Dynamic Assessment of Oligopoly, Oligopsony Power, and Cost Efficiency using the New Empirical Industrial Organization in the U.S. Beef Packing Industry

In this paper, the new empirical industrial organization approach with a dynamic model is simultaneously employed to measure the degree of oligopoly, oligopsony power, and cost efficiency in the U.S. beef packing industry. The oligopsony power is estimated with two effects: cash cattle procurement market power and captive supply market power. The model is estimated by the Generalized Method of Moments using monthly data from 1990 to 2006. The empirical results reveal the presence of market power in both the beef retail market and the cattle procurement market in the sample period. The captive supply is a source of oligopsony market power, but the effect is considerably small. The oligopsony market power is greater and less stable than oligopoly market power for the whole sample period. The cost efficiency effect outweighs the market power effects for the sample period.beef packing industry, captive supply, cost efficiency, industrial concentration, market power, NEIO, Agricultural and Food Policy, Industrial Organization, Livestock Production/Industries, Marketing, Q13,

Dynamic Assessment of Bertrand Oligopsony in the U.S. Cattle Procurement Market

The new empirical industrial organization approach with the Bertrand model is employed to measure the oligopsony market power in the U.S. cattle procurement market. The assumption of price competition (Bertrand model) based on the nature of cattle production such as cattle cycle and seasonality is used and compared to quantity competition (Cournot model). The empirical results show that the oligopsony market power exists in the U.S. cattle procurement market. The cattle cycle and seasonality affect the oligopsony market power and the cattle cycle causes the change of market power. However, concentration has a negative effect on the oligopsony market power.cattle cycle, concentration, market power, NEIO, oligopsony, seasonality, Agribusiness, Demand and Price Analysis, Industrial Organization, Livestock Production/Industries, Marketing, Q13, L13, L16,

Three Essays on Market Power in the U.S. Cattle Procurement Market

This study consists of three essays. The first essay tests the causality between captive supply and cash market price in the U.S. cattle procurement market. Three causality tests, the Granger test, the Sims test, and the Modified Wald test, were conducted for four relationships: cash market price-total captive supply, cash market price-marketing agreement, cash market price-forward contract, and cash market price-packer fed cattle. All three tests indicate that cash market price is caused by total captive supply and marketing agreement. The Modified Wald test shows the bidirectional causality between cash market price and forward contract. Also, the Modified Wald test finds no causal relationship between cash market price and packer fed cattle. Overall test results indicate that captive supply causes cash market price, and the results favor the price dependent model over the quantity dependent model.The second essay measures the impacts of concentration and captive supply on oligopoly and oligopsony market power and cost efficiency in the U.S. beef packing industry using both static and dynamic empirical industrial organization models. Two separate sources of oligopsony power are considered: the cash cattle procurement market and the captive supply market. The results show the presence of market powers in both beef retail and cattle procurement markets. The oligopsony market power is greater but more unstable than oligopoly market power throughout the entire sample period. Concentration and captive supply play a role in increasing market power. The cost efficiency effects caused by increasing concentration and captive supply outweigh the market power effects.The third essay uses the new empirical industrial organization approach with the Bertrand model to measure the oligopsony market power in the U.S. cattle procurement market. It tests whether the market power is caused by concentration, cattle cycle, and seasonality. The results show that the oligopsony market power exists in the U.S. cattle procurement market. The cattle cycle and seasonality affect the oligopsony market power and the cattle cycle causes the change in market power. However, concentration has a negative effect on the oligopsony market power.Department of Agricultural Economic

A case of partial trisomy 3p syndrome with rare clinical manifestations

Partial trisomy 3p results from either unbalanced translocation or de novo duplication. Common clinical features consist of dysmorphic facial features, congenital heart defects, psychomotor and mental retardation, abnormal muscle tone, and hypoplastic genitalia. In this paper, we report a case of partial trisomy 3p with rare clinical manifestations. A full-term, female newborn was transferred to our clinic. She had cleft lip-plate, dysgenesis of the corpus callosum, patent ductus arteriosus, pulmonary hypertension, and severe right-sided hydronephrosis, associated with ureteropelvic junction obstruction. Cytogenetic investigation revealed partial trisomy 3p; 46,XX,der(4)t(3;4) (p21.1;p16). The karyotype of her father showed a balanced translocation, t(3;4)(p21.1;p16). Therefore, the size of duplication can be an important factor

CT findings in apical versus basal involvement of pulmonary tuberculosis

PURPOSEWe aimed to compare clinical features and computed tomog- raphy (CT) findings of pulmonary tuberculosis (TB) in lower lobe basal segments and upper lobe apical or apicoposterior segments. MATERIALS AND METHODSWe retrospectively reviewed medical records and chest CT scans of 986 adults who were diagnosed with active pulmo- nary TB. Active pulmonary TB confined to the basal segments was found in 21 patients. Sixty patients had disease localized to the apical or apicoposterior segments only. Clinical features and CT abnormalities of the lung parenchyma, airways, me- diastinal and hilar lymph nodes, and pleura were compared between these two groups. RESULTSA significant difference was observed between two groups in terms of underlying disease prevalence associated with an im- munocompromised state (basal, 6/21, 28.6%; apical or apico- posterior, 3/60, 5%; P = 0.008). Chest CT findings, including consolidation (P = 0.0016), lymphadenopathy (P = 0.0297), and pleural effusion (P = 0.008), were more common in ba- sal segment TB than in apical or apicoposterior segment TB. Small nodules were less common in basal segment TB than in apical or apicoposterior segment TB (P = 0.0299). The tree-in- bud sign was the most common CT finding in both basal seg- ment TB (17/21, 81%) and apical or apicoposterior segment TB groups (53/60, 88.3%) (P = 0.4633). CONCLUSIONLower lobe basal segment TB was more commonly present with common CT findings of primary pulmonary TB including consolidation, mediastinal and hilar lymphadenopathy, and pleural effusion than apical or apicoposterior segment TB

The Traditional Herbal Medicine, Dangkwisoo-San, Prevents Cerebral Ischemic Injury through Nitric Oxide-Dependent Mechanisms

Dangkwisoo-San (DS) is an herbal extract that is widely used in traditional Korean medicine to treat traumatic ecchymosis and pain by promoting blood circulation and relieving blood stasis. However, the effect of DS in cerebrovascular disease has not been examined experimentally. The protective effects of DS on focal ischemic brain were investigated in a mouse model. DS stimulated nitric oxide (NO) production in human brain microvascular endothelial cells (HBMECs). DS (10–300 μg/mL) produced a concentration-dependent relaxation in mouse aorta, which was significantly attenuated by the nitric oxide synthase (NOS) inhibitor L-NAME, suggesting that DS causes vasodilation via a NO-dependent mechanism. DS increased resting cerebral blood flow (CBF), although it caused mild hypotension. To investigate the effect of DS on the acute cerebral injury, C57/BL6J mice received 90 min of middle cerebral artery occlusion followed by 22.5 h of reperfusion. DS administered 3 days before arterial occlusion significantly reduced cerebral infarct size by 53.7% compared with vehicle treatment. However, DS did not reduce brain infarction in mice treated with the relatively specific endothelial NOS (eNOS) inhibitor, N5-(1-iminoethyl)-L-ornithine, suggesting that the neuroprotective effect of DS is primarily endothelium-dependent. This correlated with increased phosphorylation of eNOS in the brains of DS-treated mice. DS acutely improves CBF in eNOS-dependent vasodilation and reduces infarct size in focal cerebral ischemia. These data provide causal evidence that DS is cerebroprotective via the eNOS-dependent production of NO, which ameliorates blood circulation

Regeneration of a full-thickness defect of rotator cuff tendon with freshly thawed umbilical cord-derived mesenchymal stem cells in a rat model

Background It is difficult to immediately use mesenchymal stem cells (MSCs) for the patient with rotator cuff disease because isolation and culture time are required. Thus, the MSCs would be prepared in advanced in cryopreserved condition for an off-the-shelf usage in clinic. This study investigated the efficacy of freshly thawed MSCs on the regeneration of a full-thickness tendon defect (FTD) of rotator cuff tendon in a rat model. Methods We evaluated morphology, viability, and proliferation of cultured umbilical cord-derived MSCs (C-UC MSCs) and freshly thawed umbilical cord-derived MSCs (T-UC MSCs) at passage 10 in vitro. In animal experiments, we created a FTD in the supraspinatus of rats and injected the injured tendon with saline, cryopreserved agent (CPA; control), C-UC MSCs, and T-UC MSCs, respectively. Two and 4 weeks later, macroscopic, histological, biomechanical, and cell trafficking were evaluated. T test and ANOVA were used with SPSS. Differences with p < .05 were considered statistically significant. Results T-UC MSCs had fibroblast-like morphology and showed greater than 97% viability and stable proliferation comparable to the C-UC MSCs at passage 10. In animal experiments, compared with the control group, the macroscopic appearance of the T-UC MSCs was more recovered at 2 and 4 weeks such as inflammation, defect size, neighboring tendon, swelling/redness, the connecting surrounding tissue and slidability. Histologically, the nuclear aspect ratio, orientation angle of fibroblasts, collagen organization, and fiber coherence were improved by 33.33%, 42.75%, 1.86-fold, and 1.99-fold at 4 weeks, and GAG-rich area decreased by 88.13% and 94.70% at 2 and 4 weeks respectively. Further, the T-UC MSCs showed enhanced ultimate failure load by 1.55- and 1.25-fold compared with the control group at both 2 and 4 weeks. All the improved values of T-UC MSCs were comparable to those of C-UC MSCs. Moreover, T-UC MSCs remained 8.77% at 4 weeks after injury, and there was no significant difference between C-UC MSCs and T-UC MSCs. Conclusions The morphology, viability, and proliferation of T-UC MSCs were comparable to those of C-UC MSCs. Treatment with T-UC MSCs could induce tendon regeneration of FTD at the macroscopic, histological, and biomechanical levels comparable to treatment with C-UC MSCs.This study was supported by a grant (NRF-2015M3A9E6028412) of the Bio & Medical Technology Development Program and a grant (NRF2017R1A2B2010995) awarded by the Basic Science Research Program of the National Research Foundation of Korea

MDGA1 negatively regulates amyloid precursor protein-mediated synapse inhibition in the hippocampus

Abstract Balanced synaptic inhibition, controlled by multiple synaptic adhesion proteins, is critical for proper brain function. MDGA1 (meprin, A-5 protein, and receptor protein-tyrosine phosphatase mu [MAM] domain-containing glycosylphosphatidylinositol anchor protein 1) suppresses synaptic inhibition in mammalian neurons, yet the molecular mechanisms underlying MDGA1-mediated negative regulation of GABAergic synapses remain unresolved. Here, we show that the MDGA1 MAM domain directly interacts with the extension domain of amyloid precursor protein (APP). Strikingly, MDGA1-mediated synaptic disinhibition requires the MDGA1 MAM domain and is prominent at distal dendrites of hippocampal CA1 pyramidal neurons. Down-regulation of APP in presynaptic GABAergic interneurons specifically suppressed GABAergic, but not glutamatergic, synaptic transmission strength and inputs onto both the somatic and dendritic compartments of hippocampal CA1 pyramidal neurons. Moreover, APP deletion manifested differential effects in somatostatin- and parvalbumin-positive interneurons in the hippocampal CA1, resulting in distinct alterations in inhibitory synapse numbers, transmission, and excitability. The infusion of MDGA1 MAM protein mimicked postsynaptic MDGA1 gain-of-function phenotypes that involve the presence of presynaptic APP. The overexpression of MDGA1 wild type or MAM, but not MAM-deleted MDGA1, in the hippocampal CA1 impaired novel object-recognition memory in mice. Thus, our results establish unique roles of APP-MDGA1 complexes in hippocampal neural circuits, providing unprecedented insight into trans-synaptic mechanisms underlying differential tuning of neuronal compartment-specific synaptic inhibition.Peer reviewe