Sodium metabisulfite and SO2 release: an under-recognized hazard among shrimp fishermen

Since the introduction of sodium metabisulfite as a food preservative, it has been associated with several idiosyncratic reactions (eg, bronchospasm, oculonasal symptoms, and urticaria/angioedema) in sulfite-sensitive individuals. The pathogenic mechanism of these reactions is not yet understood. We report the case of two crewmen on a shrimp trawler who were found dead in the ship's hold. Their deaths had occurred while they were applying dry sodium metabisulfite, referred to as "shrimp dip" in the shrimping industry. Postmortem examinations showed diffuse pulmonary edema consistent with death secondary to asphyxia. Associated findings were visceral congestion. Although it is possible to measure death from sodium metabisulfite with available records, its potential morbidity cannot be estimated. It is known that sodium metabisulfite can react with acids and water, releasing toxic sulfur dioxide (SO2) gas. In addition, SO2 gas reacts with respiratory tissue forming sulfureous acid, and inducing a pulmonary reaction causing hypoxemia. Furthermore, sodium metabisulfite, compared with sodium bisulfite, has a much greater propensity to release SO2 gas. We conclude that there is a need for improved education regarding the potential side effects of sodium metabisulfite, thus eliminating needless occupational morbidity and mortality.     

LINKING RIVER MANAGEMENT TO SPECIES CONSERVATION USING DYNAMIC LANDSCAPE‐SCALE MODELS

Efforts to conserve stream and river biota could benefit from tools that allow managers to evaluate landscape‐scale changes in species distributions in response to water management decisions. We present a framework and methods for integrating hydrology, geographic context and metapopulation processes to simulate effects of changes in streamflow on fish occupancy dynamics across a landscape of interconnected stream segments. We illustrate this approach using a 482 km² catchment in the southeastern US supporting 50 or more stream fish species. A spatially distributed, deterministic and physically based hydrologic model is used to simulate daily streamflow for sub‐basins composing the catchment. We use geographic data to characterize stream segments with respect to channel size, confinement, position and connectedness within the stream network. Simulated streamflow dynamics are then applied to model fish metapopulation dynamics in stream segments, using hypothesized effects of streamflow magnitude and variability on population processes, conditioned by channel characteristics. The resulting time series simulate spatially explicit, annual changes in species occurrences or assemblage metrics (e.g. species richness) across the catchment as outcomes of management scenarios. Sensitivity analyses using alternative, plausible links between streamflow components and metapopulation processes, or allowing for alternative modes of fish dispersal, demonstrate large effects of ecological uncertainty on model outcomes and highlight needed research and monitoring. Nonetheless, with uncertainties explicitly acknowledged, dynamic, landscape‐scale simulations may prove useful for quantitatively comparing river management alternatives with respect to species conservation. Published 2012. This article is a U.S. Government work and is in the public domain in the USA.     

Recent Life Events Preceding Suicide Attempts in a Personality Disorder Sample: Findings From the Collaborative Longitudinal Personality Disorders Study.

Few studies have examined the relationship between life events, suicide attempts, and personality disorders (PDs), in spite of the strong associations between PDs and suicidal behavior, and the poor coping strategies often exhibited by these individuals. The authors examined whether participants with PDs who attempted suicide during the first 3 years of a prospective, longitudinal study were more likely to experience specific life events in the month during and preceding the suicide attempt. Of 489 participants with PDs, 61 attempted suicide during the 3-year, follow-up interval. Results indicated that negative life events, particularly those pertaining to love-marriage or crime-legal matters, were significant predictors of suicide attempts, even after controlling for baseline diagnoses of borderline PD, major depressive disorders, substance use disorders, and a history of childhood sexual abuse. Therefore, certain types of negative life events are unique risk factors for imminent suicide attempts among individuals with PDs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Associations in the Course of Personality Disorders and Axis I Disorders Over Time.

In this study, the authors examined time-varying associations between schizotypal (STPD), borderline (BPD), avoidant (AVPD), or obsessive-compulsive (OCPD) personality disorders and co-occurring Axis I disorders in 544 adult participants from the Collaborative Longitudinal Personality Disorders Study. The authors tested predictions of specific longitudinal associations derived from a model of crosscutting psychobiological dimensions (L. J. Siever & K. L. Davis, 1991) with participants with the relevant Axis I disorders. The authors assessed participants at baseline and at 6-, 12-, and 24-month follow-up evaluations. BPD showed significant longitudinal associations with major depressive disorder and posttraumatic stress disorder. AVPD was significantly associated with anxiety disorders (specifically social phobia and obsessive-compulsive disorder). Two of the four personality disorders under examination (STPD and OCPD) showed little or no association with Axis I disorders. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Two-Year Stability and Change of Schizotypal, Borderline, Avoidant, and Obsessive-Compulsive Personality Disorders.

The authors examined the stability of schizotypal (STPD), borderline (BPD), avoidant (AVPD) and obsessive-compulsive (OCPD) personality disorders (PDs) over 2 years of prospective multiwave follow-up. Six hundred thirty-three participants recruited at 4 collaborating sites who met criteria for 1 or more of the 4 PDs or for major depressive disorder (MOD) without PD were assessed with semistructured interviews at baseline, 6, 12, and 24 months. Lifetable survival analyses revealed that the PD groups had slower time to remission than the MDD group. Categorically, PD remission rates range from 50% (AVPD) to 61% (STPD) for dropping below diagnostic threshold on a blind 24-month reassessment but range from 23% (STPD) to 38% (OCPD) for a more stringent definition of improvement. Dimensionally, these findings suggest that PDs may be characterized by maladaptive trait constellations that are stable in their structure (individual differences) but can change in severity or expression over time. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Synthesis of Nickel Phosphide Nanorods as Catalyst for the Hydrotreating of Methyl Oleate

Arrays of nickel phosphide nanorods were successfully synthesized by nanocasting using mesostructured silica SBA-15 as a hard template (HT-Ni₂P). After temperature-programmed reduction of the phosphate precursor infiltrated within the pore walls of SBA-15, the unsupported material was obtained by removing the silica matrix with diluted HF. The pore channel of the SBA-15 template stabilizes the Ni₂P particles, preventing sintering after the high reduction temperature and shaping their elongated morphology. Moreover, HT-Ni₂P catalyst shows an improvement in the textural properties with a significantly higher surface area than the reference sample synthesized in the absence of template. X-ray diffraction revealed that the only crystalline phase present in this material was Ni₂P. On the other hand, transmission electron microscopy shows that the catalyst is mainly constituted by agglomerates of nanorods. Through EDX microanalysis the efficient removal of silicon was confirmed. Under hydrotreating conditions, nanorods of Ni₂P show a fourfold enhancement in the conversion of methyl oleate with respect to conventional Ni₂P synthesized in absence of hard template. Nevertheless, when these data are normalized to surface area, the specific activity of HT-Ni₂P nanorods is significantly lower than that of the conventionally prepared sample. Differences in selectivity were also observed as Ni₂P nanorods favored the decarboxylation reaction leading to a higher yield of n-heptadecane.     

Lignosulfonates: effects on plant growth and survival and migration through the soil profile

The effects of Lignosite^#rm lignosulfonate, a refined lignosulfonate product that is obtained from the sulfite pulping process, on growth and survival of plants were investigated. Following applications of 0, 7500, 15,000 and 22,500 cm³#shm² to 32 plots within a forest plantation, the following were monitored: (1) live aboveground biomass of vascular plants, (2) growth of Douglar fir (Pseudotsuga menziesii) and (3) lignosulfonate migration through the soil profile. Live aboveground biomass of woody vegetation was not affected, and that of herbaceous plants was significantly decreased only at the two greatest application rates. Growth of the Douglas fir trees was not significantly affected. Lignosulfonates disappeared from the soil profile at the same rate regardless of initial concentration. Although it is not practical to use this material as a herbicide in western Washington, land application of lignosulfonates may be environmentally more attractive than traditional disposal methods.     

The coding and effector transfer of movement sequences.

Three experiments utilizing a 14-element arm movement sequence were designed to determine if reinstating the visual–spatial coordinates, which require movements to the same spatial locations utilized during acquisition, results in better effector transfer than reinstating the motor coordinates, which require the same pattern of homologous muscle activation. Results demonstrated better transfer when visual–spatial coordinates were reinstated than when motor coordinates where reinstated regardless of the amount of practice (1, 4, or 12 days; Experiments 1–3, respectively). Transfer (left to right and right to left) was symmetric when visual–spatial coordinates were reinstated but not when motor coordinates were reinstated. When motor coordinates were reinstated after 12 days of practice and vision occluded, transfer was better from right limb to left than vice versa. The data are also consistent with the notion that multiple codes (visual, spatial, and motor) are developed over practice, with each contributing to transfer performance when the respective coordinates are reinstated. Further, the results indicate a disruption of the linkage (concatenation) between subsequences when one or more coordinates are changed on the transfer test. (PsycINFO Database Record (c) 2010 APA, all rights reserved)