Reduction for natural operators on projectable connections

AbstractWe present a very simple proof of a general reduction for natural operators on torsion free projectable classical linear connections.</jats:p

Relational structures for concurrent behaviours

\ua9 2020 The Author(s). Relational structures based on acyclic relations can successfully model fundamental aspects of concurrent systems behaviour. Examples include Elementary Net systems and Mazurkiewicz traces. There are however cases where more general relational structures are needed. In this paper, we present a general model of relational structures which can be used for a broad class of concurrent behaviours. We demonstrate how this general set-up works for combined order structures which are based on two relations, viz. an acyclic ‘before’ relation and a possibly cyclic ‘not later than’ relation

A Precise Characterisation of Step Traces and Their Concurrent Histories

Step traces are an extension of Mazurkiewicz traces where each equivalence class (trace) consists of sequences of steps instead of sequences of atomic actions. Relations between the actions of the system are defined statically, as parameters of a concurrent step alphabet. By allowing only some of the possible relationships between actions, subclasses of step alphabets can be derived in a natural way. Properties of these classes can then be investigated in terms of invariant structures, i.e., the relational structures that represent the causal invariants that underlie the corresponding step traces. In this paper, we refine an earlier classification of subclasses of step alphabets and add eight new subclasses to this hierarchy. We divide these eight classes into three families on basis of the absence of a specific behavioural relation and then characterise the corresponding invariant structures

Weapon injuries in the crusader mass graves from a 13th century attack on the port city of Sidon (Lebanon).

Archaeological excavations close to St Louis' castle in Sidon, Lebanon have revealed two mass grave deposits containing partially articulated and disarticulated human skeletal remains. A minimum of 25 male individuals have been recovered, with no females or young children. Radiocarbon dating of the human remains, a crusader coin, and the design of Frankish belt buckles strongly indicate they belong to a single event in the mid-13th century CE. The skeletal remains demonstrate a high prevalence of unhealed sharp force, penetrating force and blunt force trauma consistent with medieval weaponry. Higher numbers of wounds on the back of individuals than the front suggests some were attacked from behind, possibly as they fled. The concentration of blade wounds to the back of the neck of others would be compatible with execution by decapitation following their capture. Taphonomic changes indicate the skeletal remains were left exposed for some weeks prior to being collected together and re-deposited in the defensive ditch by a fortified gateway within the town wall. Charring on some bones provides evidence of burning of the bodies. The findings imply the systematic clearance of partially decomposed corpses following an attack on the city, where adult and teenage males died as a result of weapon related trauma. The skeletons date from the second half of the Crusader period, when Christian-held Sidon came under direct assault from both the Mamluk Sultanate (1253 CE) and the Ilkhanate Mongols (1260 CE). It is likely that those in the mass graves died during one of these assaults

Estimation of a probability in inverse binomial sampling under normalized linear-linear and inverse-linear loss

Sequential estimation of the success probability $p$ in inverse binomial sampling is considered in this paper. For any estimator $\hat p$, its quality is measured by the risk associated with normalized loss functions of linear-linear or inverse-linear form. These functions are possibly asymmetric, with arbitrary slope parameters $a$ and $b$ for $\hat pp$ respectively. Interest in these functions is motivated by their significance and potential uses, which are briefly discussed. Estimators are given for which the risk has an asymptotic value as $p$ tends to $0$, and which guarantee that, for any $p$ in $(0,1)$, the risk is lower than its asymptotic value. This allows selecting the required number of successes, $r$, to meet a prescribed quality irrespective of the unknown $p$. In addition, the proposed estimators are shown to be approximately minimax when $a/b$ does not deviate too much from $1$, and asymptotically minimax as $r$ tends to infinity when $a=b$.Comment: 4 figure

Field applications of the second-generation Environmental Sample Processor (ESP) for remote detection of harmful algae: 2006-2007

We assess the application of the second-generation Environmental Sample Processor (ESP) for the detection of harmful algal bloom (HAB) species in field and laboratory settings using two molecular probe techniques: a sandwich hybridization assay (SHA) and fluorescent in situ hybridization (FISH). During spring 2006, the first time this new instrument was deployed, the ESP successfully automated application of DNA probe arrays for various HAB species and other planktonic taxa, but non-specific background binding on the SHA probe array support made results interpretation problematic. Following 2006, the DNA array support membrane that we were using was replaced with a different membrane, and the SHA chemistry was adjusted. The sensitivity and dynamic range of these modifications were assessed using 96-well plate and ESP array SHA formats for several HAB species found commonly in Monterey Bay over a range of concentrations; responses were significantly correlated (p < 0.01). Modified arrays were deployed in 2007. Compared to 2006, probe arrays showed improved signal:noise, and remote detection of various HAB species was demonstrated. We confirmed that the ESP and affiliated assays can detect HAB populations at levels below those posing human health concerns, and results can be related to prevailing environmental conditions in near real-time

Differential Levels of Stress Proteins (HSPs) in Male and Female Daphnia magna in Response to Thermal Stress: A Consequence of Sex-Related Behavioral Differences?

In two independent experiments, we compared: (1) water depth selection (and accompanying temperature selection) by male and female Daphnia magna under different kinds of environmental stress, including the presence of filamentous cyanobacteria, the risk of predation from fish, and the presence of toxic compounds; and (2) sex-dependent production of heat shock proteins (HSP60, 70, and 90) in response to a sudden change in temperature. Male D. magna selected deep water strata, which offer a relatively stable environment, and thereby avoided the threat of predation and the presence of toxic compounds in surface waters. Correlated with this behavior, males reduce their molecular defenses against stress, such as the production of heat shock proteins (HSPs), and do not maintain the physiological machinery that triggers an increase in HSP levels in response to stress. In contrast, female D. magna actively select habitats that offer optimal conditions for growth and production of offspring. Consequently, females are exposed to variable environmental conditions that may be associated with increased stress. To permit survival in these different habitats, D. magna females require molecular mechanisms to protect their cells from rapid changes in stress levels. Thus, they maintain high constitutive levels of the heat shock proteins from HSP 60, 70, and 90 families, and they have the potential to further enhance the production of the majority of these proteins under stress conditions. The results of this study indicate that the separate habitats selected by male and female D. magna result in different patterns of HSP production, leading us to hypothesize that that male and female Daphnia magna adopt different strategies to maximize the fitness of the species

Melioidosis in Tsunami Survivors

Eugene Athan, Anthony M. Allworth, Catherine Engler, Ivan Bastian, and Allen C. Chen

Numerical Study on Hydrogen–Gasoline Dual-Fuel Spark Ignition Engine

Data Availability Statement: This study did not report any data.Copyright © 2022 by the authors. Hydrogen, as a suitable and clean energy carrier, has been long considered a primary fuel or in combination with other conventional fuels such as gasoline and diesel. Since the density of hydrogen is very low, in port fuel-injection configuration, the engine’s volumetric efficiency reduces due to the replacement of hydrogen by intake air. Therefore, hydrogen direct in-cylinder injection (injection after the intake valve closes) can be a suitable solution for hydrogen utilization in spark ignition (SI) engines. In this study, the effects of hydrogen direct injection with different hydrogen energy shares (HES) on the performance and emissions characteristics of a gasoline port-injection SI engine are investigated based on reactive computational fluid dynamics. Three different injection timings of hydrogen together with five different HES are applied at low and full load on a hydrogen–gasoline dual-fuel SI engine. The results show that retarded hydrogen injection timing increases the concentration of hydrogen near the spark plug, resulting in areas with higher average temperatures, which led to NOX emission deterioration at −120 Crank angle degree After Top Dead Center (CAD aTDC) start of injection (SOI) compared to the other modes. At −120 CAD aTDC SOI for 50% HES, the amount of NOX was 26% higher than −140 CAD aTDC SOI. In the meanwhile, an advanced hydrogen injection timing formed a homogeneous mixture of hydrogen, which decreased the HC and soot concentration, so that −140 CAD aTDC SOI implied the lowest amount of HC and soot. Moreover, with the increase in the amount of HES, the concentrations of CO, CO2 and soot were reduced. Having the HES by 50% at −140 CAD aTDC SOI, the concentrations of particulate matter (PM), CO and CO2 were reduced by 96.3%, 90% and 46%, respectively. However, due to more complete combustion and an elevated combustion average temperature, the amount of NOX emission increased drastically.This research received no external funding