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1.
Public Adm Rev ; 80(5): 862-865, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32836454

RESUMEN

At this point, little is known about local government responses to the economic crisis caused by COVID-19. This crisis is happening on Main Streets around the nation. This article examines how some local governments are taking collective action in partnership with other governments as well as with organizations at the local and regional levels. What is unique is that collective action is rare as it relates to traditional economic development practices, yet it is occurring and leading to offerings of multi-institutional grants and low-interest loans. However, some newer supply- and demand-side actions are the result of a lack of resources and need for expediency. Practitioners can learn about the collaborative economic development actions that governments are taking and how these partnerships can stabilize their local economies.

2.
Anim Reprod Sci ; 98(1-2): 72-96, 2007 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-17110061

RESUMEN

The importance of oocyte quality cannot be overstated, because it impacts all subsequent events during development of the embryo, the fetus and even the resulting offspring. Oocyte metabolism plays a critical role in supporting developmental competence via multiple mechanisms. It is beginning to be understood that metabolic pathways not only affect cytoplasmic maturation but may control nuclear maturation as well. A complete understanding of the precise roles that metabolism plays in determining oocyte quality is crucial for developing efficient in vitro maturation systems to support acquisition of oocyte competence. To date, this pursuit has not been entirely successful. Work in our laboratory on porcine oocyte metabolism has elucidated some of the intricate control mechanisms at work within the oocyte, not only for energy production, but also encompassing progression of nuclear maturation, mitochondrial activity and distribution, and oxidative and ionic stresses. We hypothesize that by utilizing oocyte metabolic data, we can develop more appropriate in vitro maturation systems that result in increased oocyte and embryo developmental competence.


Asunto(s)
Oocitos/fisiología , Animales , Bovinos , Técnicas de Cultivo de Célula , Medios de Cultivo , Metabolismo Energético , Meiosis , Ratones , Mitocondrias/metabolismo , Oocitos/citología , Oocitos/metabolismo , Especificidad de la Especie , Porcinos
3.
Theriogenology ; 66(4): 945-54, 2006 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-16580060

RESUMEN

One strategy for improving fertility in cattle is mid-cycle administration of GnRH to increase progesterone secretion and delay luteolysis. This strategy might be especially useful during hot weather because heat stress increases uterine prostaglandin release and reduces development of the elongating embryo. A series of experiments was conducted to test the efficacy of GnRH for increasing fertility. There was no effect of administration of 100 microg GnRH at Day 11 after anticipated ovulation on pregnancy rates in virgin heifers subjected to timed artificial insemination (TAI) during the summer. Similarly, there was no beneficial effect of administration of GnRH at Day 11 after anticipated ovulation on pregnancy rates of lactating cows subjected to TAI in summer and winter. Three experiments tested effects of injection of GnRH at Days 14 or 15 after anticipated ovulation on pregnancy rates of lactating cows. The first experiment used 477 lactating cows subjected to TAI. Cows receiving GnRH at Day 14 had higher pregnancy rates in both summer and winter than cows receiving vehicle (20.3 versus 12.7%, P<0.02). When this experiment was repeated during summer with 137 cows, there was a negative effect of GnRH treatment at Day 14 on pregnancy rate. In the third experiment, lactating cows during summer were inseminated at detected estrus and cows were assigned to treatment with either GnRH or vehicle at Days 14 or 15 after insemination. Pregnancy rates were 25.6% (32/125) for cows receiving vehicle, 20.7% (19/92) for cows receiving GnRH at Day 14, and 20.3% (16/79) for cows receiving GnRH at Day 15. In conclusion, GnRH administration at Days 11-15 after anticipated ovulation or estrus did not consistently increase pregnancy rates in either cool or warm seasons.


Asunto(s)
Fertilidad/efectos de los fármacos , Hormona Liberadora de Gonadotropina/farmacología , Lactancia , Predicción de la Ovulación , Ovulación/efectos de los fármacos , Animales , Bovinos , Esquema de Medicación , Femenino , Fertilidad/fisiología , Fármacos para la Fertilidad Femenina/administración & dosificación , Fármacos para la Fertilidad Femenina/farmacología , Hormona Liberadora de Gonadotropina/administración & dosificación , Trastornos de Estrés por Calor/fisiopatología , Inseminación Artificial/veterinaria , Embarazo , Índice de Embarazo , Estaciones del Año , Temperatura , Factores de Tiempo , Resultado del Tratamiento
4.
Theriogenology ; 66(2): 224-33, 2006 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-16325250

RESUMEN

Pregnancy rates following transfer of an in vitro-produced (IVP) embryo are often lower than those obtained following transfer of an embryo produced by superovulation. The purpose of the current pair of experiments was to examine two strategies for increasing pregnancy rates in heat stressed, dairy recipients receiving an IVP embryo. One method was to transfer two embryos into the uterine horn ipsilateral to the CL, whereas the other method involved injection of GnRH at Day 11 after the anticipated day of ovulation. In Experiment 1, 32 virgin crossbred heifers and 26 lactating crossbred cows were prepared for timed embryo transfer by being subjected to a timed ovulation protocol. Those having a palpable CL were randomly selected to receive one (n = 31 recipients) or two (n = 27 recipients) embryos on Day 7 after anticipated ovulation. At Day 64 of gestation, the pregnancy rate tended to be higher (P = 0.07) for cows than for heifers. Heifers that received one embryo tended to have a higher pregnancy rate than those that received two embryos (41% versus 20%, respectively) while there was no difference in pregnancy rate for cows that received one or two embryos (57% versus 50%, respectively). Pregnancy loss between Day 64 and 127 only occurred for cows that received two embryos (pregnancy rate at Day 127=17%). Between Day 127 and term, one animal (a cow with a single embryo) lost its pregnancy. There was no difference in pregnancy rates at Day 127 or calving rates between cows and heifers, but females that received two embryos had lower Day-127 pregnancy rates and calving rates than females that received one embryo (P < 0.03). Of the females receiving two embryos that calved, 2 of 5 gave birth to twins. For Experiment 2, 87 multiparous, late lactation, nonpregnant Holstein cows were synchronized for timed embryo transfer as in Experiment 1. Cows received a single embryo in the uterine horn ipsilateral to the ovary containing the CL and received either 100 microg GnRH or vehicle at Day 11 after anticipated ovulation (i.e. 4 days after embryo transfer). There was no difference in pregnancy rate for cows that received the GnRH or vehicle treatment (18% versus 17%, respectively). In conclusion, neither unilateral transfer of two embryos nor administration of GnRH at Day 11 after anticipated ovulation improved pregnancy rates of dairy cattle exposed to heat stress.


Asunto(s)
Bovinos/fisiología , Transferencia de Embrión/veterinaria , Fármacos para la Fertilidad Femenina/administración & dosificación , Hormona Liberadora de Gonadotropina/administración & dosificación , Calor , Índice de Embarazo , Animales , Bovinos/embriología , Femenino , Fertilización In Vitro/veterinaria , Inseminación Artificial/veterinaria , Paridad , Embarazo , Distribución Aleatoria , Factores de Tiempo
5.
Anim Reprod Sci ; 78(1-2): 123-31, 2003 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-12753788

RESUMEN

Cytoplasmic maturation refers to a variety of cellular changes that must occur in the oocyte in order to progress through subsequent fertilization and embryonic development. Intracellular concentrations of ATP (ATPi) or glutathione (GSHi), indicative of metabolic activity or the ability of the oocyte to form a male pronucleus and cope with cellular stress, respectively, have been used as markers of cytoplasmic maturation in vitro. In the current study, our objective was to determine if concentrations of ATPi and GSHi in oocytes recovered from three groups of gilts were associated with known differences in developmental competence within these populations. In vivo matured oocytes were surgically recovered 36-38 h after the onset of estrus from first estrous gilts, multi-estrous gilts, and multi-estrous gilts receiving testosterone (1mg/2 ml per day; day 13 to estrus, day 0=day of estrus). Concentrations of ATPi and GSHi were determined using a bioluminescent somatic cell assay kit (luciferin-luciferase reaction) and the dithiobisnitrobenzoic acid (DTNB)-glutathione reductase recycling reaction, respectively. There were no differences (P>0.05) between ATPi concentrations in oocytes from the three groups (1.52 +/- 0.10, 1.51 +/- 0.11, 1.56 +/- 0.11pmol per oocyte). In contrast, oocytes from multi-estrous gilts had higher (P<0.05) concentrations of GSHi (31.53 +/- 1.66 to 33.67 +/- 2.30 pmol per oocyte) than oocytes from first estrous gilts (25.07 +/- 0.82). Administration of testosterone did not affect (P>0.05) GSHi concentrations in oocytes from multi-estrous gilts. Differences in developmental potential between the three groups of gilts were apparently not due to different concentrations of ATPi. However, GSHi concentrations were higher in oocytes from multi-estrous gilts, suggesting that reduced developmental potential of oocytes from first-estrus gilts may be related to insufficient amounts of GSHi. The beneficial effect of exogenous testosterone on the percentage of embryos surviving early gestation does not appear to be due to increased GSHi. Of the numerous potential markers of developmental potential, two were examined in the current study, and GSHi appeared to be useful for assessing porcine oocytes.


Asunto(s)
Adenosina Trifosfato/análisis , Estro , Glutatión/análisis , Oocitos/química , Porcinos/metabolismo , Testosterona/farmacología , Animales , Ácido Ditionitrobenzoico , Femenino , Glutatión Reductasa/metabolismo , Mediciones Luminiscentes
6.
Mol Reprod Dev ; 64(4): 492-8, 2003 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-12589661

RESUMEN

Glutathione (GSH) content in mature porcine oocytes is correlated with subsequent fertilization and developmental success. Adenosine triphosphate (ATP) is an important energy source for maintaining cellular activities and protein synthesis. The objective of this study was to compare GSH and ATP concentrations of in vivo and in vitro matured porcine oocytes. Ovulated, in vivo matured oocytes were frozen at -80 degrees C in groups of 10-20 (GSH) or 5-10 (ATP). In vitro oocytes were matured in either tissue culture medium-199 (TCM199) supplemented with polyvinyl alcohol (PVA) or hyaluronic acid (MAP5), or North Carolina State University-23 (NCSU23) supplemented with porcine follicular fluid (pFF) and frozen as described, or fertilized and cultured. GSH content was determined by the dithionitrobenzoic acid-glutathione disulfide (DTNB-GSSG) reductase recycling assay. ATP content was determined by using the Bioluminescent Somatic Cell Assay Kit. Oocytes matured in vitro in defined TCM199 with PVA or hyaluronic acid, or NCSU23 with pFF had significantly lower concentrations (P < 0.05) of GSH (n = 207, 9.82 +/- 0.71 pmol/oocyte; n = 104, 9.73 +/- 0.81 pmol/oocyte; n = 108, 7.89 +/- 0.66 pmol/oocyte, respectively) compared to in vivo matured oocytes (n = 217, 36.26 +/- 11.00 pmol/oocyte). Concentrations of ATP were not different between treatments (in vivo, n = 70, 0.97 +/- 0.07 pmol/oocyte; TCM-PVA, n = 117, 0.81 +/- 0.13 pmol/oocyte; TCM-MAP, n = 107, 1.02 +/- 0.18 pmol/oocyte; NCSU-pFF, n = 134, 0.71 +/- 0.08 pmol/oocyte). Intracellular ATP content does not appear to be related to developmental potential in porcine oocytes. Low intracellular GSH may be responsible, in part, for lower developmental competence observed in in vitro matured porcine oocytes.


Asunto(s)
Adenosina Trifosfato/metabolismo , Glutatión/metabolismo , Oocitos/metabolismo , Porcinos/metabolismo , Animales , Femenino , Técnicas In Vitro
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