Purchasing Power Parity Revisited: A Time-Varying Parameter Approach

We re-examine the validity of Purchasing Power Parity (PPP) proposition using Taylor's (2002) data set. Applying the Kalman filter process, our findings not only demonstrate the strong instability in the relationship between the dollar denominated foreign price levels and the US price level, but also rule out the empirical validity of the PPP hypothesis. Thus, we argue that the inference based on the Fisher-Seater methodology cannot account for the Lucas critique in the PPP testing procedure.Purchasing power parity, Fisher-Seater, time-varying parameter, Kalman filter

Assessing the Value of Network Security Technologies

Proper configuration of security technologies is critical to balance the access and protection requirements of information. The common practice of using a layered security architecture that has multiple technologies amplifies the need for proper configuration because the configuration decision about one security technology has ramifications for the configuration decisions about others. We study the impact of configuration on the value obtained from a firewall and an Intrusion Detection System (IDS). We also study how a firewall and an IDS interact with each other in terms of value contribution. We show that the firm may be worse off when it deploys a technology if the technology (either the firewall or the IDS) is improperly configured. A more serious consequence for the firm is that even if each of these (improperly configured) technologies offers a positive value when deployed alone, deploying both may be detrimental to the firm. Configuring the IDS and the firewall optimally eliminates the conflict between them, resulting in a non-negative value to the firm. When optimally configured, we find that these technologies may complement or substitute each other. Further, we find that while the optimal configuration of an IDS is the same whether it is deployed alone or together with a firewall, the optimal configuration of a firewall has a lower detection rate (i.e., allow more access) when it is deployed with an IDS than when deployed alone. Our results highlight the complex interactions between firewall and IDS technologies when they are used together in a security architecture, and, hence, the need for proper configuration in order to benefit from these technologies

An Economic Study of the Effect of Android Platform Fragmentation on Security Updates

Vendors in the Android ecosystem typically customize their devices by modifying Android Open Source Project (AOSP) code, adding in-house developed proprietary software, and pre-installing third-party applications. However, research has documented how various security problems are associated with this customization process. We develop a model of the Android ecosystem utilizing the concepts of game theory and product differentiation to capture the competition involving two vendors customizing the AOSP platform. We show how the vendors are incentivized to differentiate their products from AOSP and from each other, and how prices are shaped through this differentiation process. We also consider two types of consumers: security-conscious consumers who understand and care about security, and na\"ive consumers who lack the ability to correctly evaluate security properties of vendor-supplied Android products or simply ignore security. It is evident that vendors shirk on security investments in the latter case. Regulators such as the U.S. Federal Trade Commission have sanctioned Android vendors for underinvestment in security, but the exact effects of these sanctions are difficult to disentangle with empirical data. Here, we model the impact of a regulator-imposed fine that incentivizes vendors to match a minimum security standard. Interestingly, we show how product prices will decrease for the same cost of customization in the presence of a fine, or a higher level of regulator-imposed minimum security.Comment: 22nd International Conference on Financial Cryptography and Data Security (FC 2018

Backbench

Backbench (2010) is a large-scale multi-channel video and architectural installation, which reflects on the conditions of art production and consumption that are established within the globalised system of art biennials. Moreover the work focuses on the production of cultural discourses and the consequent impact generated by these prevalent modes of exchange, on social, political, professional and likewise on individual levels. Backbench was commissioned and produced by Manifesta 8, the Region of Murcia, Spain in 2010

The newborn lamb as a new model for studying gastroesophageal reflux

We aimed to determine whether the newborn lamb at term is a valid model for studying gastroesophageal reflux. Seven bottle-fed lambs, ages 2 to 3 days, underwent esophageal multichannel intraluminal impedance-pH monitoring (MII-pH). A total of 196 reflux episodes were recorded, including 73% alkaline and 27% weakly acidic. No acid refluxes were observed. Median bolus clearance time was 4  seconds (3; 5.5), and proximal reflux extent was 35% (26). This first report of MII-pH in the newborn mammal sets the foundations for future studies with physiological and clinical relevance to human neonates

Milk temperature influences esophageal motility in the newborn lamb

Esophageal dysmotility is common in infants. We aimed to evaluate the influence of milk temperature on esophageal motility using multichannel intraluminal impedance-pH monitoring (MII-pH). Five healthy lambs, ages 2 to 3 days, underwent a MII-pH whereas bottle-fed randomly with 50 mL of ewe milk at 26 °C, 38.5 °C, and 41.5 °C. Impedance motility parameters were studied on 5 swallows at each temperature. At 38.5 °C we noted a higher total propagation velocity and a shorter total bolus transit time (TBTT) (P < 0.05). These unique results suggest a potential role of milk temperature alterations in improving oral feeding in infants with esophageal dysmotility

Nutritional status in Turkish cystic fibrosis patients

Digitalitzat per Artypla

Agro-mophological characterization, adaptational behaviour and flower abnormalities of Lilium L. cultivars in addition to a flower with stochastic flower formula

This experiment was undertaken to determine the adaptation of Lilium L. cultivars to North-Western part of Türkiye and to define morphologic plant growth characteristics at aboveground part, including flower life and flower abnormalities. The bulbs of the three Lilium L. cultivars, ‘Profundo’, ‘Valverde’, and ‘Vonq’, were sown to perlite in pots in June, 2021, and evaluated for emergence and flowering rates, stem and plant height, stem and flower diameter, leaf and flower number, flower abnormality rates, flower fragrance degree and flower life in 2022, after one year adaptation without removing the previous sown bulbs. As the results of the cultivars differences these were determined that, at the adaptive year; the emergence rates varied between 60.42-89.58%, flowering rates changed between 43.75-87.50%, stem heights changed between 40.63-48.25 cm, plant heights changed between 52.50-59.75 cm and these data showed statistically importance. In addition to the data in the adaptive year; stem diameters, leaf numbers, flower numbers flower fragrance degree and flower longevities also showed statistical importance between cultivars. The flower abnormality rates were found between 8.3-25% in cultivars although no statistical results. Interestingly a striking, stochastic case also was observed from a flower with 8 tepals, 8 stamen and 4 lobed stigma at ‘Valverde’ contrary to well-known flower formula. It has been concluded that ‘Profundo’ has more remarkable result in terms of longevity of flower compared to the other two varieties while ‘Valverde’ and ‘Vonq’ shared the same group with some precedence in most of the agro-morphologic characteristics e.g. plant height, stem height and stem diameter. Lilium L. ‘Vonq’ showed that the highest adaptive capacity among the cultivars with the highest emergence rate (89.58) in all sowed bulbs and flowering rate (87.50) in all emerged bulbs under the study conditions in the open-air

Privacy Controls and Disclosure Behavior

We examine the relationship among privacy controls, dynamic content-sharing activities, and disclosure patterns of Facebook users based on the exogenous policy change in December 2009 that introduced granular privacy controls. Using a unique large panel dataset, we empirically assess the short-run and long-run effects of the change on wall posting and private messaging and the resulting disclosure patterns based on these sharing activities. Results show that Facebook users, on average, increase use of wall posts and decrease use of private messages after the introduction of granular privacy controls. Also, users’ disclosure patterns change to reflect the increased openness in content sharing. These effects are realized immediately and over time. To the best of our knowledge, this is the first study that relies on observational data to assess the impact of a major privacy change on dynamic content-sharing activities and the resulting disclosure patterns of Facebook users