2,137 research outputs found
Fourth Amendment Accommodations: (UN)Compelling Public Needs, Balancing Acts, and the Fiction of Consent
The problems of public housing-including crime, drugs, and gun violence- have received an enormous amount of national attention. Much attention has also focused on warrantless searches and consent searches as solutions to these problems. This Note addresses the constitutionality of these proposals and asserts that if the Supreme Court\u27s current Fourth Amendment jurisprudence is taken to its logical extremes, warrantless searches in public housing can be found constitutional. The author argues, however, that such an interpretation fails to strike the proper balance between public need and privacy in the public housing context. The Note concludes by proposing alternative consent-based regimes that would pass constitutional muster
Comprendre les brachiopodes linguloides : Obulus et Ungula comme exemples
EMIG
(2002) a revu la taxonomie du genre Obolus EICHWALD du Cambrien moyen - Ordovician basal des
régions baltes orientales dans le cadre d'un projet de révision de l'ensemble des critères de la
systématique des linguloides. Il a suggéré que les études taxonomiques antérieures sur Obolus et
les formes apparentées sont fondées à tort sur des caractères dépourvus de toute valeur
taxonomique. La révision proposées par EMIG s'appuie principalement sur les faibles variations
morphologiques observées entre taxons fossiles et récents au sein d'une seule famille de linguloide,
les Lingulidae. Notre article s'attache à démontrer la validité taxonomique des critères diagnostiques
utilisés dans la classification au sein des familles, pour la plupart éteintes, de la Superfamille des
Linguloidea, car ils présentent une bien plus grande diversité morphologique. Cette étude montre
aussi que EMIG n'a pas proposé une base satisfaisante pour étayer les changements et révisions
radicaux qu'il souhaite apporter à la taxonomie, en vigueur et largement acceptée, des Obolidae des
séries du Cambrien à l'Ordovician basal des régions baltes orientales. Obolus EICHWALD et Ungula
PANDER sont considérés comme des genres distincts comprenant les espèces Obolus apollinis
EICHWALD, O. ruchini KHAZANOVITCH et POPOV, O. transversus (PANDER), Ungula ingrica (EICHWALD), U.
inornata (MICKWITZ) et U. convexa PANDER.EMIG (2002) re-examined the taxonomy of the genus Obolus EICHWALD from the Middle
Cambrian - earliest Ordovician of the East Baltic region as part of a proposal for a wholesale revision
of the principles of linguloid systematics. He contended that previous taxonomic studies on Obolus
and related forms were carried out erroneously using characters that have no taxonomic value. EMIG´s
proposed revision is based mainly on the limited morphological diversity between fossil and Recent
taxa within a single linguloid Family, the Lingulidae. However, the present study demonstrates the
taxonomic validity of the diagnostic characters used for classification within the mostly extinct
families of the Superfamily Linguloidea, for they exhibit far more variation in morphology. This study
also shows that EMIG has provided no satisfactory basis for his radical changes and revisions to the
existing widely accepted taxonomy of the Cambrian to earliest Ordovician Obolidae of the East Baltic.
Obolus EICHWALD and Ungula PANDER are shown to constitute distinctive and discrete genera
comprising the species Obolus apollinis EICHWALD, O. ruchini KHAZANOVITCH et POPOV, O. transversus
(PANDER), Ungula ingrica (EICHWALD), U. inornata (MICKWITZ), and U. convexa PANDER
Early Ordovician (Tremadocian) brachiopods from the Eastern Alborz Mountains, Iran
Six linguliform and two rhynchonelliform brachiopods, including three new species Eurytreta ahmadii, Wahwahlingula kharbashi and Nanorthis bastamensis are described from Tremadocian strata (Paltodus deltifer deltifer conodont Biozone) in the Deh-Molla area southwest of Shahrud, Northern Iran. The fauna is dominated by micromorphic lingulides and acrotretides and shows distinct similarity to the contemporaneous micromorphic brachiopod association from Tremadocian chalcedonites of the Holy Cross Mountains, Poland. New data on the early ontogeny of the enigmatic lingulide Diencobolus show a very distinct pattern, including the presence of a metamorphic protegulum ornamented with flat-based pits and a single pair of larval setal bundles, which links this taxon to Paterula and suggests close phylogenetic relationships of both taxa to the Discinoidea
The earliest Ordovician trace fossils Cruziana and Rusophycus from Baltica
Trace fossils of the ichnogenera Cruziana and Rusophycus are described for the first time from the Lower Ordovician of Baltica. These specimens were found from the upper Tremadocianâlower Floian glauconite sandstone of the Leetse Formation in the Leetse and Uuga cliffs on the Pakri Peninsula, North-West Estonia. The one from the Leetse locality was collected already in the 19th century but was hidden in museum collections. On this piece of rock, together with the Rusophycus, brachiopods Leptembolon lingulaeformis and Thysanotos siluricus occur. They indicate that the sample comes from the strata corresponding to the Thysanotossiluricus Brachiopod Biozone of the Hunneberg Stage. Different lithology of the two newly discovered loose slabs with trace fossils found under the Uuga cliff indicates that, most probably, they originate from different levels of the glauconite sandstone exposed in this section. One of them is heavily pyritized and yields a contact surface with the underlying beige argillite of the Varangu Stage with fragments of the graptolite Kiearograptus supremus and some undescribed acrotretid and other linguloid brachiopods. The second, less strongly lithified slab contains abundant fine debris of thin-shelled unidentifiable linguloid brachiopods and probably comes from a higher level. Earlier studies of conodonts revealed that the Prioniodus elegans Conodont Zone is missing in the Uuga section, thus narrowing down the possible interval of origin of these ichnotaxa to the Paroistodus proteus zone.
Interestingly, these two slabs preserve the dissimilar pattern of grouping and orientation of the multiple Rusophycus/Cruziana traces giving some idea about the ethology of trilobites who probably left these traces. The earliest trilobites in the Ordovician succession of Estonia are recorded from the Mäeküla Member, the uppermost part of the Leetse Formation, from an interval where calcareous component first appears in the sediment and thus also the trilobites with their calcitic exoskeleton are preserved. The only trilobites recorded from the Mäeküla Member of the Leetse Formation in these two localities are specimens of Paramegistaspisleuchtenbergi who could have been the trace maker with its macropygidium being of similar size to its cephalon if the second slab would come from the same interval. However, there are more candidates, mainly isoteline trilobites with similar characteristics which are preserved in older but calcareous succession in Sweden and Norway
Siphonotretoid brachiopods – a thorny problem
Siphonotretoids are presently placed within the subphylum Linguliformea and the class Lingulata, where they constitute a small, relatively short-lived superfamily and order, appearing near the end of the mid-Cambrian, with most forms becoming extinct near the end of the Late Ordovician, but with some rare forms ranging through the Silurian and even into the early Devonian. It has been noted previously that siphonotretides are very different from all other lingulates in shell structure, ontogeny and ornamentation, and may have diverged from other lingulates already during the early Cambrian. Findings of exceptionally preserved âsoft-shelledâ possible early stem-group setigerous representatives such as Acanthotretella in the Burgess Shale and the Chengjiang fauna have strengthened this view. Exceptionally preserved siphonotretides from Iran clearly show that they are provided with organic setal structures associated with spines, and similar setal structures are known from stem brachiopods, such as Micrina and Mickwitzia, as well as from some later true rhynchonelliforms. Evidence for preserved setal structures is now also recorded from the CambrianâOrdovician boundary beds in Wyoming. In the Ordovician, the spinous structures include complex branching forms, such as the widely distributed Alichovia, and Siphonotreta itself has clear evidence of branching spines. The branching spines probably also contained setal structures, and similar forked setae are known from living annelids
Stratigraphy 12 (2) Biostratigraphy of the Cambrian-Ordovician boundary beds at Kopet-Dagh, Iran
ABSTRACT: A continuous succession comprising upper Cambrian (Furongian) to Lower Ordovician (Tremadocian) conodont biozones is reported for the first time from the Kopet-Dagh Region of northeastern Iran. Seven biostratigraphical units are recognized, including the Proconodontus tenuiserratus and Proconodontus posterocostatus zones; these two lowermost biostratigraphical units are defined by euconodont species which have not been previously reported from Iran and temperate latitude peri-Gondwana. The conodont diversity and abundance decreased significantly above the Eoconodontus notchpeakensis Zone; the conodont faunas of the succeeding Cordylodus proavus, Cordylodus lindstromi (sensu lato) and Cordylodus angulatus zones are characterised by oligotaxic to monotaxic associations dominated by species of Cordylodus. In the absence of diagnostic conodont species, the position of the lower boundary of the Ordovician System in the Kalat Valley Section can be placed somewhat below the first occurrence of the early planktonic graptolite Rhabdinopora flabelliformis, which approximately coincides with the onset of black shale deposition
One-Dimensional Quantum Liquids: Beyond the Luttinger Liquid Paradigm
For many years, the Luttinger liquid theory has served as a useful paradigm
for the description of one-dimensional (1D) quantum fluids in the limit of low
energies. This theory is based on a linearization of the dispersion relation of
the particles constituting the fluid. We review the recent progress in
understanding 1D quantum fluids beyond the low-energy limit, where the
nonlinearity of the dispersion relation becomes essential. The novel methods
which have been developed to tackle such systems combine phenomenology built on
the ideas of the Fermi edge singularity and the Fermi liquid theory,
perturbation theory in the interaction strength, and a new way of treating
finite-size integrable models. These methods can be applied to a wide variety
of 1D fluids, from 1D spin liquids to electrons in quantum wires to cold atoms
confined to a 1D trap. We review existing results for various dynamic
correlation functions, in particular the density structure factor and the
spectral function. Moreover, we show how a dispersion nonlinearity leads to
finite particle lifetimes, and discuss its impact on the transport properties
of 1D systems at finite temperatures. The conventional Luttinger liquid theory
is a special limit of the new theory, and we explain the relation between the
two.Comment: 61 pages, 18 figures, published version, minor typos correcte
Completion of the 8 MW Multi-Frequency ECRH System at ASDEX Upgrade
Over the last 15 years, the Electron Cyclotron Resonance Heating (ECRH) system at the ASDEX Upgrade tokamak has been upgraded from a 2 MW, 2 s, 140 GHz system to an 8 MW, 10 s, dual frequency system (105/140 GHz). Eight gyrotrons were in routine operation during the current experimental campaign. All gyrotrons are step-tunable operating at 105 and 140 GHz with a maximum output power of about 1 MW and 10 s pulse length. The system includes 8 transmission lines, mainly consisting of oversized corrugated waveguides (I.D. = 87 mm) with overall lengths between 50 and 70 meters including quasi-optical sections at both ends. Further improvements of the transmission lines with respect to power handling and reliability are underway
Two-particle correlations in azimuthal angle and pseudorapidity in inelastic p + p interactions at the CERN Super Proton Synchrotron
Results on two-particle ΔηΔϕ correlations in inelastic p + p interactions at 20, 31, 40, 80, and 158 GeV/c are presented. The measurements were performed using the large acceptance NA61/SHINE hadron spectrometer at the CERN Super Proton Synchrotron. The data show structures which can be attributed mainly to effects of resonance decays, momentum conservation, and quantum statistics. The results are compared with the Epos and UrQMD models.ISSN:1434-6044ISSN:1434-605
- …