494 research outputs found
Embodied Artificial Intelligence through Distributed Adaptive Control: An Integrated Framework
In this paper, we argue that the future of Artificial Intelligence research
resides in two keywords: integration and embodiment. We support this claim by
analyzing the recent advances of the field. Regarding integration, we note that
the most impactful recent contributions have been made possible through the
integration of recent Machine Learning methods (based in particular on Deep
Learning and Recurrent Neural Networks) with more traditional ones (e.g.
Monte-Carlo tree search, goal babbling exploration or addressable memory
systems). Regarding embodiment, we note that the traditional benchmark tasks
(e.g. visual classification or board games) are becoming obsolete as
state-of-the-art learning algorithms approach or even surpass human performance
in most of them, having recently encouraged the development of first-person 3D
game platforms embedding realistic physics. Building upon this analysis, we
first propose an embodied cognitive architecture integrating heterogenous
sub-fields of Artificial Intelligence into a unified framework. We demonstrate
the utility of our approach by showing how major contributions of the field can
be expressed within the proposed framework. We then claim that benchmarking
environments need to reproduce ecologically-valid conditions for bootstrapping
the acquisition of increasingly complex cognitive skills through the concept of
a cognitive arms race between embodied agents.Comment: Updated version of the paper accepted to the ICDL-Epirob 2017
conference (Lisbon, Portugal
Acute hypoglycemia impairs executive cognitive function in adults with and without type 1 diabetes
OBJECTIVE: Acute hypoglycemia impairs cognitive function in several domains. Executive cognitive function governs organization of thoughts, prioritization of tasks, and time management. This study examined the effect of acute hypoglycemia on executive function in adults with and without diabetes. RESEARCH DESIGN AND METHODS: Thirty-two adults with and without type 1 diabetes with no vascular complications or impaired awareness of hypoglycemia were studied. Two hyperinsulinemic glucose clamps were performed at least 2 weeks apart in a single-blind, counterbalanced order, maintaining blood glucose at 4.5 mmol/L (euglycemia) or 2.5 mmol/L (hypoglycemia). Executive functions were assessed with a validated test suite (Delis-Kaplan Executive Function). A general linear model (repeated-measures ANOVA) was used. Glycemic condition (euglycemia or hypoglycemia) was the within-participant factor. Between-participant factors were order of session (euglycemia-hypoglycemia or hypoglycemia-euglycemia), test battery used, and diabetes status (with or without diabetes). RESULTS: Compared with euglycemia, executive functions (with one exception) were significantly impaired during hypoglycemia; lower test scores were recorded with more time required for completion. Large Cohen d values (>0.8) suggest that hypoglycemia induces decrements in aspects of executive function with large effect sizes. In some tests, the performance of participants with diabetes was more impaired than those without diabetes. CONCLUSIONS: Executive cognitive function, which is necessary to carry out many everyday activities, is impaired during hypoglycemia in adults with and without type 1 diabetes. This important aspect of cognition has not received previous systematic study with respect to hypoglycemia. The effect size is large in terms of both accuracy and speed
IMPELLER MANUFACTURING â UNDERSTANDING THE METHODS & THEIR IMPACT ON PERFORMANCE
TutorialThis tutorial provides an overview of the manufacturing processes used to build centrifugal compressor impellers and how the various processes can impact the performance of these critically important components. Comments are offered on how client demand for higher performance drove OEMs to more advanced manufacturing methods. A brief overview is also provided on the dimensions and features that are critical to achieving the expected impeller performance. Finally, the tutorial provides a detailed discussion on the various techniques being used to fabricate impellers today and offers some insights into possible methods that will be used in the future
Cardiometabolic effects of a novel SIRT1 activator, SRT2104, in people with type 2 diabetes mellitus
Background: The cardiometabolic effects of SRT2104,
a novel SIRT1 activator, were investigated in people with
type 2 diabetes mellitus (T2DM).
Methods: Fifteen adults with T2DM underwent a
randomised, double-blind, placebo-controlled cross-over
trial and received 28 days of oral SRT2104 (2.0 g/day)
or placebo. Forearm vasodilatation (measured during
intrabrachial bradykinin, acetylcholine and sodium
nitroprusside infusions) as well as markers of glycaemic
control, lipid profile, plasma fibrinolytic factors, and
markers of platelet-monocyte activation, were measured
at baseline and at the end of each treatment period.
Results: Lipid profile and platelet-monocyte
activation were similar in both treatment arms
(p>0.05 for all). Forearm vasodilatation was
similar on exposure to acetylcholine and sodium
nitroprusside (p>0.05,respectively). Bradykinin-induced
vasodilatation was less during treatment with SRT2104
versus placebo (7.753vs9.044, respectively, mean
difference=â1.291,(95% CI â2.296 to â0.285, p=0.012)).
Estimated net plasminogen activator inhibitor type 1
antigen release was reduced in the SRT2104 arm versus
placebo (mean difference=â38.89 ng/100mL tissue/
min, (95%CI â75.47, to â2.305, p=0.038)). There were
no differences in other plasma fibrinolytic factors (p>0.05
for all). After 28 days, SRT2104 exposure was associated
with weight reduction (â0.93 kg (95% CI â1.72 to â0.15),
p=0.0236), and a rise in glycated haemoglobin (5 mmol/
mol or 0.48% (0.26 to 0.70), p=0.004)
Conclusions: In people with T2DM, SRT2104 had
inconsistent, predominantly neutral effects on endothelial
and fibrinolytic function, and no discernible effect on lipids
or platelet function. In contrast, weight loss was induced
along with deterioration in glycaemic control, suggestive of
potentially important metabolic effects.
Clinical trial registration: NCT01031108; Results
Effects of Acute Insulin-Induced Hypoglycemia on Indices of Inflammation Putative mechanism for aggravating vascular disease in diabetes
OBJECTIVE: To examine the effects of acute insulin-induced hypoglycemia on inflammation, endothelial dysfunction, and platelet activation in adults with and without type 1 diabetes. RESEARCH DESIGN AND METHODS: We studied 16 nondiabetic adults and 16 subjects with type 1 diabetes during euglycemia (blood glucose 4.5 mmol/l) and hypoglycemia (blood glucose 2.5 mmol/l). Markers of inflammation, thrombosis, and endothelial dysfunction (soluble P-selectin, interleukin-6, von Willebrand factor [vWF], tissue plasminogen activator [tPA], high-sensitivity C-reactive protein [hsCRP], and soluble CD40 ligand [sCD40L]) were measured; platelet-monocyte aggregation and CD40 expression on monocytes were determined using flow cytometry. RESULTS: In nondiabetic participants, platelet activation occurred after hypoglycemia, with increments in platelet-monocyte aggregation and P-selectin (P †0.02). Inflammation was triggered with CD40 expression increasing maximally at 24 h (3.13 ± 2.3% vs. 2.06 ± 1.0%) after hypoglycemia (P = 0.009). Both sCD40L and hsCRP (P = 0.02) increased with a nonsignificant rise in vWF and tPA, indicating a possible endothelial effect. A reduction in sCD40L, tPA, and P-selectin occurred during euglycemia (P = 0.03, P †0.006, and P = 0.006, respectively). In type 1 diabetes, both CD40 expression (5.54 ± 4.4% vs. 3.65 ± 1.8%; P = 0.006) and plasma sCD40L concentrations increased during hypoglycemia (peak 3.41 ± 3.2 vs. 2.85 ± 2.8 ng/ml; P = 0.03). Platelet-monocyte aggregation also increased significantly at 24 h after hypoglycemia (P = 0.03). A decline in vWF and P-selectin occurred during euglycemia (P †0.04). CONCLUSIONS: Acute hypoglycemia may provoke upregulation and release of vasoactive substances in adults with and without type 1 diabetes. This may be a putative mechanism for hypoglycemia-induced vascular injury
Distribution and characteristics of newly-defined subgroups of type 2 diabetes in randomised clinical trials : Post hoc cluster assignment analysis of over 12,000 study participants
Publisher Copyright: © 2022Aims: Newly-defined subgroups of type 2 diabetes mellitus (T2DM) have been reported from real-world cohorts but not in detail from randomised clinical trials (RCTs). Methods: T2DM participants, uncontrolled on different pre-study therapies (n = 12.738; 82 % Caucasian; 44 % with diabetes duration > 10 years) from 14 RCTs, were assigned to new subgroups according to age at onset of diabetes, HbA1c, BMI, and fasting C-peptide using the nearest centroid approach. Subgroup distribution, characteristics and influencing factors were analysed. Results: In both, pooled and single RCTs, âmild-obesity related diabetesâ predominated (45 %) with mean BMI of 35 kg/m2. âSevere insulin-resistant diabetesâ was found least often (4.6 %) and prevalence of âmild age-related diabetesâ (23.9 %) was mainly influenced by age at onset of diabetes and age cut-offs. Subgroup characteristics were widely comparable to those from real-world cohorts, but all subgroups showed higher frequencies of diabetes-related complications which were associated with longer diabetes duration. A high proportion of âsevere insulin-deficient diabetesâ (25.4 %) was identified with poor pre-study glycaemic control. Conclusions: Classification of RCT participants into newly-defined diabetes subgroups revealed the existence of a heterogeneous population of T2DM. For future RCTs, subgroup-based randomisation of T2DM will better define the target population and relevance of the outcomes by avoiding clinical heterogeneity.Peer reviewe
Effect of hypoglycaemia on measures of myocardial blood flow and myocardial injury in adults with and without type 1 diabetes:A prospective, randomised, open-label, blinded endpoint, cross-over study
Abstract Aims This study examined the effect of experimentallyâinduced hypoglycaemia on measures of myocardial blood flow and myocardial injury in adults with, and without, type 1 diabetes. Methods In a prospective, randomised, openâlabel, blinded, endpoint crossâover study, 17 young adults with type 1 diabetes with no cardiovascular risk factors, and 10 healthy nonâdiabetic volunteers, underwent hyperinsulinaemicâeuglycaemic (blood glucose 4.5â5.5 mmol/L) and hypoglycaemic (2.2â2.5 mmol/L) clamps. Myocardial blood flow was assessed using transthoracic echocardiography Doppler coronary flow reserve (CFR) and myocardial injury using plasma highâsensitivity cardiac troponin I (hsâcTnI) concentration. Results During hypoglycaemia, coronary flow reserve trended nonâsignificantly lower in those with type 1 diabetes than in the nonâdiabetic participants (3.54 ± 0.47 vs. 3.89 ± 0.89). A generalised linear mixedâmodel analysis examined diabetes status and euglycaemia or hypoglycaemia as factors affecting CFR. No statistically significant difference in CFR was observed for diabetes status (p = .23) or between euglycaemia and hypoglycaemia (p = .31). No changes in hsâcTnI occurred during hypoglycaemia or in the recovery period (p = .86). Conclusions A small change in CFR was not statistically significant in this study, implying hypoglycaemia may require more than coronary vasomotor dysfunction to cause harm. Further larger studies are required to investigate this putative problem
The impact of diabetes on cognitive decline:potential vascular, metabolic, and psychosocial risk factors
Older people with type 2 diabetes are at increased risk of developing cognitive impairment, for which several potential risk factors have been proposed. The present article reviews evidence in people with type 2 diabetes for associations of cognitive impairment with a range of vascular, metabolic, and psychosocial risk factors, many of which have a higher prevalence in people with type 2 diabetes than in non-diabetic adults of a similar age. Definitive research studies in this field are few in number. The risk factors may be involved in causal pathways or may act as useful markers of cerebrovascular damage (or both), and for which relatively consistent evidence is available, include poor glycemic control, hypoglycemia, microvascular disease, inflammation, and depression. For macrovascular disease, the strength of the association with cognitive impairment appears to depend on which vascular system has been examined. A role for pre-morbid ability in young adulthood as influencing the risk of both diabetes and cognitive impairment has also been suggested. The importance of considering inter-relationships between risk factors when investigating their potential contribution to cognitive impairment in future investigations is discussed. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13195-015-0130-5) contains supplementary material, which is available to authorized users
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