Multiscale Richtmyer-Meshkov instability experiments to isolate the strain rate dependence of strength.

Theoretical analysis of Richtmyer-Meshkov instability (RMI) experiments for solid strength shows that the strain rate for a given shock should be inversely proportional to the length scale of the sine wave perturbations when η_{0}k, the nondimensional amplitude to wavelength ratio, is held fixed. To isolate the effect of strain rate on strength, free-surface RMI specimens of annealed copper were prepared with three perturbation regions with the same η_{0}k but different length scales, characterized by the wavelength λ varying by a factor of 4.9 from 65 to 130 to 320µm. Three such targets with different fixed η_{0}k^{'}s were impacted to a shock pressure of 25 GPa, and the instability evolution was measured with photon Doppler velocimetry. Strengths estimated by comparing hydrocode simulation to the data increased from 700 to 1200 MPa as λ decreased. The different η_{0}k targets exercised increasing amounts of plastic strain yet showed no evidence of strain hardening. Physical regime sensitivity analysis determined that for 320-65µm wavelength perturbations, the effective strain rates increased from 8.7×10^{6} to 3.3×10^{7}s^{-1}, a factor of 3.8. Thus, the predicted strain rate scaling was mostly achieved but slightly suppressed by increased strength at higher rates. The RMI strength estimates were plotted against constitutive testing data on copper from the literature to show striking evidence of the strength upturn at higher strain rates.

A tele-health intervention to increase physical fitness in people with spinal cord injury and cardiometabolic disease or risk factors: a pilot randomized controlled trial.

STUDY DESIGN: Clinical trial. OBJECTIVES: We used a single-blind parallel-group design to test the feasibility and preliminary efficacy of a telehealth-based physical activity counseling intervention to increase physical fitness in people with SCI. SETTING: Seattle, Washington, United States. METHODS: We recruited under-active, manual wheelchair-using adults at least 1-year post-SCI who had at least two cardiometabolic risk factors/diseases. Participants underwent baseline tests of peak cardiorespiratory fitness; lipids, glucose and insulin; muscle and fat mass; self-reported physical activity, depression, pain and other factors. Participants were assigned 1:1 to treatment vs. usual care (UC) control conditions via concealed computerized randomization. Treatment was delivered via telephone and adapted from the 16-session Diabetes Prevention Program. All baseline tests were repeated at 6 months. Prespecified feasibility goals were to recruit at least nine participants/quarter and retain 85% with complete fitness testing at 6 months. Prespecified efficacy goals were to demonstrate at least a medium treatment effect size (0.50) on fitness, self-reported physical activity, and other outcomes. RESULTS: Seven participants were randomized to treatment, 8 to UC over 15 months. Maximum recruitment was only 5.4 participants/quarter. Thirteen (87%) of participants were retained. The effects of treatment on fitness and most cardiometabolic risk factors did not meet expectations, whereas the effects on self-reported physical activity, depression, and pain did meet expectations. CONCLUSIONS: The study did not meet key efficacy and feasibility objectives, yet there were some promising effects on self-report measures and lessons to be learned for designing future trials.

The Nature of Trauma Pain and Its Association with Catastrophizing and Sleep.

BACKGROUND: Nearly 2.8 million people are hospitalized in the USA annually for traumatic injuries, which include orthopedic and internal organ injuries. Early post-injury pain is predictive of poor outcomes, including inability to eventually return to work, and long-term psychological distress. The goal of the present study was to improve our scientific understanding of trauma-related pain by examining (1) the nature and frequency of inpatient trauma pain and (2) the associations between inpatient trauma pain, education, opioid analgesic equivalent use, pain catastrophizing, and sleep quality. METHOD: The study included 120 patients hospitalized at a major level I regional trauma center for the care of (1) closed long bone or calcaneus fractures and/or (2) an intraabdominal injury caused by blunt force trauma and requiring surgical repair (i.e., laparotomy). Medical records were reviewed to obtain demographic information and information about opioid use during hospitalization. In addition, participants were administered measures of average pain intensity, pain catastrophizing, and sleep quality. RESULTS: Education, opioid analgesic equivalents, catastrophizing, and poor sleep quality together accounted for 28% of the variance of average pain intensity over a 24-h period (p < .001), with each variable making a significant independent association. CONCLUSION: Two of the factors associated with pain intensity in the study sample-catastrophizing and sleep quality-are modifiable. It is therefore possible that interventions that target these variables in patients who are hospitalized for trauma could potentially result in better long-term outcomes, including a reduced risk for developing chronic pain. Research to evaluate this possibility is warranted.

The Relations of Cognitive, Behavioral, and Physical Activity Variables to Depression Severity in Traumatic Brain Injury: Reanalysis of Data From a Randomized Controlled Trial.

OBJECTIVE: To explore the relations of cognitive, behavioral, and physical activity variables to depression severity among people with traumatic brain injury (TBI) undergoing a depression treatment trial. SETTING: Community. PARTICIPANTS: Adults (N = 88) who sustained complicated mild to severe TBI within the past 10 years, met criteria for major depressive disorder, and completed study measures. DESIGN: Randomized controlled trial. METHODS: Participants were randomized to cognitive-behavioral therapy (n = 58) or usual care (n = 42). Outcomes were measured at baseline and 16 weeks. We combined the groups and used regressions to explore the relations among theoretical variables and depression outcomes. MAIN MEASURES: Depression severity was measured with the Hamilton Depression Rating Scale and Symptom Checklist-20. Theory-based measures were the Dysfunctional Attitudes Scale (DAS), Automatic Thoughts Questionnaire (ATQ), Environmental Rewards Observation Scale (EROS), and the International Physical Activity Questionnaire (IPAQ). RESULTS: Compared with non-TBI norms, baseline DAS and ATQ scores were high and EROS and IPAQ scores were low. All outcomes improved from baseline to 16 weeks except the DAS. The ATQ was an independent predictor of baseline depression. An increase in EROS scores was correlated with decreased depression. CONCLUSIONS: Increasing participation in meaningful roles and pleasant activities may be a promising approach to treating depression after TBI.

CCDC88A mutations cause PEHO-like syndrome in humans and mouse.

Progressive encephalopathy with oedema, hypsarrhythmia and optic atrophy (PEHO) syndrome is a rare Mendelian phenotype comprising severe retardation, early onset epileptic seizures, optic nerve/cerebellar atrophy, pedal oedema, and early death. Atypical cases are often known as PEHO-like, and there is an overlap with 'early infantile epileptic encephalopathy'. PEHO is considered to be recessive, but surprisingly since initial description in 1991, no causative recessive gene(s) have been described. Hence, we report a multiplex consanguineous family with the PEHO phenotype where affected individuals had a homozygous frame-shift deletion in CCDC88A (c.2313delT, p.Leu772*ter). Analysis of cDNA extracted from patient lymphocytes unexpectedly failed to show non-sense mediated decay, and we demonstrate that the mutation produces a truncated protein lacking the crucial C-terminal half of CCDC88A (girdin). To further investigate the possible role of CCDC88A in human neurodevelopment we re-examined the behaviour and neuroanatomy of Ccdc88a knockout pups. These mice had mesial-temporal lobe epilepsy, microcephaly and corpus callosum deficiency, and by postnatal Day 21, microcephaly; the mice died at an early age. As the mouse knockout phenotype mimics the human PEHO phenotype this suggests that loss of CCDC88A is a cause of the PEHO phenotype, and that CCDC88A is essential for multiple aspects of normal human neurodevelopment.

Evaluating the Psychometric Properties of 3 Depression Measures in a Sample of Persons With Traumatic Brain Injury and Major Depressive Disorder.

OBJECTIVES: To explore the psychometric properties of 3 widely used measures of depression in a sample of individuals with traumatic brain injury (TBI) and major depressive disorder and refine them to maximize efficiency. DESIGN: Secondary analysis of data from a randomized controlled trial of cognitive-behavioral therapy for depression after TBI. SETTING: Nationwide recruitment from community and clinical settings. PARTICIPANTS: One hundred adults within 10 years of complicated mild to severe TBI. INTERVENTION: Telephone and in-person cognitive-behavioral therapy. MAIN MEASURES: Patient Health Questionnaire-9 (PHQ-9), Symptom Checklist-20, and Hamilton Depression Rating Scale. RESULTS: We used Rasch rating scale analysis and multilevel modeling to investigate the 3 measures. Measurement properties of each of the depression measures were strong. We explored modifications to the rating scales to improve efficiency while retaining strong psychometric characteristics. Correlations among these revised measures were high. Treatment effects of each revised depression measure were compared using a multilevel model, and effect size estimates were comparable among the revised PHQ-9, Symptom Checklist-20, and Hamilton Depression Rating Scale. CONCLUSIONS: Although each of the 3 measures demonstrated adequate reliability, the efficiency of all 3 instruments was improved with rating scale analysis. The PHQ-9 required the fewest modifications and functions well as a measure of depression among those with TBI.

Telephone and in-person cognitive behavioral therapy for major depression after traumatic brain injury: a randomized controlled trial.

Major depressive disorder (MDD) is prevalent after traumatic brain injury (TBI); however, there is a lack of evidence regarding effective treatment approaches. We conducted a choice-stratified randomized controlled trial in 100 adults with MDD within 10 years of complicated mild to severe TBI to test the effectiveness of brief cognitive behavioral therapy administered over the telephone (CBT-T) (n = 40) or in-person (CBT-IP) (n = 18), compared with usual care (UC) (n = 42). Participants were recruited from clinical and community settings throughout the United States. The main outcomes were change in depression severity on the clinician-rated 17 item Hamilton Depression Rating Scale (HAMD-17) and the patient-reported Symptom Checklist-20 (SCL-20) over 16 weeks. There was no significant difference between the combined CBT and UC groups over 16 weeks on the HAMD-17 (treatment effect = 1.2, 95% CI: -1.5-4.0; p = 0.37) and a nonsignificant trend favoring CBT on the SCL-20 (treatment effect = 0.28, 95% CI: -0.03-0.59; p = 0.074). In follow-up comparisons, the CBT-T group had significantly more improvement on the SCL-20 than the UC group (treatment effect = 0.36, 95% CI: 0.01-0.70; p = 0.043) and completers of eight or more CBT sessions had significantly improved SCL-20 scores compared with the UC group (treatment effect = 0.43, 95% CI: 0.10-0.76; p = 0.011). CBT participants reported significantly more symptom improvement (p = 0.010) and greater satisfaction with depression care (p < 0.001), than did the UC group. In-person and telephone-administered CBT are acceptable and feasible in persons with TBI. Although further research is warranted, telephone CBT holds particular promise for enhancing access and adherence to effective depression treatment.

Validity of the Patient Health Questionnaire-9 in assessing major depressive disorder during inpatient spinal cord injury rehabilitation.

OBJECTIVE: To investigate the validity of the Patient Health Questionnaire-9 (PHQ-9) depression screening measure in people undergoing acute inpatient rehabilitation for spinal cord injury (SCI). DESIGN: We performed a blinded comparison of the PHQ-9 administered by research staff with the major depression module of the Structured Clinical Interview for the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (SCID) conducted by a mental health professional. SETTING: Inpatient rehabilitation units. PARTICIPANTS: Participants (N=142) were patients undergoing acute rehabilitation for traumatic SCI who were at least 18 years of age, English speakers, and without severe cognitive, motor speech, or psychotic disorders. We obtained the SCID on 173 (84%) of 204 eligible patients. The final sample of 142 patients (69%) consisted of those who underwent both assessments within 7 days of each other. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: PHQ-9 and SCID major depression module. RESULTS: Participants were on average 42.2 years of age, 78.2% men, and 81.7% white, and 66.9% had cervical injuries. The optimal PHQ-9 cutoff (≥11) resulted in 35 positive screens (24.6%). Key indices of criterion validity were as follows: sensitivity, 1.00 (95% confidence interval [CI], .73-1.00); specificity, .84 (95% CI, .76-.89); Youden Index, .84; positive predictive value, .40 (95% CI, .24-.58); and negative predictive value, 1.00 (95% CI, .96-1.00). The area under the receiver operator curve was .92, and κ was .50. Total PHQ-9 scores were inversely correlated with subjective health state and quality of life since SCI. CONCLUSIONS: The PHQ-9 meets criteria for good diagnostic accuracy compared with a structured diagnostic assessment for major depressive disorder even in the context of inpatient rehabilitation for acute traumatic SCI.

Preinjury alcohol and drug use among persons with spinal cord injury: implications for rehabilitation.

CONTEXT/OBJECTIVE: To describe preinjury alcohol and drug use and opportunities for secondary prevention among persons with recent spinal cord injury (SCI). DESIGN: Survey. SETTING: Acute inpatient rehabilitation program. PARTICIPANTS: Participants were 118 (84.8%) of 139 consecutive admissions who met inclusion criteria and were screened for preinjury alcohol and drug use. INTERVENTIONS: None. OUTCOME MEASURES: Alcohol and drug use, toxicology results, alcohol problems, readiness to change, and treatment preferences. RESULTS: Participants were on average 37 years old, 84% were men, and 85% were white. Fifty-one percent of the sample was considered 'at-risk' drinkers. Significant lifetime alcohol-related problems were reported by 38% of the total sample. Thirty-three percent reported recent illicit drug use and 44% of the 82 cases with toxicology results were positive for illicit drugs. Seventy-one percent of at-risk drinkers reported either considering changes in alcohol use or already taking action. Forty-one percent reported interest in trying substance abuse treatment or Alcoholics Anonymous (AA). Motivation to change alcohol use was significantly and positively associated with self-reported indicators of alcohol problem severity. CONCLUSION: Preinjury alcohol and drug abuse are common among persons with recent SCI. Substance abuse screening is feasible and detects not only salient clinical problems but also significant motivation to change and interest in AA or treatment, all of which represent an important window of opportunity for appropriate brief interventions and referrals. In contrast with the idea that alcoholism is a 'disease of denial', the majority of at-risk drinkers with new onset SCI indicate they are considering making changes.

Hostility and urine norepinephrine interact to predict insulin resistance: the VA Normative Aging Study.

OBJECTIVE: Previous research has produced mixed results pertaining to the association between hostility and insulin resistance. These inconsistent findings may be the result of a lack of studies examining potential moderators of this relationship and inconsistent measures of insulin resistance and/or hostility. We hypothesized that hostility may interact with circulating norepinephrine (NEPI) levels, indexed by 24-hour urine concentrations, to affect insulin resistance. METHODS: Six hundred forty-three men (mean age = 63.1 years) free of diabetic medications completed the Minnesota Multiphasic Personality Inventory and participated in a laboratory assessment. The Cook-Medley Hostility (Ho) and 24-hour urine NEPI were used to predict insulin resistance defined by the homeostatic model assessment (HOMA) index, 2-hour postchallenge glucose (PCGL), and insulin levels (PCIL) after controlling for nine common covariates. RESULTS: Multiple regression showed that the two-way interaction between Ho and NEPI significantly predicted HOMA and PCIL, but not PCGL, after controlling for covariates. Simple regression slopes of Ho on HOMA and PCIL were explored and indicated that, at higher levels of NEPI, higher Ho was associated with higher HOMA (beta = 0.14, p < .05). Ho was not a significant predictor of HOMA at mean and lower levels of NEPI. Similar results were obtained for PCIL, but not PCGL. Cynicism, but not other subscales of Ho, was similarly related to insulin resistance and NEPI. CONCLUSION: Individuals with high stress and high hostility were more likely to have insulin resistance. It is important to study moderators in the relationship between hostility and insulin resistance.