Glacier protection laws: Potential conflicts in managing glacial hazards and adapting to climate change.

The environmental, socioeconomic and cultural significance of glaciers has motivated several countries to regulate activities on glaciers and glacierized surroundings. However, laws written to specifically protect mountain glaciers have only recently been considered within national political agendas. Glacier Protection Laws (GPLs) originate in countries where mining has damaged glaciers and have been adopted with the aim of protecting the cryosphere from harmful activities. Here, we analyze GPLs in Argentina (approved) and Chile (under discussion) to identify potential environmental conflicts arising from law restrictions and omissions. We conclude that GPLs overlook the dynamics of glaciers and could prevent or delay actions needed to mitigate glacial hazards (e.g. artificial drainage of glacial lakes) thus placing populations at risk. Furthermore, GPL restrictions could hinder strategies (e.g. use of glacial lakes as reservoirs) to mitigate adverse impacts of climate change. Arguably, more flexible GPLs are needed to protect us from the changing cryosphere.

Involvement of the MAPK pathway in the pressure-induced synovial metaplasia procedure for the temporomandibular joint.

Abnormal pressure is an important factor that contributes to bone adaptation in the temporomandibular joint (TMJ). We determined the effect of the mitogen-activated protein kinases (MAPK) pathway on the pressure-induced synovial metaplasia procedure for the TMJ, both in vitro and in vivo. Synovial fibroblasts (SFs) were exacted from rat TMJs and exposed to different hydrostatic pressures. The protein extracts were analyzed to determine the activation of ERK1/2, JNK, and p38. Surgical anterior disc displacement (ADD) was also performed on Japanese rabbits, and the proteins of TMJ were isolated to analyze pressure-induced MAPK activation after 1, 2, 4, and 8 weeks. The results showed that the activation of ERK1/2 and JNK in SFs significantly changed with increasing hydrostatic pressure, whereas p38 activation did not change. Moreover, p38 was activated in animals 1 week after surgical ADD. The levels of p38 gradually increased after 2 and 4 weeks, and then slightly decreased but remained higher than in the control 8 weeks after surgical ADD. Nevertheless, JNK was rarely activated after the ADD treatment. Our findings suggest the involvement of MAPK activation in the pressure-induced synovial metaplasia procedure with pressure loading in TMJ.

Effect of pressure on refolding of recombinant pentameric cholera toxin B.

The production of recombinant proteins is an essential tool for the expansion of modern biological research and biotechnology. The expression of heterologous proteins in Escherichia coli often results in an incomplete folding process that leads to the accumulation of inclusion bodies (IB), aggregates that hold a certain degree of native-like secondary structure. High hydrostatic pressure (HHP) impairs intermolecular hydrophobic and electrostatic interactions, leading to dissociation of aggregates under non-denaturing conditions and is therefore a useful tool to solubilize proteins for posterior refolding. Cholera toxin (CT) is composed of a non-toxic pentamer of B subunits (CTB), a useful adjuvant in vaccines, and a toxic subunit A (CTA). We studied the process of refolding of CTB using HHP. HHP was shown to be effective for dissociation of CTB monomers from IB. Posterior incubation at atmospheric pressure of concentrated CTB (1mg/ml) is necessary for the association of the monomers. Pentameric CTB was obtained when suspensions of CTB IB were compressed at 2.4kbar for 16h in the presence of Tween 20 and incubated at 1bar for 120h. Soluble and biologically active pentameric CTB was obtained, with a yield of 213mg CTB/liter of culture. The experience gained in this study can be important to improve the refolding of proteins with quaternary structure.

Performance of fixed-pressure valve with antisiphon device SPHERA(®) in hydrocephalus treatment and overdrainage prevention.

Patients with hydrocephalus and risk factors for overdrainage may be submitted to ventricular shunt (VS) implant with antisiphon device. The objective of this study was to prospectively evaluate for two years the clinical and tomographic results of the implant of fixed-pressure valves with antisiphon device SPHERA(®) in 35 adult patients, with hydrocephalus and risk factors for overdrainage. Of these, 3 had congenital hydrocephalus in adult patients with very dilated ventricles (Evans index >50%), 3 had symptomatic overdrainage after previous VS implant (subdural hematoma, hygroma or slit ventricle syndrome), 1 had previous chronic subdural hematoma, 15 had normal pressure hydrocephalus with final lumbar pressure <5 cm H(2)O after tap test (40 mL), 6 had pseudotumor cerebri, and 7 had hydrocephalus due to other causes. Clinical improvement was observed and sustained in 94.3% of the patients during the two-year period with no computed tomography (CT) evidence of hypo or overdrainage, and no immediate early or late significant complications.

Performance of fixed-pressure valve with antisiphon device SPHERA® in hydrocephalus treatment and overdrainage prevention / Desempenho da válvula de pressão fixa com antissifão SPHERA® no tratamento da hidrocefalia e na prevenção da ocorrência de hiperdrenagem

Patients with hydrocephalus and risk factors for overdrainage may be submitted to ventricular shunt (VS) implant with antisiphon device. The objective of this study was to prospectively evaluate for two years the clinical and tomographic results of the implant of fixed-pressure valves with antisiphon device SPHERA® in 35 adult patients, with hydrocephalus and risk factors for overdrainage. Of these, 3 had congenital hydrocephalus in adult patients with very dilated ventricles (Evans index >50%), 3 had symptomatic overdrainage after previous VS implant (subdural hematoma, hygroma or slit ventricle syndrome), 1 had previous chronic subdural hematoma, 15 had normal pressure hydrocephalus with final lumbar pressure <5 cm H2O after tap test (40 mL), 6 had pseudotumor cerebri, and 7 had hydrocephalus due to other causes. Clinical improvement was observed and sustained in 94.3% of the patients during the two-year period with no computed tomography (CT) evidence of hypo or overdrainage, and no immediate early or late significant complications.

Pacientes com hidrocefalia e fatores de risco para hiperdrenagem podem ser submetidos ao implante de derivação ventricular (VS) com mecanismo antissifão. O objetivo deste trabalho foi avaliar prospectivamente os resultados clínicos e tomográficos do implante de válvulas de pressão fixa com antissifão SPHERA® em 35 pacientes adultos, com hidrocefalia e risco de hiperdrenagem, acompanhados por dois anos. Destes, 3 apresentavam hidrocefalia congênita em adulto, com ventrículos muito dilatados (índice de Evans >50%); 3 tinham hiperdrenagem sintomática pós-derivação ventricular prévia (hematoma subdural, higroma ou síndrome dos ventrículos colabados; 1 apresentava hematoma subdural crônico pregresso; 15 apresentavam hidrocefalia de pressão normal com pressão lombar final <5 cm H2O após tap test (40 mL); 6 apresentavam pseudotumor cerebral; e 7, devido a outras causas. A melhoria clínica foi detectada e sustentada em 94,3% dos pacientes no período de dois anos, sem indícios tomográficos de hipo ou hiperdrenagem e sem complicações significativas imediatas, precoces ou tardias.

Hurdle technology in fruit processing.

Conventional preservation technologies such as thermal processing ensure the safety and shelf life of fruit-derived products but can result in the loss of physicochemical and nutritional quality attributes. This review examines innovative hurdle techniques to obtain novel fruit products with fresh-like characteristics. The multifactorial processes were based on emerging preservation factors in combination or combining emerging factors with traditional ones. Selected practical examples of fruit processing using UV light, pulsed light (PL), ultrasound (US), and high hydrostatic pressure (HHP) are presented. Some issues of key importance for the design of combination processes are also addressed.

Sensory shelf-life limiting factor of high hydrostatic pressure processed avocado paste.

UNLABELLED: High hydrostatic pressure (HHP) processing pasteurizes avocado paste without a significant impact on flavor. Although HHP-treated avocado paste stored under refrigeration is safe for human consumption for months, sensory changes taking place during storage cause the rejection of the product by consumers within days. Although it is known that the shelf life of the product ends before its microbial counts are high, its sensory shelf life limiting factor remains unknown. The present study focused on the use of a trained panel and a consumer panel to determine the sensory shelf life limiting factor of HHP-treated avocado paste. The trained panel identified sour and rancid flavors as the main sensory descriptors (critical descriptors) that differentiated stored from freshly processed samples. Further data obtained from consumers identified sour flavor as the main cause for a significant decrease in the acceptability (shelf life limiting factor) of refrigerated HHP-treated avocado paste. The study allowed the elucidation of a proposed deterioration mechanism for HHP-treated avocado paste during its refrigerated shelf life. The information through this work enhances scientific knowledge of the product and proposes the sour flavor development during storage as a relevant sensory attribute that needs to be improved in order to enhance the product shelf life. PRACTICAL APPLICATION: At present, HHP is the most effective commercial nonthermal technology to process avocado paste when compared to thermal and chemical alternatives. HHP-treated avocado paste is a microbiologically stable food for a period of at least 45 d stored under refrigeration. However, previous published work indicated that consumers rejected the product after approximately 19 d of storage due to sensory changes. This manuscript presents a sensory study that permitted the identification of the critical sensory descriptor that is acting as the sensory shelf life limiting factor of the product. The data presented herein along with previous reported data allows a better understanding of the deterioration mechanism that occurs during the storage of HHP-treated avocado paste. This information is relevant and useful for the elucidation of possible alternatives to enhance the shelf life of HHP-treated avocado paste.

Thermal, high pressure, and electric field processing effects on plant cell membrane integrity and relevance to fruit and vegetable quality.

Advanced food processing methods that accomplish inactivation of microorganisms but minimize adverse thermal exposure are of great interest to the food industry. High pressure (HP) and pulsed electric field (PEF) processing are commercially applied to produce high quality fruit and vegetable products in the United States, Europe, and Japan. Both microbial and plant cell membranes are significantly altered following exposure to heat, HP, or PEF. Our research group sought to quantify the degree of damage to plant cell membranes that occurs as a result of exposure to heat, HP, or PEF, using the same analytical methods. In order to evaluate whether new advanced processing methods are superior to traditional thermal processing methods, it is necessary to compare them. In this review, we describe the existing state of knowledge related to effects of heat, HP, and PEF on both microbial and plant cells. The importance and relevance of compartmentalization in plant cells as it relates to fruit and vegetable quality is described and various methods for quantification of plant cell membrane integrity are discussed. These include electrolyte leakage, cell viability, and proton nuclear magnetic resonance (¹H-NMR).

Utilização da pressão hidrostática na conservação de alimentos / Use of the hydrostatic pressure in the food conservation

O uso da alta pressão hidrostática no processamento de alimentos representa uma grande vantagem na indústria alimentícia. A alta pressão hidrostática é uma tecnologia que não utiliza calor e mantém as qualidades nutritivas e sensoriais do produto.Esta tecnologia também garante a qualidade microbiológica dos alimentos, pois é capaz de inativar microrganismos, assim como enzimas responsáveis pela diminuição do prazo de validade do alimento. É uma tecnologia que apresenta dois principais tipos de processamento e vários alimentos já são submetidos à alta pressão hidrostática. Novas pesquisas continuam sendo desenvolvidas com o objetivo de se conseguir uma maior aplicação da alta pressão hidrostática na indústria de alimentos. Assim, novos produtos poderão ser desenvolvidos, comercializados e bem aceitos pelos consumidores.(AU)

The high hydrostatic pressure in the food processing represents a great advantage in food industry. The high hydrostatic pressure is a technology which does not need heating, therefore conserving sensory and nutritional attributes of the product. This technology garantees high food' s microbiologic attributes, as the process must disable either microorganisms or enzimes responsible for reducing the self life. This is a technology wich works through two main patterns of processing procedures and n1any foodstuffs are processed with high hydrostatic pressure. New researchs keep on being carried out on the goal of attaining other usages for high hydrostatic pressure in the food industry. Hence, new products n1ay be developed, comercialized and better satisfy customers' demand. (AU)

Utilização da pressão hidrostática na conservação de alimentos / Use of the hydrostatic pressure in the food conservation

O uso da alta pressão hidrostática no processamento de alimentos representa uma grande vantagem na indústria alimentícia. A alta pressão hidrostática é uma tecnologia que não utiliza calor e mantém as qualidades nutritivas e sensoriais do produto.Esta tecnologia também garante a qualidade microbiológica dos alimentos, pois é capaz de inativar microrganismos, assim como enzimas responsáveis pela diminuição do prazo de validade do alimento. É uma tecnologia que apresenta dois principais tipos de processamento e vários alimentos já são submetidos à alta pressão hidrostática. Novas pesquisas continuam sendo desenvolvidas com o objetivo de se conseguir uma maior aplicação da alta pressão hidrostática na indústria de alimentos. Assim, novos produtos poderão ser desenvolvidos, comercializados e bem aceitos pelos consumidores.

New insights into the mechanisms of protein misfolding and aggregation in amyloidogenic diseases derived from pressure studies.

Hydrostatic pressure is a robust tool for studying the thermodynamics of protein folding and protein interactions, as well as the dynamics and structure of folding intermediates. One of the main innovations obtained from using high pressure is the stabilization of folding intermediates such as molten-globule conformations, thus providing a unique opportunity for characterizing their structure and dynamics. Equally important is the prospect of understanding protein misfolding diseases by using pressure to populate partially folded intermediates at the junction between productive and off-pathway folding, which may give rise to misfolded proteins, aggregates, and amyloids. High hydrostatic pressure (HHP) has also been used to dissociate nonamyloid aggregates and inclusion bodies. In many proteins, the competition between correct folding and misfolding can lead to formation of insoluble aggregates, an important problem for the biotechnology industry and for human pathologies such as amyloidosis, Alzheimer's, Parkinson's, prion's, and tumor diseases. The diversity of diseases that result from protein misfolding has made this theme an important research focus for pharmaceutical and biotechnology companies. The use of high-pressure promises to contribute to the identification of the mechanisms behind these defects and creation of therapies against these diseases.

Resposta contrátil de miócitos cardíacos isolados a níveis fisiológicos de pressão hidrostática / Contractile response of isolated cardiac myocytes to physiological levels of hydrostatic pressure

Com o advento da técnica de isolamento de células cardíacas por digestão enzimática, tornaram-se possíveis inúmeros estudos sobre a atividade contrátil cardíaca. Muito se tem progredido no estudo do acoplamento excitação-contração no coração sadio e doente. Contudo, na situação fisiológica, as células do coração estão submetidas a pressões da ordem de 100 mmHg durante parte do cliclo cardíaco, condição na qual se desconhece o comportamento dos miócitos, provavelmente pela dificuldade de montagem de preparação adequada. Com a possibilidade de medição de encurtamento celular por meio da detecção de borda de sinal de vídeo, realizamos um estudo do efeito de níveis diferentes de pressão, na faixa fisiológica, sobre a atividade contrátil de miócitos ventriculares isolados de ratos adultos, usando para isto uma câmara de perfusão desenvolvida no nosso laboratório. Os resultados indicaram que, para pressões supra-atmosféricas de até 140 mm-Hg, o limiar estimulatório, amplitude do encurtamento, tempo para encurtamento máximo e duração total da contração não foram afetados significativamente. Concluímos que a pressão hidrostática aplicada não deve submeter os miócitos a qualquer tensão, indicando que estes aparentemente comportam-se como recipientes homogeneamente preenchidos de fluido incompressível.

Dissociation of a native dimer to a molten globule monomer. Effects of pressure and dilution on the association equilibrium of arc repressor.

The monomer-dimer association reaction of Arc repressor was studied by pressure-induced dissociation and by dilution. The dissociation was measured by the decrease (red shift) in the average energy of emission of the tryptophan fluorescence. Pressure dissociation also promoted a decrease in the excited-state lifetime of the single tryptophanyl residue, Trp14. These observations suggest that Trp14 becomes exposed to an aqueous environment following dissociation. The pressure-dissociation curves were concentration dependent, with p1/2 (half-dissociation pressure) shifting to higher pressures as the concentration increased. The dissociation constant (KdO) obtained by extrapolating the pressure-dissociation curves to atmospheric pressure was similar to that determined from the dilution curve (KdO = 30 nM). An anomalous steepness of dissociation in response to dilution was observed, suggesting that conformational changes occur as a result of dissociation of Arc repressor. Binding of bis(8-anilinonaphthalene-1-sulfonate) to Arc repressor was not significantly affected by pressure dissociation, whereas thermal or urea denaturation was accompanied by a dramatic decrease in binding. These results suggest that the conformational changes that follow dissociation induced by pressure are more limited than those following denaturation. The tryptophan anisotropy decreased by about one-half, suggesting the dissociation of a globular dimer to a compact monomer. On the other hand, denaturation by urea promoted an increase in anisotropy, as expected for a random-coil conformation. Dissociated Arc has the hydrodynamic properties of a folded monomer. On the other hand, dissociated Arc has a high degree of exposure of hydrophobic side-chains, and the distribution of conformations is much broader than that in the folded dimer. These features suggest that the dissociated subunit is a molten globule. The subunit interaction was substantially increased by a single amino acid substitution (Pro8----Leu), and the free energy of stabilization amounted to -2.9 kcal/mol. This increased stability suggests that residue 8 is located in the dimer interface and that part of the tertiary and most of the quaternary structure constraints result from the interaction between the intersubunit beta-strands.