Effect of stocking density of fish on water quality and growth performance of European Carp and leafy vegetables in a low-tech aquaponic system

Aquaponics (AP) is a semi-closed system of food production that combines aquaculture and hydroponics and represents a new agricultural system integrating producers and consumers. The aim of this study was to test the effect of stocking densities (APL, 2.5 kg m-3; APH, 4.6 kg m-3) on water quality, growth performance of the European Carp (Cyprinus carpio L.), and yield of leafy vegetables (catalogna, lettuce, and Swiss Chard) in a low-technology AP pilot system compared to a hydroponic cultivation. The AP daily consumption of water due to evapotranspiration was not different among treatments with an average value of 8.2 L d-1, equal to 1.37% of the total water content of the system. Dissolved oxygen was significantly (p < 0.05) different among treatments with the lowest median value recorded with the highest stocking density of fish (5.6 mg L-1) and the highest median value in the hydroponic control (8.7 mg L-1). Marketable yield of the vegetables was significantly different among treatments with the highest production in the hydroponic control for catalogna (1.2 kg m-2) and in the APL treatment for Swiss Chard (5.3 kg m-2). The yield of lettuce did not differ significantly between hydroponic control and APL system (4.0 kg m-2 on average). The lowest production of vegetables was obtained in the APH system. The final weight (515 g vs. 413 g for APL and APH, respectively), specific growth rate (0.79% d-1 vs. 0.68% d-1), and feed conversion (1.55 vs. 1.86) of European Carp decreased when stocking density increased, whereas total yield of biomass was higher in the APH system (4.45 kg m-3 vs. 6.88 kg m-3). A low mortality (3% on average) was observed in both AP treatments. Overall, the results showed that a low initial stocking density at 2.5 kg m-3 improved the production of European Carp and of leafy vegetables by maintaining a better water quality in the tested AP system

Interpersonal interactions and empathy modulate perception of threat and defensive responses

The defensive peripersonal space (DPPS) is a vital "safety margin" surrounding the body. When a threatening stimulus is delivered inside the DPPS, subcortical defensive responses like the hand-blink reflex (HBR) are adjusted depending on the perceived threat content. In three experiments, we explored whether and how defensive responses are affected by the interpersonal interaction within the DPPS of the face. In Experiment 1, we found that the HBR is enhanced when the threat is brought close to the face not only by one's own stimulated hand, but also by another person's hand, although to a significantly lesser extent. In Experiments 2 and 3, we found that the HBR is also enhanced when the hand of the participant enters the DPPS of another individual, either in egocentric or in allocentric perspective. This enhancement is larger in participants with strong empathic tendency when the other individual is in a third person perspective. These results indicate that interpersonal interactions shape perception of threat and defensive responses. These effects are particularly evident in individuals with greater tendency to having empathic concern to other people

IFNAR1 Controls Progression to Cerebral Malaria in Children and CD8+ T Cell Brain Pathology in Plasmodium berghei-Infected Mice

This publication hasn't any creative commons license associated. There is no public supplementary material available.Development of cerebral malaria (CM), a severe and fatal form of clinical Plasmodium falciparum infection, results from a damaging cascade of vascular, inflammatory, and immunological host responses that leads to brain injury. Progression to CM can be modified by host genetic factors. Our case-control study in Angolan children aimed at highlighting the role of IFN (α, β) receptor 1 (IFNAR1) in progression to CM. We report a robust association between IFNAR1 and CM protection, as well as detailed studies showing analogous protection from experimental CM in Ifnar1(-/-) mice infected with P. berghei ANKA. We developed a novel cell-transfer protocol that enables spleen cell priming in the absence of disease. This led to the discovery that IFNAR1 expression in CD8(+) T cells is crucial and can abrogate resistance to experimental CM in Ifnar1(-/-) mice. Splenic CD8(+) T cells from Ifnar1(-/-) mice are functionally activated upon infection, yet are unable to mediate experimental CM development within the brain tissue. Our findings prove that IFNAR1 signaling unleashes CD8(+) T cell effector capacity, which is vital for CM, and raises the hypothesis that the cohesive role of IFNAR1 in both human and mouse CM operates through CD8(+) T cell triggering.FCT fellowships: (SFRH/BD/33564/2008, SFRH/BPD/29354/2006)

Thermal susceptibility of the Planck-LFI receivers

This paper is part of the Prelaunch status LFI papers published on JINST: http://www.iop.org/EJ/journal/-page=extra.proc5/jinst . This paper describes the impact of the Planck Low Frequency Instrument front end physical temperature fluctuations on the output signal. The origin of thermal instabilities in the instrument are discussed, and an analytical model of their propagation and impact on the receivers signal is described. The experimental test setup dedicated to evaluate these effects during the instrument ground calibration is reported together with data analysis methods. Finally, main results obtained are discussed and compared to the requirements.Comment: This is an author-created, un-copyedited version of an article accepted for publication in Journal of Instrumentation. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The definitive publisher authenticated version is available online at 10.1088/1748-0221/4/12/T1201

Identifying the Relationship between Students Computer Hardware Skills in the Use of Electronic Information Resources in University Libraries in South-West, Nigeria

This study determined relationship between students’ computer hardware skills in the use of electronic information resources in University libraries in South-West, Nigeria. This study adopted correlation research design involving simple and multiple linear methods. The population of this study is 85,526. The sample for the study was 398. Proportionate sampling techniques were used to draw the sample. The findings revealed that there is a moderate positive and significant relationship between the students’ computer hardware skills and their use of EIR in university libraries. Also, there is a moderate positive and significant relationship between the students’ computer software skills and their use of EIR in university libraries in South- West, Nigeria; and there is a high and significant relationship among students’ computer hardware skills, computer software skill and their use of electronic information resources in the university library in South-West, Nigeria. Based on the above findings, the study recommended among others that undergraduate students should enhance their computer hardware skills since it is related with the use of electronic information resources in the universities. Research implications were also offered

Influence of Socio-Psychological Factors on Consumer Willingness to Pay (WTP) for Organic Food Products

This study evaluates consumers’ willingness to pay (WTP) a premium for organic vegetables and fruits in Pietermaritzburg metropolis, KwaZulu-Natal province, South Africa, using data collected from 210 consumers approached during their food shopping. The standard economic approach to valuation was extended by including psychological factors. The results from the empirical model show that psychological factors (behavioural control, attitude and subjective norms) exerted more influence on consumers’ WTP for organic products. In addition, socio-demographic factors such as gender, education, number of children in a household, high income and race, are statistically significant in explaining consumers’ WTP for organic food. Policy implications for advancement and improved promotion, sales and consumption of organic food products were discussed.&nbsp;&nbsp

Distillery anaerobic digestion residues as fertilizers for field vegetable crops: Performance and efficiency in mid-term successions

Understanding nitrogen use efficiency (NUE) of crops plays an important role in achieving sustainable production. Intensive agriculture has adversely affected social and environmental issues worldwide over the past few decades. Anaerobic digested residues from the distillery industry (DADRs) can be used in agriculture, thereby recycling valuable organic materials that can supply organic N. An experiment using DADRs in horticulture was conducted to evaluate the performance of different treatments on yield and NUE. The experiment was conducted for five years, growing lettuce, cauliflower, chicory, potato, Swiss chard, catalogna chicory, tomato, pepper, and melon in two different succession schemes. Five fertilization treatments were designed, including a mineral fertilization control, in which nitrogen (N) was supplied according to standard recommendations in the area. The other treatments were an unfertilized control and three treatments in which 50%, 75%, and 100% of the N were supplied by DADRs and the remaining with common chemical fertilizer. Major findings were: (1) Spring\u2013summer crops showed the lowest N-uptake and N recovery, during this period high chemical fertilization can cause environmental problems such as N leaching, and fertilization with 100% DADRs is a viable alternative; (2) fall\u2013winter crops can be fertilized by combining 50% mineral N and 50% organic N, supplying the nutrients required by the crops during the growing cycle

Identifying the Relationship between Students Computer Hardware Skills in the Use of Electronic Information Resources in University Libraries in South-West, Nigeria

This study determined relationship between students’ computer hardware skills in the use of electronic information resources in University libraries in South-West, Nigeria. This study adopted correlation research design involving simple and multiple linear methods. The population of this study is 85,526. The sample for the study was 398. Proportionate sampling techniques were used to draw the sample. The findings revealed that there is a moderate positive and significant relationship between the students’ computer hardware skills and their use of EIR in university libraries. Also, there is a moderate positive and significant relationship between the students’ computer software skills and their use of EIR in university libraries in South- West, Nigeria; and there is a high and significant relationship among students’ computer hardware skills, computer software skill and their use of electronic information resources in the university library in South-West, Nigeria. Based on the above findings, the study recommended among others that undergraduate students should enhance their computer hardware skills since it is related with the use of electronic information resources in the universities. Research implications were also offered

Impacts of Rainfall and Forest Cover Change on Runoff in Small Catchments: A Case Study of Mulunguzi and Namadzi Catchment Areas in Southern Malawi

The impacts of climate change on water resources have received much attention globally especially in the last 30 years. Rainfall, the main driver of the hydrological cycle, has been varying in parts of the world in various ways. The picture is more complicated if impacts of land cover changes on water resources are also taken into consideration. These two pose challenges which require an integrated approach to address. Not many of such studies have been conducted in Malawian catchments and other tropical regions. In this study, annual, seasonal and monthly series of rainfall and river discharge of the Mulunguzi and Namadzi River catchments, two small sub-catchments in the Lake Chilwa catchment area, were analysed for trends using the non parametric Mann-Kendall statistic and Sens slope estimator. Further, Linear regression and the RainRU model were applied to establish whether the relationship between rainfall and runoff in the two catchments has changed. Furthermore, linear regression was used to establish how increased forest cover has influenced river flows in the two catchments. The results suggest that rainfall in the Mulunguzi catchment has decreased significantly at all scales and this has also led to reduced river flows. Increased forest cover since the pre 1950s has also resulted in reduced flows but this is not as significant as the rainfall decrease. In the Namadzi catchment, the rainfall trends suggest a varying pattern with no obvious straight trends. At annual and some months timescale, the rainfall has increased significantly. The river flow on the other hand suggests an overall declining pattern. This pattern is well linked with significant forest area increments which have occurred since 1995. It is therefore important that more detailed studies should be conducted to gain further insight to these relations as both catchments are important socioeconomically.Keywords: Land use; land cover; river flow; rainfall; climate change

Hands behind your back: effects of arm posture on tactile attention in the space behind the body

Previous research has shown that tactile-spatial information originating from the front of the body is remapped from an anatomical to an external-spatial coordinate system, guided by the availability of visual information early in development. Comparably little is known about regions of space for which visual information is not typically available, such as the space behind the body. This study tests for the first time the electrophysiological correlates of the effects of proprioceptive information on tactile-attentional mechanisms in the space behind the back. Observers were blindfolded and tactually cued to detect infrequent tactile targets on either their left or right hand and to respond to them either vocally or with index finger movements. We measured event-related potentials (ERPs) to tactile probes on the hands in order to explore tactile-spatial attention when the hands were either held close together or far apart behind the observer's back. Results show systematic effects of arm posture on tactile-spatial attention different from those previously found for front space. While attentional selection is typically more effective for hands placed far apart than close together in front space, we found that selection occurred more rapidly for close than far hands behind the back, during both covert attention and movement preparation tasks. This suggests that proprioceptive space may ‘wrap’ around the body, following the hands as they extend horizontally from the front body midline to the centre of the back