Risk factors for bacterial zoonotic pathogens in acutely febrile patients in Mpumalanga Province,South Africa

Endemic zoonoses, such as Q fever and spotted fever group (SFG) rickettsiosis, are prevalent in South Africa, yet often undiagnosed. In this study, we reviewed the demographics and animal exposure history of patients presenting with acute febrile illness to community health clinics in Mpumalanga Province to identify trends and risk factors associated with exposure to Coxiella burnetii, the causative agent of Q fever, and infection by SFG Rickettsia spp. Clinical and serological data and questionnaires elucidating exposure to animals and their products were obtained from 141 acutely febrile patients between 2012 and 2016. Exposure or infection status to C. burnetii and SFG Rickettsia spp. was determined by presence of IgG or IgM antibodies. Logistic regression models were built for risk factor analysis. Clinical presentation of patients infected by SFG rickettsiosis was described. There were 37/139 (27%) patients with a positive C. burnetii serology, indicative of Q fever exposure. Patients who had reported attending cattle inspection facilities (“dip tanks”) were 9.39 times more likely to be exposed to Q fever (95% CI: 2.9–30.4). Exposure risk also increased with age (OR: 1.03, 95% CI: 1.002–1.06). Twenty‐one per cent of febrile patients (24/118) had evidence of acute infection by SFG Rickettsia spp. Similarly, attending cattle inspection facilities was the most significant risk factor (OR: 8.48, 95% CI: 1.58–45.60). Seropositivity of females showed a significant OR of 8.0 when compared to males (95% CI: 1.49–43.0), and consumption of livestock was associated with a decreased risk (OR: 0.02, 95% CI: 0.001–0.54). A trend between domestic cat contact and SFG rickettsiosis was also noted, albeit borderline non‐significant. In this endemic region of South Africa, an understanding of risk factors for zoonotic pathogens, including exposure to domestic animals, can help clinic staff with diagnosis and appropriate therapeutic management of acutely febrile patients as well as identify target areas for education and prevention strategies.     

Direct detection of the asteroidal YORP effect

The Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) effect is believed to alter the spin states of small bodies in the solar system. However, evidence for the effect has so far been indirect. We report precise optical photometric observations of a small near-Earth asteroid, (54509) 2000 PH5, acquired over 4 years. We found that the asteroid has been continuously increasing its rotation rate omega over this period by domega/dt = 2.0 (+/-0.2) x 10(-4) degrees per day squared. We simulated the asteroid's close Earth approaches from 2001 to 2005, showing that gravitational torques cannot explain the observed spin rate increase. Dynamical simulations suggest that 2000 PH5 may reach a rotation period of approximately 20 seconds toward the end of its expected lifetime.     

Modelling Wild-Oat Density in Terms of Soil Factors: A Machine Learning Approach

In crop fields, weed density varies spatially in non-random patterns. Initial knowledge of weed distribution would greatly improve weed management for Precision Agriculture operations. Site properties could be correlated to weed distribution, since the former vary among crop fields and also certain factors such as soil texture or nitrogen may condition the weed growth. This paper presents a method, based on artificial intelligence techniques, for inducing a model that appropriately predicts the heterogeneous distribution of wild-oat (Avena sterilis L.) in terms of some environmental variables. From several experiments, distinct rule sets have been found by applying a genetic algorithm to carry out the automatic learning process. The best rule set extracted was able to explain about 88% of weed variability.     

Viability of mass algal cultures preserved by freezing and freeze-drying

The microalgae Chaetoceros sp. and Phaeodactylum tricornutum were grown in semicontinuous 15 1 cultures, a volume commonly used for mid-scale inocula in aquacultural practices. The daily yields were concentrated and stored by freezing and freeze-drying for up to 1 month. After slow or fast freezing without the protective agents glycerol or Me₂SO, neither of the microalgae was capable of active growth, while with the cryoprotectants slow freezing gave good results after 7 days of storage at −20°C. After 15 and 30 days, however, microalgae growth was poor, probably due to bacterial contamination. Freeze-drying gave even worse results, which we attribute to severe losses of storage products after this treatment.     

Iron,Copper, and Zinc in Some Fish Species of the Atrato River Delta,Colombian Caribbean

The concentrations of iron (Fe), copper (Cu), and zinc (Zn) were evaluated in 96 samples of the following eight fish species: Centropomus undecimalis, Caranx hippos, Scomberomorus brasiliensis, Lutjanus purpureus, Caranx crysos, Megalops atlanticus, Elops saurus, and Epinephelus itajara collected in the Atrato River Delta in the Gulf of Urabá. Three fish were caught from each of the following common fishing grounds: Bahía Candelaria, Bahía Marirrío, Bocas del Roto, and Bocas del Atrato. Fish were captured during a one-year period, with one specimen per species in each climatic period: dry, transient, and wet. The quantification was performed by microwave plasma-atomic emission spectroscopy. The highest levels of Fe and Cu were found in Caranx crysos, and highest level of Zn in Megalops atlanticus. According to the percentage of the daily value per food serving, Caranx crysos and Caranx hippos are good sources of Fe, and Caranx crysos is a good source of Cu.     

A decision support approach for cane supply management within a sugar mill area

Increased competition between agri-food supply chains has strained relationships between farmers and processing factories while reducing individual profit margins. Decisions at different levels of the supply chain can no longer be considered independently, since they may influence profitability throughout the supply chain. This paper presents a decision support approach based on the MAGI^® simulation tool, which aims to facilitate discussion and negotiation between stakeholders while collectively exploring satisfactory solutions.The simulation tool helps sugarcane growers and millers in designing and assessing new ways of organizing cane supply management within a mill area. It addresses key issues such as restructuring mill areas or changing cane delivery allocation rules in order to increase total sugar production and total net revenue at the mill area level. This approach has been implemented for two mills in Réunion and one mill in South Africa. Simulations showed that sugar gains may be obtained by rearranging supply scheduling according to quality-based zoning within a mill area. Discussions led to further studies regarding the practicality of the best scenarios. MAGI^® is now available as freeware for testing in different settings.     

Hypnea musciformis: alternative or complement to the production of Kappaphycus alvarezii introduced in tropical countries?

Hypnea musciformis that are harvested from natural beds and introduced Kappaphycus alvarezii are the two main sources of raw material for the production of carrageenan in Brazil. The daily growth rate (DGR) and carrageenan yield (CY) of both species were evaluated in vitro and in the sea to assess the feasibility of cultivating H. musciformis as a complement or as an alternative to the production of K. alvarezii. The DGR of H. musciformis (10.8 ± 0.6% day^?1) was higher than the DGR of K. alvarezii (5.6 ± 0.3% day^?1) in vitro, and the CY extracted using NaOH (62.3 ± 0.15%) was better than using KOH (32.0 ± 0.3%). In eutrophic medium, the DGR of H. musciformis (9.4 ± 2.1% day^?1) was higher than that of K. alvarezii (5.0 ± 1.2% day^?1). However, in this condition, the CY was similar for both species (50.2 ± 3.5%), and both species were effective in removing nutrients (30% NH₄⁺, 18% NO^2? and 2.4% ). H. musciformis did not survive when cultivated in the sea, neither in monospecific nor in multispecific cultivation. Moreover, K. alvarezii grew better in monospecific cultivation throughout the year (from 1.73 to 5.15% day^?1) except during the wet period and the CY was high in both cultivation types (33.7–50.8%). We conclude that the cultivation of H. musciformis is not an alternative to K. alvarezii on the Brazilian southeastern coast. However, the results in vitro suggested its use as a complementary source of carrageenan or as a biological filter.     

Effects of two diets on lipid composition and reproductive performance of brill (Scophthalmus rhombus) eggs

The effects of two diets with different lipid composition (squid Loligo gahi and one commercial pellet for breeders) on reproductive performance and egg lipid composition of brill (Scophthalmus rhombus) were compared. A total of 36 adult brill weighing 1482 ± 432 g were randomly distributed in the experimental tanks. A flow‐through system composed of four tanks with 4.2 m² of bottom area (5.0 m³ × 1.2 m water depth) was used. The experiment lasted for approximately 5 months (168 days). From the four mature females fed squid, three ovulated. Five females fed pellets matured and ovulated. Total ovulations were of 10 and 44, by the three females fed squid and the five ovulating female fed pellets respectively. Egg viability was higher, although not significantly, for females fed pellets. This indicates that pellets could be a better food for breeding females. In general, the egg total lipid content and the lipid classes composition did not seem to be affected by diet. In contrast, results indicate that not only diets but also individual females, regardless of the diet consumed, are determinant for egg fatty acid composition, clearly modulating their composition.     

Analysis of the biodiversity of hawthorn (<Emphasis Type="Italic">Crataegus</Emphasis> spp.) from the morphological,molecular, and ethnobotanical approaches,and implications for genetic resource conservation in scenery of increasing cultivation: the case of Mexico

One hundred and forty Mexican hawthorn (Crataegus spp.) accessions from six regions are preserved at the BGT-UACH germplasm bank (Mexico), comprising the most comprehensive living collection of Mexican hawthorns with different degrees of human management. The objective of this study was to assess the biodiversity of this valuable collection from morphological, molecular (microsatellite), and ethnobotanical viewpoints in order to delineate the most adequate strategy for the conservation of the native hawthorn germplasm in the present scenario of incipient establishment of commercial hawthorn plantations, which is likely to increase. Molecular characterisation revealed that the biodiversity was chiefly (90%) placed within the regions. Morphological characterisation indicated that the group from Chiapas was the most different germplasm pool compared with the other five. This was confirmed by molecular analysis, because in spite of the lack of a phylogeographical pattern, two germplasm pools were detected: one composed mainly by accessions from Chiapas and the other mainly by accessions from the other regions. The only clear differences among the regions in the ethnobotanical study were those derived from putting hawthorns into commercial cultivation, which occurred in just one region in the centre of the country (Mexico–Puebla–Tlaxcala). As a consequence, an ex situ conservation programme is necessary for those regions shifting patterns of cultivation from traditional to commercial, regardless of whether other on-farm programmes are also implemented. The germplasm collections within each region must be exhaustive due to their high genetic diversity.     

Tracing trophic pathways through the marine ecosystem of Rapa Nui (Easter Island)

1. The structure of food webs provides important insight into biodiversity, organic matter (OM) pathways, and ecosystem functioning.
2. Stable isotope analysis (δ¹³C and δ¹⁵N) was used to characterize the trophic structure and the main OM pathways supporting food webs in the Rapa Nui coastal marine ecosystem.
3. The trophic position of consumers and isotopic niche metrics were estimated for different assemblages (i.e. mesozooplankton, emergent zooplankton, reef invertebrates, reef fishes, pelagic fishes, and seabirds). Furthermore, the relative importance of different OM sources (i.e. macroalgae, zooxanthellate corals, and particulate OM [POM]) was assessed for heterotrophic consumers using Bayesian mixing model (MixSIAR).
4. Results show a clear pattern of ¹³C and ¹⁵N enrichment from small-sized pelagic and benthic invertebrates, to reef and pelagic fishes, and seabirds. Most invertebrates were classified as primary consumers, reef fishes as secondary consumers and pelagic predators and seabirds as tertiary and quaternary consumers.
5. Isotopic niche metrics indicate a low trophic diversity for pelagic assemblages (mesozooplankton and pelagic fishes), in contrast to reef fauna (invertebrates and fishes), whose higher trophic diversity suggest the exploitation of a wider range of trophic resources. Overlapping of standard ellipses areas between reef invertebrates and reef fishes indicates that both assemblages could be sharing trophic resources.
6. Mixing models results indicate that POM is the main trophic pathway for mesozooplankton, macroalgae (Rhodophyta) for emergent zooplankton, and a mix of coral-derived OM and Rhodophyta for coral reef assemblages such as macrobenthos and reef invertebrates. In contrast, POM contribution was notably more important for some pelagic fishes and seabirds from upper trophic levels.
7. This study provides key elements for conservation efforts on coral reefs, management planning and full-implementation of the recently created Rapa Nui Multiple Use Marine Protected Area.