A conservation strategy for dugongs: implications of Australian research

1999 ◽  
Author(s):  
Helene Marsh ◽  
Carole Eros ◽  
Peter Corkeron ◽  
Barbara Breen
Keyword(s):  
Life History ◽  
Anthropogenic Impacts ◽  
Significant Proportion ◽  
Global Scale ◽  
Reproductive Rate ◽  
Conservation Strategy ◽  
Slight Reduction ◽  
Large Numbers ◽  
High Investment ◽  
Optimum Management

The dugong (Dugong dugon) is listed as vulnerable to extinction at a global scale. It has a large range that spans some forty countries and includes tropical and subtropical coastal and island waters from east Africa to Vanuatu. A significant proportion of the world’s dugongs is found in northern Australian waters where most modern dugong research has been conducted. Dugongs are long-lived animals with a low reproductive rate, long generation time, and a high investment in each offspring. Population simulations indicate that even with the most optimistic combinations of life-history parameters (e.g. low natural mortality and no human-induced mortality) a dugong population is unlikely to increase by more than 5% per year. Dugongs are vulnerable to anthropogenic impacts because of their life history and their dependence on seagrasses that are restricted to coastal habitats. Even a slight reduction in adult survivorship as a result of habitat loss, disease, hunting or incidental drowning in nets can cause a chronic decline in a dugong population. The optimum management strategy is to identify areas that consistently support large numbers of dugongs and to set these aside as dugong sanctuaries in which dugong mortality is minimized and their habitat protected.

Incomplete Intrapulmonary Lymph Node Retrieval After Routine Pathologic Examination of Resected Lung Cancer

2012 ◽  
Vol 30 (23) ◽  
pp. 2823-2828 ◽  
Author(s):  
Robert A. Ramirez ◽  
Christopher G. Wang ◽  
Laura E. Miller ◽  
Courtney A. Adair ◽  
Allen Berry ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Significant Proportion ◽  
External Control ◽  
Pathologic Examination ◽  
Resected Nsclc ◽  
Lymph Node Retrieval ◽  
Large Numbers ◽  
Pathologic Staging ◽  
Clinically Significant ◽  
Time Required

Purpose Pathologic nodal stage affects prognosis in patients with surgically resected non–small-cell lung cancer (NSCLC). Unlike examination of mediastinal lymph nodes (LNs), which depends on surgical practice, accurate examination of intrapulmonary (N1) nodes depends primarily on pathology practice. We investigated the completeness of N1 LN examination in NSCLC resection specimens and its potential impact on stage. Patients and Methods We performed a case-control study of a special pathologic examination (SPE) protocol using thin gross dissection with retrieval and microscopic examination of all LN-like material on remnant NSCLC resection specimens after routine pathologic examination (RPE). We compared LNs retrieved by the SPE protocol with nodes examined after RPE of the same lung specimens and with those of an external control cohort. Results We retrieved additional LNs in 66 (90%) of 73 patient cases and discovered metastasis in 56 (11%) of 514 retrieved LNs from 27% of all patients. We found unexpected LN metastasis in six (12%) of 50 node-negative patients. Three other patients had undetected satellite metastatic nodules. Pathologic stage was upgraded in eight (11%) of 73 patients. The time required for the SPE protocol decreased significantly with experience, with no change in the number of LNs found. Conclusion Standard pathology practice frequently leaves large numbers of N1 LNs unexamined, a clinically significant proportion of which harbor metastasis. By improving N1 LN examination, SPE can have an impact on prognosis and adjuvant management. We suggest adoption of the SPE to improve pathologic staging of resected NSCLC.

scholarly journals Conserved noncoding elements influence the transposable element landscape in Drosophila

2018 ◽  
Author(s):  
Manee M. Manee ◽  
John Jackson ◽  
Casey M. Bergman
Keyword(s):  
Transposable Element ◽  
Significant Proportion ◽  
Purifying Selection ◽  
Noncoding Dna ◽  
Frequency Spectra ◽  
Noncoding Regions ◽  
Selective Constraints ◽  
Large Numbers ◽  
Random Expectation ◽  
Conserved Noncoding Elements

AbstractHighly conserved noncoding elements (CNEs) comprise a significant proportion of the genomes of multicellular eukaryotes. The function of most CNEs remains elusive, but growing evidence indicates they are under some form of purifying selection. Noncoding regions in many species also harbor large numbers of transposable element (TE) insertions, which are typically lineage specific and depleted in exons because of their deleterious effects on gene function or expression. However, it is currently unknown whether the landscape of TE insertions in noncoding regions is random or influenced by purifying selection on CNEs. Here we combine comparative and population genomic data in Drosophila melanogaster to show that abundance of TE insertions in intronic and intergenic CNEs is reduced relative to random expectation, supporting the idea that selective constraints on CNEs eliminate a proportion of TE insertions in noncoding regions. However, we find no difference in the allele frequency spectra for polymorphic TE insertions in CNEs versus those in unconstrained spacer regions, suggesting that the distribution of fitness effects acting on observable TE insertions is similar across different functional compartments in noncoding DNA. Our results provide evidence that selective constraints on CNEs contribute to shaping the landscape of TE insertion in eukaryotic genomes, and provide further evidence supporting the conclusion that CNEs are indeed functionally constrained and not simply mutational cold spots.

scholarly journals Life history and habitat do not mediate temporal changes in body size due to climate warming in rodents

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9792
Author(s):  
Aluwani Nengovhela ◽  
Christiane Denys ◽  
Peter J. Taylor
Keyword(s):  
Life History ◽  
Body Size ◽  
Climate Warming ◽  
Life History Traits ◽  
Vegetation Type ◽  
Reproductive Rate ◽  
Temporal Changes ◽  
Temporal Response ◽  
Extrinsic Factors ◽  
African Species

Temporal changes in body size have been documented in a number of vertebrate species, with different contested drivers being suggested to explain these changes. Among these are climate warming, resource availability, competition, predation risk, human population density, island effects and others. Both life history traits (intrinsic factors such as lifespan and reproductive rate) and habitat (extrinsic factors such as vegetation type, latitude and elevation) are expected to mediate the existence of a significant temporal response of body size to climate warming but neither have been widely investigated. Using examples of rodents, we predicted that both life history traits and habitat might explain the probability of temporal response using two tests of this hypothesis. Firstly, taking advantage of new data from museum collections spanning the last 106 years, we investigated geographical and temporal variation in cranial size (a proxy for body size) in six African rodent species of two murid subfamilies (Murinae and Gerbillinae) of varying life history, degree of commensality, range size, and habitat. Two species, the commensal Mastomys natalensis, and the non-commensal Otomys unisulcatus showed significant temporal changes in body size, with the former increasing and the latter decreasing, in relation with climate warming. Commensalism could explain the increase in size with time due to steadily increasing food availability through increased agricultural production. Apart from this, we found no general life history or habitat predictors of a temporal response in African rodents. Secondly, in order to further test this hypothesis, we incorporated our data into a meta-analysis based on published literature on temporal responses in rodents, resulting in a combined dataset for 50 species from seven families worldwide; among these, 29 species showed no significant change, eight showed a significant increase in size, and 13 showed a decline in size. Using a binomial logistic regression model for these metadata, we found that none of our chosen life history or habitat predictors could significantly explain the probability of a temporal response to climate warming, reinforcing our conclusion based on the more detailed data from the six African species.

scholarly journals The biology of Limacina retroversa

1954 ◽  
Vol 33 (2) ◽  
pp. 297-312 ◽  
Author(s):  
J. E. Morton
Keyword(s):  
Life History ◽  
Breeding Season ◽  
Detailed Account ◽  
Larval Stages ◽  
Large Numbers ◽  
History Of ◽  
Clione Limacina

The Plymouth Fauna List contains records of two genera of pteropods, Limacina and Clione. Of the first, Limacina retroversa (Flem.) is by far the better-known species, apparently occurring regularly at Plymouth in large numbers in townettings from outside, and sometimes inside, the Sound. It breeds at Plymouth from June to August, and Lebour (1932) has given a detailed account of its breeding and larval stages and has discussed its role in the plankton. The second species of Limacina at Plymouth is lesueuri (d'Orbigny), which has been observed from time to time since 1906, when it was very common. The last record in the Fauna is off the Breakwater in 1920. Of the gymnosomatous pteropods, Clione limacina Phipps is the only species regularly occurring. Lebour (1931) has described the life history of this form, and mentions February to August as its months of greatest abundance. Its breeding season is June to August. Another gymnosome, tentatively referred to as Clionina longicauda, is reported by Russell (1936), and from the specimen department at Plymouth Laboratory the writer obtained some preserved specimens, not easily identifiable, of a Pneumodermopsis taken locally; its species is perhaps ciliata, recorded by Massy (1917) from the Irish Coast.

scholarly journals Density Dependence, Evolutionary Optimization, and the Diversification of Avian Life Histories

The Condor ◽  
2000 ◽  
Vol 102 (1) ◽  
pp. 9-22 ◽  
Author(s):  
Robert E. Ricklefs
Keyword(s):  
Life History ◽  
Life Table ◽  
Life Histories ◽  
Life History Traits ◽  
Evolutionary Ecology ◽  
Reproductive Rate ◽  
Empirical Modeling ◽  
Adult Survival ◽  
Life History Variation ◽  
Evolutionary Response

Abstract Although we have learned much about avian life histories during the 50 years since the seminal publications of David Lack, Alexander Skutch, and Reginald Moreau, we still do not have adequate explanations for some of the basic patterns of variation in life-history traits among birds. In part, this reflects two consequences of the predominance of evolutionary ecology thinking during the past three decades. First, by blurring the distinction between life-history traits and life-table variables, we have tended to divorce life histories from their environmental context, which forms the link between the life history and the life table. Second, by emphasizing constrained evolutionary responses to selective factors, we have set aside alternative explanations for observed correlations among life-history traits and life-table variables. Density-dependent feedback and independent evolutionary response to correlated aspects of the environment also may link traits through different mechanisms. Additionally, in some cases we have failed to evaluate quantitatively ideas that are compelling qualitatively, ignored or explained away relevant empirical data, and neglected logical implications of certain compelling ideas. Comparative analysis of avian life histories shows that species are distributed along a dominant slow-fast axis. Furthermore, among birds, annual reproductive rate and adult mortality are directly proportional to each other, requiring that pre-reproductive survival is approximately constant. This further implies that age at maturity increases dramatically with increasing adult survival rate. The significance of these correlations is obscure, particularly because survival and reproductive rates at each age include the effects of many life-history traits. For example, reproductive rate is determined by clutch size, nesting success, season length, and nest-cycle length, each of which represents the outcome of many different interactions of an individual's life-history traits with its environment. Resolution of the most basic issues raised by patterns of life histories clearly will require innovative empirical, modeling, and experimental approaches. However, the most fundamental change required at this time is a broadening of the evolutionary ecology paradigm to include a variety of alternative mechanisms for generating patterns of life-history variation.

Recent Developments in Environmental Education in Britain

1990 ◽  
Vol 6 ◽  
pp. 29-44 ◽  
Author(s):  
Monica Hale
Keyword(s):  
Environmental Education ◽  
Formal Education ◽  
National Curriculum ◽  
Global Scale ◽  
Further Education ◽  
Conservation Strategy ◽  
The Past ◽  
Recent Developments ◽  
The Uk ◽  
Programs Of Study

AbstractOver the past decade concern for the environment and, as a consequence, interest in environmental education have undergone a revival in Britain. Interest generated in the late Sixties and early Seventies was followed by a quiescent period during which few significant developments occurred. The publication of the World Conservation Strategy and the UK Response in the early Eighties, coupled with the general realisation that environmental degradation was occurring on a global scale, has caused a substantial increase in environmental interest. Recent developments in the formulation of a National Curriculum in England and Wales have provided a real opportunity to incorporate environmental education into the programs of study for every pupil between the ages of 5 to 16.The following paper concentrates on the formal education system but important developments are currently taking place in the youth sector. As the National Curriculum proceeds and becomes fully implemented it will further affect higher and further education and environmental education in industry.

Studies of the Life History and Ecology of the Ant Oecophylla longinoda Latreille

1954 ◽  
Vol 45 (1) ◽  
pp. 93-112 ◽  
Author(s):  
M. J. Way
Keyword(s):  
Life History ◽  
Apis Mellifera ◽  
East Africa ◽  
Honey Bee ◽  
Insect Species ◽  
Oecophylla Longinoda ◽  
Large Numbers ◽  
Wide Range ◽  
Nesting Habits ◽  
Food Reserves

In British East Africa Oecophylla longinoda (Latr.) var. textor Santschi is locally common in the costal region. Inland it is absent from higher altitudes and from areas where there is a pronounced dry season.In Zanzibar Island, O. longinoda at least 89 species of trees and shurbs; the largest populations occur on the clove (Jambosa caryophyllus), Citrus spp., Bridelia micrantha and Canthium zanzibaricum.The nesting habits and colony composition of O. longinoda are such that one colony may spread over a number of adjacent trees; it contains only one gravid queen.Winged virgin sexual forms are released at the beginning of the wet seasons and new colonies are initiated by a single queen, who uses her food reserves to bring the first batch of brood to maturity.In Zanzibzr, O. longinoda tends a wide range of Homoptera that produce honey-dew, but apparently “ prefers ” certain Coccids, notably Saissetia spp.The degree of attention afforded by an ant species determines the species of Homoptera which it is able to attend.The insect species preyed upon by O. longinoda include the honey bee, Apis mellifera, and the driver ant, Dorylus nigricans, of which large numbers may be destroyed.O. longinoda is of undoubted value for controlling certain coconut pests, notably Theraptus sp. (Coreidae), and its efficiency in coconut plantations could probably be much enhanced.

scholarly journals Risks of collective investment undertakings in the context of global capital markets

2020 ◽  
Vol 74 ◽  
pp. 01025
Author(s):  
Daniela Pfeiferová ◽  
Ivana Kuchařová
Keyword(s):  
Significant Proportion ◽  
Global Scale ◽  
Interest Rate Risk ◽  
Financial Risks ◽  
Counterparty Risk ◽  
Investment Funds ◽  
Specific Investment ◽  
Equity Risk ◽  
Doing Business ◽  
Definition Of

In the context of globalization, international institutional investors have taken over a significant proportion of global investment assets. Among this group also belong to collective investment undertakings whose primary motive is regulated by collecting funds from indeterminate group of natural persons and legal persons for the purpose of doing business on a global scale. As part of their reporting obligations, these entities are required to report on the risks associated with the investment and how to eliminate them. Investment firms must use risk management methods that allow these risks to be identified at any time. The main risks associated with investments in collective investment funds include global financial risks: interest rate risk, currency risk, equity risk, credit risk, counterparty risk, liquidity risk, operational risk and political risk. This article deals with the definition of specific investment risks and the options for their elimination for collective investment entities. The main goal of the article is to recommend the elimination of these risks based on the identified risks associated with collective investment.

Disturbance of the terrestrial ecosystems stability due to global-scale anthropogenic impacts

1988 ◽  
Vol 11 (3) ◽  
pp. 239-246 ◽  
Author(s):  
Yu. A. Izrael ◽  
L. M. Filippova ◽  
G. E. Insarov ◽  
F. N. Semevsky ◽  
S. M. Semenov
Keyword(s):  
Anthropogenic Impacts ◽  
Terrestrial Ecosystems ◽  
Global Scale

A contribution to the morphology and life history of Proteocephalus niloticus (Beddard, 1913) from Varanus niloticus (L.) in Ghana

Parasitology ◽  
1963 ◽  
Vol 53 (1-2) ◽  
pp. 201-215 ◽  
Author(s):  
Gwendolen Rees
Keyword(s):  
Life History ◽  
Life Cycle ◽  
Technical Staff ◽  
Large Numbers ◽  
History Of ◽  
The University ◽  
University Of Ghana ◽  
Zoology Department

1. A plerocercoid of ‘Acanthotaenia’ has been found in large numbers in ‘cysts’ in the pancreas of Rana occipitalis (Günther) in Ghana.2. ‘Cysts’ containing plerocercoids were fed to Varanus niloticus (L.). Adults of Proteocephalus niloticus (Beddard) were recovered from the intestine 3 weeks later.3. It is suggested that the life cycle involves three hosts, the first being a copepod.4. The morphology of the larva and adult is described.I wish to express my sincere gratitude to the authorities of the University of Ghana for inviting me to spend some time in the Zoology Department there. I am most grateful, also, to Professor R. D. Purchon for his kindly interest and for the facilities which he placed at my disposal. It is a pleasure to thank Dr J. D. Thomas and the technical staff for their assistance in the collection of material.

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