Physiological consequences of parasite infection in the burrowing mud shrimp, Upogebia pugettensis, a widespread ecosystem engineer

2012 ◽  
Vol 63 (1) ◽  
pp. 60 ◽  
Author(s):  
Michele Repetto ◽  
Blaine D. Griffen

The burrowing mud shrimp, Upogebia pugettensis, is an important ecosystem engineer throughout bays and estuaries along the Pacific coast of North America. Populations of U. pugettensis have recently declined throughout its range. A likely reason for this decline is the arrival of an invasive bopyrid isopod parasite, Orthione griffenis, which has colonised the system and increased in prevalence. We tested the following three hypotheses regarding this host–parasite system: (1) parasite infection is correlated with the volume of water processed by the host; (2) infection negatively affects host’s energetic state; and (3) infection causes feminisation in male hosts. We used several physiological and morphological measures to quantify the effects of this parasite infection on U. pugettensis. The parasite appears to have different physiological effects on male and female hosts. Our study provides mixed support for the previous theory that predicted the mechanistic interactions between this host and its new parasite. Recent examples from other systems have demonstrated that invasive parasites can have far-reaching influences when they infect ecosystem engineers. Given the negative effects of O. griffenis on U. pugettensis, this invasive parasite may have similarly large impacts on Pacific North-west estuaries throughout its invaded range.

Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 827
Author(s):  
Omar Mologni ◽  
Eric D. T. Nance ◽  
C. Kevin Lyons ◽  
Luca Marchi ◽  
Stefano Grigolato ◽  
...  

Cable tensile forces in winch-assist harvesting have been investigated in order to assess the safety concerns of the technology. However, the literature is lacking, particularly in regards to the impact of winch design. In this study, a Summit Winch Assist tethering a feller-director on ground slopes up to 77% was monitored for four days. The cable tensile forces were simultaneously recorded at the harvesting and anchor machine at a frequency of 100 Hz. Cameras and GNSS devices enabled a time study of the operations and the recording of machine positions. Winch functionality and design were disclosed by the manufacturer and used for the interpretation of the results. The cable tensile forces reached 296 kN at the harvesting machine and 260 kN at the anchor machine. The slow negotiation of obstacles while moving downhill recorded the highest peaks, mainly due to threshold settings of the winch in the brake system activation. Lower but significant peaks were also recorded during stationary work tasks. The peaks, however, were limited to a few events and never exceeded the endurance limit of the cable. Overall, the study confirmed recent findings in cable tensile force analysis of active winch-assist operations and provided evidence of the underlaying mechanisms that contribute to cable tensile forces.


2012 ◽  
Vol 54 (4) ◽  
pp. 179-191 ◽  
Author(s):  
Jordi Sanchez-Ribas ◽  
Gabriel Parra-Henao ◽  
Anthony Érico Guimarães

Irrigation schemes and dams have posed a great concern on public health systems of several countries, mainly in the tropics. The focus of the present review is to elucidate the different ways how these human interventions may have an effect on population dynamics of anopheline mosquitoes and hence, how local malaria transmission patterns may be changed. We discuss different studies within the three main tropical and sub-tropical regions (namely Africa, Asia and the Pacific and the Americas). Factors such as pre-human impact malaria epidemiological patterns, control measures, demographic movements, human behaviour and local Anopheles bionomics would determine if the implementation of an irrigation scheme or a dam will have negative effects on human health. Some examples of successful implementation of control measures in such settings are presented. The use of Geographic Information System as a powerful tool to assist on the study and control of malaria in these scenarios is also highlighted.


2020 ◽  
pp. 16-17
Author(s):  
Zac Waipara

We have not yet emerged into a post-COVID world. The future is fluid and unknown. As the Academy morphs under pressure, as design practitioners and educators attempt to respond to the shifting world – in the M?ori language, Te Ao Hurihuri – how might we manage such changes? There is an indigenous precedent of drawing upon the past to assist with present and future states – as the proverb ka mua ka muri indicates, ‘travelling backwards into the future,’ viewing the past spread out behind us, as we move into the unknown. Indigenous academics often draw inspiration from extant traditional viewpoints, reframing them as methodologies, and drawing on metaphor to shape solutions. Some of these frameworks, such as Te Whare Tapa Wh?, developed as a health-based model, have been adapted for educational purposes. Many examples of metaphor drawn from indigenous ways of thinking have also been adapted as design or designrelated methodologies. What is it about the power of metaphor, particularly indigenous ways of seeing, that might offer solutions for both student and teacher? One developing propositional model uses the Pacific voyager as exemplar for the student. Hohl cites Polynesian navigation an inspirational metaphor, where “navigating the vast Pacific Ocean without instruments, only using the sun, moon, stars, swells, clouds and birds as orienting cues to travel vast distances between Polynesian islands.”1 However, in these uncertain times, it becomes just as relevant for the academic staff member. As Reilly notes, using this analogy to situate two cultures working as one: “like two canoes, lashed together to achieve greater stability in the open seas … we must work together to ensure our ship keeps pointing towards calmer waters and to a future that benefits subsequent generations.”2 The goal in formulating this framework has been to extract guiding principles and construct a useful, applicable structure by drawing from research on twoexisting models based in Samoan and Hawaiian worldviews, synthesised via related M?ori concepts. Just as we expect our students to stretch their imaginations and challenge themselves, we the educators might also find courage in the face of the unknown,drawing strength from indigenous storytelling. Hohl describes the advantages of examining this approach: “People living on islands are highly aware of the limitedness of their resources, the precarious balance of their natural environment and the long wearing negative effects of unsustainable actions … from experience and observing the consequences of actions in a limited and confined environment necessarily lead to a sustainable culture in order for such a society to survive.”3 Calculated risks must be undertaken to navigate this space, as shown in this waka-navigator framework, adapted for potential use in a collaborative, studio-style classroom model. 1 Michael Hohl, “Living in Cybernetics: Polynesian Voyaging and Ecological Literacy as Models fordesign education, Kybernetes 44, 8/9 (October 2015). https://doi.org/ 10.1108/K-11-2014-0236.2 Michael P.J Reilly, “A Stranger to the Islands: Voice, Place and the Self in Indigenous Studies”(Inaugural Professorial Lecture, University of Otago, Dunedin, New Zealand, 2009).http://hdl.handle.net/10523/51833 Hohl, “Living in Cybernetics”.


Author(s):  
Richard Huzzey

This chapter analyses how Britons responded to the febrile political and social crises of the Americas in the 1860s. Although the American Civil War created a particular challenge – and great confusion – to observers in the United Kingdom, that conflict was one of a wider range of concerns in balancing the demands of rival imperial and new post-colonial powers to preserve British influence. Considering opinions expressed travel writing and political commentary, the chapter argues that Britons struggled to balance competing interests – in economic affairs, in geopolitical strategy, in imperial authority, and in suppression of the slave trade – to maintain a manifestly uncertain dominion over the Americas. Touching on British concerns stretching from the Mosquito Coast to the Pacific north--west, the chapter suggests that crises in the Americas illuminated diverse priorities and anxieties.


Author(s):  
Anna Erzsebet Szucs

Craig Santos Perez, poet and activist from Guam, uses his poetry to call attention to the negative effects of colonialism and militarization on his homeland and the Pacific. He reminds his readers of the mistreatment of his people the Chamorros, the special “unincorporated” status of Guam and the land that is taken over little by little by the US Army. His poems reveal information about the life circumstances of the author's community and respond to, as well as critique, the colonial conditions of Guam. This study looks at everyday objects mentioned in Perez's poetry and seeks to unfold the “mission” of these objects. “Everyday objects” do not only refer to traditional objects, but also, to modern objects (borrowed from western culture) which relate to the everyday life of the Indigenous people of Guam. The argument of this research is that ordinary objects, which have significance in Pacific culture, are deliberately placed in the poems by Perez. They convey the message of resistance, decolonial protest and pursuit of survival and can be considered as representations of activism.


2017 ◽  
Vol 8 (2) ◽  
pp. 640-647 ◽  
Author(s):  
Jeffrey C. Jolley ◽  
Christina T. Uh ◽  
Gregory S. Silver ◽  
Timothy A. Whitesel

Abstract Native lamprey populations are declining worldwide. In the Pacific Northwest focus on conservation and management of these ecologically and culturally important species has increased. Concern has emerged regarding the effects of sampling and handling of lamprey, with little to no attention given to the larval lifestage. We monitored the survival of larval Pacific Lamprey Entosphenus tridentatus and Lampetra spp. after backpack electrofishing, deepwater electrofishing and suction-pumping, anesthesia, and handling. We performed survival trials on wild-caught lamprey (n = 15 larvae in each trial) collected from the Clackamas River drainage in Oregon, USA, coupled with control group trials from lamprey sourced from a hatchery (n = 10 larvae). Short-term (96 h) survival was >98% with only one observed mortality. Delayed mortality (1 wk) was observed for four individuals that had fungus; two of those were positive for the bacteria Aeromonas hyrdrophila. We recorded blood hematocrit as a secondary measure of stress. The baseline, nonstressed larvae hematocrit levels did not differ from those of fish that had undergone stress through electrofishing, suction-pumping, and handling without anesthesia. Electrofishing, suction-pumping, and anesthesia showed no short-term negative effects on larval lamprey although potential long-term effects remain unstudied. These techniques appear to provide efficient and relatively safe methods for collecting and surveying larval lamprey.


1986 ◽  
Vol 1 (2) ◽  
pp. 41-43
Author(s):  
Evelyn L. Bull ◽  
Jack Ward Thomas ◽  
Kirk Horn

Abstract A questionnaire was sent to each Ranger District in the Pacific North-west Region of the USDA Forest Service to get information on present snag-management programs. Ninety-five percent of the responding Ranger Districts left snags at levels that ranged from 0.15 snags/ha (0 06/ac) to 12-15 snags/ha (5-6/ac) on all forested lands. Live trees were intentionally left as future snags on 93% of the Ranger Districts. Live trees were killed to create snags on 41% of the Ranger Districts. Management recommendations are made as to the kind of snags to leave and methods of maintaining them. West. J. Appl. For. 1:41-43, April 1986


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