hard structures
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Author(s):  
Abeer Abdulrahman Al Subait ◽  
Khadijah Mustafa Saidi ◽  
Hussain Hadi Alsagoor ◽  
Naif Mayouf Alrasheedi ◽  
Asma Gadan Alanazi ◽  
...  

When compared to adults, older persons have a higher prevalence and incidence of periodontal diseases. The prevalence of periodontitis is substantially greater in the geriatrics group, which is 75 years old on average, compared to those who are 60 years old on average. Periodontitis can lead to tooth loss if natural periodontal therapies are not used. Periodontitis is the sixth most frequent incurable illness in the world, characterized by bacterial-induced and host-mediated deterioration of both soft and hard structures around the teeth. A severe type of periodontitis affects around 10% of the world's population. Periodontitis is more frequent in adults because of its chronic and debilitating nature, with around 66% of the 65-year-old age group in the United States afflicted by chronic periodontitis. A critical component of a successful disease prevention and health promotion trajectory is having up-to-date information on demographics, clinical symptoms, and illness burden on individuals, particularly in underrepresented regions where preventive programs are targeted and executed. As a result, the purpose of this paper is to evaluate the existing research on the prevalence, incidence, and consequences of periodontal diseases in the older population.


2021 ◽  
Vol 11 (2) ◽  
pp. 134
Author(s):  
Nanang Sugianto ◽  
Refrizon Refrizon

Shear wave velocity <em>(V<sub>s</sub>)</em> structure at along of Central Bengkulu-Kepahiang crossline has been mapped. This research aims to identify the subsurface structure and to estimate the constituent material type of rock in landslide-prone areas (Central Bengkulu-Kepahiang crossline). Shear wave velocity structure on each site is obtained by the HVSR-inversion of 146 microtremor data (ambient noise recording of seismometer). <em>V<sub>s</sub></em> structure at the line mapped from the surface until to 30 meters of the depth. Groups of Vs are identified in class E (<em>V<sub>s</sub></em> &lt;180), Class D (180≤<em> V<sub>s</sub></em> &lt;360), Class C (360≤<em> V<sub>s</sub></em> &lt;760), and Class B (760≤<em> V<sub>s</sub></em> &lt;1500). The subsurface structure at the depth of 0 to 10 meters are dominated by stiff soil, very dense soil, and soft rock which has highly fractured and weathered rock properties. At the depth of 15 meters to 30 meters, the subsurface structure is dominated by hard rock but it is high potential or easy to fracturing and weathering like the properties of the rocks in areas that have landslides in the past. Based on <em>V<sub>s</sub></em> value, rock constituent materials are deposition of sand, clay, gravel and alluvium ranging from soft to relatively hard structures at the depth.


2021 ◽  
pp. 61-75
Author(s):  
Robin L. McLachlan ◽  
James B. Deemy ◽  
Kimberly K. Takagi ◽  
Damon P. Gannon

ABSTRACT Georgia’s coastline is composed of a series of short, wide, mixed-energy (tide-dominated) barrier islands, each backed by extensive marsh, topped with mobile dunes, and flanked by deep inlets. Many of the islands, particularly those along the southern Georgia coast, consist of Pleistocene cores surrounded by mobile deposits that attached during the Holocene sea-level transgression. Positioned within the head of the funnel-shaped South Atlantic Bight, tidal ranges here commonly reach ~2–3 m. As a result, inlets are numerous and the back-barrier environment hosts nearly 400,000 acres of salt marsh. Today, many of the barriers are transgressive, and hard structures such as revetments and groins are becoming increasingly more common to stabilize shorelines along the four developed islands. This field guide presents evidence of island formation, modern ecologic function, and likely future changes for three island groups: (1) Blackbeard, Cabretta, and Sapelo Islands; (2) Sea Island and St. Simons Island; and (3) Jekyll Island. The field trip provides evidence of the Pleistocene-age island cores, the natural southward migration of the mobile Holocene-age sandy shorelines, and the impacts of storm erosion and hard structures built to combat that erosion. This field guide serves as the static, print companion to an online virtual field trip (https://storymaps.arcgis.com/stories/0aa3fd921cc4458da0a19a928e5fa87c).


2021 ◽  
Vol 13 (13) ◽  
pp. 7068
Author(s):  
Irene Cinelli ◽  
Giorgio Anfuso ◽  
Sandro Privitera ◽  
Enzo Pranzini

The main aim of this paper is to analyze the development of the railway network in Sicily (Italy), where it runs close to the sea on two of the three sides of the island, and give an overview of the related impacts on coastal environment and tourism. In order to achieve such an objective, the impacts of the railway network were analyzed according to coastal typology (distinguishing between rocky and sandy coastal sectors) and distance from the shoreline (dividing distance values in concrete intervals). Rails were mostly emplaced in flat coastal areas due to the island’s rugged terrain: out of 1592 km of railway, ca. 350 km is located less than 1000 m from the shoreline (123 km on rocky sectors and 227 km on beaches and coastal plains). On sandy beaches and low sandy coastal sectors, approximately 6 km of track is within 25 m from the shoreline, a value rising to 16 km if a 50 m distance is considered, 48 km at 100 m and 103 km at 200 m distance. In correspondence of rocky platforms and high cliffed sectors, data reported for short distances between the rail and the shore are similar to ones observed along sandy coastal sectors, but differ when distance increases, i.e., there is only 32 and 47 km of railway respectively within 100 and 200 m from the shoreline. The emplacement of the railway embankment on beaches and dunes favored coastal squeeze and enhanced coastal erosion due to wave reflection on the embankment, which had to be protected by hard structures. Impacts on rocky sectors, with respect to beach and dune systems, are generally low because such sectors are usually stable (they do not need to be protected), less attractive to tourists and present small urban development. Tourism was affected by reducing landscape quality, beach access and width. More detailed studies and monitoring programs are necessary to locally assess the detailed impacts of the railway network, with this study constituting a preliminary but useful approximation to determine which coastal sectors are potentially the most affected. Results obtained in this paper can stimulate similar researches in other countries to prevent or decrease railway impacts on “Sun, Sea and Sand” tourism and, in general, on the coastal environment.


2021 ◽  
Author(s):  
Dick Shaw

Abstract F. japonica is an extremely invasive weed despite its lack of extensive sexual reproduction in most of its introduced range. It is included on various lists of invasive weeds and is one of the 100 worst invasive species as identified by the IUCN. It is a potential contaminant of soil, and its ability to tolerate a remarkable range of soil types and climates means that it has the potential to spread much further than it has to date. It has gained a fearsome reputation for breaking through hard structures in the built environment and being almost impossible to eradicate once it has taken hold and is often recognized as one of the most pernicious weeds in any recipient country.


2021 ◽  
Vol 5 (3) ◽  
pp. 114-118
Author(s):  
Syeda Asiya Butool ◽  
◽  
Nitin Kararia ◽  
Shyam Aggrawal ◽  
Rachit Mathu ◽  
...  

Abstract: Internal resorption is an asymptomatic condition in teeth seen with past history of injury. In the crown it has a clinical observation of pink mark. It is diagnosed by chance on an x-ray examination. Primal detection and resorption treatment improves prognosis of the condition. Resorption can be broadly classified into normal physiological or pathological process associated with extensive damage to hard structures of tooth such as dentin, cementum and bone. Proper diagnosis of resorption and differentiation of resorption from internal and external resorption by radiographic presentation and the correct diagnosis and treatment planning improves the prognosis of the condition. Untreated cases will cause loss or early exfoliation of the afflicted tooth [1].


Zootaxa ◽  
2021 ◽  
Vol 4950 (1) ◽  
pp. 1-45
Author(s):  
LAÍS V. RAMALHO ◽  
FERNANDO C. MORAES ◽  
LEONARDO T. SALGADO ◽  
ALEX C. BASTOS ◽  
RODRIGO L. MOURA

The reef system off the Amazon River mouth extends from Amapá state to Maranhão state along the Brazilian Equatorial Margin, encompassing more than 10,000 km2 of rhodolith beds and high-relief hard structures on the outer shelf and upper slope. This unique hard bottom mosaic is remarkable for being influenced by the turbid and hyposaline plume from the world’s largest river, and also for representing a connectivity corridor between the Caribbean and Brazil. Bryozoans were recently recognized as major reef builders in the Southwestern Atlantic, but their diversity off the Amazon River mouth remained unknown. Here, we report on recent collections obtained from 23 to 120 m depth in Northern Brazil. Sixty-five bryozoan taxa were characterized using scanning electron microscopy, including 57, five and three taxa of Cheilostomatida, Cyclostomatida and Ctenostomatida, respectively. Cribrilaria smitti and three genera (Cranosina, Glabrilaria and Thornelya) are new records for Brazil, and 13 new species are herein described: Antropora cruzeiro n. sp., Cranosina gilbertoi n. sp., Cribrilaria lateralis n. sp., Crisia brasiliensis n. sp., Glabrilaria antoniettae n. sp., Micropora amapaensis n. sp., Parasmittina amazonensis n. sp., Plesiocleidochasma arcuatum n. sp., Poricella bifurcata n. sp., Pourtalesella duoavicularia n. sp., Stephanollona domuspusilla n. sp., Therenia dianae n. sp., and Thornelya atlanticoensis n. sp. Our results highlight the biodiversity significance of the Amazon reefs and the need for more comprehensive sampling to clarify the role of bryozoans in modern turbid-zone reefs and rhodolith beds. 


2021 ◽  
Vol 28 ◽  
Author(s):  
Massimiliano Peana ◽  
Alessio Pelucelli ◽  
Serenella Medici ◽  
Rosita Cappai ◽  
Valeria Marina Nurchi ◽  
...  

Background : Essential metal ions play a specific and fundamental role in human metabolism. Their homeostasis is finely tuned and any concentration imbalance in form of deficiency or excess could lead to a progressive reduction and failure of normal biological function, to severe physiological and clinical outcomes till death. Conversely, non-essential metals are not necessary for life and only noxious effects could arise after their exposure. Large environmental amounts of such chemicals come from both natural and anthropogenic sources, with the latter being predominant because of human activities. The dissipation of toxic metals contaminates water, air, soil, and food, causing a series of chronic and acute syndromes. Objective : This review discusses the toxicity of non-essential metals considering their peculiar chemical characteristics such as different forms, hard-soft character, oxidation states, binding capabilities and solubility, which can influence their speciation in biological systems, and subsequently, the main cellular targets. Particular focus is given to selected toxic metals, major non-essential metals or semimetals related to toxicity such as mercury, lead, cadmium, chromium, nickel and arsenic. In addition, we provide indications on the possible treatments/interventions on metal poisoning based on chelation therapy. Conclusion: Toxic metal ions can exert their peculiar harmful effects in several ways. They strongly coordinate to important biological molecules on the basis of their chemical-physical characteristics (manly HSAB properties) or replace essential metal ions from their natural locations in proteins, enzymes or in hard structures such as bones or teeth. Metals with redox properties could be key inducers of reactive oxygen species, leading to oxidative stress and cellular damage. Therapeutic detoxification, through complexation of toxic metal ions by specific chelating agents, appears an efficacious clinical strategy mainly in acute cases of metal intoxication.


Zootaxa ◽  
2021 ◽  
Vol 4948 (4) ◽  
pp. 451-500
Author(s):  
YANDER L. DIEZ ◽  
MARLIES MONNENS ◽  
ROSA ISABEL AGUIRRE ◽  
RANA YURDUSEVEN ◽  
PHILIPPE JOUK ◽  
...  

The taxon Koinocystididae is the third most species-rich family within Eukalyptorhynchia. However, its diversity and phylogeny have been largely neglected in former studies. We introduce three new genera and twelve new species of Koinocystididae including Simplexcystis asymmetrica gen. n. sp. n., Galapagetula cubensis sp. n., eight species of Reinhardorhynchus gen. n. and two species of Itaipusa. This raises the total number of species within Koinocystididae from 51 to 63. We also report on new distribution records for six known species: I. divae (Cuba, Panama and New Caledonia), I. karlingi (Sardinia and Lanzarote), Reinhardorhynchus riegeri comb. n. (Cuba), R. ruffinjonesi comb. n. (Cuba and Panama), Utelga heinckei (Cuba and Lanzarote), and U. pseudoheinckei (Sardinia). Simplexcystis asymmetrica gen. n. sp. n. is characterised by a male duct running eccentrically through the copulatory bulb, lack of any hard structures in the male system, lack of a bursa, and the fact that the epithelia of the female, the male, and part of the common atrium are covered by a brush border. Galapagetula cubensis sp. n. has a caudal gonopore, a divisa-type copulatory bulb with an unarmed penis papilla, and a female duct without a sphincter. The new species of Itaipusa and Reinhardorhynchus gen. n. differ from their congeners in the detailed structure of the copulatory bulb and especially the hard structures associated with it. In a molecular phylogenetic analysis based on all available 18S and 28S rDNA sequences of koinocystidids, we found support for the monophyly of the family and the genus Utelga Marcus, 1949. The genus Itaipusa is not monophyletic in that I. sinensis forms a clade with Rhinolasius dillonicus, while other species of Itaipusa that have a copulatory bulb armed with hooks form a clade together with Sekerana stolzi. As the type species of Itaipusa (I. divae) is in neither of these clades, we erected a new genus for I. sinensis (Koinogladius gen. n.) and one for species of Itaipusa having a hook-bearing copulatory bulb (Reinhardorhynchus gen. n.), respectively. Whether the remaining species of Itaipusa form a monophylum remains uncertain. 


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