scholarly journals Estimación del valor del regadío a partir del precio de la tierra

2011 ◽  
Vol 1 (1) ◽  
pp. 115 ◽  
Author(s):  
Carlos Arias

In this paper, we estimate the value of irrigated land in the province of Leon (Spain) using land prices (irrigated and non irrigated) for two different uses (crop production and pasture) in ten different districts. The value of benefits associated with irrigation can be estimated by comparing the price of an irrigated plot of land with a similar plot of non irrigated land. The logical difficulty of finding these two similar (except for water) plots of land can be overcome using regression analysis where the effect of irrigation on land prices can be estimated after controlling for other differences in the plots of land analyzed. In the present paper, using an econometric model, we estimate the average prices associated with irrigated and non irrigated land. The difference among these average prices is an estimate of the value of irrigation. The results of this paper can be used in the analysis of new irrigation projects.

Children ◽  
2021 ◽  
Vol 8 (4) ◽  
pp. 288
Author(s):  
Wojciech Rusek ◽  
Joanna Baran ◽  
Justyna Leszczak ◽  
Marzena Adamczyk ◽  
Rafał Baran ◽  
...  

The main goal of our study was to determine how the age of children, puberty and anthropometric parameters affect the formation of body composition and faulty body posture development in children. The secondary goal was to determine in which body segments abnormalities most often occur and how gender differentiates the occurrence of adverse changes in children’s body posture and body composition during puberty. The study group consisted of 464 schoolchildren aged from 6–16. Body posture was assessed with the Zebris system. The composition of the body mass was tested with Tanita MC 780 MA body mass analyzer and the body height was measured using a portable stadiometer PORTSTAND 210. The participants were further divided due to the age of puberty. Tanner division was adopted. The cut-off age for girls is ≥10 years and for boys it is ≥12 years. The analyses applied descriptive statistics, the Pearson correlation, stepwise regression analysis and the t-test. The accepted level of significance was p < 0.05. The pelvic obliquity was lower in older children (beta = −0.15). We also see that age played a significant role in the difference in the height of the right pelvis (beta = −0.28), and the difference in the height of the right shoulder (beta = 0.23). Regression analysis showed that the content of adipose tissue (FAT%) increased with body mass index (BMI) and decreased with increasing weight, age, and height. Moreover, the FAT% was lower in boys than in girls (beta negative equal to −0.39). It turned out that older children (puberty), had greater asymmetry in the right shoulder blade (p < 0.001) and right shoulder (p = 0.003). On the other hand, younger children (who were still before puberty) had greater anomalies in the left trunk inclination (p = 0.048) as well as in the pelvic obliquity (p = 0.008). Girls in puberty were characterized by greater asymmetry on the right side, including the shoulders (p = 0.001), the scapula (p = 0.001) and the pelvis (p < 0.001). In boys, the problem related only to the asymmetry of the shoulder blades (p < 0.001). Girls were characterized by a greater increase in adipose tissue and boys by muscle tissue. Significant differences also appeared in the body posture of the examined children. Greater asymmetry within scapulas and shoulders were seen in children during puberty. Therefore, a growing child should be closely monitored to protect them from the adverse consequences of poor posture or excessive accumulation of adipose tissue in the body.


2012 ◽  
pp. 89-93
Author(s):  
Tamás Árendás ◽  
Zoltán Berzsenyi ◽  
Péter Bónis

The effect of crop production factors on the grain yield was analysed on the basis of three-factorial experiments laid out in a split-split-plot design. In the case of maize the studies were made as part of a long-term experiment set up in 1980 on chernozem soil with forest residues, well supplied with N and very well with PK. The effects of five N levels in the main plots and four sowing dates in the subplots were compared in terms of the performance of four medium early hybrids (FAO 200). In the technological adaptation experiments carried out with durum wheat, the N supplies were moderate (2010) or good (2011), while the P and K supplies were good or very good in both years. Six N top-dressing treatments were applied in the main plots and five plant protection treatments in the subplots to test the responses of three varieties. The results were evaluated using analysis of variance, while correlations between the variables were detected using regression analysis.The effect of the tested factors on the grain yield was significant in the three-factorial maize experiment despite the annual fluctuations, reflected in extremely variable environmental means. During the given period the effect of N fertilisation surpassed that of the sowing date and the genotype. Regression analysis on the N responses for various sowing dates showed that maize sown in the middle 10 days of April gave the highest yield, but the N rates required to achieve maximum values declined as sowing was delayed. In the very wet year, the yield of durum wheat was influenced to the greatest extent by the plant protection treatments, while N supplies and the choice of variety were of approximately the same importance.  In the favourable year the yielding ability was determined by topdressing and the importance of plant protection dropped to half,  while no  significant difference could be detected between the tested varieties. According to the results of regression analysis, the positive effect of plant protection could not be substituted by an increase in the N rate in either year. The achievement of higher yields was only possible by a joint intensification of plant protection and N fertilisation. Nevertheless, the use of more efficient chemicals led to a slightly, though not significantly, higher yield, with a lower N requirement. 


2021 ◽  
Vol 62 (9) ◽  
pp. 1181-1188
Author(s):  
Joong Hee Kim ◽  
Kyong Jin Cho ◽  
Ho Seok Chung

Purpose: We investigated the change in the absolute error according to the difference between anterior and total keratometry, to determine the criterion for the difference in keratometry, and to determine the indication for using total keratometry. Methods: Sagittal and total refractive power were measured with 2-, 3-, and 4-mm Pentacam® rings, and the absolute error of each was calculated in patients who underwent cataract surgery in our hospital. The correlation between the difference value the sagittal minus the total refractive power and each absolute error was analyzed by simple regression analysis. The analysis was performed by dividing the patients into two groups based on 0.6, which is the average of the difference between the sagittal and total refractive power for the 3-mm ring. Results: Sagittal power was larger than total refractive power for all rings and the absolute error obtained by applying the total refractive power was larger than the sagittal power for the 2- and 4-mm rings (p < 0.001). The simple regression analysis revealed that the absolute error using sagittal power was positively correlated with the difference between sagittal power and total refractive power. In the group with less than 0.6, the absolute error using the total refractive power of all rings was larger than the sagittal power (p < 0.001). In the group exceeding 0.6, the absolute error using the total refractive power was less than using the sagittal power for the 3 mm ring (p = 0.028). Conclusions: The greater the difference between sagittal and total refractive power, the greater the absolute error using sagittal power. Accuracy was higher in the group exceeding 0.6 after applying total refractive power measured at the 3 mm ring compared to sagittal power.


2009 ◽  
Vol 36 (8) ◽  
pp. 1686-1690 ◽  
Author(s):  
MAKOTO KAMEYAMA ◽  
SHU MEGURO ◽  
OSAMU FUNAE ◽  
YOSHIHITO ATSUMI ◽  
HIROYASU IKEGAMI

Objective.Diabetes is associated with several disorders of the hand, including stenosing flexor tenosynovitis (SFTS). The feature of SFTS in diabetics is a higher prevalence of multiple digit involvement. We examined the magnitude of the tendency for involvement of more digits by SFTS in diabetic patients than in nondiabetic patients, and attempted to clarify the factors influencing multiple digit involvement by SFTS in diabetics.Methods.The study comprised 302 diabetic patients with SFTS and 235 nondiabetic patients with SFTS. The total number of digits exhibiting SFTS within the 1-year period following the initial visit to the Department of Orthopaedic Surgery was investigated in a prospective manner. We compared the difference in the frequency of multiple digit involvement by SFTS between diabetic and nondiabetic patients using the chi-squared test. Multiple regression analysis was performed to examine the contribution of independent variables [defined as 12 factors including age, sex, type of diabetes, estimated duration of diabetes, HbA1c values, carpal tunnel syndrome, Dupuytren contracture, limited joint mobility (LJM), de Quervain's disease, diabetic retinopathy, diabetic nephropathy, and dyslipidemia] to the total number of digits affected by SFTS in diabetic patients.Results.Diabetic patients showed a significantly higher prevalence of multiple digit involvement than nondiabetic patients (p < 0.0001). Multiple regression analysis in diabetic patients revealed that the presence of LJM was positively associated with the prevalence of multiple digit involvement (r = 0.626, p < 0.0001).Conclusion.LJM in diabetics is closely associated with SFTS involving multiple digits.


2012 ◽  
Vol 41 (3) ◽  
pp. 377-390 ◽  
Author(s):  
Jorge Fernandez-Cornejo ◽  
Seth Wechsler

This study examines the impact of adopting Bt corn on farm profits, yields, and insecticide use. The study employs an econometric model that corrects for self-selection and simultaneity. The model is estimated using nationwide farm-level survey data for 2005. Regression analysis confirms that Bt adoption is associated with increased variable profits, yields, and seed demand. However, the results of this analysis suggest that Bt adoption is not significantly related to insecticide use. This result may be due to the fact that insect infestation levels were lower in 2005 than they were in previous years.


2020 ◽  
Vol 10 (03) ◽  
pp. e241-e246
Author(s):  
Pierre Delorme ◽  
Gilles Kayem ◽  
Hélène Legardeur ◽  
Louise Anne Roux-Dessarps ◽  
Guillaume Girard ◽  
...  

Abstract Objective The aim of the study is to investigate whether carbetocin prevents postpartum hemorrhage (PPH) more effectively than oxytocin Methods This historical retrospective single-center cohort study compares women who underwent cesarean deliveries during two periods. During period A, oxytocin was used as a 10-unit bolus immediately after delivery, with 20 units thereafter infused for 24 hours. During period B, carbetocin in a single 100-µg injection replaced this protocol. The main outcome was PPH, defined as a decline in hemoglobin of more than 2 g/dL after the cesarean. The analysis was performed on the overall population and then stratified by the timing of the cesareans (before or during labor). A logistic regression analysis was performed. Results This study included 1,796 women, 52% of whom had a cesarean before labor; 15% had a PPH. The crude PPH rate was lower in period B than in period A (13 vs. 17%, respectively, odds ratio 0.75, 95% confidence interval [CI]: 0.58–0.98). The difference was no longer significant in the multivariate analysis (adjusted odds ratio: 0.81, 95% CI 0.61–1.06). Results were similar when stratified by the timing of the cesareans (before or during labor). Conclusion Carbetocin is not superior to oxytocin in preventing PPH. However, it does provide the advantage of requiring a single injection.


2000 ◽  
Vol 89 (2) ◽  
pp. 629-635 ◽  
Author(s):  
Arthur Weltman ◽  
Cathy J. Pritzlaff ◽  
Laurie Wideman ◽  
Judy Y. Weltman ◽  
Jeffery L. Blumer ◽  
...  

To test the hypothesis that heightened sympathetic outflow precedes and predicts the magnitude of the growth hormone (GH) response to acute exercise (Ex), we studied 10 men [age 26.1 ± 1.7 (SE) yr] six times in randomly assigned order (control and 5 Ex intensities). During exercise, subjects exercised for 30 min (0900–0930) on each occasion at a single intensity: 25 and 75% of the difference between lactate threshold (LT) and rest (0.25LT, 0.75LT), at LT, and at 25 and 75% of the difference between LT and peak (1.25LT, 1.75LT). Mean values for peak plasma epinephrine (Epi), plasma norepinephrine (NE), and serum GH concentrations were determined [Epi: 328 ± 93 (SE), 513 ± 76, 584 ± 109, 660 ± 72, and 2,614 ± 579 pmol/l; NE: 2.3 ± 0.2, 3.9 ± 0.4, 6.9 ± 1.0, 10.7 ± 1.6, and 23.9 ± 3.9 nmol/l; GH: 3.6 ± 1.5, 6.6 ± 2.0, 7.0 ± 2.0, 10.7 ± 2.4, and 13.7 ± 2.2 μg/l for 0.25, 0.75, 1.0, 1.25, and 1.75LT, respectively]. In all instances, the time of peak plasma Epi and NE preceded peak GH release. Plasma concentrations of Epi and NE always peaked at 20 min after the onset of Ex, whereas times to peak for GH were 54 ± 6 (SE), 44 ± 5, 38 ± 4, 38 ± 4, and 37 ± 2 min after the onset of Ex for 0.25–1.75LT, respectively. ANOVA revealed that intensity of exercise did not affect the foregoing time delay between peak NE or Epi and peak GH (range 17–24 min), with the exception of 0.25LT ( P < 0.05). Within-subject linear regression analysis disclosed that, with increasing exercise intensity, change in (Δ) GH was proportionate to both ΔNE ( P = 0.002) and ΔEpi ( P = 0.014). Furthermore, within-subject multiple-regression analysis indicated that the significant GH increment associated with an antecedent rise in NE ( P = 0.02) could not be explained by changes in Epi alone ( P = 0.77). Our results suggest that exercise intensity and GH release in the human may be coupled mechanistically by central adrenergic activation.


2008 ◽  
Vol 54 (No. 8) ◽  
pp. 376-383
Author(s):  
E. Škorecová ◽  
M. Farkašová

The article is focused on the importance of using the variant calculation methods in the management of companies’ performance under the conditions of multifunctional agriculture. It mentions the difference between the calculations formed for the needs of valuating the production in the financial statements and the managerial calculations. Attention is paid to overhead costs in agriculture, their development is depicted with tables and graphs. The development of overhead costs during the time period of 1997–2006 is presented in crop production and outputs of wheat and rapeseed, in livestock production in Slovakia and in the outputs of cattle (6–24 months) and pigs (1–12 months). The fastidiousness of market environment of the globalized economies requires a gradual transformation from the classical calculation system into the managerial calculation system, which provides a multidimensional insight into the product as well as the market. The sequence of establishing the variant calculation methods is also introduced together with the reasons of under-valuating calculations in the managerial practice.


2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Jason D. Lloyd ◽  
David W. Oakley

Purpose The purpose of this study is to evaluate the increase in suicide rates for Kansas residents, as well as quantify the difference in suicide rates between men and women across the State of Kansas. Design/methodology/approach To evaluate increases in suicide rates, a joinpoint regression analysis was conducted to calculate the annual percentage change in suicide rates. To evaluate differences between sex characteristics, a one-way analysis of variance was conducted. Findings Results of a joinpoint regression analysis found that the annual percentage change in the suicide rates of Kansas did increase significantly between 2009 and 2018. Furthermore, the rate of suicide increase among women was greater than the suicide rate increases of men. Originality/value The value of this study provides context to the suicide literature that could allow for better local and statewide policy decisions.


2012 ◽  
Vol 15 (1) ◽  
pp. 116-119 ◽  
Author(s):  
Sally J. Wadsworth ◽  
Richard K. Olson ◽  
Erik G. Willcutt ◽  
John C. DeFries

The augmented multiple regression model for the analysis of data from selected twin pairs was extended to facilitate analyses of data from twin pairs and nontwin siblings. Fitting this extended model to data from both selected twin pairs and siblings yields direct estimates of heritability (h2) and the difference between environmental influences shared by members of twin pairs and those of sib or twin–sib pairs (i.e., c2(t) – c2 (s)). When this model was fitted to reading performance data from 293 monozygotic and 436 dizygotic pairs selected for reading difficulties, and 291 of their nontwin siblings, h2 = .48 ± .22, p = .03, and c2 (t) – c2 (s) = .22 ± .12, p = .06. Although the test for differential shared environmental influences is only marginally significant, the results of this analysis suggest that environmental influences on reading performance that are shared by members of twin pairs (.36) may be substantially greater than those for less contemporaneous twin–sibling pairs (.14).


Sign in / Sign up

Export Citation Format

Share Document