertheless, the proposer's offer in the next period does increase following a rejection. The probability of rejection increases when the responder has higher expectations about the amount that will be offered to him or higher beliefs about the minimal amount that other responders will accept. PMID:25762909

Predicting the conditions under which vibroacoustic resonances with external periodic loads occur in the primary coolant circuits of VVER-based NPPs

Science.gov (United States)

Proskuryakov, K. N.; Fedorov, A. I.; Zaporozhets, M. V.

2015-08-01

The accident at the Japanese Fukushima Daiichi nuclear power plant (NPP) caused by an earthquake showed the need of taking further efforts aimed at improving the design and engineering solutions for ensuring seismic resistance of NPPs with due regard to mutual influence of the dynamic processes occurring in the NPP building structures and process systems. Resonance interaction between the vibrations of NPP equipment and coolant pressure pulsations leads to an abnormal growth of dynamic stresses in structural materials, accelerated exhaustion of equipment service life, and increased number of sudden equipment failures. The article presents the results from a combined calculation-theoretical and experimental substantiation of mutual amplification of two kinds of external periodic loads caused by rotation of the reactor coolant pump (RCP) rotor and an earthquake. The data of vibration measurements at an NPP are presented, which confirm the predicted multiple amplification of vibrations in the steam generator and RCP at a certain combination of coolant thermal-hydraulic parameters. It is shown that the vibration frequencies of the main equipment may fall in the frequency band corresponding to the maximal values in the envelope response spectra constructed on the basis of floor accelerograms. The article presents the results from prediction of conditions under which vibroacoustic resonances with external periodic loads take place, which confirm the occurrence of additional earthquake-induced multiple growth of pressure pulsation intensity in the steam generator at the 8.3 Hz frequency and additional multiple growth of vibrations of the RCP and the steam generator cold header at the 16.6 Hz frequency. It is shown that at the elastic wave frequency equal to 8.3 Hz in the coolant, resonance occurs with the frequency of forced vibrations caused by the rotation of the RCP rotor. A conclusion is drawn about the possibility of exceeding the design level of equipment vibrations

Developmental constraint of insect audition

Directory of Open Access Journals (Sweden)

Strauß Johannes

2006-12-01

Full Text Available Abstract Background Insect ears contain very different numbers of sensory cells, from only one sensory cell in some moths to thousands of sensory cells, e.g. in cicadas. These differences still await functional explanation and especially the large numbers in cicadas remain puzzling. Insects of the different orders have distinct developmental sequences for the generation of auditory organs. These sensory cells might have different functions depending on the developmental stages. Here we propose that constraints arising during development are also important for the design of insect ears and might influence cell numbers of the adults. Presentation of the hypothesis We propose that the functional requirements of the subadult stages determine the adult complement of sensory units in the auditory system of cicadas. The hypothetical larval sensory organ should function as a vibration receiver, representing a functional caenogenesis. Testing the hypothesis Experiments at different levels have to be designed to test the hypothesis. Firstly, the neuroanatomy of the larval sense organ should be analyzed to detail. Secondly, the function should be unraveled neurophysiologically and behaviorally. Thirdly, the persistence of the sensory cells and the rebuilding of the sensory organ to the adult should be investigated. Implications of the hypothesis Usually, the evolution of insect ears is viewed with respect to physiological and neuronal mechanisms of sound perception. This view should be extended to the development of sense organs. Functional requirements during postembryonic development may act as constraints for the evolution of adult organs, as exemplified with the auditory system of cicadas.

New species of Simona Moulds, 2012 and Chelapsalta Moulds, 2012 cicadas (Cicadidae: Cicadettinae: Cicadettini) from Australia: comparative morphology, songs, behaviour and distributions.

Science.gov (United States)

Ewart, A; Popple, L W; Marshall, D C

2015-08-20

In 2012, Moulds established the morphologically similar cicada genera Simona and Chelapsalta, each with one Australian species (sancta Distant and puer Walker, respectively). In this paper, two new species are described within the genus Simona Moulds 2012, S. erema sp. nov. and S. retracta sp. nov., and one within the genus Chelapsalta Moulds 2012, C. myoporae sp. nov. The type species of Simona (female holotype), S. sancta (Distant, 1913), is redescribed based on a contemporary male, nominated a plesiotype, held in the Australian National Insect Collection. Melampsalta subgulosa Ashton 1914 is supported as a junior synonym of S. sancta. The species within the two genera of Simona and Chelapsalta are morphologically very similar. S. erema occurs widely through the arid regions of inland Australia, extending west from western Queensland through the Northern Territory, to central-western Western Australia, a linear distance of approximately 2200 km. S. retracta is known from a single semi-arid locality in southern inland Queensland. C. myoporae occurs widely through southeast, central and southwest Queensland, extending southwards into inland and western N.S.W. and southeastern South Australia. It tends to occur most commonly within vegetation associated with seasonal riverine floodplains, and in some areas of poorly drained and clay-rich soils. The calling songs of these three species, together with those of S. sancta and C. puer, are described. Detailed comparisons made of the songs of S. erema and C. myoporae, each from three widely separated locations, clearly exhibit structural consistency in their calling songs across their distributions. The Simona songs are complex and contain multiple elements; the species are very mobile and wary, and inhabit low dense shrubland. The songs of the two Chelapsalta species, both relatively sedentary in behaviour, in contrast consist of relatively uniform chirping and buzzing elements. It is suggested that, although the two

Prediction of rhythmic and periodic EEG patterns and seizures on continuous EEG with early epileptiform discharges.

Science.gov (United States)

Koren, J; Herta, J; Draschtak, S; Pötzl, G; Pirker, S; Fürbass, F; Hartmann, M; Kluge, T; Baumgartner, C

2015-08-01

Continuous EEG (cEEG) is necessary to document nonconvulsive seizures (NCS), nonconvulsive status epilepticus (NCSE), as well as rhythmic and periodic EEG patterns of 'ictal-interictal uncertainty' (RPPIIU) including periodic discharges, rhythmic delta activity, and spike-and-wave complexes in neurological intensive care patients. However, cEEG is associated with significant recording and analysis efforts. Therefore, predictors from short-term routine EEG with a reasonably high yield are urgently needed in order to select patients for evaluation with cEEG. The aim of this study was to assess the prognostic significance of early epileptiform discharges (i.e., within the first 30 min of EEG recording) on the following: (1) incidence of ictal EEG patterns and RPPIIU on subsequent cEEG, (2) occurrence of acute convulsive seizures during the ICU stay, and (3) functional outcome after 6 months of follow-up. We conducted a separate analysis of the first 30 min and the remaining segments of prospective cEEG recordings according to the ACNS Standardized Critical Care EEG Terminology as well as NCS criteria and review of clinical data of 32 neurological critical care patients. In 17 patients with epileptiform discharges within the first 30 min of EEG (group 1), electrographic seizures were observed in 23.5% (n = 4), rhythmic or periodic EEG patterns of 'ictal-interictal uncertainty' in 64.7% (n = 11), and neither electrographic seizures nor RPPIIU in 11.8% (n = 2). In 15 patients with no epileptiform discharges in the first 30 min of EEG (group 2), no electrographic seizures were recorded on subsequent cEEG, RPPIIU were seen in 26.7% (n = 4), and neither electrographic seizures nor RPPIIU in 73.3% (n = 11). The incidence of EEG patterns on cEEG was significantly different between the two groups (p = 0.008). Patients with early epileptiform discharges developed acute seizures more frequently than patients without early epileptiform discharges (p = 0.009). Finally, functional

Predictability of Landslide Timing From Quasi-Periodic Precursory Earthquakes

Science.gov (United States)

Bell, Andrew F.

2018-02-01

Accelerating rates of geophysical signals are observed before a range of material failure phenomena. They provide insights into the physical processes controlling failure and the basis for failure forecasts. However, examples of accelerating seismicity before landslides are rare, and their behavior and forecasting potential are largely unknown. Here I use a Bayesian methodology to apply a novel gamma point process model to investigate a sequence of quasiperiodic repeating earthquakes preceding a large landslide at Nuugaatsiaq in Greenland in June 2017. The evolution in earthquake rate is best explained by an inverse power law increase with time toward failure, as predicted by material failure theory. However, the commonly accepted power law exponent value of 1.0 is inconsistent with the data. Instead, the mean posterior value of 0.71 indicates a particularly rapid acceleration toward failure and suggests that only relatively short warning times may be possible for similar landslides in future.

Mammalian cycles: internally defined periods and interaction-driven amplitudes

Directory of Open Access Journals (Sweden)

LR Ginzburg

2015-08-01

Full Text Available The cause of mammalian cycles—the rise and fall of populations over a predictable period of time—has remained controversial since these patterns were first observed over a century ago. In spite of extensive work on observable mammalian cycles, the field has remained divided upon what the true cause is, with a majority of opinions attributing it to either predation or to intra-species mechanisms. Here we unite the eigenperiod hypothesis, which describes an internal, maternal effect-based mechanism to explain the cycles’ periods with a recent generalization explaining the amplitude of snowshoe hare cycles in northwestern North America based on initial predator abundance. By explaining the period and the amplitude of the cycle with separate mechanisms, a unified and consistent view of the causation of cycles is reached. Based on our suggested theory, we forecast the next snowshoe hare cycle (predicted peak in 2016 to be of extraordinarily low amplitude.

Five new species of grass cicadas in the genus Graminitigrina (Hemiptera: Cicadidae: Cicadettinae: Cicadettini) from Queensland and Northern Territory, Australia: comparative morphology, songs, behaviour and distributions.

Science.gov (United States)

Ewart, A; Popple, L W; Hill, K B R

2017-02-07

Five new species of small grass cicadas belonging to the genus Graminitigrina Ewart and Marques are described, together with detailed analyses of their calling songs. Four species occur in Queensland, G. aurora n. sp. from eastern central Queensland near Fairbairn Dam; G. flindensis n. sp. from central Queensland between Hughenden northwards for at least 108 km; G. einasleighi n. sp. from near The Lynd, Einasleigh River, northeastern Queensland; G. selwynensis n. sp. from the Selwyn Range, northwestern Queensland, at locations about 40 km east of Mount Isa and 25 km southwest of Cloncurry, this latter here transferred from G. bowensis Ewart and Marques; G. uluruensis n. sp. from Uluru and the Olgas in southwestern Northern Territory, extending northwards through Tennant Creek and apparently further north to near Larrimah, a linear distance of approximately 1190 km. These new species bring the known Graminitigrina species to ten, all superficially similar in colour and morphology. A key to male specimens is provided for the 10 species. Additional distribution records and additional aural song recordings are presented for G. bowensis, these requiring the transfer of populations previously identified as G. bowensis from Croydon and Georgetown, northern Gulf region, to G. karumbae Ewart and Marques. Detailed comparative analyses, including NMDS analyses, of the songs of all 10 species are provided, which show that the song parameters are appropriate to distinguish the species, although some partial overlap is noted in the waveform plots between the songs of G. uluruensis n. sp. and G. flindensis n. sp. Regional variations of song parameters are noted in the calling songs of most of the species described.

Data-Based Predictive Control with Multirate Prediction Step

Science.gov (United States)

Barlow, Jonathan S.

2010-01-01

Data-based predictive control is an emerging control method that stems from Model Predictive Control (MPC). MPC computes current control action based on a prediction of the system output a number of time steps into the future and is generally derived from a known model of the system. Data-based predictive control has the advantage of deriving predictive models and controller gains from input-output data. Thus, a controller can be designed from the outputs of complex simulation code or a physical system where no explicit model exists. If the output data happens to be corrupted by periodic disturbances, the designed controller will also have the built-in ability to reject these disturbances without the need to know them. When data-based predictive control is implemented online, it becomes a version of adaptive control. One challenge of MPC is computational requirements increasing with prediction horizon length. This paper develops a closed-loop dynamic output feedback controller that minimizes a multi-step-ahead receding-horizon cost function with multirate prediction step. One result is a reduced influence of prediction horizon and the number of system outputs on the computational requirements of the controller. Another result is an emphasis on portions of the prediction window that are sampled more frequently. A third result is the ability to include more outputs in the feedback path than in the cost function.

Time series modelling of increased soil temperature anomalies during long period

Science.gov (United States)

Shirvani, Amin; Moradi, Farzad; Moosavi, Ali Akbar

2015-10-01

Soil temperature just beneath the soil surface is highly dynamic and has a direct impact on plant seed germination and is probably the most distinct and recognisable factor governing emergence. Autoregressive integrated moving average as a stochastic model was developed to predict the weekly soil temperature anomalies at 10 cm depth, one of the most important soil parameters. The weekly soil temperature anomalies for the periods of January1986-December 2011 and January 2012-December 2013 were taken into consideration to construct and test autoregressive integrated moving average models. The proposed model autoregressive integrated moving average (2,1,1) had a minimum value of Akaike information criterion and its estimated coefficients were different from zero at 5% significance level. The prediction of the weekly soil temperature anomalies during the test period using this proposed model indicated a high correlation coefficient between the observed and predicted data - that was 0.99 for lead time 1 week. Linear trend analysis indicated that the soil temperature anomalies warmed up significantly by 1.8°C during the period of 1986-2011.

Predictable or not predictable? The MOV question

International Nuclear Information System (INIS)

Thibault, C.L.; Matzkiw, J.N.; Anderson, J.W.; Kessler, D.W.

1994-01-01

Over the past 8 years, the nuclear industry has struggled to understand the dynamic phenomena experienced during motor-operated valve (MOV) operation under differing flow conditions. For some valves and designs, their operational functionality has been found to be predictable; for others, unpredictable. Although much has been accomplished over this period of time, especially on modeling valve dynamics, the unpredictability of many valves and designs still exists. A few valve manufacturers are focusing on improving design and fabrication techniques to enhance product reliability and predictability. However, this approach does not address these issues for installed and inpredictable valves. This paper presents some of the more promising techniques that Wyle Laboratories has explored with potential for transforming unpredictable valves to predictable valves and for retrofitting installed MOVs. These techniques include optimized valve tolerancing, surrogated material evaluation, and enhanced surface treatments

Prediction of GNSS satellite clocks

International Nuclear Information System (INIS)

Broederbauer, V.

2010-01-01

This thesis deals with the characterisation and prediction of GNSS-satellite-clocks. A prerequisite to develop powerful algorithms for the prediction of clock-corrections is the thorough study of the behaviour of the different clock-types of the satellites. In this context the predicted part of the IGU-clock-corrections provided by the Analysis Centers (ACs) of the IGS was compared to the IGS-Rapid-clock solutions to determine reasonable estimates of the quality of already existing well performing predictions. For the shortest investigated interval (three hours) all ACs obtain almost the same accuracy of 0,1 to 0,4 ns. For longer intervals the individual predictions results start to diverge. Thus, for a 12-hours- interval the differences range from nearly 10 ns (GFZ, CODE) until up to some 'tens of ns'. Based on the estimated clock corrections provided via the IGS Rapid products a simple quadratic polynomial turns out to be sufficient to describe the time series of Rubidium-clocks. On the other hand Cesium-clocks show a periodical behaviour (revolution period) with an amplitude of up to 6 ns. A clear correlation between these amplitudes and the Sun elevation angle above the orbital planes can be demonstrated. The variability of the amplitudes is supposed to be caused by temperature-variations affecting the oscillator. To account for this periodical behaviour a quadratic polynomial with an additional sinus-term was finally chosen as prediction model both for the Cesium as well as for the Rubidium clocks. The three polynomial-parameters as well as amplitude and phase shift of the periodic term are estimated within a least-square-adjustment by means of program GNSS-VC/static. Input-data are time series of the observed part of the IGU clock corrections. With the estimated parameters clock-corrections are predicted for various durations. The mean error of the prediction of Rubidium-clock-corrections for an interval of six hours reaches up to 1,5 ns. For the 12-hours

Analysis of the uranium price predicted to 24 months, implementing neural networks and the Monte Carlo method like predictive tools

International Nuclear Information System (INIS)

Esquivel E, J.; Ramirez S, J. R.; Palacios H, J. C.

2011-11-01

The present work shows predicted prices of the uranium, using a neural network. The importance of predicting financial indexes of an energy resource, in this case, allows establishing budgetary measures, as well as the costs of the resource to medium period. The uranium is part of the main energy generating fuels and as such, its price rebounds in the financial analyses, due to this is appealed to predictive methods to obtain an outline referent to the financial behaviour that will have in a certain time. In this study, two methodologies are used for the prediction of the uranium price: the Monte Carlo method and the neural networks. These methods allow predicting the indexes of monthly costs, for a two years period, starting from the second bimonthly of 2011. For the prediction the uranium costs are used, registered from the year 2005. (Author)

PENGARUH VARIASI PERSENTASE EKSTRAK JANGKRIK (Gryllus sp Walk YANG BERBEDA TERHADAP TINGKAT SURVIVAL RATE BENIH IKAN MAS KOKI (Carrasius auratus L

Directory of Open Access Journals (Sweden)

Elrifadah Elrifadah

2016-10-01

Full Text Available This study Aims to Determine the effect of different variations on survival seed cicada goldfish. The method used in this study is completely randomized design with 3 treatments (A = 3%, B = 5%, and C = 7% and three replications. From these results Obtained survival rate to 83.0% Obtained treatment A, B Obtained 88.33% and 80.0% Obtained C treatment. Then the results of analysis of variance accept the hypothesis Ho that the percentage variation of different cicada extract (3%, 5% and 7% did not Affect the survival rate of seedlings goldfish. During the last condition of water quality research support for seed viability parameters goldfish.

Periodic depuration of anthracene metabolites by rainbow trout

International Nuclear Information System (INIS)

Linder, G.; Bergman, H.L.

1984-01-01

Rainbow trout Salmo gairdneri, statically exposed to 36 μg/liter anthracene (including 9- 14 C-C anthracene), bioconcentrated the polynuclear aromatic hydrocarbon 200 times the exposure concentration over 18 hours. Then, during a 96-hour clearance periods, mass-balance analysis of fish and water samples indicated that anthracene was rapidly converted to polar metabolites(s), then eliminated periodically. Maximum depuration occurred during the dark phase of a 16-hour-light: 8-hour-dark photocycle. Of the 2-3% contribution of 14 C metabolites(s) to the total 14 C residue, nearly half came from the bile. This periodic depuration may be circadian, although this requires confirmation by further work; to the extent it affects metabolic fate of bioconcentrated organics, periodic depuration undoubtedly contributes to differences between predicted and observed bioconcentration factors

There is Much More to Mendeleev's Periodic Table Than Meets the ...

Indian Academy of Sciences (India)

There is Much More to Mendeleev's Periodic. Table Than Meets the Eye. S Vatsala is at. Department of. Chemistry, Providence. College, University of. Calicnt. S Vatsala. Recognition of periodic trends in the properties of ele- ments is important for understanding and predicting the role of trace metals in biology. Introduction.

Detectability of periodic gravitational waves by initial interferometers

International Nuclear Information System (INIS)

Owen, Benjamin J

2006-01-01

I review three recent theoretical developments in neutron star physics predicting that rotating neutron stars could be very strong emitters of periodic gravitational waves. These imply a small but nonzero chance that ground-based interferometers could detect their first periodic signal in the next few years rather than after advanced upgrades. They also imply that upper limits will become astrophysically interesting before advanced upgrades. I discuss the implications for near-future searches and for the astrophysical payoffs of proposed small upgrades to initial interferometers

Skill forecasting from ensemble predictions of wind power

DEFF Research Database (Denmark)

Pinson, Pierre; Nielsen, Henrik Aalborg; Madsen, Henrik

2009-01-01

Optimal management and trading of wind generation calls for the providing of uncertainty estimates along with the commonly provided short-term wind power point predictions. Alternative approaches for the use of probabilistic forecasting are introduced. More precisely, focus is given to prediction...... risk indices aiming to give a comprehensive signal on the expected level of forecast uncertainty. Ensemble predictions of wind generation are used as input. A proposal for the definition of prediction risk indices is given. Such skill forecasts are based on the spread of ensemble forecasts (i.e. a set...... of alternative scenarios for the coming period) for a single prediction horizon or over a took-ahead period. It is shown on the test case of a Danish offshore wind farm how these prediction risk indices may be related to several levels of forecast uncertainty (and potential energy imbalances). Wind power...

The period-age relation for cepheids

International Nuclear Information System (INIS)

Efremov, Yu.N.

1978-01-01

The list of 119 cepheid-members of 55 clusters and associations of the Magellanic Clouds, the Galaxy, and M31 is given. The period-age relation is found from the data on 64 cepheids in 29 clusters for which the age determinations are available, the ages of extragalactic clusters were determined mainly from their integral colours. The U-B colours are found to be of much better age parameters than the B-V ones. The composite period-age relation agrees well with the theoretical one. The observed dispersion of the period-age relation leads to an estimate of the age dispersion about 1x10 7 years in the associations. Some peculiarities of the cepheids with the shortest periods amongst others in the same clusters are probably explained if they are overtone pulsators. The period-age relation may be used for an investigation of the recent history of star formation in the galaxies. This relation allows to determine the age gradient across the spiral arm in M31 which is in agreement with the density wave theory predictions. The distribution of cepheids in our Galaxy and neighbouring galaxies is consistent with the conception of star formation lasting for some dozen million years in cells with a dimension of some hundreds of parsecs

Advancing Environmental Prediction Capabilities for the Polar Regions and Beyond during The Year of Polar Prediction

Science.gov (United States)

Werner, Kirstin; Goessling, Helge; Hoke, Winfried; Kirchhoff, Katharina; Jung, Thomas

2017-04-01

Environmental changes in polar regions open up new opportunities for economic and societal operations such as vessel traffic related to scientific, fishery and tourism activities, and in the case of the Arctic also enhanced resource development. The availability of current and accurate weather and environmental information and forecasts will therefore play an increasingly important role in aiding risk reduction and safety management around the poles. The Year of Polar Prediction (YOPP) has been established by the World Meteorological Organization's World Weather Research Programme as the key activity of the ten-year Polar Prediction Project (PPP; see more on www.polarprediction.net). YOPP is an internationally coordinated initiative to significantly advance our environmental prediction capabilities for the polar regions and beyond, supporting improved weather and climate services. Scheduled to take place from mid-2017 to mid-2019, the YOPP core phase covers an extended period of intensive observing, modelling, prediction, verification, user-engagement and education activities in the Arctic and Antarctic, on a wide range of time scales from hours to seasons. The Year of Polar Prediction will entail periods of enhanced observational and modelling campaigns in both polar regions. With the purpose to close the gaps in the conventional polar observing systems in regions where the observation network is sparse, routine observations will be enhanced during Special Observing Periods for an extended period of time (several weeks) during YOPP. This will allow carrying out subsequent forecasting system experiments aimed at optimizing observing systems in the polar regions and providing insight into the impact of better polar observations on forecast skills in lower latitudes. With various activities and the involvement of a wide range of stakeholders, YOPP will contribute to the knowledge base needed to managing the opportunities and risks that come with polar climate change.

Skill of real-time operational forecasts with the APCC multi-model ensemble prediction system during the period 2008-2015

Science.gov (United States)

Min, Young-Mi; Kryjov, Vladimir N.; Oh, Sang Myeong; Lee, Hyun-Ju

2017-12-01

This paper assesses the real-time 1-month lead forecasts of 3-month (seasonal) mean temperature and precipitation on a monthly basis issued by the Asia-Pacific Economic Cooperation Climate Center (APCC) for 2008-2015 (8 years, 96 forecasts). It shows the current level of the APCC operational multi-model prediction system performance. The skill of the APCC forecasts strongly depends on seasons and regions that it is higher for the tropics and boreal winter than for the extratropics and boreal summer due to direct effects and remote teleconnections from boundary forcings. There is a negative relationship between the forecast skill and its interseasonal variability for both variables and the forecast skill for precipitation is more seasonally and regionally dependent than that for temperature. The APCC operational probabilistic forecasts during this period show a cold bias (underforecasting of above-normal temperature and overforecasting of below-normal temperature) underestimating a long-term warming trend. A wet bias is evident for precipitation, particularly in the extratropical regions. The skill of both temperature and precipitation forecasts strongly depends upon the ENSO strength. Particularly, the highest forecast skill noted in 2015/2016 boreal winter is associated with the strong forcing of an extreme El Nino event. Meanwhile, the relatively low skill is associated with the transition and/or continuous ENSO-neutral phases of 2012-2014. As a result the skill of real-time forecast for boreal winter season is higher than that of hindcast. However, on average, the level of forecast skill during the period 2008-2015 is similar to that of hindcast.

Effective propagation in a perturbed periodic structure

Science.gov (United States)

Maurel, Agnès; Pagneux, Vincent

2008-08-01

In a recent paper [D. Torrent, A. Hakansson, F. Cervera, and J. Sánchez-Dehesa, Phys. Rev. Lett. 96, 204302 (2006)] inspected the effective parameters of a cluster containing an ensemble of scatterers with a periodic or a weakly disordered arrangement. A small amount of disorder is shown to have a small influence on the characteristics of the acoustic wave propagation with respect to the periodic case. In this Brief Report, we inspect further the effect of a deviation in the scatterer distribution from the periodic distribution. The quasicrystalline approximation is shown to be an efficient tool to quantify this effect. An analytical formula for the effective wave number is obtained in one-dimensional acoustic medium and is compared with the Berryman result in the low-frequency limit. Direct numerical calculations show a good agreement with the analytical predictions.

Effective propagation in a perturbed periodic structure

International Nuclear Information System (INIS)

Maurel, Agnes; Pagneux, Vincent

2008-01-01

In a recent paper [D. Torrent, A. Hakansson, F. Cervera, and J. Sanchez-Dehesa, Phys. Rev. Lett. 96, 204302 (2006)] inspected the effective parameters of a cluster containing an ensemble of scatterers with a periodic or a weakly disordered arrangement. A small amount of disorder is shown to have a small influence on the characteristics of the acoustic wave propagation with respect to the periodic case. In this Brief Report, we inspect further the effect of a deviation in the scatterer distribution from the periodic distribution. The quasicrystalline approximation is shown to be an efficient tool to quantify this effect. An analytical formula for the effective wave number is obtained in one-dimensional acoustic medium and is compared with the Berryman result in the low-frequency limit. Direct numerical calculations show a good agreement with the analytical predictions

The attenuation of the periodic table

International Nuclear Information System (INIS)

Cook, N.D.

1990-01-01

Unique among models of nuclear structure, the face-centered-cubic (FCC) lattice model predicts the attenuation of the periodic table at Z < 110 and the impossibility of superheavy nuclei. The total binding energies of superheavy nuclei in the FCC model (109 < Z < 127) were calculated on the basis of parameters obtained from a least-squares best-fit for 914 nuclei (Z < 99). No indication of increased stability is found for any of the transuranic elements

Evolutionary dynamics of incubation periods.

Science.gov (United States)

Ottino-Loffler, Bertrand; Scott, Jacob G; Strogatz, Steven H

2017-12-21

The incubation period for typhoid, polio, measles, leukemia and many other diseases follows a right-skewed, approximately lognormal distribution. Although this pattern was discovered more than sixty years ago, it remains an open question to explain its ubiquity. Here, we propose an explanation based on evolutionary dynamics on graphs. For simple models of a mutant or pathogen invading a network-structured population of healthy cells, we show that skewed distributions of incubation periods emerge for a wide range of assumptions about invader fitness, competition dynamics, and network structure. The skewness stems from stochastic mechanisms associated with two classic problems in probability theory: the coupon collector and the random walk. Unlike previous explanations that rely crucially on heterogeneity, our results hold even for homogeneous populations. Thus, we predict that two equally healthy individuals subjected to equal doses of equally pathogenic agents may, by chance alone, show remarkably different time courses of disease.

Predicting formation enthalpies of metal hydrides

DEFF Research Database (Denmark)

Andreasen, A.

2004-01-01

of elements from the periodic table are yet to beexplored. Since experimental determination of thermodynamic properties of the vast combinations of elements is tedious it may be advantagous to have a predictive tool for this task. In this report different ways of predicting #DELTA#H_f for binary andternary...

Predictive power of the DASA-IV: Variations in rating method and timescales.

Science.gov (United States)

Nqwaku, Mphindisi; Draycott, Simon; Aldridge-Waddon, Luke; Bush, Emma-Louise; Tsirimokou, Alexandra; Jones, Dominic; Puzzo, Ignazio

2018-05-10

This project evaluated the predictive validity of the Dynamic Appraisal of Situational Aggression - Inpatient Version (DASA-IV) in a high-secure psychiatric hospital in the UK over 24 hours and over a single nursing shift. DASA-IV scores from three sequential nursing shifts over a 24-hour period were compared with the mean (average of three scores across the 24-hour period) and peak (highest of the three scores across the 24-hour period) scores across these shifts. In addition, scores from a single nursing shift were used to predict aggressive incidents over each of the following three shifts. The DASA-IV was completed by nursing staff during handover meetings, rating 43 male psychiatric inpatients over a period of 6 months. Data were compared to incident reports recorded over the same period. Receiver operating characteristic (ROC) curves and generalized estimating equations assessed the predictive ability of various DASA-IV scores over 24-hour and single-shift timescales. Scores from the DASA-IV based on a single shift had moderate predictive ability for aggressive incidents occurring the next calendar day, whereas scores based on all three shifts had excellent predictive ability. DASA-IV scores from a single shift showed moderate predictive ability for each of the following three shifts. The DASA-IV has excellent predictive ability for aggressive incidents within a secure setting when data are summarized over a 24-hour period, as opposed to when a single rating is taken. In addition, it has moderate value for predicting incidents over even shorter timescales. © 2018 Australian College of Mental Health Nurses Inc.

A cautionary note on decadal sea level pressure predictions from GCMs

Directory of Open Access Journals (Sweden)

Stefan Liess

2018-03-01

Full Text Available A comparison of sea level pressure (SLP trends in a subset of seven Coupled Model Intercomparison Project (CMIP phase 5 general circulation models (GCM, namely decadal simulations with CCSM4, CanCM4, MPI-ESM-LR, FGOALS-g2, MIROC4h, MIROC5, and MRI-CGCM3, to their CMIP3 counterparts reveals an unrealistically strong forecast skill in CMIP3 models for trend predictions for 2001–2011 when using the 1979–2000 period to train the forecast. Boreal-winter SLP trends over five high-, mid-, and low-latitude zones were calculated over the 1979–2000 initialization period for each ensemble member and then ranked based on their performance relative to HadSLP2 observations. The same method is used to rank the ensemble members during the 2001–2011 period. In CMIP3, 17 out of 38 ensemble members retain their rank in the 2001–2011 hindcast period and 3 retain the neighboring rank. However, numbers are much lower in more recent CMIP5 decadal predictions over the similar 2001–2010 period when using the 1981–2000 period as initialization with the same number of ensembles. Different periods were used for CMIP3 and CMIP5 because although the 1979–2000 initialization is widely used for CMIP3, CMIP5 decadal predictions are only available for 30-year periods. The conclusion to consider the forecast skill in CMIP3 predictions during 2001–2011 as unrealistic is corroborated by comparisons to earlier periods from the 1960s to the 1980s in both CMIP3 and CMIP5 simulations. Thus, although the 2001–2011 CMIP3 predictions show statistically significant forecast skill, this skill should be treated as a spurious result that is unlikely to be reproduced by newer more accurate GCMs.

Reliability of windstorm predictions in the ECMWF ensemble prediction system

Science.gov (United States)

Becker, Nico; Ulbrich, Uwe

2016-04-01

Windstorms caused by extratropical cyclones are one of the most dangerous natural hazards in the European region. Therefore, reliable predictions of such storm events are needed. Case studies have shown that ensemble prediction systems (EPS) are able to provide useful information about windstorms between two and five days prior to the event. In this work, ensemble predictions with the European Centre for Medium-Range Weather Forecasts (ECMWF) EPS are evaluated in a four year period. Within the 50 ensemble members, which are initialized every 12 hours and are run for 10 days, windstorms are identified and tracked in time and space. By using a clustering approach, different predictions of the same storm are identified in the different ensemble members and compared to reanalysis data. The occurrence probability of the predicted storms is estimated by fitting a bivariate normal distribution to the storm track positions. Our results show, for example, that predicted storm clusters with occurrence probabilities of more than 50% have a matching observed storm in 80% of all cases at a lead time of two days. The predicted occurrence probabilities are reliable up to 3 days lead time. At longer lead times the occurrence probabilities are overestimated by the EPS.

Bond return predictability in expansions and recessions

DEFF Research Database (Denmark)

Engsted, Tom; Møller, Stig Vinther; Jensen, Magnus David Sander

We document that over the period 1953-2011 US bond returns are predictable in expansionary periods but unpredictable during recessions. This result holds in both in-sample and out-of-sample analyses and using both univariate regressions and combination forecasting techniques. A simulation study...... but negative in recessions. The results are also consistent with tests showing that the expectations hypothesis of the term structure holds in recessions but not in expansions. However, the results for bonds are in sharp contrast to results for stocks showing that stock returns are predictable in recessions...... but not in expansions. Thus, our results indicate that there is not a common predictive pattern of stock and bond returns associated with the state of the economy....

Predicting Bankruptcy in Pakistan

Directory of Open Access Journals (Sweden)

Abdul RASHID

2011-09-01

Full Text Available This paper aims to identify the financial ratios that are most significant in bankruptcy prediction for the non-financial sector of Pakistan based on a sample of companies which became bankrupt over the time period 1996-2006. Twenty four financial ratios covering four important financial attributes, namely profitability, liquidity, leverage, and turnover ratios, were examined for a five-year period prior bankruptcy. The discriminant analysis produced a parsimonious model of three variables viz. sales to total assets, EBIT to current liabilities, and cash flow ratio. Our estimates provide evidence that the firms having Z-value below zero fall into the “bankrupt” whereas the firms with Z-value above zero fall into the “non-bankrupt” category. The model achieved 76.9% prediction accuracy when it is applied to forecast bankruptcies on the underlying sample.

Short-term wind power prediction

DEFF Research Database (Denmark)

Joensen, Alfred K.

2003-01-01

, and to implement these models and methods in an on-line software application. The economical value of having predictions available is also briefly considered. The summary report outlines the background and motivation for developing wind power prediction models. The meteorological theory which is relevant......The present thesis consists of 10 research papers published during the period 1997-2002 together with a summary report. The objective of the work described in the thesis is to develop models and methods for calculation of high accuracy predictions of wind power generated electricity...

Wind power prediction models

Science.gov (United States)

Levy, R.; Mcginness, H.

1976-01-01

Investigations were performed to predict the power available from the wind at the Goldstone, California, antenna site complex. The background for power prediction was derived from a statistical evaluation of available wind speed data records at this location and at nearby locations similarly situated within the Mojave desert. In addition to a model for power prediction over relatively long periods of time, an interim simulation model that produces sample wind speeds is described. The interim model furnishes uncorrelated sample speeds at hourly intervals that reproduce the statistical wind distribution at Goldstone. A stochastic simulation model to provide speed samples representative of both the statistical speed distributions and correlations is also discussed.

Stochastic long term modelling of a drainage system with estimation of return period uncertainty

DEFF Research Database (Denmark)

Thorndahl, Søren

2009-01-01

Long term prediction of maximum water levels and combined sewer overflow (CSO) in drainage systems are associated with large uncertainties. Especially on rainfall inputs, parameters, and assessment of return periods. This paper proposes a Monte Carlo based methodology for stochastic prediction of...

Time series prediction of apple scab using meteorological ...

African Journals Online (AJOL)

A new prediction model for the early warning of apple scab is proposed in this study. The method is based on artificial intelligence and time series prediction. The infection period of apple scab was evaluated as the time series prediction model instead of summation of wetness duration. Also, the relations of different ...

Inheritance of Cell-Cycle Duration in the Presence of Periodic Forcing

Science.gov (United States)

Mosheiff, Noga; Martins, Bruno M. C.; Pearl-Mizrahi, Sivan; Grünberger, Alexander; Helfrich, Stefan; Mihalcescu, Irina; Kohlheyer, Dietrich; Locke, James C. W.; Glass, Leon; Balaban, Nathalie Q.

2018-04-01

Periodic forcing of nonlinear oscillators leads to a large number of dynamic behaviors. The coupling of the cell cycle to the circadian clock provides a biological realization of such forcing. A previous model of forcing leads to nontrivial relations between correlations along cell lineages. Here, we present a simplified two-dimensional nonlinear map for the periodic forcing of the cell cycle. Using high-throughput single-cell microscopy, we have studied the correlations between cell-cycle duration in discrete lineages of several different organisms, including those with known coupling to a circadian clock and those without known coupling to a circadian clock. The model reproduces the paradoxical correlations and predicts new features that can be compared with the experimental data. By fitting the model to the data, we extract the important parameters that govern the dynamics. Interestingly, the model reproduces bimodal distributions for cell-cycle duration, as well as the gating of cell division by the phase of the clock, without having been explicitly fed into the model. In addition, the model predicts that circadian coupling may increase cell-to-cell variability in a clonal population of cells. In agreement with this prediction, deletion of the circadian clock reduces variability. Our results show that simple correlations can identify systems under periodic forcing and that studies of nonlinear coupling of biological oscillators provide insight into basic cellular processes of growth.

Long-Period Tidal Variations in the Length of Day

Science.gov (United States)

Ray, Richard D.; Erofeeva, Svetlana Y.

2014-01-01

A new model of long-period tidal variations in length of day is developed. The model comprises 80 spectral lines with periods between 18.6 years and 4.7 days, and it consistently includes effects of mantle anelasticity and dynamic ocean tides for all lines. The anelastic properties followWahr and Bergen; experimental confirmation for their results now exists at the fortnightly period, but there remains uncertainty when extrapolating to the longest periods. The ocean modeling builds on recent work with the fortnightly constituent, which suggests that oceanic tidal angular momentum can be reliably predicted at these periods without data assimilation. This is a critical property when modeling most long-period tides, for which little observational data exist. Dynamic ocean effects are quite pronounced at shortest periods as out-of-phase rotation components become nearly as large as in-phase components. The model is tested against a 20 year time series of space geodetic measurements of length of day. The current international standard model is shown to leave significant residual tidal energy, and the new model is found to mostly eliminate that energy, with especially large variance reduction for constituents Sa, Ssa, Mf, and Mt.

Real-time prediction of the occurrence of GLE events

Science.gov (United States)

Núñez, Marlon; Reyes-Santiago, Pedro J.; Malandraki, Olga E.

2017-07-01

A tool for predicting the occurrence of Ground Level Enhancement (GLE) events using the UMASEP scheme is presented. This real-time tool, called HESPERIA UMASEP-500, is based on the detection of the magnetic connection, along which protons arrive in the near-Earth environment, by estimating the lag correlation between the time derivatives of 1 min soft X-ray flux (SXR) and 1 min near-Earth proton fluxes observed by the GOES satellites. Unlike current GLE warning systems, this tool can predict GLE events before the detection by any neutron monitor (NM) station. The prediction performance measured for the period from 1986 to 2016 is presented for two consecutive periods, because of their notable difference in performance. For the 2000-2016 period, this prediction tool obtained a probability of detection (POD) of 53.8% (7 of 13 GLE events), a false alarm ratio (FAR) of 30.0%, and average warning times (AWT) of 8 min with respect to the first NM station's alert and 15 min to the GLE Alert Plus's warning. We have tested the model by replacing the GOES proton data with SOHO/EPHIN proton data, and the results are similar in terms of POD, FAR, and AWT for the same period. The paper also presents a comparison with a GLE warning system.

Sensitivity analysis of periodic errors in heterodyne interferometry

International Nuclear Information System (INIS)

Ganguly, Vasishta; Kim, Nam Ho; Kim, Hyo Soo; Schmitz, Tony

2011-01-01

Periodic errors in heterodyne displacement measuring interferometry occur due to frequency mixing in the interferometer. These nonlinearities are typically characterized as first- and second-order periodic errors which cause a cyclical (non-cumulative) variation in the reported displacement about the true value. This study implements an existing analytical periodic error model in order to identify sensitivities of the first- and second-order periodic errors to the input parameters, including rotational misalignments of the polarizing beam splitter and mixing polarizer, non-orthogonality of the two laser frequencies, ellipticity in the polarizations of the two laser beams, and different transmission coefficients in the polarizing beam splitter. A local sensitivity analysis is first conducted to examine the sensitivities of the periodic errors with respect to each input parameter about the nominal input values. Next, a variance-based approach is used to study the global sensitivities of the periodic errors by calculating the Sobol' sensitivity indices using Monte Carlo simulation. The effect of variation in the input uncertainty on the computed sensitivity indices is examined. It is seen that the first-order periodic error is highly sensitive to non-orthogonality of the two linearly polarized laser frequencies, while the second-order error is most sensitive to the rotational misalignment between the laser beams and the polarizing beam splitter. A particle swarm optimization technique is finally used to predict the possible setup imperfections based on experimentally generated values for periodic errors

Sensitivity analysis of periodic errors in heterodyne interferometry

Science.gov (United States)

Ganguly, Vasishta; Kim, Nam Ho; Kim, Hyo Soo; Schmitz, Tony

2011-03-01

Periodic errors in heterodyne displacement measuring interferometry occur due to frequency mixing in the interferometer. These nonlinearities are typically characterized as first- and second-order periodic errors which cause a cyclical (non-cumulative) variation in the reported displacement about the true value. This study implements an existing analytical periodic error model in order to identify sensitivities of the first- and second-order periodic errors to the input parameters, including rotational misalignments of the polarizing beam splitter and mixing polarizer, non-orthogonality of the two laser frequencies, ellipticity in the polarizations of the two laser beams, and different transmission coefficients in the polarizing beam splitter. A local sensitivity analysis is first conducted to examine the sensitivities of the periodic errors with respect to each input parameter about the nominal input values. Next, a variance-based approach is used to study the global sensitivities of the periodic errors by calculating the Sobol' sensitivity indices using Monte Carlo simulation. The effect of variation in the input uncertainty on the computed sensitivity indices is examined. It is seen that the first-order periodic error is highly sensitive to non-orthogonality of the two linearly polarized laser frequencies, while the second-order error is most sensitive to the rotational misalignment between the laser beams and the polarizing beam splitter. A particle swarm optimization technique is finally used to predict the possible setup imperfections based on experimentally generated values for periodic errors.

Preventive and Predictive Maintenance, Warehousing of Spares, Periodic Testing and In-Service Inspection Activities at the Nigerian Research Reactor-1 Facility

Energy Technology Data Exchange (ETDEWEB)

Yusuf, I.; Mati, A. A.; Dewu, B. B.M., [Centre for Energy Research and Training, Ahmadu Bello University, Zaria (Nigeria)

2014-08-15

The Nigerian Research Reactor–1, or NIRR-1, is sited at Centre for Energy Research and Training, Ahmadu Bello University, Zaria, Nigeria. Activities on preventive or routine maintenance have been institutionalized since the commissioning of the reactor in February 2004. This has grossly reduced the rates of corrective maintenance activities and helped the reactor management a great deal in predicting failure rates of reactor components and other auxiliary units. Routine maintenance of systems and components are being carried out on a weekly, quarterly and annual basis based on manufacturer’s recommendations, which have been reviewed and improved over the years. The paper presents the implementation of maintenance activities in NIRR-1 from its initial criticality in 2004 till today and the new scheme for periodic testing and in-service-inspection developed after an IAEA Integrated Safety Assessment of Research Reactors mission. The measures put in place are envisaged to reduce the negative impact of ageing on NIRR-1 and its auxiliary systems. (author)

Emerging approaches in predictive toxicology.

Science.gov (United States)

Zhang, Luoping; McHale, Cliona M; Greene, Nigel; Snyder, Ronald D; Rich, Ivan N; Aardema, Marilyn J; Roy, Shambhu; Pfuhler, Stefan; Venkatactahalam, Sundaresan

2014-12-01

Predictive toxicology plays an important role in the assessment of toxicity of chemicals and the drug development process. While there are several well-established in vitro and in vivo assays that are suitable for predictive toxicology, recent advances in high-throughput analytical technologies and model systems are expected to have a major impact on the field of predictive toxicology. This commentary provides an overview of the state of the current science and a brief discussion on future perspectives for the field of predictive toxicology for human toxicity. Computational models for predictive toxicology, needs for further refinement and obstacles to expand computational models to include additional classes of chemical compounds are highlighted. Functional and comparative genomics approaches in predictive toxicology are discussed with an emphasis on successful utilization of recently developed model systems for high-throughput analysis. The advantages of three-dimensional model systems and stem cells and their use in predictive toxicology testing are also described. © 2014 Wiley Periodicals, Inc.

Diffraction-Induced Bidimensional Talbot Self-Imaging with Full Independent Period Control

Science.gov (United States)

Guillet de Chatellus, Hugues; Romero Cortés, Luis; Deville, Antonin; Seghilani, Mohamed; Azaña, José

2017-03-01

We predict, formulate, and observe experimentally a generalized version of the Talbot effect that allows one to create diffraction-induced self-images of a periodic two-dimensional (2D) waveform with arbitrary control of the image spatial periods. Through the proposed scheme, the periods of the output self-image are multiples of the input ones by any desired integer or fractional factor, and they can be controlled independently across each of the two wave dimensions. The concept involves conditioning the phase profile of the input periodic wave before free-space diffraction. The wave energy is fundamentally preserved through the self-imaging process, enabling, for instance, the possibility of the passive amplification of the periodic patterns in the wave by a purely diffractive effect, without the use of any active gain.

Shock dynamics in layered periodic media

KAUST Repository

Ketcheson, David I.

2012-01-01

Solutions of constant-coeffcient nonlinear hyperbolic PDEs generically develop shocks, even if the initial data is smooth. Solutions of hyperbolic PDEs with variable coeffcients can behave very differently. We investigate formation and stability of shock waves in a one-dimensional periodic layered medium by a computational study of time-reversibility and entropy evolution. We find that periodic layered media tend to inhibit shock formation. For small initial conditions and large impedance variation, no shock formation is detected even after times much greater than the time of shock formation in a homogeneous medium. Furthermore, weak shocks are observed to be dynamically unstable in the sense that they do not lead to significant long-term entropy decay. We propose a characteristic condition for admissibility of shocks in heterogeneous media that generalizes the classical Lax entropy condition and accurately predicts the formation or absence of shocks in these media.

State updating and calibration period selection to improve dynamic monthly streamflow forecasts for an environmental flow management application

Science.gov (United States)

Gibbs, Matthew S.; McInerney, David; Humphrey, Greer; Thyer, Mark A.; Maier, Holger R.; Dandy, Graeme C.; Kavetski, Dmitri

2018-02-01

Monthly to seasonal streamflow forecasts provide useful information for a range of water resource management and planning applications. This work focuses on improving such forecasts by considering the following two aspects: (1) state updating to force the models to match observations from the start of the forecast period, and (2) selection of a shorter calibration period that is more representative of the forecast period, compared to a longer calibration period traditionally used. The analysis is undertaken in the context of using streamflow forecasts for environmental flow water management of an open channel drainage network in southern Australia. Forecasts of monthly streamflow are obtained using a conceptual rainfall-runoff model combined with a post-processor error model for uncertainty analysis. This model set-up is applied to two catchments, one with stronger evidence of non-stationarity than the other. A range of metrics are used to assess different aspects of predictive performance, including reliability, sharpness, bias and accuracy. The results indicate that, for most scenarios and metrics, state updating improves predictive performance for both observed rainfall and forecast rainfall sources. Using the shorter calibration period also improves predictive performance, particularly for the catchment with stronger evidence of non-stationarity. The results highlight that a traditional approach of using a long calibration period can degrade predictive performance when there is evidence of non-stationarity. The techniques presented can form the basis for operational monthly streamflow forecasting systems and provide support for environmental decision-making.

Periodic inspection for safety of CANDU heat transport piping systems

International Nuclear Information System (INIS)

Ellyin, F.

1979-10-01

Periodic inspection of heat transport and emergency core cooling piping systems is intended to maintain an adequate level of safety throughout the life of the plant, and to protect plant personnel and the public from the consequences of a failure and release of fission products. This report outlines a rational approach to the periodic inspection based on a fully probabilistic model. It demonstrates the methodology based on theoretical treatment and experimental data whereby the strength of a pressurized pipe or vessel containing a defect could be evaluated. It also shows how the extension of the defect at various lifetimes could be predicted. These relationships are prerequisite for the probabilistic formulation and analysis for the periodic inspection of piping systems

Color measurement of tea leaves at different drying periods using hyperspectral imaging technique.

Science.gov (United States)

Xie, Chuanqi; Li, Xiaoli; Shao, Yongni; He, Yong

2014-01-01

This study investigated the feasibility of using hyperspectral imaging technique for nondestructive measurement of color components (ΔL*, Δa* and Δb*) and classify tea leaves during different drying periods. Hyperspectral images of tea leaves at five drying periods were acquired in the spectral region of 380-1030 nm. The three color features were measured by the colorimeter. Different preprocessing algorithms were applied to select the best one in accordance with the prediction results of partial least squares regression (PLSR) models. Competitive adaptive reweighted sampling (CARS) and successive projections algorithm (SPA) were used to identify the effective wavelengths, respectively. Different models (least squares-support vector machine [LS-SVM], PLSR, principal components regression [PCR] and multiple linear regression [MLR]) were established to predict the three color components, respectively. SPA-LS-SVM model performed excellently with the correlation coefficient (rp) of 0.929 for ΔL*, 0.849 for Δa*and 0.917 for Δb*, respectively. LS-SVM model was built for the classification of different tea leaves. The correct classification rates (CCRs) ranged from 89.29% to 100% in the calibration set and from 71.43% to 100% in the prediction set, respectively. The total classification results were 96.43% in the calibration set and 85.71% in the prediction set. The result showed that hyperspectral imaging technique could be used as an objective and nondestructive method to determine color features and classify tea leaves at different drying periods.

Color measurement of tea leaves at different drying periods using hyperspectral imaging technique.

Directory of Open Access Journals (Sweden)

Chuanqi Xie

Full Text Available This study investigated the feasibility of using hyperspectral imaging technique for nondestructive measurement of color components (ΔL*, Δa* and Δb* and classify tea leaves during different drying periods. Hyperspectral images of tea leaves at five drying periods were acquired in the spectral region of 380-1030 nm. The three color features were measured by the colorimeter. Different preprocessing algorithms were applied to select the best one in accordance with the prediction results of partial least squares regression (PLSR models. Competitive adaptive reweighted sampling (CARS and successive projections algorithm (SPA were used to identify the effective wavelengths, respectively. Different models (least squares-support vector machine [LS-SVM], PLSR, principal components regression [PCR] and multiple linear regression [MLR] were established to predict the three color components, respectively. SPA-LS-SVM model performed excellently with the correlation coefficient (rp of 0.929 for ΔL*, 0.849 for Δa*and 0.917 for Δb*, respectively. LS-SVM model was built for the classification of different tea leaves. The correct classification rates (CCRs ranged from 89.29% to 100% in the calibration set and from 71.43% to 100% in the prediction set, respectively. The total classification results were 96.43% in the calibration set and 85.71% in the prediction set. The result showed that hyperspectral imaging technique could be used as an objective and nondestructive method to determine color features and classify tea leaves at different drying periods.

Quasiaxially symmetric stellarators with three field periods

International Nuclear Information System (INIS)

Garabedian, P.; Ku, L.

1999-01-01

Compact hybrid configurations with two field periods have been studied recently as candidates for a proof of principle experiment at the Princeton Plasma Physics Laboratory. This project has led us to the discovery of a family of quasiaxially symmetric stellarators with three field periods that have significant advantages, although their aspect ratios are a little larger. They have reversed shear and perform better in a local analysis of ballooning modes. Nonlinear equilibrium and stability calculations predict that the average beta limit will be at least as high as 4% if the bootstrap current turns out to be as big as that expected in comparable tokamaks. The concept relies on a combination of helical fields and bootstrap current to achieve adequate rotational transform at low aspect ratio. copyright 1999 American Institute of Physics

Selecting the minimum prediction base of historical data to perform 5-year predictions of the cancer burden: The GoF-optimal method.

Science.gov (United States)

Valls, Joan; Castellà, Gerard; Dyba, Tadeusz; Clèries, Ramon

2015-06-01

Predicting the future burden of cancer is a key issue for health services planning, where a method for selecting the predictive model and the prediction base is a challenge. A method, named here Goodness-of-Fit optimal (GoF-optimal), is presented to determine the minimum prediction base of historical data to perform 5-year predictions of the number of new cancer cases or deaths. An empirical ex-post evaluation exercise for cancer mortality data in Spain and cancer incidence in Finland using simple linear and log-linear Poisson models was performed. Prediction bases were considered within the time periods 1951-2006 in Spain and 1975-2007 in Finland, and then predictions were made for 37 and 33 single years in these periods, respectively. The performance of three fixed different prediction bases (last 5, 10, and 20 years of historical data) was compared to that of the prediction base determined by the GoF-optimal method. The coverage (COV) of the 95% prediction interval and the discrepancy ratio (DR) were calculated to assess the success of the prediction. The results showed that (i) models using the prediction base selected through GoF-optimal method reached the highest COV and the lowest DR and (ii) the best alternative strategy to GoF-optimal was the one using the base of prediction of 5-years. The GoF-optimal approach can be used as a selection criterion in order to find an adequate base of prediction. Copyright © 2015 Elsevier Ltd. All rights reserved.

Low cost metamodel for robust design of periodic nonlinear coupled micro-systems

Directory of Open Access Journals (Sweden)

Chikhaoui K.

2016-01-01

Full Text Available To achieve robust design, in presence of uncertainty, nonlinearity and structural periodicity, a metamodel combining the Latin Hypercube Sampling (LHS method for uncertainty propagation and an enriched Craig-Bampton Component Mode Synthesis approach (CB-CMS for model reduction is proposed. Its application to predict the time responses of a stochastic periodic nonlinear micro-system proves its efficiency in terms of accuracy and reduction of computational cost.

Durability and flexibility of chimpanzee grooming patterns during a period of dominance instability.

Science.gov (United States)

Koyama, Nicola F; Ronkainen, Kirsty; Aureli, Filippo

2017-11-01

Growing evidence from studies on primates and other taxa has shown that the maintenance of long-term affiliative patterns influences fitness. Thus, understanding how individuals regulate social interactions in response to environmental and social factors contributes to our understanding of the evolutionary basis of sociality. We investigated the durability of affiliation patterns in chimpanzees across three 3-month periods of varying social uncertainty depending on the degree of stability in the male hierarchy, with a 2-year gap between each period. Periods were unstable (no clear alpha male), recently stable (new alpha male just established) and stable (alpha male in place for 2 years). We focused on three features of social exchange shared by human and non-human primates: consistency of exchanges across periods, durability of preferred partners, and degree of reciprocity in each period. We compared male-to-male, female-to-female, male-to-female, and female-to-male grooming patterns. Overall, more grooming was exchanged in the stable period. Grooming patterns were not consistent across the three periods, but were only consistent between the recently stable and stable periods for female-to-female and male-to-female dyads. As predicted from the opportunistic nature of male relationships, male-to-male grooming was least likely to be correlated across all periods and males had relatively fewer durable (i.e., preferred partners in all periods) same-sex partners than females. Our predictions that grooming reciprocity would be less likely during the unstable period and in male-male dyads were only partially supported. We found grooming reciprocity in all periods for female-female dyads but only in the stable period for male-male and female-male dyads. Although long-term affiliative patterns are well studied in primates, this is the first study to investigate the association between social uncertainty and durability of affiliative patterns. Our findings suggest social

Assessment of predictive models for the failure of titanium and ferrous alloys due to hydrogen effects. Report for the period of June 16 to September 15, 1981

International Nuclear Information System (INIS)

Archbold, T.F.; Bower, R.B.; Polonis, D.H.

1982-04-01

The 1977 version of the Simpson-Puls-Dutton model appears to be the most amenable with respect to utilizing known or readily estimated quantities. The Pardee-Paton model requires extensive calculations involving estimated quantities. Recent observations by Koike and Suzuki on vanadium support the general assumption that crack growth in hydride forming metals is determined by the rate of hydride formation, and their hydrogen atmosphere-displacive transformation model is of potential interest in explaining hydrogen embrittlement in ferrous alloys as well as hydride formers. The discontinuous nature of cracking due to hydrogen embrittlement appears to depend very strongly on localized stress intensities, thereby pointing to the role of microstructure in influencing crack initiation, fracture mode and crack path. The initiation of hydrogen induced failures over relatively short periods of time can be characterized with fair reliability using measurements of the threshold stress intensity. The experimental conditions for determining K/sub Th/ and ΔK/sub Th/ are designed to ensure plane strain conditions in most cases. Plane strain test conditions may be viewed as a conservative basis for predicting delayed failure. The physical configuration of nuclear waste canisters may involve elastic/plastic conditions rather than a state of plane strain, especially with thin-walled vessels. Under these conditions, alternative predictive tests may be considered, including COD and R-curve methods. The double cantilever beam technique employed by Boyer and Spurr on titanium alloys offers advantages for examining hydrogen induced delayed failure over long periods of time. 88 references

Methods for early prediction of lactation flow in Holstein heifers

Directory of Open Access Journals (Sweden)

Vesna Gantner

2010-12-01

Full Text Available The aim of this research was to define methods for early prediction (based on I. milk control record of lactation flow in Holstein heifers as well as to choose optimal one in terms of prediction fit and application simplicity. Total of 304,569 daily yield records automatically recorded on a 1,136 first lactation Holstein cows, from March 2003 till August 2008., were included in analysis. According to the test date, calving date, the age at first calving, lactation stage when I. milk control occurred and to the average milk yield in first 25th, T1 (and 25th-45th, T2 lactation days, measuring monthcalving month-age-production-time-period subgroups were formed. The parameters of analysed nonlinear and linear methods were estimated for each defined subgroup. As models evaluation measures,adjusted coefficient of determination, and average and standard deviation of error were used. Considering obtained results, in terms of total variance explanation (R2 adj, the nonlinear Wood’s method showed superiority above the linear ones (Wilmink’s, Ali-Schaeffer’s and Guo-Swalve’s method in both time-period subgroups (T1 - 97.5 % of explained variability; T2 - 98.1 % of explained variability. Regarding the evaluation measures based on prediction error amount (eavg±eSD, the lowest average error of daily milk yield prediction (less than 0.005 kg/day, as well as of lactation milk yield prediction (less than 50 kg/lactation (T1 time-period subgroup and less than 30 kg/lactation (T2 time-period subgroup; were determined when Wood’s nonlinear prediction method were applied. Obtained results indicate that estimated Wood’s regression parameters could be used in routine work for early prediction of Holstein heifer’s lactation flow.

Field Optimization for short Period Undulators

CERN Document Server

Peiffer, P; Rossmanith, R; Schoerling, D

2011-01-01

Undulators dedicated to low energy electron beams, like Laser Wakefield Accelerators, require very short period lengths to achieve X-ray emission. However, at these short period length (LambdaU ~ 5 mm) it becomes difficult to reach magnetic field amplitudes that lead to a K parameter of >1, which is generally desired. Room temperature permanent magnets and even superconductive undulators using Nb-Ti as conductor material have proven insufficient to achieve the desired field amplitudes. The superconductor Nb$_{3}$Sn has the theoretical potential to achieve the desired fields. However, up to now it is limited by several technological challenges to much lower field values than theoretically predicted. An alternative idea for higher fields is to manufacture the poles of the undulator body from Holmium instead of iron or to use Nb-Ti wires with a higher superconductor/copper ratio. The advantages and challenges of the different options are compared in this contribution.

Practical aspects of geological prediction

International Nuclear Information System (INIS)

Mallio, W.J.; Peck, J.H.

1981-01-01

Nuclear waste disposal requires that geology be a predictive science. The prediction of future events rests on (1) recognizing the periodicity of geologic events; (2) defining a critical dimension of effect, such as the area of a drainage basin, the length of a fault trace, etc; and (3) using our understanding of active processes the project the frequency and magnitude of future events in the light of geological principles. Of importance to nuclear waste disposal are longer term processes such as continental denudation and removal of materials by glacial erosion. Constant testing of projections will allow the practical limits of predicting geological events to be defined. 11 refs

Long-Term Prediction of Satellite Orbit Using Analytical Method

Directory of Open Access Journals (Sweden)

Jae-Cheol Yoon

1997-12-01

Full Text Available A long-term prediction algorithm of geostationary orbit was developed using the analytical method. The perturbation force models include geopotential upto fifth order and degree and luni-solar gravitation, and solar radiation pressure. All of the perturbation effects were analyzed by secular variations, short-period variations, and long-period variations for equinoctial elements such as the semi-major axis, eccentricity vector, inclination vector, and mean longitude of the satellite. Result of the analytical orbit propagator was compared with that of the cowell orbit propagator for the KOREASAT. The comparison indicated that the analytical solution could predict the semi-major axis with an accuarcy of better than ~35meters over a period of 3 month.

Numerical and Experimental Investigation of Stop-Bands in Finite and Infinite Periodic One-Dimensional Structures

DEFF Research Database (Denmark)

Domadiya, Parthkumar Gandalal; Manconi, Elisabetta; Vanali, Marcello

2016-01-01

Adding periodicity to structures leads to wavemode interaction, which generates pass- and stop-bands. The frequencies at which stop-bands occur are related to the periodic nature of the structure. Thus structural periodicity can be shaped in order to design vibro-acoustic filters for reducing...... method deals with the evaluation of a vibration level difference (VLD) in a finite periodic structure embedded within an infinite one-dimensional waveguide. This VLD is defined to predict the performance in terms of noise and vibration insulation of periodic cells embedded in an otherwise uniform...

Does Carbon Dioxide Predict Temperature?

OpenAIRE

Mytty, Tuukka

2013-01-01

Does carbon dioxide predict temperature? No it does not, in the time period of 1880-2004 with the carbon dioxide and temperature data used in this thesis. According to the Inter Governmental Panel on Climate Change(IPCC) carbon dioxide is the most important factor in raising the global temperature. Therefore, it is reasonable to assume that carbon dioxide truly predicts temperature. Because this paper uses observational data it has to be kept in mind that no causality interpretation can be ma...

A novel Bayesian hierarchical model for road safety hotspot prediction.

Science.gov (United States)

Fawcett, Lee; Thorpe, Neil; Matthews, Joseph; Kremer, Karsten

2017-02-01

In this paper, we propose a Bayesian hierarchical model for predicting accident counts in future years at sites within a pool of potential road safety hotspots. The aim is to inform road safety practitioners of the location of likely future hotspots to enable a proactive, rather than reactive, approach to road safety scheme implementation. A feature of our model is the ability to rank sites according to their potential to exceed, in some future time period, a threshold accident count which may be used as a criterion for scheme implementation. Our model specification enables the classical empirical Bayes formulation - commonly used in before-and-after studies, wherein accident counts from a single before period are used to estimate counterfactual counts in the after period - to be extended to incorporate counts from multiple time periods. This allows site-specific variations in historical accident counts (e.g. locally-observed trends) to offset estimates of safety generated by a global accident prediction model (APM), which itself is used to help account for the effects of global trend and regression-to-mean (RTM). The Bayesian posterior predictive distribution is exploited to formulate predictions and to properly quantify our uncertainty in these predictions. The main contributions of our model include (i) the ability to allow accident counts from multiple time-points to inform predictions, with counts in more recent years lending more weight to predictions than counts from time-points further in the past; (ii) where appropriate, the ability to offset global estimates of trend by variations in accident counts observed locally, at a site-specific level; and (iii) the ability to account for unknown/unobserved site-specific factors which may affect accident counts. We illustrate our model with an application to accident counts at 734 potential hotspots in the German city of Halle; we also propose some simple diagnostics to validate the predictive capability of our

A periodic table of coiled-coil protein structures.

Science.gov (United States)

Moutevelis, Efrosini; Woolfson, Derek N

2009-01-23

Coiled coils are protein structure domains with two or more alpha-helices packed together via interlacing of side chains known as knob-into-hole packing. We analysed and classified a large set of coiled-coil structures using a combination of automated and manual methods. This led to a systematic classification that we termed a "periodic table of coiled coils," which we have made available at http://coiledcoils.chm.bris.ac.uk/ccplus/search/periodic_table. In this table, coiled-coil assemblies are arranged in columns with increasing numbers of alpha-helices and in rows of increased complexity. The table provides a framework for understanding possibilities in and limits on coiled-coil structures and a basis for future prediction, engineering and design studies.

Modeling long period swell in Southern California: Practical boundary conditions from buoy observations and global wave model predictions

Science.gov (United States)

Crosby, S. C.; O'Reilly, W. C.; Guza, R. T.

2016-02-01

Accurate, unbiased, high-resolution (in space and time) nearshore wave predictions are needed to drive models of beach erosion, coastal flooding, and alongshore transport of sediment, biota and pollutants. On highly sheltered shorelines, wave predictions are sensitive to the directions of onshore propagating waves, and nearshore model prediction error is often dominated by uncertainty in offshore boundary conditions. Offshore islands and shoals, and coastline curvature, create complex sheltering patterns over the 250km span of southern California (SC) shoreline. Here, regional wave model skill in SC was compared for different offshore boundary conditions created using offshore buoy observations and global wave model hindcasts (National Oceanographic and Atmospheric Administration Wave Watch 3, WW3). Spectral ray-tracing methods were used to transform incident offshore swell (0.04-0.09Hz) energy at high directional resolution (1-deg). Model skill is assessed for predictions (wave height, direction, and alongshore radiation stress) at 16 nearshore buoy sites between 2000 and 2009. Model skill using buoy-derived boundary conditions is higher than with WW3-derived boundary conditions. Buoy-driven nearshore model results are similar with various assumptions about the true offshore directional distribution (maximum entropy, Bayesian direct, and 2nd derivative smoothness). Two methods combining offshore buoy observations with WW3 predictions in the offshore boundary condition did not improve nearshore skill above buoy-only methods. A case example at Oceanside harbor shows strong sensitivity of alongshore sediment transport predictions to different offshore boundary conditions. Despite this uncertainty in alongshore transport magnitude, alongshore gradients in transport (e.g. the location of model accretion and erosion zones) are determined by the local bathymetry, and are similar for all predictions.

Periodic folding of viscous sheets

Science.gov (United States)

Ribe, Neil M.

2003-09-01

The periodic folding of a sheet of viscous fluid falling upon a rigid surface is a common fluid mechanical instability that occurs in contexts ranging from food processing to geophysics. Asymptotic thin-layer equations for the combined stretching-bending deformation of a two-dimensional sheet are solved numerically to determine the folding frequency as a function of the sheet’s initial thickness, the pouring speed, the height of fall, and the fluid properties. As the buoyancy increases, the system bifurcates from “forced” folding driven kinematically by fluid extrusion to “free” folding in which viscous resistance to bending is balanced by buoyancy. The systematics of the numerically predicted folding frequency are in good agreement with laboratory experiments.

A periodic table for cancer.

Science.gov (United States)

Epstein, Richard J

2015-01-01

Cancers exhibit differences in metastatic behavior and drug sensitivity that correlate with certain tumor-specific variables such as differentiation grade, growth rate/extent and molecular regulatory aberrations. In practice, patient management is based on the past results of clinical trials adjusted for these biomarkers. Here, it is proposed that treatment strategies could be fine-tuned upfront simply by quantifying tumorigenic spatial (cell growth) and temporal (genetic stability) control losses, as predicted by genetic defects of cell-cycle-regulatory gatekeeper and genome-stabilizing caretaker tumor suppressor genes, respectively. These differential quantifications of tumor dysfunction may in turn be used to create a tumor-specific 'periodic table' that guides rational formulation of survival-enhancing anticancer treatment strategies.

Strong influence of periodic boundary conditions on lateral diffusion in lipid bilayer membranes

Energy Technology Data Exchange (ETDEWEB)

Camley, Brian A. [Center for Theoretical Biological Physics and Department of Physics, University of California, San Diego, California 92093 (United States); Department of Physics, University of California, Santa Barbara, California 93106 (United States); Lerner, Michael G. [Department of Physics and Astronomy, Earlham College, Richmond, Indiana 47374 (United States); Laboratory of Computational Biology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892 (United States); Pastor, Richard W. [Laboratory of Computational Biology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892 (United States); Brown, Frank L. H. [Department of Physics, University of California, Santa Barbara, California 93106 (United States); Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106 (United States)

2015-12-28

The Saffman-Delbrück hydrodynamic model for lipid-bilayer membranes is modified to account for the periodic boundary conditions commonly imposed in molecular simulations. Predicted lateral diffusion coefficients for membrane-embedded solid bodies are sensitive to box shape and converge slowly to the limit of infinite box size, raising serious doubts for the prospects of using detailed simulations to accurately predict membrane-protein diffusivities and related transport properties. Estimates for the relative error associated with periodic boundary artifacts are 50% and higher for fully atomistic models in currently feasible simulation boxes. MARTINI simulations of LacY membrane protein diffusion and LacY dimer diffusion in DPPC membranes and lipid diffusion in pure DPPC bilayers support the underlying hydrodynamic model.

Strong influence of periodic boundary conditions on lateral diffusion in lipid bilayer membranes

International Nuclear Information System (INIS)

Camley, Brian A.; Lerner, Michael G.; Pastor, Richard W.; Brown, Frank L. H.

2015-01-01

The Saffman-Delbrück hydrodynamic model for lipid-bilayer membranes is modified to account for the periodic boundary conditions commonly imposed in molecular simulations. Predicted lateral diffusion coefficients for membrane-embedded solid bodies are sensitive to box shape and converge slowly to the limit of infinite box size, raising serious doubts for the prospects of using detailed simulations to accurately predict membrane-protein diffusivities and related transport properties. Estimates for the relative error associated with periodic boundary artifacts are 50% and higher for fully atomistic models in currently feasible simulation boxes. MARTINI simulations of LacY membrane protein diffusion and LacY dimer diffusion in DPPC membranes and lipid diffusion in pure DPPC bilayers support the underlying hydrodynamic model

Attributing Predictable Signals at Subseasonal Timescales

Science.gov (United States)

Shelly, A.; Norton, W.; Rowlands, D.; Beech-Brandt, J.

2016-12-01

Subseasonal forecasts offer significant economic value in the management of energy infrastructure and through the associated financial markets. Models are now accurate enough to provide, for some occasions, good forecasts in the subseasonal range. However, it is often not clear what the drivers of these subseasonal signals are and if the forecasts could be more accurate with better representation of physical processes. Also what are the limits of predictability in the subseasonal range? To address these questions, we have run the ECMWF monthly forecast system over the 2015/16 winter with a set of 6 week ensemble integrations initialised every week over the period. In these experiments, we have relaxed the band 15N to 15S to reanalysis fields. Hence, we have a set of forecasts where the tropics is constrained to actual events and we can analyse the changes in predictability in middle latitudes - in particular in regions of high energy consumption like North America and Europe. Not surprisingly, the forecast of some periods are significantly improved while others show no improvement. We discuss events/patterns that have extended range predictability and also the tropical forecast errors which prevent the potential predictability in middle latitudes from being realised.

The trajectory prediction of spacecraft by grey method

International Nuclear Information System (INIS)

Wang, Qiyue; Wang, Zhongyu; Zhang, Zili; Wang, Yanqing; Zhou, Weihu

2016-01-01

The real-time and high-precision trajectory prediction of a moving object is a core technology in the field of aerospace engineering. The real-time monitoring and tracking technology are also significant guarantees of aerospace equipment. A dynamic trajectory prediction method called grey dynamic filter (GDF) which combines the dynamic measurement theory and grey system theory is proposed. GDF can use coordinates of the current period to extrapolate coordinates of the following period. At meantime, GDF can also keep the instantaneity of measured coordinates by the metabolism model. In this paper the optimal model length of GDF is firstly selected to improve the prediction accuracy. Then the simulation for uniformly accelerated motion and variably accelerated motion is conducted. The simulation results indicate that the mean composite position error of GDF prediction is one-fifth to that of Kalman filter (KF). By using a spacecraft landing experiment, the prediction accuracy of GDF is compared with the KF method and the primitive grey method (GM). The results show that the motion trajectory of spacecraft predicted by GDF is much closer to actual trajectory than the other two methods. The mean composite position error calculated by GDF is one-eighth to KF and one-fifth to GM respectively. (paper)

Predictive value of long-term changes of growth differentiation factor-15 over a 27-year-period for heart failure and death due to coronary heart disease.

Science.gov (United States)

Fluschnik, Nina; Ojeda, Francisco; Zeller, Tanja; Jørgensen, Torben; Kuulasmaa, Kari; Becher, Peter Moritz; Sinning, Christoph; Blankenberg, Stefan; Westermann, Dirk

2018-01-01

Growth differentiation factor-15 (GDF-15), Cystatin C and C-reactive protein (CRP) have been discussed as biomarkers for prediction of cardiac diseases. The aim of this study was to investigate the predictive value of single and repeated measurements of GDF-15 compared to Cystatin C and CRP for incidence of heart failure (HF) and death due to coronary heart disease (CHD) in the general population. Levels of GDF-15, CRP and Cystatin C were determined in three repeated measurements collected 5 years apart in the DAN-MONICA (Danish-Multinational MONitoring of trends and determinants in Cardiovascular disease) cohort (participants at baseline n = 3785). Cox regression models adjusted for cardiovascular risk factors revealed significantly increased hazard ratios (HR) for GDF-15 for incident HF 1.36 (HR per interquartile range (IQR) increase, 95% confidence interval (CI): 1.16; 1.59) and for death from CHD 1.51 (HR per IQR increase, 95% CI: 1.31, 1.75) (both with p<0.001). Joint modeling of time-to-event and longitudinal GDF-15 over a median 27-year follow-up period showed that the marker evolution was positively associated with death of CHD (HR per IQR increase 3.02 95% CI: (2.26, 4.04), p < 0.001) and HF (HR per IQR increase 2.12 95% CI: (1.54, 2.92), p<0.001). However using Cox models with follow-up time starting at the time of the third examination, serial measurement of GDF-15, modeled as changes between the measurements, did not improve prediction over that of the most recent measurement. GDF-15 is a promising biomarker for prediction of HF and death due to CHD in the general population, which may provide prognostic information to already established clinical biomarkers. Repeated measurements of GDF-15 displayed only a slight improvement in the prediction of these endpoints compared to a single measurement.

Nonequilibrium ferroelectric-ferroelastic 10 nm nanodomains: wrinkles, period-doubling, and power-law relaxation.

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Scott, James F; Evans, Donald M; Katiyar, Ram S; McQuaid, Raymond G P; Gregg, J Marty

2017-08-02

Since the 1935 work of Landau-Lifshitz and of Kittel in 1946 all ferromagnetic, ferroelectric, and ferroelastic domains have been thought to be straight-sided with domain widths proportional to the square root of the sample thickness. We show in the present work that this is not true. We also discover period doubling domains predicted by Metaxas et al (2008 Phys. Rev. Lett. 99 217208) and modeled by Wang and Zhao (2015 Sci. Rep. 5 8887). We examine non-equilibrium ferroic domain structures in perovskite oxides with respect to folding, wrinkling, and relaxation and suggest that structures are kinetically limited and in the viscous flow regime predicted by Metaxas et al in 2008 but never observed experimentally. Comparisons are made with liquid crystals and hydrodynamic instabilities, including chevrons, and fractional power-law relaxation. As Shin et al (2016 Soft Matter 12 3502) recently emphasized: 'An understanding of how these folds initiate, propagate, and interact with each other is still lacking'. Inside each ferroelastic domain are ferroelectric 90° nano-domains with 10 nm widths and periodicity in agreement with the 10 nm theoretical minima predicted by Feigl et al (2014 Nat. Commun. 5 4677). Evidence is presented for domain-width period doubling, which is common in polymer films but unknown in ferroic domains. A discussion of the folding-to-period doubling phase transition model of Wang and Zhao is included.

[Predictive factors of neurological complications in the period immediately after liver transplant: experiences in the Centro de Investigaciones Médico Quirúrgicas in Cuba].

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Abdo-Cuza, A; González-Rapado, L; López-Cruz, O; Pérez-Bernal, J; Castellanos-Gutiérrez, R; Gómez-Peyre, F; Hinojosa-Pérez, R; Lage-Dávila, J; Alvarez-Rodríguez, A; Fernández-Valle, A; Fernández-Maderos, I; Samada-Suárez, M; Hernández-Perera, J C; Bernardos-Rodríguez, A

Liver transplant (LT) is today a first choice procedure in a group of hepatic diseases in their acute and chronic terminal stages. It is not, however, a technique that is completely free of complications and those of a neurological nature constitute between 8 47% of those reported. AIMS. The purpose of this study is to present the immediate neurological complications (NC) found in our patients, as well as to determine the predictive factors and their relation to the mortality rate. From the medical records of 26 patients who received LT at the CIMEQ (July 1999 December 2001), we collected a group of variables related to the donor, the surgical procedure and the post operative period and associated them to the occurrence of NC while these patients were in the ICU. NC were found in 16 patients (61.5%), the most frequent being encephalopathy (30.8%), tremor (26.9%), and convulsions (19.2%). No relation was found between the presence of NC and prior hepatic encephalopathy, the use of a suboptimal donor, nor did it represent a significant increase in the mortality rate. There was a significant relation with LT to recipients rated as grade C on the Child Pugh classification system, the presence of intraoperative hypotension (p= 0.0164) and primary dysfunction of the liver graft (p= 0.041). NC represented a significant cause of morbidity in the period following a liver transplant in our series, although they had no significant repercussion on the mortality rate. Their presence is related to variables concerning the recipient, the surgical procedure itself and the immediate post operative period.

A Bayesian test for periodic signals in red noise

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Vaughan, S.

2010-02-01

Many astrophysical sources, especially compact accreting sources, show strong, random brightness fluctuations with broad power spectra in addition to periodic or quasi-periodic oscillations (QPOs) that have narrower spectra. The random nature of the dominant source of variance greatly complicates the process of searching for possible weak periodic signals. We have addressed this problem using the tools of Bayesian statistics; in particular, using Markov Chain Monte Carlo techniques to approximate the posterior distribution of model parameters, and posterior predictive model checking to assess model fits and search for periodogram outliers that may represent periodic signals. The methods developed are applied to two example data sets, both long XMM-Newton observations of highly variable Seyfert 1 galaxies: RE J1034 + 396 and Mrk 766. In both cases, a bend (or break) in the power spectrum is evident. In the case of RE J1034 + 396, the previously reported QPO is found but with somewhat weaker statistical significance than reported in previous analyses. The difference is due partly to the improved continuum modelling, better treatment of nuisance parameters and partly to different data selection methods.

Stop Band Gap in Periodic Layers of Confined Atomic Vapor/Dielectric Medium

International Nuclear Information System (INIS)

Li Yuan-Yuan; Li Li; Lu Yi-Xin; Zhang Yan-Peng; Xu Ke-Wei

2013-01-01

A stop band gap is predicted in periodic layers of a confined atomic vapor/dielectric medium. Reflection and transmission profile of the layers over the band gap can be dramatically modified by the confined atoms and the number of layer periods. These gap and line features can be ascribed to the enhanced contribution of slow atoms induced by atom-wall collision, transient behavior of atom-light interaction and Fabry—Pérot effects in a thermal confined atomic system

PASSENGER FLOWS PREDICTION IN MAJOR TRANSPORTATION HUBS

Directory of Open Access Journals (Sweden)

O. O. Ozerova

2013-11-01

Full Text Available Purpose. An effective organization of passenger traffic, due to the reliability prediction of traffic flow in passenger transport hubs. In order to determine the parameters of prospective passenger transport areas it is essential to analyze the impact of various factors and determine the most influential ones. Methodology. The article presents the method of paired linear correlation for a more influential factors on passengers in intercity and commuter and possible use in predicting the linear regression equations. Passenger transport vessel areas and branches of industry are interconnected and are in the ratio of passengers and production. Findings. It is found that the coefficient of correlation is in complex dependence on the duration of the period of retrospective analysis. Evaluation of reliability correlation coefficients and coefficients of predictive models led to the conclusion that the population gives the most accurate prediction of passenger flows, providing account of changes in Ukraine during the period of transformation. Originality. Equations of dependence on the impact of macroeconomic indicators were obtained and the evaluation of the reliability results was received. Practical value. The results of analysis and calculations will make short-term forecasting of traffic flow.

MEM spectral analysis for predicting influenza epidemics in Japan.

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Sumi, Ayako; Kamo, Ken-ichi

2012-03-01

The prediction of influenza epidemics has long been the focus of attention in epidemiology and mathematical biology. In this study, we tested whether time series analysis was useful for predicting the incidence of influenza in Japan. The method of time series analysis we used consists of spectral analysis based on the maximum entropy method (MEM) in the frequency domain and the nonlinear least squares method in the time domain. Using this time series analysis, we analyzed the incidence data of influenza in Japan from January 1948 to December 1998; these data are unique in that they covered the periods of pandemics in Japan in 1957, 1968, and 1977. On the basis of the MEM spectral analysis, we identified the periodic modes explaining the underlying variations of the incidence data. The optimum least squares fitting (LSF) curve calculated with the periodic modes reproduced the underlying variation of the incidence data. An extension of the LSF curve could be used to predict the incidence of influenza quantitatively. Our study suggested that MEM spectral analysis would allow us to model temporal variations of influenza epidemics with multiple periodic modes much more effectively than by using the method of conventional time series analysis, which has been used previously to investigate the behavior of temporal variations in influenza data.

Predicting the 6-month risk of severe hypoglycemia among adults with diabetes: Development and external validation of a prediction model.

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Schroeder, Emily B; Xu, Stan; Goodrich, Glenn K; Nichols, Gregory A; O'Connor, Patrick J; Steiner, John F

2017-07-01

To develop and externally validate a prediction model for the 6-month risk of a severe hypoglycemic event among individuals with pharmacologically treated diabetes. The development cohort consisted of 31,674 Kaiser Permanente Colorado members with pharmacologically treated diabetes (2007-2015). The validation cohorts consisted of 38,764 Kaiser Permanente Northwest members and 12,035 HealthPartners members. Variables were chosen that would be available in electronic health records. We developed 16-variable and 6-variable models, using a Cox counting model process that allows for the inclusion of multiple 6-month observation periods per person. Across the three cohorts, there were 850,992 6-month observation periods, and 10,448 periods with at least one severe hypoglycemic event. The six-variable model contained age, diabetes type, HgbA1c, eGFR, history of a hypoglycemic event in the prior year, and insulin use. Both prediction models performed well, with good calibration and c-statistics of 0.84 and 0.81 for the 16-variable and 6-variable models, respectively. In the external validation cohorts, the c-statistics were 0.80-0.84. We developed and validated two prediction models for predicting the 6-month risk of hypoglycemia. The 16-variable model had slightly better performance than the 6-variable model, but in some practice settings, use of the simpler model may be preferred. Copyright © 2017 Elsevier Inc. All rights reserved.

A study of the anti-reflection efficiency of natural nano-arrays of varying sizes

International Nuclear Information System (INIS)

Sun Mingxia; Liang Aiping; Zheng Yongmei; Watson, Gregory S; Watson, Jolanta A

2011-01-01

The dependence of optical reflectivity and wettability on the surface topography of 32 species of cicada wing membranes has been investigated using UV-visible spectrophotometry, contact angle measurements and environmental scanning electron microscopy. The nanoscale hexagonally close packed protrusions have been shown to exhibit an anti-reflection and in some cases an anti-wetting function. The parameters of the structures were measured to be 77-148 nm in diameter, 44-117 nm in spacing and 159-481 nm in height. The transmittance spectrum and static contact angles were measured. At a wavelength range of 500-2500 nm, only minor differences in the anti-reflection performance were observed for each cicada species ascribed to the mechanism of impedance matching between cuticle and air. The transmittance properties of cicada wings were altered successfully through the scanning probe microscope-based manipulation by reducing the protrusion height via the contact mode. A near linear dependence was found between a decrease in protuberance height and a resulting increase in reflectance intensity. A diversity of wettability was observed with contact angles varying from 56.5 0 to 146.0 0 . Both effects of anti-reflection and wettability are dependent on the height of protrusions. The anti-reflection is insensitive when the wavelength is larger than the lateral feature size of the nanostructure. The stronger hydrophobic properties are generally associated with a larger diameter, closer spacing and greater height of protrusions when the wing membrane is intact.

Current-driven plasmonic boom instability in three-dimensional gated periodic ballistic nanostructures

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Aizin, G. R.; Mikalopas, J.; Shur, M.

2016-05-01

An alternative approach of using a distributed transmission line analogy for solving transport equations for ballistic nanostructures is applied for solving the three-dimensional problem of electron transport in gated ballistic nanostructures with periodically changing width. The structures with varying width allow for modulation of the electron drift velocity while keeping the plasma velocity constant. We predict that in such structures biased by a constant current, a periodic modulation of the electron drift velocity due to the varying width results in the instability of the plasma waves if the electron drift velocity to plasma wave velocity ratio changes from below to above unity. The physics of such instability is similar to that of the sonic boom, but, in the periodically modulated structures, this analog of the sonic boom is repeated many times leading to a larger increment of the instability. The constant plasma velocity in the sections of different width leads to resonant excitation of the unstable plasma modes with varying bias current. This effect (that we refer to as the superplasmonic boom condition) results in a strong enhancement of the instability. The predicted instability involves the oscillating dipole charge carried by the plasma waves. The plasmons can be efficiently coupled to the terahertz electromagnetic radiation due to the periodic geometry of the gated structure. Our estimates show that the analyzed instability should enable powerful tunable terahertz electronic sources.

Predicting restoration of kidney function during CRRT-free intervals

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Heise Daniel

2012-01-01

Full Text Available Abstract Background Renal failure is common in critically ill patients and frequently requires continuous renal replacement therapy (CRRT. CRRT is discontinued at regular intervals for routine changes of the disposable equipment or for replacing clogged filter membrane assemblies. The present study was conducted to determine if the necessity to continue CRRT could be predicted during the CRRT-free period. Materials and methods In the period from 2003 to 2006, 605 patients were treated with CRRT in our ICU. A total of 222 patients with 448 CRRT-free intervals had complete data sets and were used for analysis. Of the total CRRT-free periods, 225 served as an evaluation group. Twenty-nine parameters with an assumed influence on kidney function were analyzed with regard to their potential to predict the restoration of kidney function during the CRRT-free interval. Using univariate analysis and logistic regression, a prospective index was developed and validated in the remaining 223 CRRT-free periods to establish its prognostic strength. Results Only three parameters showed an independent influence on the restoration of kidney function during CRRT-free intervals: the number of previous CRRT cycles (medians in the two outcome groups: 1 vs. 2, the "Sequential Organ Failure Assessment"-score (means in the two outcome groups: 8.3 vs. 9.2 and urinary output after the cessation of CRRT (medians in two outcome groups: 66 ml/h vs. 10 ml/h. The prognostic index, which was calculated from these three variables, showed a satisfactory potential to predict the kidney function during the CRRT-free intervals; Receiver operating characteristic (ROC analysis revealed an area under the curve of 0.798. Conclusion Restoration of kidney function during CRRT-free periods can be predicted with an index calculated from three variables. Prospective trials in other hospitals must clarify whether our results are generally transferable to other patient populations.

Periodic and chaotic psychological stress variations as predicted by a social support buffered response model

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Field, Richard J.; Gallas, Jason A. C.; Schuldberg, David

2017-08-01

Recent work has introduced social dynamic models of people's stress-related processes, some including amelioration of stress symptoms by support from others. The effects of support may be ;direct;, depending only on the level of support, or ;buffering;, depending on the product of the level of support and level of stress. We focus here on the nonlinear buffering term and use a model involving three variables (and 12 control parameters), including stress as perceived by the individual, physical and psychological symptoms, and currently active social support. This model is quantified by a set of three nonlinear differential equations governing its stationary-state stability, temporal evolution (sometimes oscillatory), and how each variable affects the others. Chaos may appear with periodic forcing of an environmental stress parameter. Here we explore this model carefully as the strength and amplitude of this forcing, and an important psychological parameter relating to self-kindling in the stress response, are varied. Three significant observations are made: 1. There exist many complex but orderly regions of periodicity and chaos, 2. there are nested regions of increasing number of peaks per cycle that may cascade to chaos, and 3. there are areas where more than one state, e.g., a period-2 oscillation and chaos, coexist for the same parameters; which one is reached depends on initial conditions.

Unstable Periodic Orbit Analysis of Histograms of Chaotic Time Series

International Nuclear Information System (INIS)

Zoldi, S.M.

1998-01-01

Using the Lorenz equations, we have investigated whether unstable periodic orbits (UPOs) associated with a strange attractor may predict the occurrence of the robust sharp peaks in histograms of some experimental chaotic time series. Histograms with sharp peaks occur for the Lorenz parameter value r=60.0 but not for r=28.0 , and the sharp peaks for r=60.0 do not correspond to a histogram derived from any single UPO. However, we show that histograms derived from the time series of a non-Axiom-A chaotic system can be accurately predicted by an escape-time weighting of UPO histograms. copyright 1998 The American Physical Society

The effects of model complexity and calibration period on groundwater recharge simulations

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Moeck, Christian; Van Freyberg, Jana; Schirmer, Mario

2017-04-01

A significant number of groundwater recharge models exist that vary in terms of complexity (i.e., structure and parametrization). Typically, model selection and conceptualization is very subjective and can be a key source of uncertainty in the recharge simulations. Another source of uncertainty is the implicit assumption that model parameters, calibrated over historical periods, are also valid for the simulation period. To the best of our knowledge there is no systematic evaluation of the effect of the model complexity and calibration strategy on the performance of recharge models. To address this gap, we utilized a long-term recharge data set (20 years) from a large weighting lysimeter. We performed a differential split sample test with four groundwater recharge models that vary in terms of complexity. They were calibrated using six calibration periods with climatically contrasting conditions in a constrained Monte Carlo approach. Despite the climatically contrasting conditions, all models performed similarly well during the calibration. However, during validation a clear effect of the model structure on model performance was evident. The more complex, physically-based models predicted recharge best, even when calibration and prediction periods had very different climatic conditions. In contrast, more simplistic soil-water balance and lumped model performed poorly under such conditions. For these models we found a strong dependency on the chosen calibration period. In particular, our analysis showed that this can have relevant implications when using recharge models as decision-making tools in a broad range of applications (e.g. water availability, climate change impact studies, water resource management, etc.).

Design of the tool for periodic not evolvent profiles

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Anisimov Roman

2017-01-01

Full Text Available The new approach to profiling of the tool for processing of parts with periodic not evolvent profiles are considered in the article The discriminatory analysis of periodic profiles including repetition of profile both in the plane of perpendicular axis of part, and in the plane of passing along part of axis is offered. In the basis of the offered profiling method the idea of space shaping by rated surface of product of tool surface lies. The big advantage of the offered approach in profiling is its combination with the analysis of parameters of process of engineering work. It allows to predict the accuracy and surface quality of product with not evolvent periodic profile. While using the offered approach the pinion cutter for processing of wheels with internal triangular teeths and mill for processing of the screw of the counter of consumption of liquid, complex profile of which consists of several formings, have been received

Multi-model analysis in hydrological prediction

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Lanthier, M.; Arsenault, R.; Brissette, F.

2017-12-01

Hydrologic modelling, by nature, is a simplification of the real-world hydrologic system. Therefore ensemble hydrological predictions thus obtained do not present the full range of possible streamflow outcomes, thereby producing ensembles which demonstrate errors in variance such as under-dispersion. Past studies show that lumped models used in prediction mode can return satisfactory results, especially when there is not enough information available on the watershed to run a distributed model. But all lumped models greatly simplify the complex processes of the hydrologic cycle. To generate more spread in the hydrologic ensemble predictions, multi-model ensembles have been considered. In this study, the aim is to propose and analyse a method that gives an ensemble streamflow prediction that properly represents the forecast probabilities and reduced ensemble bias. To achieve this, three simple lumped models are used to generate an ensemble. These will also be combined using multi-model averaging techniques, which generally generate a more accurate hydrogram than the best of the individual models in simulation mode. This new predictive combined hydrogram is added to the ensemble, thus creating a large ensemble which may improve the variability while also improving the ensemble mean bias. The quality of the predictions is then assessed on different periods: 2 weeks, 1 month, 3 months and 6 months using a PIT Histogram of the percentiles of the real observation volumes with respect to the volumes of the ensemble members. Initially, the models were run using historical weather data to generate synthetic flows. This worked for individual models, but not for the multi-model and for the large ensemble. Consequently, by performing data assimilation at each prediction period and thus adjusting the initial states of the models, the PIT Histogram could be constructed using the observed flows while allowing the use of the multi-model predictions. The under-dispersion has been

Impact of cyclostationarity on fan broadband noise prediction

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Wohlbrandt, A.; Kissner, C.; Guérin, S.

2018-04-01

One of the dominant noise sources of modern Ultra High Bypass Ratio (UHBR) engines is the interaction of the rotor wakes with the leading edges of the stator vanes in the fan stage. While the tonal components of this noise generation mechanism are fairly well understood by now, the broadband components are not. This calls to further the understanding of the broadband noise generation in the fan stage. This article introduces a new extension to the Random Particle Mesh (RPM) method, which accommodates in-depth studies of the impact of cyclostationary wake characteristics on the broadband noise in the fan stage. The RPM method is used to synthesize a turbulence field in the stator domain using a URANS simulation characterized by time-periodic turbulence and mean flow. The rotor-stator interaction noise is predicted by a two-dimensional CAA computation of the stator cascade. The impact of cyclostationarity is decomposed into various effects, which are separately investigated. This leads to the finding that the periodic turbulent kinetic energy (TKE) and periodic flow have only a negligible effect on the radiated sound power. The impact of the periodic integral length scale (TLS) is, however, substantial. The limits of a stationary representation of the TLS are demonstrated making this new extension to the RPM method indispensable when background and wake TKE are of comparable level. Good agreement of the predictions with measurements obtained from the 2015 AIAA Fan Broadband Noise Prediction Workshop are also shown.

Periodic feedback stabilization for linear periodic evolution equations

CERN Document Server

Wang, Gengsheng

2016-01-01

This book introduces a number of recent advances regarding periodic feedback stabilization for linear and time periodic evolution equations. First, it presents selected connections between linear quadratic optimal control theory and feedback stabilization theory for linear periodic evolution equations. Secondly, it identifies several criteria for the periodic feedback stabilization from the perspective of geometry, algebra and analyses respectively. Next, it describes several ways to design periodic feedback laws. Lastly, the book introduces readers to key methods for designing the control machines. Given its coverage and scope, it offers a helpful guide for graduate students and researchers in the areas of control theory and applied mathematics.

Periodic Hydraulic Testing for Discerning Fracture Network Connections

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Becker, M.; Le Borgne, T.; Bour, O.; Guihéneuf, N.; Cole, M.

2015-12-01

Discrete fracture network (DFN) models often predict highly variable hydraulic connections between injection and pumping wells used for enhanced oil recovery, geothermal energy extraction, and groundwater remediation. Such connections can be difficult to verify in fractured rock systems because standard pumping or pulse interference tests interrogate too large a volume to pinpoint specific connections. Three field examples are presented in which periodic hydraulic tests were used to obtain information about hydraulic connectivity in fractured bedrock. The first site, a sandstone in New York State, involves only a single fracture at a scale of about 10 m. The second site, a granite in Brittany, France, involves a fracture network at about the same scale. The third site, a granite/schist in the U.S. State of New Hampshire, involves a complex network at scale of 30-60 m. In each case periodic testing provided an enhanced view of hydraulic connectivity over previous constant rate tests. Periodic testing is particularly adept at measuring hydraulic diffusivity, which is a more effective parameter than permeability for identify the complexity of flow pathways between measurement locations. Periodic tests were also conducted at multiple frequencies which provides a range in the radius of hydraulic penetration away from the oscillating well. By varying the radius of penetration, we attempt to interrogate the structure of the fracture network. Periodic tests, therefore, may be uniquely suited for verifying and/or calibrating DFN models.

Stock market index prediction using neural networks

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Komo, Darmadi; Chang, Chein-I.; Ko, Hanseok

1994-03-01

A neural network approach to stock market index prediction is presented. Actual data of the Wall Street Journal's Dow Jones Industrial Index has been used for a benchmark in our experiments where Radial Basis Function based neural networks have been designed to model these indices over the period from January 1988 to Dec 1992. A notable success has been achieved with the proposed model producing over 90% prediction accuracies observed based on monthly Dow Jones Industrial Index predictions. The model has also captured both moderate and heavy index fluctuations. The experiments conducted in this study demonstrated that the Radial Basis Function neural network represents an excellent candidate to predict stock market index.

Effective diffusion in time-periodic linear planar flow

International Nuclear Information System (INIS)

Indeikina, A.; Chang, H.

1993-01-01

It is shown that when a point source of solute is inserted into a time-periodic, unbounded linear planar flow, the large-time, time-average transport of the solute can be described by classical anisotropic diffusion with constant effective diffusion tensors. For a given vorticity and forcing period, elongational flow is shown to be the most dispersive followed by simple shear and rotational flow. Large-time diffusivity along the major axis of the time-average concentration ellipse, whose alignment is predicted from the theory, is shown to increase with vorticity for all flows and decrease with increasing forcing frequency for elongational flow and simple shear. For the interesting case of rotational flow, there exist discrete resonant frequencies where the time-average major diffusivity reaches local maxima equal to the time-average steady flow case with zero forcing frequency

Strengthening economy through tourism sector by tourist arrival prediction

Science.gov (United States)

Supriatna, A.; Subartini, B.; Hertini, E.; Sukono; Rumaisha; Istiqamah, N.

2018-03-01

Tourism sector has a tendency to be proposed as a support for national economy to many countries with various of natural resources, such as Indonesia. The number of tourist is very related with the success rate of a tourist attraction, since it is also related with planning and strategy. Hence, it is important to predict the climate of tourism in Indonesia, especially the number of domestic or international tourist in the future. This study uses Seasonal Autoregressive Integrated Moving Average (SARIMA) time series method to predict the number of tourist arrival to tourism strategic areas in Nusa Tenggara Barat. The prediction was done using the international and domestic tourist arrival to Nusa Tenggara Barat data from January 2008 to June 2016. The established SARIMA method was (0,1,1)(0,0,2)12 with MAPE error of 15.76. The prediction for the next six time periods showed that the highest number of tourist arrival is during September 2016 with 330,516 tourist arrivals. Prediction of tourist arrival hopefully might be used as reference for local and national government to make policies to strengthen national economy for a long period of time

Multiscale periodicities in aerosol optical depth over India

International Nuclear Information System (INIS)

Ramachandran, S; Ghosh, Sayantan; Verma, Amit; Panigrahi, P K

2013-01-01

Aerosols exhibit periodic or cyclic variations depending on natural and anthropogenic sources over a region, which can become modulated by synoptic meteorological parameters such as winds, rainfall and relative humidity, and long-range transport. Information on periodicity and phase in aerosol properties assumes significance in prediction as well as examining the radiative and climate effects of aerosols including their association with changes in cloud properties and rainfall. Periodicity in aerosol optical depth, which is a columnar measure of aerosol distribution, is determined using continuous wavelet transform over 35 locations (capitals of states and union territories) in India. Continuous wavelet transform is used in the study because continuous wavelet transform is better suited to the extraction of the periodic and local modulations present in various frequency ranges when compared to Fourier transform. Monthly mean aerosol optical depths (AODs) from the Moderate Resolution Imaging Spectroradiometer (MODIS) on board the Terra satellite at 1° × 1° resolution from January 2001 to December 2012 are used. Annual and quasi-biennial oscillations (QBOs) in AOD are evident in addition to the weak semi-annual (5–6 months) and quasi-triennial oscillations (∼40 months). The semi-annual and annual oscillations are consistent with the seasonal and yearly cycle of variations in AODs. The QBO type periodicity in AOD is found to be non-stationary while the annual period is stationary. The 40 month periodicity indicates the presence of long term correlations in AOD. The observed periodicities in MODIS Terra AODs are also evident in the ground-based AOD measurements made over Kanpur in the Indo-Gangetic Plain. The phase of the periodicity in AOD is stable in the mid-frequency range, while local disturbances in the high-frequency range and long term changes in the atmospheric composition give rise to unstable phases in the low-frequency range. The presence of phase

Relativistic boost as the cause of periodicity in a massive black-hole binary candidate.

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D'Orazio, Daniel J; Haiman, Zoltán; Schiminovich, David

2015-09-17

Because most large galaxies contain a central black hole, and galaxies often merge, black-hole binaries are expected to be common in galactic nuclei. Although they cannot be imaged, periodicities in the light curves of quasars have been interpreted as evidence for binaries, most recently in PG 1302-102, which has a short rest-frame optical period of four years (ref. 6). If the orbital period of the black-hole binary matches this value, then for the range of estimated black-hole masses, the components would be separated by 0.007-0.017 parsecs, implying relativistic orbital speeds. There has been much debate over whether black-hole orbits could be smaller than one parsec (ref. 7). Here we report that the amplitude and the sinusoid-like shape of the variability of the light curve of PG 1302-102 can be fitted by relativistic Doppler boosting of emission from a compact, steadily accreting, unequal-mass binary. We predict that brightness variations in the ultraviolet light curve track those in the optical, but with a two to three times larger amplitude. This prediction is relatively insensitive to the details of the emission process, and is consistent with archival ultraviolet data. Follow-up ultraviolet and optical observations in the next few years can further test this prediction and confirm the existence of a binary black hole in the relativistic regime.

Predicting suicide with the SAD PERSONS scale.

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Katz, Cara; Randall, Jason R; Sareen, Jitender; Chateau, Dan; Walld, Randy; Leslie, William D; Wang, JianLi; Bolton, James M

2017-09-01

Suicide is a major public health issue, and a priority requirement is accurately identifying high-risk individuals. The SAD PERSONS suicide risk assessment scale is widely implemented in clinical settings despite limited supporting evidence. This article aims to determine the ability of the SAD PERSONS scale (SPS) to predict future suicide in the emergency department. Five thousand four hundred sixty-two consecutive adults were seen by psychiatry consultation teams in two tertiary emergency departments with linkage to population-based administrative data to determine suicide deaths within 6 months, 1, and 5 years. Seventy-seven (1.4%) individuals died by suicide during the study period. When predicting suicide at 12 months, medium- and high-risk scores on SPS had a sensitivity of 49% and a specificity of 60%; the positive and negative predictive values were 0.9 and 99%, respectively. Half of the suicides at both 6- and 12-month intervals were classified as low risk by SPS at index visit. The area under the curve at 12 months for the Modified SPS was 0.59 (95% confidence interval [CI] range 0.51-0.67). High-risk scores (compared to low risk) were significantly associated with death by suicide over the 5-year study period using the SPS (hazard ratio 2.49; 95% CI 1.34-4.61) and modified version (hazard ratio 2.29; 95% CI 1.24-2.29). Although widely used in educational and clinical settings, these findings do not support the use of the SPS and Modified SPS to predict suicide in adults seen by psychiatric services in the emergency department. © 2017 Wiley Periodicals, Inc.

Long-term orbit prediction for Tiangong-1 spacecraft using the mean atmosphere model

Science.gov (United States)

Tang, Jingshi; Liu, Lin; Cheng, Haowen; Hu, Songjie; Duan, Jianfeng

2015-03-01

China is planning to complete its first space station by 2020. For the long-term management and maintenance, the orbit of the space station needs to be predicted for a long period of time. Since the space station is expected to work in a low-Earth orbit, the error in the a priori atmosphere model contributes significantly to the rapid increase of the predicted orbit error. When the orbit is predicted for 20 days, the error in the a priori atmosphere model, if not properly corrected, could induce a semi-major axis error of up to a few kilometers and an overall position error of several thousand kilometers respectively. In this work, we use a mean atmosphere model averaged from NRLMSISE00. The a priori reference mean density can be corrected during the orbit determination. For the long-term orbit prediction, we use sufficiently long period of observations and obtain a series of the diurnal mean densities. This series contains the recent variation of the atmosphere density and can be analyzed for various periodic components. After being properly fitted, the mean density can be predicted and then applied in the orbit prediction. Here we carry out the test with China's Tiangong-1 spacecraft at the altitude of about 340 km and we show that this method is simple and flexible. The densities predicted with this approach can serve in the long-term orbit prediction. In several 20-day prediction tests, most predicted orbits show semi-major axis errors better than 700 m and overall position errors better than 400 km.

Flow through a cylindrical pipe with a periodic array of fractal orifices

NARCIS (Netherlands)

van Melick, P.A.J.; Geurts, Bernardus J.

2013-01-01

We apply direct numerical simulation (DNS) of the incompressible Navier–Stokes equations to predict flow through a cylindrical pipe in which a periodic array of orifice plates with a fractal perimeter is mounted. The flow is simulated using a volume penalization immersed boundary method with which

Flow through a cylindrical pipe with a periodic array of fractal orifices

NARCIS (Netherlands)

van Melick, P.A.J.; Geurts, B.J.

2013-01-01

We apply direct numerical simulation (DNS) of the incompressible Navier-Stokes equations to predict flow through a cylindrical pipe in which a periodic array of orifice plates with a fractal perimeter is mounted. The flow is simulated using a volume penalization immersed boundary method with which

Recursive formulae and performance comparisons for first mode dynamics of periodic structures

Science.gov (United States)

Hobeck, Jared D.; Inman, Daniel J.

2017-05-01

Periodic structures are growing in popularity especially in the energy harvesting and metastructures communities. Common types of these unique structures are referred to in the literature as zigzag, orthogonal spiral, fan-folded, and longitudinal zigzag structures. Many of these studies on periodic structures have two competing goals in common: (a) minimizing natural frequency, and (b) minimizing mass or volume. These goals suggest that no single design is best for all applications; therefore, there is a need for design optimization and comparison tools which first require efficient easy-to-implement models. All available structural dynamics models for these types of structures do provide exact analytical solutions; however, they are complex requiring tedious implementation and providing more information than necessary for practical applications making them computationally inefficient. This paper presents experimentally validated recursive models that are able to very accurately and efficiently predict the dynamics of the four most common types of periodic structures. The proposed modeling technique employs a combination of static deflection formulae and Rayleigh’s Quotient to estimate the first mode shape and natural frequency of periodic structures having any number of beams. Also included in this paper are the results of an extensive experimental validation study which show excellent agreement between model prediction and measurement. Lastly, the proposed models are used to evaluate the performance of each type of structure. Results of this performance evaluation reveal key advantages and disadvantages associated with each type of structure.

Plasmonic energy transfer in periodically doped graphene

International Nuclear Information System (INIS)

Silveiro, I; Manjavacas, A; Thongrattanasiri, S; García de Abajo, F J

2013-01-01

We predict unprecedentedly large values of the energy-transfer rate between an optical emitter and a layer of periodically doped graphene. The transfer exhibits divergences at photon frequencies corresponding to the Van Hove singularities of the plasmonic band structure of the graphene. In particular, we find flat bands associated with regions of vanishing doping charge, which appear in graphene when it is patterned through gates of spatially alternating signs, giving rise to intense transfer rate singularities. Graphene is thus shown to provide a unique platform for fast control of optical energy transfer via fast electrostatic inhomogeneous doping. (paper)

For better or worse: Factors predicting outcomes of family care of older people over a one-year period. A six-country European study

Science.gov (United States)

Bien, Barbara; McKee, Kevin; Krevers, Barbro; Mestheneos, Elizabeth; Di Rosa, Mirko; von dem Knesebeck, Olaf; Kofahl, Christopher

2018-01-01

Objectives Demographic change has led to an increase of older people in need of long-term care in nearly all European countries. Informal carers primarily provide the care and support needed by dependent people. The supply and willingness of individuals to act as carers are critical to sustain informal care resources as part of the home health care provision. This paper describes a longitudinal study of informal care in six European countries and reports analyses that determine those factors predicting the outcomes of family care over a one-year period. Methods Analyses are based on data from the EUROFAMCARE project, a longitudinal survey study of family carers of older people with baseline data collection in 2004 and follow-up data collection a year later in six European countries (Germany, Greece, Italy, Poland, Sweden, and the United Kingdom), N = 3,348. Descriptive statistics of the sample characteristics are reported. Binary logistic random-intercept regressions were computed, predicting the outcome of change of the care dyad’s status at follow-up. Results Where care is provided by a more distant family member or by a friend or neighbour, the care-recipient is significantly more likely to be cared for by someone else (OR 1.62) or to be in residential care (OR 3.37) after one year. The same holds true if the care-recipient has memory problems with a dementia diagnosis (OR 1.79/OR 1.84). Higher dependency (OR 1.22) and behavioural problems (OR 1.76) in the care-recipient also lead to a change of care dyad status. Country of residence explained a relatively small amount of variance (8%) in whether a care-recipient was cared for by someone else after one year, but explained a substantial amount of variance (52%) in whether a care-recipient was in residential care. Particularly in Sweden, care-recipients are much more likely to be cared for by another family or professional carer or to be in residential care, whereas in Greece the status of the care dyad is much

The critical period hypothesis in second language acquisition: a statistical critique and a reanalysis.

Science.gov (United States)

Vanhove, Jan

2013-01-01

In second language acquisition research, the critical period hypothesis (cph) holds that the function between learners' age and their susceptibility to second language input is non-linear. This paper revisits the indistinctness found in the literature with regard to this hypothesis's scope and predictions. Even when its scope is clearly delineated and its predictions are spelt out, however, empirical studies-with few exceptions-use analytical (statistical) tools that are irrelevant with respect to the predictions made. This paper discusses statistical fallacies common in cph research and illustrates an alternative analytical method (piecewise regression) by means of a reanalysis of two datasets from a 2010 paper purporting to have found cross-linguistic evidence in favour of the cph. This reanalysis reveals that the specific age patterns predicted by the cph are not cross-linguistically robust. Applying the principle of parsimony, it is concluded that age patterns in second language acquisition are not governed by a critical period. To conclude, this paper highlights the role of confirmation bias in the scientific enterprise and appeals to second language acquisition researchers to reanalyse their old datasets using the methods discussed in this paper. The data and R commands that were used for the reanalysis are provided as supplementary materials.

Augmented chaos-multiple linear regression approach for prediction of wave parameters

Directory of Open Access Journals (Sweden)

M.A. Ghorbani

2017-06-01

The inter-comparisons demonstrated that the Chaos-MLR and pure MLR models yield almost the same accuracy in predicting the significant wave heights and the zero-up-crossing wave periods. Whereas, the augmented Chaos-MLR model is performed better results in term of the prediction accuracy vis-a-vis the previous prediction applications of the same case study.

Climate Prediction for Brazil's Nordeste: Performance of Empirical and Numerical Modeling Methods.

Science.gov (United States)

Moura, Antonio Divino; Hastenrath, Stefan

2004-07-01

Comparisons of performance of climate forecast methods require consistency in the predictand and a long common reference period. For Brazil's Nordeste, empirical methods developed at the University of Wisconsin use preseason (October January) rainfall and January indices of the fields of meridional wind component and sea surface temperature (SST) in the tropical Atlantic and the equatorial Pacific as input to stepwise multiple regression and neural networking. These are used to predict the March June rainfall at a network of 27 stations. An experiment at the International Research Institute for Climate Prediction, Columbia University, with a numerical model (ECHAM4.5) used global SST information through February to predict the March June rainfall at three grid points in the Nordeste. The predictands for the empirical and numerical model forecasts are correlated at +0.96, and the period common to the independent portion of record of the empirical prediction and the numerical modeling is 1968 99. Over this period, predicted versus observed rainfall are evaluated in terms of correlation, root-mean-square error, absolute error, and bias. Performance is high for both approaches. Numerical modeling produces a correlation of +0.68, moderate errors, and strong negative bias. For the empirical methods, errors and bias are small, and correlations of +0.73 and +0.82 are reached between predicted and observed rainfall.

Surgical Apgar Score Predicts Postoperative Complications in ...

African Journals Online (AJOL)

complications were determined during the thirty day post operative period. ... An ideal model to predict postoperative complications ... their SAS for purposes of risk stratification; high risk. (0-4), medium .... surgical audit (9,14). Serial monitoring ...

Effects of Long Period Ocean Tides on the Earth's Rotation

Science.gov (United States)

Gross, Richard S.; Chao, Ben F.; Desai, Shailen D.

1996-01-01

The spectra of polar motion excitation functions exhibit enhanced power in the fortnightly tidal band. This enhanced power is attributed to ocean tidal excitation. Ocean tide models predict polar motion excitation effects that differ with each other, and with observations, by factors as large as 2-3. There is a need for inproved models for the effect of long-period ocean tides on Earth's rotation.

Liquidity crisis detection: An application of log-periodic power law structures to default prediction

Science.gov (United States)

Wosnitza, Jan Henrik; Denz, Cornelia

2013-09-01

We employ the log-periodic power law (LPPL) to analyze the late-2000 financial crisis from the perspective of critical phenomena. The main purpose of this study is to examine whether LPPL structures in the development of credit default swap (CDS) spreads can be used for default classification. Based on the different triggers of Bear Stearns’ near bankruptcy during the late-2000 financial crisis and Ford’s insolvency in 2009, this study provides a quantitative description of the mechanism behind bank runs. We apply the Johansen-Ledoit-Sornette (JLS) positive feedback model to explain the rise of financial institutions’ CDS spreads during the global financial crisis 2007-2009. This investigation is based on CDS spreads of 40 major banks over the period from June 2007 to April 2009 which includes a significant CDS spread increase. The qualitative data analysis indicates that the CDS spread variations have followed LPPL patterns during the global financial crisis. Furthermore, the univariate classification performances of seven LPPL parameters as default indicators are measured by Mann-Whitney U tests. The present study supports the hypothesis that discrete scale-invariance governs the dynamics of financial markets and suggests the application of new and fast updateable default indicators to capture the buildup of long-range correlations between creditors.

Criteria for confirming sequence periodicity identified by Fourier transform analysis: application to GCR2, a candidate plant GPCR?

Science.gov (United States)

Illingworth, Christopher J R; Parkes, Kevin E; Snell, Christopher R; Mullineaux, Philip M; Reynolds, Christopher A

2008-03-01

Methods to determine periodicity in protein sequences are useful for inferring function. Fourier transformation is one approach but care is required to ensure the periodicity is genuine. Here we have shown that empirically-derived statistical tables can be used as a measure of significance. Genuine protein sequences data rather than randomly generated sequences were used as the statistical backdrop. The method has been applied to G-protein coupled receptor (GPCR) sequences, by Fourier transformation of hydrophobicity values, codon frequencies and the extent of over-representation of codon pairs; the latter being related to translational step times. Genuine periodicity was observed in the hydrophobicity whereas the apparent periodicity (as inferred from previously reported measures) in the translation step times was not validated statistically. GCR2 has recently been proposed as the plant GPCR receptor for the hormone abscisic acid. It has homology to the Lanthionine synthetase C-like family of proteins, an observation confirmed by fold recognition. Application of the Fourier transform algorithm to the GCR2 family revealed strongly predicted seven fold periodicity in hydrophobicity, suggesting why GCR2 has been reported to be a GPCR, despite negative indications in most transmembrane prediction algorithms. The underlying multiple sequence alignment, also required for the Fourier transform analysis of periodicity, indicated that the hydrophobic regions around the 7 GXXG motifs commence near the C-terminal end of each of the 7 inner helices of the alpha-toroid and continue to the N-terminal region of the helix. The results clearly explain why GCR2 has been understandably but erroneously predicted to be a GPCR.

Strong ground motion prediction using virtual earthquakes.

Science.gov (United States)

Denolle, M A; Dunham, E M; Prieto, G A; Beroza, G C

2014-01-24

Sedimentary basins increase the damaging effects of earthquakes by trapping and amplifying seismic waves. Simulations of seismic wave propagation in sedimentary basins capture this effect; however, there exists no method to validate these results for earthquakes that have not yet occurred. We present a new approach for ground motion prediction that uses the ambient seismic field. We apply our method to a suite of magnitude 7 scenario earthquakes on the southern San Andreas fault and compare our ground motion predictions with simulations. Both methods find strong amplification and coupling of source and structure effects, but they predict substantially different shaking patterns across the Los Angeles Basin. The virtual earthquake approach provides a new approach for predicting long-period strong ground motion.

Response predictions using the observed autocorrelation function

DEFF Research Database (Denmark)

Nielsen, Ulrik Dam; H. Brodtkorb, Astrid; Jensen, Jørgen Juncher

2018-01-01

This article studies a procedure that facilitates short-time, deterministic predictions of the wave-induced motion of a marine vessel, where it is understood that the future motion of the vessel is calculated ahead of time. Such predictions are valuable to assist in the execution of many marine......-induced response in study. Thus, predicted (future) values ahead of time for a given time history recording are computed through a mathematical combination of the sample autocorrelation function and previous measurements recorded just prior to the moment of action. Importantly, the procedure does not need input...... show that predictions can be successfully made in a time horizon corresponding to about 8-9 wave periods ahead of current time (the moment of action)....

Compensating for Quasi-periodic Motion in Robotic Radiosurgery

CERN Document Server

Ernst, Floris

2012-01-01

Compensating for Quasi-periodic Motion in Robotic Radiosurgery outlines the techniques needed to accurately track and compensate for respiratory and pulsatory motion during robotic radiosurgery. The algorithms presented within the book aid in the treatment of tumors that move during respiration. In Chapters 1 and 2,  the book introduces the concept of stereotactic body radiation therapy, motion compensation strategies and the clinical state-of-the-art. In Chapters 3 through 5, the author describes and evaluates new methods for motion prediction, for correlating external motion to internal organ motion, and for the evaluation of these algorithms’ output based on an unprecedented amount of real clinical data. Finally, Chapter 6 provides a brief introduction into currently investigated, open questions and further fields of research. Compensating for Quasi-periodic Motion in Robotic Radiosurgery targets researchers working in the related fields of surgical oncology, artificial intelligence, robotics and more. ...

Predicting Changes of Rainfed Barley (Hordeum vulgare L. Farming Calendar using Downscaling LARS-WG and HadCM3 Models in Lorestan Province in 2011-2030 period

Directory of Open Access Journals (Sweden)

Mahmoud Ahmadi

2017-10-01

Full Text Available Introduction The results of climate change studies in recent years confirm this phenomenon occurrence in Iran. The climatic characteristics (potential and limitations of climate are considered in the long run, to determine the pattern of cultivation and distribution of different plant species. Unfortunately, the agricultural sector due to the low speed and power compliance, will suffer the greatest impact of climate change. General circulation models provide accurate tools to predict future climatic conditions, and the necessary data for the implementation of simulation models and the development of crops under climate change conditions. The study of the effects of climate change on the agricultural sector seems to be necessary due to increase the demand for agricultural production. The aim of this study was to investigate the effects of climate change on the rainfed barley farming calendar in Lorestan province as an effective pole in cereal cultivation in Iran. Materials and methods In order to study the effects of climate change on the rainfed barley farming calendar, outputs from the HadCM3 model simulations were used. After evaluating the LARS-WG stochastic weather generator model using performance indicators and ensure the suitability of the model, this model was applied to downscale HadCM3 model outputs. A2 scenario was chosen to evaluate climate impacts for the period 2011–2030. In this study, due to the suitable temperature for germination in the region, has been emphasized only on the precipitation to find the most suitable time for barley cultivation. Planting date was calculated by Weibull probability with 50 and 75% confidence intervals. Growing degree days (GDD were used to calculate the phenological stages. For the forecast period, the same method was used to determine the farming calendar. Results Discussion The results showed that in the observation period, the earliest planting date was observed in northern province in

Forecasting inter-urban transport demand for a logistics company: A combined grey–periodic extension model with remnant correction

Directory of Open Access Journals (Sweden)

Donghui Wang

2015-12-01

Full Text Available Accurately predicting short-term transport demand for an individual logistics company involved in a competitive market is critical to make short-term operation decisions. This article proposes a combined grey–periodic extension model with remnant correction to forecast the short-term inter-urban transport demand of a logistics company involved in a nationwide competitive market, showing changes in trend and seasonal fluctuations with irregular periods different to the macroeconomic cycle. A basic grey–periodic extension model of an additive pattern, namely, the main combination model, is first constructed to fit the changing trends and the featured seasonal fluctuation periods. In order to improve prediction accuracy and model adaptability, the grey model is repeatedly modelled to fit the remnant tail time series of the main combination model until prediction accuracy is satisfied. The modelling approach is applied to a logistics company engaged in a nationwide less-than-truckload road transportation business in China. The results demonstrate that the proposed modelling approach produces good forecasting results and goodness of fit, also showing good model adaptability to the analysed object in a changing macro environment. This fact makes this modelling approach an option to analyse the short-term transportation demand of an individual logistics company.

Birth weight predicted baseline muscular efficiency, but not response of energy expenditure to calorie restriction: An empirical test of the predictive adaptive response hypothesis.

Science.gov (United States)

Workman, Megan; Baker, Jack; Lancaster, Jane B; Mermier, Christine; Alcock, Joe

2016-07-01

Aiming to test the evolutionary significance of relationships linking prenatal growth conditions to adult phenotypes, this study examined whether birth size predicts energetic savings during fasting. We specifically tested a Predictive Adaptive Response (PAR) model that predicts greater energetic saving among adults who were born small. Data were collected from a convenience sample of young adults living in Albuquerque, NM (n = 34). Indirect calorimetry quantified changes in resting energy expenditure (REE) and active muscular efficiency that occurred in response to a 29-h fast. Multiple regression analyses linked birth weight to baseline and postfast metabolic values while controlling for appropriate confounders (e.g., sex, body mass). Birth weight did not moderate the relationship between body size and energy expenditure, nor did it predict the magnitude change in REE or muscular efficiency observed from baseline to after fasting. Alternative indicators of birth size were also examined (e.g., low v. normal birth weight, comparison of tertiles), with no effects found. However, baseline muscular efficiency improved by 1.1% per 725 g (S.D.) increase in birth weight (P = 0.037). Birth size did not influence the sensitivity of metabolic demands to fasting-neither at rest nor during activity. Moreover, small birth size predicted a reduction in the efficiency with which muscles convert energy expended into work accomplished. These results do not support the ascription of adaptive function to phenotypes associated with small birth size. © 2015 Wiley Periodicals, Inc. Am. J. Hum. Biol. 28:484-492, 2016. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

Geometric pre-patterning based tuning of the period doubling onset strain during thin film wrinkling

Energy Technology Data Exchange (ETDEWEB)

Saha, Sourabh K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2017-02-16

Wrinkling of supported thin films is an easy-to-implement and low-cost fabrication technique for generation of stretch-tunable periodic micro and nano-scale structures. However, the tunability of such structures is often limited by the emergence of an undesirable period doubled mode at high strains. Predictively tuning the onset strain for period doubling via existing techniques requires one to have extensive knowledge about the nonlinear pattern formation behavior. Herein, a geometric pre-patterning based technique is introduced to delay the onset of period doubling that can be implemented to predictively tune the onset strain even with limited system knowledge. The technique comprises pre-patterning the film/base bilayer with a sinusoidal pattern that has the same period as the natural wrinkle period of the system. The effectiveness of this technique has been verified via physical and computational experiments on the polydimethylsiloxane/glass bilayer system. It is observed that the period doubling onset strain can be increased from the typical value of 20% for flat films to greater than 30% with a modest pre-pattern aspect ratio (2∙amplitude/period) of 0.15. In addition, finite element simulations reveal that (i) the onset strain can be increased up to a limit by increasing the amplitude of the pre-patterns and (ii) the delaying effect can be captured entirely by the pre-pattern geometry. As a result, one can implement this technique even with limited system knowledge, such as material properties or film thickness, by simply replicating pre-existing wrinkled patterns to generate prepatterned bilayers. Thus, geometric pre-patterning is a practical scheme to suppress period doubling that can increase the operating range of stretch-tunable wrinkle-based devices by at least 50%.

A comparative study on chaoticity of equatorial/low latitude ionosphere over Indian subcontinent during geomagnetically quiet and disturbed periods

Directory of Open Access Journals (Sweden)

K. Unnikrishnan

2010-12-01

Full Text Available In the present study, the latitudinal aspect of chaotic behaviour of ionosphere during quiet and storm periods are analyzed and compared by using GPS TEC time series measured at equatorial trough, crest and outside crest stations over Indian subcontinent, by employing the chaotic quantifiers like Lyapunov exponent (LE, correlation dimension (CD, entropy and nonlinear prediction error (NPE. It is observed that the values of LE are low for storm periods compared to those of quiet periods for all the stations considered here. The lowest value of LE is observed at the trough station, Agatti (2.38° N, Geomagnetically, and highest at crest station, Mumbai (10.09° N, Geomagnetically for both quiet and storm periods. The values of correlation dimension computed for TEC time series are in the range 2.23–2.74 for quiet period, which indicate that equatorial ionosphere may be described with three variables during quiet period. But the crest station Mumbai shows a higher value of CD (3.373 during storm time, which asserts that four variables are necessary to describe the system during storm period. The values of non linear prediction error (NPE are lower for Agatti (2.38° N, Geomagnetically and Jodhpur (18.3° N, Geomagnetically, during storm period, compared to those of quiet period, mainly because of the predominance of non linear aspects during storm periods The surrogate data test is carried out and on the basis of the significance of difference of the original data and surrogates for various aspects, the surrogate data test rejects the null hypothesis that the time series of TEC during storm and quiet times represent a linear stochastic process. It is also observed that using state space model, detrended TEC can be predicted, which reasonably reproduces the observed data. Based on the values of the above quantifiers, the features of chaotic behaviour of equatorial trough crest and outside the crest regions of ionosphere during geomagnetically

Chaos to periodicity and periodicity to chaos by periodic perturbations in the Belousov-Zhabotinsky reaction

International Nuclear Information System (INIS)

Li Qianshu; Zhu Rui

2004-01-01

A three-variable model of the Belousov-Zhabotinsky reaction system subject to external sinusoidal perturbations is investigated by means of frequency spectrum analysis. In the period-1 window of the model, the transitions from periodicity to chaos are observed; in the chaotic window, the transitions from chaos to periodicity are found. The former might be understood by the circle map of two coupled oscillators, and the latter is partly explained by the resonance between the main frequency of the chaos and the frequency of the external periodic perturbations

[Angiopoietins predict long-term outcomes after aneurysmal subarachnoid hemorrhage during an early period].

Science.gov (United States)

Wang, Yi; Wang, Dong; Wei, Huijie; Tian, Ye; Jiang, Rongcai; Yue, Shuyuan; Zhang, Jianning

2015-05-19

To evaluate the association between serum levels of angiopoietins (Ang) during an early period (within 72 h) and clinical outcomes after aneurysmal subarachnoid haemorrhage (aSAH). This prospective study was conducted at Department of Neurosurgery, Tianjin Medical University General Hospital. Blood samples from 37 aSAH patients were collected at 8 h (or GOSE). Those with GOSE > 5 were counted as a good outcome while those with GOSE ≤ 5 had a poor outcome. A total of 37 patients with aSAH and 39 healthy controls (HC) were enrolled. The aSAH patients showed a significant rise of Ang-1 within 8 h as compared with HC. The outcomes were good (n = 15) and poor (n = 22). Serum Ang-1 at 8 h (or < 8 h), 24 h and 72 h in good outcomers showed significantly higher than that in poor outcomers [(52 ± 24) vs (37 ± 17) mg/L, (62 ± 26) vs (45 ± 17) mg/L, (107 ± 27) vs (72 ± 18) mg/L]. The serum level of Ang-1 at 8 h and 24 h was one of independent risk factors for aSAH patients by multiariable Logistic regression analysis [adjected OR (95% CI) 1.095 (1.015-1.181) and 1.109 (1.016-1.211)] (P < 0.05). High serum level of Ang-1 during an early period (within 72 h) was associated with good outcomers (r = 0.627, P < 0.001). The serum levels of angiopoietins are significantly altered in aSAH patients, especially higher in good outcomers. And abnormal levels of angiopoietins may affect early brain injury (EBI) after SAH, structural integrity and recovery of blood-brain barrier (BBB) and long-term outcomes in aSAH patients.

Long-term orbit prediction for China's Tiangong-1 spacecraft based on mean atmosphere model

Science.gov (United States)

Tang, Jingshi; Liu, Lin; Miao, Manqian

Tiangong-1 is China's test module for future space station. It has gone through three successful rendezvous and dockings with Shenzhou spacecrafts from 2011 to 2013. For the long-term management and maintenance, the orbit sometimes needs to be predicted for a long period of time. As Tiangong-1 works in a low-Earth orbit with an altitude of about 300-400 km, the error in the a priori atmosphere model contributes significantly to the rapid increase of the predicted orbit error. When the orbit is predicted for 10-20 days, the error in the a priori atmosphere model, if not properly corrected, could induce the semi-major axis error and the overall position error up to a few kilometers and several thousand kilometers respectively. In this work, we use a mean atmosphere model averaged from NRLMSIS00. The a priori reference mean density can be corrected during precise orbit determination (POD). For applications in the long-term orbit prediction, the observations are first accumulated. With sufficiently long period of observations, we are able to obtain a series of the diurnal mean densities. This series bears the recent variation of the atmosphere density and can be analyzed for various periods. After being properly fitted, the mean density can be predicted and then applied in the orbit prediction. We show that the densities predicted with this approach can serve to increase the accuracy of the predicted orbit. In several 20-day prediction tests, most predicted orbits show semi-major axis errors better than 700m and overall position errors better than 600km.

Short-term predictions in forex trading

Science.gov (United States)

Muriel, A.

2004-12-01

Using a kinetic equation that is used to model turbulence (Physica A, 1985-1988, Physica D, 2001-2003), we redefine variables to model the time evolution of the foreign exchange rates of three major currencies. We display live and predicted data for one period of trading in October, 2003.

The periodic table in Flatland

International Nuclear Information System (INIS)

Kibler, M.

1995-01-01

The D-dimensional Coulomb system serves as a starting point for generating generalized atomic shells. These shells are ordered according to a generalized Madelung rule in D dimensions. This rule together with an Aufbau Prinzip is applied to produce a D-dimensional periodic table. A model is developed to rationalize the ordering of the shells predicted by the generalized Madelung rule. This model is based on the introduction of an Hamiltonian, invariant under the q-deformed algebra U q (so(D)), that breaks down the SO (D + 1) dynamical symmetry of the hydrogen atom in D dimensions. The D = 2 case (Flatland) is investigated with some details. It is shown that the neutral atoms and the (moderately) positive ions correspond to the values q = 0.8 and q = 1, respectively, of the deformation parameter q. (authors). 55 refs

Homoptera: Cicadidae

African Journals Online (AJOL)

1988-10-24

Oct 24, 1988 ... The geographical distributions, habitat preferences, plant associations and seasonal appearance of the platypleurine cicadas occurring on the Natal coastal plain, South Africa, are reported for the first time, and a key to the species is provided. Die geografiese verspreiding, habitatvoorkeur, plantassosiasies ...

Observaton of tunneling of slow and fast electromagnetic modes in coupled periodic waveguides

DEFF Research Database (Denmark)

Ha, Sangwoo; Sukhorukov, Andrey A.; Lavrinenko, Andrei

2011-01-01

We report the experimental observation of tunneling of slow and fast electromagnetic modes in coupled periodic waveguides shifted longitudinally by half of modulation period. According to the symmetry analysis, such a coupler supports two electromagnetic modes with exactly matched slow or fast...... group velocities but different phase velocities for frequencies close to the edge of the photonic band. We confirm the predicted properties of the modes by directly extracting their dispersion and group velocities from the near-field measurements using specialized Bloch-wave spectral analysis method....

VT Predicted Mean Wind Speed - 70 meter height

Data.gov (United States)

Vermont Center for Geographic Information — (Link to Metadata) Wind speed predictions at 70m are generated by a numerical model that simulates weather conditions over a 15-year period, taking into account...

VT Predicted Mean Wind Power - 50 meter height

Data.gov (United States)

Vermont Center for Geographic Information — (Link to Metadata) Wind power predictions at 50m are generated by a numerical model that simulates weather conditions over a 15-year period, taking into account...

VT Predicted Mean Wind Speed - 30 meter height

Data.gov (United States)

Vermont Center for Geographic Information — (Link to Metadata) Wind speed predictions at 30m are generated by a numerical model that simulates weather conditions over a 15-year period, taking into account...

Improving Transit Predictions of Known Exoplanets with TERMS

Directory of Open Access Journals (Sweden)

Mahadevan S.

2011-02-01

Full Text Available Transiting planet discoveries have largely been restricted to the short-period or low-periastron distance regimes due to the bias inherent in the geometric transit probability. Through the refinement of planetary orbital parameters, and hence reducing the size of transit windows, long-period planets become feasible targets for photometric follow-up. Here we describe the TERMS project that is monitoring these host stars at predicted transit times.

Next Place Prediction Based on Spatiotemporal Pattern Mining of Mobile Device Logs.

Science.gov (United States)

Lee, Sungjun; Lim, Junseok; Park, Jonghun; Kim, Kwanho

2016-01-23

Due to the recent explosive growth of location-aware services based on mobile devices, predicting the next places of a user is of increasing importance to enable proactive information services. In this paper, we introduce a data-driven framework that aims to predict the user's next places using his/her past visiting patterns analyzed from mobile device logs. Specifically, the notion of the spatiotemporal-periodic (STP) pattern is proposed to capture the visits with spatiotemporal periodicity by focusing on a detail level of location for each individual. Subsequently, we present algorithms that extract the STP patterns from a user's past visiting behaviors and predict the next places based on the patterns. The experiment results obtained by using a real-world dataset show that the proposed methods are more effective in predicting the user's next places than the previous approaches considered in most cases.

Delta-Domain Predictive Control and Identification for Control

DEFF Research Database (Denmark)

Lauritsen, Morten Bach

1997-01-01

The present thesis is concerned with different aspects of modelling, control and identification of linear systems. Traditionally, discrete-time sampled-data systems are represented using shift-operator parametrizations. Such parametrizations are not suitable at fast sampling rates. An alternative...... minimum-variance predictor as a special case and to have a well-defined continuous-time limit. By means of this new prediction method a unified framework for discrete-time and continuous-time predictive control algorithms is developed. This contains a continuous-time like discrete-time predictive...... controller which is insensitive to the choice of sampling period and has a well-defined limit in the continuous-time case. Also more conventional discrete-time predictive control methods may be described within the unified approach. The predictive control algorithms are extended to frequency weighted...

Prediction Model for Relativistic Electrons at Geostationary Orbit

Science.gov (United States)

Khazanov, George V.; Lyatsky, Wladislaw

2008-01-01

We developed a new prediction model for forecasting relativistic (greater than 2MeV) electrons, which provides a VERY HIGH correlation between predicted and actually measured electron fluxes at geostationary orbit. This model implies the multi-step particle acceleration and is based on numerical integrating two linked continuity equations for primarily accelerated particles and relativistic electrons. The model includes a source and losses, and used solar wind data as only input parameters. We used the coupling function which is a best-fit combination of solar wind/interplanetary magnetic field parameters, responsible for the generation of geomagnetic activity, as a source. The loss function was derived from experimental data. We tested the model for four year period 2004-2007. The correlation coefficient between predicted and actual values of the electron fluxes for whole four year period as well as for each of these years is stable and incredibly high (about 0.9). The high and stable correlation between the computed and actual electron fluxes shows that the reliable forecasting these electrons at geostationary orbit is possible.

Photolysis of Periodate and Periodic Acid in Aqueous Solution

DEFF Research Database (Denmark)

Sehested, Knud; Kläning, U. K.

1978-01-01

The photochemistry of periodate and periodic acid in aqueous solution was studied (i) by quantum yield measurements at low light intensity (ii) by flash photolysis, and (iii) by photolysis of glassy samples at 77 K. The photochemical studies were supplemented with pulse radiolysis studies...... of aqueous periodate solutions and with kinetic studies using stopped-flow technique. In strongly alkaline solution the photodecomposition of periodate proceeds via formation of O– and IVI. At pH solution O3 P is formed in a small...

Effects of weak nonlinearity on dispersion relations and frequency band-gaps of periodic structures

DEFF Research Database (Denmark)

Sorokin, Vladislav; Thomsen, Jon Juel

2015-01-01

of these for nonlinear problems is impossible or cumbersome, since Floquet theory is applicable for linear systems only. Thus the nonlinear effects for periodic structures are not yet fully uncovered, while at the same time applica-tions may demand effects of nonlinearity on structural response to be accounted for....... The present work deals with analytically predicting dynamic responses for nonlinear continuous elastic periodic structures. Specifically, the effects of weak nonlinearity on the dispersion re-lation and frequency band-gaps of a periodic Bernoulli-Euler beam performing bending os-cillations are analyzed......The analysis of the behaviour of linear periodic structures can be traced back over 300 years, to Sir Isaac Newton, and still attracts much attention. An essential feature of periodic struc-tures is the presence of frequency band-gaps, i.e. frequency ranges in which waves cannot propagate...

Is There a Sensitive Period in Human Incest Avoidance?

Directory of Open Access Journals (Sweden)

Liqun Luo

2011-04-01

Full Text Available Many studies support the proposition that early cosocialization with opposite-sex children has the effect of inhibiting later mutual sexual attraction, but the existence of a period in the life cycle in which individuals are sensitive to the effect of early cosocialization has been a matter of controversy. Drawing on earlier traditional psychological research, and on more recent work guided by parental investment theory, we hypothesized that only for maternal perinatal association (MPA-absent males a less-than-around-three-years age difference with the sister can predict stronger aversion to sibling incest. The results corroborated the hypothesis. The results can be interpreted as support for the existence of a sensitive period as well as for the potent role of MPA. Cross-cultural comparative studies were called on to further test the hypothesis.

An exact solution for orbit view-periods from a station on a tri-axial ellipsoidal planet

Science.gov (United States)

Tang, C. C. H.

1986-01-01

This paper presents the concise exact solution for predicting view-periods to be observed from a masked or unmasked tracking station on a tri-axial ellipsoidal surface. The new exact approach expresses the azimuth and elevation angles of a spacecraft in terms of the station-centered geodetic topocentric coordinates in an elegantly concise manner. A simple and efficient algorithm is developed to avoid costly repetitive computations in searching for neighborhoods near the rise and set times of each satellite orbit for each station. Only one search for each orbit is necessary for each station. Sample results indicate that the use of an assumed spherical earth instead of an 'actual' tri-axial ellipsoidal earth could introduce an error up to a few minutes in a view-period prediction for circular orbits of low or medium altitude. For an elliptical orbit of high eccentricity and long period, the maximum error could be even larger. The analytic treatment and the efficient algorithm are designed for geocentric orbits, but they should be applicable to interplanetary trajectories by an appropriate coordinates transformation at each view-period calculation. This analysis can be accomplished only by not using the classical orbital elements.

An exact solution for orbit view-periods from a station on a tri-axial ellipsoidal planet

Science.gov (United States)

Tang, C. C. H.

1986-08-01

This paper presents the concise exact solution for predicting view-periods to be observed from a masked or unmasked tracking station on a tri-axial ellipsoidal surface. The new exact approach expresses the azimuth and elevation angles of a spacecraft in terms of the station-centered geodetic topocentric coordinates in an elegantly concise manner. A simple and efficient algorithm is developed to avoid costly repetitive computations in searching for neighborhoods near the rise and set times of each satellite orbit for each station. Only one search for each orbit is necessary for each station. Sample results indicate that the use of an assumed spherical earth instead of an 'actual' tri-axial ellipsoidal earth could introduce an error up to a few minutes in a view-period prediction for circular orbits of low or medium altitude. For an elliptical orbit of high eccentricity and long period, the maximum error could be even larger. The analytic treatment and the efficient algorithm are designed for geocentric orbits, but they should be applicable to interplanetary trajectories by an appropriate coordinates transformation at each view-period calculation. This analysis can be accomplished only by not using the classical orbital elements.

TESTING CONVECTIVE-CORE OVERSHOOTING USING PERIOD SPACINGS OF DIPOLE MODES IN RED GIANTS

Energy Technology Data Exchange (ETDEWEB)

Montalban, J.; Noels, A.; Dupret, M.-A.; Scuflaire, R. [Institut d' Astrophysique et Geophysique de l' Universite de Liege, Allee du six Aout, 17 B-4000 Liege (Belgium); Miglio, A. [School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom); Ventura, P. [Osservatorio Astronomico di Roma-INAF, via Frascati 33, I-00040 Monteporzio Catone, Rome (Italy)

2013-04-01

Uncertainties on central mixing in main-sequence (MS) and core He-burning (He-B) phases affect key predictions of stellar evolution such as late evolutionary phases, chemical enrichment, ages, etc. We propose a test of the extension of extra-mixing in two relevant evolutionary phases based on period spacing ({Delta}P) of solar-like oscillating giants. From stellar models and their corresponding adiabatic frequencies (respectively, computed with ATON and LOSC codes), we provide the first predictions of the observable {Delta}P for stars in the red giant branch and in the red clump (RC). We find (1) a clear correlation between {Delta}P and the mass of the helium core (M{sub He}); the latter in intermediate-mass stars depends on the MS overshooting, and hence it can be used to set constraints on extra-mixing during MS when coupled with chemical composition; and (2) a linear dependence of the average value of the asymptotic period spacing (({Delta}P){sub a}) on the size of the convective core during the He-B phase. A first comparison with the inferred asymptotic period spacing for Kepler RC stars also suggests the need for extra-mixing during this phase, as evinced from other observational facts.

Configuration of the nationwide-grid expansion in Cuba for the period 2000-2015

International Nuclear Information System (INIS)

Garcia Rodirguez, B

1999-01-01

Using the prediction of the growth in electric energy consumption, a study is made of the configuration of the Nationwide-Grid (NWG) for that period. The study makes due consideration of the principle of diversity of the Energy Sources, assessing among the candidates; biomass, fossil fuels and nuclear energy

Novelty, coherence, and Mendeleev's periodic table.

Science.gov (United States)

Schindler, Samuel

2014-03-01

Predictivism is the view that successful predictions of "novel" evidence carry more confirmational weight than accommodations of already known evidence. Novelty, in this context, has traditionally been conceived of as temporal novelty. However temporal predictivism has been criticized for lacking a rationale: why should the time order of theory and evidence matter? Instead, it has been proposed, novelty should be construed in terms of use-novelty, according to which evidence is novel if it was not used in the construction of a theory. Only if evidence is use-novel can it fully support the theory entailing it. As I point out in this paper, the writings of the most influential proponent of use-novelty contain a weaker and a stronger version of use-novelty. However both versions, I argue, are problematic. With regard to the appraisal of Mendeleev' periodic table, the most contentious historical case in the predictivism debate, I argue that temporal predictivism is indeed supported, although in ways not previously appreciated. On the basis of this case, I argue for a form of so-called symptomatic predictivism according to which temporally novel predictions carry more confirmational weight only insofar as they reveal the theory's presumed coherence of facts as real.

Hierarchical Nanogaps within Bioscaffold Arrays as a High-Performance SERS Substrate for Animal Virus Biosensing

NARCIS (Netherlands)

Shao, Feng; Lu, Zhicheng; Liu, Chen; Han, Heyou; Chen, Kun; Li, Wentao; He, Qigai; Peng, Hui; Chen, Juanni

2014-01-01

A three-dimensional (3D) biomimetic SERS substrate with hierarchical nanogaps was formed on the bioscaffold arrays of cicada wings by one-step and reagents-free ion-sputtering techniques. This approach requires a minimal fabrication effort and cost and offers Ag nanoislands and Ag nanoflowers with

Uncertainties in container failure time predictions

International Nuclear Information System (INIS)

Williford, R.E.

1990-01-01

Stochastic variations in the local chemical environment of a geologic waste repository can cause corresponding variations in container corrosion rates and failure times, and thus in radionuclide release rates. This paper addresses how well the future variations in repository chemistries must be known in order to predict container failure times that are bounded by a finite time period within the repository lifetime. Preliminary results indicate that a 5000 year scatter in predicted container failure times requires that repository chemistries be known to within ±10% over the repository lifetime. These are small uncertainties compared to current estimates. 9 refs., 3 figs

Periodic Table of the Elements in the Perspective of Artificial Neural Networks

Science.gov (United States)

Lemes, Mauricio R.; Dal Pino, Arnaldo

2011-01-01

Although several chemical elements were not known by end of the 19th century, Mendeleev came up with an astonishing achievement, the periodic table of elements. He was not only able to predict the existence of (then) new elements, but also to provide accurate estimates of their chemical and physical properties. This is a profound example of the…

Real-time reservoir operation considering non-stationary inflow prediction

Science.gov (United States)

Zhao, J.; Xu, W.; Cai, X.; Wang, Z.

2011-12-01

Stationarity of inflow has been a basic assumption for reservoir operation rule design, which is now facing challenges due to climate change and human interferences. This paper proposes a modeling framework to incorporate non-stationary inflow prediction for optimizing the hedging operation rule of large reservoirs with multiple-year flow regulation capacity. A multi-stage optimization model is formulated and a solution algorithm based on the optimality conditions is developed to incorporate non-stationary annual inflow prediction through a rolling, dynamic framework that updates the prediction from period to period and adopt the updated prediction in reservoir operation decision. The prediction model is ARIMA(4,1,0), in which parameter 4 stands for the order of autoregressive, 1 represents a linear trend, and 0 is the order of moving average. The modeling framework and solution algorithm is applied to the Miyun reservoir in China, determining a yearly operating schedule during the period from 1996 to 2009, during which there was a significant declining trend of reservoir inflow. Different operation policy scenarios are modeled, including standard operation policy (SOP, matching the current demand as much as possible), hedging rule (i.e., leaving a certain amount of water for future to avoid large risk of water deficit) with forecast from ARIMA (HR-1), hedging (HR) with perfect forecast (HR-2 ). Compared to the results of these scenarios to that of the actual reservoir operation (AO), the utility of the reservoir operation under HR-1 is 3.0% lower than HR-2, but 3.7% higher than the AO and 14.4% higher than SOP. Note that the utility under AO is 10.3% higher than that under SOP, which shows that a certain level of hedging under some inflow prediction or forecast was used in the real-world operation. Moreover, the impacts of discount rate and forecast uncertainty level on the operation will be discussed.

The Asymmetric Predictive Effects of Investor Sentiment

DEFF Research Database (Denmark)

Lutz, Chandler

investors only act as corrective force during certain time periods. We also show that our index predicts implied volatility, media pessimism, and mutual fund flows. Overall, our findings are consistent with both the theories and anecdotal accounts of investor sentiment in the stock market....

Are we ready to predict late effects?

DEFF Research Database (Denmark)

Salz, Talya; Baxi, Shrujal S; Raghunathan, Nirupa

2015-01-01

BACKGROUND: After completing treatment for cancer, survivors may experience late effects: consequences of treatment that persist or arise after a latent period. PURPOSE: To identify and describe all models that predict the risk of late effects and could be used in clinical practice. DATA SOURCES:...

The dividend-price ratio does predict dividend growth: International evidence

DEFF Research Database (Denmark)

Engsted, Tom; Pedersen, Thomas Quistgaard

Unpredictable dividend growth by the dividend-price ratio is considered a 'stylized fact' in post war US data. Using long-term data, covering more than 80 years from the US and three European countries, we revisit this stylized fact, and we also report results on return predictability. We find...... similar to those for the US. For Sweden and Denmark we find no evidence of return predictability, but strong evidence of predictable dividend growth in the 'right' direction on both short and long horizons and over both the full sample periods and the post war period. We also document that implied long......-horizon coefficients from VAR's often differ substantially from direct estimates in multi-year regres- sions. Throughout, we report both standard asymptotic tests and simulated small- sample tests and, following Cochrane (2008), we investigate the joint distribution of dividend-price ratio coefficients in return...

Directional bending wave propagation in periodically perforated plates

DEFF Research Database (Denmark)

Andreassen, Erik; Manktelow, Kevin; Ruzzene, Massimo

2015-01-01

We report on the investigation of wave propagation in a periodically perforated plate. A unit cell with double-C perforations is selected as a test article suitable to investigate two-dimensional dispersion characteristics, group velocities, and internal resonances. A numerical model, formulated...... using Mindlin plate elements, is developed to predict relevant wave characteristics such as dispersion, and group velocity variation as a function of frequency and direction of propagation. Experimental tests are conducted through a scanning laser vibrometer, which provides full wave field information...... for the design of phononic waveguides with directional and internal resonant characteristics....

Next Place Prediction Based on Spatiotemporal Pattern Mining of Mobile Device Logs

Directory of Open Access Journals (Sweden)

Sungjun Lee

2016-01-01

Full Text Available Due to the recent explosive growth of location-aware services based on mobile devices, predicting the next places of a user is of increasing importance to enable proactive information services. In this paper, we introduce a data-driven framework that aims to predict the user’s next places using his/her past visiting patterns analyzed from mobile device logs. Specifically, the notion of the spatiotemporal-periodic (STP pattern is proposed to capture the visits with spatiotemporal periodicity by focusing on a detail level of location for each individual. Subsequently, we present algorithms that extract the STP patterns from a user’s past visiting behaviors and predict the next places based on the patterns. The experiment results obtained by using a real-world dataset show that the proposed methods are more effective in predicting the user’s next places than the previous approaches considered in most cases.

Solar g-modes? Comparison of detected asymptotic g-mode frequencies with solar model predictions

Science.gov (United States)

Wood, Suzannah Rebecca; Guzik, Joyce Ann; Mussack, Katie; Bradley, Paul A.

2018-06-01

After many years of searching for solar gravity modes, Fossat et al. (2017) reported detection of the nearly equally spaced high-order g-modes periods using a 15-year time series of GOLF data from the SOHO spacecraft. Here we report progress towards and challenges associated with calculating and comparing g-mode period predictions for several previously published standard solar models using various abundance mixtures and opacities, as well as the predictions for some non-standard models incorporating early mass loss, and compare with the periods reported by Fossat et al (2017). Additionally, we have a side-by-side comparison of results of different stellar pulsation codes for calculating g-mode predictions. These comparisons will allow for testing of nonstandard physics input that affect the core, including an early more massive Sun and dynamic electron screening.

Prediction skill of rainstorm events over India in the TIGGE weather prediction models

Science.gov (United States)

Karuna Sagar, S.; Rajeevan, M.; Vijaya Bhaskara Rao, S.; Mitra, A. K.

2017-12-01

Extreme rainfall events pose a serious threat of leading to severe floods in many countries worldwide. Therefore, advance prediction of its occurrence and spatial distribution is very essential. In this paper, an analysis has been made to assess the skill of numerical weather prediction models in predicting rainstorms over India. Using gridded daily rainfall data set and objective criteria, 15 rainstorms were identified during the monsoon season (June to September). The analysis was made using three TIGGE (THe Observing System Research and Predictability Experiment (THORPEX) Interactive Grand Global Ensemble) models. The models considered are the European Centre for Medium-Range Weather Forecasts (ECMWF), National Centre for Environmental Prediction (NCEP) and the UK Met Office (UKMO). Verification of the TIGGE models for 43 observed rainstorm days from 15 rainstorm events has been made for the period 2007-2015. The comparison reveals that rainstorm events are predictable up to 5 days in advance, however with a bias in spatial distribution and intensity. The statistical parameters like mean error (ME) or Bias, root mean square error (RMSE) and correlation coefficient (CC) have been computed over the rainstorm region using the multi-model ensemble (MME) mean. The study reveals that the spread is large in ECMWF and UKMO followed by the NCEP model. Though the ensemble spread is quite small in NCEP, the ensemble member averages are not well predicted. The rank histograms suggest that the forecasts are under prediction. The modified Contiguous Rain Area (CRA) technique was used to verify the spatial as well as the quantitative skill of the TIGGE models. Overall, the contribution from the displacement and pattern errors to the total RMSE is found to be more in magnitude. The volume error increases from 24 hr forecast to 48 hr forecast in all the three models.

Development and application of a statistical methodology to evaluate the predictive accuracy of building energy baseline models

Energy Technology Data Exchange (ETDEWEB)

Granderson, Jessica [Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States). Energy Technologies Area Div.; Price, Phillip N. [Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States). Energy Technologies Area Div.

2014-03-01

This paper documents the development and application of a general statistical methodology to assess the accuracy of baseline energy models, focusing on its application to Measurement and Verification (M&V) of whole-­building energy savings. The methodology complements the principles addressed in resources such as ASHRAE Guideline 14 and the International Performance Measurement and Verification Protocol. It requires fitting a baseline model to data from a ``training period’’ and using the model to predict total electricity consumption during a subsequent ``prediction period.’’ We illustrate the methodology by evaluating five baseline models using data from 29 buildings. The training period and prediction period were varied, and model predictions of daily, weekly, and monthly energy consumption were compared to meter data to determine model accuracy. Several metrics were used to characterize the accuracy of the predictions, and in some cases the best-­performing model as judged by one metric was not the best performer when judged by another metric.

Periodicity analysis of tourist arrivals to Banda Aceh using smoothing SARIMA approach

Science.gov (United States)

Miftahuddin, Helida, Desri; Sofyan, Hizir

2017-11-01

Forecasting the number of tourist arrivals who enters a region is needed for tourism businesses, economic and industrial policies, so that the statistical modeling needs to be conducted. Banda Aceh is the capital of Aceh province more economic activity is driven by the services sector, one of which is the tourism sector. Therefore, the prediction of the number of tourist arrivals is needed to develop further policies. The identification results indicate that the data arrival of foreign tourists to Banda Aceh to contain the trend and seasonal nature. Allegedly, the number of arrivals is influenced by external factors, such as economics, politics, and the holiday season caused the structural break in the data. Trend patterns are detected by using polynomial regression with quadratic and cubic approaches, while seasonal is detected by a periodic regression polynomial with quadratic and cubic approach. To model the data that has seasonal effects, one of the statistical methods that can be used is SARIMA (Seasonal Autoregressive Integrated Moving Average). The results showed that the smoothing, a method to detect the trend pattern is cubic polynomial regression approach, with the modified model and the multiplicative periodicity of 12 months. The AIC value obtained was 70.52. While the method for detecting the seasonal pattern is a periodic regression polynomial cubic approach, with the modified model and the multiplicative periodicity of 12 months. The AIC value obtained was 73.37. Furthermore, the best model to predict the number of foreign tourist arrivals to Banda Aceh in 2017 to 2018 is SARIMA (0,1,1)(1,1,0) with MAPE is 26%.

The 136 MHz/400 MHz earth station antenna-noise temperature prediction program documentation for RAE-B

Science.gov (United States)

Chin, M.

1972-01-01

A simulation study to determine the 136 MHz and 400 MHz noise temperature of the ground network antennas which will track the RAE-B satellite during data transmission periods is described. Since the noise temperature of the antenna effectively sets the signal-to-noise ratio (SNR) of the received signal, a knowledge of SNR will be helpful in locating the optimum time windows for data transmission during low-noise periods. Antenna-noise temperatures at 136 MHz and 400 MHz will be predicted for selected earth-based ground stations which will support RAE-B. The antenna-noise temperature predictions will include the effects of galactic-brightness temperature, the sun, and the brightest radio stars. Predictions will cover the ten-month period from March 1, 1973 to December 31, 1973. The RAE-B mission will be expecially susceptible to SNR degradation during the two eclipses of the Sun occurring in this period.

Foldover, quasi-periodicity, spin-wave instabilities in ultra-thin films subject to RF fields

Energy Technology Data Exchange (ETDEWEB)

D' Aquino, M. [Department of Electrical Engineering, University of Napoli ' Federico II' , Naples I-80125 (Italy)]. E-mail: mdaquino@unina.it; Bertotti, G. [Istituto Nazionale di Ricerca Metrologica (INRIM), I-10135 Turin (Italy); Serpico, C. [Department of Electrical Engineering, University of Napoli ' Federico II' , Naples I-80125 (Italy); Mayergoyz, I.D. [ECE Department and UMIACS, University of Maryland, College Park, MD 20742 (United States); Bonin, R. [Istituto Nazionale di Ricerca Metrologica (INRIM), I-10135 Turin (Italy); Guida, G. [Department of Electrical Engineering, University of Napoli ' Federico II' , Naples I-80125 (Italy)

2007-09-15

We study magnetization dynamics in a uniaxial ultra-thin ferromagnetic disk subject to spatially uniform microwave external fields. The rotational invariance of the system is such that the only admissible spatially uniform steady states are periodic (P-modes) and quasi-periodic (Q-modes) modes. The stability of P-modes versus spatially uniform and nonuniform perturbations is studied by using spin-wave analysis and the instability diagram for all possible P-modes is computed. The predictions of the spin-wave analysis are compared with micromagnetic simulations.

Particles in a magnetic field and plasma analogies: doubly periodic boundary conditions

International Nuclear Information System (INIS)

Forrester, P J

2006-01-01

The N-particle free fermion state for quantum particles in the plane subject to a perpendicular magnetic field, and with doubly periodic boundary conditions, is written in a product form. The absolute value of this is used to formulate an exactly solvable one-component plasma model and further motivates the formulation of an exactly solvable two-species Coulomb gas. The large N expansion of the free energy of both these models exhibits the same O(1) term. On the basis of a relationship to the Gaussian free field, this term is predicted to be universal for conductive Coulomb systems in doubly periodic boundary conditions

Aharonov-Bohm oscillations with fractional period in a multichannel Wigner crystal ring

International Nuclear Information System (INIS)

Krive, I.V.; Krokhin, A.A.

1997-01-01

We study the persistent current in a quasi 1D ring with strongly correlated electrons forming a multichannel Wigner crystal (WC). The influence of the Coulomb interaction manifests itself only in the presence of external scatterers that pin the WC. Two regimes of weak and strong pinning are considered. For strong pinning we predict the Aharonov-Bohm oscillations with fractional period. Fractionalization is due to the interchannel coupling in the process of quantum tunneling of the WC. The fractional period depends on the filling of the channels and may serve as an indicator of non-Fermi-liquid behaviour of interacting electrons in quasi 1D rings. (author). 20 refs

On a boom and bust year class cycle

NARCIS (Netherlands)

Diekmann, Odo; Davydova, Natalia; van Gils, Stephanus A.

2005-01-01

We motivate and describe a class of nonlinear Leslie matrix models for semelparous populations, like cicadas and Pacific salmon. We then focus on a Cushing-inspired special case for which one can show rigorously that a heteroclinic boundary cycle exists and attracts nearby orbits for a certain range

Alternatieven voor neonicotinoïden in de sierteelt onder glas : bestrijding van tabakswittevlieg en bladluis in kuipplanten en perkgoed

NARCIS (Netherlands)

Messelink, Gerben; Vijverberg, Roland; Bloemhard, Chantal; Leman, Ada

2016-01-01

The control of phloem feeding insects such as aphids, whiteflies, cicadas, mealybugs, scales and plant feeding bugs in greenhouse crops still largely depends on the use of neonicotinoids. However, the increased found negative effects on the environment will soon results in a total ban on the use of

The Recalibrated Sunspot Number: Impact on Solar Cycle Predictions

Science.gov (United States)

Clette, F.; Lefevre, L.

2017-12-01

Recently and for the first time since their creation, the sunspot number and group number series were entirely revisited and a first fully recalibrated version was officially released in July 2015 by the World Data Center SILSO (Brussels). Those reference long-term series are widely used as input data or as a calibration reference by various solar cycle prediction methods. Therefore, past predictions may now need to be redone using the new sunspot series, and methods already used for predicting cycle 24 will require adaptations before attempting predictions of the next cycles.In order to clarify the nature of the applied changes, we describe the different corrections applied to the sunspot and group number series, which affect extended time periods and can reach up to 40%. While some changes simply involve constant scale factors, other corrections vary with time or follow the solar cycle modulation. Depending on the prediction method and on the selected time interval, this can lead to different responses and biases. Moreover, together with the new series, standard error estimates are also progressively added to the new sunspot numbers, which may help deriving more accurate uncertainties for predicted activity indices. We conclude on the new round of recalibration that is now undertaken in the framework of a broad multi-team collaboration articulated around upcoming ISSI workshops. We outline the future corrections that can still be expected in the future, as part of a permanent upgrading process and quality control. From now on, future sunspot-based predictive models should thus be made more adaptable, and regular updates of predictions should become common practice in order to track periodic upgrades of the sunspot number series, just like it is done when using other modern solar observational series.

Positive periodic solutions of delayed periodic Lotka-Volterra systems

International Nuclear Information System (INIS)

Lin Wei; Chen Tianping

2005-01-01

In this Letter, for a general class of delayed periodic Lotka-Volterra systems, we prove some new results on the existence of positive periodic solutions by Schauder's fixed point theorem. The global asymptotical stability of positive periodic solutions is discussed further, and conditions for exponential convergence are given. The conditions we obtained are weaker than the previously known ones and can be easily reduced to several special cases

Depth of source from long period P-waves

International Nuclear Information System (INIS)

Roy, Falguni

1986-01-01

Short period (SP) seismograms are much better than long period (LP) seismograms to get the time resolution needed for the focal depth estimation. However, complex scattering effects due to crustal inhomogeneities and also the multi-pathing of signals usually complicate the short period records. On the other hand the seismograms from long period signals demonstrate clear coherent body waves. Therefore, for intermediate depths (15-60 km) prediction error filtering of LP signals will be useful for identifying the depth phases. Such a study has been carried out in the first part of this report. In a group of 7 events, the p p phases have been extracted from LP signals and the depths so estimated compared well with the published data. For explosions at shallow depths (depth p phases will tend to cancel each other in LP seismograms. As the source depth increases, the cancellation becomes less effective. This feature can be used for the identification of an event as well as for getting an estimate of the source depth. This phenomenon can be successfully exploited for identifying multiple explosions, because at teleseismic distances (Δ > 30 o ) no LP (around 20s period) P waves will be seen in the seismogram due to such events whereas relatively strong SP signals and LP Rayleigh waves will be observed. This phenomenon has been studied for 16 events. For three of these events having m b as high as 6.1 and presumed to be underground explosions, one could not see any P wave on remaining 13 events (which were classified as earthquakes), it was possible to set a threshold value of m b above which an earthquake should produce LP P-wave signals at a given distance. (author)

Predicting rates of inbreeding in populations undergoing selection

NARCIS (Netherlands)

Woolliams, J.A.; Bijma, P.

2000-01-01

Tractable forms of predicting rates of inbreeding (F) in selected populations with general indices, nonrandom mating, and overlapping generations were developed, with the principal results assuming a period of equilibrium in the selection process. An existing theorem concerning the relationship

A Bimodel Algorithm with Data-Divider to Predict Stock Index

Directory of Open Access Journals (Sweden)

Zhaoyue Wang

2018-01-01

Full Text Available There is not yet reliable software for stock prediction, because most experts of this area have been trying to predict an exact stock index. Considering that the fluctuation of a stock index usually is no more than 1% in a day, the error between the forecasted and the actual values should be no more than 0.5%. It is too difficult to realize. However, forecasting whether a stock index will rise or fall does not need to be so exact a numerical value. A few scholars noted the fact, but their systems do not yet work very well because different periods of a stock have different inherent laws. So, we should not depend on a single model or a set of parameters to solve the problem. In this paper, we developed a data-divider to divide a set of historical stock data into two parts according to rising period and falling period, training, respectively, two neural networks optimized by a GA. Above all, the data-divider enables us to avoid the most difficult problem, the effect of unexpected news, which could hardly be predicted. Experiments show that the accuracy of our method increases 20% compared to those of traditional methods.

APPRAISAL OF THE SNAP MODEL FOR PREDICTING NITROGEN MINERALIZATION IN TROPICAL SOILS UNDER EUCALYPTUS

Directory of Open Access Journals (Sweden)

Philip James Smethurst

2015-04-01

Full Text Available The Soil Nitrogen Availability Predictor (SNAP model predicts daily and annual rates of net N mineralization (NNM based on daily weather measurements, daily predictions of soil water and soil temperature, and on temperature and moisture modifiers obtained during aerobic incubation (basal rate. The model was based on in situ measurements of NNM in Australian soils under temperate climate. The purpose of this study was to assess this model for use in tropical soils under eucalyptus plantations in São Paulo State, Brazil. Based on field incubations for one month in three, NNM rates were measured at 11 sites (0-20 cm layer for 21 months. The basal rate was determined in in situ incubations during moist and warm periods (January to March. Annual rates of 150-350 kg ha-1 yr-1 NNM predicted by the SNAP model were reasonably accurate (R2 = 0.84. In other periods, at lower moisture and temperature, NNM rates were overestimated. Therefore, if used carefully, the model can provide adequate predictions of annual NNM and may be useful in practical applications. For NNM predictions for shorter periods than a year or under suboptimal incubation conditions, the temperature and moisture modifiers need to be recalibrated for tropical conditions.

Periodicities observed on solar flux index (F10.7) during geomagnetic disturbances

Science.gov (United States)

Adhikari, B.; Narayan, C.; Chhatkuli, D. N.

2017-12-01

Solar activities change within the period of 11 years. Sometimes the greatest event occurs in the period of solar maxima and the lowest activity occurs in the period of solar minimum. During the time period of solar activity sunspots number will vary. A 10.7 cm solar flux measurement is a determination of the strength of solar radio emission. The solar flux index is more often used for the prediction and monitoring of the solar activity. This study mainly focused on the variation on solar flux index and amount of electromagnetic wave in the atmosphere. Both seasonal and yearly variation on solar F10.7 index. We also analyzed the dataset obatained from riometer.Both instruments show seasonal and yearly variations. We also observed the solar cycle dependence on solar flux index and found a strong dependence on solar activity. Results also show that solar intensities higher during the rising phase of solar cycle. We also observed periodicities on solar flux index using wavelet analysis. Through this analysis, it was found that the power intensities of solar flux index show a high spectral variability.

Potential Predictability and Prediction Skill for Southern Peru Summertime Rainfall

Science.gov (United States)

WU, S.; Notaro, M.; Vavrus, S. J.; Mortensen, E.; Block, P. J.; Montgomery, R. J.; De Pierola, J. N.; Sanchez, C.

2016-12-01

The central Andes receive over 50% of annual climatological rainfall during the short period of January-March. This summertime rainfall exhibits strong interannual and decadal variability, including severe drought events that incur devastating societal impacts and cause agricultural communities and mining facilities to compete for limited water resources. An improved seasonal prediction skill of summertime rainfall would aid in water resource planning and allocation across the water-limited southern Peru. While various underlying mechanisms have been proposed by past studies for the drivers of interannual variability in summertime rainfall across southern Peru, such as the El Niño-Southern Oscillation (ENSO), Madden Julian Oscillation (MJO), and extratropical forcings, operational forecasts continue to be largely based on rudimentary ENSO-based indices, such as NINO3.4, justifying further exploration of predictive skill. In order to bridge this gap between the understanding of driving mechanisms and the operational forecast, we performed systematic studies on the predictability and prediction skill of southern Peru summertime rainfall by constructing statistical forecast models using best available weather station and reanalysis datasets. At first, by assuming the first two empirical orthogonal functions (EOFs) of summertime rainfall are predictable, the potential predictability skill was evaluated for southern Peru. Then, we constructed a simple regression model, based on the time series of tropical Pacific sea-surface temperatures (SSTs), and a more advanced Linear Inverse Model (LIM), based on the EOFs of tropical ocean SSTs and large-scale atmosphere variables from reanalysis. Our results show that the LIM model consistently outperforms the more rudimentary regression models on the forecast skill of domain averaged precipitation index and individual station indices. The improvement of forecast correlation skill ranges from 10% to over 200% for different

Psychometric properties of the postpartum depression screening scale beyond the postpartum period.

Science.gov (United States)

Vogeli, Jo M; Hooker, Stephanie A; Everhart, Kevin D; Kaplan, Peter S

2018-04-01

Accurate postpartum depression screening measures are needed to identify mothers with depressive symptoms both in the postpartum period and beyond. Because it had not been tested beyond the immediate postpartum period, the reliability and validity of the Postpartum Depression Screening Scale (PDSS) and its sensitivity, specificity, and predictive value for diagnoses of major depressive disorder (MDD) were assessed in a diverse community sample of 238 mothers of 4- to 15-month-old infants. Mothers (N = 238; M age = 30.2, SD = 5.3) attended a lab session and completed the PDSS, the Beck Depression Inventory-II (BDI-II), and a structured clinical interview (SCID) to diagnose MDD. The reliability, validity, specificity, sensitivity, and predictive value of the PDSS to identify maternal depression were assessed. Confirmatory factor analysis supported the construct validity of five but not seven content subscales. The PDSS total and subscale scores demonstrated acceptable to high reliability (α = 0.68-0.95). Discriminant function analysis showed the scale correctly provided diagnostic classification at a rate higher than chance alone. Sensitivity and specificity for major depressive disorder (MDD) diagnosis were good and comparable to those of the BDI-II. Even in mothers who were somewhat more diverse and had older infants than those in the original normative study, the PDSS appears to be a psychometrically sound screener for identifying depressed mothers in the 15 months after childbirth. © 2018 Wiley Periodicals, Inc.

Ambient Noise Green's Function Simulation of Long-Period Ground Motions for Reverse Faulting

Science.gov (United States)

Miyake, H.; Beroza, G. C.

2009-12-01

Long-time correlation of ambient seismic noise has been demonstrated as a useful tool for strong ground motion prediction [Prieto and Beroza, 2008]. An important advantage of ambient noise Green's functions is that they can be used for ground motion simulation without resorting to either complex 3-D velocity structure to develop theoretical Green’s functions, or aftershock records for empirical Green’s function analysis. The station-to-station approach inherent to ambient noise Green’s functions imposes some limits to its application, since they are band-limited, applied at the surface, and for a single force. We explore the applicability of this method to strong motion prediction using the 2007 Chuetsu-oki, Japan, earthquake (Mw 6.6, depth = 9 km), which excited long-period ground motions in and around the Kanto basin almost 200 km from the epicenter. We test the performance of ambient noise Green's function for long-period ground motion simulation. We use three components of F-net broadband data at KZK station, which is located near the source region, as a virtual source, and three components of six F-net stations in and around the Kanto basin to calculate the response. An advantage to applying this approach in Japan is that ambient-noise sources are active in diverse directions. The dominant period of the ambient noise for the F-net datasets is mostly 7 s over the year, and amplitudes are largest in winter. This period matches the dominant periods of the Kanto and Niigata basins. For the 9 components of the ambient noise Green’s functions, we have confirmed long-period components corresponding to Love wave and Rayleigh waves that can be used for simulation of the 2007 Chuetsu-oki earthquake. The relative amplitudes, phases, and durations of the ambient noise Green’s functions at the F-net stations in and around the Kanto basin respect to F-net KZK station are fairly well matched with those of the observed ground motions for the 2007 Chuetsu

High-power millimeter-wave mode converters in overmoded circular waveguides using periodic wall perturbations

International Nuclear Information System (INIS)

Thumm, M.

1984-07-01

This work reports on measurements and calculations (coupled mode equations) on the conversion of circular elecric TEsub(0n) gyrotron mode compositions (TE 01 to TE 04 ) at 28 and 70 GHz to the linearly polarized TE 11 mode by means of a mode converter system using periodic waveguide wall perturbations. Mode transducers with axisymmetric radius perturbations transform the TEsub(0n) gyrotron mode mixture to the more convenient TE 01 mode for long-distance transmission through overmoded waveguides. Proper matching of the phase differences between the TEsub(0n) modes and of lengths and perturbation amplitudes of the several converter sections is required. A mode converter with constant diameter and periodically perturbed curvature transfers the unpolarized TE 01 mode into the TE 11 mode which produces an almost linearly polarized millimeter-wave beam needed for efficient electron cyclotron heating (ECRH) of plasmas in thermonuclear fusion devices. The experimentally determined TEsub(0n)-to-TE 01 conversion efficiency is (98+-1)% at 28 and 70 GHz (99% predicted) while the TE 01 -to-TE 11 converter has a (96+-2)% conversion efficiency at 28 GHz (95% predicted) and (94+-2)% at 70 GHz (93% predicted); ohmic losses are included. (orig./AH)

Time-varying predictability in crude-oil markets: the case of GCC countries

International Nuclear Information System (INIS)

El Hedi Arouri, Mohamed; Thanh Huong Dinh; Duc Khuong Nguyen

2010-01-01

This paper uses a time-varying parameter model with generalized autoregressive conditional heteroscedasticity effects to examine the dynamic behavior of crude-oil prices for the period February 7, 1997-January 8, 2010. Using data from four countries of the Gulf Cooperation Council, we find evidence of short-term predictability in oil-price changes over time, except for several short sub-periods. However, the hypothesis of convergence towards weak-form informational efficiency is rejected for all markets. In addition, we explore the possibility of structural breaks in the time-paths of the estimated predictability indices and detect only one breakpoint, for the oil markets in Qatar and the United Arab Emirates. Our empirical results therefore call for new empirical research to further gauge the predictability characteristics and the determinants of oil-price changes.

Detection of hot fallout on Taiwan in the period 1971-1975

International Nuclear Information System (INIS)

Weng, P.S.; Chu, T.C.; Hsu, C.N.; Su, S.J.

1977-01-01

The observation of fallout during the period of 1971-1975 is presented. Relatively high activity from nuclear tests at Lop Nor off mainland China was detected twice in this period. The gamma-ray spectrum of the hot fallout after the 11th nuclear test is given. The high activity peaks in the figures included are indicated with corresponding dates and sequence number of the tests for easy identification and comparison. The calibration of thermoluminescent dosimeters for the low exposure rates is presented. The gross beta activities are much more likely to build up in milk and surface water samples. Their intensity and duration are more significant than other foodstuff samples, and the timing of their appearance is more predictable. (author)

From Periodic Properties to a Periodic Table Arrangement

Science.gov (United States)

Besalú, Emili

2013-01-01

A periodic table is constructed from the consideration of periodic properties and the application of the principal components analysis technique. This procedure is useful for objects classification and data reduction and has been used in the field of chemistry for many applications, such as lanthanides, molecules, or conformers classification.…

Modeled and Measured Dynamics of a Composite Beam with Periodically Varying Foam Core

Science.gov (United States)

Cabell, Randolph H.; Cano, Roberto J.; Schiller, Noah H.; Roberts Gary D.

2012-01-01

The dynamics of a sandwich beam with carbon fiber composite facesheets and foam core with periodic variations in material properties are studied. The purpose of the study is to compare finite element predictions with experimental measurements on fabricated beam specimens. For the study, three beams were fabricated: one with a compliant foam core, a second with a stiffer core, and a third with the two cores alternating down the length of the beam to create a periodic variation in properties. This periodic variation produces a bandgap in the frequency domain where vibrational energy does not readily propagate down the length of the beam. Mode shapes and natural frequencies are compared, as well as frequency responses from point force input to velocity response at the opposite end of the beam.

Getting the Most out of Macroeconomic Information for Predicting Stock Returns and Volatility

NARCIS (Netherlands)

C. Cakmakli (Cem); D.J.C. van Dijk (Dick)

2010-01-01

textabstractThis paper documents that factors extracted from a large set of macroeconomic variables bear useful information for predicting monthly US excess stock returns and volatility over the period 1980-2005. Factor-augmented predictive regression models improve upon both benchmark models that

Getting the most out of macroeconomic information for predicting stock returns and volatility

NARCIS (Netherlands)

Cakmakli, C.; van Dijk, D.

2011-01-01

This paper documents that factors extracted from a large set of macroeconomic variables bear useful information for predicting monthly US excess stock returns and volatility over the period 1980-2005. Factor-augmented predictive regression models improve upon both benchmark models that only include

Definition dependent properties of the cortical silent period in upper-extremity muscles, a methodological study

NARCIS (Netherlands)

Kuijk, A.A. van; Bakker, C.D.; Hendriks, J.C.M.; Geurts, A.C.; Stegeman, D.F.; Pasman, J.W.

2014-01-01

BACKGROUND: To explore if stimulus-response (S-R) characteristics of the silent period (SP) after transcranial magnetic stimulation (TMS) are affected by changing the SP definition and by changing data presentation in healthy individuals. This information would be clinically relevant to predict

Definition dependent properties of the cortical silent period in upper-extremity muscles, a methodological study

NARCIS (Netherlands)

van Kuijk, A.A.; Bakker, C,; Hendriks, J.J.A.; Geurts, A.H.; Stegeman, D.F.; Pasman, J.W.

2014-01-01

Background: To explore if stimulus-response (S-R) characteristics of the silent period (SP) after transcranial magnetic stimulation (TMS) are affected by changing the SP definition and by changing data presentation in healthy individuals. This information would be clinically relevant to predict

Life history theory predicts fish assemblage response to hydrologic regimes.

Science.gov (United States)

Mims, Meryl C; Olden, Julian D

2012-01-01

The hydrologic regime is regarded as the primary driver of freshwater ecosystems, structuring the physical habitat template, providing connectivity, framing biotic interactions, and ultimately selecting for specific life histories of aquatic organisms. In the present study, we tested ecological theory predicting directional relationships between major dimensions of the flow regime and life history composition of fish assemblages in perennial free-flowing rivers throughout the continental United States. Using long-term discharge records and fish trait and survey data for 109 stream locations, we found that 11 out of 18 relationships (61%) tested between the three life history strategies (opportunistic, periodic, and equilibrium) and six hydrologic metrics (two each describing flow variability, predictability, and seasonality) were statistically significant (P history strategies, with 82% of all significant relationships observed supporting predictions from life history theory. Specifically, we found that (1) opportunistic strategists were positively related to measures of flow variability and negatively related to predictability and seasonality, (2) periodic strategists were positively related to high flow seasonality and negatively related to variability, and (3) the equilibrium strategists were negatively related to flow variability and positively related to predictability. Our study provides important empirical evidence illustrating the value of using life history theory to understand both the patterns and processes by which fish assemblage structure is shaped by adaptation to natural regimes of variability, predictability, and seasonality of critical flow events over broad biogeographic scales.

Accurate Multisteps Traffic Flow Prediction Based on SVM

Directory of Open Access Journals (Sweden)

Zhang Mingheng

2013-01-01

Full Text Available Accurate traffic flow prediction is prerequisite and important for realizing intelligent traffic control and guidance, and it is also the objective requirement for intelligent traffic management. Due to the strong nonlinear, stochastic, time-varying characteristics of urban transport system, artificial intelligence methods such as support vector machine (SVM are now receiving more and more attentions in this research field. Compared with the traditional single-step prediction method, the multisteps prediction has the ability that can predict the traffic state trends over a certain period in the future. From the perspective of dynamic decision, it is far important than the current traffic condition obtained. Thus, in this paper, an accurate multi-steps traffic flow prediction model based on SVM was proposed. In which, the input vectors were comprised of actual traffic volume and four different types of input vectors were compared to verify their prediction performance with each other. Finally, the model was verified with actual data in the empirical analysis phase and the test results showed that the proposed SVM model had a good ability for traffic flow prediction and the SVM-HPT model outperformed the other three models for prediction.

Prediction method for cavitation erosion based on measurement of bubble collapse impact loads

International Nuclear Information System (INIS)

Hattori, S; Hirose, T; Sugiyama, K

2009-01-01

The prediction of cavitation erosion rates is important in order to evaluate the exact life of components. The measurement of impact loads in bubble collapses helps to predict the life under cavitation erosion. In this study, we carried out erosion tests and the measurements of impact loads in bubble collapses with a vibratory apparatus. We evaluated the incubation period based on a cumulative damage rule by measuring the impact loads of cavitation acting on the specimen surface and by using the 'constant impact load - number of impact loads curve' similar to the modified Miner's rule which is employed for fatigue life prediction. We found that the parameter Σ(F i α xn i ) (F i : impact load, n i : number of impacts and α: constant) is suitable for the evaluation of the erosion life. Moreover, we propose a new method that can predict the incubation period under various cavitation conditions.

Weakly nonlinear dispersion and stop-band effects for periodic structures

DEFF Research Database (Denmark)

Sorokin, Vladislav; Thomsen, Jon Juel

of frequency band-gaps, i.e. frequency ranges in which elastic waves cannot propagate. Most existing analytical methods in the field are based on Floquet theory [1]; e.g. this holds for the classical Hill’s method of infinite determinants [1,2], and themethod of space-harmonics [3]. However, application...... of these methods for studying nonlinear problems isimpossible or cumbersome, since Floquet theory is applicable only for linear systems. Thus the nonlinear effects for periodic structures are not yet fully uncovered, while at the same time applications may demand effects of nonlinearity on structural response...... to be accounted for.The paper deals with analytically predicting dynamic response for nonlinear elastic structures with a continuous periodic variation in structural properties. Specifically, for a Bernoulli-Euler beam with aspatially continuous modulation of structural properties in the axial direction...

Predicting nonstationary flood frequencies: Evidence supports an updated stationarity thesis in the United States

Science.gov (United States)

Luke, Adam; Vrugt, Jasper A.; AghaKouchak, Amir; Matthew, Richard; Sanders, Brett F.

2017-07-01

Nonstationary extreme value analysis (NEVA) can improve the statistical representation of observed flood peak distributions compared to stationary (ST) analysis, but management of flood risk relies on predictions of out-of-sample distributions for which NEVA has not been comprehensively evaluated. In this study, we apply split-sample testing to 1250 annual maximum discharge records in the United States and compare the predictive capabilities of NEVA relative to ST extreme value analysis using a log-Pearson Type III (LPIII) distribution. The parameters of the LPIII distribution in the ST and nonstationary (NS) models are estimated from the first half of each record using Bayesian inference. The second half of each record is reserved to evaluate the predictions under the ST and NS models. The NS model is applied for prediction by (1) extrapolating the trend of the NS model parameters throughout the evaluation period and (2) using the NS model parameter values at the end of the fitting period to predict with an updated ST model (uST). Our analysis shows that the ST predictions are preferred, overall. NS model parameter extrapolation is rarely preferred. However, if fitting period discharges are influenced by physical changes in the watershed, for example from anthropogenic activity, the uST model is strongly preferred relative to ST and NS predictions. The uST model is therefore recommended for evaluation of current flood risk in watersheds that have undergone physical changes. Supporting information includes a MATLAB® program that estimates the (ST/NS/uST) LPIII parameters from annual peak discharge data through Bayesian inference.

Overview of the first HyMeX special observation period over Croatia

Science.gov (United States)

Ivančan-Picek, Branka; Tudor, Martina; Horvath, Kristian; Stanešić, Antonio; Ivatek-Šahdan, Stjepan

2016-12-01

The HYdrological cycle in the Mediterranean EXperiment (HyMeX) is intended to improve the capabilities of predicting high-impact weather events. Within its framework, the aim of the first special observation period (SOP1), 5 September to 6 November 2012, was to study heavy precipitation events and flash floods. Here, we present high-impact weather events over Croatia that occurred during SOP1. Particular attention is given to eight intense observation periods (IOPs), during which high precipitation occurred over the eastern Adriatic and Dinaric Alps. During the entire SOP1, the operational model forecasts generally well represented medium intensity precipitation, but heavy precipitation was frequently underestimated by the ALADIN model at an 8 km grid spacing and was overestimated at a higher resolution (2 km grid spacing). During IOP2, intensive rainfall occurred over a wider area around the city of Rijeka in the northern Adriatic. The short-range maximum rainfall totals were the largest ever recorded at the Rijeka station since the beginning of measurements in 1958. The rainfall amounts measured in intervals of 20, 30 and 40 min were exceptional, with return periods that exceeded a thousand, a few hundred and one hundred years, respectively. The operational precipitation forecast using the ALADIN model at an 8 km grid spacing provided guidance regarding the event but underestimated the rainfall intensity. An evaluation of numerical sensitivity experiments suggested that the forecast was slightly enhanced by improving the initial conditions through variational data assimilation. The operational non-hydrostatic run at a 2 km grid spacing using a configuration with the ALARO physics package further improved the forecast. This article highlights the need for an intensive observation period in the future over the Adriatic region to validate the simulated mechanisms and improve numerical weather predictions via data assimilation and model improvements in descriptions

Period adding cascades: experiment and modeling in air bubbling.

Science.gov (United States)

Pereira, Felipe Augusto Cardoso; Colli, Eduardo; Sartorelli, José Carlos

2012-03-01

Period adding cascades have been observed experimentally/numerically in the dynamics of neurons and pancreatic cells, lasers, electric circuits, chemical reactions, oceanic internal waves, and also in air bubbling. We show that the period adding cascades appearing in bubbling from a nozzle submerged in a viscous liquid can be reproduced by a simple model, based on some hydrodynamical principles, dealing with the time evolution of two variables, bubble position and pressure of the air chamber, through a system of differential equations with a rule of detachment based on force balance. The model further reduces to an iterating one-dimensional map giving the pressures at the detachments, where time between bubbles come out as an observable of the dynamics. The model has not only good agreement with experimental data, but is also able to predict the influence of the main parameters involved, like the length of the hose connecting the air supplier with the needle, the needle radius and the needle length.

Predicting Acute Exacerbations in Chronic Obstructive Pulmonary Disease.

Science.gov (United States)

Samp, Jennifer C; Joo, Min J; Schumock, Glen T; Calip, Gregory S; Pickard, A Simon; Lee, Todd A

2018-03-01

With increasing health care costs that have outpaced those of other industries, payers of health care are moving from a fee-for-service payment model to one in which reimbursement is tied to outcomes. Chronic obstructive pulmonary disease (COPD) is a disease where this payment model has been implemented by some payers, and COPD exacerbations are a quality metric that is used. Under an outcomes-based payment model, it is important for health systems to be able to identify patients at risk for poor outcomes so that they can target interventions to improve outcomes. To develop and evaluate predictive models that could be used to identify patients at high risk for COPD exacerbations. This study was retrospective and observational and included COPD patients treated with a bronchodilator-based combination therapy. We used health insurance claims data to obtain demographics, enrollment information, comorbidities, medication use, and health care resource utilization for each patient over a 6-month baseline period. Exacerbations were examined over a 6-month outcome period and included inpatient (primary discharge diagnosis for COPD), outpatient, and emergency department (outpatient/emergency department visits with a COPD diagnosis plus an acute prescription for an antibiotic or corticosteroid within 5 days) exacerbations. The cohort was split into training (75%) and validation (25%) sets. Within the training cohort, stepwise logistic regression models were created to evaluate risk of exacerbations based on factors measured during the baseline period. Models were evaluated using sensitivity, specificity, and positive and negative predictive values. The base model included all confounding or effect modifier covariates. Several other models were explored using different sets of observations and variables to determine the best predictive model. There were 478,772 patients included in the analytic sample, of which 40.5% had exacerbations during the outcome period. Patients with

A Theory for the Incubation Period Following a Stress Reduction During Creep

DEFF Research Database (Denmark)

Bilde-Sørensen, Jørgen

1978-01-01

incubation period is much shorter than the time needed to establish an equilibrium structure at the new lower stress. The dependence of dislocation line tension upon line length is taken into account; as a result of this, recovery rates are predicted to depend on stress to a power larger than three......A dislocation model is presented for the phenomena following a stress reduction during creep. It is suggested that an incubation period for the production of new mobile dislocations arises because attractive junctions on the verge of breaking just before the stress reduction are no longer so after...... the stress reduction. The breaking stress of the junctions must be lowered by climb movements in the surrounding network before the junctions can break and release new mobile dislocations. On the basis of these concepts, an expression is derived for the length of the incubation period. This theoretical...

Bounded and Periodic Solutions of Semilinear Impulsive Periodic System on Banach Spaces

Directory of Open Access Journals (Sweden)

Wei W

2008-01-01

Full Text Available Abstract A class of semilinear impulsive periodic system on Banach spaces is considered. First, we introduce the -periodic PC-mild solution of semilinear impulsive periodic system. By virtue of Gronwall lemma with impulse, the estimate on the PC-mild solutions is derived. The continuity and compactness of the new constructed Poincaré operator determined by impulsive evolution operator corresponding to homogenous linear impulsive periodic system are shown. This allows us to apply Horn's fixed-point theorem to prove the existence of -periodic PC-mild solutions when PC-mild solutions are ultimate bounded. This extends the study on periodic solutions of periodic system without impulse to periodic system with impulse on general Banach spaces. At last, an example is given for demonstration.

A study of modelling simplifications in ground vibration predictions for railway traffic at grade

Science.gov (United States)

Germonpré, M.; Degrande, G.; Lombaert, G.

2017-10-01

Accurate computational models are required to predict ground-borne vibration due to railway traffic. Such models generally require a substantial computational effort. Therefore, much research has focused on developing computationally efficient methods, by either exploiting the regularity of the problem geometry in the direction along the track or assuming a simplified track structure. This paper investigates the modelling errors caused by commonly made simplifications of the track geometry. A case study is presented investigating a ballasted track in an excavation. The soil underneath the ballast is stiffened by a lime treatment. First, periodic track models with different cross sections are analyzed, revealing that a prediction of the rail receptance only requires an accurate representation of the soil layering directly underneath the ballast. A much more detailed representation of the cross sectional geometry is required, however, to calculate vibration transfer from track to free field. Second, simplifications in the longitudinal track direction are investigated by comparing 2.5D and periodic track models. This comparison shows that the 2.5D model slightly overestimates the track stiffness, while the transfer functions between track and free field are well predicted. Using a 2.5D model to predict the response during a train passage leads to an overestimation of both train-track interaction forces and free field vibrations. A combined periodic/2.5D approach is therefore proposed in this paper. First, the dynamic axle loads are computed by solving the train-track interaction problem with a periodic model. Next, the vibration transfer to the free field is computed with a 2.5D model. This combined periodic/2.5D approach only introduces small modelling errors compared to an approach in which a periodic model is used in both steps, while significantly reducing the computational cost.

Mother-Child Affect and Emotion Socialization Processes across the Late Preschool Period: Predictions of Emerging Behaviour Problems

Science.gov (United States)

Newland, Rebecca P.; Crnic, Keith A.

2011-01-01

The current study examined concurrent and longitudinal relations between maternal negative affective behaviour and child negative emotional expression in preschool age children with (n=96) or without (n=126) an early developmental risk, as well as the predictions of later behaviour problems. Maternal negative affective behaviour, child…

Predictive rhythmic tapping to isochronous and tempo changing metronomes in the nonhuman primate.

Science.gov (United States)

Gámez, Jorge; Yc, Karyna; Ayala, Yaneri A; Dotov, Dobromir; Prado, Luis; Merchant, Hugo

2018-04-30

Beat entrainment is the ability to entrain one's movements to a perceived periodic stimulus, such as a metronome or a pulse in music. Humans have a capacity to predictively respond to a periodic pulse and to dynamically adjust their movement timing to match the varying music tempos. Previous studies have shown that monkeys share some of the human capabilities for rhythmic entrainment, such as tapping regularly at the period of isochronous stimuli. However, it is still unknown whether monkeys can predictively entrain to dynamic tempo changes like humans. To address this question, we trained monkeys in three tapping tasks and compared their rhythmic entrainment abilities with those of humans. We found that, when immediate feedback about the timing of each movement is provided, monkeys can predictively entrain to an isochronous beat, generating tapping movements in anticipation of the metronome pulse. This ability also generalized to a novel untrained tempo. Notably, macaques can modify their tapping tempo by predicting the beat changes of accelerating and decelerating visual metronomes in a manner similar to humans. Our findings support the notion that nonhuman primates share with humans the ability of temporal anticipation during tapping to isochronous and smoothly changing sequences of stimuli. © 2018 New York Academy of Sciences.

Deep Belief Network Based Hybrid Model for Building Energy Consumption Prediction

Directory of Open Access Journals (Sweden)

Chengdong Li

2018-01-01

Full Text Available To enhance the prediction performance for building energy consumption, this paper presents a modified deep belief network (DBN based hybrid model. The proposed hybrid model combines the outputs from the DBN model with the energy-consuming pattern to yield the final prediction results. The energy-consuming pattern in this study represents the periodicity property of building energy consumption and can be extracted from the observed historical energy consumption data. The residual data generated by removing the energy-consuming pattern from the original data are utilized to train the modified DBN model. The training of the modified DBN includes two steps, the first one of which adopts the contrastive divergence (CD algorithm to optimize the hidden parameters in a pre-train way, while the second one determines the output weighting vector by the least squares method. The proposed hybrid model is applied to two kinds of building energy consumption data sets that have different energy-consuming patterns (daily-periodicity and weekly-periodicity. In order to examine the advantages of the proposed model, four popular artificial intelligence methods—the backward propagation neural network (BPNN, the generalized radial basis function neural network (GRBFNN, the extreme learning machine (ELM, and the support vector regressor (SVR are chosen as the comparative approaches. Experimental results demonstrate that the proposed DBN based hybrid model has the best performance compared with the comparative techniques. Another thing to be mentioned is that all the predictors constructed by utilizing the energy-consuming patterns perform better than those designed only by the original data. This verifies the usefulness of the incorporation of the energy-consuming patterns. The proposed approach can also be extended and applied to some other similar prediction problems that have periodicity patterns, e.g., the traffic flow forecasting and the electricity consumption

Does life satisfaction predict five-year mortality in community-living older adults?

Science.gov (United States)

St John, Philip D; Mackenzie, Corey; Menec, Verena

2015-01-01

Depression and depressive symptoms predict death, but it is less clear if more general measures of life satisfaction (LS) predict death. Our objectives were to determine: (1) if LS predicts mortality over a five-year period in community-living older adults; and (2) which aspects of LS predict death. 1751 adults over the age of 65 who were living in the community were sampled from a representative population sampling frame in 1991/1992 and followed five years later. Age, gender, and education were self-reported. An index of multimorbidity and the Older American Resource Survey measured health and functional status, and the Terrible-Delightful Scale assessed overall LS as well as satisfaction with: health, finances, family, friends, housing, recreation, self-esteem, religion, and transportation. Cox proportional hazards models examined the influence of LS on time to death. 417 participants died during the five-year study period. Overall LS and all aspects of LS except finances, religion, and self-esteem predicted death in unadjusted analyses. In fully adjusted analyses, LS with health, housing, and recreation predicted death. Other aspects of LS did not predict death after accounting for functional status and multimorbidity. LS predicted death, but certain aspects of LS are more strongly associated with death. The effect of LS is complex and may be mediated or confounded by health and functional status. It is important to consider different domains of LS when considering the impact of this important emotional indicator on mortality among older adults.

Towards seasonal Arctic shipping route predictions

Science.gov (United States)

Haines, K.; Melia, N.; Hawkins, E.; Day, J. J.

2017-12-01

In our previous work [1] we showed how trans-Arctic shipping routes would become more available through the 21st century as sea ice declines, using CMIP5 models with means and stds calibrated to PIOMAS sea ice observations. Sea ice will continue to close shipping routes to open water vessels through the winter months for the foreseeable future so the availability of open sea routes will vary greatly from year to year. Here [2] we look at whether the trans-Arctic shipping season period can be predicted in seasonal forecasts, again using several climate models, and testing both perfect and imperfect knowledge of the initial sea ice conditions. We find skilful predictions of the upcoming summer shipping season can be made from as early as January, although typically forecasts may show lower skill before a May `predictability barrier'. Focussing on the northern sea route (NSR) off Siberia, the date of opening of this sea route is twice as variable as the closing date, and this carries through to reduced predictability at the start of the season. Under climate change the later freeze-up date accounts for 60% of the lengthening season, Fig1 We find that predictive skill is state dependent with predictions for high or low ice years exhibiting greater skill than for average ice years. Forecasting the exact timing of route open periods is harder (more weather dependent) under average ice conditions while in high and low ice years the season is more controlled by the initial ice conditions from spring onwards. This could be very useful information for companies planning vessel routing for the coming season. We tested this dependence on the initial ice conditions by changing the initial ice state towards climatologically average conditions and show directly that early summer sea-ice thickness information is crucial to obtain skilful forecasts of the coming shipping season. Mechanisms for this are discussed. This strongly suggests that good sea ice thickness observations

Integrated lithography to prepare periodic arrays of nano-objects

International Nuclear Information System (INIS)

Sipos, Áron; Szalai, Anikó; Csete, Mária

2013-01-01

We present an integrated lithography method to prepare versatile nano-objects with variable shape and nano-scaled substructure, in wavelength-scaled periodic arrays with arbitrary symmetry. The idea is to illuminate colloid sphere monolayers by polarized beams possessing periodic lateral intensity modulations. Finite element method was applied to determine the effects of the wavelength, polarization and angle of incidence of the incoming beam, and to predict the characteristics of nano-objects, which can be fabricated on thin metal layer covered substrates due to the near-field enhancement under silica colloid spheres. The inter-object distance is controlled by varying the relative orientation of the periodic intensity modulation with respect to the silica colloid sphere monolayer. It is shown that illuminating silica colloid sphere monolayers by two interfering beams, linear patterns made of elliptical holes appear in case of linear polarization, while circularly polarized beams result in co-existent rounded objects, as more circular nano-holes and nano-crescents. The size of the nano-objects and their sub-structure is determined by the spheres diameter and by the wavelength. We present various complex plasmonic patterns made of versatile nano-objects that can be uniquely fabricated applying the inherent symmetry breaking possibilities in the integrated lithography method.

Magnetoplasmons in gapped graphene in a periodically modulated magnetic field

KAUST Repository

Tahir, Muhammad

2016-01-08

Motivated by recent experiments on long-lived magnetoplasmons in the presence of a perpendicular magnetic field, we investigate the dynamical dielectric response function of graphene in contact with a substrate using the random phase approximation. We add a periodically modulated magnetic field within the graphene plane and address both the inter and intra Landau band magnetoplasmons. Verification of the predicted magnetic modulation effects is possible by experiments analogous to those for the zero gap limit. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA.

PETN Coarsening - Predictions from Accelerated Aging Data

Energy Technology Data Exchange (ETDEWEB)

Maiti, Amitesh [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Gee, Richard H. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2011-03-30

Ensuring good ignition properties over long periods of time necessitates maintaining a good level of porosity in powders of initiator materials and preventing particle coarsening. To simulate porosity changes of such powder materials over long periods of time a common strategy is to perform accelerated aging experiments over shorter time spans at elevated temperatures. In this paper we examine historical accelerated-aging data on powders of Pentaerythritol Tetranitrate (PETN), an important energetic material, and make predictions for long-term aging under ambient conditions. Lastly, we develop an evaporation-condensation- based model to provide some mechanistic understanding of the coarsening process.

The 136 MHZ/400 MHz earth station antenna-noise temperature prediction program for RAE-B

Science.gov (United States)

Taylor, R. E.; Fee, J. J.; Chin, M.

1972-01-01

A simulation study was undertaken to determine the 136 MHz and 400 MHz noise temperature of the ground network antennas which will track the RAE-B satellite during data transmission periods. Since the noise temperature of the antenna effectively sets the signal-to-noise ratio of the received signal, a knowledge of SNR will be helpful in locating the optimum time windows for data transmission during low noise periods. Antenna noise temperatures will be predicted for selected earth-based ground stations which will support RAE-B. Telemetry data acquisition will be at 400 MHz; tracking support at 136 MHz will be provided by the Goddard Range and Range Rate (RARR) stations. The antenna-noise temperature predictions will include the effects of galactic-brightness temperature, the sun, and the brightest radio stars. Predictions will cover the ten-month period from March 1, 1973 to December 31, 1973.

Complex Dynamics of Droplet Traffic in a Bifurcating Microfluidic Channel: Periodicity, Multistability, and Selection Rules

Science.gov (United States)

Sessoms, D. A.; Amon, A.; Courbin, L.; Panizza, P.

2010-10-01

The binary path selection of droplets reaching a T junction is regulated by time-delayed feedback and nonlinear couplings. Such mechanisms result in complex dynamics of droplet partitioning: numerous discrete bifurcations between periodic regimes are observed. We introduce a model based on an approximation that makes this problem tractable. This allows us to derive analytical formulae that predict the occurrence of the bifurcations between consecutive regimes, establish selection rules for the period of a regime, and describe the evolutions of the period and complexity of droplet pattern in a cycle with the key parameters of the system. We discuss the validity and limitations of our model which describes semiquantitatively both numerical simulations and microfluidic experiments.

Entropy method of measuring and evaluating periodicity of quasi-periodic trajectories

Science.gov (United States)

Ni, Yanshuo; Turitsyn, Konstantin; Baoyin, Hexi; Junfeng, Li

2018-06-01

This paper presents a method for measuring the periodicity of quasi-periodic trajectories by applying discrete Fourier transform (DFT) to the trajectories and analyzing the frequency domain within the concept of entropy. Having introduced the concept of entropy, analytical derivation and numerical results indicate that entropies increase as a logarithmic function of time. Periodic trajectories typically have higher entropies, and trajectories with higher entropies mean the periodicities of the motions are stronger. Theoretical differences between two trajectories expressed as summations of trigonometric functions are also derived analytically. Trajectories in the Henon-Heiles system and the circular restricted three-body problem (CRTBP) are analyzed with the indicator entropy and compared with orthogonal fast Lyapunov indicator (OFLI). The results show that entropy is a better tool for discriminating periodicity in quasiperiodic trajectories than OFLI and can detect periodicity while excluding the spirals that are judged as periodic cases by OFLI. Finally, trajectories in the vicinity of 243 Ida and 6489 Golevka are considered as examples, and the numerical results verify these conclusions. Some trajectories near asteroids look irregular, but their higher entropy values as analyzed by this method serve as evidence of frequency regularity in three directions. Moreover, these results indicate that applying DFT to the trajectories in the vicinity of irregular small bodies and calculating their entropy in the frequency domain provides a useful quantitative analysis method for evaluating orderliness in the periodicity of quasi-periodic trajectories within a given time interval.

Predicting the Impact of Urban Green Areas on Microclimate Changes of Mashhad Residential Areas during the Hottest Period

Directory of Open Access Journals (Sweden)

zahra karimian

2017-09-01

between receptors was obtained at 13 hour. The trend of relative humidity changes was very similar in both residential sites. In these two sites the most differences in the relative humidity was obtained at 12 oclock.. In addition, the trend of Predicted Mean Vote (PMV in Andisheh residential block showed that these changes in central and south-west part of the site were similar. The simulation with vegetation in the sites, also, showed that the trend of temperature and relative humidity changes were similar. The trends of temperature changes in residential site, Hesabi, in the defined receptors were very similar. So that temperature increased from 12 oclock to 15. While the trend of relative humidity changes was quite the reverse. This study results showed that the difference in temperature, relative humidity and PMV between measured and simulated data were minimal in both residential sites. Moreover, the data comparison of PMV indicated that in both residential sites, despite of simulation with vegetation, the human thermal comfort did not improve, so that these sites were in the range of extreme heat stress. There are several reasons to justify this issue, such as the percentage and the type of vegetation, factors related to the topography and geography of area, building distribution and density, type and color of the building materials and surfaces, etc. However, in this part of the study, other factors were constant, except vegetation. It seems that with increase of percentage and the ratio of vegetation, changes in temperature, relative humidity and other micro-climate factors, are created, but sometimes for the reasons stated, the temperature during the hottest period of the year is too high so that increase in vegetation will have little impact on outdoor thermal comfort. It might be the simulated area on these sites as well as the type and the ratio of the selected species to reduce the temperature and increase the relative humidity have been not adequately

Effects of animal activity on the absorption rate of soils in the ...

African Journals Online (AJOL)

The rates of absorption into various microsites in Karoo soils were compared. The absorption of water by hard, bare intershrub soils was significantly increased by the presence of emergence holes of adult cicadas and near nest-mounds of the harvester ant Messor capensis. Both these insects play an important role in ...

Explicit analytical solution of a pendulum with periodically varying length

International Nuclear Information System (INIS)

Yang Tianzhi; Fang Bo; Li Song; Huang Wenhu

2010-01-01

A pendulum with periodically varying length is an interesting physical system. It has been studied by some researchers using traditional perturbation methods (for example, the averaging method). But due to the limitation of the conventional perturbation methods, the solutions are not valid for long-term prediction of the pendulum. In this paper, we use the homotopy analysis method to explore the approximate solution to this system. The method can easily self-adjust and control the convergence region. By applying the method to the governing equation of the pendulum, we obtain the approximation solution in a closed form. It is shown by the numerical method that the homotopy analysis method supplies a more accurate analytical solution for predicting the long-term behaviour of the pendulum. We believe that this system may be a good example for undergraduate and graduate students for better understanding of nonlinear oscillations.

Principles of assembly reveal a periodic table of protein complexes.

Science.gov (United States)

Ahnert, Sebastian E; Marsh, Joseph A; Hernández, Helena; Robinson, Carol V; Teichmann, Sarah A

2015-12-11

Structural insights into protein complexes have had a broad impact on our understanding of biological function and evolution. In this work, we sought a comprehensive understanding of the general principles underlying quaternary structure organization in protein complexes. We first examined the fundamental steps by which protein complexes can assemble, using experimental and structure-based characterization of assembly pathways. Most assembly transitions can be classified into three basic types, which can then be used to exhaustively enumerate a large set of possible quaternary structure topologies. These topologies, which include the vast majority of observed protein complex structures, enable a natural organization of protein complexes into a periodic table. On the basis of this table, we can accurately predict the expected frequencies of quaternary structure topologies, including those not yet observed. These results have important implications for quaternary structure prediction, modeling, and engineering. Copyright © 2015, American Association for the Advancement of Science.

Experimental investigation of flow field around the elastic flag flapping in periodic state

Science.gov (United States)

Jia, Yongxia; Jia, Lichao; Su, Zhuang; Yuan, Huijing

2018-05-01

The flapping of a flag in the wind is a classical fluid-structure problem that concerns the interaction of elastic bodies with ambient fluid. We focus on the desirable experimental results of the flow around the flapping flag. By immersing the elastic yet self-supporting heavy flag into water flow, we use particle image velocimetry (PIV) techniques to obtain the whole flow field around the midspan of the flag interacting with a fluid in periodic state. A unique PIV image processing method is used to measure near-wall flow velocities around a moving elastic flag. There exists a thin flow circulation region on the suction side of the flag in periodic state. This observation suggests that viscous flow models may be needed to improve the theoretical predictions of the flapping flag in periodic state, especially in a large amplitude.

Variable input parameter influence on river corridor prediction

NARCIS (Netherlands)

Zerfu, T.; Beevers, L.; Crosato, A.; Wright, N.

2015-01-01

This paper considers the erodible river corridor, which is the area in which the main river channel is free to migrate over a period of time. Due to growing anthropogenic pressure, predicting the corridor width has become increasingly important for the planning of development along rivers. Several

Sensitization predicts asthma development among wheezing toddlers in secondary healthcare.

Science.gov (United States)

Boersma, Nienke A; Meijneke, Ruud W H; Kelder, Johannes C; van der Ent, Cornelis K; Balemans, Walter A F

2017-06-01

Some wheezing toddlers develop asthma later in childhood. Sensitization is known to predict asthma in birth cohorts. However, its predictive value in secondary healthcare is uncertain. This study examines the predictive value of sensitization to inhalant allergens among wheezing toddlers in secondary healthcare for the development of asthma at school age (≥6 years). Preschool children (1-3 years) who presented with wheezing in secondary healthcare were screened on asthma at school age with the International Study of Asthma and Allergies in Childhood questionnaire. The positive and negative predictive value (PPV and NPV) of specific IgE to inhalant allergens (cut-off concentration 0.35 kU/L) and several non-invasive variables from a child's history (such as hospitalization, eczema, and parental atopy) were calculated. The additional predictive value of sensitization when combined with non-invasive predictors was examined in multivariate analysis and by ROC curves. Of 116 included children, 63% developed asthma at school age. Sensitization to inhalant allergens was a strong asthma predictor. The odds ratio (OR), PPV and NPV were 7.4%, 86%, and 55%, respectively. Eczema (OR 3.4) and hospital admission (OR 2.6) were significant non-invasive determinants. Adding sensitization to these non-invasive predictors in multivariate analysis resulted in a significantly better asthma prediction. The area under the ROC curve increased from 0.70 with only non-invasive predictors to 0.79 after adding sensitization. Sensitization to inhalant allergens is a strong predictor of school age asthma in secondary healthcare and has added predictive value when combined with non-invasive determinants. Pediatr Pulmonol. 2017;52:729-736. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

The periodicity of Plasmodium vivax and Plasmodium falciparum in Venezuela.

Science.gov (United States)

Grillet, María-Eugenia; El Souki, Mayida; Laguna, Francisco; León, José Rafael

2014-01-01

We investigated the periodicity of Plasmodium vivax and P. falciparum incidence in time-series of malaria data (1990-2010) from three endemic regions in Venezuela. In particular, we determined whether disease epidemics were related to local climate variability and regional climate anomalies such as the El Niño Southern Oscillation (ENSO). Malaria periodicity was found to exhibit unique features in each studied region. Significant multi-annual cycles of 2- to about 6-year periods were identified. The inter-annual variability of malaria cases was coherent with that of SSTs (ENSO), mainly at temporal scales within the 3-6 year periods. Additionally, malaria cases were intensified approximately 1 year after an El Niño event, a pattern that highlights the role of climate inter-annual variability in the epidemic patterns. Rainfall mediated the effect of ENSO on malaria locally. Particularly, rains from the last phase of the season had a critical role in the temporal dynamics of Plasmodium. The malaria-climate relationship was complex and transient, varying in strength with the region and species. By identifying temporal cycles of malaria we have made a first step in predicting high-risk years in Venezuela. Our findings emphasize the importance of analyzing high-resolution spatial-temporal data to better understand malaria transmission dynamics. Copyright © 2013 Elsevier B.V. All rights reserved.

Deterministic prediction of surface wind speed variations

Directory of Open Access Journals (Sweden)

G. V. Drisya

2014-11-01

Full Text Available Accurate prediction of wind speed is an important aspect of various tasks related to wind energy management such as wind turbine predictive control and wind power scheduling. The most typical characteristic of wind speed data is its persistent temporal variations. Most of the techniques reported in the literature for prediction of wind speed and power are based on statistical methods or probabilistic distribution of wind speed data. In this paper we demonstrate that deterministic forecasting methods can make accurate short-term predictions of wind speed using past data, at locations where the wind dynamics exhibit chaotic behaviour. The predictions are remarkably accurate up to 1 h with a normalised RMSE (root mean square error of less than 0.02 and reasonably accurate up to 3 h with an error of less than 0.06. Repeated application of these methods at 234 different geographical locations for predicting wind speeds at 30-day intervals for 3 years reveals that the accuracy of prediction is more or less the same across all locations and time periods. Comparison of the results with f-ARIMA model predictions shows that the deterministic models with suitable parameters are capable of returning improved prediction accuracy and capturing the dynamical variations of the actual time series more faithfully. These methods are simple and computationally efficient and require only records of past data for making short-term wind speed forecasts within practically tolerable margin of errors.

Prediction of hourly solar radiation with multi-model framework

International Nuclear Information System (INIS)

Wu, Ji; Chan, Chee Keong

2013-01-01

Highlights: • A novel approach to predict solar radiation through the use of clustering paradigms. • Development of prediction models based on the intrinsic pattern observed in each cluster. • Prediction based on proper clustering and selection of model on current time provides better results than other methods. • Experiments were conducted on actual solar radiation data obtained from a weather station in Singapore. - Abstract: In this paper, a novel multi-model prediction framework for prediction of solar radiation is proposed. The framework started with the assumption that there are several patterns embedded in the solar radiation series. To extract the underlying pattern, the solar radiation series is first segmented into smaller subsequences, and the subsequences are further grouped into different clusters. For each cluster, an appropriate prediction model is trained. Hence a procedure for pattern identification is developed to identify the proper pattern that fits the current period. Based on this pattern, the corresponding prediction model is applied to obtain the prediction value. The prediction result of the proposed framework is then compared to other techniques. It is shown that the proposed framework provides superior performance as compared to others

Generalized model development for a cryo-adsorber and 1-D results for the isobaric refueling period

Energy Technology Data Exchange (ETDEWEB)

Kumar, V. Senthil [India Science Lab, General Motors Global R and D, Creator Building, International Technology Park, Bangalore 560066 (India); Kumar, Sudarshan [Chemical Sciences and Material Systems Lab, General Motors Global R and D, Warren Technical Center Campus, 30500 Mound Road, Warren, MI 48090 (United States)

2010-04-15

We have developed 3-D model equations for a cryo-adsorption hydrogen storage tank, where the energy balance accommodates the temperature and pressure variation of all the thermodynamic properties. We then reduce the 3-D model to the 1-D isobaric system and study the isobaric refueling period, for simplified geometry and charging conditions. The hydrogen capacity evolution predicted by the 1-D axial bed model is significantly different than that predicted by the lumped-parameter model because of the presence of sharp temperature gradients during refueling. The 1-D model predicts a higher hydrogen capacity than the lumped-parameter model. This observation can be rationalized by the fact that a bed with temperature gradients on equilibration should desorb gas, whenever the adsorbed phase entropy is lower than the gas phase entropy. The 1-D analysis of the isobaric refueling period does not show any significant difference in hydrogen capacity evolution among the axial, single and multicartridge annular bed designs. Hence, a multicartridge annular design, though giving a slightly lower pressure drop, does not offer any heat and mass transfer enhancement over the single cartridge design. And, the single cartridge annular design appears to be optimal. (author)

Research on goal-setting method of rock drivage based on the balance among period, cost and quality

Institute of Scientific and Technical Information of China (English)

SHAN Ren-liang; CAI Wei-ling; WANG Yu-bao; LI Dong-gang; CHEN Xiang

2012-01-01

On the basis of the analysis on the disadvantages of the original goal-serting about rock drivage,this paper defined the "life cycle quality".With project management theory and the Cobb-Douglas finction,"quality-cost and quality-price curve model" and the "total cost-period prediction model" were built.Then the goal-setting method of the balance among quality,cost and period of rock drivage was constructed by finding "life cycle cost" through "life cycle quality" using "quality-cost andquality-price curve model" and ensuring period through "life cycle cost" using "total cost-period prediction model" (hereinafter referred to as the "three goals balance method")."Value contribution" which is the value of the contribution to a mine because of rock drivage,was found in the process of constructing the "quality-cost and quality-price curve model".An industrial test was done in coal mine A with the research results,staff footage efficiency improved by 24.24％,the period shortened by 14.3％,the "life cycle cost" dropped by 2.09％,the "life cycle quality price" improved by 3.29％,and value contribution increased by 25.3％.The result shows that the new goal method setting on the basis of coal mine profit maximization can ensure construction period.At the same time,it can realize cost and quality objectives and the optimization and balance of relationship among them; rewarding excavation teams by "value contribution" can combine organizational goal with personal goal,it significantly raise the employee's work efficiency.

Vertebrate fauna of the Roman period, migrations period and Medieval period in Vojvodina (Serbia

Directory of Open Access Journals (Sweden)

Radmanović Darko P.

2014-01-01

Full Text Available Based on current published and unpublished research results, a total of 16 vertebrate species members of mammal (Mammalia, bird (Aves and osteichthyes (Osteichthyes classes have been registered at 11 archaeological sites from the Roman Period in Vojvodina. Mammals dominate with 12 species and one genus, birds are present with 3 species, and osteichthyes with one. From the Migration Period, at 9 sites, 22 vertebrate species have been registered, of which 13 species and one genus of mammals, 4 species and one genus of birds, and 5 species from the Osteichthyes class. At 8 sites from the Medieval Period, 16 vertebrate species have been registered. Mammals are the most numerous class with 10 species and one genus, while birds are present with 4 species and one genus. Furthermore, two species of osteichthyes have also been registered.

Commuting periodic operators and the periodic Wigner function

International Nuclear Information System (INIS)

Zak, J

2004-01-01

Commuting periodic operators (CPO) depending on the coordinate x-hat and the momentum p-hat operators are defined. The CPO are functions of the two basic commuting operators exp(i x-hat 2π/a) and exp(i/h p-hat a), with a being an arbitrary constant. A periodic Wigner function (PWF) w(x, p) is defined and it is shown that it is applicable in a normal expectation value calculation to the CPO, as done in the original Wigner paper. Moreover, this PWF is non-negative everywhere, and it can therefore be interpreted as an actual probability distribution. The PWF w(x, p) is shown to be given as an expectation value of the periodic Dirac delta function in the phase plane. (letter to the editor)

Climate impact on airborne particulate matter concentrations in California using seven year analysis periods

Directory of Open Access Journals (Sweden)

A. Mahmud

2010-11-01

Full Text Available The effect of global climate change on the annual average concentration of fine particulate matter (PM_2.5 in California was studied using a climate-air quality modeling system composed of global through regional models. Output from the NCAR/DOE Parallel Climate Model (PCM generated under the "business as usual" global emissions scenario was downscaled using the Weather Research and Forecasting (WRF model followed by air quality simulations using the UCD/CIT airshed model. The system represents major atmospheric processes acting on gas and particle phase species including meteorological effects on emissions, advection, dispersion, chemical reaction rates, gas-particle conversion, and dry/wet deposition. The air quality simulations were carried out for the entire state of California with a resolution of 8-km for the years 2000–2006 (present climate with present emissions and 2047–2053 (future climate with present emissions. Each of these 7-year analysis periods was analyzed using a total of 1008 simulated days to span a climatologically relevant time period with a practical computational burden. The 7-year windows were chosen to properly account for annual variability with the added benefit that the air quality predictions under the present climate could be compared to actual measurements. The climate-air quality modeling system successfully predicted the spatial pattern of present climate PM_2.5 concentrations in California but the absolute magnitude of the annual average PM_2.5 concentrations were under-predicted by ~4–39% in the major air basins. The majority of this under-prediction was caused by excess ventilation predicted by PCM-WRF that should be present to the same degree in the current and future time periods so that the net bias introduced into the comparison is minimized.

Surface temperature, relative humidity (RH, rain rate, and wind speed were predicted to increase in the future climate

Predicting the Initial Lapse Using a Mobile Health Application after Alcohol Detoxification

Science.gov (United States)

Chih, Ming-Yuan

2013-01-01

The prediction and prevention of the initial lapse--which is defined as the first lapse after a period of abstinence--is important because the initial lapse often leads to subsequent lapses (within the same lapse episode) or relapse. The prediction of the initial lapse may allow preemptive intervention to be possible. This dissertation reports on…

Forward Period Analysis Method of the Periodic Hamiltonian System.

Directory of Open Access Journals (Sweden)

Pengfei Wang

Full Text Available Using the forward period analysis (FPA, we obtain the period of a Morse oscillator and mathematical pendulum system, with the accuracy of 100 significant digits. From these results, the long-term [0, 1060] (time unit solutions, ranging from the Planck time to the age of the universe, are computed reliably and quickly with a parallel multiple-precision Taylor series (PMT scheme. The application of FPA to periodic systems can greatly reduce the computation time of long-term reliable simulations. This scheme provides an efficient way to generate reference solutions, against which long-term simulations using other schemes can be tested.

Predicting Human Cooperation.

Directory of Open Access Journals (Sweden)

John J Nay

Full Text Available The Prisoner's Dilemma has been a subject of extensive research due to its importance in understanding the ever-present tension between individual self-interest and social benefit. A strictly dominant strategy in a Prisoner's Dilemma (defection, when played by both players, is mutually harmful. Repetition of the Prisoner's Dilemma can give rise to cooperation as an equilibrium, but defection is as well, and this ambiguity is difficult to resolve. The numerous behavioral experiments investigating the Prisoner's Dilemma highlight that players often cooperate, but the level of cooperation varies significantly with the specifics of the experimental predicament. We present the first computational model of human behavior in repeated Prisoner's Dilemma games that unifies the diversity of experimental observations in a systematic and quantitatively reliable manner. Our model relies on data we integrated from many experiments, comprising 168,386 individual decisions. The model is composed of two pieces: the first predicts the first-period action using solely the structural game parameters, while the second predicts dynamic actions using both game parameters and history of play. Our model is successful not merely at fitting the data, but in predicting behavior at multiple scales in experimental designs not used for calibration, using only information about the game structure. We demonstrate the power of our approach through a simulation analysis revealing how to best promote human cooperation.

Predicting respiratory motion signals for image-guided radiotherapy using multi-step linear methods (MULIN)

International Nuclear Information System (INIS)

Ernst, Floris; Schweikard, Achim

2008-01-01

Forecasting of respiration motion in image-guided radiotherapy requires algorithms that can accurately and efficiently predict target location. Improved methods for respiratory motion forecasting were developed and tested. MULIN, a new family of prediction algorithms based on linear expansions of the prediction error, was developed and tested. Computer-generated data with a prediction horizon of 150 ms was used for testing in simulation experiments. MULIN was compared to Least Mean Squares-based predictors (LMS; normalized LMS, nLMS; wavelet-based multiscale autoregression, wLMS) and a multi-frequency Extended Kalman Filter (EKF) approach. The in vivo performance of the algorithms was tested on data sets of patients who underwent radiotherapy. The new MULIN methods are highly competitive, outperforming the LMS and the EKF prediction algorithms in real-world settings and performing similarly to optimized nLMS and wLMS prediction algorithms. On simulated, periodic data the MULIN algorithms are outperformed only by the EKF approach due to its inherent advantage in predicting periodic signals. In the presence of noise, the MULIN methods significantly outperform all other algorithms. The MULIN family of algorithms is a feasible tool for the prediction of respiratory motion, performing as well as or better than conventional algorithms while requiring significantly lower computational complexity. The MULIN algorithms are of special importance wherever high-speed prediction is required. (orig.)

Predicting respiratory motion signals for image-guided radiotherapy using multi-step linear methods (MULIN)

Energy Technology Data Exchange (ETDEWEB)

Ernst, Floris; Schweikard, Achim [University of Luebeck, Institute for Robotics and Cognitive Systems, Luebeck (Germany)

2008-06-15

Forecasting of respiration motion in image-guided radiotherapy requires algorithms that can accurately and efficiently predict target location. Improved methods for respiratory motion forecasting were developed and tested. MULIN, a new family of prediction algorithms based on linear expansions of the prediction error, was developed and tested. Computer-generated data with a prediction horizon of 150 ms was used for testing in simulation experiments. MULIN was compared to Least Mean Squares-based predictors (LMS; normalized LMS, nLMS; wavelet-based multiscale autoregression, wLMS) and a multi-frequency Extended Kalman Filter (EKF) approach. The in vivo performance of the algorithms was tested on data sets of patients who underwent radiotherapy. The new MULIN methods are highly competitive, outperforming the LMS and the EKF prediction algorithms in real-world settings and performing similarly to optimized nLMS and wLMS prediction algorithms. On simulated, periodic data the MULIN algorithms are outperformed only by the EKF approach due to its inherent advantage in predicting periodic signals. In the presence of noise, the MULIN methods significantly outperform all other algorithms. The MULIN family of algorithms is a feasible tool for the prediction of respiratory motion, performing as well as or better than conventional algorithms while requiring significantly lower computational complexity. The MULIN algorithms are of special importance wherever high-speed prediction is required. (orig.)

Initializing decadal climate predictions over the North Atlantic region

Science.gov (United States)

Matei, Daniela Mihaela; Pohlmann, Holger; Jungclaus, Johann; Müller, Wolfgang; Haak, Helmuth; Marotzke, Jochem

2010-05-01

Decadal climate prediction aims to predict the internally-generated decadal climate variability in addition to externally-forced climate change signal. In order to achieve this it is necessary to start the predictions from the current climate state. In this study we investigate the forecast skill of the North Atlantic decadal climate predictions using two different ocean initialization strategies. First we apply an assimilation of ocean synthesis data provided by the GECCO project (Köhl and Stammer, 2008) as initial conditions for the coupled model ECHAM5/MPI-OM. Hindcast experiments are then performed over the period 1952-2001. An alternative approach is one in which the subsurface ocean temperature and salinity are diagnosed from an ensemble of ocean model runs forced by the NCEP-NCAR atmospheric reanalyzes for the period 1948-2007, then nudge into the coupled model to produce initial conditions for the hindcast experiments. An anomaly coupling scheme is used in both approaches to avoid the hindcast drift and the associated initial shock. Differences between the two assimilation approaches are discussed by comparing them with the observational data in key regions and processes. We asses the skill of the initialized decadal hindcast experiments against the prediction skill of the non-initialized hindcasts simulation. We obtain an overview of the regions with the highest predictability from the regional distribution of the anomaly correlation coefficients and RMSE for the SAT. For the first year the hindcast skill is increased over almost all ocean regions in the NCEP-forced approach. This increase in the hindcast skill for the 1 year lead time is somewhat reduced in the GECCO approach. At lead time 5yr and 10yr, the skill enhancement is still found over the North Atlantic and North Pacific regions. We also consider the potential predictability of the Atlantic Meridional Overturning Circulation (AMOC) and Nordic Seas Overflow by comparing the predicted values to

Analysis of the uranium price predicted to 24 months, implementing neural networks and the Monte Carlo method like predictive tools; Analisis del precio del uranio pronosticado a 24 meses, implementando redes neuronales y el metodo de Monte Carlo como herramientas predictivas

Energy Technology Data Exchange (ETDEWEB)

Esquivel E, J.; Ramirez S, J. R.; Palacios H, J. C., E-mail: jaime.esquivel@fi.uaemex.mx [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

2011-11-15

The present work shows predicted prices of the uranium, using a neural network. The importance of predicting financial indexes of an energy resource, in this case, allows establishing budgetary measures, as well as the costs of the resource to medium period. The uranium is part of the main energy generating fuels and as such, its price rebounds in the financial analyses, due to this is appealed to predictive methods to obtain an outline referent to the financial behaviour that will have in a certain time. In this study, two methodologies are used for the prediction of the uranium price: the Monte Carlo method and the neural networks. These methods allow predicting the indexes of monthly costs, for a two years period, starting from the second bimonthly of 2011. For the prediction the uranium costs are used, registered from the year 2005. (Author)

Prediction of annual precipitation on the territory of south Serbia using Markov chains

Directory of Open Access Journals (Sweden)

Lukić Predrag

2013-01-01

Full Text Available Prediction of precipitation is one of the important factors that affect the sectors such as industry, agriculture, environmental protection, and their related fields. The stochastic method based on a Markov chain model is used in the paper to predict the annual precipitation in the territory of South Serbia for the period 2009-2013. For this purpose, the precipitation data rainfall recorded on the four synoptic stations were used for the period 1980-2010. [Projekat Ministarstva nauke Republike Srbije, br. TR 37003: Razvoj hidroinformacionog sistema za praćenje i ranu najavu suša

Randomly modulated periodic signals in Alberta's electricity market

Energy Technology Data Exchange (ETDEWEB)

Hinich, M. [Texas Univ., Austin, TX (United States); Serletis, A. [Calgary Univ., AB (Canada)

2005-04-01

The physical laws that determine the delivery of power across a transmission grid require a synchronized energy balance between the injection of power at generating points and offtake at demand points. Grid operators must continuously monitor the demand process and respond quickly to fluctuations in demand. This paper presented a parametric statistical model called Randomly Modulated Periodicity (RMP) which examined Alberta's spot wholesale power market, defined on hourly intervals. The concern was to test for periodic signals that can be perfectly predicted far into the future. A univariate approach was taken, although it was acknowledged that from an economic perspective, the interest in the price of electricity is in its relationship with the electricity load as well as with the prices of other primary fuel commodities. Sections 2 and 3 of the paper discussed the RMP model for the study of periodic signals. In section 4, randomly modulated periodicity was tested in hourly electricity prices and MWh demand for Alberta, over the deregulated period after 1996. It was concluded that electricity prices have low coherence with daily and weekly cycles. The mean value at each half hour of the daily demand and the weekend demand yielded good forecasts after the end of the data series. It was suggested that a statistical forecasting based on historical demand and co-factors such as the average hourly temperature per day and patterns of industrial usage should yield better short term forecasts. The development of a statistical technology for forecasting electricity demand is a challenging area of research. 6 refs., 4 figs.

Severe rainfall prediction systems for civil protection purposes

Science.gov (United States)

Comellas, A.; Llasat, M. C.; Molini, L.; Parodi, A.; Siccardi, F.

2010-09-01

One of the most common natural hazards impending on Mediterranean regions is the occurrence of severe weather structures able to produce heavy rainfall. Floods have killed about 1000 people across all Europe in last 10 years. With the aim of mitigating this kind of risk, quantitative precipitation forecasts (QPF) and rain probability forecasts are two tools nowadays available for national meteorological services and institutions responsible for weather forecasting in order to and predict rainfall, by using either the deterministic or the probabilistic approach. This study provides an insight of the different approaches used by Italian (DPC) and Catalonian (SMC) Civil Protection and the results they achieved with their peculiar issuing-system for early warnings. For the former, the analysis considers the period between 2006-2009 in which the predictive ability of the forecasting system, based on the numerical weather prediction model COSMO-I7, has been put into comparison with ground based observations (composed by more than 2000 raingauge stations, Molini et al., 2009). Italian system is mainly focused on regional-scale warnings providing forecasts for periods never shorter than 18 hours and very often have a 36-hour maximum duration . The information contained in severe weather bulletins is not quantitative and usually is referred to a specific meteorological phenomena (thunderstorms, wind gales et c.). Updates and refining have a usual refresh time of 24 hours. SMC operates within the Catalonian boundaries and uses a warning system that mixes both quantitative and probabilistic information. For each administrative region ("comarca") Catalonia is divided into, forecasters give an approximate value of the average predicted rainfall and the probability of overcoming that threshold. Usually warnings are re-issued every 6 hours and their duration depends on the predicted time extent of the storm. In order to provide a comprehensive QPF verification, the rainfall

Time-delayed feedback technique for suppressing instabilities in time-periodic flow

Science.gov (United States)

Shaabani-Ardali, Léopold; Sipp, Denis; Lesshafft, Lutz

2017-11-01

A numerical method is presented that allows to compute time-periodic flow states, even in the presence of hydrodynamic instabilities. The method is based on filtering nonharmonic components by way of delayed feedback control, as introduced by Pyragas [Phys. Lett. A 170, 421 (1992), 10.1016/0375-9601(92)90745-8]. Its use in flow problems is demonstrated here for the case of a periodically forced laminar jet, subject to a subharmonic instability that gives rise to vortex pairing. The optimal choice of the filter gain, which is a free parameter in the stabilization procedure, is investigated in the context of a low-dimensional model problem, and it is shown that this model predicts well the filter performance in the high-dimensional flow system. Vortex pairing in the jet is efficiently suppressed, so that the unstable periodic flow state in response to harmonic forcing is accurately retrieved. The procedure is straightforward to implement inside any standard flow solver. Memory requirements for the delayed feedback control can be significantly reduced by means of time interpolation between checkpoints. Finally, the method is extended for the treatment of periodic problems where the frequency is not known a priori. This procedure is demonstrated for a three-dimensional cubic lid-driven cavity in supercritical conditions.

A Mote in Andromeda's Disk: A Periodic AGN Behind M31

Science.gov (United States)

Dorn-Wallenstein, Trevor; Levesque, Emily; Ruan, John

2018-01-01

We present the discovery of multiple periodicities in J0045+41, a z≈0.215 AGN seen through a low-absorption region of M31. We obtained moderate resolution spectroscopy of J0045+41 using GMOS at Gemini-North. We use eigenspectra derived from principle component analyses of the SDSS galaxy and quasar catalogs to decompose the spectrum into host and AGN components, and estimate the luminosity and virial mass of the central engine. Residuals to our fit reveal a blue-shifted component to the broad Hα and Hβ lines at a relative velocity of ∼4800 km s-1. We search for evidence of periodicity using g-band photometry from the Palomar Transient Factory and find evidence for multiple periodicities ranging from ∼80-350 days. Two of the detected periods are in a 1:4 ratio, which is identical to the predictions of hydrodynamical simulations of binary supermassive black hole systems. If these signals arise due to such a system, J0045+41 is well within the gravitational wave regime. We calculate the time until inspiral due to gravitational radiation, assuming reasonable values of the mass ratio of the two black holes, and the anticipated gravitational strain in the context of forthcoming low-frequency gravitational wave observatories like the Square Kilometer Array.

Development of Next Generation Multiphase Pipe Flow Prediction Tools

Energy Technology Data Exchange (ETDEWEB)

Tulsa Fluid Flow

2008-08-31

The developments of fields in deep waters (5000 ft and more) is a common occurrence. It is inevitable that production systems will operate under multiphase flow conditions (simultaneous flow of gas-oil-and water possibly along with sand, hydrates, and waxes). Multiphase flow prediction tools are essential for every phase of the hydrocarbon recovery from design to operation. The recovery from deep-waters poses special challenges and requires accurate multiphase flow predictive tools for several applications including the design and diagnostics of the production systems, separation of phases in horizontal wells, and multiphase separation (topside, seabed or bottom-hole). It is very crucial to any multiphase separation technique that is employed either at topside, seabed or bottom-hole to know inlet conditions such as the flow rates, flow patterns, and volume fractions of gas, oil and water coming into the separation devices. The overall objective was to develop a unified model for gas-oil-water three-phase flow in wells, flow lines, and pipelines to predict the flow characteristics such as flow patterns, phase distributions, and pressure gradient encountered during petroleum production at different flow conditions (pipe diameter and inclination, fluid properties and flow rates). The project was conducted in two periods. In Period 1 (four years), gas-oil-water flow in pipes were investigated to understand the fundamental physical mechanisms describing the interaction between the gas-oil-water phases under flowing conditions, and a unified model was developed utilizing a novel modeling approach. A gas-oil-water pipe flow database including field and laboratory data was formed in Period 2 (one year). The database was utilized in model performance demonstration. Period 1 primarily consisted of the development of a unified model and software to predict the gas-oil-water flow, and experimental studies of the gas-oil-water project, including flow behavior description and

STELLAR PULSATIONS AND PERIOD CHANGES IN THE SX PHOENICIS STAR XX CYGNI

International Nuclear Information System (INIS)

Yang, X. H.; Fu, J. N.; Zha, Q.

2012-01-01

Time-series photometric observations were made for the SX Phoenicis star XX Cyg between 2007 and 2011 at the Xinglong Station of National Astronomical Observatories of China. With the light curves derived from the new observations, we do not detect any secondary maximum in the descending portion of the light curves of XX Cyg, as reported in some previous work. Frequency analysis of the light curves confirms a fundamental frequency f 0 = 7.4148 cycles day –1 and up to 19 harmonics, 11 of which are newly detected. However, no secondary mode of pulsation is detected from the light curves. The O–C diagram, produced from 46 newly determined times of maximum light combined with those derived from the literature, reveals a continuous period increase with the rate of (1/P)(dP/dt) = 1.19(13) × 10 –8 yr -1 . Theoretical rates of period change due to the stellar evolution were calculated with a modeling code. The result shows that the observed rate of period change is fully consistent with period change caused by evolutionary behavior predicted by standard theoretical models.

Middle Helladic Period

DEFF Research Database (Denmark)

Sarri, Kalliopi

1999-01-01

and their quality was improved considerably toward the end of this period. The profound cultural innovations of the Middle Helladic period were initially interpreted as a result of violent population movement and troubles provoked by the coming of the first Indo-European races. However, this matter does no more...... Helladic period is considered as a period of economic and social decline it was the time during which the mainland features merged with the insular influence, that is all the Aegean elements which led to the creation of the Mycenaean civilization were mixed in a creative way....

Prediction of Seismic Damage-Based Degradation in RC Structures

DEFF Research Database (Denmark)

Kirkegaard, Poul Henning; Gupta, Vinay K.; Nielsen, Søren R.K.

Estimation of structural damage from known increase in the fundamental period of a structure after an earthquake or prediction of degradation of stiffness and strength for known damage requires reliable correlations between these response functionals. This study proposes a modified Clough-Johnsto...

Periodicity and quasi-periodicity for super-integrable hamiltonian systems

International Nuclear Information System (INIS)

Kibler, M.; Winternitz, P.

1990-01-01

Classical trajectories are calculated for two Hamiltonian systems with ring shaped potentials. Both systems are super-integrable, but not maximally super-integrable, having four globally defined single-valued integrals of motion each. All finite trajectories are quasi-periodical; they become truly periodical if a commensurability condition is imposed on an angular momentum component

The block transfer system

International Nuclear Information System (INIS)

Bradish, G.J. III; Reid, A.E.

1986-01-01

The central instrumentation control and data acquisition (CICADA) computer system is comprised of a functionally distributed hierarchical network of thirteen (13) 32-bit mini-computers that are the heart of the control, monitoring, data collection and data analysis for the tokamak fusion test reactor (TFTR). The CICADA system was designed with the goal of providing complete control, monitoring, and data acquisition for TFTR, which includes the acquisition and storage of 20M points of data within a five-minute shot cycle. It was realized early in the system design that in order to meet this goal an ancillary system would have to be provided to supplement the subsystem CAMAC systems that, due to the relatively slow throughput of the serial highways and the overhead of relaying data to the central facilities within a star network, would not provide the necessary throughput. The authors discuss how the block transfer system provided a means of moving data directly from the CAMAC crate to the application running on the central facility computers

Patterns and processes underlying evolutionary significant units in the Platypleura stridula L. species complex (Hemiptera: Cicadidae) in the Cape Floristic Region, South Africa.

Science.gov (United States)

Price, B W; Barker, N P; Villet, M H

2007-06-01

Cicadas have been shown to be useful organisms for examining the effects of distribution, plant association and geographical barriers on gene flow between populations. The cicadas of the Platypleura stridula species complex are restricted to the biologically diverse Cape Floristic Region (CFR) of South Africa. They are thus an excellent study group for elucidating the mechanisms by which hemipteran diversity is generated and maintained in the CFR. Phylogeographical analysis of this species complex using mitochondrial DNA Cytochrome Oxidase I (COI) and ribosomal 16S sequence data, coupled with preliminary morphological and acoustic data, resolves six clades, each of which has specific host-plant associations and distinct geographical ranges. The phylogeographical structure implies simultaneous or near-simultaneous radiation events, coupled with shifts in host-plant associations. When calibrated using published COI and 16S substitution rates typical for related insects, these lineages date back to the late Pliocene - early Pleistocene, coincident with vegetation change, altered drainage patterns and accelerated erosion in response to neotectonic crustal uplift and cyclic Pleistocene climate change, and glaciation-associated changes in climate and sea level.

Duplex-imprinted nano well arrays for promising nanoparticle assembly

Science.gov (United States)

Li, Xiangping; Manz, Andreas

2018-02-01

A large area nano-duplex-imprint technique is presented in this contribution using natural cicada wings as stamps. The glassy wings of the cicada, which are abundant in nature, exhibit strikingly interesting nanopillar structures over their membrane. This technique, with excellent performance despite the nonplanar surface of the wings, combines both top-down and bottom-up nanofabrication techniques. It transitions micro-nanofabrication from a cleanroom environment to the bench. Two different materials, dicing tape with an acrylic layer and a UV optical adhesive, are used to make replications at the same time, thus achieving duplex imprinting. The promise of a large volume of commercial manufacturing of these nanostructure elements can be envisaged through this contribution to speeding up the fabrication process and achieving a higher throughput. The contact angle of the replicated nanowell arrays before and after oxygen plasma was measured. Gold nanoparticles (50 nm) were used to test how the nanoparticles behaved on the untreated and plasma-treated replica surface. The experiments show that promising nanoparticle self-assembly can be obtained.

Dynamic Simulation of a Periodic 10 K Sorption Cryocooler

Science.gov (United States)

Bhandari, P.; Rodriguez, J.; Bard, S.; Wade, L.

1994-01-01

A transient thermal simulation model has been developed to simulate the dynamic performance of a multiple-stage 10 K sorption cryocooler for spacecraft sensor cooling applications that require periodic quick-cooldown (under 2 minutes) , negligible vibration, low power consumption, and long life (5 to 10 years). The model was specifically designed to represent the Brilliant Eyes Ten-Kelvin Sorption Cryocooler Experiment (BETSCE), but it can be adapted to represent other sorption cryocooler systems as well. The model simulates the heat transfer, mass transfer, and thermodynamic processes in the cryostat and the sorbent beds for the entire refrigeration cycle, and includes the transient effects of variable hydrogen supply pressures due to expansion and overflow of hydrogen during the cooldown operation. The paper describes model limitations and simplifying assumptions, with estimates of errors induced by them, and presents comparisons of performance predictions with ground experiments. An important benefit of the model is its ability to predict performance sensitivities to variations of key design and operational parameters. The insights thus obtained are expected to lead to higher efficiencies and lower weights for future designs.

Retrospective lifetime dietary patterns predict cognitive performance in community-dwelling older Australians.

Science.gov (United States)

Hosking, Diane E; Nettelbeck, Ted; Wilson, Carlene; Danthiir, Vanessa

2014-07-28

Dietary intake is a modifiable exposure that may have an impact on cognitive outcomes in older age. The long-term aetiology of cognitive decline and dementia, however, suggests that the relevance of dietary intake extends across the lifetime. In the present study, we tested whether retrospective dietary patterns from the life periods of childhood, early adulthood, adulthood and middle age predicted cognitive performance in a cognitively healthy sample of 352 older Australian adults >65 years. Participants completed the Lifetime Diet Questionnaire and a battery of cognitive tests designed to comprehensively assess multiple cognitive domains. In separate regression models, lifetime dietary patterns were the predictors of cognitive factor scores representing ten constructs derived by confirmatory factor analysis of the cognitive test battery. All regression models were progressively adjusted for the potential confounders of current diet, age, sex, years of education, English as native language, smoking history, income level, apoE ɛ4 status, physical activity, other past dietary patterns and health-related variables. In the adjusted models, lifetime dietary patterns predicted cognitive performance in this sample of older adults. In models additionally adjusted for intake from the other life periods and mechanistic health-related variables, dietary patterns from the childhood period alone reached significance. Higher consumption of the 'coffee and high-sugar, high-fat extras' pattern predicted poorer performance on simple/choice reaction time, working memory, retrieval fluency, short-term memory and reasoning. The 'vegetable and non-processed' pattern negatively predicted simple/choice reaction time, and the 'traditional Australian' pattern positively predicted perceptual speed and retrieval fluency. Identifying early-life dietary antecedents of older-age cognitive performance contributes to formulating strategies for delaying or preventing cognitive decline.

Empirical prediction of the onset dates of South China Sea summer monsoon

Science.gov (United States)

Zhu, Zhiwei; Li, Tim

2017-03-01

The onset of South China Sea summer monsoon (SCSSM) signifies the commencement of the wet season over East Asia. Predicting the SCSSM onset date is of significant importance. In this study, we establish two different statistical models, namely the physical-empirical model (PEM) and the spatial-temporal projection model (STPM) to predict the SCSSM onset. The PEM is constructed from the seasonal prediction perspective. Observational diagnoses reveal that the early onset of the SCSSM is preceded by (a) a warming tendency in middle and lower troposphere (850-500 hPa) over central Siberia from January to March, (b) a La Niña-like zonal dipole sea surface temperature pattern over the tropical Pacific in March, and (c) a dipole sea level pressure pattern with negative center in subtropics and positive center over high latitude of Southern Hemisphere in January. The PEM built on these predictors achieves a cross-validated reforecast temporal correlation coefficient (TCC) skill of 0.84 for the period of 1979-2004, and an independent forecast TCC skill of 0.72 for the period 2005-2014. The STPM is built on the extended-range forecast perspective. Pentad data are used to predict a zonal wind index over the South China Sea region. Similar to PEM, the STPM is constructed using 1979-2004 data. Based on the forecasted zonal wind index, the independent forecast of the SCSSM onset dates achieves a TCC skill of 0.90 for 2005-2014. The STPM provides more detailed information for the intraseasonal evolution during the period of the SCSSM onset (pentad 25-35). The two models proposed herein are expected to facilitate the real-time prediction of the SCSSM onset.

The importance of different frequency bands in predicting subcutaneous glucose concentration in type 1 diabetic patients.

Science.gov (United States)

Lu, Yinghui; Gribok, Andrei V; Ward, W Kenneth; Reifman, Jaques

2010-08-01

We investigated the relative importance and predictive power of different frequency bands of subcutaneous glucose signals for the short-term (0-50 min) forecasting of glucose concentrations in type 1 diabetic patients with data-driven autoregressive (AR) models. The study data consisted of minute-by-minute glucose signals collected from nine deidentified patients over a five-day period using continuous glucose monitoring devices. AR models were developed using single and pairwise combinations of frequency bands of the glucose signal and compared with a reference model including all bands. The results suggest that: for open-loop applications, there is no need to explicitly represent exogenous inputs, such as meals and insulin intake, in AR models; models based on a single-frequency band, with periods between 60-120 min and 150-500 min, yield good predictive power (error bands produce predictions that are indistinguishable from those of the reference model as long as the 60-120 min period band is included; and AR models can be developed on signals of short length (approximately 300 min), i.e., ignoring long circadian rhythms, without any detriment in prediction accuracy. Together, these findings provide insights into efficient development of more effective and parsimonious data-driven models for short-term prediction of glucose concentrations in diabetic patients.

Investigation of a breathing surrogate prediction algorithm for prospective pulmonary gating

International Nuclear Information System (INIS)

White, Benjamin M.; Low, Daniel A.; Zhao Tianyu; Wuenschel, Sara; Lu, Wei; Lamb, James M.; Mutic, Sasa; Bradley, Jeffrey D.; El Naqa, Issam

2011-01-01

Purpose: A major challenge of four dimensional computed tomography (4DCT) in treatment planning and delivery has been the lack of respiration amplitude and phase reproducibility during image acquisition. The implementation of a prospective gating algorithm would ensure that images would be acquired only during user-specified breathing phases. This study describes the development and testing of an autoregressive moving average (ARMA) model for human respiratory phase prediction under quiet respiration conditions. Methods: A total of 47 4DCT patient datasets and synchronized respiration records was utilized in this study. Three datasets were used in model development and were removed from further evaluation of the ARMA model. The remaining 44 patient datasets were evaluated with the ARMA model for prediction time steps from 50 to 1000 ms in increments of 50 and 100 ms. Thirty-five of these datasets were further used to provide a comparison between the proposed ARMA model and a commercial algorithm with a prediction time step of 240 ms. Results: The optimal number of parameters for the ARMA model was based on three datasets reserved for model development. Prediction error was found to increase as the prediction time step increased. The minimum prediction time step required for prospective gating was selected to be half of the gantry rotation period. The maximum prediction time step with a conservative 95% confidence criterion was found to be 0.3 s. The ARMA model predicted peak inhalation and peak exhalation phases significantly better than the commercial algorithm. Furthermore, the commercial algorithm had numerous instances of missed breath cycles and falsely predicted breath cycles, while the proposed model did not have these errors. Conclusions: An ARMA model has been successfully applied to predict human respiratory phase occurrence. For a typical CT scanner gantry rotation period of 0.4 s (0.2 s prediction time step), the absolute error was relatively small, 0

Appropriate Combination of Artificial Intelligence and Algorithms for Increasing Predictive Accuracy Management

Directory of Open Access Journals (Sweden)

Shahram Gilani Nia

2010-03-01

Full Text Available In this paper a simple and effective expert system to predict random data fluctuation in short-term period is established. Evaluation process includes introducing Fourier series, Markov chain model prediction and comparison (Gray combined with the model prediction Gray- Fourier- Markov that the mixed results, to create an expert system predicted with artificial intelligence, made this model to predict the effectiveness of random fluctuation in most data management programs to increase. The outcome of this study introduced artificial intelligence algorithms that help detect that the computer environment to create a system that experts predict the short-term and unstable situation happens correctly and accurately predict. To test the effectiveness of the algorithm presented studies (Chen Tzay len,2008, and predicted data of tourism demand for Iran model is used. Results for the two countries show output model has high accuracy.

COMPARING FINANCIAL DISTRESS PREDICTION MODELS BEFORE AND DURING RECESSION

Directory of Open Access Journals (Sweden)

Nataša Šarlija

2011-02-01

Full Text Available The purpose of this paper is to design three separate financial distress prediction models that will track the changes in a relative importance of financial ratios throughout three consecutive years. The models were based on the financial data from 2000 privately-owned small and medium-sized enterprises in Croatia from 2006 to 2009, and developed by means of logistic regression. Macroeconomic conditions as well as market dynamic have been changed over the mentioned period. Financial ratios that were less important in one period become more important in the next period. Composition of model starting in 2006 has been changed in the next years. It tells us what financial ratios are more important during the time of economic downturn. Besides, it helps us to understand behavior of small and medium-sized enterprises in the period of prerecession and in the period of recession.

Indonesian Stock Prediction using Support Vector Machine (SVM

Directory of Open Access Journals (Sweden)

Santoso Murtiyanto

2018-01-01

Full Text Available This project is part of developing software to provide predictive information technology-based services artificial intelligence (Machine Intelligence or Machine Learning that will be utilized in the money market community. The prediction method used in this early stages uses the combination of Gaussian Mixture Model and Support Vector Machine with Python programming. The system predicts the price of Astra International (stock code: ASII.JK stock data. The data used was taken during 17 yr period of January 2000 until September 2017. Some data was used for training/modeling (80 % of data and the remainder (20 % was used for testing. An integrated model comprising Gaussian Mixture Model and Support Vector Machine system has been tested to predict stock market of ASII.JK for l d in advance. This model has been compared with the Market Cummulative Return. From the results, it is depicts that the Gaussian Mixture Model-Support Vector Machine based stock predicted model, offers significant improvement over the compared models resulting sharpe ratio of 3.22.

ERP Indices of Stimulus Prediction in Letter Sequences

Directory of Open Access Journals (Sweden)

Edith Kaan

2014-10-01

Full Text Available Given the current focus on anticipation in perception, action and cognition, including language processing, there is a need for a method to tap into predictive processing in situations in which cue and feedback stimuli are not explicitly marked as such. To this aim, event related potentials (ERPs were obtained while participants viewed alphabetic letter sequences (“A”, “B”, “C”, “D”, “E”, …, in which the letters were highly predictable, and random sequences (“S”, “B”, “A”, “I”, “F”, “M”, …, without feedback. Occasionally, the presentation of a letter in a sequence was delayed by 300 ms. During this delay period, an increased negativity was observed for predictive versus random sequences. In addition, the early positivity following the delay was larger for predictive compared with random sequences. These results suggest that expectation-sensitive ERP modulations can be elicited in anticipation of stimuli that are not explicit targets, rewards, feedback or instructions, and that a delay can strengthen the prediction for a particular stimulus. Applications to language processing will be discussed.

The aeration period of a model nuclear waste repository

International Nuclear Information System (INIS)

Sharland, S.M.; Tasker, P.W.

1987-02-01

We have constructed a model of the evolution of oxygen in a cement backfill which includes both its depletion through the canister corrosion reactions and its migration in the cement pores. The results indicate that the duration in which mild steel waste canisters may be subject to localised corrosion is very much shorter than the intended lifetime of the repository components, provided there is no external source of oxygen. For canisters spaced 1.2m apart, the model predicts a maximum aeration period of approximately 65 years, assuming high oxygen content and diffusivity in the backfill and low leakage current on the canisters (0.01 μA cm -2 ). In such a case a reducing environment is established throughout the backfill within this period. Under conditions of more restricted oxygen transport, reducing conditions are still established within a relatively short time in the immediate vicinity of the canisters, but the oxidation potential elsewhere in the backfill is then controlled by the uniform corrosion rate of the canisters. (author)

Non-resonant terahertz field enhancement in periodically arranged nanoslits

DEFF Research Database (Denmark)

Novitsky, Andrey; Ivinskaya, Aliaksandra; Zalkovskij, Maksim

2012-01-01

We analyze ultra strong non-resonant field enhancement of THz field in periodic arrays of nanoslits cut in ultrathin metal films. The main feature of our approach is that the slit size and metal film thickness are several orders of magnitude smaller than the wavelength λ of the impinging radiatio...... by the microscopic Drude-Lorentz model taking into account retardation processes in the metal film and validated by the finite difference frequency domain method. We expect sensor and modulation applications of the predicted giant broadband field enhancement.......We analyze ultra strong non-resonant field enhancement of THz field in periodic arrays of nanoslits cut in ultrathin metal films. The main feature of our approach is that the slit size and metal film thickness are several orders of magnitude smaller than the wavelength λ of the impinging radiation...... approaches the THz wavelength but before entering the Raleigh-Wood anomaly, the field enhancement in nanoslit stays close to that in a single isolated slit, i.e., the well-known inversefrequency dependence. Both regimes are non-resonant and thus extremely broadband for P

Auditory working memory predicts individual differences in absolute pitch learning.

Science.gov (United States)

Van Hedger, Stephen C; Heald, Shannon L M; Koch, Rachelle; Nusbaum, Howard C

2015-07-01

Absolute pitch (AP) is typically defined as the ability to label an isolated tone as a musical note in the absence of a reference tone. At first glance the acquisition of AP note categories seems like a perceptual learning task, since individuals must assign a category label to a stimulus based on a single perceptual dimension (pitch) while ignoring other perceptual dimensions (e.g., loudness, octave, instrument). AP, however, is rarely discussed in terms of domain-general perceptual learning mechanisms. This is because AP is typically assumed to depend on a critical period of development, in which early exposure to pitches and musical labels is thought to be necessary for the development of AP precluding the possibility of adult acquisition of AP. Despite this view of AP, several previous studies have found evidence that absolute pitch category learning is, to an extent, trainable in a post-critical period adult population, even if the performance typically achieved by this population is below the performance of a "true" AP possessor. The current studies attempt to understand the individual differences in learning to categorize notes using absolute pitch cues by testing a specific prediction regarding cognitive capacity related to categorization - to what extent does an individual's general auditory working memory capacity (WMC) predict the success of absolute pitch category acquisition. Since WMC has been shown to predict performance on a wide variety of other perceptual and category learning tasks, we predict that individuals with higher WMC should be better at learning absolute pitch note categories than individuals with lower WMC. Across two studies, we demonstrate that auditory WMC predicts the efficacy of learning absolute pitch note categories. These results suggest that a higher general auditory WMC might underlie the formation of absolute pitch categories for post-critical period adults. Implications for understanding the mechanisms that underlie the

Lacunarity, predictability and predictive instability of the daily pluviometric regime in the Iberian Peninsula

Directory of Open Access Journals (Sweden)

M. D. Martínez

2007-01-01

Full Text Available The complexity of the daily pluviometric regime of the Iberian Peninsula is analysed from the point of view of its lacunarity, predictability and predictive instability. The database consists of daily pluviometric records obtained from 43 rain gauges in Spain and Portugal for the period 1950–1990. Five different series are generated for every rain gauge. The first series is constituted by the consecutive daily amounts. The other four consist of dry spell lengths with respect to daily amount thresholds of 0.1, 1.0, 5.0 and 10.0 mm/day. A dry spell length is defined as the number of consecutive days with rainfall amounts below one of these thresholds. The empirical lacunarity for every rain gauge is well reproduced by two power laws, the exponents varying notably from one gauge to another. The spatial distribution of the lacunarity is characterised by a north to south or southeast gradient, thus suggesting that this parameter can be a useful tool to distinguish between different pluviometric regimes. The predictability of the five series is quantified by means of the rescaled analysis and the interpretation of the Hurst exponent. Its patterns reveal that most part of the Iberian Peninsula shows signs of persistence for the daily rainfall and the dry spell series, although persistence is only clearly manifested in some small domains. The instability of possible predictive algorithms is analysed through the Lyapunov exponents. They are only computed for the series of daily amounts and for dry lengths respect to the threshold level of 0.1 mm/day due to the short number of dry spells for larger threshold levels. The series of daily amounts depict the highest instability along the Mediterranean coast. The series of dry spells show an increasing instability from NE to SW Spain, with a relevant nucleus of high Lyapunov values in the south-western Atlantic coast. As a summary, lacunarity and Hurst and Lyapunov exponents depict a relevant spatial

Latent period and temporal aspects of lung cancer among miners

International Nuclear Information System (INIS)

Sun Shiquan; Yang Xiaoou; Yang Lan; Meng Xianyu; Liu Shengen; You Zhanyun

1984-01-01

Data of lung cancer happened in the miners of this reported mine area is of great value to investigate the temporal aspects of miner's lung cancer, owing to its plenty of cases, longterm follow up and mining as child miners in early years before liberation of China. This preliminary analysis showed that the induction-latent period increased with the decrease of age at the year-of-first-employment in this mine and the protraction of follow up. In other words, even they were exposed since childhood, the excess of lung cancer never appeared until certain age for carcinogenesis. Therefore, the long-term follow up and comprehensive analysis of induction-latent period, underground duration-of-employment, time and age at start of mining would be helpful to properly estimating risk level, discovering the cause and predicting the trend of lung cancer incidence. There is no evidence to show whether child miners are more sensitive than adult miners working at the same exposure conditions

Discrete changes of current statistics in periodically driven stochastic systems

International Nuclear Information System (INIS)

Chernyak, Vladimir Y; Sinitsyn, N A

2010-01-01

We demonstrate that the counting statistics of currents in periodically driven ergodic stochastic systems can show sharp changes of some of its properties in response to continuous changes of the driving protocol. To describe this effect, we introduce a new topological phase factor in the evolution of the moment generating function which is akin to the topological geometric phase in the evolution of a periodically driven quantum mechanical system with time-reversal symmetry. This phase leads to the prediction of a sign change for the difference of the probabilities to find even and odd numbers of particles transferred in a stochastic system in response to cyclic evolution of control parameters. The driving protocols that lead to this sign change should enclose specific degeneracy points in the space of control parameters. The relation between the topology of the paths in the control parameter space and the sign changes can be described in terms of the first Stiefel–Whitney class of topological invariants. (letter)

VERY LONG-PERIOD PULSATIONS BEFORE THE ONSET OF SOLAR FLARES

Energy Technology Data Exchange (ETDEWEB)

Tan, Baolin; Huang, Jing; Tan, Chengming; Zhang, Yin [Key Laboratory of Solar Activity, National Astronomical Observatories of Chinese Academy of Sciences, Beijing 100012 (China); Yu, Zhiqiang, E-mail: bltan@nao.cas.cn [School of Astronomy and Space Sciences, University of Chinese Academy of Sciences, Beijing 100049 (China)

2016-12-20

Solar flares are the most powerful explosions occurring in the solar system, which may lead to disastrous space weather events and impact various aspects of our Earth. It remains a big challenge in modern astrophysics to understand the origin of solar flares and predict their onset. Based on the analysis of soft X-ray emission observed by the Geostationary Operational Environmental Satellite , this work reports a new discovery of very long-periodic pulsations occurring in the preflare phase before the onset of solar flares (preflare-VLPs). These pulsations typically have periods of 8–30 min and last for about 1–2 hr. They are possibly generated from LRC oscillations of plasma loops where electric current dominates the physical process during magnetic energy accumulation in the source region. Preflare-VLPs provide essential information for understanding the triggering mechanism and origin of solar flares, and may be a convenient precursory indicator to help us respond to solar explosions and the corresponding disastrous space weather events.

Predicting Risk of Suicide Attempt Using History of Physical Illnesses From Electronic Medical Records

Science.gov (United States)

Luo, Wei; Tran, Truyen; Berk, Michael; Venkatesh, Svetha

2016-01-01

Background Although physical illnesses, routinely documented in electronic medical records (EMR), have been found to be a contributing factor to suicides, no automated systems use this information to predict suicide risk. Objective The aim of this study is to quantify the impact of physical illnesses on suicide risk, and develop a predictive model that captures this relationship using EMR data. Methods We used history of physical illnesses (except chapter V: Mental and behavioral disorders) from EMR data over different time-periods to build a lookup table that contains the probability of suicide risk for each chapter of the International Statistical Classification of Diseases and Related Health Problems, 10th Revision (ICD-10) codes. The lookup table was then used to predict the probability of suicide risk for any new assessment. Based on the different lengths of history of physical illnesses, we developed six different models to predict suicide risk. We tested the performance of developed models to predict 90-day risk using historical data over differing time-periods ranging from 3 to 48 months. A total of 16,858 assessments from 7399 mental health patients with at least one risk assessment was used for the validation of the developed model. The performance was measured using area under the receiver operating characteristic curve (AUC). Results The best predictive results were derived (AUC=0.71) using combined data across all time-periods, which significantly outperformed the clinical baseline derived from routine risk assessment (AUC=0.56). The proposed approach thus shows potential to be incorporated in the broader risk assessment processes used by clinicians. Conclusions This study provides a novel approach to exploit the history of physical illnesses extracted from EMR (ICD-10 codes without chapter V-mental and behavioral disorders) to predict suicide risk, and this model outperforms existing clinical assessments of suicide risk. PMID:27400764

Prediction of Bladder Cancer Recurrences Using Artificial Neural Networks

Science.gov (United States)

Zulueta Guerrero, Ekaitz; Garay, Naiara Telleria; Lopez-Guede, Jose Manuel; Vilches, Borja Ayerdi; Iragorri, Eider Egilegor; Castaños, David Lecumberri; de La Hoz Rastrollo, Ana Belén; Peña, Carlos Pertusa

Even if considerable advances have been made in the field of early diagnosis, there is no simple, cheap and non-invasive method that can be applied to the clinical monitorisation of bladder cancer patients. Moreover, bladder cancer recurrences or the reappearance of the tumour after its surgical resection cannot be predicted in the current clinical setting. In this study, Artificial Neural Networks (ANN) were used to assess how different combinations of classical clinical parameters (stage-grade and age) and two urinary markers (growth factor and pro-inflammatory mediator) could predict post surgical recurrences in bladder cancer patients. Different ANN methods, input parameter combinations and recurrence related output variables were used and the resulting positive and negative prediction rates compared. MultiLayer Perceptron (MLP) was selected as the most predictive model and urinary markers showed the highest sensitivity, predicting correctly 50% of the patients that would recur in a 2 year follow-up period.

On which term is the prediction of the behaviour of glass necessary and reliable?

International Nuclear Information System (INIS)

Lefevre, J.

1997-01-01

The author questions the ethics of the deep underground storage of high-level radioactive wastes. The time periods that are considered for the confinement are so long that it is completely impossible to predict the way of life of people at that time and the level of knowledge they will have reached. There is a total agreement about the ethics principle of not jeopardizing life and environment of future generations but the difficulty is to draw the limits of this protection. In the regulations of most countries 2 periods of time are defined: the first 500 years and 10.000 years. 500 years is the period of high heat releases due to the decay of most fission products and is also a reasonable time during which the confining site (structures and packages) stays accessible. 10.000 years is considered as the period of time during which predictions are reliable, beyond this time uncertainties become too important and more and more numerous. (A.C.)

Design and implementation of predictive current control of three-phase PWM rectifier using space-vector modulation (SVM)

International Nuclear Information System (INIS)

Bouafia, Abdelouahab; Gaubert, Jean-Paul; Krim, Fateh

2010-01-01

This paper is concerned with the design and implementation of current control of three-phase PWM rectifier based on predictive control strategy. The proposed predictive current control technique operates with constant switching frequency, using space-vector modulation (SVM). The main goal of the designed current control scheme is to maintain the dc-bus voltage at the required level and to achieve the unity power factor (UPF) operation of the converter. For this purpose, two predictive current control algorithms, in the sense of deadbeat control, are developed for direct controlling input current vector of the converter in the stationary α-β and rotating d-q reference frame, respectively. For both predictive current control algorithms, at the beginning of each switching period, the required rectifier average voltage vector allowing the cancellation of both tracking errors of current vector components at the end of the switching period, is computed and applied during a predefined switching period by means of SVM. The main advantages of the proposed predictive current control are that no need to use hysteresis comparators or PI controllers in current control loops, and constant switching frequency. Finally, the developed predictive current control algorithms were tested both in simulations and experimentally, and illustrative results are presented here. Results have proven excellent performance in steady and transient states, and verify the validity of the proposed predictive current control which is compared to other control strategies.

PERIOD ESTIMATION FOR SPARSELY SAMPLED QUASI-PERIODIC LIGHT CURVES APPLIED TO MIRAS

Energy Technology Data Exchange (ETDEWEB)

He, Shiyuan; Huang, Jianhua Z.; Long, James [Department of Statistics, Texas A and M University, College Station, TX (United States); Yuan, Wenlong; Macri, Lucas M., E-mail: lmacri@tamu.edu [George P. and Cynthia W. Mitchell Institute for Fundamental Physics and Astronomy, Department of Physics and Astronomy, Texas A and M University, College Station, TX (United States)

2016-12-01

We develop a nonlinear semi-parametric Gaussian process model to estimate periods of Miras with sparsely sampled light curves. The model uses a sinusoidal basis for the periodic variation and a Gaussian process for the stochastic changes. We use maximum likelihood to estimate the period and the parameters of the Gaussian process, while integrating out the effects of other nuisance parameters in the model with respect to a suitable prior distribution obtained from earlier studies. Since the likelihood is highly multimodal for period, we implement a hybrid method that applies the quasi-Newton algorithm for Gaussian process parameters and search the period/frequency parameter space over a dense grid. A large-scale, high-fidelity simulation is conducted to mimic the sampling quality of Mira light curves obtained by the M33 Synoptic Stellar Survey. The simulated data set is publicly available and can serve as a testbed for future evaluation of different period estimation methods. The semi-parametric model outperforms an existing algorithm on this simulated test data set as measured by period recovery rate and quality of the resulting period–luminosity relations.

Measuring the rotation periods of 4-10 Myr T-Tauri stars in the Orion OB1 association

Science.gov (United States)

Karim, Md Tanveer; Stassun, Keivan; Briceno, Cesar; Vivas, Kathy; Raetz, Stefanie; Calvet, Nuria; Mateu, Cecilia; Downes, Juan Jose; Hernandez, Jesus; Neuhäuser, Ralph; Mugrauer, Markus; Takahashi, Hidenori; Tachihara, Kengo; Chini, Rolf; YETI

2016-01-01

Most existing studies of young stellar populations have focused on the youngest (Investigaciones de Astronomía-Quest Equatorial Survey Team (CIDA-QUEST), the Young Exoplanet Transit Initiative (YETI) and from a Kitt Peak National Observatory (KPNO) campaign. We investigated stellar rotation periods according to the type of stars (Classical or Weak-lined T-Tauri stars) and their locations, to look for population-wide trends. We detected 563 periodic variables and 1411 non-periodic variables by investigating the light curves of these stars. We find that ~ 30% of Weak-line T-Tauri stars (WTTS) and ~ 20% of Classical T-Tauri stars (CTTS) are periodic. Though we did not find any noticeable difference in rotation period between CTTS and WTTS, our study does show a change in the overall rotation periods of stars 4-10 Myr old, consistent with predictions of angular momentum evolution models, an important constraint for theoretical models for an age range for which no similar data existed.

Risk adjusted surgical audit in gynaecological oncology: P-POSSUM does not predict outcome.

Science.gov (United States)

Das, N; Talaat, A S; Naik, R; Lopes, A D; Godfrey, K A; Hatem, M H; Edmondson, R J

2006-12-01

To assess the Physiological and Operative Severity Score for the enumeration of mortality and morbidity (POSSUM) and its validity for use in gynaecological oncology surgery. All patients undergoing gynaecological oncology surgery at the Northern Gynaecological Oncology Centre (NGOC) Gateshead, UK over a period of 12months (2002-2003) were assessed prospectively. Mortality and morbidity predictions using the Portsmouth modification of the POSSUM algorithm (P-POSSUM) were compared to the actual outcomes. Performance of the model was also evaluated using the Hosmer and Lemeshow Chi square statistic (testing the goodness of fit). During this period 468 patients were assessed. The P-POSSUM appeared to over predict mortality rates for our patients. It predicted a 7% mortality rate for our patients compared to an observed rate of 2% (35 predicted deaths in comparison to 10 observed deaths), a difference that was statistically significant (H&L chi(2)=542.9, d.f. 8, prisk of mortality for gynaecological oncology patients undergoing surgery. The P-POSSUM algorithm will require further adjustments prior to adoption for gynaecological cancer surgery as a risk adjusted surgical audit tool.

Periodic Solutions and S-Asymptotically Periodic Solutions to Fractional Evolution Equations

Directory of Open Access Journals (Sweden)

Jia Mu

2017-01-01

Full Text Available This paper deals with the existence and uniqueness of periodic solutions, S-asymptotically periodic solutions, and other types of bounded solutions for some fractional evolution equations with the Weyl-Liouville fractional derivative defined for periodic functions. Applying Fourier transform we give reasonable definitions of mild solutions. Then we accurately estimate the spectral radius of resolvent operator and obtain some existence and uniqueness results.

Prediction of seebeck coefficient for compounds without restriction to fixed stoichiometry: A machine learning approach.

Science.gov (United States)

Furmanchuk, Al'ona; Saal, James E; Doak, Jeff W; Olson, Gregory B; Choudhary, Alok; Agrawal, Ankit

2018-02-05

The regression model-based tool is developed for predicting the Seebeck coefficient of crystalline materials in the temperature range from 300 K to 1000 K. The tool accounts for the single crystal versus polycrystalline nature of the compound, the production method, and properties of the constituent elements in the chemical formula. We introduce new descriptive features of crystalline materials relevant for the prediction the Seebeck coefficient. To address off-stoichiometry in materials, the predictive tool is trained on a mix of stoichiometric and nonstoichiometric materials. The tool is implemented into a web application (http://info.eecs.northwestern.edu/SeebeckCoefficientPredictor) to assist field scientists in the discovery of novel thermoelectric materials. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Reexamining financial and economic predictability with new estimators of realized variance and variance risk premium

DEFF Research Database (Denmark)

Casas, Isabel; Mao, Xiuping; Veiga, Helena

This study explores the predictive power of new estimators of the equity variance risk premium and conditional variance for future excess stock market returns, economic activity, and financial instability, both during and after the last global financial crisis. These estimators are obtained from...... time-varying coefficient models are the ones showing considerably higher predictive power for stock market returns and financial instability during the financial crisis, suggesting that an extreme volatility period requires models that can adapt quickly to turmoil........ Moreover, a comparison of the overall results reveals that the conditional variance gains predictive power during the global financial crisis period. Furthermore, both the variance risk premium and conditional variance are determined to be predictors of future financial instability, whereas conditional...

Predicting the Lifetimes of Nuclear Waste Containers

Science.gov (United States)

King, Fraser

2014-03-01

As for many aspects of the disposal of nuclear waste, the greatest challenge we have in the study of container materials is the prediction of the long-term performance over periods of tens to hundreds of thousands of years. Various methods have been used for predicting the lifetime of containers for the disposal of high-level waste or spent fuel in deep geological repositories. Both mechanical and corrosion-related failure mechanisms need to be considered, although until recently the interactions of mechanical and corrosion degradation modes have not been considered in detail. Failure from mechanical degradation modes has tended to be treated through suitable container design. In comparison, the inevitable loss of container integrity due to corrosion has been treated by developing specific corrosion models. The most important aspect, however, is to be able to justify the long-term predictions by demonstrating a mechanistic understanding of the various degradation modes.

Complexity analyses show two distinct types of nonlinear dynamics in short heart period variability recordings

Science.gov (United States)

Porta, Alberto; Bari, Vlasta; Marchi, Andrea; De Maria, Beatrice; Cysarz, Dirk; Van Leeuwen, Peter; Takahashi, Anielle C. M.; Catai, Aparecida M.; Gnecchi-Ruscone, Tomaso

2015-01-01

Two diverse complexity metrics quantifying time irreversibility and local prediction, in connection with a surrogate data approach, were utilized to detect nonlinear dynamics in short heart period (HP) variability series recorded in fetuses, as a function of the gestational period, and in healthy humans, as a function of the magnitude of the orthostatic challenge. The metrics indicated the presence of two distinct types of nonlinear HP dynamics characterized by diverse ranges of time scales. These findings stress the need to render more specific the analysis of nonlinear components of HP dynamics by accounting for different temporal scales. PMID:25806002

Test of the periodic-orbit approximation in n-disk systems

International Nuclear Information System (INIS)

Wirzba, A.

1993-01-01

The scattering of a point particle in two dimensions from two (or three) equally-sized (and spaced) circular hard disks is one of the simplest classically hyperbolic scattering problems. Because of this simplicity such systems are well suited for the study of the semiclassical periodic-orbit approximation in the cycle expansion of the dynamical zeta function applied to a quantum-mechanical scattering problem. Especially the predictions of the semiclassical cycle expansion for the quantum-mechanical resonances can be tested in these n-disk systems. Whereas for high wave numbers the cycle expansion gives quite accurate results, there are systematic deviations for low wave numbers from the exact quantum-mechanical values. The low-lying quantum-mechanical resonance poles of the 2- and 3-disk problem are constructed and compared to the cycle-expansion results. The characteristic determinant of the scattering matrix is expanded in terms of simple traces which in turn are related to the classical periodic orbits and possible creeping contributions. It will be shown that for large separations of the disks the correct resonance-pole positions can be extracted just from the knowledge of the lowest traces whose semiclassical limit are the fundamental periodic orbits. Creeping-orbit corrections are shown to be small. (orig.)

Tracing temperature in a nanometer size region in a picosecond time period.

Science.gov (United States)

Nakajima, Kaoru; Kitayama, Takumi; Hayashi, Hiroaki; Matsuda, Makoto; Sataka, Masao; Tsujimoto, Masahiko; Toulemonde, Marcel; Bouffard, Serge; Kimura, Kenji

2015-08-21

Irradiation of materials with either swift heavy ions or slow highly charged ions leads to ultrafast heating on a timescale of several picosecond in a region of several nanometer. This ultrafast local heating result in formation of nanostructures, which provide a number of potential applications in nanotechnologies. These nanostructures are believed to be formed when the local temperature rises beyond the melting or boiling point of the material. Conventional techniques, however, are not applicable to measure temperature in such a localized region in a short time period. Here, we propose a novel method for tracing temperature in a nanometer region in a picosecond time period by utilizing desorption of gold nanoparticles around the ion impact position. The feasibility is examined by comparing with the temperature evolution predicted by a theoretical model.

Heart period variability and psychopathology in urban boys at risk for delinquency.

Science.gov (United States)

Pine, D S; Wasserman, G A; Miller, L; Coplan, J D; Bagiella, E; Kovelenku, P; Myers, M M; Sloan, R P

1998-09-01

To examine associations between heart period variability (HPV) and psychopathology in young urban boys at risk for delinquency, a series of 697-11-year-old younger brothers of adjudicated delinquents received a standardized psychiatric evaluation and an assessment of heart period variability (HPV). Psychiatric symptoms were rated in two domains: externalizing and internalizing psychopathology. Continuous measures of both externalizing and internalizing psychopathology were associated with reductions in HPV components related to parasympathetic activity. These associations could not be explained by a number of potentially confounding variables, such as age, ethnicity, social class, body size, or family history of hypertension. Although familial hypertension predicted reduced HPV and externalizing psychopathology, associations between externalizing psychopathology and HPV were independent of familial hypertension. Psychiatric symptoms are associated with reduced HPV in young urban boys at risk for delinquency.

Regime shifts limit the predictability of land-system change

DEFF Research Database (Denmark)

Müller, Daniel; Sun, Zhanli; Vongvisouk, Thoumthone

2014-01-01

Payment schemes for ecosystem services such as Reducing Emissions from Deforestation and forest Degradation (REDD) rely on the prediction of ‘business-as-usual’ scenarios to ensure that emission reductions from carbon credits are additional. However, land systems often undergo periods of nonlinear...... and abrupt change that invalidate predictions calibrated on past trends. Rapid land-system change can occur when critical thresholds in broad-scale underlying drivers such as commodity prices and climate conditions are crossed or when sudden events such as political change or natural disasters punctuate long...

Resting alpha activity predicts learning ability in alpha neurofeedback

Directory of Open Access Journals (Sweden)

Wenya eNan

2014-07-01

Full Text Available Individuals differ in their ability to learn how to regulate the alpha activity by neurofeedback. This study aimed to investigate whether the resting alpha activity is related to the learning ability of alpha enhancement in neurofeedback and could be used as a predictor. A total of 25 subjects performed 20 sessions of individualized alpha neurofeedback in order to learn how to enhance activity in the alpha frequency band. The learning ability was assessed by three indices respectively: the training parameter changes between two periods, within a short period and across the whole training time. It was found that the resting alpha amplitude measured before training had significant positive correlations with all learning indices and could be used as a predictor for the learning ability prediction. This finding would help the researchers in not only predicting the training efficacy in individuals but also gaining further insight into the mechanisms of alpha neurofeedback.

Do slow orbital periodicities appear in the record of earth's magnetic reversals?

Science.gov (United States)

Stothers, Richard B.

1987-01-01

Time-series spectral analysis has been performed on the dates of geomagnetic reversals of the last 20 Myr BP and earlier. Possible evidence is found from the presence of high spectral peaks for two very long periodicities, 0.4 Myr and 1.3 Myr, that may be associated with slow variations of the earth's orbital eccentricity as predicted by Berger. However, statistical significance tests and a number of other arguments do not confirm the two detections.

Challenges estimating the return period of extreme floods for reinsurance applications

Science.gov (United States)

Raven, Emma; Busby, Kathryn; Liu, Ye

2013-04-01

Mapping and modelling extreme natural events is fundamental within the insurance and reinsurance industry for assessing risk. For example, insurers might use a 1 in 100-year flood hazard map to set the annual premium of a property, whilst a reinsurer might assess the national scale loss associated with the 1 in 200-year return period for capital and regulatory requirements. Using examples from a range of international flood projects, we focus on exploring how to define what the n-year flood looks like for predictive uses in re/insurance applications, whilst considering challenges posed by short historical flow records and the spatial and temporal complexities of flood. First, we shall explore the use of extreme value theory (EVT) statistics for extrapolating data beyond the range of observations in a marginal analysis. In particular, we discuss how to estimate the return period of historical flood events and explore the impact that a range of statistical decisions have on these estimates. Decisions include: (1) selecting which distribution type to apply (e.g. generalised Pareto distribution (GPD) vs. generalised extreme value distribution (GEV)); (2) if former, the choice of the threshold above which the GPD is fitted to the data; and (3) the necessity to perform a cluster analysis to group flow peaks to temporally represent individual flood events. Second, we summarise a specialised multivariate extreme value model, which combines the marginal analysis above with dependence modelling to generate industry standard event sets containing thousands of simulated, equi-probable floods across a region/country. These events represent the typical range of anticipated flooding across a region and can be used to estimate the largest or most widespread events that are expected to occur. Finally, we summarise how a reinsurance catastrophe model combines the event set with detailed flood hazard maps to estimate the financial cost of floods; both the full event set and also

Periodic pulling of the drift instability in a thermal plasma

International Nuclear Information System (INIS)

Abrams, R.H. Jr.

1970-01-01

The primary objective of this thesis is to show that a mode of oscillation in a plasma can be represented by a van der Pol oscillator. The results of an experiment performed on a drift wave in a Q-machine are interpreted in terms of a mechanism developed by Lashinsky. The mechanism, called periodic pulling, predicts a specific kind of spectrum for certain experimental conditions when a van der Pol oscillator is perturbed by a small signal. The observed spectrum, along with other observations, lends credence to the van der Pol oscillator model of a plasma mode

Application of Periodic 3DPCM for Core Monitoring System

International Nuclear Information System (INIS)

Jeong, Wi-Soo; Lee, Hae-Chan; Kim, Hyeong-Seog; Lee, Chang-Kue; Park, Sang-weon; Baek, Jin-su

2014-01-01

The OASIS (Online core Analysis and Simulation System) was developed for WH type PWR which has movable in-core detector. 3DPCM (3D Power Connection Method) was also developed to measure 3D core power distribution using the fixed in-core detector signals and tested for KSNP (Korea Standard Nuclear Plant) such as OPR1000 and APR1400. According to previous study, 3DPCM coupling with neutronics code shows high accuracy. However, this method requires the neutronics code results at each calculation. Therefore, the long calculation time makes it impractical in the online monitoring system requiring the real-time 3D power distribution. In this paper, the 3DPCM based alternative methodology which called periodic 3DPCM is proposed to reduce the calculation time within the reasonable accuracy. The periodic 3DPCM is proposed to reduce the number of neutronics calculation with reasonable accuracy for the application to the online monitoring system development. The periodic 3DPCM is analyzed by 3 cases of sensitivity studies. The errors for the results of power changing operation, ASI changing simulation, and lead control rod insertion are bounded in 0.25%, 1.07%, and 1.15%, respectively. If the update time is shorten as 1 hour, the errors for power changing operation and ASI changing simulation are bounded in 0.07% and 0.56%, respectively. As a result, the update time of 1 hour and prompt update at 30% control rod position change are reasonable considering both conservativeness and effectiveness to update the prediction values. OASIS program utilizing periodic 3DPCM is verified using the plant measurement data and snapshot files which were generated during 45 days operation

Prediction of Chevrel superconducting phases

International Nuclear Information System (INIS)

Savitskij, E.M.; Kiseleva, N.N.

1978-01-01

Made is an attempt of predicting the possibility of formation of compounds of Mo 3 Se 4 type structure having critical temperatures of transition into superconducting state more than 4.2 K. Cybernetic method of teaching an electronic computer to form notions is used for prediction. Prediction system constructs logic dependence of forming Chevrel superconducting phase of the Asub(x)Bsub(6)Ssub(8) composition (A being an element of the periodic system; B=Cr, Mo, W, Re) and Asub(x)Bsub(6)Ssub(8) compounds having a critical temperature of more than 4.2 K on the properties of A and B elements. A conclusion is made that W, Re, Cr do not form Chevrel phases of the Asub(x)Bsub(6)Ssub(8) composition as B component. Be, Hg, Ra, B, Ac are the reserve for obtaining Asub(x)Mosub(6)Ssub(8) phases. Agsub(x)Mosub(6)Ssub(8) compound may have a high critical temperature. The ways of a critical temperature increase for Chevrel phases are connected with the search of optimal technological conditions for already known superconducting compounds and also with introduction of impurities fixing a distance between sulfur cubes

FREEZING AND THAWING TIME PREDICTION METHODS OF FOODS II: NUMARICAL METHODS

Directory of Open Access Journals (Sweden)

Yahya TÜLEK

1999-03-01

Full Text Available Freezing is one of the excellent methods for the preservation of foods. If freezing and thawing processes and frozen storage method are carried out correctly, the original characteristics of the foods can remain almost unchanged over an extended periods of time. It is very important to determine the freezing and thawing time period of the foods, as they strongly influence the both quality of food material and process productivity and the economy. For developing a simple and effectively usable mathematical model, less amount of process parameters and physical properties should be enrolled in calculations. But it is a difficult to have all of these in one prediction method. For this reason, various freezing and thawing time prediction methods were proposed in literature and research studies have been going on.

Can superconductivity be predicted with the aid of pattern recognition techniques

International Nuclear Information System (INIS)

Pijpers, F.W.

1982-01-01

Pattern recognition techniques were employed in order to investigate the possibility to find features of the elements of the periodic system that may be relevant for the description of their behaviour with respect to superconductivity. Learning machines were constructed using those elements of the periodic system whose superconducting properties have been well studied. Relevant features appear to be the electronic work function and the number of valence electrons as given by Miedema, the specific heat, the heat of melting, the heat of sublimation, the melting point and the atomic radius. The learning machines have a predicting capability of the order of 90%. The predictive power of these machines concerning the superconducting behaviour of the alkali and alkaline-earth metals belonging to a given test set, however, appears to be less convincing

Predicting temporal trends in total absenteeism rates for civil service employees of a federal public health agency.

Science.gov (United States)

Spears, D Ross; McNeil, Carrie; Warnock, Eli; Trapp, Jonathan; Oyinloye, Oluremi; Whitehurst, Vanessa; Decker, K C; Chapman, Sandy; Campbell, Morris; Meechan, Paul

2014-06-01

This study evaluates the predictability in temporal absences trends due to all causes (total absenteeism) among employees at a federal agency. The objective is to determine how leave trends vary within the year, and determine whether trends are predictable. Ten years of absenteeism data from an attendance system were analyzed for rates of total absence. Trends over a 10-year period followed predictable and regular patterns during a given year that correspond to major holiday periods. Temporal trends in leave among small, medium, and large facilities compared favorably with the agency as a whole. Temporal trends in total absenteeism rates for an organization can be determined using its attendance system. The ability to predict employee absenteeism rates can be extremely helpful for management in optimizing business performance and ensuring that an organization meets its mission.

Prediction of pneumonia hospitalization in adults using health checkup data.

Science.gov (United States)

Uematsu, Hironori; Yamashita, Kazuto; Kunisawa, Susumu; Otsubo, Tetsuya; Imanaka, Yuichi

2017-01-01

Community-acquired pneumonia is a common cause of hospitalization, and pneumococcal vaccinations are recommended for high-risk individuals. Although risk factors for pneumonia have been identified, there are currently no pneumonia hospitalization prediction models based on the risk profiles of healthy subjects. This study aimed to develop a predictive model for pneumonia hospitalization in adults to accurately identify high-risk individuals to facilitate the efficient prevention of pneumonia. We conducted a retrospective database analysis using health checkup data and health insurance claims data for residents of Kyoto prefecture, Japan, between April 2010 and March 2015. We chose adults who had undergone health checkups in the first year of the study period, and tracked pneumonia hospitalizations over the next 5 years. Subjects were randomly divided into training and test sets. The outcome measure was pneumonia hospitalization, and candidate predictors were obtained from the health checkup data. The prediction model was developed and internally validated using a LASSO logistic regression analysis. Lastly, we compared the new model with comparative models. The study sample comprised 54,907 people who had undergone health checkups. Among these, 921 were hospitalized for pneumonia during the study period. The c-statistic for the prediction model in the test set was 0.71 (95% confidence interval: 0.69-0.73). In contrast, a comparative model with only age and comorbidities as predictors had a lower c-statistic of 0.55 (95% confidence interval: 0.54-0.56). Our predictive model for pneumonia hospitalization performed better than comparative models, and may be useful for supporting the development of pneumonia prevention measures.

From alchemy to super-actinides. The preparation, physical-chemical properties and the limits of the Periodic Table

International Nuclear Information System (INIS)

Kuruc, J.

2016-01-01

In this review a brief history of the discovery of the periodic law, discoveries of elements from the epoch of alchemy to the synthesis of actinides and transactinides is described. The preparation of transactinides (elements with Z ≥ 104 to Z = 118) is discussed, using already proposed names of the elements with Z = 113, 115, 117 and 118: nihonium, moscovium, tennessine and oganesson. The Periodic Tables are presented in short form, the long 18-column and 32-column form. The periodic table containing elements of 8"t"h and 9"t"h periods and its possible range is discussed. By extrapolation of decay half-time of the heaviest isotopes of elements from thorium up to oganesson decay half-time of unbihexium (Z = 126) was predicted about 378 seconds. (author

Simulation-Based Prediction of Equivalent Continuous Noises during Construction Processes.

Science.gov (United States)

Zhang, Hong; Pei, Yun

2016-08-12

Quantitative prediction of construction noise is crucial to evaluate construction plans to help make decisions to address noise levels. Considering limitations of existing methods for measuring or predicting the construction noise and particularly the equivalent continuous noise level over a period of time, this paper presents a discrete-event simulation method for predicting the construction noise in terms of equivalent continuous level. The noise-calculating models regarding synchronization, propagation and equivalent continuous level are presented. The simulation framework for modeling the noise-affected factors and calculating the equivalent continuous noise by incorporating the noise-calculating models into simulation strategy is proposed. An application study is presented to demonstrate and justify the proposed simulation method in predicting the equivalent continuous noise during construction. The study contributes to provision of a simulation methodology to quantitatively predict the equivalent continuous noise of construction by considering the relevant uncertainties, dynamics and interactions.

Theoretical growth rates, periods, and pulsation constants for long-period variables

International Nuclear Information System (INIS)

Fox, M.W.; Wood, P.R.