Global processes, local strategies : migration of educated Dominicans.

The aim of this thesis is to examine migration of educated Dominicans in light of global processes. Current global developments have resulted in increasingly global movements of people, yet people tend to come from certain places in large numbers rather than others. At the same time, international migration is increasingly selective, which shows in the disproportional number of educated migrants. This study discovers individual and societal motivations that explain why young educated Dominicans decide to migrate and return. The theoretical framework of this thesis underlines that migration is a dynamic process rooted in other global developments. Migratory movements should be seen as a result of interacting macro- and microstructures, which are linked by a number of intermediate mechanisms, meso-structures. The way individuals perceive opportunity structures concretises the way global developments mediate to the micro-level. The case of the Dominican Republic shows that there is a diversity of local responses to the world system, as Dominicans have produced their own unique historical responses to global changes. The thesis explains that Dominican migration is importantly conditioned by socioeconomic and educational background. Migration is more accessible for the educated middle class, because of the availability of better resources. Educated migrants also seem less likely to rely on networks to organize their migrations. The role of networks in migration differs by socioeconomic background on the one hand, and by the specific connections each individual has to current and previous migrants on the other hand. The personal and cultural values of the migrant are also pivotal. The central argument of this thesis is that a veritable culture of migration has evolved in the Dominican Republic. The actual economic, political and social circumstances have led many Dominicans to believe that there are better opportunities elsewhere. The globalisation of certain expectations on the one hand, and the development of the specifically Dominican feeling of ‘externalism’ on the other, have for their part given rise to the Dominican culture of migration. The study also suggests that the current Dominican development model encourages migration. Besides global structures, local structures are found to ve pivotal in determining how global processes are materialised in a specific place. The research for this thesis was conducted by using qualitative methodology. The focus of this thesis was on thematic interviews that reveal the subject’s point of view and give a fuller understanding of migration and mobility of the educated. The data was mainly collected during a field research phase in Santo Domingo, the Dominican Republic in December 2009 and January 2010. The principal material consists of ten thematic interviews held with educated Dominican current or former migrants. Four expert interviews, relevant empirical data, theoretical literature and newspaper articles were also comprehensively used.

The subsidence rates of suspensions of lithium stearate in n-heptane with n-alcohols as additives

Suspensions of lithium stearate in n-heptane are highly unstable, undergoing gelation even at concentrations as low as 1 g./1. The rate of subsidence of these weakly gelled suspensions is decreased at first by the addition of n-alcohols, but passes through a minimum in some cases. The minimum subsidence rate occurs while the adsorption of the alcohol is still below its saturation value. One possible explanation of the effect is that the solvent layer between particles at the junction points in the gel becomes simultaneously more polar, tending toward an increased gel strength, and also thicker, tending toward a decreased gel strength.

Photophysics of conjugated polymers: interplay between Forster energy migration and defect concentration in shaping a photochemical funnel in PPV

Recent single molecule experiments have suggested the existence of a photochemical funnel in the photophysics of conjugated polymers, like poly[2-methoxy-5-(2'-ethylhexyl)oxy-1,4-phenylenevinylene] (MEH-PPV). The funnel is believed to be a consequence of the presence of conformational or chemical defects along the polymer chain and efficient non-radiative energy transfer among different chromophore segments. Here we address the effect of the excitation energy dynamics on the photophysics of PPV. The PPV chain is modeled as a polymer with the length distribution of chromophores given either by a Gaussian or by a Poisson distribution. We observe that the Poisson distribution of the segment lengths explains the photophysics of PPV better than the Gaussian distribution. A recently proposed version of an extended particle-in-a-box' model is used to calculate the exciton energies and the transition dipole moments of the chromophores, and a master equation to describe the excitation energy transfer among different chromophores. The rate of energy transfer is assumed to be given here, as a first approximation, by the well-known Forster expression. The observed excitation population dynamics confirms the photochemical funneling of excitation energy from shorter to longer chromophores of the polymer chain. The time scale of spectral shift and energy transfer for our model polymer, with realistic values of optical parameters, is in the range of 200-300 ps. We find that the excitation energy may not always migrate towards the longest chromophore segments in the polymer chain as the efficiency of energy transfer between chromophores depends on the separation distance between the two and their relative orientation.

Identification of molecules relevant for the invasiveness of fibrosarcomas and melanomas

Cancer is becoming the leading cause of deaths in the world. As 90% of all deaths from cancer are caused by metastasis, discovery of the mechanisms behind cancer cell invasion and metastasis is of utmost importance. Only new effective therapies targeting cancer progression can reduce cancer mortality rates. The aim of this study was to identify molecules that are relevant for tumor cell invasion and spreading in fibrosarcomas and melanomas, and to analyze their potential for cancer biomarkers or therapeutic targets. First, the gene expression changes of normal cells and transformed cells showing high invasiveness, S-adenosylmethionine decarboxylase (AdoMetDC)-transfected murine fibroblasts and human melanoma cells, were studied by microarray analyses. The function of the identified candidate molecules were then studied in detail in these cell lines. Finally, the physiological relevance of the identified changes was studied by immunohistochemical analyses of human sarcoma and melanoma specimens or by a mouse xenograft model. In fibrosarcoma cells, the most remarkable change detected was a dramatic up-regulation of the actin-sequestering molecule thymosin beta 4 (TB4), which was shown to be important for the transformed phenotype of the AdoMetDC-transfected cells (Amdc-s and -as). A sponge toxin latrunculin A, inhibiting the binding of TB4 to actin, was found to selectively inhibit the migration and invasion of these cells. Further, Amdc-s-induced mouse tumors and human high-grade sarcomas were found to show intense TB4 immunostaining. In addition to TB4, integrin subunits alfa 6 and beta 7 (ItgA6 and ItgB7) were found to be up-regulated in Amdc-s and -as cells. ItgA6 was shown to dimerize mainly with ItgB1 in Amdc-s. Inhibition of ItgA6 or ItgB1 function with neutralizing antibodies fully blocked the invasiveness of Amdc-s cells, and importantly also human HT-1080 fibrosarcoma cells, in three-dimensional (3D)-Matrigel mimicking tumor extracellular matrix (ECM). By immunohistochemical analyses, strong staining for ITGA6 was detected in human high-grade fibrosarcomas and other sarcomas, especially at the invasion fronts of the tumors. In the studied melanoma cell lines, the expression levels of the adhesion-related ECM proteins tenascin-C (TN-C), fibronectin (FN), and transforming growth factor beta-induced (TGFBI) were found to be highly up-regulated. By immunohistochemistry, intense TN-C and FN staining was detected in invasive and metastatic melanoma tumors, showing co-localization (together with procollagen-I) in tubular meshworks and channels around the invading melanoma cells. In vitro, TN-C and FN were further found to directly stimulate the migration of melanoma cells in 3D-collagen-I matrix. The third candidate protein, TGFBI, was found to be an anti-adhesive molecule for melanoma cells, and knockdown of its expression in metastatic melanoma cells (TGFBI-KD cells) led to dramatically impaired tumor growth in immunocompromized mice. Interestingly, the control tumors showed intense TGFBI immunostaining in the invasion fronts, showing partial co-localization with the fibrillar FN staining, whereas the small TGFBI-KD cell-induced tumors displayed amorphous, non-fibrillar FN staining. These data suggest an important role for TGFBI in FN fibrillogenesis and melanoma progression. In conclusion, we have identified several invasion-related molecules, which show potential for cancer diagnostic or prognostic markers, or therapeutic targets. Based on our previous and present fibrosarcoma studies, we propose the possibility of using ITGA6 antagonists (affecting tumor cell adhesion) in combination with TB4 inhibitors (affecting tumor cell migration) and cathepsin L inhibitors (affecting the degradation of basement membrane and ECM proteins) for the treatment of fibrosarcomas and other tumors overexpressing these molecules. With melanoma cells, in turn, we point to the importance of three secreted ECM proteins, TN-C, FN, and TGFBI, in melanoma progression. Of these, especially the potential of TN-C as a prognostic melanoma biomarker and TGFBI as a promising therapeutic target molecule are clearly worth additional studies.

Association between molecular variation in the phosphoglucose isomerase (Pgi) locus and migration propensity in the Glanville fritillary butterfly

Habitat fragmentation produces patches of suitable habitat surrounded by unfavourable matrix habitat. A species may persist in such a fragmented landscape in an equilibrium between the extinctions and recolonizations of local populations, thus forming a metapopulation. Migration between local populations is necessary for the long-term persistence of a metapopulation. The Glanville fritillary butterfly (Melitaea cinxia) forms a metapopulation in the Åland islands in Finland. There is migration between the populations, the extent of which is affected by several environmental factors and variation in the phenotype of individual butterflies. Different allelic forms of the glycolytic enzyme phosphoglucose isomerase (Pgi) has been identified as a possible genetic factor influencing flight performance and migration rate in this species. The frequency of a certain Pgi allele, Pgi-f, follows the same pattern in relation to population age and connectivity as migration propensity. Furthermore, variation in flight metabolic performance, which is likely to affect migration propensity, has been linked to genetic variation in Pgi or a closely linked locus. The aim of this study was to investigate the association between Pgi genotype and the migration propensity in the Glanville fritillary both at the individual and population levels using a statistical modelling approach. A mark-release-recapture (MRR) study was conducted in a habitat patch network of M. cinxia in Åland to collect data on the movements of individual butterflies. Larval samples from the study area were also collected for population level examinations. Each butterfly and larva was genotyped at the Pgi locus. The MRR data was parameterised with two mathematical models of migration: the Virtual Migration Model (VM) and the spatially explicit diffusion model. VM model predicted and observed numbers of emigrants from populations with high and low frequencies of Pgi-f were compared. Posterior predictive data sets were simulated based on the parameters of the diffusion model. Lack-of-fit of observed values to the model predicted values of several descriptors of movements were detected, and the effect of Pgi genotype on the deviations was assessed by randomizations including the genotype information. This study revealed a possible difference in the effect of Pgi genotype on migration propensity between the two sexes in the Glanville fritillary. The females with and males without the Pgi-f allele moved more between habitat patches, which is probably related to differences in the function of flight in the two sexes. Females may use their high flight capacity to migrate between habitat patches to find suitable oviposition sites, whereas males may use it to acquire mates by keeping a territory and fighting off other intruding males, possibly causing them to emigrate. The results were consistent across different movement descriptors and at the individual and population levels. The effect of Pgi is likely to be dependent on the structure of the landscape and the prevailing environmental conditions.

A theory on the migration of an extraneous electron across hydrogen bonds in polypeptides

The migrating electrons in biological systems normally are extraneous and taking this into account the electron delocalisation across the hydrogen bonds in proteins is re-examined. It is seen that an extraneous electron can travel rapidly via the low-lying virtual orbitals of the hydrogen-bonded π-electronic structure of peptide units in proteins. The frequency of electron transfer decreases slowly with an increase in the path length. However, the coupling of electron and protonic motions enhances this frequency. Transfer of electrons across the hydrogen bonds in accordance with the double-exchange mechanism does not appear to be possible. This theory offers a possibility for an extraneous electron to transfer within protein structures.

Global Processes, Local Strategies : migration of educated Dominicans.

The aim of this thesis is to examine migration of educated Dominicans in light of global processes. Current global developments have resulted in increasingly global movements of people, yet people tend to come from certain places in large numbers rather than others. At the same time, international migration is increasingly selective, which shows in the disproportional number of educated migrants. This study discovers individual and societal motivations that explain why young educated Dominicans decide to migrate and return. The theoretical framework of this thesis underlines that migration is a dynamic process rooted in other global developments. Migratory movements should be seen as a result of interacting macro- and microstructures, which are linked by a number of intermediate mechanisms, meso-structures. The way individuals perceive opportunity structures concretises the way global developments mediate to the micro-level. The case of the Dominican Republic shows that there is a diversity of local responses to the world system, as Dominicans have produced their own unique historical responses to global changes. The thesis explains that Dominican migration is importantly conditioned by socioeconomic and educational background. Migration is more accessible for the educated middle class, because of the availability of better resources. Educated migrants also seem less likely to rely on networks to organize their migrations. The role of networks in migration differs by socioeconomic background on the one hand, and by the specific connections each individual has to current and previous migrants on the other hand. The personal and cultural values of the migrant are also pivotal. The central argument of this thesis is that a veritable culture of migration has evolved in the Dominican Republic. The actual economic, political and social circumstances have led many Dominicans to believe that there are better opportunities elsewhere. The globalisation of certain expectations on the one hand, and the development of the specifically Dominican feeling of ‘externalism’ on the other, have for their part given rise to the Dominican culture of migration. The study also suggests that the current Dominican development model encourages migration. Besides global structures, local structures are found to ve pivotal in determining how global processes are materialised in a specific place. The research for this thesis was conducted by using qualitative methodology. The focus of this thesis was on thematic interviews that reveal the subject’s point of view and give a fuller understanding of migration and mobility of the educated. The data was mainly collected during a field research phase in Santo Domingo, the Dominican Republic in December 2009 and January 2010. The principal material consists of ten thematic interviews held with educated Dominican current or former migrants. Four expert interviews, relevant empirical data, theoretical literature and newspaper articles were also comprehensively used.

A molecular dynamics study of cage-to-cage migration in sodium Y zeolite: role of surface-mediated diffusion

The details of cage-to-cage migration have been obtained from an analysis of the molecular dynamics trajectory of a probe adsorbate. It is observed that particles utilize the region within a radius of 2 angstrom from the window center but with diffusion taking place predominantly at 1.6 angstrom from the window center and a potential energy of nearly -12 kJ/mol. A barrier of about 0.5 kJ/mol is observed for surface-mediated diffusion. Surprisingly, for diffusion without surface mediation for a particle going from one cage center to another, there is an attractive well near the window instead of a barrier. At low adsorbate concentrations and room temperature, the predominant mode for cage-to-cage migration is surface-mediated diffusion. The analysis suggests that particles slide along the surface of the inner walls of the alpha-cages during migration from one cage to another.

Effect of stacking fault energy on the dynamic recrystallization during hot working of FCC metals: A study using processing maps

The influence of stacking fault energy (SFE) on the mechanism of dynamic recrystallization (DRX) during hot deformation of FCC metals is examined in the light of results from the power dissipation maps. The DRX domain for high SFE metals like Al and Ni occurred at homologous temperature below 0·7 and strain rates of 0·001 s−1 while for low SFE metals like Cu and Pb the corresponding values are higher than 0·8 and 100 s−1. The peak efficiencies of power dissipation are 50% and below 40% respectively. A simple model which considers the rate of interface formation (nucleation) involving dislocation generation and simultaneous recovery and the rate of interface migration (growth) occurring with the reduction in interface energy as the driving force, has been proposed to account for the effect of SFE on DRX. The calculations reveal that in high SFE metals, interface migration controls DRX while the interface formation is the controlling factor in low SFE metals. In the latter case, the occurrence of flow softening and oscillations could be accounted for by this model.

Influence of cross-correlation between dipolar and chemical shift anisotropy relaxation mechanisms upon the transverse relaxation rates of 15N in macromolecules

Heteronuclear multiple-quantum coherence relaxation rate are calculated for the individual transitions of the S spin in an AIS nuclear spin system assuming that the heteronucleus (S spin) has relaxation contributions from both intramolecular dipole-dipole and chemical shift anisotropy relaxation. The individual multiplet components of the heteronuclear zero- and double-quantum coherences are shown to have different transverse relaxation rates. The cross-correlation between the two relaxation mechanisms is shown to be the dominant cause of the calculated differential line broadening. Experimental data are presented using as an example a uniformly 15N labelled sample of human epidermal growth factor.

Macrophages in regressed and progressed uveal melanoma

Uveal melanoma (UM) is the most common primary ocular malignancy in adults. In Finland, approximately 50 new cases are diagnosed yearly. Up to 50% of UM metastasize, mostly to the liver, although other organs are also affected. Despite improvements in the management of the primary tumour, the survival rates of patients with metastatic UM are poor. Until the 1970s, UMs were treated by enucleation i.e. removal of the eye. Currently, UM is usually treated by brachytherapy, which is known to influence tumour cells and blood vessels. UMs enucleated both primarily and secondarily after brachytherapy contain tumour-infiltrating macrophages, and a high number of macrophages in primary UM is associated with a shorter survival and a higher microvascular density (MVD) within the tumour tissue. The latter is independently associated with a shorter time to metastatic death. Macrophages have several diverse roles depending on their response to variable signals from the surrounding microenvironment. They function as scavengers, as producers of angiogenic and growth factors as well as proteases, which modulate extracellular matrix. Thus, tumour invasiveness and the risk for metastasis increase with increasing macrophage density. The aim of this study was to evaluate the effects of regression and progression of UM on macrophage numbers and microcirculation factors. Tumour regression is induced by primary brachytherapy, and tumour progression is evidenced by the development of metastases. Understanding the biological behaviour of UMs in the both states may help us in finding new treatment modalities against this disease. To achieve these aims case-control analyses of irradiated UMs and primarily-enucleated eyes (34 matched pairs) were performed. UMs were stained immunohistochemically to detect macrophages, extravascular matrix (EVM) loops and networks, and MVD. Following brachytherapy, a lower MVD was observed. The average number of macrophages remained unchanged. Considering that irradiated melanomas may still contain proliferating tumour cells, a clinically-relevant consequence of my study would be the reassurance that the risk for metastasis is likely to be reduced, given that the low MVD in untreated UMs indicates a favourable prognosis. The effect of progression on macrophages was studied in a paired analysis of primarily-enucleated UM and their corresponding hepatic metastases (48 pairs). A cross-sectional histopathological analysis of these pairs was carried out by staining both specimens in a similar way to the first study. MVD was greater in hepatic metastases than in corresponding primary tumours, and the survival of the patient tended to be shorter if hepatic metastases had a higher MVD. Hepatic metastases had also more dendritic macrophages than the primary UMs. Thus, the progression to metastasis seems to alter the inflammatory status within the tumour. Furthermore, determining MVD of biopsied hepatic metastases may serve as a supplementary tool in estimating the prognosis of patients with metastatic uveal melanoma. After irradiation, the majority of treated eyes have been clinically observed to have pigmented episcleral deposits. A noncomparative clinical case series of 211 irradiated UM eyes were studied by recording the number and location of pigmented episcleral deposits during follow-up visits after brachytherapy. For the first time, the study described pigmented episcleral deposits, which are found in the most UM eyes after brachytherapy, and proved them to consist of macrophages full with engulfed melanin particles. This knowledge may save patients from unnecessary enucleation, because episcleral pigmented deposits might be mistaken for extrascleral tumour growth. The presence of pigmented macrophage-related episcleral deposits was associated with plaque size and isotope rather than with tumour size, suggesting that, in addition to tumour regression, radiation atrophy of retinal pigment epithelium and choroid contributes to the formation of the deposits. In the paired (the same 34 pairs as in the first study) cross-sectional study of irradiated and non-irradiated UMs, clinically-visible episcleral deposits and migrating macrophages in other extratumoral tissues were studied histopathologically. Resident macrophages were present in extratumoral tissues in eyes with both irradiated and non-irradiated UM. Irradiation increased both the number of CD68+ macrophages in the sclera beneath the tumour and the number of clinically-observed episcleral macrophages aggregates. Brachytherapy seemed to alter the route of migration of macrophages: after irradiation, macrophages migrated preferentially through the sclera while in non-irradiated UMs they seemed to migrate more along the choroid. In order to understand the influence of these routes on tumour progression and regression in the future, labelling and tracking of activated macrophages in vivo is required.

Proteomic Identification of Haptoglobin alpha 2 as a Glioblastoma Serum Biomarker: Implications in Cancer Cell Migration and Tumor Growth

Glioblastoma (GBM; grade IV astrocytoma) is the most malignant and common primary brain tumor in adults. Using combination of 2-DE and MALDI-TOF MS, we analyzed 14 GBM and 6 normal control sera and identified haptoglobin alpha 2 chain as an up-regulated serum protein in GBM patients. GBM-specific up-regulation was confirmed by ELISA based quantitation of haptoglobin (Hp) in the serum of 99 GBM patients as against lower grades (49 grade III/AA; 26 grade II/DA) and 26 normal individuals (p = 0.0001). Further validation using RT-qPCR on an independent set (n = 78) of tumor and normal brain (n = 4) samples and immunohistochemcial staining on a subset (n = 42) of above samples showed increasing levels of transcript and protein with tumor grade and were highest in GBM (p = < 0.0001 and < 0.0001, respectively). Overexpression of Hp either by stable integration of Hp cDNA or exogenous addition of purified Hp to immortalized astrocytes resulted in increased cell migration. RNAi-mediated silencing of Hp in glioma cells decreased cell migration. Further, we demonstrate that both human glioma and mouse melanoma cells overexpressing Hp showed increased tumor growth. Thus, we have identified haptoglobin as a GBM-specific serum marker with a role on glioma tumor growth and migration.

In-Network Computation in Random Wireless Networks: A PAC Approach to Constant Refresh Rates with Lower Energy Costs

We propose a method to compute a probably approximately correct (PAC) normalized histogram of observations with a refresh rate of Theta(1) time units per histogram sample on a random geometric graph with noise-free links. The delay in computation is Theta(root n) time units. We further extend our approach to a network with noisy links. While the refresh rate remains Theta(1) time units per sample, the delay increases to Theta(root n log n). The number of transmissions in both cases is Theta(n) per histogram sample. The achieved Theta(1) refresh rate for PAC histogram computation is a significant improvement over the refresh rate of Theta(1/log n) for histogram computation in noiseless networks. We achieve this by operating in the supercritical thermodynamic regime where large pathways for communication build up, but the network may have more than one component. The largest component however will have an arbitrarily large fraction of nodes in order to enable approximate computation of the histogram to the desired level of accuracy. Operation in the supercritical thermodynamic regime also reduces energy consumption. A key step in the proof of our achievability result is the construction of a connected component having bounded degree and any desired fraction of nodes. This construction may also prove useful in other communication settings on the random geometric graph.

Characterisation of dynamic recrystallisation in nickel using processing map for hot deformation

The hot deformation behaviour of polycrystalline nickel has been characterised in the temperature range 750-1200-degrees-C and strain rate range 0.0003-100 s-1 using processing maps developed in the basis of the dynamic materials model. The efficiency of power dissipation, given by [2m/(m + 1)]. where m is the strain rate sensitivity, is plotted as a function of temperature and strain rate to obtain a processing map. A domain of dynamic recrystallisation has been identified, with a peak efficiency of 31% occurring at 925-degrees-C and 1 s-1. The published results are in agreement with the prediction of the processing map. The variations of efficiency of power dissipation with temperature and strain rate in the dynamic recrystallisation domain are identical to the corresponding variation of hot ductility. The stress-strain curves exhibited a single peak in a single peak in the dynamic recrystallisation domain, whereas multiple peaks and 'drooping' stress-strain curves were observed at lower and higher strain rates, respectively. The results are explained on the basis of a simple model which considers dynamic recrystallisation in terms of rates of interface formation (nucleation) and migration (growth). It is shown that dynamic recrystallisation in nickel is controlled by the rate of nucleation, which is slower than the rate of migration. The rate of nucleation itself depends on the process of thermal recovery by climb, which in turn depends on self-diffusion.

Migration-Development Nexus in the Malawian Health Sector: European Union Blue Card – circular migration for development?

The European Union has agreed on implementing the Policy Coherence for Development (PCD) principle in all policy sectors that are likely to have a direct impact on developing countries. This is in order to take account of and support the EU development cooperation objectives and the achievement of the internationally agreed Millennium Development Goals. The common EU migration policy and the newly introduced EU Blue Card directive present an example of the implementation of the principle in practice: the directive is not only designed to respond to the occurring EU labour demand by attracting highly skilled third-country professionals, but is also intended to contribute to the development objectives of the migrant-sending developing countries, primarily through the tool of circular migration and the consequent skills transfers. My objective in this study is to assess such twofold role of the EU Blue Card and to explore the idea that migration could be harnessed for the benefit of development in conformity with the notion that the two form a positive nexus. Seeing that the EU Blue Card fails to differentiate the most vulnerable countries and sectors from those that are in a better position to take advantage of the global migration flows, the developmental consequences of the directive must be accounted for even in the most severe settings. Accordingly, my intention is to question whether circular migration, as claimed, could address the problem of brain drain in the Malawian health sector, which has witnessed an excessive outflow of its professionals to the UK during the past decade. In order to assess the applicability, likelihood and relevance of circular migration and consequent skills transfers for development in the Malawian context, a field study of a total of 23 interviews with local health professionals was carried out in autumn 2010. The selected approach not only allows me to introduce a developing country perspective to the on-going discussion at the EU level, but also enables me to assess the development dimension of the EU Blue Card and the intended PCD principle through a local lens. Thus these interviews and local viewpoints are at the very heart of this study. Based on my findings from the field, the propensity of the EU Blue Card to result in circular migration and to address the persisting South-North migratory flows as well as the relevance of skills transfers can be called to question. This is as due to the bias in its twofold role the directive overlooks the importance of the sending country circumstances, which are known to determine any developmental outcomes of migration, and assumes that circular migration alone could bring about immediate benefits. Without initial emphasis on local conditions, however, positive outcomes for vulnerable countries such as Malawi are ever more distant. Indeed it seems as if the EU internal interests in migration policy forbid the fulfilment of the PCD principle and diminish the attempt to harness migration for development to bare rhetoric.