Effectiveness of International Migration since Early Stage

International Migration Experience and Entrepreneurship: Evidence from Mexico

10.31235/osf.io/dfjrz ◽

2020 ◽

Author(s):

Joshua Thomas Wassink

Keyword(s):

Economic Development ◽

International Migration ◽

Early Stage ◽

Lower Probability ◽

Mexican Migration ◽

Street Vending ◽

Migration Experience ◽

Entrepreneurial Entry ◽

Annual Probability ◽

Sending Areas

This study investigates the effect of international migration experience on entrepreneurship in sending areas. To identify prosperous businesses that create jobs and encourage economic development, this study isolates businesses other than street-vending enterprises with non-family employees. Retrospective life history data from the Mexican Migration Project (N = 11,789 persons & 146,372 person-years) was used to estimate the annual probability of becoming an entrepreneur across 170 Mexican communities between 1975-2017. This study found that (1) any prior migration experience increases the probability of entrepreneurial entry relative to non-migrants; (2) accumulated months of migration experience are positively associated with the probability of entrepreneurial entry; (3) undocumented status is associated with a lower probability of entrepreneurial entry. The positive effect of accumulated migration experience on entrepreneurship suggests that international migrants can accumulate human and financial resources that are essential to early stage entrepreneurship. Thus, entrepreneurship represents an important pathway through which international migration can encourage economic development in less developed regions. At the same time, the results suggest that immigration policies in receiving countries can undercut migrants’ capacities to mobilize resources and contribute to economic development upon return. These findings suggest that target migration creates a win-win by addressing labor shortages in receiving countries, while transferring resources to sending areas that enable economic mobility and development.

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Alterations in the number of motoneurons containing immunoreactive calcitonin gene-related peptide(CGRP)& choline acetyltransferase(ChAT) in the cervical spinal cord of the wobbler mouse during the development of the motoneuron disease

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100141226 ◽

1995 ◽

Vol 53 ◽

pp. 970-971

Author(s):

L. Vacca-Galloway ◽

Y.Q. Zhang ◽

P. Bose ◽

S.H. Zhang

Keyword(s):

Spinal Cord ◽

Early Stage ◽

Cervical Spinal Cord ◽

Wild Type Mouse ◽

Reflex Response ◽

Mouse Strains ◽

Behavioral Tests ◽

Wobbler Mouse ◽

Stage 4 ◽

Stage 1

The Wobbler mouse (wr) has been studied as a model for inherited human motoneuron diseases (MNDs). Using behavioral tests for forelimb power, walking, climbing, and the “clasp-like reflex” response, the progress of the MND can be categorized into early (Stage 1, age 21 days) and late (Stage 4, age 3 months) stages. Age-and sex-matched normal phenotype littermates (NFR/wr) were used as controls (Stage 0), as well as mice from two related wild-type mouse strains: NFR/N and a C57BI/6N. Using behavioral tests, we also detected pre-symptomatic Wobblers at postnatal ages 7 and 14 days. The mice were anesthetized and perfusion-fixed for immunocytochemical (ICC) of CGRP and ChAT in the spinal cord (C3 to C5).Using computerized morphomety (Vidas, Zeiss), the numbers of IR-CGRP labelled motoneurons were significantly lower in 14 day old Wobbler specimens compared with the controls (Fig. 1). The same trend was observed at 21 days (Stage 1) and 3 months (Stage 4). The IR-CGRP-containing motoneurons in the Wobbler specimens declined progressively with age.

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Automated high-resolution microscopy: the approaches so far

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100125312 ◽

1987 ◽

Vol 45 ◽

pp. 58-61

Author(s):

W. O. Saxton

Keyword(s):

High Resolution ◽

Early Stage ◽

Automatic Recording ◽

Microprocessor Control ◽

Alternative Systems ◽

Electron Image ◽

Complete Automation ◽

Analysis System ◽

High Resolution Microscopy

Recent commercial microscopes with internal microprocessor control of all major functions have already demonstrated some of the benefits anticipated from such systems, such as continuous magnification, rotation-free diffraction and magnification, automatic recording of mutually registered focal series, and fewer control knobs. Complete automation of the focusing, stigmating and alignment of a high resolution microscope, allowing focal series to be recorded at preselected focus values as well, is still imminent rather than accomplished, however; some kind of image pick-up and analysis system, fed with the electron image via a TV camera, is clearly essential for this, but several alternative systems and algorithms are still being explored. This paper reviews the options critically in turn, and stresses the need to consider alignment and focusing at an early stage, and not merely as an optional extension to a basic proposal.

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Direct observation of Fe-Al-Zn ternary intermetallic compound and its transformation during the early stage of hot-dip galvanizing

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100151416 ◽

1993 ◽

Vol 51 ◽

pp. 1116-1117

Author(s):

C. S. Lin ◽

W. A. Chiou ◽

M. Meshii

Keyword(s):

Intermetallic Compound ◽

Reaction Rate ◽

Diffusion Rate ◽

Early Stage ◽

Zinc Bath ◽

Steel Sheets ◽

Direct Observations ◽

Solid Iron ◽

Iron And Zinc ◽

Ternary Intermetallic Compound

The galvannealed steel sheets have received ever increased attention because of their excellent post-painting corrosion resistance and good weldability. However, its powdering and flaking tendency during press forming processes strongly impairs its performance. In order to optimize the properties of galvanneal coatings, it is critical to control the reaction rate between solid iron and molten zinc.In commercial galvannealing line, aluminum is added to zinc bath to retard the diffusion rate between iron and zinc by the formation of a thin layer of Al intermetallic compound on the surface of steel at initial hot-dip galvanizing. However, the form of this compound and its transformation are still speculated. In this paper, we report the direct observations of this compound and its transformation.The specimens were prepared in a hot-dip simulator in which the steel was galvanized in the zinc bath containing 0.14 wt% of Al at a temperature of 480 °C for 5 seconds and was quenched by liquid nitrogen.

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Anisotropy of interfacial defects in the initial stage of MOVPE GaAs growth On Si

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100176095 ◽

1990 ◽

Vol 48 (4) ◽

pp. 592-593

Author(s):

C. Vannuffel ◽

C. Schiller ◽

J. P. Chevalier

Keyword(s):

Early Stage ◽

Threading Dislocations ◽

Mbe Growth ◽

Detailed Mechanism ◽

Si Substrates ◽

Initial Stage ◽

Interfacial Defects ◽

Interfacial Dislocations ◽

Step Growth ◽

Essential Problem

Recently, interest has focused on the epitaxy of GaAs on Si as a promising material for electronic applications, potentially for integration of optoelectronic devices on silicon wafers. The essential problem concerns the 4% misfit between the two materials, and this must be accommodated by a network of interfacial dislocations with the lowest number of threading dislocations. It is thus important to understand the detailed mechanism of the formation of this network, in order to eventually reduce the dislocation density at the top of the layers.MOVPE growth is carried out on slightly misoriented, (3.5°) from (001) towards , Si substrates. Here we report on the effect of this misorientation on the interfacial defects, at a very early stage of growth. Only the first stage, of the well-known two step growth process, is thus considered. Previously, we showed that full substrate coverage occured for GaAs thicknesses of 5 nm in contrast to MBE growth, where substantially greater thicknesses are required.

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