Gluon polarization tensor and dispersion relation in a weakly magnetized medium

We study the polarization and dispersion properties of gluons moving within a weakly magnetized background at one-loop order. To this end, we show two alternative derivations of the charged fermion propagator in the weak field expansion and use this expression to compute the lowest order magnetic field correction to the gluon polarization tensor. We explicitly show that, in spite of its cumbersome appearance, the gluon polarization tensor is transverse as required by gauge invariance. We also show that none of the three polarization modes develops a magnetic mass and that gluons propagate along the light cone, non withstanding that Lorentz invariance is lost due to the presence of the magnetic field. By comparing with the expression for the gluon polarization tensor valid to all orders in the magnetic field, the existence of a second solution, corresponding to a finite gluon mass, is shown to be spurious and an artifact of the lowest order approximation in the field strength. We also study the strength of the polarization modes for real gluons. We conclude that, provided the spurious solutions are discarded, the lowest order approximation to the gluon polarization and dispersion properties is good as long as the field strength is small compared to the loop fermion mass.Comment: 14 pages, 6 figures. Ref.[35] was adde

Organizing health care: an ethical perspective

Indexación: Web of Science; Scielo.Health Care at population level is a complex problem. Having this in mind, the purpose of this paper is to focus on the goods that are ethically relevant in the process of caring for health at this level. We briefly analyze some of the Chilean health statistics that, although they show important improvements along the years, demonstrate that certain conditions are to be deemed as inadequate by both healthcare providers and patients. Ethics is a central component to determine how to structure and organize health care systems and how they should operate. We emphasize Human Dignity as an ethical corner stone of the Health Care System, along with other important values such as Justice and Humanization, under the scope of the Ends of Medicine, and other components such as technical competence of providers and the financing of the whole process. We conclude that as far as a health care system is organized in a way that medical practice is well ordered, primarily and fundamentally according the Ends of Medicine and the good of persons, such a health care system is ethically adequate.http://ref.scielo.org/9bt3z

Algunas amenazas actuales a la confidencialidad en medicina

Social, technical and legal conditions of the current practice of medicine make it necessary to insist on certain actions and circumstances that may jeopardize the confidentiality of information, offered by patients to their health providers. Therefore, some effects of the current Chilean law are analyzed in this respect, regarding access to data from the clinical record of a patient. Also, the risks of putting certain data on social networking sites are analyzed, as well as some of its effects on clinical practice. The reasons because of mandatory reporting of diseases, meaning danger to public health, is allowed, are mentioned. We also discuss the difficulties involved in managing the results of preventative health screenings and its knowledge by third parties, as well as some possible violations of personal privacy, regarding dissemination of some people health information and its further mention or figuration in mass media. We conclude that it is a must for both physicians and other health team members, to safeguard confidentiality of data to which they have had access, as well as the need to know the relevant law, in order to respect human dignity of patients, each one as a person. We address the attention to the possibility that, practicing in a different way, it could endanger the reliability of clinical records, also impairing the quality of people’s health care. (Rev Med Chile 2015; 143: 358-366) Key words: Access to Information; Confidentiality; Information Dissemination; Medical Records; Social Networkin

Respecting patient intimacy

Indexación: Web of Science; Scielo.Transparency as a general rule for all our professional acts casts doubts about the statement of the Hippocratic Oath that says "Whatever I see or hear in the lives of my patients, I will keep secret, as considering all such things to be private". Medical secrecy protects the intimacy of patients, who reveal to their physicians their most hidden secrets aiming to recover their health. Therefore, physicians should receive those secrets with reverence and care, as servers and not as their owners. The values associated with the respect for personal intimacy are the anthropological basis of medical confidentiality. A medical act is performed by definition between two equally honorable individuals. Therefore, the professional honors the trust of his patient, maintaining strict confidence of what is revealed. Therefore, medical secrecy must be strengthened rather than weakened, pursuing common wealth and dignity.http://ref.scielo.org/cf3mx

An ethical and medical perspective on the voluntary termination of pregnancy

Indexación: Web of Science; Scielo.“Voluntary termination of pregnancy” can refer to actions intended to make a delivery easier, to provide medical care to the fetus, or to protect the life or health of the mother. All of these are proper medical actions and are by definition voluntary. In other cases, the expression denotes a termination of pregnancy before the embryo or fetus is viable, leading to the death of the latter. This action is constitutive of abortion under current Chilean law. The product of conception living being, who develops in the womb during pregnancy, is an individual, both in the sense that it is different from its mother and father, and in that it is a biological individual. For these reasons, such living being constitutes another patient in itself. The free and voluntary medical action of health care professionals is geared toward disease prevention or health recovery and medical terminations of pregnancy, as distinguished from abortion, are not criminalized in our country. Therefore, the idea of legalizing abortive terminations of pregnancy so that they become “legitimate health care services” is a call to the medical community, which should engage in a debate about the meaning and consequences of an eventual mandate of the State that would be at odds with the Hippocratic tradition. A woman can feel that her health is at risk due to her pregnancy, and she certainly has the right to request medical help. Health professionals should care both at the medical and emotional level for all those who require their services, especially when such persons are undergoing situations of vulnerability and distress. When requested to perform an abortion, the physician faces dilemmas that should be addressed in line with the present state of the medical art.http://ref.scielo.org/c4ypf

Experimental Granulomatous Pulmonary Nocardiosis in BALB/C Mice

Pulmonary nocardiosis is a granulomatous disease with high mortality that affects both immunosuppressed and immunocompetent patients. The mechanisms leading to the establishment and progression of the infection are currently unknown. An animal model to study these mechanisms is sorely needed. We report the first in vivo model of granulomatous pulmonary nocardiosis that closely resembles human pathology. BALB/c mice infected intranasally with two different doses of GFP-expressing Nocardia brasiliensis ATCC700358 (NbGFP), develop weight loss and pulmonary granulomas. Mice infected with 109 CFUs progressed towards death within a week while mice infected with 108 CFUs died after five to six months. Histological examination of the lungs revealed that both the higher and lower doses of NbGFP induced granulomas with NbGFP clearly identifiable at the center of the lesions. Mice exposed to 108 CFUs and subsequently to 109 CFUs were not protected against disease severity but had less granulomas suggesting some degree of protection. Attempts to identify a cellular target for the infection were unsuccessful but we found that bacterial microcolonies in the suspension used to infect mice were responsible for the establishment of the disease. Small microcolonies of NbGFP, incompatible with nocardial doubling times starting from unicellular organisms, were identified in the lung as early as six hours after infection. Mice infected with highly purified unicellular preparations of NbGFP did not develop granulomas despite showing weight loss. Finally, intranasal delivery of nocardial microcolonies was enough for mice to develop granulomas with minimal weight loss. Taken together these results show that Nocardia brasiliensis microcolonies are both necessary and sufficient for the development of granulomatous pulmonary nocardiosis in mice

Morphological characteristics of okra fruits [Abelmoschus esculentus (L.) Moench.] cultivated in the dry tropic

Objective: The objective was to evaluate the morphological characteristics of okra fruits [Abelmoschus esculentus (L.) Moench.], in the dry tropics, a crop endemic to the Afro-Mexican region. Design / Methodology / Approach: The material was collected in Cuajinicuilapa, Guerrero, Mexico. By means of a Random Complete Design (RCD), 4 repetitions of 100 fruits were selected, each one; it was evaluated: weight, number, size and shape of fruits and seeds. The data were analyzed with the procedure of Central Tendency Measurements, using SAS. Results: The fruits are heterogeneous and some are deformed, have an elongated and grooved shape, with an average weight of 10.4 g and 95 seeds of 0.05 g each; they are round with the conical microphile, the dark gray head and the white embryo. Study limitations / implications: The morphological characteristics of the okra fruit should continue to be studied with more time and established crops to broaden the panorama of decisions. Findings / conclusions: Backyard okra fruits have quality and potential for fresh or processed consumption. There is a lack of management and improvement of the crop.Objective: The objective was to evaluate the morphological characteristics of okra fruit[Abelmoschus esculentus (L.) Moench.], an endemic crop of the Afro-Mexican region, inthe dry tropics.Design/Methodology/Approach: Materials were collected in Cuajinicuilapa, in thestate of Guerrero in Mexico. Using a completely randomized design (CRD), 4 repetitionsof 100 fruits were selected, and each was evaluated for the following: weight, number,size and shape of fruits and seeds. Data were analyzed using measures of centraltendency, utilizing SAS.Results: The fruits are heterogeneous and some are deformed, they have a long andfluted shape, with an average weight of 10.4 g and 95 seeds each weighing 0.05 g. Theseeds are round with a conical micropyle, the testa is dark grey, and the embryo white.Study Limitations/Implications: It is necessary to keep studying the morphologicalcharacteristics of okra fruit for a longer period of time and to establish farming in orderto widen the outlook of decision making. Findings/Conclusions: Okra fruits from backyard farming have better quality andpotential for fresh or processed consumption. There is a lack of management andimprovement of this crop

Eficacia y seguridad de la técnica coplanar en comparación con las técnicas de derotación convencional para la corrección quirúrgica de deformidades de la columna vertebral: una evaluación de tecnología sanitaria en niños, jóvenes y adultos

A health technology assessment (HTA) was carried out to critically analyze the evidence on the efficacy and safety of the surgical correction of spinal deformities using the coplanar technique, compared to the conventional derotation techniques, in children, adolescents and adults. A systematic search of the literature was carried out in the PubMed, Cochrane Library and LILACS databases. In addition, a manual search was carried out in the reference lists of the included studies, on Google and on the websites of specialized societies and groups that produce clinical practice guidelines (CPG) and HTA. In addition, we searched ClinicalTrials.gov and the International Clinical Trial Registry Platform (ICTRP) for clinical trial records in progress or not completed. Five documents were selected for evaluation, including two CPG, a randomized clinical trial, and two observational studies. After a critical evaluation of the evidence, it was concluded that both techniques showed a similar efficacy profile in terms of relevant outcomes such as correction of curvatures in the coronal and sagittal planes, quality of life and surgical time. Likewise, the rates of screw malposition, complications and volume of blood loss did not show significant differences between both techniques. However, the profile of  opportunity cost of the systems that allow the application of the coplanar technique is not favorable in the context of the evaluation, due to its high cost concerning conventional systems.Se realizó una evaluación de tecnología sanitaria (ETS) con el objetivo de analizar críticamente la evidencia sobre la eficacia y seguridad de la corrección quirúrgica de las deformidades de la columna vertebral con el uso de la técnica coplanar, en comparación con la técnica de derotación convencional, en pacientes niños, jóvenes y adultos. Se llevó a cabo una búsqueda sistemática de la evidencia en las bases de datos de PubMed, Cochrane Library y LILACS. Además, se realizó una búsqueda manual en las listas de referencias de los estudios incluidos, así como, en Google y páginas web de sociedades especializadas y grupos que realizan guías de práctica clínica (GPC) y ETS. Adicionalmente, se buscó registros de estudios clínicos en ejecución o aún no terminados en ClinicalTrials.gov y el International Clinical Trial Registry Platform (ICTRP). Se seleccionaron cinco documentos para evaluación, incluyendo dos GPC, un ensayo clínico aleatorizado y dos estudios observacionales. Luego de la evaluación crítica de la evidencia, se concluyó que, ambas técnicas mostraron un perfil de eficacia similar en cuanto a desenlaces de relevancia como corrección de curvaturas en el plano coronal, sagital, calidad de vida y tiempo quirúrgico. Asimismo, las tasas de malposición de tornillos, complicaciones y volumen de pérdida sanguínea no mostraron diferencias significativas entre ambas técnicas. Sin embargo, el perfil de costo de oportunidad de los sistemas que permiten la aplicación de la técnica coplanar no es favorable en el contexto de la evaluación, debido a su alto costo en relación con los sistemas convencionales

The Linkages Between Photosynthesis, Productivity, Growth and Biomass in Lowland Amazonian Forests

Understanding the relationship between photosynthesis, net primary productivity and growth in forest ecosystems is key to understanding how these ecosystems will respond to global anthropogenic change, yet the linkages among these components are rarely explored in detail. We provide the first comprehensive description of the productivity, respiration and carbon allocation of contrasting lowland Amazonian forests spanning gradients in seasonal water deficit and soil fertility. Using the largest data set assembled to date, ten sites in three countries all studied with a standardized methodology, we find that (i) gross primary productivity (GPP) has a simple relationship with seasonal water deficit, but that (ii) site-to-site variations in GPP have little power in explaining site-to-site spatial variations in net primary productivity (NPP) or growth because of concomitant changes in carbon use efficiency (CUE), and conversely, the woody growth rate of a tropical forest is a very poor proxy for its productivity. Moreover, (iii) spatial patterns of biomass are much more driven by patterns of residence times (i.e. tree mortality rates) than by spatial variation in productivity or tree growth. Current theory and models of tropical forest carbon cycling under projected scenarios of global atmospheric change can benefit from advancing beyond a focus on GPP. By improving our understanding of poorly understood processes such as CUE, NPP allocation and biomass turnover times, we can provide more complete and mechanistic approaches to linking climate and tropical forest carbon cycling

The SlCBL10 calcineurin B-like protein ensures plant growth under salt stress by regulating Na+ and Ca2+ homeostasis

[EN] Characterization of a new tomato (Solanum lycopersicum) T-DNA mutant allowed for the isolation of the CALCINEURIN B-LIKE PROTEIN 10 (SlCBL10) gene whose lack of function was responsible for the severe alterations observed in the shoot apex and reproductive organs under salinity conditions. Physiological studies proved that SlCBL10 gene is required to maintain a proper low Na+/Ca2+ ratio in growing tissues allowing tomato growth under salt stress. Expression analysis of the main responsible genes for Na+ compartmentalization (i.e. Na+/H+ EXCHANGERs, SALT OVERLY SENSITIVE, HIGH-AFFINITY K+ TRANSPORTER 1; 2, H+-pyrophosphatase AVP1 [SlAVP1] and V-ATPase [SlVHA-A1]) supported a reduced capacity to accumulate Na+ in Slcbl10 mutant leaves, which resulted in a lower uploading of Na+ from xylem, allowing the toxic ion to reach apex and flowers. Likewise, the tomato CATION EXCHANGER 1 and TWO-PORE CHANNEL 1 (SlTPC1), key genes for Ca2+ fluxes to the vacuole, showed abnormal expression in Slcbl10 plants indicating an impaired Ca2+ release from vacuole. Additionally, complementation assay revealed that SlCBL10 is a true ortholog of the Arabidopsis (Arabidopsis thaliana) CBL10 gene, supporting that the essential function of CBL10 is conserved in Arabidopsis and tomato. Together, the findings obtained in this study provide new insights into the function of SlCBL10 in salt stress tolerance. Thus, it is proposed that SlCBL10 mediates salt tolerance by regulating Na+ and Ca2+ fluxes in the vacuole, cooperating with the vacuolar cation channel SlTPC1 and the two vacuolar H+-pumps, SlAVP1 and SlVHA-A1, which in turn are revealed as potential targets of SlCBL10.This study was supported by grants from the Plant KBBE Program (EUI2009-04074), the Spanish Ministerio de Economia y Competitividad (AGL2012-40150, AGL2015-64991-C3-1-R/2-R/3-R, and BIO2016-79187-R), as well as the French National Research Agency ENDOREPIGEN project. A.O.-A. was supported by a PhD fellowship from the Ministerio de Economia y Competitividad (BIO2009-11484).Egea, I.; Pineda Chaza, BJ.; Ortiz Atienza, A.; Plasencia, F.; Drevensek, S.; García Sogo, B.; Yuste-Lisbona, FJ.... (2018). The SlCBL10 calcineurin B-like protein ensures plant growth under salt stress by regulating Na+ and Ca2+ homeostasis. PLANT PHYSIOLOGY. 176(2):1676-1693. https://doi.org/10.1104/pp.17.01605S16761693176