Partial rescue of the full-field electroretinogram in patients with RPE65-related retinal dystrophy following gene augmentation therapy with voretigene neparvovec-rzyl.

PURPOSE: To present a series of patients with RPE65-related retinal dystrophy showing a partial rescue of the full-field electroretinogram (ERG) following gene replacement therapy with voretigene neparovec-rzyl (Luxturna®). METHODS: This retrospective chart review examined 17 patients treated with voretigene neparovec-rzyl (VN) at the Casey Eye Institute (2018-2022). The last pre-operative ERG and all available post-operative ERGs were analyzed to identify subjects with functional rescue. Measurements of amplitudes and implicit times were compared to data from age-matched controls and the attenuation relative to the lower limit of normal (LLN) was calculated. For comparison with other functional exams, the last pre-operative and all post-treatment best-corrected visual acuity (BCVA) data, visual field (VF) tests and full-field threshold stimulus tests (FST) were also described. RESULTS: Of patients who underwent ERGs, most had unrecordable ERGs that did not change after treatment. However, we identified three patients, treated bilaterally, who demonstrated partial rescue of the full-field ERG in both eyes which was sustained during the course of the study. CONCLUSIONS: This is the largest series of patients treated with VN showing a partial rescue of the ERG. This is also the first report of bilateral ERG rescue, as well as the first description of ERG recovery occurring in non-pediatric subjects. Full-field ERG could be used in combination with other psychophysical tests and imaging modalities to detect and deepen our understanding of the response to this gene therapy approach.

Development and Initial Validation of the Persevering Hope Scale: Measuring Wait-Power in Four Independent Samples.

Hope has been conceptualized as agency and pathways to achieve goals. However, this goal-directed conceptualization does not encapsulate all situations in which hope may be beneficial. To address the dispositional motivation to endure when a desired goal seems unattainable, unlikely, or even impossible (i.e., goal-transcendent hope), we provide initial psychometric evidence for the new Persevering Hope Scale (PHS). We developed and refined the PHS with undergraduates at a public college (Study 1) and replicated our findings in a community adult sample (Study 2). We replicated and extended these findings using longitudinal data with undergraduates at a faith-based college (Study 3) and a community sample of chronically ill adults (Study 4), and examined measurement invariance (Study 5). Scores on the PHS demonstrated robust evidence of estimated internal consistency and of criterion-related, convergent/discriminant, and incremental validity. Estimated temporal stability was modest. Partial scalar invariance was evidenced across samples, and full scalar invariance was evidenced across gender, race/ethnicity, and time. These preliminary findings suggest that the PHS is a psychometrically sound measure of persevering hope. Its use can broaden the current body of literature on trait hope to include goal-transcendent hope and advance research on the nature and benefits of this important construct.

Associations of dispositional forgivingness with facets of well-being among Colombian adults: A longitudinal outcome-wide analysis.

Many studies have reported evidence suggesting that dispositional forgivingness has positive implications for different domains of well-being. However, relatively few methodologically rigorous studies have been conducted in the Global South, particularly in post-conflict settings where forgiveness could play an important role in supporting individual well-being. In this three-wave cohort study of predominantly young adult Colombians (n = 1575), we examined the associations of dispositional forgivingness with 20 well-being outcomes across several domains of well-being: psychological distress, psychological well-being, physical health, social well-being, and character strengths/virtues. Using an outcome-wide analytic design that included extensive control for potential confounding and reverse causation by adjusting for a range of covariates assessed in Wave 1 (2017), we found that dispositional forgivingness assessed in Wave 2 (2018) was at least modestly associated with improvements in one or more facet of each well-being domain assessed approximately 1 year later in Wave 3 (2019). Associations tended to be stronger for outcomes in the domains of psychological distress, psychological well-being, social well-being, and character strengths/virtues compared to the physical health domain. These longitudinal findings suggest that dispositional forgivingness might promote individual well-being in societies with a long history of ongoing civil unrest, conflict, and war.

Kinetics and Mechanisms of Hydrothermal Dehydration of Cyclic 1,2- and 1,4-Diols.

Hydrothermal dehydration is an attractive method for deoxygenation and upgrading of biofuels because it requires no reagents or catalysts other than superheated water. Although mono-alcohols cleanly deoxygenate via dehydration under many conditions, polyols such as those derived from saccharides and related structures are known to be recalcitrant with respect to dehydration. Here, we describe detailed mechanistic and kinetic studies of hydrothermal dehydration of 1,2- and 1,4-cyclohexanediols as model compounds to investigate how interactions between the hydroxyls can control the reaction. The diols generally dehydrate more slowly and have more complex reaction pathways than simple cyclohexanol. Although hydrogen bonding between hydroxyls is an important feature of the diol reactions, hydrogen bonding on its own does not explain the reduced reactivity. Rather, it is the way that hydrogen bonding influences the balance between the E1 and E2 elimination mechanisms. We also describe the reaction pathways and follow-up secondary reactions for the slower-dehydrating diols.

Religious/spiritual struggles and psychological distress: A test of three models in a longitudinal study of adults with chronic health conditions.

OBJECTIVE: This study tested three conceptual explanatory models that have been theorized to account for the linkages between religious/spiritual (R/S) struggles and psychological distress: the primary model (i.e., R/S struggles lead to psychological distress), the secondary model (i.e., psychological distress leads to R/S struggles), and the complex model (i.e., R/S struggles and psychological distress reciprocally exacerbate each other). METHODS: Using prospective data from a sample of US adults living with chronic health conditions (n = 302), we performed a cross-lagged panel analysis with three timepoints to test for evidence of potential causal relations between R/S struggles and psychological distress. RESULTS: Consistent with the complex conceptual model of R/S struggles, we found evidence of positive reciprocal associations between R/S struggles and psychological distress. CONCLUSION: The findings highlight the importance of attending to the dynamic interplay between R/S struggles and psychological distress when working with adults who have chronic health conditions.

Seasonal hydrologic and geologic forcing drive hot spring geochemistry and microbial biodiversity.

Hot springs integrate hydrologic and geologic processes that vary over short- and long-term time scales. However, the influence of temporal hydrologic and geologic change on hot spring biodiversity is unknown. Here, we coordinated near-weekly, cross-seasonal (~140 days) geochemical and microbial community analyses of three widely studied hot springs with local precipitation data in Yellowstone National Park. One spring ('HFS') exhibited statistically significant, coupled microbial and geochemical variation across seasons that was associated with recent precipitation patterns. Two other spring communities, 'CP' and 'DS', exhibited minimal to no variation across seasons. Variability in the seasonal response of springs is attributed to differences in the timing and extent of aquifer recharge with oxidized near-surface water from precipitation. This influx of oxidized water is associated with changes in community composition, and in particular, the abundances of aerobic sulfide-/sulfur-oxidizers that can acidify waters. During sampling, a new spring formed after a period of heavy precipitation and its successional dynamics were also influenced by surface water recharge. Collectively, these results indicate that changes in short-term hydrology associated with precipitation can impact hot spring geochemistry and microbial biodiversity. These results point to potential susceptibility of certain hot springs and their biodiversity to sustained, longer-term hydrologic changes.

Ecological Dichotomies Arise in Microbial Communities Due to Mixing of Deep Hydrothermal Waters and Atmospheric Gas in a Circumneutral Hot Spring.

Little is known of how the confluence of subsurface and surface processes influences the assembly and habitability of hydrothermal ecosystems. To address this knowledge gap, the geochemical and microbial composition of a high-temperature, circumneutral hot spring in Yellowstone National Park was examined to identify the sources of solutes and their effect on the ecology of microbial inhabitants. Metagenomic analysis showed that populations comprising planktonic and sediment communities are archaeal dominated, are dependent on chemical energy (chemosynthetic), share little overlap in their taxonomic composition, and are differentiated by their inferred use of/tolerance to oxygen and mode of carbon metabolism. The planktonic community is dominated by putative aerobic/aerotolerant autotrophs, while the taxonomic composition of the sediment community is more evenly distributed and comprised of anaerobic heterotrophs. These observations are interpreted to reflect sourcing of the spring by anoxic, organic carbon-limited subsurface hydrothermal fluids and ingassing of atmospheric oxygen that selects for aerobic/aerotolerant organisms that have autotrophic capabilities in the water column. Autotrophy and consumption of oxygen by the planktonic community may influence the assembly of the anaerobic and heterotrophic sediment community. Support for this inference comes from higher estimated rates of genome replication in planktonic populations than sediment populations, indicating faster growth in planktonic populations. Collectively, these observations provide new insight into how mixing of subsurface waters and atmospheric oxygen create dichotomy in the ecology of hot spring communities and suggest that planktonic and sediment communities may have been less differentiated taxonomically and functionally prior to the rise of oxygen at ∼2.4 billion years ago (Gya). IMPORTANCE Understanding the source and availability of energy capable of supporting life in hydrothermal environments is central to predicting the ecology of microbial life on early Earth when volcanic activity was more widespread. Little is known of the substrates supporting microbial life in circumneutral to alkaline springs, despite their relevance to early Earth habitats. Using metagenomic and informatics approaches, water column and sediment habitats in a representative circumneutral hot spring in Yellowstone were shown to be dichotomous, with the former largely hosting aerobic/aerotolerant autotrophs and the latter primarily hosting anaerobic heterotrophs. This dichotomy is attributed to influx of atmospheric oxygen into anoxic deep hydrothermal spring waters. These results indicate that the ecology of microorganisms in circumneutral alkaline springs sourced by deep hydrothermal fluids was different prior to the rise of atmospheric oxygen ∼2.4 Gya, with planktonic and sediment communities likely to be less differentiated than contemporary circumneutral hot springs.

Resource Loss and Stress Outcomes in a Setting of Chronic Conflict: The Conservation of Resources Theory in the Eastern Congo.

The purpose of this cross-sectional study was to examine conservation of resources (COR) theory in the context of armed conflict in Africa. Specifically, within the setting of ongoing chronic conflict in the eastern Democratic Republic of the Congo (DRC), we tested the COR theory prediction that resource loss contributes to various stress outcomes. A randomly selected sample of 312 adults (125 men, 187 women) from villages in North Kivu, DRC completed orally administered measures of resource loss, daily stressors, and four stress outcomes: depression symptoms, anxiety symptoms, posttraumatic distress, and general distress. Consistent with COR theory, resource loss predicted all four stress outcomes above and beyond the contribution of demographics, relocation experiences, and daily stressors; however, this effect was small, ΔR2 = .02-.06. The most consistent and strongest predictors of stress outcomes were daily stressors, ßs = .42-.62; number of relocation experiences, ßs = .33-.43; and psychosocial resource loss (e.g., loss of hope, meaning or purpose in life, intimacy with friends and family, physical health of family), ßs = .17-.26. Additionally, male sex predicted depression, anxiety, and trauma symptoms, and lower educational status predicted anxiety symptoms and general distress. Our exploratory mediation analysis showed that daily stressors partially mediated all four pairs of associations between psychosocial resource loss and mental health outcomes. We discuss the findings with consideration of research on disasters generally and armed conflicts specifically. We also discuss implications for humanitarian interventions with conflict-affected populations in Africa and beyond.

Does forgiving in a collectivistic culture affect only decisions to forgive and not emotions? REACH forgiveness collectivistic in Indonesia.

According to some theorising, in collectivistic societies, forgiveness is mainly enacted to maintain relationships, not engender emotional transformation. This present study was designed to explore whether forgiveness affects decisional and emotional forgiveness in Indonesia, a country categorised as collectivistic. The evidence-based REACH Forgiveness psychoeducational group intervention was adapted to collectivistic culture (REACH forgiveness collectivistic; REACH-FC), and its efficacy was assessed in a randomised controlled trial. Undergraduates in Indonesia (N = 97; 24 male; 73 female; ages 16-21) were randomly assigned within a 2 × 3(S) quasi-experimental repeated-measures design comparing immediate treatment (IT) and waiting list (WL) conditions [Condition (IT, WL) × Time ([S] 3 time points). Harmonious value, a personality variable assessing the strength of participants' desire for group harmony, was the covariate. The condition × time (S) interactions for both decisional and emotional forgiveness were significant, challenging some previous literature. Clearly, not all forms of collectivism have similar effects when individuals and communities deal with transgressions.

Probing the geological source and biological fate of hydrogen in Yellowstone hot springs.

Hydrogen (H2 ) is enriched in hot springs and can support microbial primary production. Using a series of geochemical proxies, a model to describe variable H2 concentrations in Yellowstone National Park (YNP) hot springs is presented. Interaction between water and crustal iron minerals yields H2 that partition into the vapour phase during decompressional boiling of ascending hydrothermal fluids. Variable vapour input leads to differences in H2 concentration among springs. Analysis of 50 metagenomes from a variety of YNP springs reveals that genes encoding oxidative hydrogenases are enriched in communities inhabiting springs sourced with vapour-phase gas. Three springs in the Smokejumper (SJ) area of YNP that are sourced with vapour-phase gas and with the most H2 in YNP were examined to determine the fate of H2 . SJ3 had the most H2 , the most 16S rRNA gene templates and the greatest abundance of culturable hydrogenotrophic and autotrophic cells of the three springs. Metagenomics and transcriptomics of SJ3 reveal a diverse community comprised of abundant populations expressing genes involved in H2 oxidation and carbon dioxide fixation. These observations suggest a link between geologic processes that generate and source H2 to hot springs and the distribution of organisms that use H2 to generate energy.

Intrapersonal and interpersonal facilitators of forgiveness following spousal infidelity: A stress and coping perspective.

OBJECTIVE: Forgiveness includes processes that involve a decision to stop bitterness and thoughts of revenge (i.e., decisional forgiveness), which further motivates the forgiver towards the restoration of positive emotions (i.e., emotional forgiveness). Using stress and coping framework, this study investigated intrapersonal and interpersonal facilitators of decisional and emotional forgiveness in a Chinese marital context. METHOD: Participants were 154 respondents who had experienced or were experiencing spousal infidelity. RESULTS: Solidarity-oriented personality and perceived partner's reconciliation motivation facilitated benign attributions and empathy, then facilitated higher levels of decisional forgiveness, which promoted emotional forgiveness. Strength of marital bond before the infidelity directly predicted higher levels of emotional forgiveness. CONCLUSIONS: Our findings provide evidence for the differentiated decisional and emotional forgiveness processes after spousal infidelity and delineate different coping mechanism that triggers them, thus lending culturally appropriate evidence for clinicians who work with clients facing spousal infidelity.

Development of the Collectivist-Sensitive Trait Forgivingness Scale.

Mounting evidence suggests that experiences of forgiveness vary across cultures. However, culturally sensitive conceptualizations of forgiveness lack empirical support, in part because psychometrically sound instruments designed to capture unique aspects of forgiveness in non-Western cultures are rare. For this reason, we developed the Collectivist-Sensitive Trait Forgivingness Scale (TFS-CS), which is designed to measure trait forgivingness within societies characterized by a blend of individualistic and collectivistic worldviews. In Study 1 (N = 597), exploratory factor analysis revealed a 16-item three-factor structure of third-party forgiveness, collectivistic forgiveness, and interpersonal resentment among South Africans. In Study 2 (N = 897), the three-factor model replicated in an independent South African sample. Findings also offered preliminary evidence supporting the construct validity of the TFS-CS. Overall, these studies support a conceptualization of trait forgivingness with similarities and differences relative to Western models and highlight the importance of appreciating the influence of culture when measuring forgiveness.

Development of the Self-Forgiveness Dual-Process Scale.

Progress in the scientific study of self-forgiveness reveals a need for (a) integration of the extant self-forgiveness literature with general psychological theory, (b) development of measures that reflect nuanced conceptualizations of self-forgiveness, (c) better understanding of the impact of self-forgiveness on personal and interpersonal functioning, and (d) development of evidence-based clinical applications of self-forgiveness. Accordingly, we conceptualized self-forgiveness within the framework of Social Cognitive Theory and developed the Self-Forgiveness Dual-Process Scale to assess value reorientation (VRO) and esteem restoration (ERS) following perceived interpersonal offense. In Study 1, we identified the hypothesized 2-factor structure in a sample of university students (N = 191). For Study 2, we used an independent sample (N = 100) to replicate the factor structure and provide initial evidence of construct validity by exploring associations of value reorientation and esteem restoration with established measures of self-forgiveness, self-punishment, and self-exoneration. In Study 3, we recruited a third sample (N = 66) to assess contributions of value reorientation and esteem restoration to explain variance in offense-related rumination beyond that explained by an existing measure of state self-forgiveness. Overall, findings supported conceptualization of self-forgiveness according to processes of value reorientation and esteem restoration, distinguished self-forgiveness from other responses to wrongdoing, and revealed the unique impacts of value reorientation and esteem restoration on functioning. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Promoting forgiveness: Characteristics of the treatment, the clients, and their interaction.

Forgiveness-based group treatments to address interpersonal hurts have been shown to be efficacious across a range of therapy models (Wade, Hoyt, Kidwell, & Worthington, 2014). However, little is known about how treatment and individual characteristics may interact in predicting outcomes. The present study examined a sample of 162 community adults randomly assigned to three treatment conditions; an 8-week REACH Forgiveness intervention (Worthington, 2006), an 8-week process group, and a waitlist control. Hierarchical linear modeling (HLM) indicated that the forgiveness-based treatment was more effective than the waitlist control across a range of forgiveness-related constructs but no more effective than the process condition. Furthermore, attachment avoidance and anxiety interacted with treatment type to predict certain outcomes, indicating that the REACH Forgiveness model may be more helpful for promoting forgiveness with insecurely attached individuals. (PsycINFO Database Record

Evaluation of an online self-help version of the REACH forgiveness program: Outcomes and predictors of persistence in a community sample.

OBJECTIVE: We evaluated outcomes of an online, self-directed REACH forgiveness intervention for community-based adults. Because many participants dropped out before program completion, predictors of program persistence were also examined. METHOD: Participants (N = 130 adults, 122 female; mean age 48) completed pretreatment assessment and were randomized to immediate treatment (IT) or delayed treatment (DT). Twenty-three IT and 13 DT participants completed the 7-hour REACH forgiveness modules and postintervention assessment; 32 participants completed 3-month follow-up. RESULTS: The IT group reported greater postintervention improvements in overall forgiveness and emotional forgiveness, as well as reductions in avoidance motivations with large effect sizes and, marginally, state empathy; but revenge motivations, decisional forgiveness, and well-being indicators did not change. Most postintervention improvements were maintained at 3-month follow-up. In this online intervention, persistence was predicted by perspective taking, willingness to forgive the offender, and conscientiousness. Three-month follow-up supported maintenance of gains, particularly in overall and emotional forgiveness, and increases in trait forgiveness compared to pretreatment. CONCLUSION: An online self-directed version of REACH forgiveness applied in a community sample has potential for improving forgiveness-related responses, particularly those involving emotional forgiveness. However, methods to increase program persistence and target suitable recipients need development.

Integrating clients' religion and spirituality within psychotherapy: A comprehensive meta-analysis.

Some religious or spiritual (R/S) clients seek psychotherapy that integrates R/S values, while others may be reticent to disclose R/S-related aspects of struggles in a presumably secular setting. We meta-analyzed 97 outcome studies (N = 7,181) examining the efficacy of tailoring treatment to patients' R/S beliefs and values. We compared the effectiveness of R/S-tailored psychotherapy with no-treatment controls, alternate secular treatments, and additive secular treatments. R/S-adapted psychotherapy resulted in greater improvement in clients' psychological (g = 0.74, p < 0.000) and spiritual (g = 0.74, p < 0.000) functioning compared with no treatment and non R/S psychotherapies (psychological: g = 0.33, p < 0.001; spiritual: g = 0.43, p < 0.001). In more rigorous additive studies, R/S-accommodated psychotherapies were equally effective to standard approaches in reducing psychological distress (g = 0.13, p = 0.258), but resulted in greater spiritual well-being (g = 0.34, p < 0.000). We feature several clinical examples and conclude with evidence-based therapeutic practices.

Sphalerite is a geochemical catalyst for carbon-hydrogen bond activation.

Reactions among minerals and organic compounds in hydrothermal systems are critical components of the Earth's deep carbon cycle, provide energy for the deep biosphere, and may have implications for the origins of life. However, there is limited information as to how specific minerals influence the reactivity of organic compounds. Here we demonstrate mineral catalysis of the most fundamental component of an organic reaction: the breaking and making of a covalent bond. In the absence of mineral, hydrothermal reaction of cis- and trans-1,2-dimethylcyclohexane is extremely slow and generates many products. In the presence of sphalerite (ZnS), however, the reaction rate increases dramatically and one major product is formed: the corresponding stereoisomer. Isotope studies show that the sphalerite acts as a highly specific heterogeneous catalyst for activation of a single carbon-hydrogen bond in the dimethylcyclohexanes.

Thankful for the little things: A meta-analysis of gratitude interventions.

A recent qualitative review by Wood, Froh, and Geraghty (2010) cast doubt on the efficacy of gratitude interventions, suggesting the need to carefully attend to the quality of comparison groups. Accordingly, in a series of meta-analyses, we evaluate the efficacy of gratitude interventions (ks = 4-18; Ns = 395-1,755) relative to a measurement-only control or an alternative-activity condition across 3 outcomes (i.e., gratitude, anxiety, psychological well-being). Gratitude interventions outperformed a measurement-only control on measures of psychological well-being (d = .31, 95% confidence interval [CI = .04, .58]; k = 5) but not gratitude (d = .20; 95% CI [-.04, .44]; k = 4). Gratitude interventions outperformed an alternative-activity condition on measures of gratitude (d = .46, 95% CI [.27, .64]; k = 15) and psychological well-being (d = .17, 95% CI [.09, .24]; k = 20) but not anxiety (d = .11, 95% CI [-.08, .31]; k = 5). More-detailed subdivision was possible on studies with outcomes assessing psychological well-being. Among these, gratitude interventions outperformed an activity-matched comparison (d = .14; 95% CI [.01, .27]; k = 18). Gratitude interventions performed as well as, but not better than, a psychologically active comparison (d = -.03, 95% CI [-.13, .07]; k = 9). On the basis of these findings, we summarize the current state of the literature and make suggestions for future applied research on gratitude. (PsycINFO Database Record

Temperature-Sensitive Salmonella enterica Serovar Enteritidis PT13a Expressing Essential Proteins of Psychrophilic Bacteria.

Synthetic genes based on deduced amino acid sequences of the NAD-dependent DNA ligase (ligA) and CTP synthetase (pyrG) of psychrophilic bacteria were substituted for their native homologues in the genome of Salmonella enterica serovar Enteritidis phage type 13a (PT13a). The resulting strains were rendered temperature sensitive (TS) and did not revert to temperature resistance at a detectable level. At permissive temperatures, TS strains grew like the parental strain in broth medium and in macrophage-like cells, but their growth was slowed or stopped when they were shifted to a restrictive temperature. When injected into BALB/c mice at the base of the tail, representing a cool site of the body, the strains with restrictive temperatures of 37, 38.5, and 39°C persisted for less than 1 day, 4 to 7 days, and 20 to 28 days, respectively. The wild-type strain persisted at the site of inoculation for at least 28 days. The wild-type strain, but not the TS strains, was also found in spleen-plus-liver homogenates within 1 day of inoculation of the tail and was detectable in these organs for at least 28 days. Intramuscular vaccination of White Leghorn chickens with the PT13a strain carrying the psychrophilic pyrG gene provided some protection against colonization of the reproductive tract and induced an anti-S. enterica antibody response.

Evidence from mouse and man for a role of neuregulin 3 in nicotine dependence.

Addiction to nicotine and the ability to quit smoking are influenced by genetic factors. We used functional genomic approaches (chromatin immunoprecipitation (ChIP) and whole-genome sequencing) to identify cAMP response element-binding protein (CREB) targets following chronic nicotine administration and withdrawal (WD) in rodents. We found that chronic nicotine and WD differentially modulate CREB binding to the gene for neuregulin 3 (NRG3). Quantitative analysis of saline, nicotine and nicotine WD in two biological replicates corroborate this finding, with NRG3 increases in both mRNA and protein following WD from chronic nicotine treatment. To translate these data for human relevance, single-nucleotide polymorphisms (SNPs) across NRG3 were examined for association with prospective smoking cessation among smokers of European ancestry treated with transdermal nicotine in two independent cohorts. Individual SNP and haplotype analysis support the association of NRG3 SNPs and smoking cessation success. NRG3 is a neural-enriched member of the epidermal growth factor family, and a specific ligand for the receptor tyrosine kinase ErbB4, which is also upregulated following nicotine treatment and WD. Mice with significantly reduced levels of NRG3 or pharmacological inhibition of ErbB4 show similar reductions in anxiety following nicotine WD compared with control animals, suggesting a role for NRG3 in nicotine dependence. Although the function of the SNP in NRG3 in humans is not known, these data suggest that Nrg3/ErbB4 signaling may be an important factor in nicotine dependence.