Vacuum-jacketed transfer line installation technique

Rolling-type spacers in the form of steel balls retained in appropriate sleeves affixed at intervals to the exterior of the transfer line facilitate the installation of a vacuum-jacketed line. They act as standoffs to position the transfer line concentrically within the vacuum jacket line

Jacketed cryogenic piping is stress relieved

Jacketed design of piping used to transfer cryogenic fluids, relieves severe stresses associated with the temperature gradients that occur during transfer cycles and ambient periods. The inner /transfer/ pipe is preloaded in such a way that stress relief takes place automatically as cycling occurs

Ion chemistry in interstellar space

The temperature dependence of the bimolecular reactions of Cl(+), HCl(+), CH(+), CH2(+), N(+), NH(+), and NH2(+) reacting with H2 have been investigated. For Cl(+) and HCl(+) rate constants have been determined over the temperature range of 150 to 400 K. Preliminary data have been obtained for the other systems. The Cl(+)/H2 system shows a weak, but significant positive temperature dependence that could be important in interstellar modeling studies. The HCl(+)/H2 system shows a substantial negative temperature dependence with the rate constant approaching the collision rate at low temperatures. The association reaction CH3(+) + HCN yields CH3 HCN(+) has been theoretically modeled using statistical phase space theory. Both radiative and collisional stabilization have been included. The results are compared with experiment with good agreement obtained over wide variations in T and p. This system is potentially important in the mechanism of large molecule synthesis in interstellar space

The evolution of resistance through costly acquired immunity

We examine the evolutionary dynamics of resistance to parasites through acquired immunity. Resistance can be achieved through the innate mechanisms of avoidance of infection and reduced pathogenicity once infected, through recovery from infection and through remaining immune to infection: acquired immunity. We assume that each of these mechanisms is costly to the host and find that the evolutionary dynamics of innate immunity in hosts that also have acquired immunity are quantitatively the same as in hosts that possess only innate immunity. However, compared with resistance through avoidance or recovery, there is less likely to be polymorphism in the length of acquired immunity within populations. Long-lived organisms that can recover at intermediate rates faced with fast-transmitting pathogens that cause intermediate pathogenicity (mortality of infected individuals) are most likely to evolve long-lived acquired immunity. Our work emphasizes that because whether or not acquired immunity is beneficial depends on the characteristics of the disease, organisms may be selected to only develop acquired immunity to some of the diseases that they encounter

Disempowerment and resistance in the print industry? Reactions to surveillance-capable technology

This article offers a critique of recent characterisations of the effects of electronic technologies in the workplace. It presents detailed case study evidence that calls into question a number of common theoretical assumptions about the character of surveillance at work and the responses of employees to it

When and where do feed-forward neural networks learn localist representations?

According to parallel distributed processing (PDP) theory in psychology, neural networks (NN) learn distributed rather than interpretable localist representations. This view has been held so strongly that few researchers have analysed single units to determine if this assumption is correct. However, recent results from psychology, neuroscience and computer science have shown the occasional existence of local codes emerging in artificial and biological neural networks. In this paper, we undertake the first systematic survey of when local codes emerge in a feed-forward neural network, using generated input and output data with known qualities. We find that the number of local codes that emerge from a NN follows a well-defined distribution across the number of hidden layer neurons, with a peak determined by the size of input data, number of examples presented and the sparsity of input data. Using a 1-hot output code drastically decreases the number of local codes on the hidden layer. The number of emergent local codes increases with the percentage of dropout applied to the hidden layer, suggesting that the localist encoding may offer a resilience to noisy networks. This data suggests that localist coding can emerge from feed-forward PDP networks and suggests some of the conditions that may lead to interpretable localist representations in the cortex. The findings highlight how local codes should not be dismissed out of hand

Home is the Key: A Study of the Social Impact of Habitat for Humanity in South Carolina

Rates of housing instability are increasing in the United States, largely due to surging rental costs (Kusisto & Malas, 2018). Public housing systems are full and waiting lists are long (Evans, Sullivan & Wallskog, 2016; Katz, Kling & Liebman, 2002). Low-income homeownership policies have faced strong critiques, especially concerns of coercing people into risky financial situations (Shlay, 2006). With a human development perspective (Bronfenbrenner & Morris, 2006) and in partnership with the Habitat for Humanity program in South Carolina, this cross-sectional study examined the social benefits associated with low-income homeownership achieved through a robust preparation and support program. Using survey data collected from a sample of Habitat for Humanity homeowners in the state of South Carolina, the relationship between conceptual predictors from the literature (i.e., financial health, residential stability and psychological factors) and social benefits (i.e. collective efficacy, sense of community, neighboring and civic engagement) were explored. Additionally, the relationship between Habitat for Humanity program activities (i.e. financial literacy classes, homeownership preparation classes and sweat equity hours) and the social outcomes were explored. It was further hypothesized that the program activities would also moderate the relationship between the conceptual predictors and social benefits. Findings demonstrated that psychological factors were associated with collective efficacy (b = 0.37, p = .011) and sense of community (b = 0.33, p = .013) while financial health was related to civic engagement (b = 1.01, p = .01). Habitat for Humanity\u27s financial literacy classes contributed to an increase in collective efficacy (b = 0.11, p = .019) but to a decrease in civic engagement (b = -0.43, p = .003), while sweat equity hours were related to an increase in neighboring (b = 0.001, p = .005). Implications and limitations of the findings are included as well as a review of lessons learned in this attempt at a state level evaluation

Behavioral and Molecular Analysis of Memory in the Dwarf Cuttlefish

Complex memory has evolved because it benefits animals in all areas of life, such as remembering the location of food or conspecifics, and learning to avoid dangerous stimuli. Advances made by studying relatively simple nervous systems, such as those in gastropod mollusks, can now be used to study mechanisms of memory in more complex systems. Cephalopods offer a unique opportunity to study the mechanisms of memory in a complex invertebrates. The dwarf cuttlefish, Sepia bandensis, is a useful memory model because its fast development and small size allows it to be reared and tested in large numbers. However, primary literature regarding the behavior and neurobiology of this species is lacking. This research determined that juvenile S. bandensis exhibited short term memory (STM) and long term memory (LTM). To assess memory in dwarf cuttlefish, a memory test was conducted which utilized the predatory attack in cuttlefish. It was found that 4 week old dwarf cuttlefish retained memory of the experiment up to 4 days. Using an automated tracking software called DanioVision, this research found that cuttlefish selectively inhibit the tentacle striking phase of their predatory behavior, without inhibiting the attention and positioning phases. Determining the molecular mechanisms underlying memory is key to understanding how memory is manifested in the form of altered behavior. At the cellular level, memories are formed by altering the physical and chemical properties within specific neural circuits. The transcription factor, CREB, is responsible for transcribing genes required for initiating these long-term neuronal changes. Using immunohistochemistry, a molecular assay was developed to determine whether CREB is activated in cuttlefish arms during the memory experiment. Trained cuttlefish had a greater number of CREB positive cells in the epithelium of the arm than controls. Trained cuttlefish also had a greater average number of CREB-positive cells in positive suckers than untrained cuttlefish. These results suggest that CREB activation may result from behavioral training in cuttlefish. Lastly, it was found that the distal tip of the arm contained more CREB-positive cells than the proximal part of the arm. Spatial activation of CREB may occur predominantly in the distal portion of the arm. By locating CREB for the first time in a cephalopod, this research presents dwarf cuttlefish as interesting models for studying the molecular mechanisms of memory formation