Diachronous development of Great Unconformities before Neoproterozoic Snowball Earth.

The Great Unconformity marks a major gap in the continental geological record, separating Precambrian basement from Phanerozoic sedimentary rocks. However, the timing, magnitude, spatial heterogeneity, and causes of the erosional event(s) and/or depositional hiatus that lead to its development are unknown. We present field relationships from the 1.

Acute postnatal exposure to the pentaBDE commercial mixture DE-71 at 5 or 15 mg/kg/day does not produce learning or attention deficits in rats.

Polybrominated diphenyl ethers (PBDEs), flame retardant chemicals added to polymer products, have become ubiquitous in the environment, and they are bioaccumulating in humans and wildlife. Therefore, understanding their biological effects is important for public health. We have previously observed learning deficits in rats exposed to DE-71, a commercial PBDE mixture consisting primarily of pentabrominated diphenyl ethers, at a dose of 30 mg/kg/day from postnatal day (PND) 6 to 12.

Attitudes about depression and its treatment among mental health professionals, lay persons and immigrants and refugees in Norway.

Background: Internationally, depression is a common psychological disorder whose treatment depends upon its identification by treating professionals as well as patient utilization of mental health care systems; the latter often being hampered by cultural differences between patients and health professionals.

Method: The current study used vignettes of depressed patients which varied the culture and/or social circumstances of the patient to assess whether these variables influenced the conceptualization of depression and its treatment. Participants (N=722) included mental health professionals, lay people, immigrants, and refugees in Norway.

Thermodynamic examination of the pyrophosphate sensor helix in the thiamine pyrophosphate riboswitch.

Riboswitches are functional mRNA that control gene expression. Thiamine pyrophosphate (TPP) binds to thi-box riboswitch RNA and allosterically inhibits genes that code for proteins involved in the biosynthesis and transport of thiamine. Thiamine binding to the pyrimidine sensor helix and pyrophosphate binding to the pyrophosphate sensor helix cause changes in RNA conformation that regulate gene expression.

Pre-Columbian Andean sickness ideology and the social experience of leishmaniasis: A contextualized analysis of bioarchaeological and paleopathological data from San Pedro de Atacama, Chile.

Sociocultural concepts associated with sickness can profoundly influence social processes and individual experiences of disease. Here, we consider the role of sociocultural beliefs concerning sickness in the construction of individuals' social identities in the pre-Columbian Andes. Paleopathological analyses reveal evidence of mucocutaneous leishmaniasis, a facially disfiguring infectious disease endemic to tropical lowland rainforests, in the skeletal remains of six females buried at Coyo Oriental and Tchecar Túmulo Sur, two Middle Horizon (AD 500-1000) cemeteries in the highland desert of San Pedro de Atacama, Chile.

Neuronal morphology in the African elephant (Loxodonta africana) neocortex.

Virtually nothing is known about the morphology of cortical neurons in the elephant. To this end, the current study provides the first documentation of neuronal morphology in frontal and occipital regions of the African elephant (Loxodonta africana). Cortical tissue from the perfusion-fixed brains of two free-ranging African elephants was stained with a modified Golgi technique.

Neurolucida Lucivid versus Neurolucida camera: A quantitative and qualitative comparison of three-dimensional neuronal reconstructions.

A critical issue in quantitative neuromorphology is the accuracy and subsequent reliability of the tracing techniques employed to characterize neuronal components. Historically, the camera lucida was the only option for such investigations. In 1987, MBF Bioscience, Inc.

Why one fakes a head injury affects how one fakes a head injury.

Identifying suspect effort in neuropsychological assessments has been investigated in clinical samples and experimental simulation paradigms. While patients' incentives, such as compensation, are commonly thought to impact motivation, other motivational influences, such as attention-seeking, have been largely unexplored. To this end, undergraduates (n=202) were asked to fake a head injury on the Dot Counting Test, California Verbal Learning Test, and Benton Visual Retention Test.

Chronic postnatal DE-71 exposure: effects on learning, attention and thyroxine levels.

Polybrominated diphenyl ethers (PBDEs) are ubiquitous, bioaccumulative flame retardants. Much remains to be learned about their developmental toxicological properties, particularly with regards to chronic exposure. In two experiments, male Long-Evans rats ingested the commercial pentaBDE mixture DE-71 from birth onward, first through the milk of lactating dams (who ingested 5 or 7.

Thermodynamic examination of trinucleotide bulged RNA in the context of HIV-1 TAR RNA.

RNA structures contain many bulges and loops that are expected to be sites for inter- and intra-molecular interactions. Nucleotides in the bulge are expected to influence the structure and recognition of RNA. The same stability is assigned to all trinucleotide bulged RNA in the current secondary structure prediction models.

How to create successful discussions in science classrooms.

Professors often expect students to have the skills that are necessary to participate in discussions. Students, on the other hand, have been trained to glean information from the lecture format; their prior experiences in discussions are likely to be limited to personal opinions on topics such as stem-cell research or evolution. Sudden changes in expectations are jarring and unwelcome at any stage of life but especially when it affects our performance.

Characterization of RERG: an estrogen-regulated tumor suppressor gene.

RERG (Ras-related and estrogen-regulated growth inhibitor), a gene that encodes a small GTP binding and hydrolyzing protein (GTPase) of the Ras superfamily, was originally identified in gene microarray analysis as a gene of which expression is down-regulated in estrogen receptor (ER)-negative breast tumors. Subsequently, RERG mRNA was detected in ER-positive breast tumor-derived cell lines, but not in any of the ER-negative cell lines examined. Furthermore, a comparison of matched tumor and normal tissue samples suggests that RERG expression is lost in kidney, breast, ovary, and colon tumors.

Regional dendritic variation in neonatal human cortex: a quantitative Golgi study.

The present study quantitatively compared the basilar dendritic/spine systems of lamina V pyramidal neurons across four hierarchically arranged regions of neonatal human neocortex. Tissue blocks were removed from four Brodmann's areas (BAs) in the left hemisphere of four neurologically normal neonates (mean age=41+/- 40 days): primary (BA4 and BA3-1-2), unimodal (BA18), and supramodal cortices (BA10). Tissue was stained with a modified rapid Golgi technique.

Brief postnatal PBDE exposure alters learning and the cholinergic modulation of attention in rats.

Polybrominated diphenyl ethers (PBDEs), chemicals commonly used as flame retardants, are ubiquitous in the environment and bioaccumulate in humans and wildlife. However, little is known about their potential toxicological properties. In the present study, male Long-Evans rats orally administered the commercial PBDE mixture DE-71 or corn oil for 1 week, beginning at postnatal day (PND) 6, were tested on a visual discrimination task and two sustained attention tasks.

Cranial vault modification as a cultural artifact: a comparison of the Eurasian steppes and the Andes.

This paper details the practice of intentional cranial vault modification in the Eurasian steppes as well as in the pre-Columbian Andes focusing on the similarities and differences in how the practice was used to respond to changes in society. The appearance of vault modification in the steppes and the forms seen in the cemeteries of the Syr Darya and Amu Darya River deltas are discussed. Temporal changes in the pattern of modification are also investigated, especially the dramatic homogenization of the custom resulting from the conquests of the Huns.

Renewing the conspiracy theory debate: does Raf function alone to mediate Ras oncogenesis?

Ras proteins function as signal transducers and are mutationally activated in many human cancers. In 1993, Raf was identified as a key downstream effector of Ras signaling, and it was believed then that the primary function of Ras was simply to facilitate Raf activation. However, the subsequent discovery of other proteins that are effectors of Ras function suggested that oncogenic activities of Ras are mediated by both Raf-dependent and Raf-independent signaling.

Introductory course based on a single problem: Learning nucleic acid biochemistry from AIDS research.

In departure from the standard approach of using several problems to cover specific topics in a class, I use a single problem to cover the contents of the entire semester-equivalent biochemistry classes. I have developed a problem-based service-learning (PBSL) problem on HIV/AIDS to cover nucleic acid concepts that are typically taught in the second semester of a biochemistry class. Use of research articles on a specific topic allows developing problems such as one discussed here.

The effects of motivation, coaching, and knowledge of neuropsychology on the simulated malingering of head injury.

Two student groups, introductory psychology (n=91) and advanced neuroscience (n=34) undergraduates, were asked to malinger a head injury on Rey's 15-Item Test (FIT) and Dot Counting Test (DCT). The participants were randomly assigned to one of three motivation conditions (no motivation given, compensation, avoidance of blame for a motor vehicle accident) and to one of three coaching conditions (no coaching, coaching post-concussive symptoms, coaching symptoms plus warning of malingering detection). Analyses revealed a MotivationxStudent Group interaction on the FIT, indicating that the advanced neuroscience students, particularly when in the compensation condition, malingered the most flagrantly.

Red blood cell orientation in pulmonary capillaries and its effect on gas diffusion.

When alveoli are inflated, the stretched alveolar walls draw their capillaries into oval cross sections. This causes the disk-shaped red blood cells to be oriented near alveolar gas, thereby minimizing diffusion distance. We tested these ideas by measuring red blood cell orientation in histological slides from rapidly frozen rat lungs.

Information in the behavior stream.

The dynamic of a series of responses for four pigeons is analyzed using a discrete fast Fourier transform (FFT) and a measure of behavior's predictability. FFTs of moment-to-moment response rates reliably exhibited a continuous distribution for three of the four birds, with most of the power falling in the low frequencies-red noise. An information analysis of the predictability of a series of inter-response times (IRTs) reveals that there is some gain in prediction by knowing past behavior; moreover, predictability increases the more past behaviors are taken into account.

Regional dendritic and spine variation in human cerebral cortex: a quantitative golgi study.

The present study explored differences in dendritic/spine extent across several human cortical regions. Specifically, the basilar dendrites/spines of supragranular pyramidal cells were examined in eight Brodmann's areas (BA) arranged according to Benson's (1993, Behav Neurol 6:75-81) functional hierarchy: primary cortex (somatosensory, BA3-1-2; motor, BA4), unimodal cortex (Wernicke's area, BA22; Broca's area, BA44), heteromodal cortex (supple- mentary motor area, BA6beta; angular gyrus, BA39) and supramodal cortex (superior frontopolar zone, BA10; inferior frontopolar zone, BA11). To capture more general aspects of regional variability, primary and unimodal areas were designated as low integrative regions; heteromodal and supramodal areas were designated as high integrative regions.

Life-span dendritic and spine changes in areas 10 and 18 of human cortex: a quantitative Golgi study.

Dendritic neuropil is a sensitive indicator of the aging process and may exhibit regional cortical variations. The present study examined regional differences and age-related changes in the basilar dendrites/spines of supragranular pyramidal cells in human prefrontal (area 10) and secondary occipital (area 18) cortices. Tissue was obtained from the left hemisphere of 26 neurologically normal individuals ranging in age from 14 to 106 years (M(age) = 57 +/- 22 years; 13 males, 13 females).

Aminopeptidase activity from germinated jojoba cotyledons.

One major and two minor aminopeptidase activities from germinated jojoba (Simmondsia chinensis) cotyledon extracts were separated by ammonium sulfate precipitation and chromatofocusing. None of the activities were inhibited by 1,10 phenanthroline.The major aminopeptidase, purified 260-fold, showed a pH optimum of 6.

Proteolytic and Trypsin Inhibitor Activity in Germinating Jojoba Seeds (Simmondsia chinensis).

Changes in proteolytic activity (aminopeptidase, carboxypeptidase, endopeptidase) were followed during germination (imbibition through seedling development) in extracts from cotyledons of jojoba seeds (Simmondsia chinensis). After imbibition, the cotyledons contained high levels of sulfhydryl aminopeptidase activity (APA) but low levels of serine carboxypeptidase activity (CPA). CPA increased with germination through the apparent loss of a CPA inhibitor substance in the seed.