Nursing sickness in the mink — a metabolic mystery or a familiar foe?

Nursing sickness, the largest single cause of mortality in adult female mink (Mustela vison), is an example of a metabolic disorder, which develops when the demands for lactation require extensive mobilization of body energy reserves. The condition is characterized by progressive weight loss, emaciation, and dehydration with high concentrations of glucose and insulin in the blood. Morbidity due to nursing sickness can be as high as 15% with mortality around 8%, but the incidence is known to vary from year to year. Stress has been shown to trigger the onset of the disease and old females and females with large litters are most often affected. Increasing demand for gluconeogenesis from amino acids due to heavy milk production may be a predisposing factor. Glucose metabolism is inextricably linked to that of protein and fats. In obesity (or lipodystrophy), the ability of adipose tissue to buffer the daily influx of nutrients is overwhelmed (or absent), interfering with insulin-mediated glucose disposal and leading to insulin resistance. Polyunsaturated fatty acids of the n-3 family play an important role in modulating insulin signalling and glucose uptake by peripheral tissue. The increasing demand on these fatty acids for milk fat synthesis towards late lactation may result in deficiency in the lactating female, thus impairing glucose disposal. It is suggested that the underlying cause of mink nursing sickness is the development of acquired insulin resistance with 3 contributing key elements: obesity (or lipodystrophy), n-3 fatty acid deficiency, and high protein oxidation rate. It is recommended that mink breeder females be kept in moderate body condition during fall and winter to avoid fattening or emaciation. A dietary n-3 fatty acid supplement during the lactation period may be beneficial for improved glycemic control. Lowering of dietary protein reduces (oxidative) stress and improves water balance in the nursing females and may, therefore, prevent the development and help in the management of nursing sickness. It is also surmised that other, thus far unexplained, metabolic disorders seen in male and female mink may be related to acquired insulin resistance.     

Effect of CO2 enrichment on photosynthesis,growth and yield of tomato

Net photosynthesis of tomato plants was measured as CO₂ uptake in various light intensities, CO₂ concentrations, O₂ concentrations and temperatures during short-term experiments. Net photosynthesis increased significantly with increasing CO₂ concentration at all light intensities, even at the lowest one. The optimal temperature for photosynthesis increased with CO₂ enrichment. The changes in photosynthesis when the $\text{CO}{}_2\text{O}{}_2$ ratio was varied suggest that the effect of CO₂ enrichment is a result of a reduction in photorespiration.To determine whether the increase in photosynthesis caused by CO₂ enrichment would produce a greater yield, tomato plants were cultivated from seed to harvest in a tightly-closed greenhouse that was enriched with CO₂ continuously during the entire growing-period. The control greenhouse was ventilated by openings in the roof and door. The temperature of the 2 greenhouses was kept the same. Plants enriched with CO₂ showed a significant increase in fresh and dry weight and yield of tomatoes. The results are discussed in relation to earlier work in which CO₂ enrichment was discontinued when there was a need for ventilation.     

Gingival thickness in dogs: association with age, gender, and dental arch location

Reduced gingival thickness is one of many factors that might predispose humans to periodontal disease and subsequent gingival recession. Gingival thickness differs between individuals, and is associated with age, gender, and location on the dental arch. Different gingival phenotypes exist in the human population according to the thickness of gingiva. Similar information on gingival phenotypes in dogs is unknown. The aim of this study was to investigate the thickness of the gingiva in dogs and its relation to age, gender and location on the dental arch. For this study, 48 dogs of comparable size (40-cm at withers) were divided into three groups according to their age as follows: < 2-years of age; 2 to 8-years of age; > 8-years of age. Gingival thickness was measured in both the mandible and maxilla using a transgingival probing technique. The graded probe was inserted midway into the attached gingiva at the level of each tooth class region. Young and middle aged dogs had significantly thicker gingiva (1.67 +/- 0.17 mm and 1.68 +/- 0.18 mm, respectively) compared with older dogs (1.54 +/- 0.16 mm). There was no significant difference in gingival thickness based on location or gender Generally, the gingiva was thicker at the level of large teeth such as canine and carnassial teeth. Regions of thinner gingiva at the level of incisor and premolar teeth correlated with the regions of highest prevalence of periodontal disease found in previous studies.     

Development of Cold Tolerance in White Clover (Trifolium repens L.) in Relation to Carbohydrate and Free Amino Acid Content

Abstract

Development of cold tolerance in white clover (Trifolium repens L.) genotypes originating from various parts of Norway and grown outdoors at Tromso, latitude 69°39′N, has been studied. Stolon samples for an artificial freezing test and for chemical analysis were collected three times during the autumn. Generally, the most northern genotypes were more cold tolerant than the southern ones. Cold tolerance increased significantly from September to November in all genotypes. Content of dry matter, soluble carbohydrates, sucrose and proline in stolons increased during the hardening process. These changes were similar in both northern and southern genotypes of white clover.     

The Struggle for Tamil Eelam in Sri Lanka

Regionalism has commonly been expected to dissolve as a consequence of the administrative regional penetration of the centralized modern state and the homogenizing forces associated with modernization. This mode of reasoning has reappeared recently among authors who see globalization as a universal force that will eradicate regional economic inequalities, local identities and regional political mobilization. Contrary to these expectations, regional autonomy movements continue to play a central political role within many states. Consequently, it remains an important analytical challenge to understand the construction and politicization of regional interests. Against this background, the article presents a critical interpretation and contextual analysis of Tamil separatism in Sri Lanka. It is argued that studies of nationalist movements should seek inspiration in the contemporary dialog between three main perspectives on social movements (theories of new social movements, resource mobilization theories, and theories of collective identity) and a corresponding three‐dimensional understanding of place (location, locale, and sense of place). The paper shows how nationalist mobilization cannot be reduced to essentialist notions of primordial nations, territorial nation‐states, or internal colonialism, but instead should be understood as the outcome of cultural and political practices by a multitude of actors, operating in time‐ and place‐specific contexts.     

Removal by Snowfall of Emissions from a Coal-Fired Power Station: Observations and Modelling

A case study to determine wet deposition near a250 MW coal-fired power station unit on the southcoast of Finland was carried out during a wintertimeprecipitation event. In addition to intensivemeteorological observations, the experimental part ofthe study included the collection of 28 depositionsamples within 10 km of the power station andmeasurements of sulphur dioxide in the air at twoplaces, one inside and the other outside the downwindsector. Model estimates of the wet deposition patternwere also made, assuming a Gaussian shape and agradual rise for the plume and taking into accountinclined fall trajectories of snowflakes through the plume.By comparing the model results with the chemicalanalysis outcomes, it was inferred that for sulphuremissions in wet snowfall within the first 10 km fromthe source, the precipitation scavenging coefficientwas probably of the order of 10^-6 s^-1 orless. This implies that the percentage of emittedsulphur being scavenged in the study area was about0.7% at most. Although the observed decreases ofacidity from the mean pH-value of 4.1 occurred only indeposition samples on the leeward side of the powerstation, no significant effects of alkaline fly ashcould be confirmed. On the other hand, the modelestimates do suggest that the sulphur and particularlythe hydrochloride emissions may have added to theacidity of snow at downwind distances of 1–5 km fromthe source, but chiefly in a narrow sector whichremained between the collectors.     

The Weathering of Mineral Soil by Natural Soil Solutions

Chemical weathering is an important neutralisation process and sourceof cations in forest soil. The presence of dissolved organic matter in the soil solution can have a considerable influence on weathering release. The aim of this study is to compare the weathering potentialof natural soil solutions, collected from Norway spruce, Scots pine and birch sites, to release Al, Ca, Mg, K, Na, and Si from the fine fraction in the C horizon of a podzol. Residual organic matter in the mineral soil was removed with H₂O₂. The <0.06 mm fraction of the mineral soil was suspended in soil solution, collected from the three sites, for 11 days with continuous agitation. Ultrapure water was used as a control. The pH of the suspensions was maintained at 5.4 by bubbling with CO₂. The initial mean DOC concentrations in the soil solutions were 65, 56 and 40 mg L^-1 for the spruce, pine and birch sites, respectively. The presence of DOM in the soil solution did not significantly enhance the capacity to weather mineral soil material, and no systematic differences were found between the three sites. However, Al release from the mineral soil was slightly higher in the soil solutions containing DOM compared to the control solution with no DOM. The proportions of DOM fractions capable of enhancing weathering were comparable with those reported in earlier studies. The weathering of metals was found to be primarily due to pH-driven processes. The lack of considerable weathering enhancement by DOM could be due to the fact that the cation-binding sites of the organic ligands were already saturated by e.g. Al and Fe in the soil solution derived from these podzolic, Al- and Fe-rich soils.