Estimation of undernutrition and mean calorie intake in Africa: methodology, findings and implications

Background

Agricultural science can address a population's vitamin, amino acid and mineral malnutrition through biofortification - agronomy, plant breeding and biotechnology to develop crops with high nutrient contents. Biofortified crop varieties should be grown in areas with populations at risk of nutrient deficiency and in areas where the same crop is already grown and consumed. Information on the population at risk of nutrient deficiency is rarely available for sub-national administrative units, such as provinces, districts, and municipalities. Nor is this type of information commonly analyzed with data on agricultural production. This project developed a method to identify populations at risk of nutrient deficiency in zones with high crop production, places where biofortification interventions could be targeted.

Results

Nutrient deficiency risk data were combined with crop production and socioeconomic data to assess the suitability of establishing an intervention. Our analysis developed maps of candidate sites for biofortification interventions for nine countries in Latin America and the Caribbean. Results for Colombia, Nicaragua, and Bolivia are presented in this paper. Interventions in northern Colombia appear promising for all crops, while sites for bean biofortification are widely scattered throughout the country. The most promising sites in Nicaragua are found in the center-north region. Candidate sites for biofortification in Bolivia are found in the central part of the country, in the Andes Mountains. The availability and resolution of data limits the analysis. Some areas show opportunities for biofortification of several crops, taking advantage of their spatial coincidence. Results from this analysis should be confirmed by experts or through field visits.

Conclusion

This study demonstrates a method for identifying candidate sites for biofortification interventions. The method evaluates populations at risk of nutrient deficiencies for sub-national administrative regions, and provides a reasonable alternative to more costly, information-intensive approaches.     

我省长学制医学教育的回顾与思考

我省七年制医学教育开办了近20年,为社会培养了一批深受欢迎、质量较好和具有较高综合素质的高层次医学人才。建立与我省经济发展水平相适应的以五年制为主体、重点发展八年制的医学教育学制体系,是我省高等医学教育发展的必然趋势。     

Tissue expansion of free and pedicled flaps after transfer: possibilities and indications

Tissue expansion in combination with flap transfer has been widely reported as preexpansion of flaps, but only once as expansion of a free flap after transfer. Three free flaps and one pedicled flap were expanded after transfer. Indication, timing of expander implantation and explantation, technical aspects, and complications are reviewed. Indications for expander implantation after flap coverage were adjacent scar contracture, a secondary ulcer, or correction of contour deformity. The expander was placed as early as 4.5 months after free flap transfer. Low grade infection and seroma were complications necessitating early expander removal in two cases. The outcome was satisfactory in all four patients. Tissue expansion after flap transfer has been shown to be a reliable reconstructive option in selected cases. Indications are rare and include hypertrophic scar formation, scar contracture, secondary ulceration, or reconstructive procedures. In early free flap expansion, it is critical to avoid mechanical pressure of the pedicle. In musculocutaneous flaps, this can be accomplished by placing the expander subcutaneously. If more than 6 months have passed since transfer of the flap, the randomized blood supply is sufficient to place the expander anywhere under the flap.     

Altered electrocortical brain activity after ACL reconstruction during force control

Afferent proprioceptive information from the knee joint may be altered due to a reconstruction of the anterior cruciate ligament (ACL), which could result in changes of cortical activity. The aim of the study is to look if force sensation and cortical activation measured by EEG are influenced by an ACL‐reconstruction when performing a force reproduction task. Nine patients after ACL reconstruction and nine healthy controls were asked to reproduce 50% of their maximal voluntary isometric contraction (MVIC) reproduction. EEG power values related to frequency bands and the error in reproduction were collected while performing the force reproduction. The aberration error demonstrated no significant differences between groups. The cortical activity results in significant higher frontal Theta power during the force reproduction task with the reconstructed limb (F3 and Fz: p < 0.05) of the ACL group compared to the controls. The EEG was able to measure changes in electrocortical activity after ACL‐reconstruction in force reproduction, whereas performance data was not affected. The results were discussed in terms of differences in attentional control with involvement of the anterior cingulate cortex related to higher frontal Theta power in the ACL patients. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 29: 1383–1389, 2011     

Erh?hte Konzentrationen des excitotoxischen Neurotransmiters Glutamat im Liquor von Frühgeborenen mit progressiver posth?morrhagischer Ventrikelerweiterung

Hintergrund. Glutamat, der wichtigste erregende Transmitter im Gehirn, wirkt in zu hohen Konzentrationen neurotoxisch und kann eine neuronale Sch?digung verursachen.     

Parentage analysis by endonuclease shattering of hypervariable DNA

Single-locus DNA probes for tandem repeat sequences are now used in conjunction with particular endonucleases to characterize heritable restriction fragment lengths in parentage tests. Southern blots of this type, however, demonstrate only two attributes of an allele: its length and the presence of nucleotide sequences that are complementary to the probe. Not all restriction fragments of the same apparent length that react with the same probe are identical. Differences between comigrating fragments can be detected by the selection of a restriction enzyme that recognizes sites in a subset of the repeat sequences, and the information content of these loci is therefore increased. This report describes a paternity case in which two brothers appeared, after DNA phenotyping using Hinf I, to be the father. A second phenotyping using Hae III excluded one of the brothers.     

125I粒子对Hela细胞杀伤作用的实验研究

目的观察体外Hela细胞在^125I粒子照射下细胞凋亡和增殖的规律，探讨^125I粒子对肿瘤的杀伤作用。方法用^125I粒子照射Hela细胞，用不同的方法观察不同剂量和时间点细胞的增殖反应及形态变化。结果受照射细胞发生凋亡，于Ⅱb期出现凋亡小体；细胞凋亡率随累积剂量的增加而增加，于5Gy时出现凋亡率峰值；细胞克隆形成率显著下降，与凋亡形成呈反向关系。并有反剂量率效应。结论^125I粒子对肿瘤的治疗作用可能为早期抑制肿瘤细胞增殖，晚期使肿瘤细胞大量凋亡。     

Thickness determination of biological samples with a zeta-calibrated scanning tunneling microscope.

A single-tube scanning tunneling microscope has been zeta-calibrated by using atomic steps of crystalline gold and was used for measuring the thickness of two biological samples, metal-coated as well as uncoated. The hexagonal surface layer of the bacterium Deinococcus radiodurans with an open network-type structure shows thickness values that are strongly influenced by the substrate and the preparation method. In contrast, the thickness of the purple membrane of Halobacterium halobium with its densely packed less-corrugated structure exhibits very little variation in thickness in coated preparations and the values obtained are in good agreement with x-ray data.     

Trabecular bone architecture in female renal allograft recipients-- assessed by computed tomography

BACKGROUND: Osteopenia with decreased bone mineral density (BMD) is a frequent finding in renal allograft recipients. Data concerning the bone architecture in these patients do not exist, however. METHODS: We compared the bone architecture of 33 randomly assigned women (age 49 +/- 12 years), who had received renal allografts 5.6 +/- 5.3 years before the investigation, with 74 women (age 50 +/- 14 years) who were admitted for osteodensitometry. All patients underwent single-energy computed tomography (SEQCT) and a midvertebral high-resolution tomography with computer-assisted analysis of the trabecular vertebral body architecture. RESULTS: Progressive alteration of bone architecture was associated with increasing vertebral height loss of the vertebral body. Height reduction of a vertebral body of more than 15% was associated with a significantly lower BMD (-2.3 +/- 0.8 versus -1.1 +/- 1.1 standard deviations below normal BMD), a lower trabecular bone area (13 +/- 8% versus 42 +/- 22%) and a lower trabecular diameter (1.4 +/- 0.5 mm versus 2.2 +/- 0.8 mm) compared to recipients without height reduction. In comparison to a matched group of patients with similarly reduced BMD (1.1 +/- 1.2 versus 1.2 +/- 1.1 SD below normal BMD), renal allograft recipients showed a lower number of trabecular plates (5.6 +/- 3.1 versus 7.0 +/- 3.7) and a smaller intertrabecular surface (54 +/- 116 mm versus 75 +/- 138 mm). CONCLUSIONS: Alterations of bone architecture in renal allograft recipients were associated with progressive vertebral height loss. Despite similar bone mineral density, differences of bone architecture could be observed between renal allograft recipients and patients with osteoporosis.