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1.
PLoS One ; 17(5): e0267183, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35613082

RESUMEN

INTRODUCTION: Amyotrophic lateral sclerosis (ALS) is an invariably lethal progressive disease, causing degeneration of neurons and muscle. No current treatment halts or reverses disease advance. This single arm, open label, clinical trial in patients with ALS investigated the safety and tolerability of a novel modified low molecular weight dextran sulphate (LMW-DS, named ILB®) previously proven safe for use in healthy volunteers and shown to exert potent neurotrophic effects in pre-clinical studies. Secondary endpoints relate to efficacy and exploratory biomarkers. METHODS: Thirteen patients with ALS were treated with 5 weekly subcutaneous injections of ILB®. Safety and efficacy outcome measures were recorded weekly during treatment and at regular intervals for a further 70 days. Functional and laboratory biomarkers were assessed before, during and after treatment. RESULTS: No deaths, serious adverse events or participant withdrawals occurred during or after ILB® treatment and no significant drug-related changes in blood safety markers were evident, demonstrating safety and tolerability of the drug in this cohort of patients with ALS. The PK of ILB® in patients with ALS was similar to that seen in healthy controls. The ILB® injection elicited a transient elevation of plasma Hepatocyte Growth Factor, a neurotrophic and myogenic growth factor. Following the ILB® injections patients reported increased vitality, decreased spasticity and increased mobility. The ALSFRS-R rating improved from 36.31 ± 6.66 to 38.77 ± 6.44 and the Norris rating also improved from 70.61 ± 13.91 to 77.85 ± 14.24 by Day 36. The improvement of functions was associated with a decrease in muscle atrophy biomarkers. These therapeutic benefits decreased 3-4 weeks after the last dosage. CONCLUSIONS: This pilot clinical study demonstrates safety and tolerability of ILB® in patients with ALS. The exploratory biomarker and functional measures must be cautiously interpreted but suggest clinical benefit and have a bearing on the mechanism of action of ILB®. The results support the drug's potential as the first disease modifying treatment for patients with ALS. TRIAL REGISTRATION: EudraCT 2017-005065-47.


Asunto(s)
Esclerosis Amiotrófica Lateral , Biomarcadores , Estudios de Cohortes , Humanos , Evaluación de Resultado en la Atención de Salud
2.
J Pers Med ; 11(8)2021 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-34442438

RESUMEN

Oxidative/nitrosative stress and mitochondrial dysfunction is a hallmark of amyotrophic lateral sclerosis (ALS), an invariably fatal progressive neurodegenerative disease. Here, as an exploratory arm of a phase II clinical trial (EudraCT Number 2017-005065-47), we used high performance liquid chromatography(HPLC) to investigate changes in the metabolic profiles of serum from ALS patients treated weekly for 4 weeks with a repeated sub-cutaneous dose of 1 mg/kg of a proprietary low molecular weight dextran sulphate, called ILB®. A significant normalization of the serum levels of several key metabolites was observed over the treatment period, including N-acetylaspartate (NAA), oxypurines, biomarkers of oxidative/nitrosative stress and antioxidants. An improved serum metabolic profile was accompanied by significant amelioration of the patients' clinical conditions, indicating a response to ILB® treatment that appears to be mediated by improvement of tissue bioenergetics, decrease of oxidative/nitrosative stress and attenuation of (neuro)inflammatory processes.

3.
Thorax ; 74(10): 958-964, 2019 10.
Artículo en Inglés | MEDLINE | ID: mdl-31434752

RESUMEN

INTRODUCTION: Breathlessness is common in the population, especially in women and associated with adverse health outcomes. Obesity (body mass index (BMI) >30 kg/m2) is rapidly increasing globally and its impact on breathlessness is unclear. METHODS: This population-based study aimed primarily to evaluate the association of current BMI and self-reported change in BMI since age 20 with breathlessness (modified Research Council score ≥1) in the middle-aged population. Secondary aims were to evaluate factors that contribute to breathlessness in obesity, including the interaction with spirometric lung volume and sex. RESULTS: We included 13 437 individuals; mean age 57.5 years; 52.5% women; mean BMI 26.8 (SD 4.3); mean BMI increase since age 20 was 5.0 kg/m2; and 1283 (9.6%) reported breathlessness. Obesity was strongly associated with increased breathlessness, OR 3.54 (95% CI, 3.03 to 4.13) independent of age, sex, smoking, airflow obstruction, exercise level and the presence of comorbidities. The association between BMI and breathlessness was modified by lung volume; the increase in breathlessness prevalence with higher BMI was steeper for individuals with lower forced vital capacity (FVC). The higher breathlessness prevalence in obese women than men (27.4% vs 12.5%; p<0.001) was related to their lower FVC. Irrespective of current BMI and confounders, individuals who had increased in BMI since age 20 had more breathlessness. CONCLUSION: Breathlessness is independently associated with obesity and with weight gain in adult life, and the association is stronger for individuals with lower lung volumes.


Asunto(s)
Índice de Masa Corporal , Disnea/fisiopatología , Pulmón/fisiopatología , Obesidad Abdominal/fisiopatología , Aumento de Peso/fisiología , Estudios Transversales , Disnea/epidemiología , Disnea/etiología , Femenino , Volumen Espiratorio Forzado , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Obesidad Abdominal/complicaciones , Obesidad Abdominal/epidemiología , Pronóstico , Fumar/efectos adversos , Suecia/epidemiología
4.
Nat Commun ; 6: 6441, 2015 Mar 04.
Artículo en Inglés | MEDLINE | ID: mdl-25737320

RESUMEN

Patterns in biomass production are determined by resource input (productivity) and trophic transfer efficiency. At fixed resource input, variation in consumer biomass production has been related to food quality, metabolic type and diversity among species. In contrast, intraspecific variation in individual body size because of ontogenetic development, which characterizes the overwhelming majority of taxa, has been largely neglected. Here we show experimentally in a long-term multigenerational study that reallocating constant resource input in a two-stage consumer system from an equal resource delivery to juveniles and adults to an adult-biased resource delivery is sufficient to cause more than a doubling of total consumer biomass. We discuss how such changes in consumer stage-specific resource allocation affect the likelihood for alternative stable states in harvested populations as a consequence of stage-specific overcompensation in consumer biomass and thereby the risk of catastrophic collapses in exploited populations.


Asunto(s)
Agricultura/métodos , Cadena Alimentaria , Fundulidae/crecimiento & desarrollo , Modelos Biológicos , Factores de Edad , Animales , Biomasa , Tamaño Corporal , Simulación por Computador , Estudios Longitudinales , Dinámica Poblacional , Especificidad de la Especie
5.
J Anim Ecol ; 84(2): 414-26, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25314614

RESUMEN

Coexistence of predators that share the same prey is common. This is still the case in size-structured predator communities where predators consume prey species of different sizes (interspecific prey responses) or consume different size classes of the same species of prey (intraspecific prey responses). A mechanism has recently been proposed to explain coexistence between predators that differ in size but share the same prey species, emergent facilitation, which is dependent on strong intraspecific responses from one or more prey species. Under emergent facilitation, predators can depend on each other for invasion, persistence or success in a size-structured prey community. Experimental evidence for intraspecific size-structured responses in prey populations remains rare, and further questions remain about direct interactions between predators that could prevent or limit any positive effects between predators [e.g. intraguild predation (IGP)]. Here, we provide a community-wide experiment on emergent facilitation including natural predators. We investigate both the direct interactions between two predators that differ in body size (fish vs. invertebrate predator), and the indirect interaction between them via their shared prey community (zooplankton). Our evidence supports the most likely expectation of interactions between differently sized predators that IGP rates are high, and interspecific interactions in the shared prey community dominate the response to predation (i.e. predator-mediated competition). The question of whether emergent facilitation occurs frequently in nature requires more empirical and theoretical attention, specifically to address the likelihood that its pre-conditions may co-occur with high rates of IGP.


Asunto(s)
Cladóceros/fisiología , Conducta Competitiva , Percas/fisiología , Conducta Predatoria/fisiología , Animales , Tamaño Corporal , Cadena Alimentaria , Dinámica Poblacional , Zooplancton
6.
APMIS ; 122(6): 539-44, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24106819

RESUMEN

The aim was to investigate whether the detection and quantification of Staphylococcus epidermidis DNA in blood could distinguish S. epidermidis blood stream infections (BSIs) from blood culture contaminations in patients with hematological malignancies. The hld gene was chosen to identify S. epidermidis DNA and DNA in blood samples was detected by real-time PCR. Blood samples were obtained simultaneously with blood cultures positive for S. epidermidis (n = 30), during blood culture-negative episodes (n = 10) and episodes of bacteremia with other bacteria than S. epidermidis (n = 4) and from healthy blood donors (n = 10). In addition, DNA from S. epidermidis and a selection of other bacterial species were analyzed. Three different sets of criteria were used to classify episodes with positive blood cultures with S. epidermidis as BSIs or contaminations. All DNA preparations from S. epidermidis (n = 48) were hld-positive, but other bacterial species (n = 13) were negative. Sixteen (53%) of 30 blood samples from patients with blood cultures positive for S. epidermidis were hld-positive, but none of the controls. There was no clear association between a positive hld PCR and episodes interpreted as BSIs. In conclusion, hld PCR failed to distinguish S. epidermidis BSIs from blood culture contaminations in patients with hematological malignancies.


Asunto(s)
ADN Bacteriano/sangre , ADN Bacteriano/genética , Neoplasias Hematológicas/complicaciones , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , Infecciones Estafilocócicas/complicaciones , Staphylococcus epidermidis/genética , Staphylococcus epidermidis/aislamiento & purificación , Naranja de Acridina , Adolescente , Adulto , Anciano , Bacteriemia/complicaciones , Bacteriemia/diagnóstico , Bacteriemia/microbiología , Toxinas Bacterianas/genética , Femenino , Genes Bacterianos , Neoplasias Hematológicas/microbiología , Humanos , Masculino , Persona de Mediana Edad , Infecciones Estafilocócicas/diagnóstico , Infecciones Estafilocócicas/microbiología , Adulto Joven
7.
Ecology ; 94(7): 1487-98, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23951709

RESUMEN

Ontogenetic development is a fundamental aspect of the life history of all organisms and has major effects on population and community dynamics. We postulate a general conceptual framework for understanding these effects and claim that two potential energetics bottlenecks at the level of the individual organism--the rate by which it develops and the rate by which it reproduces--form a fundamental route to symmetry-breaking in ecological systems, leading to ontogenetic asymmetry in energetics. Unstructured ecological theory, which ignores ontogenetic development, corresponds to a limiting case only, in which mass-specific rates of biomass production through somatic growth and reproduction, and biomass loss through mortality, are independent of body size (ontogenetic symmetry). Ontogenetic symmetry results in development and reproduction being limited to the same extent by food density. In all other cases, symmetry-breaking occurs. Ontogenetic asymmetry results in increases in juvenile, adult, or even total biomass in response to mortality. At the community level, this gives rise to alternative stable states via predator-induced shifts in prey size distributions. Ontogenetic asymmetry furthermore leads to two distinct types of cycles in population dynamics, depending on whether development or reproduction is most energy limited. We discuss the mechanisms giving rise to these phenomena and the empirical support for them. We conclude that the concepts of ontogenetic symmetry and ontogenetic asymmetry form a novel and general organizing principle on which future ecological theory should be developed.


Asunto(s)
Ecosistema , Metabolismo Energético/fisiología , Modelos Biológicos , Animales , Biomasa , Tamaño Corporal
8.
PLoS One ; 8(7): e70404, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23894650

RESUMEN

Occurrence of cannibalism and inferior competitive ability of predators compared to their prey have been suggested to promote coexistence in size-structured intraguild predation (IGP) systems. The intrinsic size-structure of fish provides the necessary prerequisites to test whether the above mechanisms are general features of species interactions in fish communities where IGP is common. We first experimentally tested whether Arctic char (Salvelinus alpinus) were more efficient as a cannibal than as an interspecific predator on the prey fish ninespine stickleback (Pungitius pungitius) and whether ninespine stickleback were a more efficient competitor on the shared zooplankton prey than its predator, Arctic char. Secondly, we performed a literature survey to evaluate if piscivores in general are more efficient as cannibals than as interspecific predators and whether piscivores are inferior competitors on shared resources compared to their prey fish species. Both controlled pool experiments and outdoor pond experiments showed that char imposed a higher mortality on YOY char than on ninespine sticklebacks, suggesting that piscivorous char is a more efficient cannibal than interspecific predator. Estimates of size dependent attack rates on zooplankton further showed a consistently higher attack rate of ninespine sticklebacks compared to similar sized char on zooplankton, suggesting that ninespine stickleback is a more efficient competitor than char on zooplankton resources. The literature survey showed that piscivorous top consumers generally selected conspecifics over interspecific prey, and that prey species are competitively superior compared to juvenile piscivorous species in the zooplankton niche. We suggest that the observed selectivity for cannibal prey over interspecific prey and the competitive advantage of prey species over juvenile piscivores are common features in fish communities and that the observed selectivity for cannibalism over interspecific prey has the potential to mediate coexistence in size structured intraguild predation systems.


Asunto(s)
Canibalismo , Peces/fisiología , Conducta Predatoria , Animales , Cadena Alimentaria
9.
Am Nat ; 182(1): 53-66, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23778226

RESUMEN

Catastrophic collapses of top predators have revealed trophic cascades and community structuring by top-down control. When populations fail to recover after a collapse, this may indicate alternative stable states in the system. Overfishing has caused several of the most compelling cases of these dynamics, and in particular Atlantic cod stocks exemplify such lack of recovery. Often, competition between prey species and juvenile predators is hypothesized to explain the lack of recovery of predator populations. The predator is then considered to compete with its prey for one resource when small and to subsequently shift to piscivory. Yet predator life history is often more complex than that, including multiple ontogenetic diet shifts. Here we show that no alternative stable states occur when predators in an intermediate life stage feed on an additional resource (exclusive to the predator) before switching to piscivory, because predation and competition between prey and predator do not simultaneously structure community dynamics. We find top-down control by the predator only when there is no feedback from predator foraging on the additional resource. Otherwise, the predator population dynamics are governed by a bottleneck in individual growth occurring in the intermediate life stage. Therefore, additional resources for predators may be beneficial or detrimental for predator population growth and strongly influence the potential for top-down community control.


Asunto(s)
Ecosistema , Peces/fisiología , Cadena Alimentaria , Animales , Gadus morhua/fisiología , Modelos Biológicos , Dinámica Poblacional , Crecimiento Demográfico , Conducta Predatoria
10.
J Anim Ecol ; 82(1): 55-63, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23004014

RESUMEN

Size-dependent interactions and habitat complexity have been identified as important factors affecting the persistence of intraguild predation (IGP) systems. Habitat complexity has been suggested to promote intraguild (IG) prey and intraguild predator coexistence through weakening trophic interactions particularly the predation link. Here, we experimentally investigate the effects of habitat complexity on coexistence and invasion success of differently sized IG-predators in a size-structured IGP system consisting of the IG-predator Poecilia reticulata and a resident Heterandria formosa IG-prey population. The experiments included medium-long and long-term invasion experiments, predator-prey experiments and competition experiments to elucidate the mechanisms underlying the effect of prey refuges. Habitat complexity did not promote the coexistence of IG-predator and IG-prey, although the predation link was substantially weakened. However, the presence of habitat structure affected the invasion success of large IG-predators negatively and the invasion success of small IG-predators positively. The effect of refuges on size-dependent invasion success could be related to a major decrease in the IG-predator's capture rate and a shift in the size distribution of IG-predator juveniles. In summary, habitat complexity had two main effects: (i) the predation link was diminished, resulting in a more competition driven system and (ii) the overall competitive abilities of the two species were equalized, but coexistence was not promoted. Our results suggest that in a size-structured IGP system, individual level mechanisms may gain in importance over species level mechanisms in the presence of habitat complexity.


Asunto(s)
Tamaño Corporal , Peces/anatomía & histología , Peces/fisiología , Cadena Alimentaria , Conducta Predatoria , Animales , Femenino , Peces/crecimiento & desarrollo
11.
Oecologia ; 172(1): 119-27, 2013 May.
Artículo en Inglés | MEDLINE | ID: mdl-23053229

RESUMEN

The theory of cannibal dynamics predicts a link between population dynamics and individual life history. In particular, increased individual growth has, in both modeling and empirical studies, been shown to result from a destabilization of population dynamics. We used data from a long-term study of the dynamics of two leech (Erpobdella octoculata) populations to test the hypothesis that maximum size should be higher in a cycling population; one of the study populations exhibited a delayed feedback cycle while the other population showed no sign of cyclicity. A hump-shaped relationship between individual mass of 1-year-old leeches and offspring density the previous year was present in both populations. As predicted from the theory, the maximum mass of individuals was much larger in the fluctuating population. In contrast to predictions, the higher growth rate was not related to energy extraction from cannibalism. Instead, the higher individual mass is suggested to be due to increased availability of resources due to a niche widening with increased individual body mass. The larger individual mass in the fluctuating population was related to a stronger correlation between the densities of 1-year-old individuals and 2-year-old individuals the following year in this population. Although cannibalism was the major mechanism regulating population dynamics, its importance was negligible in terms of providing cannibalizing individuals with energy subsequently increasing their fecundity. Instead, the study identifies a need for theoretical and empirical studies on the largely unstudied interplay between ontogenetic niche shifts and cannibalistic population dynamics.


Asunto(s)
Sanguijuelas/fisiología , Animales , Conducta Animal , Tamaño Corporal , Canibalismo , Metabolismo Energético , Fertilidad , Sanguijuelas/anatomía & histología , Sanguijuelas/metabolismo , Densidad de Población , Dinámica Poblacional
12.
J Math Biol ; 66(4-5): 889-914, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-22961058

RESUMEN

Body size (≡ biomass) is the dominant determinant of population dynamical processes such as giving birth or dying in almost all species, with often drastically different behaviour occurring in different parts of the growth trajectory, while the latter is largely determined by food availability at the different life stages. This leads to the question under what conditions unstructured population models, formulated in terms of total population biomass, still do a fair job. To contribute to answering this question we first analyze the conditions under which a size-structured model collapses to a dynamically equivalent unstructured one in terms of total biomass. The only biologically meaningful case where this occurs is when body size does not affect any of the population dynamic processes, this is the case if and only if the mass-specific ingestion rate, the mass-specific biomass production and the mortality rate of the individuals are independent of size, a condition to which we refer as "ontogenetic symmetry". Intriguingly, under ontogenetic symmetry the equilibrium biomass-body size spectrum is proportional to 1/size, a form that has been conjectured for marine size spectra and subsequently has been used as prior assumption in theoretical papers dealing with the latter. As a next step we consider an archetypical class of models in which reproduction takes over from growth upon reaching an adult body size, in order to determine how quickly discrepancies from ontogenetic symmetry lead to relevant novel population dynamical phenomena. The phenomena considered are biomass overcompensation, when additional imposed mortality leads, rather unexpectedly, to an increase in the equilibrium biomass of either the juveniles or the adults (a phenomenon with potentially big consequences for predators of the species), and the occurrence of two types of size-structure driven oscillations, juvenile-driven cycles with separated extended cohorts, and adult-driven cycles in which periodically a front of relatively steeply decreasing frequencies moves up the size distribution. A small discrepancy from symmetry can already lead to biomass overcompensation; size-structure driven cycles only occur for somewhat larger discrepancies.


Asunto(s)
Biomasa , Tamaño Corporal , Modelos Biológicos , Animales , Ecosistema , Análisis Numérico Asistido por Computador , Dinámica Poblacional
13.
Palliat Support Care ; 11(3): 183-9, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23013718

RESUMEN

OBJECTIVE: The aim of this study was to compare self-estimates of the physical, psychological, and general well-being of patients with amyotrophic lateral sclerosis (ALS) and their next of kin with the assessment of the nurses and physician of these participants. METHOD: The well-being of 35 pairs of patients and their next of kin was rated by themselves, and by a physician and nurses. The well-being was examined over time, using a visual analogue scale (VAS). Patients' physical function was estimated at the same time with the Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised and the Norris scale. RESULTS: The correlations between the staff's estimates of the well-being of patients and next of kin were similar to their own estimates, even though staff to a higher degree estimated a decrease in well-being over time among the patients. The estimates by the nurses correlated better to that of the patients and next of kin in psychological and general well-being than the physicians' estimates did. SIGNIFICANCE OF RESULTS: Even though the staff's estimates of participants were roughly equivalent to their self-estimates, there were some differences. This result calls attention to the importance of working in teams in which different professional roles are combined and integrated, making it possible to form a holistic view of the situation of each family. A concern overlooked by one member of staff might be covered by another, and different focuses on the family may give a better composite picture of their life situation, which could lead to better support to the family.


Asunto(s)
Esclerosis Amiotrófica Lateral/fisiopatología , Esclerosis Amiotrófica Lateral/psicología , Familia/psicología , Estado de Salud , Cuerpo Médico de Hospitales/psicología , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Encuestas y Cuestionarios
14.
Oecologia ; 168(3): 807-18, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21971586

RESUMEN

Cross-ecosystem movements of material and energy are ubiquitous. Aquatic ecosystems typically receive material that also includes organic matter from the surrounding catchment. Terrestrial-derived (allochthonous) organic matter can enter aquatic ecosystems in dissolved or particulate form. Several studies have highlighted the importance of dissolved organic carbon to aquatic consumers, but less is known about allochthonous particulate organic carbon (POC). Similarly, most studies showing the effects of allochthonous organic carbon (OC) on aquatic consumers have investigated pelagic habitats; the effects of allochthonous OC on benthic communities are less well studied. Allochthonous inputs might further decrease primary production through light reduction, thereby potentially affecting autotrophic resource availability to consumers. Here, an enclosure experiment was carried out to test the importance of POC input and light availability on the resource use in a benthic food web of a clear-water lake. Corn starch (a C(4) plant) was used as a POC source due to its insoluble nature and its distinct carbon stable isotope value (δ(13)C). The starch carbon was closely dispersed over the bottom of the enclosures to study the fate of a POC source exclusively available to sediment biota. The addition of starch carbon resulted in a clear shift in the isotopic signature of surface-dwelling herbivorous and predatory invertebrates. Although the starch carbon was added solely to the sediment surface, the carbon originating from the starch reached zooplankton. We suggest that allochthonous POC can subsidize benthic food webs directly and can be further transferred to pelagic systems, thereby highlighting the importance of benthic pathways for pelagic habitats.


Asunto(s)
Cadena Alimentaria , Lagos , Animales , Carbono/química , Carbono/metabolismo , Sedimentos Geológicos , Luz , Zooplancton/metabolismo
15.
J Clin Nurs ; 21(9-10): 1364-73, 2012 May.
Artículo en Inglés | MEDLINE | ID: mdl-21831105

RESUMEN

AIM AND OBJECTIVES: This study aims to illuminate factors that facilitate and hinder the manageability of living with amyotrophic lateral sclerosis in patients and next of kin. Fourteen patients and 13 next of kin were interviewed. BACKGROUND: The whole family becomes affected when a person gets the disease. Therefore, it is important to identify strategies for managing the life situation among both patients and their next of kin. DESIGN: A qualitative descriptive study. METHOD: This study based on individual interviews was performed in spring 2007. The interviews were subjected to qualitative content analysis. RESULTS: The results indicate constant fluctuation between opportunities and limitations in individual ability - of patients and family members - to manage the life situation. Both patients and next of kin devised strategies to manage their situations through acceptance, living in the present and perceiving real presence and support from family, friends and authorities. Dysfunctional relationships with family members, friends, or authorities reduced the manageability of the situation. Furthermore, patients experienced difficulties managing their situations when forced into passivity and increased dependence. Next of kin experienced decreased ability to manage because of burden, lack of own time and feelings of being controlled. CONCLUSION: The fluctuations in manageability and the similarities and differences between the pairs, indicate the importance of support, both for the individual and the family. RELEVANCE TO CLINICAL PRACTICE: Fluctuations in manageability and similarities and differences between approaches to managing the situation suggest a need for input from caregivers, for the whole family. Family members need support and time for their own needs and also the opportunity to increase their awareness and understanding of the needs of other family members. This study may give health personnel insight into how to help families devise strategies to manage a complex life situation.


Asunto(s)
Esclerosis Amiotrófica Lateral/fisiopatología , Familia , Esclerosis Amiotrófica Lateral/terapia , Humanos
16.
J Anim Ecol ; 81(2): 483-93, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-22081866

RESUMEN

1. Life-history omnivory or size-induced mixed competition-predation systems have under many conditions theoretically been shown to be fragile, whereas at the same time existing empirical data suggest such systems to be common in nature. 2. In a whole lake experiment covering 17 years, we analysed the effects of the introduction of the intraguild prey roach (Rutilus rutilus) on the population size and individual performance of the intraguild predator perch (Perca fluviatilis) and on resource levels in two low productivity systems. 3. A strong long-term effect of roach on the zooplankton resource but not on the macroinvertebrate resource was present. Competitive effects of roach on perch were observed in one of the lakes the first years after the introduction, but at the end of the study no competitive effect of roach on either size class of perch was observed in any of the two lakes. In contrast, a positive predatory effect reflected in improved growth rates of older perch was present. 4. The lack of a support for a competitive effect of roach on small perch raises the question of the importance of mixed competition-predation interactions in life-history omnivorous systems and the problem of comparing descriptive data on feeding relationships with theoretical predictions based on interaction modules.


Asunto(s)
Conducta Competitiva , Cyprinidae/fisiología , Cadena Alimentaria , Percas/fisiología , Conducta Predatoria , Animales , Cyprinidae/crecimiento & desarrollo , Especies Introducidas , Invertebrados/fisiología , Lagos , Percas/crecimiento & desarrollo , Densidad de Población , Suecia , Zooplancton/fisiología
17.
Am Nat ; 178(6): 701-14, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22089866

RESUMEN

In basic intraguild predation (IGP) systems, predators and prey also compete for a shared resource. Theory predicts that persistence of these systems is possible when intraguild prey is superior in competition and productivity is not too high. IGP often results from ontogenetic niche shifts, in which the diet of intraguild predators changes as a result of growth in body size (life-history omnivory). As a juvenile, a life-history omnivore competes with the species that becomes its prey later in life. Competition can hence limit growth of young predators, while adult predators can suppress consumers and therewith neutralize negative effects of competition. We formulate and analyze a stage-structured model that captures both basic IGP and life-history omnivory. The model predicts increasing coexistence of predators and consumers when resource use of stage-structured predators becomes more stage specific. This coexistence depends on adult predators requiring consumer biomass for reproduction and is less likely when consumers outcompete juvenile predators, in contrast to basic IGP. Therefore, coexistence occurs when predation structures the community and competition is negligible. Consequently, equilibrium patterns over productivity resemble those of three-species food chains. Life-history omnivory thus provides a mechanism that allows intraguild predators and prey to coexist over a wide range of resource productivity.


Asunto(s)
Conducta Competitiva , Dieta , Cadena Alimentaria , Distribución por Edad , Animales , Modelos Biológicos , Dinámica Poblacional , Conducta Predatoria , Especificidad de la Especie
19.
Oecologia ; 167(2): 391-400, 2011 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21516310

RESUMEN

There is considerable variation in cannibalism between different species and also between individuals of different species, although relatively little is known about what creates this variation. We investigated the degree of cannibalism in guppy (Poecilia reticulata) populations originating from high and low predation environments in Trinidad, and also how cannibalism was affected by the presence of refuges. Females from two populations were allowed to feed on juveniles from two populations in aquaria trials. The cannibalism was size-dependent and varied depending on both juvenile and female origin. Low predation females were more efficient cannibals and low predation juveniles were better at avoiding cannibalism compared to high predation guppies when no refuges were present. The high predation females were superior cannibals and the high predation juveniles were better at escaping cannibalism than the low predation guppies when refuges were present. We discuss whether the differences in cannibalism and response to refuge addition relate to predation-induced habitat shifts and differences in the guppies' natural environment.


Asunto(s)
Canibalismo , Poecilia/fisiología , Adaptación Fisiológica , Distribución por Edad , Análisis de Varianza , Animales , Tamaño Corporal , Distribución de Chi-Cuadrado , Ambiente , Femenino , Cadena Alimentaria , Modelos Lineales , Trinidad y Tobago
20.
J Clin Nurs ; 20(1-2): 283-91, 2011 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-21108676

RESUMEN

AIM AND OBJECTIVES: The aims were to study health-related quality of life, anxiety and depression in patients with amyotrophic lateral sclerosis and their next of kin and to compare these results with a subset of the general Swedish population. Thirty-five pairs of patients with amyotrophic lateral sclerosis and their next of kin were studied. BACKGROUND: Life changes in many ways when a person is diagnosed with amyotrophic lateral sclerosis. Comparison between patients, next of kin and the general population are needed to get a wider understanding of their quality of life, anxiety and depression. DESIGN: A descriptive study. METHODS: All participants were studied with the SF-36 and the Hospital Anxiety and Depression Scale. Patients' physical function was assessed by the amyotrophic lateral sclerosis Functional Rating Scale-Revised and the Norris scale. RESULTS: A correlation was found in both the mental component summary in SF-36 and in anxiety between the pairs of patients and their next of kin, while no correlation was found in the physical component summary or depression. These results were not related to the patients' physical function. Both patients and their next of kin had some poorer ratings in SF-36 and in anxiety and depression than the general Swedish population. Gender or age did not affect the estimates in any of the scales. CONCLUSIONS: The results indicate that both the patient and the next of kin are affected by the disease independent of physical disability. In most pairs of patient and next of kin, the mental component summary and anxiety were affected to a similar extent. RELEVANCE TO CLINICAL PRACTICE: The results emphasise the need for medical and nursing support to both the patient and the next of kin soon after the diagnosis and during the course of the disease.


Asunto(s)
Esclerosis Amiotrófica Lateral/psicología , Ansiedad/complicaciones , Depresión/complicaciones , Familia/psicología , Calidad de Vida , Esclerosis Amiotrófica Lateral/tratamiento farmacológico , Ansiolíticos/uso terapéutico , Antidepresivos/uso terapéutico , Ansiedad/tratamiento farmacológico , Depresión/tratamiento farmacológico , Femenino , Humanos , Masculino , Encuestas y Cuestionarios , Suecia
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