Repetitive gait of passive bipedal mechanisms in a three-dimensional environment

The inherent dynamics of bipedal, kneed mechanisms are studied with emphasis on the existence and stability, of repetitive gait in a three-dimensional environment, in the absence of external, active control. The investigation is motivated by observations that sustained anthropomorphic locomotion is largely a consequence of geometric and inertial properties of the mechanism. While the modeling excludes active control, the energy dissipated in ground and knee collisions is continuously re-injected by considering gait down slight inclines. The paper describes the dependence of the resulting passive gait in vertically constrained and unconstrained mechanisms on model parameters, such as ground compliance and ground slope. We also show the possibility of achieving statically unstable gait with appropriate parameter choices.     

Growth in Children with Cerebral Palsy during five years after Selective Dorsal Rhizotomy: a practice-based study

Background  

Overweight is reported as a side effect of SDR. The aims were to study the development of weight, height and body mass index (BMI) during five years after SDR.     

Structural studies of an exopolysaccharide produced by Streptococcus thermophilus THS

The structure of an extracellular polysaccharide (EPS) from Streptococcus thermophilus THS has been determined. A combination of component analysis, methylation analysis and NMR spectroscopy shows that the polysaccharide is composed of pentasaccharide repeating units. Sequential information was obtained by two-dimensional (1)H,(1)H-NOESY and (1)H,(13)C-HMBC NMR experiments. NMR data indicate different mobility within the EPS with a stiffer backbone and a more flexible side-chain.     

Structure of an acidic polysaccharide from the marine bacterium Pseudoalteromonas aliena type strain KMM 3562T containing two residues of L-serine in the repeating unit

The structure of an acidic polysaccharide from Pseudoalteromonas aliena type strain KMM 3562(T) has been elucidated. The polysaccharide was studied by component analysis, (1)H and (13)C NMR spectroscopy, including 2D NMR experiments. A (1)H, (13)C band-selective constant-time heteronuclear multiple-bond connectivity experiment was used to determine amide linkages, between serine and uronic acid (UA) residues, via (3)J(H,C) correlations between Ser-alphaH and UA-C-6. It was found that the polysaccharide consists of pentasaccharide repeating units with the following structure: [carbohydrate structure]; see text.     

State of degradation in archeological oak from the 17th century vasa ship: substantial strength loss correlates with reduction in (holo)cellulose molecular weight

In 1628, the Swedish warship Vasa capsized on her maiden voyage and sank in the Stockholm harbor. The ship was recovered in 1961 and, after polyethylene glycol (PEG) impregnation, it was displayed in the Vasa museum. Chemical investigations of the Vasa were undertaken in 2000, and extensive holocellulose degradation was reported at numerous locations in the hull. We have now studied the longitudinal tensile strength of Vasa oak as a function of distance from the surface. The PEG-content, wood density, and cellulose microfibril angle were determined. The molar mass distribution of holocellulose was determined as well as the acid and iron content. A good correlation was found between the tensile strength of the Vasa oak and the average molecular weight of the holocellulose, where the load-bearing cellulose microfibril is the critical constituent. The mean tensile strength is reduced by approximately 40%, and the most affected areas show a reduction of up to 80%. A methodology is developed where variations in density, cellulose microfibril angle, and PEG content are taken into account, so that cell wall effects can be evaluated in wood samples with different rate of impregnation and morphologies.     

The Swedish version of the Normalization Process Theory Measure S-NoMAD: translation,adaptation, and pilot testing

Background

The original British instrument the Normalization Process Theory Measure (NoMAD) is based on the four core constructs of the Normalization Process Theory: Coherence, Cognitive Participation, Collective Action, and Reflexive Monitoring. They represent ways of thinking about implementation and are focused on how interventions can become part of everyday practice.

Aim

To translate and adapt the original NoMAD into the Swedish version S-NoMAD and to evaluate its psychometric properties based on a pilot test in a health care context including in-hospital, primary, and community care contexts.

Methods

A systematic approach with a four-step process was utilized, including forward and backward translation and expert reviews for the test and improvement of content validity of the S-NoMAD in different stages of development. The final S-NoMAD version was then used for process evaluation in a pilot study aimed at the implementation of a new working method for individualized care planning. The pilot was executed in two hospitals, four health care centres, and two municipalities in a region in northern Sweden. The S-NoMAD pilot results were analysed for validity using confirmatory factor analysis, i.e. a one-factor model fitted for each of the four constructs of the S-NoMAD. Cronbach’s alpha was used to ascertain the internal consistency reliability.

Results

In the pilot, S-NoMAD data were collected from 144 individuals who were different health care professionals or managers. The initial factor analysis model showed good fit for two of the constructs (Coherence and Cognitive Participation) and unsatisfactory fit for the remaining two (Collective Action and Reflexive Monitoring) based on three items. Deleting those items from the model yielded a good fit and good internal consistency (alphas between 0.78 and 0.83). However, the estimation of correlations between the factors showed that the factor Reflexive Monitoring was highly correlated (around 0.9) with the factors Coherence and Collective Action.

Conclusions

The results show initial satisfactory psychometric properties for the translation and first validation of the S-NoMAD. However, development of a highly valid and reliable instrument is an iterative process, requiring more extensive validation in various settings and populations. Thus, in order to establish the validity and reliability of the S-NoMAD, additional psychometric testing is needed.

     

Structural features of non-granular spherulitic maize starch

Complementary analyses of the internal structure of spherulites crystallized from high-amylose maize starch were obtained using light, electron and atomic force microscopy. Radially oriented crystalline lamellae were observed in transmission and scanning electron microscopy, as well as AFM. Internal structures consistent with the central hilum region of starch granules were observed. Spherulites were composed largely of linear or lightly branched starch polymers. Degradation of amylopectin at gelatinization temperatures of 180 degrees C was evident, but iodine binding suggested a high molecular weight (>100 DP) for the spherulitic polymers.     

Structural elucidation of the O-antigenic polysaccharide from the enteroaggregative Escherichia coli strain 180/C3 and its immunochemical relationship with E. coli O5 and O65

The structure of the O-antigen polysaccharide (PS) from the enteroaggregative Escherichia coli strain 180/C3 has been determined. Sugar and methylation analysis together with (1)H and (13)C NMR spectroscopy were the main methods used. The PS is composed of tetrasaccharide repeating units with the following structure: -->2)beta-D-Quip3NAc-(1-->3)beta-D-RIBf-(1-->4)beta-D-Galp-(1-->3)alpha-D-GalpNAc-(1-->. Analysis of NMR data indicates that the presented sequence of sugar residues also represents the biological repeating unit of the O-chain. The structure is closely related to that of O-antigen polysaccharide from E. coli O5 and partially to that of E. coli O65. The difference between the O-antigen from the 180/C3 strain and that of E. coli O5 is the linkage to the D-Quip3NAc residue, which in the latter strain is 4-O-substituted. The E. coli O65 O-antigen contains as part of its linear pentasaccharide repeating unit a similar structural element, namely -->4)-beta-d-GalpA-(1-->3)-alpha-D-GlcpNAc-(1-->2)-beta-D-Quip3NAc-(1-->, thereby indicating that a common epitope could be present for the two polysaccharides. Monospecific anti-E. coli O5 rabbit serum did not distinguish between the two positional isomeric structures neither in slide agglutination nor in an indirect enzyme immunoassay. The anti-O65 serum did react with both the 180/C3 and O5 LPS showing a partial cross-reactivity.     

Mutations in genes encoding complement inhibitors CD46 and CFH affect the age at nephritis onset in patients with systemic lupus erythematosus

Introduction

Inherited deficiencies of several complement components strongly predispose to systemic lupus erythematosus (SLE) while deficiencies of complement inhibitors are found in kidney diseases such as atypical hemolytic uremic syndrome (aHUS).

Methods

The exons of complement inhibitor genes CD46 and CFH (factor H) were fully sequenced using the Sanger method in SLE patients with nephritis originating from two cohorts from southern and mid Sweden (n = 196). All identified mutations and polymorphisms were then analyzed in SLE patients without nephritis (n = 326) and in healthy controls (n = 523).

Results

We found nonsynonymous, heterozygous mutations in CFH in 6.1% patients with nephritis, in comparison with 4.0% and 5.4% in patients without nephritis and controls, respectively. No associations of SLE or nephritis with common variants in CFH (V62I/Y402H/E936D) were found. Furthermore, we found two nonsynonymous heterozygous mutations in CD46 in SLE patients but not in controls. The A353V polymorphism, known to affect function of CD46, was found in 6.6% of nephritis patients versus 4.9% and 6.1% of the non-nephritis SLE patients and controls. The presence of mutations in CD46 and CFH did not predispose to SLE or nephritis but was associated with earlier onset of nephritis. Furthermore, we found weak indications that there is one protective and one risk haplotype predisposing to nephritis composed of several polymorphisms in noncoding regions of CD46, which were previously implicated in aHUS.

Conclusions

SLE nephritis is not associated with frequent mutations in CFH and CD46 as found in aHUS but these may be modifying factors causing earlier onset of nephritis.