Effects of rotation in the laser-pulse photoassociation in a thermal gas of atoms

Photoassociation is a possible route for the formation of chemical bonds. In this process, the binding of colliding atoms can be induced by means of a laser field. Photoassociation has been studied in the ultracold regime and also with temperatures well above millikelvins in the thermal energy domain, which is a situation commonly encountered in the laboratory. A photoassociation mechanism can be envisioned based on the use of infrared pulses to drive a transition from free colliding atoms on the electronic ground state to form a molecule directly on that state. This work takes a step in this direction, investigating the laser-pulse-driven formation of heteronuclear diatomic molecules in a thermal gas of atoms including rotational effects. Based on the assumption of full system controllability, the maximum possible photoassociation yield is deduced. The photoassociation probability is calculated as a function of the laser parameters for different temperatures. Additionally, the photoassociation yield induced by subpicosecond pulses of a priori fixed shape is compared to the maximum possible yield.

Vaccination of grazing calves with antigens from the intestinal membranes of Haemonchus contortus: effects against natural challenge with Haemonchus placei and Haemonchus similis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Rubella Vaccination of Unknowingly Pregnant Women: The Sao Paulo Experience, 2001

Background. Rubella vaccination is contraindicated during pregnancy. During mass immunization of women of childbearing age against rubella, women unknowingly pregnant may be vaccinated. To evaluate the effects of rubella vaccination during pregnancy, the Brazilian state of Sao Paulo conducted a follow-up study of pregnant women vaccinated during a rubella campaign in 2001.Methods. Women vaccinated during pregnancy were reported to a national surveillance system. In the state of Sao Paulo, follow-up of vaccinated women included household interviews. Serum samples from vaccinated women were tested for antirubella antibodies to classify susceptibility to rubella infection. Children born to susceptible mothers were tested for evidence of congenital rubella infection and evaluated for signs of congenital rubella syndrome.Results. The Sao Paulo State Health Department received 6473 notifications of women vaccinated during pregnancy. Serology performed for 5580 women identified 811 (15%) that were previously susceptible. Incidence of spontaneous abortion or stillbirth among previously susceptible vaccinated women was similar to women with prior immunity. Twenty-seven (4.7%) of 580 newborns tested had evidence of congenital rubella infection; none had congenital rubella syndrome.Conclusions. Mass rubella vaccination of women of childbearing age was not associated with adverse birth outcomes or congenital rubella syndrome among children born to women vaccinated during pregnancy.

Effects of dexmedetomidine on pulse pressure variation changes induced by hemorrhage followed by volume replacement in isoflurane-anesthetized dogs

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Frequencies of virulence genes and pulse field gel electrophoresis fingerprints in Escherichia coli isolates from canine pyometra

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Vaccination of sheep and cattle against haemonchosis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effects of primovaccination and booster vaccination on serum cortisol and humoral immune response in cattle

The objective of this study was to evaluate the effect of one or two doses of the anti-rabies vaccination on the serum concentration of cortisol and the humoral immune response in cattle as well as the correlation between serum cortisol concentrations and the titers of rabies-neutralizing antibodies. Nelore cattle were randomly assigned to one of three groups, which were vaccinated with one dose of rabies vaccine (group GVSR, N = 15), two doses of rabies vaccine (group GVR, N = 15) or were not vaccinated (group Gc, N = 15). A commercial liquid inactivated rabies vaccine was used. The stressors imposed on the cattle were vaccination, corral handling and the presence of people. Blood samples were collected on days 0, 30 and 60 post-vaccination. Serum cortisol concentrations were determined using a solid-phase radioimmunoassay, and rabies antibody titers were determined using a serum neutralization test with BHK21 cells (RFFIT). Both serum cortisol concentrations and antibody titers increased after the second (booster) vaccination (P < 0.05). In all the groups, the serum cortisol concentrations increased after the cattle were handled in the corral (P < 0.05). No correlation was observed between the serum cortisol concentrations and the antibody titers with any treatment or on any observation day. In conclusion, booster vaccination is indispensable for primovaccinated cattle in achieving high and protective levels of rabies antibodies. Although booster vaccination and frequent cattle handling in corrals are stressors, the response is not strong enough to cause immunosuppression in cattle.

Humoral Immune Responses of White-Tailed Deer (Odocoileus virginianus) to Mycobacterium bovis BCG Vaccination and Experimental Challenge with M. bovis

Monitoring of the kinetics of production of serum antibodies to multiple mycobacterial antigens can be useful as a diagnostic tool for the detection of Mycobacterium bovis infection as well as for the characterization of disease progression and the efficacy of intervention strategies in several species. The humoral immune responses to multiple M. bovis antigens by white-tailed deer vaccinated with BCG orally via a lipid-formulated bait (n = 5), orally in liquid form (n = 5), and subcutaneously (n = 6) were evaluated over time after vaccination and after experimental challenge with virulent M. bovis and were compared to the responses by unvaccinated deer (n = 6). Antibody responses were evaluated by using a rapid test (RT), a multiantigen print immunoassay (MAPIA), a lipoarabinomannan enzyme-linked immunosorbent assay (LAM-ELISA), and immunoblotting to whole-cell sonicate and recombinant antigen MPB83. MAPIA and RT detected minimal to no antibody responses over those at the baseline to multiple M. bovis antigens in vaccinated white-tailed deer after challenge. This was in contrast to the presence of more readily detectable antibody responses in nonvaccinated deer with more advanced disease. The LAM-ELISA results indicated an overall decrease in the level of production of detectable antibodies against lipoarabinomannan-enriched mycobacterial antigen in vaccinated animals compared to that in nonvaccinated animals after challenge. Immunoblot data were inconsistent but did suggest the occurrence of unique antibody responses by certain vaccinated groups to Ag85 and HSP70. These findings support further research toward the improvement and potential use of antibody-based assays, such as MAPIA, RT, and LAM-ELISA, as tools for the antemortem assessment of disease progression in white-tailed deer in both experimental and field vaccine trials.

Vaccination with Mycobacterium bovis BCG Strains Danish and Pasteur in White-tailed Deer (Odocoileus virginianus) Experimentally Challenged with Mycobacterium bovis

Wildlife reservoirs of Mycobacterium bovis represent serious obstacles to the eradication of tuberculosis in domestic livestock and the cause for many faltering bovine tuberculosis eradication programs. One approach in dealing with wildlife reservoirs of disease is to interrupt inter-species and intraspecies transmission through vaccination of deer or cattle. To evaluate the efficacy of BCG vaccination in white-tailed deer, 35 deer were assigned to one of three groups; one s.c. dose of 107 CFU of M. bovis BCG Pasteur (n = 12); 1 s.c. dose of 107 CFU of M. bovis BCG Danish (n = 11); or unvaccinated deer (n = 12). After vaccination, deer were inoculated intratonsilarly with virulent M. bovis. Lesion severity scores of the medial retropharyngeal lymph node, as well as all lymph nodes combined, were reduced in vaccinated deer compared to unvaccinated deer. BCG Danish vaccinated deer had no late stage granulomas characterized by coalescent caseonecrotic granulomas containing numerous acid-fast bacilli compared to BCG Pasteur vaccinated or unvaccinated deer where such lesions were present. Both BCG strains were isolated as late as 250 days after vaccination from deer that were vaccinated but not challenged. In white-tailed deer, BCG provides protection against challenge with virulent M. bovis. Issues related to vaccine persistence, safety and shedding remain to be further investigated.

Vaccination of White-Tailed Deer (Odocoileus virginianus) with Mycobacterium bovis Bacillus Calmette Guerin

Wildlife reservoirs of Mycobacterium bovis represent serious obstacles to the eradication of tuberculosis in domestic livestock. In Michigan, USA tuberculous white-tailed deer transmit M. bovis to cattle. One approach in dealing with this wildlife reservoir is to vaccinate deer in order to interrupt the cycle of deer to deer and deer to cattle transmission. Thirty-one white-tailed deer were assigned to one of three groups; 2 SC doses of 107 CFU of M. bovis BCG (n = 11); 1 SC dose of 107 CFU of M. bovis BCG (n = 10); or unvaccinated deer (n = 10). After vaccination, deer were inoculated intratonsilarly with 300 CFU of virulent M. bovis. Gross lesion severity scores of the medial retropharyngeal lymph node were significantly reduced in deer receiving 2 doses of BCG compared to unvaccinated deer. Vaccinated deer had fewer lymph node granulomas than unvaccinated deer, and most notably, fewer late stage granulomas characterized by coalescent caseonecrotic granulomas containing numerous acid-fast bacilli. BCG was isolated from 7/21 vaccinated deer as long as 249 days after vaccination. In one case BCG was transmitted from a vaccinated deer to an unvaccinated deer. In white-tailed deer BCG provides measurable protection against challenge with virulent M. bovis. However, persistence of vaccine within tissues as well as shedding of BCG from vaccinates remain areas for further investigation.

INVESTIGATION INTO CURRENT EFFICIENCY FOR PULSE ELECTROCHEMICAL MACHINING OF NICKEL ALLOY

INVESTIGATION INTO CURRENT EFFICIENCY FOR PULSE ELECTROCHEMICAL MACHINING OF NICKEL ALLOY Yu Zhang, M.S. University of Nebraska, 2010 Adviser: Kamlakar P. Rajurkar Electrochemical machining (ECM) is a nontraditional manufacturing process that can machine difficult-to-cut materials. In ECM, material is removed by controlled electrochemical dissolution of an anodic workpiece in an electrochemical cell. ECM has extensive applications in automotive, petroleum, aerospace, textile, medical, and electronics industries. Improving current efficiency is a challenging task for any electro-physical or electrochemical machining processes. The current efficiency is defined as the ratio of the observed amount of metal dissolved to the theoretical amount predicted from Faraday’s law, for the same specified conditions of electrochemical equivalent, current, etc [1]. In macro ECM, electrolyte conductivity greatly influences the current efficiency of the process. Since there is a certain limit to enhance the conductivity of the electrolyte, a process innovation is needed for further improvement in current efficiency in ECM. Pulse electrochemical machining (PECM) is one such approach in which the electrolyte conductivity is improved by electrolyte flushing in pulse off-time. The aim of this research is to study the influence of major factors on current efficiency in a pulse electrochemical machining process in macro scale and to develop a linear regression model for predicting current efficiency of the process. An in-house designed electrochemical cell was used for machining nickel alloy (ASTM B435) by PECM. The effects of current density, type of electrolyte, and electrolyte flow rate, on current efficiency under different experimental conditions were studied. Results indicated that current efficiency is dependent on electrolyte, electrolyte flow rate, and current density. Linear regression models of current efficiency were compared with twenty new data points graphically and quantitatively. Models developed were close enough to the actual results to be reliable. In addition, an attempt has been made in this work to consider those factors in PECM that have not been investigated in earlier works. This was done by simulating the process by using COMSOL software. However, it was found that the results from this attempt were not substantially different from the earlier reported studies.

Landscape-Genetic Analysis of Population Structure in the Texas Gray Fox Oral Rabies Vaccination Zone

In west-central Texas, USA, abatement efforts for the gray fox (Urocyon cinereoargenteus) rabies epizootic illustrate the difficulties inherent in large-scale management of wildlife disease. The rabies epizootic has been managed through a cooperative oral rabies vaccination program (ORV) since 1996. Millions of edible baits containing a rabies vaccine have been distributed annually in a 16-km to 24-km zone around the perimeter of the epizootic, which encompasses a geographic area >4 x 105 km2. The ORV program successfully halted expansion of the epizootic into metropolitan areas but has not achieved the ultimate goal of eradication. Rabies activity in gray fox continues to occur periodically outside the ORV zone, preventing ORV zone contraction and dissipation of the epizootic. We employed a landscape-genetic approach to assess gray fox population structure and dispersal in the affected area, with the aim of assisting rabies management efforts. No unique genetic clusters or population boundaries were detected. Instead, foxes were weakly structured over the entire region in an isolation by distance pattern. Local subpopulations appeared to be genetically non-independent over distances >30 km, implying that long-distance movements or dispersal may have been common in the region. We concluded that gray foxes in west-central Texas have a high potential for long-distance rabies virus trafficking. Thus, a 16-km to 24-km ORV zone may be too narrow to contain the fox rabies epizootic. Continued expansion of the ORV zone, although costly, may be critical to the long-term goal of eliminating the Texas fox rabies virus variant from the United States.

Landscape Genetics of Raccoons (Procyon lotor) Associated with Ridges and Valleys of Pennsylvania: Implications for Oral Rabies Vaccination Programs

Raccoons are the reservoir for the raccoon rabies virus variant in the United States. To combat this threat, oral rabies vaccination (ORV) programs are conducted in many eastern states. To aid in these efforts, the genetic structure of raccoons (Procyon lotor) was assessed in southwestern Pennsylvania to determine if select geographic features (i.e., ridges and valleys) serve as corridors or hindrances to raccoon gene flow (e.g., movement) and, therefore, rabies virus trafficking in this physiographic region. Raccoon DNA samples (n = 185) were collected from one ridge site and two adjacent valleys in southwestern Pennsylvania (Westmoreland, Cambria, Fayette, and Somerset counties). Raccoon genetic structure within and among these study sites was characterized at nine microsatellite loci. Results indicated that there was little population subdivision among any sites sampled. Furthermore, analyses using a model-based clustering approach indicated one essentially panmictic population was present among all the raccoons sampled over a reasonably broad geographic area (e.g., sites up to 36 km apart). However, a signature of isolation by distance was detected, suggesting that widths of ORV zones are critical for success. Combined, these data indicate that geographic features within this landscape influence raccoon gene flow only to a limited extent, suggesting that ridges of this physiographic system will not provide substantial long-term natural barriers to rabies virus trafficking. These results may be of value for future ORV efforts in Pennsylvania and other eastern states with similar landscapes.

Efficacy of Oral and Parenteral Routes of Mycobacterium bovis Bacille Calmette-Guerin Vaccination Against Experimental Bovine Tuberculosis in White-Tailed Deer (Odocoileus virginianus): A Feasibility Study

We investigated the efficacy of oral and parenteral Mycobacterium bovis bacille Calmette-Guerin Danish strain 1331 (BCG) in its ability to protect white-tailed deer (Odocoileus virginianus) against disease caused by M. bovis infection. Twenty-two white-tailed deer were divided into four groups. One group (n=5) received 109 colony-forming units (cfu) BCG via a lipid-formulated oral bait; one group (n=5) received 109 cfu BCG in culture directly to the oropharynx, one group (n=6) was vaccinated with 106 cfu BCG subcutaneously, and one group served as a control and received culture media directly to the oropharynx (n=6). All animals were challenged 3 mo after vaccination. Five months postchallenge the animals were examined for lesions. Results indicate that both oral forms of BCG and parenterally administerd BCG offered significant protection against M. bovis challenge as compared to controls. This study suggests that oral BCG vaccination may be a feasible means of controlling bovine tuberculosis in wild white-tailed deer populations.

Benefit Cost Scenarios of Potential Oral Rabies Vaccination for Skunks in California

Scenario-based analyses were computed for benefits and costs linked with hypothetical oral rabies vaccination (ORV) campaigns to contain or eliminate skunk-variant rabies in skunks (Mephitis mephitis) in California, USA. Scenario 1 assumed baiting eight zones (43,388 km2 total) that comprised 73% of known skunk rabies locations in the state. Scenario 2 also assumed baiting these eight zones, but further assumed that added benefits would result from preventing the spread of skunk-variant rabies into Los Angeles County, USA. Scenarios assumed a fixed bait cost ($1.24 each) but varied campaigns (one, two and three annual ORV applications), densities of baits (37.5/km2, 75/km2 and 150/km2), levels of prevention (50%, 75%, and 100%), and contingency expenditures if rabies recurred (20%, 40%, and 60% of campaign costs). Prorating potential annual benefits during a 12-yr time horizon yielded benefit-cost ratios (BCRs) between 0.16 and 2.91 and between 0.34 and 6.35 for Scenarios 1 and 2, respectively. Economic issues relevant to potentially managing skunk-variant rabies with ORV are discussed.