Cyclooxygenase and 5-lipoxygenase inhibitory activity of 2,6 di-t-butylphenols linked by a sulfur atom to 1,3,4-thiadiazoles and 1,3,4-oxadiazoles

The preparation of a series of 1,3,4-thiadiazoles and 1,3,4-oxadizoles linked by a thioether to 2,6-di-t-butylphenol and the inhibition of cyclooxygenase (CO) and 5-lipoxygenase (5-LO) by these compounds is dicussed.     

Evidence of biotic resistance to exotic plant invasion in degraded Bornean forests

Intact tropical forests are generally considered to be resistant to invasions by exotic species, although the shrub Clidemia hirta (Melastomataceae) is highly invasive in tropical forests outside its native range. Release from natural enemies (e.g., herbivores and pathogens) contributes to C. hirta invasion success where native melastomes are absent, and here we examine the role of enemies when C. hirta co-occurs with native Melastomataceae species and associated herbivores and pathogens. We study 21 forest sites within agricultural landscapes in Sabah, Malaysian Borneo, recording herbivory rates in C. hirta and related native Melastoma spp. plants along two 100-m transects per site that varied in canopy cover. Overall, we found evidence of enemy release; C. hirta had significantly lower herbivory (median occurrence of herbivory per plant = 79% of leaves per plant; median intensity of herbivory per leaf = 6% of leaf area) than native melastomes (93% and 20%, respectively). Herbivory on C. hirta increased when closer to native Melastoma plants with high herbivory damage, and in more shaded locations, and was associated with fewer reproductive organs on C. hirta. This suggests host-sharing by specialist Melastomataceae herbivores is occurring and may explain why invasion success of C. hirta is lower on Borneo than at locations without related native species present. Thus, natural enemy populations may provide a “biological control service” to suppress invasions of exotic species (i.e., biotic resistance). However, lower herbivory pressures in more open canopy locations may make highly degraded forests within these landscapes more susceptible to invasion.     

Noninvasive semen collection from an adult orangutan

Preservation of the genetic diversity of the captive orangutan, especially the wild-caught founders, is critical in maintaining a long-term population in zoological parks. One solution to the problem of maintaining maximum genetic diversity would be to initiate a program of artificial insemination for genetically underrepresented individuals through the banking and interinstitutional use of cryopreserved semen. However, little is known about basic orangutan semen characteristics, and current methodology is inadequate to support such a program. In this paper, we report the results of semen collection from an adult Sumatran orangutan (Pongo pygmaeus abelli), using an artificial vagina without anesthesia or electrical stimulation. A total of 27 ejaculates were evaluated during a 1-year period. The total and liquid volumes of the ejaculates at 1 h following collection were 6.1 ± 0.6 ml and 2.6 ± 0.4 ml, respectively (mean ± SEM). The liquid portion continued to exude semen for 2 h; however, 90% of the motile sperm was exuded within the first 30 min. The total number of sperm in the ejaculate was 164 ± 10⁶ ± 16.5, and the percentage of motile cells was 60 ± 2.7%. We conclude that the artificial vagina provides a promising technique for semen collection in the orangutan, and view these results as an initial step in developing methods for in vitro sperm capacitation, sperm cryopreservation, and artificial insemination. © 1993 Wiley-Liss, Inc.     

Mapping of the human homologs of the murine paired-box-containing genes

Mutations in paired-box-containing (Pax) genes have recently been found to be the primary lesions underlying human genetic disorders such as Waardenburg's Syndrome type 1 and mouse developmental mutants such as undulated (un), splotch (Sp), and small eye (Sey). In addition, PAX-6 is a strong candidate gene for aniridia in man. Eight independent Pax genes have been isolated in the mouse. All eight map to distinct regions of the mouse genome; they do not appear to be clustered in the same way as some groups of homeobox-containing genes. We have now mapped the human homologs of all eight of these genes; PAX genes are found on human Chromosomes (Chr) 1, 2, 7, 9, 10, 11, and 20.     

Environmental conditions during glycerol bioconversion affect 3-hydroxypropionic acid bioproduction by Limosilactobacillus reuteri DSM 17938

3-Hydroxypropionic acid (3-HP) is a platform molecule whose biological production was carried out by the bacterium Limosilactobacillus reuteri according to a two-step process: first, a growth phase in batch mode on glucose, then a glycerol bioconversion into 3-HP in fed-batch mode. With the objective of improving 3-HP bioproduction, this study aimed at defining the operating conditions during the bioconversion phase that increases the bioproduction performance. A central composite rotatable design allowed testing various pH levels and specific glycerol feeding rates. By establishing response surfaces, optimal conditions have been identified that were different depending on the considered output variable (final 3-HP quantity, 3-HP production yield and production rate). Of them, 3-HP final quantity and 3-HP production yield were maximized at pH 6.0 and at specific glycerol feeding rates of 60 and 55 mg_gly g_CDW⁻¹ h⁻¹, respectively. The specific 3-HP production rate was the highest at the upper limit of the specific substrate feeding rate (80 mg_gly g_CDW⁻¹ h⁻¹) but was not affected by the pH. An additional experiment was carried out at pH 6.0 and a specific glycerol feeding rate of 80 mg_gly g_CDW⁻¹ h⁻¹ to validate the previous observations. In conclusion, the results showed a significant improvement of 3-HP concentration by 13%, of specific production rate by 34% and of 3-HP volumetric productivity by 39%, as compared to the initial values.     

Feeding Response of Rats to No-Fat and High-Fat Cakes

The nutritional effects of high-fat diets have been extensively studied in laboratory animals, but as yet few experiments have examined the feeding response of animals to newly developed fat substitutes. The present study used commercially available no-fat (0% fat, 92% carbohydrate) and high-fat (41% fat, 54% carbohydrate) cake to determine the effects of fat substitutes on food preference and caloric intake in rats. The first experiment showed that nondeprived rats found the high-fat and no-fat cakes equally palatable and highly preferred to lab chow. Food deprived rats, however, preferred the high-fat cake to the no-fat cake, which may be related to its higher caloric density. In the second experiment, rats fed high-fat cake, in addition to chow, for 30 days consumed more calories and gained more weight than did rats fed no-fat cake and chow. The no-fat cake group, however, overate and gained more weight than chow-only controls. The hyperphagic response to the no-fat cake can be attributed to its carbohydrate content, moisture, and high palatability. Thus, removing fat from the cake reduced, but did not eliminate, its obesity-promoting effect. Obviously, low-fat foods must be consumed in moderation if used for weight control.     

Root traits of perennial C4 grasses contribute to cultivar variations in soil chemistry and species patterns in particulate and mineral-associated carbon pool formation

Recent studies have indicated that the C₄ perennial bioenergy crops switchgrass (Panicum virgatum) and big bluestem (Andropogon gerardii) accumulate significant amounts of soil carbon (C) owing to their extensive root systems. Soil C accumulation is likely driven by inter- and intraspecific variability in plant traits, but the mechanisms that underpin this variability remain unresolved. In this study we evaluated how inter- and intraspecific variation in root traits of cultivars from switchgrass (Cave-in-Rock, Kanlow, Southlow) and big bluestem (Bonanza, Southlow, Suther) affected the associations of soil C accumulation across soil fractions using stable isotope techniques. Our experimental field site was established in June 2008 at Fermilab in Batavia, IL. In 2018, soil cores were collected (30 cm depth) from all cultivars. We measured root biomass, root diameter, specific root length, bulk soil C, C associated with coarse particulate organic matter (CPOM) and fine particulate organic matter plus silt- and clay-sized fractions, and characterized organic matter chemical class composition in soil using high-resolution Fourier-transform ion cyclotron resonance mass spectrometry. C₄ species were established on soils that supported C₃ grassland for 36 years before planting, which allowed us to use differences in the natural abundance of stable C isotopes to quantify C₄ plant-derived C. We found that big bluestem had 36.9% higher C₄ plant-derived C compared to switchgrass in the CPOM fraction in the 0–10 cm depth, while switchgrass had 60.7% higher C₄ plant-derived C compared to big bluestem in the clay fraction in the 10–20 cm depth. Our findings suggest that the large root system in big bluestem helps increase POM-C formation quickly, while switchgrass root structure and chemistry build a mineral-bound clay C pool through time. Thus, both species and cultivar selection can help improve bioenergy management to maximize soil carbon gains and lower CO₂ emissions.     

Isolation of Histoplasma capsulatum from an oil bird (steatornis caripensis) cave in Venezuela

Summary 1.Histoplasma capsulatum was recovered from two of fifteen soil specimens collected in a Venezuelan cave. This cave, located near Caripe in the state of Monagas, harbors a large colony of the oil bird,Steatornis caripensis.2. This finding confirms the previous discovery in Tingo Maria, Peru, of the association ofH. capsulatum with oil birds.3. The relationship ofH. capsulatum with animal habitats is discussed along with the public health importance of this association.

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Zusammenfassung 1.Histoplasma capsulatum ist in zwei Bodenproben aus fünfzehn, die einer Höhle in Venezuela entnommen wurden, gefunden worden. Diese Höhle, die sich in der Nähe von Caripe, im Staate Monagas befindet, herbergt eine grosse Kolonie von Fettvögeln,Steatornis caripensis.2. Dieser Befund bestätigt die Vergesellschaftung vonH. capsulatum mit den Fettvögeln, wie es vorher bereits in Tingo Maria, Peru, entdeckt worden ist.3. Die Beziehung vonH. capsulatum zum tierischen Habitat wird diskutiert unter Betonung der Wichtigkeit dieser Vergesellschaftung vom Standpunkte des öffentlichen Gesundheitswesens.

     

The Effect of Parental Food Supply on Parental Feeding and Squab Growth in Pigeons,Columba livia

The growth and survival of nidicolous birds is determined by variables affecting the frequency and allocation of parental feedings. We manipulated adult pigeons' food supply and measured the effect of food availability and hatching order on the frequency and allocation of parental feeding, squab growth, and parental weight loss. Food availability did not affect any of the dependent variables during the first week, when squabs are fed crop milk. Throughout the remainder of the nestling period, when squabs are fed foraged grain, parents in the food-poor condition delivered fewer regurgitations and lost more weight, and then squabs gained less weight. Within broods, neither the allocation of parental feedings nor squab growth was differential, even in the food-poor environment. Apparently, production of crop milk is buffered from the parents' food supply, thus allowing both squabs to grow rapidly during the first few post-hatch days. The result is nondifferential feeding and growth within broods and delayed effects of food availability on the overall frequency of parental feeding, parental weight loss, and squab growth.