Scaling properties of a low-actuation pressure microfluidic valve

Using basic physical arguments, we present a design and method for the fabrication of microfluidic valves using multilayer soft lithography. These on-off valves have extremely low actuation pressures and can be used to fabricate active functions, such as pumps and mixers in integrated microfluidic chips. We characterized the performance of the valves by measuring both the actuation pressure and flow resistance over a wide range of design parameters, and compared them to both finite element simulations and alternative valve geometries

Gender differences in sleep disorders in the US military

The article of record as published may be found at http://dx.doi.org/10.1016/j.sleh.2017.07.015Objectives: The purpose of this study is to compare sleep disorders between male and female military personnel. Comorbid behavioral health disorders and chronic pain were also studied in relation to sleep disorders. Design: We conducted a retrospective review of military personnel who underwent a sleep medicine evaluation and an in-laboratory attended polysomnography. Initial sleep questionnaires, demographics, polysomnographic variables, and comorbid disorders of interest were reviewed and compared for each sex. Setting: All patients were referred to the Wilford Hall Ambulatory Surgical Center Sleep Disorders Center for evaluation of sleep disturbance. Participants: Our cohort consisted of 209 military personnel with 51.7% men. The cohort was relatively young with a mean age of 34.3 years. Men had a significantly higher body mass index at 29.4 vs 27.3 in women. Results: Insomnia was diagnosed in 72 women and 41 men (P b .001), whereas obstructive sleep apnea (OSA) was diagnosed in 92 men and 50 women (P b .001). Depression and anxiety were more common in women. Women had an average of 1.76 ± 1.36 comorbid conditions compared with 1.08 ± 1.19 in men. In patients diagnosed with both insomnia and OSA, women were more likely to have post-traumatic stress disorder, depression, and anxiety. Neither the Epworth Sleepiness Scale (12.8 ± 4.88) nor the Insomnia Severity Index (16.9 ± 5.33) differed between sexes. Conclusions: Gender-related differences in sleep disorders are present in active-duty personnel. Behavioral health disorders were frequent comorbid disorders, and women diagnosed with both insomnia and OSA manifested greater psychiatric comorbidity. The frequent association between sleep and behavioral health disorders in military personnel requires further study

An Initial Report of Sleep Disorders in Women in the U.S. Military

The article of record as published may be found at http://dx.doi.org/10.1093/milmed/usx116Sleep disorders are increasingly recognized in active duty service members (ADSM). While there are multiple studies in male ADSM, there are limited data regarding sleep disorders in women in the military. The purpose of this study was to characterize sleep disorders in female ADSM referred for clinical evaluation to provide a better understanding of this unique population. Materials and Methods: We conducted a retrospective review of female ADSM who underwent a sleep medicine evaluation and an attended polysomnogram (PSG). Demographic and polysomnogram variables, as well as medical records, were reviewed. Associated illnesses to include post-traumatic stress disorder, pain disorders, anxiety, and depression, were recorded. Results: The cohort consisted of 101 women. The average age was 33.9 ± 9.0 years and body mass index was 27.3 ± 4.5, with an average Epworth Sleepiness Scale score of 12.9 ± 5.2, and Insomnia Severity Index score of 17.6 ± 5.7. Overall, 36.6% were diagnosed with insomnia only, 14.9% with obstructive sleep apnea (OSA) only, and 34.7% met diagnostic criteria for both insomnia and OSA. The average apnea-hypopnea index for the entire cohort was 5.37 ± 7.04/h whereas it was 10.34 ± 3.14/h for those meeting diagnostic criteria for OSA. The women referred for sleep evaluations had the following rates of associated illnesses: pain disorders (59.4%), anxiety (48.5%), depression (46.5%), and post-traumatic stress disorder (21.8%). For patients with OSA, the relative risk of having post-traumatic stress disorder was 2.72 (95% confidence interval 1.16–6.39). Conclusions: Women in the U.S. military who have sleep disorders have a high rate of behavioral medicine and pain disorders. Interestingly, nearly 50% of active duty females referred for a sleep study have OSA while not necessarily manifesting the typical signs of obesity or increased age. The reasons for this finding are not completely understood, though factors related to military service may potentially contribute. The findings from our study indicate a need for increased awareness and evaluation of sleep disorders in women in the military, especially those with behavioral medicine disorders

What asteroseismology can do for exoplanets

We describe three useful applications of asteroseismology in the context of exoplanet science: (1) the detailed characterisation of exoplanet host stars; (2) the measurement of stellar inclinations; and (3) the determination of orbital eccentricity from transit duration making use of asteroseismic stellar densities. We do so using the example system Kepler-410 (Van Eylen et al. 2014). This is one of the brightest (V = 9.4) Kepler exoplanet host stars, containing a small (2.8 Rearth) transiting planet in a long orbit (17.8 days), and one or more additional non-transiting planets as indicated by transit timing variations. The validation of Kepler-410 (KOI-42) was complicated due to the presence of a companion star, and the planetary nature of the system was confirmed after analyzing a Spitzer transit observation as well as ground-based follow-up observations.Comment: 4 pages, Proceedings of the CoRoT Symposium 3 / Kepler KASC-7 joint meeting, Toulouse, 7-11 July 2014. To be published by EPJ Web of Conference

Sleep deprivation causes memory deficits by negatively impacting neuronal connectivity in hippocampal area CA1

Brief periods of sleep loss have long-lasting consequences such as impaired memory consolidation. Structural changes in synaptic connectivity have been proposed as a substrate of memory storage. Here, we examine the impact of brief periods of sleep deprivation on dendritic structure. In mice, we find that five hours of sleep deprivation decreases dendritic spine numbers selectively in hippocampal area CA1 and increased activity of the filamentous actin severing protein cofilin. Recovery sleep normalizes these structural alterations. Suppression of cofilin function prevents spine loss, deficits in hippocampal synaptic plasticity, and impairments in long-term memory caused by sleep deprivation. The elevated cofilin activity is caused by cAMP-degrading phosphodiesterase-4A5 (PDE4A5), which hampers cAMP-PKA-LIMK signaling. Attenuating PDE4A5 function prevents changes in cAMP-PKA-LIMK-cofilin signaling and cognitive deficits associated with sleep deprivation. Our work demonstrates the necessity of an intact cAMP-PDE4-PKA-LIMK-cofilin activation-signaling pathway for sleep deprivation-induced memory disruption and reduction in hippocampal spine density

Spin Glasses: Model systems for non-equilibrium dynamics

Spin glasses are frustrated magnetic systems due to a random distribution of ferro- and antiferromagnetic interactions. An experimental three dimensional (3d) spin glass exhibits a second order phase transition to a low temperature spin glass phase regardless of the spin dimensionality. In addition, the low temperature phase of Ising and Heisenberg spin glasses exhibits similar non-equilibrium dynamics and an infinitely slow approach towards a thermodynamic equilibrium state. There are however significant differences in the detailed character of the dynamics as to memory and rejuvenation phenomena and the influence of critical dynamics on the behaviour. In this article, some aspects of the non-equilibrium dynamics of an Ising and a Heisenberg spin glass are briefly reviewed and some comparisons are made to other glassy systems that exhibit magnetic non-equilibrium dynamics.Comment: To appear in J. Phys.: Condens. Matter, Proceedings from HFM2003, Grenobl

Comparison of initial and tertiary centre second opinion reads of multiparametric magnetic resonance imaging of the prostate prior to repeat biopsy.

OBJECTIVES: To investigate the value of second-opinion evaluation of multiparametric prostate magnetic resonance imaging (MRI) by subspecialised uroradiologists at a tertiary centre for the detection of significant cancer in transperineal fusion prostate biopsy. METHODS: Evaluation of prospectively acquired initial and second-opinion radiology reports of 158 patients who underwent MRI at regional hospitals prior to transperineal MR/untrasound fusion biopsy at a tertiary referral centre over a 3-year period. Gleason score (GS) 7-10 cancer, positive predictive value (PPV) and negative (NPV) predictive value (±95 % confidence intervals) were calculated and compared by Fisher's exact test. RESULTS: Disagreement between initial and tertiary centre second-opinion reports was observed in 54 % of cases (86/158). MRIs had a higher NPV for GS 7-10 in tertiary centre reads compared to initial reports (0.89 ± 0.08 vs 0.72 ± 0.16; p = 0.04), and a higher PPV in the target area for all cancer (0.61 ± 0.12 vs 0.28 ± 0.10; p = 0.01) and GS 7-10 cancer (0.43 ± 0.12 vs 0.2 3 ± 0.09; p = 0.02). For equivocal suspicion, the PPV for GS 7-10 was 0.12 ± 0.11 for tertiary centre and 0.11 ± 0.09 for initial reads; p = 1.00. CONCLUSIONS: Second readings of prostate MRI by subspecialised uroradiologists at a tertiary centre significantly improved both NPV and PPV. Reporter experience may help to reduce overcalling and avoid overtargeting of lesions. KEY POINTS: • Multiparametric MRIs were more often called negative in subspecialist reads (41 % vs 20 %). • Second readings of prostate mpMRIs by subspecialist uroradiologists significantly improved NPV and PPV. • Reporter experience may reduce overcalling and avoid overtargeting of lesions. • Greater education and training of radiologists in prostate MRI interpretation is advised.RWTH Aachen University Hospital (Aachen, Germany), National Institute for Health Research Cambridge Biomedical Research Centre, Cancer Research UK, Engineering and Physical Sciences Research Council Imaging Centre in Cambridge and Manchester, Cambridge Experimental Cancer Medicine Centr

Pericellular activation of hepatocyte growth factor by the transmembrane serine proteases matriptase and hepsin, but not by the membrane-associated protease uPA

HGF (hepatocyte growth factor) is a pleiotropic cytokine homologous to the serine protease zymogen plasminogen that requires canonical proteolytic cleavage to gain functional activity. The activating proteases are key components of its regulation, but controversy surrounds their identity. Using quantitative analysis we found no evidence for activation by uPA (urokinase plasminogen activator), despite reports that this is a principal activator of pro-HGF. This was unaffected by a wide range of experimental conditions, including the use of various molecular forms of both HGF and uPA, and the presence of uPAR (uPA receptor) or heparin. In contrast the catalytic domains of the TTSPs (type-II transmembrane serine proteases) matriptase and hepsin were highly efficient activators (50% activation at 0.1 and 3.4 nM respectively), at least four orders of magnitude more efficient than uPA. PS-SCL (positional-scanning synthetic combinatorial peptide libraries) were used to identify consensus sequences for the TTSPs, which in the case of hepsin corresponded to the pro-HGF activation sequence, demonstrating a high specificity for this reaction. Both TTSPs were also found to be efficient activators at the cell surface. Activation of pro-HGF by PC3 prostate carcinoma cells was abolished by both protease inhibition and matriptase-targeting siRNA (small interfering RNA), and scattering of MDCK (Madin–Darby canine kidney) cells in the presence of pro-HGF was abolished by inhibition of matriptase. Hepsin-transfected HEK (human embryonic kidney)-293 cells also activated pro-HGF. These observations demonstrate that, in contrast with the uPA/uPAR system, the TTSPs matriptase and hepsin are direct pericellular activators of pro-HGF, and that together these proteins may form a pathway contributing to their involvement in pathological situations, including cancer