Anaemia, iron status and vitamin A deficiency among adolescent refugees in Kenya and Nepal

OBJECTIVE: To investigate the prevalence of anaemia (haemoglobin<11.0 to 13.0 g dl(-1) depending on age and sex group), iron deficiency (transferrin receptor concentration>8.3 microg ml(-1)) and vitamin A deficiency (serum retinol <0.7 micromol l(-1)) in adolescent refugees. DESIGN: Cross-sectional surveys. SETTING: Kakuma refugee camp in Kenya and seven refugee camps in Nepal. SUBJECTS: Adolescent refugee residents in these camps. RESULTS: Anaemia was present in 46% (95% confidence interval (CI): 42-51) of adolescents in Kenya and in 24% (95% CI: 20-28) of adolescents in Nepal. The sensitivity of palmar pallor in detecting anaemia was 21%. In addition, 43% (95% CI: 36-50) and 53% (95% CI: 46-61) of adolescents in Kenya and Nepal, respectively, had iron deficiency. In both surveys, anaemia occurred more commonly among adolescents with iron deficiency. Vitamin A deficiency was found in 15% (95% CI: 10-20) of adolescents in Kenya and 30% (95% CI: 24-37) of adolescents in Nepal. Night blindness was not more common in adolescents with vitamin A deficiency than in those without vitamin A deficiency. In Kenya, one of the seven adolescents with Bitot's spots had vitamin A deficiency. CONCLUSIONS: Anaemia, iron deficiency and vitamin A deficiency are common among adolescents in refugee populations. Such adolescents need to increase intakes of these nutrients; however, the lack of routine access makes programmes targeting adolescents difficult. Adolescent refugees should be considered for assessment along with other at-risk groups in displaced populations.     

One-time transfers of cash or capital have long-lasting effects on microenterprises in Sri Lanka

Standard economic theory suggests that one-time business grants can have at most temporary effects, and accordingly, policies to increase incomes of the self-employed in developing countries typically rely on sustained engagement. In contrast, we found long-lasting impacts from one-time grants given in a randomized experiment to subsistence firms. Five years after we gave $100 or $200 to 115 of 197 male and 100 of 190 female Sri Lankan microenterprise owners, we found 10-percentage-point-higher enterprise survival rates, and $8-to-$12-per-month-higher profits for male-owned businesses that received the grants. Female-owned businesses showed no long-term (or short-term) impacts. Our follow-up investigation interviewed 94% of the original sample and collected survivorship data from the remaining 6%, demonstrating that tracking long-term outcomes is both feasible and worthwhile. The results suggest that one-off grants may have lasting impacts on some types of subsistence firms, challenging the view that sustained engagement is always required.     

Validation of a bulk tank milk antibody ELISA to detect dairy herds likely infected with bovine viral diarrhoea virus in New Zealand

AIMS: To assess the sensitivity and specificity of a bulk tank milk (BTM) antibody enzyme-linked immunosorbent assay (ELISA) to detect likely infection of a dairy herd with bovine vi- ral diarrhoea virus (BVDV). The ELISA was subsequently used to estimate the prevalence of likely infected herds in parts of the North Island of New Zealand.

METHODS: BTM samples from 724 randomly selected dairy herds in the Waikato, Bay of Plenty and Northland regions of New Zealand were tested for BVDV antibodies. From this group, 20 herds were again randomly selected from each of the quartiles of the ELISA percentage inhibition (%INH) result. From each participant herd, serum from 15 randomly selected calves aged 6–18 months and 15 cows was collected and tested using an indirect blocking ELISA for BVDV antibodies.

RESULTS: Among serum results from calves from 50 herds available for analysis, 34 (68%) herds were classified as likely non-infected (0-3 seropositive among 15 calves) and 16 (32%) as likely infected (5–15 seropositive among 15 calves). Receiver- operator characteristic (ROC) analysis identified an optimal cut-off for BTM of 80%INH associated with 81% sensitivity and 91% specificity for likely herd infection. The prevalence of BVDV antibodies in cows within herds and %INH for BVDV in bulk milk were positively correlated (p<0.01). The association between bulk milk %INH and the prevalence of BVDV antibodies in calves was stronger than the same association in cows. Based on the threshold of 80%INH, the 95% confidence interval (CI) for prevalence of likely infection in the 724 herds in the Waikato, Bay of Plenty and Northland regions of New Zealand was 12–17%. Vaccination against BVDV was not significantly associated with the likely infection status of the herd based on prevalence of BVDV antibodies among calves.

CONCLUSION: An ELISA test result for BVDV antibodies in BTM ≥80%INH can be used as a threshold to indicate the presence of likely infection with BVDV in dairy herds in New Zealand, with 81% sensitivity and 91% specificity.     

Genetic‐Quantitative Study of the First‐Service Pregnancy Probability of Murrah Heifers

Because of the importance of reproduction in stock breeding systems, it is necessary to find selection criteria that increase reproductive efficiency. The aim of this study was to estimate genetic parameters for the probability of conception on first service (PROB) in Murrah heifers, and its association with other traits of economic interest [age at first calving (AFC), service period, calving interval and milk yield at 270 days], with the purpose of evaluating their use as selection criteria. Reproductive information and first lactation records of 1200 Murrah heifers were used to perform two‐trait analyses between PROB and the other characteristics. Bayesian inference was used to estimate the variance components, considering PROB as threshold and the other as linear factors. The results demonstrate that this trait has heritability of 0.15, indicating the possibility of a genetic gain by using it for selection. With respect to the genetic correlation estimates, the only high‐magnitude association was with AFC (?0.899), which is the current criterion indicating sexual precocity of females. In the light of the parameters estimated, the first‐service pregnancy rate is an alternative for indication of sexual precocity, although presenting a smaller genetic gain than the current standard AFC. Nevertheless, additional research should be conducted regarding this trait to assess the economic importance of its use in dairy buffalo production systems.     

In Vitro Binding of Bile Acids by Rice Bran,Oat Bran,Barley and β‐Glucan Enriched Barley

The in vitro bile acid binding by rice bran, oat bran, dehulled barley, and β‐glucan enriched barley was determined using a mixture of bile acids at a duodenal physiological pH of 6.3. Six treatments and two blank incubations were conducted testing substrates on an equal protein basis. The relative in vitro bile acid binding of the cereal brans on an equal total dietary fiber (TDF) and insoluble dietary fiber (IDF) basis considering cholestyramine as 100% bound was rice bran 45 and 49%; oat bran 23 and 30%; dehulled barley 33 and 57%; and β‐glucan enriched barley 20 and 40%, respectively. Bile acid bindings on equal protein basis for the respective cereals were 68, 26, 41, and 49%. Bile acid binding by rice bran may account to a great extent for its cholesterol‐lowering properties, while bile acid binding by oat bran suggests that the primary mechanism of cholesterol lowering by oat bran is not due to the bile acid binding by its soluble fiber. Bile acid binding was not proportional to the soluble fiber content of the cereal brans tested. Except for dehulled barley, bile acid binding for rice bran, oat bran, and β‐glucan enriched barley appear to be related to their IDF content. Highest relative bile acid binding values for rice bran and β‐glucan enriched barley were observed on an equal protein basis, whereas highest values for dehulled barley were based on IDF. Data suggest that of all four cereals tested, bile acid binding may be related to IDF or protein anionic, cationic, physical and chemical structure, composition, metabolites, or their interaction with active binding sites.     

Transpiration-induced axial and radial tension gradients in trunks of Douglas-fir trees

We determined the axial and radial xylem tension gradients in trunks of young Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) trees. Axial specific conductivity (k(s-a)) and sap flux density (Js) were measured at four consecutive depths within the sapwood at a stem height of 1 m. By definition, at a given position in the bole, Js is a function not only of k(s-a) but also of the driving force for water movement. The Js:k(s-a) ratio was therefore used to estimate axial tension gradients and the radial gradients at a stem height of 1 m were calculated from the differences in axial tension gradients at each depth. Tracheid lumen diameter and tracheid length were used to predict differences in k(s-a) and its divergence from the theoretical k(s-a) determined by the Hagen Poisseuille equation. The ratio of k(s-a) (determined in the laboratory) to Js (measured in the field) varied with depth in the sapwood, resulting in non-uniform axial and radial tension gradients from inner to outer sapwood. Transpiration-induced axial tension gradients were in the range of 0.006-0.01 MPa m(-1) excluding the gravitational tension gradient. At a stem height of 1 m, radial tension gradients were in the range of 0.15-0.25 MPa m(-1) and were lower in the middle sapwood than in the inner or outer sapwood. Axial tension gradients were 44-50% higher in the outer sapwood than in the inner sapwood. At a stem height of 1 m, radial Js, calculated on the basis of radial tension gradients and measured radial specific conductivity (k(s-r)), was about two orders of magnitude smaller than axial Js. Our findings indicate that large radial tension gradients occur in the sapwood and clarify the role played by xylem k(s-a) and k(s-r) in determining in situ partitioning of Js in the axial and radial directions.     

Long-term resource variation and group size: A large-sample field test of the Resource Dispersion Hypothesis

Background  

The Resource Dispersion Hypothesis (RDH) proposes a mechanism for the passive formation of social groups where resources are dispersed, even in the absence of any benefits of group living per se. Despite supportive modelling, it lacks empirical testing. The RDH predicts that, rather than Territory Size (TS) increasing monotonically with Group Size (GS) to account for increasing metabolic needs, TS is constrained by the dispersion of resource patches, whereas GS is independently limited by their richness. We conducted multiple-year tests of these predictions using data from the long-term study of badgers Meles meles in Wytham Woods, England. The study has long failed to identify direct benefits from group living and, consequently, alternative explanations for their large group sizes have been sought.     

Constraints on physiological function associated with branch architecture and wood density in tropical forest trees

This study examined how leaf and stem functional traits related to gas exchange and water balance scale with two potential proxies for tree hydraulic architecture: the leaf area:sapwood area ratio (A(L):A(S)) and wood density (rho(w)). We studied the upper crowns of individuals of 15 tropical forest tree species at two sites in Panama with contrasting moisture regimes and forest types. Transpiration and maximum photosynthetic electron transport rate (ETR(max)) per unit leaf area declined sharply with increasing A(L):A(S), as did the ratio of ETR(max) to leaf N content, an index of photosynthetic nitrogen-use efficiency. Midday leaf water potential, bulk leaf osmotic potential at zero turgor, branch xylem specific conductivity, leaf-specific conductivity and stem and leaf capacitance all declined with increasing rho(w). At the branch scale, A(L):A(S) and total leaf N content per unit sapwood area increased with rho(w), resulting in a 30% increase in ETR(max) per unit sapwood area with a doubling of rho(w). These compensatory adjustments in A(L):A(S), N allocation and potential photosynthetic capacity at the branch level were insufficient to completely offset the increased carbon costs of producing denser wood, and exacerbated the negative impact of increasing rho(w) on branch hydraulics and leaf water status. The suite of tree functional and architectural traits studied appeared to be constrained by the hydraulic and mechanical consequences of variation in rho(w).     

Surface spectroscopies with synchrotron radiation

A variety of photoelectron spectroscopies using synchrotron radiation have been devised to study solid surfaces. Measurements of the energies and angular distributions of electrons photoemitted from valence levels yield detailed information on surface electronic states and the chemical bonding of adsorbed atoms and molecules. Core level studies yield surface atom positions and molecular orientations. Some highlights of recent research are presented here. The capabilities of the techniques will be extended by the forthcoming generation of new storage rings dedicated to the production of synchrotron radiation.