On the Role of Density Matrices in Bohmian Mechanics

It is well known that density matrices can be used in quantum mechanics to represent the information available to an observer about either a system with a random wave function (``statistical mixture'') or a system that is entangled with another system (``reduced density matrix''). We point out another role, previously unnoticed in the literature, that a density matrix can play: it can be the ``conditional density matrix,'' conditional on the configuration of the environment. A precise definition can be given in the context of Bohmian mechanics, whereas orthodox quantum mechanics is too vague to allow a sharp definition, except perhaps in special cases. In contrast to statistical and reduced density matrices, forming the conditional density matrix involves no averaging. In Bohmian mechanics with spin, the conditional density matrix replaces the notion of conditional wave function, as the object with the same dynamical significance as the wave function of a Bohmian system.Comment: 16 pages LaTeX, no figure

An Investigation of Coach Behaviors, Goal Motives, and Implementation Intentions as Predictors of Well-Being in Sport

The present study aimed to expand upon Smith, Ntoumanis, and Duda’s (2007) research by investigating the influence of coach behaviors and implementation intentions on goal striving in sport. Structural equation modeling analysis with a sample of 108 athletes revealed coach behaviors as predictors of goal motives, which in turn predicted psychological well-being after 8 weeks. Supplementary regression analyses showed no interaction between autonomous goal motives and implementation intentions; however, a synergistic effect was identified for controlled goal motives such that controlled motives furnished with implementation intentions resulted in lower well-being than controlled motives alone. In further analyses, the motives underlying an implementation intention were found to mediate the paths from goal motives to well-being. The findings are discussed in terms of the roles played by goal motives, implementation intentions, and implementation intention motives during goal striving

Temporal aspects of polar bear occurrences at field camps in Wapusk National Park, Canada

Wapusk National Park, University of Manitoba, University of Saskatchewan, the Social Sciences and Humanities Research Council of Canada, Hudson Bay Helicopters, the Churchill Northern Studies Centre, and EarthRangers.Interaction between polar bears (Ursus maritimus) and people is a growing concern for both bear conservation and human safety in a warming Arctic climate. Consequently, the importance of monitoring temporal trends in the proximity of polar bears to people has become critical in managing human-polar bear conflicts. Such concerns are acute in Wapusk National Park in Manitoba, Canada on the Western Hudson Bay coast, where we deployed 18 camera traps at three remote field camps from 2010–2014 (~22,100 camera-days) to monitor the frequency and timing of bears’ visits to those facilities. Following seasonal breakup of Hudson Bay’s sea ice polar bear occurrences at these camps increased throughout the summer and into fall (low in May–July and increasing sharply through August–November and then approaching zero in December when Hudson Bay freezes). We quantified age and sex class and estimated body condition of bears visiting the camps: adult males were most prevalent at Nester One camp close to where adult males congregate at Cape Churchill, whereas the two camps farther south were visited more frequently by females with dependent young, likely traveling to and from a known maternal denning area. Few subadults were observed. As expected, body condition scores declined throughout the on-shore season. Our method of monitoring polar bear occurrence on shore is robust, cost-effective, and non-invasive, and so may provide an economical complement to data gathered through more conventional techniques

Phosphorylation of Voltage-Dependent Anion Channel by Serine/Threonine Kinases Governs Its Interaction with Tubulin

Tubulin was recently found to be a uniquely potent regulator of the voltage-dependent anion channel (VDAC), the most abundant channel of the mitochondrial outer membrane, which constitutes a major pathway for ATP/ADP and other metabolites across this membrane. Dimeric tubulin induces reversible blockage of VDAC reconstituted into a planar lipid membrane and dramatically reduces respiration of isolated mitochondria. Here we show that VDAC phosphorylation is an important determinant of its interaction with dimeric tubulin. We demonstrate that in vitro phosphorylation of VDAC by either glycogen synthase kinase-3β (GSK3β) or cAMP-dependent protein kinase A (PKA), increases the on-rate of tubulin binding to the reconstituted channel by orders of magnitude, but only for tubulin at the cis side of the membrane. This and the fact the basic properties of VDAC, such as single-channel conductance and selectivity, remained unaltered by phosphorylation allowed us to suggest the phosphorylation regions positioned on the cytosolic loops of VDAC and establish channel orientation in our reconstitution experiments. Experiments on human hepatoma cells HepG2 support our conjecture that VDAC permeability for the mitochondrial respiratory substrates is regulated by dimeric tubulin and channel phosphorylation. Treatment of HepG2 cells with colchicine prevents microtubule polymerization, thus increasing dimeric tubulin availability in the cytosol. Accordingly, this leads to a decrease of mitochondrial potential measured by assessing mitochondrial tetramethylrhodamine methyester uptake with confocal microscopy. Inhibition of PKA activity blocks and reverses mitochondrial depolarization induced by colchicine. Our findings suggest a novel functional link between serine/threonine kinase signaling pathways, mitochondrial respiration, and the highly dynamic microtubule network which is characteristic of cancerogenesis and cell proliferation

On Passion and Sports Fans:A Look at Football

The purpose of the present research was to test the applicability of the Dualistic Model of Passion (Vallerand et al., 2003) to being a sport (football) fan. The model posits that passion is a strong inclination toward an activity that individuals like (or even love), that they value, and in which they invest time and energy. Furthermore, two types of passion are proposed: harmonious and obsessive passion. While obsessive passion entails an uncontrollable urge to engage in the passionate activity, harmonious passion entails a sense of volition while engaging in the activity. Finally, the model posits that harmonious passion leads to more adaptive outcomes than obsessive passion. Three studies provided support for this dualistic conceptualization of passion. Study 1 showed that harmonious passion was positively associated with adaptive behaviours (e.g., celebrate the team’s victory), while obsessive passion was rather positively associated with maladaptive behaviours (e.g., to risk losing one’s employment to go to the team’s game). Study 2 used a short Passion Scale and showed that harmonious passion was positively related to the positive affective life of fans during the 2006 FIFA World Cup, psychological health (self-esteem and life satisfaction), and public displays of adaptive behaviours (e.g., celebrating one’s team victory in the streets), while obsessive passion was predictive of maladaptive affective life (e.g., hating opposing team’s fans) and behaviours (e.g., mocking the opposing team’s fans). Finally, Study 3 examined the role of obsessive passion as a predictor of partner’s conflict that in turn undermined partner’s relationship satisfaction. Overall, the present results provided support for the Dualistic Model of Passion. The conceptual and applied implications of the findings are discussed

Cervical Cancer in Cameroon: A Three Pronged Approach to Increase Awareness, Vaccination, Screening and Treatment

Problem: Cameroon has a disproportionately high burden of cervical cancer due to low awareness that the disease is preventable with prophylactic vaccines, lack of screening and treatment of pre-cancerous lesions, and high prevalence of human immunodeficiency virus (HIV). Between 2007-2013, the Cameroon Baptist Convention Health Services (CBCHS) devised three programs to: (1) increase awareness about cervical cancer; (2) immunize girls aged 9-13 years against human papilloma virus (HPV); and (3) conduct cervical cancer screening and treatment. Approaches: In collaboration with clinicians and researchers at University of Massachusetts and Northeastern University, CBCHS conducted education programs about HPV vaccine and cervical cancer for parents, adolescents, health care workers, and community members. The HPV vaccination demonstration project was implemented in three settings: schools, healthcare facilities, and in communities. CBCHS conducted cervical cancer screening in six sites using a “see and treat approach”. Findings: Following approval by the Ministry of Health, CBCHS nurses educated girls, parents, and communities about HPV, cervical cancer, and HPV vaccine through multimedia coverage. A total of 6,851, 6,517 and 5,876 girls were immunized with first, second and third doses, respectively. Achieving an 84.6% 3-dose completion rate. Since 2007, 30,617 women have been screened with visual inspection with acetic acid and digital cervicography. Women with precancerous lesions were treated with cryotherapy or loop electrical excision procedure. Lesions suspicious for cancer were biopsied for histology. Of those screened, 3,015 (10%) self reported HIV-positivity, 19,837 (64%) were HIV-negative, and the HIV status of the remaining women was unreported (25%). The percentage of HIV infected women diagnosed with cancer was consistently higher than the percentage of HIV uninfected women diagnosed with cancer. Lessons Learned: The project demonstrated that, with adequate education of stakeholders, HPV vaccination and cervical cancer screening programs are acceptable and feasible methods to improve cervical cancer outcomes in Cameroon

Vegetation Diversity in Natural and Restored Forested Wetland Sites in Southeast Arkansas

The loss of forested wetlands in the Lower Mississippi River Alluvial Valley in Arkansas has altered regional vegetation communities. Multiple restoration projects have been established in this region to restore wetlands and the services they provide. In order to return these functions to the environment, microtopographic features were constructed in 2001 at Bob White Memorial Wetlands Research and Teaching Station (Bob White). Vegetation diversity was examined at Cut-Off Creek Wildlife Management Area (Cutoff), a naturally forested wetland, and Bob White, an area formally converted to cropland that is now undergoing forest wetland restoration. Vegetation diversity is one way to determine if restoration efforts are effectively restoring ecosystem structure and functions to natural wetland conditions. Vegetation diversity and composition were examined across three topographical features: hummocks/ridges, swales, and flats. Vegetation diversity was examined in the spring, summer, and fall. Indices were used for determining composition similarities between Bob White and Cutoff. Bob White had a species richness of 33 and Cutoff’s species richness was 47. Beta diversity between the two sites was 76 species, this value is high and suggests there is low similarity between the two sites. Sorensen-Dice Similarity Index value was calculated as 0.05, where on a scale of zero to one a low value indicates low similarity in composition. The low similarity between the two sites suggests that vegetation composition at Bob White has not been fully restored to conditions comparable to a natural setting. An explanation for this is the presence of Baccharis halimifolia (Eastern baccharis). B. halimifolia inhibits other species from colonizing. Another factor for the difference between the vegetation at Bob White and Cutoff is that Cutoff is an older forest. Hydrophyte communities in a forested wetland take 50 years after restoration begins for them to resemble a natural forested wetland. The results from this study provide mixed evidence that restoration at Bob White is succeeding; there is a high percentage of wetlands species, while vegetation lacks similarity. This study improves our understanding of the influence that anthropogenic changes have on wetland functions as agricultural lands are restored to their previous land cover. Ecosystem functions should continue to be monitored to determine time frames as these functions are restored to Bob Whit