Unary FA-presentable semigroups

Automatic presentations, also called FA-presentations, were introduced to extend nite model theory to innite structures whilst retaining the solubility of interesting decision problems. A particular focus of research has been the classication of those structures of some species that admit automatic presentations. Whilst some successes have been obtained, this appears to be a dicult problem in general. A restricted problem, also of signicant interest, is to ask this question for unary automatic presentations: auto-matic presentations over a one-letter alphabet. This paper studies unary FA-presentable semigroups. We prove the following: Every unary FA-presentable structure admits an injective unary automatic presentation where the language of representatives consists of every word over a one-letter alphabet. Unary FA-presentable semigroups are locally nite, but non-nitely generated unary FA-presentable semigroups may be innite. Every unary FA-presentable semigroup satises some Burnside identity.We describe the Green's relations in unary FA-presentable semigroups. We investigate the relationship between the class of unary FA-presentable semigroups and various semigroup constructions. A classication is given of the unary FA-presentable completely simple semigroups.PostprintPeer reviewe

Multifractal analysis of electronic states on random Voronoi-Delaunay lattices

We consider the transport of non-interacting electrons on two- and three-dimensional random Voronoi-Delaunay lattices. It was recently shown that these topologically disordered lattices feature strong disorder anticorrelations between the coordination numbers that qualitatively change the properties of continuous and first-order phase transitions. To determine whether or not these unusual features also influence Anderson localization, we study the electronic wave functions by multifractal analysis and finite-size scaling. We observe only localized states for all energies in the two-dimensional system. In three dimensions, we find two Anderson transitions between localized and extended states very close to the band edges. The critical exponent of the localization length is about 1.6. All these results agree with the usual orthogonal universality class. Additional generic energetic randomness introduced via random potentials does not lead to qualitative changes but allows us to obtain a phase diagram by varying the strength of these potentials

Vascular Endothelial Growth Factor In Cortical Development

One of the characteristics unique to mammalian evolution is the development of the neocortex. The neocortex is a highly ordered six-layered structure, the development of which is tightly regulated. The formation of the cortex is concomitantly dependent upon an outward expansion of the neuroepithelium, a tissue from which all of the neuronal subtypes and glia are born and differentiated, and the investment of blood vessels from the outer pial surface. Orchestration of neurogenesis and blood vessel investment, or angiogenesis, in the cortex is critical for development; however, these processes are often studied independent of one another. While independent investigation of neurogenesis can simplify a study, by removing the potentially confounding variable of angiogenesis, this reductionist approach ignores the fact that the two processes, neurogenesis and angiogenesis, are dependent upon each other and intimately linked. Many growth factors and transcription factors have roles in both angiogenesis and neurogenesis. Members of both the Notch and Inhibitor of DNA binding (Id) family of proteins have been shown to guide differentiation in neural stem cells, as well as to direct the migration of newly sprouting vessels. Another growth factor that has been linked to both angiogenesis and neurogenesis is Vascular endothelial growth factor A (Vegf). Vegf is a pleiotrophic factor linked to a broad range of effects in neurovascular systems including proliferation, migration and differentiation. Vegf and its receptors (VegfR1, VegfR2, Nrp1, and Nrp2) are expressed in many of the cell types critical for neurogenesis and angiogenesis. The Vegf gene is expressed as three main isoforms in the mouse brain, and these isoforms have distinct biochemical properties based on the presence or absence of a heparin sulfate proteoglycan (HSPG) binding domain. Vegf isoforms with the full HSPG-binding domain are not diffusible in the microenvironment (Vegf188) without proteolytic cleavage, those with a partial HSPG-binding domain are partially diffusible (Vegf164), and those lacking the domain entirely are freely diffusible (Vegf120). The different biochemical properties of the Vegf isoforms allow gradients of Vegf to form in the microenvironment. We hypothesize that it is through these differing gradients of Vegf isoforms, that Vegf can orchestrate neurogenesis and angiogenesis in the cortex. To investigate this, we took advantage of a transgenic mouse model in which mice express single Vegf isoforms (Vegf120 or Vegf188), or combinations of Vegf isoforms (Vegf120/188), and lack the Vegf164 isoform. These mice represent a loss of function model (no Vegf164) as well as misexpression models through which we can test the role of Vegf in cortical neurogenesis and angiogenesis

Reproduction and recruitment of the brackish water clam, Rangia cuneata in the James River, Virginia

Reproduction and recruitment of the brackish water clam Rangia cuneata were investigated in the James River, Va., from February 1970 to January 1972. Histological examinations of gonads were made, newly set clams were collected, and temperature and salinity measurements were taken from three populations living in different salinity regimes

Combined effects of changes in temperature and salinity on early stages of Rangia cuneata

Embryos and early straight-hinge larvae of Rangia cuneata were subjected to a temperature change of 8°C in 5 seconds, a salinity change of 4%o (5 to 1%0), and to the combination of both stresses. Embryos were relatively insensitive to the thermal shock but were killed by the salinity shock and by the combined salinity...,...temperature shock. Survival and growth of larvae were reduced by the salinity shock and by the combination of temperature and salinity shocks. The combination of the thermal shock and salinity change produced a mortality higher than the sum of the mortalities for either of the two factors alone

The variability of the El Nino southern oscillation and Modoki mode and their impacts on New York State climate

The El Nino Southern Oscillation (ENSO) has long been an influential climate and weather driver for many regions. Many studies have examined the variability of the phases of ENSO, leading to discovery of a separate mode of El Nino dubbed the El Nino Modoki, featuring a tripole Walker circulation. However, few studies have examined the variability of El Nino with Modoki separated from regular El Nino events. The goals of this study were to demonstrate that the El Nino signal was stronger separate from Modoki (thus leading to higher predictability), and to examine the effect of the Modoki on both a national and regional level, showing the connection between other teleconnections such as the Pacific North American teleconnection (PNA), the Arctic Oscillation (AO), and the North American Oscillation teleconnection (NAO). Using NCEP/NCAR composites, conventional El Nino events were found to have a stronger signal, with persistent features being easier to identify. Similarly, the Modoki showed a pattern that was similar but different to the regular El Nino. Using New York State for the area of regional analysis, all ENSO phases were found to modify the effect of the PNA, but the effect was different depending on location. Both of these results indicate that it is possible to generate a clearer picture of the impacts of ENSO by properly classifying these events.Includes bibliographical reference

Automatic presentations for semigroups

Special Issue: 2nd International Conference on Language and Automata Theory and Applications (LATA 2008)This paper applies the concept of FA-presentable structures to semigroups. We give a complete classification of the finitely generated FA-presentable cancellative semigroups: namely, a finitely generated cancellative semigroup is FA-presentable if and only if it is a subsemigroup of a virtually abelian group. We prove that all finitely generated commutative semigroups are FA-presentable. We give a complete list of FA-presentable one-relation semigroups and compare the classes of FA-presentable semigroups and automatic semigroups. (C) 2009 Elsevier Inc. All rights reserved.PostprintPeer reviewe

Native Americans / Asian Americans

This issue brief compares Asian Americans and Native Americans. The brief explores the similarities and differences in the two ethnoracial groups, and discusses how these similarities and differences effect their political participation

Theorizing embodied, collective and societal learning through prefigurative social movements

This paper theorizes adult learning as a multi-leveled, emergent process of interactions between individuals, groups, and societal systems. We theorize from the context of prefigurative social movements that are enacting values of direct democracy, solidarity economics, and equity. We analyze Occupy encampments as sites in which individuals, movement groups, and society learn as complex adaptive systems. The theorizing of these learning processes has implications for adult education theory, research, and practice

Lived Experiences of Nurses Caring for Limited English Proficient Patients During a Pandemic

This study addressed the need to better understand how a patient’s healthcare is influenced by lack of health literacy for limited English proficient patients during the COVID-19 pandemic. While registered nurses are a key component in the patient care continuum, there is a lack of evidence to understand the experiences caring for this vulnerable population during a pandemic. Framed by Roy’s adaptation model and Orem’s self-care deficit nursing theory, the purpose of this interpretative phenomenological study was to explore the lived experiences of registered nurses who cared for limited English patients diagnosed with COVID-19 in 2020. Seven registered nurses participated in semistructured interviews. The interviews were conducted remotely due to the ongoing COVID-19 safety guidelines in place during the time of this study. After transcribing audio interviews, the data was manually coded and four emergent themes were organized: (a) nurse compassion, (b) barriers to care, (c) patient and their family, (d) communication challenges. Twelve subthemes were identified that support the major themes. Communication challenges were the focus of the study and findings from this study could focus on a means of effective and feasible communication between healthcare providers and their target population. Positive social change is possible by recognizing the dynamic need for adequate translation resources, especially when the pandemic’s influence can quickly outpace a system’s design