Food division in the Arabian babbler nest: adult choice or nestling competition?

Many studies have found that food division among nestmates isnegatively correlated with hatrhing order. The hypothesis thatfeedings are distributed according to the provisioners' selectionis compared here with the hypothesis that feedings are dividedas a consequence of nestling competition. Food distributionamong Arabian babbler nestmates was negatively correlated withhatching order and was so skewed that many last-hatched nestlingsdied as a consequence of starvation. No feeding preference wasfound between any adult and any given nestling. No differencewas found in feeding distribution among parents, partial parents,and nonparents. When an older foreign nestling was introducedinto the nest, adults fed the newcomer more intensively thantheir own offspring, implying that feeding division among nestmateswas not determined by die feeders but by the nestlings' relativeability to obtain food. In two-nestling nests, the older nestlingobtained 62% of the feedings, on average. However, followingselective feedings of the second-hatched nestling by the investigator,which equalized the two siblings' feeding amounts by the endof their second day, no difference was found between their feedingrates. The relative advantage of the older nestlings was eliminatedby introducing a barrier into the nest. Under these conditions,feedings were distributed equally among the nestmates. Sinceneither hatching order, previous priority order, nor individualidentification were used by the provisioning adults, the proximatefactor determining food division among the neslings appearsto be the result of nestling competition     

Understanding and addressing waste of food in the Kingdom of Saudi Arabia

IntroductionMultiple estimates suggest the Kingdom of Saudi Arabia (KSA) may have one of the highest rates of wasted food globally. The KSA has limited arable lands and scarce water and thus relies on extensive imports and food subsidies to meet food demand. Accordingly, waste and loss of food are a significant concern for food security.Materials and methodsA narrative literature review was performed to identify the available information relevant to characterizing the context, magnitude of food wasted in the KSA, key contributing factors, and existing interventions and recommendations.ResultsEstimates of annual per capita waste of food ranged from 165 kg to 511 kg. Given the country's relatively limited agricultural production, the consumer and retail levels are primary targets for intervention. Key contributors to waste include culture, food valuation, policy and industry factors, and awareness and concern. The country is at an early stage of developing responses. We build upon existing approaches and recommendations, with particular emphasis on the potential role of agricultural extension staff in addressing the issue, and highlight research needs.ConclusionsGiven the potentially exceptional levels of wasted food in the KSA and the extensive evidence gaps, there is a great need for further research and action. Our review and synthesis presents numerous opportunities to advance innovative waste reduction approaches in the country, with particular relevance for other parts of the Middle East and other areas early in their efforts to address waste of food.     

GLUT4 in murine bone growth: from uptake and translocation to proliferation and differentiation

Skeletal growth, taking place in the cartilaginous growth plates of long bones, consumes high levels of glucose for both metabolic and anabolic purposes. We previously showed that Glut4 is present in growing bone and is decreased in diabetes. In the present study, we examined the hypothesis that in bone, GLUT4 gene expression and function are regulated via the IGF-I receptor (IGF-IR) and that Glut4 plays an important role in bone growth. Insulin and IGF-I actions on skeletal growth and glucose uptake were determined using mandibular condyle (MC) organ cultures and MC-derived primary cell cultures (MCDC). Chondrogenesis was determined by following proliferation and differentiation activities using immunohistochemical (IHC) analysis of proliferating cell nuclear antigen and type II collagen expression, respectively. Overall condylar growth was assessed morphometrically. GLUT4 mRNA and protein levels were determined using in situ hybridization and IHC, respectively. Glut4 translocation to the cell membrane was assessed using confocal microscopy analysis of GFP-Glut4 fusion-transfected cells and immunogold and electron microscopy on MC sections; glucose uptake was assayed by 2-deoxyglucose (2-DOG) uptake. Both IGF-I and insulin-stimulated glucose uptake in MCDC, with IGF-I being tenfold more potent than insulin. Blockage of IGF-IR abrogated both IGF-I- and insulin-induced chondrogenesis and glucose metabolism. IGF-I, but not insulin, induced Glut4 translocation to the plasma membrane. Additionally, insulin induced both GLUT4 and IGF-IR gene expression and improved condylar growth in insulin receptor knockout mice-derived MC. Moreover, silencing of GLUT4 gene in MCDC culture abolished both IGF-I-induced glucose uptake and chondrocytic proliferation and differentiation. In growing bone, the IGF-IR pathway stimulates Glut4 translocation and enhances glucose uptake. Moreover, intact Glut4 cellular levels and translocation machinery are essential for early skeletal growth.     

Blood vessels restrain pancreas branching, differentiation and growth

How organ size and form are controlled during development is a major question in biology. Blood vessels have been shown to be essential for early development of the liver and pancreas, and are fundamental to normal and pathological tissue growth. Here, we report that, surprisingly, non-nutritional signals from blood vessels act to restrain pancreas growth. Elimination of endothelial cells increases the size of embryonic pancreatic buds. Conversely, VEGF-induced hypervascularization decreases pancreas size. The growth phenotype results from vascular restriction of pancreatic tip cell formation, lateral branching and differentiation of the pancreatic epithelium into endocrine and acinar cells. The effects are seen both in vivo and ex vivo, indicating a perfusion-independent mechanism. Thus, the vasculature controls pancreas morphogenesis and growth by reducing branching and differentiation of primitive epithelial cells.     

Surface properties and reduced biofouling of graft-copolymers that possess oppositely charged groups

Microbial biofilms and their components present a major obstacle for ensuring the long-term effectiveness of membrane processes. Graft polymerization on membrane surfaces, in general, and grafting with oppositely charged monomers, have been shown to reduce biofouling significantly. In this study, surface forces and macromolecular properties of graft copolymers that possess oppositely charged groups were related to their potent antibiofouling behavior. Graft polymerization was performed using the negatively charged 3-sulphopropyl methacrylate (SPM) and positively charged [2-(methacryloyloxy)ethyl]-trimethylammonium (MOETMA) monomers to yield a copolymer layer on polyvinylidene fluoride (PVDF) surface. Quartz crystal microbalance with dissipation monitoring (QCM-D) technology was used to monitor the reduced adsorption of extracellular polymeric substances (EPS) extracted from a membrane bioreactor (MBR) wastewater treatment facility. Complemented measurements of attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy provided evaluation of the antifouling properties of the surface. Increase in water content in grafted layer exposed to 100 mM aqueous NaCl solution was observed by QCM-D. Therefore, the grafted copolymer layer is swelled in the presence of 100 mM NaCl because of reversing of polymer self-association by counterions. Force measurements by atomic force microscopy (AFM) showed an increased repulsion between a carboxylate-modified latex (CML) particle probe and a modified PVDF surface, especially in the presence of 100 mM NaCl. The hydration and swelling of the grafted polymer layer are shown to repel EPS and reduce their adsorption. Delineating the surface properties of antifouling grafted layers may lead to the design of novel antifouling surfaces.     

MULTIMINERAL CALCAREOUS DEPOSITS IN THE MARINE ALGA ACETABULARIA ACETABULUM (CHLOROPHYTA; DASYCLADACEAE)

The ultrastructure and mineralogy of cultured and wild specimens of the green algae Acetabularia acetabulum were studied. Sites of calcification were clarified using TEM and SEM. Minerology was determined via electron diffraction, energy-dispersive x-ray microanalysis, and Fourier transform infrared spectral analyses of the calcareous deposits. These deposits were found covering the surface and within the cell wall of the cultured juveniles and adult wild specimens of A. acetabulum. Deposits within and directly over the wall were amorphous calcium carbonate (ACC) in granular form. In-wall and outer cell wall ACC appear to develop independently from each other. The formation of the in-wall ACC may be mediated by the wall structure and/or chemistry, whereas mucin may be the factor mediating formation of outer cell wall ACC. In contrast to the stable in-wall ACC, outer cell wall ACC could be transitory, transforming into aragonite. In cultured cells, a small amount of monohydrocalcite crystals and calcite were found. It is possible that these were transformation products of ACC. In wild specimens, whewellite (calcium oxalate monohydrate) was present inside and outside of the cap wall. It is unclear if whewellite is present within the cytoplasm. Local and temporal differences in the microenvironments for the multiphase mineralization are suggested.     

Effects of Introducing Xpert MTB/RIF on Diagnosis and Treatment of Drug-Resistant Tuberculosis Patients in Indonesia: A Pre-Post Intervention Study

Background

In March 2012, the Xpert MTB/RIF assay (Xpert) was introduced in three provincial public hospitals in Indonesia as a novel diagnostic to detect tuberculosis and rifampicin resistance among high risk individuals.

Objective

This study assessed the effects of using Xpert in place of conventional solid and liquid culture and drug-susceptibility testing on case detection rates, treatment initiation rates, and health system delays among drug-resistant tuberculosis (TB) patients.

Methods

Cohort data on registration, test results and treatment initiation were collected from routine presumptive patient registers one year before and one year after Xpert was introduced. Proportions of case detection and treatment initiation were compared using the Pearson Chi square test and median time delays using the Mood’s Median test.

Results

A total of 975 individuals at risk of drug-resistant TB were registered in the pre-intervention year and 1,442 in the post-intervention year. After Xpert introduction, TB positivity rate increased by 15%, while rifampicin resistance rate reduced by 23% among TB positive cases and by 9% among all tested. Second-line TB treatment initiation rate among rifampicin resistant patients increased by 19%. Time from client registration to diagnosis was reduced by 74 days to a median of a single day (IQR 0–4) and time from diagnosis to treatment start was reduced by 27 days to a median of 15 days (IQR 7–51). All findings were significant with p<0.001.

Conclusion

Compared to solid and liquid culture and drug-susceptibility testing, Xpert detected more TB and less rifampicin resistance, increased second-line treatment initiation rates and shortened time to diagnosis and treatment. This test holds promise to improve rapid case finding and management of drug-resistant TB patients in Indonesia.