نتایج جستجو برای: o30

تعداد نتایج: 205  

2011
Daron Acemoglu

This paper revisits the induced innovation literature of the 1960s to which Phelps was a major contributor (Drandakis and Phelps, 1965). This literature was the first systematic study of the determinants of technical change and also the first investigation of the relationship between factor prices and technical change. I present a modern reformulation of this literature based on the tools devel...

2015
Kyle Emerick Alain de Janvry Elisabeth Sadoulet Manzoor H. Dar

We use a randomized experiment in India to show that improved technology enhances agricultural productivity by crowding in modern inputs and cultivation practices. Specifically, we show that a new rice variety that reduces downside risk by providing flood tolerance has positive effects on adoption of a more labor intensive planting method, area cultivated, fertilizer usage, and credit demand. W...

2010
Enrico Mattei Carlo Carraro Daron Acemoglu Philippe Aghion Leonardo Bursztyn David Hemous

This paper introduces endogenous and directed technical change in a growth model with environmental constraints. A unique final good is produced by combining inputs from two sectors. One of these sectors uses “dirty”machines and thus creates environmental degradation. Research can be directed to improving the technology of machines in either sector. We characterize dynamic tax policies that ach...

2010
Spyros Arvanitis

In this study we investigated the determinants of the propensity of Swiss firms to train apprentices. Innovation, firm age and competition conditions on the product market are determining factors that were especially emphasized in this investigation. We found that the skill composition of the employment, innovation activities, firm age, labour costs, capital intensity, and competitive pressures...

2013
Jin-Hyuk Kim Tin Cheuk Leung

The demand for electronic books (e-books) and the e-book readers are complementary. On the one hand, the emergence of e-book readers such as Amazon’s Kindle has triggered the recent growth of the e-book market. On the other hand, several issues in the e-book market can affect the future of the e-book reader market. Considering this complementarity, this paper quantifies the impact of digital ri...

2014
Dow-Mu Koh

The landscape of cancer imaging is being shaped by advances in oncological treatment. As the genetic and molecular aberration of cancers and cancer subtypes are being elucidated, specific cellular pathways and associated molecular receptors are recognized as potential pharmacological targets to modify or arrest cancer growth. In the past two decades, such targeted therapies are being developed ...

2014
Luciana Bertolini Marcelo Bertolini James Murray Elizabteh Maga

Diarrhea is one of the most significant issues for global health in children under the age of five. Close to 60% of mortality in this risk group is caused by pneumonia, diarrhea or measles, which is usually associated with malnutrition. In Brazil, this scenario is no different, with the Northeast semi-arid region having alarming rates of child mortality, almost twice that of the current nationa...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه علوم کشاورزی و منابع طبیعی گرگان - دانشکده علوم کشاورزی 1388

این تحقیق با هدف جداسازی و خالص‏سازی باکتری بومی آزوسپیریلوم برازیلنس و اثرات تلفیق آن با باکتری ازتوباکتر کروکوکوم روی رشد گندم رقم الوند انجام گردید. توانایی pgpr بودن این باکتری ها در شرایط آزمایشگاهی و گلخانه ای در تلقیح به تنهایی و یا تلفیق با کود اوره و مواد آلی برای ترقی دادن عملکرد، شاخص های رشد و جذب مواد غذایی گیاه گندم انجام گردید. نمونه های خاک و ریشه گندم از نواحی اطراف شهر گرگان ج...

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