bluuebunny/crossref_metadata_2025 huggingface dataset:
Critical appraisal of the management of severe malnutrition: 2. Dietary management
Authors: Brewster David R
Published: September 2006

Abstract:  In the dietary management of severe acute malnutrition in children, there is evidence to support the WHO Manual’s protocol of cautious feeding of a low energy and protein formula with small frequent feeds in the initial phase of treatment, particularly in kwashiorkor. However, this initial milk diet (WHO F‐75) might benefit from increasing the sulphur amino acid, phosphorus and potassium content and reducing the lactose content, but further studies are needed. Careful tube‐feeding results in faster initial recovery and weight gain, but has a significant risk of aspiration in poorly supervised settings. Ready‐to‐use therapeutic food is an important recent advance in the dietary management of malnutrition in ambulatory settings, allowing more effective prevention programmes and earlier discharge from hospital where community follow‐up is available. It should be included in future protocols. There is very good evidence on the use of micronutrients such as zinc, and preliminary evidence suggests that smaller doses of daily vitamin A are preferable to a single large dose on admission for severe malnutrition.
Is elective surgery traumatic for children and their parents?
Authors: Ben‐Amitay Galit , Kosov Irene , Reiss Ahuva , Toren Paz , Yoran‐Hegesh Roni , Kotler Moshe , Mozes Tamar
Published: September 2006

Aim:  The emotional consequences of elective surgery to children and to their parents have not been sufficiently studied. The aim of the present study was to prospectively assess the prevalence and severity of post‐traumatic, anxiety and depressive symptoms in this population.

Methods:  Forty children and adolescents consecutively admitted for elective surgery in a general hospital participated in the study. Their parents were also assessed. The assessments were made on the day of admission and surgery, and 1 and 6 months after the surgery.

Results:  Minor post‐traumatic symptoms of the children were noted at the first and second assessments, decreasing significantly at the 6‐month assessment. Further, the prevalence of children with elevated post‐traumatic symptoms decreased significantly between the first and second assessments. Parents scored highest for anxiety and depression at the first assessment. Their symptoms, however, decreased significantly within 1 month. A significant decrease between the first and second assessments was also noted in the prevalence of parents with elevated anxiety symptoms. At the 1‐ and 6‐month follow‐up assessments, there was a significant correlation between the children’s symptoms and their parents’.

Conclusion:  Mild post‐traumatic symptoms may accompany paediatric elective surgery and persist for at least 1 month. Parents may also manifest anxiety and depressive symptoms, which may diminish earlier, that is, immediately after the surgery or within 1 month.
Use of W‐plasty in stenotic stoma: a new solution for an old problem
Authors: Beraldo S. , Titley G. , Allan A.
Published: September 2006

Indication  Amongst late complications of stomas, stenosis can be difficult to treat. Repeated dilatations rarely achieve long‐term resolution and re‐fashioning is not always successful. Application of an existing plastic surgical technique to treat stomal stenosis is described.

Method  After marking the skin, a W‐plasty is made with a number of consecutive small triangular flaps through the skin. The corresponding mucosal margin is then made to interdigitate with this configuration and fixed using a Gillies corner stich with 5/0 Vycril rapide on a compound curved needle.

Results  Five patients underwent W‐plasty reconstruction for a stenotic stoma. Median follow up was 12.5 months (range 11–15). No patient had stenosis of the stoma on review and the patient satisfaction rate was high.

Conclusion  The W‐plasty technique is a new treatment for stenotic stoma.
Influence of constant positive airway pressure therapy on lipid storage, muscle metabolism and insulin action in obese patients with severe obstructive sleep apnoea syndrome
Authors: Trenell M. I. , Ward J. A. , Yee B. J. , Phillips C. L. , Kemp G. J. , Grunstein R. R. , Thompson C. H.
Published: September 2006

Aim:  To observe the effect of constant positive airway pressure (CPAP) therapy on regional lipid deposition, muscle metabolism and glucose homeostasis in obese patients with obstructive sleep apnoea syndrome (OSAS).

Methods:  A total of 29 obese patients underwent assessment before and after a minimum of 12‐week CPAP therapy. Abdominal adipose tissue was assessed using magnetic resonance imaging. Intramyocellular lipid (IMCL) and skeletal muscle creatine were assessed using 1H‐magnetic resonance spectroscopy. Fasting venous and arterial blood were collected. Glucose control was assessed using the homeostatic model. A subgroup of six patients were also evaluated for skeletal muscle pH, phosphocreatine (PCr) and mitochondrial function using 31P‐magnetic resonance spectroscopy. The sample was divided according to CPAP therapy, with regular users defined as a minimum nightly use of ≥4 h; 19 subjects were regular and 10 were irregular CPAP users.

Results:  Visceral adipose tissue volume and circulating leptin were reduced with regular CPAP use but not with irregular CPAP use. Regular CPAP use also produced an increase in skeletal muscle creatine and resting PCr and a decrease in muscle pH. Neither the regular nor irregular CPAP users showed any change in IMCL content, insulin sensitivity scores or mitochondrial function.

Conclusions:  These data show that regular CPAP therapy reduces visceral adipose tissue and leptin and improves skeletal muscle metabolites. In obese patients with severe OSAS, regular CPAP use does not improve glucose control, suggesting that the influence of obesity on glucose control dominates over any potential effect of OSAS.
Diabetes‐associated macrovasculopathy: pathophysiology and pathogenesis
Authors: Rahman Sayeeda , Rahman Tahminur , Ismail Aziz Al‐Shafi , Rashid Abdul Rahman A
Published: September 2006

The complications associated with diabetic vasculopathy are commonly grouped into two categories: microvascular and macrovascular complications. In diabetes, macrovascular disease is the commonest cause of mortality and morbidity and is responsible for high incidence of vascular diseases such as stroke, myocardial infarction and peripheral vascular diseases. Macrovascular diseases are traditionally thought of as due to underlying obstructive atherosclerotic diseases affecting major arteries. Pathological changes of major blood vessels leading to functional and structural abnormalities in diabetic vessels include endothelial dysfunction, reduced vascular compliance and atherosclerosis. Besides, advanced glycation end product formation interacts with specific receptors that lead to overexpression of a range of cytokines. Haemodynamic pathways are activated in diabetes and are possibly amplified by concomitant systemic hypertension. Apart from these, hyperglycaemia, non‐enzymatic glycosylation, lipid modulation, alteration of vasculature and growth factors activation contribute to development of diabetic vasculopathy. This review focuses on pathophysiology and pathogenesis of diabetes‐associated macrovasculopathy.
Targeting Aid to the Needy and Deserving: Nothing But Promises?
Authors: Nunnenkamp Peter , Thiele Rainer
Published: September 2006

By reallocating aid to where it is needed most and where a productive use is most likely, donors could help alleviate poverty in developing countries. The rhetoric of donors suggests that this insight has increasingly shaped the allocation of aid. We assess the poverty and policy orientation of bilateral and multilateral aid in different ways. In addition to presenting stylised facts based on bivariate correlations, we apply a Tobit model that captures both altruistic and selfish donor motives. We find little evidence supporting the view that the targeting of aid has improved significantly. Most donors provide higher aid to relatively poor countries, but so far the fight against poverty has not resulted in a stronger focus on needy recipients with favourable local conditions. The estimation results reveal that the policy orientation of aid critically depends on how local conditions are measured. In general, however, donors appear to be less policy‐oriented than poverty‐oriented. The response of donors to changing institutional and policy conditions in recipient countries turns out to be fairly weak. We reject the proposition that multilateral aid is clearly superior to bilateral aid in terms of rewarding poor countries with better policies and institutions.
Capital Controls Re‐examined: The Case for ‘Smart’ Controls
Authors: Duasa Jarita , Mosley Paul
Published: September 2006

The global financial crisis which began in east Asia in 1997 is not over, neither is the inquest into its implications for adjustment policy. In the wake of this crisis, we focus here on the role of capital controls, which formed a much publicised part of the crisis‐coping strategy in one country (Malaysia) and, less openly, were also deployed by other crisis‐afflicted countries. Evaluation so far has examined different target variables with different estimation methods, generally concentrating on efficiency and stability indicators and ignoring equity measures; it has also typically treated ‘control’ as a one‐zero dummy variable, ignoring the ‘quality’ of intervention and in particular the extent to which efficiency gains are obtained in exchange for controls. Partly because of these limitations, the literature has reached no consensus on the impact of controls; however, it is moving over towards acknowledging that the quality and type of controls is important, as well as their intensity. We propose an approach in which the government plays off short‐term political security against long‐term economic gain; the more insecure its political footing, the greater the weight it gives to political survival, which is likely to increase the probability of controls being imposed. The modelling of this approach generates a governmental ‘policy reaction function’ and an impact function for controls, which are estimated by simultaneous panel‐data methods across a sample of thirty developing and transitional countries between 1980–2003, using, for the period since 1996, the ‘new’ IMF dataset which differentiates between controls by type.

We find that controls appear to cause increases in income equality, and are significantly associated with political insecurity and relatively low levels of openness to trade. They do not, in our analysis, materially influence the level of whole‐economy productivity or GDP across the sample of countries examined, although they do influence productivity in particular sectors. But the dispersion around this central finding is wide: the tendency for controls to depress productivity by encouraging rent‐seeking sometimes is, and sometimes is not, counteracted by purposive government policy actions to maintain competitiveness. Whether or not this happens is vital, on both efficiency and equity grounds. We make the case for ‘smart’ capital controls – controls which are time‐limited and contain an inbuilt incentive to increased productivity.
MORAL TAINT
Authors: OSHANA MARINA A. L.
Published: September 2006

Abstract: Moral taint occurs when a person's moral record has been compromised by the introduction of something that produces disfigurement of the moral personality. Although some cases of moral taint can be explained as instances of vicarious or collective liability stemming from our voluntary associations and commitments, the idea is helpful as a heuristic device in assisting our comprehension of more vexing cases of responsibility and blame where a need for atonement exists. These are cases in which taint may be acquired by circumstantial luck. I argue that the idea of circumstantial taint—for example, the idea that people can be morally compromised by their heritage—is coherent. In such cases, although taint is not due to a deficient level of care or to an unsavory quality of will, shame is the appropriate affect and atonement the appropriate response.
How is ‘welfare‐to‐work’ shaped by contingencies of economy, welfare policy and human capital?
Authors: Cheng Tyrone
Published: September 2006

This research weighed the impact made by the economy, welfare policy and human capital on unemployed welfare mothers in the USA. Specifically, it asked how welfare mothers’ employment status, poverty status, and enrolment for Temporary Assistance for Needy Families (TANF) are affected by these three factors. Longitudinal data from the Survey of Income Program Participation (SIPP) provided a sample of TANF mothers. The SIPP data shed light on modes of economic adaptation exhibited by these mothers. Event history analysis was applied to the data (for years 1996–2000), and results were obtained showing that restrictive welfare policies combined with high unemployment can boost the number of working poor Americans by severing them from TANF. Human capital contingencies – which here comprised development of the sample's occupational skills, work experience and education – helped TANF mothers gain employment and even leave welfare. Some were able to do so and live above the poverty level. Social support, especially family support, was another factor included in this study that was found to be of some use to unemployed mothers in terms of finding work. Results bear several implications for TANF policy.
Tryptophan Depletion Increases Nausea, Headache and Photophobia in Migraine Sufferers
Authors: Drummond PD
Published: September 2006

Sensitivity to light was investigated 5 and 8 h after consumption of an amino acid drink which contained L-tryptophan (balanced amino acid condition: 19 controls and 22 migraine sufferers) or which produced a short-term reduction in brain serotonin synthesis by omitting L-tryptophan (tryptophan depletion condition: 16 controls and 16 migraine sufferers). Migraine sufferers reported more intense nausea, headache, glare- and light-induced pain than controls. In addition, glare- and light-induced pain were greater in the tryptophan depletion condition than in the balanced amino acid condition, in both migraine sufferers and controls. Eight hours after the amino acid drink, after participants had completed tests of pain sensitivity and motion sickness provocation, tryptophan depletion augmented headache in migraine sufferers and aggravated nausea in migraine sufferers and controls. These findings suggest that a reduction in brain synthesis of serotonin intensifies photophobia and other migrainous symptoms and thus might contribute to the pathogenesis of migraine.
Estimating abundance for a savanna elephant population using mark–resight methods: a case study for the Tembe Elephant Park, South Africa
Authors: Morley R. C. , van Aarde R. J.
Published: September 2006

Elephants living in dense woodlands are difficult to count. Many elephant populations in Africa occur in such conditions. Estimates of these populations based on total counts, aerial counts and dung counts often lack information on precision and accuracy. We use standard mark–recapture field methods to obtain estimates of population size with associated confidence limits. We apply this approach to a closed elephant population in the Tembe Elephant Park (300 km2), South Africa. A registration count completed in 4 months gives a known population size. We evaluate mark–recapture models against the known population size. Individual identification profiles obtained for elephants during the registration count and mark–recapture events indicate that at least 167 elephants live in the park. We consider this value as an estimate of the minimum number alive. We include 189 sightings of bulls and 37 sightings of breeding herds in the mark–recapture modelling. Of the models we test (Petersen, Schnabel, Schumacher, Jolly–Seber, Bowden's, Poisson and negative binomial), Bowden's gives an estimate closest to the registration count. Assumptions of the model are not violated. For all models except one (negative binomial), our estimates improve with increased sampling intensity. Confidence intervals do not improve with increased effort except for the Schnabel model. Mark–recapture methods should be considered as reliable estimators of population size for elephants occurring in dense woodlands and forests when other methods cannot be relied on.
Feeding responses of an oligophagous bean aphid, Megoura crassicauda, to primary and secondary substances in Vicia angustifolia
Authors: Takemura Masami , Kuwahara Yasumasa , Nishida Ritsuo
Published: September 2006

The feeding behaviour of the aphid Megoura crassicauda Mordivilko (Homoptera: Aphididae), which feeds selectively on plants in the genus Vicia (Fabaceae), was studied. The aphids deposited proteinaceous stylet sheaths intercellularly towards the phloem tissues of host plants. Similar stylet sheaths were formed on a Parafilm membrane when host‐specific acylated flavonoid glycosides [two 2″‐O‐(E)‐p‐coumaroyl esters of quercetin 3‐O‐diglycosides] present in the extracts of the narrow vetch, Vicia angustifolia L., were supplied in the solution covered by the membrane. In contrast, their corresponding deacyl analogues, present more abundantly in the host plant tissues, were not stimulatory, which suggested specificity in the structural requirements of the probing stimulants. While the aphids imbibed an artificial diet composed of primary nutrients (e.g., sucrose and amino acids) and produced a large quantity of honeydew, acylated flavonoids alone and non‐acylated flavonoids supplied with the nutrients more or less suppressed honeydew production. These findings implied that the acylated flavonoids serve as a cue to navigate the stylet sheath towards the phloem prior to sap‐sucking, whereas non‐acylated flavonoids may serve as a negative stimulus to refrain from sucking during tissue penetration before tapping the phloem, although the distribution of these compounds in the plant tissues remains unknown. Thus, the feeding behaviour of M. crassicauda appears to be controlled by multiple chemical stimuli in the process of the settling on its host plant.
Host‐plant‐mediated interaction between populations of a true omnivore and its herbivorous prey
Authors: Zhi Junrui , Margolies David C. , Nechols James R. , Boyer John E.
Published: September 2006

Western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), are competitors with twospotted spider mites, Tetranychus urticae Koch (Acari: Tetranychidae), for plant resources and potential predators on spider mites when the opportunity arises. Which interaction predominates may depend on relative population densities and individual species’ responses to the plants on which they co‐occur. We examined interactions between populations of thrips and spider mites on several cultivars of two bedding plants: impatiens (Impatiens wallerana Hook.f) cultivars ‘Impulse Orange’ and ‘Cajun Carmine’, and ivy geranium [Pelargonium peltatum (L.) L’Her ex Aiton] cultivars ‘Sybil Holmes’ and ‘Amethyst 96’. Four combinations of thrips and mite numbers were studied: thrips alone, mites alone, and two densities of thrips and mites together. We compared population numbers after 4 weeks. Overall, mite numbers increased more rapidly than thrips did, but both species increased more rapidly on impatiens than on ivy geraniums. Between impatiens cultivars, thrips and mites increased more slowly on ‘Cajun Carmine’ (i.e., it was more resistant) than on ‘Impulse Orange’. On ivy geraniums, spider mites increased more slowly on ‘Sybil Holmes’ than on ‘Amethyst 96’ but the reverse was the case for thrips. Regardless of plant species or cultivar, thrips had a strong negative effect on spider mites whenever they co‐occurred, suppressing mite population growth by around 50% compared to when mites were alone. However, the effect of spider mites on western flower thrips depended on the quality of the plant species. On impatiens, thrips co‐occurring with spider mites increased slightly more than thrips alone did, while on ivy geranium mites had a small negative effect on thrips. Contrary to expectations, thrips had a larger negative impact on spider mites on plants that were more susceptible to thrips than they did on plants more resistant to thrips. We suggest that host plants mediate the interaction between an omnivore and its herbivorous prey not only by altering individual diet choice but by changing the relative population dynamics of each species.
Host stage selection of the mealybug parasitoid Anagyrus spec. nov near sinope
Authors: Chong Juang‐Horng , Oetting Ronald D.
Published: September 2006

The mealybug parasitoid Anagyrus spec. nov near sinope (Hymenoptera: Encyrtidae) is an undescribed parasitoid of the Madeira mealybug, Phenacoccus madeirensis Green (Homoptera: Pseudococcidae). We investigated the preference of Anagyrus spec. nov near sinope for six developmental stadia (first‐ and second‐instar nymphs, third‐instar immature females, third‐ or fourth‐instar immature males, pre‐reproductive adult females, and ovipositing adult females) of P. madeirensis and the fitness consequences of the host stage selection behavior. In the no‐choice test, Anagyrus spec. nov near sinope parasitized and completed development in all host stadia except third‐instar immature males. When all host stadia were offered simultaneously, the parasitoids preferred third‐instar immature and pre‐reproductive adult females. Dissection of the stung mealybugs revealed that the clutch size (number of eggs per host) was approximately four and three in the third‐instar and pre‐reproductive females, respectively, and one egg per first‐instar nymph. Parasitoids emerged from P. madeirensis parasitized at third‐instar or pre‐reproductive adult female completed development in the shortest duration, achieved a higher progeny survival rate, larger brood and body size, and the lowest proportion of males. We showed that the continued development of mealybugs had significant influence on the fitness of the parasitoids. Although deposited as eggs in first‐ or second‐instar nymphs, parasitoids emerged from mummies that had attained third‐instar or adult development achieved similar progeny survival rate, brood size, body size, and sex ratio as those parasitoids deposited and developed in third‐instar or adult mealybugs. By delaying larval development in young mealybugs, Anagyrus spec. nov near sinope achieved higher fitness by allowing the parasitized mealybugs to grow and accumulate body size and resources. We suggest that the fitness consequence of host stage selection of a koinobiont parasitoid should be evaluated on both the time of parasitism and the time of mummification.
Outdoor flight activity and immigration of Rhyzopertha dominica into seed wheat warehouses
Authors: Toews Michael D. , Campbell James F. , Arthur Frank H. , Ramaswamy Sonny B.
Published: September 2006

The flight activity of lesser grain borer, Rhyzopertha dominica F. (Coleoptera: Bostrichidae), was monitored at two Foundation seed wheat warehouses during the 2003 and 2004 field seasons, using pheromone‐baited Lindgren funnel traps positioned indoors and outdoors. General stored‐product insect activity was also monitored using unbaited sticky traps positioned inside the warehouses around overhead doors. Pheromone‐baited traps were useful for monitoring R. dominica activity, however insect captures decreased when lures were not changed weekly. Flight peaks were documented in early May and again from September through October, and insect captures inside warehouses correlated with timing of outdoor captures. Multiple regression analyses showed that slightly more than half of the variability in R. dominica captures could be explained by mean ambient air temperature and wind speed during the 2 h preceding sunset. Stored‐product Coleoptera captured on unbaited glue boards around overhead doors included Ahasverus advena, Cryptolestes ferrugineus, R. dominica, Sitophilus oryzae, Tribolium castaneum, Trogoderma variabile, and Typhaea stercorea. Door gaskets significantly reduced the number of insect captures on glue boards placed around the overhead doors, and generally restricted their entry to ground level. These studies demonstrated that outdoor pheromone‐baited traps are effective monitoring tools for determining when grain‐handling facilities are most susceptible to infestation and that exclusion may be an effective component of a pest management program.
Patterns of social distance towards people suffering from schizophrenia in Austria: a comparison between the general public, relatives and mental health staff
Authors: Grausgruber A. , Meise U. , Katschnig H. , Schöny W. , Fleischhacker W. W.
Published: September 2006

Objective:  The aims of this study were to identify the different aspects of the attitudes towards people suffering from schizophrenia and to find factors influencing these attitudes – especially the willingness to contact people suffering from schizophrenia – as well as to obtain information on how to reduce stigma and discrimination.

Method:  We conducted a study to investigate these attitudes in Austria. A representative sample of the general public, different professional groups working in the field and relatives of mentally ill people were interviewed. The public, relatives and people working in the mental health field were asked a number of the same questions, to allow for comparisons between groups.

Results:  We found great differences in key dimensions of the attitude towards people suffering from schizophrenia between groups: these included different causal attributions to schizophrenia, different attitudes concerning the perceived success of the treatment of schizophrenia, different fears concerning perceived dangerousness and a different willingness to interact voluntarily with schizophrenia patients.

Conclusion:  The factors influencing the distance towards people suffering from schizophrenia differ between groups. Our findings should help to optimize campaigns fighting against stigma and discrimination.
Research Awareness: An Important Factor for Evidence‐Based Practice?
Authors: McSherry Robert , Artley Angela , Holloran Jan
Published: September 2006

Background: Despite the growing body of literature, the reality of getting evidence into practice remains problematic.

Objective: The purpose of this study was to establish levels of research awareness amongst registered health care professionals (RHCPs) and the influence of research awareness on evidence‐based practice activities.

Design and Methods: This was a descriptive quantitative study. A convenience sample of 2,126 registered RHCPs working in a large acute hospital in Northeast England, the United Kingdom was used. A self‐completion Research Awareness Questionnaire (RAQ) was directed towards measuring RHCP: attitudes towards research, understanding of research and the research process, and associations with practising using an evidence base. Data were entered into a Statistical Package for Social Science (SPSS) database and descriptive and inferential statistics were used.

Findings: A total of 843 questionnaires were returned. Seven hundred and thirty‐three (91%) RHCPs overwhelmingly agreed with the principle that evidence‐based practice has a large part to play in improving patient care. This point was reinforced by 86% (n= 701) of respondents strongly agreeing or agreeing with the idea that evidence‐based practice is the way forward to change clinical practice. Significant associations were noted between levels of confidence to undertake a piece of research and whether the individual had received adequate information about the research process, had basic knowledge and understanding of the research process, or had research awareness education or training.

Conclusions: The study shows that RHCPs, regardless of position or grade, have a positive attitude towards research but face many obstacles. The key obstacles are lack of time, support, knowledge, and confidence. To address these obstacles, it is imperative that the organisation adopts a structured and coordinated approach to enable and empower individuals to practice using an evidence base.
Development of respiratory control instability in heart failure: a novel approach to dissect the pathophysiological mechanisms
Authors: Manisty Charlotte H. , Willson Keith , Wensel Roland , Whinnett Zachary I. , Davies Justin E. , Oldfield William L. G. , Mayet Jamil , Francis Darrel P.
Published: September 2006

Observational data suggest that periodic breathing is more common in subjects with low F, high apnoeic thresholds or high chemoreflex sensitivity. It is, however, difficult to determine the individual effect of each variable because they are intrinsically related. To distinguish the effect of isolated changes in chemoreflex sensitivity, mean F and apnoeic threshold, we employed a modelling approach to break their obligatory in vivo interrelationship. We found that a change in mean CO2 fraction from 0.035 to 0.045 increased loop gain by 70 ± 0.083% (P < 0.0001), irrespective of chemoreflex gain or apnoea threshold. A 100% increase in the chemoreflex gain (from 800 l min−1 (fraction CO2)−1) resulted in an increase in loop gain of 275 ± 6% (P < 0.0001) across a wide range of values of steady state CO2 and apnoea thresholds. Increasing the apnoea threshold F from 0.02 to 0.03 had no effect on system stability. Therefore, of the three variables the only two destabilizing factors were high gain and high mean CO2; the apnoea threshold did not independently influence system stability. Although our results support the idea that high chemoreflex gain destabilizes ventilatory control, there are two additional potentially controversial findings. First, it is high (rather than low) mean CO2 that favours instability. Second, high apnoea threshold itself does not create instability. Clinically the apnoea threshold appears important only because of its associations with the true determinants of stability: chemoreflex gain and mean CO2.
Specific modulation of motor unit discharge for a similar change in fascicle length during shortening and lengthening contractions in humans
Authors: Pasquet Benjamin , Carpentier Alain , Duchateau Jacques
Published: September 2006

This study examines the effect of a change in fascicle length on motor unit recruitment and discharge rate in the human tibialis anterior during shortening and lengthening contractions that involved a similar change in torque. The dorsiflexor torque and the surface and intramuscular electromyograms (EMGs) from the tibialis anterior were recorded in eight subjects. The behaviour of the same motor unit (n= 63) was compared during submaximal shortening and lengthening contractions performed at a constant velocity (10 deg s−1) with the dorsiflexor muscles over a 20 deg range of motion around the ankle neutral position. Muscle fascicle length was measured non‐invasively using ultrasonography. Motor units that were active during a shortening contraction were always active during the subsequent lengthening contraction. Furthermore, additional motor units (n= 18) of higher force threshold that were recruited during the shortening contraction to maintain the required torque were derecruited first during the following lengthening contraction. Although the change in fascicle length was linear (r2 > 0.99), and similar for both shortening and lengthening contractions, modulation of discharge rate differed during the two contractions. Compared with an initial isometric contraction at short (11.9 ± 2.4 Hz) or long (11.7 ± 2.2 Hz) muscle length, discharge rate increased only slightly and stayed nearly constant throughout the lengthening contraction (12.6 ± 2.0 Hz; P < 0.05) whereas it augmented progressively and more substantially during the shortening contraction, reaching 14.5 ± 2.5 Hz (P < 0.001) at the end of the movement. In conclusion, these observations indicate a clear difference in motor unit discharge rate modulation with no change in their recruitment order between shortening and lengthening contractions when performed with a similar change in muscle fascicle length and torque.
ND3 and ND4L Subunits of Mitochondrial Complex I, Both Nucleus Encoded in
Chlamydomonas reinhardtii
, Are Required for Activity and Assembly of the Enzyme
Authors: Cardol Pierre , Lapaille Marie , Minet Pierre , Franck Fabrice , Matagne René F. , Remacle Claire
Published: September 2006

Made of more than 40 subunits, the rotenone-sensitive NADH:ubiquinone oxidoreductase (complex I) is the most intricate membrane-bound enzyme of the mitochondrial respiratory chain. In vascular plants, fungi, and animals, at least seven complex I subunits (ND1, -2, -3, -4, -4L, -5, and -6; ND is NADH dehydrogenase) are coded by mitochondrial genes. The role of these highly hydrophobic subunits in the enzyme activity and assembly is still poorly understood. In the unicellular green alga
Chlamydomonas reinhardtii
, the ND3 and ND4L subunits are encoded in the nuclear genome, and we show here that the corresponding genes, called
NUO3
and
NUO11
, respectively, display features that facilitate their expression and allow the proper import of the corresponding proteins into mitochondria. In particular, both polypeptides show lower hydrophobicity compared to their mitochondrion-encoded counterparts. The expression of the
NUO3
and
NUO11
genes has been suppressed by RNA interference. We demonstrate that the absence of ND3 or ND4L polypeptides prevents the assembly of the 950-kDa whole complex I and suppresses the enzyme activity. The putative role of hydrophobic ND subunits is discussed in relation to the structure of the complex I enzyme. A model for the assembly pathway of the
Chlamydomonas
enzyme is proposed.
Hyperinsulinaemia, hyperaminoacidaemia and post-exercise muscle anabolism: the search for the optimal recovery drink
Authors: Manninen A H
Published: September 2006

Dietary supplements and other ergogenic aids are popular among athletes. Recent studies have shown that nutritional mixtures containing protein hydrolysates, added leucine, and high-glycaemic carbohydrates greatly augment insulin secretion compared with high-glycaemic carbohydrates only. When post-exercise hyperinsulinaemia is supported by hyperaminoacidaemia induced by protein hydrolysate and leucine ingestion, net protein deposition in muscle should occur. Thus, consumption of post-exercise recovery drinks containing these nutrients in conjunction with appropriate resistance training may lead to increased skeletal muscle hypertrophy and strength. However, the long-term effects on body composition and exercise performance remain to be determined.
Cell cycle phase distribution analysis in chronic lymphocytic leukaemia: a significant number of cells reside in early G1-phase
Authors: Obermann Ellen C , Went Philip , Tzankov Alexandar , Pileri Stefano A , Hofstaedter Ferdinand , Marienhagen Joerg , Stoehr Robert , Dirnhofer Stephan
Published: September 2006

Background and Aims:Chronic lymphocytic leukaemia (CLL) is a frequent non-Hodgkin lymphoma characterised by a heterogeneous clinical course. Assessment of cell cycle phase kinetics might be important for prediction of clinical behaviour and prognosis.

Methods:Distribution of neoplastic cells in CLL within the cell cycle was evaluated by determining the labelling indices (LI, i.e. percentage of positive cells) of markers specific for late G1-phase (cyclin E), S-phase (cyclin A), and G2/M-phase (cyclin B1), and Mcm2, a novel marker of proliferative potential, in a large cohort of patients (n = 79) using tissue microarray (TMA) technology. Utilising a combination of these markers, an algorithm was developed—subtracting the combined LIs of cyclin E, cyclin A and cyclin B1 from the LI of Mcm2—to determine the percentage of tumour cells residing in early G1-phase, which is probably a critical state for the malignant potential of CLL.

Results:27.11% of cells had acquired proliferative potential as indicated by expression of Mcm2. Only a small number of cells were found to be in late G1-phase (7.16%), S-phase (3.31%) or G2/M-phase (0.98%), while 15.66% of cells were considered to be in early G1-phase.

Conclusion:Cell cycle phase distribution can easily be assessed by immunohistochemistry in routinely processed paraffin-embedded specimens. A large number of neoplastic cells in CLL have proliferative potential, with a significant sub-population residing in early G1-phase. Estimates of these cells may identify cases likely to exhibit a more aggressive biological behaviour and adverse clinical course.
Anti-pneumococcal antibody titre measurement: what useful information does it yield?
Authors: Balmer Paul , Cant Andrew J , Borrow Ray
Published: September 2006

Measuring and interpretation of the immune response to pneumococcal polysaccharides is a complex field, owing to the diversity of the pneumococcal polysaccharide capsular types, different vaccine formulations including both polysaccharide and conjugate vaccines, diverse pneumococcal serological assays, lack of immunogenicity data for the conjugate in a number of at-risk groups and complex vaccine schedules. Even the reasons for performing pneumococcal serology can be complex, as assays may be performed for one of two reasons: either to assess an individual’s immune status to the pneumococcus or to discriminate between normal and abnormal humoral immunity. This review details a history of the pneumococcal serological assays and provides some insight into when serology can prove useful, including vaccination data for certain at-risk groups.
A FLEXIBLE RUNTIME SYSTEM FOR IMAGE PROCESSING IN A DISTRIBUTED COMPUTATIONAL ENVIRONMENT FOR AN UNMANNED AERIAL VEHICLE
Authors: NORDBERG KLAS , DOHERTY PATRICK , FORSSÉN PER-ERIK , WIKLUND JOHAN , ANDERSSON PER
Published: September 2006

A runtime system for implementation of image processing operations is presented. It is designed for working in a flexible and distributed environment related to the software architecture of a newly developed UAV system. The software architecture can be characterized at a coarse scale as a layered system, with a deliberative layer at the top, a reactive layer in the middle, and a processing layer at the bottom. At a finer scale each of the three levels is decomposed into sets of modules which communicate using CORBA, allowing system development and deployment on the UAV to be made in a highly flexible way. Image processing takes place in a dedicated module located in the process layer, and is the main focus of the paper. This module has been designed as a runtime system for data flow graphs, allowing various processing operations to be created online and on demand by the higher levels of the system. The runtime system is implemented in Java, which allows development and deployment to be made on a wide range of hardware/software configurations. Optimizations for particular hardware platforms have been made using Java's native interface.
A METHOD TO CONSTRUCT FLAT MAPS OF THE BRAIN'S SURFACE AND ITS APPLICATION
Authors: DEKLERCK RUDI , GUO JUNFENG , SALOMIE ALEXANDRU , SULIGA MAREK , NYSSEN EDGARD , TAO LIU , BALERIAUX DANIELLE , CORNELIS JAN
Published: September 2006

This paper describes a surface flattening technique, which has been developed in particular to obtain a complete view of the cortical surface of the brain. However, the method is able to produce an overall planar view of any anatomical or real-life object, provided it is topologically compatible with the sphere (i.e. genus 0). It computes the shading of the original surface for rays casted from a nearby surrounding surface and unfolds this surface in a 2D plane, without introducing major distortions. The flat image consisting of the mapped shading results has the advantage that the sulci (i.e. the grooves characterizing the superficial brain geometry) of the cortical surface of the brain can be followed in their entirety, which facilitates the study and the recognition of their patterns.

The new visualization method is integrated into a versatile medical image analysis environment. A first study to assess its usefulness has been accomplished and is also reported in this paper.
LUM PROCESSOR WITH NEURAL DECISION
Authors: LUKAC RASTISLAV , GALAJDA PAVOL , GALAJDOVA ALENA
Published: September 2006

This paper focuses on impulsive noise filtering and outliers rejection in gray-scale images. The proposed method combines neural networks, lower-upper-middle (LUM) smoothers and adaptive switching operations to produce a high-quality enhanced image. Extensive experimentation reported in this paper indicates that the proposed method is sufficiently robust, achieves an excellent balance between noise suppression and signal-detail preservation, and outperforms some well-known filters both subjectively and objectively.
AN EQUATION-FREE APPROACH TO NONLINEAR CONTROL: COARSE FEEDBACK LINEARIZATION WITH POLE-PLACEMENT
Authors: SIETTOS CONSTANTINOS I. , KEVREKIDIS IOANNIS G. , KAZANTZIS NIKOLAOS
Published: September 2006

We present an application of equation-free computation to the coarse-grained feedback linearization problem of nonlinear systems described by microscopic/stochastic simulators. Feedback linearization with pole placement requires the solution of a functional equation involving the macroscopic (coarse-grained) system model. In the absence of such a closed-form model, short, appropriately initialized bursts of microscopic simulation are designed and performed, and their results used to estimate on demand the quantities required for the numerical solution of the (explicitly unavailable) functional equation. Our illustrative example is a kinetic Monte Carlo realization of a simplified heterogeneous catalytic reaction scheme.
AN EQUATION-FREE APPROACH TO COUPLED OSCILLATOR DYNAMICS: THE KURAMOTO MODEL EXAMPLE
Authors: MOON SUNG JOON , KEVREKIDIS IOANNIS G.
Published: September 2006

We present an equation-free multiscale approach to the computational study of the collective dynamics of the Kuramoto model [Kuramoto, 1984], a prototypical model for coupled oscillator populations. Our study takes place in a reduced phase space of coarse-grained "observables" of the system: the first few moments of the oscillator phase angle distribution. We circumvent the derivation of explicit dynamical equations (approximately) governing the evolution of these coarse-grained macroscopic variables; instead we use the equation-free framework [Kevrekidis et al., 2003] to computationally solve these equations without obtaining them in closed form. In this approach, the numerical tasks for the conceptually existing but unavailable coarse-grained equations are implemented through short bursts of appropriately initialized simulations of the "fine-scale", detailed coupled oscillator model. Coarse projective integration and coarse fixed point computations are illustrated.
DETERMINING THE DURATION OF CYCLES IN THE MARKET OF SECOND-HAND TANKER SHIPS, 1976–2001: IS PREDICTION POSSIBLE?
Authors: GOULIELMOS ALEXANDER M. , SIROPOULOU EFTICHIA
Published: September 2006

In this paper we have calculated the duration of cycles manifested in the prices of second-hand tanker ships, using the method of Rescale Range (R/S) Analysis. We have considered a time series of 312 monthly data, taken between the years 1976–2001, and combined R/S with a study of its V-statistic, Power Spectrum Analysis and Sharpe Ratio. Our ultimate goal is to be able to help decision-makers use this analysis in order to buy or sell a ship at the "best timing". As the sale and purchase ship market exhibits a strongly deterministic cyclical behavior with a high degree of "irregularity" (or "volatility"), we expect the techniques of Nonlinear Dynamics and Chaos Theory to be appropriate to be applied to its dynamics. We have found evidence for the existence of two cycles of tanker ship prices, of duration 4 and 8 years respectively, in the years 1976–2001, in agreement with what is expected from the theoretical analysis of freight market cycles. We have shown that our time series is not a random walk process and have used software prediction methods to demonstrate that short term forecasting of second-hand tanker prices may indeed be possible. These results are, of course, preliminary since a lot more data is needed to test their forecasting validity and hence should only be regarded as a start in this interesting area of research.
Disruption of transforming growth factor-β signaling by curcumin induces gene expression of peroxisome proliferator-activated receptor-γ in rat hepatic stellate cells
Authors: Zheng Shizhong , Chen Anping
Published: September 2006

Activation of hepatic stellate cells (HSC), the major effectors of hepatic fibrogenesis, is coupled with sequential alterations in gene expression, including an increase in receptors for transforming growth factor-β (TGF-β) and a dramatic reduction in the peroxisome proliferator-activated receptor-γ (PPAR-γ). The relationship between them remains obscure. We previously demonstrated that curcumin induced gene expression of PPAR-γ in activated HSC, leading to reducing cell proliferation, inducing apoptosis and suppressing expression of extracellular matrix genes. The underlying molecular mechanisms are largely unknown. We recently observed that stimulation of PPAR-γ activation suppressed gene expression of TGF-β receptors in activated HSC, leading to the interruption of TGF-β signaling. This observation supported our assumption of an antagonistic relationship between PPAR-γ activation and TGF-β signaling in HSC. In this study, we further hypothesize that TGF-β signaling might negatively regulate gene expression of PPAR-γ in activated HSC. The present report demonstrates that exogenous TGF-β1 inhibits gene expression of PPAR-γ in activated HSC, which is eliminated by the pretreatment with curcumin likely by interrupting TGF-β signaling. Transfection assays further indicate that blocking TGF-β signaling by dominant negative type II TGF-β receptor increases the promoter activity of PPAR-γ gene. Promoter deletion assays, site-directed mutageneses, and gel shift assays localize two Smad binding elements (SBEs) in the PPAR-γ gene promoter, acting as curcumin response elements and negatively regulating the promoter activity in passaged HSC. The Smad3/4 protein complex specifically binds to the SBEs. Overexpression of Smad4 dose dependently eliminates the inhibitory effects of curcumin on the PPAR-γ gene promoter and TGF-β signaling. Taken together, these results demonstrate that the interruption of TGF-β signaling by curcumin induces gene expression of PPAR-γ in activated HSC in vitro. Our studies provide novel insights into the molecular mechanisms of curcumin in the induction of PPAR-γ gene expression and in the inhibition of HSC activation.