6,474 research outputs found
A Time-Series Analysis of Crime and Drug Use in New York City
This report summarizes the results of a project which investigated the time series interrelationships between crime, drug use, police, and arrests in New York City. We use monthly data from 1970 through 1990 for New York City. We plot the individual time series for five different non-drug crimes, arrest rates for these crimes, drug deaths, number of police officers, and drug arrests in New York City. We find that drug usage, as proxied by drug deaths, increased from the mid-1980's to about 1988-1989. At the same time, felony drug arrests increased substantially. During the mid-1980's, there were increases in murders, assaults, and motor vehicle thefts. Robberies increased in the later 1980s and burglaries declined throughout the 1980s. Arrest rates and total arrests for non-drug crimes did not decline during this period of increased drug arrests. In a multivariate analysis, we found that the three property crimes investigated - robberies, burglaries and motor vehicle thefts - increased when there were unexpected increases in drug usage. We did not find such a relationship between drug use and murders or assaults, holding constant arrest rates and police. In addition, we found evidence of police deterrence, either directly, or through arrests, of property-related and assault offenses, but not for murders. Thus, in a time-series approach, we are able to find a causal relationship between drug usage and property-related felonies.
Evaluation of Modification of the Upper Batavia Dam on the Fox River, Illinois
Progress Report, Federal Aid Project F-136-R Segment 6Report issued on: August 2004Submitted to Office of Water Resources, Illinois Department of Natural Resource
A Review of the Diagnosis and Treatment of Ochratoxin A Inhalational Exposure Associated with Human Illness and Kidney Disease including Focal Segmental Glomerulosclerosis
Ochratoxin A (OTA) exposure via ingestion and inhalation has been described in the literature to cause kidney disease in both animals and humans. This paper reviews Ochratoxin A and its relationship to human health and kidney disease with a focus on a possible association with focal segmental glomerulosclerosis (FSGS) in humans. Prevention and treatment strategies for OTA-induced illness are also discussed, including cholestyramine, a bile-acid-binding resin used as a sequestrant to reduce the enterohepatic recirculation of OTA
The first stars of the Rho Ophiuchi Dark Cloud. XMM-Newton view of Rho Oph and its neighbors
Star formation in molecular clouds can be triggered by the dynamical action
of winds from massive stars. Furthermore, X-ray and UV fluxes from massive
stars can influence the life time of surrounding circumstellar disks. We
present the results of a 53 ks XMM-Newton observation centered on the Rho
Ophiuchi A+B binary system. Rho Ophiiuchi lies in the center of a ring of dust,
likely formed by the action of its winds. This region is different from the
dense core of the cloud (L1688 Core F) where star formation is at work. X-rays
are detected from Rho Ophiuchi as well as a group of surrounding X-ray sources.
We detected 89 X-ray sources, 47 of them have at least one counterpart in 2MASS
+ All-WISE catalogs. Based on IR and X-ray properties, we can distinguish
between young stellar objects (YSOs) belonging to the cloud and background
objects. Among the cloud members, we detect 3 debris disk objects and 22
disk-less / Class III young stars. We show that these stars have ages in
Myr, and are significantly older than the YSOs in L1688. We speculate that they
are the result of an early burst of star formation in the cloud. An X-ray
energy of ergs has been injected into the surrounding
medium during the past Myr, we discuss the effects of such energy budget in
relation to the cloud properties and dynamics.Comment: 17 pages, 9 figures, 7 tables. Accepted for publication to Astronomy
& Astrophysic
Making connections: Compartmentalization in pre -calculus students\u27 understanding of functions
Students develop knowledge constructs that they build into concepts through their experiences. Students demonstrate compartmentalization when they understand a construct or concept within one representation, but not another, or when they do not connect mathematically related ideas. For instance, a student may understand f(x) to mean plug x into the function within a symbolic representation, but the same student may understand f(x) to mean f times x within a tabular representation. A student with these understandings has a compartmentalized understanding of function notation.
A two-month study was conducted with a class of pre-calculus students enrolled in a parochial high school. The class was observed and a subset of students (n = 7) were given a series of tasks in an interview setting in order to determine their understanding of functions and in particular periodicity within the three representations: equations, graphs, and tables. The researcher studied compartmentalization in the students\u27 understanding.
Three of the seven students showed compartmentalization. All three had a compartmentalized understanding of function notation within the tabular representation.
In addition, two had compartmentalization within representations in their understanding of periodicity. Students with compartmentalization in their understanding, had the greatest difficulty in solving the interview tasks. Furthermore, those students who could not translate between representations had an automatic compartmentalization in their understanding and lacked flexibility in problem-solving.
All seven of the students preferred the symbolic representation. The students used this representation overwhelmingly in their classwork and homework. Six of the seven students attempted to find equations for the functions in the interview tasks before trying any other solution strategy. However, only one student was able to solve the interview tasks in this representation.
Some interesting conceptions of periodicity emerged in the students\u27 understandings. The students used symmetry, familiarity, and continuity to determine whether a function was periodic. The students did not work from a conventional definition of period. Instead, they constructed their own definition of periodicity by generalizing sinusoids and other familiar functions. The generalizations that the students made were often inconsistent with the conventional definitions. These unconventional understandings imply that they need experiences with more than just sinusoids
Biology, control and competition of spotted spurge Euphorbia Maculata L. in soybeans
Laboratory and greenhouse experiments to investigate factors affecting germination, dormancy, viability, and emergence of spotted spurge (Euphorbia maculata L.) were done from 1978 to 1981. Optimum germination temperatures were 25 to 30 C. The optimum pH for germina tion was 7. Germination was not significantly different at seed moisture levels of 4 and 11% during storage. Storage of spotted spurge seed at an alternating temperature regime of 4/21 C for 2 to 8 weeks reduced dormancy when compared to storage at -9/21 C and constant temperature treatments of -9, 4 and 21 C. Gibberellic acid significantly increased germination of dormant seed compared to other treatments. Seed stored at 4 C maintained viability for 2 years but declined during the third year of storage. Emergence of spotted spurge seedlings decreased with increased depth of planting and no emergence occurred from depths greater than 4 cm. The preemergence and preplant-incorporated herbicides were applied to coincide with soybean planting dates at each location. The best and most long-lasting control of spotted spurge was with metribuzin [4-ainino-6-tert-butyl-3-(methylthio)-as-triazin-5(4H)-one] and alachlor [2-chloro-2\u27,6\u27-diethyl-N-(methoxymethyl) acetanilide] were applied preemergence, Linuron [3-(3,4-dichlorophenyl)-l-methoxy-lmethylurea] applied preemergence provided poor control. Alachlor and metribuzin gave the most complete and longest-lasting control. Vernolate [s-propyl, dipropylthiocarbamate], trifluralin [a,a,a-trifluoro-2, 6-dinitro-N,N-dipropyl-£-toluidine], and pendiraethalin [^-(1-ethyIpropyl)- 3,4-dimethyl-2.b-dinitrobenzeiieamine] applied pre-plant incorporated all III \u27v n IV gave good control of spotted spurge. Herbicides applied to the soil were more effective than those applied postemergence. Bentazon [3- isopropyl-lH-2,1,3-benzothiadiazin-(4)3H-one 2,2-dioxide] and naptalam [^-1-naphthylphthalamic acid] + dinoseb [2-sec-butyl-4,6-dinitrophenol] applied postemergence provided poor control, but acifluorfen [sodium 5- [(2-chloro-4-trifluoromethyl)-phenoxy]-2-nitrobenzoate] gave fair control of spotted spurge. Competition studies were conducted to determine the influence of two spotted spurge populations and three spotted spurge removal dates on soybeans. The results indicate soybean seed yields may be reduced more by spotted spurge competition in dry conditions than when adequate moisture is available
Do early-life exposures explain why more advantaged children get eczema? Findings from the U.K. Millennium Cohort Study
Background:
Atopic dermatitis (eczema) in childhood is socially patterned, with higher incidence in more advantaged populations. However, it is unclear what factors explain the social differences.
Objectives:
To identify early-life risk factors for eczema, and to explore how early-life risk factors explain any differences in eczema.
Methods:
We estimated odds ratios (ORs) for ever having had eczema by age 5 years in 14 499 children from the U.K. Millennium Cohort Study (MCS), with a focus on maternal, antenatal and early-life risk factors and socioeconomic circumstances (SECs). Risk factors were explored to assess whether they attenuated associations between SECs and eczema.
Results:
Overall 35·1% of children had ever had eczema by age 5 years. Children of mothers with degree-level qualifications vs. no educational qualifications were more likely to have eczema (OR 1·52, 95% confidence interval 1·31–1·76), and there was a gradient across the socioeconomic spectrum. Maternal atopy, breastfeeding (1–6 weeks and ≥ 6 months), introduction of solids under 4 months or cow's milk under 9 months, antibiotic exposure in the first year of life and grime exposure were associated with an increased odds of having eczema. Female sex, Pakistani and Bangladeshi ethnicity, smoking during pregnancy, exposure to environmental tobacco smoke and having more siblings were associated with reduced odds for eczema. Controlling for maternal, antenatal and early-life characteristics (particularly maternal smoking during pregnancy, breastfeeding and number of siblings) reduced the OR for eczema to 1·26 (95% confidence interval 1·03–1·50) in the group with the highest educational qualifications compared with the least.
Conclusions:
In a representative U.K. child cohort, eczema was more common in more advantaged children. This was explained partially by early-life factors including not smoking during pregnancy, breastfeeding and having fewer siblings
Biology and control of Euzophera ostricolrella Hulst on yellow-poplar, Liriodendron tulipfera L. in Tennessee
Euzophera ostricolorella Hulst (Lepidoptera: Pyralidae) was first described as a serious pest in 1954 when it caused heavy losses in yellow-poplar, Liriodendron tulipifera L., woodlots in Kentucky and Tennessee. The borer now damages shade trees and seed orchards in Tennessee. In 1977 the borer was bivoltine in East Tennessee. Adults of the overwintering brood emerged from April 27 to June 8 and adults of the summer brood emerged from August 27 to October 10. The average incubation period of the eggs was 9 days and the pupal period was 18 days. The major larval parasites of the borer were Venturia nigricoxalis Vier. and Macrocentrus delicatus Cress. The parasitism rate was 18% and 36% respectively, for the overwin-tering and summer broods. The two most effective borer control treatments were:(1) paradichlorobenzene placed around the base of the tree and covered with a six inch mound of sawdust, and (2) lindane-oil solution sprayed into a six inch mound of sawdust placed around the base of the tree
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