Mikrokredite der Grameen Bank

In meiner Arbeit beschäftige ich mich mit Mikrokrediten der Grameen Bank. Ich lege dabei darauf Wert, dem Leser zunächst einen Einblick in das Themenfeld zu geben, weshalb zu Beginn der Arbeit die Funktionsweise und Anwendungsmöglichkeiten von Mikrokrediten erklärt werden. Darauf aufbauend werden die Mechanismen der Grameen Bank vorgestellt und dabei auf Organisationsmerkmale und Kreditvergaberichtlinien eingegangen. Im zweiten Teil meiner Arbeit wird die Case study „Women at the center – Grameen Bank borrowers after one decade” von Helen Todd analysiert. Durchgeführt wurde die Studie im Jahr 1992 in den zwei Dörfern Ghatail und Shajanpur in Bangladesch. Wichtig bei der Auswahl dieser war es, dass sie sich in Bezug auf deren Dorfstruktur nicht ähneln, um das Risiko besonderer lokaler Eigenheiten zu minimieren. Die mittels Interviews und durch Beobachtungen festgestellten Ergebnisse von 40 Grameen-Bank-Kundinnen wurden denen von 24 Frauen, die keine Kredite aufgenommen haben, gegenübergestellt und in Bezug zu meiner Forschungsfrage gesetzt. Hinsichtlich meiner Fragestellung, die lautet, ob Kredite der Grameen Bank einen nennenswerten Einfluss auf Armutsreduktion und „empowerment“ der Darlehnsnehmerinnen haben, kommt die Studie zu dem eindeutigen Ergebnis, dass sowohl betreffend Armutsreduktion, also auch hinsichtlich „empowerment“, Frauen, die ein Darlehn der Grameen Bank aufgenommen haben, gegenüber der Kontrollgruppe stark im Vordertreffen sind.My diploma thesis deals with the microcredit model of the Grameen Bank. At the beginning of my work my aim is to provide insight about functioning and application possibilities of microcredits. In this regard the organizational characteristics and underwriting standards mechanisms within the Grameen Bank are evaluated. Based on that, the case study “women at the center – Grameen Bank borrowers after one decade” is analyzed in the second part of my work. The study was carried out in 1992 in the villages of Ghatail and Shajanpur in Bangladesh. In terms of the selection it was important that those two centers differ from each other in relation to their village structure in order to minimize the risk of specific local characteristics. The identified results from 40 Grameen Bank customers which were obtained through interviews and observations were compared to the acquired data of 24 non Grameen Bank members. Concerning my research question –does microcredit allocation from the Grameen Bank have a significant influence on poverty reduction and empowerment of women members – the result of the study, regarding both poverty reduction and empowerment, is that women who have picked up a Grameen Bank loan are off much better in terms of my research question than the control group

Smad4 and Trim33/Tif1γ Redundantly Regulate Neural Stem Cells in the Developing Cortex

During central nervous system (CNS) development, proliferation and differentiation of neural stem cells (NSCs) have to be regulated in a spatio-temporal fashion. Here, we report different branches of the transforming growth factor β (TGFβ) signaling pathway to be required for the brain area-specific control of NSCs. In the midbrain, canonical TGFβ signaling via Smad4 regulates the balance between proliferation and differentiation of NSCs. Accordingly, Smad4 deletion resulted in horizontal expansion of NSCs due to increased proliferation, decreased differentiation, and decreased cell cycle exit. In the developing cortex, however, ablation of Smad4 alone did not have any effect on proliferation and differentiation of NSCs. In contrast, concomitant mutation of both Smad4 and Trim33 led to an increase in proliferative cells in the ventricular zone due to decreased cell cycle exit, revealing a functional redundancy of Smad4 and Trim33. Furthermore, in Smad4-Trim33 double mutant embryos, cortical NSCs generated an excess of deep layer neurons concurrent with a delayed and reduced production of upper layer neurons and, in addition, failed to undergo the neurogenic to gliogenic switch at the right developmental stage. Thus, our data disclose that in different regions of the developing CNS different aspects of the TGFβ signaling pathway are required to ensure proper developmen

Sox10 haploinsufficiency affects maintenance of progenitor cells in a mouse model of Hirschsprung disease

Hirschsprung disease, or congenital megacolon, is characterized by aganglionosis of the terminal bowel, which leads to intestinal obstruction and chronic constipation. Several genes involved in the disease have been identified. In particular, haploinsufficiency of SOX10, which encodes a transcription factor, results in megacolon, often in combination with other disorders. Although Hirschsprung disease has been recognized as a neurocristopathy, the cellular mechanisms that lead to aganglionosis in affected individuals are unclear. Failure of mutant enteric progenitor cells to migrate into the gut, to survive, or to differentiate into appropriate cell types at the appropriate time and in correct numbers might contribute to the disease phenotype. In the present study, we use mice with a targeted deletion of Sox10 to study the etiology of Hirschsprung disease. We demonstrate that neural crest-derived enteric progenitors that are heterozygous for the Sox10 mutation colonize the proximal intestine and are unaffected in their survival capacity. However, unlike their wild-type counterparts, mutant enteric neural crest-derived cells are unable to maintain their progenitor state and acquire preneuronal traits, which results in a reduction of the progenitor pool size. Thus, the cells that normally colonize the hindgut are depleted in the Sox10 mutant, causing the distal bowel to become aganglioni

Persistent Wnt/β-catenin signaling determines dorsalization of the postnatal subventricular zone and neural Stem cell specification into oligodendrocytes and glutamatergic neurons

In the postnatal and adult central nervous system (CNS), the subventricular zone (SVZ) of the forebrain is the main source of neural stem cells (NSCs) that generate olfactory neurons and oligodendrocytes (OLs), the myelinating cells of the CNS. Here, we provide evidence of a primary role for canonical Wnt/β-catenin signaling in regulating NSC fate along neuronal and oligodendroglial lineages in the postnatal SVZ. Our findings demonstrate that glutamatergic neuronal precursors (NPs) and oligodendrocyte precursors (OPs) are derived strictly from the dorsal SVZ (dSVZ) microdomain under the control of Wnt/β-catenin, whereas GABAergic NPs are derived mainly from the lateral SVZ (lSVZ) microdomain independent of Wnt/β-catenin. Transcript analysis of microdissected SVZ microdomains revealed that canonical Wnt/β-catenin signaling was more pronounced in the dSVZ microdomain. This was confirmed using the β-catenin-activated Wnt-reporter mouse and by pharmacological stimulation of Wnt/β-catenin by infusion of the specific glycogen synthase kinase 3β inhibitor, AR-A014418, which profoundly increased the generation of cycling cells. In vivo genetic/pharmacological stimulation or inhibition of Wnt/β-catenin, respectively, increased and decreased the differentiation of dSVZ-NSCs into glutamatergic NPs, and had a converse effect on GABAergic NPs. Activation of Wnt/β-catenin dramatically stimulated the generation of OPs, but its inhibition had no effect, indicating other factors act in concert with Wnt/β-catenin to fine tune oligodendrogliogenesis in the postnatal dSVZ. These results demonstrate a role for Wnt/β-catenin signaling within the dorsal microdomain of the postnatal SVZ, in regulating the genesis of glutamatergic neurons and OLs

WTA-WTP disparity: The role of perceived realism of the valuation setting

Based on a survey among more than 5,000 German households and a single-binary choice experiment in which we randomly split the respondents into two groups, this paper elicits both households’ willingness to pay (WTP) for power supply security and their willingness to accept (WTA) compensations for a reduced security level. In accord with numerous empirical studies, we find that the mean WTA value substantially exceeds the mean WTP bid, in our empirical example by a factor of 3.56. Yet, the WTA-WTP ratio decreases to 2.35 among respondents who believe that the hypothetical valuation setting is likely to become true. Conversely, the WTA-WTP ratio increases to 3.81 among respondents who deem the setting unlikely. Given this discrepancy, we conclude that to diminish the WTA-WTP disparity resulting from stated-preference surveys at least to some extent, inquiring about respondents’ perception on the realism of the valuation setting is an essential element of any survey design

The Ets Domain Transcription Factor Erm Distinguishes Rat Satellite Glia from Schwann Cells and Is Regulated in Satellite Cells by Neuregulin Signaling

AbstractDistinct glial cell types of the vertebrate peripheral nervous system (PNS) are derived from the neural crest. Here we show that the expression of the Ets domain transcription factor Erm distinguishes satellite glia from Schwann cells beginning early in rat PNS development. In developing dorsal root ganglia (DRG), Erm is present both in presumptive satellite glia and in neurons. In contrast, Erm is not detectable at any developmental stage in Schwann cells in peripheral nerves. In addition, Erm is downregulated in DRG-derived glia adopting Schwann cell traits in culture. Thus, Erm is the first described transcription factor expressed in satellite glia but not in Schwann cells. In culture, the Neuregulin1 (NRG1) isoform GGF2 maintains Erm expression in presumptive satellite cells and reinduces Erm expression in DRG-derived glia but not in Schwann cells from sciatic nerve. These data demonstrate that there are intrinsic differences between these glial subtypes in their response to NRG1 signaling. In neural crest cultures, Erm-positive progenitor cells give rise to two distinct glial subtypes: Erm-positive, Oct-6-negative satellite glia in response to GGF2, and Erm-negative, Oct-6-positive Schwann cells in the presence of serum and the adenylate cyclase activator forskolin. Thus, Erm-positive neural crest-derived progenitor cells and presumptive satellite glia are able to acquire Schwann cell features. Given the in vivo expression of Erm in peripheral ganglia, we suggest that ganglionic Erm-positive cells may be precursors of Schwann cells

High molecular weight mechanochromic spiropyran main chain copolymers via reproducible microwave-assisted Suzuki polycondensation

Suzuki–Miyaura polycondensation (SPC) is widely used to prepare a variety of copolymers for a broad range of applications. Although SPC protocols are often used in many instances, the limits of this method and issues of molecular weight reproducibility are not often looked at in detail. By using a spiropyran-based (SP) mechanochromic copolymer, we present an optimized protocol for the microwave-assisted synthesis of a mechanochromic, alternating copolymer P(SP-alt-C10) via SPC that allows the reproduction of molecular weight distributions. Several parameters such as microwave power, temperature, stoichiometry, and ligand are screened, leading to molecular weights up to Mw ∼ 174 kg mol−1. The process of optimization is guided by NMR end group analysis which shows that dehalogenation, oxidative deborylation and SP cleavage are the limiting factors that impede further increase of molar mass, while other classical side reactions such as protiodeborylation are not observed. Embossing films of P(SP-alt-C10) yields the colored merocyanine (MC) copolymer P(MC-alt-C10) that undergoes a thermally facilitated back reaction to P(SP-alt-C10). DFT suggests that the barrier of the SP → MC transition has two contributions, with the first one being related to the color change and the second one to internal bond reorganizations. The barrier height is 1.5 eV, which suggests that the ease of the thermally facilitated back reaction is either due to residual energy stored in the deformed polymer matrix, or arises from an MC isomer that is not in the thermodynamically most stable state