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Lay Abstract: The topic of how parents react (e.g., how they talk and act) to their child with autism or elevated likelihood of autism, often called parent responsiveness, has been studied by researchers for over 50 years. Many methods for measuring behaviors around parent responsiveness have been created depending on what researchers were interested in discovering. For example, some include only the behaviors that the parent does/says in reacting to something the child does/says. Other systems look at all behaviors in a period of time between child and parent (e.g., who talked/acted first, how much the child or parent said/did). The purpose of this article was to provide a summary of how and what researchers looked at around parent responsiveness, describe the strengths and barriers of these approaches, and suggest a "best practices" method of looking at parent responsiveness. The model suggested could make it more possible to look across studies to compare study methods and results. The model could be used in the future by researchers, clinicians, and policymakers to provide more effective services to children and their families.

End-of-life in the Intensive Care Unit (ICU) is common, costly, and can contribute to negative health outcomes for bereaved family members. Insufficient understanding of the family experience results in poor quality, highly variable care riddled with deficiencies including effective identification and application of evidence-based clinical interventions. Successfully managing the multitude of transitions, for example changes in family role or personal identity requires creative practice guided by theory. This project supports the feasibility of using peri-mortem photographs captured by family members with story-telling and a standardized measurement of grief to explore the family experience of end-of-life in the ICU. Project findings reveal shared experiential themes and emphasize the value of photography and storytelling as meaning-making interventions for families. Further study to generalize findings and develop additional preventative and therapeutic interventions at and beyond end-of-life in the ICU is needed to better meet family needs and improve their health outcomes., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Introduction: Healthcare organizations faced unique operational challenges during the COVID-19 pandemic. Assuring the safety of both patients and healthcare workers in hospitals has been the primary focus during the COVID-19 pandemic., Methods: The NIH Vaccine Program (VP) with the Vaccine Management System (VMS) was created based on the commitment of NIH leadership, program leadership, the development team, and the program team; defining Key Performance Indicators (KPIs) of the VP and the VMS; and the NIH Clinical Center's (NIH CC) interdisciplinary approach to deploying the VMS., Results: This article discusses the NIH business requirements of the VP and VMS, the target KPIs of the VP and the VMS, and the NIH CC interdisciplinary approach to deploying an organizational VMS for vaccinating the NIH workforce. The use of the DCRI Spiral-Agile Software Development Life Cycle enabled the development of a system with stakeholder involvement that could quickly adapt to changing requirements meeting the defined KPIs for the program and system. The assessment of the defined KPIs through a survey and comments from the survey support that the VP and VMS were successful., Conclusion: A comprehensive program to maintain a healthy workforce includes asymptomatic COVID testing, symptomatic COVID testing, contact tracing, vaccinations, and policy-driven education. The need to develop systems during the pandemic resulted in changes to build software quickly with the input of many more users and stakeholders then typical in a decreased amount of time., Competing Interests: No competing financial interests exist., (Copyright 2022, ABSA International 2022.)

Francisella tularensis causes disease (tularemia) in a large number of mammals, including man. We previously demonstrated enhanced efficacy of conventional antibiotic therapy for tularemia by postexposure passive transfer of immune sera developed against a F. tularensis LVS membrane protein fraction (MPF). However, the protein composition of this immunogenic fraction was not defined. Proteomic approaches were applied to define the protein composition and identify the immunogens of MPF. MPF consisted of at least 299 proteins and 2-D Western blot analyses using sera from MPF-immunized and F. tularensis LVS-vaccinated mice coupled to liquid chromatography-tandem mass spectrometry identified 24 immunoreactive protein spots containing 45 proteins. A reverse vaccinology approach that applied labeling of F. tularensis LVS surface proteins and bioinformatics was used to reduce the complexity of potential target immunogens. Bioinformatics analyses of the immunoreactive proteins reduced the number of immunogen targets to 32. Direct surface labeling of F. tularensis LVS resulted in the identification of 31 surface proteins. However, only 13 of these were reactive with MPF and/or F. tularensis LVS immune sera. Collectively, this use of orthogonal proteomic approaches reduced the complexity of potential immunogens in MPF by 96% and allowed for prioritization of target immunogens for antibody-based immunotherapies against tularemia.

Recent theory suggests that global warming may be catastrophic for tropical ectotherms. Although most studies addressing temperature effects in ectotherms utilize constant temperatures, Jensen's inequality and thermal stress considerations predict that this approach will underestimate warming effects on species experiencing daily temperature fluctuations in nature. Here, we tested this prediction in a neotropical pseudoscorpion. Nymphs were reared in control and high-temperature treatments under a constant daily temperature regime, and results compared to a companion fluctuating-temperature study. At constant temperature, pseudoscorpions outperformed their fluctuating-temperature counterparts. Individuals were larger, developed faster, and males produced more sperm, and females more embryos. The greatest impact of temperature regime involved short-term, adult exposure, with constant temperature mitigating high-temperature effects on reproductive traits. Our findings demonstrate the importance of realistic temperature regimes in climate warming studies, and suggest that exploitation of microhabitats that dampen temperature oscillations may be critical in avoiding extinction as tropical climates warm.

Protection against the intracellular bacterium Francisella tularensis within weeks of vaccination is thought to involve both cellular and humoral immune responses. However, the relative roles for cellular and humoral immunity in long lived protection against virulent F. tularensis are not well established. Here, we dissected the correlates of immunity to pulmonary infection with virulent F. tularensis strain SchuS4 in mice challenged 30 and 90 days after subcutaneous vaccination with LVS. Regardless of the time of challenge, LVS vaccination protected approximately 90% of SchuS4 infected animals. Surprisingly, control of bacterial replication in the lung during the first 7 days of infection was not required for survival of SchuS4 infection in vaccinated mice. Control and survival of virulent F. tularensis strain SchuS4 infection within 30 days of vaccination was associated with high titers of SchuS4 agglutinating antibodies, and IFN-γ production by multiple cell types in both the lung and spleen. In contrast, survival of SchuS4 infection 90 days after vaccination was correlated only with IFN-γ producing splenocytes and activated T cells in the spleen. Together these data demonstrate that functional agglutinating antibodies and strong mucosal immunity are correlated with early control of pulmonary infections with virulent F. tularensis. However, early mucosal immunity may not be required to survive F. tularensis infection. Instead, survival of SchuS4 infection at extended time points after immunization was only associated with production of IFN-γ and activation of T cells in peripheral organs., (Copyright © 2010. Published by Elsevier Ltd.. All rights reserved.)

A 2-yr experiment was conducted to compare carcass characteristics and meat palatability attributes of steers ((3/4) British, (1/4) Continental) finished postweaning as calves or yearlings. Calves and yearlings of the same contemporary group were designated to a finishing system at weaning. Calves (n = 73) were finished in the feedlot (191 d) on a high-concentrate diet. Yearlings (n = 84) grazed crop residues after weaning, followed by spring and summer pasture grazing, and concluded with a short finishing period (91 d) in the feedlot. All steers were fed to a constant, fat thickness endpoint of 1 cm. The M. longissimus lumborum steaks from each production system were aged for 7, 14, or 21 d for Warner-Bratzler shear force determination and for 7 or 14 d for in-house sensory panel evaluation. Insoluble, percent soluble, and total collagen were determined. Yearlings produced heavier (P < 0.001) carcasses with larger (P < 0.001) LM areas and lower (P < 0.001) marbling scores and quality grades. Calves possessed greater amounts of total collagen (P < 0.001), with a significantly greater percentage of soluble collagen compared with yearlings (39.72 vs. 24.38%). Calves produced steaks with lower (P < 0.001) shear force values and greater (P < 0.001) sensory ratings for flavor. The USDA Choice steaks from the calves were more (P < 0.001) tender and more (P < 0.050) palatable than Choice steaks from yearlings, and USDA Select steaks from calves were rated more tender (P < 0.001), juicy (P = 0.012), and desirable (P < 0.001) than Select steaks from yearlings. As expected, increasing aging time from 7- to 14- to 21-d produced steaks with lower (P < 0.001) shear force values, regardless of the production system. Risk probabilities showed 1.24% of the steaks from calf-finished steers and 21.22% of steaks from yearling-finished steers to be tough. Sensory rating probabilities showed the steaks from the calves were most likely to be desirable for tenderness, whereas steaks from the yearlings were most likely to be undesirable for tenderness, juiciness, flavor, and overall acceptability. Thus, calf-finished steers produce carcasses superior in quality and palatability compared with those from yearling-finished steers. However, yearling-finished steers can produce tender beef with extended aging.

A 3-yr experiment was conducted with cows and their calves to evaluate resource inputs, animal performance, and carcass characteristics of two production systems. In the control system, cows (CON; n = 99/yr) grazed pasture and were fed hay during the winter, and CON steer calves were finished in the feedlot for 211 d after weaning. In the treatment system (TRT; n = 100/yr), cows grazed pasture and crop residue during the winter and were fed hay. Treatment steer calves grazed crop residue after weaning, grazed pasture in the spring and summer, and were finished in the feedlot for 90 d. Body condition scores after TRT cows returned from crop residue grazing were greater (P < 0.01) for CON than for TRT cows. Calving rates were similar for both groups (CON = 91%; TRT = 93%). In the feedlot, CON steers had lower (P < 0.05) ADG and DMI, but were more efficient (P < 0.01) than TRT steers. Treatment steers had greater (P < 0.05) final weight, hot carcass weight and longissimus muscle area, and decreased marbling score. The cost per weaned calf and weaning breakeven were greater (P = 0.07) for the CON system than for the TRT system (CON = 455.12 dollars, 0.91 dollar/0.45 kg; TRT = 421.43 dollars, 0.84 dollar/0.45 kg). When steers were priced into the postweaning phase on an economic basis, slaughter breakeven was lower (P = 0.01), and profit potential tended (P = 0.14) to be greater for TRT steers when they were sold on a live basis. When steers were priced into the postweaning phase on a financial basis, slaughter breakeven was lower (P = 0.03) and profit potential from the sale of steers on a live basis was greater (P = 0.07) for TRT than for CON steers. Economic evaluation of the total system resulted in greater (P = 0.06) profit potential for the TRT system when steers were priced into the system on either an economic or a financial basis and when steers were sold on a live basis, but no differences were observed when steers were sold on a grid basis. Despite differences in cow weight and body condition, calving rates did not differ between systems. Although calves were herdmates, feedlot performance and carcass characteristics differed between systems. The TRT system had lower weaning and slaughter breakeven, lower cost per weaned calf, and greater profit potential when finished steers were sold on a live basis.

Several species of aquatic insects in Trout Park Nature Preserve (Elgin, IL) were observed to have small, black spots (<0.1 mm diameter) visible within their bodies. Microscopic examination revealed these spots to be coiled juveniles of a mermithid (Nematoda: Mermithidae). Based on host habitat (seepage areas and rivulets), host species (aquatic insects), and size (mean diameter of coiled juveniles = 79 &mgr;m), it is likely that these mermithids were in the genus Pheromermis. Since adult mermithids were not found, species determination was not feasible, and the possibility of a new species cannot be ruled out. Pheromermis pachysoma and Pheromermis vesparum, however, are two species known to use aquatic insects as paratenic (i.e., transport) hosts in order to reach their definitive hosts, vespid wasps. Wasp larvae are infected by consuming the flesh of adult aquatic insects that contain the coiled juveniles of these Pheromermis spp. Of the 19 macroinvertebrate species examined in this study, Pheromermis juveniles were found in 4 caddisfly species (Hesperophylax designatus, Lepidostoma liba, Glossosoma intermedium, and Diplectrona modesta) and in 2 stonefly species (Clioperla clio and Amphinemura delosa). In addition to all 6 insect species being new host records for Pheromermis infection, this also represents the first report of nematode infection in stoneflies within the Western Hemisphere and of a Pheromermis sp. in Illinois. Among trophic groups, insect detritivores have been frequently recorded infected with coiled Pheromermis juveniles because of their direct consumption of eggs, and we also observed this for detritivores in our investigation (e.g., L. liba and A. delosa). Because C. clio was intensively infected, however, our study also provided evidence that predatory insects can be paratenic hosts. Coiled juveniles were typically present in muscle and fat body and present in almost all body regions. Not every infected paratenic host had external signs of infection; thus, dissections are required for accurate determination of infection prevalence and intensity. Our findings, in conjunction with those made in previous studies, indicate that a wide variety of aquatic insects may be used as paratenic hosts by Pheromermis. Because of their small size, it is highly likely that coiled juveniles are either overlooked or mistaken for melanized integumental wounds during field studies of aquatic insects. A more careful inspection for these coiled juveniles in aquatic insects, especially detritivores and their predators in seepage areas, would probably reveal that Pheromermis is far more common than presently documented. Copyright 1999 Academic Press.

For nearly 50 years, the fingernail clam (Musculium transversum) was believed to be virtually eliminated from the Illinois River. In 1991, workers began finding substantial populations of M. transversum in the Illinois River including several beds in and around the highly polluted Chicago Sanitary District. In order to determine if populations of M. transversum from polluted sites exhibited any genetic response to the high levels of toxins and to examine the genetic structure of several populations of M. transversum for any changes due to the population crash, starch-gel electrophoresis was performed on M. transversum from three Illinois River localities and four Mississippi River basin locations. The sampled populations produced an inbreeding coefficient (FIS) of 0.929, indicating that the populations were highly inbred. The results of a suspected founder effect due to a bottleneck was suggested by an FST = 0.442. The isozyme Glucose-6-phosphate isomerase-2 (Gpi-2) produced allelic frequency patterns that were consistent with expected patterns of a pollution-tolerant allele. Polluted sites exhibited elevated frequencies of Gpi-2(100) whereas nonpolluted sites exhibited elevated frequencies of Gpi-2(74). This frequency pattern suggested that natural selection was occurring in populations under severe toxic pressures, leading to an increase in the frequency of the allele Gpi-2(100). Therefore, Gpi-2(100) is a possible pollution-tolerant mutation in M. transversum.

In this study, we sought to determine the use of transesophageal echocardiography (TEE) as the primary imaging technique to assist in the placement of endovascular catheters during minimally invasive, port-access cardiac surgery. The recent development of endovascular catheters that are placed via the femoral artery and vein has enabled patients to be placed on cardiopulmonary bypass without the need for direct visualization of the heart or great vessels via sternotomy. This has allowed cardiac surgery to be performed through smaller thoracotomy incisions. Placement of these catheters has previously been performed with fluoroscopic guidance, which has major imaging limitations. Thirty-six patients underwent port-access cardiac surgery at our institution during the study period. All patients underwent intraoperative TEE. We used TEE to visualize the coronary sinus os, right atrium and superior vena cava, and thoracic aorta to assist with placement of the coronary sinus catheter, venous cannula, and endoaortic clamp. Twenty patients underwent mitral valve surgery, 14 patients coronary artery bypass grafting, 1 patient aortic valve replacement, and 1 patient repair of an atrial septal defect by the port-access approach. TEE was able to adequately visualize the cardiac structures and assist in the placement of the endovascular catheters in all patients. Fluoroscopy was only helpful as an aid to TEE for placement of the coronary sinus catheter. TEE is an excellent imaging modality for the proper placement of these new endovascular catheters, obviating the need for fluoroscopy, except to be on standby and for placement of the coronary sinus catheter.

Objective: New techniques for minimally invasive coronary artery bypass grafting have recently emerged. The purpose of this study was to determine the safety and efficacy of Port-Access (Heartport, Inc., Redwood City, Calif.) coronary revascularization and to evaluate with angiography the early graft patency rate with this new approach., Methods: From October 1996 to May 1997, 31 patients underwent Port-Access coronary artery bypass grafting with an anterior minithoracotomy and endovascular-occlusion cardiopulmonary bypass. There were 26 men and 5 women with a mean age of 62 years (range 42 to 82 years). Fifteen patients underwent single bypass; 12 patients underwent double bypass, and 4 patients underwent triple bypass. Bypass conduits included the left internal thoracic artery (n = 30), right internal thoracic artery (n = 2), radial artery (n = 10), and saphenous vein (n = 6). Three sequential grafts were used. Angiographic studies of the bypass grafts were performed in 27 of 31 patients (87%)., Results: There were no deaths, neurologic deficits, myocardial infarctions, or aortic dissections. Conversion to sternotomy was not required in any case. There were two reoperations for bleeding, one reoperation for tamponade, and one reoperation for pulmonary embolus. Postoperative angiography revealed anastomotic patency of the left internal thoracic artery to left anterior descending artery in 26 of 26 grafts (100%) with overall anastomotic patency in 43 of 44 grafts (97.7%)., Conclusion: These results demonstrate that Port-Access coronary artery bypass can be performed accurately and safely with acceptable morbidity. This approach allows for multivessel revascularization on an arrested, protected heart with excellent anastomotic precision and reproducible early graft patency.

A research program in cerebral ischemia was initiated by our laboratory to determine optimal strategies for cerebroprotection. Four studies relating to cerebroprotection using nuclear magnetic resonance spectroscopy in a sheep model of hypothermic cardiopulmonary bypass are summarized. These showed, first, that low-flow bypass, with a flow as low as 10 mL.kg-1 x min-1, maintained normal cerebral metabolism; second, that hypothermia increases the high-energy phosphate content and the intracellular pH of the brain; third, that hyperglycemia causes a profound intracellular acidosis; and, finally, that barbiturates prevent the normal increase in high-energy phosphates associated with hypothermia.

Phosphorus 31 nuclear magnetic resonance spectroscopy was used to assess cerebral high-energy phosphate metabolism and intracellular pH in normoglycemic and hyperglycemic sheep during hypothermic circulatory arrest. Two groups of sheep (n = 8 per group) were placed in a 4.7-T magnet and cooled to 15 degrees C using cardiopulmonary bypass. Spectra were acquired before and during circulatory arrest and during reperfusion and rewarming. Intracellular pH and adenosine triphosphate levels decreased during circulatory arrest. Compared with the normoglycemic animals, the hyperglycemic group was significantly more acidotic with the greatest difference observed during the first 20 minutes of reperfusion (6.40 +/- 0.08 versus 6.08 +/- 0.06; p < 0.001). Intracellular pH returned to baseline after 30 minutes of reperfusion in the normoglycemic group but did not reach baseline until 1 hour of reperfusion in the hyperglycemic animals. Adenosine triphosphate levels were significantly higher in the hyperglycemic group during circulatory arrest. Repletion of adenosine triphosphate during reperfusion was similar for both groups. These results support the hypothesis that hyperglycemia during cerebral ischemia drives anaerobic glycolysis and thus leads to increased lactate production and an increase [corrected] in the intracellular acidosis normally associated with ischemia.

Barbiturates have been used as a method of cerebral protection in patients undergoing open heart operations. Phosphorus 31 nuclear magnetic resonance spectroscopy was used to assess barbiturate-induced alterations in the cerebral tissue energy state during cardiopulmonary bypass, hypothermic circulatory arrest, and subsequent reperfusion. Sheep were positioned in a 4.7-T magnet with a radiofrequency coil over the skull. Nuclear magnetic resonance spectra were obtained at 37 degrees C, during cardiopulmonary bypass before and after drug administration at 37 degrees C and 15 degrees C, throughout a 1-hour period of hypothermic circulatory arrest, and during a 2-hour reperfusion period. A group of animals (n = 8) was administered a bolus of sodium thiopental (40 mg/kg) during bypass at 37 degrees C followed by an infusion of 3.3 mg.kg-1 x min-1 until hypothermic arrest. A control group of animals (n = 8) received no barbiturate. The phosphocreatine/adenosine triphosphate ratio, reflecting tissue energy state, was lower during cardiopulmonary bypass at 15 degrees C in the treated animals compared with controls (1.06 +/- 0.08 versus 1.36 +/- 0.17; p < 0.001). Lower phosphocreatine/adenosine triphosphate ratios were observed throughout all periods of arrest and reperfusion in the barbiturate-treated animals compared with controls (p < or = 0.01). Thiopental prevented the increase in cerebral energy state normally observed with hypothermia and resulted in a decrease in the energy state of the brain during hypothermic circulatory arrest and subsequent reperfusion. These results suggest that thiopental administration before a period of hypothermic circulatory arrest may prove detrimental to the preservation of the energy state of the brain.

Described and illustrated for the first time is a bisexual aphelenchoidid ectoparasitic nematode found on a noctuid male moth in Guadeloupe, West Indies. Sexes are polymorphic, having in common an elongated stylet of 53-69 mum with well-developed basal knobs and double set of protractors, excretory pore near head end, multiple rows of germ cells, and a mucronate tail terminus. The male is particularly distinctive in having a low, smooth head, spicules 38-49 mum long with a tubular rostrum and a ventral arm well separated from the dorsal, an external cloacal cylinder, and a pre- and postanal pair of genital papillae. Distinctive for the female are a unique, muldnucleate uterine gland complex, lack of a functional rectum and anus, and, by marked contrast to the male, a high, hemispherical head marked by six annules and a large uninucleate renette cell.

Hemicriconemoides scottolamassesei n. sp., named after Dr. C. Scotto la Massese, from New Caledonia, is described and illustrated. Primary diagnostic characters are females with a continuous head and three lip annules, the first annule being the smallest, stylet length of 65-75 mum, vulva without lateral flaps, and acute tail terminus; J4 has a smooth cuticle without scales or spines; the male has a lateral field with two incisures. Emended measurements, descriptions, illustrations, and new records of distribution are given for H. brachyurus (Loos, 1949) Chitwood &Birchfield, 1957, H. mangiferae Siddiqi, 1961, and H. kanayaensis Nakasono &Ichinoe, 1961. Relationships of H. promissus Vovlas, 1980, based on study of paratypes, and H. intermedius Dasgupta, Raski &Van Gundy, 1969 are discussed; both are proposed as synonyms of H. brachyurus.

The roles of thermal and hydric stress in habitat selection by two species of short-horned grasshoppers was investigated through field and laboratory studies and computer simulation experiments. Psoloessa delicatula was found to possess an elaborate repertoire of thermoregulatory postures and shade seeking behavior. This grasshopper was found in habitats in the shortgrass prairie in which bare patches of ground were common. It was found to regulate its body temperature to a relatively constant level over the course of a sunny day. Eritettix simplex was found in patches of dense vegetation, and its body temperature was usually similar to ambient temperature. During controlled laboratory experiments, E. simplex nymphs lost water rapidly and thus were presumed to be restricted to more mesic environments where desiccation stress is less. A thermal energy budget model was constructed and showed that the habitat selected by P. delicatula would allow behavioral thermoregulation whereas the habitat selected by E. simplex should preclude regulation of body temperature by behavioral means.

Nitrogen content is an important factor controlling decomposition of resistant substrates. We examined the decomposition of purified cellulose in the presence of a structurally similar, resistant organic N compound, chitin. Carbon-14-labelled cellulose was added to sterile ari-dried sandy loam soil in flasks, half of which were also amended with purified chitin. Grassland soil organisms-a fungus (Fusarium oxysporum) or a bacterium (Flavobacterium sp.) with or without their respective nematode grazers (Aphelenchus avenae or Pelodera sp.) were added to the substrateamended soils, and decomposition was monitored by carbon dioxide evolution and NH 4 + -N mineralization. More 14 CO 2 was evolved and at a higher rate from the fungal treatment than from the bacterial treatment. Grazing enhanced 14 CO 2 and total CO 2 evolution and NH 4 + -N mineralization in the bacterial treatments and NH 4 + -N mineralization in the fungal treatments. Nitrogen was mineralized both from native organic sources and from chitin. The addition of chitin did not enhance and, in most cases, decreased cellulose decomposition.

Hoplolaimus indicus Sher, 1963 was found for the first time in North America as a parasite of wild rice. Supplemental descriptive data, supported by illustrations, are given which extend the known range of variability in this species. The body, stylet, and tail lengths were often greater than those in published reports from India, the esophageal gland overlap was consistently shorter than body width in most specimens, and the excretory pore and vulva were more posterior. Longitudinal striae of the basal head annule ranged from 6 to 20, number of tail atmules from 8 to 22, and the excretory pore extended at most 27 mum anterior or 22 mum posterior of the esophagointestinal valve. A taxonomic key is provided to facilitate the separation of the 13 species of Hoplolaimus having five or six esophageal gland nuclei.

Several chelators were examined for their ability to prevent the synchronous release of 24- to 48-hour stationary phase singlet cells of the dimorphic yeast Candida albicans into either the mycelial or the budding phenotypes (in a defined liquid medium at 37 degrees C; at pH 6.5 or pH 4.5, respectively). The only chelator that was found to inhibit mycelium formation completely and to restrict bud formation to about 10% was 1,10-phenanthroline at minimal concentrations of 50 microM and 230 microM, respectively. The inhibition of both phenotypes could be reversed completely by the addition of 200 microM of ZnSO4. The synchrony of recovery from inhibition by the addition of zinc paralleled that of the controls for both phenotypes, and the final number of mycelia or buds as a percentage of the control was the same (100%). These findings support the hypothesis that the lag period between the release from stationary phase and the onset of development for Candida represents the time of acquisition of a minimum threshold amount of a cation, such as zinc. The involvement of zinc in phenotypic development is discussed, suggesting that while zinc is involved in the initiation of development, it may not determine the phenotype of Candida albicans.

The optimum temperatures for population development were determined for six species of bacterial-feeding nematodes from among eight temperatures, ranging from 5 to 40 C. Four of the species are cohabiting species. The range of temperatures over which population development occurs (temperature niche breadth) is different for the cohabiting species. This difference may be a means of reducing competition between species, thus increasing temperatures over which habitats can be exploited.

Primary and secondary types housed in the Canadian National Collection of Nematodes are given for 396 species of plant-parasitic, marine, freshwater, terrestrial, and entomophagous nematodes. Species are listed in alphabetical order and include author(s), date, publication source, type category, numbers and sex, and collection accession number. Current nomenclatorial changes in status of a binomial are not given, but authority data are added for type designations made to the original type series.

A new, monotypic genus and species in the subfamily Mesorhabditinae is described and illustrated. The primary character which separates the species and genus from all others in the Rhabditidae is a lip region with six set-off and well-separated liplets of two alternating shapes. Other diagnostic characters are transverse and fine longitudinal body striations, cuticular micropores, a prismatic prostom, well-developed esophageal collar, and three denticles on each metarhabdion. Males have a peloderan, open bursa bearing two pre- and seven post-anal bursal papillae, fused spicules over 50 mum long, and paired diverticulate cement glands associated with the vas deferens.

Bacteria (Pseudomonas), amoebae (Acanthamoeba), and nematodes (Mesodiplogaster) were raised in soil microcosms with and without glucose additions. Nematode and amoebal grazing on bacteria significantly reduced bacterial populations by the end of a 24-day incubation period. Amoebal numbers decreased in the presence of nematodes with a corresponding increase in nematode numbers which reached a maximum of 230 nematodes/g of soil in the treatment with amoebae and glucose additions. After 24 days the nematode populations in the treatments without carbon additions were dominated by resistant dauer larvae indicating the unavailability of food. Although larval numbers were high in the treatments with glucose additions, the adult component of the population was still increasing at the end of the 24-day experiment. The effect of the presence of amoebae on nematode abundance was of the same magnitude as addition of 600Μg glucose-C.

Males and females of Paurodontella auriculata n. sp. are described and illustrated and the genus emended. The species is characterized by a short, robust body of 355-525 mum, a stylet length of 7-8 mum, lateral field with 5-6 incisures, and a conoid, attenuated tail 1.5 times the vulva-anus distance. Primary characters used in emending the genus are asymmetrical stylet knobs, absence of lateral lips, a deep slit-like amphid dividing the submedian lips to base of head, where open lateral sides are covered by a large auriform cuticular flap, and variable length of the basal esophageal bulb stem and male bursa.

Flows of biomass and respiratory carbon were studied in a series of propylene-oxide sterilized soil microcosms. One-half of the microcosms received three pulsed additions of 200 ppm glucose-carbon to mimic rhizosphere carbon inputs. Biotic variables were: bacteria (Pseudomonas) alone, or amoebae (Acanthamoeba) and nematodes (Mesodiplogaster) singly, or both combined in the presence of bacteria.Over the 24-day experiment, respiration was significantly higher in the microcosms containing the bacterial grazers. Biomass accumulation by amoebae was significantly higher than that by nematodes. The nematodes respired up to 30-fold more CO2 per unit biomass than did amoebae. Similar amounts of carbon flowed into both respiratory and biomass carbon in microcosms with fauna, compared with the bacteria-alone microcosms. However, partitioning of available carbon by the microfauna varied considerably, with little biomass production and relatively more CO2-C produced in the nematode-containing microcosms. The amoebae, in contrast, allocated more carbon to tissue production (about 40% assimilation efficiency) and correspondingly less to CO2.

A system that uses microbeads for the culture of bacteriophgic nematodes is described. Glass-bead culture was found to simulate a soil microcosm more closely than did agar culture i n terms of CO production , number of nematodes produced, and nematode size.

An unusual feature of the intestine in Tylenchorhynchus dubius is the presence, within the intestinal cytoplasm, of an extensive system of fibrillar bundles consisting of thin (14 nm diam) filaments and thick (70-90 nm diam), rod-like elements arranged in closely packed arrays. The larger of the fibrillar bundles, for which the term "intestinal fasciculi" is proposed, are evident in whole mounts and apparently correspond to the lateral or sinuous canals described in some other tylenchids. The nature and function of fasciculi are not known, but some possibilities are considered. Fasciculi were found in at least seven other species of Tylenchorhynchus. The intestinal cytoplasm also contains the usual sub cellular organelles and large amounts of reserve materials in the form of particulate glycogen and three types of globules. The surface of the cells bordering the lumen is elaborated into numerous microvilli which have central filaments and often bear regular external projections. Although terminal bars delimit the apical margins between cells, the frequent lack of complete lateral boundaries and extensive length of the fasciculi indicate that the intestinal epithelium is a multinucleate mosaic or syncytium.