Some Blood Parasites from Birds In Central Iowa

During 1957, 1958, and 1959, blood smears from 568 birds were examined. Ninety-nine (17.25%) of these birds were found to harbor haemosporidian parasites. Four species of birds harbored Plasmodium, four species were infected with Leucocytozoon, and five species with Haemoproteus. Trypanosomes and microfilariae were observed in two species

Blood Parasites from Birds of the Lake Okoboji Region, Iowa

Hematozoa are reported from 171 birds, representing 7 orders of 20 families and 33 species, all collected in Dickinson County, northwest Iowa, with the majority of animals being collected at the Iowa Lakeside Laboratory, Milford, Iowa. Blood parasites were observed in 67 birds (39.2%), with an incidence as follows: Haemoproteus sp., 45 (26.3%); Leucocytozoon sp., 19 (11.1%); Plasmodium sp., 4 (2.3%); Trypanosoma 3 (1.7%); and microfilariae, 29 (16.9%). An evaluation of these results indicates a dramatic decrease in the incidence of blood parasites later in the summer. The presence of parasites early in the spring is considered to be a function of relapse in birds returning to the area to build nests and to reproduce. The subsequent decrease in incidence of parasitized birds occurs as the infections run their course and become latent. A species of Plasmodium isolated from a blue jay (Cyanocita cristata) was found to be highly pathogenic, since the natural host as well as two other blue jays with induced blood infections died, with over 60% of their erythrocytes being parasitized. Using gametocyte morphology, the number of merozoites in mature schizonts and the punctiform appearance of pigment, the parasite was considered to be P. relictum. The blue jay appears to be a new host record for this parasite, at least in Iowa

Gizzard Lesions Associated with Haemoproteus sacharovi Infections of Pigeons

Becker et al. (1956) described abnormally enlarged spleens and granular gizzards observed in several killed pigeons. Blood films made from these particular birds were diagnosed as positive for Haemoproteus sacharovi. Since mourning doves represent a host for this parasite, four infected doves were killed and selected tissues sectioned and examined in an attempt to locate sites of exoerythrocytic schizogony. None were observed although the spleens of these birds were markedly swollen and colored a mottled purplish-black. Concerning pigeons, however, granular gizzards were observed in each of eight H. sacharovi infected pigeons killed. Examination of sections of infected gizzard revealed areas of small, round, dark-staining bodies. These areas were bounded by membranous capsules closely resembling mature splenic megaloschizonts of Leucocytozoon simondi. The haemosporidian character of these schizonts was further strengthened by their failure to provoke a cellular response as long as the capsule remained intact. Once the schizonts ruptured, however, an immediate phagocytic response was observed. Attempts to transmit infection by inoculating young pigeons with macerated gizzard were unsuccessful. Thus, the evidence that gizzard lesions observed in pigeons infected with H. sacharovi are sites of exoerythrocytic development is suggestive rather than conclusive

Occurrence (1956) of Haemoproteus sacharovi and Plasmodium relictum in a Central Iowa Pigeon Colony

Naturally occurring infections of Plasmodium relictum and H aemoproteus sacharovi in pigeons of Central Iowa have recently been reported (Becker, Hollander and Pattillo, 1956). In that survey, involving pigeons of all ages, both microscopic examination of stained blood films and isodiagnosis were employed, but the examination of blood films stained in Giemsa was the sole procedure relied upon in the 1956 survey. The birds concerned were young, ranging in age from two to eight weeks. All belonged to the Central Iowa colony to which reference was made in the previous paper. A total of 114 blood films was examined, distributed by dates as follows: June 29, 32; July 21, 23; September 8, 33; September 18, 26. There were a few duplications among the birds examined on September 8 and September 18. The average ages (in weeks) of the squabs on the four dates were as follows: June 29, 4.7; July 21, 3.7; September 8, 3.6; September 18, 4.4. There were, in addition, two other young squabs which will be discussed later

The Effects of Temperature and pH Upon the Exogenous Development of Eimeria tenella Railliet and Lucet, 1891, and Eimeria acervulina Tyzzer, 1929, Coccidian Parasites of the Chicken

The oocysts of the Coccidia are known to be fairly resistant to chemical disinfectants in general, but relatively susceptible to heat (Chang, 1937). The following investigation was carried out in an attempt to evaluate the combined effects of temperature and pH upon the exogenous development of oocysts of Eimeria tenella and Eimeria acervulina

Periodicity and Synchronicity of Plasmodium relictum in the Pigeon

A strain of Plasmodium relictum, isolated from a mourning dove, is being maintained by blood passage through pigeons. Studies concerning the periodicity and synchronicity of this organism indicate the length of the asexual cycle to be 24 hours correlated with a high degree of synchronicity. Segmentation occurs between 5 and 9 PM, with sporulation occurring between 5 AM and 1 PM. The pathogenicity of the strain to pigeons is moderate, with a tendency to kill several days after the crisis of infection has passed. Exoerythryocytic schizonts have been demonstrated in several of the birds that died, with these stages tending to affect the brain more than other organs. Young chickens, inoculated with infected pigeon blood, remained infected from four to ten days. However, duration of infection decreased with an increase in the age of the bird. Parasites did not develop in either six-week old or twelve-week old chickens. The taxonomic position of this particular strain of P. relictum is discussed

Coupled Macrospins: Mode Dynamics in Symmetric and Asymmetric Vertices

We report the microwave response of symmetric and asymmetric threefold clusters with nearly contacting segments that can serve as the node in a Kagome artificial spin ice lattice. The structures are patterned on a coplanar waveguide and consist of elongated and nearly-contacting ellipses with uniform thickness. Branches of the ferromagnetic resonance spectra display mode softening that correlates well with the calculations, whereas agreement between the measured and simulated static magnetization is more qualitative

Standard Neutrino Spectrum from B-8 Decay

We present a systematic evaluation of the shape of the neutrino energy spectrum produced by beta-decay of $^8$B. We place special emphasis on determining the range of uncertainties permitted by existing laboratory data and theoretical ingredients (such as forbidden and radiative corrections). We review and compare the available experimental data on the $^8$B$(\beta^+){}^8$Be$(2\alpha)$ decay chain. We analyze the theoretical and experimental uncertainties quantitatively. We give a numerical representation of the best-fit (standard-model) neutrino spectrum, as well as two extreme deviations from the standard spectrum that represent the total (experimental and theoretical) effective $\pm3\sigma$ deviations. Solar neutrino experiments that are currently being developed will be able to measure the shape of the $^8$B neutrino spectrum above about 5 MeV. An observed distortion of the $^8$B solar neutrino spectrum outside the range given in the present work could be considered as evidence, at an effective significance level greater than three standard deviations, for physics beyond the standard electroweak model. We use the most recent available experimental data on the Gamow--Teller strengths in the $A=37$ system to calculate the $^8$B neutrino absorption cross section on chlorine: $\sigma_{\rm Cl}=(1.14\pm0.11)\times10^{-42}$~cm$^2$ ($\pm3\sigma$ errors). The chlorine cross section is also given as a function of the neutrino energy. The $^8$B neutrino absorption cross section in gallium is $\sigma_{\rm Ga}=(2.46^{+2.1}_{-1.1})\times10^{-42}$ cm$^2$ ($\pm3\sigma$ errors).Comment: Revised version, to appear in Phys. Rev.

Global access to surgical care: a modelling study

Background More than 2 billion people are unable to receive surgical care based on operating theatre density alone. The vision of the Lancet Commission on Global Surgery is universal access to safe, aff ordable surgical and anaesthesia care when needed. We aimed to estimate the number of individuals worldwide without access to surgical services as defi ned by the Commission’s vision. Methods We modelled access to surgical services in 196 countries with respect to four dimensions: timeliness, surgical capacity, safety, and aff ordability. We built a chance tree for each country to model the probability of surgical access with respect to each dimension, and from this we constructed a statistical model to estimate the proportion of the population in each country that does not have access to surgical services. We accounted for uncertainty with oneway sensitivity analyses, multiple imputation for missing data, and probabilistic sensitivity analysis. Findings At least 4·8 billion people (95% posterior credible interval 4·6–5·0 [67%, 64–70]) of the world’s population do not have access to surgery. The proportion of the population without access varied widely when stratifi ed by epidemiological region: greater than 95% of the population in south Asia and central, eastern, and western sub- Saharan Africa do not have access to care, whereas less than 5% of the population in Australasia, high-income North America, and western Europe lack access. Interpretation Most of the world’s population does not have access to surgical care, and access is inequitably distributed. The near absence of access in many low-income and middle-income countries represents a crisis, and as the global health community continues to support the advancement of universal health coverage, increasing access to surgical services will play a central role in ensuring health care for all