41 research outputs found
Sedimentology and sequence stratigraphy of the paleoproterozoic Rove and Virginia formations, southwest Superior Province
The Paleoproterozoic Rove and Virginia Formations are lithostratigraphically and
chronostratigraphically correlative units which comprise the upper sedimentary strata in
the Animikie basin. They sharply overlie an intensely altered zone within the upper
Gunflint and Biwabik iron formations which was subaerially exposed by compressional
forces during the Penokean Orogeny. Dating of volcaniclastic zircons from the upper
Gunflint yielded a pre-Penokean age of 1878 Ma. Tuffaceous layers very near the base
of the Rove and Virginia Formations provided U-Pb zircon ages of approximately 1835
Ma placing commencement of sedimentation into the newly resubmerged basin during
the final stages o f Penokean igneous activity.
This study involved examination of 3200 m of drill core from eleven continuously
drilled holes and one twiced drilled hole extending over 424 km from south of Duluth to
south of Thunder Bay. Observation of the lithofacies present and their stratigraphie
relationships provided insight into the depositional environment as well as the tectonic
regime operating at the time.
The basal Rove and Virginia Formations were deposited as transgression
progressed across the depressed basinal area. They consist of black, carbonaceous shale
with thin interbeds of siltstone, very-fine grained sandstone and friable green tuffaceous
layers, possibly contributed by volcanic activity within the Penokean terrain. From
approximately 5 m above the base, siltstone and sandstone layers gradually diminish in
frequency upward, until the succession is almost completely dominated by
approximately 100 to 150 m of fissile black shale. Microscopic examination of thin
sections of this unit revealed the presence of very thin shale laminae and other laminae
composed of angular silt grains or microlayers consisting of carbon. This sediment-starved,
condensed sequence developed with increasing water depth, and with anoxic
conditions probably caused by high organic loading in the bottom sediments. A siltstone
and very-fine grained sandstone-rich unit traceable across the basin occurs midway
through the shale-dominated succession. This coarser unit thickens near both the northern
and southern margins of the basin. Above it another coarser-grained interval within the
shale-dominated succession is observed in the southern third of the basin, probably
representing sediment contributed by Penokean sources to the south. A gradational
transition between the shale and an overlying sandstone-shale unit occurs over 80 m in
the north, thinning to the south. The upper sandstone-shale unit varies in thickness, with a
maximum of 350 m, and consists of over one hundred individual coarsening upwards
parasequences. The individual packages are composed of graded, commonly massive,
fine-grained sandstones separated by shale layers millimetres to centimetres thick. Shale
units separating the parasequences are decimeters to one or two meters in thickness. The
sandstone-shale assemblage fines to the south. Approximately 500 m above the base of
the section the uppermost unit is dominated by lenticular bedding of fine-grained
sandstones in the black shale, with both current and wave ripples present. The entire
succession represents the transition from a sediment-starved basin, with exceedingly slow
deposition rates, to active deltaic progradation with sediment probably derived from the
Trans-Hudson orogenic zone to the north
Increased il-33 and il-17 in colorectal carcinoma patients with severe disease
© 2020, University of Kragujevac, Faculty of Science. All rights reserved. Colorectal cancer (CRC) represents one of the most common cancers. It is frequently diagnosed at advanced stages, indicating on need for new diagnostic markers. The aim of this study was to determine systemic and fecal values of IL-17 and IL-33 in patients with CRC and the relationship with clinicopathological aspects of disease. The blood samples and feces liquid fraction of 50 patients with CRC were analyzed. Serum and fecal levels of IL-33 and IL-17 were measured using sensitive enzyme-linked immu-nosorbent assay (ELISA) kits. Fecal levels of Il-33 and IL-17 were increased in CRC patients with poor tumor tissue differentiation. Serum IL-33 and fecal IL-17 were increased in patients with presence of lung/liver metastasis or peritoneal carcinomatosis, respec-tively, while enhanced fecal IL-33 was detected only in patients with peritoneal carcinomatosis. Positive correlation between IL-33 and IL-17 values in sera and feces, respectively was also observed. We believe that increased local values of IL-33 and IL-17, reflected trough higher fecal concentration, in CRC patients with poor tumor tissue differentiation and with presence of lung/liver metastasis or peritoneal carcinomatosis may be considered as a sign of the tumor’s malignant progression and, consequently, of a poor prognosis for patients
What differs former, light and heavy smokers? Evidence from a post-conflict setting
Background: Evidence suggests that people who live in regions affected
by the armed conflict are more likely to smoke. Objective: The purpose
of this study was to assess factors associated with smoking status in a
sample of students in the northern Kosovo province. Materials and
methods: A total of 514 students enrolled in University in Kosovska
Mitrovica, Kosovo, were recruited between April to June 2015 at Student
Public Health Center during mandatory health checks. Participants
filled in socio-demographic and behavioral questionnaire and Beck
Depression Inventory (BDI). Based on responses about smoking, students
were categorized in non-smokers, former smokers, light smokers (1-13
cigarettes/day) and heavy smokers (> 13 cigarettes/ day). Results:
Of 514 students, 116 (22.6%) classified themselves as smokers. Higher
education level of fathers (Odds ratio [OR]=2.89, 95% confidence
interval [CI] 1.30-6.44, p=0.009), not living with smokers (OR=0.42,
95%CI 0.15-0.97, p=0.017) and longer exposure to second hand smoke
(OR=1.07, 95%CI 1.01-1.13, p=0.036) was associated with former smoking.
Studying medical and natural sciences (OR=2.07, 95%CI 1.05-4.18,
p=0.040), consuming alcohol (OR=2.98, 95%CI 1.19-10.03, p=0.020),
living with smokers (OR=2.88, 95%CI 1.49-5.56, p=0.002), longer
exposure to second hand smoke (OR=1.06, 95%CI 1.01-1.11, p=0.019) and
having a more intense depressive symptoms (OR=1.08, 95%CI 1.03-1.13,
p=0.002) was associated with light smoking. Being male (OR=0.22, 95%CI
0.07-0.41, p=0.001), older (OR=1.47, 95%CI 1.21-1.78, p=0.001), living
with smokers (OR=3.78, 95%CI 1.69-8.07, p=0.001), longer daily exposure
to second-hand smoke (OR=1.10, 95%CI 1.04-1.16, p=0.001), and having
more severe depressive symptoms (OR=1.12, 95%CI 1.07-1.18, p=0.001)
were associated with heavy smoking. Conclusion: Smoking prevention and
cessation programs should include the entire community, because
exposure to environmental second hand smoke may facilitate initiation
and more intense smoking. Screening of student smokers for depression
should be prioritized in the process of rebuilding the framework for
primary and secondary prevention in the post-conflict period
Noviji rezultati oplemenjivanja voćaka u Institutu za voćarstvo, Čačak
The Fruit Research Institute Čačak has seventy years long tradition in breeding of continental fruit species. The continual multi-disciplinary scientific and research work conducted so far has resulted in the releasing of 41 different cultivars. In addition to the named and released cultivars, for promising candidate cultivars have been selected (three plums and one peach) and entered for releasing, while there is also a large number of promising genotypes that are currently under intense evaluation. The paper presents an overview of the most significant biological and productive characteristic of the 12 new cultivars of pome and stone fruits, including seven plum cultivars (Boranka, Timočanka, Zlatka, Nada, Mildora, Krina and Pozna plava), two pear cultivars (Julijana and Anđelija) and three sour cherry cultivars (Sofija, Nevena and Iskra).Institut za voćarstvo, Čačak ima sedamdeset godina dugu tradiciju oplemenjivačkog rada na stvaranju novih sorti kontinentalnih vrsta voćaka. Do sada je kao rezultat kontinuiranog, multidisciplinarnog naučnoistraživačkog rada priznata 41 sorta različitih vrsta voćaka. Pored priznatih sorti, izdvojene su četiri kandidat sorte (tri šljive i jedna breskve) koje su u postupku priznavanja, kao i veliki broj perspektivnih genotipova koji se intenzivno proučavaju. U radu je prikazan pregled najznačajnijih bioloških i proizvodnih osobina 12 novije priznatih sorti jabučastih i koštičavih vrsta voćaka, i to: sedam sorti šljive (Boranka, Timočanka, Zlatka, Nada, Mildora, Krina i Pozna plava), dve sorte kruške (Julijana i Anđelija) i tri sorte višnje (Sofija, Nevena i Iskra)
Synthesis of Stimuli-responsive, Water-soluble Poly[2-(dimethylamino)ethyl methacrylate/styrene] Statistical Copolymers by Nitroxide Mediated Polymerization
2-(Dimethylamino)ethyl methacrylate/styrene statistical copolymers (poly(DMAEMA-stat-styrene)) with feed compositions fDMAEMA = 80–95 mol%, (number average molecular weights Mn = 9.5–11.2 kg mol−1) were synthesized using succinimidyl ester-functionalized BlocBuilder alkoxyamine initiator at 80 °C in bulk. Polymerization rate increased three-fold on increasing fDMAEMA = 80 to 95 mol%. Linear Mn increases with conversion were observed up to about 50% conversion and obtained copolymers possessed monomodal, relatively narrow molecular weight distributions (polydispersity = 1.32–1.59). Copolymers with fDMAEMA = 80 and 90 mol% were also cleanly chain-extended with DMAEMA/styrene mixtures of 95 and 90 mol% DMAEMA, respectively, confirming the livingness of the copolymers. Copolymer phase behavior in aqueous solutions was examined by dynamic light scattering and UV-Vis spectroscopy. All copolymers exhibited lower critical solution temperature (LCST)-type behavior. LCST decreased with increasing styrene content in the copolymer and with increasing solution concentration. All copolymers were completely water-soluble and temperature insensitive at pH 4 but were more hydrophobic at pH 10, particularly copolymers with fDMAEMA = 80 and 85 mol%, which were water-insoluble. At pH 10, LCST of copolymers with fDMAEMA = 90 and 95 mol% were more than 10 °C lower compared to their solutions in neutral, de-ionized water. Block copolymers with two statistical blocks with different DMAEMA compositions exhibited a single LCST, suggesting the block segments were not distinct enough to exhibit separate LCSTs in water
Amphiphilic Block Copolymers with Vinyl Caprolactam as Kinetic Gas Hydrate Inhibitors
Macrosurfactants consisting of water-soluble poly(vinylcaprolactam) (PVCap) or poly(vinylpyrrolidone) (PVP) segments with comparatively shorter hydrophobic poly(styrene) (PS) or poly(2,3,4,5,6-pentafluorostyrene) (PPFS) segments were used as kinetic hydrate inhibitors (KHIs). These were synthesized with 2-cyanopropan-2-yl N-methyl-N-(pyridin-4-yl)dithiocarbamate switchable reversible addition–fragmentation chain transfer (RAFT) agent at 60 °C or 90 °C for 1-P(S/PFS) or 1-PVCap, respectively, followed by chain extension at 90 °C or 70 °C with PVCap or PVP, respectively. The addition of PVCap to the pure methane-water system resulted in a 53% reduction of methane consumption (comparable to PVP with 51% inhibition) during the initial growth phase. A PS-PVCap block copolymer comprised of 10 mol% PS and 90 mol% PVCap improved inhibition to 56% compared to the pure methane-water system with no KHIs. Substituting PS with a more hydrophobic PPFS segment further improved inhibition to 73%. By increasing the ratio of the hydrophobic PS- to PVCap- groups in the polymer, an increase of its inhibition potential was measured. For PPFS-PVCap, an increase of PPFS ratio from 5% to 10% decreased the methane formation rate by 6%. However, PPFS-PVCap block copolymers with more than 20 mol% PPFS were unable to dissolve in water due to increase in hydrophobicity and the attendant low critical micelle concentration (CMC)
Genetical polymorphism of acc synthase and ACC oxidase in Apple selections bred in Cacak
Ethylene Glycol Dicyclopentenyl (Meth)Acrylate Homo and Block Copolymers via Nitroxide Mediated Polymerization
Nitroxide-mediated polymerization (NMP), (homo and block copolymerization with styrene (S) and butyl methacrylate/S) of ethylene glycol dicyclopentenyl ether (meth)acrylates (EGDEA and EGDEMA) was studied using BlocBuilder alkoxyamines. EGDEA homopolymerization was not well-controlled, independent of temperature (90–120 °C), or additional free nitroxide (0–10 mol%) used. Number average molecular weights (Mn) achieved for poly(EGDEA) were 4.0–9.5 kg mol−1 and were accompanied by high dispersity (Ð = Mw/Mn = 1.62–2.09). Re-initiation and chain extension of the poly(EGDEA) chains with styrene (S) indicated some block copolymer formation, but a high fraction of chains were terminated irreversibly. EGDEA-stat-S statistical copolymerizations with a low mol fraction S in initial feed, fS,0 = 0.05, were slightly better controlled compared to poly(EGDEA) homopolymerizations (Ð was reduced to 1.44 compared to 1.62 at similar conditions). EGDEMA, in contrast, was successfully polymerized using a small fraction of S (fS,0 ~ 10 mol%) to high conversion (72%) to form well-defined EGDEMA-rich random copolymer (molar composition = FEGDEMA = 0.87) of Mn = 14.3 kg mol−1 and Ð = 1.38. EGDEMA-rich compositions were also polymerized with the unimolecular succinimidyl ester form of BlocBuilder initiator, NHS-BlocBuilder with similar results, although Ðs were higher ~1.6. Chain extensions resulted in monomodal shifts to higher molecular weights, indicating good chain end fidelity