long term studies
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Author(s):  
Hamidreza Barikani ◽  
Mohadeseh Heidari ◽  
Mohammadjavad Kharazifard ◽  
Amirreza Rokn

Objectives: Dental implants are a prominent scientific breakthrough and are frequently applied for replacement of the missing teeth. From the clinicians’ point of view, long-term studies are essential to find out the predictability of dental implant systems. Materials and Methods: In this retrospective study, 1,626 patients who received 4,389 Dyna implants in a private office between 2013-2019 were evaluated. All statistical analyses were performed using SPSS 25 for Windows. P values less than 0.1 were considered significant for regression analysis. Results: Dyna implantts (4389) placed from 2013 to 2019 were evaluated in this study. One-hundred and thirty-three (3.03%) implants failed during the healing period or recall visits. Eighty-nine implants (2.03%) failed immediately and 44 (1%) failed after 3 months. Conclusion: The present study showed that the Dyna dental implant system had high implant survival, and it had all the survival criteria similar to world-class dental implant systems.  


2022 ◽  
Vol preprint (2022) ◽  
Author(s):  
David Lindenmayer ◽  
Elle Bowd ◽  
Chris MacGregor ◽  
Lachlan McBurney

ABSTRACT Fire can have marked impacts on biodiversity and on ecosystem condition. However, it is the sequence of multiple fires over a prolonged period of time which can have the most marked effects on biodiversity and on ecosystem condition. A good understanding of these effects comes from long-term studies. In this article we outline some of the key perspectives on the effects of fire on ecosystems and biodiversity from two large-scale, long-term monitoring studies in south-eastern Australia. These are studies in the montane ash forests of the Central Highlands of Victoria and at Booderee National Park in the Jervis Bay Territory. These studies have shown that the effects of fires are strongly influenced by: (1) The condition of an ecosystem before a fire (e.g. the age of a forest at the time it is burnt). (2) Conditions after the fire such as the extent of herbivory in regenerating vegetation and whether the ecosystem is subject to post-fire (salvage) logging. (3) Fire history (e.g. the number of past fires and the time since the previous fire). And, (4) Interactions between fire and other ecosystem drivers such as logging. We discuss some of the key implications for conservation and resource management that arise from these studies including the need to: (a) Reduce the number of stressors in some ecosystems to facilitate post-fire recovery. (b) Recognize that pre-fire human disturbances can elevate fire severity in some forest ecosystems, with corresponding negative effects on elements of the biota, and, (c) Acknowledge the inherent patchiness of wildfires and the value of unburnt areas and places burnt at low severity as critical refugia for some species; it is critical that these locations are managed accordingly (e.g. by limited additional disturbances within them). Finally, many of the insights discussed in this article have emerged only through long-term studies. More long-term monitoring and research is needed to truly understand and better manage fire in Australian ecosystems.


2022 ◽  
Vol 962 (1) ◽  
pp. 012041
Author(s):  
N A Vikulina ◽  
S N Kayukova ◽  
L A Ishina

Abstract The article presents the data of long-term studies of communities with U. japonica in Eastern Transbaikalia, in particular, the results of anatomical studies, floristic, ecological and biological, biomorphological and arealogical analysis of the flora of elms.


2021 ◽  
Vol 7 ◽  
pp. 491-503
Author(s):  
Vilyura E. Kardashevskaya ◽  
Nyurguyana N. Egorova

In Yakutia, natural floodplain meadows and steppes have long been involved in economic activities. To develop methods of rational use, one needs to constantly consider the state of vegetation, mainly its constituent populations. Our research focuses on studying the dynamics of the vitality of the populations of the Agrostis diluta Kurcz. and steppe Psathyrostachys caespitosa (Sukaczev) Peschkova cereals. These species play an essential role in the composition of vegetation cover. We determined the vitality coefficient IVC. Our study of populations over several years has revealed the dynamic mobility of the vital structure, which is of adaptive significance and ensures the sustainability of populations. We have found that the vital structure of the cereal populations of the meadow Agrostis diluta and the steppe Psathyrostachys caespitosa during long-term studies (2007–2013 and 2007–2016, respectively) is heterogeneous. In unfavorable humidification conditions, we characterize years as depressive. Under favorable conditions of humidification, they quickly turn into thriving plants. In addition to the weather of the vegetation periods, habitat specificity affects the vitality of species populations that differ in ecological and coenotic characteristics. The Q quality index and IVC correspond to each other by year and form a clear descending order during the transition from a thriving to a depressive state. Currently, the vital state of the populations of both species is satisfactory.


Author(s):  
Mark Davis ◽  
Richard Condit

Successful management of savannas is challenging and requires knowledge of the causes and consequences of the spatial arrangement of the trees. In savannas, trees are often aggregated, and the ability of trees within the clumps to survive fires plays a significant role in determining the savannas landscape dynamics. Whether or not a tree survives a fire is often dependent on the nature of their interactions with neighboring trees, positive or negative. In cases where disturbances are episodic, detecting these interactions is only going to be possible through long-term studies. Data reported here, from twenty-five years of annual tree censusing of a large grid-plot in a frequently burned savanna, showed consistent neighbor facilitated survival, irrespective as to whether the neighbors were conspecifics or heterospecifics. The positive interactions likely involve the reduction of both herbaceous and woody fuel in denser sites, and possibly mycorrhizal sharing among nearby trees.


2021 ◽  
Vol 937 (4) ◽  
pp. 042085
Author(s):  
N Mukhutdinov ◽  
I Khalismatov ◽  
N Akramova ◽  
R Zakirov ◽  
A Zakirov ◽  
...  

Abstract The results of long-term studies of natural gases in the Bukhara-Khiva oil and gas region of Uzbekistan are summarized. The results of studying the composition of gases in hydrocarbon deposits generated by OM of continental (terrigenous deposits of the Cretaceous and Middle Jurassic) and marine (carbonate Jurassic) facies are presented. Regularities of changes in individual constituents of gases (hydrocarbons, hydrogen sulfide, carbon dioxide, nitrogen, etc.) with depth are considered; the influence exerted on the composition of gases by various factors and, above all, those of them, which, in the opinion of most researchers, are the main ones. The revealed patterns are used for predictive assessment of the distribution of various constituents of natural gases in the study area.


2021 ◽  
Vol 1 (2) ◽  
pp. 158-170
Author(s):  
Yudika Ilhami Rusdi ◽  
Rahmi Hijriani Hardianti ◽  
Lalu Wahyu Alfian ◽  
Cahya Nabila ◽  
Uni Nurul Milenia

Background: Tuberculosis (TB) is spreading globally, and more than two billion people (about 30% of the world's population) are thought to be infected with M. tuberculosis.  Tuberculosis cutis is an extrapulmonary Mycoterium tuberculosis infection that attacks the skin. Research Methods: The writing of this article includes various sources originating from scientific journals and government guidelines and related agencies. Source searches were conducted on the online portals of journal publications such as MedScape, Google Scholar and NCBI (ncbi.nlm.nih.gov). Results: Cutaneous TB can be transmitted through exposure to the lungs or infected aerosols entering the lungs. Cutaneous TB is divided into True Cutaneous TB which consists of primary and secondary TB, and Tuberculid Overall, the treatment of cutaneous TB is similar to that of systemic TB, which tends towards multi-drug therapy. Several anti-tuberculosis drugs such as isoniazid, rifampin, and pyrazinamide have been recommended as drugs for the treatment of cutaneous tuberculosis. It was reported that in a five-year follow-up approximately 12.5% ??of cutaneous TB patients showed relapse after standard anti-TB therapy. Conclusion: To reduce the mortality rate, the public needs to be given education regarding the dangers and ways to prevent TB disease to increase public awareness. More long-term studies are needed to understand the recurrence rate of various cutaneous tuberculosis under current treatment recommendations, especially in immunocompromised patients. 


Author(s):  
Gabriel Sánchez-Rivera ◽  
Leticia Gómez-Mendoza

The resilience capacity of vegetation in the Yucatan Peninsula is influenced by the winds and rains of tropical cyclones. There are no recent long-term studies on cyclonic impacts on natural vegetation in the region despite their significant effects on infrastructure and biodiversity. The objective of this study was to identify the area impacted by 21 tropical cyclones between 2000 and 2012 and to quantify the recovery capacity of the vegetation by using standardized anomalies of the normalized vegetation index (aNDVI). MODIS images from NASA’s “Terra and Aqua” satellites were used to calculate the damaged areas by analyzing the frequency of pixels corresponding to each type of vegetation per impact zone. The results showed that in 67% of the tropical cyclones, the impacts on vegetation were negative —a decrease in aNDVI—but in 33% of the cyclones, positive effects were recorded —an increase in aNDVI—. The lapse rate of vegetation recovery varied in 52% of the cases; vegetation recovered between two and three weeks after each cyclonic event, while 38% of the cases recovered within four to five weeks of the cyclone landfall. Tropical forests suffered the most significant effects, followed by hydrophilic vegetation. The most destructive hurricanes were Emily, Wilma, and Dean. The rate of recovery laps ranged from 4 to 10 weeks after the hurricane hit. The results could improve assessments of vegetation vulnerability against severe hydrometeorological events and establish priority zones for prompt inspection.


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