Financial highlights : 1974

An abstract for this article is not available.Financial markets

Financial forecasts : 1975

An abstract for this article is not available.Financial markets

The district economy in perspective : 1974

An abstract for this article is not available.Federal Reserve District, 5th

Testing Foundations of Biological Scaling Theory Using Automated Measurements of Vascular Networks

Scientists have long sought to understand how vascular networks supply blood and oxygen to cells throughout the body. Recent work focuses on principles that constrain how vessel size changes through branching generations from the aorta to capillaries and uses scaling exponents to quantify these changes. Prominent scaling theories predict that combinations of these exponents explain how metabolic, growth, and other biological rates vary with body size. Nevertheless, direct measurements of individual vessel segments have been limited because existing techniques for measuring vasculature are invasive, time consuming, and technically difficult. We developed software that extracts the length, radius, and connectivity of in vivo vessels from contrast-enhanced 3D Magnetic Resonance Angiography. Using data from 20 human subjects, we calculated scaling exponents by four methods--two derived from local properties of branching junctions and two from whole-network properties. Although these methods are often used interchangeably in the literature, we do not find general agreement between these methods, particularly for vessel lengths. Measurements for length of vessels also diverge from theoretical values, but those for radius show stronger agreement. Our results demonstrate that vascular network models cannot ignore certain complexities of real vascular systems and indicate the need to discover new principles regarding vessel lengths

Dataset concerning the analytical approximation of the Ae3 temperature.

In this paper we present a new polynomial function for calculating the local phase transformation temperature (Ae3 ) between the austenite+ferrite and the fully austenitic phase fields during heating and cooling of steel:[Formula: see text] The dataset includes the terms of the function and the values for the polynomial coefficients for major alloying elements in steel. A short description of the approximation method used to derive and validate the coefficients has also been included. For discussion and application of this model, please refer to the full length article entitled "The role of aluminium in chemical and phase segregation in a TRIP-assisted dual phase steel" 10.1016/j.actamat.2016.05.046 (Ennis et al., 2016) [1]

Analytical method to measure three-dimensional strain patterns in the left ventricle from single slice displacement data

Background: Displacement encoded Cardiovascular MR (CMR) can provide high spatial resolution measurements of three-dimensional (3D) Lagrangian displacement. Spatial gradients of the Lagrangian displacement field are used to measure regional myocardial strain. In general, adjacent parallel slices are needed in order to calculate the spatial gradient in the through-slice direction. This necessitates the acquisition of additional data and prolongs the scan time. The goal of this study is to define an analytic solution that supports the reconstruction of the out-of-plane components of the Lagrangian strain tensor in addition to the in-plane components from a single-slice displacement CMR dataset with high spatio-temporal resolution. The technique assumes incompressibility of the myocardium as a physical constraint. Results: The feasibility of the method is demonstrated in a healthy human subject and the results are compared to those of other studies. The proposed method was validated with simulated data and strain estimates from experimentally measured DENSE data, which were compared to the strain calculation from a conventional two-slice acquisition. Conclusion: This analytical method reduces the need to acquire data from adjacent slices when calculating regional Lagrangian strains and can effectively reduce the long scan time by a factor of two

Probing dynamic myocardial microstructure with cardiac magnetic resonance diffusion tensor imaging

This article is an invited editorial comment on the paper entitled “In vivo cardiovascular magnetic resonance diffusion tensor imaging shows evidence of abnormal myocardial laminar orientations and mobility in hypertrophic cardiomyopathy” by Ferreira et al., and published as Journal of Cardiovascular Magnetic Resonance 2014; 16:87

Trait-based plant mortality and preference for native versus non-native seedlings by invasive slug and snail herbivores in Hawaii

Non-native herbivores may alter plant communities through their preferential consumption of seedlings of different species. We assessed seedling herbivory by two invasive gastropod species in Hawaii, the giant African snail (Achatina fulica) and the Cuban brown slug (Veronicella cubensis). We hypothesized that six native species would suffer greater gastropod herbivory than four non-native species, and that species with short stature, thin leaves, and lacking physical defenses would suffer the greatest mortality from gastropods. Herbivory was measured during 13-day preference trials using enclosures that each contained four different woody species (two native, two non-native) and were assigned to one of three treatments: giant African snail, Cuban brown slug, or control (no gastropod). Discriminant function analysis was used to predict gastropod-induced seedling mortality from a suite of seedling characteristics. Native species did not always experience greater herbivory than non-natives species, and seedling mortality was 0–100 %. Native Pipturus albidus and Clermontia parviflora suffered 100 % mortality from V. cubensis herbivory, and P. albidus, Psychotria hawaiiensis, and Myrsine lessertiana suffered C80 % mortality from A. fulica. Two non-natives (Fraxinus uhdei, Clidemia hirta), and two natives (Metrosideros polymorpha, Diospyros sandwicensis), suffered little damage and no mortality. Non-native Ardisia elliptica suffered 10–30 %gastropod mortality, and non-native Psidium cattleianum mortality was 0–50 %. Leaf thickness best predicted species mortality caused by slugs and snails; some thicker-leaved species suffered most. Invasive snails and slugs threaten some native and non-native seedlings by directly consuming them. Current and future plant community structure in Hawaii may in part reflect the feeding preferences of invasive gastropods

Trait-based plant mortality and preference for native versus non-native seedlings by invasive slug and snail herbivores in Hawaii

Non-native herbivores may alter plant communities through their preferential consumption of seedlings of different species. We assessed seedling herbivory by two invasive gastropod species in Hawaii, the giant African snail (Achatina fulica) and the Cuban brown slug (Veronicella cubensis). We hypothesized that six native species would suffer greater gastropod herbivory than four non-native species, and that species with short stature, thin leaves, and lacking physical defenses would suffer the greatest mortality from gastropods. Herbivory was measured during 13-day preference trials using enclosures that each contained four different woody species (two native, two non-native) and were assigned to one of three treatments: giant African snail, Cuban brown slug, or control (no gastropod). Discriminant function analysis was used to predict gastropod-induced seedling mortality from a suite of seedling characteristics. Native species did not always experience greater herbivory than non-natives species, and seedling mortality was 0–100 %. Native Pipturus albidus and Clermontia parviflora suffered 100 % mortality from V. cubensis herbivory, and P. albidus, Psychotria hawaiiensis, and Myrsine lessertiana suffered C80 % mortality from A. fulica. Two non-natives (Fraxinus uhdei, Clidemia hirta), and two natives (Metrosideros polymorpha, Diospyros sandwicensis), suffered little damage and no mortality. Non-native Ardisia elliptica suffered 10–30 %gastropod mortality, and non-native Psidium cattleianum mortality was 0–50 %. Leaf thickness best predicted species mortality caused by slugs and snails; some thicker-leaved species suffered most. Invasive snails and slugs threaten some native and non-native seedlings by directly consuming them. Current and future plant community structure in Hawaii may in part reflect the feeding preferences of invasive gastropods

Neural locus of color afterimages.

After fixating on a colored pattern, observers see a similar pattern in complementary colors when the stimulus is removed. Afterimages were important in disproving the theory that visual rays emanate from the eye[1], in demonstrating inter-ocular interactions[2], and in revealing the independence of binocular-vision from eye-movements[3]. Afterimages also prove invaluable in exploring selective attention[4], filling-in[5], and consciousness[6]. Proposed physiological mechanisms for color afterimages range from bleaching of cone photo-pigments[7] to cortical adaptation[4–6, 8, 9], but direct neural measurements have not been reported. We introduce a time-varying method for evoking after-images, which provides precise measurements of adaptation and a direct link between visual percepts and neural responses[10]. We then use in vivo electrophysiological recordings to show that all three classes of primate retinal ganglion cells exhibit subtractive adaptation to prolonged stimuli, with much slower time-constants than those expected of photoreceptors. At the cessation of the stimulus, ganglion cells generate rebound responses that can provide afterimage signals for later neurons. Our results indicate that afterimage signals are generated in the retina, but may be modified like other retinal signals by cortical processes[4–6], so that evidence presented for cortical generation of color afterimages[8, 9] is explainable by spatio-temporal factors that apply to all signals