1,720,995 research outputs found
Freeze-Drying Spermatozoa as an Alternative Method for Rescuing Genetic Material of Animal
Full text linkCryopreservation is one of the commonly methods used in spermatozoa preservation in which sperm is frozen and stored in the container of liquid nitrogen. The frozen sperm is still motile after thawing, so it is possible to use it in both artificial insemination and in vitro fertilization to produce an embryo. However, this technique needs a continuous supply of liquid nitrogen and a container as a place to store the frozen sperm. The advanced technique in microinjection has led the possibility of using immotile sperm to fertilize oocyte. Therefore, the sperm preservation method may be simplified because the motility of sperm has not been taken into consideration in fertilization compared to the previous method. Freeze-drying sperm is the proposed method in which the sperm is frozen and sublimated using freeze-drying machine to produce freeze-dried sperm. The freeze-dried sperm might be stored in room temperature or in refrigerator. Several reports have claimed that freeze-dried sperm is not motile but it still has capability to fertilize oocyte, even produces offspring, because its DNA remains intact. Key words: Cryopreservation, freeze-drying, sperm, oocyt
Efektivitas Penggunaan Albumen Sebagai Medium Separasi Dalam Upaya Mengubah Rasio Alamiah Spennatozoa Pembawa Kromosom X dan Y pada Sapi
No full textIPB (Bogor Agricultural University)
No full textUpaya konservasi makhluk hidup dapat dilakukan dengan memelihara hewan hidup atau mengawetkan gamernya, khususnya spermatozoa. Pengawetan spermatozoa secara konvensional umumnya dilakukan dengan cara pembekuan untuk mempertahankan motilitasnya sehingga dapat dipakai dalam program inseminasi buatan atau fertilisasi in vitro
KID CROP KAMBING KACANG (Capra Hircus) di KABUPATEN KONAWE UTARA
Full text linkABSTRAKSalah satu variabel penentu dalam mengukur perkembangan populasi ternak di suatu wilayah adalah jumlah kelahiran anak ternak. Pada ternak kambing dan domba, produktivitas seekor induk dapat diketahui dengan menggunakan indikator nilai panen cempe. Informasi tentang nilai panen cempe, khususnya ternak Kambing Kacang di Kabupaten Konawe Utara masih kurang sehingga perlu dilakukan penelitian untuk memperoleh data tersebut. Tujuan penelitian ini adalah untuk mengetahui nilai panen cempe Kambing Kacang di Kabupaten Konawe Utara. Lokasi penelitian ditentukan dengan menggunakan dua metode, yaitu metode stratified sampling dan purposive sampling. Sedangkan penentuan responden pada desa terpilih digunakan metode sensus. Hasil penelitian menunjukkan bahwa nilai rataan panen cempe Kambing Kacang di Kabupaten Konawe Utara adalah 167,71% dengan interval kelahiran sebesar 8,61 bulan dan jumlah anak sekelahiran sebesar 1,36 ekor, sedangkan mortalitasnya mencapai 13,96%. Kesimpulan dari penelitian ini adalah produktivitas ternak Kambing Kacang di Kabupaten Konawe Utara masih cukup baik berdasarkan variable nilai panen cempenya.Kata Kunci: Kambing Kacang, Cempe, Kid Crop, Konawe Utara
Rescuing genetic material of unexpectedly die animal
No full textRat cauda epididymides were kept in 1.5-ml centrifuge tubes containing 1 ml milli-Q water or physiological saline (0.9% NaCl) and stored and freezed at -196ºC without cryoprotectant for up to 7 days. After thawing of the cauda epididymis, all spermatozoa were non-motile immediately after collection. All oocytes injected with sperm heads (nuclei) of spermatozoa collected from frozen-thawed cauda epididymis in saline were activated (100%) and gradually decreased (P0.05) in cauda epididymis frozen in milli-Q water at -196°C (86%), and in control (69%). In activated oocytes, a large proportion of sperm heads had transformed into male pronuclear formation (66-78%). When 1-cell embryos were cultured for 120 h, 7% developed to blastocyst stages. These results indicate that genetic materials of species (at least in the rat) that had unexpectedly die can be saved by a simple method. Key words: ICSI, Sperm Heads, Piezo-Injection, Frozen, Ra
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe 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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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