Endogenous R&D Investment and Market Structure: A Case Study of the Agricultural Biotechnology Industry

Over the past three decades, the agricultural biotechnology sector has been characterized by rapid innovation, market consolidation, and a more exhaustive definition of property rights. The industry attributes consistently identified by the literature and important to this analysis include: (i) endogenous sunk costs in the form of expenditures on R&D; (ii) seed and agricultural chemical technologies that potentially act as complements within firms and substitutes across firms; and (iii) property rights governing plant and seed varieties that have become more clearly defined since the 1970s. This paper adds to the stylized facts of the agricultural biotechnology industry to include the ability of firms to license technology, a phenomenon observed only recently in the market as licensing was previously precluded by high transactions costs and “anti-stacking” provisions. We extend Sutton's theoretical framework of endogenous sunk costs and market structure to incorporate the ability of firms to license technology under well-defined property rights, an observed characteristic not captured in previous analyses of the sector. Our model implies that technology licensing leads to lower levels of industry concentration then what would be found under Sutton's model, but that industry concentration remains bounded away from perfect competition as market size becomes large.licensing, market structure, R&D, agricultural biotechnology, Research and Development/Tech Change/Emerging Technologies, L22, L24, Q16,

CADASIL with Cysteine-Sparing Notch-3 Mutation

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an inherited vascular dementia1,2. The mutations implicated in CADASIL are located on Chromosome 19 within the NOTCH3 gene, which encodes a transmembrane receptor that is primarily expressed in vascular smooth muscle cells. Over one hundred distinct mutations have been described which alter the number of cysteine residues in the extracellular region and result in a CADASIL phenotype. Cysteine-sparing mutations with CADASIL phenotype have been reported four times. Two German kindreds were recently described with a CADASIL-like phenotype associated with a cysteine-sparing NOTCH3 mutation. We present another such case in a third family, with the same point mutation described in the German families. The patient is a 55-year-old Caucasian woman with five years of progressive cognitive impairment, chronic headaches, and gait instability. Prior to presenting at our clinic, she had been diagnosed with Alzheimer disease. Her neuropsychological testing (Table One) and MRI studies (Figure One), however, were more consistent with a subcortical vascular dementia. Her genetic CADASIL screen was “negative” although a missense mutation in NOTCH3 was identified. At the time of that test, no cysteine-sparing mutations causing CADASIL had been reported. Workup of other family members is ongoing. Elucidation of this case will provide corroboration of a cysteine-sparing CADASIL mutation, and will inform the discussion of whether this represents a distinct entity or a CADASIL subtype. With the field of neurogenetics rapidly evolving, interpretation of standard genetic tests may need to include literature review to ascertain the correct diagnosis

First measurement of gravitational lensing by cosmic voids in SDSS

We report the first measurement of the diminutive lensing signal arising from matter underdensities associated with cosmic voids. While undetectable individually, by stacking the weak gravitational shear estimates around 901 voids detected in SDSS DR7 by Sutter et al. (2012a), we find substantial evidence for a depression of the lensing signal compared to the cosmic mean. This depression is most pronounced at the void radius, in agreement with analytical models of void matter profiles. Even with the largest void sample and imaging survey available today, we cannot put useful constraints on the radial dark-matter void profile. We invite independent investigations of our findings by releasing data and analysis code to the public at https://github.com/pmelchior/void-lensingComment: 6 pages, 5 figures, as accepted by MNRA

Neurologic and Psychiatric Co-morbidity in Neuropsychiatry Training

Summary: Discusses a study on combined neuropsychiatry training for establishing competency in neuropsychiatry

The Differential Diagnosis of Congenital Disorders that Include Psychosis

Summary: Neuropsychiatrists should be aware of congenital disorders that can present with psychosis, however rarely. Recommends a differential diagnosticapproach based on estimated prevalence of the disorders and their most prominent associated neuropsychiatric features

The Role of Neuropsychiatrists in Medical Science

The re-emergence of neuropsychiatry in the twentieth century occurred in the context of a history of neuropsychiatric contributions to medical science. In parallel to the growth of neuropsychiatry as a medical specialty, psychiatry has benefitted from developments in neuroscience, many of these built upon foundations established by neuropsychiatrists. We sought to enumerate the contributions by psychiatrists with neurological training to advances in medical science

Negative frequency dependent prey selection by two canid predators and its implications for the conservation of a threatened rodent in arid Australia

Unprecedented anthropogenic changes to biodiversity and biogeography demand a greater understanding of the consequences of altered faunal composition for ecosystem functioning. Selective predation has important, yet poorly understood effects on ecosystem stability, and can be strongly influenced by the relative frequencies of different prey types in the environment. Yet, how predators adjust their selection for prey according to their environmental frequency is often overlooked. Here, we assessed frequency dependent selection of prey by dingoes and foxes in the Australian desert, biannually, across a nine-year period (2007-2016). Both predators exhibited potentially destabilizing, negative frequency dependent selection for prey. Foxes persisted to preferentially consume a threatened, native rodent (Notomys fuscus) when it was environmentally scarce. Bolstered by the observation that N.fuscus occurs at low densities in areas where foxes are common, our results suggest that N.fuscus is particularly vulnerable to predation by this predator; possibly because it is naive and/or lacks adaptations to avoid or escape predation by the relatively recently introduced fox. Dingoes tended to consume reptiles when they were scarce; potentially constituting a conservation concern if selected reptilian taxa are threatened. Foxes avoided, thus were unlikely to control populations of overabundant kangaroos, while both foxes and dingoes showed a preference for, and may therefore control populations of invasive rabbits. The integration of our results into the relative suites of (de)stabilizing influences exerted by dingoes and foxes is important to provide a more dynamic insight into how each predator impacts their naturally fluctuating ecosystems

Correlation of Measures of Psychotherapy Competency in Psychiatry Residents

This current study had two goals: 1. To examine the changes in various performance measuresas residents progress through psychotherapy training2. To explore correlations among various measures of psychotherapycompetence Conclusions: Resident self-assessment does not appear to reflect competenceas assessed by supervisors, or knowledge as assessed by objectivetests. Global supervisor evaluations do not appear to reliably measurecompetence. Standardized supervisor assessment instruments are needed. Further work is needed to develop reliable, valid measures ofcompetency

Reduction in apathy following epilepsy surgery

Introduction: Surgical treatment for patients with epilepsy who do not respond to antiepileptic medication can lead to changes in behavior, including new onset of neuropsychiatric symptoms such as depression and anxiety. In other cases, neuropsychiatric symptoms present before surgery may be alleviated. Because application of diagnostic criteria for primary psychiatric disorders may not be valid in assessing behavior in epilepsy populations, we sought to determine the feasibility of measuring behaviors associated with frontal-subcortical dysfunction using the Frontal Systems Behavior Scale (FrSBe) in patients who had received surgical intervention for medically refractory epilepsy. Materials and Methods: Twenty-three patients who had previously undergone epilepsy surgery and their family member informants completed the FrSBe. The FrSBe includes separate forms for patients and informants to rate symptoms associated with three frontal lobe syndromes - executive dysfunction, disinhibition, and apathy - prior to and following a neurological condition. Patients and informants were asked to rate frontal lobe behaviors before and after epilepsy surgery using the FrSBe. Results: Informants rated patients as showing a significantly greater reduction in apathy on the FrSBe compared to either disinhibition or executive dysfunction subscales. A trend in reduction of apathy following right hemisphere resection was found. Conclusions: Patients who have undergone epilepsy surgery show a reduction in apathy but it is unclear whether this behavioral change is directly related to the surgical intervention. We suggest that these preliminary findings support the utility of implementing dimensional scales such as the FrSBe to study behavioral changes following epilepsy surgery