CONTINGENT REINFORCEMENT FOR CARBON MONOXIDE REDUCTION: WITHIN-SUBJECT EFFECTS OF PAY AMOUNT

The relationship between reinforcer amount and daytime smoking reduction in smokers offered money for reduced afternoon breath carbon monoxide (CO) levels was examined. Twenty-three hired regular smokers with average baseline CO levels of about 30 ppm were exposed in random order to five sliding scale payment schedules that changed daily or weekly. Money was available for afternoon CO readings between 0 and 21 ppm with pay amount inversely related to the absolute CO reading obtained. Maximum pay amount for readings below 7 ppm varied among $0, $1.50, $3, $6, and $12 per day. Contingent reinforcement promoted CO and daytime cigarette reduction within individuals with the amount of behavior change related to the amount of payment available. Average CO levels decreased from 30 to 15 ppm as a function of pay amount whereas self-reported daytime cigarettes decreased from 12 to 5 per day. Average minutes of cigarette abstinence prior to the afternoon study contact increased from 62 to 319 minutes as a function of pay amount, whereas the percentage of available money earned increased from 22% to 48%. Nontargeted evening cigarette use also decreased during periods of daytime smoking reduction. The orderly effects of this contingent reinforcement intervention on daytime smoking of regular smoker volunteers suggest that this is a sensitive model for continued evaluation of factors that influence smoking reduction and cessation.     

A theoretical model of effective electrical conductivity and piezoresistivity of carbon nanotube composites

A theoretical model is developed to predict the electrical conductivity of polymer composites containing carbon nanotubes. It incorporates the effect of two conductivity mechanisms, electron hopping between adjacent nanotubes at the nanoscale and the transmission of electrons through conductive networks formed by nanotubes at the microscale. Based on the model, analytical expressions of both electrical conductivity and piezoresisitivity under stretching are established. The expressions are simple in form, without resorting to heavy computation, and able to give accurate estimations for both electrical conductivity and piezoresistivity.     

纳米炭在分化型甲状腺癌再手术中应用价值的研究

探讨在分化型甲状腺癌（DTC）再手术中应用纳米炭对甲状旁腺保护和引导颈淋巴结清扫的作用与价值。选取2011年2月至2014年2月湖南省人民医院乳腺甲状腺外科116例D T C再手术患者,随机分为观察组（纳米炭组）64例和对照组52例,试验组在术中先向残余甲状腺或癌灶或肿大淋巴结内注射纳米炭0．1ml～0．3ml不等,对照组不使用纳米炭。观察两组辨别甲状旁腺的个数与准确性,以及在颈淋巴结清扫个数的差异。同时观察两组术后常见并发症有无差异。观察组使再手术的D T C患者的甲状旁腺识别率为92．2％,辨别出3个及以上甲状旁腺比率为75％,均明显高于对照组的28．8％、36．5％,两组比较有显著性差异（ P＜0．05）。中央区与侧颈区淋巴结清扫的个数比较,观察组明显多于对照组（P＜0．05）。观察组不增加术后并发症,而且,其一过性的甲状旁腺功能减退的并发症尚有下降趋势（P＜0．05）。纳米炭对DTC再手术中的甲状旁腺的识别率和区域淋巴结的黑染,使甲状旁腺易于识别和保护,有利于更为彻底清扫中央区和侧颈区淋巴结,尚可降低一过性甲状旁腺功能减退的并发症。     

Static and dynamical ageing processes at room temperature in a Fe25Ni0.4C virgin martensite: effect of C redistribution at the nanoscale

The work-hardening behaviour of virgin martensitic steel has been investigated in a strictly un-aged state and after various ageing conditions. At room temperature (RT), the un-aged alloy shows astonishing tensile performances (ultimate tensile stress?=?1600?MPa/uniform elongation?=?15%) but unexpected serrations. These serrations can be suppressed by static ageing (at RT or higher) while maintaining the initial work-hardening rate (ageing at RT). Parallel investigations using atom probe tomography reveal that the distribution of carbon at the atomic scale evolves from purely homogeneous for virgin martensite to partly segregated at a very fine scale (5–10?nm) after static ageing. This particular mechanical behaviour can therefore be associated with a very local decrease in available carbon in solid solution due to redistribution and segregations on defects (nanotwins) that occurs rapidly, even after few days at RT.     

Social learning under the labeling effect: Exploring travellers’ behavior in social dilemmas

This paper presents results of a laboratory experiment, in which subjects made choices between public and private transportation when managing Personal Carbon Allowances (PCAs). The objectives of this study were twofold. Firstly, it was aimed at investigating the labeling effect under the social dilemma context. Secondly, it showed insights into the decision-making process when feedback about others’ choices was provided. A combination of the labeling effect and feedback helped individuals change their commuting pattern and increase the number of trips by public transportation under the PCAs regime. Feedback on others’ choices resulted in social learning and incentivized choice of public transportation more frequently in social dilemma situations.     

Avoidance of 20% carbon dioxide-enriched air with humans.

Four college students were exposed to a Sidman avoidance procedure to determine if an avoidance contingency involving 20% carbon dioxide-enriched air (CO2) would produce and maintain responding. In Phase 1, two conditions (contingent and noncontingent) were conducted each day. These conditions were distinguished by the presence or absence of a blue or green box on a computer screen. In the contingent condition, CO2 presentation were delivered every 3 s unless a subject pulled a plunger. Each plunger pull postponed CO2 presentations for 10 s. In the noncontingent condition, CO2 presentations occurred on the average of every 5 min independent of responding. Following stable responding in Phase 1, condition-correlated stimuli were reversed. In both conditions, plunger response rate was high during the contingent condition and low or zero during the noncontingent condition. Furthermore, subjects avoided most CO2 presentations. However, CO2 presentations did not increase verbal reports of fear. Overall, the results from the present study suggest that CO2 can be used effectively in basic studies of aversive control and in laboratory analogues of response patterns commonly referred to as anxiety.     

INCREASING OUR COMPASSION FOOTPRINT: THE ANIMALS' MANIFESTO

Our relationships with animals are wide‐ranging. When people tell me that they love animals and then harm or kill them I tell them I'm glad they don't love me. Many individuals, including scientists, ignore their responsibility when they interact with animals and fail to recognize that doing something in the name of science, which usually means in the name of humans, is not an adequate reason for intentionally causing suffering, pain, or death. “Good welfare” usually is not “good enough”. Existing regulations allow animals to be treated in regrettable ways that demean us as a species. Compassion is the key for bettering both animal and human lives. A good way to make the world a more compassionate place for animals is to increase our compassion footprint. We could begin by deciding that we will not intrude on animals' lives unless our actions are in the best interests of the animals irrespective of our desires. It is simple to make more compassionate choices about what we eat and wear and how we educate students, conduct research, and entertain ourselves at the expense of animals. The time to make these changes is long overdue.     

CONTINGENT PAYMENT PROCEDURES FOR SMOKING REDUCTION AND CESSATION

We assessed the ability of a combined contingent reinforcement and intensive monitoring procedure to promote and sustain temporary smoking cessation among 34 hired research volunteers, and the ability of a smoking reduction test to predict the subsequent initiation of abstinence. During the 5-day cutdown test, subjects were paid from $0 to $6 per day depending on the extent of reduction from baseline CO levels. During the abstinence test, breath samples were obtained three times daily and subjects were paid $4 for each CO reading ≤11 ppm. Sixty-eight percent of subjects initiated abstinence. Of the breath samples collected during the abstinence test (91% of scheduled samples), 96.5% were ≤11 ppm and 80.5% were ≤8 ppm. Subjects who earned more money during the cutdown test were more likely to abstain (r = ?0.51, p < .001). Contingent reinforcement and intensive monitoring procedures appear to have usefulness for analog studies of smoking reduction and cessation.     

Effects of cementite morphology on short-fatigue-crack propagation in binary Fe–C steel

The effects of cementite morphology on short-fatigue-crack propagation were investigated by subjecting smooth steel specimens to rotating-bending fatigue tests. Intergranular and transgranular cementite precipitation steels free of other phases were prepared through heat treatments. In the intergranular cementite precipitation steel, short-fatigue-crack propagation was decelerated at the grain boundaries, and accelerated in the grain interiors. In contrast, the transgranular precipitation steel showed the deceleration of the crack propagation in the grain interiors but not in the vicinity of the grain boundaries.     

Modification of the optical band gap of polyethylene by irradiation with electrons and gamma rays

Irradiation of polymers has become an important technique in producing special materials for electronic applications. In this study, the effects of electron and gamma irradiation on ultra-high-molecular-weight polyethylene (UHMWPE) samples have been studied using UV–Vis absorption spectroscopy. The UHMWPE samples were irradiated with electron and gamma rays with doses ranging from 25 kGy up to 500 kGy. An increase in the optical absorption and a shifting from the UV–Vis towards longer wavelengths were observed. Concomitantly, a pronounced decrease in the optical band gap was recorded as a function of dose level. The optical band gap E _g varied from 2.86 eV for a pristine sample down to ～1.98 eV and ～2 eV for samples irradiated with gamma rays and electrons at the highest doses, respectively. A correlation between E _g and the number of carbon atoms N in a formed cluster is discussed in terms of a modified Tauc equation.