To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure firstname.lastname@example.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Despite many ideas about the age and processes of sand movements and paleosol formation, there are still some uncertainties in this relations in the Nyírség, eastern Hungary. The major aim of the present study was to clarify the chronology of fossil soils and blown-sand layers in the sand dunes of the Nyírség using radiocarbon (14C) dating on soil and charcoal samples. Charcoal and soil samples were collected from buried paleosols from different sand quarries for 14C dating. The bulk organic carbon content of the buried soil and charcoal pieces recovered from buried fossil soil layers allowed parallel 14C accelerator mass spectrometry dating in several cases. The new 14C results indicate paleosol development during Younger Dryas, while the preceding interstadial was assumed as a cold and dry period when only sand movement occurred in the area. Our results also confirm and support the previous assumptions, that in the Late Glacial, the first paleosol development period was during the Bølling-Allerød Interstadial. Four soil-forming periods could be determined during the Holocene (Preboreal, Boreal, Atlantic, Subatlantic). We have also indirectly identified sand movements during the Oldest Dryas, Younger Dryas, Preboreal, Boreal, and Subatlantic phase in the study area.
In the Mesoamerican archaeological literature, collections of material regarded as somehow anomalous according to the archaeologist's expectations are often referred to as problematical deposits (PDs). Their problematical aspect originates in the researcher's current state of knowledge of the particular site, not in past behavior. PDs are site-specific, provisional classifications, and need further study to determine the function or intent of the activity that created them. A sample of 223 features designated as PDs by the University of Pennsylvania Museum's Tikal Project is examined here in an approach to understand their intent. A typology of the sample, based upon content, date, and variables of recovery context, indicates three principal intents broadly summarized as ritual, political, and site maintenance, and a category of PDs without intent. The study of PDs demands a wide-ranging approach. It provides an opportunity to reevaluate inadequate ideas and gain new insights into past cultural behavior.
Light verb constructions (LVCs) are verb and noun combinations in which the verb has lost its meaning to some degree and the noun is used in one of its original senses, typically denoting an event or an action. They exhibit special linguistic features, especially when regarded in a multilingual context. In this paper, we focus on the automatic detection of LVCs in raw text in four different languages, namely, English, German, Spanish, and Hungarian. First, we analyze the characteristics of LVCs from a linguistic point of view based on parallel corpus data. Then, we provide a standardized (i.e., language-independent) representation of LVCs that can be used in machine learning experiments. After, we experiment on identifying LVCs in different languages: we exploit language adaptation techniques which demonstrate that data from an additional language can be successfully employed in improving the performance of supervised LVC detection for a given language. As there are several annotated corpora from several domains in the case of English and Hungarian, we also investigate the effect of simple domain adaptation techniques to reduce the gap between domains. Furthermore, we combine domain adaptation techniques with language adaptation techniques for these two languages. Our results show that both out-domain and additional language data can improve performance. We believe that our language adaptation method may have practical implications in several fields of natural language processing, especially in machine translation.
Crystallization is one of the main separation and purification processes in the pharmaceutical, biotechnology, food, microelectronics, fine and bulk chemicals industries. The production of more than 70 percent of all solid products involves at least one crystallization as a key processing step, which can have a significant effect on the overall performance of the entire production process and the properties of the final product. The control of crystallization processes is challenging because of the highly nonlinear dynamics, large variations in length and time scales at which the various simultaneous mechanisms occur, variations in crystallization rates over time owing to variations in the impurity profiles of chemical feedstocks, unexpected polymorphic transformations, and nonideal mixing conditions.
Theory of mind, the ability to represent the mental states of others, is an important social cognitive process, which contributes to the development of social competence. Recent research suggests that interactions between gene and environmental factors, such as oxytocin receptor gene (OXTR) polymorphisms and maternal parenting behavior, may underlie individual differences in children's theory of mind. However, the potential influence of DNA methylation of OXTR remains unclear. The current study investigated the roles of OXTR methylation, maternal behavior, and their statistical interaction on toddlers’ early emerging theory of mind abilities. Participants included a community sample of 189 dyads of mothers and their 2- to 3-year-old children, whose salivary DNA was analyzed. Results indicated that more maternal structuring behavior was associated with better performance, on a battery of three theory of mind tasks, while higher OXTR methylation within exon 3 was associated with poorer performance. A significant interaction also emerged, such that OXTR methylation was related to theory of mind among children whose mothers displayed less structuring, when controlling for children's age, sex, ethnicity, number of child-aged siblings, verbal ability, and maternal education. Maternal structuring behavior may buffer the potential negative impact of hypermethylation on OXTR gene expression and function.
We obtain the representation of the backward shift operator on Chebyshev polynomials involving a principal value (PV) integral. Twice the backward shift on the space of square-summable sequences l2 displays chaotic dynamics, thus we provide an explicit form of a chaotic operator on L2 (−1, 1, (1−x2)–1/2) using Cauchy’s PV integral. We explicitly calculate the periodic points of the operator and provide examples of unbounded trajectories, as well as chaotic ones. Histograms and recurrence plots of shifts of random Chebyshev expansions display interesting behaviour over fractal measures.
This chapter summarizes our current understanding of the ionosphere of Saturn. We give an overview of Saturn ionospheric science from the Voyager era to the present, with a focus on the wealth of new data and discoveries enabled by Cassini, including a massive increase in the number of electron density altitude profiles. We discuss recent ground-based detections of the effect of “ring rain” on Saturn’s ionosphere, and present possible model interpretations of the observations. Finally, we outline current model-data discrepancies and indicate how future observations can help in advancing our understanding of the various controlling physical and chemical processes.
Two archaeologically unexplored mounds were studied in the area of the central Great Hungarian Plain. The age of the construction of the mounds was clarified on the basis of radiocarbon (14C) age determination of buried soil layers. Different, later-building phases of the mounds were detected by pedological and geo-electric analyses of the human-made layers. The age of the buried soils was corrected for the reservoir age of the recent soils found in the surroundings of the mounds. Radiocarbon ages of the carbon extracted from the soils at temperatures 400 and 800ºC were almost completely the same. Based on the calibrated ages of cal BP 4830–5270 (Szálka Mound) and cal BP 4880–5290 (Vajda Mound) of the buried soil layers, the identified kurgans were built by people of the Copper Age Yamnaya Culture. On the basis of the pedological and geophysical analysis of the layers, Szálka Mound and Vajda Mound were built in two and in three phases respectively from the chernozem-like humus-rich topsoil layers of the surrounding area. The former shallow quarry sites have been almost completely filled and cannot be identified at the foot of the mounds even using geodetic methods.
Carbon-based nanomaterials of different dimensions (1–3D, tubes, bundles, films, papers and sponges, graphene sheets) have been created and their characteristic properties have been discussed intensively in the literature. Due to their unique advantageous, tunable properties these materials became promising candidates in new generations of applications in many research laboratories and, recently, in industries as well. Protein-based bio-nanocomposites are referred to as materials of the future, which may serve as conceptual revolution in the development of integrated optical devices, e.g. optical switches, microimaging systems, sensors, telecommunication technologies or energy harvesting and biosensor applications. In our experiments, we designed various carbon-based nanomaterials either doped or not doped with nitrogen or sulfur during catalytic chemical vapor deposition synthesis. Radio- and isotope analytical studies have shown that the used starting materials, precursors and carriers have a strong influence on the geometry and physico-/chemical characteristics of the carbon nanotubes produced. After determining the 14C isotope constitution 53 m/m% balance was found in the reaction center protein/carbon nanotubes complex in a sensitive way that was prepared in our laboratory. The result is essential in determining the yield of conversion of light energy to chemical potential in this bio-hybrid system.
This paper analyzes the compatibility of intra-EU bilateral investment treaties—intra-EU BITs—with EU law. The status and validity of intra-EU BITs gave rise to a heated debate in Europe, which culminated in the CJEU's recent controversial judgment in Achmea. This Article demonstrates that although the CJEU approached intra-EU BITs from the angle of federalism—where they are both redundant and illegitimate—the reality is that EU law does not provide for the kind of protection afforded by BITs. The paper gives both a positivist and a critical assessment of the Achmea ruling. It argues that the judgment should be construed in the context of the underlying facts and, hence, notwithstanding the CJEU's apparently anti-arbitration attitude, its holding is rather narrow. It gives an alternative theory on intra-EU BITs' fit in the EU internal market—based on European reality—showing that the complete invalidation of intra-EU BITs is flawed because the overlap between BITs and EU law is merely partial: BITs address a subject EU law does not. This Article's central argument is that intra-EU BITs accelerate the internal market and, hence, their suppression does not lead the European integration further, but holds it back. Finally, this Article argues that the prevailing pattern of investment protection is a global scheme that cannot be arrested through regional unilateralism as essayed by the CJEU.
We aim to characterise those transformations on the set of density operators (which are the mathematical representatives of the states in quantum information theory) that preserve a so-called generalised entropy of one fixed convex combination of operators. The characterisation strengthens a recent result of Karder and Petek where the preservation of the same quantity was assumed for all convex combinations.
To investigate the effects of physiologically relevant heat shock during oocyte maturation, buffalo cumulus–oocyte complexes (COCs) were cultured at 38.5°C (control) or were exposed to 39.5°C (T1) or 40.5°C (T2) for the first 6 h of in vitro maturation (IVM), followed by 38.5°C through the next 18 h/IVM and early embryonic development up to the blastocyst stage. Gene expression analysis was performed on selected target genes (HSF-1, HSF-2, HSP-70, HSP-90, BAX, p53, SOD1, COX1, MAPK14) in denuded oocytes and their isolated cumulus cells resulting from control COCs as well as from COCs exposed to a temperature of 39.5°C (T1). The results indicated that heat shock significantly (P < 0.01) decreased the maturation rate in T1 and T2 cells compared with the control. After in vitro fertilization (IVF), cleavage rate was lower (P < 0.01) for oocytes exposed to heat stress, and the percentage of oocytes arrested at the 2- or 4-cell stage was higher (P < 0.01) than that of the control. The percentage of oocytes that developed to the 8-cell, 16-cell or blastocyst stage was lower (P < 0.01) in both T1 and T2 groups compared with the control group. mRNA expression levels for the studied genes were decreased (P < 0.05) in treated oocytes (T1) except for HSP-90 and HSF-1, which were increased. In cumulus cells isolated from COCs (T1), the expression for the target genes was upregulated except for BAX, which was downregulated. The results of this study demonstrated that exposure of buffalo oocytes to elevated temperatures for 6 h severely compromised their developmental competence and gene expression.
New developments in surface flux transport modeling and theory of flux transport dynamos have given rise to the notion that certain large active regions with anomalous properties (location, tilt angle and/or Hale/non-Hale character) may have a major impact on the course of solar activity in subsequent years, impacting also on the amplitude of the following solar cycles. Here we discuss our current understanding of the role of such “rogue” active regions in cycle-to-cycle variations of solar activity.
H9N2 is the most widespread avian influenza virus subtype in poultry worldwide. It infects a broad spectrum of host species including birds and mammals. Infections in poultry and humans vary from silent to fatal. Importantly, all AIV, which are fatal in humans (e.g. H5N1, H7N9) acquired their ‘internal’ gene segments from H9N2 viruses. Although H9N2 is endemic in the Middle East (ME) and North Africa since the late 1990s, little is known about its epidemiology and genetics on a regional level. In this review, we summarised the epidemiological situation of H9N2 in poultry and mammals in Iran, Iraq, Kuwait, Qatar, United Arab Emirates, Oman, Bahrain, Yemen, Saudi Arabia, Jordan, Palestine, Israel, Syria, Lebanon, Turkey, Egypt, Sudan, Libya, Tunisia, Algeria and Morocco. The virus has been isolated from humans in Egypt and serosurveys indicated widespread infection particularly among poultry workers and pigs in some countries. Some isolates replicated well in experimentally inoculated dogs, mice, hamsters and ferrets. Insufficient protection of immunised poultry was frequently reported most likely due to concurrent viral or bacterial infections and antigenic drift of the field viruses from outdated vaccine strains. Genetic analysis indicated several distinct phylogroups including a panzootic genotype in the Asian and African parts of the ME, which may be useful for the development of vaccines. The extensive circulation of H9N2 for about 20 years in this region where the H5N1 virus is also endemic in some countries, poses a serious public health threat. Regional surveillance and control strategy are highly recommended.