Echinococcus Infections in Man and Animals in Kenya

1. Hydatid cysts are found in more than 30 per cent of all cattle, sheep and goats in Kenya, but the disease is prevalent in man only in the semi-desert area of Turkana. Up to the time of the present investigation the life-cycle of the parasite in East Africa had not been studied, but it was suggested that wild carnivores, such as hyenas and jackals, might be the main hosts of the adult worms. 2. One hundred and forty-three carnivores, representing 23 species, have been examined. Echinococcus adults were found in 27 out of 43 domestic dogs (Canis familiaris), in three out of four hunting dogs (Lycaon pictus), in one out of nine jackals (Thos mesomelas), and in three out of 19 hyaenas (Crocuta crocuta). 3. A detailed morphological study was made of the Kenya material. After comparison with specimens from other parts of the world, it was concluded that the only species occurring in Kenya was E. granulosus, but it is possible that the minor morphological and biological differences are evidence of distinct strains. Further laboratory studies are necessary to compare the parasite from man and animals in different parts of Kenya with material from elsewhere. 4. A search was made for larval hydatids in 92 ungulates representing 18 species, and in a miscellaneous collection of nearly 2,000 rodents and primates representing a further 31 species. Only one animal was positive, a wildebeest (Gorgon taurinus). 5. The infections in the wild carnivores were all very light; only domestic dogs were heavily infected. It is concluded that the main cycle of transmission in Kenya is between dogs and domestic livestock. 6. Turkana tribesmen are the most heavily infected people in Kenya, either because the strain of parasite is more pathogenic to man in that area, or, more probably, because of the intimate contact between children and the large number of infected dogs. A particularly dangerous custom in the area is the use of dogs to clean the face and anal regions of babies when they vomit or have diarrhea. No satisfactory explanation can be given for the rarity of the disease in man in many of the other areas of Kenya where hydatids are very common in domestic animals. 7. The control of the disease will depend upon an active health-education campaign, together with the destruction of all unregistered dogs and improvement in meat hygiene.

RB25-207 The Spindle-Tuber Disease: One Cause of "Run-Out" Seed Potatoes

The spindle-tuber disease is one of the most prevalent potato diseases occurring in all parts of Nebraska. It has been found in all varieties tested. It does much damage to the potato crop, in that it reduces the yield and injures the market quality of the potatoes. This 1925 publication discusses the spindler-tuber disease also known as "running-out" or degeneracy of seed potatoes; the distribution of the disease; effect upon yield and quality; symptoms of the different potato varieties; transmission of the disease and experiments; rate of increase of the disease; dry land versus irrigation in western Nebraska; straw mulching versus cultivation in eastern Nebraska; planting times; harvesting; and control.

Optimizing Amplifier Placements in a Multiwavelength Optical LAN/MAN: The Unequally Powered Wavelengths Case

Optical networks based on passive-star couplers and employing WDM have been proposed for deployment in local and metropolitan areas. These networks suffer from splitting, coupling, and attenuation losses. Since there is an upper bound on transmitter power and a lower bound on receiver sensitivity, optical amplifiers are usually required to compensate for the power losses mentioned above. Due to the high cost of amplifiers, it is desirable to minimize their total number in the network. However, an optical amplifier has constraints on the maximum gain and the maximum output power it can supply; thus, optical amplifier placement becomes a challenging problem. In fact, the general problem of minimizing the total amplifier count is a mixed-integer nonlinear problem. Previous studies have attacked the amplifier-placement problem by adding the “artificial” constraint that all wavelengths, which are present at a particular point in a fiber, be at the same power level. This constraint simplifies the problem into a solvable mixed integer linear program. Unfortunately, this artificial constraint can miss feasible solutions that have a lower amplifier count but do not have the equally powered wavelengths constraint. In this paper, we present a method to solve the minimum amplifier- placement problem, while avoiding the equally powered wavelength constraint. We demonstrate that, by allowing signals to operate at different power levels, our method can reduce the number of amplifiers required.

Minimizing the Number of Optical Amplifiers Needed to Support a Multi-Wavelength Optical LAN/MAN

Optical networks based on passive star couplers and employing wavelength-division multiplexing (WDhf) have been proposed for deployment in local and metropolitan areas. Amplifiers are required in such networks to compensate for the power losses due to splitting and attenuation. However, an optical amplifier has constraints on the maximum gain and the maximum output power it can supply; thus optical amplifier placement becomes a challenging problem. The general problem of minimizing the total amplifier count, subject to the device constraints, is a mixed-integer non-linear problem. Previous studies have attacked the amplifier placement problem by adding the “artificial” constraint that all wavelengths, which are present at a particular point in a fiber, be at the same power level. In this paper, we present a method to solve the minimum amplifier- placement problem while avoiding the equally powered- wavelength constraint. We demonstrate that, by allowing signals to operate at different power levels, our method can reduce the number of amplifiers required in several small to medium-sized networks.

University students' assessment of entrepreneurial environments

Entrepreneurial intention is a primary step to create new venture in the entrepreneurial process. Environmental conditions are one of the main factors that are strengthening or weakening intention of prospective entrepreneur. Therefore, it is important to develop conducive environments for entrepreneurship to promote entrepreneurial intention. Moreover, the promoted entrepreneurial intention will raise the rate of new venture creation. This paper investigates the relationships between five key environments for entrepreneurship and entrepreneurial intention. The five entrepreneurial environments are: government policies and procedures, socioeconomic conditions, entrepreneurial and business skills, financial assistance, and non-financial assistance, respectively. Conjoint analysis was used to determine the significance of five environmental factors conducive to entrepreneurial intention. In this conjoint experiment, 1370 decisions were made by 137 university students. Significant relationships were found between all of these environmental factors and intention. Comparative importance of environmental factors was also calculated, along with sub-conjoint analyses based on characteristics of the sample.

The Land Grant University Movement and IANR: Animal Science Seminar Series

"The problems that exist in the world today cannot be solved by the level of thinking we were at when we created them." That quote, attributed to Albert Einstein, epitomizes for me the importance of land grant universities in the 21 st century, and whenever I hear someone say that land grants are obsolete - which, occasionally, I do hear - I want to pull that quote out and say "here - read this." When all the problems in the world have been solved, then - and only then - will land grant universities be obsolete. Maybe. I'm not really willing to commit to the idea that the day of obsolete land grants ever will come, but if all the problems in the world are one day solved, then maybe - maybe - I'd consider it.

The Land Grant University Movement and the Future of IANR UAAD

Good afternoon. It is a real pleasure for me to be here with you today, and I thank you for inviting me. I also, as I begin my remarks today, want to thank each of you for the work you do, everyday, to help make this a better university. Please know that work is both valued and appreciated. I'd like to talk with you about a couple of topics today, and after that I'm going to open the floor for questions and comments. I look forward to hearing what you have to say, too. The first topic I'm going to talk about in the next few minutes is our land grant mission. People who know me at all can tell you I am passionate about land grants because I believe being part of a land grant university and helping to advance the land grant mission is one of the great privileges and responsibilities of our times.

Dr. Edward (Ted) Elliot Eulogy

Kathy and Susie, members of the faculty, and staff of the School of Natural Resource Sciences, ladies and gentlemen. There are some things in this world that, try as we may, just cannot be adequately accomplished. One of those things, for me at least, is to express adequately what I feel about the passing of Dr. Edward (Ted) Elliot. Ted came to this University of Nebraska a few months before I arrived, and it was my distinct honor to count him among my friends at this great University. Ted was a man of exceptional scientific standing and wisdom, and his loss leaves a void in all of our lives that will not be readily filled.

Agriculture Builders of Nebraska, Inc.

There’s a story that a construction foreman one day noticed one of his workers pushing his wheelbarrow upside down around the work site. “Hey,” the foreman shouted, “turn that thing right side up!” The man with the wheelbarrow looked at him in surprise. “Don’t be silly,” he said. “Every time I do that, they put bricks in it!” I think of that story sometimes, in the midst of these difficult economic times, as our states, its people, and its university, in turn, wrestle with budge cuts. Wouldn’t it be great if we all could just turn our wheelbarrows over and say, “No thanks, no more brick! No more heavy loads to haul!”

On the Ecology and Distribution of Echinococcus spp. (Cestoda: Taeniidae), and Characteristics of Their Development in the Intermediate Host. II. Comparative Studies on the Development of Larval E. multilocularis Leuckart, 1863, in the Intermediate Host

This paper reports the results of a comparative study of the development of the larval Echinococcus multilocularis Leuckart, 1863), and associated tissue reaction in naturally and experimentally infected mammals representing 31 species. The histogenesis of the larval cestode was traced in detail in arvicoline rodents of several species, and interspecific differences were defined. In arvicoline rodents, the developing larva exhibited host-specific characteristics within about a month after infection was established. The tissue reaction in Microtus oeconomus was characterized by the production of a large quantity of detritus around the larva, and by the formation of a thick epithelioid zone. In one subspecies, M. oeconomus innuitus, development of the larva was retarded, and the detrital mass was often calcified; in another, M. oeconomus operarius, the detritus rarely became calcified and the larva proliferated more rapidly. In M. pennsylvanicus, the tissue reaction was minimal, and little detritus was present. The characteristics of the tissue reaction in M. montebelli placed it in an intermediate position between the aforementioned species. In Clethrionomys rutilus, a thin epithelioid zone and an outer zone of loose collagenous fibers composed the adventitial layer; exogenous budding was retarded in this vole. A minimal tissue reaction occurred in Lagurus curtatus. In Lemmus spp., larger cysts were characteristic, but areas of small-cystic proliferation were always present. Similar differences in species or subspecies of Citellus and Dicrostonyx were described. Lesions of alveolar bydatid disease in man also were studied. The invasive growth of the larval cestode in the human liver involves a process comparable to small-cystic proliferation in the natural intermediate hosts. Although the later stages of development of the larval cestode are inhibited in man, exogenous proliferation of vesicles continues for the life of the host. The lesion in man was compared with a morphologically similar formation produced by anomalous development of the larval E. granulosus in the bovine liver. The latter is distinguished by the absence of areas of small-cystic proliferation. Non-echinococcal lesions found in the tissues studied, some of which resembled foci caused by the larval E. multilocularis, were briefly discussed.

2007 East Campus Arbor Day Celebration

As we celebrate Arbor Day, it seems fitting to begin with a J. Sterling Morton quote. "The cultivation of trees is the cultivation of the good, the beautiful, and the ennobling in man,” Morton once said, adding, "and for one, I wish to see it become universal."

Information and Communication Technologies for Educational Development: The Case of Cybercafés at Obafemi Awolowo University, Ile-Ife, Nigeria

This study examines the use of Cybercafés/Internet resources and the evaluation of their usefulness. About eight Cybercafés located in the university community were used in this study. Questionnaires, interviews with the Cybercafé owners, staff and users as well as personal observations made during inspection of these cafés were used in this study. The data were analysed according to the background of the Internet users. The richness and high speed, accuracy, and authority were used by users to judge the quality of the Internet. Information such as the establishment of the café's facilities, membership and the future of the Cybercafés were also looked into. Finally, one can clearly see that the dominating impact of digital technology has crossed the Rubicon of controversy. The result of the survey shows that forty percent of the users learnt to use the internet by self instruction, thirty five percent learnt from colleagues or friends. Those in the sciences use the internet the most, the channel mostly used in obtaining information is the search engines. A large number of students, faculties and researchers make use of the internet in obtaining information. Many of those of those users make use of the Cybercafés in the university community.

Biotic Interrelationships of Helminth Parasitism

Biotic interrelationships in Alaska have so far suffered little from man's attempts to improve upon nature. As a result of these favorable circumstances, biological investigation in Alaska offers unusual opportunity for elucidating problems which can no longer be approached in the more populated parts of North America. One is very fortunate to have the opportunity of working under these conditions, since present trends indicate that Alaska is soon to go by the way of the great wildernesses which once existed in the United States and Canada.

AN OVERVIEW OF DEPREDATING BIRD DAMAGE CONTROL IN CALIFORNIA

To many people, California is synonomous with Disneyland, freeways, Los Angeles smog, Yosemite, the California missions, or for you bird aficionados, the California Condor. But do you think about California when you eat strawberry shortcake? You should -- California leads the nation in strawberry production. How about artichokes? California produces over 98% of the artichokes raised in the United States. Dates? California produces over 99% of the dates in the United States. Yes, California is all of these, and it is much more. California may well be the most diverse state in the United States. Within its 100.2 million acres, California has the lowest place in the U.S. in Death Valley and one of the highest mountains with Mt. Whitney. Because California is such a diverse state and has a wide variety of micro- climates, it supports a uniquely diverse agriculture. Agriculture uses only about 36 million acres of its total 100.2 million acres, and most of the cash return from crops is produced on 8,6 million acres that are irrigated. California produces about 250 crops and livestock commodities (excluding nursery crops) and provides the U.S. with about 25% of its table foods. California leads the nation in the production of 46 commercial crops and livestock commodities; its farmers and ranchers marketed $8.6 billion of crop and livestock products in 1975, and the state’s harvested farm production in 1975 set a new record at 51.1 million tons. HISTORY OF BIRD PROBLEMS Records such as this are not achieved without some risk. Crops growing in Cali- fornia have always had competition from many types of vertebrate pests. The wide variety of crops grown in California and the varied climates and situations in which they are grown has resulted in many different species of birds damaging crops. Birds have compet- ed with man for his crops since the dawn of agriculture. McAtee (1932) cited examples of bird damage that occurred in a wide variety of crops in California during the early 1900s. During the 1920s, many requests for Information and relief from damage caused by a wide variety of birds, culminated in the assignment, in May 1929, of two biologists, S. E. Piper and Johnson Neff, of the former U.S. Bio- logical Survey, to initiate field studies in California. In cooperation with the Cali- fornia Department of Food and Agriculture and County Agricultural Commissioners, the study was to determine the problems and devise control procedures relative to bird depredations. Piper and Neff found such damage as Horned Larks pulling sprouting crops, House Finches disbudding deciduous fruit trees and devouring mature fruit. Blackbirds were a problem in the rice crop. Early controls were varied and, for the most part, lacked effectiveness. Flagging of fields was common to deter Horned Larks. Windmill devices were tried to frighten birds. Shooting to kill birds was common; scarecrows were.used. The six-year study brought forth the basis of most of the depredating bird control techniques still in use in California. At the end of the study, these two biologists compiled a book called “Procedure and Methods in Controlling Birds Injurious to Crops in California.” This was and still is the “Bible” for bird damage control techniques used in California. The thorough investigations conducted by these biologists resulted in techniques that have remained valid in California for over 40 years.

FOREST ANIMAL DAMAGE CONTROL

As a nation we have gained world recognition for our ability to utilize our resources. In forestry our greatest accomplishments have been in the mechanization of harvest methods and in improvements in forest products. The renewal of this resource has been our greatest neglect. Though the end of the 19th Century marked the beginning of the conservation movement, it was not until a half century later that the force of economics through the demands of a growing population made forest re-establishment more than just a desire. Conservation in itself is a Utopian concept which requires other motivating forces to make it a reality. In the post-war years, and as late as the early 195O's, stocked land in the Pacific Northwest could be purchased for less than the cost of planting; the economic incentive was lacking. Only with sustained yield management and increased land values was there a balance in favor of true values. With greater effort placed on forest regeneration there was an increased need for methods of reducing losses to wildlife. The history of forest wildlife damage research, therefore, parallels that of forest land management; after rather austere beginnings, development became predominantly a response to economics. It was not until 1950 that the full time of one scientist was assigned to this important activity. The development of control methods for forest animal damage is a relatively new area of research. All animal life is dependent upon plants for its existence; forest wildlife is no exception. The removal of seed and foliage of undesirable plants often benefits the land managers; only when the losses or injuries are in conflict with man's interest is there damage involved. Unfortunately, the feeding activities of wildlife and the interests of the land managers are often in conflict. Few realize the breadth, scope, and subtilities associated with forest wildlife damage problems. There are not only numerous species of animals involved, but also a myriad of conditions, each combination possessing unique facets. It is a foregone conclusion that an understanding of the conditions is essential to facilitate a solution to any given problem. Though there are numerous methods of reducing animal damage, all of which have application under some situations, in this discussion emphasis will be placed on the role of chemicals and on western problems. Because of the broadness and complexity of the problem, generalizing is necessary and only brief coverage will be possible. However, an attempt will be made to discuss the use and limitations of various control methods.