21 research outputs found
Självspridning av Pinus contorta
Pinus contorta fördes in i Sverige för ett mer storskaligt brukande under 1970-talet för att fylla den förutspådda virkessvackan. Contortan importerades från Nordamerika och är idag Sveriges tredje största barrträd, då den är planterad på ca 600 000 ha. Studier av contortan hade visat att dess kottar var serotina, vilket betyder att de är kådslutna och kräver hög värme för att öppna sig. Det som dock inte tagits i så stor beaktan vid införandet i Sverige var att contortan även producerar icke-serotina kottar och att själva kottproduktionen startar redan vid 5 - 10 års ålder.
Det som senare visat sig i flertalet länder, till exempel på Nya Zeeland, var att contortan har en stor förmåga att självsprida sig på störda marker och att den höga värmen som krävs för att kottarna ska öppna sig uppnås om kottarna befinner sig på eller så nära som 30 cm från marken. Kunskapsluckan kring självspridning av contortan i Sverige är ganska stor eftersom få studier i ämnet har utförts, vilket ledde till att vi i denna litteraturstudie ville försöka sammanfatta det som finns studerat sedan tidigare och försöka skapa en bild av contortans invasiva beteende. I de studier som gjorts har det visat sig att contortan kan sprida sig på i stort sett alla marker, även på impedimentmarker, vilket kommer bli ett problem i framtiden om vi ska kunna bevara våra skyddsvärda biotoper utan exotiska trädslags inblandning.Pinus contorta was introduced in Sweden in a bigger perspective than before around the 1970s, and the reason was to fill the approaching timber shortage. The lodgepole pine (LP) was imported from North America and today it is the third biggest conifer in Sweden, and it is planted on around 600 000 ha. Studies of the lodgepole pine has shown that LP has serotinous cones, which means that they are closed with resin and needes to be heated up to open and to loose the seeds. It was not considered when the species was introduced, that it also produces non-serotinous cones and that the cone production starts when the trees are 5-10 years.
Studies from several countries (fore example New Zealand) has shown that LP has a high capability to self regenerate on disturbed land and that the high heat that is needed for the cones to open up, is fulfilled if the cones lays on the ground or is about 30 cm from the ground. The gap in knowledge about self regeneration of LP in Sweden is quite big and few studies has been made, which encourage us to try summarize accomplished studies and try to make an image of the invasiveness of LP. Results from other studies has shown that the spread of LP can occur on broadly every types of soils, even on unproductive land. This will be a problem in the future if we want to protect our natural habitats, without exotical implication
Radiosensitizers in pancreatic cancer—Preclinical and clinical exploits with molecularly targeted agents
Kit Protein (CD 117) and Proliferation Index (Ki-67) Evaluation in Well and Poorly Differentiated Neuroendocrine Tumors
Advanced pancreatic adenocarcinoma: a review of current treatment strategies and developing therapies
The Prognostic Value of Mitotic Activity Index (MAI), Phosphohistone H3 (PPH3), Cyclin B1, Cyclin A, and Ki67, Alone and in Combinations, in Node-Negative Premenopausal Breast Cancer
Proliferation, either as the main common denominator in genetic profiles, or in the form of single factors such as Ki67, is recommended for clinical use especially in estrogen receptor-positive (ER) patients. However, due to high costs of genetic profiles and lack of reproducibility for Ki67, studies on other proliferation factors are warranted. The aim of the present study was to evaluate the prognostic value of the proliferation factors mitotic activity index (MAI), phosphohistone H3 (PPH3), cyclin B1, cyclin A and Ki67, alone and in combinations. In 222 consecutive premenopausal node-negative breast cancer patients (87% without adjuvant medical treatment), MAI was assessed on whole tissue sections (predefined cut-off >= 10 mitoses), and PPH3, cyclin B1, cyclin A, and Ki67 on tissue microarray (predefined cut-offs 7th decile). In univariable analysis (high versus low) the strongest prognostic proliferation factor for 10-year distant disease-free survival was MAI (Hazard Ratio (HR)=3.3, 95% Confidence Interval (CI): 1.8-6.1), followed by PPH3, cyclin A, Ki67, and cyclin B1. A combination variable, with patients with MAI and/or cyclin A high defined as high-risk, had even stronger prognostic value (HR=4.2, 95% CI: 2.2-7). When stratifying for ER-status, MAI was a significant prognostic factor in ER-positive patients only (HR=7.0, 95% CI: 3.1-16). Stratified for histological grade, MAI added prognostic value in grade 2 (HR=7.2, 95% CI: 3.1-38) and grade 1 patients. In multivariable analysis including HER2, age, adjuvant medical treatment, ER, and one proliferation factor at a time, only MAI (HR=2.7, 95% CI: 1.1-6.7), and cyclin A (HR=2.7, 95% CI: 1.2-6.0) remained independently prognostic. In conclusion this study confirms the strong prognostic value of all proliferation factors, especially MAI and cyclin A, in all patients, and more specifically in ER-positive patients, and patients with histological grade 2 and 1. Additionally, by combining two proliferation factors, an even stronger prognostic value may be found
KRAS Mutation in Metastatic Pancreatic Ductal Adenocarcinoma: Results of a Multicenter Phase II Study Evaluating Efficacy of Cetuximab plus Gemcitabine/Oxaliplatin (GEMOXCET) in First-Line Therapy
10-year distant disease-free survival of premenopausal women with lymph-node negative breast cancer according to (a) MAI-status (b) PPH3-status, (c) cyclin B1-status, (d) cyclin A-status, and (e) Ki67-status.
<p>10-year distant disease-free survival of premenopausal women with lymph-node negative breast cancer according to (a) MAI-status (b) PPH3-status, (c) cyclin B1-status, (d) cyclin A-status, and (e) Ki67-status.</p