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Work Decrements In The Performance Of A Pursuit Task Arising From Relatively Short Periods Of Massed Practice, Abram Barch

Proceedings of the Iowa Academy of Science

In a series of articles beginning in 1948, Kimble attempted to extend two constructs of the Hullian system to the realm of motor learning. These constructs were reactive inhibition (IR) and conditioned inhibition (_SI_R). Definition and Measurement. Reactive inhibition was conceived of as a response-produced need state, a need to stop responding, which accompanies all behavior and which dissipates with rest. The effect of reactive inhibition on the learning process is to reduce the work-output level of the organism and thus to obscure the actual strength of the habit. Kimble postulated that the accumulation of a …

The Scotometer - A Dark-Tunnel Apparatus For Studying Night Vision Of Drivers, Harold I. Stalder, Donald A. Hoppe, A. R. Lauer

Proceedings of the Iowa Academy of Science

Lauer and Silver (1941) described a special dark room for studying acuity and visual discrimination under low levels of illumination. The length of the room was about 20 feet, thus precluding certain measurements where greater distances were required. The test objects were also stationary allowing only for measurements being made at a fixed distance. In connection with a recent study (1951) on perception of changes in relative distance and in variations thereof, it was necessary to construct a device which would not only give a greater distance potential, but which would allow for variations in speed of approach or recession …

The Numbers Of Fungi, G. W. Martin

Proceedings of the Iowa Academy of Science

In most reference and text-books on botany, the number of known species of fungi is given as from 75,000 to 100,000. The sources of these estimates are rarely cited but it may be inferred that most of them trace back, usually indirectly, to the number of descriptions compiled in the twenty-five volumes of Saccardo (8) which amounts to somewhat over 81,000, usually with a more or less generous allowance for the number of valid species described too late to be included in the last volume of that work, which appeared in 1931, and which have appeared since that time.

The Campbell Micro-Fossil Washer, Carlyle B. Campbell

Proceedings of the Iowa Academy of Science

I am deeply grateful for the privilege of presenting this process of micro-fossil washing, because it is a long step toward perfection in micropaleontology. With the speed and efficiency with which micro-fossils can now be removed from shales which were heretofore considered too hard to be worked, a whole new era lies before us.

A Previously Unnamed Amoeba, Mayorella Clavella, Nov. Sp., Eugene Cleveland Bovee

Proceedings of the Iowa Academy of Science

During the last quarter of the nineteenth century, a considerable number of investigators gained fame for their studies of the organisms usually placed in the order Amoebida, class Rhizopodea, subphylum Sarcodina, phylum Protozoa (Jahn, 1949), commonly referred to as the naked amoebas. Because these scientists were working in a relatively untouched field of investigation-which it still remains-their attempts to classify the organisms they saw and depicted resulted in considerable confusion as to which amoebas were really legitimate species, and which were simply varieties of established species. The inevitable "lumper" and "splitter" appeared amongst these men as they applied their taxonomic …

The Flora Of Iowa County, Nathan W. Easterly

Proceedings of the Iowa Academy of Science

Iowa County has not been neglected botanically although there has never been a complete survey of the flora of the county. Because of the energetic travels of the late Professor B. Shimek, over 300 specimens from Iowa County are included in the permanent collections in the herbarium at the State University of Iowa. Dr. Shimek has also made numerous reports of plants from Iowa County which have been used in this thesis. The first list of plants published as a flora of Iowa County was prepared by William Moerschal and Conrad Schadt, pharmacists, Amana. This list is found at the …

Iowa State Teachers College Schedule Of Classes, Winter 1951, Iowa State Teachers College

UNI Schedule of Classes

A listing and schedule of the courses being taught as well as policies and procedures concerning attending classes at the Iowa State Teachers College.

The Flora Of Cedar County, Iowa, Marcus J. Fay

Proceedings of the Iowa Academy of Science

This botanical survey of the vascular plants of Cedar County, Iowa, was made in an effort to increase our knowledge of the vegetation of eastern Iowa. Prior to this survey, relatively little botanical collecting had been done in Cedar County. Thirty-two specimens from Cedar County were found by the writer in looking through the herbarium of the State University of Iowa. These were collected by Prof. B. Shimek and Prof. W. A. Anderson. The field work was carried on for a period of one growing season. Over 4,000 miles were traveled by the writer in making the survey. The first …

Nitrate Adsorbed On Pumice As A Nitrogen Source For Plant Growth, Wayne J. Mcilrath

Proceedings of the Iowa Academy of Science

In recent years it has been shown, through the use of commercial ion-exchange material, that plants are able to utilize nitrate ions incorporated in soil or nutrient culture in an adsorbed state (Schlenkler, 1940, 1942; Converse, Gammon and Sayre, 1943; Graham and Albrecht, 1943; Jenny, 1946; Arnon and Grossenbacher, 1947; Hunter, 1948). In view of the apparent adsorptive power of pumice (Veller and Arutyunyan, 1933), it was of interest to determine whether this material could be utilized in plant nutrition studies to supply nitrogen as adsorbed nitrate. Although preliminary experimentation showed that the nitrate fixing capacity of pumice was very …

Developmental Abnormalities In Drosophila Melanogaster Induced By Ultraviolet Radiation, E. V. Enzmann

Proceedings of the Iowa Academy of Science

In a number of previous papers we have reported on modifications in the morphogenesis of Drosophila melanogaster Meig. by x-irradiation, neutron bombardment, and under adverse environmental conditions. Additional data concerning the problems involved are found in the papers of workers in the same field, who have used the same or different methods of approach (Patterson, 1929; Geigy, 1931; Henshaw, 1933; Richards and Furrow, 1925; Jones, 1936; Russel, 1940; Hartung, 1942; Lawrence, 1937; Combs and Gravett, 1937; Mavor, 1927; Bardeen, 1910; et al). A comparison of various methods used in the study of these questions show that the differences in …

On The Chemotherapeutic Action Of 3-Nitro-4-Hydroxyphenyl-Arsonic Acid Against The Coccidium Eimeria Tenella In Chickens, Neal F. Morehouse, F. Mckay

Proceedings of the Iowa Academy of Science

Morehouse and Mayfield (1946) reported that 3-nitro-4-hydroxyphenyl-arsonic acid and its sodium salts were effective in reducing hemorrhage and mortality from the coccidium Eimeria tenella when administered in the drinking water. The present investigation was undertaken to determine the activity of this arsenic acid when medication was started at various times with reference to the time of infection and to determine the stage or stages in the life-cycle affected by the compound.

Table Of Contents

Proceedings of the Iowa Academy of Science

No abstract provided.

Recent Eskers In The Wind River Mountains Of Wyoming, Mark F. Meier

Proceedings of the Iowa Academy of Science

The origin of eskers has long been a subject of controversy. These interesting features of the glacial landscape have been studied extensively in the Midwest, New England, Scandinavia, and elsewhere, but nearly all of these studies dealt with deposits left by glaciers which had long since disappeared. Theories of origin of these eskers have, therefore, been based largely on assumption and inference. To the author's knowledge the only published technical description of recent eskers are those of I. C. Russell, who in 1897 briefly described some esker-like ridges in the stagnant margin of the Malaspina Glacier in Alaska, and W. …

Comparison Of Form And Color Fields, Harold V. Gaskill Jr., Albert G. Rostenbach, Robert M. Thompson

Proceedings of the Iowa Academy of Science

Many studies have been made of the color fields of the eye and some consideration has been given the form fields. With the invention of the microscope by Leeuwenhoeck in 1722, who first made a study of the retina of the frog, much interest has been shown in the structure and functions of the retina. Some of the world's greatest histologists such as Cajal, Mueller and others have studied the structural characteristics of the retina. Very little attention has been given the functions of the retina from the point of view of psychology.

A Study Of The Effect Of Penicillin And Dihydrostreptomycin On Protozoa With Special Reference To The Problems Of Bacteria-Free Culture And Speciation In Euglena, Carol May Goodwin

Proceedings of the Iowa Academy of Science

Among the many phenomena observed in studies with streptomycin and penicillin, the apparent resistance of certain protozoa to antibiotics is of interest to the protozoologist. If this resistance exists in the case of all protozoa, then it should be possible to develop a technique involving antibiotics which can be used for obtaining bacteria-free cultures of any protozoan. The concentrations of penicillin and streptomycin used by various authors in attempts to effect isolation of specific protozoans are presented in Table 1. Speaking of sensitivity of bacteria to streptomycin, Waksman (1949) states that "within genera, the.re is considerable variation in susceptibility to …

A Cabin In The Clearing, Robert Frost

James Hearst Documents

The poem A cabin in the clearing written by Robert Frost sent as a Christmas greeting to James Hearst.

Iowa Teachers 1951 Wrestling Dopebook, Iowa State Teachers College

Athletics Media Guides

Contents:

--Thumbnail of Iowa Teachers 1951 Wrestling --1
--1951 Schedule and 1950 Results --2
--Sketch of Dave McCuskey --3-4
--McCuskey's 17-Year-Record at Iowa Teachers --5
--Assistant Coach Paul "Bo" Cameron --5
--Outlook for 1951 --6-7
--Wrestling Roster --8
--Wrestler Sketches --9-13
--Sketches of Opponents --14-15
--Record of Iowa Teachers Series with 1951 Opponents --16
--Past Results with 1951 Opponents --16
--How Iowa Teachers scored in 1950 Dual Meets --17
--How a Iowa Teachers Scored in 1950
--National Tournaments --17
--Iowa Teachers National Wrestling Champions, NCAA-NAAU --18
--Iowa Teachers Olympic Wrestlers --18
--Iowa Teachers Place-Winners in National Meets --18
--Results 1950 …

The First 75 Years, Irving H. Hart

Iowa Book Gallery

A history of Iowa State Teachers College (previously known as Iowa State Normal School and now known as the University of Northern Iowa), from 1876 to 1951.

Effect Of Iodinated Casein And Thiouracil On The Concentrations Of Carotenoids And Vitamin A In The Blood Plasma Of Young Dairy Animals, R. S. Allen, G. H. Wise, N. L. Jacobson

Proceedings of the Iowa Academy of Science

In recent years attention has been directed to the role of the thyroid gland in the metabolism of carotene and vitamin A. Drill and Truant (1947) reported that carotene administration failed to prevent xerophthalmia in thyroidectomized rats, whereas vitamin A supplementation cured the eye lesions. Moreover, Johnson and Baumann (1947), using liver storage of vitamin A as the criterion of conversion of carotene to vitamin A, found that hyperthyroid rats accumulated larger stores of vitamin A than normal rats receiving equivalent doses of carotene, but rats rendered hypothyroid by feeding either thiourea or thiouracil stored little vitamin A. Similar experiments …

Sprays For Control Of Sycamore Anthracnose, Paul H. Schuldt

Proceedings of the Iowa Academy of Science

Sycamore anthracnose, Gnomonia veneta, (Sacc. & Speg.) Klebahn (4), prevalent in Iowa (1), belongs to a group of plant diseases with life cycle patterns which suggest the use of fungicidal sprays for their control. In early spring this disease appears as a blight on the young leaves soon after they emerge from the bud (Fig. 1). The blighted leaves become brown to black and frequently appear as if they had been injured by frost. Mature leaf infection characteristically produces elongate brown streaks along the midveins and laterals (Fig. 2), and many such infected leaves fall within two or three …

Nutrition And Aeration In Relation To The Growth Of Cannabis Saliva, John R. Weber

Proceedings of the Iowa Academy of Science

The common commercial variety of dioecious hemp, Cannabis saliva when grown under favorable conditions is known to exhibit not only sexual dimorphism but certain other fairly uniform structural characteristics. Plants of the two sexes are distinguished by difference in the rate of growth, habit, and time of flowering. Certain characteristic vegetative traits such as the transition from three to five to seven compound leaflets and a modification in habit from opposite to alternate phyllotaxy, not usually correlated with sex, normally also occur with great regularity at certain stages of growth. An experiment was undertaken to determine possible variations produced in …

The Simplest Leaf Organization Found In Surveys Of Several Hundred Species Of Dicotyledons, Robert B. Wylie

Proceedings of the Iowa Academy of Science

The number of cell-layers in leaves of dicotyledons varies considerably but within fairly definite limits. Extreme thickness of epidermis or mesophyll presently retards photosynthetic activity and is usually restricted to succulents and desert types. In connection with studies of leaves representing a large number of species of dicotyledons, no mature leaf was noted having fewer than five cell-layers in the blade. The list included, in addition to many species from Iowa, a liberal collection from southern Florida, samplings from the Pacific coast states, a number from Fiji and a fairly large collection from North Island, N. Z. with scattered numbers …

Herbarium Of The State University Of Iowa, Robert F. Thorne

Proceedings of the Iowa Academy of Science

Since it was founded about 1870 by Thomas H. Macbride, the herbarium of the State University of Iowa has grown steadily until it now contains approximately 143,000 mounted or otherwise properly accessioned plant specimens. According to the best figures available for other herbaria (Jones and Meadows, 1948), our herbarium ranks about thirty-fifth in size in the United States or fourteenth in size among herbaria of state universities or state colleges.

Report On The Vii International Botanical Congress, Stockholm, July 12-20, 1950., G. W. Martin

Proceedings of the Iowa Academy of Science

It was my privilege to attend the VII International Botanical Congress as the official representative of the State University of Iowa and the Iowa Academy of Science. Although the Congress did not formally convene until July 12, the Committee on Nomenclature and the Special Committee on Fungi met on July 7 and succeeding days, in the hope that most of the nomenclatural problems could be settled in advance of the formal sessions. This proved a vain hope, and working until late at night left many things to be decided up until nearly the end of the regular session.

Screening Chemotherapeutants For Control Of Oak Wilt, Paul F. Hoffman

Proceedings of the Iowa Academy of Science

Oak wilt, caused by the fungus Chalara quercina H. (6), has been present in the upper Mississippi valley for many years. Warder in 1880 (10) and Tiemann in 1927 (9) reported oaks dying in Wisconsin with symptoms now recognized to be characteristic of oak wilt. Today oak wilt is known to be distributed over the entire state of Iowa with the exception of the northwestern corner. The disease is considered one of the principal problems encountered in oak production in the central hardwood region and considerable emphasis has been placed on the development of suitable control methods.

Vegetational Changes In Ungrazed Grassland At The Iowa Lakeside Laboratory., Sylvia Rudman, Richard W. Pohl

Proceedings of the Iowa Academy of Science

A tract of upland grassland, about 60 acres in extent, was purchased by the Iowa Lakeside Laboratory in 1930. This plot lies just to the north of the mess hall and dormitories of the laboratory. The property, of rough and hilly topography, rises to a height about ninety feet above the level of Little Miller's Bay on West Okoboji Lake and drains southeastward to Little Miller's Bay. Before the purchase of this tract by the Laboratory, it was heavily pastured, but had never been plowed. As the result of this grazing, Kentucky bluegrass (Poa pratensis L.) had become the …

Montmorillonite A Factor In The Breakdown Of Concrete Aggregate, Fred H. Dorheim

Proceedings of the Iowa Academy of Science

This investigation (Dorheim, 1950) was made m an effort to identify mineralogical or textural characteristics of limestones that might affect the durability of concrete. The Iowa State Highway Commission has found that when certain limestones were used as coarse aggregate in concrete, that concrete gave excellent service in paving. Other limestones that responded to standard testing procedures in a similar manner, gave very poor results when used in concrete paving.

Title Page - Front Matter

Proceedings of the Iowa Academy of Science

No abstract provided.

Proceedings Of The Sixty-Third Meeting Of The Iowa Academy Of Science Held At Wartburg College, Waverly, Iowa, April 20 And 21, 1951: Minutes Of The 1951 Meeting

Proceedings of the Iowa Academy of Science

No abstract provided.

Officers, Committees, Past Presidents, And Members, Iowa Academy Of Science

Proceedings of the Iowa Academy of Science

No abstract provided.