Rebecca Funk - Academia.edu (original) (raw)

Papers by Rebecca Funk

Research paper thumbnail of Farmer based organizations in Ghana

Research paper thumbnail of Gastric and enteric phytobezoars caused by ingestion of persimmon in equids

Journal of the American Veterinary Medical Association, Oct 10, 2011

Research paper thumbnail of Dynamics of Transformation: Insights from an Exploratory Review of Rice Farming in the Kpong Irrigation Project

SSRN Electronic Journal, 2000

ABSTRACT Agriculture in African South of the Sahara (SSA) can be transformed if the right public ... more ABSTRACT Agriculture in African South of the Sahara (SSA) can be transformed if the right public support is provided at the initial stage, and it can sustain itself once the enabling environment is put in place. Successes are also specific to the location of projects. In Ghana, interesting insights are obtained from the successful Kpong Irrigation Project (KIP), contrasted with other major irrigation projects in the country. Through an exploratory review, we describe how a productive system evolved in KIP and how public support for critical aspects (accumulation of crop husbandry knowledge, selection and supply of profitable varieties, and mechanization of land preparation) might have created a productive environment that the private sector could enter and fill in the market for credit, processing, mechanization of harvesting, and other institutional voids that typically have constrained agricultural transformation in the rest of SSA. Slower progress in other projects also raises a number of questions. We conclude by summarizing those questions and some testable hypotheses for future research.

Research paper thumbnail of Survivability of Candida albicans and Aspergillus fumigatus in cool extended and cryopreserved equine and canine semen

Theriogenology, 2007

Phagocytosis by polymorphonuclear neutrophils (PMNs) is an important mechanism of sperm eliminati... more Phagocytosis by polymorphonuclear neutrophils (PMNs) is an important mechanism of sperm elimination from the mare's reproductive tract. Whereas viable spermatozoa need to be protected from PMN-phagocytosis, dead and damaged spermatozoa should be eliminated from the uterus soon after ejaculation or AI. We have recently identified a specific seminal plasma protein (SPPa) that selectively protects viable spermatozoa from PMN-binding and phagocytosis. We also found that heat shocked spermatozoa were readily bound and phagocytosed by PMNs in the presence of seminal plasma. However, heat shocked spermatozoa appeared resistant to PMN-binding and phagocytosis in the absence of seminal plasma. We hypothesized that spermatozoa release substances that cause functional and/or structural changes to PMNs in the absence of seminal plasma. Three stallions were collected three times each, and spermatozoa were washed and reconstituted in a commercial semen extender (EquiPro, Minitube of America, Verona, WI, USA). Samples were stored at room temperature for 1 h (viable) or heat shocked at 45 8C (non-viable) for 1 h. This heat shock protocol has been validated to induce changes to equine spermatozoa consistent with cell death. Aliquots were divided into six equal fractions, washed three times each, centrifuged to separate spermatozoa from supernatant, and reconstituted into one of the following: (1) viable sperm + supernatant from non-viable sperm; (2) viable sperm + supernatant from viable sperm; (3) viable sperm + extender; (4) non-viable sperm + supernatant from non-viable sperm; (5) non-viable sperm + supernatant from viable sperm; (6) non-viable sperm + extender. PMN's were isolated from peripheral blood from a healthy mare, and samples were subjected to in vitro assays for PMN binding, stained and examined for PMN-sperm binding and viability of PMN's. PMNsperm binding was expressed as the percentage of PMN's (mean AE S.E.M.) that bound at least one sperm cell. PMN viability was expressed as the percentage of PMN's (mean AE S.E.M.) that were ruptured or degranulated. Differences between treatment groups were determined by randomized complete block ANOVA and Bonferroni's comparison tests. Viable sperm + extender (66.2 AE 2.1), viable sperm + supernatant from viable sperm (64.9 AE 2.1) and non-viable sperm + supernatant from viable sperm (61.0 AE 2.1), had superior PMN-binding compared to viable sperm + supernatant from non-viable sperm (43.5 AE 2.1), non-viable sperm + supernatant from non-viable sperm (39.1 AE 2.1) and non-viable sperm + extender (34.3 AE 2.1; P < 0.05). PMN-damage was less common in viable sperm + supernatant from viable sperm (17.2 AE 2.9), viable sperm + extender (19.6 AE 2.9) and non-viable sperm + supernatant from viable sperm (21.4 AE 2.9) compared to non-viable sperm + extender (64.8 AE 2.9), non-viable sperm + supernatant from non-viable sperm (70.6 AE 2.9) and live sperm + supernatant from non-viable sperm (80.6 AE 2.9; P < 0.05). In conclusion, we inferred that dead spermatozoa secreted substances that induced damage to PMNs. Previous studies have shown that seminal plasma protects PMNs from this effect, maintaining their capacity to phagocytose dead spermatozoa in the uterus.

Research paper thumbnail of Transmission of Bovine Viral Diarrhea Virus to Adult Goats from Persistently Infected Cattle

Journal of Veterinary Diagnostic Investigation, 2007

The transmission of bovine viral diarrhea virus (BVDV) from persistently infected (PI) heifers to... more The transmission of bovine viral diarrhea virus (BVDV) from persistently infected (PI) heifers to adult seronegative goats was examined in this study. Ten seronegative adult goats were exposed to 4 PI heifers. None of the goats developed any clinical signs but all goats seroconverted by 42 days after exposure to the PI cattle. Results indicate that goats are susceptible to BVDV infection when housed with PI cattle.

Research paper thumbnail of Gastric and enteric phytobezoars caused by ingestion of persimmon in equids

Journal of the American Veterinary Medical Association, 2011

Research paper thumbnail of Evaluation of diagnostic tests used for detection of bovine viral diarrhea virus and prevalence of subtypes 1a, 1b, and 2a in persistently infected cattle entering a feedlot

Journal of the American Veterinary Medical Association, 2006

Research paper thumbnail of Evaluation of the safety of vaccinating mares against equine viral arteritis during mid or late gestation or during the immediate postpartum period

Journal of the American Veterinary Medical Association, 2011

Research paper thumbnail of What Are the Manifestations of Ocular Exposure to Epichlorohydrin?

Journal of Occupational and Environmental Medicine, 2014

The Occupational Medicine Forum is prepared by the ACOEM Occupational and Environmental Medical P... more The Occupational Medicine Forum is prepared by the ACOEM Occupational and Environmental Medical Practice Committee and does not necessarily represent an official ACOEM position. The Forum is intended for health professionals and is not intended to provide medical or legal advice, including illness prevention, diagnosis or treatment, or regulatory compliance. Such advice should be obtained directly from a physician and/or attorney.

Research paper thumbnail of Farmer based organizations in Ghana

Research paper thumbnail of Farmer based organizations in Ghana

Research paper thumbnail of Gastric and enteric phytobezoars caused by ingestion of persimmon in equids

Journal of the American Veterinary Medical Association, Oct 10, 2011

Research paper thumbnail of Dynamics of Transformation: Insights from an Exploratory Review of Rice Farming in the Kpong Irrigation Project

SSRN Electronic Journal, 2000

ABSTRACT Agriculture in African South of the Sahara (SSA) can be transformed if the right public ... more ABSTRACT Agriculture in African South of the Sahara (SSA) can be transformed if the right public support is provided at the initial stage, and it can sustain itself once the enabling environment is put in place. Successes are also specific to the location of projects. In Ghana, interesting insights are obtained from the successful Kpong Irrigation Project (KIP), contrasted with other major irrigation projects in the country. Through an exploratory review, we describe how a productive system evolved in KIP and how public support for critical aspects (accumulation of crop husbandry knowledge, selection and supply of profitable varieties, and mechanization of land preparation) might have created a productive environment that the private sector could enter and fill in the market for credit, processing, mechanization of harvesting, and other institutional voids that typically have constrained agricultural transformation in the rest of SSA. Slower progress in other projects also raises a number of questions. We conclude by summarizing those questions and some testable hypotheses for future research.

Research paper thumbnail of Survivability of Candida albicans and Aspergillus fumigatus in cool extended and cryopreserved equine and canine semen

Theriogenology, 2007

Phagocytosis by polymorphonuclear neutrophils (PMNs) is an important mechanism of sperm eliminati... more Phagocytosis by polymorphonuclear neutrophils (PMNs) is an important mechanism of sperm elimination from the mare's reproductive tract. Whereas viable spermatozoa need to be protected from PMN-phagocytosis, dead and damaged spermatozoa should be eliminated from the uterus soon after ejaculation or AI. We have recently identified a specific seminal plasma protein (SPPa) that selectively protects viable spermatozoa from PMN-binding and phagocytosis. We also found that heat shocked spermatozoa were readily bound and phagocytosed by PMNs in the presence of seminal plasma. However, heat shocked spermatozoa appeared resistant to PMN-binding and phagocytosis in the absence of seminal plasma. We hypothesized that spermatozoa release substances that cause functional and/or structural changes to PMNs in the absence of seminal plasma. Three stallions were collected three times each, and spermatozoa were washed and reconstituted in a commercial semen extender (EquiPro, Minitube of America, Verona, WI, USA). Samples were stored at room temperature for 1 h (viable) or heat shocked at 45 8C (non-viable) for 1 h. This heat shock protocol has been validated to induce changes to equine spermatozoa consistent with cell death. Aliquots were divided into six equal fractions, washed three times each, centrifuged to separate spermatozoa from supernatant, and reconstituted into one of the following: (1) viable sperm + supernatant from non-viable sperm; (2) viable sperm + supernatant from viable sperm; (3) viable sperm + extender; (4) non-viable sperm + supernatant from non-viable sperm; (5) non-viable sperm + supernatant from viable sperm; (6) non-viable sperm + extender. PMN's were isolated from peripheral blood from a healthy mare, and samples were subjected to in vitro assays for PMN binding, stained and examined for PMN-sperm binding and viability of PMN's. PMNsperm binding was expressed as the percentage of PMN's (mean AE S.E.M.) that bound at least one sperm cell. PMN viability was expressed as the percentage of PMN's (mean AE S.E.M.) that were ruptured or degranulated. Differences between treatment groups were determined by randomized complete block ANOVA and Bonferroni's comparison tests. Viable sperm + extender (66.2 AE 2.1), viable sperm + supernatant from viable sperm (64.9 AE 2.1) and non-viable sperm + supernatant from viable sperm (61.0 AE 2.1), had superior PMN-binding compared to viable sperm + supernatant from non-viable sperm (43.5 AE 2.1), non-viable sperm + supernatant from non-viable sperm (39.1 AE 2.1) and non-viable sperm + extender (34.3 AE 2.1; P < 0.05). PMN-damage was less common in viable sperm + supernatant from viable sperm (17.2 AE 2.9), viable sperm + extender (19.6 AE 2.9) and non-viable sperm + supernatant from viable sperm (21.4 AE 2.9) compared to non-viable sperm + extender (64.8 AE 2.9), non-viable sperm + supernatant from non-viable sperm (70.6 AE 2.9) and live sperm + supernatant from non-viable sperm (80.6 AE 2.9; P < 0.05). In conclusion, we inferred that dead spermatozoa secreted substances that induced damage to PMNs. Previous studies have shown that seminal plasma protects PMNs from this effect, maintaining their capacity to phagocytose dead spermatozoa in the uterus.

Research paper thumbnail of Transmission of Bovine Viral Diarrhea Virus to Adult Goats from Persistently Infected Cattle

Journal of Veterinary Diagnostic Investigation, 2007

The transmission of bovine viral diarrhea virus (BVDV) from persistently infected (PI) heifers to... more The transmission of bovine viral diarrhea virus (BVDV) from persistently infected (PI) heifers to adult seronegative goats was examined in this study. Ten seronegative adult goats were exposed to 4 PI heifers. None of the goats developed any clinical signs but all goats seroconverted by 42 days after exposure to the PI cattle. Results indicate that goats are susceptible to BVDV infection when housed with PI cattle.

Research paper thumbnail of Gastric and enteric phytobezoars caused by ingestion of persimmon in equids

Journal of the American Veterinary Medical Association, 2011

Research paper thumbnail of Evaluation of diagnostic tests used for detection of bovine viral diarrhea virus and prevalence of subtypes 1a, 1b, and 2a in persistently infected cattle entering a feedlot

Journal of the American Veterinary Medical Association, 2006

Research paper thumbnail of Evaluation of the safety of vaccinating mares against equine viral arteritis during mid or late gestation or during the immediate postpartum period

Journal of the American Veterinary Medical Association, 2011

Research paper thumbnail of What Are the Manifestations of Ocular Exposure to Epichlorohydrin?

Journal of Occupational and Environmental Medicine, 2014

The Occupational Medicine Forum is prepared by the ACOEM Occupational and Environmental Medical P... more The Occupational Medicine Forum is prepared by the ACOEM Occupational and Environmental Medical Practice Committee and does not necessarily represent an official ACOEM position. The Forum is intended for health professionals and is not intended to provide medical or legal advice, including illness prevention, diagnosis or treatment, or regulatory compliance. Such advice should be obtained directly from a physician and/or attorney.

Research paper thumbnail of Farmer based organizations in Ghana