Protecting imperiled “paper parks”: potential lessons from the Sierra Chinajá, Guatemala

In many developing nations, “paper parks”, or protected areas that have little or no formal management on the ground, have resulted from the failure of protected area systems to achieve their foremost goal: biodiversity conservation. This analysis incorporates biophysical, socioeconomic, and land use/tenure data collected by a multi-disciplinary team of Guatemalan and American researchers in order to identify potential management plans and multiple-use/concession arrangements. The Sierra Chinajá is a classic paper park protected area in Guatemala. Many factors have rendered Guatemalan protected areas management policies ineffectual in the Sierra Chinajá despite the fact that it has been an “area of special protection” since 1989. Proximate causes of forest conversion mask underlying driving forces responsible for rapid biodiversity loss. Despite the fact that Guatemala’s protected areas management system is similar to that promoted by international conservation organizations it has yet to effectively conserve biodiversity. These factors suggest that protected areas management in Guatemala, and other developing nations possessing unique cultural and natural histories, must be rooted in the local context as promulgated by the local non-governmental organization ProPéten in their proposal for an official Indigenous Reserve category. The proposal suggests the devolution of management responsibilities from federal institutions to local communities in the effort to develop a community-based, site specific conservation agenda.

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Resumen  En muchos países en desarrollo, las “áreas protegidas en papel” o parques que no poseen un plan de manejo formal, han sido el resultado de la incapacidad del sistema nacional de áreas protegidas de alcanzar su meta mas importante: la conservación de la biodiversidad. El siguiente análisis incorpora datos biofísicos, socioeconómicos, de uso y tenencia de la tierra recolectados por un grupo multidisciplinario de investigadores guatemaltecos y norteamericanos con el objetivo de formular una estrategia de conservación que incorpore concesiones de usos múltiples. La Sierra de Chinajá es un ejemplo clásico de un “área protegida en papel” en Guatemala. Muchos son los factores por los cuales la política de áreas protegidas ha fracasado en la Sierra de Chinajá, a pesar de estar clasificada como un “área de Protección Especial” desde 1989. Las causas subyacentes responsables por el cambio en la cobertura forestal están escondidas debajo de los síntomas más visibles de la perdida de biodiversidad. A pesar de que el Sistema Guatemalteco de áreas Protegidas es similar al promovido por organizaciones internacionales aun no es efectivo en la conservación de la biodiversidad. Estos factores sugieren que el manejo de las áreas protegidas en Guatemala, y en otros países en desarrollo que poseen historias naturales y culturales únicas, deben estar enraizadas en el contexto local, como ha sido propuesto por la organización Pro-Peten en su propuesta por una categoría de manejo denominada Reservas Comunitarias Indígenas. La propuesta sugiere la delegación de la protección la biodiversidad de instituciones estatales a las comunidades locales con el propósito de establecer una agenda de conservación basada en el manejo comunitario.

     

Effect of substrate particle size and additional nitrogen source on production of lignocellulolytic enzymes by Pleurotus ostreatus strains

Two strains of Pleurotus ostreatus (IE-8 and CP-50) were grown on defined medium added with wheat straw extract (WSE). Mycelia from these cultures were used as an inoculum for solid fermentation using sugar cane bagasse (C:N=142). This substrate was used separately either as a mixture of heterogeneous particle sizes (average size 2.9 mm) or as batches with two different particle sizes (0.92 mm and 1.68 mm). Protein enrichment and production of lignocellulolytic enzymes on each particle size was compared. The effect of ammonium sulphate (AS) addition was also analyzed (modified C:N=20), this compound favored higher levels of protein content. Strain CP-50 showed the highest increase of protein content (48% on particle size of 1.68 mm) when compared to media with no additional N source. However, strain IE-8 produced the highest levels of all enzymes: xylanases (5.79 IU/g dry wt on heterogeneous particles) and cellulases (0.18 IU/g dry wt on smallest particles), both without the addition of AS. The highest laccase activity (0.040 IU/g dry wt) was obtained on particles of 1.68 mm in the presence of AS. Since effect of particle size and addition AS was different for each strain, these criteria should be considered for diverse biotechnological applications.     

Construction of simplified models to simulate estrogenic disruptions by esters of 4-hydroxy benzoic acid (parabens)

Four parabens (methyl, n-butyl, benzyl and isobutylparaben) were theoretically studied in order to evaluate their estrogenic activity through simplified models. The experimental structure of the human estrogen receptor ligand-binding domain in complex with 17β-estradiol was used as the starting point to construct the models. The complex between 17β-estradiol and three fragments of the estrogenic receptor (Arg, Glu and His), resulted in a reasonable simplified model of interaction. The replacement of 17-β-estradiol by parabens was evaluated by conformational analyses and interaction energy calculations at BHandHLYP/cc-PVTZ(-f)+ level of theory. According with the calculated interaction energies, methylparaben is the paraben with higher estrogenic activity, which is in agreement with experimental studies of extraction and quantification of parabens in tumors. The antibacterial activity of parabens was also explored considering the formation of potassium salts in the phenolic OH groups. From the obtained relative energy values, methylparaben is the most active preservative.     

Pseudotumoral Neuroparacoccidioidomycosis: One Case Report

Neuroparacoccidioidomycosis is the central nervous system involvement by Paracoccidioides brasiliensis, a condition that may be underdiagnosed and has been scarcely reported. We describe a case of neuroparacoccidioidomycosis in a diabetic male with antecedent of heavy cigarette smoking and alcohol abuse. Thirty years before, he lived in the Amazon area and exerted rural activities in more recent years. The patient's main complaints were headache, visual deficit, hemiparesis, and weight loss. Imaging studies detected changes in the lungs and right adrenal gland, in addition to brain lesions. Paracoccidioides brasiliensis was found in tissue samples collected by the lung and brain biopsies. The patient is under ambulatory surveillance and in use of trimethoprim-sulfamethoxazole.     

Organic matter quality in ecological studies: theory meets experiment

Despite its importance for the understanding of element cycles in ecosystems, organic matter (OM) quality has remained an elusive property that is difficult to measure. In this study, two new approaches, both of which taking into account the complete biochemical composition of the organic material during the decomposition process, have been combined to solve this problem. First, following the continuous-quality theory where quality is defined as a measure of substrate availability to the decomposers, initial litter OM qualities of a range of plant species from two experiments on litter decomposition were estimated and resulted in highly accurate fits of observed mass loss during decomposition. Applying the same theory, qualities of the litters at all stages of decomposition were then calculated. By comparison, the initial qualities of the same litters were estimated from conventional chemical fractions and resulted in much lower accurate fits. Second, near-infrared reflectance spectroscopy (NIRS), a highly precise physical method of characterising biochemical composition of OM, was used to obtain a unique spectral signature of each sample. Calibrations were performed between spectral data and calculated qualities on the first half of the sample set and the calibration equations were applied to the second half of the sample set. Results show that theoretical litter OM quality can be calibrated and predicted precisely using NIRS. OM quality, defined according to a theoretical concept of substrate availability to decomposers, then contains and summarises all the relevant biochemical information. We demonstrate how the combination of NIRS and theory allows us to accurately measure OM quality. Measurement of OM quality provides an access to a fundamental property of organic matter and opens up new possibilities for studying element cycles in ecosystems.     

Lipopolysaccharide O-chain microheterogeneity of Salmonella serotypes Enteritidis and Typhimurium

Variability in the lipopolysaccharide (LPS) of the two most prevalent Salmonella serotypes causing food-borne salmonellosis was assessed using gas chromatography analysis of neutral sugars from 43 Salmonella enterica serovar Enteritidis ( S . Enteritidis) and 20 Salmonella enterica serovar Typhimurium ( S . Typhimurium) isolates . Four substantially different types of O-chain chemotypes were detected using cluster analysis of sugar compositions; these were low-molecular-mass (LMM) LPS, glucosylated LMM LPS, high-molecular-mass (HMM) LPS and glucosylated HMM LPS. Nineteen out of 20 S . Typhimurium isolates yielded glucosylated LMM . In contrast, S . Enteritidis produced a more diverse structure, which varied according to the source and history of the isolate: 45.5% of egg isolates yielded glucosylated HMM LPS; 100% of stored strains lacked glucosylation but retained chain length in some cases; and 83.3% of fresh isolates from the naturally infected house mouse Mus musculus produced glucosylated LMM LPS. A chain length determinant ( wzz ) mutant of S . Enteritidis produced a structure similar to that of S . Typhimurium and was used to define what constituted significant differences in structure using cluster analysis. Fine mapping of the S . Enteritidis chromosome by means of a two-restriction enzyme-ribotyping technique suggested that mouse isolates producing glucosylated LMM LPS were closely related to orally invasive strains obtained from eggs, and that stored strains were accumulating genetic changes that correlated with suppression of LPS O-chain glucosylation. These results suggest that the determination of LPS chemotype is a useful tool for epidemiological monitoring of S . Enteritidis , which displays an unusual degree of diversity in its LPS O-chain.     

In Vivo NO/cGMP Signalling in the Hippocampus

In the hippocampus of freely-moving rats, basal extracellular levels of cGMP are inhibited by L-NARG or ODQ whereas they are increased by NO donors or phosphodiesterase inhibitors. Activation of NMDA receptors also augments cGMP dialysate levels in a MK-801 and L-NARG sensitive manner, an effect dramatically diminished during ageing. Experiments with AMPA, AMPA receptor antagonists and cyclothiazide revealed complex relationships with GABAergic circuits that potently control the NO/cGMP pathway. Furthermore, the activity of this neurochemical cascade is also modulated by hippocampal nicotinic receptors via enhancement of endogenous glutamate release and stimulation of NMDA receptors. From a behavioural point of view, increased hippocampal excitation leads to the appearance of epileptic-like manifestations that, however, seem unrelated to the increase of NO/cGMP formation.