Depression: an individual-level early warning indicator of virologic failure in HIV patients in South Africa.

OBJECTIVE: To identify individual-level early warning indicators of virologic failure in HIV patients receiving antiretroviral therapy (ART) in South Africa. DESIGN: A matched case-control study of individuals with and without virologic failure (VF) (>5 months on ART and HIV-1 plasma viral load >1,000 copies/mL) was conducted between June 2014 and June 2018. Of the 1,000 participants enrolled in the parent cohort, 96 experienced VF, and 199 additional controls were identified from the parent cohort and matched 1:2 (some matched 1:3) for sex, age, ART duration, and site. Participants were interviewed while clinical, pharmacy refill, laboratory, and objective pharmacological data were obtained. Multivariate conditional logistic regression models were constructed using model selection to identify factors associated with VF. Significant determinants of VF were identified using an alpha level of 0.05. RESULTS: In a full conditional model, higher cumulative ART adherence, quantified using tenofovir-diphosphate concentrations in dried blood spots (OR 0.26) and medication possession ratio (OR 0.98) were protective against VF, whereas an increase in total depression score (OR 1.20) was predictive of VF. CONCLUSION: This analysis demonstrates the importance of depression as a key individual-level early warning indicator of VF. Efforts to address mental health concerns among patients with people living with HIV could improve virologic suppression.

OBJECTIF: Identifier les indicateurs d'alerte précoce au niveau individuel de l'échec virologique chez les patients séropositifs recevant un traitement antirétroviral (TAR) en Afrique du Sud. MÉTHODE: Une étude cas-témoins appariée de personnes avec et sans échec virologique (FV, pour l'anglais « virologic failure ¼) (>5 mois sous ART et charge virale plasmatique du VIH-1 >1 000 copies/ml) a été menée entre juin 2014 et juin 2018. Sur les 1 000 participants inscrits dans la cohorte parente, 96 ont présenté une FV et 199 témoins supplémentaires ont été identifiés dans la cohorte parentale et appariés 1:2 (certains appariés 1:3) pour le sexe, l'âge, la durée du TAR et le site. Les participants ont été interrogés pendant que des données cliniques, de renouvellement de pharmacie, de laboratoire et pharmacologiques objectives ont été obtenues. Des modèles de régression logistique conditionnelle multivariée ont été construits à l'aide d'une sélection de modèles pour identifier les facteurs associés à la FV. Les déterminants significatifs de la FV ont été identifiés à l'aide d'un niveau alpha de 0,05. RÉSULTATS: Dans un modèle conditionnel complet, une observance cumulative plus élevée du TAR, quantifiée à l'aide des concentrations de ténofovir-diphosphate dans les gouttes de sang séché (OR 0,26) et du ratio de possession de médicaments (OR 0,98) protégeait contre la FV, tandis qu'une augmentation du score de dépression totale (OR 1,20) était prédictive de la FV. CONCLUSION: Cette analyse démontre l'importance de la dépression en tant qu'indicateur précoce clé au niveau individuel de la FV. Les efforts visant à résoudre les problèmes de santé mentale chez les personnes vivant avec le VIH pourraient améliorer la suppression virologique.

Prevalence and characteristics of anemia in patients with diabetes mellitus aged 50 or older in health unit area of Cadiz (Spain).

BACKGROUND: Anemia is a common comorbidity in patients with diabetes mellitus (DM), particularly in older adults. However, there is a lack of data on the prevalence and the characteristics of anemia in this population in Spain. OBJECTIVE: To describe the prevalence and the characteristics of anemia in patients with DM aged 50 or older (PDM50) in a healthcare district in the province of Cádiz. METHODS: A retrospective cross-sectional study was conducted that included outpatient's laboratory tests (OLT) performed over 30 months at PDM50. RESULTS: The prevalence of anemia was 29.9% (95% CI: 28.7%-31.1%), predominating in women (33.3% vs 26.7%; P < .01), in older people stratified by decades (61.7% in 9th decade vs 12% in 5th decade; P < .01), and in those with kidney disease (44.7% vs 28%; P < .01). Most cases were mild (68.3%), normocytic (78.7%), and hypochromic (52%). Similarly, moderate-to-severe anemia was more frequent in women (39% vs 23%), their prevalence increased with age (45% in the 9th decade vs 24% in the 5th decade), and with the progression of kidney damage, either measured by a decreased glomerular filtration rate (GFR) (49% in G4 vs 25% in G1), or the presence of albuminuria (P < .01). No association was found between DM control, based on glycated hemoglobin (HbA1c), and anemia in either sex (P = .887). CONCLUSION: This study describes a high prevalence of anemia in PDM50, particularly in women, in the most advantageous people and in the presence of kidney disease, even in early stages, highlighting the clinical importance of this coexistence.

Improvement of Magnetic Saturation in Fe3O4@Y2O3:Eu3+ Nanocomposites Through the Manipulation of Eu3+ Activators.

Fe3O4@Y2O3:Eu3+ nanocomposites and Y2O3:Eu3+ nanophosphors were synthesized using the hydrothermal method. Nanocomposites were analyzed using X-ray diffraction (XRD), Rietveld refinements, Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, photoluminescence (PL), vibrating sample magnetometer (VSM), and high-resolution transmission electron microscopy (HRTEM). Nanocomposites exhibit superparamagnetic behavior that improves with Eu3+, resulting in increased magnetic saturation. In contrast to Y2O3:Eu3+ nanophosphors, the Fe3O4@Y2O3:Eu3+ nanocomposites display a distinctive characteristic whereby the photoluminescence intensity increases with a reduced concentration of Eu3+. The requirement of increasing the thickness of the Y2O3:Eu3+ outer layer to achieve improved light emission can be circumvented by solely manipulating the concentration of activators, without compromising the magnetic saturation of the nanocomposites. The luminescent and magnetic characteristics of Fe3O4@Y2O3:Eu3+ nanocomposites can be readily optimized using straightforward synthesis parameters, making them promising candidates for potential applications in theranostic medicine.

Trastornos de la salud mental en personas sometidas a cuarentena, estudio transversal durante pandemia por COVID-19 en población chilena / The effects of quarantine on anxiety and emotional symptoms. Results of an online survey

BACKGROUND: Quarantines may exacerbate the presence of emotional symptoms or anxiety. AIM: To explore the relation between time spent in lockdown and development of depressive and anxiety symptoms. MATERIAL AND METHODS: A survey including the GAD anxiety and PHQ-9 depression scores was answered online by 1,488 subjects aged 36 ± 14 years (74% women), invited to participate through social networks. Both scores are validated for the Chilean population. RESULTS: Most responders had a private health insurance system. Sixty seven percent had clinically significant depressive symptoms and 39% had anxiety symptoms. Spending four or more weeks of lockdown (quarantine) was associated with 1.6 times higher risk of developing depressive symptoms and 2.9 times higher risk of developing anxiety symptoms. Difficulties in access to health care increased 3.3 times the risk of developing depression. Suffering a respiratory disease increased 2.39 times the risk of developing anxiety. CONCLUSIONS: There was a direct association between depressive and anxious symptoms, and the time spent of quarantine.

[The effects of quarantine on anxiety and emotional symptoms. Results of an online survey]. / Trastornos de la salud mental en personas sometidas a cuarentena, estudio transversal durante pandemia por COVID-19 en población chilena.

BACKGROUND: Quarantines may exacerbate the presence of emotional symptoms or anxiety. AIM: To explore the relation between time spent in lockdown and development of depressive and anxiety symptoms. MATERIAL AND METHODS: A survey including the GAD anxiety and PHQ-9 depression scores was answered online by 1,488 subjects aged 36 ± 14 years (74% women), invited to participate through social networks. Both scores are validated for the Chilean population. RESULTS: Most responders had a private health insurance system. Sixty seven percent had clinically significant depressive symptoms and 39% had anxiety symptoms. Spending four or more weeks of lockdown (quarantine) was associated with 1.6 times higher risk of developing depressive symptoms and 2.9 times higher risk of developing anxiety symptoms. Difficulties in access to health care increased 3.3 times the risk of developing depression. Suffering a respiratory disease increased 2.39 times the risk of developing anxiety. CONCLUSIONS: There was a direct association between depressive and anxious symptoms, and the time spent of quarantine.

Osteoarticular manifestations of systemic sclerosis: a systematic review of the literature / Manifestaciones osteoarticulares de esclerosis sistémica: una revisión sistemática de la literatura

ABSTRACT Introduction: Osteoarticular manifestations (OAM) are frequently present in patients with systemic sclerosis (SSc). These OAM are related to important functional disability and a severe impact on patient's life quality, therefore, they require special attention from clinicians. Objective: Determining the frequency of reported OAM in SSc patients, the general impact of osteoarticular manifestations in patient's condition and the tools available for diagnosis and treatment. Methodology: A systematic review of the literature was performed for information published between January 1970 and December 2018 in the medical research databases of: Medline, Embase, Lilacs, Scielo, Cochrane and clinicaltrials.gov. Results and Conclusions: A total of 116 articles were included in this review. The type and prevalence of the different OAM reported in the literature were determined. In addition to the evolution of their diagnostic methods, there are more validated methods to assess the impact of OAM in patients with SSc. Randomized clinical trials are required to establish the best treatment strategy for these patients.

RESUMEN Introducción: Las manifestaciones osteoarticulares (MOA) están presentes de forma frecuente en pacientes con esclerosis sistémica (SSc). Generan gran discapacidad funcional con un impacto importante en la calidad de vida de los pacientes, por lo que requieren especial atención por parte de los clínicos. Objetivos: Determinar la frecuencia de las MOA dentro de la SSc, su impacto en la condición general de los pacientes y las diferentes herramientas disponibles de diagnóstico y tratamiento. Metodología: Se realizó una revisión sistemática de la literatura disponible desde enero de 1970 hasta diciembre de 2018 en las bases de datos de Medline, Embase, Lilacs, Scielo, Cochrane y clinicaltrials.gov. Resultados y conclusiones: Se incluyeron un total de 116 artículos en esta revisión. Se determinaron el tipo y la prevalencia de las diferentes MOA reportadas en la literatura. Además de la evolución en los métodos diagnósticos de las mismas, cada vez existen más métodos validados para evaluar el impacto de las MOA en los pacientes con SSC. Se requieren ensayos clínicos aleatorizados que permitan establecer la mejor estrategia de tratamiento para estos pacientes.

Medical education from the point of view of medical students: Results from four participatory Delphi panels in Quito, Ecuador.

BACKGROUND: Medical curricula have historically been designed in a top-down approach, usually excluding students. While Delphi panels have been used as a tool for medical education curricula design, none have been conducted in Ecuador. In addition, no such approach has ever included students both as panelists and researchers. MATERIAL AND METHODS: Four Delphi panels were developed and conducted using a participatory approach that allowed medical students to take part both as expert panelists and researchers: specifically, students developed the questionnaire and conducted a qualitative synthesis. Questionnaire responses were anonymized and dispatched online to panelists. The information was organized and collected to develop the qualitative syntheses and prepare the final statements. RESULTS: Thirty-two medical students participated between February and May 2018. A total of 32 questions were developed, corresponding to five different categories. For some questions, consensus was reached; for other questions, general statements were obtained.Discussion and conclusion: Developing the questionnaire, responding to it and analyzing the answers allowed students to raise significant concerns regarding medical education topics proposing relevant policy and curricula change. Participatory Delphi panels can be an efficient tool to obtain organized feedback, improve student class involvement, and promote research skills.

Aceptación de la muerte y su deshospitalización / Acceptance of death and its dehospitalisation

INTRODUCCIÓN: La muerte forma parte de la vida. La conciencia de que la muerte es inevitable puede causar trastornos mentales. OBJETIVO: Determinar el nivel de ansiedad frente a la muerte en la gente mayor y su relación con la edad, el género, los aspectos sociales, la actividad física, el ocio, la autoestima, la religión y la enfermedad avanzada. Conocer sus preferencias respecto el lugar donde quieren morir. MATERIAL Y MÉTODO: Estudio observacional transversal. Entrevista estructurada y escala ansiedad frente la muerte Templer a 300 participantes sin diagnóstico de demencia seleccionados aleatoriamente entre población ≥75 años en cuatro centros de atención primaria. RESULTADOS: Un total de 288 entrevistas. Edad media 84,8 (DE: 15,2) años, 147 (51,0%) >85 años y 148 (51,4%) mujeres. El grado de ansiedad media-alta en la DAS fue mayor en las mujeres (50-39,6%; p = 0,030), en los que no realizaban actividad física (68-26,4%; p < 0,001), en los que no hacían actividades de ocio (63,5-41,7%; p = 0,007), en los pacientes con ánimo deprimido (60,4-41,6%; p < 0,008) y en los pacientes sin enfermedad crónica avanzada (48,3-35,8%; p = 0,036). La actividad física redujo 5,3 veces el riesgo de presentar ansiedad media/alta (OR=0,188; p < 0,001) y el cribado positivo para depresión la aumentó 2,9 veces (OR=2,943; p = 0,014). Un total de 255 (88,5%) afirmaron tener miedo a una muerte dolorosa; 177 (61,5%) prefieren morir en casa y 28 (9,7%) en el hospital. CONCLUSIONES: La gente mayor tiene miedo a sufrir una muerte dolorosa, aunque en general presenta niveles medios-bajos de ansiedad frente a ella. El género masculino y realizar actividades físicas/ocio se asocian a niveles más bajos de ansiedad. La enfermedad crónica avanzada produce mayor aceptación de la muerte. Predomina el deseo de morir en casa y deshospitalizar la muerte

INTRODUCTION: Death is part of life. The awareness that death is inevitable could be the cause of mental disorders. OBJECTIVE: To determine the level of death anxiety in old people as regards age, gender, social aspects, physical and leisure activities, self-esteem, religion or advanced disease, as well as their preferences on the place where they want to die. MATERIAL AND METHOD: Cross-sectional observational study. Face-to-face interviews and Death Anxiety Scale (DAS) of Templer on 300 patients over 75 years-old without a diagnosis of dementia, selected randomly in four health centres. RESULTS: A total of 288 surveys were completed. The mean age was 84.8 (15.2) years, and 147 (51.0%) were older than 85 years. The score of medium-high anxiety observed in the DAS was higher in women (50%-39.6%; P=.030), in those who did not perform physical activity (68%-26.4%; P<.001), in those who did not take part in leisure activities (63.5%-41.7%; P=.007), in patients with depressed mood (60.4%-41.6%; P<.008), and in patients without advanced disease (48.3%-3 5.8%; P=.036). The fear of having a painful death was present in 255 (88.5%). Physical activity reduced the risk of medium-high anxiety by 5.3 times (OR=.188, P<.001), and screening positive for depression increased it by 2.9 times (OR=2.943, P=.014). As regards the place where they would prefer to die, 177 (61.5%) answered «at home», and 28 (9.7%) «in the hospital.» CONCLUSIONS: Older people do fear a painful death, but they are not really afraid of dying. Male gender and performing physical or leisure activities is related to low levels of death anxiety. Advanced disease leads to greater acceptance of the end of life. The desire to die at home, and to «dehospitalise» the death prevails

[Acceptance Of Death And Its Dehospitalisation]. / Aceptación de la muerte y su deshospitalización.

INTRODUCTION: Death is part of life. The awareness that death is inevitable could be the cause of mental disorders. OBJECTIVE: To determine the level of death anxiety in old people as regards age, gender, social aspects, physical and leisure activities, self-esteem, religion or advanced disease, as well as their preferences on the place where they want to die. MATERIAL AND METHOD: Cross-sectional observational study. Face-to-face interviews and Death Anxiety Scale (DAS) of Templer on 300 patients over 75years-old without a diagnosis of dementia, selected randomly in four health centres. RESULTS: A total of 288 surveys were completed. The mean age was 84.8 (15.2) years, and 147 (51.0%) were older than 85years. The score of medium-high anxiety observed in the DAS was higher in women (50%-39.6%; P=.030), in those who did not perform physical activity (68%-26.4%; P<.001), in those who did not take part in leisure activities (63.5%-41.7%; P=.007), in patients with depressed mood (60.4%-41.6%; P<.008), and in patients without advanced disease (48.3%-3 5.8%; P=.036). The fear of having a painful death was present in 255 (88.5%). Physical activity reduced the risk of medium-high anxiety by 5.3 times (OR=.188, P<.001), and screening positive for depression increased it by 2.9 times (OR=2.943, P=.014). As regards the place where they would prefer to die, 177 (61.5%) answered «at home¼, and 28 (9.7%) «in the hospital.¼ CONCLUSIONS: Older people do fear a painful death, but they are not really afraid of dying. Male gender and performing physical or leisure activities is related to low levels of death anxiety. Advanced disease leads to greater acceptance of the end of life. The desire to die at home, and to «dehospitalise¼ the death prevails.

COMPARACIÓN DE LA EFECTIVIDAD ENTRE CRIOTERAPIA vs LA COMBINACIÓN DE ÁCIDO SALICÍLICO AL 20% + ÁCIDO LÁCTICO AL 12% PARA EL TRATAMIENTO DE VERRUGAS VULGARES EN NIÑOS Y ADOLESCENTES / A COMPARISON OF THE EFFECTIVENESS BETWEEN CRYOTHERAPY vs A COMBINATION OF 20% SALICYLIC ACID + 12% LACTIC ACID FOR THE TREATMENT OF VULGAR WARTS IN CHILDREN AND ADOLESCENTS

RESUMEN Las verrugas vulgares son neoformaciones cutáneas benignas causadas por el virus del papiloma humano 2 (HPV - 2), pero relacionadas también con los serotipos 1, 4, 7, 26 y 29. Aparecen en particular en la edad infantil, pueden localizarse en cualquier parte del cuerpo, más comúnmente en manos y antebrazos. Existen múltiples tratamientos para este tipo de verrugas, entre ellos: la aplicación de ácido salicílico y la crioterapia, considerados de primera línea; sin embargo, se han realizado pocos estudios que comparen la efectividad de los mismos, motivo por el que se realizó un ensayo clínico controlado abierto aleatorizado, en donde se comparó la efectividad de la aplicación de crioterapia vs la aplicación de una solución de ácido salicílico al 20% + ácido láctico al 12% (AS/AL), para el tratamiento de verrugas vulgares en niños y adolescentes. Se incluyeron en el estudio a 80 pacientes de entre 5 y 16 años, de ambos sexos, que padecían de verrugas vulgares en manos y antebrazos. Los 80 pacientes fueron divididos en dos grupos de 40 integrantes cada uno, un grupo recibió NL por un máximo de 7 sesiones, el otro recibió AS/AL por un período de 4 semanas. Los resultados demostraron que el nitrógeno líquido, es más efectivo que la combinación de ácido salicílico al 20% + ácido láctico al 12%, para el tratamiento de verrugas vulgares en niños y adolescentes. (OR 28,5; IC 6,011-135,121; p 0,000), la media de sesiones necesaria para lograr la curación fue de 2.1 sesiones. Los principales efectos adversos fueron el dolor (chi237.90; p 0,000) y la aparición de ampollas (chi268.83; p 0,000); sin embargo, fueron efectos leves que no necesitaron tratamiento posterior.

SUMMARY Common warts are benign skin neoplasms caused by HPV-2 virus, but also related serotypes 1, 4, 7, 26 and 29; they appear particularly in childhood, can be located anywhere in the body but most common in hands and forearms. There are many treatments for warts, including the application of salicylic acid and liquid nitrogen, considered as first-line treatments, however there are few studies comparing the effectiveness of salicylic acid vs liquid nitrogen, which is why we made a controlled clinical trial comparing the effectiveness of liquid nitrogen vs a solution of salicylic acid 20% + 12% lactic acid for treatment of common warts in children and adolescents. The study included 80 patients between 5 and 16 years of both sexes, who suffer of common warts on hands and forearms. The 80 patients were divided in two groups of 40 members each, one group received liquid nitrogen by a maximum of 7 sessions, and the other received a solution of salicylic acid 20% + 12% lactic acid for a period of 4 weeks. The results showed that liquid nitrogen is more effective than the combination of salicylic acid 20% + 12% lactic acid for the treatment of common warts in children and adolescents (OR28.5, CI 6.011 to 135.121, P 0.000). The mean number of sessions required to achieve healing was 2.1 sessions. The main adverse effects were pain (chi2 37.90, P 0.000) and blisters (chi2 68.83, P 0.000) never the less, the effects were mild and they did not need further treatment.

Quantum Anomaly and Thermodynamics of One-Dimensional Fermions with Three-Body Interactions.

We show that a system of three species of one-dimensional fermions, with an attractive three-body contact interaction, features a scale anomaly directly related to the anomaly of two-dimensional fermions with two-body contact forces. We show, furthermore, that those two cases (and their multispecies generalizations) are the only nonrelativistic systems with contact interactions that display a scale anomaly. While the two-dimensional case is well known and has been under study both experimentally and theoretically for years, the one-dimensional case presented here has remained unexplored. For the latter, we calculate the impact of the anomaly on the equation of state, which appears through the generalization of Tan's contact for three-body forces, and determine the pressure at finite temperature. In addition, we show that the third-order virial coefficient is proportional to the second-order coefficient of the two-dimensional two-body case.

Expanding the field of acute care surgery: a systematic review of the use of resuscitative endovascular balloon occlusion of the aorta (REBOA) in cases of morbidly adherent placenta.

PURPOSE: Prophylactic placement of endovascular balloon occlusion catheters has grown to be part of the surgical plans to control intraoperative hemorrhage in cases of abnormal placentation. We performed a systematic literature review to investigate the safety and effectiveness of the use of REBOA during cesarean delivery in pregnant woman with morbidly adherent placenta. METHODS: A systematic review was performed. Relevant case reports and nonrandomized studies were identified by the literature search in MEDLINE. We included studies involving pregnant woman with diagnosis of abnormal placentation who underwent cesarean delivery with REBOA placed for hemorrhage control. MINORS' criteria were used to evaluate the risk of bias of included studies. A formal meta-analysis was not performed. RESULTS: Eight studies were included in cumulative results. These studies included a total of 392 patients. Overall, REBOA was deployed in 336 patients. Six studies reported the use of REBOA as an adjunct for prophylactic hemorrhage control in pregnant woman with diagnosis of morbidly adherent placenta undergoing elective cesarean delivery. In two studies, REBOA was deployed in patients already in established hemorrhagic shock at the moment of cesarean delivery. REBOA was deployed primarily by interventional radiologists; however, one study reported a surgeon as the REBOA provider. The results from our qualitative synthesis indicate that the use of REBOA during cesarean delivery resulted in less blood loss with a low rate complications occurrence. CONCLUSION: REBOA is a feasible, safe, and effective means of prophylactic and remedial hemorrhage control in pregnant women with abnormal placentation undergoing cesarean delivery.

Giant cross-magnetic-field steps due to binary collisions between pair particles.

Giant cross-magnetic-field steps can occur as a result of positron-electron collisions. Within a constant magnetic field (e.g., 1 T), a collision between a positron and an electron can result in a correlated drift across the magnetic field for a continuous range of impact parameters. Within this range, drift distances orders of magnitude larger than that associated with like-charge collisions were observed by computer simulation. Outside of this range, the collisional behavior is similar to that for collisions between particles with the same charge. A theoretical analysis of the phenomenon using center-of-mass and relative coordinates provides insights regarding the occurrence of giant cross-magnetic-field steps.

Knowledge, attitudes and tobacco use among nursing and physiotherapy students.

BACKGROUND: As future health educators, nursing and physiotherapy students will play an essential role in the prevention of smoking. AIM: To determine the prevalence of smoking among students and to analyse their knowledge of and attitudes towards smoking. METHOD: This was a descriptive cross-sectional study using an anonymous questionnaire and conducted in a Spanish Faculty of Health Sciences in 2013. FINDINGS: 247 nursing and physiotherapy students (82.33%) participated in the study. The global prevalence of smoking (18.2%) was lower compare with the general population group of the same age. We have observed statistical significance in relation to previous studies. Nursing and physiotherapy students showed a low nicotine dependence. We found a lack of knowledge about the harmful effects of cigarette consumption on health. Statistically significant results were also found in relation to degree courses (p < 0.01) as regards students' opinions about their knowledge of strategies and methods to help patients stop smoking. CONCLUSION: Most students started smoking before commencing their university studies; consequently, interventions should focus on cessation programmes. An analysis of university curricula leading to the award of a degree in the health sciences could serve to identify educational deficiencies in order to implement the necessary modifications. IMPLICATIONS FOR NURSING AND HEALTH POLICY: This paper presents an update in tobacco use characteristics amongst nursing and physiotherapy students. Those results have showed a need to improve the curricula in order to develop specific programmes to improve knowledge, attitudes and beliefs. Measures to prevent smoking must be taken at school.

Element enrichment factor calculation using grain-size distribution and functional data regression.

In environmental geochemistry studies it is common practice to normalize element concentrations in order to remove the effect of grain size. Linear regression with respect to a particular grain size or conservative element is a widely used method of normalization. In this paper, the utility of functional linear regression, in which the grain-size curve is the independent variable and the concentration of pollutant the dependent variable, is analyzed and applied to detrital sediment. After implementing functional linear regression and classical linear regression models to normalize and calculate enrichment factors, we concluded that the former regression technique has some advantages over the latter. First, functional linear regression directly considers the grain-size distribution of the samples as the explanatory variable. Second, as the regression coefficients are not constant values but functions depending on the grain size, it is easier to comprehend the relationship between grain size and pollutant concentration. Third, regularization can be introduced into the model in order to establish equilibrium between reliability of the data and smoothness of the solutions.

Origin, patterns and anthropogenic accumulation of potentially toxic elements (PTEs) in surface sediments of the Avilés estuary (Asturias, northern Spain).

Sediment quality has been assessed within the Avilés estuary, an important industrial area in the NW of Spain. The study started with a geochemical characterization of the superficial sediments that revealed some anomalous metal(oid)s concentrations in sensitive areas such as beaches or dunes. These data were studied by means of multivariate statistical techniques and enrichment factors calculation to evaluate the correlations and geochemical origin within the different elements. A novel approach using the combination of enrichment factors with a sequential application of factor analysis, clustering and kriging was essential to identify the possible sources of pollution. The collected information suggested that Cd (strongly correlated with Zn and Pb) was the potentially toxic element most widely distributed and problematic. Furthermore, particulate emissions from Zn metallurgy, as well as dust generated by the mineral loading and stockpile activities in the port were identified as the most important sources of pollution.

Reprogramming of cassava (Manihot esculenta) microspores towards sporophytic development.

Gametes have the unique potential to enter the sporophytic pathway, called androgenesis. The plants produced are usually haploid and recombinant due to the preceding meiosis and they can double their chromosome number to form doubled haploids, which are completely homozygous. Availability of the doubled haploids facilitates mapping the genes of agronomically important traits, shortening the time of the breeding process required to produce new hybrids and homozygous varieties, and saving the time and cost for inbreeding. This study aimed to test the feasibility of using isolated and in vitro cultured immature cassava (Manihot esculenta) microspores to reprogramme and initiate sporophytic development. Different culture media and different concentrations of two ion components (Cu(2+) and Fe(2+)) were tested in two genotypes of cassava. External structural changes, nuclear divisions and cellular changes during reprogramming were analysed by scanning electron microscopy, by staining with 4',6-diamidino-2-phenylindole, and through classical histology and transmission electron microscopy. In two cassava genotypes, different developmental stages of microspores were found to initiate sporophytic cell divisions, that is, with tetrads of TMS 60444 and with mid or late uni-nucleate microspores of SM 1219-9. In the modified NLN medium (NLNS), microspore enlargements were observed. The medium supplemented with either sodium ferrous ethylene-diamine-tetraacetic acid (NaFeEDTA) or CuSO4·5H2O induced sporophytic cell division in both genotypes. A low frequency of the reprogramming and the presence of non-responsive microspores among the responsive ones in tetrads were found to be related to the viability and exine formation of the microspores. The present study clearly demonstrated that reprogramming occurs much faster in isolated microspore culture than in anther culture. This paves the way for the development of an efficient technique for the production of homozygous lines in cassava. This is the first ever detailed report of microspore reprogramming at the tetrad stage and the first report of microspore embryogenesis induction in cassava with detailed evidence.

A milestone in the doubled haploid pathway of cassava: a milestone in the doubled haploid pathway of cassava (Manihot esculenta Crantz): cellular and molecular assessment of anther-derived structures.

This study was aimed at inducing androgenesis in cultured anthers of cassava (Manihot esculenta Crantz) to develop a protocol for the production of doubled haploids. Microspore reprogramming was induced in cassava by cold or heat stress of anthers. Since the anthers contain both haploid microspores and diploid somatic cells, it was essential to verify the origin of anther-derived calli. The origin of anther-derived calli was assessed by morphological screening followed by histological analysis and flow cytometry (FCM). Additionally, simple sequence repeat (SSR) and amplified fragmented length polymorphism (AFLP) assays were used for the molecular identification of the microspore-derived calli. The study clearly demonstrated the feasibility of producing microspore-derived calli using heat- or cold-pretreated anthers. Histological studies revealed reprogramming of the developmental pathway of microspores by symmetrical division of the nucleus. Flow cytometry analysis revealed different ploidy level cell types including haploids, which confirmed their origin from the microspores. The SSR and AFLP marker assays independently confirmed the histological and FCM results of a haploid origin of the calli at the DNA level. The presence of multicellular microspores in the in vitro system indicated a switch of developmental program, which constitutes a crucial step in the design of protocols for the regeneration of microspore-derived embryos and plants. This is the first detailed report of calli, embryos, and abnormal shoots originated from the haploid cells in cassava, leading to the development of a protocol for the production of doubled haploid plants in cassava.

Semen preservation and artificial insemination in domesticated South American camelids.

Semen preservation and artificial insemination in South American camelids are reviewed giving emphasis to work done in Peru and by the authors. Reports on semen evaluation and the preservation process indicate that semen of alpacas and llamas can be manipulated by making it liquid first. Collagenase appears to be the best enzyme to eliminate viscosity. Tris buffer solution maintains a higher motility than egg-yolk citrate, phosphate buffered saline (PBS), Triladyl, and Merck-I extenders. Cooling of semen took 1h after collected, and equilibrated with 7% glycerol presented a better motility and spermatozoa survival at 1, 7, 15 and 30days after being slowly frozen in 0.25mL plastic straws. Trials of artificial insemination with freshly diluted semen and frozen-thawed semen are encouraging and needs to be tested extensively under field conditions. Recently, fertility rates varied from 3 to 67%. Semen preservation and most important, artificial insemination appear to be a reality, and could be used to improve the genetic quality of alpacas and llamas.