Population processes responsible for larger-fish-upstream distribution patterns of Arctic grayling (Thymallus arcticus) in interior Alaskan runoff rivers

1999 ◽  
Vol 56 (12) ◽  
pp. 2292-2299 ◽  
Author(s):  
Nicholas F Hughes
Keyword(s):  
Distribution Pattern ◽  
Distribution Patterns ◽  
Long Distance ◽  
Arctic Grayling ◽  
Sedentary Population ◽  
Thymallus Arcticus ◽  
Population Processes ◽  
Analyse Data ◽  
A Minor ◽  
Size Gradient

During the summer months, Arctic grayling (Thymallus arcticus) in Alaskan streams adopt a larger-older-fish-upstream distribution pattern. In this paper, I analyse data from two large interior Alaskan rivers to determine how population processes maintain this size and age gradient. These analyses support the hypothesis that age-phased recruitment and growth-dependent movement are primarily responsible for this distribution pattern. Age-phased recruitment describes the way that the mean age of fish recruiting to a reach increases upstream, from ages 0-1 in the lower river to ages 3-7 in the headwaters. This process begins with the concentration of spawning fish, and the resultant fry, in the lower reaches of the river. Downstream movement during the first year of life further concentrates young fish in the lower river. Over time, the distribution of this cohort broadens steadily as individuals move further upstream, so that fish recruiting to headwater reaches are 3-7 years old. This process contributes to both size and age gradients. Growth-dependent movement magnifies the size gradient by sorting fast-growing fish into the upper river and slow-growing fish into the lower river. This sorting results from the fact that individuals making long-distance upstream movements tend to have grown particularly rapidly that year, while individuals making long-distance downstream movements tend to have grown especially slowly that year. I rejected the hypothesis that age and size gradients are the result of whole-stream gradients in growth or mortality acting on a sedentary population. However, there was some evidence that fish did grow more slowly in the lowest 40 km of one river, although this made only a minor contribution to the size gradient and growth rates were remarkably constant for the next 120 km. There was no suggestion that spatial variation in mortality rate contributes towards the size or age gradient, but natural and sampling variability could have obscured small but significant differences between reaches.

Selection of Positions by Drift-Feeding Salmonids in Dominance Hierarchies: Model and Test for Arctic Grayling (Thymallus arcticus) in Subarctic Mountain Streams, Interior Alaska

1992 ◽  
Vol 49 (10) ◽  
pp. 1999-2008 ◽  
Author(s):  
Nicholas F. Hughes
Keyword(s):  
Bottom Topography ◽  
Lateral Diffusion ◽  
Distribution Patterns ◽  
Mountain Stream ◽  
Physical Habitat ◽  
Dominance Hierarchies ◽  
Arctic Grayling ◽  
Drift Feeding ◽  
Stream Salmonids ◽  
Thymallus Arcticus

In this work I describe a model to predict position choice by each individual in a dominance hierarchy of drift-feeding stream salmonids. This is an adaptation of Hughes and Dill's model (1990. Can. J. Fish. Aquat. Sci. 47: 2039–2048) of position choice by solitary fish. I have included the effect that prey consumption, lateral diffusion of drifting invertebrates, and entry of invertebrates into the drift have on the density of prey downstream of feeding fish and the restrictions that dominant fish place on freedom of choice by their subordinates. l assume that each fish chooses the most profitable position that its rank in the hierarchy will allow. There was an encouraging match between the distribution patterns predicted by the model and the distribution patterns actually adopted by Arctic grayling (Thymallus arcticus) in two pools of a mountain stream. This result suggests that Arctic grayling locate and rank positions based on their profitability. The predictions of reduced models, and the location of positions in relation to bottom topography and current flow, suggest that the physical habitat forms the template for distribution patterns by determining the location and ranking of the most profitable positions.

Why do Arctic Grayling (Thymallus arcticus) Get Bigger as You Go Upstream?

1994 ◽  
Vol 51 (10) ◽  
pp. 2154-2163 ◽  
Author(s):  
Nicholas F. Hughes ◽  
James B. Reynolds
Keyword(s):  
Distribution Pattern ◽  
Size Structure ◽  
Habitat Preferences ◽  
Removal Experiment ◽  
Fish Removal ◽  
Actual Distribution ◽  
Small Stream ◽  
Arctic Grayling ◽  
Size Dependent ◽  
Size Gradient

During the summer Arctic grayling in interior Alaskan streams get bigger as you go upstream. We performed a fish removal experiment in a small stream to test two hypotheses about the mechanism that produces this size gradient. The first hypothesis was that all sizes of Arctic grayling prefer positions in the headwaters, but that large fish defend these, forcing smaller ones to occupy positions further downstream (the competition for ranked positions hypothesis). The second hypothesis was that small Arctic grayling actually prefer positions in downstream reaches, and that as they grow their habitat preferences change, and they move to positions further upstream (the size-dependent habitat preference hypothesis). Under this hypothesis, exclusion by other individuals plays no part in producing the whole-stream size gradient. Using the distribution pattern of fish immediately before the removal experiment we developed two sets of rules, one for each hypothesis, to predict how a smaller post removal population, with a different size structure, should be distributed. By comparing these predictions with the actual distribution pattern of the population two years after the removal, we found that the competition for ranked positions hypothesis made much more accurate predictions than the alternative.

Analisis Rantai Nilai Komoditas Cabai Merah

2019 ◽  
Vol 2 (1) ◽  
pp. 336-346
Author(s):  
Dhamon Oridilla B
Keyword(s):  
Distribution Pattern ◽  
Distribution Patterns ◽  
Added Value ◽  
Commodity Chain ◽  
Market Prices ◽  
Data Analyst ◽  
Bargaining Position ◽  
Agricultural Business ◽  
The Government ◽  
Red Peppers

Candi Village in Bandungan District is one of the Chili Supply Sub-district for Semarang Regency and surrounding area has agro-climate suitable for the development of various agricultural commodities supported by wide market opportunity, so it is suitable for agricultural business development. The purpose of this research is to identify the distribution pattern of red pepper, to know each value of commodity chains and distribution, to design alternative distribution pattern of red pepper.Population in this research is 88 respondents from 735 of member of chilli farmer in Desa Candi with total area of 150,3 hectare consisting of rice field, moor and yard. Methods of data analyst using quantitative approach is done by using Margin Marketing Analysis. The results include: (1) The pattern of distribution of existing farming business grows naturally in accordance with the developments and needs of the perpetrators, the actors in this pattern are farmers, wholesalers, collectors, wholesalers, retailers, consumers. (2) The value of the red chili commodity chain in this naturally grown pattern often makes pricing more dominant by traders, so farmers receive prices slightly lower than market prices. (3) Some obstacles faced in distributing red peppers are the difficulty of changing the mindset of the community about advanced farming, this is best utilized by market participants (chain of distribution) who are more informed and always keep abreast of market dynamics. Conventional marketing pattern by farmer cause price level accepted by farmer in general relatively smaller compared to price received by trader. Suggestions shorten the chain of distribution patterns, increase the added value of products and improve the bargaining position of farmers and for the government always guide / accompany farmers in getting accurate market information, which can be used as farmers in bargaining, Increased market transparency can act as a trigger for the functioning of a market, improved competition and increased adaptation to meet the needs of supply and opportunity to compete with market prices. Desa Candi di Kabupaten Bandungan adalah salah satu Kecamatan Penyedia Cabai untuk Kabupaten Semarang dan sekitarnya memiliki agroklimat yang cocok untuk pengembangan berbagai komoditas pertanian yang didukung oleh peluang pasar yang luas, sehingga sangat cocok untuk pengembangan bisnis pertanian. Tujuan dari penelitian ini adalah untuk mengidentifikasi pola distribusi cabai merah, untuk mengetahui masing-masing nilai rantai komoditas dan distribusi, untuk merancang alternatif pola distribusi cabai merah. Populasi dalam penelitian ini adalah 88 responden dari 735 anggota petani cabai di Desa Candi dengan total luas 150,3 hektar yang terdiri dari sawah, tegalan dan pekarangan. Metode analis data menggunakan pendekatan kuantitatif dilakukan dengan menggunakan Analisis Pemasaran Margin. Hasil meliputi: (1) Pola distribusi usaha pertanian yang ada tumbuh secara alami sesuai dengan perkembangan dan kebutuhan pelaku, pelaku dalam pola ini adalah petani, pedagang besar, pengumpul, pedagang besar, pedagang besar, pengecer, konsumen. (2) Nilai rantai komoditas cabai merah dalam pola yang dikembangkan secara alami ini sering membuat penetapan harga lebih dominan oleh para pedagang, sehingga petani menerima harga yang sedikit lebih rendah daripada harga pasar. (3) Beberapa kendala yang dihadapi dalam mendistribusikan paprika merah adalah sulitnya mengubah pola pikir masyarakat tentang pertanian maju, hal ini paling baik digunakan oleh pelaku pasar (rantai distribusi) yang lebih banyak informasi dan selalu mengikuti perkembangan dinamika pasar. Pola pemasaran konvensional oleh petani menyebabkan tingkat harga yang diterima petani pada umumnya relatif lebih kecil dibandingkan dengan harga yang diterima pedagang. Saran mempersingkat rantai pola distribusi, meningkatkan nilai tambah produk dan meningkatkan posisi tawar petani dan bagi pemerintah selalu membimbing / menemani petani dalam mendapatkan informasi pasar yang akurat, yang dapat digunakan sebagai petani dalam tawar-menawar, Peningkatan transparansi pasar dapat bertindak sebagai pemicu berfungsinya pasar, meningkatnya kompetisi dan peningkatan adaptasi untuk memenuhi kebutuhan pasokan dan peluang untuk bersaing dengan harga pasar.

scholarly journals Disentangling relationships among eastern Mediterranean Cymbalaria including description of a novel species from the southern Peloponnese (Greece)

2021 ◽  
Vol 307 (2) ◽  
Author(s):  
Pau Carnicero ◽  
Núria Garcia-Jacas ◽  
Llorenç Sáez ◽  
Theophanis Constantinidis ◽  
Mercè Galbany-Casals
Keyword(s):  
Eastern Mediterranean ◽  
Phylogenetic Analyses ◽  
Taxonomic Revision ◽  
Distribution Patterns ◽  
Morphological Characters ◽  
Molecular Data ◽  
Morphological Data ◽  
Long Distance ◽  
Aegean Islands ◽  
Molecular Phylogenetic

AbstractThe eastern Mediterranean basin hosts a remarkably high plant diversity. Historical connections between currently isolated areas across the Aegean region and long-distance dispersal events have been invoked to explain current distribution patterns of species. According to most recent treatments, at least two Cymbalaria species occur in this area, Cymbalaria microcalyx and C. longipes. The former comprises several intraspecific taxa, treated at different ranks by different authors based on morphological data, evidencing the need of a taxonomic revision. Additionally, some populations of C. microcalyx show exclusive morphological characters that do not match any described taxon. Here, we aim to shed light on the systematics of eastern Mediterranean Cymbalaria and to propose a classification informed by various sources of evidence. We performed molecular phylogenetic analyses using ITS, 3’ETS, ndhF and rpl32-trnL sequences and estimated the ploidy level of some taxa performing relative genome size measures. Molecular data combined with morphology support the division of traditionally delimited C. microcalyx into C. acutiloba, C. microcalyx and C. minor, corresponding to well-delimited nrDNA lineages. Furthermore, we propose to combine C. microcalyx subsp. paradoxa at the species level. A group of specimens previously thought to belong to Cymbalaria microcalyx constitute a well-defined phylogenetic and morphological entity and are described here as a new species, Cymbalaria spetae. Cymbalaria longipes is non-monophyletic, but characterized by being glabrous and diploid, unlike other eastern species. The nrDNA data suggest at least two dispersals from the mainland to the Aegean Islands, potentially facilitated by marine regressions.

Australian Indigenous Ochres

2021 ◽  
Author(s):  
Jillian Huntley
Keyword(s):  
Cultural Landscapes ◽  
Cultural Practices ◽  
Distribution Patterns ◽  
Archaeological Sites ◽  
Theoretical Frameworks ◽  
Long Distance ◽  
Novel Studies ◽  
Trade And Exchange ◽  
Key Terms

Aboriginal Australians use ochre in varied cultural practices. It is found in the earliest to most recent archaeological sites and geographically across the wide-ranging geological and climatic contexts of the continent. Ochre’s importance in Aboriginal societies, coupled with its availability across Australia and its long-term durability, has led to a ubiquitous archaeological presence with considerable potential to study past cultural landscapes and intergroup interactions, including long-distance trade and exchange. Concentrating on scientific sourcing analyses, this article highlights the benefits of archaeopigment research, defining key terms (ochre, provenience, and provenance) and the technicalities of sourcing studies before discussing theoretical frameworks used in interpretations of ochre distribution patterns. The article argues that as we move away from novel studies on ethnographically well-known source locations into applied research, exceptional Australian records are well placed to investigate territoriality, mobility, intergroup and human–landscape interactions, and to explore the catalysts driving cultural diversity.

Ecological and environmental indicators of Brazil Nut Tree (Bertholletia excelsa Bonpl.) in Flona do Jamari, Rondônia

2020 ◽  
Vol 11 (7) ◽  
pp. 740-751
Author(s):  
Nilson Reinaldo Fernandes dos Santos Júnior ◽  
Diogo Martins Rosa ◽  
José Das Dores de Sá Rocha ◽  
Marta Silvana Volpato Sccoti ◽  
Scheila Cristina Biazatti ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Distribution Pattern ◽  
Geographic Location ◽  
Distribution Patterns ◽  
Environmental Indicators ◽  
Diameter Distribution ◽  
Brazil Nut ◽  
Productive Potential ◽  
Morisita Index ◽  
Individual Trees

Mapping Brazil nut trees in the Amazon is essential for indicating its distribution patterns within different ecosystems, while also being useful to estimate the species productive potential. This study aimed to evaluate the spatial distribution of Brazil nut trees in Flona do Jamari – RO, considering its environmental and topographic conditions. A census was performed for all individual trees sized ≥ 35 cm in diameter at 1.30 m breast height (DBH) above the ground of six Annual Production Units (APU) in Forest Management Unit III (FMU-III), a 11,011.2 ha area of Flona do Jamari, RO. DBH and geographic location (GPS) were collected for each tree. Structure and diameter distribution were evaluated by abundance, density, dominance, and frequency. The Morisita index was used to identify the spatial distribution pattern. The environment was defined by the local relative height found along the drainage network, by the digital model Height Above the Nearest Drainage (HAND). Most trees were among DBH intermediate classes (60 to 140 cm), and only a few were young trees (DBH < 50 cm). Brazil nut trees present a random spatial distribution and a predominant distribution pattern of 'terra-firme (solid ground)'. Such information on the species structural, spatial, and ecological patterns serve as key elements for further studies on production potential.

Comparison of the clinical outcomes and cement distribution patterns after percutaneous vertebroplasty in the treatment of thoracolumbar Kümmell’s disease and OVCFs

2020 ◽  
Author(s):  
Cheng-Liang Wang ◽  
Ji-Bin Chen ◽  
Te Li
Keyword(s):  
Bone Cement ◽  
Distribution Pattern ◽  
Operation Time ◽  
Distribution Patterns ◽  
Fracture Rate ◽  
Vas Score ◽  
Cement Distribution ◽  
Kummell’S Disease ◽  
Kümmell’S Disease ◽  
Time Point

Abstract Background The purpose of this study is to investigate and compare the therapeutic effect and distribution characteristics of bone cement in the PVP treatment for thoracolumbar Kümmell's diseases and OVCFs. Methods A prospective analysis of 35 patients with Kümmell ’s disease (K group) and 35 patients with OVCFs (O group) who underwent PVP treatment from February 2016 to February 2018 was conducted. The vertebral compression rate and degree of osteoporosis were more serious in the K group than in the O group ( P <0.05, respectively). Distribution pattern, volume and leakage rate of bone cement, operation time, VAS score, ODI, correction rates of vertebral compression and kyphosis, re-fracture rate of adjacent vertebrae in 2 years between the two groups were compared to assess clinical effect. Results The follow-up time of the two groups was 24-48 months. The amount of intraoperative bone cement injection was significantly higher in the K group than in the O group ( P =0.025). The cement distribution pattern of local solid lump was dominant in the K group (65.71%), while intercalation with trabeculae was dominant in the O group (74.29%) ( P <0.001). VAS score and ODI were significantly lower both in the two groups at 1 day, 1 year and 2 years after surgery than before surgery (all P <0.05), but significantly lower in the K group than in the O group at each time point after surgery (all P <0.05). The correction rates of kyphosis and vertebral compression in both groups was significantly corrected ( P <0.05, respectively) and gradually lost with time ( P <0.05, respectively). The correction rates of kyphosis and vertebral compression were significantly higher in the K group than in the O group at each time point after surgery (all P <0.05). Conclusions PVP has the advantages of simple operation, short operation time, small trauma and quick recovery in treating both Kümmell's disease and OVCFs. However, PVP can better restore partial vertebral height and correct kyphosis in the treatment of Kümmell's disease, while can better alleviate pain and improve ODI in the treatment of OVCFs.

Energetic status and bioelectrical impedance modeling of Arctic grayling Thymallus arcticus in interior Alaska Rivers

2019 ◽  
Vol 102 (11) ◽  
pp. 1337-1349
Author(s):  
Jeffrey A. Falke ◽  
Lauren T. Bailey ◽  
Kevin M. Fraley ◽  
Michael J. Lunde ◽  
Andrew D. Gryska
Keyword(s):  
Bioelectrical Impedance ◽  
Arctic Grayling ◽  
Interior Alaska ◽  
Impedance Modeling ◽  
Thymallus Arcticus
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