Automatic correction of hand pointing in stereoscopic depth

In order to examine whether stereoscopic depth information could drive fast automatic correction of hand pointing, an experiment was designed in a 3D visual environment in which participants were asked to point to a target at different stereoscopic depths as quickly and accurately as possible within a limited time window (≤300 ms). The experiment consisted of two tasks: "depthGO" in which participants were asked to point to the new target position if the target jumped, and "depthSTOP" in which participants were instructed to abort their ongoing movements after the target jumped. The depth jump was designed to occur in 20% of the trials in both tasks. Results showed that fast automatic correction of hand movements could be driven by stereoscopic depth to occur in as early as 190 ms.This work was supported by the Grants from the National Natural Science Foundation of China (60970062 and 61173116) and the Doctoral Fund of Ministry of Education of China (20110072110014)

Avoiding moving obstacles

To successfully move our hand to a target, we must consider how to get there without hitting surrounding objects. In a dynamic environment this involves being able to respond quickly when our relationship with surrounding objects changes. People adjust their hand movements with a latency of about 120 ms when the visually perceived position of their hand or of the target suddenly changes. It is not known whether people can react as quickly when the position of an obstacle changes. Here we show that quick responses of the hand to changes in obstacle position are possible, but that these responses are direct reactions to the motion in the surrounding. True adjustments to the changed position of the obstacle appeared at much longer latencies (about 200 ms). This is even so when the possible change is predictable. Apparently, our brain uses certain information exceptionally quickly for guiding our movements, at the expense of not always responding adequately. For reaching a target that changes position, one must at some time move in the same direction as the target did. For avoiding obstacles that change position, moving in the same direction as the obstacle is not always an adequate response, not only because it may be easier to avoid the obstacle by moving the other way, but also because one wants to hit the target after passing the obstacle. Perhaps subjects nevertheless quickly respond in the direction of motion because this helps avoid collisions when pressed for time. © 2008 Springer-Verlag

Nemo: a computational tool for analyzing nematode locomotion

The nematode Caenorhabditis elegans responds to an impressive range of chemical, mechanical and thermal stimuli and is extensively used to investigate the molecular mechanisms that mediate chemosensation, mechanotransduction and thermosensation. The main behavioral output of these responses is manifested as alterations in animal locomotion. Monitoring and examination of such alterations requires tools to capture and quantify features of nematode movement. In this paper, we introduce Nemo (nematode movement), a computationally efficient and robust two-dimensional object tracking algorithm for automated detection and analysis of C. elegans locomotion. This algorithm enables precise measurement and feature extraction of nematode movement components. In addition, we develop a Graphical User Interface designed to facilitate processing and interpretation of movement data. While, in this study, we focus on the simple sinusoidal locomotion of C. elegans, our approach can be readily adapted to handle complicated locomotory behaviour patterns by including additional movement characteristics and parameters subject to quantification. Our software tool offers the capacity to extract, analyze and measure nematode locomotion features by processing simple video files. By allowing precise and quantitative assessment of behavioral traits, this tool will assist the genetic dissection and elucidation of the molecular mechanisms underlying specific behavioral responses.Comment: 12 pages, 2 figures. accepted by BMC Neuroscience 2007, 8:8

Pelvic actinomycosis presenting with a large abscess and bowel stenosis with marked response to conservative treatment: a case report

Pelvic actinomycosis is a rare disease that can result in abscess formation, bowel obstruction, and other serious complications. Moreover, the correct diagnosis can seldom be established before radical surgery because the disease often mimics pelvic neoplasms. It has been recently recognized that pelvic actinomycosis is associated with long-term use of an intrauterine contraceptive device

The anti-inflammatory effects of dimethyl fumarate in astrocytes involve glutathione and haem oxygenase-1

DMF (dimethyl fumarate) exerts anti-inflammatory and pro-metabolic effects in a variety of cell types, and a formulation (BG-12) is being evaluated for monotherapy in multiple sclerosis patients. DMF modifies glutathione (GSH) levels that can induce expression of the anti-inflammatory protein HO-1 (haem oxygenase-1). In primary astrocytes and C6 glioma cells, BG-12 dose-dependently suppressed nitrite production induced by either LI [LPS (lipopolysaccharide) at 1 \u3bcg/ml plus IFN\u3b3 (interferon \u3b3) at 20 units/ml] or a mixture of pro-inflammatory cytokines, with greater efficacy in C6 cells. BG-12 reduced NOS2 (nitric oxide synthase 2) mRNA levels and activation of a NOS2 promoter, reduced nuclear levels of NF-\u3baB (nuclear factor \u3baB) p65 subunit and attenuated loss of I\u3baB\u3b1 (inhibitory \u3baB\u3b1) in both cell types, although with greater effects in astrocytes. In astrocytes, LI decreased mRNA levels for GSHr (GSH reductase) and GCL (c-glutamylcysteine synthetase), and slightly suppressed GSHs (GSH synthetase) mRNAs. Co-treatment with BG-12 prevented those decreased and increased levels above control values. In contrast, LI reduced GSHp (GSH peroxidase) and GCL in C6 cells, and BG-12 had no effect on those levels. BG-12 increased nuclear levels of Nrf2 (nuclear factor-erythroid 2 p45 subunit-related factor 2), an inducer of GSH-related enzymes, in astrocytes but not C6 cells. In astrocytes, GSH was decreased by BG-12 at 2 h and increased at 24 h. Prior depletion of GSH using buthionine-sulfoximine increased the ability of BG-12 to reduce nitrites. In astrocytes, BG-12 increased HO-1 mRNA levels and effects on nitrite levels were blocked by an HO-1 inhibitor. These results demonstrate that BG-12 suppresses inflammatory activation in astrocytes and C6 glioma cells, but with distinct mechanisms, different dependence on GSH and different effects on transcription factor activation

Has the 'Fast-Track' referral system affected the route of presentation and/or clinical outcomes in patients with colorectal cancer?

Background: The aim of this study is to determine whether the 'Fast-Track' referral system has changed the route by which patients present with colorectal cancer (CRC) and whether the route of presentation has any effect on clinical outcome. Methods: A retrospective cohort study of patients diagnosed with CRC under the care of two consultant colorectal surgeons between April 2006 and December 2012. The route by which patients presented was categorised as Fast-Track (FT), non-Fast-Track (non-FT) or acute. Outcome variables were operative intent, disease stage and 2- and 5-year survival. Results: A total of 558 patients were identified. One hundred ninety-seven patients (35.3%) were referred as FT, 108 (19.4%) presented acutely and 253 patients (45.3%) presented via other routes (non-FT). Over the study period, the route of presentation did not change significantly (P=0.135). There was no significant difference between FT and non-FT groups in terms of the proportion of patients undergoing potentially curative surgery (70.6 vs 74.3%, P=0.092) or with node-negative disease (48.2 vs 52.2%, P=0.796) nor was there any difference in 2-year or 5-year survival (74.1 vs 73.9%, P=0.837 and 52.3 vs 53.8%, P=0.889, respectively). Patients who presented acutely were less likely to undergo curative resection, had more advanced disease and had worse 2- and 5-year survival. Conclusions: The Fast-Track referral system has not affected the route by which patients present with CRC nor has it had any effect on clinical outcomes. Alternative strategies are required if the desired improvement in outcomes is to be achieved

Gender-related differences of renal mass supply and metabolic demand after living donor kidney transplantation

Kidney donation from female donors to male recipients has been reported to be associated with decreased allograft survival. Whether there was a gender-related inadequacy between donor nephron supply and recipient functional demand was investigated in this study. One hundred ninety-five living donor kidney transplant recipients that had neither ischemic injury, episode of rejection, nor any complication were included. Weights and heights of both donors and recipients were recorded to calculate body surface area, lean body weight, and body mass index. The donated kidney was weighed just after cold flush, and the recipient's serum creatinine (Scr) was measured on a daily basis post-operatively. When the recipient's Scr reached the baseline, a 24-h urine was collected for the amount of proteinuria (Upr), creatinine excretion (Ucr) and creatinine clearance (Ccr) calculation. The effect of donor and recipient gender was analysed by independent sample t -test. On average, male donors and recipients were heavier and taller than females. However, the mass of kidneys donated from men and women were not statistically different. The gender-related differences in post-transplant Scr and Ucr of recipients were associated with the differences in the parameters of metabolic demands of recipients rather than with the weight of implanted kidney (renal mass supply) or with pre-operative renal functions of donors (functional supply). The early graft function is not determined by donor gender. The effect of recipient gender on the graft function depends on the metabolic demands, which are higher in male recipients.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73185/1/j.1399-0012.2005.00459.x.pd

Mesoscopic organization reveals the constraints governing C. elegans nervous system

One of the biggest challenges in biology is to understand how activity at the cellular level of neurons, as a result of their mutual interactions, leads to the observed behavior of an organism responding to a variety of environmental stimuli. Investigating the intermediate or mesoscopic level of organization in the nervous system is a vital step towards understanding how the integration of micro-level dynamics results in macro-level functioning. In this paper, we have considered the somatic nervous system of the nematode Caenorhabditis elegans, for which the entire neuronal connectivity diagram is known. We focus on the organization of the system into modules, i.e., neuronal groups having relatively higher connection density compared to that of the overall network. We show that this mesoscopic feature cannot be explained exclusively in terms of considerations, such as optimizing for resource constraints (viz., total wiring cost) and communication efficiency (i.e., network path length). Comparison with other complex networks designed for efficient transport (of signals or resources) implies that neuronal networks form a distinct class. This suggests that the principal function of the network, viz., processing of sensory information resulting in appropriate motor response, may be playing a vital role in determining the connection topology. Using modular spectral analysis, we make explicit the intimate relation between function and structure in the nervous system. This is further brought out by identifying functionally critical neurons purely on the basis of patterns of intra- and inter-modular connections. Our study reveals how the design of the nervous system reflects several constraints, including its key functional role as a processor of information.Comment: Published version, Minor modifications, 16 pages, 9 figure

Emotional stress as a trigger of myasthenic crisis and concomitant takotsubo cardiomyopathy: a case report

<p>Abstract</p> <p>Introduction</p> <p>Myasthenia gravis is a neuromuscular junction post-synaptic autoimmune disorder. Myasthenic crisis is characterized by respiratory failure requiring mechanical ventilation. Takotsubo cardiomyopathy is a rare clinical syndrome defined as a profound but reversible left ventricular dysfunction in the absence of coronary artery disease.</p> <p>Case presentation</p> <p>We report a unique case of a 60-year-old Hispanic woman with myasthenia gravis who developed takotsubo cardiomyopathy and concomitant myasthenic crisis that appear to have been triggered by a stressful life event. On admission, she presented with severe mid-sternal chest pain and shortness of breath shortly after a personally significant stressful life event. A pertinent neurological examination showed bilateral facial weakness and right ptosis. The left ventriculogram showed apical ballooning with hyperdynamic proximal segments with sparing of the apex. Her troponin I level was elevated, while cardiac catheterization revealed no significant coronary artery disease. The findings were consistent with takotsubo cardiomyopathy. Shortly after cardiac catheterization, she developed bilateral ophthalmoparesis and significant bulbar and respiratory muscle weakness. Forced vital capacity values were persistently less than 1 L. The patient developed respiratory failure and required endotracheal intubation. After plasmapheresis and corticosteroid treatment, her clinical course improved with successful extubation. A normal left ventricle chamber size and a normal ejection fraction were noted by an echocardiogram repeated 10 months later.</p> <p>Conclusion</p> <p>This is the first reported case of the simultaneous triggering of both takotsubo cardiomyopathy and myasthenic crisis by the physiologic consequences of a state of severe emotional stress. We hypothesize that the mechanism underlying the rare association of takotsubo cardiomyopathy with myasthenic crisis involves excessive endogenous glucocorticoid release, a high-catecholamine state, or a combination of both. We advocate careful cardiac monitoring of myasthenia gravis patients during acute emotional or physical stress, as there is potential risk of developing takotsubo cardiomyopathy.</p

Two eyes in action

Do relative binocular disparities guide our movements in depth? In order to find out we asked subjects to move a 'cursor' to a target within a simulated horizontal plane at eye height. They did so by moving a computer mouse. We determined how quickly subjects responded to the target jumping in depth. We found that it took subjects about 200 ms to respond to changes in binocular disparity. Subjects responded just as quickly if the cursor was temporarily only visible to one eye near the time that the target jumped in depth, and less vigorously, though just as quickly, if the cursor jumped rather than the target, so the fastest binocular responses cannot be based directly on the relative retinal disparity between the target and the cursor. Subjects reacted faster to changes in the target's height in the visual field than to changes in binocular disparity, but did not react faster to changes in image size. These results suggest that binocular vision mainly improves people's everyday movements by giving them a better sense of the distances of relevant objects, rather than by relative retinal disparities being used to directly guide the movement. We propose that relative disparities only guide parts of very slow movements that require extreme precision. © Springer-Verlag 2005