1,263 research outputs found
Cross-border Violence as an External Stress: Policy Responses to Cross-border Dynamics on the Border between CĂ´te dâIvoire and Liberia
One of the key issues identified in the new policy literature on external stress is the incidence of cross-border violence and the current lack of efficient and permanent mechanisms supported by international organisations, governments and civil society to deal with the violence. The focus of this research is the border region between CĂ´te dâIvoire and Liberia.
The protracted violence which has affected the region for many years stems from the internal conflicts which afflicted both countries at different times, and which had regional dynamics and implications. Western CĂ´te dâIvoire acted as a proxy battleground in the first Liberian civil war (1989â96), and the region is the birthplace of the military and political crisis that affected CĂ´te dâIvoire from 2002 onwards. An inaccessible and neglected region, it has acted as a training ground and base for rebel groups and security forces, and it is local people who have borne the brunt of the insecurity. In 2012â13 the region experienced a resurgence of cross-border violence linked to the 2011 electoral and political crisis in CĂ´te dâIvoire. Some accuse the political elite loyal to former CĂ´te dâIvoire president, Laurent Gbagbo, who are based in Ghana, of funding military incursions by militants and Liberian partners in the west of CĂ´te dâIvoire to destabilise the region. Animosity between different communities and the limited capacity of security forces to provide safety to the people perpetuates the precarious situation.UK Department for International Developmen
Forward osmosis using organic cationic draw solutions for water recovery
Forward Osmosis (FO) is an emerging technology which has potential to operate with minimum energy input. High performance of FO systems depend on the availability of a suitable Draw Solution. Different types of Draw Solutions have been proposed, however; choosing a suitable one is still a developing area within the FO field. There is an urgent need to explore new materials in order to develop an efficient FO system. The current study aims at investigating the performance of three Draw Solutions namely, L-Alanine, DADMAC and PolyDADMAC as osmotic agents for FO. These organic cationic solutions can be used as extraction agents of water from poorer quality organic solutes such as fumaric acid solution produced in a continuous flow microbial fermentation process. The performance of the three Draw Solutions was evaluated by measuring the water flux and reverse solute diffusion at different concentrations. The viability of reconcentration of the diluted Draw Solutions was also investigated using Nanofiltration system. The performance and the efficiency of the Draw Solutions were studied via two separated bench scale systems of FO and Nanofiltration. Both Cellulose Triacetate (CTA) and Thin Film Composite (TFC) aquaporin protein FO membranes were employed under different orientations in FO set up operated for 24 hours or longer. In this study, NF90 membrane was used for reconcentration the Draw Solutions. A series of experiments were conducted to obtain the best water flux and reverse solute diffusion under various influencing operating conditions. The experiments were designed to achieve three objectives, i.e. (i) optimum operating conditions for FO system, (ii) optimum operating conditions for the reconcentration system, and (iii) implementation of the optimum operating conditions of the FO system for water recovery from a fumaric acid solution produced by a simulated industrial fermentation process. In the initial stage, L-Alanine Draw Solution demonstrated that it was the most viable agent for FO. It was established that L-Alanine Solution at 0.085 g/mL concentration achieved the highest initial water flux and the lowest reverse solute diffusion through both CTA and TFC aquaporin protein FO membranes. In the second stage, a Nanofiltration system was proven to be effective in the reconcentration of the diluted L-Alanine Draw Solution. The average rejection of L-Alanine ions achieved by NF90 membrane was 96.00%. Drawing on the previous results, the third stage was used to investigate the viability of the FO system in water recovery from fumaric acid solution produced by continuous microbial fermentation process using L-Alanine as a Draw Solution. The reduction of water content of the fumaric acid solution made it to concentrate by 26.00% and 19.80% in 32_ and 17_, respectively. Consequently, FO technology is an effective way to concentrate a fumaric acid solution produced by continuous microbial fermentation process. Based on the results, it is recommended that LAlanine should be proposed in the FO process according to its reliability and effectiveness as a viable draw agent. TFC aquaporin protein membrane is also recommended to be used in recover the water from fumaric acid solution produced by fermentation processes. Further studies should be done to investigate the viability of FO in water recovery from advanced application such as downstream bioprocessing.Dissertation (MEng)--University of Pretoria, 2017.Chemical EngineeringMEngUnrestricte
The viability of forward osmosis in the concentration of biologically produced fumaric acid using l-alanine as a draw solution
Separation and concentration processes of fumaric acid from industrial products and down streams have been
a subject of wide range in research. With the emergence of Forward Osmosis (FO) technology attention has
shifted to utilising it in downstream processing. This study has investigated the viability of FO technology in
concentration a fumaric acid solution produced by continuous microbial fermentation process using L-Alanine
as a novel draw solution (DS). Thin Film Composite (TFC) aquaporin protein flat sheet membrane was used in
the FO set up. L-Alanine was used as a DS at a concentration of 0.085 g/mL. The DS concentration was
chosen based on preliminary studies which were conducted to determine the optimal DS concentration which
achieved the highest water flux with the lowest reverse solute diffusion.
The fumaric acid produced by continuous microbial fermentation process was investigated as a Feed Solution
(FS). The biologically produced Fumaric acid was obtained from a continuous microbial fermentation process
developed by the Bioreaction Engineering group at University of Pretoria. Rhizopus oryzae fungus was utilised
in the fermentation process with glucose as the substrate. The influence of temperature on the efficiency of
the FO process was also investigated. The results show that fumaric acid solution concentrated by 26.00 %
and 19.80 % in 32 â and 17 â, respectively. The results demonstrate FO technology to be an effective way to
concentrate the fumaric acid solution produced by continuous microbial fermentation process. However,
achieving high concentration has been limited because of high residual concentration of glucose and other
minerals in the biological process. This lead to reduce the net driving osmotic force through the membrane.
The initial concentration of glucose contributed with 50.50 % of overall osmotic pressure of FS, while the initial
concentration of fumaric acid contributed only with 12.20 %. Minimising the residual glucose concentration
could lead to a doubling of the fumaric acid concentration in the FO process.http://www.aidic.it/cetam2018Chemical Engineerin
Forward osmosis for water recovery using polyelectrolyte PolyDADMAC and DADMAC draw solutions as a low pressure energy saving process
Polydiallyldimethylammonium Chloride (PolyDADMAC) is a cationic polyelectrolyte utilised widely in drinking water industry. This study has evaluated the performance of cationic organic polyelectrolyte PolyDADMAC and its monomer DADMAC as osmotic agents in Forward Osmosis (FO) process. The properties of PolyDADMAC and DADMAC draw solutions were initially studied. Thereafter, a series of experiments were conducted to examine the efficiency of these solutions for water recovery using CTA and Aquaporin flatsheet membranes under FO mode. The results show a high electrical conductivity of both draw solutions due to the presence of strong cation electrolyte (C8H6N+) in solutions. The obtained water flux and reverse solute diffusion of DADMAC were higher than PolyDADMAC at same concentrations. Factors contributing to the change of water flux and reverse solutes diffusion through membranes were addressed. CTA membranes accomplished higher water flux than the aquaporin membranes, however; the latter was more selective and provided better results of reverse solutes diffusion. Diluted draw solutions were reconcentrated via Nanofiltration-system. High ion rejection of DADMAC (96%) and poor ion rejection of PolyDADMAC (85%) were observed. Lastly, this article introduced a valuable comparison between cationic polyelectrolyte and its electrolyte based on their behaviours as draw solutes in FO process.The National Research Foundation NRF (Grant Unique Number: 100471), and the University of Pretoria, South Africa.http://www.elsevier.com/locate/desal2020-03-01hj2019Chemical Engineerin
Immunohistochemical detection improves the prognostic value of lymphatic and blood vessel invasion in primary ductal breast cancer
Background<p></p>
Lymphovascular invasion (LBVI) including lymphatic (LVI) and blood (BVI) vessel invasion is a critical step in cancer metastasis. In breast cancer, the optimal detection method of LBVI remains unclear. This research aimed to compare the prognostic value of different assessments of the LVI and BVI in patients with early breast cancer.<p></p>
Methods<p></p>
The study cohort included 360 patients with a median follow-up of 168 months. LBVI on H&E sections (LBVIH&E) was reviewed centrally and blinded to the pathology report. Immunohistochemical staining for D2-40 and Factor VIII was performed to identify LVID2â40 and BVIFVIII.<p></p>
Results<p></p>
LBVIH&E, LVID2â40 and BVIFVIII were present in 102 (28%), 127 (35%) and 59 (16%) patients respectively. In node-negative patients (206), LBVIH&E, LVID2â40 and BVIFVIII were present in 41 (20%), 53 (26%) and 21 (10%) respectively. In triple-negative patients (120), LBVIH&E, LVID2â40 and BVIFVIII were present in 35 (29%), 46 (38%) and 16 (13%) respectively. LBVIH&E was significantly associated with tumour recurrence in the whole cohort (Pâ<â0.001), node-negative patients (Pâ=â0.001) and triple-negative patients (Pâ=â0.004). LVID2â40 and BVIFVIII were significantly associated with tumour recurrence in whole cohort, node-negative (all Pâ<â0.001) and triple-negative patients (Pâ=â0.002). In multivariate survival analysis, only LVID2â40 and BVIFVIII were independent predictors of cancer specific survival in the whole cohort (Pâ=â0.023 and Pâ<â0.001 respectively), node-negative patients (Pâ=â0.004 and Pâ=â0.001 respectively) and triple-negative patients (Pâ=â0.014 and Pâ=â0.001 respectively).<p></p>
Conclusion<p></p>
Assessment of LVI and BVI by IHC using D2-40 and Factor VIII improves prediction of outcome in patients with node-negative and triple-negative breast cancer
An empirical cognitive model of the development of shared understanding of requirements
It is well documented that customers and software development teams need to share and refine understanding of the requirements throughout the software development lifecycle. The development of this shared understand- ing is complex and error-prone however. Techniques and tools to support the development of a shared understanding of requirements (SUR) should be based on a clear conceptualization of the phenomenon, with a basis on relevant theory and analysis of observed practice. This study contributes to this with a detailed conceptualization of SUR development as sequence of group-level state transi- tions based on specializing the Team Mental Model construct. Furthermore it proposes a novel group-level cognitive model as the main result of an analysis of data collected from the observation of an Agile software development team over a period of several months. The initial high-level application of the model shows it has promise for providing new insights into supporting SUR development
Building-Scale Wastewater-Based Epidemiology for SARS-CoV-2 Surveillance at Nursing Homes in A CoruĂąa, Spain
Financiado para publicaciĂłn en acceso aberto: Universidade da CoruĂąa/CISUG[Abstract] Wastewater-based epidemiology (WBE) has become an effective tool in the surveillance of
infectious diseases such as COVID-19. In this work, we performed a brief study of monitoring the
SARS-CoV-2 viral load in wastewater from six nursing homes located in the metropolitan area of A
CoruĂąa (Spain) between December 2020 and March 2021. The main objective was to detect SARSCoV-
2 outbreaks among residents and study the efficacy of the vaccination campaign. SARS-CoV-2
viral load (RNA copies per L of wastewater) was determined by reverse-transcription quantitative
PCR (RT-qPCR) using the quantification cycle (Cq) values for the nucleocapsid (N) gene. Our results
showed that the increase in viral load preceded the increase in clinical cases, favoring an early
warning system that detects COVID-19 outbreaks in advance, making it possible to contain and
stop the transmission of the virus among residents. In addition, the efficacy of the new COVID-19
vaccines was evidenced, since after the vaccination campaign in nursing homes in A CoruĂąa, it was
observed that many residents did not present any symptoms of the disease, although they excreted
high amounts of virus in their feces. WBE is a cost-effective strategy that should be implemented in
all cities to prevent new emerging diseases or future pandemic threats.EDAR Bens S.A.; INV04020EDAR Bens S.A.; INV12120EDAR Bens S.A.; INV05921EDAR Bens S.A.; INV148721Xunta de Galicia; IN607A 2016/22Xunta de Galicia; ED431C-2016/015Xunta de Galicia; ED431C-2020/14Xunta de Galicia; ED431C 2021/53Xunta de Galicia; ED431G 2019/01Xunta de Galicia; COV20/00604Funding for open access charge: Universidade da CoruĂąa/CISUG. This work was mainly supported by the grant INV00821 from ConsellerĂa de PolĂtica Social (Xunta de Galicia, Spain) to M.P. The team was also supported by EDAR Bens S.A., A CoruĂąa, Spain (grant references INV04020, INV12120, INV05921, and INV148721 to M.P.), by the National Plan for Scientific Research, Development and Technological Innovation funded by the Institute of Health Carlos III (ISCIII), SpainâGeneral Subdirection of Assessment and Promotion of the Research-European Regional Development Fund (FEDER) âA way of making Europeâ [grant references PI15/00860 to G.B., PI17/01482 and PI20/00413 to M.P.], by the Galician Innovation Agency (GAIN) (Xunta de Galicia, Spain) [grant references IN607A 2016/22 to G.B., ED431C-2016/015 and ED431C-2020/14 to R.C., ED431C 2021/53 to S.L., and ED431G 2019/01 and COV20/00604 to R.C. and S.L., by the Ministry of Economic Affairs and Digital Transformation (MINECO), Spain (grant references MTM2017-82724-R to R.C.), by the Spanish Network of Research in Infectious Diseases (CIBERINFEC, ISCIII, reference CB21/13/00055), and by the European Virus Archive Global (EVA-GLOBAL) project that has received funding from the European Unionâs Horizon 2020 research and innovation program under grant agreement No 871029. S.R.-F. was financially supported by REIPI RD16/0016/006, K.C.-P. by IN607A 2016/22 and the Spanish Association against Cancer (AECC), and J.A.V. by IN607A 2016/22
Rice plants overexpressing OsEPF1 show reduced stomatal density and increased root cortical aerenchyma formation
Stomata are adjustable pores in the aerial epidermis of plants. The role of stomata is usually described in terms of the trade-off between CO2 uptake and water loss. Little consideration has been given to their interaction with below-ground development or diffusion of other gases. We overexpressed the rice EPIDERMAL PATTERNING FACTOR1 (OsEPF1) to produce rice plants with reduced stomatal densities, resulting in lowered leaf stomatal conductance and enhanced water use efficiency. Surprisingly, we found that root cortical aerenchyma (RCA) is formed constitutively in OsEPF1OE lines regardless of tissue age and position. Aerenchyma is tissue containing air-spaces that can develop in the plant root during stressful conditions, e.g. oxygen deficiency when it functions to increase O2 diffusion from shoot to root. The relationship with stomata is unknown. We conclude that RCA development and stomatal development are linked by two possible mechanisms: first that reduced stomatal conductance inhibits the diffusion of oxygen to the root, creating an oxygen deficit and stimulating the formation of RCA, second that an unknown EPF signalling pathway may be involved. Our observations have fundamental implications for the understanding of whole plant gas diffusion and root-to-shoot signalling events
Intradermal vaccination with hollow microneedles: A comparative study of various protein antigen and adjuvant encapsulated nanoparticles
Drug Delivery TechnologySupramolecular & Biomaterials Chemistr
- âŚ