33 research outputs found

    Ecological sustainability in rangelands : the contribution of dung beetles in secondary seed dispersal (case study: Chaharmahal and Bakhtiari province, Iran)

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    Ecological sustainability has been recognized as one of the main aspects of sustainable development of rangelands, at which different kinds of animal including insects, make substantial contributions. Dung beetles, known as dung-visiting insects, play several key roles in many ecological functions from which benefit both terrestrial ecosystems and human population. Specifically, they benefit rangelands through reducing greenhouse gas emission, nutrient cycling, plant growth enhancement, trophic regulation and pollination and secondary seed dispersal. This study examined secondary seed dispersal as one of the ecological functions of dung beetles, in Chaharmahal and Bakhtiari province, Iran. We applied an experimental approach to measure ecological function (i.e. seed removal) by functional groups of dung beetles. We tested whether functional dung beetle groups influence secondary seed dispersal differently. Through repeated standardized samples of sheep dung, data obtained regularly during two different months August and November in 2013. The results show that dung beetles play a role in secondary seed dispersal. However, it is affected by seed size, so that seed removal increased in the order of, large, medium and small size, respectively. The significant differences between treatments were found for small seeds in the both months. More seeds were dispersed from treatment t02 (all combinations of functional groups except large rollers) in August, while in November more seeds from treatments t01 (dwellers plus large and small tunnelers plus large and small rollers) and t03 (the combinations of dwellers plus small tunnelers, and small rollers) were removed. As a conclusion, it is suggested that if it is to guarantee the ecological sustainability of rangelands, paying attention to the ecological functions of dung beetles is crucial

    Functionally richer communities improve ecosystem functioning: Dung removal and secondary seed dispersal by dung beetles in the Western Palaearctic

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    Aim: In several ecosystems, the diversity of functional species traits has been shown to have a stronger effect on ecosystem functioning than taxonomic diversity alone. However, few studies have explored this idea at a large geographical scale. In a multisite experiment, we unravelled the relationship between ecosystem function and functional completeness of species assemblages using dung beetles as a model group, focusing on dung removal and secondary seed dispersal. Location: Seventeen grassland locations across the Western Palaearctic. Methods: We used a randomized block design with different exclosure types to control the dung and seed removing activities of individual functional groups of the local dung beetle assemblage. We classified dung beetle species according to resource specialization and into functional groups based on dung processing behaviour (dwellers, tunnellers, rollers) and body size (small, large). Additionally, we assessed the role of other soil macro‐invertebrates. By sampling the dung beetle community and measuring the remaining dung and seeds after the experiment, the impact of each functional group was estimated. Results: Dung beetle assemblages differed along a north–south and east–west gradient. Dwellers dominated northernmost sites, whereas at lower latitudes we observed more tunnellers and rollers indicating a functional shift. Resource specialists were more abundant in southern and eastern areas. Overall, functional group diversity enhanced dung removal. More dung (+46.9%) and seeds (+32.1%) were removed in the southern sites and tunnellers and rollers were more effective. At the northernmost sites, where tunnellers were scarce or absent, other soil macro‐invertebrates removed the majority of dung. Main conclusions: The conservation of functionally complete dung beetle assemblages is crucial to maintain the ecosystem functions provided by dung beetles. Given the latitudinal variation in functional group diversity, it is reasonable to expect compositional changes due to climate change. These changes could lead to increased dung removal and a higher secondary seed dispersal rate in northern regions

    Dung beetle assemblages, dung removal and secondary seed dispersal: data from a large-scale, multi-site experiment in the Western Palaearctic

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    By manipulating faeces during feeding and breeding, dung beetles (Coleoptera: Scarabaeidae) fulfil important ecosystem functions in terrestrial ecosystems throughout the world. In a pan-European multi-site experiment (MSE), we estimated the ecosystem functions of dung removal and secondary seed dispersal by differing combinations of dung beetle functional groups. Therefore, we classified dung beetles into five functional groups according to their body size and dung manipulation method: dwellers, large and small tunnelers, and large and small rollers. Furthermore, we set up a dung beetle sampling database containing all sampled dung beetles during the project. By identifying dung beetle specimens to the species level, we obtained a detailed insight into the dung beetle communities at each study location. By establishing experimental plots allowing and inhibiting specific combinations of functional groups in the local dung beetle assemblage from removing dung and seeds, we estimated the role of each group in dung removal and secondary seed dispersal during a 4-week period. We performed all experiments in grazed (semi-)natural grasslands, and used different dung types (cattle, horse, sheep, goat or red deer) to match the herbivore species grazing in close vicinity of each of the study areas. Simultaneously, we sampled dung beetle assemblages by using pitfalls baited with the same dung types as used in the experiments. This data paper documents two datasets collected in the framework of this MSE project. All the experiments took place between 2013 and 2016 at 17 study sites in 10 countries and 11 biogeographic zones. The entire dung beetle sampling dataset was published as a sampling event dataset at GBIF. The dataset includes the sampling results of all 17 study sites, which contain 1,050 sampling events and 4,362 occurrence records of 94 species. The second dataset contains the results of the dung removal and secondary seed dispersal experiments in which we used 11 experimental treatments and the five dung types mentioned above. This experimental results dataset holds all experimental results of the MSE project (11,537 records), and was published in the online data repository Zenodo

    Amenability and Contractibility Modulo an Ideal of Banach Algebras

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    We investigate the concept of amenability modulo an ideal of Banach algebra, showing that amenability modulo an ideal can be characterized by the existence of virtual and approximate diagonal modulo an ideal. We also study the concept of contractible modulo an ideal of Banach algebra. As a consequence, we prove a version of Selivanov's theorem for a large class of semigroups, including E-inversive E-semigroup and eventually inverse semigroups

    Hereditary properties of Amenability modulo an ideal of Banach algebras

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    <p>In this paper we investigate some hereditary properties of amenability modulo an ideal of Banach algebras. We show that<br />if (eα)α(e_{\alpha})_{\alpha} is a bounded approximate identity modulo II of a Banach algebra AA and XX is a neo-unital modulo II, then (eα)α(e_{\alpha})_{\alpha} is a bounded approximate identity for XX. Moreover we show that amenability modulo an ideal of a Banach algebra AA can be only considered by the neo-unital modulo II Banach algebra over AA</p

    Gastric phytobezoars as a very unusual cause of gastric outlet obstruction

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    Bezoars are collections of indigestible foreign material found in the gastrointestinal tract. Phytobezoars are the most common among the types of bezoars. Treatment of phytobezoars is categorized into four types: chemical dissolution, endoscopic removal, adjuvant prokinetics, and surgery. Complications from phytobezoars can include gastric outlet obstruction (GOO), ileus, ulcerations, gastrointestinal bleeding, and perforation. Herein, we present an 86-year-old woman with refractory postprandial vomiting. Then, exploratory laparotomy was performed and the diagnosis was gastric phytobezoar. Phytobezoars-induced GOO is rare and its diagnosis is still a challenge

    Chronic stress but not acute stress decreases the seizure threshold in PTZ-induced seizure in mice: role of inflammatory response and oxidative stress

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    Seizure is paroxysmal abnormal electrical discharges in the cerebral cortex. Inflammatory pathways and oxidative stress are involved in the pathophysiology of seizures. Stress can induce an oxidative stress state and increase the production of inflammatory mediators in the brain. We investigated the effects of acute and chronic stresses on the seizure threshold in pentylenetetrazol (PTZ)-induced seizures in mice, considering oxidative stress and inflammatory mediators in the prefrontal cortex. In this study, 30 male Naval Medical Research Institute (NMRI) mice were divided into 3 groups, including acute stress, chronic stress, and control groups. PTZ was used for the induction of seizures. The gene expression of inflammatory markers (IL-1 beta, TNF-alpha, NLRP3, and iNOS), malondialdehyde (MDA) level, nitrite level, and total antioxidant capacity (TAC) were assessed in the prefrontal cortex and serum. Our results showed that stress could increase the expression of inflammatory cytokines genes and oxidative stress in the prefrontal cortex of the brain and serum following PTZ-induced seizures, which is associated with increased seizure sensitivity and decreased the seizure threshold. The effects of chronic stress were much more significant than acute stress. We concluded that the effects of chronic stress on seizure sensitivity and enhancement of neuroinflammation and oxidative stress are much greater than acute stress

    The Impact of Economic Sanctions on Trade in Iran An Application of Gravity Model

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    This paper examines the impact of economic sanctions on bilateral trade between Iran and 30 trading partners over the period of 1970-2006. To accomplish this Purpose, a generalized gravity model is estimated using panel data estimation method in two situations: with and without sanction. The results show that sanctions have a small negative impact on bilateral trade. By imposing sanction on Iran by its trade partners, the bilateral trade reduces 0.089 percentage point. So, the negative effects of economic sanctions on Iran's trade with trading partners is negligible

    Boron Clusters in Biomedical Applications: A Theoretical Viewpoint

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    In this chapter, we presented an analysis of the recent advances in the applications of boron clusters in biomedical fields such as the development of biosensors and drug delivery systems on the basis of quantum chemical calculations. Biosensors play an essential role in many sectors, e.g., law enforcement agencies for sensing illicit drugs, medical communities for detecting overdosed medications from human and animal bodies, etc. The drug delivery systems have theoretically been proposed for many years and subsequently implemented by experiments to deliver the drug to the targeted sites by reducing the harmful side effects significantly. Boron clusters form a rich and colorful family of atomic clusters due to their unconventional structures and bonding phenomena. Boron clusters and their complexes have various biological activities such as the drug delivery, imaging for diagnosis, treatment of cancer, and probe of protein-biomolecular interactions. For all of these reactivities, the interaction mechanisms and the corresponding energetics between biomaterials and boron clusters are of essential importance as a basic step in the understanding, and thereby design of relevant materials. During the past few years, attempts have been made to probe the nature of these interactions using quantum chemical calculations mainly with density functional theory (DFT) methods. This chapter provides a summary of the theoretical viewpoint on this issue

    Adaptation of Clinical Practice Guideline for Colorectal Cancer Screening in People with Average Risk in Isfahan Province

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    Background: Colorectal cancer (CRC) is the third most common cancer among adults in Iran. The aim of colorectal cancer screening is to reduce the cancer burden in the population by diagnosing the disease in its early stages. Methods: We adapted this guideline for the moderate CRC risk population for Isfahan to determine how to screen them and when to start and end the CRC screening. This guideline was developed by clinical appraisal and review of the evidence, available clinical guidelines, and in consultation with members of the Isfahan Chamber of Iranian association of gastroenterology and hepatology. Results: In screening people with average risk for CRC who use personal resources and personally pay all the costs, colonoscopy is recommended as the first choice to be done every 10 years. In case of negative colonoscopy, we recommend FIT test to prevention of interval cancer every 5 years. In screening of people with average risk of CRC, FIT is suggested to be done every 2 years as a first-choice method test for those who use public resources and do not pay for this service personally. In screening individuals with average risk for CRC, g-FOBT is not recommended as the first method of choice. Repeating positive guaiac test is not recommended and if positive, colonoscopy is suggested
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