There is no happiness in positive affect: the pervasive misunderstanding of the rotated circumplex model.

Research on positive affect (PA) and negative affect (NA) is often guided by the rotational variant of the circumplex model of affect (RCMA). According to the RCMA, PA and NA are posited to be orthogonal, with PA ranging from the union of positive valence and high activation (e.g., excited) to the union of negative valence and low activation (e.g., sluggish), and NA ranging from the union of negative valence and high activation (e.g., distressed) to the union of positive valence and low activation (e.g., relaxed). However, many authors incorrectly interpret the RCMA as positing that positively valenced affect (i.e., pleasure) and negatively valenced affect (i.e., displeasure)-rather than PA and NA, as defined in the RCMA-are orthogonal. This "received view" of the RCMA has led to significant confusion in the literature. The present paper articulates the "received view" of the RCMA and characterizes its prevalence in psychological research. A random sample of 140 empirical research articles on affect published in 14 high-impact journals covering a range of psychological subdisciplines were reviewed. Over half of the articles subscribing to the RCMA showed evidence of the "received view," demonstrating that misuse of the terms PA and NA in the context of the RCMA is rampant in the psychological literature. To reduce continued confusion in the literature, we recommend abandoning use of the terms positive affect and negative affect. We further recommend referring to the two dimensions of the RCMA as positive activation and negative activation, and the two poles of the valence dimension as positive valence and negative valence (or pleasure and displeasure).

Pasos Hacia La Salud II: A Superiority RCT Utilizing Technology to Promote Physical Activity in Latinas.

INTRODUCTION: Latinas face an increased risk for chronic diseases associated with insufficient physical activity (PA). The researchers previously showed that a website-based intervention could increase PA among insufficiently active Latinas, yet rates of meeting national PA guidelines were low. The original intervention was enhanced by adding additional features, content, and points of contact, including via text messaging. This study tests the efficacy of the enhanced intervention compared with the original, aimed at maximizing and sustaining PA gains across 24 months. It also examines if increases in PA differed by baseline PA. STUDY DESIGN: The researchers conducted a superiority randomized controlled trial (data collected 2018-2022, analyzed 2023). SETTING/PARTICIPANTS: Participants were 195 Spanish-speaking Latinas ages 18-65 in the Providence, RI area. INTERVENTION: The original intervention is an empirically supported Spanish-language, individually-tailored, website-delivered PA intervention. The enhanced intervention includes text messaging and additional data-driven content and interactive features. MAIN OUTCOME MEASURES: Total weekly minutes of moderate to vigorous PA (MVPA) was measured via accelerometry and self-report at 6, 12, 18, and 24 months. RESULTS: Participants in both groups increased their MVPA over 24 months. There were no significant between-group differences at 6 or 12 months; at 18 months the enhanced intervention group had higher levels of self-reported (mean (sd): 90.35 (43.55) vs 70.18 [9.99]) and accelerometer-measured (66.21 [18.26] vs 60.27 [16.00]) MVPA compared to the original intervention group. They also had higher levels of self-reported (111.17 [23.35] vs 81.44 [1.82]) and accelerometer-measured (63.76 [15.12] vs 54.86 [14.59]) MVPA at 24 months. Baseline PA moderated the intervention effect. CONCLUSIONS: This study demonstrates the potential to enhance the efficacy of website-based PA interventions by utilizing text messaging, and adding more interactive features, content, and phone support. These enhancements may be particularly beneficial in supporting long-term PA maintenance. TRIAL REGISTRATION: This study is registered at www. CLINICALTRIAL: gov (NCT03491592).

Real-world outcomes of Omnipod DASH system use in people with type 1 diabetes: Evidence from the Association of British Clinical Diabetologists (ABCD) study.

AIMS: To evaluate real-world outcomes in people with Type 1 Diabetes (PwT1D) initiated on Omnipod DASH® Insulin Management System. METHODS: Anonymized clinical data were submitted to a secure web-based tool within the National Health Service network. Hemoglobin A1c (HbA1c), sensor-derived glucometrics, total daily dose of insulin (TDD), and patient-reported outcome changes between baseline and follow-up were assessed. Individuals were classified to "new-to-pump" (switched from multiple daily injections) and "established-on-pump" (switched from a tethered insulin pump) groups. RESULTS: 276 individuals from 11 centers [66.7 % female; 92 % White British; median age 41 years (IQR 20-50); diabetes duration 20 years (IQR 11-31); 49.3 % within "new-to-pump" group] were included. Baseline HbA1c was 8.0 ± 1.3 % (64 ± 14 mmol/mol). At follow-up [3 years (IQR 1.5-3.2)], HbA1c reduced by 0.3 % [(3 mmol/mol); p = 0.002] across the total population, 0.4 % [(5 mmol/mol); p = 0.001] in those "new-to-pump" and remained unchanged in those "established-on-pump". TDD decreased in the "new-to-pump" cohort (baseline:44.9 ± 21.0units vs follow-up:38.1 ± 15.4units, p = 0.002). Of those asked, 141/143 (98.6 %) stated Omnipod DASH had a positive impact on quality of life. CONCLUSIONS: Omnipod DASH was associated with improvements in HbA1c in PwT1D "new-to-pump" and maintained previous HbA1c levels in those "established-on-pump". User satisfaction in all groups and TDD reduction in those "new-to-pump" were reported.

A comparative study of altered hemodynamics in iliac vein compression syndrome.

Introduction: Iliac vein compression syndrome (IVCS) is present in over 20% of the population and is associated with left leg pain, swelling, and thrombosis. IVCS symptoms are thought to be induced by altered pelvic hemodynamics, however, there currently exists a knowledge gap on the hemodynamic differences between IVCS and healthy patients. To elucidate those differences, we carried out a patient-specific, computational modeling comparative study. Methods: Computed tomography and ultrasound velocity and area data were used to build and validate computational models for a cohort of IVCS (N = 4, Subject group) and control (N = 4, Control group) patients. Flow, cross-sectional area, and shear rate were compared between the right common iliac vein (RCIV) and left common iliac vein (LCIV) for each group and between the Subject and Control groups for the same vessel. Results: For the IVCS patients, LCIV mean shear rate was higher than RCIV mean shear rate (550 ± 103 s-1 vs. 113 ± 48 s-1, p = 0.0009). Furthermore, LCIV mean shear rate was higher in the Subject group than in the Control group (550 ± 103 s-1 vs. 75 ± 37 s-1, p = 0.0001). Lastly, the LCIV/RCIV shear rate ratio was 4.6 times greater in the Subject group than in the Control group (6.56 ± 0.9 vs. 1.43 ± 0.6, p = 0.00008). Discussion: Our analyses revealed that IVCS patients have elevated shear rates which may explain a higher thrombosis risk and suggest that their thrombus initiation process may share aspects of arterial thrombosis. We have identified hemodynamic metrics that revealed profound differences between IVCS patients and Controls, and between RCIV and LCIV in the IVCS patients. Based on these metrics, we propose that non-invasive measurement of shear rate may aid with stratification of patients with moderate compression in which treatment is highly variable. More investigation is needed to assess the prognostic value of shear rate and shear rate ratio as clinical metrics and to understand the mechanisms of thrombus formation in IVCS patients.

Isolated central hypothyroidism: Underlying pathophysiology and relation to antidepressant and antipsychotic medications-A multi-centre South Wales study.

OBJECTIVE: Isolated biochemical central hypothyroidism is a presentation we are experiencing more frequently as endocrinologists, with variation in levels of investigation between physicians. We therefore conducted research to investigate the final diagnosis and clinical outcome of patients across multiple hospitals in South Wales with biochemical isolated central hypothyroidism; namely to establish whether this isolated biochemical picture was clinically significant. We also analysed whether there is an association between this biochemical picture and treatment with antidepressant and antipsychotic medications, and how common this is. DESIGN: We performed a retrospective observational study of patients across nine different hospitals in South Wales. We analysed patients referred to endocrinology at each site over a 6-year period with unexplained isolated biochemical central hypothyroidism. MATERIALS AND METHODOLOGY: 1022 individual patients' thyroid function test results were identified from our biochemical database using our inclusion criteria. After exclusion criteria were applied, 71 patients' results were analysed as to the final pathophysiology of their central hypothyroidism. RESULT: Of the 71 patients included in the study, none were found to have any clinically significant pathology on pituitary imaging. On reviewing their medications, 46/71 (65%) were found to be taking psychotropic medications. CONCLUSIONS: Our study strongly suggests isolated central hypothyroidism, in the absence of other pituitary hormone dysfunction or visual field defect, does not require further investigation, saving resources as well as sparing patients unnecessary anxiety. It also strongly supports a relationship between patients taking psychotropic medications and biochemical isolated central hypothyroidism, an association only described in a very limited amount of literature before this, and further supporting our previous single-centre study findings. The mechanism behind this is likely to be the suppression of thyrotropin secretion via antagonism of the dopamine-serotoninergic pathway. In our opinion, patients found to have isolated biochemical central hypothyroidism who are taking psychotropic medications can therefore be regarded to have a recognised cause for this biochemical finding and do not require further radiological investigation.

Methodological approach for an integrated female-specific study of anxiety and smoking comorbidity.

Two primary ovarian hormones that fluctuate across the female menstrual cycle-estradiol and progesterone-have been independently linked in separate literatures to nicotine reinforcement and anxiety psychopathology. We identify existing methodological limitations in these literatures, describe an example protocol that was developed to address such limitations, highlight case examples, and offer insights on the resulting advantages and challenges. This protocol was an observational, prospective, within-subjects study of female cigarette smokers who were followed over the course of a complete menstrual cycle. Non-treatment seeking, female cigarette smokers (N = 50), between the ages of 18-40 who have a normal menstrual cycle (25-35 days in length) were recruited from the community. Females with anxiety or mood psychopathology represented 38.0% of the sample. Salivary progesterone and estradiol were assessed each morning via at-home saliva collection methods. Self-reported within-day momentary ratings of anxiety and nicotine reinforcement were collected using ecological momentary assessment (EMA) via a mobile app. Protocol compliance was >85%. Within- and between-subjects heterogeneity was observed in the progesterone and estradiol, anxiety, and nicotine craving measures, especially in the context of anxiety psychopathology. We aimed to integrate the anxiety and nicotine dependence literatures and advance the empirical study of the role of ovarian hormones. This protocol reflects an intensive, yet feasible approach to collecting daily-level naturalistic data related to estradiol, progesterone, anxiety, and nicotine reinforcement.

Benefits in routinely measured liver function tests following bariatric surgery: a retrospective cohort study.

Background: Bariatric surgery is well-established to support long-term metabolic health benefits associated with considerable weight loss. Here, we aim to determine the longer-term impact of bariatric surgery on liver enzymes and associations with other metabolic improvements. Methods: One hundred patients who underwent bariatric surgery between 2007 and 2014 were included, and changes in liver enzymes, anthropometric measures and other parameters were observed over a mean 9.8 years. Results: At the time of surgery, the mean age was 45.4 ± 9.6 years, weight 141.2 ± 31.6 kg, and body mass index (BMI) 50.2 ± 10.1 kg/m2. Most patients underwent sleeve gastrectomy [n = 71] with a mean follow-up duration 9.8 ± 2.3 years. From baseline, alanine transaminase (ALT) reduced by 41.3% within 12 months post-operatively (36.6 ± 29.2 U/L to 21.5 ± 14.9 U/L, p < 0.001), which was sustained at recent follow-up (20.2 ± 10.7 U/L, p < 0.001). There were associated reductions in body weight, BMI, HbA1c, blood pressure and triglycerides. Patients with greater baseline ALT had the greatest reduction in ALT over follow-up. Conclusions: Bariatric surgery is associated with rapid and sustained improvements in routine liver enzymes at 10 years, and sustained improvements in features of the metabolic syndrome. Supplementary Information: The online version contains supplementary material available at 10.1007/s40200-023-01311-4.

Mass Spectrometric Analysis of the Active Site Tryptic Peptide of Recombinant O6-Methylguanine-DNA Methyltransferase Following Incubation with Human Colorectal DNA Reveals the Presence of an O6-Alkylguanine Adductome.

Human exposure to DNA alkylating agents is poorly characterized, partly because only a limited range of specific alkyl DNA adducts have been quantified. The human DNA repair protein, O6-methylguanine O6-methyltransferase (MGMT), irreversibly transfers the alkyl group from DNA O6-alkylguanines (O6-alkGs) to an acceptor cysteine, allowing the simultaneous detection of multiple O6-alkG modifications in DNA by mass spectrometric analysis of the MGMT active site peptide (ASP). Recombinant MGMT was incubated with oligodeoxyribonucleotides (ODNs) containing different O6-alkGs, Temozolomide-methylated calf thymus DNA (Me-CT-DNA), or human colorectal DNA of known O6-MethylG (O6-MeG) levels. It was digested with trypsin, and ASPs were detected and quantified by matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry. ASPs containing S-methyl, S-ethyl, S-propyl, S-hydroxyethyl, S-carboxymethyl, S-benzyl, and S-pyridyloxobutyl cysteine groups were detected by incubating MGMT with ODNs containing the corresponding O6-alkGs. The LOQ of ASPs containing S-methylcysteine detected after MGMT incubation with Me-CT-DNA was <0.05 pmol O6-MeG per mg CT-DNA. Incubation of MGMT with human colorectal DNA produced ASPs containing S-methylcysteine at levels that correlated with those of O6-MeG determined previously by HPLC-radioimmunoassay (r2 = 0.74; p = 0.014). O6-CMG, a putative O6-hydroxyethylG adduct, and other potential unidentified MGMT substrates were also detected in human DNA samples. This novel approach to the identification and quantitation of O6-alkGs in human DNA has revealed the existence of a human DNA alkyl adductome that remains to be fully characterized. The methodology establishes a platform for characterizing the human DNA O6-alkG adductome and, given the mutagenic potential of O6-alkGs, can provide mechanistic information about cancer pathogenesis.

Testing an insurance-based monetary incentive program for exercise: RCT design and rationale.

Participation in regular physical activity (PA) has numerous health benefits; however, as few as 10% of U.S. adults meet guidelines when device-based assessments of PA are used. The present paper presents the design and rationale for an RCT examining the efficacy of an exercise incentive program currently offered by at least three major US insurance companies, in which participants must attend a YMCA fitness facility at least 50 times within 6 months to receive an incentive. In a factorial design, incentive amount ($200, $100, $0) is crossed with a comparison of the standard gain-framed incentive program and a loss-framed incentive condition in which participants are told their membership fee is being held and will be returned or forfeited depending on their fitness facility attendance. Participants (N = 330) are randomized to gain-framed $100 incentive (n = 55), gain-framed $200 incentive (n = 55), loss-framed $100 incentive (n = 55), loss-framed $200 incentive (n = 55), or control (n = 110). Each participant is enrolled in the same condition for two consecutive 6-month periods for a total of 12 months per participant. The primary outcome is number of visits to the fitness facility over each 6-month period, verified by objective swipe-card data. Secondary outcomes include total moderate-to-vigorous PA (MVPA) over 7-day periods assessed at 3-month intervals through accelerometers (Actigraph wGT3x-BT) and self-report. Habit formation and anticipated regret are putative mediators and household income is a putative moderator of the incentive-based programs. A payer-perspective, within-trial cost-utility analysis will quantify the incremental costs per (a) quality-adjusted life year gained, (b) YMCA attendance, and (c) change in MVPA.

Guidelines for assessment of affect-related constructs.

Research on affect-related constructs as determinants of health behavior is increasing. The Affect and Health Behavior Framework (AHBF) provides a schematic structure to label, organize, and integrate affect-related constructs. To further facilitate research and theory development in health behavior science, the purpose of the present paper is to provide a critical review and guidelines for assessment of the affect-related constructs in the AHBF. The paper is organized based on the categories of constructs in the AHBF: Affective response to health behavior, incidental affect, affect processing, and affectively charged motivation. Future research should work toward parsing constructs where possible as well as identifying overlap. Researchers are advised to consider conceptual underpinnings and methodological nuances when assessing affect-related constructs in order to build a cumulative science of affective determinants of health behavior.

Diabetes management in older adults who fall: a study amongst older adults presenting to the emergency department.

INTRODUCTION: Type 2 diabetes mellitus (T2D) is associated with poor health outcomes whilst tight glycaemic targets are questionable in those aged over 70 years with increased frailty. Our aim was to examine whether people with T2D admitted to hospital with a fall, were more likely to have greater frailty, increased mortality and co-morbidity burden, or risk factors for falls than people without T2D, and whether these differences were associated with medications used for the treatment of T2D. METHODS: The Older Persons Assessment Service (OPAS) is a local emergency department (ED) service, which accepts patients on frailty criteria. The OPAS accepts patients primarily aged over 70 years who present with frailty and geriatric syndromes such as falls, with retrieval from the ED department directly to the service from triage. The OPAS databank was analysed for people with T2D admitted with a fall between June 2020-September 2022. We examined clinical outcomes relating to medication, age, Charlson co-morbidity index (CCI) and clinical frailty score (CFS). RESULTS: 1081 patients were included: 294 (27.2%) with T2D and a mean HbA1c of 53.9 (± 15.8) mmol/mol [7.1%]. People with T2D had a similar mean CFS and age compared to those without T2D, but higher mean CCI (7.0 ± 2.2 vs 5.9 ± 2.1, p < 0.001). Of those people with T2D, 175 (59.5%) and 240 (81.6%) had a HbA1c ≤ 53 mmol/mol [7.0%] and ≤ 64 mmol/mol [8.0%], respectively. In total, 48 (16.3%) people with T2D were identified to have a capillary blood glucose below 4.0 mmol/L on admission to the ED. At 12 months' follow-up, 831 (76.9%) patients were alive and 250 (23.1%) had died. People with T2D treated with insulin and/or gliclazide had a greater 1-year mortality (36.6% vs 23.6%, p < 0.05), greater frequency of hypoglycaemia (35.4% vs 11.8%, p < 0.001), and greater HbA1c (65.5 ± 17.2 mmol/mol [8.2] vs 48.9 ± 12.1 mmol/mol [6.6%]) compared to those who used other agents. Logistic regression confirmed a diagnosis of T2D was associated with 1-year mortality, but mortality was not significantly associated with hypoglycaemic-inducing agents. People with T2D were not more likely to live in deprived areas. CONCLUSIONS: A diagnosis of T2D is associated with greater 1-year mortality, and may be influenced by use of hypoglycaemia-inducing diabetes medications. Clinician awareness can support de-prescribing for patients with frailty and HbA1c < 64 mmol/mol.

Activity-Induced Pain as a Predictor of Sedentary Behavior Among Midlife Adults.

Purpose: Midlife adults have been estimated to spend over half of their waking time engaging in sedentary behavior, and greater sedentary behavior has been associated with a reduced likelihood of successful aging. Moreover, more than one-quarter of midlife adults report chronic pain, and there is reason to believe that pain may contribute to sedentary behavior among this population. The goal of these analyses was to test associations between self-reported increases in pain during activity and subsequent sedentary behavior among a sample of midlife adults with chronic pain. Methods: Participants included 200 midlife adults (age 50-64) who reported chronic pain and completed an online prospective survey. Activity-induced pain was assessed at baseline and total time spent engaging in sedentary behavior was assessed at baseline, 1-week, and 4-week follow-up assessments. Results: Activity-induced pain predicted greater sedentary behavior at 1-week (p < .05) and 4-week (p < .01) follow-up assessments, even after controlling for chronic pain intensity and baseline sedentary behavior. Conclusions: Activity-induced pain may represent an important mechanism underlying sedentary behavior among midlife adults with chronic pain, and programs designed to reduce sedentary behavior among this population may benefit from tailoring to account for the antithetical influence of activity-induced pain. Indeed, the current findings suggest that mitigating the extent to which pain increases during activity may be more important than reducing overall pain intensity when attempting to decrease sedentary behavior among this population. This and future work have the potential to inform the refinement of tailored interventions.

Brief Report: An Exploration of Alexithymia in Autistic and Nonautistic Transgender Adults.

Background: Research has shown that many autistic people have alexithymia, a psychological trait characterized by difficulties in identifying and describing emotions. It is also now clear that there is a high rate of autism among transgender people, but we know little about the intersection of autism and gender diversity or about the clinical features of autistic transgender individuals. Methods: Seventy-eight nonautistic transgender, 56 autistic transgender, 106 nonautistic cisgender, and 107 autistic cisgender adults completed the Toronto Alexithymia Scale-20 and the Autism-spectrum Quotient as part of an online study. We also used the General Alexithymia Factor Score-8 as an additional alexithymia score. Results: We found that nonautistic transgender participants reported significantly higher mean levels of alexithymia than nonautistic cisgender participants, and that there was a significant overrepresentation of individuals in this group who met the clinical cutoff for alexithymia. The difference in alexithymia between autistic cisgender and autistic transgender participants was nonsignificant, with >50% of each group scoring above the clinical cutoff point. Of note, when we used the General Alexithymia Factor Score-8, the difference between autistic transgender participants and autistic cisgender participants was significant, with autistic transgender participants reporting higher mean levels of alexithymia. Conclusion: Results suggest that nonautistic transgender individuals might be more prone to experience alexithymia (including at clinically significant levels) than nonautistic cisgender people. When autism occurs in transgender people, the average level and clinical rate of alexithymia is higher than among nonautistic transgender people and potentially higher than among autistic cisgender people. Our findings are in keeping with evidence of a subgroup of transgender people with "subclinical autism" and inconsistent with the notion that autism among transgender and gender diverse people is a "phenomimic" of autism. Lastly, our study highlights the potential importance of screening autistic and nonautistic transgender people for alexithymia.

Why is this an important issue?: Alexithymia is when a person has difficulty recognizing and describing their emotional feelings. It also includes an externally oriented thinking style. Research has shown that many autistic people experience alexithymia. Autistic people with alexithymia might require additional and specialized support and care. What was the purpose of this study?: There are a large number of transgender and gender diverse people who are autistic. However, we know little about the intersection of autism and gender diversity or about the clinical characteristics of autistic people who identify as transgender. The purpose of this study was to explore alexithymia in autistic and nonautistic transgender individuals. What did the researchers do?: We conducted an online study that included questions about people's ability to recognize and describe their emotional feelings as well as about their preference to engage with the world around them than the world inside them. Participants also answered questions that tap characteristics of autism. What were the results of the study?: We found that nonautistic transgender adults had more difficulty identifying and describing their emotional feelings than nonautistic cisgender adults. We also found that autistic transgender adults reported significantly higher levels of alexithymia than nonautistic transgender adults and potentially higher than autistic cisgender adults. What do these findings add to what was already known?: This study showed, for the first time, that (1) it is not always easy for nonautistic transgender people to identity and describe their emotional feelings and (2) autistic transgender people find at least as difficult as autistic cisgender individuals to describe and identify their emotional feelings. What are potential weaknesses in the study?: We did not examine depression and anxiety in our participants. People with depression and/or anxiety might score high on the scale we used to measure alexithymia. This was also an exploratory study, so other researchers should replicate our findings before we draw strong conclusions. How will these findings help autistic adults now or in the future?: Our findings are consistent with the notion that autism in transgender people is "real," meaning that it has the same underlying basis in autistic cisgender and autistic transgender people, and suggest that autistic transgender people might benefit from receiving support for difficulties related to autism independently of the support and treatment they might receive for gender-related needs.

Geometric phase in coupled cluster theory.

It has been well-established that the topography around conical intersections between excited electronic states is incorrectly described by coupled cluster and many other single reference theories (the intersections are "defective"). Despite this, we show both analytically and numerically that the geometric phase effect (GPE) is correctly reproduced upon traversing a path around a defective excited-state conical intersection (CI) in coupled cluster theory. The theoretical analysis is carried out by using a non-Hermitian generalization of the linear vibronic coupling approach. Interestingly, the approach qualitatively explains the characteristic (incorrect) shape of the defective CIs and CI seams. Moreover, the validity of the approach and the presence of the GPE indicate that defective CIs are local (and not global) artifacts. This implies that a sufficiently accurate coupled cluster method could predict nuclear dynamics, including geometric phase effects, as long as the nuclear wavepacket never gets too close to the conical intersections.

An ultrasound imaging and computational fluid dynamics protocol to assess hemodynamics in iliac vein compression syndrome.

OBJECTIVE: Elevated shear rates are known to play a role in arterial thrombosis; however, shear rates have not been thoroughly investigated in patients with iliac vein compression syndrome (IVCS) owing to imaging limitations and assumptions on the low shear nature of venous flows. This study was undertaken to develop a standardized protocol that quantifies IVCS shear rates and can aid in the diagnosis and treatment of patients with moderate yet symptomatic compression. METHODS: Study patients with and without IVCS had their iliac vein hemodynamics measured via duplex ultrasound (US) at two of the following three vessel locations: infrarenal inferior vena cava (IVC), right common iliac vein, and left common iliac vein, in addition to acquiring data at the right and left external iliac veins. US velocity spectra were multiplied by a weighted cross-sectional area calculated from US and computed tomography (CT) data to create flow waveforms. Flow waveforms were then scaled to enforce conservation of flow across the IVC and common iliac veins. A three-dimensional (3D), patient-specific model of the iliac vein anatomy was constructed from CT and US examination. Flow waveforms and the 3D model were used as a basis to run a computational fluid dynamics (CFD) simulation. Owing to collateral vessel flow and discrepancies between CT and US area measurements, flows in internal iliac veins and cross-sectional areas of the common iliac veins were calibrated iteratively against target common iliac flow. Simulation results on mean velocity were validated against US data at measurement locations. Simulation results were postprocessed to derive spatial and temporal values of quantities such as velocity and shear rate. RESULTS: Using our modeling protocol, we were able to build CFD models of the iliac veins that matched common iliac flow splits within 2% and measured US velocities within 10%. Proof-of-concept analyses (1 subject, 1 control) have revealed that patients with IVCS may experience elevated shear rates in the compressed left common iliac vein, more typical of the arterial rather than the venous circulation. These results encourage us to extend this protocol to a larger group of patients with IVCS and controls. CONCLUSIONS: We developed a protocol that obtains hemodynamic measurements of the IVC and iliac veins from US, creates patient-specific 3D reconstructions of the venous anatomy using CT and US examinations, and computes shear rates using calibrated CFD methods. Proof-of-concept results have indicated that patients with IVCS may experience elevated shear rates in the compressed left common iliac vein. Larger cohorts are needed to assess the relationship between venous compression and shear rates in patients with IVCS as compared with controls with noncompressed iliac veins. Further studies using this protocol may also give promising insights into whether or not to treat patients with moderate, yet symptomatic compression.

Acute effects of exercise among individuals with schizophrenia who smoke cigarettes.

People with schizophrenia (SCZ) have a shorter life expectancy than those without psychiatric conditions. Of note, people with SCZ have high rates of cigarette smoking, physical inactivity, and obesity. These factors all coalesce to contribute to compromised health in this population, with smoking as a primary contributor. Therefore, it is paramount to develop effective smoking cessation strategies for this population. The purpose of this study was to investigate whether walking at a brisk pace, relative to engaging in passive activity, would reduce acute cigarette craving, nicotine withdrawal, and negative affect (NA) among people with SCZ who smoke cigarettes. Using a within-subjects design, twenty participants completed four laboratory sessions with condition sequence counterbalanced: 1) exposure to smoking cues + treadmill walking, 2) exposure to neutral cues + treadmill walking, 3) exposure to smoking cues + passive/sedentary activity, 4) exposure to neutral cues + passive/sedentary activity. Relative to sedentary activity, walking resulted in greater decreases in nicotine withdrawal but did not significantly affect craving or NA. These results did not vary as a function of cue type. These findings suggest that walking may be a helpful strategy to reduce acute nicotine withdrawal symptoms among people with SCZ. However, it should be used in conjunction with other strategies for smoking cessation.