A correlation between BCL-2 modifying factor,p53 and livin gene expressions in cancer colon patients

Accumulating evidence has revealed that livin gene and BCL-2 modifying factor (BMF) gene are closely associated with the initiation and progression of colon carcinoma by activating or suppressing multiple malignant processes. Those genes that can detect colon - cancer are a promising approach for cancer screening and diagnosis. This study aimed to evaluate correlation between livin, BMF and p53 genes expression in colon cancer tissues of patients included in the study, and their relationship with clinicopathological features and survival outcome in those patients. In this study, 50 pathologically diagnosed early cancer colon patients included and their tissue biopsy with 50 matched adjacent normal tissue, and 50 adenoma tissue specimens were analyzed for livin gene and BMF gene expressions using real time PCR. The relationship of those genes expressions with clinicopathological features, tumor markers, Time to Progression and overall survival for those patients were correlated in cancer colon group. In this study, there was a significant a reciprocal relationship between over expression of livin gene and down regulation of BMF and p53 genes in colon cancer cells. Livin mRNA was significantly higher, while BMF and p53 mRNA were significantly lower in colorectal cancer tissue compared to benign and normal colon tissue specimens (P < 0.001), however, this finding was absent between colon adenomas and normal mucosa. There was a significant association between up regulation of livin and down regulation of BMF and p53 expressions with more aggressive tumor (advanced TNM stage), rapid progression with metastasis and decreased overall survival in cancer colon patients, hence these genes can serve as significant prognostic markers of poor outcome in colon cancer patients. This work highlights the role of livin, BMF and p53 genes in colorectal tumorigenesis and the applicability of using those genes as a diagnostic and prognostic markers in patients with colon carcinoma and as a good target for cancer colon treatment in the future.     

Biocides formulation of essential oils having antimicrobial activity

Essential oils of fennel, peppermint, caraway, eucalyptus, geranium and lemon were tested for their antimicrobial activities against some plant pathogenic micro-organisms (Fusarium oxysporum, Alternaria alternate, Penicilium italicum Penicilium digitatum and Botyritus cinerea). Essential oils of fennel, peppermint, caraway were selected as an active ingredient for the formulation of biocides due to their efficiency in controlling the tested micro-organisms. Successful emulsifiable concentrates (biocides) were prepared from these oils using different emulsifiers (Emulgator B.L.M. Tween20 and Tween80) and different fixed oils (sesame, olive, cotton and soybean oils). Physico-chemical properties of the formulated biocide (spontaneous emulsification, emulsion stability test, cold stability and heat stability tests as well as viscosity, surface tension and pH) were measured. The prepared biocides were ready to be tested for application in a future work as a safe pesticide against different pathogens.     

Metagenomic insights into strategies of carbon conservation and unusual sulfur biogeochemistry in a hypersaline Antarctic lake

Organic Lake is a shallow, marine-derived hypersaline lake in the Vestfold Hills, Antarctica that has the highest reported concentration of dimethylsulfide (DMS) in a natural body of water. To determine the composition and functional potential of the microbial community and learn about the unusual sulfur chemistry in Organic Lake, shotgun metagenomics was performed on size-fractionated samples collected along a depth profile. Eucaryal phytoflagellates were the main photosynthetic organisms. Bacteria were dominated by the globally distributed heterotrophic taxa Marinobacter, Roseovarius and Psychroflexus. The dominance of heterotrophic degradation, coupled with low fixation potential, indicates possible net carbon loss. However, abundant marker genes for aerobic anoxygenic phototrophy, sulfur oxidation, rhodopsins and CO oxidation were also linked to the dominant heterotrophic bacteria, and indicate the use of photo- and lithoheterotrophy as mechanisms for conserving organic carbon. Similarly, a high genetic potential for the recycling of nitrogen compounds likely functions to retain fixed nitrogen in the lake. Dimethylsulfoniopropionate (DMSP) lyase genes were abundant, indicating that DMSP is a significant carbon and energy source. Unlike marine environments, DMSP demethylases were less abundant, indicating that DMSP cleavage is the likely source of high DMS concentration. DMSP cleavage, carbon mixotrophy (photoheterotrophy and lithoheterotrophy) and nitrogen remineralization by dominant Organic Lake bacteria are potentially important adaptations to nutrient constraints. In particular, carbon mixotrophy relieves the extent of carbon oxidation for energy production, allowing more carbon to be used for biosynthetic processes. The study sheds light on how the microbial community has adapted to this unique Antarctic lake environment.     

Home ranges in moving habitats: polar bears and sea ice

Home range size estimates are often used to assess the amount of space required for animals to perform the activities essential for their survival and reproduction. However, in moving environments, traditional home range estimates may be ill suited to this task. In particular, traditional home range estimates are inaccurate representations of the space required by polar bears Ursus maritimus. The sea ice is the prime foraging platform of polar bears, and estimating the amount of ice encountered by bears may provide a better approximation of space use. We develop a technique to make these estimates. Our results confirm that polar bears use more space than terrestrial carnivores to find the resources and conditions they require. We also show that the traditional geographic home range can underestimate both the movement of bears and the amount of space encountered. Moreover, area of ice encountered increased with ice drift, indicating that bears living on highly mobile ice might be exposed to higher energetic costs, and potentially larger energetic gains, than bears inhabiting more stable ice. The methods and concepts presented here can serve as a foundation for new approaches to study the space use of the many species living in moving environments.     

Modeling optimal responses and fitness consequences in a changing Arctic

Animals must balance a series of costs and benefits while trying to maximize their fitness. For example, an individual may need to choose how much energy to allocate to reproduction versus growth, or how much time to spend on vigilance versus foraging. Their decisions depend on complex interactions between environmental conditions, behavioral plasticity, reproductive biology, and energetic demands. As animals respond to novel environmental conditions caused by climate change, the optimal decisions may shift. Stochastic dynamic programming provides a flexible modeling framework with which to explore these trade‐offs, but this method has not yet been used to study possible changes in optimal trade‐offs caused by climate change. We created a stochastic dynamic programming model capturing trade‐off decisions required by an individual adult female polar bear (Ursus maritimus) as well as the fitness consequences of her decisions. We predicted optimal foraging decisions throughout her lifetime as well as the energetic thresholds below which it is optimal for her to abandon a reproductive attempt. To explore the effects of climate change, we shortened the spring feeding period by up to 3 weeks, which led to predictions of riskier foraging behavior and higher reproductive thresholds. The resulting changes in fitness may be interpreted as a best‐case scenario, where bears adapt instantaneously and optimally to new environmental conditions. If the spring feeding period was reduced by 1 week, her expected fitness declined by 15%, and if reduced by 3 weeks, expected fitness declined by 68%. This demonstrates an effective way to explore a species' optimal response to a changing landscape of costs and benefits and highlights the fact that small annual effects can result in large cumulative changes in expected lifetime fitness.     

Reconstructing the reproductive history of female polar bears using cementum patterns of premolar teeth

Premolar teeth collected from 220 adult female polar bears (Ursus maritimus) from western Hudson Bay, Canada, were examined to determine whether past reproductive events are recorded in cementum. The widths of annular cementum growth layer groups (GLGs) were measured and compared as proportional width index (PWI) values to correct for age and body size bias. Known reproductive states (pregnant, with cubs, or with yearlings) were used to confirm and calibrate cementum annuli. Significant differences in PWI were observed between GLGs formed the year females were pregnant versus when accompanied by cubs or yearlings. The probability of a female having produced a cub in adulthood was determined by fitting a logistic regression model between the ΔPWI of females when pregnant and with their cubs. Logistic regression of ΔPWI (β₀ = −0.229, β₁ = −13.465, G ² = 46.55, df = 1, P < 0.001) correctly classified the presence or absence of cubs in 72% of GLGs. Cementum width did not vary between different litter sizes. Observations of females with early litter loss suggests that longer periods of lactation contributes to decreased cementum width and therefore cementum may record a minimum age of litter survival. Predictions of litter production rate (0.43 litters/female/year) derived from cementum were similar to field observations; however, age at first parturition was underestimated by 1 year. We conclude that patterns of cementum deposition may be useful to determine individual reproductive histories and establish course estimates of reproductive parameters when regular field observations are not feasible. We also conclude that reproductive parameters derived from cementum are not adequate on their own for monitoring populations which are in decline or under stress and field observation should not be replaced under these conditions.     

Polar bear (<Emphasis Type="Italic">Ursus maritimus</Emphasis>) maternity den distribution in Svalbard,Norway

The aim of the current study was to identify maternity denning areas and to describe aspects of denning behaviour in polar bears (Ursus maritimus) in Svalbard, Norway. Den observations made during aerial and ground surveys (n = 553), observations of recently emerged family groups made during capture and tagging of bears (n = 206), and dens recorded by satellite telemetry (n = 76 dens) were used to describe the distribution of dens in the Barents Sea region. Data were collected during March, April, and May from 1972 to 2010, and while most dens were abandoned during the first 2 weeks of April, there was substantial variation. The highest number of dens was recorded on the islands in the eastern and northern parts of Svalbard with fewer dens found further west on the island Spitsbergen. Females with cubs-of-the-year or their tracks indicated some denning in southern, eastern, and northern parts of Spitsbergen. Telemetry also revealed that females captured in Svalbard and the Barents Sea den in Franz Josef Land, Russia. The majority of dens (62%) in Svalbard were located on land within ca. 1 km of the shore with the most inland den 19 km from shore. Heavy exploitation of polar bears before 1973, when a hunting moratorium was implemented, likely led to reduced denning in some areas. Our observations of den distribution indicate that denning is now more widespread in the archipelago than 50 years ago and reflects a reestablishment of denning areas following years of protection.     

Body composition of three polar bear (Ursus maritimus) cubs found dead at Svalbard

We determined the body composition from the carcasses of three 3- to 4-months-old polar bear cubs found dead at Svalbard, Norway. Two of the cubs were killed by a male bear at the den and one cub died from starvation. These three carcasses weighed 70-77% of total body mass of cubs. The ash and protein content of the three carcasses were similar but the starving cub had higher water content and lower fat content than the two killed cubs. The fat content varied from 1.3% (starving cub) to 12.9% while the content of water and fat was similar (about 76%) in the three cubs. More data on the body composition of polar bear cubs at time of emergence from the den are needed to understand the breeding ecology and reproductive energetics of female polar bears.