Defining the cost of the Egyptian lymphatic filariasis elimination programme

BACKGROUND: Ultrasonography (USG) is known to be a suitable tool for diagnosis in lymphatic filariasis as the adult filarial nematode Wuchereria bancrofti in scrotal lymphatic vessels of infected men can be detected by the characteristic pattern of movement, the Filaria Dance Sign. In onchocerciasis, moving adult worms have not yet been demonstrated by USG. In addition the verification of drug effects on living adult Onchocerca volvulus filariae in trials is hampered by the lack of tools for longitudinal observation of alterations induced by potentially macrofilaricidal drugs in vivo. The present study was carried out to determine the frequency of detection of moving adult filariae of O. volvulus by USG. METHODS: In an endemic region for onchocerciasis in Ghana, 61 patients infected with onchocerciasis were recruited by palpation and onchocercomas examined by USG using an ultrasound system equipped with a 7.5 - 10 MHz linear transducer. Onchocercomas were recorded on videotape and evaluated with regard to location, number and size, as well as to movements of adult filariae. RESULTS: In the 61 patients 303 onchocercomas were found by palpation and 401 onchocercomas were detected by USG. In 18 out of 61 patients (29.5%), altogether 22 nodules with moving adult O. volvulus filariae were detected and are presented in animated ultrasound images as mp-4 videos. CONCLUSION: Ultrasonographical examinations of onchocercomas where living adult filariae can be displayed may serve as a new tool for the longitudinal observation in vivo of patients with onchocerciasis undergoing treatment and as an adjunct to histological evaluation.     

Phytoremediation of subarctic soil contaminated with diesel fuel

The effects of several plant species, native to northern latitudes, and different soil amendments, on diesel fuel removal from soil were studied. Plant treatments included Scots Pine (Pinus sylvestris), Poplar (Populus deltoides x Wettsteinii), a grass mixture (Red fescue, Fesuca rubra; Smooth meadowgrass, Poa pratensis and Perennial ryegrass, Lolium perenne) and a legume mixture (White clover, Trifolium repens and Pea, Pisum sativum). Soil amendments included NPK fertiliser, a compost extract and a microbial enrichment culture. Diesel fuel disappeared more rapidly in the legume treatment than in other plant treatments. The presence of poplar and pine enhanced removal of diesel fuel, but removal under grass was similar to that with no vegetation. Soil amendments did not enhance diesel fuel removal significantly. Grass roots accumulated diesel-range compounds. This study showed that utilisation of selected plants accelerates removal of diesel fuel in soil and may serve as a viable, low-cost remedial technology for diesel-contaminated soils in subarctic regions.     

Causality and persistence in ecological systems: a nonparametric spectral granger causality approach

Abstract Directionality in coupling, defined as the linkage relating causes to their effects at a later time, can be used to explain the core dynamics of ecological systems by untangling direct and feedback relationships between the different components of the systems. Inferring causality from measured ecological variables sampled through time remains a formidable challenge further made difficult by the action of periodic drivers overlapping the natural dynamics of the system. Periodicity in the drivers can often mask the self-sustained oscillations originating from the autonomous dynamics. While linear and direct causal relationships are commonly addressed in the time domain, using the well-established machinery of Granger causality (G-causality), the presence of periodic forcing requires frequency-based statistics (e.g., the Fourier transform), able to distinguish coupling induced by oscillations in external drivers from genuine endogenous interactions. Recent nonparametric spectral extensions of G-causality to the frequency domain pave the way for the scale-by-scale decomposition of causality, which can improve our ability to link oscillatory behaviors of ecological networks to causal mechanisms. The performance of both spectral G-causality and its conditional extension for multivariate systems is explored in quantifying causal interactions within ecological networks. Through two case studies involving synthetic and actual time series, it is demonstrated that conditional G-causality outperforms standard G-causality in identifying causal links and their concomitant timescales.     

Elevated CO2 affects photosynthetic responses in canopy pine and subcanopy deciduous trees over 10 years: a synthesis from Duke FACE

Leaf responses to elevated atmospheric CO₂ concentration (C_a) are central to models of forest CO₂ exchange with the atmosphere and constrain the magnitude of the future carbon sink. Estimating the magnitude of primary productivity enhancement of forests in elevated C_a requires an understanding of how photosynthesis is regulated by diffusional and biochemical components and up‐scaled to entire canopies. To test the sensitivity of leaf photosynthesis and stomatal conductance to elevated C_a in time and space, we compiled a comprehensive dataset measured over 10 years for a temperate pine forest of Pinus taeda, but also including deciduous species, primarily Liquidambar styraciflua. We combined over one thousand controlled‐response curves of photosynthesis as a function of environmental drivers (light, air C_a and temperature) measured at canopy heights up to 20 m over 11 years (1996–2006) to generate parameterizations for leaf‐scale models for the Duke free‐air CO₂ enrichment (FACE) experiment. The enhancement of leaf net photosynthesis (A_net) in P. taeda by elevated C_a of +200 μmol mol^?1 was 67% for current‐year needles in the upper crown in summer conditions over 10 years. Photosynthetic enhancement of P. taeda at the leaf‐scale increased by two‐fold from the driest to wettest growing seasons. Current‐year pine foliage A_net was sensitive to temporal variation, whereas previous‐year foliage A_net was less responsive and overall showed less enhancement (+30%). Photosynthetic downregulation in overwintering upper canopy pine needles was small at average leaf N (N_area), but statistically significant. In contrast, co‐dominant and subcanopy L. styraciflua trees showed A_net enhancement of 62% and no A_net–N_area adjustments. Various understory deciduous tree species showed an average A_net enhancement of 42%. Differences in photosynthetic responses between overwintering pine needles and subcanopy deciduous leaves suggest that increased C_a has the potential to enhance the mixed‐species composition of planted pine stands and, by extension, naturally regenerating pine‐dominated stands.     

Irisin immunohistochemistry in gastrointestinal system cancers

Cancer is the leading cause of morbidity and mortality worldwide. Some studies have shown that high heat kills cancer cells. Irisin is a protein involved in heat production by converting white into brown adipose tissue, but there is no information about how its expression changes in cancerous tissues. We used irisin antibody immunohistochemistry to investigate changes in irisin expression in gastrointestinal cancers compared to normal tissues. Irisin was found in human brain neuroglial cells, esophageal epithelial cells, esophageal epidermoid carcinoma, esophageal adenocarcinoma and neuroendocrine esophageal carcinoma, gastric glands, gastric adenosquamous carcinoma, gastric neuroendocrine carcinoma, gastric signet ring cell carcinoma, neutrophils in vascular tissues, intestinal glands of colon, colon adenocarcinoma, mucinous colon adenocarcinoma, hepatocytes, hepatocellular carcinoma, islets of Langerhans, exocrine pancreas, acinar cells and interlobular and interlobular ducts of normal pancreas, pancreatic ductal adenocarcinoma, and intra- and interlobular ducts of cancerous pancreatic tissue. Histoscores (area × intensity) indicated that irisin was increased significantly in gastrointestinal cancer tissues, except liver cancers. Our findings suggest that the relation of irisin to cancer warrants further investigation.     

Nitrogen-addition effects on leaf traits and photosynthetic carbon gain of boreal forest understory shrubs

Boreal coniferous forests are characterized by fairly open canopies where understory vegetation is an important component of ecosystem C and N cycling. We used an ecophysiological approach to study the effects of N additions on uptake and partitioning of C and N in two dominant understory shrubs: deciduous Vaccinium myrtillus in a Picea abies stand and evergreen Vaccinium vitis-idaea in a Pinus sylvestris stand in northern Sweden. N was added to these stands for 16 and 8 years, respectively, at rates of 0, 12.5, and 50 kg N ha^?1 year^?1. N addition at the highest rate increased foliar N and chlorophyll concentrations in both understory species. Canopy cover of P. abies also increased, decreasing light availability and leaf mass per area of V. myrtillus. Among leaves of either shrub, foliar N content did not explain variation in light-saturated CO₂ exchange rates. Instead photosynthetic capacity varied with stomatal conductance possibly reflecting plant hydraulic properties and within-site variation in water availability. Moreover, likely due to increased shading under P. abies and due to water limitations in the sandy soil under P. sylvestris, individuals of the two shrubs did not increase their biomass or shift their allocation between above- and belowground parts in response to N additions. Altogether, our results indicate that the understory shrubs in these systems show little response to N additions in terms of photosynthetic physiology or growth and that changes in their performance are mostly associated with responses of the tree canopy.