Catastrophic Stress Research Articles

Energy harvesting for damage assessment: A novel approach for detecting and evaluating structural defects in composite laminates

The presence of cutouts within mechanical equipment and systems can give rise to catastrophic stress concentrations and local buckling, leading to the initiation and propagation of damage. In addressing this issue, we leverage the concept of energy harvesting as a diagnostic approach. Beyond conventional fault diagnosis methods that rely solely on measuring changes in displacement amplitude, we propose an innovative method that harnesses the generated voltage. This novel approach investigates the impact of cutouts (holes) with varying diameters, which represent critical defects, on energy harvesting and displacement amplitude within 8-layer E-glass/epoxy composite specimens. Piezoelectric transducers are employed to execute energy harvesting, complemented by a laser displacement sensor for capturing sample displacement amplitudes. A bespoke measuring circuit is developed to quantify the stored voltage in a capacitor. Analysis of the findings reveals that the presence of damage, its severity, and its spatial distribution induce alterations akin to changes observed in displacement amplitudes. The study demonstrated that after applying the first cutout, a 75% and 65% reduction in harvested energy and a 60% and 46% decrease in displacement amplitude occurred for 14 and 10 mm cutouts respectively. By increasing the number of cutouts, these parameters depicted decreasing trends with a lower intensity. This alternative method offers an efficient, effective, and low-cost strategy for detecting and assessing damage and its severity in composite laminates. By demonstrating the correlation between damage-induced variations in harvested energy and conventional displacement measurements, our study contributes to advancing non-destructive evaluation techniques for composite structures. The effectiveness, cheapness, and convenience in implementation and detecting defects in composite laminates, are the practical implications and potential applications of the current work.

Screening of Cicer arietinum L. genotypes under combined presence of NaCl and anthracene using membership function value of stress tolerance

Polycyclic Aromatic Hydrocarbons (PAHs) are mutagenic, carcinogenic compounds that are persistent in environment and limits overall growth of plants. Anthracene is a starting member and one of the simplest compound of all 16 known PAHs. It is an integral part of many carcinogenic PAHs. Being ubiquitous, PAHs can be present in saline soils also. Salinity is the one of major catastrophic stress affecting plant development. Thus, the present study aimed at studying the combined effect of salt and PAHs on the Cicer arietinum L. (Chickpea). 10 Chickpea genotypes were screened on the basis of their response to the combined presence of NaCl and Anthracene. Optimum NaCl, Anthracene and Combined NaCl and Anthracene concentration calculated using Stress Injury Index was 40 mM, 5 mg and 60 + 5 mg A respectively. Various morphological and Physiological traits were studied and the data collected was evaluated by calculating the Stress Tolerance Index and Membership Function Value of stress tolerance as well as regression analysis was done for further validation. Results revealed that combined stress of NaCl and Anthracene have a synergistic effect on plant growth. On the basis of results obtained, GPF2 and PDG4 were selected as most tolerant and most sensitive chickpea genotypes. Of all the traits studied, dry weight of shoot was found to be the most reliable trait for studying the effect of NaCl and Anthracene alone whereas root length was found to be the most reliable trait for studying the combined effect of NaCl and Anthracene.

Coping strategies used by adult survivors in the process of recovery from disaster trauma: A narrative review

Abstract CONTEXT: The catastrophic stress of disasters and the associated secondary traumas lead to negative mental health outcomes in a great proportion of survivors. A range of coping strategies are used, which may have possible preventive and therapeutic effects related to posttraumatic stress-related manifestation. AIMS: It is essential to learn about the coping strategies employed by the survivors following disasters to reflect about their usability as possible intervention methods. This review intended to explore the literature about coping mechanisms used by adult survivors of the disasters. METHODS: Comprehensive literature search and review. RESULTS: It was observed that various coping strategies have been reported, along with posttraumatic mental health conditions. Many of the coping strategies differ in different cultures and other demographic groups. Some articles have made reference to the effectiveness of the coping strategies. It has been observed that the ways coping can be facilitated at different levels. These observations may help in designing culture-specific, pre- and post-disaster management programs for effective and holistic recovery of the survivors. CONCLUSION: There is a need to understand the coping mechanisms in different cultures and the factors associated with the resilience in the face of the massive trauma of disasters. It is probable that these could be instrumental in recovery process and expected to help in supporting disaster survivors.

Estimation of COVID-19-induced depletion of hospital resources in Ontario, Canada.

The global spread of coronavirus disease 2019 (COVID-19) continues in several jurisdictions, causing substantial strain to health care systems. The purpose of our study was to predict the effect of the COVID-19 pandemic on patient outcomes and use of hospital resources in Ontario, Canada. We developed an individual-level simulation to model the flow of patients with COVID-19 through the hospital system in Ontario. We simulated different combined scenarios of epidemic trajectory and hospital health care capacity. Our outcomes included the number of patients who needed admission to the ward or to the intensive care unit (ICU) with or without the need for mechanical ventilation, number of days to resource depletion, number of patients awaiting resources and number of deaths. We found that with effective early public health measures, hospital system resources would not be depleted. For scenarios with late or ineffective implementation of physical distancing, hospital resources would be depleted within 14-26 days, and in the worst case scenario, 13 321 patients would die while waiting for needed resources. Resource depletion would be avoided or delayed with aggressive measures to increase ICU, ventilator and acute care hospital capacities. We found that without aggressive physical distancing measures, the Ontario hospital system would have been inadequately equipped to manage the expected number of patients with COVID-19 despite a rapid increase in capacity. This lack of hospital resources would have led to an increase in mortality. By slowing the spread of the disease using public health measures and by increasing hospital capacity, Ontario may have avoided catastrophic stresses to its hospitals.

Potential Magnitude of COVID-19-Induced Healthcare Resource Depletion in Ontario, Canada

ABSTRACT Background The global spread of coronavirus disease 2019 (COVID-19) continues in several jurisdictions, causing significant strain to healthcare systems. The purpose of our study is to predict the impact of the COVID-19 pandemic on patient outcomes and the healthcare system in Ontario, Canada. Methods We developed an individual-level simulation to model the flow of COVID-19 patients through the Ontario healthcare system. We simulated different combined scenarios of epidemic trajectory and healthcare capacity. Outcomes include numbers of patients needing admission to the ward, Intensive Care Unit (ICU), and requiring ventilation; days to resource depletion; and numbers of patients awaiting resources and deaths associated with limited access to resources. Findings We demonstrate that with effective early public health measures system resources need not be depleted. For scenarios considering late or ineffective implementation of physical distancing, health system resources would be depleted within 14-26 days. Resource depletion was also avoided or delayed with aggressive measures to rapidly increase ICU, ventilator, and acute care hospital capacity. Interpretation We found that without aggressive physical distancing measures the Ontario healthcare system would have been inadequately equipped to manage the expected number of patients with COVID-19, despite the rapid capacity increase. This overall lack of resources would have led to an increase in mortality. By slowing the spread of the disease via ongoing public health measures and having increased healthcare capacity, Ontario may have avoided catastrophic stresses to its health care system.

Crosstalk between Abscisic Acid and Auxin under Osmotic Stress

Since their early migration from aquatic environments to land, plants have been susceptible to numerous variable environmental stresses, which strongly influenced their growth and development. Among these, osmotic stress is potentially one of the most catastrophic stresses. Phytohormones immensely contribute to the adaptation of plants in response to these stresses, and much research has been done regarding crosstalk between different plant hormones in synergistic or antagonistic interactions. However, the possible associations between auxin and abscisic acid (ABA) under changing environmental conditions (especially osmotic stress) have not been well clarified at this time. Biologists are becoming increasingly interested in revealing the possible crosstalk between ABA and auxin in the acquisition of these stress resistance mechanisms. Recently, progress has been made in identifying the stress perception, transduction, and possible biosynthetic signaling pathways of the two endogenous hormones and the genes that are key mediators of their pathways. However, there is still a large information gap regarding the ABA–auxin crosstalk module under osmotic stress. Given the current state of information, we focused on summarizing the converging points of ABA and auxin under osmotic stress, as this could potentially be a strong topic of extensive research in the coming years.Core Ideas We summarize the main findings on abscisic acid (ABA) and auxin under osmotic stress. We briefly explain the physiological mechanisms in which ABA and auxin have some crosstalk. We also discuss the different possible molecular associations of ABA and auxin under osmotic stress.

Depression in Youth Exposed to Disasters, Terrorism and Political Violence.

This paper reviews recent research on the depression in young people following exposure to catastrophic stresses such as disasters, terrorism and political violence. Depression is one of the commonest outcomes following mass trauma, for all ages including children and adolescents. Recent articles continue to report high prevalence of depression which often continues for years. It is often comorbid with other psychiatric disorders, especially PTSD. Post-traumatic depression in children and adolescence affects purpose of life, impairs scholastic achievements, increases suicidality and has extensive comorbidity. Besides the trauma, individual constructs, personality factors, social support, exposure to other traumatic events are some of the predicting factors. Biological and genetic basis of post-traumatic depression has been reported. Studies suggest some benefit to psychotherapeutic interventions such as trauma-focussed cognitive behavioural therapy and web-based therapy. A considerable proportion of youths develop depression following mass traumatic events. More research is required regarding the effectiveness of interventions in this population.

Catastrophic stress corrosion failure of Zr-base bulk metallic glass through hydrogen embrittlement

Zr-base bulk metallic glasses (BMG) are prone to pitting corrosion in halide containing solutions and also stress corrosion cracking (SCC) is often interpreted in this context. This work presents in situ SCC experiments on notched Zr52.5Cu17.9Ni14.6Al10Ti5 (at.%) BMG bars under 3-point bending in dilute NaCl solution. They show that pitting corrosion is only the initiating process. The pitted areas have a lower local corrosion potential and the reaction of Zr4+ to zirconyl ions in solution produces H+ that can be reduced and absorbed in the local acidic environment. So, hydrogen embrittlement causes the observed catastrophic failure and peculiar fracture surface characteristics.

Modelling of catastrophic stress development due to mixed oxide growth in thermal barrier coatings

Abstract In thermal barrier coatings (TBCs) of heavy-duty gas turbines, thermally grown oxide (TGO) develops in two stages, i.e. firstly, a thin layer of dense protective α-Al2O3 forms slowly, and then, a layer of porous detrimental mixed oxide (MO) between top coat (TC) and α-Al2O3 appears. During long-term isothermal oxidation at high temperature, the failure of TBCs usually occurs when a critical thickness of MO is reached, but the exact failure mechanism is still largely unclear, let alone the related stress development. In this paper, we analyze the stress evolution and the resultant failure modes due to the whole-layer growth of uniform MO. The results show that it is MO, rather than α-Al2O3, that is mainly responsible for the micro-cracking and/or delamination in TBCs. The fast growth of expansive MO induces catastrophic stresses, which leads to micro-cracking in the α-Al2O3 layer. The cracking of α-Al2O3 layer reduces the oxidation resistance and further accelerates the MO growth. Our theoretical analysis provides a reasonable explanation of the experimental results.

Discontinuities as a way to influence the failure mechanisms and tensile performance of hybrid carbon fiber/self-reinforced polypropylene composites

Interlayer hybrid carbon fiber/self-reinforced polypropylene composites possess a rare combination of lightness, stiffness and ductility, but they do suffer from a catastrophic stress drop when the carbon fiber layer fractures. To promote a gradual failure of the hybrids, we introduced discontinuities in the carbon fiber layer by partially cutting it at multiple locations perpendicularly to the fiber direction. By altering characteristics of the discontinuities (their length and number over the specimen width), we were able to influence the failure mechanisms and tensile performance of these hybrid composites. When the cut length was increased to 15 mm, the carbon fiber layer fragmented and delaminated at the cut sites inducing a gradual failure development in the hybrid. The concept of fracture process zone was applied to explain the failure mechanisms in these hybrid composites.

Perspectives on massive coral growth rates in a changing ocean.

The tropical ocean environment is changing at an unprecedented rate, with warming and severe tropical cyclones creating obvious impacts to coral reefs within the last few decades and projections of acidification raising concerns for the future of these iconic and economically important ecosystems. Documenting variability and detecting change in global and regional climate relies upon high-quality observational records of climate variables supplemented, prior to the mid-19th century, with reconstructions from various sources of proxy climate information. Here we review how annual density banding patterns that are recorded in the skeletons of massive reef-building corals have been used to document environmental change and impacts within coral reefs. Massive corals provide a historical perspective of continuous calcification processes that pre-date most ecological observations of coral reefs. High-density stress bands, abrupt declines in annual linear extension, and evidence of partial mortality within the skeletal growth record reveal signatures of catastrophic stress events that have recently been attributed to mass bleaching events caused by unprecedented thermal stress. Comparison of recent trends in annual calcification with century-scale baseline calcification rates reveals that the frequency of growth anomalies has increased since the late 1990s throughout most of the world's coral reef ecosystems. Continuous coral growth histories provide valuable retrospective information on the coral response to environmental change and the consequences of anthropogenic climate change. Co-ordinated efforts to synthesize and combine global calcification histories will greatly enhance our understanding of current calcification responses to a changing ocean.

Management of tooth with failed regeneration procedure

Teeth with immature root development, necrotic pulps, and apical periodontitis present multiple challenges for successful endodontic treatment. Regenerative endodontics is a contemporary approach to managing these problems. Successful regeneration depends on a race between the new tissue and bacteria populating the pulp space and on the ability of the patient to heal the dental pulp tissues. Importance of prevention of bacterial entry into the root canal and maintaining proper coronal seal should not be overemphasized. Evidence suggests that mineral trioxide aggregate (MTA) apexification may be more beneficial for severely injured teeth than a regenerative endodontic procedure. Fiber posts, in combination with composite resin or with accessory fiber posts, can be recommended alternative to cast post and core in flared roots, due to the lower risk of catastrophic failures and better stress distribution. It is the tactic of choice for reinforcing structurally weakened roots as the function, and the prognosis of the restored root is improved, compared with the use of one single, inadequately fitting post. This report is about a case with failed regeneration procedure and managed with MTA apexification and multiple fiber posts to enhance its fracture resistance of maxillary central incisor. Clinical Relevance To Interdisciplinary Dentistry Mineral trioxide aggregate apexification may be more beneficial for severely injured teeth than a regenerative endodontic procedure Large diameter posts contribute more favorably to the fracture resistance of the root postcore-crown system than small diameter posts Fiber posts, in combination with composite resin or with accessory fiber posts, can be recommended alternative to cast post and core in flared roots, because of the lower risk of catastrophic failures and better stress distribution.

EPA-1611 - Augmentation of paroxetine with mirtazapine in PTSD

The course of PTSD is often chronic and impedes individual's functioning. Subjective reports of sleep disturbance indicate that 70-91% of patients with post-traumatic stress disorder (PTSD) have difficulty falling or staying asleep. Nightmares are reported by 19-71% of patients, depending on the severity of their PTSD and their exposure to physical aggression. Paroxetine is a potent and selective inhibitor of the neuronal reuptake of serotonin, effective in PTSD. Mirtazapine is a noradrenergic and specific serotonergic antidepressant, its primary use is the treatment of major depressive disorder and other mood disorders and it is helpful in PTSD by suppressing nightmare activity or in blocking the memory of the dream state upon awakening. Mirtazapine's unique mechanism of action may account for its success in augmentation. Combining mirtazapine with a SSRI has been shown to be superior to antidepressants alone and improve sleep in patients with PTSD.The purpose of present study was to asses efficacy and tolerability of augmentation of paroxetine with mirtazapine in PTSD. It is single centre, nonrandomized, open-label, parallel group study, in 20 inpatients diagnosed as PTSD, according to ICD-10 Classification, received paroxetine alone (30-40 mg AM.) or in combination with mirtazapine (30-45 mg b.t.). Subjects were divided into two groups-paroxetine group (13) and paroxetine/mirtazapine group (17). Paroxetine as monotherapy or combined with mirtazapine is effective and safe in treatment of PTSD, however, mirtazapine co-therapy might produce a more rapid response, with the positive result of this use of mirtazapine for this disorder, given the devastating effects of the nightmares and sleeplessness caused by catastrophic stress.

Body temperature and respiratory dynamics in un-shaded beef cattle

In this study body temperature (BT, °C) and panting score (PS, 0-4.5; where 0 = no panting/no stress and 4.5 = catastrophic stress) data were obtained from 30 Angus steers housed outside over 120 days Steers were implanted with a BT transmitter on day -31, BT was recorded at 30-min intervals to a data logger and downloaded each day to a database. The cattle were housed in ten outdoor un-shaded pens with an earthen floor, eight of which had a pen floor area of 144 m2 (three transmitter steers plus five non-transmitter steers; 18 m2/steer) and two had an area of 168 m2 (three transmitter steers and six non-transmitter steers; 18.7 m2/steer). Only data from the transmitter steers were used in this study. The PS of the steers was obtained daily (± 15 min) at 0600 hours (AM), 1200 hours (MD) and 1600 hours (PM). At the same times climate variables (ambient temperature, black globe temperature, solar radiation, relative humidity, wind speed and rainfall) were obtained from an on-site weather station. PS observations were made from outside the pens so as not to influence cattle responses. The two closest BT values to the time when PS was obtained were downloaded retrospectively from a logger and averaged. A total of 8,352 observations were used to generate second order polynomial response curves: (AM) y = 39.08 + 0.009 x + 0.137x2 (R2 = 0.94; P < 0.001) (MD) y = 39.09 + 0.914x − 0.080x2 (R2 = 0.89; P < 0.001) and (PM) y = 39.52 + 0.790x − 0.068x2 (R2 = 0.83; P < 0.001) where y = BT (°C) and x PS. These data suggest that PS is a good indicator of body temperature. The BT at MD corresponded to slightly lower PS compared with PM, e.g., for PS 1; BT at MD = 39.1 ± 0.05 °C whereas BT at PM = 39.5 ± 0.05 °C. However during AM, BT was lower (P < 0.05) at PS 1, 2 and 2.5 compared with MD and PM. For example, when PS was 2.5 the BT at AM was 40.2 ± 0.04 °C, at MD it was 40.9 ± 0.04 °C and at PM BT was 41.1 ± 0.04 °C. When PS was 0 the BT at AM and MD were similar. The AM response curve suggests animals attempt to increase heat dissipation during the cooler AM period relative to MD and PM. Morning observation of cattle (before feeding) are crucial for effective heat load management especially on days when high heat load is expected. The MD and PM observations provide a good indication of the impact of high environmental heat load on cattle. Differences in PS between AM and PM observations suggest that more research is needed to determine the effect of night time conditions on BT, PS and overall respiratory dynamics of cattle during periods of hot weather.

LIM Domains Target Actin Regulators Paxillin and Zyxin to Sites of Stress Fiber Strain

Contractile actomyosin stress fibers are critical for maintaining the force balance between the interior of the cell and its environment. Consequently, the actin cytoskeleton undergoes dynamic mechanical loading. This results in spontaneous, stochastic, highly localized strain events, characterized by thinning and elongation within a discrete region of stress fiber. Previous work showed the LIM-domain adaptor protein, zyxin, is essential for repair and stabilization of these sites. Using live imaging, we show paxillin, another LIM-domain adaptor protein, is also recruited to stress fiber strain sites. Paxillin recruitment to stress fiber strain sites precedes zyxin recruitment. Zyxin and paxillin are each recruited independently of the other. In cells lacking paxillin, actin recovery is abrogated, resulting in slowed actin recovery and increased incidence of catastrophic stress fiber breaks. For both paxillin and zyxin, the LIM domains are necessary and sufficient for recruitment. This work provides further evidence of the critical role of LIM-domain proteins in responding to mechanical stress in the actin cytoskeleton.

Casing Ultradeep, Ultralong Salt Sections in Deep Water

This article, written by Assistant Technology Editor Karen Bybee, contains highlights of paper SPE 114273, "Casing Ultradeep, Ultralong Salt Sections in Deep Water: A Case Study for Failure Diagnosis and Risk Mitigation in Record-Depth Well," by Jincai Zhang, SPE, Shell Oil Company; William Standifird, SPE, Knowledge Systems; and Chris Lenamond, SPE, Nexen Petroleum U.S.A., originally prepared for the 2008 SPE Annual Technical Conference and Exhibition, Denver, 21-24 September. The paper has not been peer reviewed. The deepest well drilled to date in the Gulf of Mexico (GOM), the Well 1 discovery well in Green Canyon, required setting casing in a 15,000-ft-thick section of tectonically active salt. After casing collapsed in the initial wellbore, a comprehensive model was developed to characterize wellbore stability, the salt-creep mechanism and its implications for well design, and mitigation options for future well construction. Introduction Subsalt and near-salt formations are among the most attractive exploration prospects in many operating areas including the GOM, offshore West Africa, Brazil, the southern North Sea, Egypt, and the Middle East. One of the characteristic features of the northern GOM salt trend is that the salt bodies are highly mobile. High mobility has two significant implications for wells drilled through salt: "creeping" salt masses can exert catastrophic stresses on casing, and in areas near the salt/rock interface, salt movement can create unstable rubble zones that can make drilling difficult or impossible. One of the key challenges for well construction in subsalt environments is maintaining casing integrity. Salt-induced casing collapse has occurred in a number of GOM wells, including Well 1. Well 1 was drilled in 2005 and, at the time of construction, was the deepest well in the GOM. The well was drilled through a salt body more than 15,000 ft thick and eventually reached a total depth of more than 28,000 ft true vertical depth. The casing collapsed near the base of the salt nearly 3 months after the salt section was cased. The wellbore was abandoned and was sidetracked successfully to reach 34,189 ft. The objective of this study was to characterize the salt-creep mechanism and its implications for casing failure in Well 1 and to develop options for well design to avoid future failure events. Well 1 experienced drilling-fluid losses and hole ballooning in the subsalt formations. Given the extreme depths, fluid losses and hole ballooning could jeopardize the feasibility of future projects in the area. Analysis of the geomechanical environment reveals many challenges; northern-GOM salt bodies are among the most varied and complex in the world. Some are active; some are passive. On a local geologic scale, the dynamics of salt creep are dependent on such factors as temperature, salt mineralogy, and overburden.

Sustained blood pressure increase after an acute stressor: the effects of the 11 September 2001 attack on the New York City World Trade Center

Effects of catastrophic stress on blood pressure are well documented, but usually few measurements were taken before the event occurred, and the people studied were directly involved or geographically close to the disaster. The impact of the 11 September 2001 (9/11) attacks in New York City had far greater reach, and has been sustained by subsequent events. To test the hypothesis that, after the 9/11 attacks, blood pressures in the population affected would be increased compared with that in both the preceding months and the same period during the previous year. We used data available from a current study of blood pressure in four sites in the USA that enabled us to examine them from two perspectives: a mixed (within and between groups) analysis that tested the overall differences in blood pressure before and after 9/11, and a within-subjects model to examine the more focused issue of individual change in blood pressure after 9/11. The blood pressures of 427 hypertensive individuals were telemonitored at four sites. An additional 101 patients had been monitored at two sites during the same period in the previous year. Mean systolic blood pressure was significantly greater during the 2 months after 9/11, across the four sites, compared with that assessed during the previous 2 months (range of observed differences 1.7-3.8 mmHg). At the two sites for which data were available for the same period in the year 2000, there was also a significant effect for the same period during the preceding year for systolic blood pressure. However, at both these sites the effect at 2000 was significantly smaller than the effect at 2001. Blood pressure also generally increased among those individuals in whom monitoring overlapped the 9/11 event. The World Trade Center attacks produced a substantial and sustained increase in blood pressure that appears to be independent of seasonal effects, and which has important implications for morbidity and financial burden. The ubiquitous continuing reference to the events in the news reports may contribute to the sustained effects.

High-Reliability Topological Architectures for Networks Under Stress

In this paper, we consider the design of a physical network topology that meets a high level of reliability using unreliable network elements. We are motivated by the use of networks and, in particular, all-optical networks, for high-reliability applications which involve unusual and catastrophic stresses. Our network model is one in which nodes are invulnerable and links are subject to failure - a good approximation for optical networks with passive nodes and vulnerable fiber under stress of disconnection - and we focus on statistically independent link failures with initial steps taken toward generalization to dependent link failures. Our reliability metrics are the all-terminal connectedness measure and the less commonly considered two-terminal connectedness measure. We compare in the low and high stress regimes, via analytical approximations and simulations, common commercial architectures designed for all-terminal reliability when links are very reliable with alternative architectures which are mindful of both of our reliability metrics and regimes of stress. We derive new results especially for one of these alternative architectures, Harary graphs, which have been shown to possess attractive reliability properties. Furthermore, we show that for independent link failures network design should be optimized with respect to reliability under high stress, as reliability under low stress is less sensitive to graph structure; and that under high stress, very high node degrees and small network diameters are required to achieve moderate reliability performance. Finally, in our discussion of correlated failure models, we show the danger in relying on an independent failure model and the need for the network architect to minimize component failure dependencies.

EFFECTS OF A LONG-TERM PSYCHOSOCIAL NURSING INTERVENTION ON ADOLESCENTS EXPOSED TO CATASTROPHIC STRESS

This research tested the effects of a long-term psychosocial nursing intervention designed to decrease mental distress in adolescents following a catastrophic event. Advanced Practice Psychiatric Nurses conducted the Catastrophic Stress Intervention (CSI) in two South Carolina high schools for three years following Hurricane Hugo. The CSI consisted of nine protocols designed to decrease adolescents' mental distress by increasing their understanding of stress and by enhancing their self-efficacy and social support. Adolescents ( N = 1030) were randomized to intervention or control groups and completed one baseline and five postintervention measures of mental distress, self-efficacy, and social support. The hypothesis was that intervention adolescents would have less mental distress than control adolescents. The research also addressed the particular time points at which differences between intervention and control adolescents might be shown. Repeated measures multivariate analysis of variance, with exposure to the hurricane, self-efficacy, and social support as control variables, showed that intervention adolescents reported less mental distress than control adolescents at 12, 18, and 24 months but that this difference dissipated by 30 and 36 months. Implications for the CSI and timing of interventions with adolescents after a catastrophic event are discussed.

Threatened obligatory riverine fishes in human‐modified Polish rivers

Abstract – The fate of obligatory riverine fish species (rheophils), which are the objects of anglers' exploitation (chub –Leuciscus cephalus, nase –Chondrostoma nasus, barbel –Barbus barbus, gudgeon –Gobio gobio), and brown trout (Salmo trutta m. fario) and grayling (Thymallus thymallus) (in the Gwda River basin only), were investigated in large alluvial rivers (Pilica and Warta) and in the medium‐sized Gwda River basin. The Pilica (1973) and the Warta (1986–1987) were divided by large dams without fish ladders in their middle courses. The Gwda River was divided by only a few dams along its course, but its tributaries carrying pure water had numerous small dams that supplied water for fish farms. Other stresses influencing fish populations in these rivers were: pollution, overfishing, hydroelectric plants and bank revetments. Because the listed stresses occurred alternately and at various periods of time in these rivers, this enabled attributing the cause for extinction and reduction of the abundance and distribution. In the salmon Gwda River basin, a drastic decrease in spatial distribution and reduction of occurrence ranges of brown trout, grayling and barbel was evident in respect to the first study period (1980s) in the 1990s. In the large, alluvial Pilica River, nase, barbel and dace are on the edge of extinction and chub and gudgeon are vulnerable. In the Warta's tailwater, barbel is an extinct species, and chub, dace and gudgeon are vulnerable ones. In a site in the backwater, none of the above mentioned species became extinct, but their abundance and occurrence frequency decreased a bit in respect to the pre‐impoundment period. Roach‐generalist, which was used in this research as a “control” species, increased in abundance in all 3 rivers. These investigations univocally proved that the dams cause catastrophic stress for obligatory riverine species.NOTE