Digestive protease activities, growth and feed utilisation in Atlantic salmon (Salmo salar L.)

This dissertation consists of the following papers, referred to in the text by their Roman numerals.The specific activities of trypsin and chymotrypsin in the pyloric caeca were investigated in individually labeled Atlantic salmon (Salmo salar L.). Photoperiod (natural or 24 h) and feed protein quality (two levels of digestibility) were used as growth affecting factors in two grow-out experiments. Parameters indicative of protein growth and metabolism, i.e. plasma and white muscle free amino acid (FAA) concentrations, white muscle RNA concentrations, and white muscle protein synthesis capacity (RNA/protein ratio) were also measured. The feasibility of using free hydroxyproline (Hyp) concentration in the white muscle as an indicator of the rate of tissue protein breakdown (turnover) was assessed. Further, an in vitro digestibility assay was developed to evaluate the effects of industrial processing conditions on feed protein digestibility. Digestion using crude pyloric caecal extracts was standardised by trypsin activity and compared with growth experiments to predict the effects of feed protein quality on specific growth rate (SGR) and feed conversion efficiency (FCE). Finally, dorsal aorta cannulation of fish was assessed as a tool for evaluating feed protein quality (containing no free or supplemented amino acids) through repeated measurements of plasma FAA concentrations after feeding. Trypsin (T) and chymotrypsin (C) showed high covariation in all experiments, regardless of whether growth was affected indirectly (through photoperiod manipulation) or directly (through feed protein quality). Groups exhibiting different feed conversion efficiencies (FCE) had different activity ratios of trypsin to chymotrypsin (T/C ratio). The T/C ratio seemed to be more sensitive than growth measurements to slight differences in feed protein quality and might have an application as an indicator of growth performance. In salmon reared under different photoperiods, SGR correlated with trypsin activity and T/C ratio on individual basis. These correlations could possibly be explained by a predominant influence of feed intake on growth under these conditions. In contrast to trypsin activity, chymotrypsin activity was uncorrelated to SGR variation. Plasma essential (EAA) and total (TFAA) free amino acid concentrations did not show consistent relationships with other biochemical parameters and growth rate. White muscle EAA, however, decreased with SGR, while white muscle TFAA and Hyp concentrations showed an increasing trend. Of all measured parameters, Hyp level in white muscle showed the highest correlation with growth rate. An observed inverse relation between SGR and white muscle RNA concentrations indicated a lower relative protein synthetic activity at higher growth rates and could indicate a shift to a higher importance of lipid deposition at high feed intakes. This was consistent with an increased protein turnover, indicated by elevated white muscle free Hyp levels, suggesting a lower efficiency of protein retention at high growth rates and that a higher fraction of ingested amino acids were used as energy substrates. Fish meal raw material, drying temperature and duration of drying affected feed protein digestibility in vitro. This reduction in digestibility was concomitant with a higher incidence of disulphide bond formation in the feed proteins, demonstrating a negative effect of disulphide bond formation on feed protein quality. Digestibility of the experimental diets measured in vitro correlated with SGR and FCE after three months of feeding, but differences in SGR between feed quality groups did not reach statistical significance in either 150 g or 2 kg salmon. However, 2 kg salmon fed restricted rations showed significantly higher FCE in the ‘high’ protein quality feed groups. Differences in FCE at the end of the experiment seemed to be preceded by differences in trypsin and chymotrypsin specific activities one month earlier. Trypsin activity was unaffected by feed protein quality, possibly only reflecting the similar feed intake in the experimental groups. This resulted in a relationship between chymotrypsin activity and feed in vitro digestibility when standardised by trypsin activity. Fish groups given feeds of ‘high’ protein quality had relatively higher RNA concentrations in the white muscle than groups given ‘low’ quality feeds, indicating a positive effect of feed protein digestibility on muscle ribosome concentration, and possibly protein synthetic activity. At the same time, white muscle Hyp concentrations were significantly lower in the ‘high’ quality dietary groups, indicating a lower protein turnover rate and potentially higher protein retention efficiency in these fish. However, this was not detectable as a difference in fillet protein content after three months of feeding. White muscle ratios of essential to nonessential free amino acids (EAA/NEAA ratio) were higher in groups with higher FCE, whereas plasma values showed no specific pattern, except after starvation and refeeding, where EAA/NEAA ratios were higher with higher FCE. No correlations were found between digestive protease activity and other parameters on an individual basis. A possible explanation for these findings could be that growth rate in this case was limited by feed protein digestibility and unrelated to feed intake. High and low quality feeds were selected from the protein quality study in order to investigate amino acid uptake following feeding. Feed intake was positively correlated with the sum of EAA in plasma 6 h post-feeding. Variation in plasma FAA profiles was to a large extent explained by individual differences in feed intake, but individual differences in metabolism of specific amino acids were indicated. However, feeds of different protein qualities could still be distinguished through significant differences in plasma EAA profiles after statistical correction for these factors. The results indicate that the relationship between trypsin and chymotrypsin activity (T/C ratio) may have an application as an indicator of differences in growth performance between groups of fish, both when growth is affected by external factors and diet quality. The different mechanisms through which growth differences were affected under the two specific experimental setups suggest that the T/C ratio could have a broader application also outside the limitations of the current studies. In particular, the method may be useful for determining the nutritional and growth status of fish in the wild where food consumption cannot be measured. However, this remains to be validated. The relationship between white muscle Hyp concentrations and protein turnover deserves further investigation, as this parameter showed strong correlation with growth rates. Further studies of the hormonal and genetic mechanisms regulating trypsin and chymotrypsin activity, and how they are affected by dietary and exogenous factors need to supplement future studies in this field. These studies demonstrated the suitability and efficiency of small-scale assays for the evaluation of feed protein quality. Further development of such methods is recommended as alternatives or supplements to regular time-consuming growth experiments.Doktorgra

Fertility sparing treatment of a malignant uterine perivascular epithelioid cell tumor: A case report

• Perivascular epithelioid cell tumors (PEComas) are a family of rare, poorly defined mesenchymal tumors of uncertain malignant potential. • Treatment for PEComas has most commonly involved excisional biopsy or surgical resection. • The use of mTOR inhibitors may provide the best medical treatment as well as a fertility-sparing treatment option

Recession Experiences During Early Adulthood Shape Prosocial Attitudes Later in Life

This paper explores whether the experience of a severe recession during early adulthood shapes individuals’ prosocial attitudes. The analysis uses survey responses to experimentally validated questions that measure prosocial attitudes for approximately 65,000 respondents in 75 countries. The identification approach exploits variation in recession experiences across 78 different birth cohorts. We find that exposure to a recession during early adulthood is associated with lower levels of prosociality later in life. The effect only emerges for experiences during impressionable years (age 18-25), mainly affects prosocial attitudes among men, and is orthogonal to the effect of experiences with democracy

Effect of live-storage period and temperature on oxygen consumption rate in the cold-water sea cucumber Parastichopus tremulus

Sea cucumbers are of great significance in marine ecosystems all over the world. The red sea cucumber Parastichopus tremulus is also considered commercially interesting but very little information is available on its ecology and physiology. This study aimed at investigating this North Atlantic species` oxygen demand in relation to live-storage period and temperature in an attempt to deliver some physiological puzzle pieces useful in a potential aquacultural context. Oxygen consumption rate (OCR) was measured in P. tremulus stored in a flow-through system for up to one year, and in recirculation systems at different temperatures (4, 8 and 12°C) for up to four weeks. Throughout the experimental period, biometric data were collected from the different treatment groups and a condition index (CI) calculated. The results showed that long-term storage affected OCR and CI, which increased and decreased with time, respectively. Storage at 4°C resulted in significantly lower OCR and higher CI compared to 8 and 12°C after four weeks, suggesting that 4°C may be best for maintaining body mass during short-term storage, whereas storage at 8 and 12°C may require supplementary feeding to avoid biomass loss. Data presented in this study may be useful for a range of applications, for example in a prospective aquaculture setting, for optimizing live seafood storage, but also for impact assessment and management of wild stocks

Om å møte mennesker med manisk lidelse : en intervensjonsstudie fra akuttpsykiatrien

Norsk: Denne studien er en del av Prosjekt Undervisningsavdeling, som er et fireårig forsknings- og utviklingssamarbeid mellom Høgskolen i Hedmark, Avdeling for sykepleierutdanning og et psykiatrisk sykehus – nærmere bestemt ’Akuttposten’. Hensikten med denne studien er å utvikle dypere forståelse for mani som fenomen og lidelse for å kunne møte mennesker med denne lidelsen med en faglig og etisk velbegrunnet praksis. Gjennom litteraturstudier, fokusgruppeintervjuer og fortellinger har man søkt å få en dypere forståelse for mani som fenomen og lidelse. Litteraturstudiene viste at manien kan betraktes langs et kontinuum fra mild, moderat til alvorlig mani. Personalet i akuttpsykiatrien møter mennesker med de to siste ytringsformene. En av de største utfordringene i arbeidet med maniske personer er at de ofte kommer til behandling mot sin vilje, fordi de ikke kjenner seg syke eller i behov av hjelp. Litteraturen beskriver tre former for lidelse som den maniske person kan oppleve, nemlig sykdomslidelse, eksistensiell lidelse og lidelse som følge av sykepleie og behandling. Med bakgrunn i denne flerdimensjonale lidelsen, beskrives en aktuell psykiatrisk sykepleiepraksis – og forslag til forbedring presenteres. Fokusgrupper og fortellinger ble benyttet for å beskrive og for å oppnå en dypere forståelse for hvordan postpersonalet arbeider med – og møter - maniske personers reaksjoner. Resultatene fra studien vil være nyttige, fordi de fokuserer de mellommenneskelige sidene knyttet til arbeid med mennesker med mani innen en akuttpsykiatrisk kontekst. Dette området er underrapportert i forskningslitteraturen, og det er derfor behov for videre forskning for å sikre en kvalitativ god sykepleie og omsorg.English: This study is a part of a four-year research collaboration between Hedmark College, Department of Nursing Education, and an acute ward in a psychiatric hospital. The aim of this study was to gain a deeper understanding of the phenomenon of mania and to generate knowledge of evidence-based practice in the area to enable psychiatric nursing staff to apply this knowledge in the encounter with persons suffering from this disorder. The methods used were: literature review, focus group interviews and story telling. The results from the literature review show that the phenomenon of mania could be interpreted as a continuum, spanning from mild through moderate to severe mania. Acute psychiatric staff are facing the most severe manifestations of the disorder. One of the greatest challenges of working with persons suffering from mania is that they are often admitted involuntarily and that they do not perceive themselves as being ill or in need of help. The result of the literature review showed three forms of suffering: suffering caused by the disorder, existential suffering and suffering from the care provided being perceived as non-caring. All three forms of suffering may be experienced by persons suffering from mania. Evidence-based psychiatric nursing practice related to this multi-dimensional mental suffering is described. Focus groups and story telling were used to describe and to gain a deeper understanding of how psychiatric nurses provide care for and encounter reactions from persons suffering from mania. This approach gave implications for alternative actions in practice. The results promote an awareness of the possibilities inherent in the encounter between human beings in the context of acute psychiatric care. There is a lack of studies as well as a need for further research in this area to ensure high quality care

Viability, motility, ATP content and fertilizing potential of sperm from Atlantic salmon (Salmo salar L.) in milt stored before cryopreservation

Artificial fertilization is increasingly used in aquaculture, mostly applying short-term cold stored milt. Large scale cryopreservation of milt could be valuable for increased flexibility and acceleration of breeding progress. The aim of this study was to assess viability, motility and ATP content of sperm from Atlantic salmon as a function of storage time, before and after cryopreservation. The objective was also to investigate whether in vitro parameters were associated with sperm fertilizing ability after cryopreservation. Milt from six mature Atlantic salmon males were collected twice, one week apart. The milt was stored undiluted at 5 °C in cell culture flasks for six days. Samples were taken on days 1, 3 and 6 of storage for cryopreservation. In total, 36 batches were diluted to a standardized sperm concentration of 2 × 109 spermatozoa/mL, filled into 0.5 mL French medium straws and cryopreserved. In vitro analyses were assessed on the same sample for the 72 combinations of male, collection week, days of storage and cold stored or frozen-thawed. Fertilization trials with cryopreserved milt were carried out for all 36 batches in triplicate for each combination of male, collection week, storage time and sperm:egg ratios of either 2 or 4 × 106 sperm per egg, respectively, totally 218 experimental units, including two egg controls. There was a significant influence of storage and collection week on sperm quality parameters, both cold stored and cryopreserved, and cryopreservation had a significant effect on all tested sperm quality parameters. High correlations for cold stored vs cryopreserved samples was demonstrated for ATP content (p < 0.00001), motility and velocity parameters (p < 0.001), but not for viability, straightness and linearity. The overall percentage of fertilization achieved was 73.9 ± 1.7%. Sperm collected in week 2 showed significantly lower fertility when cryopreserved after six days of storage than after 1 or 3 days for sperm to egg ratios of 2 × 106 (p < 0.005), while there was no such effect for milt collected in week 1. Several post-thaw sperm parameters were correlated to fertilization rates, while curvilinear velocity best explained variations in fertilization by modelling. Our results suggest that cryopreservation of Atlantic salmon milt should be performed soon after milt collection to maximize the cryopreserved sperm quality. Fertilization results seems not to be compromised by storage for three days before cryopreservation.publishedVersio

Use of immobilized cryopreserved bovine semen in a blind artificial insemination trial

AbstractTo make timing of artificial insemination (AI) relative to ovulation less critical, methods for prolonging shelf life of spermatozoa in vivo after AI have been attempted to be developed. Encapsulation of sperm cells is a documented technology, and recently, a technology in which sperm cells are embedded in alginate gel has been introduced and commercialized. In this study, standard processed semen with the Biladyl extender (control) was compared with semen processed by sperm immobilization technology developed by SpermVital AS in a blind field trial. Moreover, in vitro acrosome and plasma membrane integrity was assessed and compared with AI fertility data for possible correlation. Semen from 16 Norwegian Red young bulls with unknown fertility was collected and processed after splitting the semen in two aliquots. These aliquots were processed with the standard Biladyl extender or the SpermVital extender to a final number of 12 × 106 and 25 × 106 spermatozoa/dose, respectively. In total, 2000 semen doses were produced from each bull, divided equally by treatment. Artificial insemination doses were set up to design a blinded AI regime; 5 + 5 straws from each extender within ejaculates in ten-straw goblets were distributed to AI technicians and veterinarians all over Norway. Outcomes of the inseminations were measured as 56-day nonreturn rate (NRR). Postthaw sperm quality was assessed by flow cytometry using propidium iodide and Alexa 488–conjugated peanut agglutinin to assess the proportion of plasma membrane and acrosome-intact sperm cells, respectively. In total, data from 14,125 first inseminations performed over a 12-month period, 7081 with Biladyl and 7044 with SpermVital semen, were used in the statistical analyses. There was no significant difference in 56-day NRR for the two semen categories, overall NRR being 72.5% and 72.7% for Biladyl and SpermVital, respectively. The flow cytometric results revealed a significant higher level of acrosome-intact live spermatozoa in Biladyl-processed semen compared to SpermVital semen. The results indicate that the level of acrosome-intact live spermatozoa in the AI dose did not affect the 56-day NRR for the two semen processing methods. In conclusion, this study has showed that immobilized spermatozoa provide equal fertility results as standard processed semen when AI is performed in a blinded field trial, although the immobilization procedure caused increased sperm damage evaluated in vitro compared to standard semen processing procedure

Survivorship Care For Women Living With Ovarian Cancer: Protocol For a Randomized Controlled Trial

BACKGROUND: Ovarian cancer ranks 12th in cancer incidence among women in the United States and 5th among causes of cancer-related death. The typical treatment of ovarian cancer focuses on disease management, with little attention given to the survivorship needs of the patient. Qualitative work alludes to a gap in survivorship care; yet, evidence is lacking to support the delivery of survivorship care for individuals living with ovarian cancer. We developed the POSTCare survivorship platform with input from survivors of ovarian cancer and care partners as a means of delivering patient-centered survivorship care. This process is framed by the chronic care model and relevant behavioral theory. OBJECTIVE: The overall goal of this study is to test processes of care that support quality of life (QOL) in survivorship. The specific aims are threefold: first, to test the efficacy of the POSTCare platform in supporting QOL, reducing depressive symptom burden, and reducing recurrence worry. In our second aim, we will examine factors that mediate the effect of the intervention. Our final aim focuses on understanding aspects of care platform design and delivery that may affect the potential for dissemination. METHODS: We will enroll 120 survivors of ovarian cancer in a randomized controlled trial and collect data at 12 and 24 weeks. Each participant will be randomized to either the POSTCare platform or the standard of care process for survivorship. Our population will be derived from 3 clinics in Texas; each participant will have received some combination of treatment modalities; continued maintenance therapy is not exclusionary. RESULTS: We will examine the impact of the POSTCare-O platform on QOL at 12 weeks after intervention as the primary end point. We will look at secondary outcomes, including depressive symptom burden, recurrence anxiety, and physical symptom burden. We will identify mediators important to the impact of the intervention to inform revisions of the intervention for subsequent studies. Data collection was initiated in November 2023 and will continue for approximately 2 years. We expect results from this study to be published in early 2026. CONCLUSIONS: This study will contribute to the body of survivorship science by testing a flexible platform for survivorship care delivery adapted for the specific survivorship needs of patients with ovarian cancer. The completion of this project will contribute to the growing body of science to guide survivorship care for persons living with cancer. TRIAL REGISTRATION: ClinicalTrials.gov NCT05752448; https://clinicaltrials.gov/study/NCT05752448. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): PRR1-10.2196/48069

Impacts of a warming climate on concentrations of organochlorines in a fasting high arctic marine bird: Direct vs. indirect effects?

The present study examined how climate changes may impact the concentrations of lipophilic organochlorines (OCs) in the blood of fasting High Arctic common eiders (Somateria mollissima) during incubation. Polychlorinated biphenyls (PCBs), 1-dichloro-2,2-bis (p-chlorophenyl) ethylene (p,p′-DDE), hexachlorobenzene (HCB) and four chlordane compounds (oxychlordane, trans-chlordane and trans- and cis-nonachlor) were measured in females at chick hatching (n = 223) over 11 years (2007–2017). Firstly, median HCB and p,p′-DDE concentrations increased ~75 % over the study period, whereas median chlordane concentrations doubled (except for oxychlordane). PCB concentrations, in contrast, remained stable over the study period. Secondly, both body mass and clutch size were negatively associated with OC levels, suggesting that females with high lipid metabolism redistributed more OCs from adipose tissue, and that egg production is an important elimination route for OCs. Thirdly, the direct climate effects were assessed using the mean effective temperature (ET: air temperature and wind speed) during incubation, and we hypothesized that a low ET would increase redistribution of OCs. Contrary to expectation, the ET was positively correlated to most OCs, suggesting that a warmer climate may lead to higher OCs levels, and that the impact of ET may not be direct. Finally, potential indirect impacts were examined using the Arctic Oscillation (AO) in the three preceding winters (AOwinter 1–3) as a proxy for potential long-range transport of OCs, and for local spring climate conditions. In addition, we used chlorophyll a (Chla) as a measure of spring primary production. There were negative associations between AOwinter 1 and HCB, trans-chlordane and trans-nonachlor, whereas oxychlordane and cis-chlordane were negatively associated with Chla. This suggests that potential indirect climate effects on eiders were manifested through the food chain and not through increased long-range transport, although these relationships were relatively weak.Impacts of a warming climate on concentrations of organochlorines in a fasting high arctic marine bird: Direct vs. indirect effects?publishedVersio