A region within murine chromosome 7F4, syntenic to the human 11q13 amplicon, is frequently amplified in 4NQO-induced oral cavity tumors

Our previous reports have shown that two thirds of 4-nitroquinoline-1-oxide (4NQO)-induced murine oral squamous cell carcinomas (SCC) have Hras1 mutations. Loss of heterozygosity (LOH) involving the distal portion of chromosome (Chr) 7 occurred in half of the tumors with Hras1 mutations. Here, we demonstrate that five of six tumors with LOH have 4-8-fold amplification involving the distal portion of Chr 7 (7F4). Ccnd1. Fgf4 and Fgf3, within the most telomeric region of Chr 7 (70.5 cM), are co-amplified. The region is syntenic to a previously identified human amplicon at 11q13. Only one out of eight tumors without LOH at Chr 7 had twofold amplification; the other seven had no detectable amplification. Significant amplification is restricted to the chromosome with the Hras1 mutation. Gene amplification occurred without overexpression since only one of five tumors with amplification and one of six tumors without Ccnd1 amplification expressed increased protein. Although amplification of 11q13 occurs rather frequently in human tumors, 4NQO-induced oral cavity tumors in inbred mice are the first example of a murine tumor with consistent amplification. Our observations are strikingly similar to human head and neck SCC where overexpression of genes within the 11q13 amplicon is inconsistently detected. The amplification of genes localized to human 11q13 and the syntenic region on murine Chr 7 during tumorigenesis suggests that similar structural elements are present which predispose these regions to amplification during malignant transformation.     

Influence of physiologic hyperglucagonemia on basal and insulin-inhibited splanchnic glucose output in normal man

To evaluate the effects of physiologic hyperglucagonemia on splanchnic glucose output, glucagon was infused in a dose of 3 ng/kg per min to healthy subjects in the basal state and after splanchnic glucose output had been inhibited by an infusion of glucose (2 mg/kg per min). In the basal state, infusion of glucagon causing a 309 +/- 25 pg/ml rise in plasma concentration was accompanied by a rapid increase in splanchnic glucose output to values two to three times basal by 7-15 min. The rise in arterial blood glucose (0.5-1.5 mM) correlated directly with the increment in splanchnic glucose output. Despite continued glucagon infusion, and in the face of stable insulin levels, splanchnic glucose output declined after 22 min, returning to basal levels by 30-45 min. In the subjects initially receiving the glucose infusion, arterial insulin concentration rose by 5-12 muU/ml, while splanchnic glucose output fell by 85-100%. Infusion of glucagon causing an increment in plasma glucagon concentration of 272 +/- 30 pg/ml reversed the inhibition in splanchnic glucose production within 5 min. Splanchnic glucose output reached a peak increment 60% above basal levels at 10 min, and subsequently declined to levels 20-25% below basal at 30-45 min. These findings provide direct evidence that physiologic increments in plasma glucagon stimulate splanchnic glucose output in the basal state and reverse insulin-mediated inhibition of splanchnic glucose production in normal man. The transient nature of the stimulatory effect of glucagon on splanchnic glucose output suggests the rapid development of inhibition or reversal of glucagon action. This inhibition does not appear to depend on increased insulin secretio.     

Prospective study of postpartum depression: Prevalence, course, and predictive factors.

[Correction Notice: An erratum for this article was reported in Vol 94(2) of Journal of Abnormal Psychology (see record 2008-10964-001). Much of the data reported in Tables 4 and 5 are incorrect. Most of the errors are small and they do not affect the p values shown in the tables, with three exceptions which are provided in the erratum.] 99 women (mean age 26.5 yrs) were followed from the 2nd trimester of pregnancy until about 6 mo postpartum. Depression diagnostic and severity assessments were conducted during pregnancy and after delivery. Instruments included the Beck Depression Inventory and an interview adapted from the Schedule of Affective Disorders and Schizophrenia. Depression severity decreased steadily from the 2nd trimester until 9 wks postpartum. Approximately 9% of the Ss during pregnancy and 12% of the Ss during the postpartum period were diagnosed as having a major or minor depression. A model of depression was constructed to account for both postpartum depression symptomatology and the syndrome of postpartum depression. Predictor variables (e.g., prepartum depression symptomatology, obstetric risk factors) accounted for about 50% of the variance in depressive symptomatology. Predictor variables (e.g., depression history, stressful childcare events) accounted for about 30% of the variance in diagnostic status. Findings underscore the importance of studying changes in depression diagnostic status as well as changes in level of depressive symptomatology in prospective studies. (43 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of observer metamerism in the determination of human color-matching functions

This article addresses the results of the recent North and Fairchild article on observer metamerism. It reports on the results of a different experiment that produced similar results to those of North and Fairchild. The history of observer metamerism is outlined briefly and some possible sources of the large variations in inter-observer matches are suggested. Finally, a plea for a commercially viable special index of metamerism for change in observer is formulated. © 1995 John Wiley & Sons, Inc.     

Joint Rate-and-Power Allocation for Multi-channel Spectrum Sharing Networks with Balanced QoS Provisioning and Power Saving

In this paper we study the joint rate-and-power allocation for multi-channel spectrum sharing networks with balanced QoS provisioning and power saving. We formulate this cross-layer optimization problem as a non-cooperative game G _JRPA in which each user has a coupled two-tuple strategy, i.e., simultaneous rate and multi-channel power allocations. A multi-objective cost function is proposed to represent user’s awareness of both QoS provisioning and power saving. We analyze the properties of Nash equilibrium (N.E.) for our G _JRPA , including its existence, and properties of QoS provisioning and power saving. Furthermore, we derive a layered structure by applying the Lagrangian dual decomposition to G _JRPA and design a distributed algorithm to find the N.E.. Simulation results are presented to show the validity of our game theoretic formulation and the performance of our proposed algorithm. Detailed studies on the performance tradeoff between QoS provisioning and power saving are also carried out.

A carbon nanotube needle biosensor

A carbon nanotube needle biosensor was developed to provide fast, cost effective and highly sensitive electrochemical detection of biomolecules. The sensor was fabricated based on an array of aligned multi-wall carbon nanotubes synthesized by chemical vapor deposition. A bundle of nanotubes in the array was welded onto the tip of a tungsten needle under a microscope. The needle was then encased in glass and a polymer coating leaving only the tip of the needle exposed. Cyclic voltammetry was performed to examine the redox behavior of the nanotube needle. The cyclic voltammetry results showed a steady-state response attributable to radial diffusion with a high steady-state current density. An amperometric sensor was then developed for glucose detection by physically attaching glucose oxidase on the nanotube needle. The amperometric response of these nanotube needles showed a high sensitivity with a low detection limit. It is expected that the nanotube needle can be sharpened to increase the sensitivity to the point where the current is almost too small to measure. The simple manufacturing method should allow commodity level production of highly sensitive electronic biosensors.     

In silico design of small RNA switches

The discovery of natural RNA sensors that respond to a change in the environment by a conformational switch can be utilized for various biotechnological and nanobiotechnological advances. One class of RNA sensors is the riboswitch: an RNA genetic control element that is capable of sensing small molecules, responding to a deviation in ligand concentration with a structural change. Riboswitches are modularly built from smaller components. Computational methods can potentially be utilized in assembling these building block components and offering improvements in the biochemical design process. We describe a computational procedure to design RNA switches from building blocks with favorable properties. To achieve maximal throughput for genetic control purposes, future designer RNA switches can be assembled based on a computerized preprocessing buildup of the constituent domains, namely the aptamer and the expression platform in the case of a synthetic riboswitch. Conformational switching is enabled by the RNA versatility to possess two highly stable states that are energetically close to each other but topologically distinct, separated by an energy barrier between them. Initially, computer simulations can produce a list of short sequences that switch between two conformers when trigerred by point mutations or temperature. The short sequences should possess an additional desirable property; when these selected small RNA switch segments are attached to various aptamers, the ligand binding mechanism should replace the aforementioned event triggers, which will no longer be effective for crossing the energy barrier. In the assembled RNA sequence, energy minimization folding predictions should then show no difference between the folded structure of the entire sequence relative to the folded structure of each of its constituents. Moreover, energy minimization methods applied on the entire sequence could aid at this preprocessing stage by exhibiting high mutational robustness to capture the stability of the formed hairpin in the expression platform. The above computer-assisted assembly procedure together with application specific considerations may further be tailored for therapeutic gene regulation. Index Terms-Design of RNA switches, energy minimization methods, RNA folding predictions.     

Comparison of arterial transit times estimated using arterial spin labeling

Objective  

To compare arterial transit time estimates from two efficient transit time mapping techniques using arterial spin labeling (ASL)—flow encoded arterial spin tagging (FEAST) and Look-Locker ASL (LL-ASL). The effects of bipolar gradients and label location were investigated.     

Very low energy homes in the United States: Perspectives on performance from measured data

We present measured annual performance data from a dozen recent-vintage very low energy homes in North America. Many of the designs combine greater energy efficiency with solar electric photovoltaic power in an attempt to create Zero Energy Homes (ZEH). We also provide measured data from the first home constructed to the German Passivhaus standard in the United States. Several projects either exceeded or come very close to true net zero energy when evaluated over a year.The data indicate that very low energy use buildings can very readily be achieved in North America. Annual energy use half that or less than standard housing can be achieved for an equivalent cost of $0.10/kWh from the efficiency investment. In general, the better cost effectiveness seen from energy efficiency measures indicates that greater investment in conservation should be a prerequisite to installation of solar water heating and solar electricity in Zero Energy Homes. However, over emphasis in efficiency is also possible. This suggests that optimization tools such as BEopt and EGUSA, which characterize both renewable resource performance and that also of specific combinations of energy efficiency measures, will best guide designers to locate the most economically favorable mix to reach an energy neutral level.