243 research outputs found
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Ambystoma barbouri
Number of Pages: 4Integrative BiologyGeological Science
The Conservation of Unisexual Vertebrate Populations
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73310/1/j.1523-1739.1995.09040956.x.pd
A New Species Of The Miniaturized Frog Genus Paedophryne (Anura: Microhylidae) From Papua New Guinea
ABSTRACT â I describe a new species of Paedophryne from low-elevation foothill
rainforest on Normanby Island off southeastern Papua New Guinea. This new species is
the largest member of the genus so far discovered, with body length of the sole adult male
11.1 mm, and with adult females ranging from 10.6â11.6 mm. As well, it differs from
other species in the genus in having smooth dorsal skin, a disc on the second toe, relatively larger first digits, and in a number of body proportions and details of color pattern. As for other species in the genus, it is an inhabitant of rainforest leaf litter restricted to a portion of the East Papuan Composite Terrane, an agglomeration of terranes that were assembled offshore of New Guinea and sutured to it during the early Miocene.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/122719/1/OP745.pd
The Risk to Hawai'i from Snakes
We assessed the risk to Hawai'i's native species and human quality of
life posed by the introduction of alien snake species. An examination of Hawai'i
Department of Agriculture records from 1990 to 2000 indicated hundreds of
credible snake sightings in the state, mostly of free-roaming animals that were
not recovered. These snakes arrived primarily through smuggling of pet animals,
but some snakes are accidentally introduced as cargo stowaways. Most recovered
specimens are of species potentially capable of inflicting substantial
harm to native birds and the poultry industry if they become established. Some
may affect native freshwater fish. An analysis of the frequency with which snakes
are smuggled into the state, the suitability of the local environment to snake
welfare, and the ecological threats posed by recovered snake species leads us to
conclude that snakes pose a continuing high risk to Hawai'i. Mitigation of this
threat can only be achieved by altering the human behavior leading to their
widespread introduction. There are a variety of reasons why this behavior has
not been successfully curtailed heretofore, and we propose a series of measures
that should reduce the rate of snake introduction into Hawai'i. Failure to
achieve this reduction will make successful establishment of ecologically dangerous
snakes in Hawai'i a virtual certainty
Neotropical Frogs in Hawaii: Status and Management Options for an Unusual Introduced Pest
Two species of Neotropical frog, Eleutherodactylus coqui and E. planiroshir, have been introduced into the state of Hawaii via the horticulture trade. Since 1997 frog colonies within the state have rapidly spread from accidental and intentional causes, and frog abundance within colonies has grown rapidly. Colonies of these frogs are currently known from 262+ locations on the island of Hawaii, 45+ on Maui, 35+ on Oahu, and 2+ on Kauai Although these frogs were originally restricted to horticulture sites, they are now found in residential areas, resorts and hotels, and public lands. Within their native range, they may reach densities of 20,000 frog/ha Given the current population irruptions of these frogs in Hawaii, similar densities are being reached and exceeded. Due to the high potential biomass of introduced frogs there are realistic anthropogenic (economic and quality of life) and ecological concerns associated with their spread. Since 1998, research has been conducted with the goal of developing control techniques for these frogs. A primary result of this research effort was the determination that a spray application of a 2.0% concentration caffeine and water solution can effectively eliminate local frog populations. The aforementioned research result was used to support a United States Environmental Protection Agency Sec. 18 (Emergency) Registration for the use of a 2% caffeine solution for Eleutherodactylus frog control in the State of Hawaii by the Hawaii Department of Agriculture. Although this tool is available for localized control of frogs, efforts by federal, state, and county agencies to control this pest in Hawaii has been hampered by a lack of funding, unclear legal jurisdiction, and bureaucratic inertia
Gastrointestinal helminths of Choerophryne proboscidea and Xenorhina parkerorum (Anura: Microhylidae) from Papua New Guinea
Understanding the psychological impact of the COVID-19 pandemic and containment measures: an empirical model of stress
Epidemics such as COVID-19 and corresponding containment measures are assumed to cause psychological stress. In a survey during the lockdown in Switzerland (n = 1565), we found substantially increased levels of stress in the population. In particular, individuals who did not agree with the containment measures, as well as those who saw nothing positive in the crisis, experienced high levels of stress. In contrast, individuals who are part of a risk group or who are working in healthcare or in essential shops experienced similar stress lev-els as the general public. The psychological mechanisms that determine stress, caused by the COVID-19 pandemic and containment measures, are not yet clear. Thus, we conducted a path analysis to gain a deeper understanding of the psychological mechanisms that lead to stress. Experiencing fear of the disease is a key driver for being worried. Our model fur-ther shows that worries about the individual, social, and economic consequences of the cri-sis, strongly boost stress. The infection rate in the canton (i.e., state) of residence also contributes to stress. Positive thinking and perceived social, organizational, and govern-mental support mitigate worries and stress. Our findings indicate that containment mea-sures increase worries and stress, especially for those who feel that these measures either are not sufficient or go too far. Thus, highlighting positive aspects of the crisis and convinc-ing people of the effectiveness and necessity of mitigation measures can, not only promote compliance, but also reduce stress. Our model suggests that people who feel protected by the authorities have fewer worries, which can, in turn, limit the negative impact of the crisis on mental health
Hidden diversity in semi-fossorial Melanesian forest snakes: A revision of the Toxicocalamus loriae complex (Squamata, Elapidae) from New Guinea
© 2022 The Authors. Published by Senckenberg Gesellschaft fĂŒr Naturforschung. This is an open access article available under a Creative Commons licence. The published version can be accessed at the following link on the publisherâs website: https://vertebrate-zoology.arphahub.com/article/89647/With its conservative set of scalation characters, Toxicocalamus loriae is a morphologically confusing species to which a wide array of phenotypes has been assigned. Careful analysis of 224 museum specimens reveals that multiple distinct species remain hidden under the name T. loriae and that diagnostic, species-level differences are more nuanced in this group of snakes than among other members of the genus. Our taxonomic reassessment leads us to resurrect the species T. lamingtoni comb. nov., T. loennbergii comb. nov., and T. nymani comb. nov. from synonymy with T. loriae, retain only T. pratti as a synonym, and describe three new species. As a consequence, T. loriae is no longer recognized as ranging throughout the entire island of New Guinea but is instead restricted to the southern versant of the Papuan Peninsula, and T. lamingtoni and T. spilorhynchus sp. nov. are species restricted to that same peninsulaâs northern versant. Toxicocalamus loennbergii is known only from the type series taken on the Onin Peninsula in West Papua, Indonesia, Toxicocalamus atratus sp. nov. is a high-elevation (800â2200 m) Central Highlands endemic, and T. vertebralis sp. nov. ranges from the Central Highlands of Papua New Guinea eastward into the Wau area of Morobe Province. Toxicocalamus nymani inhabits a geologically more heterogenous region, occurring from the Central Highlands eastward to the Huon Peninsula, including Karkar Island, and adjacent areas of Madang Province as well as the northernmost reaches of the Papuan Peninsula. We expect that denser geographic sampling across New Guinea and focussed specimen collection of a few known populations will result in the recognition of additional species in this complex
Congener diversity, topographic heterogeneity and humanâassisted dispersal predict spread rates of alien herpetofauna at a global scale
Understanding the factors that determine rates of range expansion is not only crucial for developing risk assessment schemes and management strategies for invasive species, but also provides important insight into the ability of species to disperse in response to climate change. However, there is little knowledge on why some invasions spread faster than others at large spatiotemporal scales. Here, we examine the effects of human activities, species traits and characteristics of the invaded range on spread rates using a global sample of alien reptile and amphibian introductions. We show that spread rates vary remarkably among invaded locations within a species, and differ across biogeographical realms. Spread rates are positively related to the richness of native congeneric species and humanâassisted dispersal in the invaded range but are negatively correlated with topographic heterogeneity. Our findings highlight the importance of environmental characteristics and humanâassisted dispersal in developing robust frameworks for predicting species' range shifts.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/107378/1/ele12286.pd
Capillary Density of Skeletal Muscle: A Contributing Mechanism for Exercise Intolerance in Class IIâIII Chronic Heart Failure Independent of Other Peripheral Alterations
AbstractOBJECTIVESThe study was conducted to determine if the capillary density of skeletal muscle is a potential contributor to exercise intolerance in class IIâIII chronic heart failure (CHF).BACKGROUNDPrevious studies suggest that abnormalities in skeletal muscle histology, contractile protein content and enzymology contribute to exercise intolerance in CHF.METHODSThe present study examined skeletal muscle biopsies from 22 male patients with CHF compared with 10 age-matched normal male control patients. Aerobic capacities, myosin heavy chain (MHC) isoforms, enzymes, and capillary density were measured.RESULTSThe patients with CHF demonstrated a reduced peak oxygen consumption when compared to controls (15.0 ± 2.5 vs. 19.8 ± 5.0 ml·kgâ1·minâ1, p <0.05). Using cell-specific antibodies to directly assess vascular density, there was a reduction in capillary density in CHF measured as the number of endothelial cells/fiber (1.42 ± 0.28 vs. 1.74 ± 0.35, p = 0.02). In CHF, capillary density was inversely related to maximal oxygen consumption (r = 0.479, p = 0.02). The MHC IIx isoform was found to be higher in patients with CHF versus normal subjects (28.5 ± 13.6 vs. 19.5 ± 9.4, p <0.05).CONCLUSIONSThere was a significant reduction in microvascular density in patients with CHF compared with the control group, without major differences in other usual histologic and biochemical aerobic markers. The inverse relationship with peak oxygen consumption seen in the CHF group suggests that a reduction in microvascular density of skeletal muscle may precede other skeletal muscle alterations and play a critical role in the exercise intolerance characteristic of patients with CHF
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