Motion pattern analysis of gait in horseback riding by means of Principal Component Analysis

As a consequence of the three interacting systems of horse, saddle, and rider, horseback riding is a very complex movement that is difficult to characterize by a limited number of biomechanical parameters or characteristic curves. Principal Component Analysis (PCA) is a technique for reducing multidimensional datasets to a minimal (i.e., optimally economic) set of dimensions. To apply PCA to horseback riding data, a "pattern vector" composed of the horizontal velocities of a set of body markers was determined. PCA was used to identify the major dynamic constituents of the three natural gaits of the horse: walk, trot, and canter. It was found that the trot is characterized by only one major component accounting for about 90% of the data's variance. Based on a study involving 13 horses with the same rider, additional phase plane analyses of the order parameter dynamics revealed a potential influence of the saddle type on movement coordination for the majority of horses.

[Thoracic actinomycosis: diagnostic pitfalls and therapeutic considerations]

We report two patients admitted to our hospital suspected to suffer from cancer in the lung or mediastinum, respectively. Both patients had a diagnosis of thoracic actinomycosis. A 76 year old man revealed pulmonary and endobronchial actinomycosis associated with broncholithiasis. Diagnosis was achieved by bronchoscopy. Therapy with ampicillin/sulbactam was successful. A 36 year old patient presented with bilateral pleural effusions, extended pericardial, mediastinal and pulmonary actinomycosis with pericarditis constrictiva and superior vena cava syndrome. Diagnosis was finally made by cardiac surgery with therapeutic pericardectomy. Prolonged therapy with ampicillin/sulbactam was administered with satisfactory result. Here we discuss the importance to include actinomycosis in the differential diagnosis of pulmonary affections and mediastinal masses in order to avoid diagnostic errors and to limit invasive procedures to the necessary amount. We illustrate the need of an individualized treatment approach.

Detection of adverse events in a Scottish hospital using a consensus-based methodology

OBJECTIVE

To determine, using a consensus based methodology, the rate and nature of adverse events (AEs) among patients admitted to acute medicine, acute surgery and obstetrics in a large teaching hospital in Scotland.

METHODS

Retrospective case-note review of 450 medical, nursing and medication records to identify and classify adverse events. For 354 patients whose length of stay was greater than 24 hours, the overall adverse event rate was 7.9% which ranged from 0% in obstetrics, 7.2% in acute medicine to 13% in acute surgery. Among all AEs, 43% were deemed preventable by a consensus group and 59% of the AEs contributed to a proportion of the patients' hospital stay or led to hospital readmission. Whilst nurse identification of adverse events was highly specific (94%), its sensitivity was poor (43%). Only 10% of the identified AEs were identified by the hospital's voluntary reporting system for adverse events. The estimated additional cost of adverse events in terms of bed days was ł69,189 which if extrapolated Scotland-wide could cost ł297 million per annum.

CONCLUSIONS

This study supports the need to continue the traditional retrospective record review to identify adverse events. The current hospital-based reporting of adverse events does not provide a complete measure of adverse events and needs to be complemented by other measures.

[Bullectomy as emergency intervention in a mechanically ventilated patient with refractory type II respiratory failure due to chronic obstructive lung disease (COPD)]

A 44-year-old female patient presented with an extensive exacerbation of severe chronic obstructive lung disease (COPD) and bullous emphysema. Because of a severe type II respiratory failure, the patient was intubated and mechanically ventilated. Respiratory failure was refractory despite appropriate ventilation regimes and pCO2 values ranged from 110 mm Hg to 180 mm Hg. Chest radiography revealed hyperinflation of two giant bullae with mediastinal shifting to the left lung. We describe a successful rescue bullectomy.

Reliability and performance-dependent variations of muscle function variables during isometric knee extension

Despite the common use of standardised methods analysing neuromuscular function during knee extension, there is a lack of test-retest reliability studies. Furthermore, for most of the investigated variables it is unknown which changes of values indicate an enhancement of performance. The aim of the present study was to investigate performance-dependent variations of muscle functions during isometric contraction of knee extensors and to examine test-retest reliability of their measurement methods. For test-retest reliability sports students completed three test sessions. Highly skilled athletes, sports students and untrained subjects were investigated to determine the performance-dependent variations. The following variables were analysed: maximal voluntary contraction (MVC), voluntary activation (VA), absolute muscle reaction time (AR), muscle endurance (ME), and EMG frequency analysis (MF) of m. vastus lateralis (VL), m. vastus medialis (VM) and m. rectus femoris (RF). RESULTS TEST-RETEST-RELIABILITY: A high reliability between session 1 vs. 2 and session 2 vs. 3 was shown for MVC (ICC=0.92 and .97), VA (0.92/0.95) and ME (0.87/0.95). ICC in AR (0.23) was low between the first and second session and moderate between the second and third session (0.74). MF of VL, VM and RF showed low ICC between sessions. PERFORMANCE DEPENDENT VARIATIONS: Significant differences in nearly all variables (except VA) were found between trained (athletes and sports students) and untrained subjects.

Birth plans and health facility based delivery in rural Uganda

OBJECTIVES

To evaluate whether the completion of birth plans is associated with delivery in a health facility and the perceptual causes of birth plan completion and health facility based delivery were explored according to a well-tested health behaviour theory.

DESIGN

A community survey.

SETTING

Rakai and Luwero districts.

SUBJECTS

A total of 415 (202 in Rakai and 213 in Luwero district) respondents were randomly selected and interviewed using a mixed survey questionnaire composed of open and close-ended questions.

MAIN OUTCOME MEASURES

Health facility based delivery.

RESULTS

The results demonstrate a statistically significant relationship between the completion of birth plans and delivery in a health facility (OR = 1.86, 95% CI =1.1, 3.1). The fear of consequences of delivering at home was found to be an important driving force in promoting the completion of birth plans, thereby indirectly influencing the likelihood of delivery in a health facility.

CONCLUSION

Given the empirical evidence presented here, this study suggests that birth plans are an important tool in improving the rate of health facility based deliveries and thus essential in the fight against maternal mortality in Uganda. It is further recommended that campaigns market the use of birth plans as a way to reduce uncertainty and manage fear and the unknown about pregnancy.

Sexual imprinting on a novel blue ornament in zebra finches

Abstract

Sexual imprinting plays an important role for the development of mate preferences in birds. We tested whether male and female zebra finches Taeniopygia guttata sexually imprinted on an evolutionary novel trait, a blue feather on the forehead in parents. Additionally, we tested whether males and females would transfer a learned preference for the blue feather to a preference for blue leg bands, and whether a potential mate with two novel blue traits can amplify its attractiveness. Offspring were raised by parents in four different imprinting groups: (1) both parents unadorned; (2) the mother adorned only; (3) the father adorned only; (4) both parents adorned with the blue feather. After young reached maturity, we tested their mate preference for adorned and unadorned conspecifics of the opposite sex in binary choice tests. Females of the father adorned imprinting group sexually imprinted on the blue feather, and females reared by adorned parents showed a tendency to prefer adorned males. None of the males sexually imprinted on the blue feather. Our study replicates the results of a previous study on sexual imprinting on a red feather in zebra finches. We, therefore, propose a sex difference in the learning process of sexual imprinting. Females sexually imprinted on the blue feather did not transfer the learned preference to males with blue leg bands, and two novel blue traits could not amplify the attractiveness in males and females for the opposite sex. Our study emphasizes the role of sexual imprinting for the cultural evolution in mate preferences in zebra finches.

Inverse blood pressure rhythm of transgenic hypertensive TGR(mREN2)27 rats: role of norepinephrine and expression of tyrosine-hydroxylase and reuptake1-transporter

Transgenic hypertensive TGR(mREN2)27 rats (TGR) exhibit an inverse circadian blood pressure profile from the age of 8 to 9 wk. To investigate the role of the sympathetic nervous system in this pathological blood pressure rhythm, we examined postnatal changes in catecholamine concentration, expression of tyrosine-hydroxylase (TH), and norepinephrine (NE) reuptake(1)-transporter (NET) in the heart, adrenal glands, and hypothalamus of non-hypertensive TGR at an age of 4 wk and of hypertensive TGR at an age of 10 wk and compared these to normotensive, age-matched Sprague-Dawley rats. Rats were kept under synchronized light:dark (LD) conditions of 12:12 h. Blood pressure and heart rate were monitored by radiotelemetry, catecholamines by high performance liquid chromatography, expression of TH and NET (mRNA) by RT-PCR, and TH protein by Western blots. In normotensive 4 wk-old Sprague-Dawley rats, cardiac NE concentrations were circadian phase-dependent with lower values at ZT12.5, with no differences observed, in 10-wk-old animals. At both ages however, sympathetic tone was higher during the dark phase, as shown by a higher turnover of NE. This observation confirms earlier data, which indicate that the endogenous amine concentration may not mirror its turnover rate. TGR at either age had lower cardiac NE as well as lower TH expression and did not display a circadian phase-dependency. The increased cardiac NE turnover rate in the dark phase in non-hypertensive TGR was lost in hypertensive rats. Both cardiac NE concentrations and TH expression decreased with age in both strains. In adrenal glands, NE and epinephrine (E) were not circadian phase-dependent in both strains but increased with age. NE concentrations in the hypothalamus were neither circadian phase-dependent nor different in both strains and at both ages. However, sympathetic tone of NE in the hypothalamus, as indicated by the turnover rate, was greater during the dark phase in both strains at an age of 10 wk. Expression of TH and NET were greatly reduced in adrenal glands when compared to Sprague-Dawley rats; whereas, expression of TH in the hypothalamus was significantly increased in hypertensive TGR. These data indicate that the transgene in TGR leads to an increased central stimulation of the sympathetic nervous system and to a consecutive down-regulation in the peripheral organs. It is of interest that rhythmicity in the studied parameters was lost in hypertensive TGR, except in the turnover of NE in the hypothalamus. We concluded that the data on key mechanisms of regulation of the sympathetic system in TGR cannot explain the inverse blood pressure rhythm observed in this transgenic rat strain.

Fundamental and harmonic emission from the rear side of a thin overdense foil irradiated by an intense ultrashort laser pulse

The emission of fundamental and harmonic radiation from the rear side of thin foils in the thickness range 50-460 nm irradiated by intense frequency doubled Ti:sapphire laser pulses of the duration of 150 fs and intensities up to a few 10(18) W/cm(2) was investigated. Following up a previous study of the rear side harmonic emission [Teubner, Phys. Rev. Lett. 92, 185001 (2004)], we measured the emission efficiencies, polarization properties, and the spectral shapes of the fundamental frequency and the second harmonic. Rear side emission is only observed when the obliquely incident laser light is p -polarized. Particle-in-cell (PIC) simulations indicate that the foils remain strongly overdense during the interaction with the laser pulse and that the rear side emission is caused by energetic electron bunches which are generated at the front side by resonance absorption. They are accelerated into the foil and drive strong plasma oscillations at the fundamental and higher harmonic frequencies.

Increased soluble VCAM-1 serum levels in preeclampsia are not correlated to urinary excretion or circadian blood pressure rhythm

OBJECTIVE

Soluble vascular cell adhesion molecule-1 (VCAM-1) is known to be elevated in serum of patients with preeclampsia, but there are no data available on the significance of urinary VCAM-1 excretion in preeclampsia. The aim of our study was to uncover possible circadian rhythms of VCAM-1 plasma levels and urinary VCAM-1 excretion in uncomplicated and hypertensive pregnancies and to ascertain their relation to blood pressure.

STUDY DESIGN

A total of 10 normotensive and 10 preeclamptic pregnant women were included in this study. Venous blood was collected hourly, and urine samples were taken every 2 h over a period of 24 h. VCAM-1 levels were determined by ELISA. We compared these results with the circadian blood pressure rhythm.

RESULTS

The median VCAM-1 plasma levels were significantly (P < 0.01) increased in preeclamptic patients (851.5 ng/mL) in comparison to normotensive pregnant women (659.3 ng/mL) without any circadian rhythm being apparent; however, the urinary excretion of VCAM-1 showed a typical circadian rhythm, with a higher excretion rate during daytime.

CONCLUSION

For the first time we have demonstrated that urinary VCAM-1 excretion in pregnancy shows a circadian rhythm without correlation to plasma levels or the circadian blood pressure rhythm. In contrast, VCAM-1 serum levels did not show a diurnal rhythm. We assume that VCAM-1 serum levels do not correlate with systemic blood pressure or urinary excretion.

Circadian periodicity of cerebral blood flow revealed by laser-Doppler flowmetry in awake rats: relation to blood pressure and activity

Cardiovascular parameters such as arterial blood pressure (ABP) and heart rate display pronounced circadian variation. The present study was performed to detect whether there is a circadian periodicity in the regulation of cerebral perfusion. Normotensive Sprague-Dawley rats (SDR, approximately 15 wk old) and hypertensive (mREN2)27 transgenic rats (TGR, approximately 12 wk old) were instrumented in the abdominal aorta with a blood pressure sensor coupled to a telemetry system for continuous recording of ABP, heart rate, and locomotor activity. After 5-12 days, a laser-Doppler flow (LDF) probe was attached to the skull by means of a guiding device to measure changes in brain cortical blood flow (CBF). After the animals recovered from anesthesia, measurements were taken for 3-4 days. The time series were analyzed with respect to the midline estimating statistic of rhythm (i.e., mean value of a periodic event after fit to a cosine function), amplitude, and acrophase (i.e., phase angle that corresponds to the peak of a given period) of the 24-h period. The LDF signal displayed a significant circadian rhythm, with the peak occurring at around midnight in SDR and TGR, despite inverse periodicity of ABP in TGR. This finding suggests independence of LDF periodicity from ABP regulation. Furthermore, the acrophase of the LDF was consistently found before the acrophase of the activity. From the present data, it is concluded that there is a circadian periodicity in the regulation of cerebral perfusion that is independent of circadian changes in ABP and probably is also independent of locomotor activity. The presence of a circadian periodicity in CBF may have implications for the occurrence of diurnal alterations in cerebrovascular events in humans.

The expression of legumain, an asparaginyl endopeptidase that controls antigen processing, is reduced in endotoxin-tolerant monocytes

The exposition of monocytes to lipopolysaccharide (LPS) primarily causes a massive inflammatory response that is then followed by a hyporesponsive state of these cells. This latter state is called endotoxin tolerance and is characterized by (i) the attenuated production of proinflammatory mediators after repeated LPS treatment, and (ii) the diminished antigen presentation and T-cell stimulation capacity. The data presented here indicate that LPS priming causes a specific decrease in the expression of legumain (the asparaginyl endopeptidase responsible for the key step in antigen processing) in monocytes. In these cells, the fraction of major histocompatibility complex (MHC) class II loaded with CLIP was increased. In contrast to monocytes, LPS priming provoked an increase of legumain expression in B cells. Reduced monocytic expression of legumain was also found in critically ill patients supporting the suitability of endotoxin tolerance as an experimental model of clinical postinflammatory immunodeficiency.

Second order autocorrelation of an XUV attosecond pulse train

Temporal widths of an attosecond (asec) XUV radiation pulse train, formed by the superposition of higher order harmonics, have been recently determined utilizing a 2nd order autocorrelation measurement. An assessment of the validity of the approach, for the broadband XUV radiation of asec pulses, is implemented through ab initio calculations modeling the spectral and temporal response of the two-XUV-photon He ionization detector employed. The measured width of the asec bursts is discussed in terms of the spectral phases of the individual harmonics, as well as in terms of the spatially modulated temporal width of the radiation, and is found in reasonable agreement with the expected duration.

Is there an interaction between interleukin-10 and interleukin-22?

Interleukin(IL)-10 and IL-22 are structurally related cytokines. Their heterodimeric receptors consist of the cytokine-specific chains IL-10R1 and IL-22R1, respectively, and the common chain IL-10R2. This study focused on the question of whether IL-10 modulates IL-22 effects and vice versa. This question is important because IL-10 and IL-22 exert anti- and proinflammatory effects, respectively, and, as we show here, are simultaneously present in both systemic and local inflammation. The revealed lacking concomitance of IL-10R1 and IL-22R1 on identical cells excluded any possible interaction between IL-10 and IL-22 apart from the competition for IL-10R2. To study this competition, monocytes and hepatocytes were chosen. The dependence of the cytokine action on IL-10R2 was verified. Interestingly, no influence of IL-22 on IL-10 effects was observed. The same was true when IL-22 was used in complex with IL-22-binding protein. Similarly, no influence of IL-10 was found on IL-22 action. This missing competition seemed to be due to a lack of binding between IL-10R2 and the native cytokines in the absence of their corresponding R1 chain. However, IL-10R2 interacted with defined IL-10- and IL-22-derived peptides supporting the hypothesis that cytokine binding to its corresponding R1 chain creates a binding site on this cytokine for IL-10R2.

No pre-existing bias in sailfin molly females, Poecilia latipinna, for a sword in males

The origination of female mate preference is still not well known and may depend on genetic predispositions, social environment and sensory stimuli in the environment. Females of different populations, which live in different environments, may therefore differ in a pre-existing bias for male traits. Previous studies within the genus Xiphophorus and Priapella (Poeciliidae) have indicated that females have a latent preference for a sword in males, even though conspecific males do not express a sword. In a recent study Basolo (2002a) found such a pre-existing bias for artificially sworded males in sailfin molly females from a Louisiana population. To investigate whether Poecilia latipinna females exhibit in general a pre-existing bias for sworded males or whether populations differ in a pre-existing female preference for sworded males, we tested P. latipinna females from a Texas population for a latent preference for sworded males. We tested in video playback experiments whether sailfin molly females P. latipinna have a latent preference for males with an artificial coloured plastic sword on TV monitors. Using video playbacks we first showed in a conditioning experiment that females perceived yellow plastic swords. Females preferred to associate with conspecific males to conspecific females on TV monitors. Females, however, did not exhibit a preference for males with a coloured sword over males with a transparent sword. Our result contradicts results of a previous study showing that sailfin molly females from a different population exhibited a preference for live males with an artificial sword. Pre-existing biases for novel male traits in females may differ between populations within a species. Thus, environmental factors may influence the development of pre-existing biases and might, therefore, drive the evolution of latent preferences in different populations differently.

Harmonic emission from the rear side of thin overdense foils irradiated with intense ultrashort laser pulses

The harmonic emission from thin solid carbon and aluminum foils, irradiated by 150 fs long frequency-doubled Ti:sapphire laser pulses at lambda=395 nm and peak intensities of a few 10(18) W/cm(2), has been studied. In addition to the harmonics emitted from the front side in the specular direction, we observe harmonics up to the 10th order, including the fundamental from the rear side in the direction of the incident beam, while the foil is still strongly overdense. The experimental observations are well reproduced by particle-in-cell simulations. They reveal that strong coupling between the laser-irradiated side and the rear side occurs via the nonlocal electron current driven by the laser light.

[Genet(h)ics: the philosophical concept of the discourse ethics and consequences for the research community]

The research community is increasingly confronted with the problem of ethic responsibility. Ethic reflection might be integrated as a part of one's own research projects. This question is discussed against the background of Jürgen Habermas' discourse ethics, which considers the diverse state of being in the modern age as the basis. In this situation, the process of understanding ("Verständigungsprozess") the norms assumed to be valid receives extraordinary significance, since this process of understanding itself inheres authorizing function for the norms. Taking this philosophicial approach seriously, researchers have the specific responsibility not to perform the ethical judgement based on facts alone. Since researchers might be predestined to envisage the ethical implication of their own research at an early stage, they have the possibility to activate the process of understanding about relevant ethical norms themselves as early as possible.

Direct observation of attosecond light bunching

Temporal probing of a number of fundamental dynamical processes requires intense pulses at femtosecond or even attosecond (1 as = 10(-18) s) timescales. A frequency 'comb' of extreme-ultraviolet odd harmonics can easily be generated in the interaction of subpicosecond laser pulses with rare gases: if the spectral components within this comb possess an appropriate phase relationship to one another, their Fourier synthesis results in an attosecond pulse train. Laser pulses spanning many optical cycles have been used for the production of such light bunching, but in the limit of few-cycle pulses the same process produces isolated attosecond bursts. If these bursts are intense enough to induce a nonlinear process in a target system, they can be used for subfemtosecond pump-probe studies of ultrafast processes. To date, all methods for the quantitative investigation of attosecond light localization and ultrafast dynamics rely on modelling of the cross-correlation process between the extreme-ultraviolet pulses and the fundamental laser field used in their generation. Here we report the direct determination of the temporal characteristics of pulses in the subfemtosecond regime, by measuring the second-order autocorrelation trace of a train of attosecond pulses. The method exhibits distinct capabilities for the characterization and utilization of attosecond pulses for a host of applications in attoscience.