The Ability of Horseshoe Crabs (Limulus polyphemus) To Detect Changes in Temperature

Previous studies have suggested that horseshoe crabs prefer warm water, suggesting that they may be able to detect changes in water temperature. The overall goal of this study was to test this hypothesis. Our specific objectives were to: 1) find out if horseshoe crabs can detect temperature changes; 2) determine the magnitude of temperature change they can detect, and; 3) determine whether their temperature receptors are located internally or externally. Animals were placed in a light-tight chamber that received a constant flow of cooled seawater. Their heart rates were continuously recorded and a change in heart rate following the addition of warmer water was used as an indicator that they sensed the change in temperature. The results showed that 50% of horseshoe crabs responded to a temperature change of 1°C, while 100% responded to a temperature change of 2.6°C. Over half of the horseshoe crabs also responded to a rate of temperature change of less than 1.5°C. Both of these results indicate that horseshoe crabs can, indeed, sense temperature changes. Also, the horseshoe crabs typically showed a response before their internal temperature changed, indicating that their temperature receptors are most likely located externally

Feeling cold is contagious

Seeing someone plunge into an ice-cold bath induces feelings of cold. However, it was recently demonstrated that viewing another's skin temperature change also induces a small congruent temperature change in the observer. This synchronization suggests top-down influences on peripheral temperature regulation mechanisms and lends supports to somatic-simulation theories of inter-subjectivity

Non-classical correlation of cascaded photon pairs emitted from quantum dot

We studied the quantum correlation between the photon pairs generated by biexciton cascade decays of self-assembled quantum dots, and determined the temperature behavior associated with so-called sudden change of the quantum correlation. The relationship between the fine structure splitting and the sudden change temperature is also provided. Our study indicates that this correlation behavior sudden change temperature is independent on the back ground noise in the system and far lower than entanglement sudden death temperature, therefore it should be easier to observe the phenomenon of correlation sudden change in experiments than to observe entanglement sudden death

The likely effects of thermal climate change on vertebrate skeletal muscle mechanics with possible consequences for animal movement and behaviour

Climate change can involve alteration in the local temperature that an animal is exposed to, which in turn may affect skeletal muscle temperature. The underlying effects of temperature on the mechanical performance of skeletal muscle can affect organismal performance in key activities, such as locomotion and fitness-related behaviours, including prey capture and predator avoidance. The contractile performance of skeletal muscle is optimized within a specific thermal range. An increased muscle temperature can initially cause substantial improvements in force production, faster rates of force generation, relaxation, shortening, and production of power output. However, if muscle temperature becomes too high, then maximal force production and power output can decrease. Any deleterious effects of temperature change on muscle mechanics could be exacerbated by other climatic changes, such as drought, altered water, or airflow regimes that affect the environment the animal needs to move through. Many species will change their location on a daily, or even seasonal basis, to modulate the temperature that they are exposed to, thereby improving the mechanical performance of their muscle. Some species undergo seasonal acclimation to optimize muscle mechanics to longer-term changes in temperature or undergo dormancy to avoid extreme climatic conditions. As local climate alters, species either cope with the change, adapt, avoid extreme climate, move, or undergo localized extinction events. Given that such outcomes will be determined by organismal performance within the thermal environment, the effects of climate change on muscle mechanics could have a major impact on the ability of a population to survive in a particular location

Temperature sensitive oscillator

An oscillator circuit for sensing and indicating temperature by changing oscillator frequency with temperature comprises a programmable operational amplifier which is operated on the roll-off portion of its gain versus frequency curve and has its output directly connected to the inverting input to place the amplifier in a follower configuration. Its output is also connected to the non-inverting input by a capacitor with a crystal or other tuned circuit also being connected to the non-inverting input. A resistor is connected to the program input of the amplifier to produce a given set current at a given temperature, the set current varying with temperature. As the set current changes, the gain-bandwidth of the amplifier changes and, in turn, the reflected capacitance across the crystal changes, thereby providing the desired change in oscillator frequency by pulling the crystal. There is no requirement that a crystal employed with this circuit display either a linear frequency change with temperature or a substantial frequency change with temperature

Accurate Frequency Domain Modelling of an Electric Furnace

Controllers of industrial furnaces may operate differently in different temperature ranges. The controller has different parameter sets for each of these ranges. The operation of controllers is switched according to the temperature. It is desirable to change the parameters continuously following the temperature. The continuous change of parameters instead of mode switching may decrease the switching transients and lead to more accurate temperature control. A laboratory-scale electric furnace is investigated in this paper. The main focus is on the temperature dependent behavior of the furnace. The objective is to build up a temperature dependent model that is capable to describe the furnace in a wider temperature range

Efficiency Gains from "What"-Flexibility in Climate Policy: An Integrated CGE Assessment

We investigate the importance of ?what?-flexibility on top of ?where?- and ?when?-flexibility for alternative emission control schemes that prescribe long-term temperature targets and eventually impose additional constraints on the rate of temperature change. We find that ?what?-flexibility substantially reduces the compliance costs under alternative emission control schemes. When comparing policies that simply involve long-term temperature targets against more stringent strategies that include additional constraints on the rate of temperature increase, it turns out that the latter involve huge additional costs. These costs may be interpreted as additional insurance payments if damages should not only dependent on absolute temperature change but also on the rate of temperature change. --Climate policy,Integrated Assessment,What-flexibility

Kinetic equation approach to diffusive superconducting hybrid devices

We present calculations of the temperature-dependent electrostatic and chemical potential distributions in disordered normal metal-superconductor structures. We show that they differ appreciably in the presence of a superconducting terminal and propose an experiment to measure these two different potential distributions. We also compute the resistance change in these structures due to a recently proposed mechanism which causes a finite effect at zero temperature. The relative resistance change due to this effect is of the order of the interaction parameter in the normal metal. Finally a detailed calculation of the resistance change due to the temperature dependence of Andreev reflection in diffusive systems is presented. We find that the maximal magnitude due to this thermal effect is in general much larger than the magnitude of the novel effect.Comment: 11 pages LaTeX including 8 Postscript figures. A copy of the file is also available at http://www.tn.tudelft.nl/tn/thssci.htm

Self-organizing, two-temperature Ising model describing human segregation

A two-temperature Ising-Schelling model is introduced and studied for describing human segregation. The self-organized Ising model with Glauber kinetics simulated by M\"uller et al. exhibits a phase transition between segregated and mixed phases mimicking the change of tolerance (local temperature) of individuals. The effect of external noise is considered here as a second temperature added to the decision of individuals who consider change of accommodation. A numerical evidence is presented for a discontinuous phase transition of the magnetization.Comment: 5 pages, 4 page