The Texas construction sector: the tail that wagged the dog

The boom-to-bust days of the Texas construction industry will linger in people's memory for many years. D'Ann Petersen, Keith Phillips, and Mine Yucel examine the factors that led to the rise and fall of the Texas construction industry and determine the role the industry played in the state's volatile economy during the 1970s and 1980s. ; Petersen, Phillips, and Yucel employ an econometric model to analyze the roles residential and nonresidential construction played in the state's economic fluctuations from 1976 through 1990. The authors find that, although large swings in oil prices were the greatest source of economic instability in the Texas economy, the construction sector also played an important and independent role in the changing fortunes of the state. The authors' results show that the homebuilding sector, in particular, had a large impact on the Texas economy. In addition, the authors find that the state's economy needs several years to adjust to shocks in the construction industry. Consequently, the current expansion in residential construction is likely to have positive economic effects in the years ahead.Construction industry ; Texas

Analysis and optimization of DNA delivery into chickpea (Cicer arietinum L.) seedlings by Agrobacterium tumefacience

The main purpose of this study was to develop a non-tissue culture based Agrobacterium mediated transformation method for chickpea. The influences of several factors were investigated on the transferof -glucuronidase (GUS) gene into chickpea (Cicer arietinum) seedlings during the early stages of Agrobacterium-mediated gene transfer, including cocultivation period in liquid induction medium (2, 8,16 and 24 h), strains of Agrobacterium tumefaciens (C58C1, EHA105, KYRT1) containing the plasmid pTJK136, developmental stage (16 h imbibed and 40 h germinated), microwounding, vacuum infiltration(200, 400, 600 mmHg for 20 and 40 min) and genotype (5 different). The number of GUS-expressing foci was counted to evaluate the gene transfer process. The KYRT1/pTJK136 strain of A. tumefaciens wassignificantly more effective for transformation than the  58C1/pTJK136 and EHA105/pTJK136 strains. The highest transient GUS activity was obtained from 16  h imbibed seedlings of cv.Uzunlu woundedwith a needle and co-cultivated in liquid induction medium for 24 h with the KYRT1 strain (226 GUS foci/per explant)

The fourth degree parabola (Bi-quadratic parabola) as a transition curve

Prijelazne krivulje su u konstrukciji modernih cesta i željezničkih pruga elementi jednako bitni kod poravnanja kao i zakrivljenja (kružnog). Kako bi se spriječila iznenadna promjena centrifugalne sile, prijelazna se krivulja mora primijeniti zbog djelovanja sile gibanja u oštroj krivulji. Tijekom godina proširila se primjena klotoida na mnoge zemlje svijeta. Međutim, u ovom istraživanju, da bi se eliminirali problemi povezani s prometnom dinamikom, stvoreni klotoidom kod vozila pri velikim brzinama, ispituje se parabola četvrtog stupnja (bi-kvadratna parabola). U ovom se radu analizira mogućnost uporabe bi-kvadratnih parabola pri definiranju prijelaznih krivulja tijekom projektiranja prijevoznih sredstava. Opisuju se osnovna svojstva bi-kvadratnih parabola, njihovi osnovni matematički izrazi, računanje koordinata točke te pogonsko-dinamičke karakteristike bi-kvadratnih parabola. Daje se funkcija promjene zakrivljenosti i bočnog udarnog opterećenja duž bi-kvadratne parabole.The transition curves in the modern road and railway construction are route elements equally crucial as alignment and curve (circular). In order to prevent a sudden change of the centrifugal force, the transition curve must be applied due to the impact of the motion in a sharp curve. Over the years the application of the clothoid has become widespread in many countries in the world. However, in this study, in order to eliminate the problems concerning the road dynamics, created by clothoid for vehicles at high speed, the fourth degree parabola (Bi-quadratic parabola) is examined. The possibility of using bi-quadratic parabola in defining transition curves during design of transportation facilities is analyzed in the paper. Basic properties of bi-quadratic parabolas, their fundamental mathematical expression, calculation of point coordinates, driving-dynamic characteristics of bi-quadratic parabolas are described, and the function of change in curvature and lateral impact along the bi-quadratic parabola is presented

The morphometric measurement of the brain stem in Turkish healthy subjects according to age and sex

Background: This paper determined the morphometric measurements of the brainstem including mesencephalon, pons and medulla using magnetic resonance imaging (MRI) in Turkish healthy population. Materials and methods: Two hundred sixty-three (263; 158 females and 105 males) subjects aged from 18 to 65 years were included in this study. The measurements were taken from subjects having brain MRI in the Radiology Department. Statistical analysis was done by SPSS 21.00 package programme. ANOVA test and χ2 test were used to determine the relation between measurements and age and sex groups. The p < 0.05 value was considered as significant. Results: The overall means and standard deviations of the measurements were: pons anteroposterior diameter, 15.41 ± 1.27 mm; pons vertical diameter, 22.02 ± 2.07 mm; mesencephalon anteroposterior diameter 9.39 ± 1.00 mm; mesencephalon vertical diameter, 15.20 ± 1.53 mm; distance between the interpeduncular fissure and aqueduct, 11.72 ± 1.58 mm; distance from cerebral peduncles to aqueduct, 13.64 ± 1.66 mm; anterior surface of the pons midway between the mesencephalon and medulla to the fourth ventricular floor, 21.62 ± 1.64 mm; the shortest anteroposterior diameter of the medulla at the pontomedullary junction, 13.46 ± 1.28 mm, and the shortest anteroposterior diameter of the medulla at the medullospinal junction, 10.24 ± 1.43 mm in females, respectively, whereas the corresponding values were 15.58 ± 1.53 mm; 22.64 ± 2.35 mm; 9.37 ± 1.66 mm; 15.64 ± 1.52 mm; 11.14 ± 1.31 mm; 13.01 ± 1.30 mm; 21.97 ± 1.65 mm;13.47 ± 1.19 mm; 9.91 ± 1.35 mm in males, respectively. There were significant differences in some parameters such as pons vertical diameter, mesencephalon vertical diameter, distance between the interpeduncular fissure and aqueduct, and distance between cerebral peduncles to aqueduct between sexes. Conclusions: The brainstem dimensions of healthy population provide important and useful knowledge in terms of comparison of abnormalities clinically. These data may be valuable for the representatives of clinical disciplines

PTPN22 gene polymorphism in Takayasu's arteritis

Objective. Takayasu's arteritis (TA) is a chronic, rare granulomatous panarteritis of unknown aetiology involving mainly the aorta and its major branches. In this study, genetic susceptibility to TA has been investigated by screening the functional single nucleotide polymorphism (SNP) of PTPN22 gene encoding the lymphoid-specific protein tyrosine phosphatase. Methods. Totally, 181 patients with TA and 177 healthy controls are genotyped by PCR-RFLP method for the SNP rs2476601 (A/G) of PTPN22 gene. Polymorphic region was amplified by PCR and digested with Xcm I enzyme. Results. Detected frequencies of heterozygous genotype (AG) were 5.1% (9/177) in control group and 3.8% (7/181) in TA group (P = 0.61, odds ratio: 0.75, 95% CI: 0.3, 2.0). No association with angiographic type, vascular involvement or prognosis of TA was observed either. Conclusion. The distribution of PTPN22 polymorphism did not reveal any association with TA in Turkey. © The Author 2008. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved