scholarly journals Cretaceous amniote integuments recorded through a taphonomic process unique to resins

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Sergio Álvarez-Parra ◽  
Xavier Delclòs ◽  
Mónica M. Solórzano-Kraemer ◽  
Luis Alcalá ◽  
Enrique Peñalver
Keyword(s):  
The Other ◽  
Characteristic Scale ◽  
Sticky Traps ◽  
Fossil Records ◽  
Mammalian Hair

AbstractFossil records of vertebrate integuments are relatively common in both rocks, as compressions, and amber, as inclusions. The integument remains, mainly the Mesozoic ones, are of great interest due to the panoply of palaeobiological information they can provide. We describe two Spanish Cretaceous amber pieces that are of taphonomic importance, one bearing avian dinosaur feather remains and the other, mammalian hair. The preserved feather remains originated from an avian dinosaur resting in contact with a stalactite-shaped resin emission for the time it took for the fresh resin to harden. The second piece shows three hair strands recorded on a surface of desiccation, with the characteristic scale pattern exceptionally well preserved and the strands aligned together, which can be considered the record of a tuft. These assemblages were recorded through a rare biostratinomic process we call “pull off vestiture” that is different from the typical resin entrapment and embedding of organisms and biological remains, and unique to resins. The peculiarity of this process is supported by actualistic observations using sticky traps in Madagascar. Lastly, we reinterpret some exceptional records from the literature in the light of that process, thus bringing new insight to the taphonomic and palaeoecological understanding of the circumstances of their origins.

scholarly journals Magnetic Decreases (MDs) and mirror modes: two different plasma β changing mechanisms

2010 ◽  
Vol 17 (5) ◽  
pp. 467-479 ◽  
Author(s):  
B. T. Tsurutani ◽  
G. S. Lakhina ◽  
O. P. Verkhoglyadova ◽  
E. Echer ◽  
F. L. Guarnieri
Keyword(s):  
Free Energy ◽  
Energetic Particle ◽  
Ponderomotive Force ◽  
Interplanetary Space ◽  
The Other ◽  
Characteristic Scale ◽  
Physical Processes ◽  
Scale Size ◽  
Mirror Mode ◽  
Energetic Particle Transport

Abstract. We discuss two different physical processes that create localized high β plasma regions. One is nonlinear wave-steepening, generating magnetic decreases (MDs) by a ponderomotive force. The other is the mirror instability generating alternating high and low β plasma regions. It is demonstrated that MDs and mirror modes are observationally quite different structures. MDs spatially occur in interplanetary space and mirror modes primarily in planetary magnetosheaths. MDs are characterized by: 1) variable (exponentially decreasing number with increasing) angular changes, 2) variable (exponentially decreasing) thicknesses, and 3) no characteristic inter-event spacings. In sharp contrast, mirror modes are characterized by: 1) little or no angular changes across the structures, 2) a characteristic scale size, and 3) are quasiperiodic in nature. Arguments are presented for the recently observed magnetic dips in the heliosheath being mirror mode structures. The sources of free energy for instability are discussed. Both structures are important for energetic particle transport in astrophysical and heliospheric plasmas.

Evaluation of Foliar-Applied Insecticides on Abundance of Parasitoids of Bemisia argentifolii (Homoptera: Aleyrodidae) in Vegetables2

2000 ◽  
Vol 35 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Alvin M. Simmons ◽  
D. Michael Jackson
Keyword(s):  
Relative Abundance ◽  
Kansas City ◽  
The Other ◽  
Bemisia Argentifolii ◽  
Vegetable Crops ◽  
Sticky Traps ◽  
Bayer Corporation ◽  
Field Plots

The relative abundance of parasitoids of Bemisia argentifolii Bellows & Perring was studied in insecticide-treated and untreated field plots of cantaloupe, collard, cucumber, and tomato. Treatments were made using foliar-applied chlorpyrifos (Lorsban®, DowElanco, Indianapolis, IN) in 1994, and foliar-applied imidacloprid (Provado®, Bayer Corporation, Kansas City, MO) in 1995 and 1996. Yellow sticky cards were used to monitor parasitoids associated with B. argentifolii in plots untreated or treated weekly in 1994 and bi-weekly in 1995 and 1996 with insecticide over 10 wks. The abundance of parasitoids varied among fields and across years. Five species of parasitoids were captured: Eretmocerus sp., Encarsia nigricephala Dozier, E. pergandiella Howard, E. quaintancei Howard, and E. strenua (Silvestri). The first three species comprised approximately 95% of the captured parasitoids. Parasitoids persisted in all field locations and crops whether the vegetables were treated or not. Parasitoids were captured in the treated plots throughout the study, although in fewer numbers than in the untreated plots. Overall, about 60 to 70% of parasitoids captured were from plots without insecticide. Whitefly captures on the sticky traps were relatively high in collard compared with the other crops studied. In addition, more E. nigricephala and E. pergandiella were collected in collard than in the other vegetable crops.

The first fossil horntail wasp (Hymenoptera: Siricidae) from Lower Cretaceous Crato Formation in Brazil

2020 ◽  
Vol 3 (4) ◽  
pp. 382-389
Author(s):  
CORENTIN JOUAULT ◽  
JEAN-MARC POUILLON ◽  
ANDRÉ NEL
Keyword(s):  
Lower Cretaceous ◽  
New Genus ◽  
Sister Group ◽  
The Other ◽  
Northeastern Brazil ◽  
Crown Group ◽  
The Family ◽  
Group Relationships ◽  
Fossil Records ◽  
New Discovery

A new wood wasp, Cratosirex sennlaubi gen. et sp. nov., is described and figured from one specimen collected from the Lower Cretaceous Crato Formation in northeastern Brazil. This new genus is placed in the new siricid subfamily Cratosiricinae subfam. nov., based on a combination of plesiomorphic and autapomorphic characters. The presence of small and sub-equal forewing cells 1R1 and 2R1 is a synapomorphy with the extant subfamily Siricinae, absent in the other extinct subfamilies †Auliscinae and †Gigasiricinae, supporting a sister group relationships with the Siricinae. Our new discovery expands the distribution range of Siricidae fossil records, highlights the antiquity of the family, and emphasizes the need for more studies of this particular insect lineage in the Mesozoic deposits. Currently, all the representatives of the crown group of the extant Siricidae are Cenozoic.

scholarly journals The inseparability of sampling and time and its influence on attempts to unify the molecular and fossil records

Paleobiology ◽  
2018 ◽  
Vol 44 (4) ◽  
pp. 561-574 ◽  
Author(s):  
Melanie J. Hopkins ◽  
David W. Bapst ◽  
Carl Simpson ◽  
Rachel C. M. Warnock
Keyword(s):  
Mathematical Models ◽  
Fossil Record ◽  
Evolutionary History ◽  
Molecular Data ◽  
The Other ◽  
Deep Time ◽  
Approaches To Studying ◽  
Data Source ◽  
Fossil Records ◽  
Estimate Uncertainty

AbstractThe two major approaches to studying macroevolution in deep time are the fossil record and reconstructed relationships among extant taxa from molecular data. Results based on one approach sometimes conflict with those based on the other, with inconsistencies often attributed to inherent flaws of one (or the other) data source. Any contradiction between the molecular and fossil records represents a failure of our ability to understand the imperfections of our data, as both are limited reflections of the same evolutionary history. We therefore need to develop conceptual and mathematical models that jointly explain our observations in both records. Fortunately, the different limitations of each record provide an opportunity to test or calibrate the other, and new methodological developments leverage both records simultaneously. However, we must reckon with the distinct relationships between sampling and time in the fossil record and molecular phylogenies. These differences impact our recognition of baselines and the analytical incorporation of age estimate uncertainty.

DENSIDAD POBLACIONAL DE MOSCABLANCA Bemisia spp. (HEMIPTERA: ALEYROIDIDAE) EN EL VALLE DE GUAYMAS-EMPALME, SONORA, MÉXICO/ POPULATION DENSITY OF WHITEFLY IN THE GUAYMAS-EMPALME VALLEY, SONORA, MEXICO

Biotecnia ◽  
2016 ◽  
Vol 18 (3) ◽  
pp. 9-13
Author(s):  
Juan José Pacheco-Covarrubias ◽  
Joel Soto Nolasco ◽  
Juan Manuel Valenzuela Valenzuela
Keyword(s):  
Population Density ◽  
Population Growth ◽  
Bemisia Tabaci ◽  
The Other ◽  
Sticky Traps ◽  
Influence Of Temperature ◽  
Heat Units ◽  
Pest Infestation ◽  
Important Pest ◽  
Number Of Individuals

La mosca blanca (Bemisia tabaci) es la plaga más importante en el valle de Guaymas-Empalme, Sonora. Se determinó su densidad poblacional mediante la captura regional de adultos a través de trampas amarillas pegajosas. Los resultados indican valores de pendiente de 0.011, 0.014, 0.0045 y 0.0027 para los ciclos 2011-12, 2012-13, 2013-14 y 2014-15, respectivamente; dichos valores son diferentes estadísticamente entre sí (0.01) prueba de “t”. Por otra parte, el número promedio de individuos capturados por semana para los ciclos antes mencionados fue de 0.67, 0.80, 0.31 y 0.14, respectivamente. Finalmente, el cálculo del número de generaciones que en teoría se pueden acumular mediante Unidades Calor fue de 13.5, 9.36, 15.32, 11.96, para los ciclos antes mencionados. Los resultados no detectan evidencia determinante de la influencia de la temperatura ni del alimento sobre el crecimiento poblacional de la plaga, por lo que el manejo de focos de infestación de la plaga y el ordenamiento de fechas de cultivos son determinante para la definición del estatus fitosanitario de la plaga. ABSTRACT Whitefly is the most important pest in the Guaymas-Empalme valley, Sonora. México. The population density of whitefly was evaluated trough regional capture of whitefly adults through yellow sticky traps. The data indicate slope values of 0.011, 0.014, 0.0045 and 0.0027 for 2011-12 , 2012-13, 2013-14 and 2014-15 cycles, respectively; these values are statistically different from each other (0.01) test “t”. Moreover, the average number of individuals caught weekly was 0.67, 0.80, 0.31 and 0.14. Finally, the number of generations which in theory can be accumulated by heat units was 13.5, 9.36, 15.32, 11.96. The results did not detect evidence of the influence of temperature and crops on the population growth of the pest; on the other hand the management of outbreaks of pest infestation and crop dates control are crucial for defining the pest status.

scholarly journals The peculiar Jeans length

2021 ◽  
Vol 81 (8) ◽  
Author(s):  
Christos G. Tsagas
Keyword(s):  
Relative Motion ◽  
Deceleration Parameter ◽  
Bulk Flow ◽  
The Other ◽  
Characteristic Scale ◽  
Hubble Expansion ◽  
Other Hand ◽  
Peculiar Motion ◽  
The Universe

AbstractTypical observers in the universe do not follow the smooth Hubble expansion, but move relative to it. Such bulk peculiar motions introduce a characteristic scale that is closely analogous to the familiar Jeans length. This “peculiar Jeans length” marks the threshold below which relative-motion effects dominate the linear kinematics. There, cosmological measurements can vary considerably between the bulk-flow frame and that of the Hubble expansion, entirely due to the observers’ relative motion. When dealing with the deceleration parameter, we find that the peculiar Jeans length varies between few and several hundred Mpc. On these scales, the deceleration parameter measured by the bulk-flow observers can be considerably larger (or smaller) than its Hubble-frame counterpart. This depends on whether the peculiar motion is locally expanding (or contracting), relative to the background expansion. Then, provided expanding and contracting bulk flows are randomly distributed, nearly half of the observers in the universe could be misled to think that their cosmos is over-decelerated. The rest of them, on the other hand, may come to believe that their universe is under-decelerated, or even accelerated in some cases. We make two phenomenological predictions that could in principle support this scenario.

HYMENOPTEROUS PARASITOIDS OF THE EASTERN JUNIPER BARK BEETLE, PHLOEOSINUS DENTATUS (COLEOPTERA: SCOLYTIDAE)

1974 ◽  
Vol 106 (8) ◽  
pp. 869-872 ◽  
Author(s):  
C. Wayne Berisford
Keyword(s):  
Bark Beetle ◽  
The Other ◽  
Southern Pine Beetle ◽  
Southern Pine ◽  
Alternate Host ◽  
Sticky Traps ◽  
Red Cedar ◽  
Pine Beetle

AbstractNine species of hymenopterous parasitoids were trapped on sticky traps as they were attracted to red cedar logs infested with the eastern jumper bark beetle, Phloeosinus dentatus (Say). All were successfully reared from infested logs. The parasitoids Cheiropachus arizoninsis (Ashmead), Eurytoma aequabilis Bugbee, Heydenia unica Cook & Davis, and Spathius impus Matthews were reared directly from P. dentatus larvae.Five species of parasitoids reared from P. dentatus larvae or from infested logs commonly attack the southern pine beetle and Ips spp. beetles, indicating that P. dentatus may be an important alternate host when the other host populations are low.

scholarly journals Notes on the Herpetofauna of Kampung Giam, Padawan, Sarawak

1970 ◽  
Vol 3 (2) ◽  
pp. 47-52
Author(s):  
Ramlah Zainudin ◽  
Jennifer Ubung Nawan ◽  
Marcie Elene Marcus Jopony ◽  
Muhammad Fadzil Amram ◽  
Nordianah Nasip ◽  
...  
Keyword(s):  
Conservation Management ◽  
The Other ◽  
Species Assemblage ◽  
Sticky Traps ◽  
Other Hand ◽  
The Family ◽  
Study Sites

Padawan lies at one of the proposed Sarawak Geopark, yet information on the herpetofauna of the area islimited. A survey was conducted from 16 August 2008 to 24 August 2008 to determine species assemblage andrelative abundance of herpetofauna at Kampung Giam, Padawan. Sampling involved stream and forest transects,quadrat, pitfall and sticky traps at four study sites along Sungai Sewa. A total of 13 species of frogs (62individuals), eight species of lizards (nine individuals) and four species of snake (one individual each) werecaptured. The area was dominated by the family of Ranidae (83.9%), followed by Bufonidae (8%),Dicroglossidae (3.2%), Microhylidae (3.2%) and Megophryidae (1.6%). The most abundant and dominantspecies was Odorrana hosii, with 36 individuals caught. In addition three endemic Bornean frogs namelyLimnonectes leporinus, Meristogenys phaeomerus and Meristogenys orphnocnemis were also captured in thisstudy, which account for 33.33% endemism. The reptiles caught, on the other hand, were relatively low withonly 12 species and 13 individuals captured. Nevertheless this study provides an increment of Sarawak faunaldatabase for conservation management of Bornean fauna as well as the Sarawak Geopark.

Stromatoporoids from the Famennian (Devonian) Wabamun Formation, Normandville oilfield, north–central Alberta, Canada

1988 ◽  
Vol 62 (03) ◽  
pp. 411-419 ◽  
Author(s):  
Colin W. Stearn
Keyword(s):  
Patch Reef ◽  
Abundant Species ◽  
The Other ◽  
North Central ◽  
Biotic Crisis

Stromatoporoids are the principal framebuilding organisms in the patch reef that is part of the reservoir of the Normandville field. The reef is 10 m thick and 1.5 km2in area and demonstrates that stromatoporoids retained their ability to build reefal edifices into Famennian time despite the biotic crisis at the close of Frasnian time. The fauna is dominated by labechiids but includes three non-labechiid species. The most abundant species isStylostroma sinense(Dong) butLabechia palliseriStearn is also common. Both these species are highly variable and are described in terms of multiple phases that occur in a single skeleton. The other species described areClathrostromacf.C. jukkenseYavorsky,Gerronostromasp. (a columnar species), andStromatoporasp. The fauna belongs in Famennian/Strunian assemblage 2 as defined by Stearn et al. (1988).

D. The Line Spectrum of Pulsating Variable Stars

1967 ◽  
Vol 28 ◽  
pp. 207-244
Author(s):  
R. P. Kraft
Keyword(s):  
Variable Stars ◽  
The Other ◽  
Line Spectrum ◽  
Afternoon Session ◽  
Empirical Information ◽  
Pulsating Variable Stars ◽  
Almost Continuous ◽  
Informal Approach

(Ed. note:Encouraged by the success of the more informal approach in Christy's presentation, we tried an even more extreme experiment in this session, I-D. In essence, Kraft held the floor continuously all morning, and for the hour and a half afternoon session, serving as a combined Summary-Introductory speaker and a marathon-moderator of a running discussion on the line spectrum of cepheids. There was almost continuous interruption of his presentation; and most points raised from the floor were followed through in detail, no matter how digressive to the main presentation. This approach turned out to be much too extreme. It is wearing on the speaker, and the other members of the symposium feel more like an audience and less like participants in a dissective discussion. Because Kraft presented a compendious collection of empirical information, and, based on it, an exceedingly novel series of suggestions on the cepheid problem, these defects were probably aggravated by the first and alleviated by the second. I am much indebted to Kraft for working with me on a preliminary editing, to try to delete the side-excursions and to retain coherence about the main points. As usual, however, all responsibility for defects in final editing is wholly my own.)

Sign in / Sign up

Export Citation Format

Share Document