A new approach to accurate measurement of uniaxial joint angles based on a combination of accelerometers and gyroscopes.

A new method of measuring joint angle using a combination of accelerometers and gyroscopes is presented. The method proposes a minimal sensor configuration with one sensor module mounted on each segment. The model is based on estimating the acceleration of the joint center of rotation by placing a pair of virtual sensors on the adjacent segments at the center of rotation. In the proposed technique, joint angles are found without the need for integration, so absolute angles can be obtained which are free from any source of drift. The model considers anatomical aspects and is personalized for each subject prior to each measurement. The method was validated by measuring knee flexion-extension angles of eight subjects, walking at three different speeds, and comparing the results with a reference motion measurement system. The results are very close to those of the reference system presenting very small errors (rms = 1.3, mean = 0.2, SD = 1.1 deg) and excellent correlation coefficients (0.997). The algorithm is able to provide joint angles in real-time, and ready for use in gait analysis. Technically, the system is portable, easily mountable, and can be used for long term monitoring without hindrance to natural activities.

Experimental manipulation of colony genetic diversity had no effect on short-term task efficiency in the Argentine ant Linepithema humile

Genetic diversity might increase the performance of social groups by improving task efficiency or disease resistance, but direct experimental tests of these hypotheses are rare. We manipulated the level of genetic diversity in colonies of the Argentine ant Linepithema humile, and then recorded the short-term task efficiency of these experimental colonies. The efficiency of low and high genetic diversity colonies did not differ significantly for any of the following tasks: exploring a new territory, foraging, moving to a new nest site, or removing corpses. The tests were powerful enough to detect large effects, but may have failed to detect small differences. Indeed, observed effect sizes were generally small, except for the time to create a trail during nest emigration. In addition, genetic diversity had no statistically significant impact on the number of workers, males and females produced by the colony, but these tests had low power. Higher genetic diversity also did not result in lower variance in task efficiency and productivity. In contrast to genetic diversity, colony size was positively correlated with the efficiency at performing most tasks and with colony productivity. Altogether, these results suggest that genetic diversity does not strongly improve short-term task efficiency in L. humile, but that worker number is a key factor determining the success of this invasive species.

Higher CNS penetration-effectiveness of long-term combination antiretroviral therapy is associated with better HIV-1 viral suppression in cerebrospinal fluid.

OBJECTIVES: To determine HIV-1 RNA in cerebrospinal fluid (CSF) of successfully treated patients and to evaluate if combination antiretroviral treatments with higher central nervous system penetration-effectiveness (CPE) achieve better CSF viral suppression. METHODS: Viral loads (VLs) and drug concentrations of lopinavir, atazanavir, and efavirenz were measured in plasma and CSF. The CPE was calculated using 2 different methods. RESULTS: The authors analyzed 87 CSF samples of 60 patients. In 4 CSF samples, HIV-1 RNA was detectable with 43-82 copies per milliliter. Median CPE in patients with detectable CSF VL was significantly lower compared with individuals with undetectable VL: CPE of 1.0 (range, 1.0-1.5) versus 2.3 (range, 1.0-3.5) using the method of 2008 (P = 0.011) and CPE of 6 (range, 6-8) versus 8 (range, 5-12) using the method of 2010 (P = 0.022). The extrapolated CSF trough levels for atazanavir (n = 12) were clearly above the 50% inhibitory concentration (IC50) in only 25% of samples; both patients on atazanavir/ritonavir with detectable CSF HIV-1 RNA had trough levels in the range of the presumed IC50. The extrapolated CSF trough level for lopinavir (n = 42) and efavirenz (n = 18) were above the IC50 in 98% and 78%, respectively, of samples, including the patients with detectable CSF HIV-1 RNA. CONCLUSIONS: This study suggests that treatment regimens with high intracerebral efficacy reflected by a high CPE score are essential to achieve CSF HIV-1 RNA suppression. The CPE score including all drug components was a better predictor for treatment failure in the CSF than the sole concentrations of protease inhibitor or nonnucleoside reverse transcriptase inhibitor in plasma or CSF.

Short-term moderate hypocapnia augments detection of optimal cerebral perfusion pressure.

An autoregulation-oriented strategy has been proposed to guide neurocritical therapy toward the optimal cerebral perfusion pressure (CPPOPT). The influence of ventilation changes is, however, unclear. We sought to find out whether short-term moderate hypocapnia (HC) shifts the CPPOPT or affects its detection. Thirty patients with traumatic brain injury (TBI), who required sedation and mechanical ventilation, were studied during 20 min of normocapnia (5.1±0.4 kPa) and 30 min of moderate HC (4.4±3.0 kPa). Monitoring included bilateral transcranial Doppler of the middle cerebral arteries (MCA), invasive arterial blood pressure (ABP), and intracranial pressure (ICP). Mx -autoregulatory index provided a measure for the CPP responsiveness of MCA flow velocity. CPPOPT was assessed as the CPP at which autoregulation (Mx) was working with the maximal efficiency. During normocapnia, CPPOPT (left: 80.65±6.18; right: 79.11±5.84 mm Hg) was detectable in 12 of 30 patients. Moderate HC did not shift this CPPOPT but enabled its detection in another 17 patients (CPPOPT left: 83.94±14.82; right: 85.28±14.73 mm Hg). The detection of CPPOPT was achieved via significantly improved Mx-autoregulatory index and an increase of CPP mean. It appeared that short-term moderate HC augmented the detection of an optimum CPP, and may therefore usefully support CPP-guided therapy in patients with TBI.

Multi-modal assessment of long-term erythropoietin treatment after neonatal hypoxic-ischemic injury in rat brain.

Erythropoietin (EPO) has been recognized as a neuroprotective agent. In animal models of neonatal brain injury, exogenous EPO has been shown to reduce lesion size, improve structure and function. Experimental studies have focused on short course treatment after injury. Timing, dose and length of treatment in preterm brain damage remain to be defined. We have evaluated the effects of high dose and long-term EPO treatment in hypoxic-ischemic (HI) injury in 3 days old (P3) rat pups using histopathology, magnetic resonance imaging (MRI) and spectroscopy (MRS) as well as functional assessment with somatosensory-evoked potentials (SEP). After HI, rat pups were assessed by MRI for initial damage and were randomized to receive EPO or vehicle. At the end of treatment period (P25) the size of resulting cortical damage and white matter (WM) microstructure integrity were assessed by MRI and cortical metabolism by MRS. Whisker elicited SEP were recorded to evaluate somatosensory function. Brains were collected for neuropathological assessment. The EPO treated animals did not show significant decrease of the HI induced cortical loss at P25. WM microstructure measured by diffusion tensor imaging was improved and SEP response in the injured cortex was recovered in the EPO treated animals compared to vehicle treated animals. In addition, the metabolic profile was less altered in the EPO group. Long-term treatment with high dose EPO after HI injury in the very immature rat brain induced recovery of WM microstructure and connectivity as well as somatosensory cortical function despite no effects on volume of cortical damage. This indicates that long-term high-dose EPO induces recovery of structural and functional connectivity despite persisting gross anatomical cortical alteration resulting from HI.

Nestling barn owls assess short-term variation in the amount of vocally competing siblings.

Assessing the amount of rivals is crucial to optimally adjust investment into a contest. If laboratory animals show numerical abilities, little is known about the ecological implications particularly in young animals. The two to nine barn owl (Tyto alba) siblings vocally compete for priority of access to food resources before parents actually deliver them. In dyads, the individual that vocalizes at the highest rate in the absence of parents deters its siblings from competing for next delivered prey. We tested the novel hypothesis that to optimally adjust vocal investment, barn owl nestlings assess how many of their siblings are currently competing. To singleton owlets, we broadcasted a fixed global number of calls emitted by one, two or four pre-recorded unfamiliar nestlings. We could thus distinguish the independent effect on singletons' vocal behavior of the global number of calls produced by a brood from the number of competitors that produced these calls. Overall, nestlings retreated more from vocal contest when facing more competitors. However, in front of one highly motivated competitor, nestlings refrained from vocalizing to a larger extent than when competing against more but less motivated individuals. Therefore, young animals assess variation in the number of currently competing siblings based on individual-specific vocal cues.

One minute of grief: Emotional processing in short-term dynamic psychotherapy for adjustment disorder.

OBJECTIVE: Depth of emotional processing has shown to be related to outcome across approaches to psychotherapy. Moreover, a specific emotional sequence has been postulated and tested in several studies on experiential psychotherapy (Pascual-Leone & Greenberg, 2007). This process-outcome study aims at reproducing the sequential model of emotional processing in psychodynamic psychotherapy for adjustment disorder and linking these variables with ultimate therapeutic outcome. METHOD: In this study, 32 patients underwent short-term dynamic psychotherapy. On the basis of reliable clinical change statistics, a subgroup (n = 16) presented with good outcome and another subgroup (n = 16) had a poor outcome in the end of treatment. The strongest alliance session of each case was rated using the observer-rated system Classification of Affective Meaning States. Reliability coefficients for the measure were excellent (κ = .82). RESULTS: Using 1 min as the fine-grained unit of analysis, results showed that the experience of fundamentally adaptive grief was more common in the in-session process of patients with good outcome, compared with those with poor outcomes (χ2 = 6.56, p = .01, d = 1.23). This variable alone predicted 19% of the change in depressive symptoms as measured by the Beck Depression Inventory at the end of treatment. Moreover, sequences of the original model were supported and related to outcome. CONCLUSIONS: These results are discussed within the framework of the sequential model of emotional processing and its possible relevance for psychodynamic psychotherapy. (PsycINFO Database Record (c) 2015 APA, all rights reserved).

Short-term and sustained renal effects of angiotensin II receptor blockade in healthy subjects.

We investigated the short-term and sustained hormonal and renal effects of angiotensin II (Ang II) receptor blockade in normotensive healthy volunteers. Twenty-four subjects maintained on a fixed sodium diet were randomized to receive for 8 days a placebo or 10 or 50 mg doses of the Ang II antagonist irbesartan (SR 47436, BMS 186295) according to a double-blind, parallel group design. Plasma renin activity, plasma immunoreactive Ang II and aldosterone levels, blood pressure, renal hemodynamics, and urinary electrolyte excretion were measured for 8 hours after the first and eighth administration of each dose of irbesartan or placebo. Ang II receptor blockade with irbesartan induced a dose-dependent compensatory increase in plasma renin activity and plasma angiotensin levels and a significant decrease in plasma aldosterone levels. The compensatory rise in plasma renin activity and Ang II levels was more pronounced on day 8, reflecting a long duration of the blocking effect of irbesartan. Irbesartan induced small changes in blood pressure and did not significantly modify renal blood flow and glomerular filtration rate. However, a significant decrease in filtration fraction was observed during receptor blockade on days 1 and 8. The tubular effects of irbesartan were characterized by a dose-dependent increase in sodium and chloride excretions. Interestingly, the cumulative natriuretic response to Ang II receptor blockade was similar on days 1 and 8, suggesting that in these subjects, renal Ang II receptors are not blocked over 24 hours during repeated administration even though this antagonist has a long duration of action (t1/2 of 15 to 17 hours).(ABSTRACT TRUNCATED AT 250 WORDS)

Short-term overexpression of a constitutively active form of AMP-activated protein kinase in the liver leads to mild hypoglycemia and fatty liver.

AMP-activated protein kinase (AMPK) is a major therapeutic target for the treatment of diabetes. We investigated the effect of a short-term overexpression of AMPK specifically in the liver by adenovirus-mediated transfer of a gene encoding a constitutively active form of AMPKalpha2 (AMPKalpha2-CA). Hepatic AMPKalpha2-CA expression significantly decreased blood glucose levels and gluconeogenic gene expression. Hepatic expression of AMPKalpha2-CA in streptozotocin-induced and ob/ob diabetic mice abolished hyperglycemia and decreased gluconeogenic gene expression. In normal mouse liver, AMPKalpha2-CA considerably decreased the refeeding-induced transcriptional activation of genes encoding proteins involved in glycolysis and lipogenesis and their upstream regulators, SREBP-1 (sterol regulatory element-binding protein-1) and ChREBP (carbohydrate response element-binding protein). This resulted in decreases in hepatic glycogen synthesis and circulating lipid levels. Surprisingly, despite the inhibition of hepatic lipogenesis, expression of AMPKalpha2-CA led to fatty liver due to the accumulation of lipids released from adipose tissue. The relative scarcity of glucose due to AMPKalpha2-CA expression led to an increase in hepatic fatty acid oxidation and ketone bodies production as an alternative source of energy for peripheral tissues. Thus, short-term AMPK activation in the liver reduces blood glucose levels and results in a switch from glucose to fatty acid utilization to supply energy needs.

Oligoanalgesia in the emergency department: short-term beneficial effects of an education program on acute pain.

STUDY OBJECTIVE: Acute pain is the most frequent complaint in emergency department (ED) admissions, but its management is often neglected, placing patients at risk of oligoanalgesia. We evaluate the effect of the implementation of guidelines for pain management in ED patients with pain at admission or anytime during their stay in our ED. METHODS: This prospective pre-post intervention cohort study included data collection both before and after guideline implementation. Consecutive adult patients admitted with acute pain from any cause or with pain at any time after admission were enrolled. The quality of pain management was evaluated according to information in the ED medical records by using a standardized collection form, and its impact on patients was recorded with a questionnaire at discharge. RESULTS: Two hundred forty-nine and 192 patients were included during pre- and postintervention periods. Pain was documented in 61% and 76% of nurse and physician notes, respectively, versus 78% and 85% after the intervention (difference 17%/9%; 95% confidence interval [CI] 8% to 26%/2% to 17%, respectively). Administration of analgesia increased from 40% to 63% (difference 23%; 95% CI 13% to 32%) and of morphine from 10% to 27% (difference 17%; 95% CI 10% to 24%). Mean doses of intravenous morphine increased from 2.4 mg (95% CI 1.9 to 2.9 mg) to 4.6 mg (95% CI 3.9 to 5.3 mg); administration of nonsteroidal antiinflammatory drugs and acetaminophen increased as well. There was a greater reduction of visual analogue scale score after intervention: 2.1 cm (95% CI 1.7 to 2.4 cm) versus 2.9 cm (95% CI 2.5 to 3.3 cm), which was associated with improved patient satisfaction. CONCLUSION: Education program and guidelines implementation for pain management lead to improved pain management, analgesia, and patient satisfaction in the ED.

How do the different components of episodic memory develop? Role of executive functions and short-term feature-binding abilities.

This study investigated the development of all 3 components of episodic memory (EM), as defined by Tulving, namely, core factual content, spatial context, and temporal context. To this end, a novel, ecologically valid test was administered to 109 participants aged 4-16 years. Results showed that each EM component develops at a different rate. Ability to memorize factual content emerges early, whereas context retrieval abilities continue to improve until adolescence, due to persistent encoding difficulties (isolated by comparing results on free recall and recognition tasks). Exploration of links with other cognitive functions revealed that short-term feature-binding abilities contribute to all EM components, and executive functions to temporal and spatial context, although ability to memorize temporal context is predicted mainly by age.