A well, situated on Listerlandet in the western part of Blekinge in Sweden, has a very high content of nitrate. Water with a too high content of nitrate is hazardous to human health, in particular to small children. The area surrounding the well is mostly drained agricultural land with some larger farms for chicken and mink. The well takes its water from the bedrock and is deeper than most other wells affected by nitrate. The bedrock in the area is dominated by limestone with a relatively high flow of water. This thesis was performed in order to find the source of the nitrate. A groundwater model, simulating the water flow, was created. The model was used to trace the particles flowing to the well in order to find the most likely source. GMS Modflow and Modpath were used to create the model. The validation of the model shows that the model is good enough to be used for further investigation of the groundwater in the area. The model result indicates that the original source for most of the nitrate is some large mink farms situated on the slope of a hill south of the well. Calculation shows that it takes the water 25 years to flow from the farms to the well. There is also a probable contribution of nitrate from the agriculture in the vicinity of the well. But an extensive drainage system brings most of the water from the cultivated area into the Baltic Sea. Conclusions are that a large amount of mink farms placed in a small area contributes to the high content of nitrate in the well. Further examinations are needed to show which measures should be taken in order to diminish the content of nitrate in the well. / En brunn som förser Hörvik med dricksvatten har en hög halt av nitrat. Hörvik ligger på Listerlandet i västra Blekinge. Vatten med för hög nitrathalt är hälsovådligt för människor i allmänhet och spädbarn i synnerhet. Området som omger brunnen består till största delen av dränerad jordbruksmark med några större djurgårdar för broiler och mink. Brunnen är bergborrad och går djupare än de flesta andra nitratpåverkade brunnar i Sverige. Berggrunden i området domineras av kalkberg med ett relativt högt vattenflöde. Ett projektarbete utfördes för att ta reda på ursprungskällan till nitratet. I arbetet skapades en grundvattenmodell som skulle simulera vattenflödena i området och sedan spåra en partikels väg till brunnen för att ta reda på den mest troliga källan. GMS Modflow och Modpath är de dataverktyg som användes. Valideringen av modellen visar att den fungerar tillfredsställande och kan användas för fortsatta undersökningar av grundvattenförhållanden i området. Modellresultat tyder på att ursprungskällan för den största delen av nitratet är några stora minkfarmar som ligger på en sluttning upp mot Listers huvud söder om brunnen; dock har det tagit ca 25 år för vattnet att ta sig från ursprungskällan till brunnen. Jordbruket i närheten av brunnen bidrar sannolikt med en del nitrat, men en omfattande dränering leder den större delen av vattnet från jordbruksområdet ut i Östersjön. Slutsatsen är att ett stort antal minkfarmar i ett begränsat område är en bidragande orsak till brunnens höga nitrathalt. Vidare undersökningar bör visa vilka åtgärder som behövs för att minska nitrathalten i brunnen.

Content: The utilization of mink waste generated through the industrial process attracted both industry and academia interests. In this study, the use of hydrogen peroxide as an oxidizing agent onto collagen producing self-crosslinking which extracting from mink solid waste was studied by infrared spectrum, fluorescence spectrum and thermal properties. The effect of hydrogen peroxide dosage and reaction temperature on the degree of oxidative self-crosslinking of collagen was analyzed by the changes of molecular structure and thermal stability. It was found that, hydroxide groups on the collagen side-chains can be oxidized to aldehyde groups and carboxyl groups by hydrogen peroxide in alkaline environment. These oxidized groups can crosslink with functional groups on collagen by covalent bond and ionic bond, changing collagen molecular structure and improving thermal stability. When the dosage of hydrogen peroxide was 14.74% and reaction temperature was 40℃ ±, the oxidative self-crosslinking of collagen was the strongest. This study provided theoretical basis for the high-value utilization of mink wastes. Take-Away: 1. The oxidative self-crosslink of collagen extracted mink solid waste was studied. 2. Hydrogen peroxide was applied as environment friendly oxidant. 3. The change of functional groups and degree of crosslinks during the oxidation was studied via infrared, fluorescence spectrum and differential scanning calorimetry.

Semi-aquatic mammals have evolved to forage in both aquatic and terrestrial environments, and they generally lack locomotor specialisation for either. Having relatively unspecialised adaptations, some semi-aquatic species are generalist foragers, and their activity and diving patterns provide insight into constraints on their foraging behaviour. The recent miniaturisation and improved accuracy of logging devices allow remote data collection from small (<1kg), shallow-diving species. The development of analytical methods has lagged behind technological advances (and techniques developed for fully aquatic animals do not account for the variability of behaviour typical of semi-aquatic animals and their switching between terrestrial and aquatic environments). I applied and developed novel analytical techniques to identify activities and diving patterns of a semi-aquatic mustelid, the American mink (Neovison vison), fitted with Time-Depth Recorders (TDRs). Using a hidden Markov model (HMM) algorithm allowed me to classify dives into three states to identify clustering, and describe sequential diving patterns by mink. TDRs were used to determine active/inactive periods on the basis of rapid TDR temperature changes, and this method was validated empirically. Having developed this methodology, I applied it to 18 datasets collected from 14 mink in lowland England. Terrestrial activity of mink was positively related to ambient temperature (across both sexes), however aquatic activity, especially diving, appeared to be more influenced by daylight than by temperature. Mink showed intersexual differences, with males being more nocturnal and more active on land, and females more diurnal, and more persistent in diving. There was considerable variability between sexes and individuals. This is the first study to use HMM to classify the dives of a semi-aquatic animal, and the first to use TDR temperature records to identify mammalian activity patterns. These methods will be generally applicable to animals that make rapid transitions between environments and have thus far been difficult to study.

Mercury (Hg) is a toxicant of global concern, but few strategies exist to evaluate its biological effects on the ecosystem. Piscivorous wildlife, such as mink (Mustela vison), are particularly at risk because they can bioaccumulate Hg to concentrations known to impair neurological systems. Given that biochemical changes in the brain precede functional and structural impairments, I evaluated the use of neurochemicals as early-warning biomarkers of Hg toxicity in mink. Initial studies demonstrated that neurochemical biomarkers could be measured from mink carcasses collected from the field, as long as factors such as storage temperature and freeze thaw cycles were accounted for. To determine if Hg could directly impair neurochemicals in mink, an in vitro study demonstrated that Hg (HgCl2 and MeHg) could inhibit radioligand binding to the muscarinic cholinergic (mACh) receptor in the cerebellum and cerebral cortex regions of the brain. By analyzing whole brains collected from wild mink, it was demonstrated that a significant positive correlation existed between concentrations of brain Hg and levels of mACh receptors. These field observations were confirmed by results from a controlled methyl Hg (MeHg) feeding trial in captive mink, whereby sub-chronic exposure of mink to 0.5 - 2 ppm MeHg (ecologically relevant levels) resulted in significant increases in acetylcholinesterase activity and mACh receptor levels in specific brain regions. Collectively, these results demonstrated that exposure of mink to environmentally realistic concentrations of Hg can be related to alterations in neurochemicals at multiple tiers of biological organization. Given the importance of a functional nervous system in wildlife health, the physiological and ecological significance of these findings need further exploration. The results demonstrate that neurochemical approaches may be novel biomarkers to assess the ecotoxicology of Hg, and by extension, other pollutants o

No description available.

<p>  </p> <p>Semi-aquatic mammals, such as American beavers (<em>Castor canadensis</em>), muskrats (<em>Ondatra zibethicus</em>), North American river otters (<em>Lontra canadensis</em>), and American mink (<em>Neogale</em> <em>vison</em>), often play important roles in their ecosystem. Beavers and muskrats can manipulate plant community structure through the use of woody debris and forbs. As mesocarnivores, North American river otters and American mink can also drive community structure through the predation. Traditionally, these species are monitored using sign surveys (i.e., walking transects and visually identifying scat, tracks, and latrines). Camera trapping has also been used to survey semi-aquatic species occupancy to a lesser extent. However, due to their almost exclusive use of edge habitat, they may be ideal species to camera trap. Another more recently employed survey method is environmental DNA (eDNA), which involves the extraction of DNA from environmental samples (such as soil, water, air, and snow) to determine species occupancy. In this study, I evaluate environmental DNA and camera trapping as survey methods for detecting semi-aquatic mammals around northeastern Indiana. In the first chapter, I used eDNA sampling and camera trapping to monitor seven sites for three weeks during March – May 2021 in order to determine the presence of American mink. I found that the naïve occupancy for each site was 0.86. Although the detection probability of eDNA was lower than that of camera trapping (0.25 and 0.36, respectively), the occupancy models created suggest that there was no difference in detection probability between the two methods. I also compared the cost and time spent per sample and found that both were 20% lower for eDNA than camera trapping. The results of my study suggest eDNA may be a cost- and time-effective method for surveying for American mink occupancy. The objective of my second chapter was to determine the number of camera traps required to obtain reliable data for detecting semi-aquatic mammals. A minimum requirement for number of camera traps would be useful knowledge for wildlife managers in terms of budgeting and resource management and could also help to refine current camera trapping methodologies. I camera trapped four ponds for four weeks during June – July 2021, varying the number of camera traps (1 – 5) used at each pond each week. I collected a total of 66,543 photos and detected one semi-aquatic mammal throughout the study period (<em>Neogale vison</em>). Due to the lack of semi-aquatic mammals detected, I could not perform any analyses.</p>

Data derived largely from ecclesiastical (mostly churchwardens') accounts, foxhunting statistics, local scientific society records and 19th and 20th century literature sources from a wide range of published material, have provided detailed evidence of the status and changes in distribution over the past four centuries in Yorkshire for fox (Vulpes vulpes), badger (Meles meles), otter (Lutra lutra), pine marten (Martes martes), stoat (Mustela erminea), weasel (M. nivalis), polecat (M. putorius), American mink (M. vison), wildcat (Felis silvestris) and domestic cat (Felis catus). In the case of the domestic cat, questionnaire surveys quantified population sizes and predatory activity in rural, suburban and urban situations. Evidence of the former distribution of all the carnivores studied provides a credible historical basis for biodiversity action planning and the substantial archived database and bibliography provide further research opportunities.

La diapause embryonnaire se manifeste par un arrêt réversible du développement embryonnaire durant la période de préimplantation et induit un retard de l’implantation. Chez le vison américain, une diapause embryonnaire obligatoire caractérise chaque gestation. Si les mécanismes de contrôle de la diapause embryonnaire obligatoire chez cette espèce sont bien connus, le rôle utérin impliqué dans la réactivation de l’embryon demeure, quant à lui, encore inconnu. Le sujet de ce doctorat a consisté dans un premier temps à explorer l’environnement utérin à la sortie de la diapause embryonnaire afin de caractériser, dans un deuxième temps, les principaux acteurs utérins qui provoquent la réactivation de l’embryon. Nous avons effectué une analyse du transcriptome utérin à l’émergence de la diapause embryonnaire ce qui a permis de construire une librairie de 123 séquences d’ADNc utérines différentiellement exprimées à la réactivation de l’embryon et homologues à des séquences de gènes connues chez d’autres espèces. Ces gènes sont impliqués dans la régulation du métabolisme (25 %), de l’expression génique (21 %), de la transduction de signal (15 %), du cycle cellulaire (15 %), du transport (10 %) et de la structure cellulaire (9 %), reflétant ainsi d’importantes modifications utérines à la réactivation embryonnaire. Nous avons validé l’expression différentielle de dix gènes ainsi identifiés : GDF3 (growth and differentiation 3), ALCAM (activated leukocyte cell adhesion molecule), ADIPOR1 (adiponectin receptor 1), HMGN1 (high mobility group N1), TXNL1 (thioredoxin like 1), TGM2 (tissue transglutaminase 2), SPARC (secreted protein acidic rich in cystein), et trois gènes codant pour AZIN1 (antizyme inhibitor 1), ODC1 (ornithine decarboxylase 1) et SAT1 (spermidine/spermine N1-acetyltransferase), des enzymes impliquées dans la biosynthèse des polyamines. Le patron de l’expression spatio-temporel de SPARC et d’HMGN1 illustrent spécifiquement un remodelage tissulaire et de la chromatine au niveau utérin à la sortie de la diapause embryonnaire. Ayant mesuré une augmentation des concentrations utérines en polyamines à la reprise du développement embryonnaire, nous avons émis l’hypothèse que les polyamines seraient impliquées dans les événements menant à la sortie de la diapause. L’inhibition de la biosynthèse des polyamines par un traitement à l’ α-difluoromethylornithine (DFMO) a provoqué une diminution significative de la proliferation cellulaire dans les embryons à la réactivation, un retard du moment de l’implantation, mais n’a pas affecté le succès de la reproduction. De manière similaire, nous avons induit un état de dormance dans les cellules de trophoblaste de vison en présence DFMO dans le milieu de culture, et constaté que cet état était réversible. En conclusion, cette étude a non seulement ouvert de nouveaux horizons quant à la compréhension du rôle utérin dans les événements menant à la sortie de la diapause embryonnaire, mais a démontré pour la première fois, l’existence de facteurs utérins indispensables à la réactivation de l’embryon: les polyamines. / Embryonic diapause is characterized by a reversible arrest of blastocyst development prior to implantation and delay in implantation. In the American mink, embryonic diapause is a characteristic of each gestation. Although the mechanisms which control obligate embryonic diapause of this species are well known, the role of the uterus involved in blastocyst reactivation remains elusive. The subject of this doctoral research consisted first in exploring the uterine environment at the emergence of embryonic diapause in order to subsequently determine, the main factors in the uterus that provoke reactivation of the embryo. We have undertaken an analysis of the uterine transcriptome at the emergence of embryonic diapause which has enabled us to set up a library of 123 cDNA uterine sequences differentially expressed at blastocyst reactivation, and homologue gene sequences known in other species. Twenty-five percent of these genes are implicated in genetic expression, 15 % in cell signal transduction, 15 % in cell cycle, 10 % in transport and 9 % in cell structure. All of them reflect significant uterine modifications at blastocyst reactivation. We have validated differential expression of ten genes, identified as: GDF3 (growth and differentiation 3), ALCAM (activated leukocyte cell adhesion molecule), ADIPOR1 (adiponectin receptor 1), HMGN1 (high mobility group N1), TXNL1 (thioredoxine like 1), TGM2 (tissue transglutaminase 2), SPARC (secreted protein acidic rich in cystein), and three genes encoding for AZIN1 (antizyme inhibitor 1), ODC1 (ornithine decarboxylase 1) and SAT1 (spermidine/spermine N1-acetyltransferase), which are enzymes implicated in polyamine biosynthesis. The spatio-temporal expression patterns of SPARC and HMGN1 illustrate tissue and chromatin remodelling in the uterus at the termination of embryonic diapause. Having measured an increase in concentration of polyamines in the uterus at the resumption of blastocyst development, we have hypothetized that polyamines are implicated in the emergence of blastocysts from diapause. We inhibited polyamine biosynthesis in pregnant mink females during early blastocyst reactivation. The inhibition of polyamine biosynthesis through treatment with α-difluoromehtylornithine (DFMO) provoked a major reduction in cell proliferation in blastocysts at reactivation and a delay in the timing of implantation, but did not affect the success of reproduction. Similarly, we induced a reversible dormant state in cultured mink trophoblast cells traited with DFMO. To conclude, not only are results of this study a breakthrough in the understanding of the role of the uterus in stimulating at the emergence of blastocysts from embryonic diapause, but also, for the very first time, they indicate the existence of uterine factors, the polyamines, that are responsible for blastocysts reactivation.

La diapause embryonnaire se manifeste par un arrêt réversible du développement embryonnaire durant la période de préimplantation et induit un retard de l’implantation. Chez le vison américain, une diapause embryonnaire obligatoire caractérise chaque gestation. Si les mécanismes de contrôle de la diapause embryonnaire obligatoire chez cette espèce sont bien connus, le rôle utérin impliqué dans la réactivation de l’embryon demeure, quant à lui, encore inconnu. Le sujet de ce doctorat a consisté dans un premier temps à explorer l’environnement utérin à la sortie de la diapause embryonnaire afin de caractériser, dans un deuxième temps, les principaux acteurs utérins qui provoquent la réactivation de l’embryon. Nous avons effectué une analyse du transcriptome utérin à l’émergence de la diapause embryonnaire ce qui a permis de construire une librairie de 123 séquences d’ADNc utérines différentiellement exprimées à la réactivation de l’embryon et homologues à des séquences de gènes connues chez d’autres espèces. Ces gènes sont impliqués dans la régulation du métabolisme (25 %), de l’expression génique (21 %), de la transduction de signal (15 %), du cycle cellulaire (15 %), du transport (10 %) et de la structure cellulaire (9 %), reflétant ainsi d’importantes modifications utérines à la réactivation embryonnaire. Nous avons validé l’expression différentielle de dix gènes ainsi identifiés : GDF3 (growth and differentiation 3), ALCAM (activated leukocyte cell adhesion molecule), ADIPOR1 (adiponectin receptor 1), HMGN1 (high mobility group N1), TXNL1 (thioredoxin like 1), TGM2 (tissue transglutaminase 2), SPARC (secreted protein acidic rich in cystein), et trois gènes codant pour AZIN1 (antizyme inhibitor 1), ODC1 (ornithine decarboxylase 1) et SAT1 (spermidine/spermine N1-acetyltransferase), des enzymes impliquées dans la biosynthèse des polyamines. Le patron de l’expression spatio-temporel de SPARC et d’HMGN1 illustrent spécifiquement un remodelage tissulaire et de la chromatine au niveau utérin à la sortie de la diapause embryonnaire. Ayant mesuré une augmentation des concentrations utérines en polyamines à la reprise du développement embryonnaire, nous avons émis l’hypothèse que les polyamines seraient impliquées dans les événements menant à la sortie de la diapause. L’inhibition de la biosynthèse des polyamines par un traitement à l’ α-difluoromethylornithine (DFMO) a provoqué une diminution significative de la proliferation cellulaire dans les embryons à la réactivation, un retard du moment de l’implantation, mais n’a pas affecté le succès de la reproduction. De manière similaire, nous avons induit un état de dormance dans les cellules de trophoblaste de vison en présence DFMO dans le milieu de culture, et constaté que cet état était réversible. En conclusion, cette étude a non seulement ouvert de nouveaux horizons quant à la compréhension du rôle utérin dans les événements menant à la sortie de la diapause embryonnaire, mais a démontré pour la première fois, l’existence de facteurs utérins indispensables à la réactivation de l’embryon: les polyamines. / Embryonic diapause is characterized by a reversible arrest of blastocyst development prior to implantation and delay in implantation. In the American mink, embryonic diapause is a characteristic of each gestation. Although the mechanisms which control obligate embryonic diapause of this species are well known, the role of the uterus involved in blastocyst reactivation remains elusive. The subject of this doctoral research consisted first in exploring the uterine environment at the emergence of embryonic diapause in order to subsequently determine, the main factors in the uterus that provoke reactivation of the embryo. We have undertaken an analysis of the uterine transcriptome at the emergence of embryonic diapause which has enabled us to set up a library of 123 cDNA uterine sequences differentially expressed at blastocyst reactivation, and homologue gene sequences known in other species. Twenty-five percent of these genes are implicated in genetic expression, 15 % in cell signal transduction, 15 % in cell cycle, 10 % in transport and 9 % in cell structure. All of them reflect significant uterine modifications at blastocyst reactivation. We have validated differential expression of ten genes, identified as: GDF3 (growth and differentiation 3), ALCAM (activated leukocyte cell adhesion molecule), ADIPOR1 (adiponectin receptor 1), HMGN1 (high mobility group N1), TXNL1 (thioredoxine like 1), TGM2 (tissue transglutaminase 2), SPARC (secreted protein acidic rich in cystein), and three genes encoding for AZIN1 (antizyme inhibitor 1), ODC1 (ornithine decarboxylase 1) and SAT1 (spermidine/spermine N1-acetyltransferase), which are enzymes implicated in polyamine biosynthesis. The spatio-temporal expression patterns of SPARC and HMGN1 illustrate tissue and chromatin remodelling in the uterus at the termination of embryonic diapause. Having measured an increase in concentration of polyamines in the uterus at the resumption of blastocyst development, we have hypothetized that polyamines are implicated in the emergence of blastocysts from diapause. We inhibited polyamine biosynthesis in pregnant mink females during early blastocyst reactivation. The inhibition of polyamine biosynthesis through treatment with α-difluoromehtylornithine (DFMO) provoked a major reduction in cell proliferation in blastocysts at reactivation and a delay in the timing of implantation, but did not affect the success of reproduction. Similarly, we induced a reversible dormant state in cultured mink trophoblast cells traited with DFMO. To conclude, not only are results of this study a breakthrough in the understanding of the role of the uterus in stimulating at the emergence of blastocysts from embryonic diapause, but also, for the very first time, they indicate the existence of uterine factors, the polyamines, that are responsible for blastocysts reactivation.

Tema : Audinių prieinkstinių liaukų histopatologinis tyrimas. Tyrimo objektas: X ūkio 6 mėnesių amžiaus audinių prieinkstinių liaukų histologiniai preparatai. Atlikimo vieta: Lietuvos Sveikatos Mokslų Universiteto Veterinarijos Akademijos Patologijos centras. Darbo apimtis: 41 puslapis, naudoti 43 literatūros šaltiniai, 31 paveikslas. Tyrimo tikslas: Įvertinti audinių prieinkstinių liaukų histomorfologinius pokyčius. Tyrimo uždaviniai: 1. Atlikti histologinį ir histocheminį mėginių tyrimus. 2. Įvertinti audinių prieinkstinių liaukų histopatologijas. Tyrimo metodai: Rutininio skrodimo metu buvo paimta 40 audinių prieinkstinių liaukų pataloginė medžiaga (n=40), fiksuota 10 proc. neutraliu formalino tirpalu, atliktas mėginių dažymas hematoksilinu eozinu ir Kongo raudonuoju. Histologinio tyrimo metu įvertintos prieinkstinių liaukų patologijos. Tyrimo duomenų statistinis įvertinimas atliktas, naudojant Microsoft Exel (2010) programą. Paskaičiuotas įvairių patologijų pasireiškimo dažnumas, jų pasiskirstymas žievėje ir šerdyje (proc.). Taip pat įvertinta, kaip pasiskirstė patologijos žievės zonose, jų pasireiškimo dažnumas procentais. Išvados: 1. Atlikus histologinį tyrimą pakitusių audinių antinksčių rasta 92 proc. 2. Atlikus histocheminį prieinkstinių liaukų tyrimą, baltymo amiloido sankaupų prieinkstinėse liaukose nerasta. 3. Didžiausią dalį patologinių pokyčių sudaro plazmocitų infiltracija (70 proc.) ir hemosiderozė (17 proc.). 4. Mažiausią dalį patologinių pokyčių... [toliau žr. visą tekstą] / Theme: Histopathological research of mink adrenal glands Study object: adrenal gland histological samples (preparations) of 6-month-old minks from farm X. Venue of performance: in Pathology Center of the Veterinary Academy of the Lithuanian University of Health Sciences Volume of the paper: the total volume of the work comprises 41,i.e. 31 picture. The aim of the research: to evaluate histomorphologic changes of mink adrenal glands. Tasks of the work: 1. to make histological and histochemical analysis of samples. 2. to evaluate histopathologies of mink adrenal glands. Research methods: during the routine autopsy was taken pathological material of adrenal glands (n = 40) of 40 minks, which was fixed 10 per cent with neutral formalin solution, and samples dyeing with hematoxylin eosin and Congo red were carried out. Statistical evaluation of the survey data carried out using Microsoft Excel (2010) program. Calculated the frequency of the appearance of various pathologies, their distribution in the cortex and core (in percent). Also, has been assessed the distribution of pathology in cortex areas and their frequency of occurrence percentage (in percent). The most important conclusions : 1. An analysis of 40 male minks adrenal glands histological results showed that 92 per cent. analyzed samples demonstrate a change. 2. The largest part of the pathological changes consist of infiltration by plasmocytes (70 percent.) and hemosiderosis (17 percent.). 3. The smallest part of the... [to full text]