Optical signature of erythrocytes by light scattering in microfluidic flows

A camera-based light scattering approach coupled with a viscoelasticity-induced cell migration technique has been used to characterize the morphological properties of erythrocytes in microfluidic flows. We have obtained the light scattering profiles (LSPs) of individual living cells in microfluidic flows over a wide angular range and matched them with scattering simulations to characterize their morphological properties. The viscoelasticity-induced 3D cell alignment in microfluidic flows has been investigated by bright-field and holographic microscopy tracking, where the latter technique has been used to obtain precise cell alignment profiles in-flow. Such information allows variable cell probability control in microfluidic flows at very low viscoelastic polymer concentrations, obtaining cell measurements that are almost physiological. Our results confirm the possibility of precise, label-free analysis of individual living erythrocytes in microfluidic flows

Agreement between NRS-2002 and MUST nutrition risk scores – a retrospective study

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The National Food Consumption Survey (NFCS): South Africa, 1999

Objective: The aim of the National Food Consumption Survey (NFCS) in South Africa was to determine the nutrient intakes and anthropometric status of children (1-9 years old), as well as factors that influence their dietary intake. Design: This was a cross-sectional survey of a nationally representative sample of all children aged 1-9 years in South Africa. A nationally representative sample with provincial representation was selected using 1996 Census information. Subjects: Of the 3120 children who were originally sampled data were obtained from 2894, a response rate of 93%. Methods: The sociodemographic status of each household was assessed by a questionnaire. Dietary intake was assessed by means of a 24-hour recall and a food-frequency questionnaire from the caregivers of the children. Food purchasing practices were determined by means of a food procurement questionnaire. Hunger was assessed by a modified hunger scale questionnaire. Nutritional status was determined by means of anthropometric measurements: height, weight, head circumference and arm circumference. Results: At the national level, stunting (height-for-age below minus two standard deviations (< -2SD) from the reference median) was by far the most common nutritional disorder, affecting nearly one in five children. The children least affected (17%) were those living in urban areas. Even with regard to the latter, however, children living in informal urban areas were more severely affected (20%) compared with those living in formal urban areas (16%). A similar pattern emerged for the prevalence of underweight (weight-for-age < -2SD), with one in 10 children being affected at the national level. Furthermore, one in 10 (13%) and one in four (26%) children aged 1-3 years had an energy intake less than half and less than two-thirds of their daily energy needs, respectively. For South African children as a whole, the intakes of energy, calcium, iron, zinc, selenium, vitamins A, D, C and E, riboflavin, niacin, vitamin B6 and folic acid were below two-thirds of the Recommended Dietary Allowances. At the national level, data from the 24-hour recalls indicated that the most commonly consumed food items were maize, sugar, tea, whole milk and brown bread. For South African children overall, one in two households (52%) experienced hunger, one in four (23%) were at risk of hunger and only one in four households (25%) appeared food-secure. Conclusion: The NFCS indicated that a large majority of households were food-insecure and that energy deficit and micronutrient deficiencies were common, resulting in a high prevalence of stunting. These results were used as motivation for the introduction of mandatory fortification in South Africa. © The Authors 2005.Conference Pape

CHC22 and CHC17 clathrins have distinct biochemical properties and display differential regulation and function

Clathrins are cytoplasmic proteins that play essential roles in endocytosis and other membrane traffic pathways. Upon recruitment to intracellular membranes, the canonical clathrin triskelion assembles into a polyhedral protein coat that facilitates vesicle formation and captures cargo molecules for transport. The triskelion is formed by trimerization of three clathrin heavy-chain subunits. Most vertebrates have two isoforms of clathrin heavy chains, CHC17 and CHC22, generating two clathrins with distinct cellular functions. CHC17 forms vesicles at the plasma membrane for receptor-mediated endocytosis and at the trans-Golgi network for organelle biogenesis. CHC22 plays a key role in intracellular targeting of the insulin-regulated glucose transporter 4 (GLUT4), accumulates at the site of GLUT4 sequestration during insulin resistance, and has also been implicated in neuronal development. Here, we demonstrate that CHC22 and CHC17 share morphological features, in that CHC22 forms a triskelion and latticed vesicle coats. However, cellular CHC22-coated vesicles were distinct from those formed by CHC17. The CHC22 coat was more stable to pH change and was not removed by the enzyme complex that disassembles the CHC17 coat. Moreover, the two clathrins were differentially recruited to membranes by adaptors, and CHC22 did not support vesicle formation or transferrin endocytosis at the plasma membrane in the presence or absence of CHC17. Our findings provide biochemical evidence for separate regulation and distinct functional niches for CHC17 and CHC22 in human cells. Furthermore, the greater stability of the CHC22 coat relative to the CHC17 coat may be relevant to its excessive accumulation with GLUT4 during insulin resistance. [Abstract copyright: Copyright © 2017, The American Society for Biochemistry and Molecular Biology.

An Evaluation of Grazing Value of Maize and Companion Crops for Wintering Lactating Ewes

Northwestern KwaZulu-Natal (KZN), in South Africa, is well known for its sheep production from natural rangeland in summer (October to May). During winter, however, the nutritional value of the rangeland cannot maintain young growing sheep or pregnant and lactating ewes. With this in mind, Lyle (1991) suggested the use of planted pastures for the winter. Crichton et al. (1998) and Esterhuizen & Niemand (1989) suggested the use of maize crop residues for both cattle and sheep during winter, whereas Moore (1997) evaluated grazing (not harvested) maize for this purpose. He found that the crude protein content of the crop was inadequate and for this protein-rich companion crops were evaluated in this study

The Relationship between Servant Leadership, Affective Commitment: Organizational Citizenship Behavior and Team Effectiveness

The goal of the study was to conduct an analysis of the relationships between servant leadership, affective team commitment, OCB and team effectiveness in the South African school system. A non-probability sample made up of 288 school teachers was drawn from 38 schools in the Western Cape Province of South Africa. Item analysis and confirmatory factor analysis were used to analyse the data. Positive relationships were found between servant leadership and team effectiveness; servant leadership and affective team commitment, affective team commitment and team effectiveness, servant leadership and OCB; affective team commitment and OCB; and OCB and team effectiveness

Rule-based modelling provides an extendable framework for comparing candidate mechanisms underpinning clathrin polymerisation

Abstract Polymerisation of clathrin is a key process that underlies clathrin-mediated endocytosis. Clathrin-coated vesicles are responsible for cell internalization of external substances required for normal homeostasis and life –sustaining activity. There are several hypotheses describing formation of closed clathrin structures. According to one of the proposed mechanisms cage formation may start from a flat lattice buildup on the cellular membrane, which is later transformed into a curved structure. Creation of the curved surface requires rearrangement of the lattice, induced by additional molecular mechanisms. Different potential mechanisms require a modeling framework that can be easily modified to compare between them. We created an extendable rule-based model that describes polymerisation of clathrin molecules and various scenarios of cage formation. Using Global Sensitivity Analysis (GSA) we obtained parameter sets describing clathrin pentagon closure and the emergence/production and closure of large-size clathrin cages/vesicles. We were able to demonstrate that the model can reproduce budding of the clathrin cage from an initial flat array

An Agronomic Evaluation of Grazing Maize Combined with Companion Crops for Sheep in Northwestern KwaZulu-Natal, South Africa

Northwestern KwaZulu-Natal (KZN), in South Africa, is well known for its sheep production from natural rangeland in summer (October to May). During winter however, the nutritional value of the rangeland cannot maintain young growing sheep or pregnant and lactating ewes. With this in mind Lyle (1991) suggested the use of planted pastures for the winter. Crichton, Gertenbach & Henning (1998) and Esterhuizen & Niemand (1989) suggested maize crop residues for both cattle and sheep during winter, whereas Moore (1997) evaluated grazing maize (not harvested) for this purpose. He found that the protein content of the crop was inadequate and for this reason, protein rich companion crops were evaluated in this study

An Agronomic Evaluation of Grazing Maize Combined with Companion Crops for Sheep in Northwestern KwaZulu-Natal, South Africa

Northwestern KwaZulu-Natal (KZN), in South Africa, is well known for its sheep production from natural rangeland in summer (October to May). During winter however, the nutritional value of the rangeland cannot maintain young growing sheep or pregnant and lactating ewes. With this in mind Lyle (1991) suggested the use of planted pastures for the winter. Crichton, Gertenbach & Henning (1998) and Esterhuizen & Niemand (1989) suggested maize crop residues for both cattle and sheep during winter, whereas Moore (1997) evaluated grazing maize (not harvested) for this purpose. He found that the protein content of the crop was inadequate and for this reason, protein rich companion crops were evaluated in this study

Agreement between estimated and measured heights and weights in hospitalised patients – a restrospective study

No Abstrac