Trade with the People\u27s Republic of China: Current Status and Future Prospects

Since the normalization of diplomatic relations with the People\u27s Republic of China (PRC) in 1979, U.S. trade with China has developed rapidly. In particular, 1980 saw significant developments in the institutional framework of U.S.-China trade relations, with the signing of several new trade-related bilateral agreements and a number of high-level visits in both directions.2 At the same time, China has begun to update its domestic legal system as it plans to integrate more fully into the international economic order.3 The last year has also witnessed the cancellation of certain large development projects, and delay in the implementation of others, as the Chinese readjust their economic plans and priorities. This Perspective will first discuss the current status of U.S.-China trade relations, with an emphasis on the developments of 1980. It will then present our view of the Chinese economy and prospects for the future development of China\u27s foreign trade. Changes in the Chinese legal system will be mentioned only briefly, as those matters are treated in detail elsewhere in this issue

The Pulmonary Component of the Second Sound in Right Ventricular Failure

Sound within the pulmonary artery was measured in 24 patients to determine if right ventricular failure modifies the amplitude of the pulmonary component of the second sound (P2). The amplitude of P2 in eight patients with right ventricular failure secondary to pulmonary hypertension (2610 ± 370 dynes/cm2) did not differ from P2 in eight patients with pulmonary hypertension not accompanied by right ventricular failure (3120 ± 710 dynes/cm2). In both groups, the amplitude of P2 exceeded control subjects (520 ± 70 dynes/cm2) (P \u3c .001 and P \u3c .01, respectively). The maximal rate of development of the pressure gradient across the closed pulmonary valve was higher in patients with right ventricular failure (580 ± 100 mm Hg/sec) than in control subjects (150 ± 30 mm Hg/sec) (P \u3c .001) and maximal negative dp/dt was also higher in patients with failure (750 ± 70 mm Hg/sec vs 190 ± 20 mm Hg/sec) (P \u3c .001). The maximal rate of change of the diastolic pressure gradient correlated linearly with maximal negative dp/dt (r=.89). These observations indicate that P2 is accentuated in patients with right ventricular failure secondary to pulmonary hypertension. The accentuation results from the augmented rate of development of the diastolic pressure gradient, which reflects an augmented right ventricular negative dp/dt. Therefore, an accentuated P2 remains valid as a clinical sign of pulmonary hypertension whether or not right ventricular failure occurs

A conserved circadian function for the Neurofibromatosis 1 gene

Summary: Loss of the Neurofibromatosis 1 (Nf1) protein, neurofibromin, in Drosophila disrupts circadian rhythms of locomotor activity without impairing central clock function, suggesting effects downstream of the clock. However, the relevant cellular mechanisms are not known. Leveraging the discovery of output circuits for locomotor rhythms, we dissected cellular actions of neurofibromin in recently identified substrates. Herein, we show that neurofibromin affects the levels and cycling of calcium in multiple circadian peptidergic neurons. A prominent site of action is the pars intercerebralis (PI), the fly equivalent of the hypothalamus, with cell-autonomous effects of Nf1 in PI cells that secrete DH44. Nf1 interacts genetically with peptide signaling to affect circadian behavior. We extended these studies to mammals to demonstrate that mouse astrocytes exhibit a 24-hr rhythm of calcium levels, which is also attenuated by lack of neurofibromin. These findings establish a conserved role for neurofibromin in intracellular signaling rhythms within the nervous system. : Bai et al. show that the gene mutated in the disease Neurofibromatosis 1 is required for maintaining levels or cycling of calcium in circadian neurons in Drosophila and in mammalian cells. These effects likely account for effects of Nf1 on circadian behavior in Drosophila and may be relevant in explaining sleep phenotypes in patients. Keywords: circadian rhythms, neurofibromatosis 1, Drosophila, peptide signaling, cycling of calcium, mouse astrocyte

Intracardiac Phonocardiography in Subaortic Stenosis

The purpose of this study is to explore the value of intracardiac sound recordings for the verification of subaortic stenosis. Intracardiac sound was measured in ten patients with subaortic obstructions. Seven had idiopathic hypertrophic subaortic stenosis, two had a subvalvular membrane, and one had a subvalvular tunnel. In each patient, a systolic murmur was recorded within the left ventricle distal to the obstruction. The murmur was of lower amplitude distal to the aortic valve, and it was of even lower amplitude or absent proximal to the obstruction. In the presence of entrapment, no intraventricular murmur occurred although an apparent subvalvular pressure gradient was observed. The identification and localization of the maximal intensity of a systolic murmur in the ventricular outflow tract may assist in the verification of a subvalvular obstruction and help distinguish between artifactual pressure gradients and gradients indicative of subvalvular stenosis

Correlations between the Electronic Properties of \u3cem\u3eShewanella oneidensis\u3c/em\u3e Cytochrome \u3cem\u3ec\u3c/em\u3e Nitrite Reductase (ccNiR) and Its Structure: Effects of Heme Oxidation State and Active Site Ligation

The electrochemical properties of Shewanella oneidensis cytochrome c nitrite reductase (ccNiR), a homodimer that contains five hemes per protomer, were investigated by UV–visible and electron paramagnetic resonance (EPR) spectropotentiometries. Global analysis of the UV–vis spectropotentiometric results yielded highly reproducible values for the heme midpoint potentials. These midpoint potential values were then assigned to specific hemes in each protomer (as defined in previous X-ray diffraction studies) by comparing the EPR and UV–vis spectropotentiometric results, taking advantage of the high sensitivity of EPR spectra to the structural microenvironment of paramagnetic centers. Addition of the strong-field ligand cyanide led to a 70 mV positive shift of the active site’s midpoint potential, as the cyanide bound to the initially five-coordinate high-spin heme and triggered a high-spin to low-spin transition. With cyanide present, three of the remaining hemes gave rise to distinctive and readily assignable EPR spectral changes upon reduction, while a fourth was EPR-silent. At high applied potentials, interpretation of the EPR spectra in the absence of cyanide was complicated by a magnetic interaction that appears to involve three of five hemes in each protomer. At lower applied potentials, the spectra recorded in the presence and absence of cyanide were similar, which aided global assignment of the signals. The midpoint potential of the EPR-silent heme could be assigned by default, but the assignment was also confirmed by UV–vis spectropotentiometric analysis of the H268M mutant of ccNiR, in which one of the EPR-silent heme’s histidine axial ligands was replaced with a methionine

Assessment of the Orifice Area of Bioprosthetic Valves by Orifice-View Roentgenography

Orifice-view angiography permits us to visualize en face the orifice of the aortic or mitral valve. The radiopaque annulus of bioprosthetic valves assists in permitting the angiographer to position the patient exactly, so that the valve can be seen as if looking directly into the orifice. Orifice-view angiography of porcine bioprosthetic valves has been useful in assessing the size and configuration of the valve orifice. It can reveal a failure of leaflet opening that would indicate degeneration, even when hemodynamic measurements remain equivocal

Genome-wide Functional Analysis of CREB/Long-Term Memory-Dependent Transcription Reveals Distinct Basal and Memory Gene Expression Programs

SummaryInduced CREB activity is a hallmark of long-term memory, but the full repertoire of CREB transcriptional targets required specifically for memory is not known in any system. To obtain a more complete picture of the mechanisms involved in memory, we combined memory training with genome-wide transcriptional analysis of C. elegans CREB mutants. This approach identified 757 significant CREB/memory-induced targets and confirmed the involvement of known memory genes from other organisms, but also suggested new mechanisms and novel components that may be conserved through mammals. CREB mediates distinct basal and memory transcriptional programs at least partially through spatial restriction of CREB activity: basal targets are regulated primarily in nonneuronal tissues, while memory targets are enriched for neuronal expression, emanating from CREB activity in AIM neurons. This suite of novel memory-associated genes will provide a platform for the discovery of orthologous mammalian long-term memory components

Search for cytotoxic agents in multiple Laurencia complex seaweed species (Ceramiales, Rhodophyta) harvested from the Atlantic Ocean with emphasis on the Brazilian State of Espírito Santo

The development of new anti-cancer drugs of algal origin represents one of the least explored frontiers in medicinal chemistry. In this regard, the diversity of micro- and macroalgae found in Brazilian coastal waters can be viewed as a largely untapped natural resource. In this report, we describe a comparative study on the cytotoxic properties of extracts obtained from the Laurencia complex: Laurencia aldingensis, L. catarinensis, L. dendroidea, L. intricata, L. translucida, L. sp, and Palisada flagellifera. All of these species were collected in the coastal waters of the State of Espírito Santo, Brazil. Four out of the twelve samples initially investigated were found to show significant levels of toxicity towards a model tumor cell line (human uterine sarcoma, MES-SA). The highest levels of cytotoxicity were typically associated with non-polar (hexane) algal extracts, while the lowest levels of cytotoxicity were found with the corresponding polar (methanol) extracts. In this report, we also describe a biological model currently in development that will not only facilitate the search for new anti-cancer drug candidates of algal origin, but also permit the identification of compounds capable of inducing the destruction of multi-drug resistant tumors with greater efficiency than the pharmaceuticals currently in clinical use.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Ministério da SaúdeMinistério de Ciência e TecnologiaCNPq - INCT-Redoxom

Electrical Stimulation Modulates High γ Activity and Human Memory Performance.

Direct electrical stimulation of the brain has emerged as a powerful treatment for multiple neurological diseases, and as a potential technique to enhance human cognition. Despite its application in a range of brain disorders, it remains unclear how stimulation of discrete brain areas affects memory performance and the underlying electrophysiological activities. Here, we investigated the effect of direct electrical stimulation in four brain regions known to support declarative memory: hippocampus (HP), parahippocampal region (PH) neocortex, prefrontal cortex (PF), and lateral temporal cortex (TC). Intracranial EEG recordings with stimulation were collected from 22 patients during performance of verbal memory tasks. We found that high γ (62-118 Hz) activity induced by word presentation was modulated by electrical stimulation. This modulatory effect was greatest for trials with poor memory encoding. The high γ modulation correlated with the behavioral effect of stimulation in a given brain region: it was negative, i.e., the induced high γ activity was decreased, in the regions where stimulation decreased memory performance, and positive in the lateral TC where memory enhancement was observed. Our results suggest that the effect of electrical stimulation on high γ activity induced by word presentation may be a useful biomarker for mapping memory networks and guiding therapeutic brain stimulation

CHANG-ES XI: Circular Polarization in the Cores of Nearby Galaxies

We detect 5 galaxies in the CHANG-ES (Continuum Halos in Nearby Galaxies -- an EVLA Survey) sample that show circular polarization (CP) at L-band in our high resolution data sets. Two of the galaxies (NGC~4388 and NGC~4845) show strong Stokes $V/I\,\equiv\,m_C\,\sim\,2$\%, two (NGC~660 and NGC~3628) have values of $m_C\sim \,0.3$\%, and NGC~3079 is a marginal detection at $m_C\sim \,0.2$\%. The two strongest $m_C$ galaxies also have the most luminous X-ray cores and the strongest internal absorption in X-rays. We have expanded on our previous Faraday conversion interpretation and analysis and provide analytical expressions for the expected $V$ signal for a general case in which the cosmic ray electron energy spectral index can take on any value. We provide examples as to how such expressions could be used to estimate magnetic field strengths and the lower energy cutoff for CR electrons. Four out of our detections are {\it resolved}, showing unique structures, including a {\it jet} in NGC~4388 and a CP `conversion disk' in NGC~4845. The conversion disk is inclined to the galactic disk but is perpendicular to a possible outflow direction. Such CP structures have never before been seen in any galaxy to our knowledge. None of the galaxy cores show linear polarization at L-band. Thus CP may provide a unique probe of physical conditions deep into radio AGNs.Comment: 30 pages, 4 figures, accepted to MNRA