The form of cosmic string cusps

We classify the possible shapes of cosmic string cusps and how they transform under Lorentz boosts. A generic cusp can be brought into a form in which the motion of the cusp tip lies in the plane of the cusp. The cusp whose motion is perpendicular to this plane, considered by some authors, is a special case and not the generic situation. We redo the calculation of the energy in the region where the string overlaps itself near a cusp, which is the maximum energy that can be released in radiation. We take into account the motion of a generic cusp and the resulting Lorentz contraction of the string core. The result is that the energy scales as $\sqrt {rL}$ instead of the usual value of $r^{1/3} L^{2/3}$, where $r$ is the string radius and $L$ and is the typical length scale of the string. Since $r << L$ for cosmological strings, the radiation is strongly suppressed and could not be observed.Comment: 15 pages, ReVTex, 2 postscript figures with eps

Temperature Sequence of Eggs from Oviposition Through Distribution: Production—Part 1

During Egg Safety Action Plan hearings in Washington, DC, many questions were raised concerning the egg temperature (T) used in the risk assessment model. Therefore, a national study was initiated to determine the T of eggs from oviposition through distribution. In part 1; researchers gathered data on internal and surface egg T from commercial egg production facilities. An infrared thermometer was used to rapidly measure surface T, and internal T was determined by probing individual eggs. The main effects were geographic region (state) and season evaluated in a factorial design. Egg T data were recorded in the production facilities in standardized comparisons. Regression analysis (P \u3c 0.0001) showed that the R2 (0.952) between infrared egg surface T and internal T was very high, and validated further use of the infrared thermometer. Hen house egg surface and internal T were significantly influenced by state, season, and the state × season interaction. Mean hen house egg surface T was 27.3 and 23.8°C for summer and winter, respectively, with 29.2 and 26.2°C for egg internal T (P \u3c 0.0001). Hen house eggs from California had the lowest surface and internal T in winter among all the states (P \u3c 0.0001), whereas the highest egg surface T were recorded during summer in North Carolina, Georgia, and Texas, and the highest internal T were recorded from Texas and Georgia. Cooling of warm eggs following oviposition was significantly influenced by season, state, and their interaction. Egg internal T when 3/4 cool was higher in summer vs. winter and higher in North Carolina and Pennsylvania compared with Iowa. The time required to 3/4 cool eggs was greater in winter than summer and greater in Iowa than in other states. These findings showed seasonal and state impacts on ambient T in the hen house that ultimately influenced egg surface and internal T. More important, they showed opportunities to influence cooling rate to improve internal and microbial egg quality

Temperature Sequence of Eggs from Oviposition Through Distribution: Transportation—Part 3

The Egg Safety Action Plan released in 1999 raised many questions concerning egg temperature used in the risk assessment model. Therefore, a national study by researchers in California, Connecticut, Georgia, Iowa, Illinois, North Carolina, Pennsylvania, and Texas was initiated to determine the internal and external temperature sequence of eggs from oviposition through distribution. Researchers gathered data from commercial egg production, processing, and distribution facilities. The experimental design was a mixed model with random effects for season and a fixed effect for duration of the transport period (long or short haul). It was determined that processors used refrigerated transport trucks (REFER) as short-term storage (STS) in both the winter and summer. Therefore, this summary of data obtained from REFER also examines the impact of their use as STS. Egg temperature data were recorded for specific loads of eggs during transport to point of resale or distribution to retailers. To standardize data comparisons between loads, they were segregated between long and short hauls. The summer egg temperatures were higher in the STS and during delivery. Egg temperature was not significantly reduced during the STS phase. Egg temperature decreases were less (P \u3c 0.0001) during short delivery hauls 0.6°C than during long hauls 7.8°C. There was a significant season × delivery interaction (P \u3c 0.05) for the change in the temperature differences between the egg and ambient temperature indicated as the cooling potential. This indicated that the ambient temperature during long winter deliveries had the potential to increase egg temperature. The REFER used as STS did not appreciably reduce internal egg temperature. These data suggest that the season of year affects the temperature of eggs during transport. Eggs are appreciably cooled on the truck, during the delivery phase, which was contrary to the original supposition that egg temperatures would remain static during refrigerated transport. These data indicate that refrigerated transport should be a component in future assessments of egg safety

Protecting climate with forests

Policies for climate mitigation on land rarely acknowledge biophysical factors, such as reflectivity, evaporation, and surface roughness. Yet such factors can alter temperatures much more than carbon sequestration does, and often in a conflicting way. We outline a framework for examining biophysical factors in mitigation policies and provide some best-practice recommendations based on that framework. Tropical projects-avoided deforestation, forest restoration, and afforestation-provide the greatest climate value, because carbon storage and biophysics align to cool the Earth. In contrast, the climate benefits of carbon storage are often counteracted in boreal and other snow-covered regions, where darker trees trap more heat than snow does. Managers can increase the climate benefit of some forest projects by using more reflective and deciduous species and through urban forestry projects that reduce energy use. Ignoring biophysical interactions could result in millions of dollars being invested in some mitigation projects that provide little climate benefit or, worse, are counter-productive

Temperature Sequence of Eggs from Oviposition Through Distribution: Processing—Part 2

The Egg Safety Action Plan released in 1999 raised questions concerning egg temperature used in the risk assessment model. Therefore, a national study was initiated to determine the internal and external temperature sequence of eggs from oviposition through distribution. Researchers gathered data from commercial egg production, shell egg processing, and distribution facilities. The experimental design was a mixed model with 2 random effects for season and geographic region and a fixed effect for operation type (inline or offline). For this report, internal and external egg temperature data were recorded at specific points during shell egg processing in the winter and summer months. In addition, internal egg temperatures were recorded in pre- and postshell egg processing cooler areas. There was a significant season × geographic region interaction (P \u3c 0.05) for both surface and internal temperatures. Egg temperatures were lower in the winter vs. summer, but eggs gained in temperature from the accumulator to the postshell egg processing cooler. During shell egg processing, summer egg surface and internal temperatures were greater (P\u3c 0.05) than during the winter. When examining the effect of shell egg processing time and conditions, it was found that 2.4 and 3.8°C were added to egg surface temperatures, and 3.3 and 6.0°C were added to internal temperatures in the summer and winter, respectively. Internal egg temperatures were higher (P \u3c 0.05) in the preshell egg processing cooler area during the summer vs. winter, and internal egg temperatures were higher (P \u3c 0.05) in the summer when eggs were ¾ cool (temperature change required to meet USDA-Agricultural Marketing Service storage regulation of 7.2°C) in the postshell egg processing area. However, the cooling rate was not different (P \u3e 0.05) for eggs in the postshell egg processing cooler area in the summer vs. winter. Therefore, these data suggest that season of year and geographic location can affect the temperature of eggs during shell egg processing and should be a component in future assessments of egg safety

Dynamical models for sand ripples beneath surface waves

We introduce order parameter models for describing the dynamics of sand ripple patterns under oscillatory flow. A crucial ingredient of these models is the mass transport between adjacent ripples, which we obtain from detailed numerical simulations for a range of ripple sizes. Using this mass transport function, our models predict the existence of a stable band of wavenumbers limited by secondary instabilities. Small ripples coarsen in our models and this process leads to a sharply selected final wavenumber, in agreement with experimental observations.Comment: 9 pages. Shortened version of previous submissio

Investigating hyper-vigilance for social threat of lonely children

The hypothesis that lonely children show hypervigilance for social threat was examined in a series of three studies that employed different methods including advanced eye-tracking technology. Hypervigilance for social threat was operationalized as hostility to ambiguously motivated social exclusion in a variation of the hostile attribution paradigm (Study 1), scores on the Children’s Rejection-Sensitivity Questionnaire (Study 2), and visual attention to socially rejecting stimuli (Study 3). The participants were 185 children (11 years-7 months to 12 years-6 months), 248 children (9 years-4 months to 11 years-8 months) and 140 children (8 years-10 months to 12 years-10 months) in the three studies, respectively. Regression analyses showed that, with depressive symptoms covaried, there were quadratic relations between loneliness and these different measures of hypervigilance to social threat. As hypothesized, only children in the upper range of loneliness demonstrated elevated hostility to ambiguously motivated social exclusion, higher scores on the rejection sensitivity questionnaire, and disengagement difficulties when viewing socially rejecting stimuli. We found that very lonely children are hypersensitive to social threat

Comparison of vitrified and unvitrified Eocene woody tissues by TMAH thermochemolysis – implications for the early stages of the formation of vitrinite

Samples of vitrified and unvitrified Eocene woody plant tissues collected from the Fossil Forest site, Geodetic Hills, Axel Heiberg Island, have been characterized by TMAH thermochemolysis. All samples are gymnosperm-derived, are of very low maturity and all share the same post-depositional geologic history. Differences in the distributions of products observed from vitrified and unvitrified samples suggest that vitrification of woody tissue is associated with modification of the lignin C3 side chain, following loss of all or most of the carbohydrate present in the precursor woody tissues. The key driver of vitrification appears to be physical compression of the tissue following biological removal of cellulosic materials

Searching for a Stochastic Background of Gravitational Waves with LIGO

The Laser Interferometer Gravitational-wave Observatory (LIGO) has performed the fourth science run, S4, with significantly improved interferometer sensitivities with respect to previous runs. Using data acquired during this science run, we place a limit on the amplitude of a stochastic background of gravitational waves. For a frequency independent spectrum, the new limit is $\Omega_{\rm GW} < 6.5 \times 10^{-5}$. This is currently the most sensitive result in the frequency range 51-150 Hz, with a factor of 13 improvement over the previous LIGO result. We discuss complementarity of the new result with other constraints on a stochastic background of gravitational waves, and we investigate implications of the new result for different models of this background.Comment: 37 pages, 16 figure

New Zealand athletes' attitudes towards seeking sport psychology consultation

The aim of this study was to use the Sport Psychology Attitudes-Revised (SPA-R) questionnaire (Martin, Kellman, Lavallee & Page, 2002) to develop an understanding of the attitudes elite New Zealand athletes (N = 112) hold towards sport psychology so that services can be tailored to accommodate these views. The influence of athlete characteristics such as nationality, gender, age, level of competition achieved, and previous use of sport psychology on attitudes was explored. Further, the SPA-R was used as a measure of attitudes within the Theory of Reasoned Action (TRA; Ajzen & Fishbein, 1980) and Theory Planned Behaviour (TPB; Ajzen, 1985, 1991), and integrated with measures of subjective norm and perceived behavioural control to investigate the influence of these variables on predicting athletes' intention to use sport psychology. Results suggested that New Zealand athletes generally held positive attitudes regarding sport psychology, with gender and previous experience of sport psychology significantly influencing attitudes. Regression analyses indicated that the TPB was a better model than the TRA for predicting intention, and the variables predicted 39.7% of variance in intention to use sport psychology. The only SPA-R subscale that contributed significantly was confidence in sport psychology, and perceived behavioural control and subjective norm also contributed significantly. These findings suggest the SPA-R may have limited value in predicting intentions, although the TPB could provide a useful theoretical framework to direct interventions aimed at increasing athletes' intention to use sport psychology