Artificial Intelligence Algorithms Enable Automated Characterization of the Positive and Negative Dielectrophoretic Ranges of Applied Frequency.

The present work describes the phenomenological approach to automatically determine the frequency range for positive and negative dielectrophoresis (DEP)-an electrokinetic force that can be used for massively parallel micro- and nano-assembly. An experimental setup consists of the microfabricated chip with gold microelectrode array connected to a function generator capable of digitally controlling an AC signal of 1 V (peak-to-peak) and of various frequencies in the range between 10 kHz and 1 MHz. The suspension of latex microbeads (3-µm diameter) is either attracted or repelled from the microelectrodes under the influence of DEP force as a function of the applied frequency. The video of the bead movement is captured via a digital camera attached to the microscope. The OpenCV software package is used to digitally analyze the images and identify the beads. Positions of the identified beads are compared for successive frames via Artificial Intelligence (AI) algorithm that determines the cloud behavior of the microbeads and algorithmically determines if the beads experience attraction or repulsion from the electrodes. Based on the determined behavior of the beads, algorithm will either increase or decrease the applied frequency and implement the digital command of the function generator that is controlled by the computer. Thus, the operation of the study platform is fully automated. The AI-guided platform has determined that positive DEP (pDEP) is active below 500 kHz frequency, negative DEP (nDEP) is evidenced above 1 MHz frequency and the crossover frequency is between 500 kHz and 1 MHz. These results are in line with previously published experimentally determined frequency-dependent DEP behavior of the latex microbeads. The phenomenological approach assisted by live AI-guided feedback loop described in the present study will assist the active manipulation of the system towards the desired phenomenological outcome such as, for example, collection of the particles at the electrodes, even if, due to the complexity and plurality of the interactive forces, model-based predictions are not available.

Guided Healing of Damaged Microelectrodes via Electrokinetic Assembly of Conductive Carbon Nanotube Bridges.

The subject of healing and repair of damaged microelectrodes has become of particular interest as the use of integrated circuits, energy storage technologies, and sensors within modern devices has increased. As the dimensions of the electrodes shrink together with miniaturization of all the elements in modern electronic devices, there is a greater risk of mechanical-, thermal-, or chemical-induced fracture of the electrodes. In this research, a novel method of electrode healing using electrokinetically assembled carbon nanotube (CNT) bridges is presented. Utilizing the previously described step-wise CNT deposition process, conductive bridges were assembled across ever-larger electrode gaps, with the width of electrode gaps ranging from 20 microns to well over 170 microns. This work represents a significant milestone since the longest electrically conductive CNT bridge previously reported had a length of 75 microns. To secure the created conductive CNT bridges, they are fixed with a layer of electrodeposited polypyrrole (a conductive polymer). The resistance of the resulting CNT bridges, and its dependence on the size of the electrode gap, is evaluated and explained. Connecting electrodes via conductive CNT bridges can find many applications from nanoelectronics to neuroscience and tissue engineering.

Anxiety, Depression, and the Interpersonal Theory of Suicide in a Community Sample of Adults with Autism Spectrum Disorder.

The present study examines occurrence of depression, anxiety, and suicidality in adults with autism spectrum disorder (ASD), relationships between social difficulties and mental health, and application of the Interpersonal Theory of Suicide in this population. Ninety-eight adults with ASD completed an online survey. Data were analyzed using bivariate correlations, independent samples t-tests, and simple mediational analyses. A substantial proportion reported a lifetime history of anxiety (63%), depression (55%), and suicide attempts (19%), as well as recent suicidal ideation (12%). Social difficulty was associated with higher psychiatric concerns. Thwarted belongingness and perceived burdensomeness were associated with social dissatisfaction, current suicidal ideation, and history of depression. Results suggest the need for widespread screening and intervention services for co-occurring psychiatric conditions in this population.

Is the Higher Number of Suicide Attempts in Bipolar Disorder vs. Major Depressive Disorder Attributable to Illness Severity?

The present study represents an early stage investigation into the phenomenon whereby those with bipolar disorder attempt suicide more frequently than those with unipolar depression, but do not tend to attempt suicide during mania. Data for this study were obtained from baseline measurements collected in a randomized treatment study at a major southwestern United States military medical center. We demonstrated the rarity of suicide attempts during mania, the higher frequency of suicide attempts in those with bipolar disorder compared to those with depression, and the persistence of effects after accounting for severity of illness. These results provide the impetus for the development and testing of theoretical explanations.

The interpersonal theory of suicide: A systematic review and meta-analysis of a decade of cross-national research.

Over the past decade, the interpersonal theory of suicide has contributed to substantial advances in the scientific and clinical understanding of suicide and related conditions. The interpersonal theory of suicide posits that suicidal desire emerges when individuals experience intractable feelings of perceived burdensomeness and thwarted belongingness and near-lethal or lethal suicidal behavior occurs in the presence of suicidal desire and capability for suicide. A growing number of studies have tested these posited pathways in various samples; however, these findings have yet to be evaluated meta-analytically. This paper aimed to (a) conduct a systematic review of the unpublished and published, peer-reviewed literature examining the relationship between interpersonal theory constructs and suicidal thoughts and behaviors, (b) conduct meta-analyses testing the interpersonal theory hypotheses, and (c) evaluate the influence of various moderators on these relationships. Four electronic bibliographic databases were searched through the end of March, 2016: PubMed, Medline, PsycINFO, and Web of Science. Hypothesis-driven meta-analyses using random effects models were conducted using 122 distinct unpublished and published samples. Findings supported the interpersonal theory: the interaction between thwarted belongingness and perceived burdensomeness was significantly associated with suicidal ideation; and the interaction between thwarted belongingness, perceived burdensomeness, and capability for suicide was significantly related to a greater number of prior suicide attempts. However, effect sizes for these interactions were modest. Alternative configurations of theory variables were similarly useful for predicting suicide risk as theory-consistent pathways. We conclude with limitations and recommendations for the interpersonal theory as a framework for understanding the suicidal spectrum. (PsycINFO Database Record

Sex Differences in Suicide-Related Symptoms in a Large Military Sample.

Little research has focused on suicide-related symptoms in female servicemembers, despite high rates of suicidal behaviors. This study examined sex differences in suicide-related risk factors in 3,374 U.S. Army Recruiters (91.9% male). Female servicemembers had a greater number of past major depressive and suicidal ideation episodes than males; there were no differences in suicide attempt histories or mental health visits. Females reported significantly fewer symptoms of current suicidal ideation, perceived burdensomeness, and acquired capability. No significant sex differences emerged for thwarted belongingness, insomnia, or agitation. Our findings provide evidence for sex differences in rates of suicide-related symptoms among military personnel.

The role of stressful life events preceding death by suicide: Evidence from two samples of suicide decedents.

Stressful life events (SLEs) are associated with increased risk for suicidal behavior. Less is known regarding the intensity of SLEs and how this may vary as a function of suicide attempt history. As a large percentage of suicide decedents do not have a history of suicidal behavior, SLEs precipitating suicide may help characterize suicidality in this understudied population. This paper examines the intensity, number, and accumulation of SLEs preceding death by suicide among decedents with varying suicide attempt histories. Suicide attempts, SLEs, and suicide methods were examined in two samples: 62 prison-based and 117 community-based suicide decedents. Regression was used to compare the level of stressor precipitating death by suicide in decedents who died on a first attempt versus multiple previous attempts. A non-significant trend was observed in the prison population which was supported by significant findings in the community-based sample. Decedents who died on a first attempt experienced a stressor of a lower magnitude when compared to decedents with multiple previous suicide attempts. We discuss the implications of these findings in relation to the stress-diathesis model for suicide.

Total sleep time as a predictor of suicidal behaviour.

Insomnia symptoms are a known predictor of suicide; however, less is known about the relationship between hypersomnia and suicide, and how total sleep time may better account for suicidal ideation compared with subjective reports of insomnia symptoms. In the present secondary data analysis, a squared term confirmed the importance of both short and long total sleep time on suicidal behaviour. Total sleep time had a significant positive direct effect on suicidal behaviour (b = 0.20, SE = 0.08, P < 0.05), significant negative direct effects on insomnia symptoms (b = -1.67, SE = 0.13, P < 0.0001) and on depressive symptoms (b = -1.76, SE = 0.29, P < 0.0001). Depression had a significant positive effect on suicidal behaviour (b = 0.17, SE = 0.01, P < 0.0001), and significantly mediated the relationship between total sleep time and suicidal behaviour, but insomnia symptoms did not. Total sleep time squared had a significant positive relationship with suicidal behaviour (b = 0.02, SE = 0.01, P < 0.05), significant negative direct effects on insomnia symptoms (b = -0.12, SE = 0.01, P < 0.0001) and on depressive symptoms (b = -0.12, SE = 0.02, P < 0.0001). Depression had a significant positive effect on suicidal behaviour (b = 0.17, SE = 0.01, P < 0.0001), and significantly mediated the relationship between total sleep time and suicidal behaviour. These results suggest the importance of assessing for total sleep time in clinical settings with regard to suicide risk.

Investigating insomnia as a cross-sectional and longitudinal predictor of loneliness: Findings from six samples.

Loneliness has been repeatedly associated with sleep problems; however, there is a dearth of research examining the prospective relationship between insomnia and loneliness, as well as this association controlling for other psychiatric symptoms. This study evaluated the cross-sectional and prospective relationship between insomnia and loneliness using six samples: 666 undergraduates; 2785 Army recruiters; 208 adults with a history of suicidality and/or depression; 343 adult psychiatric outpatients; 326 young adults at elevated suicide risk; and 183 undergraduates. A meta-analysis also was conducted to examine the magnitude of the relationship between insomnia and loneliness across the six studies. More severe insomnia symptoms were significantly associated with greater feelings of loneliness while accounting for some (e.g., anxiety, nightmares) but not all (i.e., depression) psychiatric covariates. Findings underscore the strength of the association between insomnia and loneliness and suggest that depression may account for this relationship. Additional studies are needed to further establish the temporal relationship between these variables, delineate the role of depression in the association between insomnia and loneliness, and test whether insomnia may confer unique risk for subsequent loneliness.

Acute suicidal affective disturbance: Factorial structure and initial validation across psychiatric outpatient and inpatient samples.

BACKGROUND: A new clinical entity, Acute Suicidal Affective Disturbance (ASAD), was recently proposed to characterize rapid-onset, acute suicidality including the cardinal symptom of behavioral intent. This study examines the proposed ASAD criteria factor-analytically and in relation to correlates of suicidal behavior and existing psychiatric disorders in samples of psychiatric outpatients and inpatients. METHODS: Two samples of psychiatric outpatients (N=343, aged 18-71 years, 60.6% female, 74.9% White) and inpatients (N=7,698, aged 15-99 years, 57.2% female, 87.8% White) completed measures of their ASAD symptoms and psychological functioning. RESULTS: Across both samples, results of a confirmatory factor analysis supported the unidimensional nature of the ASAD construct. Additionally, results provided evidence for the convergent and discriminant validity of ASAD, demonstrating its relation to, yet distinction from, other psychiatric disorders and correlates of suicide in expected ways. Importantly, ASAD symptoms differentiated multiple attempters, single attempters, and non-attempters, as well as attempters, ideators, and non-suicidal patients, and was an indicator of past suicide attempts above and beyond symptoms of depression and other psychiatric disorders. LIMITATIONS: This study utilized cross-sectional data and did not use a standardized measure of ASAD. CONCLUSIONS: ASAD criteria formed a unidimensional construct that was associated with suicide-related variables and other psychiatric disorders in expected ways. If supported by future research, ASAD may fill a gap in the current diagnostic classification system (DSM-5) by characterizing and predicting acute suicide risk.

Suicidal ideation in transgender people: Gender minority stress and interpersonal theory factors.

Research has revealed alarmingly high rates of suicidal ideation (SI) and suicide attempts among transgender and gender nonconforming (TGNC) people. This study aims to analyze the role of factors from the gender minority stress and resilience (GMSR) model (Testa, Habarth, Peta, Balsam, & Bockting, 2015), the interpersonal-psychological theory of suicide (IPTS; Joiner, 2005; Van Orden et al., 2010), and the potential integration of these factors, in explaining SI in this population. A convenience sample of 816 TGNC adults responded to measures of current SI, gender minority stressors, and IPTS factors. Path analysis was utilized to test 2 models. Model 1 evaluated the associations between external minority stressors and SI through internal minority stressors. Model 2 examined the relationships between internal minority stressors and SI through IPTS variables (perceived burdensomeness and thwarted belongingness). All GMSR external stressors (rejection, nonaffirmation, victimization, and discrimination), internal stressors (internalized transphobia, negative expectations, and nondisclosure), and IPTS factors (thwarted belongingness and perceived burdensomeness) were related to SI. Both models demonstrated good fit. Model 1 revealed that rejection, nonaffirmation, and victimization were related to SI through experiences of internalized transphobia and negative expectations. Model 2 indicated that internalized transphobia and negative expectations were associated with SI through IPTS factors. The models demonstrate pathways through which GMSR and IPTS constructs relate to one another and confer risk for SI among TGNC individuals. These pathways and several recently proposed constructs examined here provide promising directions for future research and clinical interventions in this area. (PsycINFO Database Record

Acquired capability for suicide among individuals with American Indian/Alaska Native backgrounds within the military.

The present study observes a military sample across race to better understand suicide risk among American Indian/Alaska Native (AI/AN) individuals utilizing the Interpersonal Theory of Suicide. In a sample of 3,387 Army recruiters, multivariate analysis of variance was used to compare the means across race on acquired capability and pain tolerance. AI/AN individuals demonstrated higher levels of acquired capability for suicide (p = .056) and pain tolerance (p = .028). These findings indicate that acquired capability and pain tolerance are key elements involved in suicide risk among AI/AN individuals within the military.

Insomnia brings soldiers into mental health treatment, predicts treatment engagement, and outperforms other suicide-related symptoms as a predictor of major depressive episodes.

Given the high rates of suicide among military personnel and the need to characterize suicide risk factors associated with mental health service use, this study aimed to identify suicide-relevant factors that predict: (1) treatment engagement and treatment adherence, and (2) suicide attempts, suicidal ideation, and major depressive episodes in a military sample. Army recruiters (N = 2596) completed a battery of self-report measures upon study enrollment. Eighteen months later, information regarding suicide attempts, suicidal ideation, major depressive episodes, and mental health visits were obtained from participants' military medical records. Suicide attempts and suicidal ideation were very rare in this sample; negative binomial regression analyses with robust estimation were used to assess correlates and predictors of mental health treatment visits and major depressive episodes. More severe insomnia and agitation were significantly associated with mental health visits at baseline and over the 18-month study period. In contrast, suicide-specific hopelessness was significantly associated with fewer mental health visits. Insomnia severity was the only significant predictor of major depressive episodes. Findings suggest that assessment of sleep problems might be useful in identifying at-risk military service members who may engage in mental health treatment. Additional research is warranted to examine the predictive validity of these suicide-related symptom measures in a more representative, higher suicide risk military sample.

Manifestations of overarousal account for the association between cognitive anxiety sensitivity and suicidal ideation.

BACKGROUND: Recent evidence suggests an association between cognitive anxiety sensitivity and suicidal ideation. Cognitive anxiety sensitivity has also been implicated as a precursor to various forms of overarousal. These manifestations of overarousal (i.e., agitation, insomnia, nightmares, and anger) may account for the association between cognitive anxiety sensitivity and suicidal ideation. METHODS: In Study 1, undergraduate students selectively sampled for recent suicidal ideation completed all measures online. In Study 2, clinical outpatients completed all measures prior to their initial intake appointments at a psychology clinic. RESULTS: Study 1 demonstrated that agitation and insomnia individually and jointly accounted for the association between cognitive anxiety sensitivity and suicidal ideation, controlling for general anxiety and demographic variables. Study 2 replicated and extended these findings, such that, controlling for demographics, general anxiety, and physical and social anxiety sensitivity, agitation and anger each independently and together accounted for the association between cognitive anxiety sensitivity and suicidal ideation, whereas insomnia and nightmares did not. LIMITATIONS: This study utilized a cross-sectional design and self-report measures in both samples as well as a sample of undergraduate students in Study 1. CONCLUSIONS: Together, these findings suggest that agitation and anger may explain the previously established relationship between cognitive anxiety sensitivity and suicidal ideation. Targeting cognitive anxiety sensitivity in treatment may in turn reduce these forms of overarousal and thereby suicide risk.

A Minority Stress Model for Suicidal Ideation in Gay Men.

There is a dearth of research on mechanisms underlying higher rates of suicidal ideation among gay men compared to heterosexual men. The purpose of this study was to establish the link between social/psychological predictor variables and suicidal ideation by testing a hypothesized minority stress model. Structural equation modeling was used to assess the relationships posited in the model using data from a community sample of 167 gay men. Model fit was adequate and hypothesized relationships were partially supported. Also, depressive symptoms partially mediated the relationship between (less) outness predicting suicidal ideation. These findings imply that therapeutic approaches targeting the coming out process may be more effective than approaches targeting internalized homophobia when suicidal ideation is indicated in the clinical presentation of gay and bisexual men.

Dangerous Words? An Experimental Investigation of the Impact of Detailed Reporting About Suicide on Subsequent Risk.

OBJECTIVE: Media reporting guidelines exist for suicide-related content; however, no experimental studies have examined the impact of guideline violations. As such, we utilized an experimental design to determine whether reading an article about suicide that violated guidelines would impact mood and suicidality relative to the same article without violations and to an article detailing death by cancer, both immediately and during 1-month follow-up. METHOD: 273 students were randomly assigned to read one of three articles (1) an article that violated suicide reporting guidelines, (2) the same article with violations removed, or (3) an article that details death by cancer. RESULTS: Individuals assigned to read the original suicide article were no more upset immediately afterwards or during 1-month follow-up. Amongst participants with prior ideation, those who read the original article reported a lower likelihood of future attempt relative to either other condition. CONCLUSION: Results indicate some reporting guidelines may be unnecessary. Amongst individuals at risk for suicide, some guideline violations may be associated with a decreased likelihood of future attempt and result in a decrease in negative affect. Clinically, these results highlight the potential utility of exposing clients to in depth educational materials about suicide while mitigating concerns regarding certain aspects of the content.

Considerations regarding online methods for suicide-related research and suicide risk assessment.

Frequent advances in technology provide new and exciting opportunities for conducting suicide research and suicide risk assessments. However, to the authors' knowledge, best practices for using technology, specifically the Internet, to conduct research protocols involving suicide risk assessments have not been examined. In research contexts, the use of technology for research on suicidal behavior and suicide risk assessment can offer benefits relative to other forms of data collection. These advantages, which include increased validity, feasibility, and efficiency, as well as improvements in data collection and management, are presented. Considerations regarding the implementation of an online system for suicide risk assessment as well as limitations and future directions are discussed.

"HIV testing is so gay": the role of masculine gender role conformity in HIV testing among men who have sex with men.

Men who have sex with men (MSM) account for more than half of all new cases of HIV infection in the United States. Yet, many MSM are unaware of their HIV serostatus. Consistent with research indicating that gender role conformity impacts health behaviors, this study examined how masculine norms may influence HIV testing among MSM in the United States. Data from 170 self-identified MSM (age M = 46.45, SD = 12.18) of self-reported negative or unknown HIV serostatus living in the United States were used in this study. About half (52%) of participants reported that they had been tested for HIV within the past 12 months; 48% reported that they had not. Logistic regression was used to examine the association between domains of masculine gender role conformity and HIV testing within the past 12 months, controlling for number of sexual partners in the last 12 months. The masculine norm of heterosexual self-presentation (i.e., desire to be perceived by others as heterosexual) was negatively associated with HIV testing (B = -0.74, SE B = 0.36, O.R. = 0.48, 95% CI [0.24, 0.96]), after controlling for the effect of number of sexual partners. Psychologists and other health professionals may remain mindful of potential implications of HIV testing among MSM, including potential for MSM to view HIV testing as an "outing" procedure.