Did life grind to a start?

نویسندگان
چکیده

برای دانلود باید عضویت طلایی داشته باشید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Breastfeeding in the Hospital is a Good Start to Life

در ماه مارس ۱۹۹۲ از طریق یونیسف و سازمان بهداشت جهانی طرح ابتکاری بیمارستان دوستدار کودک (Baby friendly hospital)، به منظور ترویج تغذیه با شیر مادر ، راه اندازی شد. در این بیمارستانها تدابیری جهت بالا بودن سطح سلامت و بهبود وضعیت نوزادان تازه متولد شده اتخاذ گردید. اولین متمم این طرح ابتکاری، تشویق جهت تغذیه نوزادان با شیر مادر بود که برای نشان دادن این موضوع، نظامنامه بین المللی از طرف WHO به ...

متن کامل

Did the Universe start at Zero Metallicity?

Standard Big Bang nucleosynthesis predicts an essentially zero primordial metallicity. I speculate on possible metal (i.e. nucleon number A ≥ 12) production in scenarios of inhomogeneous Big Bang nucleosynthesis. It is conceivable, though not necessarily probable, that some primordial metallicity is synthesized if a small fraction of all cosmic baryons reside in very high-density regions. Such ...

متن کامل

When did the 2001 recession really start ?

The paper develops a non-parametric, non-stationary framework for business-cycle dating based on an innovative statistical methodology known as Adaptive Weights Smoothing (AWS). The methodology is used both for the study of the individual macroeconomic time series relevant to the dating of the business cycle as well as for the estimation of their joint dynamic. Since the business cycle is defin...

متن کامل

Why did life emerge?

Many mechanisms, functions and structures of life have been unraveled. However, the fundamental driving force that propelled chemical evolution and led to life has remained obscure. The 2 law of thermodynamics, written as an equation of motion, reveals that elemental abiotic matter evolves from the equilibrium via chemical reactions that couple to external energy toward complex biotic nonequili...

متن کامل

Wingless Signaling: An Axin to Grind

Negative regulation of Wingless/Wnt signaling plays an important role in embryonic patterning and is also needed for tumor suppression in adult tissues. New findings in Drosophila reveal a novel mechanism for down-regulating the activity of the Wingless/Wnt pathway.

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

ژورنال

عنوان ژورنال: Nature

سال: 2008

ISSN: 0028-0836,1476-4687

DOI: 10.1038/452161a