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Gaseous mixtures of diatomic hydrogen isotopologues and helium are often encountered in the nuclear energy industry and in analytical chemistry. Compositions of stored mixtures can vary due to interactions with storage and handling materials. When tritium is present, it decays to form ions and helium-3, both of which can lead to further compositional variation. Monitoring of composition is typically achieved by mass spectrometry, a method that is bulky and energy-intensive. Mass spectrometers disperse sample material through vacuum pumps, which is especially troublesome if tritium is present. Our ultimate goal is to create a compact, fast, low-power sensor that can determine composition with minimal gas consumption and waste generation, as a complement to mass spectrometry that can be instantiated more widely. We propose calorimetry of metal hydrides as an approach to this, due to the strong isotope effect on gas absorption, and demonstrate the sensitivity of measured heat flow to atomic composition of the gas. Peak shifts are discernible when mole fractions change by at least 1%. A mass flow restriction results in a unique dependence of the measurement on helium concentration. A mathematical model is presented as a first step toward prediction of the peak shapes and positions. The model includes a useful method to compute estimates of phase diagrams for palladium in the presence of arbitrary mixtures of hydrogen isotopologues. We expect that this approach can be used to deduce unknown atomic compositions from measured calorimetric data over a useful range of partial pressures of each component.

Hydrogen storage materials with high capacity are highly desirable. Currently none of the existing storage materials can meet the requirement of motor vehicle applications. We report a new hydrogen storage generation system, LiAlH4 + NH3. The two components are stored in separate containers when there is no demand for hydrogen, while the two components mix, hydrogen can be generated, up to 13 wt.% H2 at ambient temperature, on-demand. The H2 formation is exothermic with a high rate, suggesting that this is unlikely to be a reversible hydrogen storage material. More investigation is needed to improve or to maximize the degree of conversion.

Isotherms for H2/D2–Pd0.8Ag0.2 systems have been measured over a low temperature range, 198–323 K. Such low temperature data for this system have not been obtained previously. The absorption kinetics was found to be fast. The isotherms at low temperatures are compared with literature values at or above 313 K, as well as those for H2(D2)–Pd systems. The H/D isotope effect and the separation factors in the plateau range over Pd0.8Ag0.2 are calculated at various temperatures and discussed, based on the isotherms. Enthalpies are extracted from van’t Hoff plots and compared with calorimetric values and the results from the literature for both absorption and desorption processes. A method is given for using isotherm information from single isotope systems to estimate the separation factor for the mixed isotope systems and this is a helpful tool. The challenge of measuring absorption isotherms at low temperatures and low pressures is discussed. Sample pre-treatment, non-soluble impurity accumulation in an absorption process and thermal transpiration effects are examined.

This case study describes recent experiences with two classes of "Generation Me" psychology majors. The teacher compares the self-descriptions and behaviors of current college students with those of students from three earlier decades. Through self-critical reflections, he evaluates his instructional decisions with the two classes. He concludes that meaningful learning is best served by maintaining academic standards—even when there is some lessening of student and teacher comfort levels.

A Sieverts' apparatus coupled with a residual gas analysis is used to measure the concentration variations of hydrogen isotopes in the gas and solid phases during exchange and isothermal decomposition of mixed hydrides. beta-phase palladium hydrides with known ratios of H:D, Pd(H x D 1- x ) y (0x1, y0.6), are prepared by H 2 with PdD y or D 2 with PdH y exchange, and their desorption isotherms are reported here at 323 K. A higher equilibrium pressure in isothermal desorption of mixed hydrides is associated with a higher ratio of D/H in the initial mixed hydrides in beta-phase. The composition of the gas desorbed from a mixed hydride varies; i.e., the ratio of D/H in gas decreases with the sum of (H + D) in Pd. The values of the separation factor alpha during desorption at 323 K and during H-D exchange at 248 K are discussed and compared with those in the literature. Desorption isotherms of mixed isotope hydrides are between those of the single isotope hydrides of H-Pd and D-Pd, however, plateaus slope more than those of pure isotope hydrides. The origin of the plateau sloping in the mixed hydrides can be attributed to the compositional variations during desorption, i.e., the equilibrium pressure is greater when D/H ratio in solid is greater. A simple model is proposed in this study that agrees well with experimental results.

Hydrogen energy may provide the means to an environmentally friendly future. One of the problems related to its application for transportation is “on board” storage. Hydrogen storage in solids has long been recognized as one of the most practical approaches for this. Recently the hydrogen storage system, (Li 3 N + 2H 2 ⇔ LiNH 2 + 2LiH), was introduced by Chen et al. [P. Chen, Z. Xiong, J. Luo, J. Lin, K.L. Tan, Nature 420 (2002) 302–304. [1] ]. This type of material has attracted a great attention of the researchers from the metal hydride research community due to its high reversible storage capacity, up to 11.5 wt%. Currently the Li–Mg–N–H system has been shown to be able to deliver 5.2 wt% reversibly at a H 2 pressure of 30 bar and temperature of 200 °C. The accessibility of the capacity beyond 5.2 wt% is being actively explored. One of the issues related to the application of the metal–N–H storage systems is NH 3 formation that takes place simultaneously with H 2 release. NH 3 formation will not only damage the catalyst in a fuel cell, but also accelerate the cyclic instability of the H-storage material since the metal–N–H system turns into a metal–H system after loosing nitrogen and, therefore, it would not function at the temperature and pressure range designed for the metal–N–H system. The accurate determination of the amounts of NH 3 in the H 2 is, therefore, very important and has not been previously reported. Here a novel method to quantify NH 3 in the desorbed H 2 , the Draeger Tube, is reported as being suitable for this purpose. The results indicate that the concentration of NH 3 in desorbed H 2 increases with the desorption temperature. For the (2LiNH 2 + MgH 2 ) system the NH 3 concentration was found to be 180 ppm at 180 °C and 720 ppm at 240 °C.

We have developed a new method to measure the composition of gaseous mixtures of any two hydrogen isotopes, as well as an inert gas component. When tritium is one of those hydrogen isotopes, there is usually some helium present, because the tritium decays to form helium at a rate of about 1% every 2 months. The usual way of measuring composition of these mixtures involves mass spectrometry, which involves bulky, energy-intensive, expensive instruments, including vacuum pumps that can quite undesirably disperse tritium. Our approach uses calorimetry of a small quantity of hydrogen-absorbing material to determine gas composition without consuming or dispersing the analytes. Our work was a proof of principle using a rather large and slow benchtop calorimeter. Incorporation of microfabricated calorimeters, such as those that have been developed in Sandia’s MicroChemLab program or that are now commercially available, would allow for faster measurements and a smaller instrument footprint.

Photosystem II light-harvesting complexes were isolated from a number of ulvophycean algae. Some of these light-harvesting complexes displayed unusual features, most notably a high apparent molecular weight (ca. 58,000) when isolated by lithium doderyl sulfate polyarrylamide gel electrophoresis. Other ulvophycean light-harvesting complexes had a low-molecular weight (ca. 30,000). The distribution of the high-molecular weight complex was limited to certain members of the Caulerpales and Blastophysa rhizopus (Siphanocladales). Within the Caulerpales, there were also spectral differences between the high-molecular weight and low-molecular weight light-harvesting complex types. The differences in light-harvesting complexes in the Ulvophyceae suggest that there are two lines of evolution in the Caulerpales and that Blastophysa may be an intermediate between the Siphon-ocladales and the Caulerpales.

The three-dimensional structure of the flagellar apparatus of Uroglena americana Calkins (Uroglenopsis americana [Calkins] Lemmerman) was determined using serial section reconstruction. The three microtubular rootlet systems (R2, R3, and R4) follow the general pattern found in other chrysophytes. The R2 rootlet originates between the basal bodies of the mastigoneme-bearing long flagellum (F1) and the short smooth flagellum (F2) and is attached to the former by a fibrous connection. The R3 rootlet system originates as a trough-shaped band of six microtubules spanning the distance between the proximal ends of the F1 and F2 basal bodies. The six-membered rootlet splits into two parts (designated R3 and R3) which circle the depression from which the F2 flagellum emerges in counter-clockwise direction. These two rootlets pass beneath the F2 basal body and descend into the cell alongside the chloroplast. The R4 rootlet originates in fibrous material which passes diagonally over the F2 basal body, forms a clockwise loop about three-quarters of the way around the depression, and ends in the cytoplasm. In place of a typical chrysophyte R1 rootlet, U. americana has a different array of microtubules attached to the F1 basal body which we have designated the descending rootlet (DR). This rootlet is a hairpin-shaped structure lying just below the surface of the cell; its longitudinal axis is predominantly parallel to the longitudinal axis of the cell. The DR resembles the bypassing rootlet which occurs in phaeophyte zoospores. Other chrysophytes may possess rootlets which are similar to the DR found in Uroglena.

The three-dimensional structure of the flagellar apparatus of Dinobryon cylindrioum Imhof. (UTEX no. LB 2266) was determined using serial section reconstruction. Four microtubular rootlet systems (R1, R2, R3, and R4)and a rhizoplast are present, following the general pattern found in other chrysophytes. The R1 rootlet, containing seven microtubules, originates at the basal body of the long flagellum that bears mastigonemes (F1). The R1 rootlet forms an arc which curves in clockwise direction (when viewed from the anterior end of the cell) approximately halfway around the pit from which the short smooth flagellum (F2) emerges. Numerous microtubules cascade from the exterior-facing side of this rootlet to the tail of the cell. The R2 rootlet originates between the F1 and F2 basal bodies, is attached to the F1 basal body by a fibrous connection, and forms a clockwise arc above the R1 rootlet. This rootlet extends approximately one quarter of the way around the pit. The R3 rootlet system originates as a trough-shaped band of six microtubules spanning the distance between the proximal ends of the F1 and F2 basal bodies. The six-membered rootlet splits into two parts, designated R3 and R3. Both parts circle the pit in counter-clockwise direction, pass beneath the F2 basal body, and descend into the cell alongside the chloroplast. The R4 rootlet originates in fibrous material, passes diagonally over the top of the F2 basal body, forms a clockwise loop at least three quarters of the way around the pit to the interior of the R3 and R3 rootlets, and ends in the cytoplasm. Similarities of rootlet origins and other details of the flagellar apparatus of D. cylindricum with those of other heterokont organisms reinforce the idea that these organisms are phylogenetically related.

Recent development work on the EUV electric capillary discharge source been has focused on two areas: increasing EUV power generation and minimizing debris deposition on plasma facing optics. To achieve high-power operation, a pulser capable of driving the source up to 1.7 kHz and a new high-power lamp have been integrated. An EUV flux of 9 W into p-sr and a 2 percent bandwidth has been generated in burst mode at 1000 Hz. Three additional parametric studies are discussed. The first compares the EUV power generation and spectral output for three different capillary materials. The second study compares the source efficiency for 3 mm and 6 mm length capillaries. And the third parametric study measures the EUV output stability over a one million pulse run. The second focus area has been to increase mirror reflectance lifetimes through the further development of the gas curtain debris mitigation approach. A new gas curtain laboratory has been built with more than a 10x increase in flow capability and a 10x reduction in chamber background pressure. Measurements of the gas curtain efficiency have demonstrated a reduction in particulate deposition rate of at least a factor of eighty.

Progress continues on the development of the EUV Electric Capillary Discharge Source. Over the past year we have studied the high average power operational characteristics, used interferometry to measure the in-capillary electron density, and further reduced the debris deposition rate on plasma facing optics. A pulser capable of driving the source at up to 1 kHz was acquired and preliminary testing is in progress. EUV flux and spectral emission measurements were made for pure xenon and xenon-helium mixtures using a new electrode designed to prevent debris from depositing on multilayer optics. Finally, through improvements in capillary and electrode design and material properties coupled with the assistance of mitigation approaches, we have been able to significantly reduce the amount of debris generated by the source thereby increasing the reflectance lifetime of plasma-facing optics.

We report on the development of an electric capillary discharge source that radiates with comparable efficiency at both 13.5 nm and 11.4 nm, two wavelengths of interest for EUV lithography. The discharge source is comprised of a low- pressure, xenon-filled, small diameter capillary tube with electrodes attached to both ends. A high-voltage electric pulse applied across the capillary tube generates an intense plasma that radiates in the EUV. This source is capable of producing 7 mJ/steradian per pulse in a 0.3 nm bandwidth centered at 13.4 nm. In this paper we will address three significant issues related to the successful development of this source: minimization of debris generation, thermal management, and imaging quality.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The capabilities of the EUV 10x microstepper have been substantially improved over the past year. The key enhancement was the development of a new projection optics system with reduced wavefront error, reduced flare, and increased numerical aperture. These optics and concomitant developments in EUV reticles and photoresists have enabled dramatic improvements in EUV imaging, illustrated by resolution of 70 nm dense lines and spaces (L/S). CD linearity has been demonstrated for dense L/S over the range 100 nm to 80 nm, both for the imaging layer and for subsequent pattern transfer. For a +/- 10 percent CD specification, we have demonstrated a process latitude of +/- micrometers depth of focus and 10 percent dose range for dense 100 nm L/S.

Introduction The complex institutional issue of faculty salary equity has legal, financial, and personal ramifications [2, 10, 22, 29]. Of course, any effective faculty reward system should be part of an institution's strategic planning process [10] and should reflect the institution's culture [30]. Ideally, equity systems should be responsive to organizational, interpersonal, and market factors [9, 10, 28, 29] as well as the political circumstances operating within the institution [30, 31]. From a more general perspective, Cascio maintains, "The dominant concern among compensation managers for the 1990s and beyond is how the compensation system links with organization and human resource strategies" [6, p. 422]. In spite of this acknowledged need for a comprehensive, planned approach, many institutions have responded to faculty equity issues in an ad hoc, reactionary manner [10]. This approach results in a variety of serious negative consequences including litigation, inefficient use of human resources, morale and productivity problems, and a violation of the ethical treatment of employees [6, 7, 10, 21, 27]. The purpose of this article is to describe how our institution, Frostburg State University [FSU], transformed a multiple regression approach to equity into a value-based prescriptive process of developing faculty salary goals. The historical setting and the formation of the task force will be described, followed by an examination of the issues, values, and factors used to design the model. Finally, applications of the model are presented. Institutional Characteristics and Setting Frostburg State is a regional comprehensive university located in rural northwestern Maryland. The university enrolled more than forty-six hundred undergraduate students and more than eight hundred graduate students in 1994. Its undergraduates were predominantly full-time (89%), while its graduate students were largely part-time students (81%). The institution employed 244 full-time faculty in academic year 1994-95. Following the relatively common path of development from teacher's college to liberal arts college to comprehensive university, FSU has, for at least the past twenty-five years, continuously emphasized teaching as the primary role of faculty. Across three major revisions of its faculty evaluation system between 1971 and 1995 the university placed substantially greater weight upon teaching than upon other categories of evaluation, such as scholarship and service.(1) Further, demonstrated excellence in teaching is the institution's primary criterion for promotion to the upper faculty ranks. The institution's emphasis on the teaching role has been expressed as well in long-standing efforts to sustain small-to-moderate class sizes. For example, in 1994-95, 85% of all classes enrolled 30 or fewer students, and the modal class size was 18 students. Student-faculty ratios have been relatively stable, ranging between 16 to 1 and 18 to 1. Like other rural institutions, Frostburg has had to cope with a particular economic pressure unlike those facing urban and/or doctorate-granting institutions: the dearth of qualified part-time faculty and/or graduate teaching assistants. Getz and Siegfried [16] have described a national trend to substitute part-time for full-time faculty in the face of the rising costs of higher education. Rural universities cannot resort to this cost reduction strategy to the degree available to nonrural institutions. The outcome for FSU has been a heavy reliance on the most expensive form of staffing - full-time, fully benefited faculty. In the sciences, for example, in 1994-95 full-time faculty taught 90% of all science classes. The resulting high proportion and high numbers of full-time teaching faculty have placed great pressure on faculty salaries because the available funds are distributed among a larger-than-normal number of full- time faculty, especially when compared to other schools in the University of Maryland System. …

SUMMARY Some observations on the cytokinetic and mitotic mechanism in the filamentous green algae Ulothrix zonata (Weber & Mohr) Kutzing and U. tenuissima Kutzing are presented. The general pattern of division appears to be similar in both species, and includes a precocious cleavage furrow formed at late interphase. Cross wall formation is not completed until telophase. By late prophase the centriole pair has duplicated, and each daughter pair migrates to a position distinctly lateral to the spindle poles. As soon as the daughter nuclei have separated, formation of the new septum is completed by coalescence of presumably Golgi derived vesicles in the plane of the pre-mitotically developed cleavage invagination, so there is no ingrowth of the furrow itself. A phycoplast as typically found in certain other filamentous green algae (e.g., Stigeoclonium) is not formed. A comparable division mechanism has been reported previously in four cases, i.e., in Ulva, Pseudendoclonium, Trichosarcina, and in an alga of uncertain identity (UTEX strain LB 653). It is concluded that these taxa are related organisms, and can be referred to as Ulvophyceae sensu Stewart & Mattox. The taxonomic status of a number of doubtful species of Ulothrix is discussed in the light of both light microscopical and electron microscopical evidence.

The stephanokont flagellar apparatus of the zoospores ofDerbesia tenuissima (De Not.) Crouan is examined and compared to the flagellar apparatuses of other green algae. The flagella ofDerbesia are attached to two of three bands which lie at the junction of the body and papilla. Serial longitudinal and cross sections reveal that the basal bodies are attached to the bands along their sides and at their proximal ends. The bands are not striated in any plane. The lack of striation in the bands and the partial covering of the proximal end of the basal bodies by one of the bands closely resemble the type of flagellar connection system described as the “Bryopsis-type” byMelkonian (1980). Zoospores of ulvalean green algae also possess these features, suggesting that green siphons are phylogenetically related to theUlvales. It is proposed that green siphons be tentatively classified in theUlvaphyceae rather than in theChlorophyceae orCharophyceae.

The flagellar apparatus of Urospora penicilliformis (Roth) Aresch. is unique, or at least very unusual among green algae. The flagellar axonemes are rigid, and contain wing-like projections. There are no central microtubules in the most proximal part of the axoneme. The transition region contains a series of electron dense transverse lamellae rather than a single septum, and lacks a stellate pattern. There is no cartwheel pattern in the proximal part of the basal bodies. The latter are associated with four different types of fibrous elements: ascending striated fibers that attach to an electron dense plate in the papillar center, lateral striated fibers that parallel microtubular roots, fibrous elements that link adjacent basal bodies, and finally two massive striated fibers that descend into the cell, passing closely along the nucleus (system II fibers, or rhizoplasts). Each of the four microtubular flagellar roots is sandwiched between two system I striated structures. The roots are probably equal; they contain proximally four, and distally up to eight microtubules. Based on the zoospore flagellar apparatus, it is concluded that the multinucleate U. penicilliformis is related to the Ulvaphyceae. Finally, a possible explanation in functional terms is given for the peculiar external morphology and behavior of the zoospore.

SUMMARY Pseudendoclonium basiliense and Trichosarcina polymorpha are essentially identical with regard to the fine structural details of cell division even though one was previously classified in the Chaetophorales and the other in the Ulvales. Cell division in the 2 genera is also shown to be like that in Ulva, as previously suggested might be the case. The combination of mitotic and cytokinetic characteristics common to the 3 genera is distinctive: (1) precocious development of a thick cleavage furrow, (2) centrioles distinctly lateral to polar fenestrae, (3) collapse of the interzonal spindle at telophase, and. (4) a cleavage furrow not associated with microtubules. It is suggested that features of vegetative cell division presently provide the best, characteristics for defining the Ulvaceae and that the use of growth habit should be abandoned. Despite the fact that a phycoplast is not present, in these algae, it is concluded that their affinities lie with genera that do possess a phycoplast.

This fine structural study of the quadriflagellate zoospore of Ulothrix zonata (Weber & Mohr) Kutzing, with special attention to the flagellar root system, demonstrates that it is very similar to the zoospore of Ulva lactuca L. in several aspects. Common features include the presence of a cruciate root system (4-2-4-2 type), a non-striated band that connects basal bodies, a so-called terminal cap, and system I and system II striated root components. Only slight differences exist, i.e. in the shape of the terminal cap, and in the number and position of the system II root components. It is concluded that the taxonomic affinities of U. zonata lie with the Ulvaphyceae sensu Stewart and Mattox rather than with the Chlorophyceae. Additional support for this conclusion is the discovery of tiny, flat body scales on the zoospore of U. zonata. A summary of the distinctive characteristics of the Chlorophyceae, Charophyceae and Ulvaphyceae reflecting the current state of knowledge is given.

The components of the flagellar apparatuses of the male and female gametes of Derbesia tenuissima (De Not.) Crouan are compared with those in other swarmers of green algae. Both the male and female gametes were found to have a cruciate microtubular root system, a non-striated capping plate which connects basal bodies, two electron dense terminal caps which partially cover the proximal end of the basal bodies, and two small system II fibrous roots. Similarities exist between these components and those suggested to be typical of ulvalean swarmers. Based upon these similarities, it is proposed that the Caulerpales be classified in the Ulvaphyceae rather than in the Charophyceae or Chlorophyceae.

SUMMARY Scaly green monads are often placed in a separate class, Prasinophyceae, and have been considered to be among the most, primitive of green algae. Platymonas possesses rhizoplasts which resemble sarcomeric structures. At prophase, extranuclear spindle micro-tubules emanate from a granular region which appears to arise through dissolution or dispersion of the rhizoplasts. It is probable that the rhizoplasts are largely consumed during the formation of the spindle and only small fragments are left at metaphase. The rhizoplasts can be seen again at telophase but are short at this stage. The basal bodies are not at the spindle poles but remain at their interphase position. The interzonal spindle collapses early at telophase, and shortly thereafter cleavage microtubules appear. These microtubules extend from the region of the basal bodies to the posterior of the cell. The events of cell division are compared with these events in other green algae and in Ochromonas. The functional and phylogenetic significance of the observations is discussed.

SUMMARY At prophase in Pleurastrum, extranuclear spindle microtubules develop from the region of centrioles, which lie lateral to the nucleus midway between the future sites of the metaphase spindle poles. The microtubules then move laterally to overarch the nucleus and finally become incorporated into the spindle. The centrioles do not migrate and therefore lie in the same plane as the chromosomes at metaphase. At telophase, 2, more different systems of microtubules develop from the vicinity of the centrioles—a phycoplast and extensive arrays of microtubules that ensheath the daughter nuclei. Cell division in the filamentous Pleurastrum is compared to that in the green flagellate, Platymonas. The similarities between cell division in the 2 algae are interpreted as evidence: (i) that rhizoplasts (which in Platymonas resemble myofibrils) are somehow homologous to microtubules; and, (ii) that cell division in Pleurastrum differs from cell division in other examined filamentous chlorophycean genera because Pleurastrum has an independent evolutionary origin from a monad with Platymonas-like characteristics.

The origin of a cell wall was an event of fundamental importance in the evolution of plants. In the green algae, cell walls apparently had independent origins in at least three lines of evolution. In this paper, the components of the cell wall were determined and compared in four filamentous green algae representing the charophycean, chlorophycean and ulvacean evoluationary lines. The walls of all four have hydroxyproline-containing proteins which separate into five or six bands upon SDS gel electrophoresis. Variation does exist, with the charophyte possessing fast moving electrophoretic bands and high hydroxyproline content, the chlorophytes having intermediate movement of bands and lower hydroxyproline content, and the ulvaecean representative possessing slow moving bands and a very low, if not questionable, hydroxyproline and saccharide content. Qualitative and quantitative estimates of wall proteins and sugars have been determined and compared. A hypothetical scheme of cell wall evolution based on these data, those of previous analyses, and recent phylogenetic schemes is presented. Although sound conclusions cannot be made until more information is available, the scheme might help to emphasize the areas most in need of additional research.

The major components of the internal flagellar apparatus of Chilomonas paramecium Ehr. are two large microtubular roots and a striated root paralleled by three microtubules. The two microtubular roots overlap at the basal bodies. One microtubular root follows a curved path in the anterior of the cell, and the other extends straight to the posterior passing through a groove in the nucleus. The striated root extends laterally from the basal bodies. Except that it is smaller, the posteriorly directed root bears a strong resemblance to the axostyle of oxymonads. The overall arrangement and structure of the flagellar roots is similar to the pelta, axostyle and costa of trichomonads and the pelta and axostyle of oxymonads, groups of mitochondrion-less, largely parasitic or symbiotic protozoans. An affinity between cryptomonads and oxymonads or trichomonads would have many phylogenetic implications, some of which are discussed.

The chlorophycean genus Schizomeris is usually considered to be a member of the Ulvales, often in the family Schizomeridaceae. However, Schizomeris differs from Ulva in several important cytological aspects. In Ulva cytokinesis is by furrowing; there are no microtubules associated with the cleavage furrow and there are no plasmodesmata. In Schizomeris cytokinesis is by cell plate formation with associated phycoplast microtubules, and plasmodesmata are present in the transverse walls. Schizomeris is similar to the investigated chaetophoralean algae in these and other respects. At present Schizomeris should be considered a distinct genus, apparently related to the Chaetophorales.

A light-harvesting pigment-protein complex has been isolated fromMantoniella squamata (Micromonadophyceae, Chlorophyta) by nondenaturing polyacrylamide-gel electrophoresis. The complex runs as two bands of molecular weights 54,000 and 55,000. There are two constituent polypeptides of molecular weights 20,500 and 22,000. Antibodies were raised to the 20,500-dalton polypeptides from this complex and to the 24,500-dalton polypeptide from the analogous complex ofPedinomonas minor (Micromonadophyceae). The antibodies to theM. squamata polypeptide are specific for both polypeptides of theM. squamata light-harvesting complex, as well as for a 27,000-dalton polypeptide of undetermined function. The antibodies to theP. minor polypeptide are specific for polypeptide components of the light-harvesting complex of that alga. The antibodies specific for theM. squamata light-harvesting complex polypeptides do not cross react with any polypeptides ofP. minor thylakoid membranes, as demonstrated by crossed immunoelectrophoresis. Similarly, no polypeptides ofM. squamata thylakoids cross react with the antibodies specific forP. minor light-harvesting complex polypeptides. These results indicate that the light-harvesting complex ofM. squamata is structurally very different from that ofP. minor. In a survey of several land plants and green algae, including representatives of all classes of green algae, a light-harvesting complex homologous to that ofM. squamata was found only inMicromonas pusilla. All other organisms tested possessed a lightharvesting complex homologous to that ofP. minor. The evolutionary and taxonomic implications of the novelM. squamata light-harvesting complex are discussed.

In the first paper of this series it was shown that mitosis and cytokinesis in Schizomeris are more like those events in Stigeoclonium rather than Ulva. It was concluded that Schizomeris should be included in the Chaetophorales. The present work shows that the zoospores of Schizomeris are somewhat different from those of both Stigeoclonium and Ulva. It is concluded that Schizomeris should be retained in a separate family of the Chaetophorales. Specifically, quadriflagellate zoospores of Schizomeris lack a two-stranded microtubular root, but rather have four, wide, cruciately arranged microtubular roots which probably contain an equal number of microtubules. Evolution in green algal motile cells is briefly discussed, and it is suggested that a flagellar ring such as occurs in the Oedogoniales may have evolved from quadriflagellate zoospores similar to those of Schizomeris.

The fine structure of the male and female gametes of Pseudobryopsis, particularly that of the flagellar apparatus, is compared with that of swarmers of other green algae. There is general similarity, with differences in detail, to the Ulvales and other green siphons that have been studied. The similarities include overlapping basal bodies, the capping plate type of connective between basal bodies, terminal caps, and system II fibrous roots (rhizoplasts). The capping plate of the female gamete differs from that in other green siphons and the Ulvales in form and in the presence of a faint striation. A diagram illustrating the actual arrangement of the components of the flagellar apparatus is given, along with a discussion of the fact that the mirror image of the true arrangement has been given in some reports on ulvaphycean algae.

Mesostigma virideLauterborn (Prasinophyceae) is the first green flagellate found to have multilayered structures (MLS) in its flagellar apparatus. MLS's were previously known from green algae only in charophycean swarmers, linking theCharophyceae to the origin of land plants, whose male gametes (when flagellated) also possess an MLS.M. viride is, therefore, probably more closely related to the origin of theCharophyceae than any other green flagellate that has been thoroughly studied so far. The occurrence of MLS's in green flagellates and apparently in other algae and protozoans suggests that an MLS occurred in an ancient group of flagellates and has survived in various protistan lines, including the line of green algae related to land plants. The occurrence of a synistosome inM. viride and other of its characteristics suggest that it is more closely related toPyramimonas than to other genera of scaly green flagellates.

The modes of inheritance of chemically induced chlorophyll-deficient phenotypes in Mimulus cardinalis reveal that the chloroplast is controlled by the genome and the plastome. Three of the chlorophyll-deficient mutants in M. cardinalis are inherited through nuclear recessive genes and two are inherited through plastome genes. One chlorophyll-deficient mutant was sterile and could not be analyzed genetically. Ultrastructural analysis of the six mutant types reveals that each possesses a unique defective chloroplast type(s) in comparison to the genotypically and phenotypically normal chloroplasts. Based on plastid ultrastructure it seems reasonable to assume that the mutations, genome and plastome, are non-allelic or at least significantly different forms of the same allele. The isolation of these types of mutants provide suitable material needed to study the effects of specific biochemical blocks and the elucidation of developmental pathways leading to chloroplast biogenesis. The mutants also provide valuable information concerning the interrelationship between the nucleic acid of the genome and the plastome.

A fucoxanthin-chlorophyll a/c-protein complex has been isolated from the prymnesiophyte Pavlova gyrans. Thylakoid membranes were treated with the mild anionic detergent sodium taurodeoxycholate followed by sucrose density gradient centrifugation. The brown fraction produced by this procedure was treated with Triton X-100 followed by a second sucrose density gradient centrifugation. A brown fraction isolated from this gradient was shown to be a light-harvesting complex nearly identical to that which is present in the diatom Phaeodactylum tricornutum. The complexes from the two organisms have nearly identical absorption and flourescence spectra, both complexes contain fucoxanthin and two other carotenoids, both contain four polypeptides of similar molecular weights, and polypeptides from both complexes cross react with antibodies raised to polypeptides of the Phaeodactylum tricornutum complex. Results suggest a common evolutionary origin for these light-harvesting complexes, in apparent contrast to the great differences in cell structure between prymnesiophytes and diatoms.

Chlorokybus atmophyticus has a sarcinoid growth habit and produces scale-covered zoospores. Flagella are laterally inserted and attached internally to a multilayered structure characteristic of the Charophyceae. There are two kinds of pyrenoid in each cell, a feature previously observed in only one scaly green flagellate. C. atmophyticus demonstrates that the sarcinoid growth habit arose independently at least twice in the green algae and cannot be used to define taxonomic groups unless combined with other criteria. It is further concluded that C. atmophyticus should be classified in a separate family Chlorokybaceae and a separate order Chlorokybales. THE CHAROPHYCEAE iS of central interest among green algae because it includes forms related to the ancestry of land plants. An understanding of the evolution of habit and mode of reproduction within the class is essential to the understanding of adaptations leading to early archegoniates and is also of more strictly phycological concern in the comparison of Charophyceae with other green algal groups.

A yellow-leaved plastome mutant of Hosta (Hosta sieboldii Ingram complex, Liliaceae) known as 'Wogan Gold' lacks normal granal stacks, but has numerous stroma lamellae extending throughout the chloroplast. The chlorophyll a/b ratio is 0.76 in the mutant and 2.9 in wild type. The mutant contains a qualitatively normal pattern of other photosynthetic co-pigments. SDS-polyacrylamide gel electrophoresis showed a deficiency in the photosystem (PS) II light-harvesting complex. Since PS II is localized mainly in the granal region, the absence of the light-harvesting complex may explain the loss of granal stacking in this mutant.

Ten years of validity research concerning the Slosson Intelligence Test (SIT) is reviewed. The equivalence of the SIT to the Stanford-Binet and the Wechsler Scales is examined and the relationship of the SIT to achievement measures is described. The importance of supplementing correlational findings with regression analysis, mean difference data, and information on misclassification is emphasized by the reviewers. Decisions concerning individuals based on SIT IQ scores are viewed as particularly risky in situations involving groups of subjects characterized by a relatively narrow range of IQ scores.

SUMMARY This investigation describes the cytology of the ulotrichalean genera Ulothrix and Stigeoclonium. Cellular organization is similar to the degree that interphase cells of the 2 genera cannot be distinguished with certainly. In Stigeoclonium, the nuclear envelope becomes disrupted at the end of prophase, and centrioles enter the nucleoplasm. At metaphase the nuclear envelope is again intact, and some of the spindle tubules appear to be contiguous with the nuclear envelope. The spindle in Ulothrix is essentially open with, no attachment of spindle tubules to the nuclear envelope and with, centrioles on the spindle-cytoplasm interface at the spindle poles. Spindle poles are blunt in Stigeoclonium and pointed in Ulothrix. Cytokinesis is by cell plate formation in both genera, but there is no phragmoplast.

The zoospores of Pseudendoclonium basiliense and Trichosarcina polymorpha possess body scales similar to scales in Chara, Nitella, Coleochaete, and certain green monads that are often placed in a separate class, the Prasinophyceae. Otherwise, the zoospores are of the "ulotrichalean" type; that is, the basal bodies of the four flagella are two L-shaped pairs arranged in mirror-image relation. It is concluded that "prasinophytes" are not separable from the Chlorophyceae. Scales are indistinct and of brief occurrence on the zoospores of T. polymorpha, but in P. basiliense scales occur on the outer surface of the cell walls of germlings and on the walls of aplanospores. Evolution of more complex motile cells of plants is briefly discussed. It is suggested that Pseudendoclonium and certain other chaetophoralean or ulotrichalean algae might be better included in the same order with Ulva, Enteromorpha, Percursaria, and Trichosarcina, but a firm decision awaits studies of mitosis and cytokinesis.