104 research outputs found
Food Security Monitoring for Developing Countries in the Age of Big Data
Approximately 817 million people are currently estimated to be undernourished and 85 million people across 46 countries are estimated to be in need of food emergency assistance over the course of 2019. Conflict, migration and climate-related disasters are expected to further exacerbate already existing risks to food security. Important pillars that contribute to anticipating crises and informing a potential emergency response are early warning and monitoring systems. The emergence of big data as well as increasing Internet and mobile phone adoption rates across developing countries have enabled the inclusion of different, timelier, more frequent and spatially disaggregated data, as well as the at-risk population itself into monitoring systems. This dissertation is placed at the intersection of food security monitoring, early warning and big data. The first part of this thesis focuses on exploring the information content of current early warning systems (EWSs) for food security risks. We evaluate the information content of the four largest international monitoring system for food security against a conceptual benchmark. We find that EWSs have partially moved towards the inclusion of more diverse indicators for risk monitoring. However, our results further show that timely information is missing, information is published irregularly and the geographical scope of monitoring systems is smaller than stated. Subsequently, this thesis explores ways to improve monitoring systems for food security by using two strings of new data, i.e. Internet metadata and direct assessments from the at-risk population gathered via mobile phones. We test whether Internet metadata in the form of Google search queries (GSQ) can improve now-casts of crop prices in Ethiopia, Kenya, Mozambique, Malawi, Rwanda, Tanzania, Uganda, Zambia and Zimbabwe. In an pseudo-out-of-sample, one-step-ahead forecasting environment, we find models containing the Google search-string textit{maize} to beat the benchmark model in 8 of the 9 countries. By including the GSQ data, we reduce the now-casting error of maize prices between 3% and 23% and achieve the largest improvements for Malawi, Kenya, Zambia and Tanzania with improvements larger than 14%. Furthermore, using a citizen-science approach this thesis analyzes whether the at-risk population can validly assess the food security status of their community, by collecting near real-time food security assessments over an 8 month period from the local population in Kenya. We test the validity of the gathered information against standard food security indicators, i.e. the food consumption score (FCS) and reduced coping strategy index (rCSI), using Pooled Poisson, Negative Binomial and Poisson Fixed Effects models. We find robust results that the assessments from the at-risk population conform to the FCS and rCSI observed during the study period.ErnĂ€hrungssicherheits-Monitoring fĂŒr EntwicklungslĂ€nder im Zeitalter von Big Data SchĂ€tzungen zufolge sind derzeit rund 817 Millionen Menschen unterernĂ€hrt und 85 Millionen Menschen in 46 verschiedenen LĂ€ndern werden im Laufe des Jahres 2019 auf Nahrungsmittelhilfe angewiesen sein. Voraussichtlich werden Konflikte, Migration und klimabedingte Katastrophen die bereits bestehenden Risiken fĂŒr die ErnĂ€hrungssicherheit in Zukunft weiter verschĂ€rfen. FrĂŒhwarn- und Ăberwachungssysteme fĂŒr die ErnĂ€hrungssicherheit sind in diesem Kontext wichtige SĂ€ulen, die zur Antizipation von Krisen beitragen und eine potenzielle Notfallintervention auslösen und gestalten. Das Aufkommen von Big Data sowie steigende Internet- und Handy-Nutzung in EntwicklungslĂ€ndern haben die Einbeziehung verschiedener, hĂ€ufiger und rĂ€umlich detaillierter Daten sowie die Integration der gefĂ€hrdeten Bevölkerung selbst in Ăberwachungssysteme ermöglicht. Diese Dissertation befindet sich an der Schnittstelle von FrĂŒhwarnsystemen fĂŒr die ErnĂ€hrungssicherheit und Big Data. ZunĂ€chst untersucht diese Dissertation den Informationsgehalt aktueller FrĂŒhwarnsysteme (EWSs) fĂŒr ErnĂ€hrungssicherheitsrisiken. Dabei wird der Informationsgehalt von vier groĂen, internationalen Ăberwachungssystemen fĂŒr die ErnĂ€hrungssicherheit anhand eines konzeptionellen Benchmarks fĂŒr FrĂŒhwarnsystem analysiert. Wir stellen fest, dass EWSs eine breite Bandweite an Indikatoren abdecken und der anfĂ€ngliche Fokus auf VerfĂŒgbarkeit ebenfalls um die Zugangskomponente zu Nahrung erweitert wurde. Unsere Ergebnisse zeigen jedoch weiterhin, dass zeitnahe Information fehlt, Information unregelmĂ€Ăig veröffentlicht wird und die geografische Reichweite der Ăberwachungssysteme geringer ist als angegeben. AnschlieĂend untersucht diese Arbeit Möglichkeiten, Ăberwachungssysteme fĂŒr die ErnĂ€hrungssicherheit zu verbessern, indem sie das Potenzial zwei neuer Datenströme fĂŒr FrĂŒhwarnsysteme untersucht, i.e. Internet-Metadaten und die direkten EinschĂ€tzungen der Risikopopulation selbst. Wir prĂŒfen, ob Modelle, basierend auf Internet-Metadaten in Form von Google-Suchanfragen (GSQ) die textit{now-casts} von Maispreisen in Ăthiopien, Kenia, Mosambik, Malawi, Ruanda, Tansania, Uganda, Sambia und Simbabwe verbessern können. In einer textit{Now-Casting, Pseudo-Out-of-Sample-}Umgebung, finden wir, dass Modelle, die den Google-Suchstring textit{maize} enthalten, das Benchmark-Modell in 8 der 9 LĂ€nder schlagen. Durch die Einbeziehung der GSQ-Daten reduzieren wir den Forecasting-Fehler von Maispreisen zwischen 3% und 23% und erzielen die gröĂten Verbesserungen in Malawi, Kenia, Sambia und Tansania mit mehr als 14%. Desweitern analysiert diese Dissertation anhand eines Citzen-Science Ansatzes, ob lokale Teilnehmer den ErnĂ€hrungssicherheitsstatus der lokalen Bevölkerung einschĂ€tzen können. Anhand von Mobiltelefonen und in nahezu Echtzeit wurden dazu ĂŒber einen Zeitraum von acht Monaten Bewertungen der ErnĂ€hrungssicherheit von der lokalen Bevölkerung in Kenia gesammelt. In Pooled-Poisson-, Negative-Binomial- und Poisson-Fixed-Effects-Modellen analysieren wir die ValiditĂ€t der gesammelten Informationen im Vergleich zu Indikatoren fĂŒr die ErnĂ€hrungssicherheit, i.e. Lebensmittelkonsum (FCS) und BewĂ€ltigungsstrategien (rCSI). Wir finden robuste Ergebnisse, dass die EinschĂ€tzungen der Risikopopulation mit den Werten des FCS und rCSI ĂŒbereinstimmen, die wĂ€hrend des Untersuchungszeitraums beobachtet wurden
Public Distribution System in India - Leakage, Self-Selection and Targeting Errors
Despite the large-scale antipoverty programs, especially food and nutrition programs, 15 per cent of Indian population is undernourished. India's current implementation of the world largest food aid program, the National Food Security Act (NFSA), experiences many challenges and needs rigorous analysis. Current study analyzes consumption patterns of wheat and rice delivered through the Public Distribution System in India. Further, impact of the subsidy on market grain consumption is quantified. The household consumption analysis using cross-sectional econometric techniques reveals targeting errors of the Public Distribution System. There is a negative self-selection of the richer households; however the migrant workers and female-led households are not well covered. The Above Poverty Line quota seems to have higher leakage rate, which strongly affects consumption of the subsidized grains. For the Below Poverty Line cardholders, subsidized grains are imperfect substitutes for the market grains. Further, subsidized grains are found to increase total consumption of wheat and rice. Because of high targeting errors, higher total demand for wheat and rice might result in higher market prices and have negative consequences for the poor excluded from the system. To our knowledge, this is the first empirical analysis of the various targeting errors and reasons for under-purchase on all India level. The results further contribute to the growing evidence that the PDS crowds in consumption of wheat and rice
Mitotane Nanocarriers for the Treatment of Adrenocortical Carcinoma: Evaluation of Albumin-Stabilized Nanoparticles and Liposomes in a Preclinical In Vitro Study with 3D Spheroids
Adrenocortical carcinoma (ACC) is a heterogeneous malignancy related to poor prognosis and limited treatment options. The orphan drug mitotane (MT) is still a cornerstone in ACC therapy, however, its application is characterized by low aqueous solubility, poor bioavailability, and unfavorable pharmacokinetics, often resulting in below-target plasma concentrations or toxic side effects. Throughout the last decades, nanoparticulate formulations have become attractive carriers to improve anticancer therapy. In this study, injectable MT liposomes (DOPC-MT) and albumin-stabilized MT nanoparticles (BSA-MT) were investigated in depth with respect to their physicochemical properties, and their colloidal and therapeutical stability upon storage. Furthermore, in vitro cytotoxicity was evaluated using the ACC model cell line NCI-H295R for preparing multicellular tumor spheroids, and was compared to non-malignant human dermal fibroblasts. Our results clearly demonstrate that BSA-MT, unlike DOPC-MT, represents a stable and storable MT formulation with a high drug concentration in an aqueous medium. Dual centrifugation was established as a reproducible method for nanoparticle preparation. Although an efficient cytotoxic effect on ACC tumor spheroids was demonstrated, concomitant low toxicity to fibroblasts suggests that higher drug concentrations may be tolerated in vivo. Consequently, BSA-MT is a novel and promising therapeutical approach to address key challenges in MT treatment
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Localization of carbon nanotubes in polyamide 6 blends with non-reactive and reactive rubber
Blending of two immiscible polymer matrices can be an effective way to combine favourable properties of both blend partners. The additional incorporation of multiwalled carbon nanotubes (MWCNTs) in such thermoplastic blends may further enhance the blend properties and especially generate electrical conductivity. In the present study, 20 wt.% of non-reactive rubber and maleic anhydride functionalized rubber were melt blended with polyamide 6 and 3 wt.% MWCNTs by using different incorporation strategies. For the blends containing non-reactive rubber, the MWCNTs were always localized selectively in the thermodynamically preferred polyamide phase as shown by TEM images and electrical measurements. Interestingly, the different strategies resulted in different localization behaviours of the MWCNTs in case of the reactive rubber. These findings demonstrate the significant influence of maleic anhydride groups of the rubber component on localization of MWCNTs in the different blend phases which results in different values of electrical volume resistivity of the blends. © 2014 The Authors. Published by Elsevier Ltd
Managing financial crises in emerging market economies - experience with the involvement of private sector creditors
Ensuring the involvement of private sector creditors in the resolution of sovereign debt crises is crucial to ensure an effective management and orderly resolution of those crises. A review of experience gained in past financial crises suggests that crisis management practices have been largely following a case-by-case approach. This has led to some uncertainty about how the official sector addresses different types of crises, which in turn might partially account for the very mixed results achieved so far. From a global welfare perspective, the resolution of international financial crises is too costly and takes too long. Efforts to improve predictability of crisis resolution processes â through guiding debtor, creditor and official sector behaviour â could lower overall costs of such crises and bring about a better distribution of these costs. Past experience with such private sector involvement shows that, in certain cases, existing instruments have successfully contributed to minimising the economic disruptions caused by crises. However, the effective use of these instruments requires predictable and strong commitment of all parties involved. Key variables in that regard are the countryâs economic fundamentals and its track record prior to the crisis, underscoring the importance of effective surveillance and crisis prevention. Success also hinges on the countryâs resolve to implement necessary domestic adjustment measures. A transparent process providing for early dialogue between a debtor and its creditors also facilitates private sector involvement. Finally, the IMF plays a key role in crisis situations, as accurate and timely diagnosis by the IMF helps identify at an early stage the need for private sector involvement.Sovereign default, bond restructuring, emerging markets, financial crises, moral hazard, international financial architecture.
Detection of volatile organic compounds in headspace of Klebsiella pneumoniae and Klebsiella oxytoca colonies
Introduction: Early diagnosis of infections and sepsis is essential as adequate
therapy improves the outcome. Unfortunately, current diagnostics are invasive
and time-consuming, making diagnosis difficult, especially in neonatology.
Novel non-invasive analytical methods might be suitable to detect an infection
at an early stage and might even allow identification of the pathogen. Our aim is
to identify specific profiles of volatile organic compounds (VOCs) of bacterial
species.
Methods: Using multicapillary column-coupled ion mobility spectrometry (MCC/
IMS), we performed headspace measurements of bacterial cultures from skin and
anal swabs of premature infants obtained during weekly screening for bacterial
colonization according to KRINKO. We analyzed 25 Klebsiella pneumoniae (KP)
cultures on MacConkey (MC) agar plates, 25 Klebsiella oxytoca (KO) cultures on
MC agar and 25 bare MC agar plates as a control group.
Results: Using MCC/IMS, we identified a total of 159 VOC peaks. 85 peaks allowed
discriminating KP and bare MC agar plates, and 51 peaks comparing KO and bare
MC agar plates and 6 peaks between KP and KO (significance level of p < 0.05 after
Bonferroni post hoc analysis), respectively. Peaks P51 (n-Decane) and P158
(Phenylethyl Alcohol), showed the best sensitivity/specificity/ positive predictive
value/negative predictive value of 99.9% each (p < 0.001) for KP. P158 showed
the best sensitivity/specificity/positive predictive value/negative predictive value
of 99.9% each (p < 0.001) for KO. Comparing KP and KO, best differentiation
was enabled using peaks P72, P97 and P16 with sensitivity/specificity/positive
predictive value/negative predictive value of 76.0%, 84.0%, 82.6%, 77.8%,
respectively (p < 0.05)
Sex Differences in the Frequencies of B and T Cell Subpopulations of Human Cord Blood
Cord blood represents a link between intrauterine and early extrauterine development.
Cord blood cells map an important time frame in human immune imprinting processes. It is unknown
whether the sex of the newborn affects the lymphocyte subpopulations in the cord blood. Nine B and
twenty-one T cell subpopulations were characterized using flow cytometry in human cord blood from
sixteen male and twenty-one female newborns, respectively. Except for transitional B cells and naĂŻve
B cells, frequencies of B cell counts across all subsets was higher in the cord blood of male newborns
than in female newborns. The frequency of naĂŻve thymus-negative Th cells was significantly higher
in male cord blood, whereas the remaining T cell subpopulations showed a higher count in the
cord blood of female newborns. Our study is the first revealing sex differences in the B and T cell
subpopulations of human cord blood. These results indicate that sex might have a higher impact for
the developing immune system, urging the need to expand research in this area
Managing financial crises in emerging market economies - experience with the involvement of private sector creditors
Ensuring the involvement of private sector creditors in the resolution of sovereign debt crises is crucial to ensure an effective management and orderly resolution of those crises. A review of experience gained in past financial crises suggests that crisis management practices have been largely following a case-by-case approach. This has led to some uncertainty about how the official sector addresses different types of crises, which in turn might partially account for the very mixed results achieved so far. From a global welfare perspective, the resolution of international financial crises is too costly and takes too long. Efforts to improve predictability of crisis resolution processes â through guiding debtor, creditor and official sector behaviour â could lower overall costs of such crises and bring about a better distribution of these costs. Past experience with such private sector involvement shows that, in certain cases, existing instruments have successfully contributed to minimising the economic disruptions caused by crises. However, the effective use of these instruments requires predictable and strong commitment of all parties involved. Key variables in that regard are the countryâs economic fundamentals and its track record prior to the crisis, underscoring the importance of effective surveillance and crisis prevention. Success also hinges on the countryâs resolve to implement necessary domestic adjustment measures. A transparent process providing for early dialogue between a debtor and its creditors also facilitates private sector involvement. Finally, the IMF plays a key role in crisis situations, as accurate and timely diagnosis by the IMF helps identify at an early stage the need for private sector involvement
Detection of volatile organic compounds in headspace of Klebsiella pneumoniae and Klebsiella oxytoca colonies
IntroductionEarly diagnosis of infections and sepsis is essential as adequate therapy improves the outcome. Unfortunately, current diagnostics are invasive and time-consuming, making diagnosis difficult, especially in neonatology. Novel non-invasive analytical methods might be suitable to detect an infection at an early stage and might even allow identification of the pathogen. Our aim is to identify specific profiles of volatile organic compounds (VOCs) of bacterial species.MethodsUsing multicapillary column-coupled ion mobility spectrometry (MCC/IMS), we performed headspace measurements of bacterial cultures from skin and anal swabs of premature infants obtained during weekly screening for bacterial colonization according to KRINKO. We analyzed 25 Klebsiella pneumoniae (KP) cultures on MacConkey (MC) agar plates, 25 Klebsiella oxytoca (KO) cultures on MC agar and 25 bare MC agar plates as a control group.ResultsUsing MCC/IMS, we identified a total of 159 VOC peaks. 85 peaks allowed discriminating KP and bare MC agar plates, and 51 peaks comparing KO and bare MC agar plates and 6 peaks between KP and KO (significance level of pâ<â0.05 after Bonferroni post hoc analysis), respectively. Peaks P51 (n-Decane) and P158 (Phenylethyl Alcohol), showed the best sensitivity/specificity/ positive predictive value/negative predictive value of 99.9% each (pâ<â0.001) for KP. P158 showed the best sensitivity/specificity/positive predictive value/negative predictive value of 99.9% each (pâ<â0.001) for KO. Comparing KP and KO, best differentiation was enabled using peaks P72, P97 and P16 with sensitivity/specificity/positive predictive value/negative predictive value of 76.0%, 84.0%, 82.6%, 77.8%, respectively (pâ<â0.05).DiscussionWe developed a method for the analysis of VOC profiles of bacteria. Using MCC/IMS, we demonstrated that VOCs derived from bacteria are clearly distinguishable from a bare agar plate. Characteristic peaks obtained by MCC/IMS are particularly suitable for the species-specific identification and differentiation of KP and KO. Thus, MCC/IMS might be a useful tool for in vitro diagnostics. Future studies must clarify whether similar patterns of VOCs can be detected in vivo in patients that are colonized or infected with KP or KO to enable rapid and accurate diagnosis of bacterial colonization
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