Search

Introduction: Low back pain is a common problem affecting millions worldwide. Even after surgical treatment some patients do not improve; others suffer from persistent radiculopathy. We define Complex Chronic Low Back Pain (CCLBP) as any low back pain that has lasted for at least three months and has at least two triggering pain mechanisms. Objective: To describe our experience with plateletrich plasma (PRP) therapy in managing CCLBP with a neuropathic component Methods: Quantitative, retrospective analysis from 57 medical records of patients treated with PRP for CCLBP. We used IBMSPSS 21 to obtain descriptive statistics, Chi-square, Student T and Odds-Ratio. Results: The mean age of our sample was 59.8 (±14.4) years, with 6.51 (±8.7) years of pain and a follow-up of 9 (±12.2) months. 33.3% had lumbar surgery, 29.8% had lumbar trauma, 31.6% used a walking aid, 56.7% had MODIC changes on MRI, and 42% of them received intraosseous-PRP technic. 84.2% reported severe pain (VAS 8-10). The results showed that 96.5% of patients experienced some improvement after PRP treatment. Additionally, 10.5% experienced pain suppression. No significant differences in age, lumbar trauma, lumbar surgery, diseases, or the use of walking aids between patients who benefited from PRP treatment and those who did not. VAS after treatment shows significance (p<0.01) with 5.36±2.6 points. Subjects with less than five years of radicular pain had an improvement greater than 3 points on VAS (OR 7.38, IC95% 1.72-31.7). Conclusion: Autologous platelet-rich plasma injections for chronic low back pain with a neuropathic component are an effective alternative to address CCLBP's current challenge. New studies with greater statistical power are necessary to make a statement of efficacy, but with the data obtained, it seems a promising option. [ABSTRACT FROM AUTHOR]

Forecasts about the effects of new technologies on labor demand are generally pessimistic. However, little is known about the current level of technology adoption and its effect on labor demand, particularly in developing countries. This paper exploits a national representative employer survey and administrative data from Peru to offer empirical evidence in this regard. Our results show that the adoption of new technologies by firms is still incipient in the country. However, when adopted, they slightly reduce the demand for workers in the medium term, particularly those in high-skilled and non-routine occupations, with a temporary job contract, and during the COVID-19 pandemic. [ABSTRACT FROM AUTHOR]

Is terrorism just another form of criminal activity, as many nations' justice systems assume? We offer an initial answer using face-to-face interviews and structured surveys in thirty-five Spanish prisons. Recent theories of extreme sacrifice inform this direct observational and comparative study. Islamist terrorists display levels of self-sacrifice for their primary reference group similar to that of Latino gangs, but greater willingness to sacrifice for primary values than other inmates (non-radical Muslims, Latino gangs, and delinquent bands). This disposition is motivated by stronger perceived injustice, discrimination, and a visceral commitment to such values (risk/radicalization factors). Nevertheless, state authorities, prison staff, and families are (protective/de-radicalization) factors apt to reduce willingness to sacrifice and keep foreign fighters, now being released in large numbers, from returning to terrorism. [ABSTRACT FROM AUTHOR]

This paper studies the role of cognitive skills, socioemotional skills, aspirations and expectations on the likelihood of being NEET (not in education, employment or training) using a novel sample of 15 to 24 year old residents of seven Latin American and Caribbean countries. After controlling for sociodemographic household conditions, we find that numeracy and literacy skills, core self‐evaluation, extraversion and educational aspirations are robust correlates of being NEET. We also find cross country heterogeneity. That is, in some countries, passion and perseverance for long‐term goals, neuroticism and labour market information biases are additional factors associated with being NEET. © 2020 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Despite its low nutrient concentration, the high amount of biomass accumulated in the tree stem makes it an important nutrient sink. Hence, nutrient loss through timber removal at harvesting is a major cause of nutrient impoverishment at some forest sites. The present study was designed to test the following hypotheses: (a) nutrient allocation in the different tree tissues would be affected by (re)translocation processes related with leaf senescence; hence, (b) timber may have a higher nutrient concentration during the defoliated period (in deciduous species); and consequently, (c) modifying harvesting time could influence nutrient export. To test these hypotheses, the present study analyzes the intra-annual dynamics of foliar and trunk nutrient concentration in a planted teak (Tectona grandis L.f.) forest in Costa Rica. Samples from nine trees were taken at nine sampling times between June 2012 and August 2013. The results confirm the above-mentioned hypotheses and reveal that modifying harvesting time have different consequences: (1) when harvesting occurs between August and October, it reduces the N-P-K exported through timber harvesting by 24-29-43%; (2) when harvesting occurs in December, the reduction is 28-29-14%. Harvesting between August and October (rainy season) may involve logistical difficulties. Harvesting slightly earlier than usual (i.e., December, just after the rainy season but before leaf senescence) would therefore be an efficient approach to reducing nutrient export through timber extraction. [ABSTRACT FROM AUTHOR]

Vochysia guatemalensis Donn. Smith is a native species commonly used in small-scale reforestation programs in Costa Rica recognized for its fast growth under acidic and unfertile soil conditions. This study aimed to evaluate the nutrient concentration dynamics on individual trees of V. guatemalensis of increasing ages, in order to improve the understanding some aspects of its ecology as well as management of this tree species. Nutrient (N, P, K, Ca, Mg, S, Fe, Mn, Cu, Zn, and B) and Al concentration in stems, branches and foliage were measured using false time series (also known as chronosequences) in 13 different tree stands (2-21 years) found in the Caribbean lowlands of Costa Rica. N, K and S concentrations in the stems showed a significant inverse relationship with DBH; while P, S, and Cu foliar contents increased with DBH. Average foliar concentrations of N, Ca, K, Mg, Fe, Zn, Mn, B, and Al showed little or no variation with tree growth. Foliar Al concentration (21, 297-28, 826 mg kg) was higher than previously reported as toxic for non-Al accumulating species (<1000 mg kg), confirming V. guatemalensis as an Al hyper accumulator. Our results reinforce the possibility of using V. guatemalensis for timber production, especially to improve the income of small farmers farming on very acidic soils. The nutrient concentrations that were obtained for different tree components provide baseline information for further studies where the objective is to evaluate the nutritional status of a site. [ABSTRACT FROM AUTHOR]

Copyright of World Journal of Emergency Surgery is the property of BioMed Central and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study aims at assessing the nutrient sustainability of highly productive teak plantations in Central America by analyzing the nutrient accumulation dynamics at different ages and the allocation patterns throughout a rotation period. Three teak plantations (28 stands of different ages) were selected in Costa Rica and Panama, and nutrient and biomass accumulation and allocation in different tree components (bole, bark, branches and foliage) were measured in the best performing trees between 1 and 19 years of age. A stand of 150 teak trees ha-1 at age 19 would accumulate (kg ha-1) 405 N, 661 Ca, 182 K, 111 Mg, 33 P, 53 S, 9 Fe, 0.47 Mn, 0.22 Cu, 0.92 Zn, 1 B; whereas the expected nutrient export by timber harvest (bole and bark) is (kg ha-1) 220 N, 281 Ca, 88 K, 63 Mg, 23 P, 39 S, 6 Fe, 0.13 Mn, 0.10 Cu, 0.21 Zn, 0.40 B. Our results suggest that teak nutrition should pay special attention to N and K, the nutrients most accumulated by teak along with Ca. In addition, P and B could also be limiting the productivity of planted teak stands due to their general soil deficiencies. Proposed models estimate the amount of nutrients removed from the site during timber harvests, information that can be used by plantation managers to avoid soil nutrient depletion, approaching sustainability in forest plantation management. [ABSTRACT FROM AUTHOR]

The design of fertilization plans to cover large areas is complex, due to the considerable number of soil samples and soil fertility variables that must be taken into account. Classifying forest stands in groups according to their soil fertility (i.e. in nutrient management areas) can be very helpful to this respect and it is considered to be a first step in what has been called precision forestry. For this paper, we explore the capability of multivariate analyses of topsoil data to be used as tools for evaluating and classifying soil fertility. A case study from a teak ( Tectona grandis L.f.) plantation in Costa Rica was used to evaluate and illustrate how to use multivariate analysis with these aims. A topsoil (0-20 cm) database with soil test results assembled by Panamerican Woods Ltd. was used. Different multivariate techniques [Principal Component Analysis, Non-metric Multidimensional Scaling (NMDS), Cluster analysis] were performed and compared. Cluster analysis resulted as an appropriate tool for grouping soil samples into soil fertility classes. Therefore, it is considered as a promising tool which would help to design a fertilization program to meet the specific needs of each group of stands with relatively homogeneous soil fertility properties. NMDS is also a suitable complementary tool to graphically explore the similarities within groups and the differences between them. The application of procedures similar to those being reported may help to optimize the design of nutritional and fertilization plans across large forest plantations, by using multivariate analysis to establish fertilization regimes that are appropriate to groups of stands of more homogeneous soil fertility. [ABSTRACT FROM AUTHOR]