Consequences of Mishandling Frozen Semen and Embryos

Abstract Biological cells like bovine sperm and embryos are frozen by exposing them to cryoprotectants then slow cooling the samples at specific rates to allow the exodus of intracellular water molecules prior to being plunged into liquid nitrogen for long term storage. Slow cooling rates along with cryoprotectants allow the formation of very small ice crystals in the extracellular solutions during freezing. The primary goal during cell freezing is to remove intracellular water, which minimizes the formation of intracellular ice that is created when intracellular water molecules crystallize at sub-freezing temperatures. Intracellular ice damages cell membranes, cellular organelles, and even chromosomes therefore intracellular water must be removed before reaching crystallizing temperatures. Bovine embryos are typically exposed to either glycerol or ethylene glycol for several minutes at room temperature and then ramped to a temperature of about -35° Celsius (C) before being plunged into liquid nitrogen ( -196° C). It is important to note for both sperm and embryos that once they are cooled to a point below -130° C, the glass transition temperature of water, they cannot be raised above that temperature and then be re-exposed to below -130° C or cell damage can occur 8 . The damage to the cells is caused by a reorganization or transformation of very small ice crystals in the extracellular fluids into much larger crystals during the temperature changes from below -130° C to above -130° C, and back to below -130° C. This biological effect is called recrystallization. Damage occurs when the transformed large crystals physically invade the cell membranes and cellular organelles of either sperm or embryos. The severity of damage to cells is dependent upon two factors; one, how high the temperature gets above -130° C, and two, the duration of exposure above -130° C. Rapatz 8 reported that although some cell damage can occur at -130° C ice is relatively stable at -100° C, but becomes more vulnerable at -80° C. Since the temperature in the necks of most standard ranch Dewars ranges from to -75° C all the way to room temperature, it is very common for frozen semen and embryos to be exposed and damaged, or even destroyed, during routine handling by those involved in daily Dewar management. The purpose of this paper is to review the damaging effects of recrystallization, and to point out common mistakes made by those who routinely handle frozen semen and embryos on the farm or ranch. Also, the economics of damaged semen and embryos due to mishandling will be discussed

Atrasentan and renal events in patients with type 2 diabetes and chronic kidney disease (SONAR): a double-blind, randomised, placebo-controlled trial

Background: Short-term treatment for people with type 2 diabetes using a low dose of the selective endothelin A receptor antagonist atrasentan reduces albuminuria without causing significant sodium retention. We report the long-term effects of treatment with atrasentan on major renal outcomes. Methods: We did this double-blind, randomised, placebo-controlled trial at 689 sites in 41 countries. We enrolled adults aged 18–85 years with type 2 diabetes, estimated glomerular filtration rate (eGFR)25–75 mL/min per 1·73 m 2 of body surface area, and a urine albumin-to-creatinine ratio (UACR)of 300–5000 mg/g who had received maximum labelled or tolerated renin–angiotensin system inhibition for at least 4 weeks. Participants were given atrasentan 0·75 mg orally daily during an enrichment period before random group assignment. Those with a UACR decrease of at least 30% with no substantial fluid retention during the enrichment period (responders)were included in the double-blind treatment period. Responders were randomly assigned to receive either atrasentan 0·75 mg orally daily or placebo. All patients and investigators were masked to treatment assignment. The primary endpoint was a composite of doubling of serum creatinine (sustained for ≥30 days)or end-stage kidney disease (eGFR <15 mL/min per 1·73 m 2 sustained for ≥90 days, chronic dialysis for ≥90 days, kidney transplantation, or death from kidney failure)in the intention-to-treat population of all responders. Safety was assessed in all patients who received at least one dose of their assigned study treatment. The study is registered with ClinicalTrials.gov, number NCT01858532. Findings: Between May 17, 2013, and July 13, 2017, 11 087 patients were screened; 5117 entered the enrichment period, and 4711 completed the enrichment period. Of these, 2648 patients were responders and were randomly assigned to the atrasentan group (n=1325)or placebo group (n=1323). Median follow-up was 2·2 years (IQR 1·4–2·9). 79 (6·0%)of 1325 patients in the atrasentan group and 105 (7·9%)of 1323 in the placebo group had a primary composite renal endpoint event (hazard ratio [HR]0·65 [95% CI 0·49–0·88]; p=0·0047). Fluid retention and anaemia adverse events, which have been previously attributed to endothelin receptor antagonists, were more frequent in the atrasentan group than in the placebo group. Hospital admission for heart failure occurred in 47 (3·5%)of 1325 patients in the atrasentan group and 34 (2·6%)of 1323 patients in the placebo group (HR 1·33 [95% CI 0·85–2·07]; p=0·208). 58 (4·4%)patients in the atrasentan group and 52 (3·9%)in the placebo group died (HR 1·09 [95% CI 0·75–1·59]; p=0·65). Interpretation: Atrasentan reduced the risk of renal events in patients with diabetes and chronic kidney disease who were selected to optimise efficacy and safety. These data support a potential role for selective endothelin receptor antagonists in protecting renal function in patients with type 2 diabetes at high risk of developing end-stage kidney disease. Funding: AbbVie

Transvaginal ultrasound-guided oocyte retrieval in cattle: state-of-the-art and its impact on the in vitro fertilization embryo production outcome

Transvaginal ultrasound-guided oocyte retrieval (commonly called OPU) and in vitro embryo production (IVP) in cattle has shown significant progress in recent years, in part, as a result of a better understanding of the full potential of these tools by end users. The combination of OPU and IVP (OPU-IVP) has been successfully and widely commercially used worldwide. The main advantages are a greater number of embryos and pregnancies per unit of time, faster genetic progress due to donor quick turn around and more elite sires mating combinations, larger spectrum of female age (calves, prepuberal, heifer, cow) and condition (open, pregnant) from which to retrieve oocytes, a reduced number of sperm (even sexed) required to fertilize the oocytes, among other benefits. OPU-IVP requires significant less donor preparation in comparison to conventional embryo transfer (<50% of usual FSH injections needed) to the extent of no stimulating hormones (FSH) are necessary. Donor synchronization, stimulation, OPU technique, oocyte competence, embryo performance, and its impact on cryopreservation and pregnancy are discussed.EEA BarrowFil: Ferre, Luis Bernardo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Barrow; Argentina.Fil: Alvarez-Gallardo, Horacio. Universidad Nacional Autónoma de México. Facultad de Estudios Superiores Cuautitlán. Laboratorio de Reproducción; MéxicoFil: Romo, Salvador. Universidad Nacional Autónoma de México. Facultad de Estudios Superiores Cuautitlán. Laboratorio de Reproducción; MéxicoFil: Fresno, Cristóbal. Anáhuac University of México. Health Sciences Research Center (CICSA); MéxicoFil: Stroud, Todd. Hoofstock Genetics; Estados UnidosFil: Stroud, Brad. Stroud Veterinary Embryo Services, Inc.; Estados UnidosFil: Lindsey, Brad. Ovitra Biotechnology, Inc.; Estados UnidosFil: Kjelland, M.E. Conservation, Genetics and Biotech, LLC; Estados UnidosFil: Kjelland, M.E. Mayville State University; Estados Unido

Size and composition resolved aerosol fluxes above a pine forest and their response to biogenic chemistry

Fluxes of aerosols were measured above a loblolly pine plantation at Duke Forest, North Carolina, during the CELTIC campaign (Chemical Emission, Loss, Transformation, and Interactions with Canopies). Measurements were made by eddy covariance for total number fluxes (using two condensation particle counters with different cut-offs), size-segregated particle fluxes (using an optical particle spectrometer) and for individual sub-micron aerosol components by aerosol mass spectrometry (AMS). The fluxes of particle numbers, sulphate and organic components show bi-directional behaviour with consistent diurnal patterns, while nitrate was always deposited. The reasons for the bi-directional behaviour are discussed, and the measurements are used to estimate particle growth rates due to vapour uptake that would be consistent with the observations. Aerosol measurements are integrated with measurements of biogenic volatile organic compounds (BVOCs) at different scales (branch emissions, in-canopy gradients and canopy scale fluxes). The measurements demonstrate that organic emissions during midday are linked to the peak in plant emissions and photo-chemistry, and point to a yet unidentified source of reactive sulphur compounds in the forest canopy

A Reference Genome Assembly of American Bison, \u3ci\u3eBison bison bison\u3c/i\u3e

Bison are an icon of the American West and an ecologically, commercially, and culturally important species. Despite numbering in the hundreds of thousands today, conservation concerns remain for the species, including the impact on genetic diversity of a severe bottleneck around the turn of the 20th century and genetic introgression from domestic cattle. Genetic diversity and admixture are best evaluated at genome-wide scale, for which a high-quality reference is necessary. Here, we use trio binning of long reads from a bison-Simmental cattle (Bos taurus taurus) male F1 hybrid to sequence and assemble the genome of the American plains bison (Bison bison bison). The male haplotype genome is chromosome-scale, with a total length of 2.65 Gb across 775 scaffolds (839 contigs) and a scaffold N50 of 87.8 Mb. Our bison genome is ∼13× more contiguous overall and ∼3400× more contiguous at the contig level than the current bison reference genome. The bison genome sequence presented here (ARS-UCSC-bison1.0) will enable new research into the evolutionary history of this iconic megafauna species and provide a new tool for the management of bison populations in federal and commercial herds

A Reference Genome Assembly of Simmental Cattle, \u3ci\u3eBos taurus taurus\u3c/i\u3e

Genomics research has relied principally on the establishment and curation of a reference genome for the species. However, it is increasingly recognized that a single reference genome cannot fully describe the extent of genetic variation within many widely distributed species. Pangenome representations are based on high-quality genome assemblies of multiple individuals and intended to represent the broadest possible diversity within a species. A Bovine Pangenome Consortium (BPC) has recently been established to begin assembling genomes from more than 600 recognized breeds of cattle, together with other related species to provide information on ancestral alleles and haplotypes. Previously reported de novo genome assemblies for Angus, Brahman, Hereford, and Highland breeds of cattle are part of the initial BPC effort. The present report describes a complete single haplotype assembly at chromosome-scale for a fullblood Simmental cow from an F1 bison-cattle hybrid fetus by trio binning. Simmental cattle, also known as Fleckvieh due to their red and white spots, originated in central Europe in the 1830s as a triple-purpose breed selected for draught, meat, and dairy production. There are over 50 million Simmental cattle in the world, known today for their fast growth and beef yields. This assembly (ARS-Simm1.0) is similar in length to the other bovine assemblies at 2.86 Gb, with a scaffold N50 of 102 Mb (max scaffold 156.8 Mb) and meets or exceeds the continuity of the best Bos taurus reference assemblies to date

From Daily Life to Philosophy

Item does not contain fulltextThis article argues that the little everyday things of life often provide excellent entries into the intellectual problems of academic philosophy. This is illustrated with an analysis of four small stories taken from daily life in which people are in agony because they do not know what to do. It is argued that the crucial question in these stories is a philosophical question—not a closed request for empirical or formal information but an open question about how best to conceive of human experience. A discussion follows of the merits and shortcomings of transcendentalism as an attempt by philosophers to make progress. It is argued that reformulating questions is what philosophers can do to contribute to people's comfort in life. This is illustrated with an argument showing that in the small stories discussed the question of what to do should be reformulated as the question of who to be

A reference genome assembly of Simmental cattle, Bos taurus taurus

Genomics research has relied principally on the establishment and curation of a reference genome for the species. However, it is increasingly recognized that a single reference genome cannot fully describe the extent of genetic variation within many widely distributed species. Pangenome representations are based on high-quality genome assemblies of multiple individuals and intended to represent the broadest possible diversity within a species. A Bovine Pangenome Consortium (BPC) has recently been established to begin assembling genomes from more than 600 recognized breeds of cattle, together with other related species to provide information on ancestral alleles and haplotypes. Previously reported de novo genome assemblies for Angus, Brahman, Hereford, and Highland breeds of cattle are part of the initial BPC effort. The present report describes a complete single haplotype assembly at chromosome-scale for a fullblood Simmental cow from an F1 bison-cattle hybrid fetus by trio binning. Simmental cattle, also known as Fleckvieh due to their red and white spots, originated in central Europe in the 1830s as a triple-purpose breed selected for draught, meat, and dairy production. There are over 50 million Simmental cattle in the world, known today for their fast growth and beef yields. This assembly (ARS_Simm1.0) is similar in length to the other bovine assemblies at 2.86 Gb, with a scaffold N50 of 102 Mb (max scaffold 156.8 Mb) and meets or exceeds the continuity of the best Bos taurus reference assemblies to date

A Reference Genome Assembly of American Bison, Bison bison bison.

Bison are an icon of the American West and an ecologically, commercially, and culturally important species. Despite numbering in the hundreds of thousands today, conservation concerns remain for the species, including the impact on genetic diversity of a severe bottleneck around the turn of the 20th century and genetic introgression from domestic cattle. Genetic diversity and admixture are best evaluated at genome-wide scale, for which a high-quality reference is necessary. Here, we use trio binning of long reads from a bison-Simmental cattle (Bos taurus taurus) male F1 hybrid to sequence and assemble the genome of the American plains bison (Bison bison bison). The male haplotype genome is chromosome-scale, with a total length of 2.65 Gb across 775 scaffolds (839 contigs) and a scaffold N50 of 87.8 Mb. Our bison genome is ~13× more contiguous overall and ~3400× more contiguous at the contig level than the current bison reference genome. The bison genome sequence presented here (ARS-UCSC_bison1.0) will enable new research into the evolutionary history of this iconic megafauna species and provide a new tool for the management of bison populations in federal and commercial herds