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1.
AbstractThe article describes certain stream deposited pottery sherds and projectile points found in south eastern Nebraska. Some of the sherds are attributable to the Sterns Creek complex and to the more general category of the Early Ceramic Period on the Central Plains. Most of the projectile points suggest preceramic affinities including the Logan Creek and Angostura complexes. 相似文献
2.
AimsBanksia attenuata is a resprouting species growing in deep sand, while B. sessilis is a fire-killed species occurring in shallow sand over laterite or limestone. We aimed to discover the ecophysiological basis for their different distributions by exploring their investment in deep non-cluster roots and shallow cluster roots, and their cluster-root functioning. MethodsDeep-pot (1 m), shallow-pot (400 mm), hydroponic experiments and phosphorus (P)-extraction experiment were carried out. Biomass allocation, cluster-root exudation, plant P and leaf manganese (Mn) concentrations were measured. ResultsBanksia attenuata allocated more biomass to deep roots and less biomass to cluster roots than B. sessilis did in deep pots. The two Banksias released similar carboxylates in all experiments, with similar carboxylate-exudation rates in hydroponics. The carboxylate amount per unit cluster root of B. sessilis grown in shallow pots was greater than that of B. attenuata, and B, sessilis acquired more P than B. attenuata did in limestone substrate. ConclusionsGreater investment in deep roots for water uptake accounts for the presence of B. attenuata in deep sand, and vice versa for the absence of B. sessilis. A larger investment in cluster roots, which released greater amounts of carboxylates, likely accounts for B. sessilis occurring over limestone. Trade-offs in investment and cluster-root functioning support the species’ distribution patterns and life histories. Leaf Mn concentration was a good proxy for the plant capacity to acquire P. 相似文献
3.
Soil fungi can facilitate calcification. Mushroom Morchella sp . mycelium induced the formation of carbonate concretions on the surface of an organic-based growing media amended with sand and ground limestone. According to SEM observation and X-ray-tomographic microscopy a dense mycelial network induced calcification. The CaCO 3 content of concretions (?: 0.3–1.5 cm) was found to be at 30%. Microsparitic calcite cemented the pores between the sand grains forming a dense clogging microstructure. Besides water uptake by the mycelium, a high evaporation rate and a decrease in pCO 2 contributed to the formation of the concretions. Fungal mycelium in the concretions is surrounded by voids indicating that at the surface of the mycelium, calcification is counteracted most probably by the release of organic acids. 相似文献
4.
AbstractAboriginal pottery excavated at a pedlar’s post, dated 1768-1774, is described and named the François Variety of the fabric-impressed type of Wascana Ware. The diagnostic feature of François sherds is the use of European cloth for impressing the vessel surfaces. It is suggested that the François Variety can be a hori-·zon marker for the early historic period in Saskatchewan. 相似文献
5.
AbstractDecorative design motifs on Great Oasis Incised rim sherds from the Great Oasis site in Minnesota are illustrated and described. The usefulness of using decorative modes in ceramic comparisons with pottery of the Over focus is suggested. 相似文献
6.
We studied the effects of limestone sand additions in Bear and Rock runs, two chronically and episodically acidified streams in southwestern Pennsylvania, U.S.A. Linn Run, a nearby episodically acidified stream, served as a reference stream. Our objectives were to evaluate the effects of doubling recommended limestone sand amounts on water quality and macroinvertebrates on Bear and Rock runs and to assess substrate changes resulting from limestone sand inundation. Approximately 23 and 6 tonnes of limestone sand were added annually to the headwaters of Bear and Rock runs, respectively, from 1999 to 2001. In 2002, amounts were doubled. Macroinvertebrate communities were assessed from 1999 to 2003 at points above and below the sand additions on Bear Run and Rock Run. Small, plastic substrate samplers were used to assess sand substrate effects. Doubling annual limestone sand amounts resulted in significantly improved pH and acid‐neutralizing capacity; however, total dissolved aluminum increased significantly downstream ( α≤ 0.05). Macroinvertebrate density and diversity were not significantly affected, but an increase in acid‐sensitive taxa was observed at a site 3,500 m downstream. Substrate sampler data indicated a significant negative relationship between amount of sand deposited and density of macroinvertebrates. The mixed water quality and benthic macroinvertebrate results were reasonably consistent with earlier work and call into question the use of limestone sand in the restoration of chronically and episodically acidified waters. 相似文献
7.
The formation of biogenic fabrics in limestone by two fungi, Serpula himantioides and a polymorphic fungal isolate from limestone identified as a Cephalotrichum (syn. Doratomyces) sp., was investigated. The fungal cultures were grown in laboratory microcosms consisting of Carboniferous limestone and after 21 d incubation at 25°C, biomineralization of fungal filaments was observed. Environmental electron scanning microscopy (ESEM) and X-ray micro-analysis (EDXA) of crystalline precipitates on the hyphae of S. himantioides demonstrated that the secondary crystals exhibited different crystalline forms but were similar in elemental composition to the original limestone. Powder X-ray diffraction (XRD) of crystalline precipitates showed they were composed of a mixture of calcite (CaCO 3 ) and calcium oxalate monohydrate (CaC 2 O 4 · H 2 O). Analysis of crystals precipitated on the hyphae of the limestone isolate, using ESEM and EDXA, showed that the crystals exhibited similar morphological characteristics and elemental composition to the original limestone. XRD showed that they were composed solely of calcite (CaCO 3 ) or of calcite with some calcium oxalate dihydrate (CaC 2 O 4 · 2H 2 O). These results provide direct experimental evidence for the precipitation of calcite (CaCO 3 ) and also secondary mycogenic minerals, on fungal hyphae in low nutrient calcareous environments, and suggest that fungi may play a wider role in the biogeochemical carbon cycle than has previously been appreciated. 相似文献
8.
Instream limestone sand application is used at many sites in Pennsylvania to neutralize acidic stream water resulting from acid deposition. However, questions remain about the effectiveness of limestone sand in the treatment of acid waters, such as reduced contact time at high flow, remobilization of aluminum, and adverse effects on macroinvertebrates. A 1‐year evaluation of limestone sand application to Bear Run, an acidic stream in southwestern Pennsylvania, was begun in 1999. Another nearby acid stream, Linn Run, served as a control. Water quality during baseflow and episodic acidification events, along with fish and macroinvertebrates, were monitored to evaluate impacts of the sand application. Hydrogen ion (H + ) concentration and total dissolved aluminum (TDA) were significantly reduced, and acid neutralizing capacity was significantly increased downstream of the limestone sand application compared with the upstream site on Bear Run. These parameters at the downstream sites were also different (∝ 0.10) from the comparable sites on the control stream. TDA and hydrogen ion concentrations were significantly decreased (∝ 0.10) compared with concentrations before the sand application to Bear Run but not on the control stream. No fish were present upstream of the sand application site, and only a few fish were found downstream at the mouth of Bear Run. Standing crop, number of taxa, and Shannon‐Weaver diversity index values indicated that macroinvertebrate populations were negatively impacted 300 m downstream from the sand application and improved at the site 1,600 m downstream. Although water quality was improved on Bear Run, benefits to macroinvertebrates depended on downstream location, and fish populations did not show improvement. 相似文献
9.
The larvae of the pit‐making antlion Myrmeleon bore Tjeder live in open sand in riverbeds with a substratum consisting of various particle sizes. We analyzed the spatial distribution of their pits in a sandy floodplain to determine their larval and adult responses to the heterogeneous substrate. The spatial distribution pattern of their pits had an aggregated distribution, and there was a significant positive correlation between pit density and the ratio of medium‐size sand particles to total weight of sand. We examined the size of sand particles selected in the larval pit‐building behavior and the oviposition behavior of the adult. Both larvae and adults selected medium‐size sand particles. The larvae of M. bore are relatively sedentary predators and rarely move great distances. Thus, the present results suggest that habitat selection by adult females is a major factor causing the aggregative distribution of the pits. 相似文献
10.
AbstractCherokee Mountain Rock Shelter is south of Denver, in Douglas County, Colorado, and overlooks Plum Creek near the small town of Sedalia. The shelter was formed in a sandstone conglomerate in an area of high bluffs and gently rolling hills. Three intermixed levels were excavated, with artifacts from each dating from the Late Prehistoric Period. A few sherds, suggestive of a Shoshonean occupation, were in the top two levels. 相似文献
11.
AbstractTwo rock and earth mounds in the Stockton Reservoir area provide data on two separate burial complexes previously unknownin thewestern Ozark Highlands. The Eureka Mound contained primary inhwnations with associations similar to those innearby Woodland and Mississippian mounds, but is unique in yielding a Caddoan water bottle of the Spiro Engraved type, and is dated about A. D. 1000-1450. This trade vessel, and Caddoan sherds from other sites in southwestern Missouri, provides leads to Caddoan contacts with groups in the Ozark Highlands. The Comstock Mound contained a single primary burial in a central pit associated with White trade goods which date around A.D. 1800. The mound may be of Osage Indian origin, but this identification is open to question because of transient Indian groups pas sing through the area about A. D. 1800. 相似文献
12.
Abstract A new station of Dianthus glacialis Haenke ssp. glacialis, on the Stelvio National Park in Cedech Valley (Valfurva-Lombardy). – The author refers to a new station of Dianthus glacialis Haenke ssp. glacialis on the Stelvio National Park in Cedech Valley, 2700 m. Many specimens collected have very short stems (f. reducta f. nova) in comparison with the forma normale which has the stems 1–5 (10) cm long. Examination of the soil characteristics of the station suggests the possibility that the plant grows in this station rich in limestone, since it is protected from the limestone by a certain stratum of organic matter. 相似文献
13.
Background and AimsPhosphorus (P) and nitrogen (N) are essential nutrients that frequently limit primary productivity in terrestrial ecosystems. Efficient use of these nutrients is important for plants growing in nutrient-poor environments. Plants generally reduce foliar P concentration in response to low soil P availability. We aimed to assess ecophysiological mechanisms and adaptive strategies for efficient use of P in Banksia attenuata (Proteaceae), naturally occurring on deep sand, and B. sessilis, occurring on shallow sand over laterite or limestone, by comparing the allocation of P among foliar P fractions. MethodsWe carried out pot experiments with slow-growing B. attenuata, which resprouts after fire, and faster growing opportunistic B. sessilis, which is killed by fire, on substrates with different P availability using a randomized complete block design. We measured leaf P and N concentrations, photosynthesis, leaf mass per area, relative growth rate and P allocated to major biochemical fractions in B. attenuata and B. sessilis. Key ResultsThe two species had similarly low foliar total P concentrations, but distinct patterns of P allocation to P-containing fractions. The foliar total N concentration of B. sessilis was greater than that of B. attenuata on all substrates. The foliar total P and N concentrations in both species decreased with decreasing P availability. The relative growth rate of both species was positively correlated with concentrations of both foliar nucleic acid P and total N, but there was no correlation with other P fractions. Faster growing B. sessilis allocated more P to nucleic acids than B. attenuata did, but other fractions were similar. ConclusionsThe nutrient allocation patterns in faster growing opportunistic B. sessilis and slower growing B. attenuata revealed different strategies in response to soil P availability which matched their contrasting growth strategy. 相似文献
14.
The radula is the ingesta-gathering structure in Mollusca. As interface, it has to perform various tasks without functional deterioration caused by wear. Wear prevention is well investigated in mollusks that forage on rocks and that generate high punctual pressure with their hard teeth, which contain high inorganic contents at their tips. In mollusks that forage on softer substrate, such as sand surfaces, and have relatively soft teeth, wear prevention has not been a focus of study before. Here, we studied the teeth of Limnotrochus thomsoni, which are used for raking algae from sand. For comparison, we investigated the soft outer teeth of Lavigeria grandis, which are used in gathering particles after the ingesta is loosed from the rock surface. SEM revealed scratches on all surfaces of the teeth and suggests that every tooth side interacts with abrasive particles during foraging. Analysis of stomach content revealed that sand particles of 10–20 μm diameter are ingested. By EDX/EDS, we studied the composition of the teeth and determined that high proportions of Ca are present on all surfaces, which could be an adaptation to reduce abrasion. Finally, we here present evidence for the existence of a canal within the teeth, which could potentially serve as delivery pathway of minerals during tooth maturation and has not been previously detected in Gastropoda. 相似文献
15.
The effect of granular coral limestone and Leca as adsorbents for removing Acid Cyanine 5R (AC5R) from aqueous solution was studied. The optimum pH and adsorbent particles size in both adsorbents were determined to be 3 and 297 μm, respectively. The optimum dosages of coral limestone and granular Leca were 0.150 and 0.145 g/mg of dye, respectively. Also, results have shown that the adsorption efficiency by both coral limestone and Leca increased with the decreasing adsorbent particles size. Moreover, under similar conditions, the maximum removal efficiency by granular coral limestone and Leca was 94% and 88%, respectively. The results revealed that the performance of granular coral limestone was better in AC5R removal than that of Leca granulated under such condition. In total, granular coral limestone and Leca act as suitable adsorbents for removing dye pollutants from an aqueous solution. 相似文献
16.
Summary The first known troglobiotic species belonging to the ground beetle tribe Patrobini is reported from a limestone cave called Lianhua Dong in Pengzhou, a suburb county-level city in northern Chengdu, Sichuan Province, China. Troglopatrobus zhouchaoi n. gen., n. sp., is an eyeless and large-sized patrobine beetle with extremely elongated body (esp. head and elytra) and appendages. Duvalioblemus ( Shublemus) liyuani n. subgen., n. sp., a minute anophthalmic trechine species, is also discovered from the same cave. It is the first cave-dwelling species belonging to this genus already known as endogean from Sichuan and Yunnan provinces. 相似文献
17.
BackgroundPhlebotomine sand flies are vectors of Leishmania parasites. During blood feeding, sand flies deposit into the host skin immunogenic salivary proteins which elicit specific antibody responses. These anti-saliva antibodies enable an estimate of the host exposure to sand flies and, in leishmaniasis endemic areas, also the risk for Leishmania infections. However, the use of whole salivary gland homogenates as antigen has several limitations, and therefore, recombinant salivary proteins have been tested to replace them in antibody detection assays. In this study, we have used for the first time sand fly salivary recombinant proteins in a longitudinal field study on dogs. ConclusionsThese results suggest that P. perniciosus rSP03B protein is a valid alternative to whole saliva and could be used in large-scale serological studies. This novel method could be a practical and economically-sound tool to detect the host exposure to sand fly bites in CanL endemic areas. 相似文献
18.
Asplenium cornutissimum, a new species from Guangxi, southern China, is described, illustrated, and compared to three similar species: A. pulcherrimum, A. coenobiale, and A. tenuifolium. So far, the new species is known only from the limestone region in southern Guangxi, from 750–825 m. It grows exclusively
in karst caves. 相似文献
19.
BackgroundPhlebotomine sand flies (Diptera: Psychodidae) are important vectors of various human and animal pathogens such as Bartonella bacilliformis, Phlebovirus, and parasitic protozoa of the genus Leishmania, causative agent of leishmaniases that account among most significant vector-borne diseases. The Maghreb countries Mauritania, Morocco, Algeria, Tunisia, and Libya occupy a vast area of North Africa and belong to most affected regions by these diseases. Locally varying climatic and ecological conditions support diverse sand fly fauna that includes many proven or suspected vectors. The aim of this review is to summarize often fragmented information and to provide an updated list of sand fly species of the Maghreb region with illustration of species-specific morphological features and maps of their reported distribution. Materials and methodsThe literature search focused on scholar databases to review information on the sand fly species distribution and their role in the disease transmissions in Mauritania, Morocco, Algeria, Tunisia, and Libya, surveying sources from the period between 1900 and 2020. Reported distribution of each species was collated using Google Earth, and distribution maps were drawn using ArcGIS software. Morphological illustrations were compiled from various published sources. Results and conclusionsIn total, 32 species of the genera Phlebotomus ( Ph.) and Sergentomyia ( Se.) were reported in the Maghreb region (15 from Libya, 18 from Tunisia, 23 from Morocco, 24 from Algeria, and 9 from Mauritania). Phlebotomus mariae and Se. africana subsp. asiatica were recorded only in Morocco, Ph. mascitti, Se. hirtus, and Se. tiberiadis only in Algeria, whereas Ph. duboscqi, Se. dubia, Se. africana africana, Se. lesleyae, Se. magna, and Se. freetownensis were reported only from Mauritania. Our review has updated and summarized the geographic distribution of 26 species reported so far in Morocco, Algeria, Tunisia, and Libya, excluding Mauritania from a detailed analysis due to the unavailability of accurate distribution data. In addition, morphological differences important for species identification are summarized with particular attention to closely related species such as Ph. papatasi and Ph. bergeroti, Ph. chabaudi, and Ph. riouxi, and Se. christophersi and Se. clydei. 相似文献
20.
BackgroundDogs are the primary reservoir for human visceral leishmaniasis due to Leishmania infantum. Phlebotomine sand flies maintain zoonotic transmission of parasites between dogs and humans. A subset of dogs is infected transplacentally during gestation, but at what stage of the clinical spectrum vertically infected dogs contribute to the infected sand fly pool is unknown. Methodology/Principal findingsWe examined infectiousness of dogs vertically infected with L. infantum from multiple clinical states to the vector Lutzomyia longipalpis using xenodiagnosis and found that vertically infected dogs were infectious to sand flies at differing rates. Dogs with mild to moderate disease showed significantly higher transmission to the vector than dogs with subclinical or severe disease. We documented a substantial parasite burden in the skin of vertically infected dogs by RT-qPCR, despite these dogs not having received intradermal parasites via sand flies. There was a highly significant correlation between skin parasite burden at the feeding site and sand fly parasite uptake. This suggests dogs with high skin parasite burden contribute the most to the infected sand fly pool. Although skin parasite load and parasitemia correlated with one another, the average parasite number detected in skin was significantly higher compared to blood in matched subjects. Thus, dermal resident parasites were infectious to sand flies from dogs without detectable parasitemia. Conclusions/SignificanceTogether, our data implicate skin parasite burden and earlier clinical status as stronger indicators of outward transmission potential than blood parasite burden. Our studies of a population of dogs without vector transmission highlights the need to consider canine vertical transmission in surveillance and prevention strategies. 相似文献
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