rco-3, a gene involved in glucose transport and conidiation in Neurospora crassa

Macroconidiation in Neurospora crassa is influenced by a number of environmental cues, including the nutritional status of the growing organism. Conidia formation is normally observed when the fungus is exposed to air. However, carbon limitation can induce conidiation in mycclia submerged in an aerated liquid medium. A mutant was previously isolated that could conidiate in submerged culture without imposing nutrient limitation and the gene responsible for this phenotype (rco-3) has now been cloned. RCO3 exhibits sequence similarity to members of the sugar transporter gene superfamily, with greatest similarity to glucose transporters of yeast. Consistent with this structural similarity, we find that glucose transport activity is altered in the mutant. However, growth of the mutant in media containing alternate carbon sources does not suppress conidiation in submerged culture. The properties of the mutant suggest that RCO3 is required for expression of glucose transport activity, glucose regulation of gene expression, and general carbon repression of development.     

Thermally induced changes in metal solubility of contaminated soils is linked to mineral recrystallization and organic matter transformations

Soils are biogeochemical systems under continual modification by biological and chemical processes. Trace element solid-solution partitioning is thus influenced by long-term changes to these solid phases. We study Pb, Cd, Zn, and Cu solution speciation and solid-phase dynamics in two soils of volcanic origin (Te Akatea and Egmont, high in noncrystalline aluminosilicates), an oxisol from Brazil (Oxisol, high in oxides of Al and Fe), and several sludge-treated soils (labeled NYS soils, high in organic materials). Total soluble (by ICP) and labile (by ASV) concentrations of Pb, Cd, Zn, and Cu were determined after incubation of the soils for about 1.5 yr at room (23 degrees C) and elevated (70 degrees C) temperatures. Changes occurring to the solid phases were monitored by FTIR and extraction with oxalate and pyrophosphate. It is shown that induced hydrolysis or decomposition of organic materials in soils results in increases in both labile and total soluble concentrations of Pb, Cd, Cu, and Zn in solution. Labile and total soluble concentrations of Cu and Zn increase concomitantly with dissolved organic carbon (DOC); the nonlabile soluble fraction also increases with increasing DOC. Similarly, the concentration of Cd and Pb in solution increases with increasing DOC; however, most soluble Cd and Pb is asv-labile. Only in the Egmont soil (mineralogy dominated by proto-imogolite allophane) was reduced Pb solubility observed after prolonged equilibration and heating. Lead solubility increased after partial crystallization of amorphous minerals in the Te Akatea and the Oxisol. Thus, for most of the metal-soil systems studied, prolonged thermal treatment at 70 degrees C increased total soluble and asv-labile metals, suggesting that aging effects on metals in contaminated soils could release metals to labile forms in some cases.     

Ethology and comparative psychology.

An analysis of the relationship between ethology and comparative psychology is presented by an ethologist whose background was in agriculture, animal breeding, and evolutionary genetics. The view is presented that today, comparative psychology is largely an American name for the ethological work taking place in psychology departments throughout the world. Generally, those studying animal behavior or human ethology fill an important niche in psychology departments, providing the biological, particularly the evolutionary, complement to other fields of psychology. This role is functional, rather than having a theoretical foundation different from ethology. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The importance of generalizability for anomaly detection

In security-related areas there is concern over novel “zero-day” attacks that penetrate system defenses and wreak havoc. The best methods for countering these threats are recognizing “nonself” as in an Artificial Immune System or recognizing “self” through clustering. For either case, the concern remains that something that appears similar to self could be missed. Given this situation, one could incorrectly assume that a preference for a tighter fit to self over generalizability is important for false positive reduction in this type of learning problem. This article confirms that in anomaly detection as in other forms of classification a tight fit, although important, does not supersede model generality. This is shown using three systems each with a different geometric bias in the decision space. The first two use spherical and ellipsoid clusters with a k-means algorithm modified to work on the one-class/blind classification problem. The third is based on wrapping the self points with a multidimensional convex hull (polytope) algorithm capable of learning disjunctive concepts via a thresholding constant. All three of these algorithms are tested using the Voting dataset from the UCI Machine Learning Repository, the MIT Lincoln Labs intrusion detection dataset, and the lossy-compressed steganalysis domain. Gilbert “Bert” Peterson is an Assistant Professor of Computer Engineering at the Air Force Institute of Technology. Dr. Peterson received a BS degree in Architecture, and an M.S. and Ph.D. in Computer Science at the University of Texas at Arlington. He teaches and conducts research in digital forensics and artificial intelligence. Brent McBride is a Communications and Information Systems officer in the United States Air Force. He received a B.S. in Computer Science from Brigham Young University and an M.S. in Computer Science from the Air Force Institute of Technology. He currently serves as Senior Software Engineer at the Air Force Wargaming Institute.     

Treatment of dairy cows with recombinant bovine somatotropin: genetic and phenotypic aspects

Thirty-four multiparous and primiparous Holstein cows were utilized to examine the association between the response to long-term administration of recombinant bovine somatotropin and the cow's phenotypic and genetic production potential. Cows representing a range of phenotypic and genetic production potentials were assigned to one of four treatment groups: 0, 12.5, 25.0, or 50.0 mg recombinant bovine somatotropin daily. They were injected daily for 266 d beginning on d 24 to 35 postpartum. Pretreatment milk and fat yields were used to predict daily yields over the lactation and allowed treatment groups to serve as their own controls. Actual minus predicted yield estimated the response to treatment for milk, fat, and FCM for each cow. Milk composition (fat, protein, and lactose percentage) was not significantly affected by treatment. Response in yield for milk, fat, and FCM was significant during the treatment period (266 d). Milk yield increased by 18.5, 19.9, and 21.4%; fat yield increased by 13.4, 20.3, and 18.1%; and FCM increased by 16.3%, 19.7%, and 21.1% after receipt of 12.5, 25.0 and 50.0 mg recombinant bovine somatotropin, respectively. Differences in response were not significant. The dramatic effect recombinant bovine somatotropin has on production requires that alternative approaches be adopted in the future for accurate genetic evaluation of sires and dams if somatotropin is discriminantly used in the national herd.     

Intermittency phenomena in electrical connectors

Fretting is known to be a major cause of contact deterioration and failure, particularly in tin-plated contacts. During fretting the contact resistance generally increases slowly with time. Superimposed on this slow increase in contact resistance are rapid changes in contact resistance within fractions of a second, called intermittences or short duration discontinuities. Although intermittences have been reported by several authors, they are frequently overlooked in traditional fretting experiments and not much is known about their origin. The present study aims at filling this gap. A test apparatus has been built to measure the contact voltage-drop profile during an intermittence and fretting experiments on tin-plated copper contacts have been carried out. The results lead to a set of requirements for a model to explain intermittency phenomena     

The cholecystokinin-A receptor mediates inhibition of food intake yet is not essential for the maintenance of body weight

Food intake and body weight are determined by a complex interaction of regulatory pathways. To elucidate the contribution of the endogenous peptide cholecystokinin, mice lacking functional cholecystokinin-A receptors were generated by targeted gene disruption. To explore the role of the cholecystokinin-A receptor in mediating satiety, food intake of cholecystokinin-A receptor-/- mice was compared with the corresponding intakes of wild-type animals and mice lacking the other known cholecystokinin receptor subtype, cholecystokinin-B/gastrin. Intraperitoneal administration of cholecystokinin failed to decrease food intake in mice lacking cholecystokinin-A receptors. In contrast, cholecystokinin diminished food intake by up to 90% in wild-type and cholecystokinin-B/gastrin receptor-/- mice. Together, these findings indicate that cholecystokinin-induced inhibition of food intake is mediated by the cholecystokinin-A receptor. To explore the long-term consequences of either cholecystokinin-A or cholecystokinin-B/gastrin receptor absence, body weight as a function of age was compared between freely fed wild-type and mutant animals. Both cholecystokinin-A and cholecystokinin-B/gastrin receptor-/- mice maintained normal body weight well into adult life. In addition, each of the two receptor-/- strains had normal pancreatic morphology and were normoglycemic. Our results suggest that although cholecystokinin plays a role in the short-term inhibition of food intake, this pathway is not essential for the long-term maintenance of body weight.     

Testing the robustness of the dysphoria factor of the Simms et al. (2002) model of posttraumatic stress disorder.

The Simms et al. (2002) four-factor structure of posttraumatic stress disorder (PTSD) has been supported in many factor analytic studies, and the specificity of the dysphoria factor has been questioned because of its strong associations with measures of depression and anxiety. This study addressed this issue by conducting a confirmatory factor analysis while controlling for the symptoms of major depression (MD) and generalized anxiety disorder (GAD). Data from individuals who satisfied Criterion A of the diagnostic criteria for a Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM–IV) diagnosis of PTSD (n = 12,467) in the 2004–2005 National Epidemiologic Study on Alcohol and Related Conditions (NESARC) were used in the analysis. The results showed that after controlling for MD and GAD, the factor loadings for dysphoria items were significantly attenuated, although they remained relatively high and statistically significant. The present findings contribute to the debate regarding how PTSD should be conceptualized and assessed in future issues of the DSM. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Inhibitory effect on LPS-induced tumor necrosis factor in calves treated with chlorpromazine or pentoxifylline

The inhibitory effect of chlorpromazine (CPZ), pentoxifylline (PTX) and dexamethasone (DEX) was investigated in a model of endotoxin shock in Holstein calves following an intravenous administration of Esherichia coli endotoxin (LPS). Initial correlations with its effects on the levels of tumor necrosis factor (TNF), a pivotal mediator of endotoxin shock, and clinical signs were obtained. The pretreatment of CPZ or DEX significantly decreased the serum levels of TNF, and reduced endotoxic shock. But the pretreatment of PTX hardly reduced the increase of serum TNF levels and endotoxin shock. The levels of serum endotoxin were not significantly different a minute of postinjection of LPS in calves. The results of this study indicate that pretreatment of CPZ or DEX inhibit various biological effects on endotoxin in calves.     

Experimental toxoplasmosis in broiler chicks

To evaluate chicken toxoplasmosis both as an economic and a public health subject, 84 broiler chicks of a commercial strain, 30 days old, were distributed into seven groups of 12 birds (three replications of four chicks) experimentally infected with three developing T. gondii stages of the P strain as follows: tachyzoites, intravenous (two groups: 5.0 x 10(5) and 5.0 x 10(6)), cysts, per os (two groups: 1.0 x 10(2) and 1.0 x 10(3)) and oocysts, per os (three groups: 5.0 x 10(2), 5.0 x 10(3) and 5.0 x 10(4)). Twelve chicks received only a placebo (control group). During the next 30 days the following parameters were estimated: productivity (weight gain and feed conversion), clinical signs, including rectal temperature and parasitemia (bioassay). No clinical signs suggesting toxoplasmosis were seen and no statistical differences on productivity standards were found in comparison between inoculated and control chicks. However, fowls inoculated with tachyzoites and oocysts occasionally showed hyperthermia. Some haematological changes were detected in fowls inoculated with T. gondii. Anatomo-histopathological changes were not observed. From 14 parasitemias detected, 35.7% appeared on the 5th day after inoculation and 57.1% of them resulted from oocysts inoculation. After 30-35 days all birds were slaughtered: fragments from 12 organs or tissues from each of them were subjected to artificial peptic digestion and after that injected into T. gondii antibody-free mice (IIFR). T. gondii was detected in brain (12), pancreas (five), spleen (five), retina (five), kidney (two), heart (four), proventriculus (three), liver (two), intestine (two), lung (one), and skeletal muscle (one). Similar to observations with parasitemia, from 42 T. gondii isolations, 59.5% came from chicks which had received oocysts. It can thus be inferred that the developing form, expelled by cats, is the most important for T. gondii chicken infection and that brain is the most infected organ in birds. Attention must be paid to the potential importance of chicken meat in public health, since T. gondii was isolated from skeletal and heart muscles.