77 research outputs found

    Intelligent Insect–Computer Hybrid Robot: Installing Innate Obstacle Negotiation and Onboard Human Detection onto Cyborg Insect

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    Developing small mobile robots for Urban Search and Rescue (USAR) is a major challenge due to constraints in size and power required to perform vital functions such as obstacle navigation, victim detection, and wireless communication. Drawing upon the idea that insects’ locomotion can be controlled, what if we further utilize the insects’ intrinsic ability to avoid obstacles? Herein, a cockroach hybrid robot (≈ 1.5 cm height, 5.7 cm length) that implements the abovementioned functions is developed. It is tested in an arena with randomly placed obstacles, and a motion capture system is used to track the insect's position among the untracked obstacles. A navigation algorithm that uses an inertial measurement unit (IMU) is developed to heuristically predict the insect's situation and stimulate the insect to escape nearby obstacles. The utilization of insect's intrinsic locomotor ability and low-powered IMU reduces the onboard power load, allowing the addition of a human-detecting function. An image classification model enables the use of an onboard low-resolution infrared camera for human detection. Consequently, a single hybrid robot is established that includes locomotion control, autonomous navigation in obstructed areas, onboard human detection, and wireless communication, representing a significant step toward real USAR application

    Heterologous expression and characterization of CpI, OcpA, and novel serine-type carboxypeptidase OcpB from Aspergillus oryzae

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    In the genome of Aspergillus oryzae, 12 genes have been predicted to encode serine-type carboxypeptidases. However, the carboxypeptidase activities of the proteins encoded by these genes have not yet been confirmed experimentally. In this study, we have constructed three of these 12 genes overexpressing strains using Aspergillus nidulans and characterized their overproduced recombinant proteins. Of these three genes, one was previously named cpI; the other two have not been reported yet, and hence, we named them ocpA and ocpB. The recombinant proteins released amino acid residues from the C terminus of peptides, and the activity of the enzymes was inhibited by phenylmethylsulfonyl fluoride, indicating the enzymes to be serine-type carboxypeptidases. Recombinant OcpA, OcpB, and CpI were stable at 45°C, 55°C, and 55°C, respectively, at a low pH. The enzymatic properties of recombinant OcpB were different from those of any reported serine-type carboxypeptidase. On the other hand, recombinant OcpA had similar enzymatic properties to A. oryzae carboxypeptidases O1 and O2. The DNA and N-terminal amino acid sequences of carboxypeptidases O1 and O2 from A. oryzae IAM2640 were similar to those of OcpA. Result of transcriptional analysis of ocpA, ocpB, and cpI suggest differences in transcriptional regulation between these genes

    Transcriptional Repressor Gfi1 Integrates Cytokine-Receptor Signals Controlling B-Cell Differentiation

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    Hematopoietic stem cell differentiation is specified by cytokines and transcription factors, but the mechanisms controlling instructive and permissive signalling networks are poorly understood. We provide evidence that CLP1-dependent IL7-receptor mediated B cell differentiation is critically controlled by the transcriptional repressor Gfi1. Gfi1-deficient progenitor B cells show global defects in IL7Rα-dependent signal cascades. Consequently, IL7-dependent trophic, proliferative and differentiation-inducing responses of progenitor B cells are perturbed. Gfi1 directly regulates expression levels of IL7Rα and indirectly controls STAT5 signalling via expression of SOCS3. Thus, Gfi1 selectively specifies IL7-dependent development of B cells from CLP1 progenitors, providing clues to the transcriptional networks integrating cytokine signals and lymphoid differentiation

    Subcortical volumetric abnormalities in bipolar disorder.

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    Considerable uncertainty exists about the defining brain changes associated with bipolar disorder (BD). Understanding and quantifying the sources of uncertainty can help generate novel clinical hypotheses about etiology and assist in the development of biomarkers for indexing disease progression and prognosis. Here we were interested in quantifying case-control differences in intracranial volume (ICV) and each of eight subcortical brain measures: nucleus accumbens, amygdala, caudate, hippocampus, globus pallidus, putamen, thalamus, lateral ventricles. In a large study of 1710 BD patients and 2594 healthy controls, we found consistent volumetric reductions in BD patients for mean hippocampus (Cohen's d=-0.232; P=3.50 × 10(-7)) and thalamus (d=-0.148; P=4.27 × 10(-3)) and enlarged lateral ventricles (d=-0.260; P=3.93 × 10(-5)) in patients. No significant effect of age at illness onset was detected. Stratifying patients based on clinical subtype (BD type I or type II) revealed that BDI patients had significantly larger lateral ventricles and smaller hippocampus and amygdala than controls. However, when comparing BDI and BDII patients directly, we did not detect any significant differences in brain volume. This likely represents similar etiology between BD subtype classifications. Exploratory analyses revealed significantly larger thalamic volumes in patients taking lithium compared with patients not taking lithium. We detected no significant differences between BDII patients and controls in the largest such comparison to date. Findings in this study should be interpreted with caution and with careful consideration of the limitations inherent to meta-analyzed neuroimaging comparisons.Molecular Psychiatry advance online publication, 9 February 2016; doi:10.1038/mp.2015.227

    Subcortical volumes across the lifespan: Data from 18,605 healthy individuals aged 3-90 years

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    Age has a major effect on brain volume. However, the normative studies available are constrained by small sample sizes, restricted age coverage and significant methodological variability. These limitations introduce inconsistencies and may obscure or distort the lifespan trajectories of brain morphometry. In response, we capitalized on the resources of the Enhancing Neuroimaging Genetics through Meta-Analysis (ENIGMA) Consortium to examine age-related trajectories inferred from cross-sectional measures of the ventricles, the basal ganglia (caudate, putamen, pallidum, and nucleus accumbens), the thalamus, hippocampus and amygdala using magnetic resonance imaging data obtained from 18,605 individuals aged 3-90 years. All subcortical structure volumes were at their maximum value early in life. The volume of the basal ganglia showed a monotonic negative association with age thereafter; there was no significant association between age and the volumes of the thalamus, amygdala and the hippocampus (with some degree of decline in thalamus) until the sixth decade of life after which they also showed a steep negative association with age. The lateral ventricles showed continuous enlargement throughout the lifespan. Age was positively associated with inter-individual variability in the hippocampus and amygdala and the lateral ventricles. These results were robust to potential confounders and could be used to examine the functional significance of deviations from typical age-related morphometric patterns

    Global, regional, and national incidence, prevalence, and mortality of HIV, 1980–2017, and forecasts to 2030, for 195 countries and territories: a systematic analysis for the Global Burden of Diseases, Injuries, and Risk Factors Study 2017

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    Background Understanding the patterns of HIV/AIDS epidemics is crucial to tracking and monitoring the progress of prevention and control efforts in countries. We provide a comprehensive assessment of the levels and trends of HIV/AIDS incidence, prevalence, mortality, and coverage of antiretroviral therapy (ART) for 1980–2017 and forecast these estimates to 2030 for 195 countries and territories. Methods We determined a modelling strategy for each country on the basis of the availability and quality of data. For countries and territories with data from population-based seroprevalence surveys or antenatal care clinics, we estimated prevalence and incidence using an open-source version of the Estimation and Projection Package—a natural history model originally developed by the UNAIDS Reference Group on Estimates, Modelling, and Projections. For countries with cause-specific vital registration data, we corrected data for garbage coding (ie, deaths coded to an intermediate, immediate, or poorly defined cause) and HIV misclassification. We developed a process of cohort incidence bias adjustment to use information on survival and deaths recorded in vital registration to back-calculate HIV incidence. For countries without any representative data on HIV, we produced incidence estimates by pulling information from observed bias in the geographical region. We used a re-coded version of the Spectrum model (a cohort component model that uses rates of disease progression and HIV mortality on and off ART) to produce age-sex-specific incidence, prevalence, and mortality, and treatment coverage results for all countries, and forecast these measures to 2030 using Spectrum with inputs that were extended on the basis of past trends in treatment scale-up and new infections. Findings Global HIV mortality peaked in 2006 with 1·95 million deaths (95% uncertainty interval 1·87–2·04) and has since decreased to 0·95 million deaths (0·91–1·01) in 2017. New cases of HIV globally peaked in 1999 (3·16 million, 2·79–3·67) and since then have gradually decreased to 1·94 million (1·63–2·29) in 2017. These trends, along with ART scale-up, have globally resulted in increased prevalence, with 36·8 million (34·8–39·2) people living with HIV in 2017. Prevalence of HIV was highest in southern sub-Saharan Africa in 2017, and countries in the region had ART coverage ranging from 65·7% in Lesotho to 85·7% in eSwatini. Our forecasts showed that 54 countries will meet the UNAIDS target of 81% ART coverage by 2020 and 12 countries are on track to meet 90% ART coverage by 2030. Forecasted results estimate that few countries will meet the UNAIDS 2020 and 2030 mortality and incidence targets. Interpretation Despite progress in reducing HIV-related mortality over the past decade, slow decreases in incidence, combined with the current context of stagnated funding for related interventions, mean that many countries are not on track to reach the 2020 and 2030 global targets for reduction in incidence and mortality. With a growing population of people living with HIV, it will continue to be a major threat to public health for years to come. The pace of progress needs to be hastened by continuing to expand access to ART and increasing investments in proven HIV prevention initiatives that can be scaled up to have population-level impact
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