Lag 0 associations stratified by level of urbanicity are presented in (for numerical results, see Table S1). These analyses did not suggest large differences in the associations of outdoor PM2.5 concentrations with ED visits by level of urbanicity. For the three most common outcomes (asthma/wheeze, otitis media, and upper respiratory infections) the association estimates were similar across urbanicity levels (p-values from the generalized Wald test for “H0: the three stratum-specific ORs are equal,” the null hypothesis we were testing, were 0.85, 0.99, and 0.69, respectively). In contrast, the ORs for the less common outcomes tended to be negative in urban areas and positive in less urban areas (p-value for differences across strata of 0.12–0.15), although estimates were imprecise. The lag 1 results similarly did not suggest large differences in associations by level of urbanicity (results not shown).
We also conducted sensitivity analyses to examine the impact of missing data on OR estimates. In the two most extreme cases, we either a) only analyzed ZIP codes that had complete 1-km grid PM2.5 estimates or b) analyzed as many data as possible (i.e., so long as a ZIP code had at least one 1-km grid PM2.5 estimate it was included in the analysis). We also examined results for a range of missing data scenarios between these two extremes. These sensitivity analyses informed our decision to exclude a ZIP code when > 70% of the grid estimates were missing on a given day.
Over the last decade generative grammar has moved away from using phrasestructure rules as the basic specifiers of syntactic structure; instead, thetheory has come to see phrase structure as the instantiation of a number oflicensing relations, chiefly theta-role assignment, case, agreement, andpredication. The licensing of phrase structure has, however, been conceived ina static way: although the elements being licensed may move in the course of aderivation in order to reach the positions in which licensing takes place, thepositions themselves are fixed for each relation. In this paper we explore theconsequences of abandoning this static view, and taking instead a dynamicapproach in which the licensing positions themselves may change in the courseof a derivation.
This paper presents an account of the statistical patterns in thedevelopment of 'do' forms in various sentence types in English. Unlikeprevious works on the rise of 'do'-support, it takes into account theevolution of 'do'-support in imperatives. We show that the development of'do' forms in negative imperatives cannot be explained with a clausestructure that has only one INFL projection and one NegP, as in Roberts (1985)and Kroch (1989b). We therefore propose a more articulated clause structure,which we argue is already necessary to explain the syntax of Middle Englishinfinitivals. We argue that the syntax of negative infinitivals in MiddleEnglish can be accounted for if we posit two possible syntactic positions fornegation and an intermediate functional projection, which we assume to be anAspect Phrase (AspP), between the two negation projections. This articulatedstructure enables us to distinguish two types of verb movement: movementover the lower negation and movement over the higher negation. We show that thepatterns in the development of do-support in imperatives as well as inquestions and negative declaratives can be explained if the loss of verbmovement occurs in two steps in the history of English with the loss of thehigher movement preceding the loss of the lower movement.
This paper presents a largely quantitative description of the alternationbetween XV and VX word order in Early Middle English, based on the parsedcorpus of Middle English that we have been constructing for the past threeyears. With that corpus, which is now approximately 300,000 words in size, wecan easily define grammatical contexts and retrieve specified example types forfurther study and counting. Using the simplest of the data analysis techniquesallowed by our corpus, we have discovered that the patterning of the XV/VXalternation in the earliest Middle English prose documents differssubstantially from text to text and that the texts divide into two main groups:1) the Katherine group and Ancrene Riwle texts of the West Midlands and 2) the``Book of Vices and Virtues'' and other texts of the Southeast Midlands andKent. We will argue, on the one hand, that both groups exhibit grammarcompetition between a base generated verb-final and verb-medial VP, but, on theother, that grammars of the texts in these two groups also differ in a morecomplex way. Specifically, we will try to show that in the Katherine grouptexts XV word order is predominantly due, not to base generation but to theleftward movement of constituents, while in the Vices texts VX word order issimilarly not due to base generation but predominantly to rightwardextraposition.
This handout will help you solve your memo-writing problems by discussing what a memo is, describing the parts of memos, and providing examples and explanations that will make your memos more effective.
The HATS presentation introduces students and instructors to the basic elements of document design. The presentation outlines how to use headings, (information) access, typography (fonts), and space in routine professional documents to promote user-centered communication.
This handout discusses how to write good abstracts for reports. It covers informational and descriptive abstracts and gives pointers for success.
A white paper is a certain type of report that is distinctive in terms of purpose, audience, and organization. This resource will explain these issues and provide some other tips to enhance white paper content.
These are some of the better papers that have been handed in in past semesters. Note, however, that these papers are far from perfect. I'm really hoping that you will provide me with some better examples this semester! Also note that the style and formatting of these papers don't conform to the standards we are using this semester.
Remember, there is no one correct way to say anything. There is no one correct way to order or word your paper. There are, however, ways that are clearly wrong. And, in most cases, there is only one way to spell a given word! Most of you have probably written less than a handful of term papers. Writing clearly and concisely is more difficult than you may think. Remember not to feel too bad if a fellow student, Writing Fellow, or professor has a large number of "negative" comments on a paper you think of as being nearly perfect. It's like playing music. If you've never spent much time listening to the symphony, not only will you have a tough time playing classical music well, you probably will have a hard time even if you sound well. Since the purpose of your paper is to convey information to other people, other people's opinions of your work matter! Have other's read your paper, and listen to their comments. Accepting criticism is not easy, but it's the only way to learn to write.
This handout provides overviews and examples of how to use tone in business writing. This includes considering the audience and purpose for writing.
We observed that short-term changes in lag 0 and lag 1 PM2.5 concentrations were associated with ED visits for asthma or wheeze and with ED visits for upper respiratory infections. Broadly, these findings are consistent with previous literature that also shows associations between PM2.5 and pediatric respiratory disease (). We found little evidence of effect modification by level of urbanicity, even though the composition of PM2.5 differs in urban and rural areas (). For example, motor vehicle engine combustion particles comprise a larger proportion of PM2.5 in urban areas, whereas nonmetropolitan areas tend to have proportionately greater contributions from biogenic, forest fire, and ammonia emissions (). A limitation of our study is that particle composition was not characterized. Furthermore, although sample size for these two outcomes was large, we might not have detected effect modification if it was of small magnitude.