scholarly journals Landscape structured by physical settings and benthic polychaete and avifauna habitat uses in a mangrove-vegetated estuary

2019 ◽  
Author(s):  
Shang-Shu Shih ◽  
Tzung-Su Ding ◽  
Chang-Po Chen ◽  
Shou-Chung Huang ◽  
Hwey-Lian Hsieh

AbstractMangrove expansion monopolizes estuarine landscapes by diminishing habitat diversity and hence biodiversity. Physical landcover types, including mangrove vegetation, influence polychaete and avifauna habitat uses. The connections between the physical to biota-associated landscapes warrant investigation. We determine how to best describe the landscape in a mangrove-vegetated wetland according to the physical, polychaete and bird domains and identify what physical attributes would affect the biota-associated landscapes. Differences among the physical and biota-associated landscapes were evaluated using multivariate ordination analyses. Six physical landcover types were aligned along elevation, inundation and sedimentary gradients. The polychaete-associated landscape was structured by three landcover types, mainly mangroves and tidal flats with intermediate and high inundation. Deposit-feeding spionid and nereid, carnivorous goniadid and suspension-feeding sabellid polychaetes depended on the different landcover types. Shorebirds occurred distinctively in tidal flats with large, open surface areas. Egrets characterized tidal flats and mangroves, and foliage and ground gleaners characterized mangroves. Open tidal flats are crucial to polychaetes, which are the main prey of shorebirds and are also important to egret foraging. Our results suggest that effective management strategies for conserving these migratory birds require the maintenance of open tidal flats in the landscape.

Plant Disease ◽  
2004 ◽  
Vol 88 (7) ◽  
pp. 724-730 ◽  
Author(s):  
S. A. Pereyra ◽  
R. Dill-Macky ◽  
A. L. Sims

Survival and inoculum production of Gibberella zeae (Schwein.) Petch (anamorph Fusarium graminearum (Schwabe)), the causal agent of Fusarium head blight of wheat and barley, was related to the rate of wheat (Triticum aestivum L.) residue decomposition. Infested wheat residue, comprising intact nodes, internodes, and leaf sheaths, was placed in fiberglass mesh bags on the soil surface and at 7.5- to 10-cm and 15- to 20-cm depths in chisel-plowed plots and 15 to 20 cm deep in moldboard-plowed plots in October 1997. Residue was sampled monthly from April through November during 1998 and every 2 months through April to October 1999. Buried residue decomposed faster than residue placed on the soil surface. Less than 2% of the dry-matter residue remained in buried treatments after 24 months in the field, while 25% of the residue remained in the soil-surface treatment. Survival of G. zeae on node tissues was inversely related to the residue decomposition rate. Surface residue provided a substrate for G. zeae for a longer period of time than buried residue. Twenty-four months after the initiation of the trial, the level of colonization of nodes in buried residue was half the level of colonization of residue on the soil surface. Colonization of node tissues by G. zeae decreased over time, but increased for other Fusarium spp. Ascospores of G. zeae were still produced on residue pieces after 23 months, and these spores were capable of inducing disease. Data from this research may assist in developing effective management strategies for residues infested with G. zeae.


2021 ◽  
Author(s):  
Atal Ahmadzai

Alerted by increasing water insecurity and energy demand, countries, mainly in the Global South, are building dams of unprecedented magnitude. Hundreds of large dams (≥ 100 metres) have been constructed since 2000, with hundreds more under construction. Analyses of the physical attributes of these dams present a concerning image. While they create expansive reservoirs with large surface areas, they have inefficient surface area-to-volume ratios ('S2VR'). Their unprecedented size and the reservoirs’ expansive surface area, indicate severe environmental costs, mainly through ecological disturbances to the (riverine) aquatic ecosystems; and greenhouse gas emissions (GHG). Other ecological costs due to the larger S2VR include a high evaporation rate and compromised biodiversity of a wider area, both up- and downstream. The safety and environmental aspects of these large dams should be robustly scrutinised.


Author(s):  
John K. Keogh ◽  
Brendan F. Keegan

Morphological study of the podia of the suspension feeding Amphiura filiformis and the deposit feeding Amphiura chiajei revealed sensory–secretory complexes in the podial epidermis, consisting of four cells, two secretory and two sensory. Large mucus cells were found in association, but not exclusively, with the sensory–secretory complexes. In A. filiformis, mucus cells stained positively for both acid and neutral mucopolysaccharides, while, in A. chiajei, these cells stained only for acid mucopolysaccharides. The surfaces of the arm podia in A. chiajei were relatively smooth, while the arm podia of A. filiformis bear papillae. The sensory–secretory complexes open through numerous paired pores, with each pair having an intervening cilium. Pores were restricted to the podial tip in A. chiajei, while in A. filiformis they are concentrated on the podial tip and on the papillae. Amphiura chiajei shows very little differentiation of the podia along the length of the arm. In A. filiformis, the distal podia have papillae throughout their entire length, with pores being found on the head region and the papillar tips. Here, the papillae are oriented in such a way (i.e. facing inward towards the ventral arm plate) as to increase the area of the filtering surface of the podium, serviced by the sticky secretions from the sensory–secretory complexes. The proximal podia are relatively simple in structure and are thought to function more in the transportation of mucus wrapped particles to the mouth rather than in their capture. The difference in structure of the podia and chemical composition of podial secretory cells are taken to reflect the difference in feeding styles of the two species.


Insects ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 994
Author(s):  
Alina S. Puig ◽  
Sarah Wurzel ◽  
Stephanie Suarez ◽  
Jean-Philippe Marelli ◽  
Jerome Niogret

Theobroma cacao is affected by viruses on every continent where the crop is cultivated, with the most well-known ones belonging to the Badnavirus genus. One of these, cacao mild mosaic virus (CaMMV), is present in the Americas, and is transmitted by several species of Pseudococcidae (mealybugs). To determine which species are associated with virus-affected cacao plants in North America, and to assess their potential as vectors, mealybugs (n = 166) were collected from infected trees in Florida, and identified using COI, ITS2, and 28S markers. The species present were Pseudococcus jackbeardsleyi (38%; n = 63), Maconellicoccus hirsutus (34.3%; n = 57), Pseudococcus comstocki (15.7%; n = 26), and Ferrisia virgata (12%; n = 20). Virus acquisition was assessed by testing mealybug DNA (0.8 ng) using a nested PCR that amplified a 500 bp fragment of the movement protein–coat protein region of CaMMV. Virus sequences were obtained from 34.6 to 43.1% of the insects tested; however, acquisition did not differ among species, X2 (3, N = 166) = 0.56, p < 0.91. This study identified two new mealybug species, P. jackbeardsleyi and M. hirsutus, as potential vectors of CaMMV. This information is essential for understanding the infection cycle of CaMMV and developing effective management strategies.


2018 ◽  
Vol 7 (3.1) ◽  
pp. 150
Author(s):  
Sunil Patil ◽  
Chhanwal I.L

Poultry plays a significant role in the Indian economy. Around 60 billion chickens are raised per annum as a basis of food for both their eggs and meat. Poultry meat is in significant source of minerals, protein and various vitamins to balance the diet of human. Broiler farming is an important source of family income depending on size of the farm. Chicken farming in Commercial way is the most fruitful business in India and all around the world. Proper farm management practice and care of birds will result in decent profit in a short span of time. In this paper, we are discussing various diseases caused to poultry hen and their preventing or treating methods. Our results shows that some of disease cannot be cured and only it can be prevented. Spreading of disease with the help of contaminated equipment and infected poultry trade is measured as foremost means of spreading of poultry disease. In some countries migratory birds have also been foremost means of spreading of poultry disease like highly pathogenic viruses. 


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Jaya Kaushik ◽  
◽  
Sandeep Shankar ◽  
Anargh V ◽  
Renu M ◽  
...  

Objective: To formulate a protocol for safe and effective management of an ophthalmologic practice in a hospital or a clinic during the Covid - 19 pandemic. Methods and analysis: Literature was reviewed regarding Covid-19 pandemic and ophthalmology. The following key words were used. Covid-19, telemedicine, challenges, management strategy. Result: An efficient protocol for ophthalmology practice during the Covid-19 pandemic was established which covered various protective measures that are essential and vital in the Covid-19 pandemic. Conclusion: An evidence-based protocol was formulated which may be modified in future as per the latest developments and trends in the ongoing pandemic.


2014 ◽  
Author(s):  
Andreas Schröder ◽  
Joel E Dimsdale

Somatic symptoms that cannot be attributed to organic disease account for 15 to 20% of primary care consultations and up to 50% in specialized settings. About 6% of the general population has chronic somatic symptoms that affect functioning and quality of life. This chapter focuses on the recognition and effective management of patients with excessive and disabling somatic symptoms. The clinical presentation of somatic symptoms is categorized into three groups of patients: those with multiple somatic symptoms, those with health anxiety, and those with conversion disorder. The chapter provides information to assist with making a diagnosis and differential diagnosis. Management includes ways to improve the physician–patient interaction that will benefit the patient, a step-care model based on illness severity and complexity, and psychological and pharmacologic treatment. The chapter is enhanced by figures and tables that summarize health anxiety, symptoms, differential diagnoses, and management strategies, as well as by case studies and examples. This review contains  5 highly rendered figures, 10 tables, and 235 references.


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