Preliminary Trial: Motility Comparisons of a Unique Freezing Technology (UFT) to Liquid Nitrogen Mist Methodology for Cryopreservation of Porcine Spermatozoa     

HA Goolsby  JR Blanton  PZ Cotter  SD Prien 《Reproduction in domestic animals》2004,39(5):328-332

The motility outcomes of boar semen frozen with newly developed freezing techniques using a new unique freezing technology (UFT) compared with traditional liquid nitrogen methodology were investigated with the intent of improving current fertility outcomes using semen. The UFT is an electronically controlled cooling chamber that houses an organic fluid bath that can be maintained at temperatures below 0 degrees C without solidifying to freeze samples. Four ejaculates from four different boars were collected for this trial. Samples were handled consistently during the pre- and post-freeze processing. From each ejaculate, samples were separated into eight cryopreservation treatment groups, six UFT variations and two control liquid nitrogen groups, immediately before freezing, in replicates of two. After the initial cryopreservation was complete, all samples were stored in liquid nitrogen for at least 48 h. Post-thaw motilities and original motility return percentages were assessed on a random, individual-sample basis. After the initial evaluations, samples from two boars were recollected and frozen using the UFT for breeding purposes. Four sows were bred with the UFT frozen semen to confirm fertility capability. When assessing the individual UFT techniques, all of six UFT techniques had improved post-thaw motilities. However, treatments F (micro = 29%, return micro = 37%) and J (micro = 27%, return micro = 34%) showed the highest statistical improvement for post-thaw (p < 0.05) and original motility percent returns (p < 0.05) when compared with either the control cryo-tube (micro = 15%, return micro = 19%) or straw groups (micro = 12%, return micro = 16%). The UFT semen had a 50% conception rate, with an average of seven piglets from the sows that farrowed. Our preliminary data suggest a higher motility return with a slower pre-freeze phase below the freezing point before the acceleration to liquid nitrogen temperatures. The preliminary data suggest that the UFT could be utilized as a potential cryopreservation option for boar semen.  相似文献   

Inheritance of morphological characters and glycoalkaloids in potatoes of somatic hybrids between dihaploid Solanum acauleand tetraploid Solanum tuberosum.     

N Kozukue  S Misoo  T Yamada  O Kamijima  M Friedman 《Journal of agricultural and food chemistry》1999,47(10):4478-4483

Steroidal glycoalkaloids occur in potatoes and are reported to impart resistance to phytopathogens including bacteria, fungi, and insects. Because glycoalkaloids can be passed to progenies during breeding programs designed to develop improved potatoes, it is of importance to determine the quality of desired characteristics and the composition of glycoalkaloids of new somatic hybrids. The objective of this study was to determine the appearance, size, and shape (morphological characters) as well as the glycoalkaloid content of potato tubers of somatic hybrids between tetraploid Solanum tuberosum cv. Dejima (2n = 4x = 48 chromosomes) and the dihaploid clone ATDH-1 (2n = 2x = 24 chromosomes) induced by anther culture from Solanum acuale-T (acl-T, 2n = 4x = 48 chromosomes). Tuber size and shape in somatic hybrids were in accord with those of cv. Dejima, whereas the tuber skin color resembled that of ATDH-1. Thin-layer chromatography, high-performance liquid chromatography, and gas-liquid chromatography/mass spectrometry studies showed that the two steroidal glycoalkaloids (alpha-chaconine and alpha-solanine) were present in the tubers of S. tuberosum, whereas acl-T and ATDH-1 tubers were found to contain alpha-tomatine and demissine. The concentrations of total glycoalkaloids in both acl-T and ATDH-1 was >100 mg/100 g of fresh weight tuber cortex, much higher than in S. tuberosum. All somatic hybrids, except one clone, contained four glycoalkaloids (alpha-chaconine, alpha-solanine, alpha-tomatine, and demissine) derived from the fusion parents. The lack of alpha-tomatine in the remaining clone may be due to somaclonal variation. The results show that character expression is influenced by ploidy level and that total glycoalkaloid levels in most somatic hybrids were intermediate between those of the fusion parents. The possible significance of these findings for plant breeding and food safety is discussed.  相似文献   

Geography limits island small‐scale fishery production          下载免费PDF全文

Hampus Eriksson  Kim Friedman  Moses Amos  Ian Bertram  Kalo Pakoa  Rebecca Fisher  Neil Andrew 《Fish and Fisheries》2018,19(2):308-320

Interacting social and ecological processes shape productivity and sustainability of island small‐scale fisheries (SSF). Understanding limits to productivity through historical catches help frame future expectations and management strategies, but SSF are dispersed and unaccounted, so long‐term standardized data are largely absent for such analyses. We analysed 40 years of trade statistics of a SSF product that enter international markets (sea cucumber) from 14 Pacific Island Countries and Territories (PICT) against response variables to test predictors of fishery production: (i) scale, (ii) productivity and (iii) socio‐economics. Combined production in PICT peaked over 20 years ago, driven by exploitation trends in Melanesia that accounted for 90% of all production since 1971. The size of island fisheries (as measured by total exports), and the duration and magnitude of fishery booms were most influenced by ungovernable environmental variables, in particular land area. The large and high islands of Melanesia sustained larger booms over longer periods than atoll nations. We hypothesize that land area is a proxy for land‐based nutrient availability and habitat diversity, and therefore the productivity of the shallow water areas where SSF are operating. PICT need to tailor management based on the intrinsic productivity of shallow inshore habitats: harvests from atoll nations will need to be smaller per unit area than at the high islands. Particularly countries with low productivity fisheries must consider the crucial economic “safety nets” that export SSF make up for dispersed island populations and incorporate them into broader development and island resilience strategies.  相似文献   

Retinal atrophy in albino rats associated with Pituranthos triradiatus (umbelliferae)-induced photosensitization     

A Nyska  Y R Bar Ishak  D Ashkenazy  J Friedman  Y Kashman  J Lelyveld 《Veterinary pathology》1984,21(5):551-552

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Increasing prevalence of internal black spot of potatoes on the New York City market     

B. A. Friedman  S. M. Ringel 《American Journal of Potato Research》1958,35(4):466-467

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Implantation of chicken embryonic tissue and cells into unfertilised eggs     

Z Pancer  N Snapir  B Robinzon  A Friedman 《British poultry science》1991,32(2):261-270

1. Chick embryo cells and halved embryos were successfully implanted into unfertilised eggs. Yolks containing implants were placed in recipient eggshells, covered by transparent vacuum-formed plastic cones and incubated for 72 h. 2. Dispersed cells were obtained from eggs expelled from the uterus or from eggs that had been laid. Implantation of these cells often resulted in aggregation and epithelial growth, in several cases with axial development. 3. Growth of implanted halved embryos of different ages was often observed, including one 10-somite embryo. Non-axial epithelia, sometimes with a central hole, a central fluid-filled cellular vesicle or a vesicle only, were also observed. 4. In another culture system, whole and halved embryos obtained from laid eggs were cultured on a vitelline membrane stretched across semi-solid egg albumen. During the 72 h incubation, axial development was observed only in whole embryos, while halved embryos grew either into epithelia containing fluid-filled cellular vesicles or into vesicles only. 5. It was found that daily drainage of the accumulating fluid from the embryo compartment encouraged axial development in halved embryos, and almost abolished vesicle formation. Holes were formed in half the embryos cultured on a vitelline membrane. 6. It appeared that physical and biological conditions could inflict serious malformations on the implants.  相似文献   

A herd level analysis of a Corynebacterium pseudotuberculosis outbreak in a dairy cattle herd     

Yeruham I  Friedman S  Perl S  Elad D  Berkovich Y  Kalgard Y 《Veterinary dermatology》2004,15(5):315-320

Corynebacterium pseudotuberculosis infection in an Israeli dairy cattle herd is described. The disease was characterized by ulcerative granulomatous lesions, which occurred in an epidemic form. Thirty-two cows and two heifers were affected, the ratio of the number affected to number at risk being 17.5 : 1 and 9.5 : 1, respectively. The culling rate was 50% of the affected animals. Most of the affected animals were cows (91.2%), with one first-calving cow (2.9%) and two heifers (5.9%) also affected. The infection occurred during the summer to autumn months (August-December), and lasted 118 days. The incubation period is about 2 months. The disease appeared in two clinical forms - cutaneous and mastitic - or as a mixed form. C. pseudotuberculosis organisms that were isolated from the ulcerative granulomatous lesions and from milk samples failed to reduce nitrate. A decrease in milk production (4%) and an increase in the bulk-milk somatic cell count from a herd mean of 240 x 10(3) mL(-1) to 460 x 10(3) mL(-1) were noted during the morbidity period. The organism was isolated from milk samples of eight animals (25%). Clinical, epizootiological and microbiological aspects of the infection are described.  相似文献   

Association between milk production, somatic cell count and bacterial dermatoses in three dairy cattle herds     

Yeruham I  Friedman S  Elad D  Perl S 《Australian veterinary journal》2000,78(4):250-253

OBJECTIVE: To determine the correlations between three bacterial dermatoses in cattle, milk production and bulk-milk somatic cell count (BMSCC). DESIGN: Field observations in three dairy cattle herds. METHODS: Milk production, BMSCC, fertility and all herd diseases were recorded by computerised dairy management systems. Each herd was visited twice weekly and the clinical signs, course of diseases and morbidity and culling rates were noted. Bulk-tank milk was sampled twice monthly and analysed for somatic cell count. Bacteriological and histological examinations were carried out from samples collected from affected animals in the respective herds. RESULTS: The acute exudative form of dermatophilosis was diagnosed only in first-calving cows. The morbidity rate was 53% and the culling rate was 16% of the affected animals. The BMSCC increased by a factor of 2.4 times, and there was an average loss of milk production of 30%/cow/day in affected animals. Ulcerative lymphangitis was diagnosed in first-calving cows (22%) and older cows (15%). The culling rate was 28%. The BMSCC increased by a factor of 17.3 times, and the average loss of milk production was 5.5%/affected animal/day. Papillomatous digital dermatitis (PDD) was diagnosed in first-calving cows (25%) and in older cows (18%). The culling rate was 8%. The BMSCC increased by a factor of two times, and the average loss of milk production was 1.7%/affected animal/day. CONCLUSIONS: The correlations between three skin diseases (ulcerative lymphangitis, dermatophilosis, papillomatous digital dermatitis), milk production and BMSCC have been found to be unfavourable.  相似文献   

Deletional tolerance mediated by extrathymic Aire-expressing cells     

Gardner JM  Devoss JJ  Friedman RS  Wong DJ  Tan YX  Zhou X  Johannes KP  Su MA  Chang HY  Krummel MF  Anderson MS 《Science (New York, N.Y.)》2008,321(5890):843-847

The prevention of autoimmunity requires the elimination of self-reactive T cells during their development and maturation. The expression of diverse self-antigens by stromal cells in the thymus is essential to this process and depends, in part, on the activity of the autoimmune regulator (Aire) gene. Here we report the identification of extrathymic Aire-expressing cells (eTACs) resident within the secondary lymphoid organs. These stromally derived eTACs express a diverse array of distinct self-antigens and are capable of interacting with and deleting na?ve autoreactive T cells. Using two-photon microscopy, we observed stable antigen-specific interactions between eTACs and autoreactive T cells. We propose that such a secondary network of self-antigen-expressing stromal cells may help reinforce immune tolerance by preventing the maturation of autoreactive T cells that escape thymic negative selection.  相似文献   

Resolving the structure of ionized helium in the intergalactic medium with the far ultraviolet spectroscopic explorer     

Kriss GA  Shull JM  Oegerle W  Zheng W  Davidsen AF  Songaila A  Tumlinson J  Cowie LL  Deharveng JM  Friedman SD  Giroux ML  Green RF  Hutchings JB  Jenkins EB  Kruk JW  Moos HW  Morton DC  Sembach KR  Tripp TM 《Science (New York, N.Y.)》2001,293(5532):1112-1116

The neutral hydrogen (H I) and ionized helium (He II) absorption in the spectra of quasars are unique probes of structure in the early universe. We present Far-Ultraviolet Spectroscopic Explorer observations of the line of sight to the quasar HE2347-4342 in the 1000 to 1187 angstrom band at a resolving power of 15,000. We resolve the He II Lyman alpha (Lyalpha) absorption as a discrete forest of absorption lines in the redshift range 2.3 to 2.7. About 50 percent of these features have H I counterparts with column densities N(H I) > 10(12.3) per square centimeter that account for most of the observed opacity in He II Lyalpha. The He II to H I column density ratio ranges from 1 to >1000, with an average of approximately 80. Ratios of <100 are consistent with photoionization of the absorbing gas by a hard ionizing spectrum resulting from the integrated light of quasars, but ratios of >100 in many locations indicate additional contributions from starburst galaxies or heavily filtered quasar radiation. The presence of He II Lyalpha absorbers with no H I counterparts indicates that structure is present even in low-density regions, consistent with theoretical predictions of structure formation through gravitational instability.  相似文献