Sustainability in German development cooperation: Meta-evaluation

This meta-evaluation ‘Sustainability in German development cooperation’ is part of DEval’s thematic focus on sustainability. The meta-evaluationis complemented by an accompanying evaluation synthesis. Linked by an integrated evaluation design, the two reports share a common database and pursue complementary objectives

Sustainability in German development cooperation: Evaluation synthesis

This evaluation synthesis 'Sustainability in German development cooperation' is part of DEval’s thematic focus on sustainability. The evaluation synthesis is supported by an accompanying meta-evaluation. Linked by an integrated evaluation design, the two reports share a common database and pursue complementary objectives

Euler, Jacobi, and Missions to Comets and Asteroids

Whenever a freely spinning body is found in a complex rotational state, this means that either the body is a recent victim of an impact or a tidal interaction, or is a fragment of a recently disrupted progenitor. Another factor (relevant for comets) is outgassing. Due to impacts, tidal forces and outgassing, the asteroidal and cometary precession must be a generic phenomenon: while some rotators are in the state of visible tumbling, a much larger amount of objects must be performing narrow-cone precession not so easily observable from the Earth. The internal dissipation in a freely precessing top leads to relaxation (gradual damping of the precession) and sometimes to spontaneous changes in the rotation axis. Recently developed theory of dissipative precession of a rigid body reveals that this is a highly nonlinear process: while the body is precessing at an angular rate $\omega$, the precession-caused stresses and strains in the body contain components oscillating at other frequencies. Dependent upon the spin state, those frequencies may be higher or, most remarkably, lower than the precession rate. In many states dissipation at the harmonics is comparable to or even exceeds that at the principal frequency. For this and other reasons, in many spin states the damping of asteroidal and cometary wobble happens faster, by several orders, than believed previously. This makes it possible to measure the precession-damping rate. The narrowing of the precession cone through the period of about a year can be registered by the currently available spacecraft-based observational means. However, in the near-separatrix spin states a precessing rotator can considerably slow down its relaxation.Comment: 21 pages, 1 figur

e-Learning und Change Management

E-Learning bietet Chancen, neue Lernformen einzuführen und zu unterstützen. Die vorliegenden Projekterfahrungen, die im Rahmen unterschiedlicher Förder­programme gemacht wurden, zeigen jedoch, dass die Einlösung und die Sicherung dieser Potenziale wesentliche Veränderungen der Rahmenbedingungen in Hoch­schulen erfordert. Dies betrifft vor allem die Entwicklung neuer Kompetenzen sowie neue und neu auszurichtende Support-, Beratungs- und Schulungsangebote und schließlich eine Veränderung der Lernkultur. Gleichzeitig stellt sich das Problem, das sich die hiermit erforderlichen Veränderungsprozesse gerade im Hochschulbereich einer Steuerung teilweise entziehen bzw. deren gezielte Beeinflussung - im Sinne eines "Change Management" - eine besondere Herausforderung darstellen. Das Themenheft stellt in diesem Zusammenhang relevante Veränderungsprozesse dar und diskutiert Möglichkeiten zu deren Gestaltung. Es werden konkrete Ansatz­punkte in Hochschulen vorgestellt die deutlich machen, welche Veränderungs­prozesse erforderlich sind, um e-Learning als Innovation in der Lehre dauerhaft zu etablieren, und welche Erfahrungen mit entsprechenden Strategien des Change Management gemacht worden sind. 25.02.2007 | Dieter EULER & Michael KERRES (Hrsg.

Nachhaltigkeit in der deutschen Entwicklungszusammenarbeit: Meta-Evaluierung

Die vorliegende Meta-Evaluierung "Nachhaltigkeit in der deutschen Entwicklungszusammenarbeit" ist Teil des DEval-Themenschwerpunktes Nachhaltigkeit. Die Meta-Evaluierung wird durch eine begleitende Evaluierungssynthese ergänzt. Im Rahmen eines integrierten Evaluierungsdesigns basieren beide Berichte auf einer gemeinsamen Datengrundlage und haben komplementäre Ziele

Nachhaltigkeit in der deutschen Entwicklungszusammenarbeit: Evaluierungssynthese

Die vorliegende Evaluierungssynthese "Nachhaltigkeit in der deutschen Entwicklungszusammenarbeit" ist Teil des DEval-Themenschwerpunktes Nachhaltigkeit. Die Evaluierungssynthese wird durch eine begleitende Meta-Evaluierung unterstützt. Im Rahmen eines integrierten Evaluierungsdesigns basieren beide Berichte auf einer gemeinsamen Datengrundlage und haben komplementäre Ziele

In vitro blood sample assessment: investigating correlation of laboratory hemoglobin and spectral properties of dual-energy CT measurements (ρ/Z)

Objectives: Our study comprised a single-center retrospective in vitro correlation between spectral properties, namely ρ/Z values, derived from scanning blood samples using dual-energy computed tomography (DECT) with the corresponding laboratory hemoglobin/hematocrit (Hb/Hct) levels and assessed the potential in anemia-detection. Methods: DECT of 813 patient blood samples from 465 women and 348 men was conducted using a standardized scan protocol. Electron density relative to water (ρ or rho), effective atomic number (Z$_{eff}$), and CT attenuation (Hounsfield unit) were measured. Results: Positive correlation with the Hb/Hct was shown for ρ (r-values 0.37–0.49) and attenuation (r-values 0.59–0.83) while no correlation was observed for Z$_{eff}$ (r-values −0.04 to 0.08). Significant differences in attenuation and ρ values were detected for blood samples with and without anemia in both genders (p value < 0.001) with area under the curve ranging from 0.7 to 0.95. Depending on the respective CT parameters, various cutoff values for CT-based anemia detection could be determined. Conclusion: In summary, our study investigated the correlation between DECT measurements and Hb/Hct levels, emphasizing novel aspects of ρ and Z$_{eff}$ values. Assuming that quantitative changes in the number of hemoglobin proteins might alter the mean Z$_{eff}$ values, the results of our study show that there is no measurable correlation on the atomic level using DECT. We established a positive in vitro correlation between Hb/Hct values and ρ. Nevertheless, attenuation emerged as the most strongly correlated parameter with identifiable cutoff values, highlighting its preference for CT-based anemia detection. Clinical relevance statement: By scanning multiple blood samples with dual-energy CT scans and comparing the measurements with standard laboratory blood tests, we were able to underscore the potential of CT-based anemia detection and its advantages in clinical practice. Key Points: ° Prior in vivo studies have found a correlation between aortic blood pool and measured hemoglobin and hematocrit. ° Hemoglobin and hematocrit correlated with electron density relative to water and attenuation but not Z$_{eff}$. ° Dual-energy CT has the potential for additional clinical benefits, such as CT-based anemia detection

Gender differences in smallholders' socioeconomic networks and acquisition of seed of improved wheat varieties in Ethiopia

Enhancing farmers' access to improved seeds is essential to increase productivity and ensure food security in the Global South. However, for many socially marginalized groups, seed access is constrained by the weak institutions governing the input supply chains and the dissemination of information. Using cross-sectional survey data collected from 1,088 farming households in three major wheat-growing regional states of Ethiopia in 2021, this paper assesses empirically how participation in different socioeconomic institutions by men and women farmers shapes their access to and acquisition of seed of improved wheat varieties. The results show that the seed market in the study area is largely informal, where the recycling of wheat seeds from the previous season is a common practice among both male- and female-headed households. However, a significant difference exists between male- and female-headed households regarding patterns of varietal use, with male farmers growing newer wheat varieties more frequently. Men are also more active than women in local social and economic institutions, and their participation is positively associated with the adoption of new wheat varieties. Thus, strengthening the local social and economic institutions and supporting equitable participation of both male- and female-headed households in these institutions could facilitate the diffusion of quality seeds of improved and recently released wheat varieties in countries where the informal seed system plays a major role in seed acquisition

Inter-observer agreement according to three methods of evaluating mammographic density and parenchymal pattern in a case control study:impact on relative risk of breast cancer

BACKGROUND: Mammographic breast density and parenchymal patterns are well-established risk factors for breast cancer. We aimed to report inter-observer agreement on three different subjective ways of assessing mammographic density and parenchymal pattern, and secondarily to examine what potential impact reproducibility has on relative risk estimates of breast cancer. METHODS: This retrospective case–control study included 122 cases and 262 age- and time matched controls (765 breasts) based on a 2007 screening cohort of 14,736 women with negative screening mammograms from Bispebjerg Hospital, Copenhagen. Digitised randomized film-based mammograms were classified independently by two readers according to two radiological visual classifications (BI-RADS and Tabár) and a computerized interactive threshold technique measuring area-based percent mammographic density (denoted PMD). Kappa statistics, Intraclass Correlation Coefficient (ICC) (equivalent to weighted kappa), Pearson’s linear correlation coefficient and limits-of-agreement analysis were used to evaluate inter-observer agreement. High/low-risk agreement was also determined by defining the following categories as high-risk: BI-RADS’s D3 and D4, Tabár’s PIV and PV and the upper two quartiles (within density range) of PMD. The relative risk of breast cancer was estimated using logistic regression to calculate odds ratios (ORs) adjusted for age, which were compared between the two readers. RESULTS: Substantial inter-observer agreement was seen for BI-RADS and Tabár (κ=0.68 and 0.64) and agreement was almost perfect when ICC was calculated for the ordinal BI-RADS scale (ICC=0.88) and the continuous PMD measure (ICC=0.93). The two readers judged 5% (PMD), 10% (Tabár) and 13% (BI-RADS) of the women to different high/low-risk categories, respectively. Inter-reader variability showed different impact on the relative risk of breast cancer estimated by the two readers on a multiple-category scale, however, not on a high/low-risk scale. Tabár’s pattern IV demonstrated the highest ORs of all density patterns investigated. CONCLUSIONS: Our study shows the Tabár classification has comparable inter-observer reproducibility with well tested density methods, and confirms the association between Tabár’s PIV and breast cancer. In spite of comparable high inter-observer agreement for all three methods, impact on ORs for breast cancer seems to differ according to the density scale used. Automated computerized techniques are needed to fully overcome the impact of subjectivity