Annual patterns of nutrients and chlorophyll in a subtropical coastal lagoon under the upwelling influence (SW of Baja-California Peninsula)

10 páginas, 6 figuras, 1 tablaThe coastal lagoon of Bahía-Magdalena, located on the west coast of the Peninsula of Baja-California, is a subtropical ecosystem with an arid climate and very little freshwater input. During the 2005–2011 period the thermohaline properties varied between cold and warm half-yearly periods. They were influenced by the Transitional Water mass transported by the South California Current from February to July and by the Subtropical Surface Water from August to January. The nutrient concentrations increased (viz up to 16 μM of nitrate) from March to June, when the upwelling index was the highest. Similarly, the inter-annual variation of chlorophyll-a showed a six-monthly pattern with the highest average monthly concentrations being found in June (5 mg m−3in situ or 8 mg m−3 based on satellite information) and the lowest in December–January. A spatial zoning was also observed in the lagoon with a shallow inner zone that is warmer and richer in chlorophyll-a than the deeper closed mouth area. In the Bahía-Magdalena lagoon a spatial-temporal division into two zones and two seasons was repeated year after year with only minor differences. During the first semester in the outer zone, years 2006 and 2007 were colder and nutrient rich while 2010 was warmer, according to the upwelling conditions in the Southern California Region. Hence, among the coastal lagoons that present a prevailing marine influence, the coastal system of Bahía-Magdalena corresponds to an unusual type of subtropical coastal lagoon where the nutrient input is mainly due to upwelling phenomena.his article was supported by the SIP Mexican projects of the Instituto Politécnico Nacional from 2005 to 2011 in cooperation with the Spanish project CTM2011-28792-C02 financed by the ‘Ministerio de Economía y Competitividad’. We are very grateful to the Mexican COFAA (IPN) organism and EDI program for their grants and to the Mexican governmental agency CONACYT for financing the sabbatical (ref. 169030) of Dr. Rafael Cervantes-Duarte at the IIM (CSIC) of Spain during 2012.Peer reviewe

Efecto de la marea en la concentración de nutrientes, clorofila a y parámetros físicos y químicos en una laguna costera subtropical (Bahía Magdalena, México)

Background. Magdalena Bay is a subtropical coastal lagoon of northwestern Mexico with important ecological considerations and numerous fisheries. Knowledge of hydrodynamics and water quality are essential for establishing best management practices for the Bay. Goals. The aim of the study was to analyze the influence of the tide on the variation and transport of nutrients and chlorophyll a between the inner lagoon and the adjacent ocean as a fertilization mechanism in the area. Methods. Samples were obtained in June, August, and November 2005 at a site close to the mouth (24o 57´ N and 112o 03´ W). The samples were obtained every 2 hours during each tidal cycle at three different depths (0, 15, and 30 m). Temperature and salinity were measured using a CTD. Nutrients, chlorophyll a, and oxygen were measured at a laboratory. Results. Three climatic-oceanographic conditions were identified: upwelling (June), stratification (August), and negative effects during the ENSO (November). The correlation between tidal range and other variables was significant (p <0.05) in August, compared to June and November. Conclusions. The transport of net nutrients associated with the tidal cycle depends on the season and the state of the tide and is considered high compared to other smaller systems. This explains the high organic productivity in this coastal region.Antecedentes. Bahía Magdalena es una laguna costera subtropical de alta importancia ecológica y pesquera del noroeste (NO) de México, donde se requiere consolidar el conocimiento de los procesos hidrodinámicos y la calidad de sus aguas para mejorar su aprovechamiento. Objetivos. Analizar la influencia de la marea en la variación y transporte de nutrientes y clorofila a entre la laguna y el océano adyacente como mecanismo de fertilización de la región. Métodos. Se realizaron tres muestreos en junio, agosto y noviembre de 2005 en un sitio aproximadamente a 5 km de la boca (24o 57´ N y 112º 03´ O). Se tomaron muestras cada 2 horas durante cada ciclo de marea para medir nutrientes, clorofila a y oxígeno a tres profundidades (0, 15 y 30 m), así como temperatura y salinidad mediante un CTD. Resultados. Se identificaron tres condiciones climático-oceanográficas: surgencias (junio), estratificación (agosto) y ENSO (El Niño Southern Oscilation) negativo (noviembre). La relación entre amplitud de marea y las variables medidas fue mayor en agosto (p < 0.05) respecto a junio y noviembre. Conclusiones. El transporte neto de nutrientes por ciclo de marea depende de la época del año y el estado de la marea y se considera alto comparado con otros sistemas de menores dimensiones y explica la elevada productividad orgánica en esta región costera

Modelo estacional de producción primaria estimada mediante fluorescencia natural en una región costera del Golfo de California, México

The goal of this research was to study the main factors that control the primary productivity (PP) and integrated primary productivity (PPI) during a seasonal cycle in La Paz bay. We carried out eight cruises between June 2000 and June 2001. At each cruise were recorded the vertical profiling of temperature, light and chlorophyll fluorescence using natural fluorescence equipment (PNF-300) and also were taken discrete samples to determinate nitrate concentration at 6 depths in the euphotic zone (Ze). Using the PNF-300 data set we estimated the PP and PPI. The vertical temperature distribution was stratified between June to September, mixed between November and February. During March and May was considered as a stabilization period. Nitrate concentration 0-70 m were 0.34 to 19.08 µM-NO3. The 3 µM-NO3 isolines variation were useful to characterize the stratification and mixed water conditions in the water column. The PP vertical profiles ranged between 0.01 mg C m-3 h-1 in deepest euphotic zone and 20.57 mg C m-3 h-1 near to the surface. It was confirmed the existence of two seasons in the primary production cycle: high productivity from March to August and low productivity from September to February. Each season mode depends of the light penetration factors and the water column stratification. A lineal model based in the critical depth as a important parameter to explain the seasonal variability of the phytoplankton primary productivity variation.Con el propósito de estudiar los principales factores que controlan la productividad primaria (PP) en la Bahía de La Paz durante un ciclo estacional, se llevaron a cabo 8 muestreos en el periodo de junio del 2000 a junio del 2001. En cada muestreo se realizaron perfiles verticales de temperatura, luz y fluorescencia de la clorofila, mediante un equipo de fluorescencia natural (PNF-300) y se tomaron muestras discretas para análisis de nitratos en 6 profundidades dentro de la zona eufótica (Ze). Las estimaciones de PP y producción primaria integrada (PPI) se hicieron a partir de la información del PNF-300. La distribución vertical de temperatura mostró de junio a septiembre una columna de agua estratificada y de noviembre a febrero una columna bien mezclada. De marzo a mayo pueden ser considerados como meses de estabilización de la columna de agua. Las concentraciones de nitratos de 0 a 70 m variaron de 0.34 a 19.08 µM. El comportamiento espacio temporal de la isolínea de 3 µM-NO3 es un indicador visual útil para seguir las condiciones de estratificación y mezcla en la columna de agua. Los perfiles verticales de PP presentaron un intervalo de variación de 0.01 mg C m-3 h-1 en la parte más profunda a 20.57 mg C m-3 h-1 cerca de la superficie. Se confirmó la existencia de dos épocas en el ciclo estacional de la productividad primaria: de alta productividad de marzoagosto y otra de baja productividad de septiembrefebrero, y cuya estructura depende, entre otros factores, de la variabilidad estacional de la penetración de luz y de la estratificación de la columna de agua. Se presenta un modelo lineal basado en la profundidad crítica como un parámetro importante en la explicación de la variabilidad estacional de la productividad primaria

Comparación de reflectancia in situ 443/555 y 490/555 con Clorofila a y Materia Suspendida Total en Bahía de La Paz, B.C.S., México

Con el propósito de analizar las características bio-ópticas del agua superficial de la Bahía de La Paz y la laguna Ensenada de La Paz se llevaron a cabo muestreos en los meses de junio, septiembre, noviembre de 1997 y enero de 1998. De acuerdo a las características hidrológicas y batimétricas, la bahía se dividió en profunda y somera y la laguna en canal y somera. La distribución de temperatura mostró el patrón típico estacional, mínimas en enero (22.5 °C) y máximas en septiembre (>30 °C). Las concentraciones promedio de clorofila a (Cla) y material suspendido total (MST) fueron menores en la bahía (0.26 a 0.65 mg Cla m-3 y 0.5 a 1.2 g MST m-3) que en la laguna (0.5 2.4 mg Cla m-3 y 0.98 a 5.6 g MST m-3). Asimismo, el coeficiente de atenuación de luz difusa (KdPAR) fue más bajo en la bahía que en la laguna, debido a la menor cantidad de MST y fitoplancton. El mejor ajuste entre reflectancia 443/555 y 490/555 vs. la Cla y MST, respectivamente, fue potencial (A = 0.8023 * B-0.819 y A = 1.2401 * B-0.8011). La concentración de MST vs. KdPAR presentó alta correlación lineal (r2 =0.96), y menor entre Cla vs. KdPAR (r2 =0.77). Las altas correlaciones entre las mediciones radiométricas y las concentraciones de Cla y MST superficiales en las aguas de la bahía de La Paz y la laguna, prueban la capacidad de la aplicación de las técnicas de sensores remotos para estimar Cla y MST, en aguas costeras del Golfo de California

Patrones de abundancia de los estadios tempranos de la sardina del Pacífico (Sardinops sagax) durante un periodo de enfriamiento en una laguna costera al sur de la corriente de California

Abundance patterns of eggs and larvae of the Pacific sardine, Sardinops sagax (Jenyns, 1842), in Bahía Magdalena, Baja California Sur, were analysed during a cooling period south of the California Current from 2005 to 2009. The thermohaline characteristics and zooplankton abundance were good descriptors of the potential spawning habitat. Individual quotient analyses showed a predominance of eggs and larvae within a SST range of 16 to 18°C, at low salinities (33.9-34.1) and at low density gradient variability (0.009-0.029), associated with deeper waters (25-40 m) near the main entrance, where the transparency was intermediate (6-8 m) and zooplankton abundance was relatively high ( > 316 ml/1000 m3). Increments within different class intervals meant that neither dissolved inorganic nitrogen (DIN), phosphates nor chlorophyll a predominated. The large interannual fluctuations in sardine spawning activity and preferential temperatures observed in historical and recent data suggest that two sardine stocks spawn in Bahia Magdalena: one stock spawned in the period 1981-1989 and one stock spawned in the period 1997-2009. The influence of cooling and warming periods as additional components of the regional environmental framework is analysed and discussed.Los patrones de abundancia de huevos y larvas de la sardina del Pacífico, Sardinops sagax, en Bahía Magdalena, Baja California Sur, fueron analizados durante un periodo de enfriamiento al sur de la Corriente de California de 2005 a 2009. La combinación de las características termohalinas y abundancia del zooplancton fueron buenos indicadores del hábitat potencial del desove. El análisis individual de cocientes mostró una predominancia de huevos y larvas en el intervalo de temperatura superficial del mar entre 16 y 18°C, a baja salinidad (33.9-34.1), y valores bajos de la diferencia del gradiente de densidad (0.009-0.029) asociados a las aguas profundas (25-40 m) cercanas a la entrada principal, donde la profundidad de transparencia fue intermedia (6-8 m), y la abundancia del zooplancton fue relativamente alta ( > 316 ml/1000 m3). El Nitrógeno Inorgánico Disuelto (DIN), fosfatos y clorofila a no revelan una clara predominancia, debido a incrementos en diferentes intervalos de clases. La amplia fluctuación interanual de la actividad reproductiva de la sardina y temperaturas preferenciales observadas en datos históricos y recientes sugiere la reproducción de dos poblaciones en Bahía Magdalena (1981-1989 y 1997-2009). La influencia de los periodos de enfriamiento y calentamiento como complemento de marco ambiental regional es analizada y discutida

Variabilidad estacional de la productividad primaria y su relación con la estratificación vertical en la Bahía de la Paz, B. C. S.

Primary productivity (pp) during October of 1996, March, April, May, June, July, September, November of 1997 and January of 1998, was estimated via natural fluorescence in La Paz bay. Simultaneously to pp vertical temperatura profiles (CTD) were registered to determine the structure of the water column, which was calculated by using the stratification index (?) from 0 to 100 m depth. The highest average values in pp (16 mg C m-3 h-1) were observed during the spring and the minimum values of ? (50 J m-3)  corresponded to a almost homogeneous water column. In contrast, to other seasons (summer and autumn), the pp fell to minimum values (2 to 5 mg C m-3 h-1), while ? increased significantly (249 and 347 J m-3). The results indicated a lineal dependence between pp and water column mixture (r2 = 0.62, p <0.05) during the summer months. Periods with high stratification seem to inhibit the fertilization on the surface layer, while the well mixed water column facilitate the fertilization process. Therefore, it is evident that the water column stratification in La Paz bay plays an important role mechanism that controls the pp and partially explains the seasonal variability.Se estimó la productividad primaria (pp) vía fluorescencia natural en la bahía de La Paz durante octubre de 1996, marzo, abril, mayo, junio, julio, septiembre, noviembre de 1997, y enero de 1998. Simultáneamente a los registros de pp se realizaron perfiles verticales de temperatura (CTD) para determinar la estructura de la columna de agua, y de los cuales se estimó el índice de estratificación (?) de 0 a 100 m de profundidad. Durante primavera se observaron los valores promedio más altos de pp (16 mg C m-3 h-1) y valores bajos de ? (50 J m-3) que corresponden a una columna de agua casi homogénea. En contraste, en las subsecuentes estaciones (verano y otoño), la pp decreció a valores mínimos (2 y 5 mg C m-3 h-1), mientras que ? se incrementó significativamente (249 y 347 J m-3). Los resultados indican que existe una dependencia lineal de la pp y la mezcla en la columna de agua (r2 = 0.62, p<0.05) durante los meses de verano. Periodos con una alta estratificación tienden posiblemente a inhibir la fertilización de la capa superficial, mientras que una columna de agua bien mezclada facilita el proceso de fertilización. Por lo tanto, es evidente que en la Bahía de La Paz la estratificación asume un papel importante como mecanismo que controla la pp y explica parcialmente la variabilidad estacional observada en la bahía

COVID-19 Severity and Survival over Time in Patients with Hematologic Malignancies: A Population-Based Registry Study

Mortality rates for COVID-19 have declined over time in the general population, but data in patients with hematologic malignancies are contradictory. We identified independent prognostic factors for COVID-19 severity and survival in unvaccinated patients with hematologic malignancies, compared mortality rates over time and versus non-cancer inpatients, and investigated post COVID-19 condition. Data were analyzed from 1166 consecutive, eligible patients with hematologic malignancies from the population-based HEMATO-MADRID registry, Spain, with COVID-19 prior to vaccination roll-out, stratified into early (February–June 2020; n = 769 (66%)) and later (July 2020–February 2021; n = 397 (34%)) cohorts. Propensity-score matched non-cancer patients were identified from the SEMI-COVID registry. A lower proportion of patients were hospitalized in the later waves (54.2%) compared to the earlier (88.6%), OR 0.15, 95%CI 0.11–0.20. The proportion of hospitalized patients admitted to the ICU was higher in the later cohort (103/215, 47.9%) compared with the early cohort (170/681, 25.0%, 2.77; 2.01–3.82). The reduced 30-day mortality between early and later cohorts of non-cancer inpatients (29.6% vs. 12.6%, OR 0.34; 0.22–0.53) was not paralleled in inpatients with hematologic malignancies (32.3% vs. 34.8%, OR 1.12; 0.81–1.5). Among evaluable patients, 27.3% had post COVID-19 condition. These findings will help inform evidence-based preventive and therapeutic strategies for patients with hematologic malignancies and COVID-19 diagnosis.Depto. de MedicinaFac. de MedicinaTRUEFundación Madrileña de Hematología y HemoterapiaFundación Leucemia y LinfomaAsociación Madrileña de Hematología y Hemoterapiapu

Height and body-mass index trajectories of school-aged children and adolescents from 1985 to 2019 in 200 countries and territories: a pooled analysis of 2181 population-based studies with 65 million participants

Summary Background Comparable global data on health and nutrition of school-aged children and adolescents are scarce. We aimed to estimate age trajectories and time trends in mean height and mean body-mass index (BMI), which measures weight gain beyond what is expected from height gain, for school-aged children and adolescents. Methods For this pooled analysis, we used a database of cardiometabolic risk factors collated by the Non-Communicable Disease Risk Factor Collaboration. We applied a Bayesian hierarchical model to estimate trends from 1985 to 2019 in mean height and mean BMI in 1-year age groups for ages 5–19 years. The model allowed for non-linear changes over time in mean height and mean BMI and for non-linear changes with age of children and adolescents, including periods of rapid growth during adolescence. Findings We pooled data from 2181 population-based studies, with measurements of height and weight in 65 million participants in 200 countries and territories. In 2019, we estimated a difference of 20 cm or higher in mean height of 19-year-old adolescents between countries with the tallest populations (the Netherlands, Montenegro, Estonia, and Bosnia and Herzegovina for boys; and the Netherlands, Montenegro, Denmark, and Iceland for girls) and those with the shortest populations (Timor-Leste, Laos, Solomon Islands, and Papua New Guinea for boys; and Guatemala, Bangladesh, Nepal, and Timor-Leste for girls). In the same year, the difference between the highest mean BMI (in Pacific island countries, Kuwait, Bahrain, The Bahamas, Chile, the USA, and New Zealand for both boys and girls and in South Africa for girls) and lowest mean BMI (in India, Bangladesh, Timor-Leste, Ethiopia, and Chad for boys and girls; and in Japan and Romania for girls) was approximately 9–10 kg/m2. In some countries, children aged 5 years started with healthier height or BMI than the global median and, in some cases, as healthy as the best performing countries, but they became progressively less healthy compared with their comparators as they grew older by not growing as tall (eg, boys in Austria and Barbados, and girls in Belgium and Puerto Rico) or gaining too much weight for their height (eg, girls and boys in Kuwait, Bahrain, Fiji, Jamaica, and Mexico; and girls in South Africa and New Zealand). In other countries, growing children overtook the height of their comparators (eg, Latvia, Czech Republic, Morocco, and Iran) or curbed their weight gain (eg, Italy, France, and Croatia) in late childhood and adolescence. When changes in both height and BMI were considered, girls in South Korea, Vietnam, Saudi Arabia, Turkey, and some central Asian countries (eg, Armenia and Azerbaijan), and boys in central and western Europe (eg, Portugal, Denmark, Poland, and Montenegro) had the healthiest changes in anthropometric status over the past 3·5 decades because, compared with children and adolescents in other countries, they had a much larger gain in height than they did in BMI. The unhealthiest changes—gaining too little height, too much weight for their height compared with children in other countries, or both—occurred in many countries in sub-Saharan Africa, New Zealand, and the USA for boys and girls; in Malaysia and some Pacific island nations for boys; and in Mexico for girls. Interpretation The height and BMI trajectories over age and time of school-aged children and adolescents are highly variable across countries, which indicates heterogeneous nutritional quality and lifelong health advantages and risks

COVID-19 symptoms at hospital admission vary with age and sex: results from the ISARIC prospective multinational observational study

Background: The ISARIC prospective multinational observational study is the largest cohort of hospitalized patients with COVID-19. We present relationships of age, sex, and nationality to presenting symptoms. Methods: International, prospective observational study of 60 109 hospitalized symptomatic patients with laboratory-confirmed COVID-19 recruited from 43 countries between 30 January and 3 August 2020. Logistic regression was performed to evaluate relationships of age and sex to published COVID-19 case definitions and the most commonly reported symptoms. Results: ‘Typical’ symptoms of fever (69%), cough (68%) and shortness of breath (66%) were the most commonly reported. 92% of patients experienced at least one of these. Prevalence of typical symptoms was greatest in 30- to 60-year-olds (respectively 80, 79, 69%; at least one 95%). They were reported less frequently in children (≤ 18 years: 69, 48, 23; 85%), older adults (≥ 70 years: 61, 62, 65; 90%), and women (66, 66, 64; 90%; vs. men 71, 70, 67; 93%, each P < 0.001). The most common atypical presentations under 60 years of age were nausea and vomiting and abdominal pain, and over 60 years was confusion. Regression models showed significant differences in symptoms with sex, age and country. Interpretation: This international collaboration has allowed us to report reliable symptom data from the largest cohort of patients admitted to hospital with COVID-19. Adults over 60 and children admitted to hospital with COVID-19 are less likely to present with typical symptoms. Nausea and vomiting are common atypical presentations under 30 years. Confusion is a frequent atypical presentation of COVID-19 in adults over 60 years. Women are less likely to experience typical symptoms than men

Worldwide trends in hypertension prevalence and progress in treatment and control from 1990 to 2019: a pooled analysis of 1201 population-representative studies with 104 million participants.

BACKGROUND: Hypertension can be detected at the primary health-care level and low-cost treatments can effectively control hypertension. We aimed to measure the prevalence of hypertension and progress in its detection, treatment, and control from 1990 to 2019 for 200 countries and territories. METHODS: We used data from 1990 to 2019 on people aged 30-79 years from population-representative studies with measurement of blood pressure and data on blood pressure treatment. We defined hypertension as having systolic blood pressure 140 mm Hg or greater, diastolic blood pressure 90 mm Hg or greater, or taking medication for hypertension. We applied a Bayesian hierarchical model to estimate the prevalence of hypertension and the proportion of people with hypertension who had a previous diagnosis (detection), who were taking medication for hypertension (treatment), and whose hypertension was controlled to below 140/90 mm Hg (control). The model allowed for trends over time to be non-linear and to vary by age. FINDINGS: The number of people aged 30-79 years with hypertension doubled from 1990 to 2019, from 331 (95% credible interval 306-359) million women and 317 (292-344) million men in 1990 to 626 (584-668) million women and 652 (604-698) million men in 2019, despite stable global age-standardised prevalence. In 2019, age-standardised hypertension prevalence was lowest in Canada and Peru for both men and women; in Taiwan, South Korea, Japan, and some countries in western Europe including Switzerland, Spain, and the UK for women; and in several low-income and middle-income countries such as Eritrea, Bangladesh, Ethiopia, and Solomon Islands for men. Hypertension prevalence surpassed 50% for women in two countries and men in nine countries, in central and eastern Europe, central Asia, Oceania, and Latin America. Globally, 59% (55-62) of women and 49% (46-52) of men with hypertension reported a previous diagnosis of hypertension in 2019, and 47% (43-51) of women and 38% (35-41) of men were treated. Control rates among people with hypertension in 2019 were 23% (20-27) for women and 18% (16-21) for men. In 2019, treatment and control rates were highest in South Korea, Canada, and Iceland (treatment >70%; control >50%), followed by the USA, Costa Rica, Germany, Portugal, and Taiwan. Treatment rates were less than 25% for women and less than 20% for men in Nepal, Indonesia, and some countries in sub-Saharan Africa and Oceania. Control rates were below 10% for women and men in these countries and for men in some countries in north Africa, central and south Asia, and eastern Europe. Treatment and control rates have improved in most countries since 1990, but we found little change in most countries in sub-Saharan Africa and Oceania. Improvements were largest in high-income countries, central Europe, and some upper-middle-income and recently high-income countries including Costa Rica, Taiwan, Kazakhstan, South Africa, Brazil, Chile, Turkey, and Iran. INTERPRETATION: Improvements in the detection, treatment, and control of hypertension have varied substantially across countries, with some middle-income countries now outperforming most high-income nations. The dual approach of reducing hypertension prevalence through primary prevention and enhancing its treatment and control is achievable not only in high-income countries but also in low-income and middle-income settings. FUNDING: WHO