A High-Frequency Homogenization Approach Near the Dirac Points in Bubbly Honeycomb Crystals

Abstract In (Ammari et al. in SIAM J Math Anal. arXiv:1811.03905), the existence of a Dirac dispersion cone in a bubbly honeycomb phononic crystal comprised of bubbles of arbitrary shape is shown. The aim of this paper is to prove that, near the Dirac points, the Bloch eigenfunctions is the sum of two eigenmodes. Each eigenmode can be decomposed into two components: one which is slowly varying and satisfies a homogenized equation, while the other is periodic across each elementary crystal cell and is highly oscillating. The slowly oscillating components of the eigenmodes satisfy a system of Dirac equations. Our results in this paper prove for the first time a near-zero effective refractive index near the Dirac points for the plane-wave envelopes of the Bloch eigenfunctions in a sub-wavelength metamaterial. They are illustrated by a variety of numerical examples. We also compare and contrast the behaviour of the Bloch eigenfunctions in the honeycomb crystal with that of their counterparts in a bubbly square crystal, near the corner of the Brillouin zone, where the maximum of the first Bloch eigenvalue is attained.

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The Atmospheric δ13C Record as Derived from 56 Pinyon Trees at 14 Sites in the Southwestern United States

Radiocarbon ◽

10.1017/s0033822200012054 ◽

1989 ◽

Vol 31 (03) ◽

pp. 469-474 ◽

Cited By ~ 44

Author(s):

S W Leavitt ◽

Austin Long

Keyword(s):

High Frequency ◽

Ice Core ◽

Ring Width ◽

Ice Cores ◽

The Other ◽

Core Data ◽

Single Tree ◽

Pinyon Pine ◽

The Individual ◽

First Time

We have developed a master δ13C chronology from 14 pinyon pine sites in 6 states of the southwestern U S. Two of the individual isotopic chronologies, reported here for the first time, and 10 of those previously reported (Leavitt & Long, 1986; 1988) are from sites where cores from 4 trees were pooled prior to analysis, and the other 2 are merged from groups of 4 single-tree chronologies (sites) developed in an earlier phase of research (Leavitt & Long, 1985). Regressions of first differences of ring-width indices and δ13C values from each site were used to “correct” individual δ13C chronologies for climate effects which appear primarily related to high-frequency δ13C fluctuations, many of which are common among sites. These climate-corrected chronologies were normalized as deviations from their respective 1800–1849 δ13C means, and these normalized chronologies were averaged into the master. The overall δ13C drop from 1600 to the present is ca 1.2–1.4, consistent with recent ice-core data showing a drop of 1.14 ± 0.15% from 1740 to present (Friedli et al, 1986). However, the δ13C decline in the late 19th and early 20th centuries is greater in the pinyon chronology than that of the ice cores, thus supporting a greater biospheric CO2 input to the atmosphere than that indicated in the ice-core data.

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Molecular Bases ofβ-Thalassemia in the Eastern Province of Saudi Arabia

Journal of Biomedicine and Biotechnology ◽

10.1155/jbb.2005.322 ◽

2005 ◽

Vol 2005 (4) ◽

pp. 322-325 ◽

Cited By ~ 21

Author(s):

Amein K. Al-Ali ◽

Suad Al-Ateeq ◽

Burhan W. Imamwerdi ◽

Saleh Al-Sowayan ◽

Mohammed Al-Madan ◽

...

Keyword(s):

Saudi Arabia ◽

High Frequency ◽

Mean Corpuscular Volume ◽

The Other ◽

Corpuscular Volume ◽

Eastern Province ◽

The World ◽

Recessive Disorders ◽

Molecular Bases ◽

First Time

β-thalassemia is a group of heterogeneous recessive disorders common in many parts of the world. Al-Qatif and Al-Hassa oases in the Eastern Province of Saudi Arabia are regions known for high frequency of these disorders. Using two molecular methods, based on multiplexing-amplification refractory system and reverse hybridization principles, the spectrum ofβ-thalassemia in the region was studied. Sixty-nine subjects with knownβ-thalassemia disease and volunteers with high hemoglobinA2(HbA2)and low mean corpuscular volume (MCV) were included in this study. Ten mutations were detected in 91% of the subjects under study. Six of these mutations had previously been observed while the other four mutations are reported here for the first time. In addition, four of the mutations accounted for76.8% of the subjects studied. IVSII-1 (G>A), IVSI-5 (G>A), and codon 39 (C>T) mutations were found to be the most frequent. However, the frequencies of different mutations reported here are slightly different from those reported earlier. A number of these mutations were also found in the neighboring countries, which can be explained in terms of gene flow.

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Darwin's two competing phylogenetic trees: marsupials as ancestors or sister taxa?

Archives of Natural History ◽

10.3366/anh.2012.0091 ◽

2012 ◽

Vol 39 (2) ◽

pp. 217-233 ◽

Cited By ~ 4

Author(s):

J. David Archibald

Keyword(s):

Fossil Record ◽

Evolutionary Biology ◽

Phylogenetic Trees ◽

Charles Darwin ◽

The Other ◽

Charles Lyell ◽

Single Origin ◽

Molecular Studies ◽

Richard Owen ◽

First Time

Studies of the origin and diversification of major groups of plants and animals are contentious topics in current evolutionary biology. This includes the study of the timing and relationships of the two major clades of extant mammals – marsupials and placentals. Molecular studies concerned with marsupial and placental origin and diversification can be at odds with the fossil record. Such studies are, however, not a recent phenomenon. Over 150 years ago Charles Darwin weighed two alternative views on the origin of marsupials and placentals. Less than a year after the publication of On the origin of species, Darwin outlined these in a letter to Charles Lyell dated 23 September 1860. The letter concluded with two competing phylogenetic diagrams. One showed marsupials as ancestral to both living marsupials and placentals, whereas the other showed a non-marsupial, non-placental as being ancestral to both living marsupials and placentals. These two diagrams are published here for the first time. These are the only such competing phylogenetic diagrams that Darwin is known to have produced. In addition to examining the question of mammalian origins in this letter and in other manuscript notes discussed here, Darwin confronted the broader issue as to whether major groups of animals had a single origin (monophyly) or were the result of “continuous creation” as advocated for some groups by Richard Owen. Charles Lyell had held similar views to those of Owen, but it is clear from correspondence with Darwin that he was beginning to accept the idea of monophyly of major groups.

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Sphagnum mosses (Sphagnaceae, Bryophyta) of mires Chefandzar and Masota in North Ossetia (Caucasus)

Novosti sistematiki nizshikh rastenii ◽

10.31111/nsnr/2018.52.2.455 ◽

2018 ◽

Vol 52 (2) ◽

pp. 455-462 ◽

Cited By ~ 2

Author(s):

G. Ya. Doroshina ◽

I. A. Nikolajev

Keyword(s):

Plant Communities ◽

The Other ◽

North Caucasus ◽

Sphagnum Mosses ◽

Greater Caucasus ◽

The North ◽

First Time ◽

North Ossetia

Sphagnum mires on the Greater Caucasus are rare, characterized by the presence of relict plant communities of glacial age and are in a stage of degradation. The study of Sphagnum of Chefandzar and Masota mires is carried out for the first time. Seven species of Sphagnum are recorded. Their distribution and frequency within the North Caucasus are analyzed. Sphagnum contortum, S. platyphyllum, S. russowii, S. squarrosum are recorded for the first time for the study area and for the flora of North Ossetia. The other mosses found in the study area are listed.

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An Epistemological Criticism of Social Entrepreneurship: Is Social Entrepreneurship a Sound Scientific Field of Research

10.31124/advance.7091927.v1 ◽

2018 ◽

Author(s):

Amir Forouharfar

Keyword(s):

Social Entrepreneurship ◽

Social Constructivism ◽

Social Epistemology ◽

American English ◽

Meta Analysis ◽

Research Question ◽

Knowledge Structure ◽

Scientific Field ◽

The Other ◽

First Time

The paper was shaped around the pivotal question: Is SE a sound and scientific field of research? The question has given a critical tone to the paper and has also helped to bring out some of the controversial debates in the realm of SE. The paper was organized under five main discussions to be able to provide a scientific answer to the research question: (1) is “social entrepreneurship” an oxymoron?, (2) the characteristics of SE knowledge, (3) sources of social entrepreneurship knowledge, (4) SE knowledge: structure and limitations and (5) contributing epistemology-making concepts for SE. Based on the sections, the study relied on the relevant philosophical schools of thought in Epistemology (e.g. Empiricism, Rationalism, Skepticism, Internalism vs. Externalism, Essentialism, Social Constructivism, Social Epistemology, etc.) to discuss these controversies around SE and proposes some solutions by reviewing SE literature. Also, to determine the governing linguistic discourse in the realm of SE, which was necessary for our discussion, Corpus of Contemporary American English (COCA) for the first time in SE studies was used. Further, through the study, SE buzzwords which constitute SE terminology were derived and introduced to help us narrowing down and converging the thoughts in this field and demarking the epistemological boundaries of SE. The originality of the paper on one hand lies in its pioneering discussions on SE epistemology and on the other hand in paving the way for a construction of sound epistemology for SE; therefore in many cases after preparing the philosophical ground for the discussions, it went beyond the prevalent SE literature through meta-analysis to discuss the cases which were raised. The results of the study verified previously claimed embryonic pre-paradigmatic phase in SE which was far from a sound and scientific knowledge, although the scholarly endeavors are the harbingers of such a possibility in the future which calls for further mature academic discussion and development of SE knowledge by the SE academia.

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A Nabatean port on the Red Sea: note on the pottery finds from al-Qusayr (al-Wajh, Saudi Arabia)

10.31338/uw.2083-537x.pam29.1.23 ◽

2020 ◽

Author(s):

Caroline Durand

Keyword(s):

Saudi Arabia ◽

19Th Century ◽

Red Sea ◽

Point Of View ◽

The Other ◽

Trade Routes ◽

Other Hand ◽

Roman Egypt ◽

Pottery Sherds ◽

First Time

Al-Qusayr is located 40 km south of modern al-Wajh, roughly 7 km from the eastern Red Sea shore. This site is known since the mid-19th century, when the explorer R. Burton described it for the first time, in particular the remains of a monumental building so-called al-Qasr. In March 2016, a new survey of the site was undertaken by the al-‘Ula–al-Wajh Survey Project. This survey focused not only on al-Qasr but also on the surrounding site corresponding to the ancient settlement. A surface collection of pottery sherds revealed a striking combination of Mediterranean and Egyptian imports on one hand, and of Nabataean productions on the other hand. This material is particularly homogeneous on the chronological point of view, suggesting a rather limited occupation period for the site. Attesting contacts between Mediterranean merchants, Roman Egypt and the Nabataean kingdom, these new data allow a complete reassessment of the importance of this locality in the Red Sea trade routes during antiquity.

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Status of Family Fissidentaceae in Gujarat

Cryptogam Biodiversity and Assessment ◽

10.21756/cba.v1i1.11022 ◽

2016 ◽

Vol 1 (1) ◽

Author(s):

D.G. Shah ◽

D.N. Mehta ◽

R.V. Gujar

Keyword(s):

Distinct Species ◽

The State ◽

The Other ◽

Land Plants ◽

Reproductive Structures ◽

The Family ◽

The Status ◽

Vegetative Characters ◽

First Time ◽

Different Parts

Bryophytes are the second largest group of land plants and are also known as the amphibians of the plant kingdom. 67 species of bryophytes have been reported from select locations across the state of Gujrat. The status of family fissidentaceae which is a large moss family is being presented in this paper. Globally the family consists of 10 genera but only one genus, Fissidens Hedw. has been collected from Gujarat. Fissidens is characterized by a unique leaf structure and shows the presence of three distinct lamina, the dorsal, the ventral and the vaginant lamina. A total of 8 species of Fissidens have been reported from the state based on vegetative characters as no sporophyte stages were collected earlier. Species reported from the neighboring states also showed the absence of sporophytes. The identification of different species was difficult due to substantial overlap in vegetative characters. Hence a detailed study on the diversity of members of Fissidentaceae in Gujarat was carried out between November 2013 and February 2015. In present study 8 distinct species of Fissidens have been collected from different parts of the state. Three species Fissidens splachnobryoides Broth., Fissidens zollingerii Mont. and Fissidens curvato-involutus Dixon. have been identified while the other five are still to be identified. Fissidens zollingerii Mont. and Fissidens xiphoides M. Fleisch., which have been reported as distinct species are actually synonyms according to TROPICOS database. The presence of sexual reproductive structures and sporophytes for several Fissidens species are also being reported for the first time from the state.

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Keeping the Vision Alive: The Role of Networks in National Memorial Building A Case Study of the Vietnam Women’s Memorial and the Black Revolutionary War Patriots Memorial

Public Voices ◽

10.22140/pv.104 ◽

2016 ◽

Vol 11 (1) ◽

pp. 89

Author(s):

Amy Probsdorfer Kelley ◽

John C. Morris

Keyword(s):

Network Analysis ◽

Revolutionary War ◽

The Other ◽

Perceived Popularity ◽

National Mall ◽

Compare And Contrast

The process to win approval to build a national memorial on the National Mall inWashington, DC is both long and complex. Many memorials are proposed, but few are chosen to inhabit the increasingly scarce space available on the Mall. Through the use of network analysis we compare and contrast two memorial proposals, with an eye toward understanding why one proposal was successful while the other seems to have failed. We conclude that the success of a specific memorial has less to do with the perceived popularity of the person or event to be memorialized, and more to do with how the sponsors use the network of people and resources available to advocate for a given proposal.

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Chance or Necessity—The Fungi Co−Occurring with Formica polyctena Ants

Insects ◽

10.3390/insects12030204 ◽

2021 ◽

Vol 12 (3) ◽

pp. 204

Author(s):

Igor Siedlecki ◽

Michał Gorczak ◽

Alicja Okrasińska ◽

Marta Wrzosek

Keyword(s):

Molecular Identification ◽

High Frequency ◽

Its Rdna ◽

The Other ◽

Formica Polyctena ◽

Ant Nests ◽

Mutualistic Fungi ◽

The Tropics ◽

High Diversity ◽

Better Than

Studies on carton nesting ants and domatia−dwelling ants have shown that ant–fungi interactions may be much more common and widespread than previously thought. Until now, studies focused predominantly on parasitic and mutualistic fungi–ant interactions occurring mostly in the tropics, neglecting less−obvious interactions involving the fungi common in ants’ surroundings in temperate climates. In our study, we characterized the mycobiota of the surroundings of Formica polyctena ants by identifying nearly 600 fungal colonies that were isolated externally from the bodies of F. polyctena workers. The ants were collected from mounds found in northern and central Poland. Isolated fungi were assigned to 20 genera via molecular identification (ITS rDNA barcoding). Among these, Penicillium strains were the most frequent, belonging to eight different taxonomic sections. Other common and widespread members of Eurotiales, such as Aspergillus spp., were isolated very rarely. In our study, we managed to characterize the genera of fungi commonly present on F. polyctena workers. Our results suggest that Penicillium, Trichoderma, Mucor, Schwanniomyces and Entomortierella are commonly present in F. polyctena surroundings. Additionally, the high diversity and high frequency of Penicillium colonies isolated from ants in this study suggest that representatives of this genus may be adapted to survive in ant nests environment better than the other fungal groups, or that they are preferentially sustained by the insects in nests.

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Second-order neutrosophic boundary-value problem

Complex & Intelligent Systems ◽

10.1007/s40747-020-00268-8 ◽

2021 ◽

Author(s):

Sandip Moi ◽

Suvankar Biswas ◽

Smita Pal(Sarkar)

Keyword(s):

Differential Equation ◽

Boundary Value Problem ◽

Differential Calculus ◽

Boundary Value ◽

Second Order ◽

Numerical Examples ◽

Different Types ◽

First Time

AbstractIn this article, some properties of neutrosophic derivative and neutrosophic numbers have been presented. This properties have been used to develop the neutrosophic differential calculus. By considering different types of first- and second-order derivatives, different kind of systems of derivatives have been developed. This is the first time where a second-order neutrosophic boundary-value problem has been introduced with different types of first- and second-order derivatives. Some numerical examples have been examined to explain different systems of neutrosophic differential equation.

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