Persistent Place-Making in Prehistory: the Creation, Maintenance, and Transformation of an Epipalaeolithic Landscape

Most archaeological projects today integrate, at least to some degree, how past people engaged with their surroundings, including both how they strategized resource use, organized technological production, or scheduled movements within a physical environment, as well as how they constructed cosmologies around or created symbolic connections to places in the landscape. However, there are a multitude of ways in which archaeologists approach the creation, maintenance, and transformation of human-landscape interrelationships. This paper explores some of these approaches for reconstructing the Epipalaeolithic (ca. 23,000–11,500 years BP) landscape of Southwest Asia, using macro- and microscale geoarchaeological approaches to examine how everyday practices leave traces of human-landscape interactions in northern and eastern Jordan. The case studies presented here demonstrate that these Epipalaeolithic groups engaged in complex and far-reaching social landscapes. Examination of the Early and Middle Epipalaeolithic (EP) highlights that the notion of “Neolithization” is somewhat misleading as many of the features we use to define this transition were already well-established patterns of behavior by the Neolithic. Instead, these features and practices were enacted within a hunter-gatherer world and worldview

Velocity and relative number density determination within a pulsed laser ablation plume via Doppler planar laser-induced fluorescence

Pulsed laser ablation plumes expanding into a low-pressure background gas were studied. An Sr target was ablated with the frequency-tripled output of a Nd:YAG laser focused to provide an intensity of approx. 3 × 10 W/cm at the surface of the target. Neutral Sr atoms were probed with an Nd:YAG-pumped tunable dye laser system and Sr ions were probed with an N-laser-pumped tunable dye laser system. All beams were directed vertically downward onto the sample, with the probe beams formed into a sheet either by a set of cylindrical lenses or by expansion via a prism. The subsequent fluorescence was detected at 90° to the probe beams via an intensified CCD camera

Detection of bright trion states using the fine structure emission of single CdSe/ZnS colloidal quantum dots

We report direct observation of the lowest two states of the band-edge exciton fine structure in the photoluminescence from single CdSe/ZnS core/shell nanocrystals at cryogenic temperatures. The temperature dependence of this spectral fingerprint reveals exciton spin relaxation rates as low as 10 mu s(-1). The fine structure is also dependent on the nanocrystal charge state facilitating the identification of a bright negatively charged trion state with a quantum yield comparable to that of neutral emission

Spontaneous Spectral Diffusion in CdSe Quantum Dots

Spectral diffusion of the emission line of single colloidal nanocrystals is generally regarded as a random process. Here, we show that each new spectral position has a finite memory of previous spectral positions, as evidenced by persistent anticorrelations in time series of spectral jumps. The anticorrelation indicates that there is an enhanced probability of the charge distribution around the nanocrystal returning to a previous configuration. We show both statistically and directly that this memory manifests as an observable spontaneous “relaxation” in the absence of a pump laser, so that spectral diffusion progresses in a manner of “two steps forward and one step back”

High-enthalpy expansion tube experiments with gas injection

An experimental study was conducted to develop a system for superorbital high-enthalpy pow simulation with gas injection. The expansion tube X-2 was used as the base facility. The synchronization of the gas injection to the expansion tube operation and the effect of the gas injection on the high-enthalpy flow generation performance are carefully discussed. When hydrogen was injected, the performance of the acceleration tube operation was not degraded, whereas with nitrogen injection the shock speed was significantly decreased. Hypersonic shock layers with gas injection were visualized by the schlieren method. This system is expected to be used as a tool to simulate a hypersonic shock layer with ablation for a reentry capsule

Moderate intensity physical activity prevents increased blood glucose concentrations, fat pad deposition and cardiac action potential prolongation following diet-induced obesity in a juvenile-adolescent rat model

BACKGROUND: Both obesity and a lack of physical activity have been associated with an elevated risk of cardiovascular disease (CVD). The incidence of obesity is increasing, especially in juvenile-adolescents. While there is limited research examining the chronic effects of obesity in adolescent humans and animal models of this condition, little is also known concerning how moderate physical activity might prevent or attenuate secondary cardiovascular complications induced by obesity during adolescence. We investigated the effects of diet-induced obesity (consisting of a high-fat, high-carbohydrate diet (HFHC)) on biometric indices, vascular and airway function, cardiovascular function, systemic oxidative stress and markers of inflammation in a juvenile-adolescent rodent model. Four groups were used: control (CON), physical activity (PA) treated, HFHC and HFHC + PA (n = 16 per group). HFHC feeding started at 4 weeks of age for a period of 12 weeks. Physical activity treatment was initiated (PA and HFHC + PA groups) when the animals were 8 weeks of age, for 8 weeks. RESULTS: Physical activity in juvenile-adolescent healthy rats showed no change in comparison to the CON group in all experimental parameters except for increases in lipid peroxidation, decreases in inflammatory cytokines, improvements in vascular reactivity and decreased atrial responses to positive chronotropic agents. The HFHC animals were mildly hyperglycemic, hypertensive, displayed renal hypertrophy and showed increased retroperitoneal fat pad deposition compared to the CON group. HFHC + PA rats were also hypertensive, however showed improvements in cardiac electrophysiology, body weight, fat pad deposition and inflammatory signaling, in comparison to the HFHC fed rats and CON animals. CONCLUSION: In conclusion, in a juvenile-adolescent animal model of diet-induced obesity engagement in physical activity is beneficial in reducing the inflammatory effects of obesity