123,162 research outputs found
Die Anwendung von Mikrosatelliten zum Studium der Sozialstruktur bei Großsäugetieren : am Beispiel von italienischem Wolf und Damwild
No full textScandura M. The use of microsatellites in the study of social structure in large mammals : Italian wolf and fallow deer as case studies. Bielefeld (Germany): Bielefeld University; 2004.The content of the present PhD thesis deals with the application of microsatellite analysis to the study of two species of large mammals, referring to some aspects of their social and mating systems. The Italian wolf (Canis lupus) and the fallow deer (Dama dama) were chosen as case studies, since genetic investigations on their populations result, for different reasons, problematic.
The wolf in Italy is a particularly protected species, recovering throughout the peninsula from the effects of a recent bottleneck. Sampling wolves may not rely on capturing or killing them, therefore an alternative, non-invasive, approach was adopted in my study. Scats, shed hairs and blood drops collected on the snow represented the main source of DNA for the analysis. Methodological cares were necessary to obtain reliable wolf genotypes. A set of ten canine microsatellites was employed to achieve unique multilocus genotypes in the population. Fifty-two individuals were typed in the period 1998 - 2003. In some cases, pack composition was determined, confirming that familiar bonds are at the basis of wolf social units. An unpredictable high local differentiation was found among geographic areas. Early dispersal seem to be common in the population, but its effects on the gene flow are not detectable, at least at my study scale. I proposed that most of this dispersal may be unsuccessful or over long distances. The study population, indeed, seem to have reached a high level of local saturation, with clumped pack territories and high reproductive rates, and thus possibly represents a source, from which wolves disperse toward sink areas.
The second study involves an enclosed population of fallow deer. Lekking is seldom observed in mammals, and among them, it is more common in ungulate species. Fallow deer is one of the most studied lekking ungulate and this particular population is object of long-term researches on male mating strategies. Mature bucks in the population join into leks during the breeding season: a costly strategy, which apparently does not guarantee high direct benefits (fitness). In this study, for the first time, I used a molecular approach to verify the existence of a genetic basis to lek formation. The recourse to microsatellites enabled to overcome the strong limitation due to the extremely monomorphism of the species, documented in several studies. Though the low variability even at microsatellite loci, the hypotheses of kin selection (territorial bucks in a lek are relatives) and of heterozygosity advantage (territorial bucks in a lek have an overall high heterozygosity) were tested and resulted not supported by data. Hence, future studies should be addressed towards phenotypic variation and consider in detail physiological and ecological factors, in order to clarify the reasons why lekking takes place in fallow deer
Lek-associated movement of a putative Ebolavirus reservoir, the hammer-headed fruit bat (<i>Hypsignathus monstrosus</i>), in northern Republic of Congo
No full textThe biology and ecology of Africa’s largest fruit bat remains largely understudied and enigmatic despite at least two highly unusual attributes. The acoustic lek mating behavior of the hammer-headed bat (Hypsignathus monstrosus) in the Congo basin was first described in the 1970s. More recently molecular testing implicated this species and other African bats as potential reservoir hosts for Ebola virus and it was one of only two fruit bat species epidemiologically linked to the 2008 Luebo, Democratic Republic of Congo, Ebola outbreak. Here we share findings from the first pilot study of hammer-headed bat movement using GPS tracking and accelerometry units and a small preceding radio-tracking trial at an apparent lekking site. The radio-tracking revealed adult males had high rates of nightly visitation to the site compared to females (only one visit) and that two of six females day-roosted ~100 m west of Libonga, the nearest village that is ~1.6 km southwest. Four months later, in mid-April 2018, five individual bats, comprised of four males and one female, were tracked from two to 306 days, collecting from 67 to 1022 GPS locations. As measured by mean distance to the site and proportion of nightly GPS locations within 1 km of the site (percent visitation), the males were much more closely associated with the site (mean distance 1.4 km; 51% visitation), than the female (mean 5.5 km; 2.2% visitation). Despite the small sample size, our tracking evidence supports our original characterization of the site as a lek, and the lek itself is much more central to male than female movement. Moreover, our pilot demonstrates the technical feasibility of executing future studies on hammer-headed bats that will help fill problematic knowledge gaps about zoonotic spillover risks and the conservation needs of fruit bats across the continent.</div
A Multi-Language Comparison of Influences on Author Verification using Character N-Grams
No full textWe create a new multi-language corpus for author verification based on Wikipedia talkpages, and evaluate the influence that differences in topic and time have on character n-gram author profiles. Topic alignment between two texts is found to increase author verification precision, and an authors writing style is found to change over time, but not more significantly after 3 years than after 1 year.Information ArchitectureWISElectrical Engineering, Mathematics and Computer Scienc
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Improving population size estimation at western capercaillie leks: lek counts versus genetic methods
No full textThe western capercaillie Tetrao urogallus, hereafter capercaillie, is the largest galliform bird present in the boreal and montane forests of the Western Palearctic. Precise and accurate methods for estimating the number of individuals and/or their densities are crucial for the proper management of its free‐ranging populations. However, obtaining reliable estimates of the abundance of populations of wild species and, particularly, of birds is not a simple task. In the case of lek‐mating birds such as capercaillie, surveys are traditionally based on lek counts, that is, counts of calling males present in their mating areas: the leks. This study was carried out on the Pyrenees at six capercaillie leks where two different lek counting approaches were performed: hide‐based and walk‐based. The results were compared with those obtained from an estimate of minimum population size (MPE) derived from genotyping all faeces samples found in the lek area, and with a population size estimate derived from a genetic mark‐recapture model (N^o) of each capercaillie lek. The results of N^o were used to estimate the detection rate (D) of both lek count approaches. Our results show that traditional lek counts do not detect all male capercaillies since the detection rate was 0.34 (95% CI: 0.26–0.43) for hide‐ and 0.56 (95% CI: 0.43–0.68) for walk‐based lek counts. Our results suggest that the walk‐based lek counts were more efficient than the hide‐based ones, providing more accurate results compared to the N^o estimate. The combination of non‐invasive sampling with genetic mark‐recapture model was found to be the most reliable method for obtaining the N^o of leks given that traditional lek counts underestimate the number of capercaillie and, furthermore, can cause disturbance to the species at these sites
Lek site defines annual spatial use of male Black Grouse (Tetrao tetrix)
No full textAdult male Black Grouse (
Tetrao tetrix
) are assumed to use the same lek throughout their
life-span and juveniles are rarely observed settling far from their natal areas. Here we re-
port results on a study of lek site fidelity in male Black Grouse using mark-recapture, ra-
dio-telemetry, and lek observations between 1984 and 1992. Data were collected at two
sites in central Sweden with six and two lek
s, respectively. A total of 306 Black Grouse
(230 full-grown adult and juvenile males, and 76 chicks) were captured and tagged. We
found that all recaptured males tagged as chicks (
n
= 7) were caught on the lek closest to
their initial capture site. Twenty-six percent (
n
= 59) of individuals ringed as full-grown
were recaptured at least once in the subseque
nt springs. Fewer individuals attended leks
during the mating period than the premating period (
t
(15)
= 3.06,
P
= 0.008). Juvenile males
were closer to the lek in the premating period (95% confidence interval = 0.45–0.65 km)
than in the mating period (0.73–1.13 km), in contrast to adults, which were closer to leks
in the mating period (0.44–0.61 km) than the premating period (0.80–0.95 km). Inter-lek
movement probability of the birds was 15% (
n
= 9) in the study area. Male Black Grouse
remain close to their lek all year round and their recruitment is local. This indicates that
leks consist of well-defined local populations
, which have limited interactions with other
leks
Song sharing and repertoire change as indicators of social structure in the Noisy Scrub-bird
No full textThe Endangered Noisy Scrub-bird is a small passerine that is seldom seen but often heard in its range on the south coast of Western Australia. The difficulties in observing this cryptic bird mean that little is known about its social system. The loud, conspicuous territorial song of the male provides a convenient, non-intrusive means by which to study this species.
The aim of this project was to investigate the patterns of song sharing and repertoire change in the Noisy Scrub-bird to provide indications of the social structure. It was found that groups of up to ten territorial males shared the same set of about five song types. Song groups were discrete, with members of a song group sharing most, if not all, of their song types. Males from different song groups had no song types in common.
Repertoire change was rapid and, with the exception of one individual, was found in every territorial male studied in the Mt Gardner population. It occurred simultaneously in all members of a song group, with males making the same changes to their shared songs. The source of repertoire change was mainly modification of existing song types with occasional divergence of a single song type into two distinct song types, as well as some innovation providing new song types. The average life of a song type was approximately 6 months. Although some song types persisted for the entire 16 month sampling period, they were continually modified and a year later could no longer be recognised as the same type.
Translocation of eight male scrub-birds to the Porongurup National Park provided an opportunity to combine individuals that initially did not share any songs. This allowed the process of song group formation to be studied. Within a one to two month period these males altered their songs so that they shared with their new neighbours. There was some evidence that the songs of dominant males were copied. Observation of the population established on Bald Island by translocation confirmed that there were no appreciable long-term effects on the songs of translocated Noisy Scrub-birds. Song group size, repertoire size and levels of song sharing were very similar to those found in the Mt Gardner population.
The striking feature of Noisy Scrub-bird song groupings was their discreteness and cohesiveness even in the presence of continual repertoire change. It is suggested that each song group consists of a dominant male whose songs are more attractive to females and/or effective in territory defence. This dominant male is surrounded by subordinate males that copy his effective songs. Repertoire change can be explained by the dominant male continually making changes to his songs, with the other males copying these changes to retain their mimicked effectiveness. Each song group may in fact represent a dispersed lek. The scenario suggested to explain Noisy Scrub-bird song groupings bears striking similarities to the hotshot hypothesis to explain lek formation whereby males cluster around a successful male.
This study demonstrates the potential of using song to investigate aspects of the social system of a species which is otherwise very difficult to observe. Management of an Endangered species such as the Noisy Scrub-bird will always benefit from increased knowledge about their social system. For example, this study showed that taking males from different song groups for translocation probably has little impact on their success at the new site because of their ability to rapidly alter their songs to form new song groups. An additional benefit of regularly monitoring the songs of translocated males was that it allowed ongoing identification of individuals, even though their songs were continually changing
The vanishing author in computer-generated works: a critical analysis of recent Australian case law
No full textAbstract
The use of software is ubiquitous in the creation of many copyright works, yet the requirement in copyright law that every work have a human author who engages in independent intellectual effort means that its use may prevent copyright subsistence. Several recent Australian cases have refocused attention on authorship as an essential criterion of copyright subsistence, and these cases suggest that much computer-produced output may be authorless and thus lack copyright protection. This article, the first in a two-part series, analyses how each case deals with the question of authorship of computer-produced works and why the use of software diminishes copyright protection for a significant number of computer-generated works. The article critiques the application of conventional notions of human authorship developed in the pre-computer age to modern productions and suggests alternative approaches to authorship that satisfy both the major objectives of copyright policy and the need to adapt to the computer age. The article argues that, without a broader judicial approach to authorship of computer-generated works, Parliament must remedy the lacuna in protection for these ‘authorless’ works. Possible solutions for reform are suggested. In a forthcoming article, the author comprehensively examines those reform proposals
“PROGRAM ACARA LEK-LEKAN SOLO DI SOLO RADIO” (Studi korelasi antara motivasi dan perilaku dengan kepuasan mendengarkan program acara Lek-lekan Solo di Solo Radio bagi perkumpulan pendengar program acara Lek-lekan Solo di Solo Radio/Lek-lekan Community )
No full textRadio siaran adalah format yang cukup digemari oleh masyarakat. Solo Radio
adalah salah satu radio siaran swasta di kota Solo. Lek-Lekan Solo adalah salah satu
program acara di Solo Radio. Acara ini membahas seputar masalah seni budaya.
Walaupun acara ini baru mengudara lepas tengah malam, acara ini cukup mendapat
tempat di hati para pendengar. Terbukti dengan dibentuknya sebuah perkumpulan
penggemar acara Lek-Lekan Solo yang diberi nama Lek-lekan Community. Penelitian ini
bertujuan untuk meneliti apakah motif dan bagaimanakah perilaku mendengarkan dengan
kepuasan mendengarkan program acara Lek-lekan Solo di Solo Radio bagi perkumpulan
pendengar program acara Lek-lekan Solo di Solo Radio.
Penelitian ini menggunakan studi korelasi, yaitu menjelaskan hubungan antar
variabel-variabel penelitian pengujian hipotesis dengan model Uses and Gratifications.
Berdasarkan model Uses and Gratifications tersebut penulis akan berusaha menemukan
hubungan dari variabel-variabel yang diukur. Disini penulis hanya meneliti beberapa
variabel yaitu variabel independen (motivasi mendengarkan), variabel intervening
(perilaku mendengarkan), dan variabel dependen (kepuasan mendengarkan). Tipe
penelitian ini adalah explanatory research, dimana penelitian ini untuk menjawab
hubungan antara satu variabel dengan variabel lain. Dalam hal ini peneliti melakukan
pengujian hipotesis. Subjek yang diteliti adalah perkumpulan pendengar program acara
Lek-lekan Solo di Solo Radio, yaitu Lek-lekan Community. Karena penelitian ini
penelitian kuantitatif, maka dalam penelitian ini data yang sudah terkumpul akan
dianalisis dengan teknik statistik. Analisa data dilakukan dengan menggunakan tata
jenjang Spearman.
Sebagian besar perkumpulan pendengar Lek-Lekan Solo mendengarkan program
acara Lek-Lekan untuk mendapatkan informasi tentang seni budaya, sebanyak 76 %
responden. Dengan sebanyak 50 % responden yang merasa terpenuhi kebutuhannya akan
motivasi mendapatkan informasi seputar seni budaya.
Variabel pertama yang diuji adalah variabel motivasi mendengarkan (X) dengan
perilaku mendengarkan (Z). Dan variabel kedua yang diuji adalah variabel perilaku
mendengarkan (Z) dengan kepuasan mendengarkan (Y). Dengan memperhatikan derejat
kebebasan df = N- 2 = 50 – 2 = 48 serta taraf signifikannya 0.05 maka nilai df terletak
antara angka 40 dan 60 sehingga dapat diketahui t tabelnya antara 1,684 dan 1,671.
Dari hasil perhitungan dengan menggunakan rumus diatas, diambil kesimpulan
bahwa hipotesis yang dibuat oleh penulis adalah benar. Ada hubungan yang signifikan
antara motivasi mendengarkan. Dan perilaku mendengarkan dengan kepuasan
mendengarkan program acara L;ek-Lekan Solo di Solo Radio
Variation (mean ± SE) in male sage-grouse lek response from 2007–2011 to identical development density, in 2004 (4-year time lag) and 2006 (1-year time lag), Wyoming, USA.
No full text<p>In 2004 the average sage-grouse lek increase was +3.2 males/lek/year (n = 36 leks) and the average sage-grouse lek decline was −5.7 males/lek/year (n = 153 leks). In 2006 the average sage-grouse lek increase was +3.3 males/lek/year (n = 42 leks) and the average sage-grouse lek decline was −4.9 males/lek/year (n = 125 leks).</p
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