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Hormonal contraceptives and marriage [Psychological and Cognitive Sciences]

PNAS Early Edition Articles - Mon, 11/17/2014 - 14:26
How are hormonal contraceptives (HCs) related to marital well-being? Some work suggests HCs suppress biological processes associated with women’s preferences for partner qualities reflective of genetic fitness, qualities that may be summarized by facial attractiveness. Given that realizing such interpersonal preferences positively predicts relationship satisfaction, any changes in women’s preferences...

Uncleaved caspase-1 is active in response to LT [Immunology and Inflammation]

PNAS Early Edition Articles - Mon, 11/17/2014 - 14:26
Inflammasomes are caspase-1–activating multiprotein complexes. The mouse nucleotide-binding domain and leucine rich repeat pyrin containing 1b (NLRP1b) inflammasome was identified as the sensor of Bacillus anthracis lethal toxin (LT) in mouse macrophages from sensitive strains such as BALB/c. Upon exposure to LT, the NLRP1b inflammasome activates caspase-1 to produce mature...

Pattern formation of photoactivated polymers [Applied Physical Sciences]

PNAS Early Edition Articles - Mon, 11/17/2014 - 14:26
Since the pioneering work of Turing on the formation principles of animal coat patterns [Turing AM (1952) Phil Trans R Soc Lond B 237(641):37–72], such as the stripes of a tiger, great effort has been made to understand and explain various phenomena of self-assembly and pattern formation. Prominent examples are...

New decades in age and the search for meaning [Psychological and Cognitive Sciences]

PNAS Early Edition Articles - Mon, 11/17/2014 - 14:26
Although humans measure time using a continuous scale, certain numerical ages inspire greater self-reflection than others. Six studies show that adults undertake a search for existential meaning when they approach a new decade in age (e.g., at ages 29, 39, 49, etc.) or imagine entering a new epoch, which leads...

APE1 is dispensable for S-region cleavage in CSR [Immunology and Inflammation]

PNAS Early Edition Articles - Mon, 11/17/2014 - 14:26
Activation-induced cytidine deaminase (AID) is essential for antibody diversification, namely somatic hypermutation (SHM) and class switch recombination (CSR). The deficiency of apurinic/apyrimidinic endonuclease 1 (Ape1) in CH12F3-2A B cells reduces CSR to ∼20% of wild-type cells, whereas the effect of APE1 loss on SHM has not been examined. Here we...

Atmospheric turbulence and inertia-gravity waves [Earth, Atmospheric, and Planetary Sciences]

PNAS Early Edition Articles - Mon, 11/17/2014 - 14:26
Midlatitude fluctuations of the atmospheric winds on scales of thousands of kilometers, the most energetic of such fluctuations, are strongly constrained by the Earth’s rotation and the atmosphere’s stratification. As a result of these constraints, the flow is quasi-2D and energy is trapped at large scales—nonlinear turbulent interactions transfer energy...

Harm to others outweighs harm to self [Psychological and Cognitive Sciences]

PNAS Early Edition Articles - Mon, 11/17/2014 - 14:26
Concern for the suffering of others is central to moral decision making. How humans evaluate others’ suffering, relative to their own suffering, is unknown. We investigated this question by inviting subjects to trade off profits for themselves against pain experienced either by themselves or an anonymous other person. Subjects made...

Fast high-resolution 3D TIRF microscopy [Biophysics and Computational Biology]

PNAS Early Edition Articles - Mon, 11/17/2014 - 14:26
Total internal reflection fluorescence microscopy (TIRFM) is the method of choice to visualize a variety of cellular processes in particular events localized near the plasma membrane of live adherent cells. This imaging technique not relying on particular fluorescent probes provides a high sectioning capability. It is, however, restricted to a...

TOP1 inhibition impairs synaptic function [Neuroscience]

PNAS Early Edition Articles - Mon, 11/17/2014 - 14:26
Topotecan is a topoisomerase 1 (TOP1) inhibitor that is used to treat various forms of cancer. We recently found that topotecan reduces the expression of multiple long genes, including many neuronal genes linked to synapses and autism. However, whether topotecan alters synaptic protein levels and synapse function is currently unknown....

Connectivity dynamics and seizure onset zone [Neuroscience]

PNAS Early Edition Articles - Mon, 11/17/2014 - 14:26
The human brain is a dynamic networked system. Patients with partial epileptic seizures have focal regions that periodically diverge from normal brain network dynamics during seizures. We studied the evolution of brain connectivity before, during, and after seizures with graph-theoretic techniques on continuous electrocorticographic (ECoG) recordings (5.4 ± 1.7 d...

Vibrio fischeri colonization factor discovery [Microbiology]

PNAS Early Edition Articles - Mon, 11/17/2014 - 14:26
Animal epithelial tissue becomes reproducibly colonized by specific environmental bacteria. The bacteria (microbiota) perform critical functions for the host’s tissue development, immune system development, and nutrition; yet the processes by which bacterial diversity in the environment is selected to assemble the correct communities in the host are unclear. To understand...

Structural properties of TG2 in solution [Biochemistry]

PNAS Early Edition Articles - Mon, 11/17/2014 - 14:26
The multifunctional enzyme transglutaminase 2 (TG2) is the target of autoantibodies in the gluten-sensitive enteropathy celiac disease. In addition, the enzyme is responsible for deamidation of gluten peptides, which are subsequently targeted by T cells. To understand the regulation of TG2 activity and the enzyme’s role as an autoantigen in...

Circadian misalignment and energy metabolism [Physiology]

PNAS Early Edition Articles - Mon, 11/17/2014 - 14:26
Eating at a time when the internal circadian clock promotes sleep is a novel risk factor for weight gain and obesity, yet little is known about mechanisms by which circadian misalignment leads to metabolic dysregulation in humans. We studied 14 adults in a 6-d inpatient simulated shiftwork protocol and quantified...

Apocenter insufficient for Europa plume detection [Earth, Atmospheric, and Planetary Sciences]

PNAS Early Edition Articles - Mon, 11/17/2014 - 14:26
We report far-ultraviolet observations of Jupiter’s moon Europa taken by Space Telescope Imaging Spectrograph (STIS) of the Hubble Space Telescope (HST) in January and February 2014 to test the hypothesis that the discovery of a water vapor aurora in December 2012 by local hydrogen (H) and oxygen (O) emissions with...

Aptamer photoregulation in vivo [Applied Biological Sciences]

PNAS Early Edition Articles - Mon, 11/17/2014 - 14:26
The in vivo application of aptamers as therapeutics could be improved by enhancing target-specific accumulation while minimizing off-target uptake. We designed a light-triggered system that permits spatiotemporal regulation of aptamer activity in vitro and in vivo. Cell binding by the aptamer was prevented by hybridizing the aptamer to a photo-labile...

CREB regulation by phosphorylation and acetylation [Biochemistry]

PNAS Early Edition Articles - Mon, 11/17/2014 - 14:26
In the fasted state, increases in catecholamine signaling promote adipocyte function via the protein kinase A-mediated phosphorylation of cyclic AMP response element binding protein (CREB). CREB activity is further up-regulated in obesity, despite reductions in catecholamine signaling, where it contributes to the development of insulin resistance. Here we show that...

Genetic code reduction [Evolution]

PNAS Early Edition Articles - Mon, 11/17/2014 - 14:26
Expanding the genetic code is an important aim of synthetic biology, but some organisms developed naturally expanded genetic codes long ago over the course of evolution. Less than 1% of all sequenced genomes encode an operon that reassigns the stop codon UAG to pyrrolysine (Pyl), a genetic code variant that...

Credit scores, health, and human capital [Psychological and Cognitive Sciences]

PNAS Early Edition Articles - Mon, 11/17/2014 - 14:26
Credit scores are the most widely used instruments to assess whether or not a person is a financial risk. Credit scoring has been so successful that it has expanded beyond lending and into our everyday lives, even to inform how insurers evaluate our health. The pervasive application of credit scoring...

Influenza-neutralizing antibody stoichiometry [Biophysics and Computational Biology]

PNAS Early Edition Articles - Mon, 11/17/2014 - 14:26
The ability of antibodies binding the influenza hemagglutinin (HA) protein to neutralize viral infectivity is of key importance in the design of next-generation vaccines and for prophylactic and therapeutic use. The two antibodies CR6261 and CR8020 have recently been shown to efficiently neutralize influenza A infection by binding to and...

Regulation of the GSR in Alphaproteobacteria [Microbiology]

PNAS Early Edition Articles - Mon, 11/17/2014 - 14:26
The general stress response (GSR) in Alphaproteobacteria was recently shown to be controlled by a partner-switching mechanism that is triggered by phosphorylation of the response regulator PhyR. Activation of PhyR ultimately results in release of the alternative extracytoplasmic function sigma factor σEcfG, which redirects transcription toward the GSR. Little is...
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