For example, the EPA completed its draft toxicological review of perchlorate in 2002 and proposed an RfD of 0. 00003 milligrams per kilogram per day ( mg / kg / day ) based primarily on studies that identified neurodevelopmental deficits in rat pups.

According to the EPA, " n aggregate daily exposure to a at or below the RfD ( expressed as 100 percent or less of the RfD ) is generally considered acceptable by EPA.

The NOAEL was then divided by the standard 10-fold inter-and 10-fold intraspecies uncertainty factors to arrive at the RfD of 0. 005 mg / kg / day.

A RfD that has been divided by an additional uncertainty factor that only applies to certain populations is called a " population adjusted dose " or PAD.

As with the acute RfD, the chronic RfD of 3 × 10 < sup >− 4 </ sup > mg / kg / day was determined by dividing this NOAEL by the inter-and intraspecies uncertainty factors.

Because the RfD assumes " a dose below below which no adverse noncarcinogenic health effects should result from a lifetime of exposure ", the critical step in all chemical risk and regulatory threshold calculations is dependent upon a properly derived dose at which no observed adverse effects ( NOEAL ) were seen which is then divided by an uncertainty factor that considers inadequacies of the study, animal-to-human extrapolation, sensitive sub-populations, and inadequacies of the database.

Ginsberg and Rice, in a commentary submitted to the journal Environmental Health Perspectives ( EHP ), argued that the 2005 NAS RfD was not protective of human health based on the following:

The EPA determined the acute RfD to be 0. 005 mg / kg / day based on a study in which male rats were administered a one-time dose of chlorpyrifos and blood cholinesterase activity was monitored.

The EPA defines an oral reference dose ( abbreviated RfD ) as:

" For example, the EPA set an acute RfD for children of 0. 0015 mg / kg / day for the organochlorine insecticide endosulfan, based on neurological effects observed in test animals.

The EPA then looked at dietary exposure to endosulfan, and found that for the most exposed 0. 1 % of children age 1 – 6, their daily consumption of the endosulfan exceeded this RfD.

The EPA also determined a chronic RfD for chlorpyrifos exposure based on studies in which animals were administered low doses of the pesticide for two years.

If adverse effects are observed at all dose levels tested, then the smallest dose tested, the " Lowest observed adverse effect level " or LOAEL, is used to calculate the RfD.

If studies using human subjects are used to determine a RfD, then the interspecies uncertainty factor can be reduced to 1, but generally the 10-fold intraspecies uncertainty factor is retained.

As an example, consider the following determination of the RfD for the insecticide chlorpyrifos, adapted from the EPA's Interim Reregistration Eligibility Decision for chlorpyrifos.

The RfD that is derived is not always agreed upon.

Therefore, additional safety factors, they argued, are necessary when extrapolating from the point of departure to the RfD.

Although there has generally been consensus with the Greer et al study, there is not consensus with regard to developing a perchlorate RfD.

One of the key differences results from how the point of departure is viewed ( i. e., NOEL or LOAEL ), or whether a benchmark dose should be used to derive the RfD.

Though his election was interpreted by many Southerners as the forerunner of a dangerous shift in the federal balance in favor of the Union, Lincoln himself proposed no such change in the rights the Constitution gave the states.

The traditional method proceeds by the technique of free association, punctuated by interpretations proposed by the psychoanalytic interviewer.

New machinery of coordination should not be our primary objective in the foreseeable future -- though perhaps the `` political general staff '' of Western leaders proposed by Sir Anthony Eden would serve a useful purpose.

recommend to the Congress from time to time authorization for construction and operation, or for participation in the construction and operation, of a demonstration plant for any process which he determines, on the basis of subsections ( A ) and ( B ) above, has great promise of accomplishing the purposes of this Act, such recommendation to be accompanied by a report on the size, location, and cost of the proposed plant and the engineering and economic details with respect thereto ; ;

The decrees proposed by the amici curiae were filed in August of 1958.

I again proposed a reduction in the Army National Guard and Army Reserve -- from their present strengths of 400,000 and 300,000, respectively, to 360,000 and 270,000 by the end of the fiscal year 1961.

In the event the rupees set aside for loans under Section 104 ( E ) of the Act are not advanced within six years from the date of this Agreement because the Export-Import Bank of Washington has not approved loans or because proposed loans have not been mutually agreeable to the Export-Import Bank of Washington and the Department of Economic Affairs of the Government of India, the Government of the United States of America may use the rupees for any purpose authorized by Section 104 of the Act.

`` We, the Subscribers, do agree, that as soon as a convenient Number of Persons have subscribed to this, or a similar Writing, We will present a petition to the Hon'ble General Court of the Commonwealth of Massachusetts, praying for an Act incorporating into a Body politic the subscribers to such Writing with Liberty to build such a Bridge, and a Right to demand a Toll equal to that received at Malden Bridge, and on like Terms, and if such an Act shall be obtained, then we severally agree each with the others, that we will hold in the said Bridge the several shares set against our respective Names, the whole into two hundred shares being divided, and that we will pay such sums of Money at such Times and in such Manners, as by the said proposed Corporation, shall be directed and required ''.

A technique by which it is proposed to enter with compulsion into the very heart of a man and determine his values may often in fact seem the more unlimited aggression.

Vandiver opened his race for governor in 1958 with a battle in the Legislature against the issuance of $50 million worth of additional rural roads bonds proposed by then Gov. Marvin Griffin.

-- President Kennedy today proposed a mammoth new medical care program whereby social security taxes on 70 million American workers would be raised to pay the hospital and some other medical bills of 14.2 million Americans over 65 who are covered by social security or railroad retirement programs.

`` I would expect the proposed committee to hold public hearings '', Mr. Notte said, `` to obtain the views of the general public and religious, labor and special-interest groups affected by these laws ''.

Twelve projects proposed by private groups are at the contract-negotiation stage, Gordon Boyce, director of relations with the voluntary agencies, said in a Washington interview.

Six of these were proposed by religious groups.

Samuel D. Goodis, representing the Philadelphia Hotel Association, objected on Tuesday to a proposed boost by the city in licensing fees, saying that occupancy rates in major hotels here ranged from 48 to 74 percent last year.

" However, as Stocking notes, Tylor mainly concerned himself with describing and mapping the distribution of particular elements of culture, rather than with the larger function, and he generally seemed to assume a Victorian idea of progress rather than the idea of non-directional, multilineal cultural development proposed by later anthropologists.

In music an " answer " ( also known as countersubject ) is the technical name in counterpoint for the repetition or modification by one part or instrument of a theme proposed by another.

The working principle of a yupana is unknown, but in 2001 an explanation of the mathematical basis of these instruments was proposed by Italian mathematician Nicolino De Pasquale.

A third concept was proposed in 1923 by Gilbert N. Lewis which includes reactions with acid-base characteristics that do not involve a proton transfer.

Campbell proposed that the heroic mythological stories from culture to culture followed a similar underlying pattern, starting with the " call to adventure ", followed by a hazardous journey, and eventual triumph.

Many definitions of art have been proposed by philosophers and others who have characterized art in terms of mimesis, expression, communication of emotion, or other values.

In the book, he proposed and explained in detail a new theory of humankind: mankind as a " time-binding " class of life ( humans perform time binding by the transmission of knowledge and abstractions through time which are accreted in cultures ).