21 research outputs found

    Melanism as a potential thermal benefit in eastern fox squirrels (Sciurus niger)

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    Melanistic fox squirrels (Sciurus niger) have expanded westward and increased in frequency in the Omaha, Nebraska, and Council Bluffs, Iowa, metropolitan areas. The selective advantage of melanism is currently unknown, but thermal advantages have been hypothesized, especially in winter. No difference in metabolic response curves were measured between melanistic (black) and rufus (orange) fox squirrels. When exposed to sunny skies, both melanistic and rufus squirrels had higher surface (skin and fur) temperature as ambient temperatures increased. Melanistic squirrel surface temperatures did not differ when squirrels were exposed to sunny or cloudy skies. However, rufus individuals showed significantly lower increases in surface temperatures when under cloudy skies. During fall months, rufus individuals were about 1.5 times more active throughout the day than melanistic individuals. However, in winter, melanistic fox squirrels were approximately 30% more active in the mornings (before 13:00) compared to rufus squirrels. Pre-winter body condition was higher in melanistic (25.5 ± 1.8 g/cm) compared to rufus (20.30 ± 3.6 g/cm) fox squirrels; however, there were no significant differences between melanistic (22.8 ± 1.4 g/cm) and rufus (23.9 ± 0.8 g/cm) fox squirrel post-winter body condition. The results of this study indicate that melanistic fox squirrels may have a slight winter thermal advantage over rufus fox squirrels by maintaining higher skin temperatures

    Tallness is associated with risk of testicular cancer: evidence for the nutrition hypothesis

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    The pathogenesis of testicular germ cell tumours (GCTs) is potentially influenced by high-energy nutrition during infancy. As adult height is a proxy for childhood nutrition, we investigated the role of nutrition in GCT pathogenesis by comparing stature of patients with healthy men. In a matched case–control study, 6415 patients with GCT were compared with healthy army conscripts (1:6 matching modus) with regard to height (cm) and body mass index (BMI; kg/m2). Statistical analysis involved tabulation of descriptive height measures and BMI. Conditional logistic regression models were used to quantify the association of GCT with height, with odds ratios (OR) adjusted for BMI. The literature was searched for studies on stature in GCT patients. Body size is significantly associated with risk of GCT, very tall men (>195 cm) having a GCT risk of OR=3.35 (95% confidence intervals (CI): 2.88–3.90; adjusted). Short stature is protective (OR=0.798; 95% CI: 0.68–0.93). Both histologic subgroups are associated with tallness. Of 16 previous reports, 7 were confirmative, 5 had null and 4 equivocal results. The association of stature with GCT risk accords with the nutrition hypothesis of GCT. This study expands the current view of GCT tumorigenesis by suggesting that high-calorie intake in childhood promotes GCT precursors originating in utero

    Procedures for obtaining optimal SEM images of coccolithophore debris in coccolith limestones

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    Coccolith debris in fossil zooplankton faecal pellets and the mode of its preservation are the unique source of data on the mode of feeding and digestion by ancient zooplankters. The animals are virtually absent in the fossil record in another form than their coprolites. However, minute structural details of coccospheres and their debris in the coccolith limestone are much less legible than in modern sediments. This paper presents how clear SEM images of details of coccolith plates in complete and dismembered coccospheres from fossil zooplankton faecal pellets can be obtained from thin sections of coccolith limestone. The images allow us to study the structural and compositional details of coccolith plates as well as their arrangements within the coccospheres and fossil faecal pellets

    The Sokoliska Limestone, a new regional marker horizon of coccolith laminites in the Oligocene of the Outer Carpathians : diagnostic features and stratigraphic position

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    Isochronous horizons of pelagic coccolith limestones are important regional stratigraphic markers in the Oligocene sequences of the Outer Carpathians. Three widely recognized limestone horizons are the Tylawa Limestones, the Jasło Limestone and the Zagórz Limestone horizons. Another regional marker horizon is described here, the Sokoliska Limestone horizon, situated between the Jasło Limestone and Zagórz Limestone horizons in the nannoplankton NP24 Zone. Its lithologic characteristics allow it to be distinguished from the other limestones, especially under the optical microscope. Its dark laminae are greatly enriched in non-calcareous material. The limestone contains tests of planktonic foraminifers, but these are much less abundant than in the Jasło Limestone. The boundaries with the marly shales above and below are often more gradational than is the case with the other limestone horizons.The Sokoliska Limestone has been recognized over a distance of ca.550 km in the Skole (Tarcãu) and Silesian units of the eastern and northern parts of the Outer Carpathians. Four sections of the Sokoliska Limestone horizonin the Polish and Romanian Carpathians are described; the exposure in the Sokoliska cliff of the Solinka River at Bukowiec was selected as the reference locality

    The Tylawa Limestones – a regional marker horizon in the Lower Oligocene of the Paratethys : diagnostic characteristics from the type area

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    Three units of laminated coccolith limestone are used as regional chronohorizons in the Oligocene of the Outer Carpathians. Two of them – the Tylawa Limestones and the Jasło Limestone display a similar type of lamination and their discrimination is in some cases problematic. We provide a detailed mesoscopic and microscopic lithological description of the Tylawa Limestones from the type locality at Tylawa and from Rudawka Rymanowska – the best exposure in the Polish Carpathians. The finely laminated limestone layers are up to 5.5 cm thick and are dispersed through a section more than 100 m thick. They are grouped in clusters. They differ from the younger Jasło Limestone in: (1) an absence of foraminifers, (2) a mass occurrence of Reticulofenestra ornata Müller, (3) the presence of voids after pennate diatoms, (4) dark laminae which are more pronounced than in the Jasło Limestone

    The use of a natural resource in the interior design of the main building of the Pedagogical University of Cracow

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    W pracy przedstawiono ciekawe rozwiązanie dekoracyjne posadzki z 1973 r. znajdującej się na parterze i pierwszym piętrze gmachu głównego Uniwersytetu Pedagogicznego im. Komisji Edukacji Narodowej w Krakowie. Posadzka ta jest ułożona z nieregularnych i różnorodnych kolorystycznie płyt surowca naturalnego, tzw. „marmurów” świętokrzyskich. Reprezentują one kilka odmian skał pochodzących z kamieniołomów z okolic Chęcin, przede wszystkim z Bolechowic (skała najczęściej wykorzystywana do celów dekoracyjnych), a także z Szewc i Łabędziowa, a być może też z Jaźwicy. Skały te tradycyjnie są nazywane marmurami. Pod względem petrograficznym nie są to jednak skały metamorficzne, lecz zwięzłe i masywne, częściowo przekrystalizowane, wapienie z liczną fauną. Są wieku paleozoicznego – środkowo- i górnodewońskie. Już od XVI w. były cennym surowcem zdobniczym. Omawiana posadzka ma walory edukacyjne i może mieć znaczenie geoturystyczne. Wybrane i opisane okazy skał, reprezentujących różne rodzaje litologiczne, mogą przyczynić się do utworzenia dydaktycznej ścieżki geoturystycznej, która będzie pomocna w zajęciach z przedmiotów związanych z naukami o Ziemi (np. geologia, paleontologia, surowce skalne).The paper presents an interesting decorative flooring solution from 1973 on the ground and first floors of the main building of the Pedagogical University of Cracow, named after the Commission of National Education. This flooring is composed of irregular, variably coloured natural stone slabs: the so-called Holy Cross Mountains „marbles”. They represent several rock types from limestone quarries near Chęciny, including mainly Bolechowice, but also Szewce, Łabędziów and Jaźwica. These rocks are traditionally called marbles. However, in fact, petrographically, they are not metamorphic rocks, but strongly lithified and massive, partially crystallized limestones with numerous fossils. They are of Paleozoic age: Middle and Upper Devonian. The type of flooring composed of irregular panels of different sizes and colours is currently rarely used in interior design despite giving an aesthetically pleasing mosaic effect with an interesting pattern. The flooring made of assorted Holy Cross Mountains “marbles” can have a great educational value and great geotouristic significance. Selected and described rocks of different lithological types can be used to create a geotouristic educational path that will be helpful in teaching of subjects related to Earth sciences (e.g. geology, paleontology, rock materials)

    Melanism as a potential thermal benefit in eastern fox squirrels (\u3ci\u3eSciurus niger\u3c/i\u3e)

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    Melanistic fox squirrels (Sciurus niger) have expanded westward and increased in frequency in the Omaha, Nebraska, and Council Bluffs, Iowa, metropolitan areas. The selective advantage of melanism is currently unknown, but thermal advantages have been hypothesized, especially in winter. No difference in metabolic response curves were measured between melanistic (black) and rufus (orange) fox squirrels. When exposed to sunny skies, both melanistic and rufus squirrels had higher surface (skin and fur) temperature as ambient temperatures increased. Melanistic squirrel surface temperatures did not differ when squirrels were exposed to sunny or cloudy skies. However, rufus individuals showed significantly lower increases in surface temperatures when under cloudy skies. During fall months, rufus individuals were about 1.5 times more active throughout the day than melanistic individuals. However, in winter, melanistic fox squirrels were approximately 30% more active in the mornings (before 13:00) compared to rufus squirrels. Pre-winter body condition was higher in melanistic (25.5 ± 1.8 g/cm) compared to rufus (20.30 ± 3.6 g/cm) fox squirrels; however, there were no significant differences between melanistic (22.8 ± 1.4 g/cm) and rufus (23.9 ± 0.8 g/cm) fox squirrel post-winter body condition. The results of this study indicate that melanistic fox squirrels may have a slight winter thermal advantage over rufus fox squirrels by maintaining higher skin temperatures

    Pliocene agglutinated benthic foraminifera from Site U1341 in the Bering Sea (IODP Expedition 323)

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    We present the first record of benthic foraminiferal assemblages from 92 samples collected at approximately 3 m resolution in the bottom part of Hole U1341B drilled in the southern Bering Sea during Integrated Ocean Drilling Program (IODP) Expedition 323. Pliocene agglutinated foraminifera are generally rare within highly diatomaceous claystones occurring from base of the hole at 601.87 metres below sea floor (mbsf) to ~320 mbfs. The agglutinated foraminiferal assemblages are strongly dominated by the infaunal genera Eggerella, Karreriella, Martinotiella, and Spirosigmoilina. The calcareouscemented Eggerella and Martinottiella are canaliculated with pores that are open to the test surface. Tubular agglutinated foraminifera are rare and are only found in isolated samples. The ecological information gained from this assemblage supports other proxy information indicating high levels of organic productivity and severely hypoxic conditions in the Bering Sea deep water during the Pliocene

    Dostępność walorów geoturystycznych Doliny Chochołowskiej (Tatry, Polska) dla osób niepełnosprawnych ruchowo

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    The purpose of this contribution is to present the geotourist path in the Chochołowska Valley for the disabled with limited mobility, as well as for the elderly. The Chochołowska Valley is the most westward valley in the Polish Tatra Mountains (Western Tatras). It is the longest and largest valley in the Polish Tatra Mountains, with an area of 35 km2 and 10 km in length. The highest peak located in the Chochołowska Valley is the Starorobociański Wierch at 2176 m a.s.l. The altitude at the end of the valley around Siwa Polana, is about 900 m a.s.l. (from 910 m a.s.l. to 920 m a.s.l.). At the Polana Huciska, where the geotoursit path ends, the altitude is about 1000 m a.s.l. The length of the path is 3.5 km, and the altitude difference over this distance is 100 meters. The Chochołowska Valley is developed in sedimentary rocks (limestones, marls, dolomites), belonging to two nappes: Choč Nappe (e.g. Siwiańskie Turnie outcrop) and Križna Nappe (e.g. Niżna Brama Chochołowska Rock Gate). The valley administratively belongs to the Witów village. A green tourist trail was marked through the valley. It start from the Siwa Polana to the mountain hut named after John Paul II on Polana Chochołowska. An asphalt road is from Siwa Polana to the Polana Huciska. The Chochołowska Valley is one of the most beautiful Tatra valleys with numerous rock outcrops and is considered to have a high geotouristic potential. The proposed geotourist path includes selected outcrops, which can be easily accessed by people with limited mobility, including people in wheelchairs. This path runs along a wide asphalt road, and any additional equipment (e.g. a freewheel for wheelchairs) is not required. A large car parking lot is available at the beginning of the proposed path (Siwa Polana), as well as sanitary and catering facilities.W niniejszym artykule została opisana propozycja trasy geoturystycznej w Dolinie Chochołowskiej dla osób niepełnosprawnych z ograniczonym stopniem poruszania się oraz dla osób starszych. Dolina Chochołowska jest najbardziej na zachód wysuniętą doliną walną w Tatrach Polskich (Tatry Zachodnie). Jest to najdłuższa i największa dolina w Tatrach Polskich. Jej powierzchnia wynosi 35 km2, a długość 10 km. Najwyższym szczytem położonym nad Doliną Chochołowską jest Starorobociański Wierch (2176 m n.p.m.). Wysokość bezwzględna u wylotu doliny, w rejonie Siwej Polany, wynosi około 900 m n.p.m. (od 910 m n.p.m. do 920 m n.p.m.), a na Polanie Huciska około 1000 m n. p. m. Długość naszej ścieżki geoturystycznej wynosi 3,5 km, a różnica wysokości na tej odległości wynosi 100 metrów. Dolina Chochołowska jest wypreparowana w skałach osadowych (wapienie, margle, dolomity) dwóch płaszczowin: choczańskiej (Siwiań- skie Turnie) i kriżniańskiej (Niżna Brama Chochołowska). Dolina ta administracyjnie należy do wsi Witów. Dnem doliny został popro- wadzony zielony szlak turystyczny do górskiego schroniska im. Jana Pawła II na Polanie Chochołowskiej. Do połowy doliny, do Polany Huciska, została doprowadzona droga asfaltowa. Dolina Chochołowska jest jedną z piękniejszych dolin tatrzańskich o wysokim potencjale geoturystycznym w związku ze znajdującymi się tu licznymi odsłonięciami skalnymi. W niniejszym artykule prezentujemy wybrane odsłonięcia łatwo dostępne, do których mogą dostać się bezproblemowo (płaska i szeroka nawierzchnia drogi) osoby z ograniczonym stopniem poruszania się, w tym również na wózkach inwalidzkich. Proponowana ścieżka geoturystyczna przebiega opisywaną drogą asfaltową, co nie wymaga konieczności używania dodatkowych sprzętów (np. freewheel w przypadku wózków). Na początku proponowanej trasy (Siwa Polana) jest duży parking dla samochodów i niezbędna infrastruktura sanitarno-gastronomiczna

    Late Albian calcareous dinocysts and calcitarchs record linked to environmental changes during the final phase of OAE 1d – a case study from the Tatra Mountains, Central Western Carpathians

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    Calcareous dinocysts and calcitarchs have been investigated for the first time within the Upper Albian limestone and marl succession of the Zabijak Formation from the High-Tatric Unit in the Tatra Mountains (Central Western Carpathians), related to the Oceanic Anoxic Event 1d (OAE 1d). Four groups of morphotaxa of calcareous dinocysts have been distinguished. They totally dominate the assemblages, and belong to the pithonellids. They are represented by Pithonella sphaerica (Kaufmann in Heer) and P. ovalis (Kaufmann in Heer), which dominate, as well as P. trejoi Bonet and P. lamellata Keupp in Keupp and Kienel, which are less abundant. Two other morphotaxa, Colomisphaera gigantea (Borza) and Cadosina oraviensis Borza, occur sporadically in the assemblages. Both forms represent the calcitarch group, which assembled calcispheres of unknown taxonomic affinity. The calcareous dinocyst and calcitarch diversity is low to moderate, compared to the general species richness known from Late Albian assemblages in other Western Tethyan sections. This is interpreted as a result of nutrient input fluctuations due to changes in the circulation pattern of surface and intermediate waters. The changes in the P. sphaerica/P. ovalis ratio along the Upper Albian section are here correlated with short-term (third-order) sea level fluctuations including transgressive and regressive events and a highstand. Pelletization processes might have influenced cyst abundance on the sea floor, especially during periods with oligotrophic surface waters
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