Related adjustment of firm production after demand shocks.

Multiproduct firms often diversify into technologically related activities to exploit efficiencies of joint production; however, unrelated products in the company's portfolio provide access to distinct markets and can help to avoid industry-specific shocks. Yet, the underlying mechanisms of related and unrelated diversification are still poorly understood. Here we investigate diversification decisions of firms in periods when corporations' markets are hit by a demand shocks. In these times, cost efficiency considerations might drive firms to reduce costs by narrowing product portfolios and focusing on combinations of technologically related products, in which economies of scope and mutual capabilities can be exploited. To test this hypothesis, we consider two measures of demand shocks, decreasing sales volumes on the product market and increasing import competition; and analyze their association with changes of product portfolios of Hungarian firms in the 2003-2012 period. We find that production has become more coherent in terms of technological relatedness after firms were exposed to demand shocks. Evidence suggests related adjustment of firm production after demand shocks such that products unrelated to firms' core product are dropped from the portfolio but related products are added.

How Social Capital is Related to Migration Between Communities?

In addition to economic and infrastructural factors, social connections of people also influence migration patterns. This influence can be attributed to the resources that are made available by social contacts: social capital, which can also be utilized in the process of migration. Based on previous literature, we identify three different aspects of social capital and test their relationship with domestic migration simultaneously. First, we analyse if the intensity of connections within communities (local social capital) restrains from migration. Second, if the intensity of connections between two communities (bridging social capital) is associated with increased migration between them. Finally, we consider, if the extent to which local community networks exhibit open or closed structures (bonding social capital) contributes to higher or lower migration rates. We create indicators for these measures using archived online social network data, covering 40% of the adult population of Hungary, and combine them with official migration data of 175 subregions. Based on point-to-point gravity and negative binomial models, we find that bridging social capital between subregions is associated with increased migration flows, but we do not find that local social capital restrains from migration.

Do Co-Worker Networks Increase or Decrease Productivity Differences?

Do labor mobility and co-worker networks contribute to convergence or divergence between regions? Based on the previous literature, labor mobility contributes to knowledge transfer between firms. Therefore, mobility may contribute to decreasing productivity differences, while limited mobility sustains higher differences. The effect of co-worker networks, however, can be two-fold in this process; they transmit information about potential jobs, which may enhance the mobility of workers-even between regions-and this enhanced mobility may contribute to levelling of differences. However, if mobility between regions involves movement costs, co-worker networks may concentrate locally-possibly contributing to the persistence of regional differences. In this paper, we build an agent-based model of labor mobility across firms and regions with knowledge spillovers that reflects key empirical observations on labor markets. We analyze the impact of network information provided about potential employers in this model and find that it contributes to increasing inter-regional mobility, and subsequently, to decreasing regional differences. We also find that both the density of coworker networks, as well as their regional concentrations, decrease if network information is available.

Nicotine interferes with purinergic signaling in smooth muscle cells isolated from urinary bladders of patients with lower urinary tract symptoms.

In patients with outlet obstruction, the contraction of the base is reduced compared to that of healthy individuals, while the contraction of the dome is not affected. Here, we investigated the cellular mechanisms that might be responsible for cholinergic effects blocking non-adrenergic non-cholinergic contractions in the base of the urinary bladder. Smooth muscle cells either from the base or from the dome of human urinary bladders were cultured to determine the contribution of cholinergic and purinergic mechanisms to their Ca2+ homeostasis. While ATP evoked Ca2+ transients in all the cells, nicotine and carbachol induced Ca2+ transients only in 56% and 44% of the cells, respectively. When ATP was administered together with nicotine or carbachol, the amplitudes of the Ca2+ transients recorded from cells prepared from the base of bladders were significantly smaller (42 ± 6% with nicotine and 56 ± 9% with carbachol) than those evoked by ATP alone. This inhibition was much less apparent in the dome of bladders. The inhibition between the cholinergic and purinergic signaling pathways reported in this work may decrease the strength of the contraction of the base of the urinary bladder in patients with outlet obstruction during voiding.

Percutaneous endoscopic ureterolithotomy of two different stones in a single session.

The authors report a rare case of percutaneous endoscopic ureterolithotomy of 2 ureteral stones. Extracorporeal shock-wave lithotripsy (SWL) treatment of the renal stone was performed. The stone was crushed into 2 pieces, with 1 of them located in the upper part, and the other in the middle part of the ureter. Further SWL treatments and ureteroscopy were unsuccessful. The authors then decided to perform a percutaneous ureterolithotomy. In conclusion, percutaneous ureterolithotomy is a good choice of treatment, when ureteral stones cannot be removed by SWL or ureteroscopy.

[Ostiolitholapaxy]. / Ostiolitholapaxia.

The authors developed a new, minimally invasive technique for the removal of impacted iuxtavesical ureteral stones, using nephroscope and a grasping forceps. They named this technique ostiolitholapaxy. The authors present their detailed technique and results. Between 1. 1. 1995 and 31. 12. 2006 48 operations were performed. In 41 cases the stones were removed successfully. In seven unsuccessful cases the stones were extracted by ureteroscopy. The authors worked up 41 successful cases presenting the steps and technical details of the procedure. Average stone size was 5,2 (3-12) mm. Male and female ratio was 23/18. In 19 patients local and in 22 patients spinal anaesthesia was performed. Among the patients who underwent local anaesthesia there were 13 (68,4%) female and 6 (31,6%) male patients. Average operating time was 8,5 (3,5-35) minutes. Mean follow-up time was 95,3 (2-143) months. The success rate of the procedure was 85,41%. There were no intraoperative complications. In the mentioned period no ureteral stricture and/or reflux-uropathy has developed. Due to the simplicity, efficacy of this technique and the fact that it can be performed even in local anaesthesia, this procedure can be useful in case of small symptomatic iuxtavesical stones as a quick and safe stone removal intervention.

Results of percutaneous endoscopic ureterolithotomy compared to that of ureteroscopy.

Percutaneous endoscopic ureterolithotomy is not a well-known method for the treatment of impacted ureteral stones. The authors performed a retrospective study to compare the effectiveness of this procedure to ureteroscopy for the treatment of ureteral calculi. Impacted ureteral stones were removed in 93 patients by percutaneous endoscopic ureterolithotomy (Group 1). In 142 patients, ureteroscopy was performed for the treatment of the ureteral stones (Group 2). The same instruments were used to carry out percutaneous endoscopic ureterolithotomy as were used for percutaneous nephrolithotomy. During these interventions, a direct percutaneous puncture and extraction of the stones was performed. The average diameter of the stones was 11 +/- 4 mm in Group 1 and 7 +/- 2 mm in Group 2. The average operating time was 32 +/- 11 minutes in Group 1 and 41 +/- 29 minutes in Group 2. The average duration of hospitalization following the operations was 7.2 +/- 3.1 days in Group 1 and 3.5 +/- 2.5 days in Group 2. In Group 1, the average time of the operations was significantly lower (p 0.006), and the duration of postoperative hospital stay was significantly higher (p < 0.001), compared to Group 2. In Group 1, retroperitoneal hematoma occurred in 1 patient and prolonged urine leakage was detected in 2 cases, whereas in Group 2, pyelonephritis occurred in 5 patients following the operation. In conclusion, the operating time of percutaneous endoscopic ureterolithotomy is shorter and the rate of complications comparable with that of ureteroscopy. Percutaneous endoscopic ureterolithotomy is suggested for the removal of impacted ureteral stones instead of open surgical ureterolithotomy.