Luminescence Dating of Beach Dunes and Fluvial Sediments, Nayarit, Mexico

The Pacific coast of the state of Nayarit, Mexico, is dominated by extensive sand dune systems and lagoons. 16 samples from three transects through dunes near the town of Santa Cruz were collected to establish ages of the beach dune ridges and establish a robust chronology, to assist in understanding the depositional rates associated with different phases of the evolution of the strand plain. In addition, three samples were collected from a fluvial terrace on the San Pedro River which enters the Pacific near the southernmost of the dune transects. Quartz grains were extracted from the samples, and analysed using an Optically Stimulated Luminescence (OSL) method to determine stored dose and ages. The samples collected nearest the current coast have produced dates of 1500-1900AD, with samples further from the coast being progressively older, spanning a period of over 2000 years with oldest measured date of 400BC. The dates for the upper samples from the San Pedro River is consistent with the ages of the dunes nearest the coast, with the lower sample date closer to the dates of the older dunes further from the coast, indicating that this fluvial deposit was laid down over the same time period as the dune formation

Rise in the use of section 136 of the Mental Health Act 1983 in England and Wales: a viewpoint on Loughran (2018)

This article provides a critical viewpoint on Loughran’s recent work in 'Medicine, Science and the Law' on the causes of the rise in the police’s use of section 136 (s136) of the Mental Health Act 1983 (Loughran M. Detention under section 136: why is it increasing? 'Med Sci Law' 2018; 58: 268–274). The rate of this rise seems significant: by 2014, it was five times more likely that a person in England would be detained in a hospital under s136 than it was in 2000, and the trend has continued to the present day. This viewpoint considers the significance of the s136 rise from the theoretical perspective of causal analysis

A Structural Comparison of Ordered and Non-Ordered Ion Doped Silicate Bioactive Glasses

One of the key benefits of sol-gel-derived glasses is the presence of a mesoporous structure and the resulting increase in surface area. This enhancement in textural properties has a significant e ect on the physicochemical properties of the materials. In this context the aim of this study was to investigate how sol-gel synthesis parameters can influence the textural and structural properties of mesoporous silicate glasses. We report the synthesis and characterization of metal ion doped sol-gel derived glasses with di erent dopants in the presence or absence of a surfactant (Pluronic P123) used as structure-directing templating agent. Characterization was done by several methods. Using a structure directing agent led to larger surface areas and highly ordered mesoporous structures. The chemical structure of the non-ordered glasses was modified to a larger extent than the one of the ordered glasses due to increased incorporation of dopant ions into the glass network. The results will help to further understand how the properties of sol-gel glasses can be controlled by incorporation of metal dopants, in conjunction with control over the textural properties, and will be important to optimize the properties of sol-gel glasses for specific applications, e.g., drug delivery, bone regeneration, wound healing, and antibacterial materials.European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 643050, project “HyMedPoly

Possibility Semantics for Intuitionistic Logic

The paper investigates interpretations of propositional and first-order logic in which validity is defined in terms of partial indices; sometimes called possibilities but here understood as non-empty subsets of a set W of possible worlds. Truth at a set of worlds is understood to be truth at every world in the set. If all subsets of W are permitted the logic so determined is classical first-order predicate logic. Restricting allowable subsets and then imposing certain closure conditions provides a modelling for intuitionistic predicate logic. The same semantic interpretation rules are used in both logics for all the operators

Thoughts on Relevance of IS Research

The discussion of whether research is relevant should include attention to a frame of reference for the meaning of relevance. This paper argues that three elements belong in such a frame. One is a clear identification of what interests or stakes are involved in the research, and whose interests are served. Another element is whether the research is intended to produce knowledge for its own sake or is intended to solve a particular practical problem. Lastly, different time frames can lead to completely different judgements about relevance and value. This complexity suggests considerable caution should apply to evaluating the relevance of IS or any other body of research

Photosynthietic characteristics of Zea mays seedlings grown under controlled environmental conditions

Studies were carried out on the effect of irradiance, illumination time and limited water and nutrient application on the activities of the carboxylating enzymes in relation to leaf position in Zea mays L. seedlings. “The ratio phosphoenolpyruvate (PEP) carboxylase:ribulose-1,5-biphosphate (RuBP) carboxylase increased in the first-formed leaves with increased irradiance, and varied markedly in these leaves throughout the photoperiod. Conditions of water and nutrient deprivation reduced the activity of PEP carboxylase to a greater extent than RuBP carboxylase, in all the leaves of 3-week old plants.The initial photosynthetic products and δ13C values were investigated in 3-week old seedlings. 14CO2 was fixed predominantly into C4 acids in all leaves, and these leaves also had δ13C values of – 11,5%0.The results indicate that growth conditions influence the photosynthetic characteristics of individual leaves, and that the C4 syndrome is not necessarily present in its entirety in Z. mays.S. Afr. J. Bot. 1982, 1: 64- 6

Cosmic microwave background multipole alignments in slab topologies

Several analyses of the microwave sky maps from the Wilkinson Microwave Anisotropy Probe (WMAP) have drawn attention to alignments amongst the low-order multipoles. Amongst the various possible explanations, an effect of cosmic topology has been invoked by several authors. We focus on an alignment of the first four multipoles (\ell = 2 to 5) found by Land and Magueijo (2005), and investigate the distribution of their alignment statistic for a set of simulated cosmic microwave background maps for cosmologies with slab-like topology. We find that this topology does offer a modest increase in the probability of the observed value, but that even for the smallest topology considered the probability of the observed value remains below one percent.Comment: 6 pages RevTex with 6 figures included. Minor changes to match version accepted as Physical Review D Rapid Communicatio