Sociality in animals depends on identification and recognition of conspecifics and social interactions can be a key driving force in ecological processes. We capitalized on the environmentally ...dependent sociality and unique reproductive strategy of the self-fertilizing mangrove rivulus (
Kryptolebias marmoratus
) to disentangle the influence of relatedness and familiarity on conspecific recognition. We also compared the importance of vision and chemosensation as primary phenotypic sensory cues in distinguishing individual fish and prey. Using lab-reared, isogenic rivulus, we presented a focal fish with the choice between two conspecifics (related and/or familiar). We determined that there was no clear impact of relatedness on short term association preferences in the two isogenic lineages we tested. Rather, rivulus preferentially associated with unrelated, familiar individuals over unrelated, unfamiliar individuals. Next, we used both isogenic lab lineages and wild-caught rivulus to determine the primary sensory modality involved in recognition by measuring aggressive behavior while manipulating the type of sensory information (visual and chemosensory) available during binary association trials. Our data indicate that this mangrove fish uses primarily visual cues and familiarity templates for mediating social interactions, contributing to the growing body of knowledge on recognition systems in fishes.
Significance statement
Social relationships depend on the assessment of potential partners. We know that fishes can discriminate among individuals; however, how they recognize each other is more complex. We capitalized on the unique social behavior and reproductive strategy of a small mangrove fish to determine if they preferentially recognize related individuals, familiar individuals, or a combination of the two. We also asked if they used vision and/or smell as their primary mode of recognition. Here, we show that these fish prefer to associate with familiar yet unrelated individuals, possibly because there are more direct benefits associating with fish they have previously encountered. We also concluded that these fish use vision over smell to recognize other individuals even in murky mangrove water. Social behaviors are likely to change as a result of environmental change. Thus, understanding how fish recognize each other has important implications for their conservation and how they will respond to environmental challenges.
We show here that wild Atlantic salmon parr and smolt from thermally distinct river systems were impacted differently by cooler and warmer thermal variability. Growth, thermal tolerance and swimming ...performance were all impacted by river of origin, thermal acclimation temperature and life stage, highlighting the potential need for more river specific conservation guidelines.
Abstract
Temperature in many natural aquatic environments follows a diel cycle, but to date, we know little on how diel thermal cycles affect fish biology. The current study investigates the growth, development and physiological performance of wild Atlantic salmon collected from the Miramichi and Restigouche rivers (NB, Canada). Fish were collected as parr and acclimated to either 16–21 or 19–24°C diel thermal cycles throughout the parr and smolt life stages. Both Miramichi and Restigouche Atlantic salmon parr grew at similar rates during 16–21 or 19–24°C acclimations. However, as smolts, the growth rates of the Miramichi (−8% body mass day−1) and Restigouche (−38% body mass day−1) fish were significantly slower at 19–24°C, and were in fact negative, indicating loss of mass in this group. Acclimation to 19–24°C also increased Atlantic salmon CTmax. Our findings suggest that both life stage and river origin impact Atlantic salmon growth and performance in the thermal range used herein. These findings provide evidence for local adaptation of Atlantic salmon, increased vulnerability to warming temperatures, and highlight the differential impacts of these ecologically relevant diel thermal cycles on the juvenile life stages in this species.
Heat shock proteins (HSPs) and antioxidants are key cellular defenses against stress. Seals routinely undergo protracted fasting, which is normally associated with physiological stress in other ...animals. We tested the hypotheses that (1) relative HSP70 protein abundance is higher in liver and blubber of fasting relative to suckling wild gray seal pups; (2) differences in HSP70 are mirrored in tissue superoxide dismutase (SOD) and catalase activity, as well as glutathione levels; (3) extracellular HSP70 correlates with hepatic and blubber HSP70 abundance; and (4) protein carbonylation, an index of oxidative damage, is lower in tissues with higher levels of these cellular stress markers. In contrast to our expectation, suckling pups had higher relative HSP70 abundance and glutathione levels in liver and blubber and higher hepatic catalase activity. Plasma HSP70 did not correlate with liver or blubber abundance of the protein. Suckling pups did not experience greater protein carbonylation, suggesting that cellular protective mechanisms prevent protein damage despite an apparent increase in cellular stress. SOD activity was not affected by nutritional state, but in blubber tissue, it was positively correlated with blubber thickness. Greater requirements for antioxidants and HSPs in suckling pups or in animals with thicker blubber could arise from rapid protein synthesis, high metabolic fuel availability, and/or exposure to lipophilic toxins. Developmental and nutritional changes in cellular defenses have important implications for gray seals’ susceptibility to additional stress exposure.
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, IZUM, KILJ, NMLJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
To investigate feasibility and safety of stereotactic ablative radiotherapy in the management of prostate cancer while employing MR/CT fusion for delineation, fiducial marker seeds for positioning ...and Varian RapidArc with flattening filter free (FFF) delivery.
41 patients were treated for low-intermediate risk prostate cancer with initial prostate-specific antigen of ≤20 ng ml
, Gleason score 6-7. Patients had MR/CT fusion for delineation of prostate ±seminal vesicles. CT/MR fusion images were used for delineation and planned using flattening filter free modality. Verification on treatment was cone beam CT imaging with fiducial markers for matching. Patients had Radiation Therapy Oncology Group scoring for genitourinary and gastointestinal symptoms at baseline, week 4, 10 and 18.
Clinically acceptable plans were achieved for all patients, all plans achieved the objective clinical target volume D99% ≥ 95%, and for planning target volume D95% ≥ 95%. Rectum dose constraints were met for 95.1% for V18 Gy ≤ 35%, 80% V28 Gy ≤ 10%. A total of 32 (78.0%) plans achieved all rectum dose constraints. Grade 1 acute genitourinary symptoms were 53.7% of patients at baseline, 90.2% 95% CI (76.8-97.3%) (p = 0.0005) at treatment 5, falling to 78.0% (62.4-89.4%) at week 4, and 75.0% (58.8-87.3%) by week 10 and 52.5% (36.1-68.5%) (p = 1.00) at week 18. Acute gastrointestinal symptoms were 5% at baseline, 46.3% 95% CI (30.7-62.6%) at treatment 5, week 4 43.9% 95% CI (28.5-60.3%), week 10 25.0% (11.1-42.3%), and declined slightly by week 18 -20.095% CI (12.7-41.2) p = 0.039. Overall 75.6% (31/41) of patients experienced Grade 1-2 toxicity during or after treatment.
This planning and delivery technique is feasible, safe and efficient. A homogeneous dose can be delivered to prostate with confidence, whilst limiting high dose to nearby structures. The use of this technology can be applied safely within further randomized study protocols. Advances in knowledge: Multimodality imaging for delineation and linac-based image-guided RT with FFF for the treatment of prostate stereotactic ablative radiotherapy.
We conclude that the heat shock response is enhanced in juvenile compared with adult rainbow trout,
Oncorhynchus mykiss
. We have shown that the magnitude of the inducible heat shock response, as ...measured by increases in the heat shock protein (Hsp) Hsp70 is significantly greater in the hearts of fingerling than in adult trout following an acute (1 h) heat stress at 25 °C. Juvenile fish also express higher levels of constitutive Hsps (Hsc70, Hsp90) in their tissues, possibly reflecting higher rates of protein synthesis and increased chaperone function in this early life stage. This robust heat shock response in juvenile trout may contribute to a greater thermal resistance that is often observed in young salmonid fish.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The retention of a nucleus in the mature state of fish red blood cells (RBCs) and the ability to easily collect and manipulate blood in nonterminal experiments make blood an ideal tissue on which to ...study the cellular stress response in fish. Through the use of the cGRASP 16K salmonid microarray, we investigated differences in RBC global gene transcription in fish held under control conditions (11 degrees C) and exposed to heat stress (1 h at 25 degrees C followed by recovery at 11 degrees C). Repeated blood sampling (via a dorsal aorta cannula) enables us to examine the individual stress response over time. Samples were taken preheat stress (representing individual control) and at 4 and 24 h postheat stress (representing early and late transcriptional regulation). Approximately 3,000 microarray features had signal above threshold when hybridized with RBC RNA-derived targets, and cannulation did not have a detectable effect on RBC mRNA expression at the investigated time points. Genes involved in the stress response, immune response, and apoptosis were among those showing the highest dysregulation during both early and late transcriptional regulation. Additionally, genes related to the differentiation and development of blood cells were transcriptionally upregulated at the 24 h time point. This study provides a broader understanding of the mechanisms underpinning the stress response in fish and the discovery of novel genes that are regulated in a stress specific manner. Moreover, salmonid transcripts that are consistently dysregulated in blood in response to heat stress are potential candidates of nonlethal biomarkers of exposure to this particular stressor.
The inhalation of zinc oxide engineered nanomaterials (ENMs) has been linked to cardiorespiratory dysfunction in mammalian models but the effects of aquatic ENM exposure on fish have not been fully ...investigated. Nano-zinc oxide (nZnO) is widely used in consumer products such as sunscreens and can make its way into aquatic ecosystems from domestic and commercial wastewater. This study examined the impact of an environmentally relevant nZnO formulation on cardiorespiratory function and energy metabolism in the white sucker (Catostomus commersonii), a freshwater teleost fish. Evidence of oxidative and cellular stress was present in gill tissue, including increases in malondialdehyde levels, heat shock protein (HSP) expression, and caspase 3/7 activity. Gill Na
+
/K
+
-ATPase activity was also higher by approximately three-fold in nZnO-treated fish, likely in response to increased epithelial permeability or structural remodeling. Despite evidence of toxicity in gill, plasma cortisol and lactate levels did not change in animals exposed to 1.0 mg L
−1
nZnO. White suckers also exhibited a 35% decrease in heart rate during nZnO exposure, with no significant changes in resting oxygen consumption or tissue energy stores. Our results suggest that tissue damage or cellular stress resulting from nZnO exposure activates gill neuroepithelial cells, triggering a whole-animal hypoxic response. An increase in parasympathetic nervous signaling will decrease heart rate and may reduce energy demand, even in the face of an environmental toxicant. We have shown that acute exposure to nZnO is toxic to white suckers and that ENMs have the potential to negatively impact cardiorespiratory function in adult fish.
Intensity-modulated radiation therapy (IMRT) planning is an inherently multi-criteria task. A multi-criteria workflow (MCW) typically passes the following steps: create an optimisation model with ...multiple criteria, approximate the Pareto frontier, and visualise the generated plans to the decision-maker (DM) for inspection. This interactive plan selection and manipulation allow to create better treatment plans as judged by physicians. However, once an optimisation model is specified, optimisation objectives cannot be modified any more. Thus this fixed model implies that a planner has to guess an appropriate model to begin with. Only after Pareto frontier approximation is calculated, the planner can assess the goodness of the model by exploring the trade-offs. The shortcoming of a MCW becomes apparent when the proposed model fails to generate expected trade-offs and the planner is thus forced to refine the model and repeat the calculations. To circumvent this drawback in the MCW, we propose a local multi-criteria workflow (L-MCW) designed and implemented in a collaboration between Fraunhofer ITWM and Varian Medical Systems. L-MCW enables local exploration around an initial, promising plan. The initial plan is automatically inferred by a knowledge-based algorithm (RapidPlan™). The decision-maker can thus evaluate trade-offs in the most interesting region surrounding the initial plan. Clinical results of the combination of knowledge-based planning and L-MCW with a cohort of Prostate and stereotactic ablative radiotherapy (SABR) Lung cases demonstrate substantially reduced planning time and improved organ-at-risk sparing compared to manual planning. The L-MCW provides an intuitive and flexible mechanism to adapt knowledge-based-planning models to similar, but not identical clinical situations and allows the practitioner to quickly determine and realise the most beneficial trade-offs in a treatment plan.
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