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1.
F1000Res ; 12: 901, 2023.
Article in English | MEDLINE | ID: mdl-39239132

ABSTRACT

Background: This paper aims to examine the efficiency of Mexico's dairy farms within its four regions of Tlaxcala Stated. Methods: The Envelopment Data Analysis (DEA) applied to the variable returns to a scale model (VRS) for the year 2020. Also, Examine the statistical accuracy of efficiency estimation using bootstrap resampling techniques. The results reveal that Tlaxcala's dairy farm efficiency, on the other hand, was adversely influenced by three inputs (costs): cost of investment in livestock, the total annual cost for feeding, reproduction, diseases and treatments, preventive medicine, sanitation, milking, fuel, and total labor. Results: The efficiency distribution among farms using VRS, CRS, and FDH technologies reveals varying patterns. Under VRS and CRS, the majority of farms exhibit high efficiency within the 0 to less than 0.2 range, while FDH displays a broader distribution, with notable efficiency at 1 and across various ranges. These findings highlight the diverse landscape of efficiency levels across different technological approaches within the agricultural sector, offering valuable insights for optimization strategies and resource allocation. Conclusions: The utilization of Bootstrap methodology enhances the reliability of efficiency assessments by providing robust statistical techniques that accommodate non-normal data distributions. By incorporating Bootstrap, decision-makers can obtain more accurate estimates of efficiency levels and confidence intervals, thereby making informed decisions regarding resource allocation and optimization strategies within the agricultural sector. As part of the study, provided The Policy suggestions.


Subject(s)
Dairying , Farms , Dairying/methods , Dairying/economics , Mexico , Animals , Cattle
2.
F1000Res ; 11: 1382, 2022.
Article in English | MEDLINE | ID: mdl-39185140

ABSTRACT

Background: This work was focused on measuring environmental inefficiency in Mexican dairy farms, considering climate change variables related to the emission of greenhouse gases (GHG) and planetary geomagnetic activity. Methods: The applied methodology measures the eco-efficiency of Mexican dairy farms using the empirical application of a stochastic frontier model of the bioeconomy. The productive sector of the bioeconomy studied was the eco-intensification of the livestock production system (dairies). The environmental inefficiency effect was assumed to be a distribution-independent truncation of a normal distribution with constant variance, while the mean was a linear environmental function of the observable variable. Results: The results showed that the coefficients of the frontier model were highly significant, highlighting the investment in livestock (50%). The inefficiency model had an impact on climate variation with greenhouse gas emissions CH4 (1.96%). The results of the environmental technical efficiency in geometric average were 81.28%. The producers that reached the border with a technical efficiency equal to 1 are the references for the rest, marking the relative technical efficiency. Conclusions: It was concluded that the coefficients in the model were very significant, showing the level of investment in livestock (50%). The low-performance model estimates the impact of climate change on GHG emissions CH4 (1.96%) explaining the trend of increasing GHG emissions, keeping in view that the management of food and cattle during the study period were affected by summer feeding, which allowed considering the activity of GHG emissions. According to the results, the geometric mean environmental performance of engineering is 81.28%.


Subject(s)
Greenhouse Gases , Livestock , Animals , Climate Change , Mexico , Models, Theoretical , Environment , Cattle , Dairying/economics
3.
J Environ Radioact ; 99(10): 1578-82, 2008 Oct.
Article in English | MEDLINE | ID: mdl-18243446

ABSTRACT

The RPII radon (Rn) laboratory holds accreditation for the International Standard ISO/IEC 17025. A requirement of this standard is an estimate of the uncertainty of measurement. This work shows two approaches to estimate the uncertainty. The bottom-up approach involved identifying the components that were found to contribute to the uncertainty. Estimates were made for each of these components, which were combined to give a combined uncertainty of 13.5% at a Rn concentration of approximately 2500 Bq m(-3) at the 68% confidence level. By applying a coverage factor of k=2, the expanded uncertainty is +/-27% at the 95% confidence level. The top-down approach used information previously gathered from intercomparison exercises to estimate the uncertainty. This investigation found an expanded uncertainty of +/-22% at approximately 95% confidence level. This is good agreement for such independent estimates.


Subject(s)
Radiation Monitoring/methods , Radon/analysis , Ireland , Radiation Monitoring/standards , Radiation Monitoring/statistics & numerical data , Uncertainty
4.
J Environ Radioact ; 99(10): 1520-4, 2008 Oct.
Article in English | MEDLINE | ID: mdl-18243444

ABSTRACT

In situ gamma spectrometry provides a fast method to determine (137)Cs inventories in soils. To improve the accuracy of the estimates, one can use not only the information on the photopeak count rates but also on the peak to forward-scatter ratios. Before applying this procedure to field measurements, a calibration including several experimental simulations must be carried out in the laboratory. In this paper it is shown that Monte Carlo methods are a valuable tool to minimize the number of experimental measurements needed for the calibration.


Subject(s)
Radiation Monitoring/instrumentation , Radiation Monitoring/methods , Calibration , Cesium Radioisotopes/analysis , Cesium Radioisotopes/standards , Monte Carlo Method , Reproducibility of Results , Spectrometry, Gamma/methods
5.
J Environ Radioact ; 99(10): 1553-7, 2008 Oct.
Article in English | MEDLINE | ID: mdl-18243443

ABSTRACT

A new system has been developed for the detection of low radioactivity levels of fission products and actinides using coincidence techniques. The device combines a phoswich detector for alpha/beta/gamma-ray recognition with a fast digital card for electronic pulse analysis. The phoswich can be used in a coincident mode by identifying the composed signal produced by the simultaneous detection of alpha/beta particles and X-rays/gamma particles. The technique of coincidences with phoswich detectors was proposed recently to verify the Nuclear Test Ban Treaty (NTBT) which established the necessity of monitoring low levels of gaseous fission products produced by underground nuclear explosions. With the device proposed here it is possible to identify the coincidence events and determine the energy and type of coincident particles. The sensitivity of the system has been improved by employing liquid scintillators and a high resolution low energy germanium detector. In this case it is possible to identify simultaneously by alpha/gamma coincidence transuranic nuclides present in environmental samples without necessity of performing radiochemical separation. The minimum detectable activity was estimated to be 0.01 Bq kg(-1) for 0.1 kg of soil and 1000 min counting.


Subject(s)
Radiation Monitoring/instrumentation , Radiation Monitoring/methods , Radioactivity , Reproducibility of Results
6.
J Environ Radioact ; 166(Pt 2): 390-397, 2017 Jan.
Article in English | MEDLINE | ID: mdl-27681529

ABSTRACT

One of the requirements of the recently approved EU-BSS (European Basic Safety Standards Directive, EURATOM, 2013) is the design and implementation of national radon action plans in the member states (Annex XVIII). Such plans require radon surveys. The analysis of indoor radon data is supported by the existing knowledge about geogenic radiation. With this aim, we used the terrestrial gamma dose rate data from the MARNA project. In addition, we considered other criterion regarding the surface of Spain, population, permeability of rocks, uranium and radium contain in soils because currently no data are available related to soil radon gas concentration and permeability in Spain. Given that, a Spanish radon map was produced which will be part of the European Indoor Radon Map and a component of the European Atlas of Natural Radiation. The map indicates geographical areas with high probability of finding high indoor radon concentrations. This information will support legislation regarding prevention of radon entry both in dwellings and workplaces. In addition, the map will serve as a tool for the development of strategies at all levels: individual dwellings, local, regional and national administration.


Subject(s)
Air Pollutants, Radioactive/analysis , Background Radiation , Radiation Monitoring , Radon/analysis , Gamma Rays , Radium/analysis , Spain , Surveys and Questionnaires , Uranium/analysis
7.
Appl Radiat Isot ; 64(10-11): 1287-90, 2006.
Article in English | MEDLINE | ID: mdl-16554167

ABSTRACT

Silicon photodiodes are well suited to detect alphas coming from different sources as neutron reactions or radon daughters. In this work a radon in air detecting device, using an 18x18 mm silicon PIN photodiode is studied. The ionized airborne decay products formed during radon diffusion were focused by an accelerating high voltage to the PIN surface. Several conducting rings were disposed inside a cylindrical PVC vessel in such a way that they reproduced the electric field created by a punctual charge located behind PIN position. Alpha spectra coming from the neutral and ionized species deposited on the PIN surface, dominated by 218Po and 214Po progeny peaks, were recorded for varying conditions. Those include radon concentration from a Pylon source, high voltage (thousands of volts) and PIN inverse bias voltage. Different parameters such as temperature and humidity were also registered during data acquisition. The increase in the particle collection efficiency with respect to zero electric field was compared with the corresponding to a parallel plates configuration. A discussion is made in terms of the most appropriate voltages for different radon concentrations.


Subject(s)
Air Pollutants, Radioactive/analysis , Alpha Particles , Radiation Monitoring/instrumentation , Radon/analysis , Spectrum Analysis/instrumentation , Transducers , Equipment Design , Equipment Failure Analysis , Radiation Dosage , Radiation Monitoring/methods , Reproducibility of Results , Semiconductors , Sensitivity and Specificity , Spectrum Analysis/methods
8.
Arch Intern Med ; 159(8): 872-6, 1999 Apr 26.
Article in English | MEDLINE | ID: mdl-10219934

ABSTRACT

BACKGROUND: Fever of intermediate duration (FID), characterized by a febrile syndrome lasting from 7 to 28 days, is a frequent condition in clinical practice, but its epidemiological and etiologic features are not well described. Murine typhus (MT) is a worldwide illness; nevertheless, to our knowledge, no studies describing its epidemiological and clinical characteristics have been performed in the south of Spain. Also, its significance as a cause of FID is unknown. OBJECTIVE: To determine the epidemiological features, clinical characteristics, and prognosis of MT and, prospectively, its incidence as a cause of FID. DESIGN: Prospective study of cases of MT over 17 years (1979-1995) and of all cases of FID treated in a tertiary teaching hospital in Seville, Spain. RESULTS: One hundred and four cases of MT were included, and MT was the cause in 6.7% of 926 cases of FID. Insect bites were reported in only 3.8% of the cases of MT previous to the onset of illness. Most cases (62.5%) occurred in the summer and fall. A high frequency of rash (62.5%) was noted. Arthromyalgia (77%), headache (71%), and respiratory (25%) and gastrointestinal (23%) symptoms were also frequent. Laboratory findings were unspecific. Organ complications were uncommon (8.6%), but they were severe in 4 cases. The mean duration of fever was 12.5 days. Cure was achieved in all cases, although only 44 patients received specific treatment. CONCLUSIONS: Murine typhus is prevalent in the south of Spain and is a significant cause of FID. Clinical signs are benign, but some patients may develop severe complications. A high degree of clinical suspicion is required for diagnosis.


Subject(s)
Fever/microbiology , Mice/microbiology , Typhus, Epidemic Louse-Borne/complications , Adolescent , Adult , Aged , Aged, 80 and over , Animals , Antibodies, Bacterial/blood , Child , Fever/epidemiology , Fever/immunology , Fluoroimmunoassay , Humans , Middle Aged , Prospective Studies , Rickettsia typhi/immunology , Seasons , Spain/epidemiology , Time Factors , Typhus, Epidemic Louse-Borne/epidemiology , Typhus, Epidemic Louse-Borne/immunology
9.
J Interferon Cytokine Res ; 17(2): 107-12, 1997 Feb.
Article in English | MEDLINE | ID: mdl-9058317

ABSTRACT

Platelet-activating factor (PAF) was tested for its ability to alter yields of human interferon (IFN) produced from peripheral blood mononuclear cells (PBMC). Using different concentrations of phytohemagglutinin (PHA) we could not demonstrate a consistent effect of PAF at any concentration tested on the yield of IFN-gamma. Similarly, although PAF was associated with a slight enhancement of IFN-gamma yields when PBMC were induced by interleukin-2 (IL-2), the results were not statistically significant. No effect was observed on the accumulation of human IFN-gamma mRNA induced by PHA. Furthermore, PAF did not enhance yields of IFN-gamma when the cells were induced by poly I:poly C. We conclude that although PAF may have a role in sepsis, it is not likely that this is in any way related to its ability to significantly alter the yield of interferons.


Subject(s)
Interferon-gamma/biosynthesis , Leukocytes, Mononuclear/drug effects , Platelet Activating Factor/pharmacology , Case-Control Studies , Cell Division/drug effects , Humans , In Vitro Techniques , Interferon-alpha/biosynthesis , Interferon-gamma/blood , Leukocytes, Mononuclear/metabolism , Reference Values
10.
Dis Markers ; 8(2): 85-91, 1990.
Article in English | MEDLINE | ID: mdl-2387126

ABSTRACT

Increased incidence of infections, cancer, monoclonal gammopathies and rheumatic diseases in aged humans has been described. Histocompatibility antigens are involved in the regulation of immune response and it has been suggested that age-related alterations in the murine immune system may be due to changes in the expression of these antigens on the immunocompetent cells. In this paper we study the expression of HLA-DR/DP and HLA-DQ antigens on monocytes from healthy human elderly donors. Results show that peripheral blood monocytes from elderly subjects express decreased levels of HLA-DR/DP antigens (61.5 + 16.3) when compared to young controls (82.5 + 8.5) and increased levels of HLA-DQ antigens (40.4 + 16.8 and 23.6 + 7.1, respectively). The abnormal levels of expression of HLA-class II molecules could be related to the altered immune functions observed in elderly people.


Subject(s)
Aging/immunology , Histocompatibility Antigens Class II/blood , Monocytes/immunology , Aged , Aged, 80 and over , Female , HLA-DP Antigens/blood , HLA-DQ Antigens/blood , HLA-DR Antigens/blood , Humans , Male
11.
Br J Radiol ; 67(800): 770-4, 1994 Aug.
Article in English | MEDLINE | ID: mdl-8087482

ABSTRACT

Radiolabelled human polyclonal immunoglobulin G (IgG) has been successful in identifying inflammatory/infectious processes in human and animal models. We studied 71 patients with suspicion of inflammation of varied origin and location (44 of musculoskeletal location and 27 other) using 99Tcm. IgG images correctly identified 21/22 inflammatory sites of musculoskeletal origin and only 4/14 sites of soft-tissue location. Five false negative studies corresponded to granulomatous processes, three of them tuberculosis. Four false positive studies were obtained in the musculoskeletal group corresponding to three synovial tumours and a Charcot joint. No false positive results were seen in the soft tissue group. 99Tcm-IgG performs well in the identification of bone-joint lesions and rules out non-inflammatory conditions (with the important exception of tumours). The role of 99Tcm-IgG in soft-tissue inflammatory sites, especially in highly vascular organs is inferior, with a high yield of false negative studies. Granulomatous lesions probably represent situations of low or absent IgG uptake.


Subject(s)
Immunoglobulin G , Immunoglobulins , Inflammation/diagnostic imaging , Musculoskeletal Diseases/diagnostic imaging , Technetium , Adolescent , Adult , Aged , Arthritis, Reactive/diagnostic imaging , Child , Child, Preschool , Female , Humans , Knee Joint/diagnostic imaging , Male , Middle Aged , Predictive Value of Tests , Radionuclide Imaging , Sacroiliac Joint/diagnostic imaging
12.
Rev Esp Cardiol ; 51 Suppl 2: 71-8, 1998.
Article in Spanish | MEDLINE | ID: mdl-9658952

ABSTRACT

Infective endocarditis is a life-threatening infective complication in parenteral drug abusers. The tricuspid valve is the structure most frequently affected and Staphylococcus aureus the predominant microorganism. Fever, multiple pulmonary emboli and sustained bacteremia by S. aureus are signs of clinical alert for right-sided endocarditis in these patients. Echocardiography has developed a significant improvement in diagnosis and the transthoracic mode has a considerable reliability when high suspicion is established. Outcome is usually favourable with mortality less than 10%. Recent studies have made shorter treatments possible in selected patients and oral therapy is also considered. HIV infection, in advanced status, may indicate a worse survival rate.


Subject(s)
Endocarditis, Bacterial/etiology , HIV Infections/complications , Substance Abuse, Intravenous/complications , Anti-Bacterial Agents/therapeutic use , Clinical Trials as Topic , Endocarditis, Bacterial/diagnosis , Endocarditis, Bacterial/drug therapy , Humans , Multicenter Studies as Topic , Odds Ratio , Prognosis , Risk Factors
13.
Radiat Prot Dosimetry ; 162(1-2): 58-62, 2014 Nov.
Article in English | MEDLINE | ID: mdl-25013034

ABSTRACT

Indoor radon mapping still represents a valuable tool for drawing the picture of the exposure of general public due to radon and radon progeny inhalation in a residential context. The information provided by means of a map is useful not only as awareness and strategic element for authorities and policy-makers, but also as a scientific start-up point in the design of epidemiological and other specific studies on exposure to natural radiation. The requirements for a good mapping are related to harmonisation criteria coming from European recommendations, as well as to national/local characteristics and necessities. Around 12,000 indoor radon measurements have been made since the Spanish national radon programme began at the end of the 1980s. A significant proportion of them resulted from the last campaign performed from 2009 to 12. This campaign completed the first version of a map based on a grid 10 × 10 km(2). In this paper, the authors present the main results of a new map together with the criteria adopted to improve the number of measurements and the statistical significance of them.


Subject(s)
Air Pollutants, Radioactive/analysis , Air Pollution, Indoor/analysis , Radiation Monitoring , Radiation Protection , Radon/analysis , Housing , Humans , Spain
14.
Radiat Prot Dosimetry ; 155(4): 459-66, 2013 Aug.
Article in English | MEDLINE | ID: mdl-23413092

ABSTRACT

The last nuclear accident in Fukushima nuclear power plant has increased the necessity for measuring radiation in the environment. Therefore, radiation monitors providing results traceable throughout the country become essential and it is very important to test them under the same environmental conditions. The first intercomparison of natural radioactivity under field conditions was held in Saelices el Chico (Salamanca, Spain) in May 2011, including an exercise on environmental dose rate. This article presents the results achieved by 19 instruments belonging to 12 institutions from 7 different countries. The tested detectors are proportional counters, ionisation chambers, Geiger-Müller and scintillators measuring dose rate in three stations with reference values from 110 to 1800 nGy h(-1). All the results were given in terms of air kerma (nGy h(-1)) and the measurements show agreement within 25 % in all the sites. Evaluation criteria based on accuracy and statistical uncertainty were also carried out and 25 % of participants passed the test in all sites.


Subject(s)
Environmental Monitoring/methods , Gamma Rays , Radiation Monitoring/methods , Air Pollution, Radioactive , Background Radiation , Calibration , Congresses as Topic , Internationality , Nuclear Power Plants , Photons , Radiation Dosage , Radioactive Hazard Release , Reference Values , Reproducibility of Results , Risk Assessment , Scintillation Counting/methods , Soil Pollutants, Radioactive/analysis , Spain , Temperature , Universities
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