A study of mitochondrial membranes in relation to elementary particles

Elementary particles that commonly have been seen by electron microscopy to be attached by stalks to mitochondrial cristae in negatively stained preparations, were not apparent in similarly stained mitochondria from exponentially growing wild-type Neurospora crassa when these were isolated in sucrose solution containing 1 x 10^-3 M EDTA. However, elementary particles were easily demonstrable in electron micrographs if the mitochondria were isolated without EDTA in the sucrose solution. A biochemical study indicated that both kinds of mitochondrial preparations, isolated in the presence or absence of EDTA, had about the same capacity for oxidative phosphorylation. Observations on rat-liver mitochondria also suggested that the stalked elementary particles were more easily demonstrated if the preparation was made in the absence of EDTA. It was difficult to demonstrate elementary particles in wild-type Neurospora mitochondria isolated with or without EDTA and subsequently prepared for electron microscopy by spreading on the surface of an aqueous solution of potassium phosphotungstate. Elementary particles could be demonstrated in poky Neurospora mitochondria isolated with EDTA if the mitochondria were spread on the surface of an aqueous solution of phosphotungstate. It was concluded that biochemical functions associated with elementary particles are independent of structural configuration as seen by electron microscopy

Health Insurance and the Supply of Entrepreneurs

Some commentators have suggested that the absence of portable health insurance impedes people from leaving their jobs to start new firms. We investigate this belief by comparing wage-earners who become self-employed during a given period of time with their counterparts who do not. By examining the impact of variables relating to the health insurance and health status of these workers and their families, we can infer whether the lack of health insurance portability affects the probability that they become self-employed. The evidence does not support the conjecture that the current health insurance system affects the propensity to become self-employed. Hence, whatever its other merits, there is no reason to believe that the introduction of universal health insurance would significantly enhance entrepreneurial activity.

Linking development to climate adaptation: Leveraging generic and specific capacities to reduce vulnerability to drought in NE Brazil

AbstractTo respond to climate impact, poor agricultural households in less developed regions rely on different types of assets that define their overall adaptive capacity (AC). However not all assets build capacity equally. In this study we argue that building AC requires a combination of interventions that address not only climate-related risks (specific capacity) but also the structural deficits (e.g., lack of income, education, health, political power) (generic capacity) that shape vulnerability. Focusing on rainfed agriculture in NE Brazil, we investigate how households leverage and combine generic and specific capacities to reduce vulnerability. Particularly we explore: 1) the relative importance of different kinds of capacity in shaping vulnerability on these households and 2) how the level of generic capacities (particularly as a result of Brazil’s anti-poverty program Bolsa Família) influences the adoption of specific ones. We find that both kinds of capacity matter, as relatively higher levels of generic capacity (in terms of income in general, and climate-neutral income specifically) are associated with higher levels of specific capacity (irrigation). In addition we find that while Bolsa Família has been positive in increasing income, it has not been sufficient to manage the risk of food insecurity during drought events, suggesting a 'poverty trap' in which families are constantly coping with drought but failing to overcome the conditions that make them vulnerable. Our findings indicate that in order to decrease climate vulnerability of poor agricultural households, development interventions, such as anti-poverty programs, have to go beyond cash transfer and should incorporate risk management policies that enhance synergies between generic and specific capacities

Improving marine disease surveillance through sea temperature monitoring, outlooks and projections

To forecast marine disease outbreaks as oceans warm requires new environmental surveillance tools. We describe an iterative process for developing these tools that combines research, development and deployment for suitable systems. The first step is to identify candidate host-pathogen systems. The 24 candidate systems we identified include sponges, corals, oysters, crustaceans, sea stars, fishes and sea grasses (among others). To illustrate the other steps, we present a case study of epizootic shell disease (ESD) in the American lobster. Increasing prevalence of ESD is a contributing factor to lobster fishery collapse in southern New England (SNE), raising concerns that disease prevalence will increase in the northern Gulf of Maine under climate change. The lowest maximum bottom temperature associated with ESD prevalence in SNE is 12 degrees C. Our seasonal outlook for 2015 and long-term projections show bottom temperatures greater than or equal to 12 degrees C may occur in this and coming years in the coastal bays of Maine. The tools presented will allow managers to target efforts to monitor the effects of ESD on fishery sustainability and will be iteratively refined. The approach and case example highlight that temperature-based surveillance tools can inform research, monitoring and management of emerging and continuing marine disease threats

Efficacy of N-acetyl cysteine in traumatic brain injury

In this study, using two different injury models in two different species, we found that early post-injury treatment with NAcetyl Cysteine (NAC) reversed the behavioral deficits associated with the TBI. These data suggest generalization of a protocol similar to our recent clinical trial with NAC in blast-induced mTBI in a battlefield setting [1], to mild concussion from blunt trauma. This study used both weight drop in mice and fluid percussion injury in rats. These were chosen to simulate either mild or moderate traumatic brain injury (TBI). For mice, we used novel object recognition and the Y maze. For rats, we used the Morris water maze. NAC was administered beginning 30-60 minutes after injury. Behavioral deficits due to injury in both species were significantly reversed by NAC treatment. We thus conclude NAC produces significant behavioral recovery after injury. Future preclinical studies are needed to define the mechanism of action, perhaps leading to more effective therapies in man

Internal deformation of the subducted Nazca slab inferred from seismic anisotropy

Within oceanic lithosphere a fossilized fabric is often preserved originating from the time of plate formation. Such fabric is thought to form at the mid-ocean ridge when olivine crystals align with the direction of plate spreading1, 2. It is unclear, however, whether this fossil fabric is preserved within slabs during subduction or overprinted by subduction-induced deformation. The alignment of olivine crystals, such as within fossil fabrics, can generate anisotropy that is sensed by passing seismic waves. Seismic anisotropy is therefore a useful tool for investigating the dynamics of subduction zones, but it has so far proved difficult to observe the anisotropic properties of the subducted slab itself. Here we analyse seismic anisotropy in the subducted Nazca slab beneath Peru and find that the fast direction of seismic wave propagation aligns with the contours of the slab. We use numerical modelling to simulate the olivine fabric created at the mid-ocean ridge, but find it is inconsistent with our observations of seismic anisotropy in the subducted Nazca slab. Instead we find that an orientation of the olivine crystal fast axes aligned parallel to the strike of the slab provides the best fit, consistent with along-strike extension induced by flattening of the slab during subduction (A. Kumar et al., manuscript in preparation). We conclude that the fossil fabric has been overprinted during subduction and that the Nazca slab must therefore be sufficiently weak to undergo internal deformation