Hormonal Mechanisms as Potential Constraints on Evolution: Examples from the Anura

نویسندگان

چکیده

برای دانلود رایگان 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

the effect of traffic density on the accident externality from driving the case study of tehran

در این پژوهش به بررسی اثر افزایش ترافیک بر روی تعداد تصادفات پرداخته شده است. به این منظور 30 تقاطع در شهر تهران بطور تصادفی انتخاب گردید و تعداد تصادفات ماهیانه در این تقاطعات در طول سالهای 89-90 از سازمان کنترل ترافیک شهر تهران استخراج گردید و با استفاده از مدل داده های تابلویی و نرم افزار eviews مدل خطی و درجه دوم تخمین زده شد و در نهایت این نتیجه حاصل شد که تقاطعات پر ترافیک تر تعداد تصادفا...

15 صفحه اول

from orientation to orientalism: research on the evolution of the concept and examples of "orientalism"

many expressed definition on «orientalism», including the western concept is the ambiguity of the term with negative connotations, especially in relation to the colonization of europe, is verifiable. edward said's efforts for demystification of it, something of this complexity did not reduce, but anti-western discourse, became the focus of the review. emphasizing the contrast between the e...

متن کامل

Mechanisms and constraints shaping the evolution of body plan segmentation.

Segmentation of the major body axis into repeating units is arguably one of the major inventions in the evolution of animal body plan pattering. It is found in current day vertebrates, annelids and arthropods. Most segmented animals seem to use a clock-and-wavefront type mechanism in which oscillations emanating from a posterior growth zone become transformed into an anterior posterior sequence...

متن کامل

Constraints on the Higgs Boson Properties from the Effective Potential

We review the constraints on Higgs boson properties from effective potential methods. In the Standard Model, the requirement of stability (or metastability) of the standard electroweak minimum puts an upper bound on the scale of new physics as a function of the Higgs mass. This upper bound is below the Planck scale if the Higgs weights < ∼ 130 GeV. In supersymmetric extensions of the Standard M...

متن کامل

The Different Mechanisms of Action Potential Propagation in the Heart

It was thought previously that cardiac muscle gap junctions provide low-resistance connections between cells and permit the local-circuit current to flow. Some evidences show that myocardial cells may not require low-resistance connections for successful propagation of the action potential (AP). It seems that some other types of mechanisms must be involved in AP propagation. In this article, we...

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: American Zoologist

سال: 1997

ISSN: 0003-1569

DOI: 10.1093/icb/37.6.482