دانلود گزارش کارورزی و کار آموزی

چکیده : 

In the analysis of contingency tables, the odds ratio is a measure commonly used to

summarize the strength of association between two categorical variables, say R and S.

When a vector of continuous variables X is also observed for each individual in the table,

then it is important to analyze whether and how the degree of association (odds ratio)

varies locally with X. In this article, several nonparametric estimators of this conditional or

local odds ratio are proposed, to summarize the strength of local association between R and

S given X. The nonparametric estimators are constructed using kernel regression, to allow

for maximum flexibility. Confidence intervals based on these nonparametric estimators

are also developed. Simulation studies show that our proposed (amended) local odds ratio

estimators can outperform the model-based counterparts from logistic regression and

Generalized Additive Models, without the need for a linearity or additivity assumption

چکیده :

Escape tactics and optimal refuge use have attracted considerable interest, but the influence of pregnancy

on escape tactics remains understudied. For instance, embryonic sensitivity to environmental

conditions and maternal constraints vary dramatically across pregnancy, and these dynamics should

modulate the costebenefit balance of refuge use. We experimentally studied thermoregulation and

refuge use in pregnant and nonreproductive aspic vipers, Vipera aspis, at different stages of gestation

(first, middle and last third). We determined preferred body temperatures (Tset) in a cost-free environment

to test for fecundity and stage dependencies of maternal Tset. Then, we examined behavioural

responses to repeated simulated predatory attacks. Pregnant females were extremely precise thermoregulators

compared with nonreproductive females, and Tset was independent of litter size or gestation

stage. After simulated attacks, pregnant females limited their time spent in the refuge and thereby their

deviation from Tset. By contrast, nonreproductive females had a greater response to predation exposure

and adjusted their response to risk level. Contrary to our predictions, pregnant females did not vary their

behaviour based on gestation stage, despite increasing physical burden as pregnancy progressed. Overall,

our results illustrate that pregnant females alter their behaviour to benefit their developing embryos

thermally despite risk to themselves (increased exposure). By doing so, however, the female realizes a

benefit by accelerating temperature-sensitive developmental time and thus reducing the duration of

pregnancy and associated physical burden.

چکیده : 

Many lepidopteran caterpillars appear to gain protection from insect-eating birds because they possess

eyespots, a pair of conspicuous markings on the body generally thought to resemble the eyes of a

predator. Similarly, many caterpillars widen their anterior body segments when threatened, and this

defensive posture may also deter attack because it emphasizes the caterpillar’s eyes and/or allows the

caterpillar to resemble a snake more closely. Yet, given that this behaviour is not limited to caterpillars

with eyespots, it is possible that the defensive posture may serve as a predator deterrent in itself. To

disentangle the protective value of eyespots and widened anterior body segments, we created four types

of artificial caterpillar in a 22 factorial design and deployed them on tree branches in the field where

they were exposed to predation attempts by wild birds. The ‘survivorship’ of the artificial caterpillars was

monitored over 90 h in six locations.We found a clear survival advantage for artificial prey with eyespots

or a widened head shape. However, prey possessing both eyespots and a widened head did not survive

longer than prey with either characteristic alone, suggesting that the traits did not act synergistically to

deter attack. Interestingly though, only caterpillars in the eyespot-defensive posture treatment received

more pecks directed towards the anterior ‘head’ region. Collectively, this study demonstrates clearly that

caterpillars possessing either eyespots or widened anterior body segments are likely to experience

reduced predation by wild birds, even at northern latitudes where there are relatively few arboreal

snakes.

چکیده : 

Statement of Financial Accounting Standard No. 130 (SFAS 130) was released

in 1997 which required publicly traded companies to separately report comprehensive

income in the financial statements. SFAS 130 prescribed three

alternative formats for the presentation without mandating any one specific

format. SFAS 130 also required certain details of comprehensive income to be

displayed prominently in the financial statements. The current study examined

the presentation of comprehensive income by a sample of companies traded on

the NASDAQ market to determine the predominant method of presentation

among these companies, five years after SFAS 130 became effective. Results of

the examination of one hundred annual reports showed that a majority of the

sampled companies used the third approach, which was to present comprehensive

income as part of the Statement of Stockholders’ Equity, as against the first

two approaches that favored presentation of comprehensive income on the face

of the Income Statement or in a separate statement. Further, the paper also

discusses some ancillary findings pertaining to the presentation of the details of

comprehensive income.

چکیده : 

This paper proposes growth mixture modeling to assess intervention effects in longitudinal randomized

trials. Growth mixture modeling represents unobserved heterogeneity among the subjects using a finitemixture

random effects model. The methodology allows one to examine the impact of an intervention

on subgroups characterized by different types of growth trajectories. Such modeling is informative

when examining effects on populations that contain individuals who have normative growth as well as

non-normative growth. The analysis identifies subgroup membership and allows theory-based modeling

of intervention effects in the different subgroups. An example is presented concerning a randomized

intervention in Baltimore public schools aimed at reducing aggressive classroom behavior, where only

students who were initially more aggressive showed benefits from the intervention