Reaction of ethyl 2-amino-4,6-O-benzylidene-2-deoxy-d-gluconate with acetylenic esters

Ethyl 2-amino-4,6-O-benzylidene-2-deoxy-d-gluconate adds to acetylenic esters to give sugar enaminones. The following acetylene derivatives have been employed: methyl propiolate, ethyl phenylpropiolate, and dimethyl acetylenedicarboxylate (6). With compound 6, the reaction leads to a mixture of the expected enaminone and the isomeric oxazolidine derivative. The structures and configurations of the new compounds were studied by spectroscopic and chemical methods.     

Dissociation by Chelating Agents and Substructure of the Thermophilic Bacteriophage TP84

The thermophilic bacteriophage TP84 is dissociated into its head, tail, and released deoxyribonucleic acid (DNA) by chelating agents such as ethylenediaminetetraacetic acid (EDTA) and phosphate. The phage is more sensitive to EDTA than to phosphate, and dialysis against either agent causes more effective dissociation than standing in their presence. The tail possesses a knobbed structure which is inserted into the head of the intact phage and to which the DNA appears to be attached. The method of dissociating TP84 described in this paper provides a source of undamaged structural components and intact strands of DNA for subsequent investigations. A possible mechanism of chelate inactivation is discussed.     

Abnormal Intranuclear and Cytoplasmic Formations Associated with a Chemically Induced, Transplantable Chicken Sarcoma

Thirty GRCH/15 tumors (a 1, 2, 5, 6-dibenzanthracene-induced chicken sarcoma) were examined in the light and the electron microscope. Associated with the sarcoma were two types of abnormal intranuclear lesions, one in the form of a vacuole, the other as an aggregate containing glycogen. In the electron microscope, one type of lesion observed showed an organized microfibrillar structure. Abnormal cytoplasmic formations occurred as massed clusters of thread-like or tubular material, which gave rise to small bodies with concentric shell structure; similar bodies were found associated with vacuoles.     

Inheritance of foreign genes in transgenic bean (Phaseolus vulgaris L.) co-transformed via particle bombardment

Exploiting the biolistic process we have generated stable transgenic bean (Phaseolus vulgaris L.) plants with unlinked and linked foreign genes. Co-transformation was conducted using plasmid constructions containing a fusion of the gus and neo genes, which were co-introduced with the methionine-rich 2S albumin gene isolated from the Brazil nut and the antisense sequence of AC1, AC2, AC3 and BC1 genes from the bean golden mosaic geminivirus. The results revealed a co-transformation frequency ranging from 40% to 50% when using unlinked genes and 100% for linked genes. The introduced foreign genes were inherited in a Mendelian fashion in most of the transgenic bean lines. PCR and Southern blot hybridization confirmed the integration of the foreign genes in the plant genome.     

Autoradiographic comparison of [I]LSD-labeled 5-HT2A receptor distribution in rat and guinea pig brain

Although the density and distribution of 5-HT_2A(5-hydroxytryptamine-2A) receptors is well established for rat brain, the 5-HT_2A receptor distribution and density in guinea pig brain has not been extensively studied. In the present in vitro study, we have utilized ¹²⁵I-lysergic acid diethylamide ([¹²⁵I]LSD) to quantify and compare 5-HT_2A receptor density in coronal sections of rat and guinea pig brain. Spiperone (1 μM) and sulpiride (1 μM) were used to displace [¹²⁵I]LSD binding from 5-HT_2A and D₂ binding sites, respectively. Ligand binding was quantified by computer-aided image analysis densitometry (MCID). Similar to the rat, areas of highest specific 5-HT_2A receptor binding (fmol/mg protein) in guinea pig brain included the claustrum and Layer 4 of the cerebral cortex. Significant binding was also found in remaining neocortical layers, islands of Calleja, caudate putamen, olfactory bulb, nucleus accumbens, and choroid plexus. While the rat brain exhibited a high level of specific binding in the tenia tecta and mammillary nuclei, little binding was observed in these regions in the guinea pig. In both rat and guinea pig, low specific binding was found in amygdaloid, thalamic, or cerebellar areas. These studies indicate a general similarity between 5-HT_2A binding site distribution and relative density in guinea pig and rat brain but point to a few brain regions where significant differences exist.     

Associations of esterase 6 allozyme and activity variation with reproductive fitness inDrosophila melanogaster

Previous studies have shown that the esterase 6 (EST6) enzyme ofD. melanogaster is mainly produced in the sperm ejaculatory duct of the adult male and comparisons of wild-type males with laboratory null mutants have suggested that the enzyme plays a role in reproductive fitness. In this study we have compared 18 field-derived lines each isoallelic forEst6 for differences in five components of male reproductive fitness. No consistent fitness differences were found among lines differing in respect of the two major allozyme classes EST6-F and EST6-S, despite other evidence that these two classes are not selectively equivalent in the field. However, differences in reproductive fitness were found among lines differing in the minor mobility variants that segregate within EST6-F and EST6-S. A failure to distinguish among these minor forms may explain the discrepancies in previous studies on the effects of the major EST6 allozymes on reproductive fitness. The most significant associations we have found between EST6 and reproductive fitness were due to variation in EST6 activity levels. Male EST6 activity levels were found to be positively correlated with their time to first mating, negatively correlated with the numbers of eggs laid and progeny produced by their mates, and negatively correlated with the frequency with which their mates remate. We conclude that some EST6 variants differ in components of male reproductive fitness operative in laboratory cultures. However, the evidence for fitness differences is stronger for variants affecting the amount, rather than the structure of the enzyme, and the direction of the differences varies between some of the fitness components tested.     

Disruption of Potential α-Helix in the G Loop of the Guinea: Pig 5-Hydroxytryptamine2 Receptor Does Not Prevent Receptor Coupling to Phosphoinositide Hydrolysis

Abstract: Heterogeneity of the 5-hydroxytryptamine₂ (5-HT₂) receptor across species has been implicated in several pharmacological and physiological studies. Although 5-HT₂ receptors in the rat have been linked to increases in Phosphoinositide (PI) hydrolysis, little evidence exists to support the association of guinea pig 5-HT₂ receptors with Pl hydrolysis, the second messenger generally linked with 5-HT₂receptors. In the present study, we have taken a molecular and biochemical approach to determining whether species differences in brain 5-HT₂ receptors exist between rat and guinea pig. First, we isolated partial cortical 5-HT_a receptor cDNA clones that encompassed the third intracellular loop, a receptor area putatively important in receptor-effector coupling. The amino acid sequences deduced from the cDNA clones for rat and guinea pig brain 5-HT₂ receptor were 97% homologous. However, the guinea pig 5-HT₂ receptor had two tandem substitutions that disrupted a potential alpha helix in the region of the third cytoplasmic loop, which theoretically could alter the intracellular coupling of the guinea pig cortical 5-HT₂ receptor. Because of these molecular differences, we examined further the pharmacological activation of the brain 5-HT₂ receptor from guinea pig. 5-HT and the 5-HT₂ receptor agonist α-methyl-5-HT increased PI hydrolysis in guinea pig cortical slices whereas the 5-HT_1c receptor agonist 5-methyltryptamine was significantly less potent. In addition, the 5-HT₂ receptor antagonists LY53857, ketanserin, and spiperone blocked 5-HT-stimulated Pl hydrolysis. These pharmacological data suggested that activation of the 5-HT₂ receptor in guinea pig cortical slices was associated with PI hydrolysis. Thus, although areas of the guinea pig brain 5-HT₂ receptor that influence receptor-effector coupling were different from the rat, such differences were not critical to receptor-effector coupling because, as in the rat, guinea pig brain 5-HT₂ receptors were also coupled to PI hydrolysis.     

Responses of seed of Stylosanthes humilis to germination regulators

Seed of Stlosanthes humilis both have hard integuments and display physiological dormancy, the latter being lost during post-harvest ageing. Ethrel and l-aminocyclopropane-1-carboxylic acid (ACC) partially released scarified young seed from physiological dormancy. Cobalt and silver ions and abscisic acid inhibited germination of scarified non-dormant seed. Abscisic acid also inhibited germination of voung seed promoted by ACC. Thiourea and ethrel plus benzyladenine showed the greatest efficacy in breaking seed dormancy.     

Aotus from the southwestern Amazon region is geographically and chromosomally intermediate betweenA. azarae boliviensis andA. infulatus

We described the karyotypes detected in 23Aotus specimens captured on Southwestern Amazon region (63°30'W, 9°00'S). This region should be occupied byA. nigriceps. However, the animals described here have a fur pattern and a karyotypes similar to those ofA. azarae boliviensis andA. infulatus. The females presented 50 chromosomes and the males 49 as a consequence of fusion between the chromosome Y and an autosome. This sample presented polymorphisms of G- and C-banding and NOR-staining. These animals are karyotypically intermediate betweenA. a. boliviensis andA. infulatus. The taxonomy and karyotypic evolution of these taxa are discussed.     

Smartphone repairability indexes in practice: Linking repair scores to industrial design features

Policymaking mediates the relationships between manufacturers and consumers, thus defining the boundaries for the philosophies of production set forth by major companies. Research states that policymaking falls short in addressing the waste issues, natural resources consumption, greenhouse gas emissions, and other negative impacts posed by premature obsolescence; only recently have the “right-to-repair” guidelines demanded by environmental organizations and communities of citizens been included in policymaking. The introduction of the Index of Repairability in France as information at the point of sale aims to inform consumers and support their decision-making in purchasing more repairable products. In this paper, we consider the two Indexes of Repairability publicly available to consumers—in the French legislation and iFixit—and assess their application to smartphones from three manufacturers. The study establishes links between the scores and the industrial design features that promote or hinder repairability, service factors and information for self-repair, authorized repair, and independent repair. Data collection considers the available information for consumers and citizens by using netnography and secondary data from manufacturers, policymakers, and communities of users. Our findings suggest that higher scores that indicate easier repairability are not limited to product architectures that follow design for disassembly guidelines. Smartphones that are difficult to repair can still score high, and thus be perceived as easier to repair, if manufacturers provide high quality and affordable service. This paper discusses the results of the ongoing development of repairability scores for smartphones, thus suggesting paths for future research to improve methods and policies to support a longer lifetime of products.