Growth and setting of gas bubbles in a viscoelastic matrix imaged by X-ray microtomography: the evolution of cellular structures in fermenting wheat flour dough.

X-ray tomography is a relevant technique for the dynamic follow-up of gas bubbles in an opaque viscoelastic matrix, especially using image analysis. It has been applied here to pieces of fermenting wheat flour dough of various compositions, at two different voxel sizes (15 and 5 µm). The resulting evolution of the main cellular features shows that the creation of cellular structures follows two regimes that are defined by a characteristic time of connectivity, tc [30 and 80 min]: first (t ≤ tc), bubbles grow freely and then (t ≥ tc) they become connected since the percolation of the gas phase is limited by liquid films. During the first regime, bubbles can be tracked and the local strain rate can be measured. Its values (10(-4)-5 × 10(-4) s(-1)) are in agreement with those computed from dough viscosity and internal gas pressure, both of which depend on the composition. For higher porosity, P = 0.64 in our case, and thus occurring in the second regime, different cellular structures are obtained and XRT images show deformed gas cells that display complex shapes. The comparison of these images with confocal laser scanning microscopy images suggests the presence of liquid films that separate these cells. The dough can therefore be seen as a three-phase medium: viscoelastic matrix/gas cell/liquid phase. The contributions of the different levels of matter organization can be integrated by defining a capillary number (C = 0.1-1) that makes it possible to predict the macroscopic dough behavior.

Processing & rheological properties of wheat flour dough and bread containing high levels of soluble dietary fibres blends.

Wheat flour doughs were processed with soluble dietary fibres (DF) added up to 40% (w/w flour). DF were made of a ternary mixture of maltodextrins (MT, 3/5), pectins (PE, 1/5) and inulin (IN, 1/5). The addition of DF decreased the specific mechanical energy developed by the mixer, mainly because of water addition. It increased the ratio of storage moduli and the elongational viscosity of the dough, but decreased the strain hardening index. Energy input and rheological changes at mixing largely explained the decreases of porosity characteristic time and stability time during fermentation. It was possible to add up to 30% DF with a moderate increase of bread density, and 20%, with little change of crumb cellular structure. Hence, the changes of bread crumb texture were not mainly due to bread density, but rather likely to the changes of properties of the intrinsic material. Results obtained by addition of single fibre source, especially inulin, deviated from the main trends observed for texture and rheological properties. These results provide a good basis to design breads with increased dietary fibre content.

Bioavailability of starch in bread rich in amylose: metabolic responses in healthy subjects and starch structure.

OBJECTIVE: This study investigated whether postprandial metabolic responses to bread could be lowered by substituting high amylose maize starch for a part of the flour. DESIGN AND SUBJECTS: Eight healthy subjects consumed test meals of equivalent nutritional composition based on white wheat bread, bread rich in amylose (HAWB) and spaghetti as a breakfast meal. Blood samples were collected to measure insulin and glucose concentration during two hours after consumption. The degree of starch crystallinity was investigated by X-ray diffraction and DSC analysis. RESULTS: HAWB produced low glycaemic (60 +/- 18) and insulinaemic (57 +/- 20) indexes similar to those of spaghetti (83 +/- 46, 61 +/- 16). In vitro amylase hydrolysis of the three foods showed that high amylose content in HAWB significantly lowered starch degradation in bread without affecting hydrolysis kinetics. Addition of amylose in dough increased the resistant starch content of HAWB (14% of dry matter). The resistant starch fraction was mainly composed of crystalline amylose (B-type X-ray diffraction pattern, melting temperature 105 degrees C) attributable to native high amylose maize starch incompletely gelatinised during bread-cooking. CONCLUSIONS: Bread produced by the substitution of high amylose maize starch for a part of wheat flour showed a low glycaemic index. Resistant starch in HAWB corresponded to native crystalline amylose not gelatinised during normal bread-processing conditions.

Evidence of 131I and (134,137)Cs activities in Bordeaux, France due to the Fukushima nuclear accident.

Following the Fukushima nuclear accident, low-background gamma spectrometry measurements were performed with HPGe detectors at the PRISNA platform located at the CENBG laboratory in Bordeaux, France. Different kinds of samples were collected and measured between March 26 and May 14, 2011. The first fission product observed was (131)I with maximum activity values of 2.4 mBq/m(3) in atmospheric dusts in air, 3.5 Bq/L in rain water, 15 Bq/kg in grass and 0.9 Bq/L in cow milk. The (134,137)Cs isotopes were also detected in air and in grass at a maximum level of 0.2 mBq/m(3) and 0.7 Bq/kg respectively, around one order of magnitude less than (131)I activity, but they were below detection limits in the other samples. All these activity values were consistent with others measured in France by IRSN and were well below those reported in May 1986 after the Chernobyl accident.

A setup combining magneto-optical Kerr effect and conversion electron Mössbauer spectrometry for analysis of the near-surface magnetic properties of thin films.

We propose a system allowing the characterization of thin magnetic multilayer structures that combine conversion electron Mossbauer spectrometry (CEMS) under applied magnetic field with the magneto-optical Kerr effect (MOKE) technique. Measured hysteresis loops obtained from the MOKE part are used for investigation of sample surface magnetic properties. The CEMS part of such a system is suitable for studying the spatial spin distribution during magnetization reversal under applied magnetic field, whose values are established from the measured MOKE loop. The combined technique is demonstrated on the results obtained at 300 K on an exchange-coupled ferrimagnetic amorphous GdFe/TbFe bilayer, where the center of the GdFe layer is enriched in (57)Fe. Both techniques confirm in-plane uniaxial anisotropy. The spin structure at the position of the probe layer is analyzed for several values of the external magnetic field applied in the hard magnetization axis direction.

Open fractures of the shaft of the tibia treated by intramedullary nailing.

The technique and results of treating 57 selected open tibial shaft fractures by intramedullary nailing are reviewed. All but three of the the fractures were located in the middle third of the tibia; two thirds of these were transverse or short obliques. Excellent or good results were obtained in 87.7 percent of all cases. The mean time to union of Type I fractures was 12.6 weeks, of Type II fractures 15 weeks, and of Type III fractures 20.5 weeks. Complications included two infections in two of the Type III fractures.

Musculoskeletal complaints, functional capacity, personality and psychosocial factors.

OBJECTIVES: The aim of the research was to study the association between psychosocial and personality factors, and neck and wrist-hand musculoskeletal complaints, taking account of the occupational factors of force, posture and repetitiveness, and non-occupational risk factors such as sport, hobbies, medical history. METHODS: During personal interviews 133 women from seven different companies, working at constraining workplaces (very repetitive work), answered several questionnaires. These concerned: personal characteristics and history; work characteristics; psychosocial factors (perception and appreciation of the work situation, satisfaction at work, stress symptoms, Karasek questionnaire) and personality factors (neuroticism, conscientiousness, type-A behavior). They also undertook functional and psychomotor tests (wrist angles, grip strength and a dexterity test). Logistic regression models were calculated. RESULTS: Wrist-hand complaints appear to be associated with some personal characteristics (smoking habits, fewer hobbies), work constraints (fewer breaks, heavy lifting efforts) and some personality (introversion) and psychosocial factors (worse appreciation of work). Neck complaints are also associated with some personal characteristics (young people, small, bad health, hormonal problems, fewer hobbies), some personality (urgency of time) and psychosocial factors (constraints as seen by the supervisor). CONCLUSION: The study confirms the multifactorial character of the musculoskeletal disorders and underlines the need for a global ergonomic approach to work situations, taking into account all their physical, psychological and social components.

Gene induction of stilbene biosynthesis in Scots pine in response to ozone treatment, wounding, and fungal infection.

The S-adenosyl-L-methionine:pinosylvin-O-methyltransferase (PMT) gene was sequenced from Scots pine (Pinus sylvestris). The open reading frame is arranged in two exons spaced by one 102-bp intron. Promoter regulatory elements such as two "CAAT" boxes and one "TATA" box were identified. Several cis-regulatory elements were recognized: stress-responsive elements (Myb-responsive elements) as well as G, H, and GC boxes. Moreover, elicitor-responsive elements (W boxes) and a sequence resembling the simian virus 40 enhancer core were found. In phloem and needles of control trees, the transcripts of stilbene synthase (STS) and PMT were hardly detectable. Increased ozone fumigation up to 0.3 microL L(-1) enhanced the transcript level of STS and PMT in needles but not in healthy phloem. Wounding, e.g. mock inoculation, of stem-phloem was characterized by a transient increase in STS and PMT transcripts, which was more pronounced in the case of fungal inoculation. Combination of fungal-challenge or mock treatment with ozone resulted in a positive interaction at 0.3 microL L(-1). Scots pine stilbene formation appeared to be induced via STS and PMT gene expression upon ozone and fungal stress as well as wounding. The broad stress-responsiveness is in agreement with the range of various cis-acting elements detected in the STS and PMT promoters.

Molecular cloning and functional expression of a stress-induced multifunctional O-methyltransferase with pinosylvin methyltransferase activity from Scots pine (Pinus sylvestris L.).

Formation of pinosylvin (PS) and pinosylvin 3-O-monomethyl ether (PSM), as well as the activities of stilbene synthase (STS) and S-adenosyl-1-methionine (SAM):pinosylvin O-methyltransferase (PMT), were induced strongly in needles of Scots pine seedlings upon ozone treatment, as well as in cell suspension cultures of Scots pine upon fungal elicitation. A SAM-dependent PMT protein was purified and partially characterised. A cDNA encoding PMT was isolated from an ozone-induced Scots pine cDNA library. Southern blot analysis of the genomic DNA suggested the presence of a gene family. The deduced protein sequence showed the typical highly conserved regions of O-methyltransferases (OMTs), and average identities of 20-56% to known OMTs. PMT expressed in Escherichia coli corresponded to that of purified PMT (40 kDa) from pine cell cultures. The recombinant enzyme catalysed the methylation of PS, caffeic acid, caffeoyl-CoA and quercetin. Several other substances, such as astringenin, resveratrol, 5-OH-ferulic acid, catechol and luteolin, were also methylated. Recombinant PMT thus had a relatively broad substrate specificity. Treatment of 7-year old Scots pine trees with ozone markedly increased the PMT mRNA level. Our results show that PMT represents a new SAM-dependent OMT for the methylation of stress-induced pinosylvin in Scots pine needles.

Active epidemiological surveillance of musculoskeletal disorders in a shoe factory.

AIMS: (1) To evaluate an active method of surveillance of musculoskeletal disorders (MSDs). (2) To compare different criteria for deciding whether or not a work situation could be considered at high risk of MSDs in a large, modern shoe factory. METHODS: A total of 253 blue collar workers were interviewed and examined by the same physician in 1996; 191 of them were re-examined in 1997. Risk factors of MSDs were assessed for each worker by standardised job site work analysis. Prevalence and incidence rates of carpal tunnel syndrome, rotator cuff syndrome, and tension neck syndrome were calculated for each of the nine main types of work situation. Different criteria used to assess situations with high risk of MSDs were compared. RESULTS: On the basis of prevalence data, three types of work situation were detected to be at high risk of MSDs: cutting, sewing, and assembly preparation. The three types of work situations identified on the basis of incidence data (sewing preparation, mechanised assembling, and finishing) were different from those identified by prevalence data. At least one recognised risk factor for MSDs was identified for all groups of work situations. The ergonomic risk could be considered as serious for the four types of work situation having the highest ergonomic scores (sewing, assembly preparation, pasting, and cutting). CONCLUSION: The results of the health surveillance method depend largely on the definition of the criteria used to define the risk of MSDs. The criteria based on incidence data are more valid than those based on prevalence data. Health and risk factor surveillance must be combined to predict the risk of MSDs in the company. However, exposure assessment plays a greater role in determining the priorities for ergonomic intervention.