Efecto de los incendios en la cobertura vegetal, almacenamiento de carbono y biomasa vegetal de un humedal costero / Effect of fires on vegetation cover, carbon storage and plant biomass in a coastal wetland

Resumen Introducción: Los humedales se encuentran entre los ecosistemas más productivos, pero actualmente están siendo degradados o eliminados a un ritmo acelerado por múltiples actividades antrópicas. En la costa central de Perú, los humedales sufren incendios recurrentes, y los efectos poco estudiados incluyen el nivel de emisiones y el secuestro de carbono por quema. Objetivo: Estimar el carbono en la biomasa aérea afectada por el fuego y el carbono recuperado por la vegetación al cabo de un año. Métodos: Trabajamos en el humedal costero Los Pantanos de Villa (Lima, Perú) y comparamos áreas quemadas (32 cuadrantes, 1 m2) y no afectadas (33 cuadrantes). Resultados: La vegetación afectada fue predominantemente herbácea y dominada por Phragmites australis, Schoenoplectus americanus, Typha dominguensis y Cladium jamaicense. El incendio afectó 1 147.0 t de biomasa vegetal que almacenó 381.8 t de carbono, generando la emisión de 1 397.1 t de CO2 a la atmósfera. Al cabo de un año se había recuperado el 79 % de la cobertura vegetal, pero solo el 26 % de la biomasa vegetal viva y el 12.8 % del carbono contenido en la vegetación. Conclusiones: Los indicadores apropiados de la resiliencia de los humedales al fuego deben considerar que los humedales afectados por el fuego recuperan rápidamente la cobertura vegetal, pero no el almacenamiento de carbono y la biomasa vegetal.

Abstract Introduction: Wetlands are among the most productive ecosystems, but currently are being degraded or eliminated at accelerated rates by multiple anthropic activities. In the central coast of Peru, wetlands suffer recurring fires, and the little-studied effects include the level of emissions and carbon sequestration by burning. Objective: To estimate carbon in aerial biomass affected by fire, and carbon recovered by the vegetation after one year. Methods: We worked in Los Pantanos de Villa (Lima, Peru) coastal wetland and compared burnt (32 quadrants, 1 m2) and unaffected areas (33 quadrants). Results: The vegetation affected was predominantly herbaceous and dominated by Phragmites australis, Schoenoplectus americanus, Typha dominguensis and Cladium jamaicense. Fire affected 1 147.0 t of plant biomass that stored 381.8 t of carbon, generating the emission of 1 397.1 t of CO2 into the atmosphere. After one year, 79 % of the vegetation cover had recovered, but only 26 % of the plant biomass and 12.8 % of vegetation carbon. Conclusions: Appropriate indicators of wetland fire resilience should consider that fire-impacted wetland rapidly recovers plant cover, but not carbon storage and plant biomass.

Carbon and nutrient burial within Peruvian coastal marsh driven by anthropogenic activities.

This research assessed carbon and nutrient burial during the past ~60 years within a Peruvian coastal marsh ecosystem affected by anthropogenic activities, by examining total organic carbon (TOC), total nitrogen (TN) and isotopes (δ13C and δ15N) tracers in two dated sediment cores. Significantly higher TOC and TN burial, up to 416.4 ± 65.0 and 0.7 ± 0.1 g m-2 year-1 respectively, were observed after an uncontrolled urban expansion starting in the early 1970's to the 1990's. The TOC and TN burial rates were up to twofold higher than those observed for preserved coastal marshes. Furthermore, the decreased δ13C values (-16.1 ± 0.6 ‰) and increasing δ15N values (+10.6 ± 2.6 ‰) indicate higher deposition of algal material and urban sewage during the same period. The higher burial rates during 1970's-1990's and reduced rates thereafter evidenced the role of coastal marsh ecosystems plays in sequestering carbon and nutrients.

Primary recovery of hyaluronic acid produced in Streptococcus equi subsp. zooepidemicus using PEG-citrate aqueous two-phase systems.

Given its biocompatibility, rheological, and physiological properties, hyaluronic acid (HA) has become a biomaterial of increasing interest with multiple applications in medicine and cosmetics. In recent decades, microbial fermentations have become an important source for the industrial production of HA. However, due to its final applications, microbial HA must undergo critical and long purification processes to ensure clinical and cosmetic grade purity. Aqueous two-phase systems (ATPS) have proven to be an efficient technique for the primary recovery of high-value biomolecules. Nevertheless, their implementation in HA downstream processing has been practically unexplored. In this work, polyethylene glycol (PEG)-citrate ATPS were used for the first time for the primary recovery of HA produced with an engineered strain of Streptococcus equi subsp. zooepidemicus. The effects of PEG molecular weight (MW), tie-line length (TLL), volume ratio (VR), and sample load on HA recovery and purity were studied with a clarified fermentation broth as feed material. HA was recovered in the salt-rich bottom phase, and its recovery increased when a PEG MW of 8000 g mol-1 was used. Lower VR values (0.38) favoured HA recovery, whereas purity was enhanced by a high VR (3.50). Meanwhile, sample load had a negative impact on both recovery and purity. The ATPS with the best performance was PEG 8000 g mol-1, TLL 43% (w/w), and VR 3.50, showing 79.4% HA recovery and 74.5% purity. This study demonstrated for the first time the potential of PEG-citrate ATPS as an effective primary recovery strategy for the downstream process of microbial HA.

Comparative Economic Analysis Between Endogenous and Recombinant Production of Hyaluronic Acid.

Hyaluronic acid (HA) is a biopolymer with a wide range of applications, mainly in the cosmetic and pharmaceutical sectors. Typical industrial-scale production utilizes organisms that generate HA during their developmental cycle, such as Streptococcus equi sub. zooepidemicus. However, a significant disadvantage of using Streptococcus equi sub. zooepidemicus is that it is a zoonotic pathogen, which use at industrial scale can create several risks. This creates opportunities for heterologous, or recombinant, production of HA. At an industrial scale, the recovery and purification of HA follow a series of precipitation and filtration steps. Current recombinant approaches are developing promising alternatives, although their industrial implementation has yet to be adequately assessed. The present study aims to create a theoretical framework to forecast the advantages and disadvantages of endogenous and recombinant strains in production with the same downstream strategy. The analyses included a selection of the best cost-related recombinant and endogenous production strategies, followed by a sensitivity analysis of different production variables in order to identify the three most critical parameters. Then, all variables were analyzed by varying them simultaneously and employing multiple linear regression. Results indicate that, regardless of HA source, production titer, recovery yield and bioreactor scale are the parameters that affect production costs the most. Current results indicate that recombinant production needs to improve current titer at least 2-fold in order to compete with costs of endogenous production. This study serves as a platform to inform decision-making for future developments and improvements in the recombinant production of HA.

Macroinvertebrados acuáticos en arroyos asociados con bofedales altoandinos, Ayacucho Perú

Introducción: Los arroyos asociados a bofedales se hallan en ambientes donde las condiciones son extremas con temperaturas muy variables, baja presión atmosférica e intensa radiación solar. Sin embargo, existen ensamblajes de macroinvertebrados asociados a estos ambientes, cuya información es escasa. A escala global y regional, las características de los macroinvertebrados cambian con el aumento de la latitud y altitud (disminución de la riqueza y variación de la composición). A nivel local, también se puede agregar el efecto de las aguas ácidas y de elevada conductividad proveniente de manantiales que se unen a los arroyos, que generan heterogeneidad en la calidad de agua y consecuentemente en las características de los macroinvertebrados. Objetivo: Comparar la diversidad, composición y abundancia de macroinvertebrados y las características fisicoquímicas del agua de arroyos asociados a dos bofedales altoandinos, ubicados en el departamento de Ayacucho, Perú. Metodología: Se estudiaron once estaciones ubicados en arroyos de dos bofedales: 7 en Guitarrachayocc (G) de 43 ha (n = 28) y 4 en Pichccahuasi (P) de 28 ha (n = 8). Se empleó una red de Surber (0.3 mm de malla, área de muestreo de 1 200 cm2), para realizar muestreos mensuales de octubre de 2016 a abril de 2017. Análisis de componentes principales (PCA) y análisis de varianza multivariante no paramétrico (NP-MANOVA) se aplicaron para comparar las características del agua. Además, se utilizó un análisis de coordenadas principales (PCoA) y NP-MANOVA para comparar el ensamblaje. La prueba no paramétrica de Kruskal-Wallis (α = 0.05) se utilizó para comparar las abundancias absolutas de los taxa principales. Resultados: Las características del agua fueron heterogéneas, con pH de 3.2 (± 0.4) a 7.6 (± 0.1), conductividad de 168.9 (± 91) µS/cm a 1 117 (± 159.3) µS/cm; diferencias que fueron significativas (p < 0.05) al comparar las estaciones de muestreo, donde el agua de G6 presenta los mínimos valores de pH y los máximos de conductividad, al igual que cloruros. Se recolectaron un total de 8 126 individuos, distribuidos en 26 taxa de 20 familias, 11 órdenes y cinco clases. Los insectos fueron el grupo más diverso y abundante. A pesar a la cercanía de los arroyos de los bofedales, presentaron diferencias: en G, se registró 25 taxa, con dominancia de Macrelmis sp., Dicrotendipes sp., Claudioperla sp., Meridialaris sp. y en P, 9, con dominancia de Pedrowygomya sp., Hyalella sp. y Dicrotendipes sp. La densidad fue de 475 ind./m2 y de 31 ind./m2 para el bofedal G y P respectivamente, estos valores fueron estadísticamente diferentes (p < 0.05). El PCoA y el PCA confirmados por NP-MANOVA mostraron que G6 es diferente (p < 0.05) dentro de G porque recibe el aporte de agua de un manantial. Conclusiones: La riqueza, composición y densidad de los macroinvertebrados son diferentes en los arroyos según el bofedal al cual se halla asociado. La contribución de los manantiales a los arroyos genera cambios drásticos en la calidad del agua y los macroinvertebrados, determinando la formación de ensamblajes con diferente riqueza y estructura.

Introduction: Streams associated with high Andean wetlands are found in environments where conditions are extreme, highly variable temperature, low atmospheric pressure, intense solar radiation. The macroinvertebrate assemblages have been poorly studied compared to streams located at lower altitudes. On a global and regional scale, the characteristics of macroinvertebrates change with the increase in latitude and altitude (decreasing in richness and variation in composition). At the local level, the effect of acidic waters with high conductivity from springs that join streams generate heterogeneity in water quality and consequently in the characteristics of macroinvertebrate structure. Objective: To compare the diversity, composition and abundance of macroinvertebrates and the physicochemical characteristics of stream water in two high Andean wetlands in Peru. Methodology: Eleven stations located in streams of two high Andean wetlands were studied: 7 in Guitarrachayocc (G) of 43 ha (n = 28) and 4 in Pichccahuasi (P) of 28 ha (n = 8). A Surber sampler (0.3 mm mesh, sampling area of 1 200 cm2) was used to carry out monthly samplings from October 2016 to April 2017. Principal Component Analysis (PCA) and Non-Parametric-Multivariate-Analysis-Of-Variance (NP-MANOVA) were applied to compare water characteristics. The macroinvertebrate assemblages from the two streams were compared by using a Principal coordinate analysis (PCoA), NP-MANOVA, and a non-parametric Kruskal-Wallis test (α = 0.05). Results: The characteristics of the water were heterogeneous, with significant differences in pH which ranged from 3.2 (± 0.4) to 7.6 (± 0.1) and conductivity ranging from 168.9 (± 91.0) µS / cm to 1 117.0 (± 159.3) µS / cm. In particular, G6 presented the lowest pH values and the highest electrical conductivity, as well as chlorides. A total of 8 126 individuals were collected, distributed in 26 taxa from 20 families, 11 orders and five classes. Insects were the most diverse and abundant group. Differences were found between the streams of the highland wetlands, despite their proximity: in G, 25 taxa were registered, with a dominance of Macrelmis sp., Dicrotendipes sp., Claudioperla sp. and Meridialaris sp. and in P, 9, with a dominance of Pedrowygomya sp., Hyalella sp. and Dicrotendipes sp. The density was 475 ind./m2 and 31 ind./m2 for G and P respectively, these values were statistically different (p < 0.05). The PCoA and PCA confirmed by NP-MANOVA showed that G6 was different (p < 0.05) within G because it receives water contribution from a spring. Conclusions: The richness, composition and density of macroinvertebrates were different in streams depending on the bofedal with which it is associated. The contribution of the springs to the streams generates drastic changes in the quality of the water and the macroinvertebrates, determining the formation of assemblages with different richness and structure.

Por qué los Humedales de Puerto Viejo perdieron su protección legal: analizando los motivos / Why the Wetlands of Puerto Viejo did loses its legal protection: analyzing the motives

Los humedales de Puerto Viejo son un ecosistema marino costero ubicado en el Sur de la ciudad de Lima. El año 2008, este ecosistema fue protegido por el estado y declarado Zona Reservada Humedales de Puerto Viejo, una categoría transitoria que brinda el SINANPE (Sistema Nacional de Áreas Naturales Protegidas por el Estado). En abril del 2017, una Resolución Ministerial declaró la desafectación de los Humedales de Puerto Viejo, perdiendo la categoría de Zona Reservada y quedando desprotegida legalmente. El presente trabajo analiza y discute los criterios técnicos de desafectación (representatividad, eficiencia, consistencia, conectividad, equilibrio, complementariedad y coherencia externa) que fueron aplicados a los Humedales de Puerto Viejo

Puerto Viejo wetlands is a coastal marine ecosystem southern of Lima. Since 2008, this wetlands was protected by the Peruvian State and declared a Wetland Reserved Zone of Puerto Viejo, a transitory category provided by SINANPE (Sistema Nacional de Áreas Naturales Protegidas por el Estado). In April 2017, a Ministerial Resolution did reversal [desafectación] the transitory protection of Puerto Viejo Wetlands, losing the category of Reserved Zone and being legally unprotected. The present work analyzes and discusses the technical criteria for the reversal (representativeness, efficiency, consistency, connectivity, equilibrium, complementarity and external coherence) that were applied to Puerto Viejo Wetland

Surgical treatment of multiple intracardiac and pulmonary artery tumor implants embolic from uterine intravascular leiomyomatosis.

Intravenous uterine leiomyomatosis is the invasion of the para-uterine veins by bundles of benign uterine muscle. These muscle bundles can grow and extend directly to pelvic organs or embolize to the right cardiac chambers or pulmonary artery. We report a patient who presented with two large mobile atrial masses that were seen on echocardiography. She was treated by excision of a 18cm mass from the right atrium, two masses from the right ventricle and a huge mass from the pulmonary artery. The tricuspid valve that was rendered insufficient, was repaired by the creation of PTFE neo chordae. Two weeks later a massively enlarged uterus, ovaries, a paracolic and three intraluminal masses in the inferior vena cava were removed. The patient recovered well. One year after surgery she was asymptomatic and no masses are seen in her echocardiogram. The tricuspid valve was competent. Patients presenting with cardiac tumors from intravenous uterine leiomyomatosis must undergo aggressive surgical management to achieve a cure. We recommend a two stage (thoracic and abdominal) approach.

The use of ultrasound for placement of intravenous catheters.

Ultrasound has been used to aid cannulation of veins of the neck, chest, antecubital fossa, and femoral vein. This investigation compared the traditional method of peripheral intravenous (IV) cannulation of veins of the hands and forearms with ultrasound-guided IV cannulation of these veins. After obtaining institutional review board approval and written informed consent, 35 adult subjects with a history or suspicion of difficult IV cannulation were prospectively enrolled with 16 subjects randomly assigned to the traditional group and 19 to the ultrasound group. Time taken for successful venous cannulation and number of attempts between the groups were compared using a Mann-Whitney U test. The number of subjects in whom IV cannulation was successful on the first attempt was compared between the groups using the Fisher exact test. No significant differences were noted between groups in demographics, time to successful cannulation, number of attempts, and number of subjects in whom IV cannulation was successful on the first attempt. Ultrasound was as efficacious as the traditional method of IV cannulation in this subset of patients. Future investigations should examine the efficacy of the ultrasound-guided technique of IV cannulation of these veins in patients in whom the traditional method failed.