The reproductive biology and ecology of Gammarus duebeni (Crustacea: Amphipoda) in southern England

1983 ◽  
Vol 63 (3) ◽  
pp. 517-540 ◽  
Author(s):  
Martin Sheader
Keyword(s):  
Life Cycle ◽  
Egg Production ◽  
Breeding Strategy ◽  
Female Size ◽  
Temperature Dependent ◽  
Southern Limit ◽  
Factors Affecting ◽  
North East ◽  
The North ◽  
Test Estuary

A study was made of the life cycle and reproductive ecology of Gammarus duebeni in the Test Estuary on the south coast of England. The species is towards the southern limit of its distributional range in the north-east Atlantic, which results in breeding continuing throughout much of the year. The breeding strategy employed was found to vary with season. The size of eggs produced and the rate of egg production were both temperature dependent, whereas the proportion of production expended on eggs and the number of eggs per brood, although probably influenced by temperature appeared to be controlled by food availability and female size. Factors affecting the mortality of eggs within the marsupium and breeding synchrony were considered in relation to season. The life cycle consisted of two major overlapping generations.

Socio-cultural factors and transnational entrepreneurship

2011 ◽  
Vol 29 (2) ◽  
pp. 119-134 ◽  
Author(s):  
David Urbano ◽  
Nuria Toledano ◽  
Domingo Ribeiro-Soriano
Keyword(s):  
Latin American ◽  
Role Models ◽  
Cultural Factors ◽  
Eastern European ◽  
Factors Affecting ◽  
North East ◽  
The North ◽  
Entrepreneurial Attitudes ◽  
Transnational Entrepreneurship ◽  
Entrepreneurial Activities

This article addresses theoretical and empirical issues concerning the emergent field of transnational entrepreneurship. We discuss issues regarding the antecedents of transnational entrepreneurship focusing specifically on the socio-cultural factors affecting this phenomenon in the Spanish context. Entrepreneurship, ethnic and transnational entrepreneurship literature is combined with institutional approach to explain what and how different socio-cultural factors influence the emergence and development of transnational entrepreneurship in Catalonia (in the north-east of Spain). We do this by looking at four case studies of transnational entrepreneurs with different ethnicity (Ecuadorian, Latin American; Moroccan, North African; Chinese, Asian; and Romanian, Eastern European). Important differences between socio-cultural factors that affect the emergence of transnational entrepreneurship (role models, immigrants’ entrepreneurial attitudes) and those that facilitate the development of transnational entrepreneurial activities (transnational networks and immigrants’ perceptions of the culture and opportunities of the host society) are found.

scholarly journals A case based, combined LCA and S-ROI methodology for sustainable mining in the Suceava County, Romania

2021 ◽  
Vol 15 (2) ◽  
pp. 209-2020
Author(s):  
Ruxandra Ionce ◽  
Iuliana Gabriela Breaban
Keyword(s):  
Life Cycle Assessment ◽  
Life Cycle ◽  
Value Chain ◽  
Return On Investment ◽  
Environmental Benefits ◽  
Great Opportunity ◽  
Mining Sites ◽  
North East ◽  
The North ◽  
Impact Reduction

LCA (Life Cycle Assessment) is a useful tool in decision-making for most businesses that opt for sustainability and offers the possibility to compare different products, processes, and value chain scenarios, both real and hypothetical. Coupled with S-ROI (Sustainable Return on Investment), the LCA has a great potential in using available data for existing mining sites in the North-East Region of Romania to assess the economic, social and environmental benefits of certain sustainability measures on a local and regional level. The article will explore this approach of combining the two methodologies: LCA (Life Cycle Assessment) and S-ROI (Sustainable Return on Investment), with necessary adjustments according to the characteristics of the local mining activities, to show key investment areas that can improve the value chain of copper exploitation and preparation in the mining perimeter Mănăila. The case of the copper mine in Mănăila offers a great opportunity to apply the current LICYMIN (Life Cycle of Mining) research and to use available Ecoinvent data for the copper ore by comparing the current value chain scenario with a proposed scenario that includes a different location for a mining ore preparation unit, closer to the quarry. The results will give an insight into the potential social and economic impact (the measure can translate into a higher local employment rate, better social stability, lower transportation costs, etc.) as well as the environmental impact (reduction of GHG emission, pollution, and energy efficiency) of the suggested changes.

scholarly journals Distribution of marine, benthic, shell bearing gastropods along the Norwegian coast

2009 ◽  
Vol 28 ◽  
Author(s):  
Tore Høisæter
Keyword(s):  
Continental Slope ◽  
Main Part ◽  
Geographic Area ◽  
Species Level ◽  
Western Slope ◽  
Southern Limit ◽  
North East ◽  
The North ◽  
The North Sea ◽  
The One

Based on literature data and my extensive material from along the coast, the distribution of shell bearing marine, benthic gastropods known from Norwegian waters, is outlined. The geographic area covered goes down to c. 1200 m on the continental slope, and extends from the Swedish border<br />in the south to the Russian border in the north-east. On the slope the distribution is restricted to an area east of 0°, and south of 72° N. Neither the North Sea nor the western ‘slope’ of the Norwegian Trench are included. Systematics and nomenclature follow Clemam (Check List of European Marine Mollusca) closely. The emphasis is on the distribution of each species within the designated area, but taxonomic and nomenclaturial problems are discussed wherever considered relevant. Altogether 365 species level taxa are included, of which 326 are considered as definitely belonging to the Norwegian fauna. The rest are recorded as doubtful, either because only empty shells have been found, or their confirmed distribution falls outside the limits here defined. Of the ‘species’ included, I consider at least 18 to be undescribed, while another 16 were described from Norwegian material after Høisæter (1986) was published. The northern distributional limit is extended for 47 species, while 11 species have received a new southern limit. Sixty six species have a generic name diferent from the one used in Høisæter (1986), while 35 species have another specific name. All changes are listed in the main part of the article, and references are given to the sources for the changes. Four faunal components are recognized: a slope component, species mainly found in negative temperatures on the continental slope, between 500 and 1200 m; an Arctic component, species in Norway almost exclusively found in East Finnmark; a group of species in Norway found only or mainly on the Skagerrak coast or in Oslofjorden; and finally the main group found along most of the coast.

Variation in fecundity in the lesser sandeel: implications for regional management

2010 ◽  
Vol 91 (6) ◽  
pp. 1273-1280 ◽  
Author(s):  
Philip Boulcott ◽  
Peter J. Wright
Keyword(s):  
North Sea ◽  
Egg Production ◽  
Oocyte Diameter ◽  
Isolated Populations ◽  
Potential Fecundity ◽  
North East ◽  
The North ◽  
Regional Management ◽  
Parental Stock ◽  
The North Sea

The number of eggs produced by a parental stock is central to fisheries advice on recruitment potential. However, stock based estimates of egg production may give a misleading index of recruitment potential in stocks containing several reproductively isolated populations. This paper examines the ability of length, condition and oocyte developmental stage to predict levels of potential fecundity in the sandeel, Ammodytes marinus, in three important fished areas in the North Sea. Our results indicate that regional variation in this relationship exists, with fecundity in central areas of the North Sea being higher than those found just off the north-east UK. Oocyte diameter was also found to have a significant effect on potential fecundity, suggesting a down-regulation of oocyte numbers arising from pre-ovulatory atresia, however, this effect was not apparent in every model tested. Our findings have relevance to the local sustainability of spawning components and thus the regional management of the North Sea sandeel stock.

Factors affecting hospital admission and length of stay of poisoned patients in the North East of England

1996 ◽  
Vol 15 (11) ◽  
pp. 915-919 ◽  
Author(s):  
Shl Thomas ◽  
S. Lewis ◽  
L. Bevan ◽  
S. Bhattacharyya ◽  
MG Bramble ◽  
...  
Keyword(s):  
Length Of Stay ◽  
Hospital Admission ◽  
Hospital Stay ◽  
Patient Characteristics ◽  
Case Mix ◽  
Prolonged Stay ◽  
Factors Affecting ◽  
North East ◽  
The North ◽  
The Impact

1 Poisoning is a common reason for presentation to hospital and hospital admission but there is no agreed policy for managing these patients. This study exam ined the management of patients presenting with poisoning and the factors affecting the probability of hospital admission and prolonged stay. 2 Data on all cases of poisoning presenting to six Accident and Emergency departments in the North East of England over 12 weeks in 1994 was collected prospectively from A&E notes. Length of stay and outcome were recorded from hospital computer records. 3 Overall, 73% of patients were admitted to a medical ward. Probability of admission was not independently affected by age or gender but was increased in those with intentional poisoning (Odds Ratio (OR) 3.3 [95% CI 1.8, 6.1]), a history of self harm (OR 1.7, [1.0, 2.9]) or potentially hazardous poisoning (OR 3.7 [2.1, 6.6]). There were significant variations between hospitals (50 - 80%) which could not be attributed to case mix. 4 Prolonged stay ( > 2 nights) was more common in patients over 65 years (OR 6.8 [2.9, 16.1]), those with intentional poisoning (OR 2.7 [1.1, 6.6]) and those with potentially hazardous poisoning (OR 2.6 [1.4, 4.9]). Mean hospital stay was 1.5 days and varied signifi cantly between hospitals from 0.8 to 2.1 days and this was independent of case mix. 5 There are appreciable variations in the management of poisoning between hospitals which are not explained by patient characteristics. Savings would occur if rates of admission and duration of stay were reduced by those hospitals where admission is more frequent or hospital stay is longer. However, the impact of this on long term morbidity is unknown.

Tectono-stratigraphic history of northern Amdrup Land, eastern North Greenland: implications for the northernmost East Greenland shelf

2000 ◽  
pp. 167-191
Author(s):  
Lars Stemmerik ◽  
Birgitte D. Larsen ◽  
Finn Dalhoff
Keyword(s):  
Plate Boundary ◽  
Southern Limit ◽  
East Greenland ◽  
North East ◽  
The North ◽  
Upper Proterozoic ◽  
Structural Style ◽  
History Of ◽  
Land Changes ◽  
North Greenland

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Stemmerik, L., Larsen, B. D., & Dalhoff, F. (2000). Tectono-stratigraphic history of northern Amdrup Land, eastern North Greenland: implications for the northernmost East Greenland shelf. Geology of Greenland Survey Bulletin, 187, 167-191. https://doi.org/10.34194/ggub.v187.5192 _______________ The NW–SE-oriented Sommerterrasserne fault in Amdrup Land marks the southern limit of Mesozoic compression related to the transform plate boundary between North Greenland and Svalbard. Structural style in Amdrup Land changes across the fault; Carboniferous, Permian and Jurassic sediments in northern Amdrup Land north-east of the fault are gently folded, with NE– SW-trending fold axes, whereas they are gently dipping south of the fault. The Sommerterrasserne fault is regarded as the south-eastern extension of the Trolle Land fault zone of eastern Peary Land. Upper Moscovian carbonates of the Foldedal Formation rest unconformably on isoclinally folded Upper Proterozoic sediments of the Independence Fjord Group in northern Amdrup Land and are conformably overlain by chert-rich limestones of the Permian Kim Fjelde and Midnatfjeld Formations. Locally, up to 70 m of Jurassic sandstone and siltstone are preserved in the axes of the synclines, resting conformably on Permian limestones; the folding thus post-dates their deposition. The folding of the sediments to the north-east of the Sommerterrasserne fault most likely took place during the latest Cretaceous; it is post-dated by a post- Paleocene extensional event.

THE LIFE-HISTORY AND HABITS OF THE LARCH BARK BEETLE, IPS CEMBRAE (COLEOPTERA: SCOLYTIDAE), IN THE NORTH-EAST OF SCOTLAND

1970 ◽  
Vol 102 (2) ◽  
pp. 226-239 ◽  
Author(s):  
R. A. Balogun
Keyword(s):  
Life History ◽  
Life Cycle ◽  
Bark Beetle ◽  
Egg Laying ◽  
Larval Instars ◽  
North East ◽  
The North ◽  
Host Trees ◽  
Ips Cembrae

AbstractAn investigation of the life-history and habits of Ips cembrae (Heer) has been made at the Ord wood, Cawdor Estate in Nairnshire. The species is polygamous and has a 1-year life cycle with two broods a year. The first broods result from eggs laid in May and June, producing teneral adults in August and September, and the second arise from egg-laying in late September and early October; these second broods generally overwinter under bark in the larval and pupal stages, and the adults emerge the following spring. There are three larval instars before pupation. Maturation feeding of the young beetles and regeneration feeding of the old ones take place either under the bark where broods have developed, or by attacking fresh host trees.

scholarly journals A comparative analysis of canyon and non-canyon populations of the deep-sea scavenging amphipod Paralicella caperesca

2015 ◽  
Vol 96 (8) ◽  
pp. 1687-1699 ◽  
Author(s):  
Grant A. Duffy ◽  
Zoe R.S. Gutteridge ◽  
Michael H. Thurston ◽  
Tammy Horton
Keyword(s):  
Deep Sea ◽  
Feeding Strategy ◽  
Submarine Canyon ◽  
Female Size ◽  
Amphipod Species ◽  
North East ◽  
The North ◽  
Continental Slopes ◽  
Sexual Characteristics ◽  
Total Body

Existing population studies of deep-sea amphipods have focused on species that inhabit deep-sea vent or trench environments but few cosmopolitan species have been studied. Here we provide new insight into the life history and population ecology of the pan-oceanic scavenging amphipod Paralicella caperesca and discuss the influence of nutrient-rich submarine canyon environments on the growth and reproduction of this species. Data were collected through the dissection and measurement of 2997 P. caperesca from 14 samples taken from abyssal plains, continental slopes and submarine canyons in the North-East Atlantic. Sexual dimorphism was less pronounced than observed for other scavenging amphipod species but females were significantly larger and had shorter antennae than males. The size of oostegites in female P. caperesca varied considerably within size classes, ovaries contained a relatively large number of oocytes, and no empty ovaries were observed. These factors, in combination with absence of mature females, suggest that P. caperesca practices semelparity, a reproductive strategy that complements the feeding strategy of this obligate necrophage. Five male and seven female size-grouped cohorts were identified for P. caperesca. Cohorts from deep-sea submarine canyon populations showed consistently larger mean total body lengths than non-canyon cohorts. Individuals from canyon samples also expressed sexual characteristics at smaller sizes than non-canyon individuals. We hypothesize that these trends are indicative of nutrient-mediated growth, maturation, and reproduction in P. caperesca. The species is able to grow and reproduce relatively quickly in response to increased nutrient input in canyon environments and therefore dominates scavenging amphipod assemblages.

scholarly journals Habitat Suitability modeling of Urial (Ovis orientalis arkal) in the Samelghan plain by using Maximum Entropy Method

2021 ◽  
Author(s):  
Abbas Naqibzadeh ◽  
Jalil Sarhangzadeh ◽  
Ahad Sotoudeh ◽  
Marjan Mashkour ◽  
Judith Thomalsky
Keyword(s):  
Maximum Entropy ◽  
Habitat Suitability ◽  
Model Performance ◽  
Threshold Value ◽  
Entropy Method ◽  
Suitable Habitat ◽  
Factors Affecting ◽  
Habitat Suitability Modeling ◽  
North East ◽  
The North

Habitat suitability models are useful tools for a variety of wildlife management objectives. Distributions of wildlife species can be predicted for geographical areas that have not been extensively surveyed. The basis of these models' work is to minimize the relationship between species distribution and biotic and abiotic environments. For some species, there is information about presence and absence that allows the use of a variety of standard statistical methods, however, the absence data is not available for most species. Nowadays, the methods that need presence-only data are expanded. One of these methods is the Maximum Entropy (MaxEnt) modeling. The purpose of this study is to model the habitat of Urial ( Ovis orientalis arkal ) in the Samelghan plain in the North East of Iran with the MaxEnt method. This algorithm uses the Jackknife plot and percent contribution values to determine the significance of the variables. The results showed that variables such as southern aspects, Juniperus-Acer, Artemisia-Perennial plants, slope 0-5%, and asphalt road were the most important factors affecting the species’ habitat selection. The area under curve (AUC) Receiver Operating Characteristic (ROC) showed an excellent model performance. Suitable habitat was classified based on the threshold value (0.0513) and the ROC, which based on the results 28% of the area was a suitable habitat for Urial.

scholarly journals Biogeography of key mesozooplankton species in the North Atlantic, by manual counting methods, and egg production of <i>Calanus finmarchicus</i>

2014 ◽  
Vol 7 (1) ◽  
pp. 225-242
Author(s):  
W. Melle ◽  
J. A. Runge ◽  
E. Head ◽  
S. Plourde ◽  
C. Castellani ◽  
...  
Keyword(s):  
North Atlantic ◽  
Egg Production ◽  
Colour Index ◽  
Calanus Finmarchicus ◽  
Female Size ◽  
The North ◽  
Manual Counting ◽  
Basin Scale ◽  
The North Atlantic ◽  
Scale Data

Abstract. Here we present a new, pan-Atlantic compilation of data on key mesozooplankton species, including the possibly most important copepod, Calanus finmarchicus. Distributional data of ten representative zooplankton taxa, from recent (2000–2009) Continuous Plankton Recorder data, are presented, along with basin-scale data of the phytoplankton colour index. Then we present a compilation of data on C. finmarchicus including observations of abundance, demography, egg production and female size with accompanying data on temperature and chlorophyll. This is a contribution by Canadian, European and US scientists and their institutions. http://doi.pangaea.de/10.1594/PANGAEA.820732, http://doi.pangaea.de/10.1594/PANGAEA.824423, http://doi.pangaea.de/10.1594/PANGAEA.828393.

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