Multiband diffusion-weighted MRI of the eye and orbit free of geometric distortions using a RARE-EPI hybrid

Diffusion-weighted imaging (DWI) provides information on tissue microstructure. Single-shot echo planar imaging (EPI) is the most common technique for DWI applications in the brain, but is prone to geometric distortions and signal voids. Rapid acquisition with relaxation enhancement [RARE, also known as fast spin echo (FSE)] imaging presents a valuable alternative to DWI with high anatomical accuracy. This work proposes a multi-shot diffusion-weighted RARE-EPI hybrid pulse sequence, combining the anatomical integrity of RARE with the imaging speed and radiofrequency (RF) power deposition advantage of EPI. The anatomical integrity of RARE-EPI was demonstrated and quantified by center of gravity analysis for both morphological images and diffusion-weighted acquisitions in phantom and in vivo experiments at 3.0 T and 7.0 T. The results indicate that half of the RARE echoes in the echo train can be replaced by EPI echoes whilst maintaining anatomical accuracy. The reduced RF power deposition of RARE-EPI enabled multiband RF pulses facilitating simultaneous multi-slice imaging. This study shows that diffusion-weighted RARE-EPI has the capability to acquire high fidelity, distortion-free images of the eye and the orbit. It is shown that RARE-EPI maintains the immunity to B0 inhomogeneities reported for RARE imaging. This benefit can be exploited for the assessment of ocular masses and pathological changes of the eye and the orbit

The uniting of Europe and the foundation of EU studies: revisiting the neofunctionalism of Ernst B. Haas

This article suggests that the neofunctionalist theoretical legacy left by Ernst B. Haas is somewhat richer and more prescient than many contemporary discussants allow. The article develops an argument for routine and detailed re-reading of the corpus of neofunctionalist work (and that of Haas in particular), not only to disabuse contemporary students and scholars of the normally static and stylized reading that discussion of the theory provokes, but also to suggest that the conceptual repertoire of neofunctionalism is able to speak directly to current EU studies and comparative regionalism. Neofunctionalism is situated in its social scientific context before the theory's supposed erroneous reliance on the concept of 'spillover' is discussed critically. A case is then made for viewing Haas's neofunctionalism as a dynamic theory that not only corresponded to established social scientific norms, but did so in ways that were consistent with disciplinary openness and pluralism

Farmer access to irrigation scheduling advice leads to sustainable intensification of high value crops

United States Agency for International Developmen

Constraints of small-scale irrigated fodder production and nutrition assessment for livestock feed, a case study in Ethiopia

Livestock is an integral part of the agricultural system in sub-Saharan Africa, serving as a food source, income, fertilizer, and power for farming and transportation. However, the productivity of the livestock system has been hampered due to a lack of sufficient quantity and quality feed. This study evaluates the gaps and constraints of fodder and nutritional potential for livestock feed using small-scale irrigation (SSI). The study comprised of 30 randomly selected farmers from two different ecological zones in Ethiopia. Half of the farmers cultivated Napier grass (Pennisetum purpureum) in the Robit watershed in northern Ethiopia, and the other half cultivated mixed vetch (Lathyrus cicera) and oats (Avena sativa) in Lemo watershed in southern Ethiopia. The Soil and Water Assessment Tool (SWAT) and Agricultural Policy Environmental eXtender (APEX) were applied in an integrated manner to assess the impacts of SSI at the watershed and field-scale levels, respectively. The watershed-scale analysis showed that there is a substantial amount of surface runoff and shallow groundwater recharge that could be used for dry season fodder production using irrigation. Field data calibrated APEX model indicated that Napier yield could be maximized with 550 mm of water in Robit watershed. While in the Lemo watershed, maximum vetch and oats yield may be achieved with 250 mm of water. The major constraints for Napier and oats production in the study sites were soil fertility, especially nitrogen and phosphorus, and vetch production was limited by high temperature. Fodder samples were collected at the time of harvest to evaluate feed quality. The nutritional analysis indicated that Napier grass has a higher dry matter and ash (mineral) content compared to oats and vetch. However, vetch has higher crude protein content (18%) compared to Napier (10%) and oats (6%). Overall the study indicated that cultivating vetch provided superior performance in terms of providing quality feed and environmental services

Are language production problems apparent in adults who no longer meet diagnostic criteria for attention-deficit/hyperactivity disorder?

In this study, we examined sentence production in a sample of adults (N = 21) who had had attention-deficit/hyperactivity disorder (ADHD) as children, but as adults no longer met DSM-IV diagnostic criteria (APA, 2000). This “remitted” group was assessed on a sentence production task. On each trial, participants saw two objects and a verb. Their task was to construct a sentence using the objects as arguments of the verb. Results showed more ungrammatical and disfluent utterances with one particular type of verb (i.e., participle). In a second set of analyses, we compared the remitted group to both control participants and a “persistent” group, who had ADHD as children and as adults. Results showed that remitters were more likely to produce ungrammatical utterances and to make repair disfluencies compared to controls, and they patterned more similarly to ADHD participants. Conclusions focus on language output in remitted ADHD, and the role of executive functions in language production

Radiofrequency antenna concepts for human cardiac MR at 14.0 T

OBJECTIVE: To examine the feasibility of human cardiac MR (CMR) at 14.0 T using high-density radiofrequency (RF) dipole transceiver arrays in conjunction with static and dynamic parallel transmission (pTx). MATERIALS AND METHODS: RF arrays comprised of self-grounded bow-tie (SGBT) antennas, bow-tie (BT) antennas, or fractionated dipole (FD) antennas were used in this simulation study. Static and dynamic pTx were applied to enhance transmission field (B(1)(+)) uniformity and efficiency in the heart of the human voxel model. B(1)(+) distribution and maximum specific absorption rate averaged over 10 g tissue (SAR(10g)) were examined at 7.0 T and 14.0 T. RESULTS: At 14.0 T static pTx revealed a minimum B(1)(+)(ROI) efficiency of 0.91 μT/√kW (SGBT), 0.73 μT/√kW (BT), and 0.56 μT/√kW (FD) and maximum SAR(10g) of 4.24 W/kg, 1.45 W/kg, and 2.04 W/kg. Dynamic pTx with 8 kT points indicate a balance between B(1)(+)(ROI) homogeneity (coefficient of variation  1.11 µT/√kW) at 14.0 T with a maximum SAR(10g) < 5.25 W/kg. DISCUSSION: MRI of the human heart at 14.0 T is feasible from an electrodynamic and theoretical standpoint, provided that multi-channel high-density antennas are arranged accordingly. These findings provide a technical foundation for further explorations into CMR at 14.0 T

Phosphorus export from two contrasting rural watersheds in the (sub) humid Ethiopian highlands

Establishing worldwide sustainable and phosphorus efficient cropping systems is urgently needed because the supply of suitable phosphate rock is limited, and excess phosphorus in streams causes eutrophication. One of the impediments in the developing world for sustainable P practices is the lack of studies on P transport and its eventual disposition in the environment. One of these regions with few studies is the Ethiopian Highlands, with permeable volcanic soils. The objective was to establish baseline data on P watershed export in the (sub)humid highlands. Two contrasting watersheds were selected near Lake Tana. For 2 years, stream discharge and sediment, total P, dissolved P, and bioavailable particulate P concentrations were determined at the watershed outlet. The first watershed is the 57 km2 Dangishta, with lava intrusion dikes, forcing subsurface flow through faults to the surface and preventing gully formation. Subsurface flow was half of the 1745 mm annual precipitation, and surface runoff and erosion were minimal. The second watershed is the 9 km2 Robit Bata with 1,420 mm precipitation. The banks of several river banks were slumping. The upper part of the watershed generates saturation excess runoff. A hillslope aquifer in the lower part provided interflow. The average sediment concentrations of 10.5 g L−1 in the stream in Robit Bata (11 times that in Dangishta) reflected the sediments from banks slipping in the stream. The hydrology and the soil loss directly affected the phosphorus export. In Dangishta, the total P concentration averaged 0.5 mg L−1 at the outlet. In Robit Bata, the average total P concentration was 2 mg L−1. The bioavailable particulate P concentration was only twice the concentration in the runoff water. The low phosphorus content of the subsoil slipping in Robit Bata moderated biologically available particulate P at the outlet. Average dissolved P concentrations for both watersheds were around 0.1 mg L−1 in the low range found in temperate climates. It reflects the difference in length of time that phosphorus fertilizers have been applied. Our research concludes that commonly implemented practices such as strengthening river banks and stabilizing gully might not lead to improved water quality in Lake Tana

Modeling recursive RNA interference.

An important application of the RNA interference (RNAi) pathway is its use as a small RNA-based regulatory system commonly exploited to suppress expression of target genes to test their function in vivo. In several published experiments, RNAi has been used to inactivate components of the RNAi pathway itself, a procedure termed recursive RNAi in this report. The theoretical basis of recursive RNAi is unclear since the procedure could potentially be self-defeating, and in practice the effectiveness of recursive RNAi in published experiments is highly variable. A mathematical model for recursive RNAi was developed and used to investigate the range of conditions under which the procedure should be effective. The model predicts that the effectiveness of recursive RNAi is strongly dependent on the efficacy of RNAi at knocking down target gene expression. This efficacy is known to vary highly between different cell types, and comparison of the model predictions to published experimental data suggests that variation in RNAi efficacy may be the main cause of discrepancies between published recursive RNAi experiments in different organisms. The model suggests potential ways to optimize the effectiveness of recursive RNAi both for screening of RNAi components as well as for improved temporal control of gene expression in switch off-switch on experiments

Die Europäisierung der öffentlichen Aufgaben

Die zunehmende Europäisierung der öffentlichen Aufgaben ist einer der wichtigsten Trends im Wandel der Staatstätigkeit in der Bundesrepublik Deutschland und in anderen Mitgliedstaaten der Europäischen Union. In diesem Essay werden die Stufen der Europäisierung der Staatstätigkeit nachgezeichnet, in Weiterführung von Lindberg/Scheingold (1970) und Schmitter (1996) quantifiziert und hinsichtlich ihrer Kosten und ihres Nutzen erörtert. Inhalt: Stufen der Europäisierung der öffentlichen Aufgaben Der Europäisierungsgrad der öffentlichen Aufgaben von 1950 bis zum Ende des 20. Jahrhunderts Vom Nutzen und von den Kosten der Europäisierung der öffentlichen Angelegenheiten Verzeichnis der zitierten Literatu

Motion-compensated fat-water imaging for 3D cardiac MRI at ultra-high fields

PURPOSE: Respiratory motion-compensated (MC) 3D cardiac fat-water imaging at 7T. METHODS: Free-breathing bipolar 3D triple-echo gradient-recalled-echo (GRE) data with radial phase-encoding (RPE) trajectory were acquired in 11 healthy volunteers (7M\4F, 21-35 years, mean: 30 years) with a wide range of body mass index (BMI; 19.9-34.0 kg/m2 ) and volunteer tailored B(1)(+) shimming. The bipolar-corrected triple-echo GRE-RPE data were binned into different respiratory phases (self-navigation) and were used for the estimation of non-rigid motion vector fields (MF) and respiratory resolved (RR) maps of the main magnetic field deviations (ΔB0 ). RR ΔB0 maps and MC ΔB0 maps were compared to a reference respiratory phase to assess respiration-induced changes. Subsequently, cardiac binned fat-water images were obtained using a model-based, respiratory motion-corrected image reconstruction. RESULTS: The 3D cardiac fat-water imaging at 7T was successfully demonstrated. Local respiration-induced frequency shifts in MC ΔB(0) maps are small compared to the chemical shifts used in the multi-peak model. Compared to the reference exhale ΔB0 map these changes are in the order of 10 Hz on average. Cardiac binned MC fat-water reconstruction reduced respiration induced blurring in the fat-water images, and flow artifacts are reduced in the end-diastolic fat-water separated images. CONCLUSION: This work demonstrates the feasibility of 3D fat-water imaging at UHF for the entire human heart despite spatial and temporal B(1)(+) and B0 variations, as well as respiratory and cardiac motion